Patent Application
20220136013
Throughout this application, various publications are referenced, including referenced in parenthesis. The disclosures of all publications mentioned in this application in their entireties are hereby incorporated by reference into this application in order to provide additional description of the art to which this invention pertains and of the features in the art which can be employed with this invention.
This application incorporates-by-reference nucleotide sequences which are present in the file named “200225_90868-A-PCT_Sequence_Listing_AWG.txt”, which is 6,847 kilobytes in size, and which was created on Feb. 13, 2020 in the IBM-PC machine format, having an operating system compatibility with MS-Windows, which is contained in the text file filed Feb. 25, 2020 as part of this application.
There are several classes of DNA variation in the human genome, including insertions and deletions, differences in the copy number of repeated sequences, and single nucleotide polymorphisms (SNPs). A SNP is a DNA sequence variation occurring when a single nucleotide (adenine (A), thymine (T), cytosine (C), or guanine (G)) in the genome differs between human subjects or paired chromosomes in an individual. Over the years, the different types of DNA variations have been the focus of the research community either as markers in studies to pinpoint traits or disease causation or as potential causes of genetic disorders.
A genetic disorder is caused by one or more abnormalities in the genome. Genetic disorders may be regarded as either “dominant” or “recessive.” Recessive genetic disorders are those which require two copies (i.e., two alleles) of the abnormal/defective gene to be present. In contrast, a dominant genetic disorder involves a gene or genes which exhibit(s) dominance over a normal (functional/healthy) gene or genes. As such, in dominant genetic disorders only a single copy (i.e., allele) of an abnormal gene is required to cause or contribute to the symptoms of a particular genetic disorder. Such mutations include, for example, gain-of-function mutations in which the altered gene product possesses a new molecular function or a new pattern of gene expression. Other examples include dominant negative mutations, which have a gene product that acts antagonistically to the wild-type allele.
Autosomal dominant Chronic mucocutaneous candidiasis (CMC) is characterized by susceptibility to candida infection of skin, nails, and mucous membranes.
Signal transducer and activator of transcription 1 (STAT1) encodes a transcription factor belonging to the signal transducers and activator of transcription family shown to be involved in regulation of the development of various types of immune cells. Several gain-of-function mutations in the coiled coil domain or the DNA binding domain of STAT1 were shown to be associated with autosomal dominant chronic mucocutaneous candidiasis (CMC).
Disclosed is an approach for knocking out the expression of a dominant-mutated allele by disrupting the dominant-mutated allele or degrading the resulting mRNA.
The present disclosure provides a method for utilizing at least one naturally occurring nucleotide difference or polymorphism (e.g., single nucleotide polymorphism (SNP)) for distinguishing/discriminating between two alleles of a gene, one allele bearing a mutation such that it encodes a mutated protein causing a disease phenotype (“mutated allele”) and a particular sequence in a SNP position (REF/SNP), and the other allele encoding for a functional protein (“functional allele”). In some embodiments, the SNP position is utilized for distinguishing/discriminating between two alleles of a gene bearing one or more disease associated mutations, such as to target one of the alleles bearing both the particular sequence in the SNP position (SNP/REF) and a disease associated mutation. In some embodiments, the disease-associated mutation is targeted. In some embodiments, the method further comprises the step of knocking out expression of the mutated protein and allowing expression of the functional protein.
The present disclosure also provides a method for modifying in a cell a mutant allele of the signal transducer and activator of transcription 1 (STAT1) gene having a mutation associated with chronic mucocutaneous candidiasis (CMC), the method comprising
According to embodiments of the present invention, there is provided a first RNA molecule comprising a guide sequence portion having 17-25 contiguous nucleotides containing nucleotides in the sequence set forth in any one of SEQ ID NOs 1-37365.
According to some embodiments of the present invention, there is provided a composition comprising an RNA molecule comprising a guide sequence portion having 17-25 contiguous nucleotides containing nucleotides in the sequence set forth in any one of SEQ ID NOs 1-37365 and a CRISPR nuclease.
According to some embodiments of the present invention, there is provided a method for inactivating a mutant STAT1 allele in a cell, the method comprising delivering to the cell a composition comprising an RNA molecule comprising a guide sequence portion having 17-25 contiguous nucleotides containing nucleotides in the sequence set forth in any one of SEQ ID NOs 1-37365 and a CRISPR nuclease. In some embodiments, the cell is a stem cell. In some embodiments, the stem cell is a hematopoietic stem/progenitor cell (HSC). In some embodiments, the delivering to the cell is performed in vitro, ex vivo, or in vivo. In some embodiments, the method is performed ex vivo and the cell is provided/explanted from an individual patient. In some embodiments, the method further comprises the step of introducing the resulting cell, with the modified/knocked out mutant STAT1 allele, into the individual patient (e.g. autologous transplantation).
According to some embodiments of the present invention, there is provided a method for treating CMC, the method comprising delivering to a cell of a subject having CMC a composition comprising an RNA molecule comprising a guide sequence portion having 17-25 contiguous nucleotides containing nucleotides in the sequence set forth in any one of SEQ ID NOs 1-37365 and a CRISPR nuclease.
According to some embodiments of the present invention, there is provided use of a composition comprising an RNA molecule comprising a guide sequence portion having 17-25 contiguous nucleotides containing nucleotides in the sequence set forth in any one of SEQ ID NOs 1-37365 and a CRISPR nuclease for inactivating a mutant STAT1 allele in a cell, comprising delivering to the cell the composition comprising an RNA molecule comprising a guide sequence portion having 17-25 contiguous nucleotides containing nucleotides in the sequence set forth in any one of SEQ ID NOs 1-37365 and a CRISPR nuclease.
According to embodiments of the present invention, there is provided a medicament comprising an RNA molecule comprising a guide sequence portion having 17-25 contiguous nucleotides containing nucleotides in the sequence set forth in any one of SEQ ID NOs 1-37365 and a CRISPR nuclease for use in inactivating a mutant STAT1 allele in a cell, wherein the medicament is administered by delivering to the cell the composition comprising an RNA molecule comprising a guide sequence portion having 17-25 contiguous nucleotides containing nucleotides in the sequence set forth in any one of SEQ ID NOs 1-37365 and a CRISPR nuclease.
According to some embodiments of the present invention, there is provided use of a composition comprising an RNA molecule comprising a guide sequence portion having 17-25 contiguous nucleotides containing nucleotides in the sequence set forth in any one of SEQ ID NOs 1-37365 and a CRISPR nuclease for treating ameliorating or preventing CMC, comprising delivering to a cell of a subject having or at risk of having CMC the composition of comprising an RNA molecule comprising a guide sequence portion having 17-25 contiguous nucleotides containing nucleotides in the sequence set forth in any one of SEQ ID NOs 1-37365 and a CRISPR nuclease. In some embodiments, the method is performed ex vivo and the cell is provided/explanted from the subject. In some embodiments, the method further comprises the step of introducing the resulting cell, with the modified/knocked out mutant STAT1 allele, into the subject (e.g. autologous transplantation).
According to some embodiments of the present invention, there is provided a medicament comprising the composition comprising an RNA molecule comprising a guide sequence portion having 17-25 contiguous nucleotides containing nucleotides in the sequence set forth in any one of SEQ ID NOs 1-37365 and a CRISPR nuclease for use in treating ameliorating or preventing CMC, wherein the medicament is administered by delivering to a cell of a subject having or at risk of having CMC the composition comprising an RNA molecule comprising a guide sequence portion having 17-25 contiguous nucleotides containing nucleotides in the sequence set forth in any one of SEQ ID NOs 1-37365 and a CRISPR nuclease.
According to some embodiments of the present invention, there is provided a kit for inactivating a mutant STAT1 allele in a cell, comprising an RNA molecule comprising a guide sequence portion having 17-25 contiguous nucleotides containing nucleotides in the sequence set forth in any one of SEQ ID NOs 1-37365, a CRISPR nuclease, and/or a tracrRNA molecule; and instructions for delivering the RNA molecule; CRISPR nuclease, and/or the tracrRNA to the cell.
According to some embodiments of the present invention, there is provided a kit for treating CMC in a subject, comprising an RNA molecule comprising a guide sequence portion having 17-25 contiguous nucleotides containing nucleotides in the sequence set forth in any one of SEQ ID NOs 1-37365, a CRISPR nuclease, and/or a tracrRNA molecule; and instructions for delivering the RNA molecule; CRISPR nuclease, and/or the tracrRNA to a cell of a subject having or at risk of having CMC.
Unless otherwise defined, all technical and/or scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention pertains. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of embodiments of the invention, exemplary methods and/or materials are described below. In case of conflict, the patent specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and are not intended to be necessarily limiting.
It should be understood that the terms “a” and “an” as used above and elsewhere herein refer to “one or more” of the enumerated components. It will be clear to one of ordinary skill in the art that the use of the singular includes the plural unless specifically stated otherwise. Therefore, the terms “a,” “an” and “at least one” are used interchangeably in this application.
For purposes of better understanding the present teachings and in no way limiting the scope of the teachings, unless otherwise indicated, all numbers expressing quantities, percentages or proportions, and other numerical values used in the specification and claims, are to be understood as being modified in all instances by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained. At the very least, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.
Unless otherwise stated, adjectives such as “substantially” and “about” modifying a condition or relationship characteristic of a feature or features of an embodiment of the invention, are understood to mean that the condition or characteristic is defined to within tolerances that are acceptable for operation of the embodiment for an application for which it is intended. Unless otherwise indicated, the word “or” in the specification and claims is considered to be the inclusive “or” rather than the exclusive or, and indicates at least one of, or any combination of items it conjoins.
In the description and claims of the present application, each of the verbs, “comprise,” “include” and “have” and conjugates thereof, are used to indicate that the object or objects of the verb are not necessarily a complete listing of components, elements or parts of the subject or subjects of the verb. Other terms as used herein are meant to be defined by their well-known meanings in the art.
The terms “nucleic acid template” and “donor”, refer to a nucleotide sequence that is inserted or copied into a genome. The nucleic acid template comprises a nucleotide sequence, e.g., of one or more nucleotides, that will be added to or will template a change in the target nucleic acid or may be used to modify the target sequence. A nucleic acid template sequence may be of any length, for example between 2 and 10,000 nucleotides in length, preferably between about 100 and 1,000 nucleotides in length, more preferably between about 200 and 500 nucleotides in length. A nucleic acid template may be a single stranded nucleic acid, a double stranded nucleic acid. In some embodiments, the nucleic acid template comprises a nucleotide sequence, e.g., of one or more nucleotides, that corresponds to wild type sequence of the target nucleic acid, e.g., of the target position. In some embodiments, the nucleic acid template comprises a nucleotide sequence, e.g., of one or more ribonucleotides, that corresponds to wild type sequence of the target nucleic acid, e.g., of the target position. In some embodiments, the nucleic acid template comprises modified nucleotides.
In some embodiments of the present invention, a DNA nuclease is utilized to affect a DNA break at a target site to induce cellular repair mechanisms, for example, but not limited to, non-homologous end-joining (NHEJ) or homology-directed repair (HDR). During classical NHEJ, two ends of a double-strand break (DSB) site are ligated together in a fast but also inaccurate manner (i.e. frequently resulting in mutation of the DNA at the cleavage site in the form of small insertion or deletions) whereas during HDR, an intact homologous DNA donor is used to replace the DNA surrounding the cleavage site in an accurate manner. HDR can also mediate the precise insertion of exogenous DNA at the break site. Accordingly, the term “homology-directed repair” or “HDR” refers to a mechanism for repairing DNA damage in cells, for example, during repair of double-stranded and single-stranded breaks in DNA. HDR requires nucleotide sequence homology and uses a “nucleic acid template” (nucleic acid template or donor template used interchangeably herein) to repair the sequence where the double-stranded or single break occurred (e.g., DNA target sequence). This results in the transfer of genetic information from, for example, the nucleic acid template to the DNA target sequence. HDR may result in alteration of the DNA target sequence (e.g., insertion, deletion, mutation) if the nucleic acid template sequence differs from the DNA target sequence and part or all of the nucleic acid template polynucleotide or oligonucleotide is incorporated into the DNA target sequence. In some embodiments, an entire nucleic acid template polynucleotide, a portion of the nucleic acid template polynucleotide, or a copy of the nucleic acid template is integrated at the site of the DNA target sequence.
