Patent Application
20220175970
The instant application contains a Sequence Listing which has been submitted electronically in ASCII format and is hereby incorporated by reference in its entirety. Said ASCII copy, created on Feb. 21, 2019, is named 080170-091190-WOPT_SL.txt and is 116,872 bytes in size.
The present invention relates to the field of gene therapy, including capsid-free vectors for controlled expression of a transgene or isolated polynucleotides in a subject or cell. The technology described herein relates to methods of controlled expression of a transgene in vivo from a capsid-free DNA vectors with closed ends (ceDNA) vector where the expression level can be sustained at desired level for a predetermined time or increased with one or more subsequent administrations (e.g., a booster administration, or re-dose).
Gene therapy aims to improve clinical outcomes for patients suffering from either genetic mutations or acquired diseases caused by an aberration in the gene expression profile. Gene therapy includes the treatment or prevention of medical conditions resulting from defective genes or abnormal regulation or expression, e.g. underexpression or overexpression, that can result in a disorder, disease, malignancy, etc. For example, a disease or disorder caused by a defective gene might be treated, prevented or ameliorated by delivery of a corrective genetic material to a patient, by altering or silencing a defective gene, or delivering a therapeutic antibody, e.g., resulting in the therapeutic expression of the genetic material within the patient.
The basis of gene therapy is to supply a transcription cassette with an active gene product (sometimes referred to as a transgene), e.g., that can result in a positive gain-of-function effect, a negative loss-of-function effect, or another outcome. Gene therapy can also be used to treat a disease or malignancy caused by other factors. Human monogenic disorders can be treated by the delivery and expression of a normal gene to the target cells. Delivery and expression of a corrective gene in the patient's target cells can be carried out via numerous methods, including the use of engineered viruses and viral gene delivery vectors. Among the many virus-derived vectors available (e.g., recombinant retrovirus, recombinant lentivirus, recombinant adenovirus, and the like), recombinant adeno-associated virus (rAAV) is gaining popularity as a versatile vector in gene therapy.
Adeno-associated viruses (AAV) belong to the parvoviridae family and more specifically constitute the dependoparvovirus genus. Vectors derived from AAV (i.e., recombinant AAV (rAVV) or AAV vectors) are attractive for delivering genetic material because (i) they are able to infect (transduce) a wide variety of non-dividing and dividing cell types including myocytes and neurons; (ii) they are devoid of the virus structural genes, thereby diminishing the host cell responses to virus infection, e.g., interferon-mediated responses; (iii) wild-type viruses are considered non-pathologic in humans; (iv) in contrast to wild type AAV, which are capable of integrating into the host cell genome, replication-deficient AAV vectors lack the rep gene and generally persist as episomes, thus limiting the risk of insertional mutagenesis or genotoxicity; and (v) in comparison to other vector systems, AAV vectors are generally considered to be relatively poor immunogens and therefore do not trigger a significant immune response (see ii), thus gaining persistence of the vector DNA and potentially, long-term expression of the therapeutic transgenes.
However, there are several major deficiencies in using AAV particles as a gene delivery vector. One major drawback associated with rAAV is its limited viral packaging capacity of about 4.5 kb of heterologous DNA (Dong et al., 1996; Athanasopoulos et al., 2004; Lai et al., 2010), and as a result, use of AAV vectors has been limited to less than 150,000 Da protein coding capacity. The second drawback is that as a result of the prevalence of wild-type AAV infection in the population, candidates for rAAV gene therapy have to be screened for the presence of neutralizing antibodies that eliminate the vector from the patient. A third drawback is related to the capsid immunogenicity that prevents re-administration to patients that were not excluded from an initial treatment. The immune system in the patient can respond to the vector which effectively acts as a “booster” shot to stimulate the immune system generating high titer anti-AAV antibodies that preclude future treatments. Some recent reports indicate concerns with immunogenicity in high dose situations. Another notable drawback is that the onset of AAV-mediated gene expression is relatively slow, given that single-stranded AAV DNA must be converted to double-stranded DNA prior to heterologous gene expression.
Additionally, conventional AAV virions with capsids are produced by introducing a plasmid or plasmids containing the AAV genome, rep genes, and cap genes (Grimm et al., 1998). However, such encapsidated AAV virus vectors were found to inefficiently transduce certain cell and tissue types and the capsids also induce an immune response.
Additionally, traditional gene therapy vectors for delivery of transgenes (e.g. adeno-associated virus (AAV), adenovirus, lentivirus vectors, etc.) are typically limited to a single administration of the vector to patients, due in part to the patient's immune response to viral proteins. Additionally, for sustained long term expression of the transgene, it is typically is required to administer a high titer on the initial administration, which can lead to deleterious side effects. As such, traditional viral vectors for gene therapy lack utility due to lack of sustained, long term transgene expression. In addition, the range of transgene genetic material suitable for delivery in such viral vectors is limited by the viral packaging capacity of the viral capsid proteins (e.g. about 4.5 kb for AAV), thereby excluding delivery of larger transgenes for therapy. With respect to conventional adeno-associated virus (AAV) vectors for gene therapy, their use is limited due to the single administration to patients (owing to the patient immune response), the limited range of transgene genetic material suitable for delivery in AAV vectors due to minimal viral packaging capacity (about 4.5 kb), and slow AAV-mediated gene expression.
Additionally, there have been a number of reports raising concern about using too high a dose of a viral vector. Most viral vectors also suffer the immunogenicity concerns raised about AAV.
Accordingly, there is need in the field for a technology that allows multiple doses of a vector for gene therapy. In addition, there is a need in the art for methods of controlling gene expression from a gene therapy vector with minimal off-target effects, and there remains an important unmet need for controllable recombinant DNA vectors with improved production and/or expression properties. Further, as will be appreciated by a skilled physician, the ability to titrate the expression/dose of a transgene is desired to customize a gene therapy treatment based on a subject's particular set of symptoms and/or severity of disease and further to minimize side effects or toxicity.
The invention described herein is a capsid-free DNA vector with covalently-closed ends (referred to herein as a “closed-ended DNA vector” or a “ceDNA vector”) for controlled expression of a transgene in a cell, e.g., to treat a disease. In particular, the technology described herein relates to capsid-free close-ended DNA (ceDNA) vectors for controlled expression of a transgene, including but not limited to any of, sustained expression of a transgene, long-term controlled expression of a transgene, dose-dependent and/or tritratable expression of a transgene, and repeat dosing of a transgene using the vectors described herein. Accordingly, the methods disclosed herein enable one to personalize gene therapy throughout an individual's lifespan to express a transgene at a level that meets the individual's needs, by sustaining the transgene expression level at a predetermined level for a pre-determined time, or alternatively, increasing the expression of the transgene in a dose-dependent manner, by one or more administration after the initial priming administration, thereby controlling the transgene expression level to a desired expression level or desired expression level range based on the concentration of ceDNA vector in the re-dose administration, allowing for a controlled and specific increases in the expression of the transgene in the cell or subject.
Accordingly, in some embodiments a ceDNA vector as disclosed herein can be re-administered (also referred to herein as a “redose” or “booster” administration) to continue transgene expression level at a predetermined level for a predetermined time, or to increase the expression level of the transgene above a prior expression level which was achieved on a first, or prior ceDNA vector administration, where the second administration or booster administration does not generate an immune reaction that prevents expression of the transgene by not generating an immune response to the vector itself that impacts expression of the transgene, or where the immune reaction is less as compared to a re-administration of a viral vector comprising viral proteins, including but not limited to a viral vector comprising a capsid, such as a parvovirus or a lentivirus.
Without wishing to be limited to theory, research shows that long-term transgene expression using conventional AAV viral vectors wanes over time. One way to ensure long-term transgene expression using conventional AAV vectors has traditionally been to increase the titre and dose of the delivered AAV vector at the initial administration. However, it is known that too high a titre or dose of the AAV vector can result in a variety of side-effects. Furthermore, as discussed above, re-administration of an AAV viral vector is traditionally not possible due to immune responses. Ways to circumvent causing an immune response to re-administration of AAV vectors typically require re-administration of an AAV vector with a different capsid configuration as compared to the AAV vector administered on any previous administrations. Such strategies however, can still pose significant risk to the subject by inducing an immune response to the AAV vector and potentially deleterious effects.
Herein, the invention provides a method for controlled expression of a transgene, including long term expression using a close-ended DNA (ceDNA) vector. It is demonstrated herein that a ceDNA vector can titrated to increase the transgene expression levels by, e.g., repeat or re-administration of the ceDNA vector. Additionally, the level of transgene expression can be maintained over a long term, and if any drop in expression levels is observed, a redose administration of the ceDNA vector can be used to maintain the desired level or even to increase the level of transgene expression if desirable for the subject and/or the disease or disorder to be treated.
Accordingly, provided herein are methods of administering ceDNA vectors for sustaining and/or increasing the level of expression of a transgene from a ceDNA vector in a cell or a subject, and where the expression level can be sustained or increased with one or more subsequent administrations (e.g., a re-dose or a booster administration). In the event that ceDNA-delivered transgene expression decreases for any reason, re-dosing of the ceDNA vector can re-establish or maintain the desired expression of the transgene at a desired level. Also provided herein are methods for personalized gene therapy, such that the level of expression of a transgene expressed by the ceDNA vector can be increased incrementally, or in a step-by-step manner, with one or more administrations after an initial priming administration (e.g., at time 0), thereby tailoring (e.g., titration) of the level of expression of the transgene to a desired expression level or within a desired expression level range, as needed by the subject.
Accordingly, in some embodiments, the ceDNA vectors and methods disclosed herein can be used to titrate or effectuate an increase in the level of expression of a transgene by a ceDNA vector, and where the expression level of the transgene can be titrated in a dose-dependent manner with one or more subsequent administrations (e.g., a dose-dependent re-dose or booster administration). As such, the methods disclosed herein enable one to personalize gene therapy throughout an individual's lifespan to express a transgene at a level that meets the individual's needs, by sustaining the transgene expression level at a predetermined level, or alternatively, increasing the expression of the transgene in a dose-dependent manner, by one or more administration after the initial priming administration (e.g., at time 0), thereby controlling the transgene expression level to a desired expression level or desired expression level range based on the concentration of ceDNA vector in the re-dose administration, allowing for a controlled and specific increases in the expression of the transgene in the cell or subject.
Accordingly, in some embodiments a ceDNA vector as disclosed herein can be re-administered (also referred to herein as a “redose” or “booster” administration) to continue transgene expression level at a predetermined level for a predetermined time, or to increase the expression level of the transgene above a prior expression level which was achieved on a first, or prior ceDNA vector administration.
Accordingly, one aspect of the technology described herein relates to the use of ceDNA vector in methods for controlled transgene expression, for example, in a method for modulating expression levels of a transgene, or for a controlled increase in the transgene expression level, or for a dose-dependent expression of a transgene level in a cell or a subject, wherein the ceDNA vector comprises at least one heterologous nucleotide sequence (e.g., a transgene) operatively linked to a promoter and positioned between two inverted terminal repeat sequences, where the ITR sequences can be asymmetric, or symmetric, or substantially symmetrical as these terms are defined herein, wherein at least one of the ITRs comprises a functional terminal resolution site and a Rep binding site, and optionally the heterologous nucleic acid sequence encodes a transgene, and wherein the vector is not in a viral capsid.
In some embodiments, a ceDNA vector as described herein are capsid-free, linear duplex DNA molecules formed from a continuous strand of complementary DNA with covalently-closed ends (linear, continuous and non-encapsidated structure), which comprises two inverted terminal repeat (ITR) sequences flanking a transgene which is operatively linked to a promoter or other regulatory switch as described herein. The 5′ ITR and the 3′ ITR can have the same symmetrical three-dimensional organization with respect to each other, (i.e., symmetrical or substantially symmetrical), or alternatively, the 5′ ITR and the 3′ ITR can have different three-dimensional organization with respect to each other (i.e., asymmetrical ITRs), as these terms are defined herein. In addition, the ITRs can be from the same or different serotypes. In some embodiments, a ceDNA vector can comprise ITR sequences that have a symmetrical three-dimensional spatial organization such that their structure is the same shape in geometrical space, or have the same A, C-C′ and B-B′ loops in 3D space (i.e., they are the same or are mirror images with respect to each other). In some embodiments, one ITR can be from one AAV serotype, and the other ITR can be from a different AAV serotype.
Accordingly, some aspects of the technology described herein relate to a ceDNA vector for controlled transgene expression, including but not limited to, sustained or long-term expression of a transgene, dose-dependent or tritratable expression of a transgene, or repeated dosing of a transgene, where the ceDNA vector comprises ITR sequences selected from any of: (i) at least one WT ITR and at least one modified AAV inverted terminal repeat (ITR) (e.g., asymmetric modified ITRs); (ii) two modified ITRs where the mod-ITR pair have a different three-dimensional spatial organization with respect to each other (e.g., asymmetric modified ITRs), or (iii) symmetrical or substantially symmetrical WT-WT ITR pair, where each WT-ITR has the same three-dimensional spatial organization, or (iv) symmetrical or substantially symmetrical modified ITR pair, where each mod-ITR has the same three-dimensional spatial organization. The ceDNA vectors disclosed herein can be produced in eukaryotic cells, thus devoid of prokaryotic DNA modifications and bacterial endotoxin contamination in insect cells.
In some embodiments, the methods and ceDNA vectors as described herein allow a personalized genetic medicine approach, i.e., titrating an increase in the level of the transgene expression by re-dose administrations in a concentration-dependent manner. It is envisioned that increases in the transgene expression can be achieved in a dose-dependent, step-by-step manner using re-dose administrations, thus increasing the expression level of the transgene by a defined or certain amount by each re-dose administration. This enables controlled increases in the level of the transgene expression in a dose-dependent manner, and can be done incrementally. Accordingly, 1, 2, 3, 4, 5 or 6 or more than 6 re-doses of a define amount of ceDNA can be administered in order to increase the level of expression the transgene by a defined amount each time, to achieve a desired level, or to a desired expression level range, which is higher than the expression level achieved with the prior administration, or prior to this re-dose administration.
Accordingly, in some embodiments, A method of regulating expression of a transgene in a host comprising: (i) administering a sufficient amount of a ceDNA vector as disclosed herein comprising a nucleic acid cassette containing at least one transgene operably linked to a promoter between flanking inverted terminal repeats (ITRs), to the host to express measurable levels of the transgene, wherein the transgene encodes a desired protein; and (ii) administering at least a second dose of the ceDNA vector comprising the at least one transgene or a modified transgene between flanking ITRs to (i) continue expression of the desired protein at a predetermined level for a predetermined time or (ii) modulate expression of the desired protein to a predetermined level, wherein the second administration of the ceDNA vector does not generate an immune reaction that prevents expression of the desired protein.
One aspect of the technology described herein relates to use of a ceDNA vector in a method for sustaining a desired level of expression of a transgene in a cell, method comprising: (a) administering to a cell at a first time point a first dose of a ceDNA vector to achieve expression of a transgene from the ceDNA vector, and (b) administering to the cell at a second time point another dose of the same or a different ceDNA vector to increase the level of expression of the transgene to a desired level, or to compensate for any decrease in expression level of the transgene after the initial ceDNA vector administration. It will be appreciated that such incremental increases in transgene expression permits titration of dosing in a subject to a desired level for such subject. In some embodiments, use of a ceDNA vector in a method for sustaining the level of expression of a transgene in a cell expresses the transgene at a desired expression level for at least 42 days. In some embodiments, the ceDNA vector expresses the transgene at a desired expression level for at least 84 days. In some embodiments, the ceDNA vector expresses the transgene at a desired expression level for at least 132 days.
In some embodiments, the ceDNA vector used in the methods described herein, e.g., in a method for sustaining expression of a transgene in a cell and/or for treating a subject with a disease, is administered in combination with a pharmaceutically acceptable carrier and/or excipient. In some embodiments, a ceDNA vector is administered at a second time point is administered at least 30 days, or at least 60 days or between 60-90 days, or between 90-120 days, or between about 3-6 months, or between 6-12 months, or between 1-2 years, or 2-3 years after the first time point.
In addition to a re-dose administration of a ceDNA vector to simply increase the level of transgene expression if expression levels have decreased over time (e.g., to continue transgene expression at a desired pre-determined level), in some embodiments, the methods and compositions of re-administration of a ceDNA vector can increase the level of transgene in a dose-dependent manner—that is, a re-dose administration of a defined amount of a ceDNA vector can effect a defined increase in expression level of a transgene. Stated differently and using arbitrary units for illustrative purposes only, a lunit dose of the ceDNA in a re-dose administration will achieve a 10% increase in the level of transgene expression from a prior level, and a 2 unit dose of the cDNA vector will achieve a 20% increase in the level of the transgene from a prior level, and a 0.5 unit dose of the ceDNA will achieve a 5% increase in the level of expression of the transgene from a prior level.
Accordingly, in one embodiment, a ceDNA vector as disclosed herein for controlled transgene expression can be used for increasing the level of expression of a transgene in a cell or a subject in a controlled manner. For example, the expression level of the transgene can be increased with one or more subsequent administrations (e.g., a re-dose or a booster administration) of the ceDNA vector.
Another aspect of the technology herein relates to a method for increasing expression of a transgene in a cell, e.g., to increase the expression level of a transgene above a prior expression level that was achieved with a prior ceDNA administration, the method comprising: (a) administering to a cell at a first time point, a priming dose of a ceDNA vector to achieve expression of a transgene, and (b) administering to the cell at a second time point, a dose of a ceDNA vector to increase the expression level of the transgene as compared to the level of expression of the transgene achieved after administration of the ceDNA vector at the first time point, or to increase the expression level of the transgene to achieve a desired expression level.
In all aspects described herein, a ceDNA vector is administered at any time point (e.g. a first, second, third time point etc.) is administered in combination with a pharmaceutically acceptable carrier, and can be optionally administered with a carrier, for example, a particle, liposome or lipid nanoparticle (LNP). In all aspects herein, a ceDNA vector administered at any of: the first, second or any subsequent time point, is administered in combination with a pharmaceutically acceptable carrier.
In all aspects described herein, a ceDNA vector used in the methods for controlled transgene expression as described herein, e.g., in a method for sustaining expression of a transgene, or for a controlled increase in the expression of the transgene, or for a dose-dependent expression of the transgene, and/or for treating a subject with a disease, the ceDNA vector administered at any of: the first, second or any subsequent time point, is administered in combination with a pharmaceutically acceptable carrier and/or excipient.
In some embodiments, where more than one administration of the ceDNA is administered (e.g., at a second or any subsequent time point), the second time point, or any subsequent time point is at least 10 days or between 10-30 days, or at least 30 days, or between 30-60 days, at least 60 days, or between 60-90 days, or between 90-120 days, or between about 3-6 months, or between 6-12 months, or at least a year, after the ceDNA vector administration at the first time point, or the previous time point.
In some embodiments, a ceDNA vector administered at the first, second or any subsequent time point is the same ceDNA vector comprising the same transgene, or a modified transgene, and in alternative embodiments, a ceDNA vector administered at the first, second or any subsequent time point is a different ceDNA vector comprising the same transgene, or a modified transgene, e.g., a different ceDNA vector with a different promoter operatively linked to the same transgene, or a modified transgene. In some embodiments, the promoter is an inducible or repressible promoter. The transgene can also be part of a regulatory switch, as disclosed herein.
In some embodiments, a ceDNA vector used in the methods described herein for controlled transgene expression, the ceDNA vector administered at the first, second or any subsequent time point is the same ceDNA vector comprising the same transgene, or a modified transgene. In alternative embodiments, the ceDNA vector administered at the first, second or any subsequent time point is a different ceDNA vector comprising the same transgene, or a modified transgene, for example, but not limited to, where the different ceDNA vector has a different promoter operatively linked to the same transgene, or to a modified transgene, or a different transgene. For illustrative purposes only, a ceDNA vector administered at the first timepoint can comprise a transgene and a first promoter or regulatory switch, and a ceDNA administered at a second or subsequent timepoint can comprise the same or a modified transgene and a second promoter or regulatory switch, where the first and second promoter (or regulator switch) are different promoters or different regulatory switches. Exemplary regulatory switches are defined herein.
In some embodiments, use of ceDNA vector in the methods for controlled transgene expression as described herein, e.g., in a method for sustaining expression of a transgene, or for a controlled increase in the expression of the transgene, or for a dose-dependent expression of the transgene, and/or for treating a subject with a disease, can optionally comprise a step of administering to the cell, at one or more time points after the second time point, a further dose of the ceDNA vector to increase the expression level of the transgene as compared to the level of expression of the transgene achieved after administration of the ceDNA vector at the second time point or previous time point, or to increase the expression level of the transgene to maintain a desired sustained expression level, wherein the composition administered at the one or more time points after the second time point comprises a ceDNA vector as described herein.
In some embodiments, the ceDNA vector useful in the methods disclosed herein for controlled transgene expression allows for expression of the transgene at a therapeutically effective amount.
In some embodiments, increasing the predetermined dose of the ceDNA vector administered at a second time point, or any subsequent time point, increases the expression level of the transgene in the cell and/or subject. In some embodiments, a predetermined dose of a ceDNA vector administered to the cell or subject at second time point, or subsequent time point, is determined using a dose-dependent relationship for the ceDNA vector to achieve the desired level of expression of the transgene in the cell or subject.
In some embodiments, a predetermined dose of the ceDNA vector administered at the second or any subsequent time point, is in an amount that is between 2-fold and 10-fold the dose of the ceDNA vector administered at the first time point. In some embodiments, a predetermined dose of the ceDNA vector administered at the second or any subsequent time point, is in an amount that increases the expression of the transgene by at least 3-fold, or at least 5-fold, or least 10-fold, or between 2-15 fold or between 2-20 fold, or more than 20-fold as compared the expression of the transgene achieved after administration of the ceDNA at the first time point or previous time point. In some embodiments, the desired expression level of transgene achieved after the administration of the composition at one or more time points after the second time point is a therapeutically effective amount of the transgene.
Aspects of the invention relate to methods to produce a ceDNA vector used in the methods for controlled transgene expression as described herein, e.g., in a method for sustaining expression of a transgene, or for a controlled increase in the expression of the transgene, or for a dose-dependent expression of the transgene, and/or for treating a subject with a disease. In all aspects, the capsid free, non-viral DNA vector (ceDNA vector) for controlled transgene expression is obtained from a plasmid (referred to herein as a “ceDNA-plasmid”) comprising a polynucleotide expression construct template comprising in this order: a first 5′ inverted terminal repeat (e.g. AAV ITR); a heterologous nucleic acid sequence; and a 3′ ITR (e.g. AAV ITR), where the 5′ ITR and 3′ITR can be asymmetric relative to each other, or symmetric (e.g., WT-ITRs or modified symmetric ITRs) as defined herein.
A ceDNA vector useful in the methods for controlled transgene expression as described herein, (e.g., in a method for sustaining expression levels of a transgene, and/or for a controlled increase in the transgene expression level, or for a dose-dependent transgene expression level) is obtainable by a number of means that would be known to the ordinarily skilled artisan after reading this disclosure. For example, a polynucleotide expression construct template used for generating the ceDNA vectors of the present invention can be a ceDNA-plasmid (e.g. see
In a permissive host cell, in the presence of e.g., Rep, the polynucleotide template having at least two ITRs replicates to produce ceDNA vectors. ceDNA vector production undergoes two steps: first, excision (“rescue”) of template from the template backbone (e.g. ceDNA-plasmid, ceDNA-bacmid, ceDNA-baculovirus genome etc.) via Rep proteins, and second, Rep mediated replication of the excised ceDNA vector. Rep proteins and Rep binding sites of the various AAV serotypes are well known to those of ordinary skill in the art. One of ordinary skill understands to choose a Rep protein from a serotype that binds to and replicates the nucleic acid sequence based upon at least one functional ITR. For example, if the replication competent ITR is from AAV serotype 2, the corresponding Rep would be from an AAV serotype that works with that serotype such as AAV2 ITR with AAV2 or AAV4 Rep but not AAV5 Rep, which does not. Upon replication, the covalently-closed ended ceDNA vector continues to accumulate in permissive cells and ceDNA vector is preferably sufficiently stable over time in the presence of Rep protein under standard replication conditions, e.g. to accumulate in an amount that is at least 1 pg/cell, preferably at least 2 pg/cell, preferably at least 3 pg/cell, more preferably at least 4 pg/cell, even more preferably at least 5 pg/cell.
Accordingly, one aspect of the invention relates to a process of producing a ceDNA vector useful in the methods for controlled transgene expression as described herein, comprising the steps of: a) incubating a population of host cells (e.g. insect cells) harboring the polynucleotide expression construct template (e.g., a ceDNA-plasmid, a ceDNA-bacmid, and/or a ceDNA-baculovirus), which is devoid of viral capsid coding sequences, in the presence of a Rep protein under conditions effective and for a time sufficient to induce production of the ceDNA vector within the host cells, and wherein the host cells do not comprise viral capsid coding sequences; and b) harvesting and isolating the ceDNA vector from the host cells. The presence of Rep protein induces replication of the vector polynucleotide with a modified ITR to produce the ceDNA vector in a host cell. However, no viral particles (e.g. AAV virions) are expressed. Thus, there is no virion-enforced size limitation.
The presence of the ceDNA vector useful for controlled expression of the transgene as described herein is isolated from the host cells can be confirmed by digesting DNA isolated from the host cell with a restriction enzyme having a single recognition site on the ceDNA vector and analyzing the digested DNA material on denaturing and non-denaturing gels to confirm the presence of characteristic bands of linear and continuous DNA as compared to linear and non-continuous DNA.
In another embodiment of this aspect and all other aspects provided herein, the transgene expressed in a controlled manner from the ceDNA vector is therapeutic transgene, e.g., a protein of interest, including but not limited to, a receptor, a toxin, a hormone, an enzyme, or a cell surface protein. In another embodiment of this aspect and all other aspects provided herein, the protein of interest is a receptor. In another embodiment of this aspect and all other aspects provided herein, the protein of interest is an enzyme. Exemplary genes to be targeted and proteins of interest are described in detail in the methods of use and methods of treatment sections herein.
In some embodiments, the present application may be defined in any of the following paragraphs:
A method of regulating expression of a transgene in a subject comprising: (a) administering to a subject a sufficient amount of a non-viral, capsid-free close-ended DNA (ceDNA) vector comprising a nucleic acid cassette containing at least one transgene operably linked to a promoter between flanking inverted terminal repeats (ITRs), to express a measurable level of the transgene, wherein the transgene encodes a desired protein to treat a disease; and (b) titrating the ceDNA vector by administering to the subject at least a second dose of the ceDNA vector comprising the at least one transgene between flanking ITRs to obtain the transgene expression of the desired protein at a predetermined level for a predetermined time or to increase the transgene expression of the desired protein to a predetermined level.
In some embodiments, the subject is assessed at a predetermined time after step (a), e.g., at least 30 days, or at least 60 days, or between 60-90 days or longer than 90 days after step (a), to determine the titrating dose. For example, in some embodiments, the subject is assessed to determine the disease state in the subject after step (a) and/or the level of desired protein expressed by the ceDNA vector in the subject. In some embodiments, assessment of the disease state is an assessment of at least one symptom of the disease in the subject. In some embodiments, if the disease state of the subject has remained at a steady state, or has not improved, or where the disease state has declined in the subject, for example, as compared to the disease state at the time of the first administration of the ceDNA vector or any time before step (a), the subject is administered a second dose of the ceDNA vector according to step (b). The disease state for any given disease can be determined by a physician or person of skill in the art, and includes assessing one or more clinical symptoms and/or biomarkers of the disease, including protein biomarkers, miRNA and mRNA biomarkers and the like. In some embodiments, if the level of transgene expression in the subject has declined from a predetermined level or declined from a therapeutically effective amount, the subject is administered a second dose of the ceDNA vector according to step (b). In some embodiments, the level of the transgene expression is determined by measuring the level of the transgene (e.g., measuring protein level or mRNA levels) expressed from the ceDNA vector in a biological sample obtained from the subject. In some embodiments, the biological sample is selected from a blood sample, plasma, synovial fluid, CSF, saliva, or tissue biopsy sample. In some embodiments, where the ceDNA vector expresses a transgene encoding a desired protein or therapeutic gene and a reporter protein, the level of the transgene can be determined by measuring the desired reporter protein expressed from the ceDNA vector in vivo, using methods commonly known to persons of ordinary skill in the art. In some embodiments, the titrating the ceDNA vector is determining the level of transgene expressed from the ceDNA vector and administering a second dose of the ceDNA vector to the subject to adjust or modulate the transgene expression to a predetermined desired level.
Another aspect of the technology described herein relates to a method of regulating expression of a transgene in a subject comprising: (a) administering a sufficient amount of a non-viral capsid-free close-ended DNA (ceDNA) vector comprising a nucleic acid cassette containing at least one transgene operably linked to a promoter between flanking inverted terminal repeats (ITRs), to the subject to express a measurable level of the transgene, wherein the transgene encodes a desired protein; and (b) administering to the subject at least a second dose of the ceDNA vector comprising the at least one transgene, or a modified transgene, between flanking ITRs to (i) continue expression of the desired protein at a predetermined level for a predetermined time or (ii) modulate expression of the desired protein to a predetermined level.
In all aspects herein, the second administration of the ceDNA vector to the subject does not generate an immune reaction sufficient to prevent obtaining the predetermined level of expression of the desired protein.
In some embodiments, the ceDNA vector is administered to the subject at first administration, or a second administration or any subsequent administration in combination with a pharmaceutically acceptable carrier.
In some embodiments, the second administration of the ceDNA vector is at a time when the level of the expression of the transgene decreases from a desired predetermined level, for example, in some embodiments, the second administration is at least about 30 days, or at least about 60 days, or at least about 90 days after the first administration. When more than two doses of the ceDNA vector are administered to the subject, each redose (e.g., 3rd, 4th, 5th, 6th and subsequent redoses) are administered at a time when the level of the expression of the transgene decreases or drops from a desired predetermined level achieved from the previous administration, for example, in some embodiments, each re-administration is at least about 30 days, or at least about 60 days, or at least about 90 days after the previous ceDNA vector administration.
In some embodiments, the method comprises administering at least three or more administrations of the ceDNA vector to the subject, and where at least three administrations of the ceDNA vector are administered, none of the administrations generate an immune response to the ceDNA vector that prevents the achieving the predetermined level of expression of the desired protein.
In some embodiments, the ceDNA vector is administered to the subject on a periodic schedule, e.g., every 2-months, every 3 months, every 6 months, every 12 months, every 18 months and the like.
In some embodiments, the second administration is to increase the level of expression of the desired protein, e.g., to prolong the expression of the desired protein at a predetermined level of expression.
In all aspects herein, the transgene encodes a therapeutic protein and the desired level of expression of the transgene is a therapeutically effective amount of the therapeutic protein. In some embodiments, the transgene is a genetic medicine selected from any of: a nucleic acid, an inhibitor, peptide or polypeptide, antibody or antibody fragment, fusion protein, antigen, antagonist, agonist, RNAi molecule, etc. In some embodiments, the desired protein or therapeutic protein is an inhibitor protein, for example, but not limited to, an antibody or antigen-binding fragment, or a fusion protein. In some embodiments, the desired protein or therapeutic protein replaces a defective protein or a protein that is not being expressed or being expressed at low levels. In some embodiments, the transgene is under the control of a regulatory switch, as defined herein.
In some embodiments, the ceDNA vector comprises a promoter which is an inducible or repressible promoter.
In some embodiments, the ceDNA vector administered at the first, second or any subsequent time point is the same type of ceDNA vector comprising the same transgene, or a modified transgene. For example, stated differently, the same ceDNA vector is administered to the subject multiple times and is comparable to administering the same serotype of viral vector to a subject multiple times.
In some embodiments, a ceDNA vector administered to the subject at second administration or any subsequent administration thereafter (e.g., a redose administration) has a different promoter operatively linked to the same transgene, or a modified transgene, as compared to the promoter in the ceDNA vector administered at an earlier timepoint or administration.
In some embodiments, a ceDNA vector administered at the first administration, or second administration or any subsequent administration thereafter comprises two inverted terminal repeat sequences (ITRs) that are AAV ITRs, and can be, e.g., AAV-2, or any ITR selected from Table 1, or AAV1, AAV3, AAV4, AAV5, AAV 5, AAV7, AAV8, AAV9, AAV10, AAV 11, AAV12, AAVrh8, AAVrh10, AAV-DJ, and AAV-DJ8. In some embodiments, at least one ITR comprises a functional terminal resolution site and a Rep binding site. In some embodiments, the flanking ITRs in a ceDNA vector administered at the first administration, or second administration or any subsequent administration thereafter are symmetric or substantially symmetrical or asymmetric, as defined herein. In some embodiments, one or both of the ITRs are wild type, or wherein both of the ITRs are wild-type. In some embodiments, the flanking ITRs are from different viral serotypes. In some embodiments, where the flanking ITRs are both wild type, they can be selected from any AAV serotype as shown in Table 1.
In some embodiments, the flanking ITRs in a ceDNA vector administered at the first administration, or second administration or any subsequent administration thereafter can comprise a sequence selected from the sequences in Tables 2, 4A, 4B or 5 herein.
In some embodiments, at least one of the ITRs in a ceDNA vector administered at the first administration, or second administration or any subsequent administration thereafter is altered from a wild-type AAV ITR sequence by a deletion, addition, or substitution that affects the overall three-dimensional conformation of the ITR. In some embodiments, one or both of the ITRs in a ceDNA vector administered at the first administration, or second administration or any subsequent administration thereafter is derived from an AAV serotype selected from AAV1, AAV2, AAV3, AAV4, AAV5, AAV6, AAV7, AAV8, AAV9, AAV10, AAV11, and AAV12.
In some embodiments, one or both of the ITRs in a ceDNA vector administered at the first administration, or second administration or any subsequent administration thereafter are synthetic. In some embodiments, one or both of the ITRs is not a wild type ITR, or wherein both of the ITRs are not wild-type.
In some embodiments, one or both of the ITRs in a ceDNA vector administered at the first administration, or second administration or any subsequent administration thereafter is modified by a deletion, insertion, and/or substitution in at least one of the ITR regions selected from A, A′, B, B′, C, C′, D, and D′. In some embodiments, a deletion, insertion, and/or substitution results in the deletion of all or part of a stem-loop structure normally formed by the A, A′, B, B′ C, or C′ regions. In some embodiments, one or both of the ITRs are modified by a deletion, insertion, and/or substitution that results in the deletion of all or part of a stem-loop structure normally formed by the B and B′ regions. In some embodiments, one or both of the ITRs are modified by a deletion, insertion, and/or substitution that results in the deletion of all or part of a stem-loop structure normally formed by the C and C′ regions. In some embodiments, one or both of the ITRs are modified by a deletion, insertion, and/or substitution that results in the deletion of part of a stem-loop structure normally formed by the B and B′ regions and/or part of a stem-loop structure normally formed by the C and C′ regions. In some embodiments, one or both of the ITRs comprise a single stem-loop structure in the region that normally comprises a first stem-loop structure formed by the B and B′ regions and a second stem-loop structure formed by the C and C′ regions. In some embodiments, one or both of the ITRs comprise a single stem and two loops in the region that normally comprises a first stem-loop structure formed by the B and B′ regions and a second stem-loop structure formed by the C and C′ regions.
In some embodiments, both ITRs in a ceDNA vector administered at the first administration, or second administration or any subsequent administration thereafter are altered in a manner that results in an overall three-dimensional symmetry when the ITRs are inverted relative to each other.
In some embodiments, a ceDNA vector administered at the first administration, or second administration or any subsequent administration thereafter comprises at least one heterologous nucleotide sequence under the control of at least one regulatory switch, for example, at least one regulatory switch is selected from a binary regulatory switch, a small molecule regulatory switch, a passcode regulatory switch, a nucleic acid-based regulatory switch, a post-transcriptional regulatory switch, a radiation-controlled or ultrasound controlled regulatory switch, a hypoxia-mediated regulatory switch, an inflammatory response regulatory switch, a shear-activated regulatory switch, and a kill switch. Regulatory switches are disclosed herein in more detail below.
In some embodiments, a ceDNA vector administered at the first administration, or second administration or any subsequent administration thereafter is administered to a subject that has a disease or disorder selected from, e.g., cancer, autoimmune disease, a neurodegenerative disorder, hypercholesterolemia, acute organ rejection, multiple sclerosis, post-menopausal osteoporosis, skin conditions, asthma, or hemophilia. In some embodiments, a subject with cancer has a solid tumor, soft tissue sarcoma, lymphoma, and leukemia. In some embodiments, the subject has an autoimmune disease, e.g., selected from rheumatoid arthritis and Crohn's disease. In some embodiments, the subject has a skin condition, e.g., is selected from psoriasis and atopic dermatitis. In some embodiments, the subject has a neurodegenerative disorder, e.g., Alzheimer's disease, ALS, Parkinson's Disease, Huntington's Disease.
In some embodiments, the method disclosed herein further comprise administering to the subject, at one or more time points after the second time point, a dose of the ceDNA vector to increase the expression level of the heterologous nucleic acid sequence (e.g., the transgene) as compared to the level of expression of the transgene achieved after administration of the ceDNA vector at the second time point or previous time point, or to increase the expression level of the transgene to achieve a desired expression level.
In some embodiments, a predetermined dose of the ceDNA vector administered to the subject at a second or any subsequent time point, is in an amount that is between 2-fold and 10-fold the dose of the ceDNA vector composition administered at the first time point. In some embodiments, a predetermined dose of the ceDNA vector composition administered at the second or any subsequent time point, is in an amount that increases the expression of the transgene by at least 3-fold, or at least 5-fold, or least 10-fold, or between 2-15 fold or 2-20 fold as compared the level of expression of the transgene after administration of the ceDNA vector at the first time point or previous administration. In some embodiments, a predetermined dose of the ceDNA vector administered at the second administration, or second time point, is determined using a dose-dependent relationship for the ceDNA vector to achieve the desired level of expression of the transgene in the cell.
These and other aspects of the invention are described in further detail below.
Embodiments of the present disclosure, briefly summarized above and discussed in greater detail below, can be understood by reference to the illustrative embodiments of the disclosure depicted in the appended drawings. However, the appended drawings illustrate only typical embodiments of the disclosure and are therefore not to be considered limiting of scope, for the disclosure may admit to other equally effective embodiments.
Described herein are methods and compositions comprising novel capsid-free DNA vectors with covalently-closed ends (ceDNA) for controlled expression of a transgene, e.g., to enable sustained expression of the desired transgene at a desired and for a predetermined time, or to modulate expression of the transgene level (including increasing the expression level) in a cell, either in vivo or in vitro and where the expression level of the transgene can be increased with at least one (i.e., one or more) subsequent administrations (e.g., a booster administration, or re-dose).
A ceDNA vector and methods as disclosed herein enable one to sustain the expression level of a transgene in vitro and in vivo in a host cell or subject, i.e., to maintain expression to a desired level, or to stop any deterioration in the expression level by at least one re-administration (herein also referred to as a re-dose or booster administration) at a time point after the initial administration.
A ceDNA vector and methods as disclosed herein enable one to increase the expression level of a transgene from a prior level in vitro and in vivo, i.e., to increase expression to, or above a desired level, or to increase the expression level to within a desired expression range, by at least one re-administration (herein also referred to as “re-dose” or “booster” administration) at a time point after the initial administration.
That is, expression of the transgene expressed by the ceDNA can be increased above a level from the prior administration. If the prior administration was an initial dose (i.e., a priming dose), then a re-dose administration at a second time point can be used to increase the expression level of the transgene. Similarly, if the prior administration was a second administration (i.e., a re-dose administration), then an additional re-dose administration can be used to increase the level of expression of the transgene to a level higher than, or a to a desired expression level or range, than the prior re-dose administration. Therefore, the technology, methods and ceDNA vector as disclosed herein can be used to incrementally, in a controlled manner, increase the expression level of the transgene to a desired expression level. Such a step-wise and incremental increases in expression level of the transgene is advantageous for treatment of a subject, as it allows one to titrate the level of expression of the transgene to a particular individual, based on the subject's need and/or efficacy of the ceDNA vector and/or expressed transgene (e.g., genetic medicine) in the subject, without the risk of having to have a high initial dose administered in excess of what is actually needed and/or without the immune complications associated with other AAV-based vectors.
Unless otherwise defined herein, scientific and technical terms used in connection with the present application shall have the meanings that are commonly understood by those of ordinary skill in the art to which this disclosure belongs. It should be understood that this invention is not limited to the particular methodology, protocols, and reagents, etc., described herein and as such can vary. The terminology used herein is for the purpose of describing particular embodiments only, and is not intended to limit the scope of the present invention, which is defined solely by the claims. Definitions of common terms in immunology and molecular biology can be found in The Merck Manual of Diagnosis and Therapy, 19th Edition, published by Merck Sharp & Dohme Corp., 2011 (ISBN 978-0-911910-19-3); Robert S. Porter et al. (eds.), Fields Virology, 6th Edition, published by Lippincott Williams & Wilkins, Philadelphia, Pa., USA (2013), Knipe, D. M. and Howley, P. M. (ed.), The Encyclopedia of Molecular Cell Biology and Molecular Medicine, published by Blackwell Science Ltd., 1999-2012 (ISBN 9783527600908); and Robert A. Meyers (ed.), Molecular Biology and Biotechnology: a Comprehensive Desk Reference, published by VCH Publishers, Inc., 1995 (ISBN 1-56081-569-8); Immunology by Werner Luttmann, published by Elsevier, 2006; Janeway's Immunobiology, Kenneth Murphy, Allan Mowat, Casey Weaver (eds.), Taylor & Francis Limited, 2014 (ISBN 0815345305, 9780815345305); Lewin's Genes XI, published by Jones & Bartlett Publishers, 2014 (ISBN-1449659055); Michael Richard Green and Joseph Sambrook, Molecular Cloning: A Laboratory Manual, 4th ed., Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y., USA (2012) (ISBN 1936113414); Davis et al., Basic Methods in Molecular Biology, Elsevier Science Publishing, Inc., New York, USA (2012) (ISBN 044460149X); Laboratory Methods in Enzymology: DNA, Jon Lorsch (ed.) Elsevier, 2013 (ISBN 0124199542); Current Protocols in Molecular Biology (CPMB), Frederick M. Ausubel (ed.), John Wiley and Sons, 2014 (ISBN 047150338X, 9780471503385), Current Protocols in Protein Science (CPPS), John E. Coligan (ed.), John Wiley and Sons, Inc., 2005; and Current Protocols in Immunology (CPI) (John E. Coligan, ADA M Kruisbeek, David H Margulies, Ethan M Shevach, Warren Strobe, (eds.) John Wiley and Sons, Inc., 2003 (ISBN 0471142735, 9780471142737), the contents of which are all incorporated by reference herein in their entireties.