Insertion of an exogenous sequence (also called a “donor sequence,” donor template,” “donor molecule” or “donor”), for example, for correction of a mutant gene or for increased expression of a wild-type gene can also be carried out. It will be readily apparent that the donor sequence is typically not identical to the genomic sequence where it is placed. A donor sequence can contain a non-homologous sequence flanked by two regions of homology to allow for efficient HDR at the location of interest. Additionally, donor sequences can comprise a vector molecule containing sequences that are not homologous to the region of interest in cellular chromatin. A donor molecule can contain several, discontinuous regions of homology to cellular chromatin. For example, for targeted insertion of sequences not normally present in a region of interest, said sequences can be present in a donor nucleic acid molecule and flanked by regions of homology to sequence in the region of interest.
The donor polynucleotide can be DNA or RNA, single-stranded and/or double-stranded and can be introduced into a cell in linear or circular form. See, e.g., U.S. Patent Publication Nos. 20100047805; 20110281361; 20110207221; and 20190330620. If introduced in linear form, the ends of the donor sequence can be protected (e.g., from exonucleolytic degradation) by methods known to those of skill in the art. For example, one or more dideoxynucleotide residues are added to the 3′ terminus of a linear molecule and/or self-complementary oligonucleotides are ligated to one or both ends. See, for example, Chang et al. (1987) Proc. Natl. Acad. Sci. USA 84:4959-4963; Nehls et al. (1996) Science 272:886-889. Additional methods for protecting exogenous polynucleotides from degradation include, but are not limited to, addition of terminal amino group(s) and the use of modified internucleotide linkages such as, for example, phosphorothioates, phosphoramidates, and O-methyl ribose or deoxyribose residues.
Accordingly, embodiments of the present invention using a donor template for HDR may be DNA or RNA, single-stranded and/or double-stranded and can be introduced into a cell in linear or circular form. In embodiments of the present invention using: (1) a nuclease associated with an RNA molecule comprising a guide sequence to affect a double strand break in a gene prior to HDR and (2) a donor template for HDR.
A donor sequence may also be an oligonucleotide and be used for gene correction or targeted alteration of an endogenous sequence. The oligonucleotide may be introduced to the cell on a vector, may be electroporated into the cell, or may be introduced via other methods known in the art. The oligonucleotide can be used to ‘ correct’ a mutated sequence in an endogenous gene (e.g., the sickle mutation in beta globin), or may be used to insert sequences with a desired purpose into an endogenous locus (e.g. a splice acceptor sequence).
A polynucleotide can be introduced into a cell as part of a vector molecule having additional sequences such as, for example, replication origins, promoters and genes encoding antibiotic resistance. Moreover, donor polynucleotides can be introduced as naked nucleic acid, as nucleic acid complexed with an agent such as a liposome or poloxamer, or can be delivered by viruses (e.g., adenovirus, AAV, herpesvirus, retrovirus, lentivirus and integrase defective lentivirus (IDLV)).
The donor is may be inserted so that its expression is driven by the endogenous promoter at the integration site, namely the promoter that drives expression of the endogenous gene into which the donor is inserted. However, it will be apparent that the donor may comprise a promoter and/or enhancer, for example a constitutive promoter or an inducible or tissue specific promoter.
The donor molecule may be inserted into an endogenous gene such that all, some or none of the endogenous gene is expressed. For example, a transgene as described herein may be inserted into an endogenous locus such that some (N-terminal and/or C-terminal to the transgene) or none of the endogenous sequences are expressed, for example as a fusion with the transgene. In other embodiments, a transgene (e.g., with or without additional coding sequences such as for the endogenous gene) is integrated into any endogenous locus, for example a safe-harbor locus, for example a CCRS gene, a CXCR4 gene, a PPP1R12c (also known as AAVS1) gene, an albumin gene or a Rosa gene. See, e.g., U.S. Pat. Nos. 7,951,925 and 8,110,379; U.S. Publication Nos. 20080159996; 201000218264; 20100291048; 20120017290; 20110265198; 20130137104; 20130122591; 20130177983 and 20130177960 and U.S. Provisional Application No. 61/823,689).
When endogenous sequences (endogenous or part of the transgene) are expressed with the transgene, the endogenous sequences may be full-length sequences (wild-type or mutant) or partial sequences. Preferably the endogenous sequences are functional. Non-limiting examples of the function of these full length or partial sequences include increasing the serum half-life of the polypeptide expressed by the transgene (e.g., therapeutic gene) and/or acting as a carrier.
Furthermore, although not required for expression, exogenous sequences may also include transcriptional or translational regulatory sequences, for example, promoters, enhancers, insulators, internal ribosome entry sites, sequences encoding 2A peptides and/or polyadenylation signals.
In certain embodiments, the donor molecule comprises a sequence selected from the group consisting of a gene encoding a protein (e.g., a coding sequence encoding a protein that is lacking in the cell or in the individual or an alternate version of a gene encoding a protein), a regulatory sequence and/or a sequence that encodes a structural nucleic acid such as a microRNA or siRNA.
As used herein, the term “modified cells” refers to cells in which a double strand break is affected by a complex of an RNA molecule and the CRISPR nuclease as a result of hybridization with the target sequence, i.e. on-target hybridization. The term “modified cells” may further encompass cells in which a repair or correction of a mutation was affected following the double strand break.
This invention provides a modified cell or cells obtained by use of any of the methods described herein. In an embodiment these modified cell or cells are capable of giving rise to progeny cells. In an embodiment these modified cell or cells are capable of giving rise to progeny cells after engraftment. As a non-limiting example, the modified cells may be hematopoietic stem cell (HSC), or any cell suitable for an allogenic cell transplant or autologous cell transplant.
This invention also provides a composition comprising these modified cells and a pharmaceutically acceptable carrier. Also provided is an in vitro or ex vivo method of preparing this, comprising mixing the cells with the pharmaceutically acceptable carrier.
As used herein, the term “targeting sequence” or “targeting molecule” refers a nucleotide sequence or molecule comprising a nucleotide sequence that is capable of hybridizing to a specific target sequence, e.g., the targeting sequence has a nucleotide sequence which is at least partially complementary to the sequence being targeted along the length of the targeting sequence. The targeting sequence or targeting molecule may be part of an RNA molecule that can form a complex with a CRISPR nuclease with the targeting sequence serving as the targeting portion of the CRISPR complex. When the molecule having the targeting sequence is present contemporaneously with the CRISPR molecule the RNA molecule is capable of targeting the CRISPR nuclease to the specific target sequence. Each possibility represents a separate embodiment. An RNA molecule can be custom designed to target any desired sequence.
The term “targets” as used herein, refers to a targeting sequence or targeting molecule's preferential hybridization to a nucleic acid having a targeted nucleotide sequence. It is understood that the term “targets” encompasses variable hybridization efficiencies, such that there is preferential targeting of the nucleic acid having the targeted nucleotide sequence, but unintentional off-target hybridization in addition to on-target hybridization might also occur. It is understood that where an RNA molecule targets a sequence, a complex of the RNA molecule and a CRISPR nuclease molecule targets the sequence for nuclease activity.
The “guide sequence portion” of an RNA molecule refers to a nucleotide sequence that is capable of hybridizing to a specific target DNA sequence, e.g., the guide sequence portion has a nucleotide sequence which is fully complementary to the DNA sequence being targeted along the length of the guide sequence portion. In some embodiments, the guide sequence portion is 17, 18, 19, 20, 21, 22, 23, 24, or 25 nucleotides in length, or approximately 17-25, 17-24, 17-22, 17-21, 18-25, 18-24, 18-23, 18-22, 18-21, 19-25, 19-24, 19-23, 19-22, 19-21, 19-20, 20-22, 18-20, 20-21, 21-22, or 17-20 nucleotides in length. The entire length of the guide sequence portion is fully complementary to the DNA sequence being targeted along the length of the guide sequence portion. The guide sequence portion may be part of an RNA molecule that can form a complex with a CRISPR nuclease with the guide sequence portion serving as the DNA targeting portion of the CRISPR complex. When the DNA molecule having the guide sequence portion is present contemporaneously with the CRISPR molecule the RNA molecule is capable of targeting the CRISPR nuclease to the specific target DNA sequence. Each possibility represents a separate embodiment. An RNA molecule can be custom designed to target any desired sequence.
In embodiments of the present invention, an RNA molecule comprises a guide sequence portion having 17-25 contiguous nucleotides containing nucleotides in the sequence set forth in any one of SEQ ID NOs 1-37365.
The RNA molecule and or the guide sequence portion of the RNA molecule may contain modified nucleotides. Exemplary modifications to nucleotides/polynucleotides may be synthetic and encompass polynucleotides which contain nucleotides comprising bases other than the naturally occurring adenine, cytosine, thymine, uracil, or guanine bases. Modifications to polynucleotides include polynucleotides which contain synthetic, non-naturally occurring nucleosides e.g., locked nucleic acids. Modifications to polynucleotides may be utilized to increase or decrease stability of an RNA. An example of a modified polynucleotide is an mRNA containing 1-methyl pseudo-uridine. For examples of modified polynucleotides and their uses, see U.S. Pat. No. 8,278,036. PCT International Publication No. WO/2015/006747, and Weissman and Kariko, 2015, (9):1416-7, hereby incorporated by reference.
As used herein, “contiguous nucleotides” set forth in a SEQ ID NO refers to nucleotides in a sequence of nucleotides in the order set forth in the SEQ ID NO without any intervening nucleotides.
In embodiments of the present invention, the guide sequence portion may be 22 nucleotides in length in the sequence of 22 contiguous nucleotides set forth in any one of SEQ ID NOs: 1-37365. In embodiments of the present invention, the guide sequence portion may be less than 22 nucleotides in length. For example, in embodiments of the present invention the guide sequence portion may be 17, 18, 19, 20, or 21 nucleotides in length. In such embodiments the guide sequence portion may consist of 17, 18, 19, 20, or 21 nucleotides, respectively, in the sequence of 17-22 contiguous nucleotides set forth in any one of SEQ ID NOs: 1-37365. For example, a guide sequence portion having 17 nucleotides in the sequence of 17 contiguous nucleotides set forth in SEQ ID NO: 37383 may consist of any one of the following nucleotide sequences (nucleotides excluded from the contiguous sequence are marked in strike-through):
AAAAUGUACUUGGUUCC
AAAAAUGUACUUGGUUC
AAAAAAUGUACUUGGUU
In embodiments of the present invention, the guide sequence portion may be greater than 20 nucleotides in length. For example, in embodiments of the present invention the guide sequence portion may be 21, 22, 23, 24 or 25 nucleotides in length. In such embodiments the guide sequence portion comprises 17-25 nucleotides containing the sequence of 20, 21 or 22 contiguous nucleotides set forth in any one of SEQ ID NOs: 1-37383 and additional nucleotides fully complimentary to a nucleotide or sequence of nucleotides adjacent to the 3′ end of the target sequence, 5′ end of the target sequence, or both.
In embodiments of the present invention a CRISPR nuclease and an RNA molecule comprising a guide sequence portion form a CRISPR complex that binds to a target DNA sequence to effect cleavage of the target DNA sequence. CRISPR nucleases, e.g. Cpfl, may form a CRISPR complex comprising a CRISPR nuclease and RNA molecule without a further tracrRNA molecule. Alternatively, CRISPR nucleases, e.g. Cas9, may form a CRISPR complex between the CRISPR nuclease, an RNA molecule, and a tracrRNA molecule.
In embodiments of the present invention, the RNA molecule may further comprise the sequence of a tracrRNA molecule. Such embodiments may be designed as a synthetic fusion of the guide portion of the RNA molecule and the trans-activating crRNA (tracrRNA). (See Jinek (2012) Science). Embodiments of the present invention may also form CRISPR complexes utilizing a separate tracrRNA molecule and a separate RNA molecule comprising a guide sequence portion. In such embodiments the tracrRNA molecule may hybridize with the RNA molecule via basepairing and may be advantageous in certain applications of the invention described herein.