As used herein, the terms “heterologous nucleotide sequence” and “transgene” are used interchangeably and refer to a nucleic acid of interest (other than a nucleic acid encoding a capsid polypeptide) that is incorporated into and may be delivered and expressed by a ceDNA vector as disclosed herein. Transgenes of interest include, but are not limited to, nucleic acids encoding polypeptides, preferably therapeutic (e.g., for medical, diagnostic, or veterinary uses) or immunogenic polypeptides (e.g., for vaccines). In some embodiments, nucleic acids of interest include nucleic acids that are transcribed into therapeutic RNA. Transgenes included for use in the ceDNA vectors of the invention include, but are not limited to, those that express or encode one or more polypeptides, peptides, ribozymes, aptamers, peptide nucleic acids, siRNAs, RNAis, miRNAs, lncRNAs, antisense oligo- or polynucleotides, antibodies, antigen binding fragments, or any combination thereof. A transgene can be a “genetic medicine” and encompasses any of: an inhibitor, nucleic acid, oligonucleotide, silencing nucleic acid, miRNA, RNAi, antagonist, agonist, polypeptide, peptide, antibody or antibody fragments, fusion proteins, or variants thereof, epitopes, antigens, aptamers, ribosomes, and the like. A transgene used herein in the ceDNA vector is not limited in size.
The term “genetic medicine” as disclosed herein relates to any DNA structure or nucleic acid sequence that can be used to treat or prevent a disease or disorder in a subject.
As used herein, the terms “expression cassette” and “transcription cassette” are used interchangeably and refer to a linear stretch of nucleic acids that includes a transgene that is operably linked to one or more promoters or other regulatory sequences sufficient to direct transcription of the transgene, but which does not comprise capsid-encoding sequences, other vector sequences or inverted terminal repeat regions. An expression cassette may additionally comprise one or more cis-acting sequences (e.g., promoters, enhancers, or repressors), one or more introns, and one or more post-transcriptional regulatory elements.
As used herein, the term “terminal repeat” or “TR” includes any viral terminal repeat or synthetic sequence that comprises at least one minimal required origin of replication and a region comprising a palindrome hairpin structure. A Rep-binding sequence (“RBS”) (also referred to as RBE (Rep-binding element)) and a terminal resolution site (“TRS”) together constitute a “minimal required origin of replication” and thus the TR comprises at least one RBS and at least one TRS. TRs that are the inverse complement of one another within a given stretch of polynucleotide sequence are typically each referred to as an “inverted terminal repeat” or “ITR”. In the context of a virus, ITRs mediate replication, virus packaging, integration and provirus rescue. As was unexpectedly found in the invention herein, TRs that are not inverse complements across their full length can still perform the traditional functions of ITRs, and thus the term ITR is used herein to refer to a TR in a ceDNA genome or ceDNA vector that is capable of mediating replication of ceDNA vector. It will be understood by one of ordinary skill in the art that in complex ceDNA vector configurations more than two ITRs or asymmetric ITR pairs may be present. The ITR can be an AAV ITR or a non-AAV ITR, or can be derived from an AAV ITR or a non-AAV ITR. For example, the ITR can be derived from the family Parvoviridae, which encompasses parvoviruses and dependoviruses (e.g., canine parvovirus, bovine parvovirus, mouse parvovirus, porcine parvovirus, human parvovirus B-19), or the SV40 hairpin that serves as the origin of SV40 replication can be used as an ITR, which can further be modified by truncation, substitution, deletion, insertion and/or addition. Parvoviridae family viruses consist of two subfamilies: Parvovirinae, which infect vertebrates, and Densovirinae, which infect invertebrates. Dependoparvoviruses include the viral family of the adeno-associated viruses (AAV) which are capable of replication in vertebrate hosts including, but not limited to, human, primate, bovine, canine, equine and ovine species.
The terms “polynucleotide” and “nucleic acid,” used interchangeably herein, refer to a polymeric form of nucleotides of any length, either ribonucleotides or deoxyribonucleotides. Thus, this term includes single, double, or multi-stranded DNA or RNA, genomic DNA, cDNA, DNA-RNA hybrids, or a polymer including purine and pyrimidine bases or other natural, chemically or biochemically modified, non-natural, or derivatized nucleotide bases. “Oligonucleotide” generally refers to polynucleotides of between about 5 and about 100 nucleotides of single- or double-stranded DNA. However, for the purposes of this disclosure, there is no upper limit to the length of an oligonucleotide. Oligonucleotides are also known as “oligomers” or “oligos” and may be isolated from genes, or chemically synthesized by methods known in the art. The terms “polynucleotide” and “nucleic acid” should be understood to include, as applicable to the embodiments being described, single-stranded (such as sense or antisense) and double-stranded polynucleotides.
The term “nucleic acid construct” as used herein refers to a nucleic acid molecule, either single- or double-stranded, which is isolated from a naturally occurring gene or which is modified to contain segments of nucleic acids in a manner that would not otherwise exist in nature or which is synthetic. The term nucleic acid construct is synonymous with the term “expression cassette” when the nucleic acid construct contains the control sequences required for expression of a coding sequence of the present disclosure. An “expression cassette” includes a DNA coding sequence operably linked to a promoter.
By “hybridizable” or “complementary” or “substantially complementary” it is meant that a nucleic acid (e.g., RNA) includes a sequence of nucleotides that enables it to non-covalently bind, i.e. form Watson-Crick base pairs and/or G/U base pairs, “anneal”, or “hybridize,” to another nucleic acid in a sequence-specific, antiparallel, manner (i.e., a nucleic acid specifically binds to a complementary nucleic acid) under the appropriate in vitro and/or in vivo conditions of temperature and solution ionic strength. As is known in the art, standard Watson-Crick base-pairing includes: adenine (A) pairing with thymidine (T), adenine (A) pairing with uracil (U), and guanine (G) pairing with cytosine (C). In addition, it is also known in the art that for hybridization between two RNA molecules (e.g., dsRNA), guanine (G) base pairs with uracil (U). For example, G/U base-pairing is partially responsible for the degeneracy (i.e., redundancy) of the genetic code in the context of tRNA anti-codon base-pairing with codons in mRNA. In the context of this disclosure, a guanine (G) of a protein-binding segment (dsRNA duplex) of a subject DNA-targeting RNA molecule is considered complementary to a uracil (U), and vice versa. As such, when a G/U base-pair can be made at a given nucleotide position a protein-binding segment (dsRNA duplex) of a subject DNA-targeting RNA molecule, the position is not considered to be non-complementary, but is instead considered to be complementary.
The terms “peptide,” “polypeptide,” and “protein” are used interchangeably herein, and refer to a polymeric form of amino acids of any length, which can include coded and non-coded amino acids, chemically or biochemically modified or derivatized amino acids, and polypeptides having modified peptide backbones.
A DNA sequence that “encodes” a particular RNA or protein gene product is a DNA nucleic acid sequence that is transcribed into the particular RNA and/or protein. A DNA polynucleotide may encode an RNA (mRNA) that is translated into protein, or a DNA polynucleotide may encode an RNA that is not translated into protein (e.g., tRNA, rRNA, or a DNA-targeting RNA; also called “non-coding” RNA or “ncRNA”).
As used herein, the term “genomic safe harbor gene” or “safe harbor gene” refers to a gene or loci that a nucleic acid sequence can be inserted such that the sequence can integrate and function in a predictable manner (e.g., express a protein of interest) without significant negative consequences to endogenous gene activity, or the promotion of cancer. In some embodiments, a safe harbor gene is also a loci or gene where an inserted nucleic acid sequence can be expressed efficiently and at higher levels than a non-safe harbor site.
As used herein, the term “gene delivery” means a process by which foreign DNA is transferred to host cells for applications of gene therapy.
As used herein, the term “terminal repeat” or “TR” includes any viral terminal repeat or synthetic sequence that comprises at least one minimal required origin of replication and a region comprising a palindrome hairpin structure. A Rep-binding sequence (“RBS”) (also referred to as RBE (Rep-binding element)) and a terminal resolution site (“TRS”) together constitute a “minimal required origin of replication” and thus the TR comprises at least one RBS and at least one TRS. TRs that are the inverse complement of one another within a given stretch of polynucleotide sequence are typically each referred to as an “inverted terminal repeat” or “ITR”. In the context of a virus, ITRs mediate replication, virus packaging, integration and provirus rescue. As was unexpectedly found in the invention herein, TRs that are not inverse complements across their full length can still perform the traditional functions of ITRs, and thus the term ITR is used herein to refer to a TR in a ceDNA genome or ceDNA vector that is capable of mediating replication of ceDNA vector. It will be understood by one of ordinary skill in the art that in complex ceDNA vector configurations more than two ITRs or asymmetric ITR pairs may be present. The ITR can be an AAV ITR or a non-AAV ITR, or can be derived from an AAV ITR or a non-AAV ITR. For example, the ITR can be derived from the family Parvoviridae, which encompasses parvoviruses and dependoviruses (e.g., canine parvovirus, bovine parvovirus, mouse parvovirus, porcine parvovirus, human parvovirus B-19), or the SV40 hairpin that serves as the origin of SV40 replication can be used as an ITR, which can further be modified by truncation, substitution, deletion, insertion and/or addition. Parvoviridae family viruses consist of two subfamilies: Parvovirinae, which infect vertebrates, and Densovirinae, which infect invertebrates. Dependoparvoviruses include the viral family of the adeno-associated viruses (AAV) which are capable of replication in vertebrate hosts including, but not limited to, human, primate, bovine, canine, equine and ovine species. For convenience herein, an ITR located 5′ to (upstream of) an expression cassette in a ceDNA vector is referred to as a “5′ ITR” or a “left ITR”, and an ITR located 3′ to (downstream of) an expression cassette in a ceDNA vector is referred to as a “3′ ITR” or a “right ITR”.
A “wild-type ITR” or “WT-ITR” refers to the sequence of a naturally occurring ITR sequence in an AAV or other dependovirus that retains, e.g., Rep binding activity and Rep nicking ability. The nucleotide sequence of a WT-ITR from any AAV serotype may slightly vary from the canonical naturally occurring sequence due to degeneracy of the genetic code or drift, and therefore WT-ITR sequences encompassed for use herein include WT-ITR sequences as result of naturally occurring changes taking place during the production process (e.g., a replication error).
As used herein, the term “substantially symmetrical WT-ITRs” or a “substantially symmetrical WT-ITR pair” refers to a pair of WT-ITRs within a single ceDNA genome or ceDNA vector that are both wild type ITRs that have an inverse complement sequence across their entire length. For example, an ITR can be considered to be a wild-type sequence, even if it has one or more nucleotides that deviate from the canonical naturally occurring sequence, so long as the changes do not affect the properties and overall three-dimensional structure of the sequence. In some aspects, the deviating nucleotides represent conservative sequence changes. As one non-limiting example, a sequence that has at least 95%, 96%, 97%, 98%, or 99% sequence identity to the canonical sequence (as measured, e.g., using BLAST at default settings), and also has a symmetrical three-dimensional spatial organization to the other WT-ITR such that their 3D structures are the same shape in geometrical space. The substantially symmetrical WT-ITR has the same A, C-C′ and B-B′ loops in 3D space. A substantially symmetrical WT-ITR can be functionally confirmed as WT by determining that it has an operable Rep binding site (RBE or RBE′) and terminal resolution site (trs) that pairs with the appropriate Rep protein. One can optionally test other functions, including transgene expression under permissive conditions.
As used herein, the phrases of “modified ITR” or “mod-ITR” or “mutant ITR” are used interchangeably herein and refer to an ITR that has a mutation in at least one or more nucleotides as compared to the WT-ITR from the same serotype. The mutation can result in a change in one or more of A, C, C′, B, B′ regions in the ITR, and can result in a change in the three-dimensional spatial organization (i.e. its 3D structure in geometric space) as compared to the 3D spatial organization of a WT-ITR of the same serotype.
As used herein, the term “asymmetric ITRs” also referred to herein as “asymmetric ITR pairs” refers to a pair of ITRs within a single ceDNA genome or ceDNA vector that are not inverse complements across their full length. The difference in sequence between the two ITRs may be due to nucleotide addition, deletion, truncation, or point mutation. In one embodiment, one ITR of the pair may be a wild-type AAV sequence and the other a non-wild-type or synthetic sequence. In another embodiment, neither ITR of the pair is a wild-type AAV sequence and the two ITRs differ in sequence from one another. For convenience herein, an ITR located 5′ to (upstream of) an expression cassette in a ceDNA vector is referred to as a “5′ ITR” or a “left ITR”, and an ITR located 3′ to (downstream of) an expression cassette in a ceDNA vector is referred to as a “3′ ITR” or a “right ITR”. As one non-limiting example, an asymmetric ITR pair does not have a symmetrical three-dimensional spatial organization to their cognate ITR such that their 3D structures are different shapes in geometrical space. Stated differently, an asymmetrical ITR pair have the different overall geometric structure, i.e., they have different organization of their A, C-C′ and B-B′ loops in 3D space (e.g., one ITR may have a short C-C′ arm and/or short B-B′ arm as compared to the cognate ITR). The difference in sequence between the two ITRs may be due to one or more nucleotide addition, deletion, truncation, or point mutation. In one embodiment, one ITR of the asymmetric ITR pair may be a wild-type AAV ITR sequence and the other ITR a modified ITR as defined herein (e.g., a non-wild-type or synthetic ITR sequence). In another embodiment, neither ITRs of the asymmetric ITR pair is a wild-type AAV sequence and the two ITRs are modified ITRs that have different shapes in geometrical space (i.e., a different overall geometric structure). In some embodiments, one mod-ITRs of an asymmetric ITR pair can have a short C-C′ arm and the other ITR can have a different modification (e.g., a single arm, or a short B-B′ arm etc.) such that they have different three-dimensional spatial organization as compared to the cognate asymmetric mod-ITR.
As used herein, the term “symmetric ITRs” refers to a pair of ITRs within a single ceDNA genome or ceDNA vector that are mutated or modified relative to wild-type dependoviral ITR sequences and are inverse complements across their full length. Neither ITRs are wild type ITR AAV2 sequences (i.e., they are a modified ITR, also referred to as a mutant ITR), and can have a difference in sequence from the wild type ITR due to nucleotide addition, deletion, substitution, truncation, or point mutation. For convenience herein, an ITR located 5′ to (upstream of) an expression cassette in a ceDNA vector is referred to as a “5′ ITR” or a “left ITR”, and an ITR located 3′ to (downstream of) an expression cassette in a ceDNA vector is referred to as a “3′ ITR” or a “right ITR”.
As used herein, the terms “substantially symmetrical modified-ITRs” or a “substantially symmetrical mod-ITR pair” refers to a pair of modified-ITRs within a single ceDNA genome or ceDNA vector that are both that have an inverse complement sequence across their entire length. For example, the a modified ITR can be considered substantially symmetrical, even if it has some nucleotide sequences that deviate from the inverse complement sequence so long as the changes do not affect the properties and overall shape. As one non-limiting example, a sequence that has at least 85%, 90%, 95%, 96%, 97%, 98%, or 99% sequence identity to the canonical sequence (as measured using BLAST at default settings), and also has a symmetrical three-dimensional spatial organization to their cognate modified ITR such that their 3D structures are the same shape in geometrical space. Stated differently, a substantially symmetrical modified-ITR pair have the same A, C-C′ and B-B′ loops organized in 3D space. In some embodiments, the ITRs from a mod-ITR pair may have different reverse complement nucleotide sequences but still have the same symmetrical three-dimensional spatial organization—that is both ITRs have mutations that result in the same overall 3D shape. For example, one ITR (e.g., 5′ ITR) in a mod-ITR pair can be from one serotype, and the other ITR (e.g., 3′ ITR) can be from a different serotype, however, both can have the same corresponding mutation (e.g., if the 5′ITR has a deletion in the C region, the cognate modified 3′ITR from a different serotype has a deletion at the corresponding position in the C′ region), such that the modified ITR pair has the same symmetrical three-dimensional spatial organization. In such embodiments, each ITR in a modified ITR pair can be from different serotypes (e.g. AAV1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, and 12) such as the combination of AAV2 and AAV6, with the modification in one ITR reflected in the corresponding position in the cognate ITR from a different serotype. In one embodiment, a substantially symmetrical modified ITR pair refers to a pair of modified ITRs (mod-ITRs) so long as the difference in nucleotide sequences between the ITRs does not affect the properties or overall shape and they have substantially the same shape in 3D space. As a non-limiting example, a mod-ITR that has at least 95%, 96%, 97%, 98% or 99% sequence identity to the canonical mod-ITR as determined by standard means well known in the art such as BLAST (Basic Local Alignment Search Tool), or BLASTN at default settings, and also has a symmetrical three-dimensional spatial organization such that their 3D structure is the same shape in geometric space. A substantially symmetrical mod-ITR pair has the same A, C-C′ and B-B′ loops in 3D space, e.g., if a modified ITR in a substantially symmetrical mod-ITR pair has a deletion of a C-C′ arm, then the cognate mod-ITR has the corresponding deletion of the C-C′ loop and also has a similar 3D structure of the remaining A and B-B′ loops in the same shape in geometric space of its cognate mod-ITR.
The term “flanking” refers to a relative position of one nucleic acid sequence with respect to another nucleic acid sequence. Generally, in the sequence ABC, B is flanked by A and C. The same is true for the arrangement A×B×C. Thus, a flanking sequence precedes or follows a flanked sequence but need not be contiguous with, or immediately adjacent to the flanked sequence. In one embodiment, the term flanking refers to terminal repeats at each end of the linear duplex ceDNA vector.
As used herein, the term “ceDNA genome” refers to an expression cassette that further incorporates at least one inverted terminal repeat region. A ceDNA genome may further comprise one or more spacer regions. In some embodiments the ceDNA genome is incorporated as an intermolecular duplex polynucleotide of DNA into a plasmid or viral genome.
As used herein, the term “ceDNA spacer region” refers to an intervening sequence that separates functional elements in the ceDNA vector or ceDNA genome. In some embodiments, ceDNA spacer regions keep two functional elements at a desired distance for optimal functionality. In some embodiments, ceDNA spacer regions provide or add to the genetic stability of the ceDNA genome within e.g., a plasmid or baculovirus. In some embodiments, ceDNA spacer regions facilitate ready genetic manipulation of the ceDNA genome by providing a convenient location for cloning sites and the like. For example, in certain aspects, an oligonucleotide “polylinker” containing several restriction endonuclease sites, or a non-open reading frame sequence designed to have no known protein (e.g., transcription factor) binding sites can be positioned in the ceDNA genome to separate the cis—acting factors, e.g., inserting a timer, 12mer, 18mer, 24mer, 48mer, 86mer, 176mer, etc. between the terminal resolution site and the upstream transcriptional regulatory element. Similarly, the spacer may be incorporated between the polyadenylation signal sequence and the 3′-terminal resolution site.
As used herein, the terms “Rep binding site, “Rep binding element, “RBE” and “RBS” are used interchangeably and refer to a binding site for Rep protein (e.g., AAV Rep 78 or AAV Rep 68) which upon binding by a Rep protein permits the Rep protein to perform its site-specific endonuclease activity on the sequence incorporating the RBS. An RBS sequence and its inverse complement together form a single RBS. RBS sequences are known in the art, and include, for example, 5′-GCGCGCTCGCTCGCTC-3′ (SEQ ID NO: 60), an RBS sequence identified in AAV2. Any known RBS sequence may be used in the embodiments of the invention, including other known AAV RBS sequences and other naturally known or synthetic RBS sequences. Without being bound by theory it is thought that the nuclease domain of a Rep protein binds to the duplex nucleotide sequence GCTC, and thus the two known AAV Rep proteins bind directly to and stably assemble on the duplex oligonucleotide, 5′-(GCGC)(GCTC)(GCTC)(GCTC)-3′ (SEQ ID NO: 60). In addition, soluble aggregated conformers (i.e., undefined number of inter-associated Rep proteins) dissociate and bind to oligonucleotides that contain Rep binding sites. Each Rep protein interacts with both the nitrogenous bases and phosphodiester backbone on each strand. The interactions with the nitrogenous bases provide sequence specificity whereas the interactions with the phosphodiester backbone are non- or less-sequence specific and stabilize the protein-DNA complex.
As used herein, the terms “terminal resolution site” and “TRS” are used interchangeably herein and refer to a region at which Rep forms a tyrosine-phosphodiester bond with the 5′ thymidine generating a 3′ OH that serves as a substrate for DNA extension via a cellular DNA polymerase, e.g., DNA pol delta or DNA pol epsilon. Alternatively, the Rep-thymidine complex may participate in a coordinated ligation reaction. In some embodiments, a TRS minimally encompasses a non-base-paired thymidine. In some embodiments, the nicking efficiency of the TRS can be controlled at least in part by its distance within the same molecule from the RBS. When the acceptor substrate is the complementary ITR, then the resulting product is an intramolecular duplex. TRS sequences are known in the art, and include, for example, 5′-GGTTGA-3′ (SEQ ID NO: 61), the hexanucleotide sequence identified in AAV2. Any known TRS sequence may be used in the embodiments of the invention, including other known AAV TRS sequences and other naturally known or synthetic TRS sequences such as AGTT (SEQ ID NO: 62), GGTTGG (SEQ ID NO: 63), AGTTGG (SEQ ID NO: 64), AGTTGA (SEQ ID NO: 65), and other motifs such as RRTTRR (SEQ ID NO: 66).
As used herein, the term “ceDNA-plasmid” refers to a plasmid that comprises a ceDNA genome as an intermolecular duplex.
As used herein, the term “ceDNA-bacmid” refers to an infectious baculovirus genome comprising a ceDNA genome as an intermolecular duplex that is capable of propagating in E. coli as a plasmid, and so can operate as a shuttle vector for baculovirus.
As used herein, the term “ceDNA-baculovirus” refers to a baculovirus that comprises a ceDNA genome as an intermolecular duplex within the baculovirus genome.
As used herein, the terms “ceDNA-baculovirus infected insect cell” and “ceDNA-BIIC” are used interchangeably, and refer to an invertebrate host cell (including, but not limited to an insect cell (e.g., an Sf9 cell)) infected with a ceDNA-baculovirus.
As used herein, the term “closed-ended DNA vector” refers to a capsid-free DNA vector with at least one covalently closed end and where at least part of the vector has an intramolecular duplex structure.
As used herein, the terms “ceDNA vector” and “ceDNA” are used interchangeably and refer to a closed-ended DNA vector comprising at least one terminal palindrome. In some embodiments, the ceDNA comprises two covalently-closed ends.
As defined herein, “reporters” refer to proteins that can be used to provide detectable read-outs. Reporters generally produce a measurable signal such as fluorescence, color, or luminescence. Reporter protein coding sequences encode proteins whose presence in the cell or organism is readily observed. For example, fluorescent proteins cause a cell to fluoresce when excited with light of a particular wavelength, luciferases cause a cell to catalyze a reaction that produces light, and enzymes such as β-galactosidase convert a substrate to a colored product. Exemplary reporter polypeptides useful for experimental or diagnostic purposes include, but are not limited to β-lactamase, β-galactosidase (LacZ), alkaline phosphatase (AP), thymidine kinase (TK), green fluorescent protein (GFP) and other fluorescent proteins, chloramphenicol acetyltransferase (CAT), luciferase, and others well known in the art.
As used herein, the term “effector protein” refers to a polypeptide that provides a detectable read-out, either as, for example, a reporter polypeptide, or more appropriately, as a polypeptide that kills a cell, e.g., a toxin, or an agent that renders a cell susceptible to killing with a chosen agent or lack thereof. Effector proteins include any protein or peptide that directly targets or damages the host cell's DNA and/or RNA. For example, effector proteins can include, but are not limited to, a restriction endonuclease that targets a host cell DNA sequence (whether genomic or on an extrachromosomal element), a protease that degrades a polypeptide target necessary for cell survival, a DNA gyrase inhibitor, and a ribonuclease-type toxin. In some embodiments, the expression of an effector protein controlled by a synthetic biological circuit as described herein can participate as a factor in another synthetic biological circuit to thereby expand the range and complexity of a biological circuit system's responsiveness.
Transcriptional regulators refer to transcriptional activators and repressors that either activate or repress transcription of a gene of interest. Promoters are regions of nucleic acid that initiate transcription of a particular gene Transcriptional activators typically bind nearby to transcriptional promoters and recruit RNA polymerase to directly initiate transcription. Repressors bind to transcriptional promoters and sterically hinder transcriptional initiation by RNA polymerase. Other transcriptional regulators may serve as either an activator or a repressor depending on where they bind and cellular and environmental conditions. Non-limiting examples of transcriptional regulator classes include, but are not limited to homeodomain proteins, zinc-finger proteins, winged-helix (forkhead) proteins, and leucine-zipper proteins.
As used herein, a “repressor protein” or “inducer protein” is a protein that binds to a regulatory sequence element and represses or activates, respectively, the transcription of sequences operatively linked to the regulatory sequence element. Preferred repressor and inducer proteins as described herein are sensitive to the presence or absence of at least one input agent or environmental input. Preferred proteins as described herein are modular in form, comprising, for example, separable DNA-binding and input agent-binding or responsive elements or domains.
As used herein, “carrier” includes any and all solvents, dispersion media, vehicles, coatings, diluents, antibacterial and antifungal agents, isotonic and absorption delaying agents, buffers, carrier solutions, suspensions, colloids, and the like. The use of such media and agents for pharmaceutically active substances is well known in the art. Supplementary active ingredients can also be incorporated into the compositions. The phrase “pharmaceutically-acceptable” refers to molecular entities and compositions that do not produce a toxic, an allergic, or similar untoward reaction when administered to a host.
As used herein, an “input agent responsive domain” is a domain of a transcription factor that binds to or otherwise responds to a condition or input agent in a manner that renders a linked DNA binding fusion domain responsive to the presence of that condition or input. In one embodiment, the presence of the condition or input results in a conformational change in the input agent responsive domain, or in a protein to which it is fused, that modifies the transcription-modulating activity of the transcription factor.
The term “in vivo” refers to assays or processes that occur in or within an organism, such as a multicellular animal. In some of the aspects described herein, a method or use can be said to occur “in vivo” when a unicellular organism, such as a bacterium, is used. The term “ex vivo” refers to methods and uses that are performed using a living cell with an intact membrane that is outside of the body of a multicellular animal or plant, e.g., explants, cultured cells, including primary cells and cell lines, transformed cell lines, and extracted tissue or cells, including blood cells, among others. The term “in vitro” refers to assays and methods that do not require the presence of a cell with an intact membrane, such as cellular extracts, and can refer to the introducing of a programmable synthetic biological circuit in a non-cellular system, such as a medium not comprising cells or cellular systems, such as cellular extracts.
The term “promoter,” as used herein, refers to any nucleic acid sequence that regulates the expression of another nucleic acid sequence by driving transcription of the nucleic acid sequence, which can be a heterologous target gene encoding a protein or an RNA. Promoters can be constitutive, inducible, repressible, tissue-specific, or any combination thereof. A promoter is a control region of a nucleic acid sequence at which initiation and rate of transcription of the remainder of a nucleic acid sequence are controlled. A promoter can also contain genetic elements at which regulatory proteins and molecules can bind, such as RNA polymerase and other transcription factors. In some embodiments of the aspects described herein, a promoter can drive the expression of a transcription factor that regulates the expression of the promoter itself, or that of another promoter used in another modular component of the synthetic biological circuits described herein. Within the promoter sequence will be found a transcription initiation site, as well as protein binding domains responsible for the binding of RNA polymerase. Eukaryotic promoters will often, but not always, contain “TATA” boxes and “CAT” boxes. Various promoters, including inducible promoters, may be used to drive the expression of transgenes in the ceDNA vectors disclosed herein. A promoter sequence may be bounded at its 3′ terminus by the transcription initiation site and extends upstream (5′ direction) to include the minimum number of bases or elements necessary to initiate transcription at levels detectable above background.
The term “enhancer” as used herein refers to a cis-acting regulatory sequence (e.g., 50-1,500 base pairs) that binds one or more proteins (e.g., activator proteins, or transcription factor) to increase transcriptional activation of a nucleic acid sequence. Enhancers can be positioned up to 1,000,000 base pars upstream of the gene start site or downstream of the gene start site that they regulate. An enhancer can be positioned within an intronic region, or in the exonic region of an unrelated gene.
A promoter can be said to drive expression or drive transcription of the nucleic acid sequence that it regulates. The phrases “operably linked,” “operatively positioned,” “operatively linked,” “under control,” and “under transcriptional control” indicate that a promoter is in a correct functional location and/or orientation in relation to a nucleic acid sequence it regulates to control transcriptional initiation and/or expression of that sequence. An “inverted promoter,” as used herein, refers to a promoter in which the nucleic acid sequence is in the reverse orientation, such that what was the coding strand is now the non-coding strand, and vice versa. Inverted promoter sequences can be used in various embodiments to regulate the state of a switch. In addition, in various embodiments, a promoter can be used in conjunction with an enhancer.
A promoter can be one naturally associated with a gene or sequence, as can be obtained by isolating the 5′ non-coding sequences located upstream of the coding segment and/or exon of a given gene or sequence. Such a promoter can be referred to as “endogenous.” Similarly, in some embodiments, an enhancer can be one naturally associated with a nucleic acid sequence, located either downstream or upstream of that sequence.
In some embodiments, a coding nucleic acid segment is positioned under the control of a “recombinant promoter” or “heterologous promoter,” both of which refer to a promoter that is not normally associated with the encoded nucleic acid sequence it is operably linked to in its natural environment. A recombinant or heterologous enhancer refers to an enhancer not normally associated with a given nucleic acid sequence in its natural environment. Such promoters or enhancers can include promoters or enhancers of other genes; promoters or enhancers isolated from any other prokaryotic, viral, or eukaryotic cell; and synthetic promoters or enhancers that are not “naturally occurring,” i.e., comprise different elements of different transcriptional regulatory regions, and/or mutations that alter expression through methods of genetic engineering that are known in the art. In addition to producing nucleic acid sequences of promoters and enhancers synthetically, promoter sequences can be produced using recombinant cloning and/or nucleic acid amplification technology, including PCR, in connection with the synthetic biological circuits and modules disclosed herein (see, e.g., U.S. Pat. Nos. 4,683,202, 5,928,906, each incorporated herein by reference). Furthermore, it is contemplated that control sequences that direct transcription and/or expression of sequences within non-nuclear organelles such as mitochondria, chloroplasts, and the like, can be employed as well.
As described herein, an “inducible promoter” is one that is characterized by initiating or enhancing transcriptional activity when in the presence of, influenced by, or contacted by an inducer or inducing agent. An “inducer” or “inducing agent,” as defined herein, can be endogenous, or a normally exogenous compound or protein that is administered in such a way as to be active in inducing transcriptional activity from the inducible promoter. In some embodiments, the inducer or inducing agent, i.e., a chemical, a compound or a protein, can itself be the result of transcription or expression of a nucleic acid sequence (i.e., an inducer can be an inducer protein expressed by another component or module), which itself can be under the control or an inducible promoter. In some embodiments, an inducible promoter is induced in the absence of certain agents, such as a repressor. Examples of inducible promoters include but are not limited to, tetracycline, metallothionine, ecdysone, mammalian viruses (e.g., the adenovirus late promoter; and the mouse mammary tumor virus long terminal repeat (MMTV-LTR)) and other steroid-responsive promoters, rapamycin responsive promoters and the like.
The terms “DNA regulatory sequences,” “control elements,” and “regulatory elements,” used interchangeably herein, refer to transcriptional and translational control sequences, such as promoters, enhancers, polyadenylation signals, terminators, protein degradation signals, and the like, that provide for and/or regulate transcription of a non-coding sequence (e.g., DNA-targeting RNA) or a coding sequence (e.g., site-directed modifying polypeptide, or Cas9/Csn1 polypeptide) and/or regulate translation of an encoded polypeptide.
The term “operably linked” refers to a juxtaposition wherein the components so described are in a relationship permitting them to function in their intended manner. For instance, a promoter is operably linked to a coding sequence if the promoter affects its transcription or expression. An “expression cassette” includes a heterologous DNA sequence that is operably linked to a promoter or other regulatory sequence sufficient to direct transcription of the transgene in the ceDNA vector. Suitable promoters include, for example, tissue specific promoters. Promoters can also be of AAV origin.
The term “subject” as used herein refers to a human or animal, to whom treatment, including prophylactic treatment, with the ceDNA vector according to the present invention, is provided. Usually the animal is a vertebrate such as, but not limited to a primate, rodent, domestic animal or game animal. Primates include but are not limited to, chimpanzees, cynomologous monkeys, spider monkeys, and macaques, e.g., Rhesus. Rodents include mice, rats, woodchucks, ferrets, rabbits and hamsters. Domestic and game animals include, but are not limited to, cows, horses, pigs, deer, bison, buffalo, feline species, e.g., domestic cat, canine species, e.g., dog, fox, wolf, avian species, e.g., chicken, emu, ostrich, and fish, e.g., trout, catfish and salmon. In certain embodiments of the aspects described herein, the subject is a mammal, e.g., a primate or a human A subject can be male or female. Additionally, a subject can be an infant or a child. In some embodiments, the subject can be a neonate or an unborn subject, e.g., the subject is in utero. Preferably, the subject is a mammal. The mammal can be a human, non-human primate, mouse, rat, dog, cat, horse, or cow, but is not limited to these examples. Mammals other than humans can be advantageously used as subjects that represent animal models of diseases and disorders. In addition, the methods and compositions described herein can be used for domesticated animals and/or pets. A human subject can be of any age, gender, race or ethnic group, e.g., Caucasian (white), Asian, African, black, African American, African European, Hispanic, Mideastern, etc. In some embodiments, the subject can be a patient or other subject in a clinical setting. In some embodiments, the subject is already undergoing treatment. In some embodiments, the subject is an embryo, a fetus, neonate, infant, child, adolescent, or adult. In some embodiments, the subject is a human fetus, human neonate, human infant, human child, human adolescent, or human adult. In some embodiments, the subject is an animal embryo, or non-human embryo or non-human primate embryo. In some embodiments, the subject is a human embryo.
As used herein, the term “host cell”, includes any cell type that is susceptible to transformation, transfection, transduction, and the like with a nucleic acid construct or ceDNA expression vector of the present disclosure. As non-limiting examples, a host cell can be an isolated primary cell, pluripotent stem cells, CD34+ cells), induced pluripotent stem cells, or any of a number of immortalized cell lines (e.g., HepG2 cells). Alternatively, a host cell can be an in situ or in vivo cell in a tissue, organ or organism.
The term “exogenous” refers to a substance present in a cell other than its native source. The term “exogenous” when used herein can refer to a nucleic acid (e.g., a nucleic acid encoding a polypeptide) or a polypeptide that has been introduced by a process involving the hand of man into a biological system such as a cell or organism in which it is not normally found and one wishes to introduce the nucleic acid or polypeptide into such a cell or organism. Alternatively, “exogenous” can refer to a nucleic acid or a polypeptide that has been introduced by a process involving the hand of man into a biological system such as a cell or organism in which it is found in relatively low amounts and one wishes to increase the amount of the nucleic acid or polypeptide in the cell or organism, e.g., to create ectopic expression or levels. In contrast, the term “endogenous” refers to a substance that is native to the biological system or cell.
The term “sequence identity” refers to the relatedness between two nucleotide sequences. For purposes of the present disclosure, the degree of sequence identity between two deoxyribonucleotide sequences is determined using the Needleman-Wunsch algorithm (Needleman and Wunsch, 1970, supra) as implemented in the Needle program of the EMBOSS package (EMBOSS: The European Molecular Biology Open Software Suite, Rice et al., 2000, supra), preferably version 3.0.0 or later. The optional parameters used are gap open penalty of 10, gap extension penalty of 0.5, and the EDNAFULL (EMBOSS version of NCBI NUC4.4) substitution matrix. The output of Needle labeled “longest identity” (obtained using the −nobrief option) is used as the percent identity and is calculated as follows: (Identical Deoxyribonucleotides.times.100)/(Length of Alignment-Total Number of Gaps in Alignment). The length of the alignment is preferably at least 10 nucleotides, preferably at least 25 nucleotides more preferred at least 50 nucleotides and most preferred at least 100 nucleotides.
The term “homology” or “homologous” as used herein is defined as the percentage of nucleotide residues that are identical to the nucleotide residues in the corresponding sequence on the target chromosome, after aligning the sequences and introducing gaps, if necessary, to achieve the maximum percent sequence identity. Alignment for purposes of determining percent nucleotide sequence homology can be achieved in various ways that are within the skill in the art, for instance, using publicly available computer software such as BLAST, BLAST-2, ALIGN, ClustalW2 or Megalign (DNASTAR) software. Those skilled in the art can determine appropriate parameters for aligning sequences, including any algorithms needed to achieve maximal alignment over the full length of the sequences being compared. In some embodiments, a nucleic acid sequence (e.g., DNA sequence), for example of a homology arm, is considered “homologous” when the sequence is at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or more, identical to the corresponding native or unedited nucleic acid sequence (e.g., genomic sequence) of the host cell.
The term “heterologous,” as used herein, means a nucleotide or polypeptide sequence that is not found in the native nucleic acid or protein, respectively. A heterologous nucleic acid sequence may be linked to a naturally-occurring nucleic acid sequence (or a variant thereof) (e.g., by genetic engineering) to generate a chimeric nucleotide sequence encoding a chimeric polypeptide. A heterologous nucleic acid sequence may be linked to a variant polypeptide (e.g., by genetic engineering) to generate a nucleotide sequence encoding a fusion variant polypeptide.
A “vector” or “expression vector” is a replicon, such as plasmid, bacmid, phage, virus, virion, or cosmid, to which another DNA segment, i.e. an “insert”, may be attached so as to bring about the replication of the attached segment in a cell. A vector can be a nucleic acid construct designed for delivery to a host cell or for transfer between different host cells. As used herein, a vector can be viral or non-viral in origin and/or in final form, however for the purpose of the present disclosure, a “vector” generally refers to a ceDNA vector, as that term is used herein. The term “vector” encompasses any genetic element that is capable of replication when associated with the proper control elements and that can transfer gene sequences to cells. In some embodiments, a vector can be an expression vector or recombinant vector.
As used herein, the term “expression vector” refers to a vector that directs expression of an RNA or polypeptide from sequences linked to transcriptional regulatory sequences on the vector. The sequences expressed will often, but not necessarily, be heterologous to the cell. An expression vector may comprise additional elements, for example, the expression vector may have two replication systems, thus allowing it to be maintained in two organisms, for example in human cells for expression and in a prokaryotic host for cloning and amplification. The term “expression” refers to the cellular processes involved in producing RNA and proteins and as appropriate, secreting proteins, including where applicable, but not limited to, for example, transcription, transcript processing, translation and protein folding, modification and processing. “Expression products” include RNA transcribed from a gene, and polypeptides obtained by translation of mRNA transcribed from a gene. The term “gene” means the nucleic acid sequence which is transcribed (DNA) to RNA in vitro or in vivo when operably linked to appropriate regulatory sequences. The gene may or may not include regions preceding and following the coding region, e.g., 5′ untranslated (5′UTR) or “leader” sequences and 3′ UTR or “trailer” sequences, as well as intervening sequences (introns) between individual coding segments (exons).
By “recombinant vector” is meant a vector that includes a heterologous nucleic acid sequence, or “transgene” that is capable of expression in vivo. It should be understood that the vectors described herein can, in some embodiments, be combined with other suitable compositions and therapies. In some embodiments, the vector is episomal. The use of a suitable episomal vector provides a means of maintaining the nucleotide of interest in the subject in high copy number extra chromosomal DNA thereby eliminating potential effects of chromosomal integration.
The phrase “genetic disease” as used herein refers to a disease, partially or completely, directly or indirectly, caused by one or more abnormalities in the genome, especially a condition that is present from birth. The abnormality may be a mutation, an insertion or a deletion. The abnormality may affect the coding sequence of the gene or its regulatory sequence. The genetic disease may be, but not limited to DMD, hemophilia, cystic fibrosis, Huntington's chorea, familial hypercholesterolemia (LDL receptor defect), hepatoblastoma, Wilson's disease, congenital hepatic porphyria, inherited disorders of hepatic metabolism, Lesch Nyhan syndrome, sickle cell anemia, thalassaemias, xeroderma pigmentosum, Fanconi's anemia, retinitis pigmentosa, ataxia telangiectasia, Bloom's syndrome, retinoblastoma, and Tay-Sachs disease.
The term “biomarker” as used herein is meant any assayable characteristic or composition that can be used to identify a condition (e.g., a disease) or the status of a condition (e.g., disease state) of the subject or a sample. A biomarker can, in some examples disclosed herein, be a gene whose expression characteristics can be used to identify a condition or status of a condition in a subject or sample. In other examples, a biomarker can be a gene product. In some embodiments, the term “biomarker” refers to a polypeptide expressed endogenously in an individual or found or sequestered in a biological sample from an individual.
By “gene product” is meant a transcript (e.g., mRNA), nucleic acid (e.g., miRNA), or protein. Thus, disclosed herein are biomarkers whose presence, absence, or relative amount can be used to identify a condition or status of a condition in a subject or sample. In one particular example, a biomarker can be a gene product whose presence or absence in a subject is characteristic of a subject having or not having a particular neurodegenerative disease, having a particular risk for developing a disease, (e.g., a neurodegenerative disease), or being at a particular stage of disease. In still another example, a biomarker can be a gene product whose increase or decrease indicates a particular disease state, a particular risk for developing a disease, or a particular stage of disease. In another example, a biomarker can be a group of various gene products, the presence or absence of which is indicative of a subject having or not having a particular disease, having a particular risk for developing a disease, or being at a particular stage of disease. In a further example, a biomarker can be a group of gene products whose pattern of increasing and decreasing expression characterizes a particular disease or lack thereof. Still further, a biomarker can be a gene product or group of gene products whose pattern of expression is characteristic of the presence or absence of a disease, or a particular prognosis or outcome of a disease. As used herein, a biomarker can be a surrogate for other clinical tests. Biomarkers identified herein can be measured to determine levels, expression, activity, or to detect variants. As used throughout when detecting levels of expression or activity are discussed, it is understood that this could reflect variants of a given biomarker. Variants include amino acid or nucleic acid variants or post translationally modified variants.
The term “biological sample” as used herein refers to a cell or population of cells or a quantity of tissue or fluid from a subject. Most often, the sample has been removed from a subject, but the term “biological sample” can also refer to cells or tissue analyzed in vivo, i.e. without removal from the subject. Often, a “biological sample” will contain cells from the subject, but the term can also refer to non-cellular biological material, such as non-cellular fractions of blood, saliva, or urine, that can be used to measure gene expression or protein expression levels. Biological samples include, but are not limited to, tissue biopsies, scrapes (e.g. buccal scrapes), whole blood, plasma, serum, urine, saliva, cell culture, or cerebrospinal fluid. Biological samples also include tissue biopsies, cell culture. A biological sample or tissue sample can refer to a sample of tissue or fluid isolated from an individual, including but not limited to, for example, blood, plasma, serum, tumor biopsy, urine, stool, sputum, spinal fluid, pleural fluid, nipple aspirates, lymph fluid, the external sections of the skin, respiratory, intestinal, and genitourinary tracts, tears, saliva, milk, cells (including but not limited to blood cells), tumors, organs, and also samples of in vitro cell culture constituent. In some embodiments, the sample is from a resection, bronchoscopic biopsy, or core needle biopsy of a primary or metastatic tumor, or a cellblock from pleural fluid. In addition, fine needle aspirate samples are used. Samples can be either paraffin-embedded or frozen tissue. The sample can be obtained by removing a sample of cells from a subject, but can also be accomplished by using previously isolated cells (e.g. isolated by another person), or by performing analysis of the level of transgene expression from the ceDNA vector in vivo. Biological sample also refers to a sample of tissue or fluid isolated from an individual, including but not limited to, for example, blood, plasma, serum, tumor biopsy, urine, stool, sputum, spinal fluid, pleural fluid, nipple aspirates, lymph fluid, the external sections of the skin, respiratory, intestinal, and genitourinary tracts, tears, saliva, milk, cells (including but not limited to blood cells), tumors, organs, and also samples of in vitro cell culture constituent. In some embodiments, the biological samples can be prepared, for example biological samples can be fresh, fixed, frozen, or embedded in paraffin.
The term “blood sample” or “blood” as used herein include, but are not limited to, whole blood, serum or plasma. In some embodiments, the whole blood sample is further processed into serum or plasma samples. The term also includes a mixture of the above-mentioned samples.
The term “inhibitor” as used herein refers to any agent or entity which results in the inhibition of a proteins biological activity. By a “decrease” or “inhibition” used in the context of the level of activity of a gene refers to a reduction in protein or nucleic acid level or biological activity in a cell, a cell extract, or a cell supernatant. For example, such inhibition may be due to decreased binding of the polypeptide to its endogenous ligand, or by non-completive binding of an inhibitor to a polypeptide to reduce catalytic activity or affinity for target ligand etc., or alternatively to reduced RNA stability, transcription, or translation, increased protein degradation, or RNA interference. Preferably, a decrease is at least about 5%, at least about 10%, at least about 25%, at least about 50%, at least about 75%, at least about 80%, or even at least about 90% of the level of expression or activity under control conditions. The term “inhibiting” as used herein as it pertains to the inhibition of the activity of topoisomerase I protein or variants thereof does not necessarily mean complete inhibition of expression and/or activity. Rather, expression or activity of the protein, polypeptide or polynucleotide is inhibited to an extent, and/or for a time, sufficient to produce the desired effect.
The terms “lower”, “reduced”, “reduction” or “decrease” or “inhibit” are all used herein generally to mean a decrease by a statistically significant amount. However, for avoidance of doubt, “lower”, “reduced”, “reduction” or “decrease” or “inhibit” means a decrease by at least 10% as compared to a reference level, for example a decrease by at least about 20%, or at least about 30%, or at least about 40%, or at least about 50%, or at least about 60%, or at least about 70%, or at least about 80%, or at least about 90% or up to and including a 100% decrease (i.e. absent level as compared to a reference sample), or any decrease between 10-100% as compared to a reference level.
The terms “increased”, “increase” or “enhance” or “higher” are all used herein to generally mean an increase by a statically significant amount; for the avoidance of any doubt, the terms “increased”, “increase” or “enhance” or “higher” means an increase of at least 10% as compared to a reference level, for example an increase of at least about 20%, or at least about 30%, or at least about 40%, or at least about 50%, or at least about 60%, or at least about 70%, or at least about 80%, or at least about 90% or up to and including a 100% increase or any increase between 10-100% as compared to a reference level, or at least about a 2-fold, or at least about a 3-fold, or at least about a 4-fold, or at least about a 5-fold or at least about a 10-fold increase, or any increase between 2-fold and 10-fold or greater as compared to a reference level.
By an “increase” in the expression or activity of a gene or protein is meant a positive change in protein or polypeptide or nucleic acid level or activity in a cell, a cell extract, or a cell supernatant. For example, such an increase may be due to increased RNA stability, transcription, or translation, or decreased protein degradation. Preferably, this increase is at least 5%, at least about 10%, at least about 25%, at least about 50%, at least about 75%, at least about 80%, at least about 100%, at least about 200%, or even about 500% or more over the level of expression or activity under control conditions.
As used herein the term “comprising” or “comprises” is used in reference to compositions, methods, and respective component(s) thereof, that are essential to the method or composition, yet open to the inclusion of unspecified elements, whether essential or not.
As used herein the term “consisting essentially of” refers to those elements required for a given embodiment. The term permits the presence of elements that do not materially affect the basic and novel or functional characteristic(s) of that embodiment. The use of “comprising” indicates inclusion rather than limitation.
The term “consisting of” refers to compositions, methods, and respective components thereof as described herein, which are exclusive of any element not recited in that description of the embodiment.
As used herein the term “consisting essentially of” refers to those elements required for a given embodiment. The term permits the presence of additional elements that do not materially affect the basic and novel or functional characteristic(s) of that embodiment of the invention.
As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” include plural references unless the context clearly dictates otherwise. Thus for example, references to “the method” includes one or more methods, and/or steps of the type described herein and/or which will become apparent to those persons skilled in the art upon reading this disclosure and so forth. Similarly, the word “or” is intended to include “and” unless the context clearly indicates otherwise. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of this disclosure, suitable methods and materials are described below. The abbreviation, “e.g.” is derived from the Latin exempli gratia, and is used herein to indicate a non-limiting example. Thus, the abbreviation “e.g.” is synonymous with the term “for example.”
Other than in the operating examples, or where otherwise indicated, all numbers expressing quantities of ingredients or reaction conditions used herein should be understood as modified in all instances by the term “about.” The term “about” when used in connection with percentages can mean±1%. The present invention is further explained in detail by the following examples, but the scope of the invention should not be limited thereto.
Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member can be referred to and claimed individually or in any combination with other members of the group or other elements found herein. One or more members of a group can be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is herein deemed to contain the group as modified thus fulfilling the written description of all Markush groups used in the appended claims.
In some embodiments of any of the aspects, the disclosure described herein does not concern a process for cloning human beings, processes for modifying the germ line genetic identity of human beings, uses of human embryos for industrial or commercial purposes or processes for modifying the genetic identity of animals which are likely to cause them suffering without any substantial medical benefit to man or animal, and also animals resulting from such processes.
Other terms are defined herein within the description of the various aspects of the invention.
All patents and other publications; including literature references, issued patents, published patent applications, and co-pending patent applications; cited throughout this application are expressly incorporated herein by reference for the purpose of describing and disclosing, for example, the methodologies described in such publications that might be used in connection with the technology described herein. These publications are provided solely for their disclosure prior to the filing date of the present application. Nothing in this regard should be construed as an admission that the inventors are not entitled to antedate such disclosure by virtue of prior invention or for any other reason. All statements as to the date or representation as to the contents of these documents is based on the information available to the applicants and does not constitute any admission as to the correctness of the dates or contents of these documents.
The description of embodiments of the disclosure is not intended to be exhaustive or to limit the disclosure to the precise form disclosed. While specific embodiments of, and examples for, the disclosure are described herein for illustrative purposes, various equivalent modifications are possible within the scope of the disclosure, as those skilled in the relevant art will recognize. For example, while method steps or functions are presented in a given order, alternative embodiments may perform functions in a different order, or functions may be performed substantially concurrently. The teachings of the disclosure provided herein can be applied to other procedures or methods as appropriate. The various embodiments described herein can be combined to provide further embodiments. Aspects of the disclosure can be modified, if necessary, to employ the compositions, functions and concepts of the above references and application to provide yet further embodiments of the disclosure. Moreover, due to biological functional equivalency considerations, some changes can be made in protein structure without affecting the biological or chemical action in kind or amount. These and other changes can be made to the disclosure in light of the detailed description. All such modifications are intended to be included within the scope of the appended claims.
Specific elements of any of the foregoing embodiments can be combined or substituted for elements in other embodiments. Furthermore, while advantages associated with certain embodiments of the disclosure have been described in the context of these embodiments, other embodiments may also exhibit such advantages, and not all embodiments need necessarily exhibit such advantages to fall within the scope of the disclosure.
The technology described herein is further illustrated by the following examples which in no way should be construed as being further limiting. It should be understood that this invention is not limited to the particular methodology, protocols, and reagents, etc., described herein and as such can vary. The terminology used herein is for the purpose of describing particular embodiments only, and is not intended to limit the scope of the present invention, which is defined solely by the claims.
I. Method for Controlled Expression of a Transgene Using a ceDNA Vector
Described herein are methods of administration of ceDNA vectors in vivo or in vitro, that enable either (i) sustained expression of level of a transgene for a predetermined period of time (i.e., maintaining transgene expression levels), or (ii) to increase the expression level of the transgene in a dose-dependent manner, the method comprising at least one (e.g., one or more) subsequent administrations (e.g., a “booster” or “re-dose” administration) of the ceDNA vector.
Accordingly, the technology described herein relates administration of a ceDNA vector in vivo, where the level of transgene expression is sustained at a desired level or increased in level with one or more subsequent administrations (e.g., a booster administration, or re-dose). The ceDNA vectors disclosed herein enable an increase in the level of transgene expression from a prior level in vitro and in vivo. The increase in the level of transgene can be to, or above a desired level, or to increase the expression level to within a desired expression range, by at least one re-administration (herein also referred to as “re-dose”) at any time point after the initial administration. In some cases, the desired increase is to correct a naturally-occurring decrease in those levels such that the final dose is a return to the previously desired level, e.g., a sustained dose level. That such re-dose administration or repeated doses of a ceDNA vector as disclosed herein can be used to increase the level of transgene expression is possible because the ceDNA vector has no capsid to provoke a host immune response (e.g., the vector has non-immunogenic properties) and thus offers significant advantages over existing AAV vector technology, where re-doses are not possible due to immune responses or AAV immunity in the host from a prior AAV exposure, or e.g. from the initial AAV vector administration. Thus, to achieve a high level of expression using rAAV vectors, an initial high dose is typically required and re-doses are either not possible and/or not effective due to immune response issues. In contrast, one or more re-dose administrations of a ceDNA vector as disclosed herein can be administered to increase the level of expression of a transgene, e.g., to increase the level of expression to a desired expression level, or above a desired threshold level or within a desired expression level range.
Accordingly, the present invention relates to methods and ceDNA vectors for controlled transgene expression for any of: (i) maintain or sustain the level of transgene expression at a desired level for a predetermined time by re-administration of ceDNA vector at one or more time points, (ii) increasing transgene expression level by re-administration of ceDNA vector at one or more time points or (iii) dose-dependent transgene expression by administration of the ceDNA vector in a dose-dependent manner (i.e., titratable expression of the transgene). As discussed herein, the cDNA vectors are unique as compared to other viral vectors in that the ceDNA vector can be administered to the subject multiple times, e.g., over a short period of time (e.g., several months), or over a long period of time (e.g., over several years) to allow the expression of the transgene to be controlled, thereby enabling one to customize or tailor the gene therapy to the needs of the subject.
A. Increased or Dose-Dependent Controlled Expression from the Transgene
(i) Controlled Trans Gene Expression: Sustained Trans Gene Expression by Re-Administration of ceDNA Vector
One aspect of the technology described herein relates to use of a ceDNA vector as disclosed herein in a method for maintaining or sustaining the level of expression of a transgene in a cell, the method comprising: (a) administering to a cell at a first time point, a priming dose of a ceDNA vector to achieve expression of a transgene, and (b) administering to the cell at a second time point, a dose of a ceDNA vector to compensate for any decrease in expression level of the transgene after the ceDNA vector administration at the first time point.
As shown in
Expression of the transgene typically occurs within about 7-20 days after the re-dose administration, and maintains that level of expression (i.e., is sustained expression) of the transgene from after the re-dose administration for at least about 30 days, or about 60 days, or about 90 days, or about 120 days or longer than 120 days after administration of the second dose (i.e., the re-dose, or administration at the second or subsequent time point).
Another aspect of the technology described herein relates to a method for treating a disease in a subject, or alternatively, a method for controlled transgene expression in a subject, the method comprising: (a) administering to the subject at a first time point, a priming dose of a composition comprising a ceDNA vector as described herein, to achieve expression of the transgene at a first level (or first amount), and (b) administering to the subject at a second time point, a dose or amount of a ceDNA vector to maintain the expression level of the transgene at a desired sustained expression level, where the sustained expression level is a higher level of expression as compared to the level of transgene expression which achieved if only the initial (i.e., priming) administration of the ceDNA vector at the first time point was given, thereby treating the disease in the subject.
Accordingly, in some embodiments a ceDNA vector as disclosed herein can be re-administered (also referred to herein as “re-dosed”) to maintain a desired transgene expression level, where the ceDNA vector comprises two ITR sequences (e.g., a symmetric ITR pair or asymmetric ITR pair as described herein) flanking a transgene polynucleotide sequence operatively linked to a promoter.
In some embodiments, use of a ceDNA vector in a method for sustaining the level of expression of a transgene in a cell expresses the transgene at a desired expression level for at least 42 days. In some embodiments, the ceDNA vector expresses the transgene at a desired expression level for at least 84 days. In some embodiments, the ceDNA vector expresses the transgene at a desired expression level for at least 132 days. For illustrative purposes only, a ceDNA vector produced by the methods disclosed in Example 1 can sustain the expression level of a transgene in a murine model of CD-1 IGS mice at a higher level from days 7-28 post-administration as compared to similar close-ended DNA vectors produced by other methods and tested in the same mouse model.
In some embodiments, the increased transgene expression is not dose-dependent, or not entirely dose dependent, but it is sustained expression, in that the increased expression of the transgene occurs typically within 7-20 days after the re-dose administration, and maintains that level of increased expression of the transgene from the re-dose for at least about 30 days, or at least about 60 days, or at least about 90 days, or at least about 120 days or longer than about 120 days after administration of the second dose (i.e., the re-dose, or administration at the second or subsequent time point).
The specific dose response relationship for a given ceDNA vector or composition disclosed herein can be determined by means well known to those of skill in the art, including e.g., as described in Example 6. The ceDNA vector as disclosed herein can be titrated by administration of additional doses of the ceDNA vector at one or more times following the initial administration as required to achieve the desired level of expression. More than one, 2, 3, 4, 5 or 6 or more repeat administrations can be administered in order to titrate the expression levels of a transgene at or near a desired level. Typically, each repeat administration is administered approximately 7-days before a decrease in the expression of the transgene from the previous administration is observed. In effect, the repeated administrations serve to titrate the expression level of the transgene to a desired level, or stated another way, the repeated administrations enable the expression level of the transgene to be maintained within a desired expression level range, e.g., at a desired range which is therapeutic to treat a disease or disorder or within the therapeutic window of the composition.
In some embodiments, a ceDNA vector described herein can be used to tailor the level of transgene expression in vivo, where the level of expression is increased from a prior level (where the prior level is the level after a prior priming or re-dose administration) to a desired expression level, or within a desired expression level range, or above a desired threshold level in vivo, where the increased expression level is sustained or maintained between about 30-60 days, or between about 40-70 days, or between about 50-80 days, or between about 60-90 days, or between about 70-100 days or between about 80-110 days, or between about 40-120 days, or longer than 120 days after the re-dose administration of the ceDNA vector.
In some embodiments, the ceDNA vector used in the methods described herein, e.g., in a method for sustaining expression of a transgene in a cell and/or for treating a subject with a disease, is administered in combination with a pharmaceutically acceptable carrier and/or excipient. In some embodiments, a ceDNA vector is administered at a second time point is administered at least 30 days, or at least 60 days or between 60-90 days, or between 90-120 days, or between about 3-6 months, or between 6-12 months, or between 1-2 years, or 2-3 years after the first time point.
(ii) Controlled Transgene Expression: Increasing Transgene Expression by Re-Administration of ceDNA Vector
In addition to a re-dose administration of a ceDNA vector to simply increase the level of transgene expression if expression levels have decreased over time (e.g., to continue or maintain the transgene expression at a desired pre-determined level), in some embodiments, the methods and compositions of re-administration of a ceDNA vector can increase the level of transgene in a dose-dependent manner—that is, a re-dose administration of a defined amount of a ceDNA vector can effect a defined increase in expression level of a transgene. Stated differently and using arbitrary units for illustrative purposes only, a lunit dose of the ceDNA in a re-dose administration will achieve a 10% increase in the level of transgene expression from a prior level, and a 2 unit dose of the cDNA vector will achieve a 20% increase in the level of the transgene from a prior level, and a 0.5 unit dose of the ceDNA will achieve a 5% increase in the level of expression of the transgene from a prior level.
Accordingly, in one embodiment, a ceDNA vector as disclosed herein for controlled transgene expression can be used for increasing the level of expression of a transgene in a cell or a subject in a controlled manner. For example, the expression level of the transgene can be increased with one or more subsequent administrations (e.g., a re-dose or a booster administration) of the ceDNA vector.
The ceDNA vectors as described herein enable a dose- or concentration dependent re-dose administration of the ceDNA at one or more points after the initial priming administration to increase the expression level of the transgene by a defined amount in vivo. In some embodiments, the increase in transgene expression by a defined amount can bring the transgene expression level in vivo at, or above a desired threshold (or predetermined level), or within a desired expression level range, where the desired threshold or desired expression level range is above the transgene expression level of the prior administration (i.e., the initial priming administration or a prior re-dose administration).
Stated differently, the dose-dependent re-dose administration disclosed herein adds to the transgene expression level. The increased transgene expression is dose-dependent, and is a sustainable expression—that is, the expression of the transgene at the higher level (due to the dose-dependent re-dose administration) is maintained for a defined period of time, or does not decrease, or drop below the level of expression observed without the re-dose administration.
Typically, each dose-dependent re-dose is administered approximately 7-days before the desired increase in the expression of the transgene is desired. In effect, the dose-dependent re-doses serve to titrate the expression level of the transgene to a desired level, or desired expression level range, or stated another way, the dose-dependent re-doses enable the expression level of the transgene to be increased by a defined amount above the prior expression level, and that the increases can be in at least one dose-dependent re-dose administration, or alternatively, in incremental increases with more than one dose-dependent re-dose administration, such that the transgene is increased in a controlled, titrated manner to be expressed at a level that is within a desired expression level range, e.g., at a desired range which is therapeutic to treat a disease or disorder.
In some embodiments, a desired range of expression level, or desired expression level range of the transgene may be a therapeutically effective amount of transgene to effectively treat or reduce a symptom of a disease. Accordingly, in some embodiments, to achieve such a therapeutically effective amount of transgene, one can increase the level of expression of the transgene using one or more re-dose administrations as described herein, to incrementally increase the levels to the therapeutically effective amount of the transgene. Therefore, in some embodiments, a subject can be administered a priming dose of ceDNA vector that expresses the transgene at a low expression level (i.e., a sub-therapeutically effective amount), and one or more re-dose administrations can be administered to the subject over a period of time to increase the expression level until a desired therapeutic effect is achieved. Such a strategy allows the subject's body to adjust to the level of the expressed transgene, and effectively allows titration or adjusting (in this case, increasing) the level of the expression of the transgene in increments to reach a desired therapeutic goal or effect and/or prevent over medication and/or side effects due to over expression of the transgene. Alternatively, in some embodiments, a subject can be administered a priming dose of ceDNA vector that expresses the transgene at a desired expression level when the subject is an infant or child, typically a low expression level, and one or more dose-dependent re-dose administrations can be administered to the subject over a period of time as the subject grows to increase the expression level so that the therapeutic effect is maintained.
B. Timing and Amount of ceDNA Vector in Re-Administration
The level of expression of a transgene from a ceDNA vector as disclosed herein can be increased from a prior level (i.e., expression level achieved from a prior priming administration at day 0, or a prior re-dose) by re-administration (i.e., re-dose) of the ceDNA vector at one or more times following the initial administration. Typically, the re-dose administration to increase the level of expression to a desired level or a desired expression level range is administered about 7 days, or more than 7 days before the increase in expression is desired. As an illustrative example, if an increase in the level of transgene expression is desired at about 30-days after the prior administration (i.e., a priming or prior re-dose administration), then a re-dose can be given at 28 days or earlier. Similarly, if an increase in the transgene expression is desired at about 90 days (or about 3-months) after a prior administration (i.e., a priming or prior re-dose administration), then a re-dose can be administered at about 83 or 84 days or earlier in order to increase the level of the transgene expression at or around 90 days to a desired level or within a desired expression level range, where the desired level or desired expression level range is above the transgene expression level achieved with the prior administration.
As discussed herein, as the methods and ceDNA vectors described herein allow a personalized genetic medicine approach, i.e., titrating the level of the transgene expression in a step-by-step manner with re-dose administrations to increase the expression levels incrementally, it is envisioned that 1, 2, 3, 4, 5 or 6 or more than 6 re-doses can be administered over time in order to increase the level of expression the transgene to a desired level, or to a desired expression level range, which is higher than the expression level achieved with the prior administration, or prior to this re-dose administration. The incremental increases in expression level of the transgene by each re-dose administration can be the same, i.e., each re-dose administration can increase the expression level of the transgene by about 10% from the prior expression level, or can be different, i.e., a first re-dose administration can increase the expression about 10% from the prior expression level, and a second re-dose administration can increase the expression about 20% from the prior expression level. Typically, each re-dose is administered approximately 7-days before the desired increase in the expression of the transgene is desired. In effect, the re-doses serve to titrate the expression level of the transgene to a desired level or desired expression level range, or stated another way, the re-doses enable the expression level of the transgene to be increased above the prior expression level, and that the increases can be incremental with one or more re-dose administration such that the transgene is expressed at a level that is within a desired expression level range, e.g., at a desired range which is therapeutic to treat a disease or disorder.
In some embodiments, a re-dose to increase the transgene expression level is at least about 20 days, or at least about 30 days, or at least about 40 days, or at least about 50 days, or at least about 60 days, or between about 60-90 days, or between about 90-120 days, or between about 120-150 days after a prior administration (e.g., an initial priming administration at day 0, or a prior re-dose administration) of the ceDNA composition.
In some embodiments, the technology described herein relates to a re-dose of ceDNA for increasing transgene expression in vivo, where expression of the transgene can be increased by one or more re-doses (i.e., re-administration or booster administrations) of the ceDNA composition. In some embodiments, the dose (or amount) of ceDNA vector in the re-dose administration at a second or subsequent time point is the same, or a different amount to the dose (i.e., amount) of ceDNA in the administration prior to, or proceeding this re-dose administration (an initial priming administration at day 0, or a prior re-dose administration). As one example, if the amount of ceDNA administered at the first time point is 1 mg/kg, the amount in the re-dose administration at a second or subsequent time point can be 1 mg/kg, or less than 1 mg/kg or more than 1 mg/kg. In some embodiments, the re-dose can be at an amount selected from any of: about 2 mg/kg, about 3 mg/kg, about 4 mg/kg, about 5 mg/kg, about 6 mg/kg, about 7 mg/kg, about 8 mg/kg, about 9 mg/kg, about 10 mg/kg, or between about 2-5 mg/kg, or between 5-10 mg/kg, or between 10-15 mg/kg or greater than 15 mg/kg.
In some embodiments, to increase the expression level of the transgene by one or more re-dose administrations (i.e., sequential re-dose administrations to incrementally increase the transgene expression level), each re-dose administration can be the same, i.e., each re-dose administration can increase the expression level of the transgene by about 10% from the prior expression level, or can be different, i.e., a first re-dose administration can increase the expression about 10% from the prior expression level, and a second re-dose administration can increase the expression about 20% from the prior expression level.
In some embodiments, where more than one re-dose is administered, the amount of increase in the expression level of the transgene by each re-dose administration can be the same, i.e., each re-dose administered can increase the expression level of the transgene by about 10% from the prior expression level, or can be different, i.e., a first re-dose administration can increase the expression about 10% from the prior expression level, and a second re-dose administration can increase the expression about 20% from the prior expression level. In some embodiments, where more than one re-dose is administered, the amount of increase in the expression level of the transgene by each re-dose administration can be the same, i.e., each re-dose administered can increase the expression level of the transgene by about 1-fold, or 2-fold, or 3-fold etc. from the prior expression level, or can be different, i.e., a first re-dose administration can increase the expression about 2-fold from the prior expression level, and a second re-dose administration can increase the expression about 6-fold from the prior expression level, or about 6-fold from the expression level achieved from the initial priming administration.
In some embodiments, the ceDNA vector is the same ceDNA vector administered at the prime administration (i.e., first administration at time 0) as that administered to the cell or subject at a second or any subsequent administration (e.g., re-dose administrations). In some embodiments, the ceDNA vector can be the same ceDNA vector. For illustrative purposes only, re-administration of viral vectors, e.g., AAV vectors usually are a different serotype to that administered previously. In contrast, a ceDNA vector in a re-administration is the same as the ceDNA vector administered previously, —that is, the ceDNA vector has not changed such that it is equivalent to administering the same serotype of AAV multiple times.
That being said, while it is the equivalent of the same ceDNA vector serotype being re-administered, in some embodiments, the ceDNA vector administered at a second or any subsequent administration (e.g., re-dose administrations) after the initial prime administration is different, such, as, e.g., different ITR-pair, a different promoter operatively linked to the transgene, a different transgene or modified transgene or the like. In some embodiments, the transgene gene is the same, or can be a modified transgene.
In some embodiments, the intervals between the first administration (i.e., priming administration) of a ceDNA vector and a re-dose administration (i.e., at a second time point, or any subsequent time point after that, e.g., 3rd, 4th, 5th, 6th, 7th, 8th, 9th, 10th etc.) can be at least 30 days, or at least 60 days, or at least 80 days, or between 60-90 days, or between 90-120 days, or between about 2-3 months, or between about 3-6 months, or between about 6-12 months, or at about 1 year or between 1-2 years, or at about 2 years or between 2-3 years, or at about 3 years or between 3-4 years, or at about 5 years or between 5-6 years, or between 5-10 years, or between 10-20 years etc. after the prior administration (i.e., the priming dose or a prior-re-dose administration). As discussed herein, in one embodiment a re-dose administration to increase the level of expression of a transgene is administered about 7 days, or more than 7 days (e.g., between 8-10, or 14 days) before an increase in expression is desired.
For illustration purposes only, if the amount of the ceDNA vector in the initial administration at day 0 is set at an arbitrary unit of 1, then the amount of ceDNA vector in a re-dose administration, at a second, third, fourth, fifth, sixth time point can be selected from any of 2-fold, 3-fold, 4-fold, 5-fold, 6-fold, 7-fold, 8-fold, 9-fold, 10-fold, 11-fold, 12-fold, 13-fold, 14-fold, 15-fold, or between 15-20-fold, or between 20-50-fold greater (or more) than the amount of ceDNA vector in the initial administration at day 0.
In some embodiments, if the amount of the ceDNA vector in the initial administration at day 0 results in a level of expression that is given an arbitrary unit of 1-fold, then the amount of ceDNA vector in a re-dose administration, at a second, third, fourth, fifth, sixth time point can be an amount of a ceDNA vector that results in an increase in the level of expression of the transgene by at least 2-fold, 3-fold, 4-fold, 5-fold, 6-fold, 7-fold, 8-fold, 9-fold, 10-fold, 11-fold, 12-fold, 13-fold, 14-fold, 15-fold, or between 15-20-fold, or between 20-50-fold greater (or more) as compared to the level of transgene expression from the initial administration of the ceDNA vector at day 0.
In some embodiments, a re-dose is administered in the same manner, or same route of administration as the initial administration of the ceDNA at day 0. In some embodiments, a re-dose is administered in a different manner or by a different route of administration as the initial administration of the ceDNA at day 0. In some embodiments, when the initial administration (i.e., prime administration at time 0) is followed by one or more re-doses (i.e., booster administrations), the administration can be by intravenous administration, intranasal or intramuscular administration—or any other medically appropriate route of administration of the composition comprising ceDNA vector.
A ceDNA vector as disclosed herein can be administered to a subject at a first time point (e.g., the initial administration, e.g. at day 0), and at a time after the first time point if necessary or desired. A ceDNA vector as disclosed herein can be administered at a second time point to titrate the levels of the transgene at a desired level (e.g., above a threshold value for efficacy) or within a desired expression level range (e.g., within the therapeutic window of the composition). It is envisioned that more than one dose of ceDNA vector as disclosed herein, can be administered to the subject, e.g., a repeated administration can be given at any one or more of: a second time point, a third time point, a fourth time point, etc. It is encompassed that additional doses can be administered to maintain the desired level of transgene expression (i.e., to maintain or sustain the same level of transgene expression). The intervals between the first and second or any two successive re-doses do not need to be the same.
In some embodiments, a predetermined transgene expression level (also referred to as desired range of expression level, or desired expression level range of the transgene) may be a therapeutically effective amount of transgene to effectively treat or reduce a symptom of a disease. Accordingly, in some embodiments, to achieve such a therapeutically effective amount of transgene, one can maintain the level of transgene expression and/or increase the level of expression of the transgene, as disclosed herein, using one or more re-dose administrations as described herein, to incrementally increase the levels to the therapeutically effective amount of the transgene. Therefore, in some embodiments, a subject can be administered a priming dose of ceDNA vector that expresses the transgene at a desired expression level, typically a low expression level (i.e., a sub-therapeutically effective amount), and one or more dose-dependent re-dose administrations can be administered to the subject over a period of time to increase the expression level until a desired therapeutic effect is achieved. Such a strategy allows the subject's body to adjust to the level of the expressed transgene, and effectively allows titration or adjusting (in this case, increasing) the level of the expression of the transgene in at least one dose-dependent re-dose administration or more (i.e., in at least two or more increments) to reach a desired therapeutic goal or effect and/or prevent over medication and/or side effects due to over expression of the transgene. Alternatively, in some embodiments, a subject can be administered a priming dose of ceDNA vector that expresses the transgene at a desired expression level when the subject is an infant or child, typically a low expression level, and one or more dose-dependent re-dose administrations can be administered to the subject over a period of time as the subject grows to increase the expression level so that the therapeutic effect is maintained. Similarly, in some embodiments, a subject can be administered a priming dose of ceDNA vector that expresses the transgene at a desired expression level in the subject, and one or more dose-dependent re-dose administrations can be administered to the subject over a period of time as the subject gains weight etc. to increase the expression level so that the therapeutic effect is maintained.
That is, a ceDNA vector as disclosed herein is administered to a subject at a first time point (e.g., the initial administration, e.g. at day 0), and at time after the first time point, a ceDNA vector as disclosed herein is administered at a second time point to increase the level of expression of the transgene to a predetermined transgene expression level (e.g., to a desired level or within a desired expression level range), where the predetermined transgene expression level is above the level of the expression of transgene prior to the re-dose administration. In some embodiments, a predetermined transgene expression level is not necessarily the therapeutically effective amount of the transgene, it is envisioned that more than one dose-dependent re-doses of a ceDNA vector as disclosed herein, can be administered to the subject at any one or more of: a second time point, a third time point, a fourth time point, etc. where the transgene is increased to a predetermined transgene expression level. It is encompassed that dose-dependent re-doses can be administered to increase the level of expression of the transgene by a defined amount which is dependent on the dose of the ceDNA in the re-dose administration, and in some embodiments, can be used to increase the expression levels in a step-by-step manner to achieve an expression level that is a therapeutically effective amount of the transgene (e.g., is a level that produces a desired therapeutic effect or reduces one or more symptoms of the disease or disorder).
While the re-dose administration results in a dose-dependent increase in expression of the transgene, in some embodiments the effect of the re-dose administration is synergistic, —that is, the increase in transgene expression is greater than the sum of the single administrations. For example, as demonstrated in
In particular embodiments described herein, it may be desirable to select a dose low on the dose-response curve of the ceDNA for the initial administration (i.e., at a first time point, i.e., day 0) and optionally to increase the dose (i.e., level of transgene expression) in increments with one or more dose-dependent re-dose administrations at a second, third, fourth etc., administrations to induce a therapeutic effect while also preventing onset of untoward side effects or intolerance to the composition. In one embodiment, the dose response relationship for a given ceDNA vector is used to determine and/or estimate an optimal dose for effective treatment of a given disease that is well within the bounds of the therapeutic window of the composition. That is, titration of the dose of ceDNA vectors as described herein using an initial priming administration (e.g., at day 0) and incremental dose-dependent increase in re-dose administrations at subsequent time points can be achieved maximize the therapeutic effect of the expressed transgene while also minimizing side effects or unwanted toxicity.
In vivo and/or in vitro assays can optionally be employed to help identify optimal dosage ranges of the ceDNA vector in re-administrations to achieve a predetermined transgene expression level. The precise dose of ceDNA vector in the initial priming administration (e.g., at time 0) and each re-administration thereafter will also depend on the route of administration, and the seriousness of the condition, and should be decided according to the judgment of the person of ordinary skill in the art and each subject's circumstances. Effective doses can be extrapolated from dose-response curves derived from in vitro or animal model test systems.
A ceDNA vector for controlled transgene expression is administered in sufficient amounts to transfect the cells of a desired tissue and to provide sufficient levels of transgene expression without undue adverse effects. Conventional and pharmaceutically acceptable routes of administration include, but are not limited to, those described above in the “Administration” section, such as direct delivery to the selected organ (e.g., intraportal delivery to the liver), oral, inhalation (including intranasal and intratracheal delivery), intraocular, intravenous, intramuscular, subcutaneous, intradermal, intratumoral, and other parental routes of administration. Routes of administration can be combined, if desired.
The dose of the amount of a ceDNA vector in the initial priming administration (e.g., at time 0) and each re-administration thereafter for controlled transgene expression required to achieve a particular “therapeutic effect,” will vary based on several factors including, but not limited to: the route of nucleic acid administration, the level of gene or RNA expression required to achieve a therapeutic effect, the specific disease or disorder being treated, and the stability of the gene(s), RNA product(s), or resulting expressed protein(s). One of skill in the art can readily determine a ceDNA vector dose range to treat a patient having a particular disease or disorder based on the aforementioned factors, as well as other factors that are well known in the art.
Dosage regime can be adjusted to provide the optimum therapeutic response. For example, the oligonucleotide can be repeatedly administered, e.g., several doses can be administered daily or the dose can be proportionally reduced as indicated by the exigencies of the therapeutic situation. One of ordinary skill in the art will readily be able to determine appropriate doses and schedules of administration of the subject oligonucleotides, whether the oligonucleotides are to be administered to cells or to subjects.
A “therapeutically effective dose” will fall in a relatively broad range that can be determined through clinical trials and will depend on the particular application (neural cells will require very small amounts, while systemic injection would require large amounts). For example, for direct in vivo injection into skeletal or cardiac muscle of a human subject, a therapeutically effective dose will be on the order of from about 1 μg to 100 g of the ceDNA vector. If exosomes or microparticles are used to deliver the ceDNA vector, then a therapeutically effective dose can be determined experimentally, but is expected to deliver from 1 μg to about 100 g of vector. Moreover, a therapeutically effective dose is an amount ceDNA vector that expresses a sufficient amount of the transgene to have an effect on the subject that results in a reduction in one or more symptoms of the disease, but does not result in significant off-target or significant adverse side effects.
Formulation of pharmaceutically-acceptable excipients and carrier solutions is well-known to those of skill in the art, as is the development of suitable dosing and treatment regimens for using the particular compositions described herein in a variety of treatment regimens.
For in vitro transfection, an effective amount of a ceDNA vector to be delivered to cells (1×106 cells) will be on the order of 0.1 to 100 μg ceDNA vector, preferably 1 to 20 μg, and more preferably 1 to 15 μg or 8 to 10 μg. Larger ceDNA vectors will require higher doses. If exosomes or microparticles are used, an effective in vitro dose can be determined experimentally but would be intended to deliver generally the same amount of the ceDNA vector.
Without wishing to be bound by any particular theory, the lack of typical anti-viral immune response elicited by administration of a ceDNA vector as described by the disclosure (i.e., the absence of capsid components) allows the ceDNA vector to be administered to a host on multiple occasions. In some embodiments, the number of occasions in which a heterologous nucleic acid is delivered to a subject is in a range of 2 to 10 times (e.g., 2, 3, 4, 5, 6, 7, 8, 9, or 10 times). In some embodiments, a ceDNA vector is delivered to a subject more than 10 times.
In particular embodiments, more than one administration (e.g., two, three, four or more administrations) may be employed to achieve the desired level of gene expression over a period of various intervals, e.g., daily, weekly, monthly, yearly, etc.
In some embodiments, a transgene encoded by a ceDNA vector for controlled transgene expression as disclosed herein can be regulated by a regulatory switch, inducible or repressible promotor so that it is expressed in a subject for at least 1 hour, at least 2 hours, at least 5 hours, at least 10 hours, at least 12 hours, at least 18 hours, at least 24 hours, at least 36 hours, at least 48 hours, at least 72 hours, at least 1 week, at least 2 weeks, at least 1 month, at least 2 months, at least 6 months, at least 12 months/one year, at least 2 years, at least 5 years, at least 10 years, at least 15 years, at least 20 years, at least 30 years, at least 40 years, at least 50 years or more. In one embodiment, the expression can be achieved by repeated administration of the ceDNA vectors described herein at predetermined or desired intervals. Alternatively, controlled expression from a ceDNA vector as disclosed herein can further comprise components of a gene editing system (e.g., CRISPR/Cas, TALENs, zinc finger endonucleases etc.) to permit insertion of the one or more nucleic acid sequences encoding the transgene for substantially permanent treatment or “curing” the disease. Such ceDNA vectors comprising gene editing components are disclosed in International Application PCT/US18/64242, and can include the 5′ and 3′ homology arms (e.g., SEQ ID NO: 151-154, or sequences with at least 40%, 50%, 60%, 70% or 80% homology thereto) for insertion of the nucleic acid encoding the transgene into safe harbor regions, such as, but not including albumin gene or CCR5 gene.
The duration of treatment depends upon the subject's clinical progress and responsiveness to therapy. Continuous, relatively low maintenance doses are contemplated after an initial higher therapeutic dose.
II. Personalized Gene Therapy
As discussed herein, the methods and ceDNA vectors as described herein allow a personalized genetic medicine approach, i.e., dose-dependent titration of the level of the transgene expression using re-doses, e.g., in a step-by-step manner with one or more re-dose administrations, in order to increase the transgene expression levels by a certain amount with each re-dose administration. As such, the re-doses can be used to titrate the expression level of the transgene in increments. Accordingly, in some embodiments 1, 2, 3, 4, 5 or 6 or more than 6 dose-dependent re-doses can be administered in order to either maintain and/or or increase the level of expression the transgene by a defined amount each time (i.e., each re-dose), to increase the expression level to a desired level, or to a desired expression level range, which is higher than the expression level achieved with the prior administration, or prior to this re-dose administration.
The ability of a skilled artisan to titrate the dose of a composition comprising a ceDNA vectors as described herein based on the dose-response relationship for the vector is beneficial for the treatment of disease in a variety of ways. At a minimum, a skilled artisan can increase the dose of the ceDNA vector when an increase in the effect is desired (e.g., expression of a transgene). Alternatively, a skilled artisan can select a dose that is known to achieve a level of expression that is therapeutic based on prior knowledge of the dose-response relationship for the ceDNA composition. In some embodiments, it may be desirable to select a dose relatively high on the dose-response curve, for example, to accelerate treatment for a subject having severe symptoms of a given disease. In contrast, it is generally desirable to select a dose low on the dose-response curve and optionally to increase the dose in increments to induce a therapeutic effect while also preventing onset of untoward side effects or intolerance to the composition. In one embodiment, the dose response relationship for a given ceDNA vector is used to determine and/or estimate an optimal dose for effective treatment of a given disease that is well within the bounds of the therapeutic window of the composition. That is, titration of the dose of ceDNA vectors as described herein maximize the therapeutic effect of the expressed transgene while also minimizing side effects or unwanted toxicity.
As an illustrative example only, subjects with cystic fibrosis can have differing severity of disease, and/or respond differently to the same level of transgene expression of the CFTR1 gene, and/or have a lower or higher than normal drug clearance, and thus, by increasing the expression of the CFTR1 transgene in a step-by-step manner with one or more re-dose administrations of a ceDNA vector comprising a CFTR1 transgene allows the level of expression of the CFTR1 transgene to be increased in incremental steps, i.e., to a level of expression that is effective at reducing one or more symptoms of the cystic fibrosis disease in that particular subject. Previously, such a personalized approach, or titration method to increase the expression level of a transgene was either not effective, and/or not possible due to the immune responses associated with other viral-based vectors such as AAV vectors.
In some embodiments, a dose-dependent re-dose administration allows for a controlled increase in the level of transgene expression, and therefore, the methods and compositions as disclosed herein allows a personalized medicine approach to gene therapy. As an illustrative example only, subjects with cystic fibrosis can have different severity of disease, and/or respond differently to the same level of transgene expression of the CFTR1 gene, and/or have a lower or higher than normal drug clearance, and thus, a controlled increase of the expression of the CFTR1 transgene by one or more dose-dependent re-dose administrations of a ceDNA vector comprising a CFTR1 transgene allows the level of expression of the CFTR1 transgene to be increased in a controlled manner, and in some embodiments, the controlled increased in expression can be in increased to a level of expression that is effective at reducing one or more symptoms of the cystic fibrosis disease in that particular subject. Previously, such a personalized approach, or titration method to dose-dependently increase the expression level of a transgene was either not effective, and/or not possible due to the immune responses associated with other viral- or AAV-based vectors.
As discussed herein, in some embodiments, a subject is assessed at a predetermined time after a first administration of a ceDNA vector, e.g., at any timepoint at least 30 days, or at least 60 days, or between 60-90 days or longer than 90 days after the first administration of a ceDNA vector to determine the titrating dose. For example, in some embodiments, the subject is assessed to determine the disease state of the subject after a first administration of a ceDNA vector and/or the level of transgene expressed by the ceDNA vector in the subject.
In some embodiments, assessment of the disease state is an assessment of at least one symptom of the disease in the subject. The disease state for any given disease can be determined by a physician or person of skill in the art, and includes assessing one or more clinical symptoms and/or biomarkers of the disease, including protein biomarkers, miRNA and mRNA biomarkers and other molecular profiling systems.
In some embodiments, assessment of the disease state in a subject can be determined using molecular profiling in combination with clinical characterization of a patient such as observations made by a physician (such as a code from the International Classification of Diseases, for example, and the dates such codes were determined), laboratory test results, x-rays, biopsy results, statements made by the patient, and any other medical information typically relied upon by a physician to make a diagnosis in a specific disease. Methods to determine a disease state based on molecular profiling in a subject are disclosed in patents and US patent applications, U.S. Pat. Nos. 7,167,734, 9,372,193, 9,383,365, 2006/0224191, 2011/0172501, 2009/0104596, 2009/0023149 which are each incorporated herein in their entireties.
In some embodiments, the methods described herein can be used to titrate the ceDNA vector to the subject for individualized medical intervention for a particular disease state.
Examining the changes of a variety of biomarkers provides information about the status of the subject from which the biomarkers are obtained. Understanding how biomarkers change (e.g., increase, decrease, no change) with disease progression so that by measuring a single biological sample at a single point in time permits verification (e.g., disease or no disease), disease typing, and characterization of a disease state (e.g., early or “onset” versus late or “recovery” phase).
In some embodiments, biomarkers to assess the state of disease progression, such as onset or recovery, based on the level of each of the biomarkers as well as their trend (increase, decrease or constant) with time can be assessed. Profiling biomarkers for a subject disease state can also be combined with other techniques, such as stable isotope ratios naturally occurring in breath (e.g., U.S. Pat. No. 5,912,178), for assessing whether an individual is healthy or in a disease state. Disease states are detected by measuring changes in biomarker levels, and particularly, a plurality of biomarkers interrelated within a biological pathway associated with the disease state. In some embodiments, a particular disease state can be characterized by detecting and analyzing complex signals from NMR spectra to determine biomarkers whose levels are changing as the disease progresses. This initial disease state assessment allows for “fingerprinting” the dynamic changes associated with disease progression and assists in assessing current status of the disease progression and process. When the disease state is identified, the administration of the ceDNA vector can be tailored and/or titrated to the subject so as to reduce the disease time course.