The term “tracr mate sequence” refers to a sequence sufficiently complementary to a tracrRNA molecule so as to hybridize to the tracrRNA via basepairing and promote the formation of a CRISPR complex. (See U.S. Pat. No. 8,906,616). In embodiments of the present invention, the RNA molecule may further comprise a portion having a tracr mate sequence.
A “gene,” for the purposes of the present disclosure, includes a DNA region encoding a gene product, as well as all DNA regions which regulate the production of the gene product, whether or not such regulatory sequences are adjacent to coding and/or transcribed sequences. Accordingly, a gene includes, but is not necessarily limited to, promoter sequences, terminators, translational regulatory sequences such as ribosome binding sites and internal ribosome entry sites, enhancers, silencers, insulators, boundary elements, replication origins, matrix attachment sites and locus control regions.
“Eukaryotic” cells include, but are not limited to, fungal cells (such as yeast), plant cells, animal cells, mammalian cells and human cells.
The term “nuclease” as used herein refers to an enzyme capable of cleaving the phosphodiester bonds between the nucleotide subunits of nucleic acid. A nuclease may be isolated or derived from a natural source. The natural source may be any living organism. Alternatively, a nuclease may be a modified or a synthetic protein which retains the phosphodiester bond cleaving activity. Gene modification can be achieved using a nuclease, for example a CRISPR nuclease.
As used herein, the term “HSC” refers to both hematopoietic stem cells and hematopoietic stem progenitor cells. Non-limiting examples of stem cells include bone marrow cells, myeloid progenitor cells, a multipotent progenitor cells, a lineage restricted progenitor cells.
As used herein, “progenitor cell” refers to a lineage cell that is derived from stem cell and retains mitotic capacity and multipotency (e.g., can differentiate or develop into more than one but not all types of mature lineage of cell). As used herein “hematopoiesis” or “hemopoiesis” refers to the formation and development of various types of blood cells (e.g., red blood cells, megakaryocytes, myeloid cells (e.g., monocytes, macrophages and neutrophil), and lymphocytes) and other formed elements in the body (e.g., in the bone marrow).
The term “single nucleotide polymorphism (SNP) position”, as used herein, refers to a position in which a single nucleotide DNA sequence variation occurs between members of a species, or between paired chromosomes in an individual. In the case that a SNP position exists at paired chromosomes in an individual, a SNP on one of the chromosomes is a “heterozygous SNP.” The term SNP position refers to the particular nucleic acid position where a specific variation occurs and encompasses both a sequence including the variation from the most frequently occurring base at the particular nucleic acid position (also referred to as “SNP” or alternative “ALT”) and a sequence including the most frequently occurring base at the particular nucleic acid position (also referred to as reference, or “REF”). Accordingly, the sequence of a SNP position may reflect a SNP (i.e. an alternative sequence variant relative to a consensus reference sequence within a population), or the reference sequence itself.
According to embodiments of the present invention, there is provided a method for modifying in a cell a mutant allele of the signal transducer and activator of transcription 1 (STAT1) gene having a mutation associated with chronic mucocutaneous candidiasis (CMC), the method comprising
In some embodiments, the first RNA molecule targets the CRISPR nuclease to the mutation associated with CMC.
In some embodiments, the mutation associated with CMC is any one of 2:190969075_T_C, 2:190969230_G_A, 2:190969443_T_C, 2:190969771_T_G, 2:190969782_C_G, 2:190970341_A_G, 2:190975830_A_G, 2:190975860_G_T, 2:190976881_T_C, 2:190976971_G_T, 2:190976990_T_C, 2:190978930_A_G, 2:190978964_C_A, 2:190978967_GCT_G, 2:190978972_C_T, 2:190978985_T_C, 2:190979759_C_T, 2:190979816_G_A, 2:190979824_C_G, 2:190980614_C_T, 2:190980623_A_C, 2:190982415_T_C, 2:190983651_C_T, 2:190983657_C_T, 2:190983699_C_A, 2:190984307_T_C, 2:190984316_G_T, 2:190984360_G_C, 2:190985612_C_T, 2:190985626_G_C, 2:190985634_G_A, 2:190985634_G_C, 2:190985663_A_G, 2:190985665_A_G, 2:190986906_A_C, 2:190986907_T_C, 2:190986913_T_C, 2:190986913_T_G, 2:190986921_G_A, 2:190986924_C_T, 2:190986942_CT_TA, 2:190987035_G_A, 2:190987040_C_A, 2:190987045_AC_TA, 2:190989622_A_G, 2:190989649_T_C, 2:190989659_C_A, 2:190989660_A_C, 2:190991241_T_G, 2:190991258_T_A, 2:190991295_A_G, 2:190991307_C_G, 2:190991325_A_C, 2:190995071_G_A, 2:190995129_G_T, 2:190995139_T_C, 2:190995143_T_C, 2:190995148_T_A, 2:190995151_T_C, 2:190995173_T_C, 2:190995184_C_T, 2:190995185_G_A, 2:190995185_G_C, 2:190995193_T_G, 2:190995205_G_A, 2:190995209_C_T, 2:190997889_G_A, 2:190997890_G_GC, 2:190997919_C_T, 2:190997927_C_T, 2:190998244_C_T, 2:190998246_T_C, 2:190998247_C_A, 2:190999630_G_T, 2:190999647_A_G, 2:190999649_T_A, 2:190999659_A_T, 2:190999673_T_C, 2:190999674_C_G, 2:190999689_T_G, 2:191001113_CTCTT_C, 2:191001124_T_A, 2:191001129_A_T, 2:191001156_G_A, 2:191007651_T_A, 2:191007665_G_C, 2:191009043_C_T, 2:191009050_T_C, 2:191009915_AT_A, 2:191013689_A_T, 2:191014155_G_C, and 2:191014182_G_A.
In some embodiments, the guide sequence portion of the first RNA molecule comprises 17-25 contiguous nucleotides containing nucleotides in the sequence set forth in any one of SEQ ID NOs 1-37365 which targets a mutation associated with CMC.
In some embodiments, the method further comprising introduction of a donor DNA molecule for homology directed repair (HDR), alteration, or replacement of a desired sequence of the STAT1 allele.
In some embodiments, the first RNA molecule targets the CRISPR nuclease to a SNP position of the mutant allele.
In some embodiments, the SNP position is any one of rs10199181, rs11682932, rs11692579, rs12693590, rs1914408, rs2066795, rs2280235, rs41375144, rs41430444, rs62179911, rs73979324, 2:190961761_C_T, 2:190963870_A_G, 2:190977033_G_A, 2:190995803_C_T, 2:191017537_C_T, rs12693591, rs11386507, rs398105121, rs3215260, rs112292924, rs11889555, rs12693589, rs13029247, rs55658633, rs13005843, rs5837215, rs13029532, rs59420375, rs73064614, rs7562024, 2:191021099_T_C, 2:191021367_T_C, rs11688154, rs12693588, rs13010343, rs3088307, rs36234022, rs6752638, rs6755660, 2:190963477_A_T, 2:190963479_C_A, 2:190985840_T_C, rs1400657, rs6718902, 2:190971704_T_TTC, rs10437, rs11887698, rs2066802, rs34997637, rs7558921, 2:190961656_A_G, 2:190972045_T_C, 2:190973115_T_C, rs11885069, rs12987796, rs17817076, rs2030171, rs36116009, rs4853537, 2:191015776_C_G, rs41454245, rs760275441, rs1491049196, rs11677408, rs12464143, rs151232124, rs796493321, rs41474144, rs10173099, rs11693463, rs16833157, rs2280234, rs4853455, 2:190966079_A_C, rs7597768, rs36014758, 2:190964627_C_G, rs36077929, rs16833172, 2:190972908_C_T, rs3755312, 2:191018047_C_G, rs16833177, rs2280232, rs13395505, rs10208033, rs12468579, rs2066806, rs4327257, rs1168, rs6711082, rs1547550, rs16833146, rs3771300, rs7575823, rs10195683, rs34230248, rs45528632, rs45467700, 2:190989913_C_A, rs11904548, rs67960489, 2:191005594_G_A, rs6751855, 2:190974738_G_A, rs7576984, rs71403203, rs4853532, rs6745710, rs397814979, rs2066797, 2:190961689_G_GTTT, 2:190961689_G_GTTTT, 2:190961689_G_GT, rs113477796, rs7565237, rs1467198, rs762997161, rs10190333, rs1491128973, rs72330702, 2:190971836_C_G, 2:191015242_G_GTT, 2:191015242_G_GT, rs60976990, 2:190991701_G_T, and 2:190988561_G_A.
In some embodiments, the guide sequence portion of the first RNA molecule comprises 17-25 contiguous nucleotides containing nucleotides in the sequence set forth in any one of SEQ ID NOs 1-37365 which targets a SNP position of the mutant allele.
In some embodiments, the SNP position is in Exon 3 of STAT1.
In some embodiments, the SNP position is rs2066802.
In some embodiments, the SNP position contains a heterozygous SNP.
In some embodiments, the method further comprises introduction of a second RNA molecule comprising a guide sequence portion capable of complexing with a CRISPR nuclease, wherein the complex of the second RNA molecule and CRISPR nuclease affects a second double strand break in the STAT1 gene.
In some embodiments, the second RNA molecule is a non-discriminatory gRNA that targets both a functional STAT1 allele and the mutant STAT1 allele.
In some embodiments, the second RNA molecule targets a STAT1 intron.
In some embodiments, a STAT1 exon is excised by the first and second RNA molecules, and wherein the exon is selected from the group consisting of Exon 3, 4, 7, 8, 9, 14, 18, 19, 20, and 21.
In some embodiments, the guide sequence portion of the second RNA molecule comprises 17-25 contiguous nucleotides containing nucleotides in the sequence set forth in any one of SEQ ID NOs 1-37365 other than the sequence of the first RNA molecule.
According to embodiments of the present invention, there is provided a modified cell obtained by the method of any one of the embodiments presented herein.
According to embodiments of the present invention, there is provided a first RNA molecule comprising a guide sequence portion having 17-25 contiguous nucleotides containing nucleotides in the sequence set forth in any one of SEQ ID NOs 1-37365.
According to embodiments of the present invention, there is provided a composition comprising the first RNA molecule and a CRISPR nuclease.
In some embodiments, the composition further comprises a second RNA molecule comprising a guide sequence portion.
In some embodiments, the 17-25 nucleotides of the guide sequence portion of the second RNA molecule is a different sequence from the sequence of the guide sequence portion of the first RNA molecule.
In some embodiments, the guide sequence portion of the second RNA molecule comprises 17-25 contiguous nucleotides containing nucleotides in the sequence set forth in any one of SEQ ID NOs 1-37365 other than the sequence of the first RNA molecule.
According to embodiments of the present invention, there is provided a method for inactivating a mutant STAT1 allele in a cell, the method comprising delivering to the cell the composition of any one of the embodiments presented herein.
According to embodiments of the present invention, there is provided a method for treating CMC, the method comprising delivering to a cell of a subject having CMC the composition of any one of the embodiments presented herein.
According to embodiments of the present invention, there is provided use of any one of the compositions presented herein for inactivating a mutant STAT1 allele in a cell, comprising delivering to the cell the composition of any one of the embodiments presented herein.
According to embodiments of the present invention, there is provided a medicament comprising the composition of any one of the embodiments presented herein for use in inactivating a mutant STAT1 allele in a cell, wherein the medicament is administered by delivering to the cell the composition of any one of the embodiments presented herein.
According to embodiments of the present invention, there is provided use of the composition of any one of the embodiments presented herein for treating ameliorating or preventing CMC, comprising delivering to a cell of a subject having or at risk of having CMC the composition of any one of the embodiments presented herein.
According to embodiments of the present invention, there is provided a medicament comprising the composition of any one of the embodiments presented herein for use in treating ameliorating or preventing CMC, wherein the medicament is administered by delivering to a cell of a subject having or at risk of having CMC the composition of any one of the embodiments presented herein.
According to embodiments of the present invention, there is provided a kit for inactivating a mutant STAT1 allele in a cell, comprising the RNA molecule of any one of the embodiments presented herein, a CRISPR nuclease, and/or a tracrRNA molecule; and instructions for delivering the RNA molecule; CRISPR nuclease, and/or the tracrRNA to the cell.