In some embodiments, one can assess a disease state by assessing the biomarker profile within a biological sample obtained from a subject. The specific biomarkers that are measured are determined from an analysis of the key biochemical pathways underlying the disease and the associated host immune response. In an embodiment, a standard biomarker profile is obtained from a healthy individual and from an individual with the disease. Comparing the biomarker profile from the biological sample to the standard biomarker profile (healthy and disease) permits a disease state to be positively identified. Optionally, a second biological sample is isolated from the patient at a second time point or disease progression time point to obtain a biomarker profile trend (e.g., which biomarkers are changing between the first and second samples), thereby providing further information about the disease status or state of the patient. In some embodiments, a standard biomarker profile is assessed at one or more of the following times; before the first administration of the ceDNA vector, after at least 30 days, or at least 60 days, or between 60-90 days or longer than 90 days after the first administration of a ceDNA vector, or after at least 30 days, or at least 60 days, or between 60-90 days or longer than 90 days after the second (e.g., redose) administration of a ceDNA vector, or after at least 30 days, or at least 60 days, or between 60-90 days or longer than 90 days after any subsequent administrations (e.g., redose administrations) of a ceDNA vector.
Protein biomarkers have been identified for diabetes, Alzheimer's Disease, and cancer. (See, for Example, U.S. Pat. Nos. 7,125,663; 7,097,989; 7,074,576; and 6,925,389, which are incorporated herein in their entirety). Methods for detection of protein biomarkers, such as mass spectrometry and specific binding to antibodies, can also be used. High throughput expression analysis methods using microarrays can be used for mRNA biomarkers, as well as focused arrays and qPCR for multiple relevant genes to identify stress related genes see. e.g., WO2007106685A2. DNA microarrays have been used to measure gene expression in tumor samples from patients and to facilitate diagnosis. Gene expression can reveal the presence of cancer in a patient, its type, stage, and origin, and whether genetic mutations are involved. Gene expression may even have a role in predicting the efficacy of chemotherapy. Over recent decades, the National Cancer Institute (NCI) has tested compounds, including chemotherapy agents, for their effect in limiting the growth of 60 human cancer cell lines. The NCI has also measured gene expression in these 60 cancer cell lines using DNA microarrays. Various studies have explored the relationship between gene expression and compound effect using the NCI datasets. Critical time is often lost due to a trial and error approach to finding an effective chemotherapy for patients with cancer. In addition, cancer cells often develop resistance to a previously effective therapy. In such situations, patient outcome could be greatly improved by early detection of such resistance.
In some embodiments, the level of biomarker expression of a disease state is determined by measuring the level of mRNA transcribed from the gene(s), by detecting the level of a protein product of the gene(s), or by detecting the level of the biological activity of a protein product of the gene(s). In some embodiments, the level of a biomarker (including miRNA biomarkers) of a disease state is measured using a quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Such methods to measure gene expression products, e.g., protein level, include ELISA (enzyme linked immunosorbent assay), western blot, and immunoprecipitation, immunofluorescence using detection reagents such as an antibody or protein binding agents. Alternatively, a peptide can be detected in a subject by introducing into a subject a labeled anti-peptide antibody and other types of detection agent. For example, the antibody can be labeled with a radioactive marker whose presence and location in the subject is detected by standard imaging techniques.
In certain embodiments, the gene expression products can be determined by measuring the level of messenger RNA (mRNA) expression of a disease biomarker. Such molecules can be isolated, derived, or amplified from a biological sample, such as a whole blood or plasma, e.g., platelet rich plasma. Detection of mRNA expression is known by persons skilled in the art, and comprise, for example but not limited to, PCR procedures, RT-PCR, Northern blot analysis, differential gene expression, RNA protection assay, microarray analysis, hybridization methods etc. In some embodiments, the level of the mRNAs can be measured using quantitative RT-PCR. In general, the PCR procedure describes a method of gene amplification which is comprised of (i) sequence-specific hybridization of primers to specific genes or sequences within a nucleic acid sample or library, (ii) subsequent amplification involving multiple rounds of annealing, elongation, and denaturation using a thermostable DNA polymerase, and (iii) screening the PCR products for a band of the correct size. The primers used are oligonucleotides of sufficient length and appropriate sequence to provide initiation of polymerization, i.e. each primer is specifically designed to be complementary to a strand of the genomic locus to be amplified. In an alternative embodiment, mRNA level of gene expression products described herein can be determined by reverse-transcription (RT) PCR and by quantitative RT-PCR (QRT-PCR) or real-time PCR methods. Methods of RT-PCR and QRT-PCR are well known in the art.
In some embodiments, methods to measure one or more biomarkers for a disease state, or the level of the expression of the transgene from the ceDNA vector can an assay selected from any of: immunohistochemical (IHC) analysis and/or a micro array analysis, a comparative genomic hybridization (CGH) micro array, a single nucleotide polymorphism (SNP) micro array, a fluorescent in-situ hybridization (ISH), an in-situ hybridization (ISH), and a proteomic array.
The term “Microarray” as used herein means a device employed by any method that quantifies one or more subject oligonucleotides, e.g., DNA or RNA, or analogues thereof, at a time. One exemplary class of microarrays consists of DNA probes attached to a glass or quartz surface. Many microarrays, e.g., those made by Affymetrix, use several probes for determining the expression of a single gene. The DNA microarray can contain oligonucleotide probes that may be, e.g., full-length cDNAs complementary to an RNA or cDNA fragments that hybridize to part of an RNA. Exemplary RNAs include mRNA, miRNA, and miRNA precursors. Exemplary microarrays also include a “nucleic acid microarray” having a substrate-bound plurality of nucleic acids, hybridization to each of the plurality of bound nucleic acids being separately detectable. The substrate can be solid or porous, planar or non-planar, unitary or distributed. Exemplary nucleic acid microarrays include all of the devices so called in Schena (ed.), DNA Microarrays: A Practical Approach (Practical Approach Series), Oxford University Press (1999); Nature Genet. 21(1)(suppl.):1-60 (1999); and Schena (ed.), Microarray Biochip: Tools and Technology, Eaton Publishing Company/BioTechniques Books Division (2000). Additionally, exemplary nucleic acid microarrays can include a substrate-bound plurality of nucleic acids in which the plurality of nucleic acids is disposed on a plurality of beads, rather than on a unitary planar substrate, as is described, inter alia, in Brenner et al., Proc. Natl. Acad. Sci. USA 97(4):1665-1670 (2000). Examples of nucleic acid microarrays may be found in U.S. Pat. Nos. 6,391,623, 6,383,754, 6,383,749, 6,380,377, 6,379,897, 6,376,191, 6,372,431, 6,351,712 6,344,316, 6,316,193, 6,312,906, 6,309,828, 6,309,824, 6,306,643, 6,300,063, 6,287,850, 6,284,497, 6,284,465, 6,280,954, 6,262,216, 6,251,601, 6,245,518, 6,263,287, 6,251,601, 6,238,866, 6,228,575, 6,214,587, 6,203,989, 6,171,797, 6,103,474, 6,083,726, 6,054,274, 6,040,138, 6,083,726, 6,004,755, 6,001,309, 5,958,342, 5,952,180, 5,936,731, 5,843,655, 5,814,454, 5,837,196, 5,436,327, 5,412,087, and 5,405,783, herein incorporated by reference.
Exemplary microarrays can also include “peptide microarrays” or “protein microarrays” having a substrate-bound plurality of polypeptides, the binding of a oligonucleotide, a peptide, or a protein to the plurality of bound polypeptides being separately detectable. Alternatively, the peptide microarray, can have a plurality of binders, including, but not limited to, monoclonal antibodies, polyclonal antibodies, phage display binders, yeast 2 hybrid binders, aptamers, that can specifically detect the binding of specific oligonucleotides, peptides, or proteins. Examples of peptide arrays may be found in International Patent Publication Nos. WO 02/31463, WO 02/25288, WO 01/94946, WO 01/88162, WO 01/68671, WO 01/57259, WO 00/61806, WO 00/54046, WO 00/47774, WO 99/40434, WO 99/39210, and WO 97/42507, and in U.S. Pat. Nos. 6,268,210, 5,766,960, and 5,143,854, herein incorporated by reference.
In some embodiments, if the disease state of the subject has remained at a steady state, or has not improved, or where the disease state has declined in the subject, for example, as compared to the disease state at the time of the first administration of the ceDNA vector or any time before administration of the ceDNA vector, the subject is administered a second dose of the ceDNA vector, e.g., wherein in some embodiments, the amount of ceDNA vector administered is a titrated dose.
In alternative embodiments, if the level of transgene expression in the subject has declined from a predetermined level or declined from a therapeutically effective amount, e.g., dropped from the initial transgene expression level after the first administration of the ceDNA vector, the subject is administered a second dose of the ceDNA vector e.g., wherein in some embodiments, the amount of ceDNA vector administered is a titrated dose. In some embodiments, the level of the transgene expression is determined by measuring the level of the transgene (e.g., measuring protein level and/or mRNA levels) expressed from the ceDNA vector in a biological sample obtained from the subject. In some embodiments, the biological sample is selected from any of: blood, plasma, synovial fluid, CSF, saliva, or tissue biopsy sample.
In some embodiments, where the ceDNA vector expresses a reporter protein in addition to a transgene encoding a desired protein or therapeutic gene, the level of the transgene can be determined by measuring the level of reporter protein expressed from the ceDNA vector in vivo, using methods commonly known to persons of ordinary skill in the art. In some embodiments, the titrating the ceDNA vector is determining the level of transgene expressed from the ceDNA vector and administering a second dose of the ceDNA vector to the subject to adjust or modulate the transgene expression to a predetermined desired level.
III. ceDNA Vector in General
Embodiments of the invention are based on methods and compositions comprising close ended linear duplexed (ceDNA) vectors that can express a transgene, as defined herein. The ceDNA vectors described herein are not limited by size, thereby permitting, for example, expression of all of the components necessary for expression of a transgene from a single vector. The ceDNA vector is preferably duplex, e.g. self-complementary, over at least a portion of the molecule, such as the expression cassette (e.g. ceDNA is not a double stranded circular molecule). The ceDNA vector has covalently closed ends, and thus is resistant to exonuclease digestion (e.g. exonuclease I or exonuclease III), e.g. for over an hour at 37° C. In some embodiments, a ceDNA vector as disclosed herein is translocated to the nucleus where expression of the transgene in the ceDNA vector, e.g., genetic medicine transgene can occur. In some embodiments, a ceDNA vector as disclosed herein translocated to the nucleus where expression of the transgene, e.g., genetic medicine transgene located between the two ITRs can occur.
In general, a ceDNA vector disclosed herein, comprises in the 5′ to 3′ direction: a first adeno-associated virus (AAV) inverted terminal repeat (ITR), a nucleotide sequence of interest (for example an expression cassette as described herein) and a second AAV ITR. The ITR sequences selected from any of: (i) at least one WT ITR and at least one modified AAV inverted terminal repeat (mod-ITR) (e.g., asymmetric modified ITRs); (ii) two modified ITRs where the mod-ITR pair have a different three-dimensional spatial organization with respect to each other (e.g., asymmetric modified ITRs), or (iii) symmetrical or substantially symmetrical WT-WT ITR pair, where each WT-ITR has the same three-dimensional spatial organization, or (iv) symmetrical or substantially symmetrical modified ITR pair, where each mod-ITR has the same three-dimensional spatial organization.
Encompassed herein are methods and compositions comprising the ceDNA vector, which may further include a delivery system, such as but not limited to, a liposome nanoparticle delivery system. Nonlimiting exemplary liposome nanoparticle systems encompassed for use are disclosed herein. In some aspects, the disclosure provides for a lipid nanoparticle comprising ceDNA and an ionizable lipid. For example, a lipid nanoparticle formulation that is made and loaded with a ceDNA vector obtained by the process is disclosed in International Application PCT/US2018/050042, filed on Sep. 7, 2018, which is incorporated herein.
The ceDNA vectors as disclosed herein have no packaging constraints imposed by the limiting space within the viral capsid. ceDNA vectors represent a viable eukaryotically-produced alternative to prokaryote-produced plasmid DNA vectors, as opposed to encapsulated AAV genomes. This permits the insertion of control elements, e.g., regulatory switches as disclosed herein, large transgenes, multiple transgenes etc.
The expression cassette can also comprise an internal ribosome entry site (IRES) (e.g., SEQ ID NO: 190) and/or a 2A element. The cis-regulatory elements include, but are not limited to, a promoter, a riboswitch, an insulator, a mir-regulatable element, a post-transcriptional regulatory element, a tissue- and cell type-specific promoter and an enhancer. In some embodiments the ITR can act as the promoter for the transgene. In some embodiments, the ceDNA vector comprises additional components to regulate expression of the transgene, for example, a regulatory switch, which are described herein in the section entitled “Regulatory Switches” for controlling and regulating the expression of the transgene, and can include if desired, a regulatory switch which is a kill switch to enable controlled cell death of a cell comprising a ceDNA vector.
The expression cassette can comprise more than 4000 nucleotides, 5000 nucleotides, 10,000 nucleotides or 20,000 nucleotides, or 30,000 nucleotides, or 40,000 nucleotides or 50,000 nucleotides, or any range between about 4000-10,000 nucleotides or 10,000-50,000 nucleotides, or more than 50,000 nucleotides. In some embodiments, the expression cassette can comprise a transgene in the range of 500 to 50,000 nucleotides in length. In some embodiments, the expression cassette can comprise a transgene in the range of 500 to 75,000 nucleotides in length. In some embodiments, the expression cassette can comprise a transgene which is in the range of 500 to 10,000 nucleotides in length. In some embodiments, the expression cassette can comprise a transgene which is in the range of 1000 to 10,000 nucleotides in length. In some embodiments, the expression cassette can comprise a transgene which is in the range of 500 to 5,000 nucleotides in length. The ceDNA vectors do not have the size limitations of encapsidated AAV vectors, thus enable delivery of a large-size expression cassette to provide efficient transgene. In some embodiments, the ceDNA vector is devoid of prokaryote-specific methylation.
ceDNA expression cassette can include, for example, an expressible exogenous sequence (e.g., open reading frame) or transgene that encodes a protein that is either absent, inactive, or insufficient activity in the recipient subject or a gene that encodes a protein having a desired biological or a therapeutic effect. The transgene can encode a gene product that can function to correct the expression of a defective gene or transcript. In principle, the expression cassette can include any gene that encodes a protein, polypeptide or RNA that is either reduced or absent due to a mutation or which conveys a therapeutic benefit when overexpressed is considered to be within the scope of the disclosure.
The expression cassette can comprise any transgene useful for treating a disease or disorder in a subject. A ceDNA vector can be used to deliver and express any gene of interest in the subject, which includes but are not limited to, nucleic acids encoding polypeptides, or non-coding nucleic acids (e.g., RNAi, miRs etc.), as well as exogenous genes and nucleotide sequences, including virus sequences in a subjects' genome, e.g., HIV virus sequences and the like. Preferably a ceDNA vector disclosed herein is used for therapeutic purposes (e.g., for medical, diagnostic, or veterinary uses) or immunogenic polypeptides. In certain embodiments, a ceDNA vector is useful to express any gene of interest in the subject, which includes one or more polypeptides, peptides, ribozymes, peptide nucleic acids, siRNAs, RNAis, antisense oligonucleotides, antisense polynucleotides, or RNAs (coding or non-coding; e.g., siRNAs, shRNAs, micro-RNAs, and their antisense counterparts (e.g., antagoMiR)), antibodies, antigen binding fragments, or any combination thereof.
The expression cassette can also encode polypeptides, sense or antisense oligonucleotides, or RNAs (coding or non-coding; e.g., siRNAs, shRNAs, micro-RNAs, and their antisense counterparts (e.g., antagoMiR)). Expression cassettes can include an exogenous sequence that encodes a reporter protein to be used for experimental or diagnostic purposes, such as β-lactamase, β-galactosidase (LacZ), alkaline phosphatase, thymidine kinase, green fluorescent protein (GFP), chloramphenicol acetyltransferase (CAT), luciferase, and others well known in the art.
Sequences provided in the expression cassette, expression construct of a ceDNA vector described herein can be codon optimized for the target host cell. As used herein, the term “codon optimized” or “codon optimization” refers to the process of modifying a nucleic acid sequence for enhanced expression in the cells of the vertebrate of interest, e.g., mouse or human, by replacing at least one, more than one, or a significant number of codons of the native sequence (e.g., a prokaryotic sequence) with codons that are more frequently or most frequently used in the genes of that vertebrate. Various species exhibit particular bias for certain codons of a particular amino acid. Typically, codon optimization does not alter the amino acid sequence of the original translated protein. Optimized codons can be determined using e.g., Aptagen's Gene Forge® codon optimization and custom gene synthesis platform (Aptagen, Inc., 2190 Fox Mill Rd. Suite 300, Herndon, Va. 20171) or another publicly available database.
In some embodiments, a transgene expressed by the ceDNA vector for controlled expression as disclosed herein is a therapeutic gene. In some embodiments, a therapeutic gene is an antibody, or antibody fragment, or antigen-binding fragment thereof, or a fusion protein. In some embodiments, the antibody or fusion protein thereof is an activating antibody or a neutralizing antibody or antibody fragment and the like. In some embodiments, a ceDNA vector for controlled gene expression comprises an antibody or fusion protein as disclosed in International patent PCT/US19/18016, filed on Feb. 14, 2019, which is incorporated herein in its entirety by reference.
In particular, a therapeutic gene is one or more therapeutic agent(s), including, but not limited to, for example, protein(s), polypeptide(s), peptide(s), enzyme(s), antibodies, antigen binding fragments, as well as variants, and/or active fragments thereof, for use in the treatment, prophylaxis, and/or amelioration of one or more symptoms of a disease, dysfunction, injury, and/or disorder. Exemplary therapeutic genes are described herein in the section entitled “Method of Treatment”.
There are many structural features of ceDNA vectors that differ from plasmid-based expression vectors. ceDNA vectors may possess one or more of the following features: the lack of original (i.e. not inserted) bacterial DNA, the lack of a prokaryotic origin of replication, being self-containing, i.e., they do not require any sequences other than the two ITRs, including the Rep binding and terminal resolution sites (RBS and TRS), and an exogenous sequence between the ITRs, the presence of ITR sequences that form hairpins, and the absence of bacterial-type DNA methylation or indeed any other methylation considered abnormal by a mammalian host. In general, it is preferred for the present vectors not to contain any prokaryotic DNA but it is contemplated that some prokaryotic DNA may be inserted as an exogenous sequence, as a nonlimiting example in a promoter or enhancer region. Another important feature distinguishing ceDNA vectors from plasmid expression vectors is that ceDNA vectors are single-strand linear DNA having closed ends, while plasmids are always double-strand DNA.
ceDNA vectors produced by the methods provided herein preferably have a linear and continuous structure rather than a non-continuous structure, as determined by restriction enzyme digestion assay (
There are several advantages of using a ceDNA vector as described herein over plasmid-based expression vectors, such advantages include, but are not limited to: 1) plasmids contain bacterial DNA sequences and are subjected to prokaryotic-specific methylation, e.g., 6-methyl adenosine and 5-methyl cytosine methylation, whereas capsid-free AAV vector sequences are of eukaryotic origin and do not undergo prokaryotic-specific methylation; as a result, capsid-free AAV vectors are less likely to induce inflammatory and immune responses compared to plasmids; 2) while plasmids require the presence of a resistance gene during the production process, ceDNA vectors do not; 3) while a circular plasmid is not delivered to the nucleus upon introduction into a cell and requires overloading to bypass degradation by cellular nucleases, ceDNA vectors contain viral cis-elements, i.e., ITRs, that confer resistance to nucleases and can be designed to be targeted and delivered to the nucleus. It is hypothesized that the minimal defining elements indispensable for ITR function are a Rep-binding site (RBS; 5′-GCGCGCTCGCTCGCTC-3′ (SEQ ID NO: 60) for AAV2) and a terminal resolution site (TRS; 5′-AGTTGG-3′ (SEQ ID NO: 64) for AAV2) plus a variable palindromic sequence allowing for hairpin formation; and 4) ceDNA vectors do not have the over-representation of CpG dinucleotides often found in prokaryote-derived plasmids that reportedly binds a member of the Toll-like family of receptors, eliciting a T cell-mediated immune response. In contrast, transductions with capsid-free AAV vectors disclosed herein can efficiently target cell and tissue-types that are difficult to transduce with conventional AAV virions using various delivery reagent.
IV. ITRs
As disclosed herein, ceDNA vectors for controlled transgene expression contain a transgene or heterologous nucleic acid sequence positioned between two inverted terminal repeat (ITR) sequences, where the ITR sequences can be an asymmetrical ITR pair or a symmetrical- or substantially symmetrical ITR pair, as these terms are defined herein. A ceDNA vector as disclosed herein can comprise ITR sequences that are selected from any of: (i) at least one WT ITR and at least one modified AAV inverted terminal repeat (mod-ITR) (e.g., asymmetric modified ITRs); (ii) two modified ITRs where the mod-ITR pair have a different three-dimensional spatial organization with respect to each other (e.g., asymmetric modified ITRs), or (iii) symmetrical or substantially symmetrical WT-WT ITR pair, where each WT-ITR has the same three-dimensional spatial organization, or (iv) symmetrical or substantially symmetrical modified ITR pair, where each mod-ITR has the same three-dimensional spatial organization, where the methods of the present disclosure may further include a delivery system, such as but not limited to a liposome nanoparticle delivery system.
In some embodiments, the ITR sequence can be from viruses of the Parvoviridae family, which includes two subfamilies: Parvovirinae, which infect vertebrates, and Densovirinae, which infect insects. The subfamily Parvovirinae (referred to as the parvoviruses) includes the genus Dependovirus, the members of which, under most conditions, require coinfection with a helper virus such as adenovirus or herpes virus for productive infection. The genus Dependovirus includes adeno-associated virus (AAV), which normally infects humans (e.g., serotypes 2, 3A, 3B, 5, and 6) or primates (e.g., serotypes 1 and 4), and related viruses that infect other warm-blooded animals (e.g., bovine, canine, equine, and ovine adeno-associated viruses). The parvoviruses and other members of the Parvoviridae family are generally described in Kenneth I. Berns, “Parvoviridae: The Viruses and Their Replication,” Chapter 69 in FIELDS VIROLOGY (3d Ed. 1996).
While ITRs exemplified in the specification and Examples herein are AAV2 WT-ITRs, one of ordinary skill in the art is aware that one can as stated above use ITRs from any known parvovirus, for example a dependovirus such as AAV (e.g., AAV1, AAV2, AAV3, AAV4, AAV5, AAV 5, AAV7, AAV8, AAV9, AAV10, AAV 11, AAV12, AAVrh8, AAVrh10, AAV-DJ, and AAV-DJ8 genome. E.g., NCBI: NC 002077; NC 001401; NC001729; NC001829; NC006152; NC 006260; NC 006261), chimeric ITRs, or ITRs from any synthetic AAV. In some embodiments, the AAV can infect warm-blooded animals, e.g., avian (AAAV), bovine (BAAV), canine, equine, and ovine adeno-associated viruses. In some embodiments the ITR is from B19 parvovirus (GenBank Accession No: NC 000883), Minute Virus from Mouse (MVM) (GenBank Accession No. NC 001510); goose parvovirus (GenBank Accession No. NC 001701); snake parvovirus 1 (GenBank Accession No. NC 006148). In some embodiments, the 5′ WT-ITR can be from one serotype and the 3′ WT-ITR from a different serotype, as discussed herein.
An ordinarily skilled artisan is aware that ITR sequences have a common structure of a double-stranded Holliday junction, which typically is a T-shaped or Y-shaped hairpin structure (see e.g.,
In some embodiments, a ceDNA vector as described herein comprises, in the 5′ to 3′ direction: a first adeno-associated virus (AAV) inverted terminal repeat (ITR), a nucleotide sequence of interest (for example an expression cassette as described herein) and a second AAV ITR, where the first ITR (5′ ITR) and the second ITR (3′ ITR) are symmetric, or substantially symmetrical with respect to each other—that is, a ceDNA vector can comprise ITR sequences that have a symmetrical three-dimensional spatial organization such that their structure is the same shape in geometrical space, or have the same A, C-C′ and B-B′ loops in 3D space. In such an embodiment, a symmetrical ITR pair, or substantially symmetrical ITR pair can be modified ITRs (e.g., mod-ITRs) that are not wild-type ITRs. A mod-ITR pair can have the same sequence which has one or more modifications from wild-type ITR and are reverse complements (inverted) of each other. In alternative embodiments, a modified ITR pair are substantially symmetrical as defined herein, that is, the modified ITR pair can have a different sequence but have corresponding or the same symmetrical three-dimensional shape.
(i) Wildtype ITRs
In some embodiments, the symmetrical ITRs, or substantially symmetrical ITRs are wild type (WT-ITRs) as described herein. That is, both ITRs have a wild type sequence, but do not necessarily have to be WT-ITRs from the same AAV serotype. That is, in some embodiments, one WT-ITR can be from one AAV serotype, and the other WT-ITR can be from a different AAV serotype. In such an embodiment, a WT-ITR pair are substantially symmetrical as defined herein, that is, they can have one or more conservative nucleotide modification while still retaining the symmetrical three-dimensional spatial organization.
Accordingly, as disclosed herein, ceDNA vectors for controlled transgene expression contain a transgene or heterologous nucleic acid sequence positioned between two flanking wild-type inverted terminal repeat (WT-ITR) sequences, that are either the reverse complement (inverted) of each other, or alternatively, are substantially symmetrical relative to each other—that is a WT-ITR pair have symmetrical three-dimensional spatial organization. In some embodiments, a wild-type ITR sequence (e.g. AAV WT-ITR) comprises a functional Rep binding site (RBS; e.g. 5′-GCGCGCTCGCTCGCTC-3′ for AAV2, SEQ ID NO: 60) and a functional terminal resolution site (TRS; e.g. 5′-AGTT-3′, SEQ ID NO: 62).
In one aspect, ceDNA vectors for controlled transgene expression are obtainable from a vector polynucleotide that encodes a heterologous nucleic acid operatively positioned between two WT inverted terminal repeat sequences (WT-ITRs) (e.g. AAV WT-ITRs). That is, both ITRs have a wild type sequence, but do not necessarily have to be WT-ITRs from the same AAV serotype. That is, in some embodiments, one WT-ITR can be from one AAV serotype, and the other WT-ITR can be from a different AAV serotype. In such an embodiment, the WT-ITR pair are substantially symmetrical as defined herein, that is, they can have one or more conservative nucleotide modification while still retaining the symmetrical three-dimensional spatial organization. In some embodiments, the 5′ WT-ITR is from one AAV serotype, and the 3′ WT-ITR is from the same or a different AAV serotype. In some embodiments, the 5′ WT-ITR and the 3′WT-ITR are mirror images of each other, that is they are symmetrical. In some embodiments, the 5′ WT-ITR and the 3′ WT-ITR are from the same AAV serotype.
WT ITRs are well known. In one embodiment the two ITRs are from the same AAV2 serotype. In certain embodiments one can use WT from other serotypes. There are a number of serotypes that are homologous, e.g. AAV2, AAV4, AAV6, AAV8. In one embodiment, closely homologous ITRs (e.g. ITRs with a similar loop structure) can be used. In another embodiment, one can use AAV WT ITRs that are more diverse, e.g., AAV2 and AAV5, and still another embodiment, one can use an ITR that is substantially WT—that is, it has the basic loop structure of the WT but some conservative nucleotide changes that do not alter or affect the properties. When using WT-ITRs from the same viral serotype, one or more regulatory sequences may further be used. In certain embodiments, the regulatory sequence is a regulatory switch that permits modulation of the activity of the ceDNA.
In some embodiments, one aspect of the technology described herein relates to a ceDNA vector, wherein the ceDNA vector comprises at least one heterologous nucleotide sequence, operably positioned between two wild-type inverted terminal repeat sequences (WT-ITRs), wherein the WT-ITRs can be from the same serotype, different serotypes or substantially symmetrical with respect to each other (i.e., have the symmetrical three-dimensional spatial organization such that their structure is the same shape in geometrical space, or have the same A, C-C′ and B-B′ loops in 3D space). In some embodiments, the symmetric WT-ITRs comprises a functional terminal resolution site and a Rep binding site. In some embodiments, the heterologous nucleic acid sequence encodes a transgene, and wherein the vector is not in a viral capsid.
In some embodiments, the WT-ITRs are the same but the reverse complement of each other. For example, the sequence AACG in the 5′ ITR may be CGTT (i.e., the reverse complement) in the 3′ ITR at the corresponding site. In one example, the 5′ WT-ITR sense strand comprises the sequence of ATCGATCG and the corresponding 3′ WT-ITR sense strand comprises CGATCGAT (i.e., the reverse complement of ATCGATCG). In some embodiments, the WT-ITRs ceDNA further comprises a terminal resolution site and a replication protein binding site (RPS) (sometimes referred to as a replicative protein binding site), e.g. a Rep binding site.
Exemplary WT-ITR sequences for use in the ceDNA vectors for controlled transgene expression comprising WT-ITRs are shown in Table 2 herein, which shows pairs of WT-ITRs (5′ WT-ITR and the 3′ WT-ITR).
As an exemplary example, the present disclosure provides a ceDNA vector comprising a promoter operably linked to a transgene (e.g., heterologous nucleic acid sequence), with or without the regulatory switch, where the ceDNA is devoid of capsid proteins and is: (a) produced from a ceDNA-plasmid (e.g., see
In some embodiments, the flanking WT-ITRs are substantially symmetrical to each other. In this embodiment the 5′ WT-ITR can be from one serotype of AAV, and the 3′ WT-ITR from a different serotype of AAV, such that the WT-ITRs are not identical reverse complements. For example, the 5′ WT-ITR can be from AAV2, and the 3′ WT-ITR from a different serotype (e.g. AAV1, 3, 4, 5, 6, 7, 8, 9, 10, 11, and 12. In some embodiments, WT-ITRs can be selected from two different parvoviruses selected from any to of: AAV1, AAV2, AAV3, AAV4, AAV5, AAV6, AAV7, AAV8, AAV9, AAV10, AAV11, AAV12, AAV13, snake parvovirus (e.g., royal python parvovirus), bovine parvovirus, goat parvovirus, avian parvovirus, canine parvovirus, equine parvovirus, shrimp parvovirus, porcine parvovirus, or insect AAV. In some embodiments, such a combination of WT ITRs is the combination of WT-ITRs from AAV2 and AAV6. In one embodiment, the substantially symmetrical WT-ITRs are when one is inverted relative to the other ITR at least 90% identical, at least 95% identical, at least 96% . . . 97% . . . 98% . . . 99% . . . 99.5% and all points in between, and has the same symmetrical three-dimensional spatial organization. In some embodiments, a WT-ITR pair are substantially symmetrical as they have symmetrical three-dimensional spatial organization, e.g., have the same 3D organization of the A, C-C′. B-B′ and D arms. In one embodiment, a substantially symmetrical WT-ITR pair are inverted relative to the other, and are at least 95% identical, at least 96% . . . 97% . . . 98% . . . 99% . . . 99.5% and all points in between, to each other, and one WT-ITR retains the Rep-binding site (RBS) of 5′-GCGCGCTCGCTCGCTC-3′ (SEQ ID NO: 60) and a terminal resolution site (trs). In some embodiments, a substantially symmetrical WT-ITR pair are inverted relative to each other, and are at least 95% identical, at least 96% . . . 97% . . . 98% . . . 99% . . . 99.5% and all points in between, to each other, and one WT-ITR retains the Rep-binding site (RBS) of 5′-GCGCGCTCGCTCGCTC-3′ (SEQ ID NO: 60) and a terminal resolution site (trs) and in addition to a variable palindromic sequence allowing for hairpin secondary structure formation. Homology can be determined by standard means well known in the art such as BLAST (Basic Local Alignment Search Tool), BLASTN at default setting.
In some embodiments, the structural element of the ITR can be any structural element that is involved in the functional interaction of the ITR with a large Rep protein (e.g., Rep 78 or Rep 68). In certain embodiments, the structural element provides selectivity to the interaction of an ITR with a large Rep protein, i.e., determines at least in part which Rep protein functionally interacts with the ITR. In other embodiments, the structural element physically interacts with a large Rep protein when the Rep protein is bound to the ITR. Each structural element can be, e.g., a secondary structure of the ITR, a nucleotide sequence of the ITR, a spacing between two or more elements, or a combination of any of the above. In one embodiment, the structural elements are selected from the group consisting of an A and an A′ arm, a B and a B′ arm, a C and a C′ arm, a D arm, a Rep binding site (RBE) and an RBE′ (i.e., complementary RBE sequence), and a terminal resolution sire (trs).
By way of example only, Table 1 indicates exemplary combinations of WT-ITRs.
By way of example only, Table 2 shows the sequences of exemplary WT-ITRs from some different AAV serotypes.
In some embodiments, the nucleotide sequence of the WT-ITR sequence can be modified (e.g., by modifying 1, 2, 3, 4 or 5, or more nucleotides or any range therein), whereby the modification is a substitution for a complementary nucleotide, e.g., G for a C, and vice versa, and T for an A, and vice versa.
In certain embodiments of the present invention, the synthetically produced ceDNA vector does not have a WT-ITR consisting of the nucleotide sequence selected from any of: SEQ ID NOs: 1, 2, 5-14. In alternative embodiments of the present invention, if a ceDNA vector has a WT-ITR comprising the nucleotide sequence selected from any of: SEQ ID NOs: 1, 2, 5-14, then the flanking ITR is also WT and the ceDNA vector comprises a regulatory switch, e.g., as disclosed herein and in International application PCT/US18/49996 (e.g., see Table 11 of PCT/US18/49996). In some embodiments, the ceDNA vector comprises a regulatory switch as disclosed herein and a WT-ITR selected having the nucleotide sequence selected from any of the group consisting of: SEQ ID NO: 1, 2, 5-14.
The ceDNA vector described herein can include WT-ITR structures that retains an operable RBE, trs and RBE′ portion.
B. Modified ITRs (Mod-ITRs) in General for ceDNA Vectors for Controlled Transgene Expression Comprising Asymmetric ITR Pairs or Symmetric ITR Pairs
As discussed herein, a ceDNA vector can comprise a symmetrical ITR pair or an asymmetrical ITR pair. In both instances, one or both of the ITRs can be modified ITRs—the difference being that in the first instance (i.e., symmetric mod-ITRs), the mod-ITRs have the same three-dimensional spatial organization (i.e., have the same A-A′, C-C′ and B-B′ arm configurations), whereas in the second instance (i.e., asymmetric mod-ITRs), the mod-ITRs have a different three-dimensional spatial organization (i.e., have a different configuration of A-A′, C-C′ and B-B′ arms).
In some embodiments, a modified ITR is an ITRs that is modified by deletion, insertion, and/or substitution as compared to a wild-type ITR sequence (e.g. AAV ITR). In some embodiments, at least one of the ITRs in the ceDNA vector comprises a functional Rep binding site (RBS; e.g. 5′-GCGCGCTCGCTCGCTC-3′ for AAV2, SEQ ID NO: 60) and a functional terminal resolution site (TRS; e.g. 5′-AGTT-3′, SEQ ID NO: 62.) In one embodiment, at least one of the ITRs is a non-functional ITR. In one embodiment, the different or modified ITRs are not each wild type ITRs from different serotypes.
Specific alterations and mutations in the ITRs are described in detail herein, but in the context of ITRs, “altered” or “mutated” or “modified”, it indicates that nucleotides have been inserted, deleted, and/or substituted relative to the wild-type, reference, or original ITR sequence. The altered or mutated ITR can be an engineered ITR. As used herein, “engineered” refers to the aspect of having been manipulated by the hand of man. For example, a polypeptide is considered to be “engineered” when at least one aspect of the polypeptide, e.g., its sequence, has been manipulated by the hand of man to differ from the aspect as it exists in nature.
In some embodiments, a mod-ITR may be synthetic. In one embodiment, a synthetic ITR is based on ITR sequences from more than one AAV serotype. In another embodiment, a synthetic ITR includes no AAV-based sequence. In yet another embodiment, a synthetic ITR preserves the ITR structure described above although having only some or no AAV-sourced sequence. In some aspects, a synthetic ITR may interact preferentially with a wild type Rep or a Rep of a specific serotype, or in some instances will not be recognized by a wild-type Rep and be recognized only by a mutated Rep.
The skilled artisan can determine the corresponding sequence in other serotypes by known means. For example, determining if the change is in the A, A′, B, B′, C, C′ or D region and determine the corresponding region in another serotype. One can use BLAST® (Basic Local Alignment Search Tool) or other homology alignment programs at default status to determine the corresponding sequence. The invention further provides populations and pluralities of ceDNA vectors for controlled transgene expression comprising mod-ITRs from a combination of different AAV serotypes—that is, one mod-ITR can be from one AAV serotype and the other mod-ITR can be from a different serotype. Without wishing to be bound by theory, in one embodiment one ITR can be from or based on an AAV2 ITR sequence and the other ITR of the ceDNA vector can be from or be based on any one or more ITR sequence of AAV serotype 1 (AAV1), AAV serotype 4 (AAV4), AAV serotype 5 (AAV5), AAV serotype 6 (AAV6), AAV serotype 7 (AAV7), AAV serotype 8 (AAV8), AAV serotype 9 (AAV9), AAV serotype 10 (AAV10), AAV serotype 11 (AAV11), or AAV serotype 12 (AAV12).
Any parvovirus ITR can be used as an ITR or as a base ITR for modification. Preferably, the parvovirus is a dependovirus. More preferably AAV. The serotype chosen can be based upon the tissue tropism of the serotype. AAV2 has a broad tissue tropism, AAV1 preferentially targets to neuronal and skeletal muscle, and AAV5 preferentially targets neuronal, retinal pigmented epithelia, and photoreceptors. AAV6 preferentially targets skeletal muscle and lung. AAV8 preferentially targets liver, skeletal muscle, heart, and pancreatic tissues. AAV9 preferentially targets liver, skeletal and lung tissue. In one embodiment, the modified ITR is based on an AAV2 ITR.
More specifically, the ability of a structural element to functionally interact with a particular large Rep protein can be altered by modifying the structural element. For example, the nucleotide sequence of the structural element can be modified as compared to the wild-type sequence of the ITR. In one embodiment, the structural element (e.g., A arm, A′ arm, B arm, B′ arm, C arm, C′ arm, D arm, RBE, RBE′, and trs) of an ITR can be removed and replaced with a wild-type structural element from a different parvovirus. For example, the replacement structure can be from AAV1, AAV2, AAV3, AAV4, AAV5, AAV6, AAV7, AAV8, AAV9, AAV10, AAV11, AAV12, AAV13, snake parvovirus (e.g., royal python parvovirus), bovine parvovirus, goat parvovirus, avian parvovirus, canine parvovirus, equine parvovirus, shrimp parvovirus, porcine parvovirus, or insect AAV. For example, the ITR can be an AAV2 ITR and the A or A′ arm or RBE can be replaced with a structural element from AAV5. In another example, the ITR can be an AAV5 ITR and the C or C′ arms, the RBE, and the trs can be replaced with a structural element from AAV2. In another example, the AAV ITR can be an AAV5 ITR with the B and B′ arms replaced with the AAV2 ITR B and B′ arms.
By way of example only, Table 3 indicates exemplary modifications of at least one nucleotide (e.g., a deletion, insertion and/or substitution) in regions of a modified ITR, where X is indicative of a modification of at least one nucleic acid (e.g., a deletion, insertion and/or substitution) in that section relative to the corresponding wild-type ITR. In some embodiments, any modification of at least one nucleotide (e.g., a deletion, insertion and/or substitution) in any of the regions of C and/or C′ and/or B and/or B′ retains three sequential T nucleotides (i.e., TTT) in at least one terminal loop. For example, if the modification results in any of: a single arm ITR (e.g., single C-C′ arm, or a single B-B′ arm), or a modified C-B′ arm or C′-B arm, or a two arm ITR with at least one truncated arm (e.g., a truncated C-C′ arm and/or truncated B-B′ arm), at least the single arm, or at least one of the arms of a two arm ITR (where one arm can be truncated) retains three sequential T nucleotides (i.e., TTT) in at least one terminal loop. In some embodiments, a truncated C-C′ arm and/or a truncated B-B′ arm has three sequential T nucleotides (i.e., TTT) in the terminal loop.
In some embodiments, mod-ITR for use in a ceDNA vector comprising an asymmetric ITR pair, or a symmetric mod-ITR pair as disclosed herein can comprise any one of the combinations of modifications shown in Table 3, and also a modification of at least one nucleotide in any one or more of the regions selected from: between A′ and C, between C and C′, between C′ and B, between B and B′ and between B′ and A. In some embodiments, any modification of at least one nucleotide (e.g., a deletion, insertion and/or substitution) in the C or C′ or B or B′ regions, still preserves the terminal loop of the stem-loop. In some embodiments, any modification of at least one nucleotide (e.g., a deletion, insertion and/or substitution) between C and C′ and/or B and B′ retains three sequential T nucleotides (i.e., TTT) in at least one terminal loop. In alternative embodiments, any modification of at least one nucleotide (e.g., a deletion, insertion and/or substitution) between C and C′ and/or B and B′ retains three sequential A nucleotides (i.e., AAA) in at least one terminal loop In some embodiments, a modified ITR for use herein can comprise any one of the combinations of modifications shown in Table 3, and also a modification of at least one nucleotide (e.g., a deletion, insertion and/or substitution) in any one or more of the regions selected from: A′, A and/or D. For example, in some embodiments, a modified ITR for use herein can comprise any one of the combinations of modifications shown in Table 3, and also a modification of at least one nucleotide (e.g., a deletion, insertion and/or substitution) in the A region. In some embodiments, a modified ITR for use herein can comprise any one of the combinations of modifications shown in Table 3, and also a modification of at least one nucleotide (e.g., a deletion, insertion and/or substitution) in the A′ region. In some embodiments, a modified ITR for use herein can comprise any one of the combinations of modifications shown in Table 3, and also a modification of at least one nucleotide (e.g., a deletion, insertion and/or substitution) in the A and/or A′ region. In some embodiments, a modified ITR for use herein can comprise any one of the combinations of modifications shown in Table 3, and also a modification of at least one nucleotide (e.g., a deletion, insertion and/or substitution) in the D region.
In one embodiment, the nucleotide sequence of the structural element can be modified (e.g., by modifying 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 or more nucleotides or any range therein) to produce a modified structural element. In one embodiment, the specific modifications to the ITRs are exemplified herein (e.g., SEQ ID NOS: 3, 4, 15-47, 101-116 or 165-187, or shown in
In some embodiments, a modified ITR can for example, comprise removal or deletion of all of a particular arm, e.g., all or part of the A-A′ arm, or all or part of the B-B′ arm or all or part of the C-C′ arm, or alternatively, the removal of 1, 2, 3, 4, 5, 6, 7, 8, 9 or more base pairs forming the stem of the loop so long as the final loop capping the stem (e.g., single arm) is still present (e.g., see ITR-21 in
In some embodiments, a modified ITR can have between 1 and 50 (e.g. 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, or 50) nucleotide deletions relative to a full-length wild-type ITR sequence. In some embodiments, a modified ITR can have between 1 and 30 nucleotide deletions relative to a full-length WT ITR sequence. In some embodiments, a modified ITR has between 2 and 20 nucleotide deletions relative to a full-length wild-type ITR sequence.
In some embodiments, a modified ITR does not contain any nucleotide deletions in the RBE-containing portion of the A or A′ regions, so as not to interfere with DNA replication (e.g. binding to an RBE by Rep protein, or nicking at a terminal resolution site). In some embodiments, a modified ITR encompassed for use herein has one or more deletions in the B, B′, C, and/or C region as described herein.
In some embodiments, a synthetically produced ceDNA vector comprising a symmetric ITR pair or asymmetric ITR pair comprises a regulatory switch as disclosed herein and at least one modified ITR selected having the nucleotide sequence selected from any of the group consisting of: SEQ ID NO: 3, 4, 15-47, 101-116 or 165-187.
In another embodiment, the structure of the structural element can be modified. For example, the structural element a change in the height of the stem and/or the number of nucleotides in the loop. For example, the height of the stem can be about 2, 3, 4, 5, 6, 7, 8, or 9 nucleotides or more or any range therein. In one embodiment, the stem height can be about 5 nucleotides to about 9 nucleotides and functionally interacts with Rep. In another embodiment, the stem height can be about 7 nucleotides and functionally interacts with Rep. In another example, the loop can have 3, 4, 5, 6, 7, 8, 9, or 10 nucleotides or more or any range therein.
In another embodiment, the number of GAGY binding sites or GAGY-related binding sites within the RBE or extended RBE can be increased or decreased. In one example, the RBE or extended RBE, can comprise 1, 2, 3, 4, 5, or 6 or more GAGY binding sites or any range therein. Each GAGY binding site can independently be an exact GAGY sequence or a sequence similar to GAGY as long as the sequence is sufficient to bind a Rep protein.
In another embodiment, the spacing between two elements (such as but not limited to the RBE and a hairpin) can be altered (e.g., increased or decreased) to alter functional interaction with a large Rep protein. For example, the spacing can be about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, or 21 nucleotides or more or any range therein.
The ceDNA vector described herein can include an ITR structure that is modified with respect to the wild type AAV2 ITR structure disclosed herein, but still retains an operable RBE, trs and RBE′ portion.
In some embodiments, the modified ITR (e.g., the left or right ITR) of the synthetically produced ceDNA vector described herein has modifications within the loop arm, the truncated arm, or the spacer. Exemplary sequences of ITRs having modifications within the loop arm, the truncated arm, or the spacer are listed in Table 2 (i.e., SEQ ID NOS: 135-190, 200-233); Table 3 (e.g., SEQ ID Nos: 234-263); Table 4 (e.g., SEQ ID NOs: 264-293); Table 5 (e.g., SEQ ID Nos: 294-318 herein); Table 6 (e.g., SEQ ID NO: 319-468; and Tables 7-9 (e.g., SEQ ID Nos: 101-110, 111-112, 115-134) or Table 10A or 10B (e.g., SEQ ID Nos: 9, 100, 469-483, 484-499) of International application PCT/US18/49996, which is incorporated herein in its entirety by reference.
In some embodiments, the modified ITR for use in a ceDNA vector comprising an asymmetric ITR pair, or symmetric mod-ITR pair is selected from any or a combination of those shown in Tables 2, 3, 4, 5, 6, 7, 8, 9 and 10A-10B of International application PCT/US18/49996 which is incorporated herein in its entirety by reference.
Additional exemplary modified ITRs for use in a ceDNA vector comprising an asymmetric ITR pair, or symmetric mod-ITR pair in each of the above classes are provided in Tables 4A and 4B. The predicted secondary structure of the Right modified ITRs in Table 4A are shown in
Table 4A and Table 4B show exemplary right and left modified ITRs.
In one embodiment, a ceDNA vector comprises, in the 5′ to 3′ direction: a first adeno-associated virus (AAV) inverted terminal repeat (ITR), a nucleotide sequence of interest (for example an expression cassette as described herein) and a second AAV ITR, where the first ITR (5′ ITR) and the second ITR (3′ ITR) are asymmetric with respect to each other—that is, they have a different 3D-spatial configuration from one another. As an exemplary embodiment, the first ITR can be a wild-type ITR and the second ITR can be a mutated or modified ITR, or vice versa, where the first ITR can be a mutated or modified ITR and the second ITR a wild-type ITR. In some embodiment, the first ITR and the second ITR are both mod-ITRs, but have different sequences, or have different modifications, and thus are not the same modified ITRs, and have different 3D spatial configurations. Stated differently, a ceDNA vector with asymmetric ITRs comprises ITRs where any changes in one ITR relative to the WT-ITR are not reflected in the other ITR; or alternatively, where the asymmetric ITRs have a the modified asymmetric ITR pair can have a different sequence and different three-dimensional shape with respect to each other. Exemplary asymmetric ITRs in the ceDNA vector and for use to generate a ceDNA-plasmid are shown in Table 4A and 4B.
In an alternative embodiment, a synthetically produced ceDNA vector comprises two symmetrical mod-ITRs—that is, both ITRs have the same sequence, but are reverse complements (inverted) of each other. In some embodiments, a symmetrical mod-ITR pair comprises at least one or any combination of a deletion, insertion, or substitution relative to wild type ITR sequence from the same AAV serotype. The additions, deletions, or substitutions in the symmetrical ITR are the same but the reverse complement of each other. For example, an insertion of 3 nucleotides in the C region of the 5′ ITR would be reflected in the insertion of 3 reverse complement nucleotides in the corresponding section in the C′ region of the 3′ ITR. Solely for illustration purposes only, if the addition is AACG in the 5′ ITR, the addition is CGTT in the 3′ ITR at the corresponding site. For example, if the 5′ ITR sense strand is ATCGATCG with an addition of AACG between the G and A to result in the sequence ATCGAACGATCG (SEQ ID NO: 51). The corresponding 3′ ITR sense strand is CGATCGAT (the reverse complement of ATCGATCG) with an addition of CGTT (i.e. the reverse complement of AACG) between the T and C to result in the sequence CGATCGTTCGAT (SEQ ID NO: 49) (the reverse complement of ATCGAACGATCG) (SEQ ID NO: 51).
In alternative embodiments, the modified ITR pair are substantially symmetrical as defined herein—that is, the modified ITR pair can have a different sequence but have corresponding or the same symmetrical three-dimensional shape. For example, one modified ITR can be from one serotype and the other modified ITR be from a different serotype, but they have the same mutation (e.g., nucleotide insertion, deletion or substitution) in the same region. Stated differently, for illustrative purposes only, a 5′ mod-ITR can be from AAV2 and have a deletion in the C region, and the 3′ mod-ITR can be from AAV5 and have the corresponding deletion in the C′ region, and provided the 5′ mod-ITR and the 3′ mod-ITR have the same or symmetrical three-dimensional spatial organization, they are encompassed for use herein as a modified ITR pair.
In some embodiments, a substantially symmetrical mod-ITR pair has the same A, C-C′ and B-B′ loops in 3D space, e.g., if a modified ITR in a substantially symmetrical mod-ITR pair has a deletion of a C-C′ arm, then the cognate mod-ITR has the corresponding deletion of the C-C′ loop and also has a similar 3D structure of the remaining A and B-B′ loops in the same shape in geometric space of its cognate mod-ITR. By way of example only, substantially symmetrical ITRs can have a symmetrical spatial organization such that their structure is the same shape in geometrical space. This can occur, e.g., when a G-C pair is modified, for example, to a C-G pair or vice versa, or A-T pair is modified to a T-A pair, or vice versa. Therefore, using the exemplary example above of modified 5′ ITR as a ATCGAACGATCG (SEQ ID NO: 51), and modified 3′ ITR as CGATCGTTCGAT (SEQ ID NO: 49) (i.e., the reverse complement of ATCGAACGATCG (SEQ ID NO: 51)), these modified ITRs would still be symmetrical if, for example, the 5′ ITR had the sequence of ATCGAACCATCG (SEQ ID NO: 50), where G in the addition is modified to C, and the substantially symmetrical 3′ ITR has the sequence of CGATCGTTCGAT (SEQ ID NO: 49), without the corresponding modification of the T in the addition to a. In some embodiments, such a modified ITR pair are substantially symmetrical as the modified ITR pair has symmetrical stereochemistry.
Table 5 shows exemplary symmetric modified ITR pairs (i.e. a left modified ITRs and the symmetric right modified ITR). The bold (red) portion of the sequences identify partial ITR sequences (i.e., sequences of A-A′, C-C′ and B-B′ loops), also shown in
CTCACTGAGGCCGCCCGGGAAACCCG
GGCGTGCGCCTCAGTGAGCGAGCGAG
TCGCTCGCTCACTGAGGCGCAC
CGCGCAGAGAGGGAGTGGCCAACTCC
GCCCGGGTTTCCCGGGCGGCC
TCAGTGAGCGAGCGAGCGCGC
CTCACTGAGGCCGTCGGGCGACCTTTG
GTCGCCCGGCCTCAGTGAGCGAGCGA
TCGCTCGCTCACTGAGGCCGG
GCGCGCAGAGAGGGAGTGGCCAACTC
GCGACCAAAGGTCGCCCGACG
GCCTCAGTGAGCGAGCGAGCG
CGCAGCTGCCTGCAGG
CTCACTGAGGCCGCCCGGGCAAAGCCC
GGGCGTCGGCCTCAGTGAGCGAGCGA
TCGCTCGCTCACTGAGGCCGAC
GCGCGCAGAGAGGGAGTGGCCAACTC
GCCCGGGCTTTGCCCGGGCGG
CCTCAGTGAGCGAGCGAGCGC
GCAGCTGCCTGCAGG
CTCACTGAGGCGCCCGGGCGTCGGGC
GACCTTTGGTCGCCCGGCCTCAGTGAG
TCGCTCGCTCACTGAGGCCGG
CGAGCGAGCGCGCAGAGAGGGAGTG
GCGACCAAAGGTCGCCCGACG
CCCGGGCGCCTCAGTGAGCGA
GCGAGCGCGCAGCTGCCTGCA
CTCACTGAGGCAAAGCCTCAGTGAGCG
AGCGAGCGCGCAGAGAGGGAGTGGC
TCGCTCGCTCACTGAGGCTTTG
CCTCAGTGAGCGAGCGAGCGC
GCAGCTGCCTGCAGG
CTCACTGAGGCCGCCCGGGCAAAGCCC
GGGCGTCGGGCGACTTTGTCGCCCGG
TCGCTCGCTCACTGAGGCCGG
CCTCAGTGAGCGAGCGAGCGCGCAGA
GCGACAAAGTCGCCCGACGCC
CGGGCTTTGCCCGGGCGGCCT
CAGTGAGCGAGCGAGCGCGCA
CTCACTGAGGCCGCCCGGGCAAAGCCC
GGGCGTCGGGCGATTTTCGCCCGGCCT
TCGCTCGCTCACTGAGGCCGG
CAGTGAGCGAGCGAGCGCGCAGAGAG
GCGAAAATCGCCCGACGCCCG
GGCTTTGCCCGGGCGGCCTCA
GTGAGCGAGCGAGCGCGCAGC
CTCACTGAGGCCGCCCGGGCAAAGCCC
GGGCGTCGGGCGTTTCGCCCGGCCTCA
TCGCTCGCTCACTGAGGCCGG
GTGAGCGAGCGAGCGCGCAGAGAGG
GCGAAACGCCCGACGCCCGGG
CTTTGCCCGGGCGGCCTCAGTG
AGCGAGCGAGCGCGCAGCTGC
CTCACTGAGGCCGCCCGGGCAAAGCCC
GGGCGTCGGGCTTTGCCCGGCCTCAGT
TCGCTCGCTCACTGAGGCCGG
GAGCGAGCGAGCGCGCAGAGAGGGA
GCAAAGCCCGACGCCCGGGCT
TTGCCCGGGCGGCCTCAGTGA
GCGAGCGAGCGCGCAGCTGCC
CTCACTGAGGCCGCCCGGGAAACCCG
GGCGTCGGGCGACCTTTGGTCGCCCG
TCGCTCGCTCACTGAGGCCGG
GCCTCAGTGAGCGAGCGAGCGCGCAG
GCGACCAAAGGTCGCCCGACG
CCCGGGTTTCCCGGGCGGCCTC
AGTGAGCGAGCGAGCGCGCAG
CTCACTGAGGCCGCCCGGAAACCGGG
CGTCGGGCGACCTTTGGTCGCCCGGCC
TCGCTCGCTCACTGAGGCCGG
TCAGTGAGCGAGCGAGCGCGCAGAGA
GCGACCAAAGGTCGCCCGACG
CCCGGTTTCCGGGCGGCCTCAG
TGAGCGAGCGAGCGCGCAGCT
CTCACTGAGGCCGCCCGAAACGGGCG
TCGGGCGACCTTTGGTCGCCCGGCCTC
TCGCTCGCTCACTGAGGCCGG
AGTGAGCGAGCGAGCGCGCAGAGAG
GCGACCAAAGGTCGCCCGACG
CCCGTTTCGGGCGGCCTCAGTG
AGCGAGCGAGCGCGCAGCTGC
CTCACTGAGGCCGCCCAAAGGGCGTC
GGGCGACCTTTGGTCGCCCGGCCTCAG
TCGCTCGCTCACTGAGGCCGG
TGAGCGAGCGAGCGCGCAGAGAGGG
GCGACCAAAGGTCGCCCGACG
CCCTTTGGGCGGCCTCAGTGAG
CGAGCGAGCGCGCAGCTGCCT
CTCACTGAGGCCGCCAAAGGCGTCGG
GCGACCTTTGGTCGCCCGGCCTCAGTG
TCGCTCGCTCACTGAGGCCGG
AGCGAGCGAGCGCGCAGAGAGGGAG
GCGACCAAAGGTCGCCCGACG
CCTTTGGCGGCCTCAGTGAGCG
AGCGAGCGCGCAGCTGCCTGC
CTCACTGAGGCCGCAAAGCGTCGGGC
GACCTTTGGTCGCCCGGCCTCAGTGAG
TCGCTCGCTCACTGAGGCCGG
CGAGCGAGCGCGCAGAGAGGGAGTG
GCGACCAAAGGTCGCCCGACG
CTTTGCGGCCTCAGTGAGCGA
GCGAGCGCGCAGCTGCCTGCA
CTCACTGAGGCCGAAACGTCGGGCGA
CCTTTGGTCGCCCGGCCTCAGTGAGCG
TCGCTCGCTCACTGAGGCCGG
AGCGAGCGCGCAGAGAGGGAGTGGC
GCGACCAAAGGTCGCCCGACG
TTTCGGCCTCAGTGAGCGAGC
GAGCGCGCAGCTGCCTGCAGG
In some embodiments, a ceDNA vector comprising an asymmetric ITR pair can comprise an ITR with a modification corresponding to any of the modifications in ITR sequences or ITR partial sequences shown in any one or more of Tables 4A-4B herein, or the sequences shown in
V. Exemplary ceDNA Vectors for Controlled Transgene Expression
As described above, the present disclosure relates to recombinant ceDNA expression vectors and ceDNA vectors for controlled transgene expression that encode a transgene comprising any one of: an asymmetrical ITR pair, a symmetrical ITR pair, or substantially symmetrical ITR pair as described above. In certain embodiments, the disclosure relates to recombinant ceDNA vectors for controlled transgene expression having flanking ITR sequences and a transgene, where the ITR sequences are asymmetrical, symmetrical or substantially symmetrical relative to each other as defined herein, and the ceDNA further comprises a nucleotide sequence of interest (for example an expression cassette comprising the nucleic acid of a transgene) located between the flanking ITRs, wherein said nucleic acid molecule is devoid of viral capsid protein coding sequences.
The ceDNA vector for controlled transgene expression may be any ceDNA vector that can be conveniently subjected to recombinant DNA procedures including nucleotide sequence(s) as described herein, provided at least one ITR is altered. The ceDNA vectors of the present disclosure are compatible with the host cell into which the ceDNA vector is to be introduced. In certain embodiments, the ceDNA vectors may be linear. In certain embodiments, the ceDNA vectors may exist as an extrachromosomal entity. In certain embodiments, the ceDNA vectors of the present disclosure may contain an element(s) that permits integration of a donor sequence into the host cell's genome. As used herein “transgene” and “heterologous nucleotide sequence” are synonymous.
Referring now to
A. Regulatory Elements.
The ceDNA vectors as described herein comprising an asymmetric ITR pair or symmetric ITR pair as defined herein, can further comprise a specific combination of cis-regulatory elements. The cis-regulatory elements include, but are not limited to, a promoter, a riboswitch, an insulator, a mir-regulatable element, a post-transcriptional regulatory element, a tissue- and cell type-specific promoter and an enhancer. In some embodiments, the ITR can act as the promoter for the transgene. In some embodiments, the ceDNA vector for controlled transgene expression comprises additional components to regulate expression of the transgene, for example, regulatory switches as described herein, to regulate the expression of the transgene, or a kill switch, which can kill a cell comprising the ceDNA vector. Regulatory elements, including Regulatory Switches that can be used in the present invention are more fully discussed in International application PCT/US18/49996, which is incorporated herein in its entirety by reference.
In embodiments, the second nucleotide sequence includes a regulatory sequence, and a nucleotide sequence encoding a nuclease. In certain embodiments the gene regulatory sequence is operably linked to the nucleotide sequence encoding the nuclease. In certain embodiments, the regulatory sequence is suitable for controlling the expression of the nuclease in a host cell. In certain embodiments, the regulatory sequence includes a suitable promoter sequence, being able to direct transcription of a gene operably linked to the promoter sequence, such as a nucleotide sequence encoding the nuclease(s) of the present disclosure. In certain embodiments, the second nucleotide sequence includes an intron sequence linked to the 5′ terminus of the nucleotide sequence encoding the nuclease. In certain embodiments, an enhancer sequence is provided upstream of the promoter to increase the efficacy of the promoter. In certain embodiments, the regulatory sequence includes an enhancer and a promoter, wherein the second nucleotide sequence includes an intron sequence upstream of the nucleotide sequence encoding a nuclease, wherein the intron includes one or more nuclease cleavage site(s), and wherein the promoter is operably linked to the nucleotide sequence encoding the nuclease.
The ceDNA vectors produced synthetically, or using a cell-based production method as described herein in the Examples, can further comprise a specific combination of cis-regulatory elements such as WHP posttranscriptional regulatory element (WPRE) (e.g., SEQ ID NO: 67) and BGH polyA (SEQ ID NO: 68). Suitable expression cassettes for use in expression constructs are not limited by the packaging constraint imposed by the viral capsid.
It will be appreciated by one of ordinary skill in the art that promoters used in the ceDNA vectors of the invention should be tailored as appropriate for the specific sequences they are promoting. For example, a guide RNA may not require a promoter at all, since its function is to form a duplex with a specific target sequence on the native DNA to effect a recombination event. In contrast, a nuclease encoded by the ceDNA vector would benefit from a promoter so that it can be efficiently expressed from the vector—and, optionally, in a regulatable fashion.
Expression cassettes of the present invention include a promoter, which can influence overall expression levels as well as cell-specificity. For transgene expression, they can include a highly active virus-derived immediate early promoter. Expression cassettes can contain tissue-specific eukaryotic promoters to limit transgene expression to specific cell types and reduce toxic effects and immune responses resulting from unregulated, ectopic expression. In preferred embodiments, an expression cassette can contain a synthetic regulatory element, such as a CAG promoter (SEQ ID NO: 72). The CAG promoter comprises (i) the cytomegalovirus (CMV) early enhancer element, (ii) the promoter, the first exon and the first intron of chicken beta-actin gene, and (iii) the splice acceptor of the rabbit beta-globin gene. Alternatively, an expression cassette can contain an Alpha-1-antitrypsin (AAT) promoter (SEQ ID NO: 73 or SEQ ID NO: 74), a liver specific (LP1) promoter (SEQ ID NO: 75 or SEQ ID NO: 76), or a Human elongation factor-1 alpha (EF1a) promoter (e.g., SEQ ID NO: 77 or SEQ ID NO: 78). In some embodiments, the expression cassette includes one or more constitutive promoters, for example, a retroviral Rous sarcoma virus (RSV) LTR promoter (optionally with the RSV enhancer), or a cytomegalovirus (CMV) immediate early promoter (optionally with the CMV enhancer, e.g., SEQ ID NO: 79). Alternatively, an inducible promoter, a native promoter for a transgene, a tissue-specific promoter, or various promoters known in the art can be used.
Suitable promoters, including those described above, can be derived from viruses and can therefore be referred to as viral promoters, or they can be derived from any organism, including prokaryotic or eukaryotic organisms. Suitable promoters can be used to drive expression by any RNA polymerase (e.g., pol I, pol II, pol III). Exemplary promoters include, but are not limited to the SV40 early promoter, mouse mammary tumor virus long terminal repeat (LTR) promoter; adenovirus major late promoter (Ad MLP); a herpes simplex virus (HSV) promoter, a cytomegalovirus (CMV) promoter such as the CMV immediate early promoter region (CMVIE), a rous sarcoma virus (RSV) promoter, a human U6 small nuclear promoter (U6, e.g., SEQ ID NO: 80) (Miyagishi et al., Nature Biotechnology 20, 497-500 (2002)), an enhanced U6 promoter (e.g., Xia et al., Nucleic Acids Res. 2003 Sep. 1; 31(17)), a human H1 promoter (H1) (e.g., SEQ ID NO: 81), a CAG promoter (SEQ ID NO: 72), a human alpha 1-antitypsin (HAAT) promoter (e.g., SEQ ID NO: 82), and the like. In certain embodiments, these promoters are altered at their downstream intron containing end to include one or more nuclease cleavage sites. In certain embodiments, the DNA containing the nuclease cleavage site(s) is foreign to the promoter DNA.
In one embodiment, the promoter used is the native promoter of the gene encoding the therapeutic protein. The promoters and other regulatory sequences for the respective genes encoding the therapeutic proteins are known and have been characterized. The promoter region used may further include one or more additional regulatory sequences (e.g., native), e.g., enhancers, (e.g. SEQ ID NO: 79 and SEQ ID NO: 83), including a SV40 enhancer (SEQ ID NO: 126).
Non-limiting examples of suitable promoters for use in accordance with the present invention include the CAG promoter of, for example (SEQ ID NO: 72), the HAAT promoter (SEQ ID NO: 82), the human EF1-α promoter (SEQ ID NO: 77) or a fragment of the EF1a promoter (SEQ ID NO: 78), IE2 promoter (e.g., SEQ ID NO: 84) and the rat EF1-α promoter (SEQ ID NO: 85), or 1E1 promoter fragment (SEQ ID NO: 125).
A sequence encoding a polyadenylation sequence can be included in the ceDNA vector for controlled transgene expression to stabilize an mRNA expressed from the ceDNA vector, and to aid in nuclear export and translation. In one embodiment, the ceDNA vector does not include a polyadenylation sequence. In other embodiments, the vector includes at least 1, at least 2, at least 3, at least 4, at least 5, at least 10, at least 15, at least 20, at least 25, at least 30, at least 40, least 45, at least 50 or more adenine dinucleotides. In some embodiments, the polyadenylation sequence comprises about 43 nucleotides, about 40-50 nucleotides, about 40-55 nucleotides, about 45-50 nucleotides, about 35-50 nucleotides, or any range there between. In some embodiments, where the ceDNA vector for controlled transgene expression can comprises two transgenes, e.g., in the case of controlled expression of an antibody, a ceDNA vector can comprise a nucleic acid encoding an antibody heavy chain (e.g., an exemplary heavy chain is SEQ ID NO: 57) and a nucleic acid encoding an antibody light chain (e.g., an exemplary light chain is SEQ ID NO: 58), and there can be a polyadenylation 3′ of the first transgene, and an IRES (e.g., SEQ ID NO: 190) located between the first and second transgene (e.g., between the nucleic acid encoding an antibody heavy chain and the nucleic acid encoding an antibody light chain). In such embodiments, a ceDNA vector for controlled transgene expression that encodes more than one transgene (e.g., 2, or 3 or more) can comprise an IRES (internal ribosome entry site) sequence (SEQ ID NO: 190), e.g., where the IRES sequence is located 3′ of a polyadenylation sequence, such that a second transgene (e.g., antibody or antigen-binding fragment) that is located 3′ of a first transgene, is translated and expressed by the same ceDNA vector, such that the ceDNA vector can express two or more transgenes encoded by the ceDNA vector.
The expression cassettes can include a poly-adenylation sequence known in the art or a variation thereof, such as a naturally occurring sequence isolated from bovine BGHpA (e.g., SEQ ID NO: 68) or a virus SV40 pA (e.g., SEQ ID NO: 86), or a synthetic sequence (e.g., SEQ ID NO: 87). Some expression cassettes can also include SV40 late polyA signal upstream enhancer (USE) sequence. In some embodiments, the, USE can be used in combination with SV40 pA or heterologous poly-A signal.
The expression cassettes can also include a post-transcriptional element to increase the expression of a transgene. In some embodiments, Woodchuck Hepatitis Virus (WHP) posttranscriptional regulatory element (WPRE) (e.g., SEQ ID NO: 67) is used to increase the expression of a transgene. Other posttranscriptional processing elements such as the post-transcriptional element from the thymidine kinase gene of herpes simplex virus, or hepatitis B virus (HBV) can be used. Secretory sequences can be linked to the transgenes, e.g., VH-02 (SEQ ID NO: 88) and VK-A26 sequences (SEQ ID NO: 89), or IgK signal sequence (SEQ ID NO: 128), Glu secretory signal sequence (SEQ ID NO: 188) or TND secretory signal sequence (SEQ ID NO: 189).
(iii). Nuclear Localization Sequences
In some embodiments, the vector encoding an RNA guided endonuclease comprises one or more nuclear localization sequences (NLSs), for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more NLSs. In some embodiments, the one or more NLSs are located at or near the amino-terminus, at or near the carboxy-terminus, or a combination of these (e.g., one or more NLS at the amino-terminus and/or one or more NLS at the carboxy terminus). When more than one NLS is present, each can be selected independently of the others, such that a single NLS is present in more than one copy and/or in combination with one or more other NLSs present in one or more copies. Non-limiting examples of NLSs are shown in Table 6.
B. Additional Components of ceDNA Vectors
The ceDNA vectors of the present disclosure may contain nucleotides that encode other components for gene expression. For example, to select for specific gene targeting events, a protective shRNA may be embedded in a microRNA and inserted into a recombinant ceDNA vector designed to integrate site-specifically into the highly active locus, such as an albumin locus. Such embodiments may provide a system for in vivo selection and expansion of gene-modified hepatocytes in any genetic background such as described in Nygaard et al., A universal system to select gene-modified hepatocytes in vivo, Gene Therapy, Jun. 8, 2016. The ceDNA vectors of the present disclosure may contain one or more selectable markers that permit selection of transformed, transfected, transduced, or the like cells. A selectable marker is a gene the product of which provides for biocide or viral resistance, resistance to heavy metals, prototrophy to auxotrophs, NeoR, and the like. In certain embodiments, positive selection markers are incorporated into the donor sequences such as NeoR. Negative selections markers may be incorporated downstream the donor sequences, for example a nucleic acid sequence HSV-tk encoding a negative selection marker may be incorporated into a nucleic acid construct downstream the donor sequence.
In embodiments, the ceDNA vector for controlled transgene expression produced using the synthetic process as described herein can be used for gene editing, for example, as disclosed in International Application PCT/US2018/064242, filed on Dec. 6, 2018, which is incorporated herein in its entirety by reference, and may include one or more of: a 5′ homology arm, a 3′ homology arm, a polyadenylation site upstream and proximate to the 5′ homology arm. Exemplary homology arms are 5′ and 3′ albumin homology arms (SEQ ID NO: 151 and 152) or CCR5 5′- and 3′ homology arms (e.g., SEQ ID NO: 153, 154).
A molecular regulatory switch is one which generates a measurable change in state in response to a signal. Such regulatory switches can be usefully combined with the ceDNA vectors described herein to control the output of expression of the transgene from the ceDNA vector. In some embodiments, the ceDNA vector for controlled transgene expression comprises a regulatory switch that serves to fine tune expression of the transgene. For example, it can serve as a biocontainment function of the ceDNA vector. In some embodiments, the switch is an “ON/OFF” switch that is designed to start or stop (i.e., shut down) expression of the gene of interest in the ceDNA in a controllable and regulatable fashion. In some embodiments, the switch can include a “kill switch” that can instruct the cell comprising the ceDNA vector to undergo cell programmed death once the switch is activated. Exemplary regulatory switches encompassed for use in a ceDNA vector for controlled transgene expression can be used to regulate the expression of a transgene, and are more fully discussed in International application PCT/US18/49996, which is incorporated herein in its entirety by reference
In some embodiments, the ceDNA vector for controlled transgene expression comprises a regulatory switch that can serve to controllably modulate expression of the transgene. For example, the expression cassette located between the ITRs of the ceDNA vector for controlled transgene expression may additionally comprise a regulatory region, e.g., a promoter, cis-element, repressor, enhancer etc., that is operatively linked to the gene of interest, where the regulatory region is regulated by one or more cofactors or exogenous agents. By way of example only, regulatory regions can be modulated by small molecule switches or inducible or repressible promoters. Nonlimiting examples of inducible promoters are hormone-inducible or metal-inducible promoters. Other exemplary inducible promoters/enhancer elements include, but are not limited to, an RU486-inducible promoter, an ecdysone-inducible promoter, a rapamycin-inducible promoter, and a metallothionein promoter.
A variety of art-known small-molecule based regulatory switches are known in the art and can be combined with the ceDNA vectors disclosed herein to form a regulatory-switch controlled ceDNA vector. In some embodiments, the regulatory switch can be selected from any one or a combination of: an orthogonal ligand/nuclear receptor pair, for example retinoid receptor variant/LG335 and GRQCIMFI, along with an artificial promoter controlling expression of the operatively linked transgene, such as that as disclosed in Taylor, et al. BMC Biotechnology 10 (2010): 15; engineered steroid receptors, e.g., modified progesterone receptor with a C-terminal truncation that cannot bind progesterone but binds RU486 (mifepristone) (U.S. Pat. No. 5,364,791); an ecdysone receptor from Drosophila and their ecdysteroid ligands (Saez, et al., PNAS, 97(26)(2000), 14512-14517; or a switch controlled by the antibiotic trimethoprim (TMP), as disclosed in Sando R 3rd; Nat Methods. 2013, 10(11):1085-8. In some embodiments, the regulatory switch to control the transgene or expressed by the ceDNA vector for controlled transgene expression is a pro-drug activation switch, such as that disclosed in U.S. Pat. Nos. 8,771,679, and 6,339,070.
(iii) “Passcode” Regulatory Switches
In some embodiments the regulatory switch can be a “passcode switch” or “passcode circuit”. Passcode switches allow fine tuning of the control of the expression of the transgene from the ceDNA vector for controlled transgene expression when specific conditions occur—that is, a combination of conditions need to be present for transgene expression and/or repression to occur. For example, for expression of a transgene to occur at least conditions A and B must occur. A passcode regulatory switch can be any number of conditions, e.g., at least 2, or at least 3, or at least 4, or at least 5, or at least 6 or at least 7 or more conditions to be present for transgene expression to occur. In some embodiments, at least 2 conditions (e.g., A, B conditions) need to occur, and in some embodiments, at least 3 conditions need to occur (e.g., A, B and C, or A, B and D). By way of an example only, for gene expression from a ceDNA to occur that has a passcode “ABC” regulatory switch, conditions A, B and C must be present. Conditions A, B and C could be as follows; condition A is the presence of a condition or disease, condition B is a hormonal response, and condition C is a response to the transgene expression. For example, if the transgene edits a defective EPO gene, Condition A is the presence of Chronic Kidney Disease (CKD), Condition B occurs if the subject has hypoxic conditions in the kidney, Condition C is that Erythropoietin-producing cells (EPC) recruitment in the kidney is impaired; or alternatively, HIF-2 activation is impaired. Once the oxygen levels increase or the desired level of EPO is reached, the transgene turns off again until 3 conditions occur, turning it back on.
In some embodiments, a passcode regulatory switch or “Passcode circuit” encompassed for use in the ceDNA vector for controlled transgene expression comprises hybrid transcription factors (TFs) to expand the range and complexity of environmental signals used to define biocontainment conditions. As opposed to a deadman switch which triggers cell death in the presence of a predetermined condition, the “passcode circuit” allows cell survival or transgene expression in the presence of a particular “passcode”, and can be easily reprogrammed to allow transgene expression and/or cell survival only when the predetermined environmental condition or passcode is present.
Any and all combinations of regulatory switches disclosed herein, e g, small molecule switches, nucleic acid-based switches, small molecule-nucleic acid hybrid switches, post-transcriptional transgene regulation switches, post-translational regulation, radiation-controlled switches, hypoxia-mediated switches and other regulatory switches known by persons of ordinary skill in the art as disclosed herein can be used in a passcode regulatory switch as disclosed herein. Regulatory switches encompassed for use are also discussed in the review article Kis et al., J R Soc Interface. 12: 20141000 (2015), and summarized in Table 1 of Kis. In some embodiments, a regulatory switch for use in a passcode system can be selected from any or a combination of the switches in Table 11.
In some embodiments, the regulatory switch to control the transgene expressed by the ceDNA is based on a nucleic-acid based control mechanism. Exemplary nucleic acid control mechanisms are known in the art and are envisioned for use. For example, such mechanisms include riboswitches, such as those disclosed in, e.g., US2009/0305253, US2008/0269258, US2017/0204477, WO2018026762A1, U.S. Pat. No. 9,222,093 and EP application EP288071, and also disclosed in the review by Villa J K et al., Microbiol Spectr. 2018 May; 6(3). Also included are metabolite-responsive transcription biosensors, such as those disclosed in WO2018/075486 and WO2017/147585. Other art-known mechanisms envisioned for use include silencing of the transgene with an siRNA or RNAi molecule (e.g., miR, shRNA). For example, the ceDNA vector for controlled transgene expression can comprise a regulatory switch that encodes a RNAi molecule that is complementary to the transgene expressed by the ceDNA vector. When such RNAi is expressed even if the transgene is expressed by the ceDNA vector, it will be silenced by the complementary RNAi molecule, and when the RNAi is not expressed when the transgene is expressed by the ceDNA vector the transgene is not silenced by the RNAi.
In some embodiments, the regulatory switch is a tissue-specific self-inactivating regulatory switch, for example as disclosed in US2002/0022018, whereby the regulatory switch deliberately switches transgene expression off at a site where transgene expression might otherwise be disadvantageous. In some embodiments, the regulatory switch is a recombinase reversible gene expression system, for example as disclosed in US2014/0127162 and U.S. Pat. No. 8,324,436.
In some embodiments, the regulatory switch to control the transgene or gene of interest expressed by the ceDNA vector for controlled transgene expression is a post-transcriptional modification system. For example, such a regulatory switch can be an aptazyme riboswitch that is sensitive to tetracycline or theophylline, as disclosed in US2018/0119156, GB201107768, WO2001/064956A3, EP Patent 2707487 and Beilstein et al., ACS Synth. Biol., 2015, 4 (5), pp 526-534; Zhong et al., Elife. 2016 Nov. 2; 5. pii: e18858. In some embodiments, it is envisioned that a person of ordinary skill in the art could encode both the transgene and an inhibitory siRNA which contains a ligand sensitive (OFF-switch) aptamer, the net result being a ligand sensitive ON-switch.
Any known regulatory switch can be used in the ceDNA vector to control the gene expression of the transgene expressed by the ceDNA vector, including those triggered by environmental changes. Additional examples include, but are not limited to; the BOC method of Suzuki et al., Scientific Reports 8; 10051 (2018); genetic code expansion and a non-physiologic amino acid; radiation-controlled or ultra-sound controlled on/off switches (see, e.g., Scott S et al., Gene Ther. 2000 July; 7(13):1121-5; U.S. Pat. Nos. 5,612,318; 5,571,797; 5,770,581; 5,817,636; and WO1999/025385A1. In some embodiments, the regulatory switch is controlled by an implantable system, e.g., as disclosed in U.S. Pat. No. 7,840,263; US2007/0190028A1 where gene expression is controlled by one or more forms of energy, including electromagnetic energy, that activates promoters operatively linked to the transgene in the ceDNA vector.
In some embodiments, a regulatory switch envisioned for use in the ceDNA vector for controlled transgene expression is a hypoxia-mediated or stress-activated switch, e.g., such as those disclosed in WO1999060142A2, U.S. Pat. Nos. 5,834,306; 6,218,179; 6,709,858; US2015/0322410; Greco et al., (2004) Targeted Cancer Therapies 9, 5368, as well as FROG, TOAD and NRSE elements and conditionally inducible silence elements, including hypoxia response elements (HREs), inflammatory response elements (IREs) and shear-stress activated elements (SSAEs), e.g., as disclosed in U.S. Pat. No. 9,394,526. Such an embodiment is useful for turning on expression of the transgene from the ceDNA vector for controlled transgene expression after ischemia or in ischemic tissues, and/or tumors.
Other embodiments of the invention relate to a ceDNA vector for controlled transgene expression comprising a kill switch. A kill switch as disclosed herein enables a cell comprising the ceDNA vector to be killed or undergo programmed cell death as a means to permanently remove an introduced ceDNA vector from the subject's system. It will be appreciated by one of ordinary skill in the art that use of kill switches in the ceDNA vectors of the invention would be typically coupled with targeting of the ceDNA vector to a limited number of cells that the subject can acceptably lose or to a cell type where apoptosis is desirable (e.g., cancer cells). In all aspects, a “kill switch” as disclosed herein is designed to provide rapid and robust cell killing of the cell comprising the ceDNA vector in the absence of an input survival signal or other specified condition. Stated another way, a kill switch encoded by a ceDNA vector herein can restrict cell survival of a cell comprising a ceDNA vector to an environment defined by specific input signals. Such kill switches serve as a biological biocontainment function should it be desirable to remove the ceDNA vector from a subject or to ensure that it will not express the encoded transgene.
VI. Detailed method of Production of a ceDNA Vector
A. Production in General
Certain methods for the production of a ceDNA vector for controlled transgene expression comprising an asymmetrical ITR pair or symmetrical ITR pair as defined herein is described in section IV of International application PCT/US18/49996 filed Sep. 7, 2018, which is incorporated herein in its entirety by reference. In some embodiments, a ceDNA vector for controlled transgene expression for use in the methods and compositions as disclosed herein can be produced using insect cells, as described herein. In anterlative embodiments, a for use in the methods and compositions as disclosed herein can be produced synthetically, and in some embodiments, in a cell-free method, as disclosed on International Application PCT/US19/14122, filed Jan. 18, 2019, which is incorporated herein in its entirety by reference.
As described herein, in one embodiment, a ceDNA vector for controlled transgene expression can be obtained, for example, by the process comprising the steps of: a) incubating a population of host cells (e.g. insect cells) harboring the polynucleotide expression construct template (e.g., a ceDNA-plasmid, a ceDNA-Bacmid, and/or a ceDNA-baculovirus), which is devoid of viral capsid coding sequences, in the presence of a Rep protein under conditions effective and for a time sufficient to induce production of the ceDNA vector within the host cells, and wherein the host cells do not comprise viral capsid coding sequences; and b) harvesting and isolating the ceDNA vector from the host cells. The presence of Rep protein induces replication of the vector polynucleotide with a modified ITR to produce the ceDNA vector in a host cell. However, no viral particles (e.g. AAV virions) are expressed. Thus, there is no size limitation such as that naturally imposed in AAV or other viral-based vectors.
The presence of the ceDNA vector isolated from the host cells can be confirmed by digesting DNA isolated from the host cell with a restriction enzyme having a single recognition site on the ceDNA vector and analyzing the digested DNA material on a non-denaturing gel to confirm the presence of characteristic bands of linear and continuous DNA as compared to linear and non-continuous DNA.
In yet another aspect, the invention provides for use of host cell lines that have stably integrated the DNA vector polynucleotide expression template (ceDNA template) into their own genome in production of the non-viral DNA vector, e.g. as described in Lee, L. et al. (2013) Plos One 8(8): e69879. Preferably, Rep is added to host cells at an MOI of about 3. When the host cell line is a mammalian cell line, e.g., HEK293 cells, the cell lines can have polynucleotide vector template stably integrated, and a second vector such as herpes virus can be used to introduce Rep protein into cells, allowing for the excision and amplification of ceDNA in the presence of Rep and helper virus.
In one embodiment, the host cells used to make the ceDNA vectors described herein are insect cells, and baculovirus is used to deliver both the polynucleotide that encodes Rep protein and the non-viral DNA vector polynucleotide expression construct template for ceDNA, e.g., as described in
The ceDNA vector is then harvested and isolated from the host cells. The time for harvesting and collecting ceDNA vectors described herein from the cells can be selected and optimized to achieve a high-yield production of the ceDNA vectors. For example, the harvest time can be selected in view of cell viability, cell morphology, cell growth, etc. In one embodiment, cells are grown under sufficient conditions and harvested a sufficient time after baculoviral infection to produce ceDNA vectors but before a majority of cells start to die because of the baculoviral toxicity. The DNA vectors can be isolated using plasmid purification kits such as Qiagen Endo-Free Plasmid kits. Other methods developed for plasmid isolation can be also adapted for DNA vectors. Generally, any nucleic acid purification methods can be adopted.
The DNA vectors can be purified by any means known to those of skill in the art for purification of DNA. In one embodiment, ceDNA vectors are purified as DNA molecules. In another embodiment, the ceDNA vectors are purified as exosomes or microparticles.
The presence of the ceDNA vector can be confirmed by digesting the vector DNA isolated from the cells with a restriction enzyme having a single recognition site on the DNA vector and analyzing both digested and undigested DNA material using gel electrophoresis to confirm the presence of characteristic bands of linear and continuous DNA as compared to linear and non-continuous DNA. FIG. 4C and
B. ceDNA Plasmid
A ceDNA-plasmid is a plasmid used for later production of a ceDNA vector. In some embodiments, a ceDNA-plasmid can be constructed using known techniques to provide at least the following as operatively linked components in the direction of transcription: (1) a modified 5′ ITR sequence; (2) an expression cassette containing a cis-regulatory element, for example, a promoter, inducible promoter, regulatory switch, enhancers and the like; and (3) a modified 3′ ITR sequence, where the 3′ ITR sequence is symmetric relative to the 5′ ITR sequence. In some embodiments, the expression cassette flanked by the ITRs comprises a cloning site for introducing an exogenous sequence. The expression cassette replaces the rep and cap coding regions of the AAV genomes.
In one aspect, a ceDNA vector for controlled transgene expression is obtained from a plasmid, referred to herein as a “ceDNA-plasmid” encoding in this order: a first adeno-associated virus (AAV) inverted terminal repeat (ITR), an expression cassette comprising a transgene, and a mutated or modified AAV ITR, wherein said ceDNA-plasmid is devoid of AAV capsid protein coding sequences. In alternative embodiments, the ceDNA-plasmid encodes in this order: a first (or 5′) modified or mutated AAV ITR, an expression cassette comprising a transgene, and a second (or 3′) modified AAV ITR, wherein said ceDNA-plasmid is devoid of AAV capsid protein coding sequences, and wherein the 5′ and 3′ ITRs are symmetric relative to each other. In alternative embodiments, the ceDNA-plasmid encodes in this order: a first (or 5′) modified or mutated AAV ITR, an expression cassette comprising a transgene, and a second (or 3′) mutated or modified AAV ITR, wherein said ceDNA-plasmid is devoid of AAV capsid protein coding sequences, and wherein the 5′ and 3′ modified ITRs are have the same modifications (i.e., they are inverse complement or symmetric relative to each other).