According to embodiments of the present invention, there is provided a kit for treating CMC in a subject, comprising the RNA molecule of any one of the embodiments presented herein, a CRISPR nuclease, and/or a tracrRNA molecule; and instructions for delivering the RNA molecule; CRISPR nuclease, and/or the tracrRNA to a cell of a subject having or at risk of having CMC.
The present disclosure provides a method for utilizing at least one naturally occurring nucleotide difference or polymorphism (e.g., single nucleotide polymorphism (SNP)) for distinguishing/discriminating between two alleles of a gene, one allele bearing a mutation such that it encodes a mutated protein causing a disease phenotype (“mutated allele”) and a particular sequence in a SNP position (SNP/REF), and the other allele encoding for a functional protein (“functional allele”). The method further comprises the step of knocking out expression of the mutated protein and allowing expression of the functional protein. In some embodiments, the method is for treating, ameliorating, or preventing a dominant negative genetic disorder.
According to embodiments of the present invention, there is provided a first RNA molecule comprising a guide sequence portion having 17-25 contiguous nucleotides containing nucleotides in the sequence set forth in any one of SEQ ID NOs 1-37365.
According embodiments of the present invention, an RNA molecule may further comprise a portion having a sequence which binds to a CRISPR nuclease.
According to embodiments of the present invention, the sequence which binds to a CRISPR nuclease is a tracrRNA sequence.
According to embodiments of the present invention, an RNA molecule may further comprise a portion having a tracr mate sequence.
According to embodiments of the present invention, an RNA molecule may further comprise one or more linker portions.
According to embodiments of the present invention, an RNA molecule may be up to 300, 290, 280, 270, 260, 250, 240, 230, 220, 210, 200, 190, 180, 170, 160, 150, 140, 130, 120, 110, or 100 nucleotides in length. Each possibility represents a separate embodiment. In embodiments of the present invention, the RNA molecule may be 17 up to 300 nucleotides in length, 100 up to 300 nucleotides in length, 150 up to 300 nucleotides in length, 200 up to 300 nucleotides in length, 100 to 200 nucleotides in length, or 150 up to 250 nucleotides in length. Each possibility represents a separate embodiment.
According to some embodiments of the present invention, there is provided a composition comprising an RNA molecule comprising a guide sequence portion having 17-25 contiguous nucleotides containing nucleotides in the sequence set forth in any one of SEQ ID NOs 1-37365 and a CRISPR nuclease.
According to embodiments of the present invention, the composition may comprise a second RNA molecule comprising a guide sequence portion.
According to embodiments of the present invention, the guide sequence portion of the second RNA molecule comprises 17-25 contiguous nucleotides containing nucleotides in the sequence set forth in any one of SEQ ID NOs 1-37365.
According to embodiments of the present invention, the 17-25 nucleotides of the guide sequence portion of the second RNA molecule are in a different sequence from the sequence of the guide sequence portion of the first RNA molecule
Embodiments of the present invention may comprise a tracrRNA molecule.
According to some embodiments of the present invention, there is provided a method for inactivating a mutant STAT1 allele in a cell, the method comprising delivering to the cell a composition comprising an RNA molecule comprising a guide sequence portion having 17-25 contiguous nucleotides containing nucleotides in the sequence set forth in any one of SEQ ID NOs 1-37365 and a CRISPR nuclease.
According to some embodiments of the present invention, there is provided a method for treating CMC, the method comprising delivering to a cell of a subject having CMC a composition comprising an RNA molecule comprising a guide sequence portion having 17-25 contiguous nucleotides containing nucleotides in the sequence set forth in any one of SEQ ID NOs 1-37365 and a CRISPR nuclease.
According to embodiments of the present invention, the composition comprises a second RNA molecule comprising a guide sequence portion having 17-25 contiguous nucleotides containing nucleotides in the sequence set forth in any one of SEQ ID NOs 1-37365.
According to embodiments of the present invention, the 17-25 nucleotides of the guide sequence portion of the second RNA molecule are in a different sequence from the sequence of the guide sequence portion of the first RNA molecule
According to embodiments of the present invention, the CRISPR nuclease and the RNA molecule or RNA molecules are delivered to the subject and/or cells substantially at the same time or at different times.
According to embodiments of the present invention, the tracrRNA is delivered to the subject and/or cells substantially at the same time or at different times as the CRISPR nuclease and RNA molecule or RNA molecules.
According to embodiments of the present invention, the first RNA molecule targets a SNP or disease-causing mutation in an exon or promoter of a mutated allele, and wherein the second RNA molecule targets a SNP in the same or a different exon of the mutated allele, a SNP in an intron, or a sequence in an intron present in both the mutated or functional allele.
According to embodiments of the present invention, the first RNA molecule or the first and the second RNA molecules target a SNP in the promoter region, the start codon, or the untranslated region (UTR) of a mutated allele.
According to embodiments of the present invention, the first RNA molecule or the first and the second RNA molecules targets at least a portion of the promoter and/or the start codon and/or a portion of the UTR of a mutated allele.
According to embodiments of the present invention, the first RNA molecule targets a portion of the promoter, a first SNP in the promoter, or a SNP upstream to the promoter of a mutated allele and the second RNA molecule is targets a second SNP, which is downstream of the first SNP, and is in the promoter, in the UTR, or in an intron or in an exon of a mutated allele.
According to embodiments of the present invention, the first RNA molecule targets a SNP in the promoter, upstream of the promoter, or the UTR of a mutated allele and the second RNA molecule is designed to target a sequence which is present in an intron of both the mutated allele and the functional allele.
According to embodiments of the present invention, the first RNA molecule targets a SNP in an intron of a mutated allele, and wherein the second RNA molecule targets a SNP in an intron of the mutated allele, or a sequence in an intron present in both the mutated and functional allele.
According to embodiments of the present invention, the first RNA molecule targets a sequence upstream of the promotor which is present in both a mutated and functional allele and the second RNA molecule targets a SNP or disease-causing mutation in any location of the gene.
According to embodiments of the present invention, there is provided a method comprising removing an exon containing a disease-causing mutation from a mutated allele, wherein the first RNA molecule or the first and the second RNA molecules target regions flanking an entire exon or a portion of the exon.
According to embodiments of the present invention, there is provided a method comprising removing multiple exons, the entire open reading frame of a gene, or removing the entire gene.
According to embodiments of the present invention, the first RNA molecule targets a SNP or disease-causing mutation in an exon or promoter of a mutated allele, and wherein the second RNA molecule targets a SNP in the same or a different exon of the mutated allele, a SNP in an intron, or a sequence in an intron present in both the mutated or functional allele.
According to embodiments of the present invention, the first RNA molecule or the first and the second RNA molecules target an alternative splicing signal sequence between an exon and an intron of a mutant allele.
According to embodiments of the present invention, the second RNA molecule targets a sequence present in both a mutated allele and a functional allele.
According to embodiments of the present invention, the second RNA molecule targets an intron.
According to embodiments of the present invention, there is provided a method comprising subjecting the mutant allele to insertion or deletion by an error prone non-homologous end joining (NHEJ) mechanism, generating a frameshift in the mutated allele's sequence.
According to embodiments of the present invention, the frameshift results in inactivation or knockout of the mutated allele.
According to embodiments of the present invention, the frameshift creates an early stop codon in the mutated allele.
According to embodiments of the present invention, the frameshift results in nonsense-mediated mRNA decay of the transcript of the mutant allele.
According to embodiments of the present invention, the inactivating or treating results in a truncated protein encoded by the mutated allele and a functional protein encoded by the functional allele.
According to some embodiments of the present invention, there is provided use of a composition comprising an RNA molecule comprising a guide sequence portion having 17-25 contiguous nucleotides containing nucleotides in the sequence set forth in any one of SEQ ID NOs 1-37365 and a CRISPR nuclease inactivating a mutant STAT1 allele in a cell, comprising delivering to the cell the RNA molecule comprising a guide sequence portion having 17-25 contiguous nucleotides containing nucleotides in the sequence set forth in any one of SEQ ID NOs 1-37365 and the CRISPR nuclease.
According to embodiments of the present invention, there is provided a medicament comprising an RNA molecule comprising a guide sequence portion having 17-25 contiguous nucleotides containing nucleotides in the sequence set forth in any one of SEQ ID NOs 1-37365 and a CRISPR nuclease for use in inactivating a mutant STAT1 allele in a cell, wherein the medicament is administered by delivering to the cell the composition comprising an RNA molecule comprising a guide sequence portion having 17-25 contiguous nucleotides containing nucleotides in the sequence set forth in any one of SEQ ID NOs 1-37365 and a CRISPR nuclease.
According to some embodiments of the present invention, there is provided use of a composition comprising an RNA molecule comprising a guide sequence portion having 17-25 contiguous nucleotides containing nucleotides in the sequence set forth in any one of SEQ ID NOs 1-37365 and a CRISPR nuclease for treating ameliorating or preventing CMC, comprising delivering to a cell of a subject having or at risk of having CMC the composition of comprising an RNA molecule comprising a guide sequence portion having 17-25 contiguous nucleotides containing nucleotides in the sequence set forth in any one of SEQ ID NOs 1-37365 and a CRISPR nuclease.
According to some embodiments of the present invention, there is provided a medicament comprising the composition comprising an RNA molecule comprising a guide sequence portion having 17-25 contiguous nucleotides containing nucleotides in the sequence set forth in any one of SEQ ID NOs 1-37365 and a CRISPR nuclease for use in treating ameliorating or preventing CMC, wherein the medicament is administered by delivering to a cell of a subject having or at risk of having CMC: the composition comprising an RNA molecule comprising a guide sequence portion having 17-25 contiguous nucleotides containing nucleotides in the sequence set forth in any one of SEQ ID NOs 1-37365 and a CRISPR nuclease.
According to some embodiments of the present invention, there is provided a kit for inactivating a mutant STAT1 allele in a cell, comprising an RNA molecule comprising a guide sequence portion having 17-25 contiguous nucleotides containing nucleotides in the sequence set forth in any one of SEQ ID NOs 1-37365, a CRISPR nuclease, and/or a tracrRNA molecule; and instructions for delivering the RNA molecule; CRISPR nuclease, and/or the tracrRNA to the cell.
According to some embodiments of the present invention, there is provided a kit for treating CMC in a subject, comprising an RNA molecule comprising a guide sequence portion having 17-25 contiguous nucleotides containing nucleotides in the sequence set forth in any one of SEQ ID NOs 1-37365, a CRISPR nuclease, and/or a tracrRNA molecule; and instructions for delivering the RNA molecule; CRISPR nuclease, and/or the tracrRNA to a cell of a subject having or at risk of having CMC.
In embodiments of the present invention, the RNA molecule comprises a guide sequence portion having 17-25 contiguous nucleotides containing nucleotides in the sequence set forth in any one of SEQ ID NOs 1-37365.
The compositions and methods of the present disclosure may be utilized for treating, preventing, ameliorating, or slowing progression of an autosomal dominant genetic disorder, such as CMC.
In some embodiments, a mutated allele is deactivated by delivering to a cell an RNA molecule which targets a SNP in the promoter region, the start codon, or the untranslated region (UTR) of the mutated allele.
In some embodiments, a mutated allele is inactivated by removing at least a portion of the promoter and/or removing the start codon and/or a portion of the UTR. In some embodiments, the method of deactivating a mutated allele comprises removing at least a portion of the promoter. In such embodiments one RNA molecule may be designed for targeting a first SNP in the promoter or upstream to the promoter and another RNA molecule is designed to target a second SNP, which is downstream of the first SNP, and is in the promoter, in the UTR, or in an intron or in an exon.
Alternatively, one RNA molecule may be designed for targeting a SNP in the promoter, or upstream of the promoter, or the UTR and another RNA molecule is designed to target a sequence which is present in an intron of both the mutated allele and the functional allele. Alternatively, one RNA molecule may be designed for targeting a sequence upstream of the promotor which is present in both the mutated and functional allele and the other guide is designed to target a SNP or disease-causing mutation in any location of the gene e.g., in an exon, intron, UTR, or downstream of the promoter.