In a further embodiment, the ceDNA-plasmid system is devoid of viral capsid protein coding sequences (i.e. it is devoid of AAV capsid genes but also of capsid genes of other viruses). In addition, in a particular embodiment, the ceDNA-plasmid is also devoid of AAV Rep protein coding sequences. Accordingly, in a preferred embodiment, ceDNA-plasmid is devoid of functional AAV cap and AAV rep genes GG-3′ for AAV2) plus a variable palindromic sequence allowing for hairpin formation.
A ceDNA-plasmid of the present invention can be generated using natural nucleotide sequences of the genomes of any AAV serotypes well known in the art. In one embodiment, the ceDNA-plasmid backbone is derived from the AAV1, AAV2, AAV3, AAV4, AAV5, AAV 5, AAV7, AAV8, AAV9, AAV10, AAV 11, AAV12, AAVrh8, AAVrh10, AAV-DJ, and AAV-DJ8 genome. E.g., NCBI: NC 002077; NC 001401; NC001729; NC001829; NC006152; NC 006260; NC 006261; Kotin and Smith, The Springer Index of Viruses, available at the URL maintained by Springer (at www web address: oesys.springer.de/viruses/database/mkchapter.asp?virID=42.04.)(note—references to a URL or database refer to the contents of the URL or database as of the effective filing date of this application) In a particular embodiment, the ceDNA-plasmid backbone is derived from the AAV2 genome. In another particular embodiment, the ceDNA-plasmid backbone is a synthetic backbone genetically engineered to include at its 5′ and 3′ ITRs derived from one of these AAV genomes.
A ceDNA-plasmid can optionally include a selectable or selection marker for use in the establishment of a ceDNA vector-producing cell line. In one embodiment, the selection marker can be inserted downstream (i.e., 3′) of the 3′ ITR sequence. In another embodiment, the selection marker can be inserted upstream (i.e., 5′) of the 5′ ITR sequence. Appropriate selection markers include, for example, those that confer drug resistance. Selection markers can be, for example, a blasticidin S-resistance gene, kanamycin, geneticin, and the like. In a preferred embodiment, the drug selection marker is a blasticidin S-resistance gene.
An Exemplary ceDNA (e.g., rAAV0) is produced from an rAAV plasmid. A method for the production of a rAAV vector, can comprise: (a) providing a host cell with a rAAV plasmid as described above, wherein both the host cell and the plasmid are devoid of capsid protein encoding genes, (b) culturing the host cell under conditions allowing production of an ceDNA genome, and (c) harvesting the cells and isolating the AAV genome produced from said cells.
C. Exemplary Method of Making the ceDNA Vectors from ceDNA Plasmids
Methods for making capsid-less ceDNA vectors are also provided herein, notably a method with a sufficiently high yield to provide sufficient vector for in vivo experiments.
In some embodiments, a method for the production of a ceDNA vector for controlled transgene expression comprises the steps of: (1) introducing the nucleic acid construct comprising an expression cassette and two symmetric ITR sequences into a host cell (e.g., Sf9 cells), (2) optionally, establishing a clonal cell line, for example, by using a selection marker present on the plasmid, (3) introducing a Rep coding gene (either by transfection or infection with a baculovirus carrying said gene) into said insect cell, and (4) harvesting the cell and purifying the ceDNA vector. The nucleic acid construct comprising an expression cassette and two ITR sequences described above for the production of ceDNA vector for controlled transgene expression can be in the form of a ceDNA plasmid, or Bacmid or Baculovirus generated with the ceDNA plasmid as described below. The nucleic acid construct can be introduced into a host cell by transfection, viral transduction, stable integration, or other methods known in the art.
D. Cell lines:
Host cell lines used in the production of a ceDNA vector for controlled transgene expression can include insect cell lines derived from Spodoptera frugiperda, such as Sf9 Sf21, or Trichoplusia ni cell, or other invertebrate, vertebrate, or other eukaryotic cell lines including mammalian cells. Other cell lines known to an ordinarily skilled artisan can also be used, such as HEK293, Huh-7, HeLa, HepG2, HeplA, 911, CHO, COS, MeWo, NIH3T3, A549, HT1 180, monocytes, and mature and immature dendritic cells. Host cell lines can be transfected for stable expression of the ceDNA-plasmid for high yield ceDNA vector production.
CeDNA-plasmids can be introduced into Sf9 cells by transient transfection using reagents (e.g., liposomal, calcium phosphate) or physical means (e.g., electroporation) known in the art. Alternatively, stable Sf9 cell lines which have stably integrated the ceDNA-plasmid into their genomes can be established. Such stable cell lines can be established by incorporating a selection marker into the ceDNA-plasmid as described above. If the ceDNA-plasmid used to transfect the cell line includes a selection marker, such as an antibiotic, cells that have been transfected with the ceDNA-plasmid and integrated the ceDNA-plasmid DNA into their genome can be selected for by addition of the antibiotic to the cell growth media. Resistant clones of the cells can then be isolated by single-cell dilution or colony transfer techniques and propagated.
E. Isolating and Purifying ceDNA Vectors:
Examples of the process for obtaining and isolating ceDNA vectors are described in
In one aspect, a polynucleotide encodes the AAV Rep protein (Rep 78 or Rep68) is delivered to a producer cell in a plasmid (Rep-plasmid), a bacmid (Rep-bacmid), or a baculovirus (Rep-baculovirus). The Rep-plasmid, Rep-bacmid, and Rep-baculovirus can be generated by methods described above.
Methods to produce a ceDNA-vector, which is an exemplary ceDNA vector, are described herein. Expression constructs used for generating a ceDNA vectors of the present invention can be a plasmid (e.g., ceDNA-plasmids), a Bacmid (e.g., ceDNA-bacmid), and/or a baculovirus (e.g., ceDNA-baculovirus). By way of an example only, a ceDNA-vector can be generated from the cells co-infected with ceDNA-baculovirus and Rep-baculovirus. Rep proteins produced from the Rep-baculovirus can replicate the ceDNA-baculovirus to generate ceDNA-vectors. Alternatively, ceDNA vectors can be generated from the cells stably transfected with a construct comprising a sequence encoding the AAV Rep protein (Rep78/52) delivered in Rep-plasmids, Rep-bacmids, or Rep-baculovirus. CeDNA-Baculovirus can be transiently transfected to the cells, be replicated by Rep protein and produce ceDNA vectors.
The bacmid (e.g., ceDNA-bacmid) can be transfected into a permissive insect cells such as Sf9, Sf21, Tni (Trichoplusia ni) cell, High Five cell, and generate ceDNA-baculovirus, which is a recombinant baculovirus including the sequences comprising the symmetric ITRs and the expression cassette. ceDNA-baculovirus can be again infected into the insect cells to obtain a next generation of the recombinant baculovirus. Optionally, the step can be repeated once or multiple times to produce the recombinant baculovirus in a larger quantity.
The time for harvesting and collecting ceDNA vectors described herein from the cells can be selected and optimized to achieve a high-yield production of the ceDNA vectors. For example, the harvest time can be selected in view of cell viability, cell morphology, cell growth, etc. Usually, cells can be harvested after sufficient time after baculoviral infection to produce ceDNA vectors (e.g., ceDNA vectors) but before majority of cells start to die because of the viral toxicity. The ceDNA-vectors can be isolated from the Sf9 cells using plasmid purification kits such as Qiagen ENDO-FREE PLASMID® kits. Other methods developed for plasmid isolation can be also adapted for ceDNA vectors. Generally, any art-known nucleic acid purification methods can be adopted, as well as commercially available DNA extraction kits.
Alternatively, purification can be implemented by subjecting a cell pellet to an alkaline lysis process, centrifuging the resulting lysate and performing chromatographic separation. As one nonlimiting example, the process can be performed by loading the supernatant on an ion exchange column (e.g. SARTOBIND Q®) which retains nucleic acids, and then eluting (e.g. with a 1.2 M NaCl solution) and performing a further chromatographic purification on a gel filtration column (e.g. 6 fast flow GE). The capsid-free AAV vector is then recovered by, e.g., precipitation.
In some embodiments, ceDNA vectors can also be purified in the form of exosomes, or microparticles. It is known in the art that many cell types release not only soluble proteins, but also complex protein/nucleic acid cargoes via membrane microvesicle shedding (Cocucci et al, 2009; EP 10306226.1) Such vesicles include microvesicles (also referred to as microparticles) and exosomes (also referred to as nanovesicles), both of which comprise proteins and RNA as cargo. Microvesicles are generated from the direct budding of the plasma membrane, and exosomes are released into the extracellular environment upon fusion of multivesicular endosomes with the plasma membrane. Thus, ceDNA vector-containing microvesicles and/or exosomes can be isolated from cells that have been transduced with the ceDNA-plasmid or a bacmid or baculovirus generated with the ceDNA-plasmid.
Microvesicles can be isolated by subjecting culture medium to filtration or ultracentrifugation at 20,000×g, and exosomes at 100,000×g. The optimal duration of ultracentrifugation can be experimentally-determined and will depend on the particular cell type from which the vesicles are isolated. Preferably, the culture medium is first cleared by low-speed centrifugation (e.g., at 2000×g for 5-20 minutes) and subjected to spin concentration using, e.g., an AMICON® spin column (Millipore, Watford, UK). Microvesicles and exosomes can be further purified via FACS or MACS by using specific antibodies that recognize specific surface antigens present on the microvesicles and exosomes. Other microvesicle and exosome purification methods include, but are not limited to, immunoprecipitation, affinity chromatography, filtration, and magnetic beads coated with specific antibodies or aptamers. Upon purification, vesicles are washed with, e.g., phosphate-buffered saline. One advantage of using microvesicles or exosome to deliver ceDNA-containing vesicles is that these vesicles can be targeted to various cell types by including on their membranes proteins recognized by specific receptors on the respective cell types. (See also EP 10306226)
Another aspect of the invention herein relates to methods of purifying ceDNA vectors from host cell lines that have stably integrated a ceDNA construct into their own genome. In one embodiment, ceDNA vectors are purified as DNA molecules. In another embodiment, the ceDNA vectors are purified as exosomes or microparticles.
FIG. 5 of International application PCT/US18/49996 shows a gel confirming the production of ceDNA from multiple ceDNA-plasmid constructs using the method described in the Examples. The ceDNA is confirmed by a characteristic band pattern in the gel, as discussed with respect to
VII. Pharmaceutical Compositions
In another aspect, pharmaceutical compositions are provided. The pharmaceutical composition comprises a closed-ended DNA vector, e.g., ceDNA vector for controlled transgene expression produced using the synthetic process as described herein and a pharmaceutically acceptable carrier or diluent.
The ceDNA vectors as disclosed herein can be incorporated into pharmaceutical compositions suitable for administration to a subject for in vivo delivery to cells, tissues, or organs of the subject. Typically, the pharmaceutical composition comprises a ceDNA-vector as disclosed herein and a pharmaceutically acceptable carrier. For example, the ceDNA vectors described herein can be incorporated into a pharmaceutical composition suitable for a desired route of therapeutic administration (e.g., parenteral administration). Passive tissue transduction via high pressure intravenous or intra-arterial infusion, as well as intracellular injection, such as intranuclear microinjection or intracytoplasmic injection, are also contemplated. Pharmaceutical compositions for therapeutic purposes can be formulated as a solution, microemulsion, dispersion, liposomes, or other ordered structure suitable to high ceDNA vector concentration. Sterile injectable solutions can be prepared by incorporating the ceDNA vector compound in the required amount in an appropriate buffer with one or a combination of ingredients enumerated above, as required, followed by filtered sterilization including a ceDNA vector can be formulated to deliver a transgene in the nucleic acid to the cells of a recipient, resulting in the therapeutic expression of the transgene or donor sequence therein. The composition can also include a pharmaceutically acceptable carrier.
Pharmaceutically active compositions comprising a ceDNA vector for controlled transgene expression can be formulated to deliver a transgene for various purposes to the cell, e.g., cells of a subject.
The ceDNA vectors disclosed herein can be incorporated into pharmaceutical compositions suitable for administration to a subject for in vivo delivery to cells, tissues, or organs of the subject. Typically, the pharmaceutical composition comprises the DNA-vectors disclosed herein and a pharmaceutically acceptable carrier. For example, the ceDNA vectors of the invention can be incorporated into a pharmaceutical composition suitable for a desired route of therapeutic administration (e.g., parenteral administration). Passive tissue transduction via high pressure intravenous or intraarterial infusion, as well as intracellular injection, such as intranuclear microinjection or intracytoplasmic injection, are also contemplated. Pharmaceutical compositions for therapeutic purposes can be formulated as a solution, microemulsion, dispersion, liposomes, or other ordered structure suitable to high ceDNA vector concentration. Sterile injectable solutions can be prepared by incorporating the ceDNA vector compound in the required amount in an appropriate buffer with one or a combination of ingredients enumerated above, as required, followed by filtered sterilization.
Pharmaceutically active compositions comprising a ceDNA vector can be formulated to deliver a transgene in the nucleic acid to the cells of a recipient, resulting in the therapeutic expression of the transgene therein. The composition can also optionally include a pharmaceutically acceptable carrier and/or excipient.
The compositions and vectors provided herein can be used to deliver a transgene for various purposes. In some embodiments, the transgene encodes a protein or functional RNA that is intended to be used for research purposes, e.g., to create a somatic transgenic animal model harboring the transgene, e.g., to study the function of the transgene product. In another example, the transgene encodes a protein or functional RNA that is intended to be used to create an animal model of disease. In some embodiments, the transgene encodes one or more peptides, polypeptides, or proteins, which are useful for the treatment or prevention of disease states in a mammalian subject. The transgene can be transferred (e.g., expressed in) to a patient in a sufficient amount to treat a disease associated with reduced expression, lack of expression or dysfunction of the gene. In some embodiments, the transgene is a gene editing molecule (e.g., nuclease). In certain embodiments, the nuclease is a CRISPR-associated nuclease (Cas nuclease).
Pharmaceutical compositions for therapeutic purposes typically must be sterile and stable under the conditions of manufacture and storage. Sterile injectable solutions can be prepared by incorporating the ceDNA vector compound in the required amount in an appropriate buffer with one or a combination of ingredients enumerated above, as required, followed by filtered sterilization.
In certain circumstances, it will be desirable to deliver a ceDNA composition or vector as disclosed herein in suitably formulated pharmaceutical compositions disclosed herein either subcutaneously, intraopancreatically, intranasally, parenterally, intravenously, intramuscularly, intrathecally, systemic administration, or orally, intraperitoneally, or by inhalation.
It is specifically contemplated herein that the compositions described herein comprise a ceDNA vector for controlled transgene expression at a given dose that is determined by the dose-response relationship of the ceDNA vector, for example, a “unit dose” that, upon administration, can be reliably expected to produce a desired effect or level of expression of the genetic medicine in a typical subject.
Pharmaceutical compositions for therapeutic purposes typically must be sterile and stable under the conditions of manufacture and storage. The composition can be formulated as a solution, microemulsion, dispersion, liposomes, or other ordered structure suitable to high ceDNA vector concentration. Sterile injectable solutions can be prepared by incorporating the ceDNA vector compound in the required amount in an appropriate buffer with one or a combination of ingredients enumerated above, as required, followed by filtered sterilization.
A ceDNA vector for controlled transgene expression as disclosed herein can be incorporated into a pharmaceutical composition suitable for topical, systemic, intra-amniotic, intrathecal, intracranial, intra-arterial, intravenous, intralymphatic, intraperitoneal, subcutaneous, tracheal, intra-tissue (e.g., intramuscular, intracardiac, intrahepatic, intrarenal, intracerebral), intrathecal, intravesical, conjunctival (e.g., extra-orbital, intraorbital, retroorbital, intraretinal, subretinal, choroidal, sub-choroidal, intrastromal, intracameral and intravitreal), intracochlear, and mucosal (e.g., oral, rectal, nasal) administration. Passive tissue transduction via high pressure intravenous or intraarterial infusion, as well as intracellular injection, such as intranuclear microinjection or intracytoplasmic injection, are also contemplated.
In some aspects, the methods provided herein comprise delivering one or more ceDNA vectors as disclosed herein to a host cell. Also provided herein are cells produced by such methods, and organisms (such as animals, plants, or fungi) comprising or produced from such cells. Methods of delivery of nucleic acids can include lipofection, nucleofection, microinjection, biolistics, liposomes, immunoliposomes, polycation or lipid:nucleic acid conjugates, naked DNA, and agent-enhanced uptake of DNA. Lipofection is described in e.g., U.S. Pat. Nos. 5,049,386, 4,946,787; and 4,897,355) and lipofection reagents are sold commercially (e.g., Transfectam™ and Lipofectin™). Delivery can be to cells (e.g., in vitro or ex vivo administration) or target tissues (e.g., in vivo administration).
Various techniques and methods are known in the art for delivering nucleic acids to cells. For example, nucleic acids, such as ceDNA can be formulated into lipid nanoparticles (LNPs), lipidoids, liposomes, lipid nanoparticles, lipoplexes, or core-shell nanoparticles. Typically, LNPs are composed of nucleic acid (e.g., ceDNA) molecules, one or more ionizable or cationic lipids (or salts thereof), one or more non-ionic or neutral lipids (e.g., a phospholipid), a molecule that prevents aggregation (e.g., PEG or a PEG-lipid conjugate), and optionally a sterol (e.g., cholesterol).
Another method for delivering nucleic acids, such as ceDNA to a cell is by conjugating the nucleic acid with a ligand that is internalized by the cell. For example, the ligand can bind a receptor on the cell surface and internalized via endocytosis. The ligand can be covalently linked to a nucleotide in the nucleic acid. Exemplary conjugates for delivering nucleic acids into a cell are described, example, in WO2015/006740, WO2014/025805, WO2012/037254, WO2009/082606, WO2009/073809, WO2009/018332, WO2006/112872, WO2004/090108, WO2004/091515 and WO2017/177326.
Nucleic acids, such as ceDNA, can also be delivered to a cell by transfection. Useful transfection methods include, but are not limited to, lipid-mediated transfection, cationic polymer-mediated transfection, or calcium phosphate precipitation. Transfection reagents are well known in the art and include, but are not limited to, TurboFect Transfection Reagent (Thermo Fisher Scientific), Pro-Ject Reagent (Thermo Fisher Scientific), TRANSPASS™ P Protein Transfection Reagent (New England Biolabs), CHARIOT™ Protein Delivery Reagent (Active Motif), PROTEOJUICE™ Protein Transfection Reagent (EMD Millipore), 293fectin, LIPOFECTAMINE™ 2000, LIPOFECTAMINE™ 3000 (Thermo Fisher Scientific), LIPOFECTAMINE™ (Thermo Fisher Scientific), LIPOFECTIN™ (Thermo Fisher Scientific), DMRIE-C, CELLFECTIN™ (Thermo Fisher Scientific), OLIGOFECTAMINE™ (Thermo Fisher Scientific), LIPOFECTACE™, FUGENE™ (Roche, Basel, Switzerland), FUGENE™ HD (Roche), TRANSFECTAM™ (Transfectam, Promega, Madison, Wis.), TFX-10™ (Promega), TFX-20™ (Promega), TFX-50™ (Promega), TRANSFECTIN™ (BioRad, Hercules, Calif.), SILENTFECT™ (Bio-Rad), Effectene™ (Qiagen, Valencia, Calif.), DC-chol (Avanti Polar Lipids), GENEPORTER™ (Gene Therapy Systems, San Diego, Calif.), DHARMAFECT 1™ (Dharmacon, Lafayette, Colo.), DHARMAFECT 2™ (Dharmacon), DHARMAFECT 3™ (Dharmacon), DHARMAFECT 4™ (Dharmacon), ESCORT™ III (Sigma, St. Louis, Mo.), and ESCORT™ IV (Sigma Chemical Co.). Nucleic acids, such as ceDNA, can also be delivered to a cell via microfluidics methods known to those of skill in the art.
ceDNA vectors as described herein can also be administered directly to an organism for transduction of cells in vivo. Administration is by any of the routes normally used for introducing a molecule into ultimate contact with blood or tissue cells including, but not limited to, injection, infusion, topical application and electroporation. Suitable methods of administering such nucleic acids are available and well known to those of skill in the art, and, although more than one route can be used to administer a particular composition, a particular route can often provide a more immediate and more effective reaction than another route.
Methods for introduction of a nucleic acid vector ceDNA vector for controlled transgene expression as disclosed herein can be delivered into hematopoietic stem cells, for example, by the methods as described, for example, in U.S. Pat. No. 5,928,638.
The ceDNA vectors in accordance with the present invention can be added to liposomes for delivery to a cell or target organ in a subject. Liposomes are vesicles that possess at least one lipid bilayer. Liposomes are typical used as carriers for drug/therapeutic delivery in the context of pharmaceutical development. They work by fusing with a cellular membrane and repositioning its lipid structure to deliver a drug or active pharmaceutical ingredient (API). Liposome compositions for such delivery are composed of phospholipids, especially compounds having a phosphatidylcholine group, however these compositions may also include other lipids. Exemplary liposomes and liposome formulations, including but not limited to polyethylene glycol (PEG)-functional group containing compounds are disclosed in International Application PCT/US2018/050042, filed on Sep. 7, 2018 and in International application PCT/US2018/064242, filed on Dec. 6, 2018, e.g., see the section entitled “Pharmaceutical Formulations”.]
Various delivery methods known in the art or modification thereof can be used to deliver ceDNA vectors in vitro or in vivo. For example, in some embodiments, ceDNA vectors are delivered by making transient penetration in cell membrane by mechanical, electrical, ultrasonic, hydrodynamic, or laser-based energy so that DNA entrance into the targeted cells is facilitated. For example, a ceDNA vector for controlled transgene expression can be delivered by transiently disrupting cell membrane by squeezing the cell through a size-restricted channel or by other means known in the art. In some cases, a ceDNA vector alone is directly injected as naked DNA into skin, thymus, cardiac muscle, skeletal muscle, or liver cells. In some cases, a ceDNA vector is delivered by gene gun. Gold or tungsten spherical particles (1-3 μm diameter) coated with capsid-free AAV vectors can be accelerated to high speed by pressurized gas to penetrate into target tissue cells.
Compositions comprising a ceDNA vector for controlled transgene expression and a pharmaceutically acceptable carrier are specifically contemplated herein. In some embodiments, the ceDNA vector for controlled transgene expression is formulated with a lipid delivery system, for example, liposomes as described herein. In some embodiments, such compositions are administered by any route desired by a skilled practitioner. The compositions may be administered to a subject by different routes including orally, parenterally, sublingually, transdermally, rectally, transmucosally, topically, via inhalation, via buccal administration, intrapleurally, intravenous, intra-arterial, intraperitoneal, subcutaneous, intramuscular, intranasal intrathecal, and intraarticular or combinations thereof. For veterinary use, the composition may be administered as a suitably acceptable formulation in accordance with normal veterinary practice. The veterinarian may readily determine the dosing regimen and route of administration that is most appropriate for a particular animal. The compositions may be administered by traditional syringes, needleless injection devices, “microprojectile bombardment gene guns”, or other physical methods such as electroporation (“EP”), hydrodynamic methods, or ultrasound.
In some cases, a ceDNA vector for controlled transgene expression is delivered by hydrodynamic injection, which is a simple and highly efficient method for direct intracellular delivery of any water-soluble compounds and particles into internal organs and skeletal muscle in an entire limb.
In some cases, ceDNA vectors are delivered by ultrasound by making nanoscopic pores in membrane to facilitate intracellular delivery of DNA particles into cells of internal organs or tumors, so the size and concentration of plasmid DNA have great role in efficiency of the system. In some cases, ceDNA vectors are delivered by magnetofection by using magnetic fields to concentrate particles containing nucleic acid into the target cells.
In some cases, chemical delivery systems can be used, for example, by using nanomeric complexes, which include compaction of negatively charged nucleic acid by polycationic nanomeric particles, belonging to cationic liposome/micelle or cationic polymers. Cationic lipids used for the delivery method includes, but not limited to monovalent cationic lipids, polyvalent cationic lipids, guanidine containing compounds, cholesterol derivative compounds, cationic polymers, (e.g., poly(ethylenimine), poly-L-lysine, protamine, other cationic polymers), and lipid-polymer hybrid.
In some embodiments, a ceDNA vector for controlled transgene expression as disclosed herein is delivered by being packaged in an exosome. Exosomes are small membrane vesicles of endocytic origin that are released into the extracellular environment following fusion of multivesicular bodies with the plasma membrane. Their surface consists of a lipid bilayer from the donor cell's cell membrane, they contain cytosol from the cell that produced the exosome, and exhibit membrane proteins from the parental cell on the surface. Exosomes are produced by various cell types including epithelial cells, B and T lymphocytes, mast cells (MC) as well as dendritic cells (DC). Some embodiments, exosomes with a diameter between 10 nm and 1 μm, between 20 nm and 500 nm, between 30 nm and 250 nm, between 50 nm and 100 nm are envisioned for use. Exosomes can be isolated for a delivery to target cells using either their donor cells or by introducing specific nucleic acids into them. Various approaches known in the art can be used to produce exosomes containing capsid-free AAV vectors of the present invention.
In some embodiments, a ceDNA vector for controlled transgene expression as disclosed herein is delivered by a lipid nanoparticle. Generally, lipid nanoparticles comprise an ionizable amino lipid (e.g., heptatriaconta-6,9,28,31-tetraen-19-yl 4-(dimethylamino)butanoate, DLin-MC3-DMA, a phosphatidylcholine (1,2-distearoyl-sn-glycero-3-phosphocholine, DSPC), cholesterol and a coat lipid (polyethylene glycol-dimyristolglycerol, PEG-DMG), for example as disclosed by Tam et al. (2013). Advances in Lipid Nanoparticles for siRNA delivery. Pharmaceuticals 5(3): 498-507.
In some embodiments, a lipid nanoparticle has a mean diameter between about 10 and about 1000 nm. In some embodiments, a lipid nanoparticle has a diameter that is less than 300 nm. In some embodiments, a lipid nanoparticle has a diameter between about 10 and about 300 nm. In some embodiments, a lipid nanoparticle has a diameter that is less than 200 nm. In some embodiments, a lipid nanoparticle has a diameter between about 25 and about 200 nm. In some embodiments, a lipid nanoparticle preparation (e.g., composition comprising a plurality of lipid nanoparticles) has a size distribution in which the mean size (e.g., diameter) is about 70 nm to about 200 nm, and more typically the mean size is about 100 nm or less.
Various lipid nanoparticles known in the art can be used to deliver ceDNA vector for controlled transgene expression disclosed herein. For example, various delivery methods using lipid nanoparticles are described in U.S. Pat. Nos. 9,404,127, 9,006,417 and 9,518,272.
In some embodiments, a ceDNA vector for controlled transgene expression disclosed herein is delivered by a gold nanoparticle. Generally, a nucleic acid can be covalently bound to a gold nanoparticle or non-covalently bound to a gold nanoparticle (e.g., bound by a charge-charge interaction), for example as described by Ding et al. (2014). Gold Nanoparticles for Nucleic Acid Delivery. Mol. Ther. 22(6); 1075-1083. In some embodiments, gold nanoparticle-nucleic acid conjugates are produced using methods described, for example, in U.S. Pat. No. 6,812,334.
In some embodiments, a ceDNA vector for controlled transgene expression as disclosed herein is conjugated (e.g., covalently bound to an agent that increases cellular uptake. An “agent that increases cellular uptake” is a molecule that facilitates transport of a nucleic acid across a lipid membrane. For example, a nucleic acid can be conjugated to a lipophilic compound (e.g., cholesterol, tocopherol, etc.), a cell penetrating peptide (CPP) (e.g., penetratin, TAT, Syn1B, etc.), and polyamines (e.g., spermine). Further examples of agents that increase cellular uptake are disclosed, for example, in Winkler (2013). Oligonucleotide conjugates for therapeutic applications. Ther. Deliv. 4(7); 791-809.
In some embodiments, a ceDNA vector for controlled transgene expression as disclosed herein is conjugated to a polymer (e.g., a polymeric molecule) or a folate molecule (e.g., folic acid molecule). Generally, delivery of nucleic acids conjugated to polymers is known in the art, for example as described in WO2000/34343 and WO2008/022309. In some embodiments, a ceDNA vector for controlled transgene expression as disclosed herein is conjugated to a poly(amide) polymer, for example as described by U.S. Pat. No. 8,987,377. In some embodiments, a nucleic acid described by the disclosure is conjugated to a folic acid molecule as described in U.S. Pat. No. 8,507,455.
In some embodiments, a ceDNA vector for controlled transgene expression as disclosed herein is conjugated to a carbohydrate, for example as described in U.S. Pat. No. 8,450,467.
Alternatively, nanocapsule formulations of a ceDNA vector for controlled transgene expression as disclosed herein can be used. Nanocapsules can generally entrap substances in a stable and reproducible way. To avoid side effects due to intracellular polymeric overloading, such ultrafine particles (sized around 0.1 μm) should be designed using polymers able to be degraded in vivo. Biodegradable polyalkyl-cyanoacrylate nanoparticles that meet these requirements are contemplated for use.
The ceDNA vectors in accordance with the present invention can be added to liposomes for delivery to a cell or target organ in a subject. Liposomes are vesicles that possess at least one lipid bilayer. Liposomes are typical used as carriers for drug/therapeutic delivery in the context of pharmaceutical development. They work by fusing with a cellular membrane and repositioning its lipid structure to deliver a drug or active pharmaceutical ingredient (API). Liposome compositions for such delivery are composed of phospholipids, especially compounds having a phosphatidylcholine group, however these compositions may also include other lipids.
The formation and use of liposomes is generally known to those of skill in the art. Liposomes have been developed with improved serum stability and circulation half-times (U.S. Pat. No. 5,741,516). Further, various methods of liposome and liposome like preparations as potential drug carriers have been described (U.S. Pat. Nos. 5,567,434; 5,552,157; 5,565,213; 5,738,868 and 5,795,587).
F. Exemplary liposome and Lipid Nanoparticle (LNP) Compositions
The ceDNA vectors in accordance with the present invention can be added to liposomes for delivery to a cell, e.g., a cell in need of expression of the transgene. Liposomes are vesicles that possess at least one lipid bilayer. Liposomes are typical used as carriers for drug/therapeutic delivery in the context of pharmaceutical development. They work by fusing with a cellular membrane and repositioning its lipid structure to deliver a drug or active pharmaceutical ingredient (API). Liposome compositions for such delivery are composed of phospholipids, especially compounds having a phosphatidylcholine group, however these compositions may also include other lipids.
Lipid nanoparticles (LNPs) comprising ceDNA are disclosed in International Application PCT/US2018/050042, filed on Sep. 7, 2018, and International Application PCT/US2018/064242, filed on Dec. 6, 2018 which are incorporated herein in their entirety and envisioned for use in the methods and compostions as disclosed herein.
In some aspects, a lipid nanoparticle comprising a ceDNA is an ionizable lipid.
Generally, the lipid particles are prepared at a total lipid to ceDNA (mass or weight) ratio of from about 10:1 to 30:1. In some embodiments, the lipid to ceDNA ratio (mass/mass ratio; w/w ratio) can be in the range of from about 1:1 to about 25:1, from about 10:1 to about 14:1, from about 3:1 to about 15:1, from about 4:1 to about 10:1, from about 5:1 to about 9:1, or about 6:1 to about 9:1. The amounts of lipids and ceDNA can be adjusted to provide a desired N/P ratio, for example, N/P ratio of 3, 4, 5, 6, 7, 8, 9, 10 or higher. Generally, the lipid particle formulation's overall lipid content can range from about 5 mg/ml to about 30 mg/mL. Ionizable lipids are also referred to as cationic lipids herein. Exemplary ionizable lipids are described in International PCT patent publications WO2015/095340, WO2015/199952, WO2018/011633, WO2017/049245, WO2015/061467, WO2012/040184, WO2012/000104, WO2015/074085, WO2016/081029, WO2017/004143, WO2017/075531, WO2017/117528, WO2011/022460, WO2013/148541, WO2013/116126, WO2011/153120, WO2012/044638, WO2012/054365, WO2011/090965, WO2013/016058, WO2012/162210, WO2008/042973, WO2010/129709, WO2010/144740, WO2012/099755, WO2013/049328, WO2013/086322, WO2013/086373, WO2011/071860, WO2009/132131, WO2010/048536, WO2010/088537, WO2010/054401, WO2010/054406, WO2010/054405, WO2010/054384, WO2012/016184, WO2009/086558, WO2010/042877, WO2011/000106, WO2011/000107, WO2005/120152, WO2011/141705, WO2013/126803, WO2006/007712, WO2011/038160, WO2005/121348, WO2011/066651, WO2009/127060, WO2011/141704, WO2006/069782, WO2012/031043, WO2013/006825, WO2013/033563, WO2013/089151, WO2017/099823, WO2015/095346, and WO2013/086354, and US patent publications US2016/0311759, US2015/0376115, US2016/0151284, US2017/0210697, US2015/0140070, US2013/0178541, US2013/0303587, US2015/0141678, US2015/0239926, US2016/0376224, US2017/0119904, US2012/0149894, US2015/0057373, US2013/0090372, US2013/0274523, US2013/0274504, US2013/0274504, US2009/0023673, US2012/0128760, US2010/0324120, US2014/0200257, US2015/0203446, US2018/0005363, US2014/0308304, US2013/0338210, US2012/0101148, US2012/0027796, US2012/0058144, US2013/0323269, US2011/0117125, US2011/0256175, US2012/0202871, US2011/0076335, US2006/0083780, US2013/0123338, US2015/0064242, US2006/0051405, US2013/0065939, US2006/0008910, US2003/0022649, US2010/0130588, US2013/0116307, US2010/0062967, US2013/0202684, US2014/0141070, US2014/0255472, US2014/0039032, US2018/0028664, US2016/0317458, and US2013/0195920, the contents of all of which are incorporated herein by reference in their entirety.
In some embodiments, the ionizable lipid is MC3 (6Z,9Z,28Z,31Z)-heptatriaconta-6,9,28,31-tetraen-19-yl-4-(dimethylamino) butanoate (DLin-MC3-DMA or MC3) having the following structure:
VIII. Methods of Delivering ceDNA Vectors
In some embodiments, a ceDNA vector for controlled transgene expression can be delivered to a target cell in vitro or in vivo by various suitable methods. ceDNA vectors alone can be applied or injected. CeDNA vectors can be delivered to a cell without the help of a transfection reagent or other physical means. Alternatively, ceDNA vectors can be delivered using any art-known transfection reagent or other art-known physical means that facilitates entry of DNA into a cell, e.g., liposomes, alcohols, polylysine-rich compounds, arginine-rich compounds, calcium phosphate, microvesicles, microinjection, electroporation and the like.
In contrast, transductions with capsid-free AAV vectors disclosed herein can efficiently target cell and tissue-types that are difficult to transduce with conventional AAV virions using various delivery reagent.
In another embodiment, a ceDNA vector for controlled transgene expression is administered to the CNS (e.g., to the brain or to the eye). The ceDNA vector for controlled transgene expression may be introduced into the spinal cord, brainstem (medulla oblongata, pons), midbrain (hypothalamus, thalamus, epithalamus, pituitary gland, substantia nigra, pineal gland), cerebellum, telencephalon (corpus striatum, cerebrum including the occipital, temporal, parietal and frontal lobes, cortex, basal ganglia, hippocampus and portaamygdala), limbic system, neocortex, corpus striatum, cerebrum, and inferior colliculus. The ceDNA vector may also be administered to different regions of the eye such as the retina, cornea and/or optic nerve. The ceDNA vector may be delivered into the cerebrospinal fluid (e.g., by lumbar puncture). The ceDNA vector may further be administered intravascularly to the CNS in situations in which the blood-brain barrier has been perturbed (e.g., brain tumor or cerebral infarct).
In some embodiments, the ceDNA vector for controlled transgene expression can be administered to the desired region(s) of the CNS by any route known in the art, including but not limited to, intrathecal, intra-ocular, intracerebral, intraventricular, intravenous (e.g., in the presence of a sugar such as mannitol), intranasal, intra-aural, intra-ocular (e.g., intra-vitreous, sub-retinal, anterior chamber) and peri-ocular (e.g., sub-Tenon's region) delivery as well as intramuscular delivery with retrograde delivery to motor neurons.
In some embodiments, the ceDNA vector for controlled transgene expression is administered in a liquid formulation by direct injection (e.g., stereotactic injection) to the desired region or compartment in the CNS. In other embodiments, the ceDNA vector can be provided by topical application to the desired region or by intra-nasal administration of an aerosol formulation. Administration to the eye may be by topical application of liquid droplets. As a further alternative, the ceDNA vector can be administered as a solid, slow-release formulation (see, e.g., U.S. Pat. No. 7,201,898). In yet additional embodiments, the ceDNA vector can used for retrograde transport to treat, ameliorate, and/or prevent diseases and disorders involving motor neurons (e.g., amyotrophic lateral sclerosis (ALS); spinal muscular atrophy (SMA), etc.). For example, the ceDNA vector can be delivered to muscle tissue from which it can migrate into neurons.
IX. Additional Uses of the ceDNA Vectors
The compositions and ceDNA vectors as described herein can be used to express a target gene or transgene for various purposes. In some embodiments, the resulting transgene encodes a protein or functional RNA that is intended to be used for research purposes, e.g., to create a somatic transgenic animal model harboring the transgene, e.g., to study the function of the transgene product. In another example, the transgene encodes a protein or functional RNA that is intended to be used to create an animal model of disease. In some embodiments, the resulting transgene encodes one or more peptides, polypeptides, or proteins, which are useful for the treatment, prevention, or amelioration of disease states or disorders in a mammalian subject. The resulting transgene can be transferred (e.g., expressed in) to a subject in a sufficient amount to treat a disease associated with reduced expression, lack of expression or dysfunction of the gene. In some embodiments the resulting transgene can be expressed in a subject in a sufficient amount to treat a disease associated with increased expression, activity of the gene product, or inappropriate upregulation of a gene that the resulting transgene suppresses or otherwise causes the expression of which to be reduced. In yet other embodiments, the resulting transgene replaces or supplements a defective copy of the native gene. It will be appreciated by one of ordinary skill in the art that the transgene may not be an open reading frame of a gene to be transcribed itself; instead it may be a promoter region or repressor region of a target gene, and the ceDNA vector may modify such region with the outcome of so modulating the expression of a gene of interest.
In some embodiments, the transgene encodes a protein or functional RNA that is intended to be used to create an animal model of disease. In some embodiments, the transgene encodes one or more peptides, polypeptides, or proteins, which are useful for the treatment or prevention of disease states in a mammalian subject. The transgene can be transferred (e.g., expressed in) to a patient in a sufficient amount to treat a disease associated with reduced expression, lack of expression or dysfunction of the gene.
X. Methods of Use
A ceDNA vector for controlled transgene expression as disclosed herein can also be used in a method for the delivery of a nucleotide sequence of interest (e.g., a transgene) to a target cell (e.g., a host cell). The method may in particular be a method for delivering a transgene to a cell of a subject in need thereof and treating a disease of interest. The invention allows for the in vivo expression of a transgene, e.g., a protein, antibody, nucleic acid such as miRNA etc. encoded in the ceDNA vector in a cell in a subject such that therapeutic effect of the expression of the transgene occurs. These results are seen with both in vivo and in vitro modes of ceDNA vector delivery.
In addition, the invention provides a method for the delivery of a transgene in a cell of a subject in need thereof, comprising multiple administrations of the ceDNA vector of the invention comprising said nucleic acid or transgene of interest to titrate the transgene expression to the desired level.
The ceDNA vector nucleic acid(s) are administered in sufficient amounts to transfect the cells of a desired tissue and to provide sufficient levels of gene transfer and expression without undue adverse effects. Conventional and pharmaceutically acceptable routes of administration include, but are not limited to, intravenous (e.g., in a liposome formulation), direct delivery to the selected organ (e.g., intraportal delivery to the liver), intramuscular, and other parental routes of administration. Routes of administration may be combined, if desired.
Closed-ended DNA vector (e.g. ceDNA vector) delivery is not limited to delivery gene replacements. For example, conventionally produced (e.g., using a cell-based production method or synthetically produced closed-ended DNA vectors) (e.g., ceDNA vectors) as described herein may be used with other delivery systems provided to provide a portion of the gene therapy. One non-limiting example of a system that may be combined with the synthetically produced ceDNA vectors in accordance with the present disclosure includes systems which separately deliver one or more co-factors or immune suppressors for effective gene expression of the transgene.
The invention also provides for a method of treating a disease in a subject comprising introducing into a target cell in need thereof (in particular a muscle cell or tissue) of the subject a therapeutically effective amount of a ceDNA vector, optionally with a pharmaceutically acceptable carrier. While the ceDNA vector for controlled transgene expression can be introduced in the presence of a carrier, such a carrier is not required. The ceDNA vector selected comprises a nucleotide sequence of interest useful for treating the disease. In particular, the ceDNA vector may comprise a desired exogenous DNA sequence operably linked to control elements capable of directing transcription of the desired polypeptide, protein, or oligonucleotide encoded by the exogenous DNA sequence when introduced into the subject. The ceDNA vector can be administered via any suitable route as provided above, and elsewhere herein.
The compositions and vectors provided herein can be used to deliver a transgene for various purposes. In some embodiments, the transgene encodes a protein or functional RNA that is intended to be used for research purposes, e.g., to create a somatic transgenic animal model harboring the transgene, e.g., to study the function of the transgene product. In another example, the transgene encodes a protein or functional RNA that is intended to be used to create an animal model of disease. In some embodiments, the transgene encodes one or more peptides, polypeptides, or proteins, which are useful for the treatment or prevention of disease states in a mammalian subject. The transgene can be transferred (e.g., expressed in) to a patient in a sufficient amount to treat a disease associated with reduced expression, lack of expression or dysfunction of the gene.
In principle, the expression cassette can include a nucleic acid or any transgene that encodes a protein or polypeptide that is either reduced or absent due to a mutation or which conveys a therapeutic benefit when overexpressed is considered to be within the scope of the invention. Preferably, noninserted bacterial DNA is not present and preferably no bacterial DNA is present in the ceDNA compositions provided herein.
A ceDNA vector for controlled transgene expression is not limited to one species of ceDNA vector. As such, in another aspect, multiple ceDNA vectors comprising different transgenes or the same transgene but operatively linked to different promoters or cis-regulatory elements can be delivered simultaneously or sequentially to the target cell, tissue, organ, or subject. Therefore, this strategy can allow for the gene therapy or gene delivery of multiple genes simultaneously. It is also possible to separate different portions of the transgene into separate ceDNA vectors (e.g., different domains and/or co-factors required for functionality of the transgene) which can be administered simultaneously or at different times, and can be separately regulatable, thereby adding an additional level of control of expression of the transgene. Delivery can also be performed multiple times and, importantly for gene therapy in the clinical setting, in subsequent increasing or decreasing doses, given the lack of an anti-capsid host immune response due to the absence of a viral capsid. It is anticipated that no anti-capsid response will occur as there is no capsid.