In some embodiments, the method of deactivating a mutated allele comprises an exon skipping step comprising removing an exon containing a disease-causing mutation from the mutated allele. Removing an exon containing a disease-causing mutation in the mutated allele requires two RNA molecules which target regions flanking the entire exon or a portion of the exon. Removal of an exon containing the disease-causing mutation may be designed to eliminate the disease-causing action of the protein while allowing for expression of the remaining protein product which retains some or all of the wild-type activity. As an alternative to single exon skipping, multiple exons, the entire open reading frame or the entire gene can be excised using two RNA molecules flanking the region desired to be excised.
In some embodiments, the method of deactivating a mutated allele comprises delivering two RNA molecules to a cell, wherein one RNA molecule targets a SNP or disease-causing mutation in an exon or promoter of the mutated allele, and wherein the other RNA molecule targets a SNP in the same or a different exon of the mutated allele, a SNP in an intron, or a sequence in an intron present in both the mutated or functional allele.
In some embodiments, an RNA molecule is used to target a CRISPR nuclease to an alternative splicing signal sequence between an exon and an intron of a mutant allele, thereby destroying the alternative splicing signal sequence in the mutant allele.
Any one of, or combination of, the above-mentioned strategies for deactivating a mutant allele may be used in the context of the invention.
Additional strategies may be used to deactivate a mutated allele. For example, in embodiments of the present invention, an RNA molecule is used to direct a CRISPR nuclease to an exon or a splice site of a mutated allele in order to create a double-stranded break (DSB), leading to insertion or deletion of nucleotides by an error-prone non-homologous end-joining (NHEJ) mechanism and formation of a frameshift mutation in the mutated allele. The frameshift mutation may result in: (1) inactivation or knockout of the mutated allele by generation of an early stop codon in the mutated allele, resulting in generation of a truncated protein; or (2) nonsense mediated mRNA decay of the transcript of the mutant allele. In further embodiments, one RNA molecule is used to direct a CRISPR nuclease to a promotor of a mutated allele.
In some embodiments, the method of deactivating a mutated allele further comprises enhancing activity of the functional protein such as by providing a protein/peptide, a nucleic acid encoding a protein/peptide, or a small molecule such as a chemical compound, capable of activating/enhancing activity of the functional protein.
According to some embodiments, the present disclosure provides an RNA sequence (also referred to as an ‘RNA molecule’) which binds to/associates with and/or directs the RNA guided DNA nuclease e.g., CRISPR nuclease to a sequence comprising at least one nucleotide which differs between a mutated allele and a functional allele (e.g., SNP) of a gene of interest (i.e., a sequence of the mutated allele which is not present in the functional allele).
In some embodiments, the method comprises the steps of: contacting a mutated allele of a gene of interest with an allele-specific RNA molecule and a CRISPR nuclease e.g., a Cas9 protein, wherein the allele-specific RNA molecule and the CRISPR nuclease e.g., Cas9 associate with a nucleotide sequence of the mutated allele of the gene of interest which differs by at least one nucleotide from a nucleotide sequence of a functional allele of the gene of interest, thereby modifying or knocking-out the mutated allele.
In some embodiments, the allele-specific RNA molecule and a CRISPR nuclease is introduced to a cell encoding the gene of interest. In some embodiments, the cell encoding the gene of interest is in a mammalian subject. In some embodiments, the cell encoding the gene of interest is in a plant.
In some embodiments, the cleaved mutated allele is further subjected to insertion or deletion (indel) by an error prone non-homologous end joining (NHEJ) mechanism, generating a frameshift in the mutated allele's sequence. In some embodiments, the generated frameshift results in inactivation or knockout of the mutated allele. In some embodiments, the generated frameshift creates an early stop codon in the mutated allele and results in generation of a truncated protein. In such embodiments, the method results in the generation of a truncated protein encoded by the mutated allele and a functional protein encoded by the functional allele. In some embodiments, a frameshift generated in a mutated allele using the methods of the invention results in nonsense-mediated mRNA decay of the transcript of the mutant allele.
In some embodiments, the mutated allele is an allele of STAT1 gene. In some embodiments, the RNA molecule targets a SNP which co-exists with/is genetically linked to the mutated sequence associated with CMC genetic disorder. In some embodiments, the RNA molecule targets a SNP which is highly prevalent in the population and exists in the mutated allele having the mutated sequence associated with CMC genetic disorder and not in the functional allele of an individual subject to be treated. In some embodiments, a disease-causing mutation within a mutated STAT1 allele is targeted.
In some embodiments, the SNP is within an exon of the gene of interest. In such embodiments, a guide sequence portion of an RNA molecule may be designed to associate with a sequence of the exon of the gene of interest.
In some embodiments, SNP is within an intron or an exon of the gene of interest. In some embodiments, SNP is in close proximity to a splice site between the intron and the exon. In some embodiments, the close proximity to a splice site is 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 nucleotides upstream or downstream to the splice site. Each possibility represents a separate embodiment of the present invention. In such embodiments, a guide sequence portion of an RNA molecule may be designed to associate with a sequence of the gene of interest which comprises the splice site.
In some embodiments, the method is utilized for treating a subject having a disease phenotype resulting from the heterozygote STAT1 gene. In such embodiments, the method results in improvement, amelioration or prevention of the disease phenotype.
Embodiments referred to above refer to a CRISPR nuclease, RNA molecule(s), and tracrRNA being effective in a subject or cells at the same time. The CRISPR, RNA molecule(s), and tracrRNA can be delivered substantially at the same time or can be delivered at different times but have effect at the same time. For example, this includes delivering the CRISPR nuclease to the subject or cells before the RNA molecule and/or tracr RNA is substantially extant in the subject or cells.
In one embodiment, the cell is a stem cell. In one embodiment, the cell is an embryonic stem cell. In some embodiment, the stem cell is a hematopoietic stem/progenitor cell (HSC).
One of skill in the art will appreciate that all subjects with any type of heterozygote genetic disorder (e.g., dominant genetic disorder) may be subjected to the methods described herein. In one embodiment, the present invention may be used to target a gene involved in, associated with, or causative of dominant genetic disorders such as, for example, CMC. In some embodiments, the dominant genetic disorder is CMC. In some embodiments, the target gene is the STAT1 gene (Entrez Gene, gene ID No: 6772). Non-limiting examples of mutation previously characterized as gain of function mutations associated with CMC phenotype include mutations in the following locations: rs387906759 (p.A267V, c.800C>T), rs387906758 (c.820C>T, p.R274W), rs387906760 (c.821G>A, p.R274Q), and rs587777630 (c.1154C>T, p.T385M).
STAT1 editing strategies include, but are not limited to, (1) truncation; (2) inhibiting expression of a mutated STAT1 allele; (3) inducing a frameshift in Exon 3 by targeting SNP rs2066802 and mediating single DSB, leading to nonsense-mediated decay (NMD); and (4) targeting a STAT1 mutation to induce a frameshift or correct the mutation using homology directed repair (HDR), preferably with a donor molecule or donor template.
Notably, STAT1 may be truncated until at least exon 21 without causing a pathogenic affect. Indeed, healthy individuals harbor frameshift mutations in exon 21 and may express a shorter splice variant that contains 22 exons. Truncation can be achieved by several approaches. For example, excision may be achieved by targeting STAT1 with two different sgRNA molecules. STAT1 exons that can be excised and lead to a frameshift are: Exons 3, 4, 7, 8, 9, 14, 18, 19, 20 and 21. The further upstream the excision is located, the more mutations it will cover. The excision is preferably done by mediating a DNA double-strand break (DSB) in the introns flanking the desired exon. One DSB is preferably allele specific. As a non-limiting example, excision of Exon 4 may be achieved by targeting SNPs in Intron 5 (e.g. rs2030171 and rs10183196) and a utilizing a second non-discriminating gRNA in Intron 3, thereby deleting a fragment of ˜3-5 kb. In another approach, truncation can be achieved by introducing a splice acceptor by HDR. A splice acceptor sequence can be introduced using, for example, a double-stranded donor oligonucleotide (dsODN) template. As in the case of excision, the further upstream this sequence is inserted, the more mutations it will cover.
In another editing strategy, expression of a mutated STAT1 allele may be inhibited. This can be achieved by excising the poly-A signal in the 3′UTR region, which would lead to unstable transcript. Notably, a shorter STAT1 transcript naturally exists (NM_139266). The poly-A signal of that transcript is located in Intron 22 and also needs to be excised in this specific example. The length of the excised fragment would be >6 kb.
In some embodiments, the sequence specific nuclease is selected from CRISPR nucleases, or a functional variant thereof. In some embodiments, the sequence specific nuclease is an RNA guided DNA nuclease. In such embodiments, the RNA sequence which guides the RNA guided DNA nuclease (e.g., Cpfl) binds to and/or directs the RNA guided DNA nuclease to the sequence comprising at least one nucleotide which differs between a mutated allele and its counterpart functional allele (e.g., SNP). In some embodiments, the CRISPR complex does not further comprise a tracrRNA. In a non-limiting example, in which the RNA guided DNA nuclease is a CRISPR protein, the at least one nucleotide which differs between the dominant mutated allele and the functional allele may be within the PAM site and/or proximal to the PAM site within the region that the RNA molecule is designed to hybridize to. A skilled artisan will appreciate that RNA molecules can be engineered to bind to a target of choice in a genome by commonly known methods in the art.
In embodiments of the present invention, a type II CRISPR system utilizes a mature crRNA:tracrRNA complex directs a CRISPR nuclease, e.g. Cas9, to the target DNA via Watson-Crick base-pairing between the crRNA and the protospacer on the target DNA next to the protospacer adjacent motif (PAM), an additional requirement for target recognition. The CRISPR nuclease then mediates cleavage of target DNA to create a double-stranded break within the protospacer. A skilled artisan will appreciate that each of the engineered RNA molecule of the present invention is further designed such as to associate with a target genomic DNA sequence of interest next to a protospacer adjacent motif (PAM), e.g., a PAM matching the sequence relevant for the type of CRISPR nuclease utilized, such as for a non-limiting example, NGG or NAG, wherein “N” is any nucleobase, for Streptococcus pyogenes Cas9 WT (SpCAS9); NNGRRT for Staphylococcus aureus (SaCas9); NNNVRYM for Jejuni Cas9 WT; NGAN or NGNG for SpCas9-VQR variant; NGCG for SpCas9-VRER variant; NGAG for SpCas9-EQR variant; NNNNGATT for Neisseria meningitidis (NmCas9); or TTTV for Cpfl. RNA molecules of the present invention are each designed to form complexes in conjunction with one or more different CRISPR nucleases and designed to target polynucleotide sequences of interest utilizing one or more different PAM sequences respective to the CRISPR nuclease utilized.
In some embodiments, an RNA-guided DNA nuclease e.g., a CRISPR nuclease, may be used to cause a DNA break at a desired location in the genome of a cell. The most commonly used RNA-guided DNA nucleases are derived from CRISPR systems, however, other RNA-guided DNA nucleases are also contemplated for use in the genome editing compositions and methods described herein. For instance, see U.S. Patent Publication No. 2015-0211023, incorporated herein by reference.
CRISPR systems that may be used in the practice of the invention vary greatly. CRISPR systems can be a type I, a type II, or a type III system. Non-limiting examples of suitable CRISPR proteins include Cas3, Cas4, Cas5, Cas5e (or CasD), Cas6, Cas6e, Cas6f, Cas7, Cas8al, Cas8a2, Cas8b, Cas8c, Cas9, Cas10, Casl Od, CasF, CasG, CasH, Csyl, Csy2, Csy3, Csel (or CasA), Cse2 (or CasB), Cse3 (or CasE), Cse4 (or CasC), Cscl, Csc2, Csa5, Csn2, Csm2, Csm3, Csm4, Csm5, Csm6, Cmrl, Cmr3, Cmr4, Cmr5, Cmr6, Csbl, Csb2, Csb3, Csxl7, Csxl4, Csxl0, Csxl6, CsaX, Csx3, Cszl, Csxl5, Csfl, Csf2, Csf3, Csf4, and Cul966.