The invention also provides for a method of treating a disease in a subject comprising introducing into a target cell in need thereof (in particular a muscle cell or tissue) of the subject a therapeutically effective amount of a ceDNA vector as disclosed herein, optionally with a pharmaceutically acceptable carrier. While the ceDNA vector can be introduced in the presence of a carrier, such a carrier is not required. The ceDNA vector implemented comprises a nucleotide sequence of interest useful for treating the disease. In particular, the ceDNA vector may comprise a desired exogenous DNA sequence operably linked to control elements capable of directing transcription of the desired polypeptide, protein, or oligonucleotide encoded by the exogenous DNA sequence when introduced into the subject. The ceDNA vector for controlled transgene expression can be administered via any suitable route as provided above, and elsewhere herein.
XI. Methods of Treatment
The technology described herein also demonstrates methods for making, as well as methods of using the disclosed ceDNA vectors in a variety of ways, including, for example, ex situ, in vitro and in vivo applications, methodologies, diagnostic procedures, and/or gene therapy regimens.
Provided herein is a method of treating a disease or disorder in a subject comprising introducing into a target cell in need thereof (for example, a muscle cell or tissue, or other affected cell type) of the subject a therapeutically effective amount of a ceDNA vector, optionally with a pharmaceutically acceptable carrier. While the ceDNA vector can be introduced in the presence of a carrier, such a carrier is not required. The ceDNA vector implemented comprises a nucleotide sequence of interest useful for treating the disease. In particular, the ceDNA vector may comprise a desired exogenous DNA sequence operably linked to control elements capable of directing transcription of the desired polypeptide, protein, or oligonucleotide encoded by the exogenous DNA sequence when introduced into the subject. The ceDNA vector for controlled transgene expression can be administered via any suitable route as provided above, and elsewhere herein.
Disclosed herein are ceDNA vector compositions and formulations that include one or more of the ceDNA vectors of the present invention together with one or more pharmaceutically-acceptable buffers, diluents, or excipients. Such compositions may be included in one or more diagnostic or therapeutic kits, for diagnosing, preventing, treating or ameliorating one or more symptoms of a disease, injury, disorder, trauma or dysfunction. In one aspect the disease, injury, disorder, trauma or dysfunction is a human disease, injury, disorder, trauma or dysfunction.
Another aspect of the technology described herein provides a method for providing a subject in need thereof with a diagnostically- or therapeutically-effective amount of a ceDNA vector, the method comprising providing to a cell, tissue or organ of a subject in need thereof, an amount of the ceDNA vector as disclosed herein; and for a time effective to enable expression of the transgene from the ceDNA vector thereby providing the subject with a diagnostically- or a therapeutically-effective amount of the protein, peptide, nucleic acid expressed by the ceDNA vector. In a further aspect, the subject is human
Another aspect of the technology described herein provides a method for diagnosing, preventing, treating, or ameliorating at least one or more symptoms of a disease, a disorder, a dysfunction, an injury, an abnormal condition, or trauma in a subject. In an overall and general sense, the method includes at least the step of administering to a subject in need thereof one or more of the disclosed ceDNA vectors, in an amount and for a time sufficient to diagnose, prevent, treat or ameliorate the one or more symptoms of the disease, disorder, dysfunction, injury, abnormal condition, or trauma in the subject. In a further aspect, the subject is human
Another aspect is use of the ceDNA vector for controlled transgene expression as a tool for treating or reducing one or more symptoms of a disease or disease states. There are a number of inherited diseases in which defective genes are known, and typically fall into two classes: deficiency states, usually of enzymes, which are generally inherited in a recessive manner, and unbalanced states, which may involve regulatory or structural proteins, and which are typically but not always inherited in a dominant manner. For deficiency state diseases, ceDNA vectors can be used to deliver transgenes to bring a normal gene into affected tissues for replacement therapy, as well, in some embodiments, to create animal models for the disease using antisense mutations. For unbalanced disease states, ceDNA vectors can be used to create a disease state in a model system, which could then be used in efforts to counteract the disease state. Thus the ceDNA vectors and methods disclosed herein permit the treatment of genetic diseases. As used herein, a disease state is treated by partially or wholly remedying the deficiency or imbalance that causes the disease or makes it more severe.
In some embodiments, the ceDNA vector for controlled transgene expression delivers the transgene into a subject host cell. In some embodiments, the subject host cell is a human host cell, including, for example blood cells, stem cells, hematopoietic cells, CD34+ cells, liver cells, cancer cells, vascular cells, muscle cells, pancreatic cells, neural cells, ocular or retinal cells, epithelial or endothelial cells, dendritic cells, fibroblasts, or any other cell of mammalian origin, including, without limitation, hepatic (i.e., liver) cells, lung cells, cardiac cells, pancreatic cells, intestinal cells, diaphragmatic cells, renal (i.e., kidney) cells, neural cells, blood cells, bone marrow cells, or any one or more selected tissues of a subject for which gene therapy is contemplated. In one aspect, the subject host cell is a human host cell.
The present disclosure also relates to recombinant host cells as mentioned above, including ceDNA vectors as described herein. Thus, one can use multiple host cells depending on the purpose as is obvious to the skilled artisan. A construct or ceDNA vector for controlled transgene expression including donor sequence is introduced into a host cell so that the donor sequence is maintained as a chromosomal integrant as described earlier. The term host cell encompasses any progeny of a parent cell that is not identical to the parent cell due to mutations that occur during replication. The choice of a host cell will to a large extent depend upon the donor sequence and its source. The host cell may also be a eukaryote, such as a mammalian, insect, plant, or fungal cell. In one embodiment, the host cell is a human cell (e.g., a primary cell, a stem cell, or an immortalized cell line). In some embodiments, the host cell can be administered the ceDNA vector for controlled transgene expression ex vivo and then delivered to the subject after the gene therapy event. A host cell can be any cell type, e.g., a somatic cell or a stem cell, an induced pluripotent stem cell, or a blood cell, e.g., T-cell or B-cell, or bone marrow cell. In certain embodiments, the host cell is an allogenic cell. For example, T-cell genome engineering is useful for cancer immunotherapies, disease modulation such as HIV therapy (e.g., receptor knock out, such as CXCR4 and CCR5) and immunodeficiency therapies. MHC receptors on B-cells can be targeted for immunotherapy. In some embodiments, gene modified host cells, e.g., bone marrow stem cells, e.g., CD34+ cells, or induced pluripotent stem cells can be transplanted back into a patient for expression of a therapeutic protein.
B. Exemplary Transgenes and Diseases to be Treated with a ceDNA Vector
The ceDNA vectors are also useful for correcting a defective gene. As a non-limiting example, DMD gene of Duchene Muscular Dystrophy can be delivered using the ceDNA vectors as disclosed herein.
A ceDNA vector for controlled transgene expression or a composition thereof can be used in the treatment of any hereditary disease. As a non-limiting example, the ceDNA vector or a composition thereof e.g. can be used in the treatment of transthyretin amyloidosis (ATTR), an orphan disease where the mutant protein misfolds and aggregates in nerves, the heart, the gastrointestinal system etc. It is contemplated herein that the disease can be treated by deletion of the mutant disease gene (mutTTR) using the ceDNA vector systems described herein. Such treatments of hereditary diseases can halt disease progression and may enable regression of an established disease or reduction of at least one symptom of the disease by at least 10%.
In another embodiment, a ceDNA vector for controlled transgene expression can be used in the treatment of ornithine transcarbamylase deficiency (OTC deficiency), hyperammonaemia or other urea cycle disorders, which impair a neonate or infant's ability to detoxify ammonia. As with all diseases of inborn metabolism, it is contemplated herein that even a partial restoration of enzyme activity compared to wild-type controls (e.g., at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95% or at least 99%) may be sufficient for reduction in at least one symptom OTC and/or an improvement in the quality of life for a subject having OTC deficiency. In one embodiment, a nucleic acid encoding OTC can be inserted behind the albumin endogenous promoter for in vivo protein replacement.
In another embodiment, a ceDNA vector for controlled transgene expression can be used in the treatment of phenylketonuria (PKU) by delivering a nucleic acid sequence encoding a phenylalanine hydroxylase enzyme to reduce buildup of dietary phenylalanine, which can be toxic to PKU sufferers. As with all diseases of inborn metabolism, it is contemplated herein that even a partial restoration of enzyme activity compared to wild-type controls (e.g., at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95% or at least 99%) may be sufficient for reduction in at least one symptom of PKU and/or an improvement in the quality of life for a subject having PKU. In one embodiment, a nucleic acid encoding phenylalanine hydroxylase can be inserted behind the albumin endogenous promoter for in vivo protein replacement.
In another embodiment, a ceDNA vector for controlled transgene expression can be used in the treatment of glycogen storage disease (GSD) by delivering a nucleic acid sequence encoding an enzyme to correct aberrant glycogen synthesis or breakdown in subjects having GSD. Non-limiting examples of enzymes that can be delivered and expressed using the ceDNA vectors and methods as described herein include glycogen synthase, glucose-6-phosphatase, acid-alpha glucosidase, glycogen debranching enzyme, glycogen branching enzyme, muscle glycogen phosphorylase, liver glycogen phosphorylase, muscle phosphofructokinase, phosphorylase kinase, glucose transporter-2 (GLUT-2), aldolase A, beta-enolase, phosphoglucomutase-1 (PGM-1), and glycogenin-1. As with all diseases of inborn metabolism, it is contemplated herein that even a partial restoration of enzyme activity compared to wild-type controls (e.g., at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95% or at least 99%) may be sufficient for reduction in at least one symptom of GSD and/or an improvement in the quality of life for a subject having GSD. In one embodiment, a nucleic acid encoding an enzyme to correct aberrant glycogen storage can be inserted behind the albumin endogenous promoter for in vivo protein replacement.
The ceDNA vectors described herein are also contemplated for use in the treatment of any of; of Leber congenital amaurosis (LCA), polyglutamine diseases, including polyQ repeats, and alpha-1 antitrypsin deficiency (A1AT). LCA is a rare congenital eye disease resulting in blindness, which can be caused by a mutation in any one of the following genes: GUCY2D, RPE65, SPATA7, AIPL1, LCA5, RPGRIP1, CRX, CRB1, NMNAT1, CEP290, IMPDH1, RD3, RDH12, LRAT, TULP1, KCNJ13, GDF6 and/or PRPH2. It is contemplated herein that the ceDNA vectors and compositions and methods as described herein can be adapted for delivery of one or more of the genes associated with LCA in order to correct an error in the gene(s) responsible for the symptoms of LCA. Polyglutamine diseases include, but are not limited to: dentatorubropallidoluysian atrophy, Huntington's disease, spinal and bulbar muscular atrophy, and spinocerebellar ataxia types 1, 2, 3 (also known as Machado-Joseph disease), 6, 7, and 17. A1AT deficiency is a genetic disorder that causes defective production of alpha-1 antitrypsin, leading to decreased activity of the enzyme in the blood and lungs, which in turn can lead to emphysema or chronic obstructive pulmonary disease in affected subjects. Treatment of a subject with an A1AT deficiency is specifically contemplated herein using the ceDNA vectors or compositions thereof as outlined herein. It is contemplated herein that a ceDNA vector for controlled transgene expression comprising a nucleic acid encoding a desired protein for the treatment of LCA, polyglutamine diseases or A1AT deficiency can be admininstered to a subject in need of treatment.
In further embodiments, the compositions comprising a ceDNA vector for controlled transgene expression as described herein can be used to deliver a viral sequence, a pathogen sequence, a chromosomal sequence, a translocation junction (e.g., a translocation associated with cancer), a non-coding RNA gene or RNA sequence, a disease associated gene, among others.
Any nucleic acid or target gene of interest may be delivered or expressed by a ceDNA vector for controlled transgene expression as disclosed herein. Target nucleic acids and target genes include, but are not limited to nucleic acids encoding polypeptides, or non-coding nucleic acids (e.g., RNAi, miRs etc.) preferably therapeutic (e.g., for medical, diagnostic, or veterinary uses) or immunogenic (e.g., for vaccines) polypeptides. In certain embodiments, the target nucleic acids or target genes that are targeted by the ceDNA vectors as described herein encode one or more polypeptides, peptides, ribozymes, peptide nucleic acids, siRNAs, RNAis, antisense oligonucleotides, antisense polynucleotides, antibodies, antigen binding fragments, or any combination thereof.
In particular, a gene target or transgene for expression by the ceDNA vector for controlled transgene expression as disclosed herein can encode, for example, but is not limited to, protein(s), polypeptide(s), peptide(s), enzyme(s), antibodies, antigen binding fragments, as well as variants, and/or active fragments thereof, for use in the treatment, prophylaxis, and/or amelioration of one or more symptoms of a disease, dysfunction, injury, and/or disorder. In one aspect, the disease, dysfunction, trauma, injury and/or disorder is a human disease, dysfunction, trauma, injury, and/or disorder.
The expression cassette can also encode encode polypeptides, sense or antisense oligonucleotides, or RNAs (coding or non-coding; e.g., siRNAs, shRNAs, micro-RNAs, and their antisense counterparts (e.g., antagoMiR)). Expression cassettes can include an exogenous sequence that encodes a reporter protein to be used for experimental or diagnostic purposes, such as β-lactamase, β-galactosidase (LacZ), alkaline phosphatase, thymidine kinase, green fluorescent protein (GFP), chloramphenicol acetyltransferase (CAT), luciferase, and others well known in the art.
Sequences provided in the expression cassette, expression construct of a ceDNA vector for controlled transgene expression described herein can be codon optimized for the host cell. As used herein, the term “codon optimized” or “codon optimization” refers to the process of modifying a nucleic acid sequence for enhanced expression in the cells of the vertebrate of interest, e.g., mouse or human, by replacing at least one, more than one, or a significant number of codons of the native sequence (e.g., a prokaryotic sequence) with codons that are more frequently or most frequently used in the genes of that vertebrate. Various species exhibit particular bias for certain codons of a particular amino acid. Typically, codon optimization does not alter the amino acid sequence of the original translated protein. Optimized codons can be determined using e.g., Aptagen's Gene Forge® codon optimization and custom gene synthesis platform (Aptagen, Inc., 2190 Fox Mill Rd. Suite 300, Herndon, Va. 20171) or another publicly available database.
Many organisms display a bias for use of particular codons to code for insertion of a particular amino acid in a growing peptide chain. Codon preference or codon bias, differences in codon usage between organisms, is afforded by degeneracy of the genetic code, and is well documented among many organisms. Codon bias often correlates with the efficiency of translation of messenger RNA (mRNA), which is in turn believed to be dependent on, inter alia, the properties of the codons being translated and the availability of particular transfer RNA (tRNA) molecules. The predominance of selected tRNAs in a cell is generally a reflection of the codons used most frequently in peptide synthesis. Accordingly, genes can be tailored for optimal gene expression in a given organism based on codon optimization.
Given the large number of gene sequences available for a wide variety of animal, plant and microbial species, it is possible to calculate the relative frequencies of codon usage (Nakamura, Y., et al. “Codon usage tabulated from the international DNA sequence databases: status for the year 2000” Nucl. Acids Res. 28:292 (2000)).
As noted herein, a ceDNA vector for controlled transgene expression as disclosed herein can encode a protein or peptide, or therapeutic nucleic acid sequence or therapeutic agent, including but not limited to one or more agonists, antagonists, anti-apoptosis factors, inhibitors, receptors, cytokines, cytotoxins, erythropoietic agents, glycoproteins, growth factors, growth factor receptors, hormones, hormone receptors, interferons, interleukins, interleukin receptors, nerve growth factors, neuroactive peptides, neuroactive peptide receptors, proteases, protease inhibitors, protein decarboxylases, protein kinases, protein kinase inhibitors, enzymes, receptor binding proteins, transport proteins or one or more inhibitors thereof, serotonin receptors, or one or more uptake inhibitors thereof, serpins, serpin receptors, tumor suppressors, diagnostic molecules, chemotherapeutic agents, cytotoxins, or any combination thereof.
The ceDNA vectors are also useful for ablating gene expression. For example, in one embodiment a ceDNA vector for controlled transgene expression can be used to express an antisense nucleic acid or functional RNA to induce knockdown of a target gene. As a non-limiting example, expression of CXCR4 and CCR5, HIV receptors, have been successfully ablated in primary human T-cells, See Schumann et al. (2015), PNAS 112(33): 10437-10442, herein incorporated by reference in its entirety. Another gene for targeted inhibition is PD-1, where the ceDNA vector can express an inhibitory nucleic acid or RNAi or functional RNA to inhibit the expression of PD-1. PD-1 expresses an immune checkpoint cell surface receptor on chronically active T cells that happens in malignancy. See Schumann et al. supra.
In some embodiments, a ceDNA vectors is useful for correcting a defective gene by expressing a transgene that targets the diseased gene. Non-limiting examples of diseases or disorders amenable to treatment by a ceDNA vector as disclosed herein, are listed in Tables A-C along with their and their associated genes of US patent publication 2014/0170753, which is herein incorporated by reference in its entirety.
In alternative embodiments, the ceDNA vectors are used for insertion of an expression cassette for expression of a therapeutic protein or reporter protein in a safe harbor gene, e.g., in an inactive intron. In certain embodiments, a promoter-less cassette is inserted into the safe harbor gene. In such embodiments, a promoter-less cassette can take advantage of the safe harbor gene regulatory elements (promoters, enhancers, and signaling peptides), a non-limiting example of insertion at the safe harbor locus is insertion into to the albumin locus that is described in Blood (2015) 126 (15): 1777-1784, which is incorporated herein by reference in its entirety. Insertion into Albumin has the benefit of enabling secretion of the transgene into the blood (See e.g., Example 22). In addition, a genomic safe harbor site can be determined using techniques known in the art and described in, for example, Papapetrou, ER & Schambach, A. Molecular Therapy 24(4):678-684 (2016) or Sadelain et al. Nature Reviews Cancer 12:51-58 (2012), the contents of each of which are incorporated herein by reference in their entirety. It is specifically contemplated herein that safe harbor sites in an adeno associated virus (AAV) genome (e.g., AAVS1 safe harbor site) can be used with the methods and compositions described herein (see e.g., Oceguera-Yanez et al. Methods 101:43-55 (2016) or Tiyaboonchai, A et al. Stem Cell Res 12(3):630-7 (2014), the contents of each of which are incorporated by reference in their entirety). For example, the AAVS1 genomic safe harbor site can be used with the ceDNA vectors and compositions as described herein for the purposes of hematopoietic specific transgene expression and gene silencing in embryonic stem cells (e.g., human embryonic stem cells) or induced pluripotent stem cells (iPS cells). In addition, it is contemplated herein that synthetic or commercially available homology-directed repair donor templates for insertion into an AASV1 safe harbor site on chromosome 19 can be used with the ceDNA vectors or compositions as described herein. For example, homology-directed repair templates, and guide RNA, can be purchased commercially, for example, from System Biosciences, Palo Alto, Calif., and cloned into a ceDNA vector.
In some embodiments, the ceDNA vectors are used for expressing a transgene, or knocking out or decreasing expression of a target gene in a T cell, e.g., to engineer the T cell for improved adoptive cell transfer and/or CAR-T therapies (see, e.g., Example 24). In some embodiments, the ceDNA vector for controlled transgene expression as described herein can express transgenes that knock-out genes. Non-limiting examples of therapeutically relevant knock-outs of T cells are described in PNAS (2015) 112(33):10437-10442, which is incorporated herein by reference in its entirety.
In general, the ceDNA vector for controlled transgene expression as disclosed herein can be used to deliver any transgene in accordance with the description above to treat, prevent, or ameliorate the symptoms associated with any disorder related to gene expression. Illustrative disease states include, but are not-limited to: cystic fibrosis (and other diseases of the lung), hemophilia A, hemophilia B, thalassemia, anemia and other blood disorders, AIDS, Alzheimer's disease, Parkinson's disease, Huntington's disease, amyotrophic lateral sclerosis, epilepsy, and other neurological disorders, cancer, diabetes mellitus, muscular dystrophies (e.g., Duchenne, Becker), Hurler's disease, adenosine deaminase deficiency, metabolic defects, retinal degenerative diseases (and other diseases of the eye), mitochondriopathies (e.g., Leber's hereditary optic neuropathy (LHON), Leigh syndrome, and subacute sclerosing encephalopathy), myopathies (e.g., facioscapulohumeral myopathy (FSHD) and cardiomyopathies), diseases of solid organs (e.g., brain, liver, kidney, heart), and the like. In some embodiments, the ceDNA vectors as disclosed herein can be advantageously used in the treatment of individuals with metabolic disorders (e.g., ornithine transcarbamylase deficiency).
In some embodiments, the ceDNA vector for controlled transgene expression described herein can be used to treat, ameliorate, and/or prevent a disease or disorder caused by mutation in a gene or gene product. Exemplary diseases or disorders that can be treated with a ceDNA vectors include, but are not limited to, metabolic diseases or disorders (e.g., Fabry disease, Gaucher disease, phenylketonuria (PKU), glycogen storage disease); urea cycle diseases or disorders (e.g., ornithine transcarbamylase (OTC) deficiency); lysosomal storage diseases or disorders (e.g., metachromatic leukodystrophy (MLD), mucopolysaccharidosis Type II (MPSII; Hunter syndrome)); liver diseases or disorders (e.g., progressive familial intrahepatic cholestasis (PFIC); blood diseases or disorders (e.g., hemophilia (A and B), thalassemia, and anemia); cancers and tumors, and genetic diseases or disorders (e.g., cystic fibrosis).
As still a further aspect, a ceDNA vector for controlled transgene expression as disclosed herein may be employed to deliver a heterologous nucleotide sequence in situations in which it is desirable to regulate the level of transgene expression (e.g., transgenes encoding hormones or growth factors, as described herein).
Accordingly, in some embodiments, the ceDNA vector for controlled transgene expression described herein can be used to correct an abnormal level and/or function of a gene product (e.g., an absence of, or a defect in, a protein) that results in the disease or disorder. The ceDNA vector can produce a functional protein and/or modify levels of the protein to alleviate or reduce symptoms resulting from, or confer benefit to, a particular disease or disorder caused by the absence or a defect in the protein. For example, treatment of OTC deficiency can be achieved by producing functional OTC enzyme; treatment of hemophilia A and B can be achieved by modifying levels of Factor VIII, Factor IX, and Factor X; treatment of PKU can be achieved by modifying levels of phenylalanine hydroxylase enzyme; treatment of Fabry or Gaucher disease can be achieved by producing functional alpha galactosidase or beta glucocerebrosidase, respectively; treatment of MLD or MPSII can be achieved by producing functional arylsulfatase A or iduronate-2-sulfatase, respectively; treatment of cystic fibrosis can be achieved by producing functional cystic fibrosis transmembrane conductance regulator; treatment of glycogen storage disease can be achieved by restoring functional G6Pase enzyme function; and treatment of PFIC can be achieved by producing functional ATP8B1, ABCB11, ABCB4, or TJP2 genes.
In alternative embodiments, the ceDNA vectors as disclosed herein can be used to provide an antisense nucleic acid to a cell in vitro or in vivo. For example, where the transgene is a RNAi molecule, expression of the antisense nucleic acid or RNAi in the target cell diminishes expression of a particular protein by the cell. Accordingly, transgenes which are RNAi molecules or antisense nucleic acids may be administered to decrease expression of a particular protein in a subject in need thereof. Antisense nucleic acids may also be administered to cells in vitro to regulate cell physiology, e.g., to optimize cell or tissue culture systems.
In some embodiments, exemplary transgenes encoded by the ceDNA vector for controlled transgene expression include, but are not limited to: X, lysosomal enzymes (e.g., hexosaminidase A, associated with Tay-Sachs disease, or iduronate sulfatase, associated, with Hunter Syndrome/MPS II), erythropoietin, angiostatin, endostatin, superoxide dismutase, globin, leptin, catalase, tyrosine hydroxylase, as well as cytokines (e.g., a interferon, β-interferon, interferon-γ, interleukin-2, interleukin-4, interleukin 12, granulocyte-macrophage colony stimulating factor, lymphotoxin, and the like), peptide growth factors and hormones (e.g., somatotropin, insulin, insulin-like growth factors 1 and 2, platelet derived growth factor (PDGF), epidermal growth factor (EGF), fibroblast growth factor (FGF), nerve growth factor (NGF), neurotrophic factor-3 and 4, brain-derived neurotrophic factor (BDNF), glial derived growth factor (GDNF), transforming growth factor-α and -β, and the like), receptors (e.g., tumor necrosis factor receptor).
In some exemplary embodiments, the transgene encodes a monoclonal antibody specific for one or more desired targets. Exemplary ceDNA vectors for controlled expression of antibodies and fusion proteins in the methods as disclosed herein are disclosed in International Application PCT/US19/18016, filed on Feb. 14, 2019, which is incorporated herein in its entirety by reference.
In some exemplary embodiments, more than one transgene is encoded by the ceDNA vector. In some exemplary embodiments, the transgene encodes a fusion protein comprising two different polypeptides of interest. In some embodiments, the transgene encodes an antibody, including a full-length antibody or antibody fragment, as defined herein. In some embodiments, the antibody is an antigen-binding domain or an immunoglobulin variable domain sequence, as that is defined herein. Other illustrative transgene sequences encode suicide gene products (thymidine kinase, cytosine deaminase, diphtheria toxin, cytochrome P450, deoxycytidine kinase, and tumor necrosis factor), proteins conferring resistance to a drug used in cancer therapy, and tumor suppressor gene products.
In a representative embodiment, the transgene expressed by the ceDNA vector for controlled transgene expression can be used for the treatment of muscular dystrophy in a subject in need thereof, the method comprising: administering a treatment-, amelioration- or prevention-effective amount of ceDNA vector described herein, wherein the ceDNA vector comprises a heterologous nucleic acid encoding dystrophin, a mini-dystrophin, a micro-dystrophin, myostatin propeptide, follistatin, activin type II soluble receptor, IGF-1, anti-inflammatory polypeptides such as the Ikappa B dominant mutant, sarcospan, utrophin, a micro-dystrophin, laminin-α2, α-sarcoglycan, β-sarcoglycan, γ-sarcoglycan, δ-sarcoglycan, IGF-1, an antibody or antibody fragment against myostatin or myostatin propeptide, and/or RNAi against myostatin. In particular embodiments, the ceDNA vector can be administered to skeletal, diaphragm and/or cardiac muscle as described elsewhere herein.
In some embodiments, the ceDNA vector for controlled transgene expression can be used to deliver a transgene to skeletal, cardiac or diaphragm muscle, for production of a polypeptide (e.g., an enzyme) or functional RNA (e.g., RNAi, microRNA, antisense RNA) that normally circulates in the blood or for systemic delivery to other tissues to treat, ameliorate, and/or prevent a disorder (e.g., a metabolic disorder, such as diabetes (e.g., insulin), hemophilia (e.g., VIII), a mucopolysaccharide disorder (e.g., Sly syndrome, Hurler Syndrome, Scheie Syndrome, Hurler-Scheie Syndrome, Hunter's Syndrome, Sanfilippo Syndrome A, B, C, D, Morquio Syndrome, Maroteaux-Lamy Syndrome, etc.) or a lysosomal storage disorder (such as Gaucher's disease [glucocerebrosidase], Pompe disease [lysosomal acid .alpha.-glucosidase] or Fabry disease [alpha.-galactosidase A]) or a glycogen storage disorder (such as Pompe disease [lysosomal acid a glucosidase]). Other suitable proteins for treating, ameliorating, and/or preventing metabolic disorders are described above.
In other embodiments, the ceDNA vector for controlled transgene expression as disclosed herein can be used to deliver a transgene in a method of treating, ameliorating, and/or preventing a metabolic disorder in a subject in need thereof. Illustrative metabolic disorders and transgenes encoding polypeptides are described herein. Optionally, the polypeptide is secreted (e.g., a polypeptide that is a secreted polypeptide in its native state or that has been engineered to be secreted, for example, by operable association with a secretory signal sequence as is known in the art).
Another aspect of the invention relates to a method of treating, ameliorating, and/or preventing congenital heart failure or PAD in a subject in need thereof, the method comprising administering a ceDNA vector for controlled transgene expression as described herein to a mammalian subject, wherein the ceDNA vector comprises a transgene encoding, for example, a sarcoplasmic endoreticulum Ca2+-ATPase (SERCA2a), an angiogenic factor, phosphatase inhibitor I (I-1), RNAi against phospholamban; a phospholamban inhibitory or dominant-negative molecule such as phospholamban S16E, a zinc finger protein that regulates the phospholamban gene, β2-adrenergic receptor, .beta.2-adrenergic receptor kinase (BARK), PI3 kinase, calsarcan, a .beta.-adrenergic receptor kinase inhibitor (βARKct), inhibitor 1 of protein phosphatase 1, S100A1, parvalbumin, adenylyl cyclase type 6, a molecule that effects G-protein coupled receptor kinase type 2 knockdown such as a truncated constitutively active βARKct, Pim-1, PGC-1α, SOD-1, SOD-2, EC-SOD, kallikrein, HIF, thymosin-β4, mir-1, mir-133, mir-206 and/or mir-208.
The ceDNA vectors as disclosed herein can be administered to the lungs of a subject by any suitable means, optionally by administering an aerosol suspension of respirable particles comprising the ceDNA vectors, which the subject inhales. The respirable particles can be liquid or solid. Aerosols of liquid particles comprising the ceDNA vectors may be produced by any suitable means, such as with a pressure-driven aerosol nebulizer or an ultrasonic nebulizer, as is known to those of skill in the art. See, e.g., U.S. Pat. No. 4,501,729. Aerosols of solid particles comprising the ceDNA vectors may likewise be produced with any solid particulate medicament aerosol generator, by techniques known in the pharmaceutical art.
In some embodiments, the ceDNA vectors can be administered to tissues of the CNS (e.g., brain, eye). In particular embodiments, the ceDNA vectors as disclosed herein may be administered to treat, ameliorate, or prevent diseases of the CNS, including genetic disorders, neurodegenerative disorders, psychiatric disorders and tumors. Illustrative diseases of the CNS include, but are not limited to Alzheimer's disease, Parkinson's disease, Huntington's disease, Canavan disease, Leigh's disease, Refsum disease, Tourette syndrome, primary lateral sclerosis, amyotrophic lateral sclerosis, progressive muscular atrophy, Pick's disease, muscular dystrophy, multiple sclerosis, myasthenia gravis, Binswanger's disease, trauma due to spinal cord or head injury, Tay Sachs disease, Lesch-Nyan disease, epilepsy, cerebral infarcts, psychiatric disorders including mood disorders (e.g., depression, bipolar affective disorder, persistent affective disorder, secondary mood disorder), schizophrenia, drug dependency (e.g., alcoholism and other substance dependencies), neuroses (e.g., anxiety, obsessional disorder, somatoform disorder, dissociative disorder, grief, post-partum depression), psychosis (e.g., hallucinations and delusions), dementia, paranoia, attention deficit disorder, psychosexual disorders, sleeping disorders, pain disorders, eating or weight disorders (e.g., obesity, cachexia, anorexia nervosa, and bulemia) and cancers and tumors (e.g., pituitary tumors) of the CNS.
Ocular disorders that may be treated, ameliorated, or prevented with the ceDNA vectors of the invention include ophthalmic disorders involving the retina, posterior tract, and optic nerve (e.g., retinitis pigmentosa, diabetic retinopathy and other retinal degenerative diseases, uveitis, age-related macular degeneration, glaucoma). Many ophthalmic diseases and disorders are associated with one or more of three types of indications: (1) angiogenesis, (2) inflammation, and (3) degeneration. In some embodiments, the ceDNA vector for controlled transgene expression as disclosed herein can be employed to deliver anti-angiogenic factors; anti-inflammatory factors; factors that retard cell degeneration, promote cell sparing, or promote cell growth and combinations of the foregoing. Diabetic retinopathy, for example, is characterized by angiogenesis. Diabetic retinopathy can be treated by delivering one or more anti-angiogenic factors either intraocularly (e.g., in the vitreous) or periocularly (e.g., in the sub-Tenon's region). One or more neurotrophic factors may also be co-delivered, either intraocularly (e.g., intravitreally) or periocularly. Additional ocular diseases that may be treated, ameliorated, or prevented with the ceDNA vectors of the invention include geographic atrophy, vascular or “wet” macular degeneration, Stargardt disease, Leber Congenital Amaurosis (LCA), Usher syndrome, pseudoxanthoma elasticum (PXE), x-linked retinitis pigmentosa (XLRP), x-linked retinoschisis (XLRS), Choroideremia, Leber hereditary optic neuropathy (LHON), Archomatopsia, cone-rod dystrophy, Fuchs endothelial corneal dystrophy, diabetic macular edema and ocular cancer and tumors.
In some embodiments, inflammatory ocular diseases or disorders (e.g., uveitis) can be treated, ameliorated, or prevented by the ceDNA vectors of the invention. One or more anti-inflammatory factors can be expressed by intraocular (e.g., vitreous or anterior chamber) administration of the ceDNA vector for controlled transgene expression as disclosed herein. In other embodiments, ocular diseases or disorders characterized by retinal degeneration (e.g., retinitis pigmentosa) can be treated, ameliorated, or prevented by the ceDNA vectors of the invention. intraocular (e.g., vitreal administration) of the ceDNA vector as disclosed herein encoding one or more neurotrophic factors can be used to treat such retinal degeneration-based diseases. In some embodiments, diseases or disorders that involve both angiogenesis and retinal degeneration (e.g., age-related macular degeneration) can be treated with the ceDNA vectors of the invention. Age-related macular degeneration can be treated by administering the ceDNA vector as disclosed herein encoding one or more neurotrophic factors intraocularly (e.g., vitreous) and/or one or more anti-angiogenic factors intraocularly or periocularly (e.g., in the sub-Tenon's region). Glaucoma is characterized by increased ocular pressure and loss of retinal ganglion cells. Treatments for glaucoma include administration of one or more neuroprotective agents that protect cells from excitotoxic damage using the ceDNA vector as disclosed herein. Accordingly, such agents include N-methyl-D-aspartate (NMDA) antagonists, cytokines, and neurotrophic factors, can be delivered intraocularly, optionally intravitreally using the ceDNA vector as disclosed herein.
In other embodiments, the ceDNA vector for controlled transgene expression as disclosed herein may be used to treat seizures, e.g., to reduce the onset, incidence or severity of seizures. The efficacy of a therapeutic treatment for seizures can be assessed by behavioral (e.g., shaking, ticks of the eye or mouth) and/or electrographic means (most seizures have signature electrographic abnormalities). Thus, the ceDNA vector for controlled transgene expression as disclosed herein can also be used to treat epilepsy, which is marked by multiple seizures over time. In one representative embodiment, somatostatin (or an active fragment thereof) is administered to the brain using the ceDNA vector as disclosed herein to treat a pituitary tumor. According to this embodiment, the ceDNA vector as disclosed herein encoding somatostatin (or an active fragment thereof) is administered by microinfusion into the pituitary. Likewise, such treatment can be used to treat acromegaly (abnormal growth hormone secretion from the pituitary). The nucleic acid (e.g., GenBank Accession No. J00306) and amino acid (e.g., GenBank Accession No. P01166; contains processed active peptides somatostatin-28 and somatostatin-14) sequences of somatostatins as are known in the art. In particular embodiments, the ceDNA vector can encode a transgene that comprises a secretory signal as described in U.S. Pat. No. 7,071,172.
Another aspect of the invention relates to the use of a ceDNA vector for controlled transgene expression as described herein to produce antisense RNA, RNAi or other functional RNA (e.g., a ribozyme) for systemic delivery to a subject in vivo. Accordingly, in some embodiments, the ceDNA vector can comprise a transgene that encodes an antisense nucleic acid, a ribozyme (e.g., as described in U.S. Pat. No. 5,877,022), RNAs that affect spliceosome-mediated trans-splicing (see, Puttaraju et al., (1999) Nature Biotech. 17:246; U.S. Pat. Nos. 6,013,487; 6,083,702), interfering RNAs (RNAi) that mediate gene silencing (see, Sharp et al., (2000) Science 287:2431) or other non-translated RNAs, such as “guide” RNAs (Gorman et al., (1998) Proc. Nat. Acad. Sci. USA 95:4929; U.S. Pat. No. 5,869,248 to Yuan et al.), and the like.
In some embodiments, the ceDNA vector for controlled transgene expression can further also comprise a transgene that encodes a reporter polypeptide (e.g., an enzyme such as Green Fluorescent Protein, or alkaline phosphatase). In some embodiments, a transgene that encodes a reporter protein useful for experimental or diagnostic purposes, is selected from any of: β-lactamase, β-galactosidase (LacZ), alkaline phosphatase, thymidine kinase, green fluorescent protein (GFP), chloramphenicol acetyltransferase (CAT), luciferase, and others well known in the art. In some aspects, ceDNA vectors comprising a transgene encoding a reporter polypeptide may be used for diagnostic purposes or as markers of the ceDNA vector's activity in the subject to which they are administered.
In some embodiments, the ceDNA vector for controlled transgene expression can comprise a transgene or a heterologous nucleotide sequence that shares homology with, and recombines with a locus on the host chromosome. This approach may be utilized to correct a genetic defect in the host cell.
In some embodiments, the ceDNA vector for controlled transgene expression can comprise a transgene that can be used to express an immunogenic polypeptide in a subject, e.g., for vaccination. The transgene may encode any immunogen of interest known in the art including, but not limited to, immunogens from human immunodeficiency virus, influenza virus, gag proteins, tumor antigens, cancer antigens, bacterial antigens, viral antigens, and the like.
D. Testing for Successful Gene Expression Using a ceDNA Vector
Assays well known in the art can be used to test the efficiency of gene delivery by a ceDNA vector can be performed in both in vitro and in vivo models. Knock-in or knock-out of a desired transgene by ceDNA can be assessed by one skilled in the art by measuring mRNA and protein levels of the desired transgene (e.g., reverse transcription PCR, western blot analysis, and enzyme-linked immunosorbent assay (ELISA)). Nucleic acid alterations by ceDNA (e.g., point mutations, or deletion of DNA regions) can be assessed by deep sequencing of genomic target DNA. In one embodiment, ceDNA comprises a reporter protein that can be used to assess the expression of the desired transgene, for example by examining the expression of the reporter protein by fluorescence microscopy or a luminescence plate reader. For in vivo applications, protein function assays can be used to test the functionality of a given gene and/or gene product to determine if gene expression has successfully occurred. For example, it is envisioned that a point mutation in the cystic fibrosis transmembrane conductance regulator gene (CFTR) inhibits the capacity of CFTR to move anions (e.g., Cl) through the anion channel, can be corrected by delivering a functional (i.e., non-mutated) CFTR gene to the subject with a ceDNA vector. Following administration of a ceDNA vector, one skilled in the art can assess the capacity for anions to move through the anion channel to determine if the CFTR gene has been delivered and expressed. One skilled will be able to determine the best test for measuring functionality of a protein in vitro or in vivo.
It is contemplated herein that the effects of gene expression of the transgene from the ceDNA vector in a cell or subject can last for at least 1 month, at least 2 months, at least 3 months, at least four months, at least 5 months, at least six months, at least 10 months, at least 12 months, at least 18 months, at least 2 years, at least 5 years, at least 10 years, at least 20 years, or can be permanent.
In some embodiments, a transgene in the expression cassette, expression construct, or ceDNA vector described herein can be codon optimized for the host cell. As used herein, the term “codon optimized” or “codon optimization” refers to the process of modifying a nucleic acid sequence for enhanced expression in the cells of the vertebrate of interest, e.g., mouse or human (e.g., humanized), by replacing at least one, more than one, or a significant number of codons of the native sequence (e.g., a prokaryotic sequence) with codons that are more frequently or most frequently used in the genes of that vertebrate. Various species exhibit particular bias for certain codons of a particular amino acid. Typically, codon optimization does not alter the amino acid sequence of the original translated protein. Optimized codons can be determined using e.g., Aptagen's Gene Forge® codon optimization and custom gene synthesis platform (Aptagen, Inc.) or another publicly available database.
XII. Administration
Exemplary modes of administration of the ceDNA vector for controlled transgene expression disclosed herein includes oral, rectal, transmucosal, intranasal, inhalation (e.g., via an aerosol), buccal (e.g., sublingual), vaginal, intrathecal, intraocular, transdermal, intraendothelial, in utero (or in ovo), parenteral (e.g., intravenous, subcutaneous, intradermal, intracranial, intramuscular [including administration to skeletal, diaphragm and/or cardiac muscle], intrapleural, intracerebral, and intraarticular), topical (e.g., to both skin and mucosal surfaces, including airway surfaces, and transdermal administration), intralymphatic, and the like, as well as direct tissue or organ injection (e.g., to liver, eye, skeletal muscle, cardiac muscle, diaphragm muscle or brain).
Administration of the ceDNA vector for controlled transgene expression can be to any site in a subject, including, without limitation, a site selected from the group consisting of the brain, a skeletal muscle, a smooth muscle, the heart, the diaphragm, the airway epithelium, the liver, the kidney, the spleen, the pancreas, the skin, and the eye. Administration of the ceDNA vector for controlled transgene expression can also be to a tumor (e.g., in or near a tumor or a lymph node). The most suitable route in any given case will depend on the nature and severity of the condition being treated, ameliorated, and/or prevented and on the nature of the particular ceDNA vector that is being used. Additionally, ceDNA permits one to administer more than one transgene in a single vector, or multiple ceDNA vectors (e.g. a ceDNA cocktail).
Administration of the ceDNA vector for controlled transgene expression disclosed herein to skeletal muscle according to the present invention includes but is not limited to administration to skeletal muscle in the limbs (e.g., upper arm, lower arm, upper leg, and/or lower leg), back, neck, head (e.g., tongue), thorax, abdomen, pelvis/perineum, and/or digits. The ceDNA as disclosed herein vector can be delivered to skeletal muscle by intravenous administration, intra-arterial administration, intraperitoneal administration, limb perfusion, (optionally, isolated limb perfusion of a leg and/or arm; see, e.g. Arruda et al., (2005) Blood 105: 3458-3464), and/or direct intramuscular injection. In particular embodiments, the ceDNA vector as disclosed herein is administered to a limb (arm and/or leg) of a subject (e.g., a subject with muscular dystrophy such as DMD) by limb perfusion, optionally isolated limb perfusion (e.g., by intravenous or intra-articular administration. In certain embodiments, the ceDNA vector for controlled transgene expression as disclosed herein can be administered without employing “hydrodynamic” techniques.
Administration of the ceDNA vector for controlled transgene expression as disclosed herein to cardiac muscle includes administration to the left atrium, right atrium, left ventricle, right ventricle and/or septum. The ceDNA vector as described herein can be delivered to cardiac muscle by intravenous administration, intra-arterial administration such as intra-aortic administration, direct cardiac injection (e.g., into left atrium, right atrium, left ventricle, right ventricle), and/or coronary artery perfusion. Administration to diaphragm muscle can be by any suitable method including intravenous administration, intra-arterial administration, and/or intra-peritoneal administration. Administration to smooth muscle can be by any suitable method including intravenous administration, intra-arterial administration, and/or intra-peritoneal administration. In one embodiment, administration can be to endothelial cells present in, near, and/or on smooth muscle.
In some embodiments, a ceDNA vector for controlled transgene expression according to the present invention is administered to skeletal muscle, diaphragm muscle and/or cardiac muscle (e.g., to treat, ameliorate and/or prevent muscular dystrophy or heart disease (e.g., PAD or congestive heart failure).