In some embodiments, the RNA-guided DNA nuclease is a CRISPR nuclease derived from a type II CRISPR system (e.g., Cas9). The CRISPR nuclease may be derived from Streptococcus pyogenes, Streptococcus thermophilus, Streptococcus sp., Staphylococcus aureus, Neisseria meningitidis, Treponema denticola, Nocardiopsis dassonvillei, Streptomyces pristinaespiralis, Streptomyces viridochromogenes, Streptomyces viridochromogenes, Streptosporangiurn roseurn, Streptosporangiurn roseum, Alicyclobacillus acidocaldarius, Bacillus pseudomycoides, Bacillus selenitireducens, Exiguobacterium sibiricum, Lactobacillus delbrueckii, Lactobacillus salivarius, Microscilla marina, Burkholderiales bacterium, Polaromonas naphthalenivorans, Polaromonas sp., Crocosphaera watsonii, Cyanothece sp., Microcystis aeruginosa, Synechococcus sp., Acetohalobiurn arabaticum, Ammonifex degensii, Caldicelulosiruptor becscii, Candidatus Desulforudis, Clostridium botulinum, Clostridium difficile, Finegoldia magna, Natranaerobius thermophilus, Pelotomaculumthermopropionicum, Acidithiobacillus caldus, Acidithiobacillus ferrooxidans, Allochromatiurn vinosurn, Marinobacter sp., Nitrosococcus halophilus, Nitrosococcus watsoni, Pseudoalteromonas haloplanktis, Ktedonobacter racemifer, Methanohalobiurn evestigatum, Anabaena variabilis, Nodularia spumigena, Nostoc sp., Arthrospira maxima, Arthrospira platensis, Arthrospira sp., Lyngbya sp., Microcoleus chthonoplastes, Oscillatoria sp., Petrotoga mobilis, Thermosipho africanus, Acaryochloris marina, or any species which encodes a CRISPR nuclease with a known PAM sequence. CRISPR nucleases encoded by uncultured bacteria may also be used in the context of the invention. (See Burstein et al. Nature, 2017). Variants of CRIPSR proteins having known PAM sequences e.g., SpCas9 D1135E variant, SpCas9 VQR variant, SpCas9 EQR variant, or SpCas9 VRER variant may also be used in the context of the invention.
Thus, an RNA guided DNA nuclease of a CRISPR system, such as a Cas9 protein or modified Cas9 or homolog or ortholog of Cas9, or other RNA guided DNA nucleases belonging to other types of CRISPR systems, such as Cpfl and its homologs and orthologs, may be used in the compositions of the present invention.
In certain embodiments, the CRIPSR nuclease may be a “functional derivative” of a naturally occurring Cas protein. A “functional derivative” of a native sequence polypeptide is a compound having a qualitative biological property in common with a native sequence polypeptide. “Functional derivatives” include, but are not limited to, fragments of a native sequence and derivatives of a native sequence polypeptide and its fragments, provided that they have a biological activity in common with a corresponding native sequence polypeptide. A biological activity contemplated herein is the ability of the functional derivative to hydrolyze a DNA substrate into fragments. The term “derivative” encompasses both amino acid sequence variants of polypeptide, covalent modifications, and fusions thereof. Suitable derivatives of a Cas polypeptide or a fragment thereof include but are not limited to mutants, fusions, covalent modifications of Cas protein or a fragment thereof. Cas protein, which includes Cas protein or a fragment thereof, as well as derivatives of Cas protein or a fragment thereof, may be obtainable from a cell or synthesized chemically or by a combination of these two procedures. The cell may be a cell that naturally produces Cas protein, or a cell that naturally produces Cas protein and is genetically engineered to produce the endogenous Cas protein at a higher expression level or to produce a Cas protein from an exogenously introduced nucleic acid, which nucleic acid encodes a Cas that is same or different from the endogenous Cas. In some cases, the cell does not naturally produce Cas protein and is genetically engineered to produce a Cas protein.
In some embodiments, the CRISPR nuclease is Cpfl. Cpfl is a single RNA-guided endonuclease which utilizes a T-rich protospacer-adjacent motif. Cpfl cleaves DNA via a staggered DNA double-stranded break. Two Cpfl enzymes from Acidaminococcus and Lachnospiraceae have been shown to carry out efficient genome-editing activity in human cells. (See Zetsche et al. (2015) Cell.).
Thus, an RNA guided DNA nuclease of a Type II CRISPR System, such as a Cas9 protein or modified Cas9 or homologs, orthologues, or variants of Cas9, or other RNA guided DNA nucleases belonging to other types of CRISPR systems, such as Cpfl and its homologs, orthologues, or variants, may be used in the present invention.
In some embodiments, the guide molecule comprises one or more chemical modifications which imparts a new or improved property (e.g., improved stability from degradation, improved hybridization energetics, or improved binding properties with an RNA guided DNA nuclease). Suitable chemical modifications include, but are not limited to: modified bases, modified sugar moieties, or modified inter-nucleoside linkages. Non-limiting examples of suitable chemical modifications include: 4-acetylcytidine, 5-(carboxyhydroxymethyl)uridine, 2′-O-methylcytidine, 5-carboxymethylaminomethyl-2-thiouridine, 5-carboxymethylaminomethyluridine, dihydrouridine, 2′-O-methylpseudouridine, “beta, D-galactosylqueosine”, 2′-O-methylguanosine, inosine, N6-isopentenyladenosine, 1-methyladenosine, 1-methylpseudouridine, 1-methylguanosine, I-methylinosine, “2,2-dimethylguanosine”, 2-methyladenosine, 2-methylguanosine, 3-methylcytidine, 5-methylcytidine, N6-methyladenosine, 7-methylguanosine, 5-methylaminomethyluridine, 5-methoxyaminomethyl-2-thiouridine, “beta. D-mannosylqueuosine”, 5-methoxycarbonylmethyl-2-thiouridine, 5-methoxycarbonylmethyluridine, 5-methoxyuridine, 2-methylthio-N6-isopentenyladenosine, N-((9-beta-D-ribofuranosyl-2-methylthiopurine-6-yl)carbamoyl)threonine, N-((9-beta-D-ribofuranosylpurine-6-yl)N-methylcarbamoyl)threonine, uridine-5-oxyacetic acid-methylester, uridine-5-oxyacetic acid, wybutoxosine, queuosine, 2-thiocytidine, 5-methyl-2-thiouridine, 2-thiouridine, 4-thiouridine, 5-methyluridine, N-((9-beta-D-ribofuranosylpurine-6-yl)-carbamoyl)threonine, 2′-O-methyl-5-methyluridine, 2′-O-methyluridine, wybutosine, “3-(3-amino-3-carboxy-propyl)uridine, (acp3)u”, 2′-O-methyl (M), 3′-phosphorothioate (MS), 3′-thioPACE (MSP), pseudouridine, or 1-methyl pseudo-uridine. Each possibility represents a separate embodiment of the present invention.
Guide Sequences which Specifically Target a Mutant Allele
A given gene may contain thousands of SNPs. Utilizing a 25 base pair target window for targeting each SNP in a gene would require hundreds of thousands of guide sequences. Any given guide sequence when utilized to target a SNP may result in degradation of the guide sequence, limited activity, no activity, or off-target effects. Accordingly, suitable guide sequences are necessary for targeting a given gene. By the present invention, a novel set of guide sequences have been identified for knocking out expression of a mutated STAT1 protein, inactivating a mutant STAT1 gene allele, and treating CMC.
The present disclosure provides guide sequences capable of specifically targeting a mutated allele for inactivation while leaving the functional allele unmodified. The guide sequences of the present invention are designed to, and are most likely to, specifically differentiate between a mutated allele and a functional allele. Of all possible guide sequences which target a mutated allele desired to be inactivated, the specific guide sequences disclosed herein are specifically effective to function with the disclosed embodiments.
Briefly, the guide sequences may have properties as follows: (1) target SNP/insertion/deletion/indel with a high prevalence in the general population, in a specific ethnic population or in a patient population is above 1% and the SNP/insertion/deletion/indel heterozygosity rate in the same population is above 1%; (2) target a location of a SNP/insertion/deletion/indel proximal to a portion of the gene e.g., within 5 k bases of any portion of the gene, for example, a promoter, a UTR, an exon or an intron; and (3) target a mutant allele using an RNA molecule which targets a founder or common pathogenic mutations for the disease/gene. In some embodiments, the prevalence of the SNP/insertion/deletion/indel in the general population, in a specific ethnic population or in a patient population is above 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, or 15% and the SNP/insertion/deletion/indel heterozygosity rate in the same population is above 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, or 15%. Each possibility represents a separate embodiment and may be combined at will.
For each gene, according to SNP/insertion/deletion/indel any one of the following strategies may be used to deactivate the mutated allele: (1) Knockout strategy using one RNA molecule—one RNA molecule is utilized to direct a CRISPR nuclease to a mutated allele and create a double-strand break (DSB) leading to formation of a frameshift mutation in an exon or in a splice site region of the mutated allele; (2) Knockout strategy using two RNA molecules—two RNA molecules are utilized. A first RNA molecule targets a region in the promoter or an upstream region of a mutated allele and another RNA molecule targets downstream of the first RNA molecule in a promoter, exon, or intron of the mutated allele; (3) Exon(s) skipping strategy—one RNA molecule may be used to target a CRISPR nuclease to a splice site region, either at the 5′end of an intron (donor sequence) or the 3′ end of an intron (acceptor sequence), in order to destroy the splice site. Alternatively, two RNA molecules may be utilized such that a first RNA molecule targets an upstream region of an exon and a second RNA molecule targets a region downstream of the first RNA molecule, thereby excising the exon(s). Based on the locations of identified SNPs/insertions/deletions/indels for each mutant allele, any one of, or a combination of, the above-mentioned methods to deactivate the mutant allele may be utilized.
When only one RNA molecule is used is that the location of the SNP is in an exon or in close proximity (e.g., within 20 basepairs) to a splice site between the intron and the exon. When two RNA molecules are used, guide sequences may target two SNPs such that the first SNP is upstream of exon 1 e.g., within the 5′ untranslated region, or within the promoter or within the first 2 kilobases 5′ of the transcription start site, and the second SNP is downstream of the first SNP e.g., within the first 2 kilobases 5′ of the transcription start site, or within intron 1, 2 or 3, or within exon 1, exon 2, or exon 3.
Guide sequences of the present invention may target a SNP in the upstream portion of the targeted gene, preferably upstream of the last exon of the targeted gene. Guide sequences may target a SNP upstream to exon 1, for example within the 5′ untranslated region, or within the promoter or within the first 4-5 kilobases 5′ of the transcription start site.
Guide sequences of the present invention may also target a SNP within close proximity (e.g., within 50 basepairs, more preferably with 20 basepairs) to a known protospacer adjacent motif (PAM) site.
Guide sequences of the present invention also may target: (1) a heterozygous SNP for the targeted gene; (2) a heterozygous SNPs upstream and downstream of the gene; (3) a SNPs with a prevalence of the SNP/insertion/deletion/indel in the general population, in a specific ethnic population, or in a patient population above 1%; (4) have a guanine-cytosine content of greater than 30% and less than 85%; (5) have no repeat of 4 or more thymine/uracil or 8 or more guanine, cytosine, or adenine; (6) having no off-target identified by off-target analysis; and (7) preferably target Exons over Introns or be upstream of a SNP rather than downstream of a SNP.
In embodiments of the present invention, the SNP may be upstream or downstream of the gene. In embodiments of the present invention, the SNP is within 4,000 base pairs upstream or downstream of the gene.
The at least one nucleotide which differs between the mutated allele and the functional allele, may be upstream, downstream or within the sequence of the disease-causing mutation of the gene of interest. The at least one nucleotide which differs between the mutated allele and the functional allele, may be within an exon or within an intron of the gene of interest. In some embodiments, the at least one nucleotide which differs between the mutated allele and the functional allele is within an exon of the gene of interest. In some embodiments, the at least one nucleotide which differs between the mutated allele and the functional allele is within an intron or an exon of the gene of interest, in close proximity to a splice site between the intron and the exon e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 nucleotides upstream or downstream to the splice site.
In some embodiments, the at least one nucleotide is a single nucleotide polymorphisms (SNPs). In some embodiments, each of the nucleotide variants of the SNP may be expressed in the mutated allele. In some embodiments, the SNP may be a founder or common pathogenic mutation.
Guide sequences may target a SNP which has both (1) a high prevalence in the general population e.g., above 1% in the population; and (2) a high heterozygosity rate in the population, e.g., above 1%. Guide sequences may target a SNP that is globally distributed. A SNP may be a founder or common pathogenic mutation. In some embodiments, the prevalence in the general population is above 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, or 15%. Each possibility represents a separate embodiment. In some embodiments, the heterozygosity rate in the population is above 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, or 15%. Each possibility represents a separate embodiment.
In some embodiments, the at least one nucleotide which differs between the mutated allele and the functional allele is linked to/co-exists with the disease-causing mutation in high prevalence in a population. In such embodiments, “high prevalence” refers to at least 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%. Each possibility represents a separate embodiment of the present invention. In one embodiment, the at least one nucleotide which differs between the mutated allele and the functional allele, is a disease-associated mutation. In some embodiments, the SNP is highly prevalent in the population. In such embodiments, “highly prevalent” refers to at least 10%, 11%, 12%, 13%, 14%, 15%, 20%, 30%, 40%, 50%, 60%, or 70% of a population. Each possibility represents a separate embodiment of the present invention.
Guide sequences of the present invention may satisfy any one of the above criteria and are most likely to differentiate between a mutated allele from its corresponding functional allele.
The RNA molecule compositions described herein may be delivered to a target cell by any suitable means. RNA molecule compositions of the present invention may be targeted to any cell which contains and/or expresses a mutated allele, including any mammalian or plant cell. For example, in one embodiment the RNA molecule specifically targets a mutated STAT1 allele and the target cell is an HSC. The delivery to the cell may be performed in-vitro, ex-vivo, or in-vivo. Further, the nucleic acid compositions described herein may be delivered as one or more of DNA molecules, RNA molecules, Ribonucleoproteins (RNP), nucleic acid vectors, or any combination thereof.
In some embodiments, the RNA molecule comprises a chemical modification, Non-limiting examples of suitable chemical modifications include 2′-0-methyl (M), 2′-0-methyl, 3′phosphorothioate (MS) or 2′-0-methyl, 3′thioPACE (MSP), pseudouridine, and 1-methyl pseudo-uridine. Each possibility represents a separate embodiment of the present invention.
Any suitable viral vector system may be used to deliver nucleic acid compositions e.g., the RNA molecule compositions of the subject invention. Conventional viral and non-viral based gene transfer methods can be used to introduce nucleic acids and target tissues. In certain embodiments, nucleic acids are administered for in vivo or ex vivo gene therapy uses. Non-viral vector delivery systems include naked nucleic acid, and nucleic acid complexed with a delivery vehicle such as a liposome or poloxamer. For a review of gene therapy procedures, see Anderson (1992) Science 256:808-813; Nabel & Felgner (1993) TIBTECH 11:211-217; Mitani & Caskey (1993) TIBTECH 11:162-166; Dillon (1993) TIBTECH 11:167-175; Miller (1992) Nature 357:455-460; Van Brunt (1988) Biotechnology 6(10):1149-1154; Vigne (1995) Restorative Neurology and Neuroscience 8:35-36; Kremer & Perricaudet (1995) British Medical Bulletin 51(1):31-44; Haddada et al. (1995) in Current Topics in Microbiology and Immunology Doerfler and Bohm (eds.); and Yu et al. (1994) Gene Therapy 1:13-26.
Methods of non-viral delivery of nucleic acids and/or proteins include electroporation, lipofection, microinjection, biolistics, particle gun acceleration, virosomes, liposomes, immunoliposomes, lipid nanoparticles (LNPs), polycation or lipid:nucleic acid conjugates, artificial virions, and agent-enhanced uptake of nucleic acids or can be delivered to plant cells by bacteria or viruses (e.g., Agrobacterium, Rhizobium sp. NGR234, Sinorhizoboiummeliloti, Mesorhizobium loti, tobacco mosaic virus, potato virus X, cauliflower mosaic virus and cassava vein mosaic virus). (See, e.g., Chung et al. (2006) Trends Plant Sci. 11(1):1-4). Sonoporation using, e.g., the Sonitron 2000 system (Rich-Mar), can also be used for delivery of nucleic acids. Cationic-lipid mediated delivery of proteins and/or nucleic acids is also contemplated as an in vivo, ex vivo, or in vitro delivery method. (See Zuris et al. (2015) Nat. Biotechnol. 33(1):73-80; see also Coelho et al. (2013) N. Engl. J. Med. 369, 819-829; Judge et al. (2006) Mol. Ther. 13, 494-505; and Basha et al. (2011) Mol. Ther. 19, 2186-2200).
Additional exemplary nucleic acid delivery systems include those provided by Amaxa® Biosystems (Cologne, Germany), Maxcyte, Inc. (Rockville, Md.), BTX Molecular Delivery Systems (Holliston, Mass.) and Copernicus Therapeutics Inc., (see, e.g., U.S. Pat. No. 6,008,336). 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™, Lipofectin™ and Lipofectamine™ RNAiMAX). Cationic and neutral lipids that are suitable for efficient receptor-recognition lipofection of polynucleotides include those of Felgner, WO 91/17424, WO 91/16024. Delivery can be to cells (ex vivo administration) or target tissues (in vivo administration).
The preparation of lipid:nucleic acid complexes, including targeted liposomes such as immunolipid complexes, is well known to one of skill in the art (See, e.g., Crystal (1995) Science 270:404-410; Blaese et al. (1995) Cancer Gene Ther. 2:291-297; Behr et al. (1994) Bioconjugate Chem. 5:382-389; Remy et al. (1994) Bioconjugate Chem. 5:647-654; Gao et al. (1995) Gene Therapy 2:710-722; Ahmad et al. (1992) Cancer Res. 52:4817-4820; U.S. Pat. Nos. 4,186,183, 4,217,344, 4,235,871, 4,261,975, 4,485,054, 4,501,728, 4,774,085, 4,837,028, and 4,946,787).
Additional methods of delivery include the use of packaging the nucleic acids to be delivered into EnGeneIC delivery vehicles (EDVs). These EDVs are specifically delivered to target tissues using bispecific antibodies where one arm of the antibody has specificity for the target tissue and the other has specificity for the EDV. The antibody brings the EDVs to the target cell surface and then the EDV is brought into the cell by endocytosis. Once in the cell, the contents are released (See MacDiarmid et al (2009) Nature Biotechnology 27(7):643).
The use of RNA or DNA viral based systems for viral mediated delivery of nucleic acids take advantage of highly evolved processes for targeting a virus to specific cells in the body and trafficking the viral payload to the nucleus. Viral vectors can be administered directly to patients (in vivo) or they can be used to treat cells in vitro and the modified cells are administered to patients (ex vivo). Conventional viral based systems for the delivery of nucleic acids include, but are not limited to, retroviral, lentivirus, adenoviral, adeno-associated, vaccinia and herpes simplex virus vectors for gene transfer.
The tropism of a retrovirus can be altered by incorporating foreign envelope proteins, expanding the potential target population of target cells. Lentiviral vectors are retroviral vectors that are able to transduce or infect non-dividing cells and typically produce high viral titers. Selection of a retroviral gene transfer system depends on the target tissue. Retroviral vectors are comprised of cis-acting long terminal repeats with packaging capacity for up to 6-10 kb of foreign sequence. The minimum cis-acting LTRs are sufficient for replication and packaging of the vectors, which are then used to integrate the therapeutic gene into the target cell to provide permanent transgene expression. Widely used retroviral vectors include those based upon murine leukemia virus (MuLV), gibbon ape leukemia virus (GaLV), Simian Immunodeficiency virus (SIV), human immunodeficiency virus (HIV), and combinations thereof (See, e.g., Buchschacher et al. (1992) J. Virol. 66:2731-2739; Johann et al. (1992) J. Virol. 66:1635-1640; Sommerfelt et al. (1990) Virol. 176:58-59; Wilson et al. (1989) J. Virol. 63:2374-2378; Miller et al. (1991) J. Virol. 65:2220-2224; PCT/US94/05700).
At least six viral vector approaches are currently available for gene transfer in clinical trials, which utilize approaches that involve complementation of defective vectors by genes inserted into helper cell lines to generate the transducing agent.
pLASN and MFG-S are examples of retroviral vectors that have been used in clinical trials (Dunbar et al. (1995) Blood 85:3048-305; Kohn et al. (1995) Nat. Med. 1:1017-102; Malech et al. (1997) PNAS 94:22 12133-12138). PA317/pLASN was the first therapeutic vector used in a gene therapy trial. (Blaese et al. (1995). Transduction efficiencies of 50% or greater have been observed for MFG-S packaged vectors. (Ellem et al. (1997) Immunol Immunother. 44(1):10-20; Dranoff et al. (1997) Hum. Gene Ther. 1:111-2).
Packaging cells are used to form virus particles that are capable of infecting a host cell. Such cells include 293 cells, which package adenovirus, AAV, and Psi-2 cells or PA317 cells, which package retrovirus. Viral vectors used in gene therapy are usually generated by a producer cell line that packages a nucleic acid vector into a viral particle. The vectors typically contain the minimal viral sequences required for packaging and subsequent integration into a host (if applicable), other viral sequences being replaced by an expression cassette encoding the protein to be expressed. The missing viral functions are supplied in trans by the packaging cell line. For example, AAV vectors used in gene therapy typically only possess inverted terminal repeat (ITR) sequences from the AAV genome which are required for packaging and integration into the host genome. Viral DNA is packaged in a cell line, which contains a helper plasmid encoding the other AAV genes, namely rep and cap, but lacking ITR sequences. The cell line is also infected with adenovirus as a helper. The helper virus promotes replication of the AAV vector and expression of AAV genes from the helper plasmid. The helper plasmid is not packaged in significant amounts due to a lack of ITR sequences. Contamination with adenovirus can be reduced by, e.g., heat treatment to which adenovirus is more sensitive than AAV. Additionally, AAV can be produced at clinical scale using baculovirus systems (see U.S. Pat. No. 7,479,554).
In many gene therapy applications, it is desirable that the gene therapy vector be delivered with a high degree of specificity to a particular tissue type. Accordingly, a viral vector can be modified to have specificity for a given cell type by expressing a ligand as a fusion protein with a viral coat protein on the outer surface of the virus. The ligand is chosen to have affinity for a receptor known to be present on the cell type of interest. For example, Han et al. (1995) Proc. Natl. Acad. Sci. USA 92:9747-9751, reported that Moloney murine leukemia virus can be modified to express human heregulin fused to gp70, and the recombinant virus infects certain human breast cancer cells expressing human epidermal growth factor receptor. This principle can be extended to other virus-target cell pairs, in which the target cell expresses a receptor and the virus expresses a fusion protein comprising a ligand for the cell-surface receptor. For example, filamentous phage can be engineered to display antibody fragments (e.g., FAB or Fv) having specific binding affinity for virtually any chosen cellular receptor. Although the above description applies primarily to viral vectors, the same principles can be applied to nonviral vectors. Such vectors can be engineered to contain specific uptake sequences which favor uptake by specific target cells.
Gene therapy vectors can be delivered in vivo by administration to an individual patient, typically by systemic administration (e.g., intravitreal, intravenous, intraperitoneal, intramuscular, subdermal, or intracranial infusion) or topical application, as described below. Alternatively, vectors can be delivered to cells ex vivo, such as cells explanted from an individual patient (e.g., lymphocytes, bone marrow aspirates, tissue biopsy) or universal donor hematopoietic stem cells, followed by reimplantation of the cells into a patient, optionally after selection for cells which have incorporated the vector. A non-limiting exemplary ex vivo approach may involve removal of tissue (e.g., peripheral blood, bone marrow, and spleen) from a patient for culture, nucleic acid transfer to the cultured cells (e.g., hematopoietic stem cells), followed by grafting the cells to a target tissue (e.g., bone marrow, and spleen) of the patient. In some embodiments, the stem cell or hematopoietic stem cell may be further treated with a viability enhancer.
Ex vivo cell transfection for diagnostics, research, or for gene therapy (e.g., via re-infusion of the transfected cells into the host organism) is well known to those of skill in the art. In a preferred embodiment, cells are isolated from the subject organism, transfected with a nucleic acid composition, and re-infused back into the subject organism (e.g., patient). Various cell types suitable for ex vivo transfection are well known to those of skill in the art (See, e.g., Freshney et al. (1994) Culture of Animal Cells, A Manual of Basic Technique, 3rd ed, and the references cited therein for a discussion of how to isolate and culture cells from patients).