In some embodiments, cells are removed from a subject, a ceDNA vector is introduced therein, and the cells are then replaced back into the subject. Methods of removing cells from subject for treatment ex vivo, followed by introduction back into the subject are known in the art (see, e.g., U.S. Pat. No. 5,399,346; the disclosure of which is incorporated herein in its entirety). Alternatively, a ceDNA vector is introduced into cells from another subject, into cultured cells, or into cells from any other suitable source, and the cells are administered to a subject in need thereof.
Cells transduced with a ceDNA vector are preferably administered to the subject in a “therapeutically-effective amount” in combination with a pharmaceutical carrier. Those skilled in the art will appreciate that the therapeutic effects need not be complete or curative, as long as some benefit is provided to the subject.
In some embodiments, the ceDNA vector for controlled transgene expression can encode a transgene (sometimes called a heterologous nucleotide sequence) that is any polypeptide that is desirably produced in a cell in vitro, ex vivo, or in vivo. For example, in contrast to the use of the ceDNA vectors in a method of treatment as discussed herein, in some embodiments the ceDNA vectors may be introduced into cultured cells and the expressed gene product isolated therefrom, e.g., for the production of antigens or vaccines.
The ceDNA vectors can be used in both veterinary and medical applications. Suitable subjects for ex vivo gene delivery methods as described above include both avians (e.g., chickens, ducks, geese, quail, turkeys and pheasants) and mammals (e.g., humans, bovines, ovines, caprines, equines, felines, canines, and lagomorphs), with mammals being preferred. Human subjects are most preferred. Human subjects include neonates, infants, juveniles, and adults.
One aspect of the technology described herein relates to a method of delivering a transgene to a cell. Typically, for in vitro methods, the ceDNA vector for controlled transgene expression may be introduced into the cell using the methods as disclosed herein, as well as other methods known in the art. ceDNA vectors disclosed herein are preferably administered to the cell in a biologically-effective amount. If the ceDNA vector is administered to a cell in vivo (e.g., to a subject), a biologically-effective amount of the ceDNA vector is an amount that is sufficient to result in transduction and expression of the transgene in a target cell.
In some embodiments, the pharmaceutical compositions can conveniently be presented in unit dosage form. A unit dosage form will typically be adapted to one or more specific routes of administration of the pharmaceutical composition. In some embodiments, the unit dosage form is adapted for administration by inhalation. In some embodiments, the unit dosage form is adapted for administration by a vaporizer. In some embodiments, the unit dosage form is adapted for administration by a nebulizer. In some embodiments, the unit dosage form is adapted for administration by an aerosolizer. In some embodiments, the unit dosage form is adapted for oral administration, for buccal administration, or for sublingual administration. In some embodiments, the unit dosage form is adapted for intravenous, intramuscular, or subcutaneous administration. In some embodiments, the unit dosage form is adapted for intrathecal or intracerebroventricular administration. In some embodiments, the pharmaceutical composition is formulated for topical administration. The amount of active ingredient which can be combined with a carrier material to produce a single dosage form will generally be that amount of the compound which produces a therapeutic effect.
XIII. Various Applications
The compositions and ceDNA vectors provided herein can be used to deliver a transgene for various purposes as described above. In some embodiments, a transgene can encode a protein or be a functional RNA, and in some embodiments, can be a protein or functional RNA that is modified for research purposes, e.g., to create a somatic transgenic animal model harboring one or more mutations or a corrected gene sequence, e.g., to study the function of the target gene. In another example, the transgene encodes a protein or functional RNA to create an animal model of disease.
In some embodiments, the transgene encodes one or more peptides, polypeptides, or proteins, which are useful for the treatment, amelioration, or prevention of disease states in a mammalian subject. The transgene expressed by the ceDNA vector for controlled transgene expression is administered to a patient in a sufficient amount to treat a disease associated with an abnormal gene sequence, which can result in any one or more of the following: reduced expression, lack of expression or dysfunction of the target gene.
In some embodiments, the ceDNA vectors are envisioned for use in diagnostic and screening methods, whereby a transgene is transiently or stably expressed in a cell culture system, or alternatively, a transgenic animal model.
Another aspect of the technology described herein provides a method of transducing a population of mammalian cells. In an overall and general sense, the method includes at least the step of introducing into one or more cells of the population, a composition that comprises an effective amount of one or more of the ceDNA disclosed herein.
Additionally, the present invention provides compositions, as well as therapeutic and/or diagnostic kits that include one or more of the disclosed ceDNA vectors or ceDNA compositions, formulated with one or more additional ingredients, or prepared with one or more instructions for their use.
A cell to be administered the ceDNA vector for controlled transgene expression as disclosed herein may be of any type, including but not limited to neural cells (including cells of the peripheral and central nervous systems, in particular, brain cells), lung cells, retinal cells, epithelial cells (e.g., gut and respiratory epithelial cells), muscle cells, dendritic cells, pancreatic cells (including islet cells), hepatic cells, myocardial cells, bone cells (e.g., bone marrow stem cells), hematopoietic stem cells, spleen cells, keratinocytes, fibroblasts, endothelial cells, prostate cells, germ cells, and the like. Alternatively, the cell may be any progenitor cell. As a further alternative, the cell can be a stem cell (e.g., neural stem cell, liver stem cell). As still a further alternative, the cell may be a cancer or tumor cell. Moreover, the cells can be from any species of origin, as indicated above.
Some Embodiments of the Technology Described Herein can be Defined According to any of the Following Numbered Paragraphs:
c. incubating a population of insect cells harboring the vector polynucleotide, which is devoid of viral capsid coding sequences in the presence of Rep protein under conditions effective and for time sufficient to induce production of the capsid-free, non-viral DNA vector within the insect cells, wherein the insect cells do not comprise production capsid-free, non-viral DNA within the insect cells; and
The following examples are provided by way of illustration not limitation. It will be appreciated by one of ordinary skill in the art that ceDNA vectors can be constructed from any of the wild-type or modified ITRs described herein, and that the following exemplary methods can be used to construct and assess the activity of such ceDNA vectors. While the methods are exemplified with certain ceDNA vectors, they are applicable to any ceDNA vector in keeping with the description.
Production of the ceDNA vectors using a polynucleotide construct template is described in Example 1 of PCT/US18/49996, which is incorporated herein in its entirety by reference. For example, a polynucleotide construct template used for generating the ceDNA vectors of the present invention can be a ceDNA-plasmid, a ceDNA-Bacmid, and/or a ceDNA-baculovirus. Without being limited to theory, in a permissive host cell, in the presence of e.g., Rep, the polynucleotide construct template having two symmetric ITRs and an expression construct, where at least one of the ITRs is modified relative to a wild-type ITR sequence, replicates to produce ceDNA vectors. ceDNA vector production undergoes two steps: first, excision (“rescue”) of template from the template backbone (e.g. ceDNA-plasmid, ceDNA-bacmid, ceDNA-baculovirus genome etc.) via Rep proteins, and second, Rep mediated replication of the excised ceDNA vector.
An exemplary method to produce ceDNA vectors is from a ceDNA-plasmid as described herein. Referring to
Production of ceDNA-Bacmids:
DH10Bac competent cells (MAX EFFICIENCY® DH10Bac™ Competent Cells, Thermo Fisher) were transformed with either test or control plasmids following a protocol according to the manufacturer's instructions. Recombination between the plasmid and a baculovirus shuttle vector in the DH10Bac cells were induced to generate recombinant ceDNA-bacmids. The recombinant bacmids were selected by screening a positive selection based on blue-white screening in E. coli (Φ80dlacZΔM15 marker provides α-complementation of the β-galactosidase gene from the bacmid vector) on a bacterial agar plate containing X-gal and IPTG with antibiotics to select for transformants and maintenance of the bacmid and transposase plasmids. White colonies caused by transposition that disrupts the β-galactoside indicator gene were picked and cultured in 10 ml of media.
The recombinant ceDNA-bacmids were isolated from the E. coli and transfected into Sf9 or Sf21 insect cells using FugeneHD to produce infectious baculovirus. The adherent Sf9 or Sf21 insect cells were cultured in 50 ml of media in T25 flasks at 25° C. Four days later, culture medium (containing the P0 virus) was removed from the cells, filtered through a 0.45 μm filter, separating the infectious baculovirus particles from cells or cell debris.
Optionally, the first generation of the baculovirus (P0) was amplified by infecting naïve Sf9 or Sf21 insect cells in 50 to 500 ml of media. Cells were maintained in suspension cultures in an orbital shaker incubator at 130 rpm at 25° C., monitoring cell diameter and viability, until cells reach a diameter of 18-19 nm (from a naïve diameter of 14-15 nm), and a density of ˜4.0E+6 cells/mL. Between 3 and 8 days post-infection, the P1 baculovirus particles in the medium were collected following centrifugation to remove cells and debris then filtration through a 0.45 μm filter.
The ceDNA-baculovirus comprising the test constructs were collected and the infectious activity, or titer, of the baculovirus was determined. Specifically, four×20 ml Sf9 cell cultures at 2.5E+6 cells/ml were treated with P1 baculovirus at the following dilutions: 1/1000, 1/10,000, 1/50,000, 1/100,000, and incubated at 25-27° C. Infectivity was determined by the rate of cell diameter increase and cell cycle arrest, and change in cell viability every day for 4 to 5 days.
A “Rep-plasmid” was produced in a pFASTBAC™-Dual expression vector (ThermoFisher) comprising both the Rep78 (SEQ ID NO: 131 or 133) or Rep68 (SEQ ID NO: 130) and Rep52 (SEQ ID NO: 132) or Rep40 (SEQ ID NO: 129). The Rep-plasmid was transformed into the DH10Bac competent cells (MAX EFFICIENCY® DH10Bac™ Competent Cells (Thermo Fisher) following a protocol provided by the manufacturer. Recombination between the Rep-plasmid and a baculovirus shuttle vector in the DH10Bac cells were induced to generate recombinant bacmids (“Rep-bacmids”). The recombinant bacmids were selected by a positive selection that included-blue-white screening in E. coli (Φ80dlacZΔM15 marker provides α-complementation of the β-galactosidase gene from the bacmid vector) on a bacterial agar plate containing X-gal and IPTG. Isolated white colonies were picked and inoculated in 10 ml of selection media (kanamycin, gentamicin, tetracycline in LB broth). The recombinant bacmids (Rep-bacmids) were isolated from the E. coli and the Rep-bacmids were transfected into Sf9 or Sf21 insect cells to produce infectious baculovirus.
The Sf9 or Sf21 insect cells were cultured in 50 ml of media for 4 days, and infectious recombinant baculovirus (“Rep-baculovirus”) were isolated from the culture. Optionally, the first generation Rep-baculovirus (P0) were amplified by infecting naïve Sf9 or Sf21 insect cells and cultured in 50 to 500 ml of media. Between 3 and 8 days post-infection, the P1 baculovirus particles in the medium were collected either by separating cells by centrifugation or filtration or another fractionation process. The Rep-baculovirus were collected and the infectious activity of the baculovirus was determined. Specifically, four×20 mL Sf9 cell cultures at 2.5×106 cells/mL were treated with P1 baculovirus at the following dilutions, 1/1000, 1/10,000, 1/50,000, 1/100,000, and incubated. Infectivity was determined by the rate of cell diameter increase and cell cycle arrest, and change in cell viability every day for 4 to 5 days.
ceDNA Vector Generation and Characterization
With reference to
Yields of ceDNA vectors produced and purified from the Sf9 insect cells were initially determined based on UV absorbance at 260 nm.
ceDNA vectors can be assessed by identified by agarose gel electrophoresis under native or denaturing conditions as illustrated in
Structures of the isolated ceDNA vectors were further analyzed by digesting the DNA obtained from co-infected Sf9 cells (as described herein) with restriction endonucleases selected for a) the presence of only a single cut site within the ceDNA vectors, and b) resulting fragments that were large enough to be seen clearly when fractionated on a 0.8% denaturing agarose gel (>800 bp). As illustrated in
Therefore, to demonstrate in a qualitative fashion that isolated ceDNA vectors are covalently closed-ended as is required by definition, the samples were digested with a restriction endonuclease identified in the context of the specific DNA vector sequence as having a single restriction site, preferably resulting in two cleavage products of unequal size (e.g., 1000 bp and 2000 bp). Following digestion and electrophoresis on a denaturing gel (which separates the two complementary DNA strands), a linear, non-covalently closed DNA will resolve at sizes 1000 bp and 2000 bp, while a covalently closed DNA (i.e., a ceDNA vector) will resolve at 2× sizes (2000 bp and 4000 bp), as the two DNA strands are linked and are now unfolded and twice the length (though single stranded). Furthermore, digestion of monomeric, dimeric, and n-meric forms of the DNA vectors will all resolve as the same size fragments due to the end-to-end linking of the multimeric DNA vectors (see
As used herein, the phrase “assay for the Identification of DNA vectors by agarose gel electrophoresis under native gel and denaturing conditions” refers to an assay to assess the close-endedness of the ceDNA by performing restriction endonuclease digestion followed by electrophoretic assessment of the digest products. One such exemplary assay follows, though one of ordinary skill in the art will appreciate that many art-known variations on this example are possible. The restriction endonuclease is selected to be a single cut enzyme for the ceDNA vector of interest that will generate products of approximately ⅓× and ⅔× of the DNA vector length. This resolves the bands on both native and denaturing gels. Before denaturation, it is important to remove the buffer from the sample. The Qiagen PCR clean-up kit or desalting “spin columns,” e.g. GE HEALTHCARE ILUSTRA™ MICROSPIN™ G-25 columns are some art-known options for the endonuclease digestion. The assay includes for example, i) digest DNA with appropriate restriction endonuclease(s), 2) apply to e.g., a Qiagen PCR clean-up kit, elute with distilled water, iii) adding 10× denaturing solution (10×=0.5 M NaOH, 10 mM EDTA), add 10× dye, not buffered, and analyzing, together with DNA ladders prepared by adding 10× denaturing solution to 4×, on a 0.8-1.0% gel previously incubated with 1 mM EDTA and 200 mM NaOH to ensure that the NaOH concentration is uniform in the gel and gel box, and running the gel in the presence of 1× denaturing solution (50 mM NaOH, 1 mM EDTA). One of ordinary skill in the art will appreciate what voltage to use to run the electrophoresis based on size and desired timing of results. After electrophoresis, the gels are drained and neutralized in 1×TBE or TAE and transferred to distilled water or 1×TBE/TAE with 1×SYBR Gold. Bands can then be visualized with e.g. Thermo Fisher, SYBR® Gold Nucleic Acid Gel Stain (10,000× Concentrate in DMSO) and epifluorescent light (blue) or UV (312 nm).
The purity of the generated ceDNA vector can be assessed using any art-known method. As one exemplary and non-limiting method, contribution of ceDNA-plasmid to the overall UV absorbance of a sample can be estimated by comparing the fluorescent intensity of ceDNA vector to a standard. For example, if based on UV absorbance 4 μg of ceDNA vector was loaded on the gel, and the ceDNA vector fluorescent intensity is equivalent to a 2 kb band which is known to be 1 μg, then there is 1 μg of ceDNA vector, and the ceDNA vector is 25% of the total UV absorbing material. Band intensity on the gel is then plotted against the calculated input that band represents—for example, if the total ceDNA vector is 8 kb, and the excised comparative band is 2 kb, then the band intensity would be plotted as 25% of the total input, which in this case would be 0.25 μg for 1.0 μg input. Using the ceDNA vector plasmid titration to plot a standard curve, a regression line equation is then used to calculate the quantity of the ceDNA vector band, which can then be used to determine the percent of total input represented by the ceDNA vector, or percent purity.
For illustrative purposes, Example 1 describes the production of ceDNA vectors using an insect cell based method and a polynucleotide construct template, and is also described in Example 1 of PCT/US18/49996, which is incorporated herein in its entirety by reference. For example, a polynucleotide construct template used for generating the ceDNA vectors of the present invention according to Example 1 can be a ceDNA-plasmid, a ceDNA-Bacmid, and/or a ceDNA-baculovirus. Without being limited to theory, in a permissive host cell, in the presence of e.g., Rep, the polynucleotide construct template having two symmetric ITRs and an expression construct, where at least one of the ITRs is modified relative to a wild-type ITR sequence, replicates to produce ceDNA vectors. ceDNA vector production undergoes two steps: first, excision (“rescue”) of template from the template backbone (e.g. ceDNA-plasmid, ceDNA-bacmid, ceDNA-baculovirus genome etc.) via Rep proteins, and second, Rep mediated replication of the excised ceDNA vector.
An exemplary method to produce ceDNA vectors in a method using insect cell is from a ceDNA-plasmid as described herein. Referring to
Production of ceDNA-Bacmids:
DH10Bac competent cells (MAX EFFICIENCY® DH10Bac™ Competent Cells, Thermo Fisher) were transformed with either test or control plasmids following a protocol according to the manufacturer's instructions. Recombination between the plasmid and a baculovirus shuttle vector in the DH10Bac cells were induced to generate recombinant ceDNA-bacmids. The recombinant bacmids were selected by screening a positive selection based on blue-white screening in E. coli (Φ80dlacZΔM15 marker provides α-complementation of the β-galactosidase gene from the bacmid vector) on a bacterial agar plate containing X-gal and IPTG with antibiotics to select for transformants and maintenance of the bacmid and transposase plasmids. White colonies caused by transposition that disrupts the β-galactoside indicator gene were picked and cultured in 10 ml of media.
The recombinant ceDNA-bacmids were isolated from the E. coli and transfected into Sf9 or Sf21 insect cells using FugeneHD to produce infectious baculovirus. The adherent Sf9 or Sf21 insect cells were cultured in 50 ml of media in T25 flasks at 25° C. Four days later, culture medium (containing the P0 virus) was removed from the cells, filtered through a 0.45 μm filter, separating the infectious baculovirus particles from cells or cell debris.
Optionally, the first generation of the baculovirus (P0) was amplified by infecting naïve Sf9 or Sf21 insect cells in 50 to 500 ml of media. Cells were maintained in suspension cultures in an orbital shaker incubator at 130 rpm at 25° C., monitoring cell diameter and viability, until cells reach a diameter of 18-19 nm (from a naive diameter of 14-15 nm), and a density of ˜4.0E+6 cells/mL. Between 3 and 8 days post-infection, the P1 baculovirus particles in the medium were collected following centrifugation to remove cells and debris then filtration through a 0.45 μm filter.
The ceDNA-baculovirus comprising the test constructs were collected and the infectious activity, or titer, of the baculovirus was determined. Specifically, four×20 ml Sf9 cell cultures at 2.5E+6 cells/ml were treated with P1 baculovirus at the following dilutions: 1/1000, 1/10,000, 1/50,000, 1/100,000, and incubated at 25-27° C. Infectivity was determined by the rate of cell diameter increase and cell cycle arrest, and change in cell viability every day for 4 to 5 days.
A “Rep-plasmid” was produced in a pFASTBAC™-Dual expression vector (ThermoFisher) comprising both the Rep78 (SEQ ID NO: 131 or 133) or Rep68 (SEQ ID NO: 130) and Rep52 (SEQ ID NO: 132) or Rep40 (SEQ ID NO: 129). The Rep-plasmid was transformed into the DH10Bac competent cells (MAX EFFICIENCY® DH10Bac™ Competent Cells (Thermo Fisher) following a protocol provided by the manufacturer. Recombination between the Rep-plasmid and a baculovirus shuttle vector in the DH10Bac cells were induced to generate recombinant bacmids (“Rep-bacmids”). The recombinant bacmids were selected by a positive selection that included-blue-white screening in E. coli (Φ80dlacZΔM15 marker provides α-complementation of the β-galactosidase gene from the bacmid vector) on a bacterial agar plate containing X-gal and IPTG. Isolated white colonies were picked and inoculated in 10 ml of selection media (kanamycin, gentamicin, tetracycline in LB broth). The recombinant bacmids (Rep-bacmids) were isolated from the E. coli and the Rep-bacmids were transfected into Sf9 or Sf21 insect cells to produce infectious baculovirus.
The Sf9 or Sf21 insect cells were cultured in 50 ml of media for 4 days, and infectious recombinant baculovirus (“Rep-baculovirus”) were isolated from the culture. Optionally, the first generation Rep-baculovirus (P0) were amplified by infecting naïve Sf9 or Sf21 insect cells and cultured in 50 to 500 ml of media. Between 3 and 8 days post-infection, the P1 baculovirus particles in the medium were collected either by separating cells by centrifugation or filtration or another fractionation process. The Rep-baculovirus were collected and the infectious activity of the baculovirus was determined. Specifically, four×20 mL Sf9 cell cultures at 2.5×106 cells/mL were treated with P1 baculovirus at the following dilutions, 1/1000, 1/10,000, 1/50,000, 1/100,000, and incubated. Infectivity was determined by the rate of cell diameter increase and cell cycle arrest, and change in cell viability every day for 4 to 5 days.
ceDNA Vector Generation and Characterization
Sf9 insect cell culture media containing either (1) a sample-containing a ceDNA-bacmid or a ceDNA-baculovirus, and (2) Rep-baculovirus described above were then added to a fresh culture of Sf9 cells (2.5E+6 cells/ml, 20 ml) at a ratio of 1:1000 and 1:10,000, respectively. The cells were then cultured at 130 rpm at 25° C. 4-5 days after the co-infection, cell diameter and viability are detected. When cell diameters reached 18-20 nm with a viability of ˜70-80%, the cell cultures were centrifuged, the medium was removed, and the cell pellets were collected. The cell pellets are first resuspended in an adequate volume of aqueous medium, either water or buffer. The ceDNA vector was isolated and purified from the cells using Qiagen MIDI PLUS™ purification protocol (Qiagen, 0.2 mg of cell pellet mass processed per column).
Yields of ceDNA vectors produced and purified from the Sf9 insect cells were initially determined based on UV absorbance at 260 nm. The purified ceDNA vectors can be assessed for proper closed-ended configuration using the electrophoretic methodology described in Example 5.
Synthetic production of the ceDNA vectors is described in Examples 2-6 of International Application PCT/US19/14122, filed Jan. 18, 2019, which is incorporated herein in its entirety by reference. One exemplary method of producing a ceDNA vector using a synthetic method that involves the excision of a double-stranded DNA molecule. In brief, a ceDNA vector can be generated using a double stranded DNA construct, e.g., see
In some embodiments, a construct to make a ceDNA vector comprises a regulatory switch as described herein.
For illustrative purposes, Example 2 describes producing ceDNA vectors as exemplary closed-ended DNA vectors generated using this method. However, while ceDNA vectors are exemplified in this Example to illustrate in vitro synthetic production methods to generate a closed-ended DNA vector by excision of a double-stranded polynucleotide comprising the ITRs and expression cassette (e.g., heterologous nucleic acid sequence) followed by ligation of the free 3′ and 5′ ends as described herein, one of ordinary skill in the art is aware that one can, as illustrated above, modify the double stranded DNA polynucleotide molecule such that any desired closed-ended DNA vector is generated, including but not limited to, doggybone DNA, dumbbell DNA and the like.
The method involves (i) excising a sequence encoding the expression cassette from a double-stranded DNA construct and (ii) forming hairpin structures at one or more of the ITRs and (iii) joining the free 5′ and 3′ ends by ligation, e.g., by T4 DNA ligase.
The double-stranded DNA construct comprises, in 5′ to 3′ order: a first restriction endonuclease site; an upstream ITR; an expression cassette; a downstream ITR; and a second restriction endonuclease site. The double-stranded DNA construct is then contacted with one or more restriction endonucleases to generate double-stranded breaks at both of the restriction endonuclease sites. One endonuclease can target both sites, or each site can be targeted by a different endonuclease as long as the restriction sites are not present in the ceDNA vector template. This excises the sequence between the restriction endonuclease sites from the rest of the double-stranded DNA construct. Upon ligation a closed-ended DNA vector is formed.
One or both of the ITRs used in the method may be wild-type ITRs. Modified ITRs may also be used, where the modification can include deletion, insertion, or substitution of one or more nucleotides from the wild-type ITR in the sequences forming B and B′ arm and/or C and C′ arm (see, e.g.,
In a non-limiting example, ITR-6 Left and Right (SEQ ID NOS: 111 and 112), include 40 nucleotide deletions in the B-B′ and C-C′ arms from the wild-type ITR of AAV2. Nucleotides remaining in the modified ITR are predicted to form a single hairpin structure. Gibbs free energy of unfolding the structure is about −54.4 kcal/mol. Other modifications to the ITR may also be made, including optional deletion of a functional Rep binding site or a Trs site.
Another exemplary method of producing a ceDNA vector using a synthetic method that involves assembly of various oligonucleotides, is provided in Example 3 of PCT/US19/14122, where a ceDNA vector is produced by synthesizing a 5′ oligonucleotide and a 3′ ITR oligonucleotide and ligating the ITR oligonucleotides to a double-stranded polynucleotide comprising an expression cassette.
As disclosed herein, the ITR oligonucleotides can comprise WT-ITRs or modified ITRs (e.g., see,
Another exemplary method of producing a ceDNA vector using a synthetic method is provided in Example 4 of PCT/US19/14122, and uses a single-stranded linear DNA comprising two sense ITRs which flank a sense expression cassette sequence and are attached covalently to two antisense ITRs which flank an antisense expression cassette, the ends of which single stranded linear DNA are then ligated to form a closed-ended single-stranded molecule. One non-limiting example comprises synthesizing and/or producing a single-stranded DNA molecule, annealing portions of the molecule to form a single linear DNA molecule which has one or more base-paired regions of secondary structure, and then ligating the free 5′ and 3′ ends to each other to form a closed single-stranded molecule.
An exemplary single-stranded DNA molecule for production of a ceDNA vector comprises, from 5′ to 3′:
A single-stranded DNA molecule for use in the exemplary method of Example 4 can be formed by any DNA synthesis methodology described herein, e.g., in vitro DNA synthesis, or provided by cleaving a DNA construct (e.g., a plasmid) with nucleases and melting the resulting dsDNA fragments to provide ssDNA fragments.
Annealing can be accomplished by lowering the temperature below the calculated melting temperatures of the sense and antisense sequence pairs. The melting temperature is dependent upon the specific nucleotide base content and the characteristics of the solution being used, e.g., the salt concentration. Melting temperatures for any given sequence and solution combination are readily calculated by one of ordinary skill in the art.
The free 5′ and 3′ ends of the annealed molecule can be ligated to each other, or ligated to a hairpin molecule to form the ceDNA vector. Suitable exemplary ligation methodologies and hairpin molecules are described in Examples 2 and 3.
Any of the DNA vector products produced by the methods described herein, e.g., including the insect cell based production methods described in Example 1, or synthetic production methods described in Examples 2-4 can be purified, e.g., to remove impurities, unused components, or byproducts using methods commonly known by a skilled artisan; and/or can be analyzed to confirm that DNA vector produced, (in this instance, a ceDNA vector) is the desired molecule. An exemplary method for purification of the DNA vector, e.g., ceDNA is using Qiagen Midi Plus purification protocol (Qiagen) and/or by gel purification,
The following is an exemplary method for confirming the identity of ceDNA vectors.
ceDNA vectors can be assessed by identified by agarose gel electrophoresis under native or denaturing conditions as illustrated in
Structures of the isolated ceDNA vectors were further analyzed by digesting the purified DNA with restriction endonucleases selected for a) the presence of only a single cut site within the ceDNA vectors, and b) resulting fragments that were large enough to be seen clearly when fractionated on a 0.8% denaturing agarose gel (>800 bp). As illustrated in
Therefore, to demonstrate in a qualitative fashion that isolated ceDNA vectors are covalently closed-ended as is required by definition, the samples were digested with a restriction endonuclease identified in the context of the specific DNA vector sequence as having a single restriction site, preferably resulting in two cleavage products of unequal size (e.g., 1000 bp and 2000 bp). Following digestion and electrophoresis on a denaturing gel (which separates the two complementary DNA strands), a linear, non-covalently closed DNA will resolve at sizes 1000 bp and 2000 bp, while a covalently closed DNA (i.e., a ceDNA vector) will resolve at 2× sizes (2000 bp and 4000 bp), as the two DNA strands are linked and are now unfolded and twice the length (though single stranded). Furthermore, digestion of monomeric, dimeric, and n-meric forms of the DNA vectors will all resolve as the same size fragments due to the end-to-end linking of the multimeric DNA vectors (see
As used herein, the phrase “assay for the Identification of DNA vectors by agarose gel electrophoresis under native gel and denaturing conditions” refers to an assay to assess the close-endedness of the ceDNA by performing restriction endonuclease digestion followed by electrophoretic assessment of the digest products. One such exemplary assay follows, though one of ordinary skill in the art will appreciate that many art-known variations on this example are possible. The restriction endonuclease is selected to be a single cut enzyme for the ceDNA vector of interest that will generate products of approximately ⅓× and ⅔× of the DNA vector length. This resolves the bands on both native and denaturing gels. Before denaturation, it is important to remove the buffer from the sample. The Qiagen PCR clean-up kit or desalting “spin columns,” e.g. GE HEALTHCARE ILUSTRA™ MICROSPIN™ G-25 columns are some art-known options for the endonuclease digestion. The assay includes for example, i) digest DNA with appropriate restriction endonuclease(s), 2) apply to e.g., a Qiagen PCR clean-up kit, elute with distilled water, iii) adding 10× denaturing solution (10×=0.5 M NaOH, 10 mM EDTA), add 10× dye, not buffered, and analyzing, together with DNA ladders prepared by adding 10× denaturing solution to 4×, on a 0.8-1.0% gel previously incubated with 1 mM EDTA and 200 mM NaOH to ensure that the NaOH concentration is uniform in the gel and gel box, and running the gel in the presence of 1× denaturing solution (50 mM NaOH, 1 mM EDTA). One of ordinary skill in the art will appreciate what voltage to use to run the electrophoresis based on size and desired timing of results. After electrophoresis, the gels are drained and neutralized in 1×TBE or TAE and transferred to distilled water or 1×TBE/TAE with 1×SYBR Gold. Bands can then be visualized with e.g. Thermo Fisher, SYBR® Gold Nucleic Acid Gel Stain (10,000× Concentrate in DMSO) and epifluorescent light (blue) or UV (312 nm). The foregoing gel-based method can be adapted to purification purposes by isolating the ceDNA vector from the gel band and permitting it to renature.
The purity of the generated ceDNA vector can be assessed using any art-known method. As one exemplary and non-limiting method, contribution of ceDNA-plasmid to the overall UV absorbance of a sample can be estimated by comparing the fluorescent intensity of ceDNA vector to a standard. For example, if based on UV absorbance 4 μg of ceDNA vector was loaded on the gel, and the ceDNA vector fluorescent intensity is equivalent to a 2 kb band which is known to be 1 μg, then there is 1 μg of ceDNA vector, and the ceDNA vector is 25% of the total UV absorbing material. Band intensity on the gel is then plotted against the calculated input that band represents—for example, if the total ceDNA vector is 8 kb, and the excised comparative band is 2 kb, then the band intensity would be plotted as 25% of the total input, which in this case would be 0.25 μg for 1.0 μg input. Using the ceDNA vector plasmid titration to plot a standard curve, a regression line equation is then used to calculate the quantity of the ceDNA vector band, which can then be used to determine the percent of total input represented by the ceDNA vector, or percent purity.
A ceDNA vector was produced according to the methods described in Example 1 above, using a ceDNA plasmid comprising a CAG promoter (SEQ ID NO: 72) and a luciferase transgene (SEQ ID NO: 56) flanked between asymmetric ITRs (e.g., a 5′ WT-ITR (SEQ ID NO: 2) and a 3′ mod-ITR (SEQ ID NO: 3) and was assessed in different treatment paragams in vivo. This ceDNA vector was used in all subsequent experiments described in Examples 6-10. In Example 6, the ceDNA vector was purified and formulated with a lipid nanoparticle (LNP ceDNA) and injected into the tail vein of each CD-1® IGS mice. Liposomes were formulated with a suitable lipid blend comprising four components to form lipid nanoparticles (LNP) liposomes, including cationic lipids, helper lipids, cholesterol and PEG-lipids.
To assess the sustained expression of the transgene in vivo from the ceDNA vector over a long time period, the LNP-ceDNA was administered in sterile PBS by tail vein intravenous injection to CD-1® IGS mice of approximately 5-7 weeks of age. Three different dosage groups were assessed: 0.1 mg/kg, 0.5 mg/kg, and 1.0 mg/kg, ten mice per group (except 1.0 mg/kg which had 15 mice per group). Injections were administered on day 0. Five mice from each of the groups were injected with an additional identical dose on day 28. Luciferase expression was measured by IVIS imaging following intravenous administration into CD-1® IGS mice (Charles River Laboratories; WT mice). Luciferase expression was assessed by IVIS imaging following intraperitoneal injection of 150 mg/kg luciferin substrate on days 3, 4, 7, 14, 21, 28, 31, 35, and 42, and routinely (e.g., weekly, biweekly or every 10-days or every 2 weeks), between days 42-110 days. The results are shown in
An extension study was performed to investigate the effect of a re-dose, e.g., a re-administration of LNP-ceDNA expressing luciferase of the LNP-ceDNA treated subjects. In particular, it was assessed to determine if expression levels can be increased by one or more additional administrations of the ceDNA vector.
In this study, the biodistribution of luciferase expression from a ceDNA vector was assessed by IVIS in CD-1® IGS mice after an initial intravenous administration of 1.0 mg/kg (i.e., a priming dose) at days 0 and 28 (Group A). A second administration of a ceDNA vector was administered via tail vein injection of 3 mg/kg (Group B) or 10 mg/kg (Group C) in 1.2 mL in the tail vein at day 84. In this study, five (5) CD-1® mice were used in each of Groups A, B and C. IVIS imaging of the mice for luciferase expression was performed prior to the additional dosing at days 49, 56, 63, and 70 as described above, as well as post-redose on day 84 and on days 91, 98, 105, 112, and 132. Luciferase expression was assessed and detected in all three Groups A, B and C until at least 110 days (the longest time period assessed).
The level of expression of luciferase was shown to be increased by a re-dose (i.e., re-administration of the ceDNA composition) of the LNP-ceDNA-Luc, as determined by assessment of luciferase activity in the presence of luciferin. The results are shown in
Group A shows luciferase expression in CD-1® IGS mice after intravenous administration of 1 mg/kg of a ceDNA vector into the tail vein at days 0 and 28. Group B and C show luciferase expression in CD-1® IGS mice administered 1 mg/kg of a ceDNA vector at a first time point (day 0) and re-dosed with administration of a ceDNA vector at a second time point of 84 days. Unexpectedly, the second administration (i.e., re-dose) of the ceDNA vector increased expression by at least 7-fold, even up to 17-fold.
Unexpectedly, a 3-fold increase in the dose (i.e., the amount) of ceDNA vector in a re-dose administration in Group B (i.e., 3 mg/kg administered at re-dose) resulted in a 7-fold increase in expression of the luciferase. Also unexpectedly, a 10-fold increase in the amount of ceDNA vector in a re-dose administration (i.e., 10 mg/kg re-dose administered) in Group C resulted in a 17-fold increase in expression of the luciferase. Thus, the second administration (i.e., re-dose) of the ceDNA increased expression by at least 7-fold, even up to 17-fold. This shows that the increase in transgene expression from the re-dose is greater than expected and dependent on the dose or amount of the ceDNA vector in the re-dose administration, and appears to be synergistic to the initial transgene expression from the initial priming administration at day 0. That is, the dose-dependent increase in transgene expression is not additive, rather, the expression level of the transgene is dose-dependent and greater than the sum of the amount of the ceDNA vector administered at each time point.
Both Groups B and C showed significant dose-dependent increase in expression of luciferase as compared to control mice (Group A) that were not re-dosed with a ceDNA vector at the second time point. Taken together, these data show that the expression of a transgene from ceDNA vector can be increased in a dose-dependent manner by re-dose (i.e., re-administration) of the ceDNA vector at least a second time point.
Taken together, these data in
The reproducibility of the results in Example 6 with a different lipid nanoparticle was assessed in vivo in mice. Mice were dosed on day 0 with either ceDNA vector comprising a luciferase transgene driven by a CAG promoter that was encapsulated in an LNP different from that used in Example 6 or with that same LNP comprising polyC but lacking ceDNA or a luciferase gene. Specifically, male CD-1@ mice of approximately 4 weeks of age were treated with a single injection of 0.5 mg/kg LNP-TTX-luciferase or control LNP-polyC, administered intravenously via lateral tail vein on day 0. At day 14 animals were dosed systemically with luciferin at 150 mg/kg via intraperitoneal injection at 2.5 mL/kg. At approximately 15 minutes after luciferin administration each animal was imaged using an In Vivo Imaging System (“IVIS”).
As shown in
In a separate experiment, the localization of LNP-delivered ceDNA within the liver of treated animals was assessed. A ceDNA vector comprising a functional transgene of interest was encapsulated in the same LNP as used in Example 7 and administered to mice in vivo at a dose level of 0.5 mg/kg by intravenous injection. After 6 hours the mice were terminated and liver samples taken, formalin fixed and paraffin-embedded using standard protocols. RNAscope® in situ hybridization assays were performed to visualize the ceDNA vectors within the tissue using a probe specific for the ceDNA transgene and detecting using chromogenic reaction and hematoxylin staining (Advanced Cell Diagnostics).
The sustainability of ceDNA vector transgene expression in tissues other than the liver was assessed to determine tolerability and expression of a ceDNA vector after ocular administration in vivo. On day 0, male Sprague Dawley rats of approximately 9 weeks of age were injected sub-retinally with 5 μL of either ceDNA vector comprising a luciferase transgene formulated with jetPEI® transfection reagent (Polyplus) or plasmid DNA encoding luciferase formulated with jetPEI®, both at a concentration of 0.25 μg/μL. Four rats were tested in each group. Animals were sedated and injected sub-retinally in the right eye with the test article using a 33 gauge needle. The left eye of each animal was untreated. Immediately after injection eyes were checked with optical coherence tomography or fundus imaging in order to confirm the presence of a subretinal bleb. Rats were treated with buprenorphine and topical antibiotic ointment according to standard procedures.
At days 7, 14, 21, 28, and 35, the animals in both groups were dosed systemically with freshly made luciferin at 150 mg/kg via intraperitoneal injection at 2.5 mL/kg. at 5-15 minutes post luciferin administration, all animals were imaged using IVIS while under isoflurane anesthesia. Total Flux [p/s] and average Flux (p/s/sr/cm2) in a region of interest encompassing the eye were obtained over 5 minutes of exposure. The results were graphed as average radiance of each treatment group in the treated eye (“injected”) relative to the average radiance of each treatment group in the untreated eye (“uninjected”) (
In situations where one or more of the transgenes encoded in the gene expression cassette of the ceDNA vector is expressed in a host environment (e.g., cell or subject) where the expressed protein is recognized as foreign, the possibility exists that the host will mount an adaptive immune response that may result in undesired depletion of the expression product, which could potentially be confused for lack of expression. In some cases this may occur with a reporter molecule that is heterologous to the normal host environment. Accordingly, ceDNA vector transgene expression was assessed in vivo in the Rag2 mouse model which lacks B and T cells and therefore does not mount an adaptive immune response to non-native murine proteins such as luciferase. Briefly, c57bl/6 and Rag2 knockout mice were dosed intravenously via tail vein injection with 0.5 mg/kg of LNP-encapsulated ceDNA vector expressing luciferase or a polyC control at day 0, and at day 21 certain mice were redosed with the same LNP-encapsulated ceDNA vector at the same dose level. All testing groups consisted of 4 mice each. IVIS imaging was performed after luciferin injection as described in Example 9 at weekly intervals.
Comparing the total flux observed from the IVIS analyses, the fluorescence observed in the wild-type mice (an indirect measure of the presence of expressed luciferase) dosed with LNP-ceDNA vector-Luc decreased gradually after day 21 whereas the Rag2 mice administered the same treatment displayed relatively constant sustained expression of luciferase over the 42 day experiment (
As described in Example 10, undesired host immune response may in some cases artificially dampen what would otherwise be sustained expression of one or more desired transgenes from an introduced ceDNA vector. Two approaches were taken to assess the impact of avoiding and/or dampening potential host immune response on sustained expression from a ceDNA vector. First, since the ceDNA-Luc vector used in the preceding examples was under the control of a constitutive CAG promoter, a similar construct was made using a liver-specific promoter (hAAT) or a different constitutive promoter (hEF-1) to see whether avoiding prolonged exposure to myeloid cells or non-liver tissue reduced any observed immune effects. Second, certain of the ceDNA-luciferase constructs were engineered to be reduced in CpG content, a known trigger for host immune reaction. ceDNA-encoded luciferase gene expression upon administration of such engineered and promoter-switched ceDNA vectors to mice was measured.
Three different ceDNA vectors were used, each encoding luciferase as the transgene. The first ceDNA vector had a high number of unmethylated CpG (˜350) and comprised the constitutive CAG promoter (“ceDNA CAG”); the second had a moderate number of unmethylated CpG (˜60) and comprised the liver-specific hAAT promoter (“ceDNA hAAT low CpG”); and the third was a methylated form of the second, such that it contained no unmethylated CpG and also comprised the hAAT promoter (“ceDNA hAAT No CpG”). The ceDNA vectors were otherwise identical. The vectors were prepared as described above.
Four groups of four male CD-1® mice, approximately 4 weeks old, were treated with one of the ceDNA vectors encapsulated in an LNP or a polyC control. On day 0 each mouse was administered a single intravenous tail vein injection of 0.5 mg/kg ceDNA vector in a volume of 5 mL/kg. Body weights were recorded on days −1, −, 1, 2, 3, 7, and weekly thereafter until the mice were terminated. Whole blood and serum samples were taken on days 0, 1, and 35. In-life imaging was performed on days 7, 14, 21, 28, and 35, and weekly thereafter using an in vivo imaging system (IVIS). For the imaging, each mouse was injected with luciferin at 150 mg/kg via intraperitoneal injection at 2.5 mL/kg. After 15 minutes, each mouse was anaesthetized and imaged. The mice were terminated at day 93 and terminal tissues collected, including liver and spleen. Cytokine measurements were taken 6 hours after dosing on day 0.
While all of the ceDNA-treated mice displayed significant fluorescence at days 7 and 14, the fluorescence decreased rapidly in the ceDNA CAG mice after day 14 and more gradually decreased for the remainder of the study. In contrast, the total flux for the ceDNA hAAT low CpG and No CpG-treated mice remained at a steady high level (
All publications and references, including but not limited to patents and patent applications, cited in this specification and Examples herein are incorporated by reference in their entirety as if each individual publication or reference were specifically and individually indicated to be incorporated by reference herein as being fully set forth. Any patent application to which this application claims priority is also incorporated by reference herein in the manner described above for publications and references.
This application is a 35 U.S.C. § 371 national stage filing of International Application No. PCT/US2019/018927, filed Feb. 21, 2019, which in turn claims benefit under 35 U.S.C. § 119(e) of U.S. Provisional Application Nos. 62/633,882, filed Feb. 22, 2018; 62/633,757, filed Feb. 22, 2018; 62/633,795, filed Feb. 22, 2018; and 62/746,762, filed Oct. 17, 2018. The contents of each of the aforementioned applications are incorporated herein by reference in their entireties.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US19/18927 | 2/21/2019 | WO | 00 |
| Number | Date | Country | |
|---|---|---|---|
| 62633757 | Feb 2018 | US | |
| 62633882 | Feb 2018 | US | |
| 62633795 | Feb 2018 | US | |
| 62746762 | Oct 2018 | US |