Suitable cells include, but are not limited to, eukaryotic cells and/or cell lines. Non-limiting examples of such cells or cell lines generated from such cells include COS, CHO (e.g., CHO—S, CHO-K1, CHO-DG44, CHO-DUXB11, CHO-DUKX, CHOK1SV), VERO, MDCK, WI38, V79, B14AF28-G3, BHK, HaK, NSO, SP2/0-Ag14, HeLa, HEK293 (e.g., HEK293-F, HEK293-H, HEK293-T), perC6 cells, any plant cell (differentiated or undifferentiated), as well as insect cells such as Spodopterafugiperda (Sf), or fungal cells such as Saccharomyces, Pichia and Schizosaccharomyces. In certain embodiments, the cell line is a CHO-K1, MDCK or HEK293 cell line. Additionally, primary cells may be isolated and used ex vivo for reintroduction into the subject to be treated following treatment with a guided nuclease system (e.g. CRISPR/Cas). Suitable primary cells include peripheral blood mononuclear cells (PBMC), and other blood cell subsets such as, but not limited to, CD4+ T cells or CD8+ T cells. Suitable cells also include stem cells such as, by way of example, embryonic stem cells, induced pluripotent stem cells, hematopoietic stem cells (CD34+), neuronal stem cells and mesenchymal stem cells.
In one embodiment, stem cells are used in ex vivo procedures for cell transfection and gene therapy. The advantage to using stem cells is that they can be differentiated into other cell types in vitro, or can be introduced into a mammal (such as the donor of the cells) where they will engraft in the bone marrow. Methods for differentiating CD34+ cells in vitro into clinically important immune cell types using cytokines such a GM-CSF, IFN-gamma, and TNF-alpha are known (as a non-limiting example see, Inaba et al., J. Exp. Med. 176:1693-1702 (1992)).
Stem cells are isolated for transduction and differentiation using known methods. For example, stem cells are isolated from bone marrow cells by panning the bone marrow cells with antibodies which bind unwanted cells, such as CD4+ and CD8+ (T cells), CD45+ (panB cells), GR-1 (granulocytes), and Tad (differentiated antigen presenting cells) (as a non-limiting example see Inaba et al. (1992) J. Exp. Med. 176:1693-1702). Stem cells that have been modified may also be used in some embodiments.
Vectors (e.g., retroviruses, liposomes, etc.) containing therapeutic nucleic acid compositions 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 (e.g., eye drops and cream) 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. According to some embodiments, the composition is delivered via IV injection.
Vectors suitable for introduction of transgenes into immune cells (e.g., T-cells) include non-integrating lentivirus vectors. See, e.g., U.S. Patent Publication No. 2009-0117617.
Pharmaceutically acceptable carriers are determined in part by the particular composition being administered, as well as by the particular method used to administer the composition. Accordingly, there is a wide variety of suitable formulations of pharmaceutical compositions available, as described below (See, e.g., Remington's Pharmaceutical Sciences, 17th ed., 1989).
In accordance with some embodiments, there is provided an RNA molecule which binds to/associates with and/or directs the RNA guided DNA nuclease to a sequence comprising at least one nucleotide which differs between a mutated allele and a functional allele (e.g., SNP) of a gene of interest (i.e., a sequence of the mutated allele which is not present in the functional allele). The sequence may be within the disease associated mutation. The sequence may be upstream or downstream to the disease associated mutation. Any sequence difference between the mutated allele and the functional allele may be targeted by an RNA molecule of the present invention to inactivate the mutant allele, or otherwise disable its dominant disease-causing effects, while preserving the activity of the functional allele.
The disclosed compositions and methods may also be used in the manufacture of a medicament for treating dominant genetic disorders in a patient.
Without being bound by any theory or mechanism, the instant invention may be utilized to apply a CRISPR nuclease to process the mutated pathogenic STAT1 allele and not the functional STAT1 allele, such as to prevent expression of the mutated pathogenic allele or to produce a truncated non-pathogenic peptide from the mutated pathogenic allele, in order to prevent CMC. A specific guide sequence may be selected from Table 2 based on the targeted SNP and the type of CRISPR nuclease used (required PAM sequence).
The STAT1 gene is located in chromosome 2 and encodes the STAT1 protein. Two alternatively spliced transcript variants encoding distinct isoforms of STAT1 have been previously described Isoform alpha (NM_007315.3) that includes 25 exons and isoform beta (NM_139266) that includes 22 exons. Notably, healthy individuals that harbor frameshift mutations in exon 21 were previously identified.
One optional strategy is to truncate STAT1 upstream to exon 22 without causing a pathogenic effect. Truncation may be achieved by excision using 2 gRNAs, at least one of the gRNAs targets an allele specific sequence in a SNP position. The exons that can be excised and would lead to a frameshift or a knockout are: 3, 4, 7, 8, 9, 14, 18, 19, 20 and 21. The excision may be achieved by mediating a DSB in introns flanking the desired exon.
In a non-limiting example excision of exon 3, which would knockout the gene, may be achieved by utilizing a first gRNA that targets a particular sequence in a SNP position in intron 2 (e.g., rs36077929, rs13029532, rs16833172) which is specific for the mutated allele, and a second gRNA that targets a particular sequence in a SNP position in intron 3 such as rs41507345 which is specific for the mutated allele, wherein one of the gRNAs may target a sequence which is common for both the mutated allele and functional allele.
In a non-limiting example excision of exon 4 may be achieved by utilizing a first gRNA that targets a particular sequence in a SNP position in intron 3 such as rs41507345 which is specific for the mutated allele, and a second gRNA that targets a particular sequence in a SNP position in intron 4 (e.g., rs10199181 and rs201136414) which is specific for the mutated allele, wherein one of the gRNAs may target a sequence which is common for both the mutated allele and functional allele.
In a non-limiting example excision of exon 7 may be achieved by utilizing a first gRNA that targets a particular sequence in a SNP position in intron 6 such as rs41454245 which is specific for the mutated allele, and a second gRNA that targets a particular sequence in a SNP position in intron 7 such as rs36116009 which is specific for the mutated allele, wherein one of the gRNAs may target a sequence which is common for both the mutated allele and functional allele.
In a non-limiting example excision of exon 8 may be achieved by utilizing a first gRNA that targets a particular sequence in a SNP position in intron 7 such as rs36116009 which is specific for the mutated allele, and a second gRNA that targets a sequence in intron 8 which is common for both the mutated allele and functional allele.
In a non-limiting example excision of exon 9 may be achieved by utilizing a first gRNA that targets a particular sequence in a SNP position in intron 9 (e.g., rs12693591, rs10167514, rs41474144, and rs16833157) which is specific for the mutated allele, and a second gRNA that targets a particular sequence in a SNP position in intron 10 (e.g., rs34230248, rs45528632, rs12693590, rs34997637, rs11904548, rs10190333, rs45467700, and rs12464143) which is specific for the mutated allele, wherein one of the gRNAs may target a sequence which is common for both the mutated allele and functional allele.
In a non-limiting example excision of exon 14 may be achieved by utilizing a first gRNA that targets a particular sequence in a SNP position in intron 14 such as rs2280233 and rs2280232 which is specific for the mutated allele, and a second gRNA that targets a sequence in intron 13 which is common for both the mutated allele and functional allele.
In a non-limiting example excision of exon 18 may be achieved by utilizing a first gRNA that targets a particular sequence in a SNP position in intron 17 (e.g., rs16833146) which is specific for the mutated allele, and a second gRNA that targets a particular sequence in a SNP position in intron 18 (e.g., rs1547550, rs5837215, rs3755312, rs4327257) which is specific for the mutated allele, wherein one of the gRNAs may target a sequence which is common for both the mutated allele and functional allele.
In a non-limiting example excision of exon 19 may be achieved by utilizing a first gRNA that targets a particular sequence in a SNP position in intron 18 (e.g., rs1547550, rs5837215, rs3755312, and rs4327257) which is specific for the mutated allele, and a second gRNA that targets a sequence in intron 19 which is common for both the mutated allele and functional allele.
In a non-limiting example excision of exon 20 may be achieved by utilizing a first gRNA that targets a particular sequence in a SNP position in intron 20 such as rs2280235 which is specific for the mutated allele, and a second gRNA that targets a sequence in intron 19 which is common for both the mutated allele and functional allele.
In a non-limiting example excision of exon 21 may be achieved by utilizing a first gRNA that targets a particular sequence in a SNP position in intron 20 (e.g., rs2280235) which is specific for the mutated allele, and a second gRNA that targets a particular sequence in a SNP position in intron 21 (e.g., rs2066804, rs7597768, rs41375144, rs13010343) which is specific for the mutated allele, wherein one of the gRNAs may target a sequence which is common for both the mutated allele and functional allele.
Another optional strategy is to inhibit the expression of the mutated allele by excision of the PolyA-signal in the 3′UTR region of the mutated allele of both transcripts, that may lead to an unstable transcript. In a non-limiting example, excision of the PolyA-signal may be achieved by using a first gRNA to target a sequence in a downstream SNP position (e.g., rs1168, rs73064614, rs17748980, and rs12987796) which is specific for the mutated allele, and a second gRNA to target a sequence in intron 23 which is common for both the mutated allele and functional allele.
Another optional strategy is to introduce a frameshift in exon 3 by utilizing one gRNA to target a SNP position in exon 3, such as rs2066802 and mediate a single DSB.
Although a large number of guide sequences can be designed to target a mutated allele, the nucleotide sequences described in Tables 2 identified by SEQ ID NOs: 1-2426 below were specifically selected to effectively implement the methods set forth herein and to effectively discriminate between alleles.
Table 2 shows guide sequences designed for use as described in the embodiments above to associate with different SNPs within a sequence of a mutated STAT1 allele. Each engineered guide molecule is further designed such as to associate with a target genomic DNA sequence of interest that lies next to a protospacer adjacent motif (PAM), e.g., a PAM matching the sequence NGG or NAG, where “N” is any nucleobase. The guide sequences were designed to work in conjunction with one or more different CRISPR nucleases, including, but not limited to, e.g. SpCas9WT (PAM SEQ: NGG), SpCas9.VQR.1 (PAM SEQ: NGAN), SpCas9.VQR.2 (PAM SEQ: NGNG), SpCas9.EQR (PAM SEQ: NGAG), SpCas9.VRER (PAM SEQ: NGCG), SaCas9WT (PAM SEQ: NNGRRT), NmCas9WT (PAM SEQ: NNNNGATT), Cpfl (PAM SEQ: TTTV), or JeCas9WT (PAM SEQ: NNNVRYM). RNA molecules of the present invention are each designed to form complexes in conjunction with one or more different CRISPR nucleases and designed to target polynucleotide sequences of interest utilizing one or more different PAM sequences respective to the CRISPR nuclease utilized.
Examples are provided below to facilitate a more complete understanding of the invention. The following examples illustrate the exemplary modes of making and practicing the invention. However, the scope of the invention is not limited to specific embodiments disclosed in these Examples, which are for purposes of illustration only.
Guide sequences comprising 17-25 contiguous nucleotides containing nucleotides in the sequence set forth in any one of SEQ ID NOs 1-37365 are screened for high on target activity using SpCas9 in HeLa cells. On target activity is determined by DNA capillary electrophoresis analysis.
The STAT1 editing strategies include excision of either Exon 3, Exon 4 or Exon 4-5 of a mutated allele (See strategies a1, a2, and a3,
The guides which were chosen for further experiments are sg10 (SEQ ID NO: 24295), sg18 (SEQ ID NO: 25501), sg19 (SEQ ID NO: 17213), sg22 (SEQ ID NO: 15340) and sg28 (SEQ ID NO: 35795) which are the most active guides for Intron 2 rs16833172, Exon 3 rs2066802, Intron 4 rs10199181, Intron 5 rs10183196, and Intron 3, respectively.
To support the validity of our editing strategies, HSCs from a healthy donor (Lonza Lot: 3017500) homozygous to reference or alternative forms of the SNPs were nucleofected with RNPs of WT-SpCas9 protein complexed with either, sg10ref (SEQ ID NO: 24295), sg18 ref (SEQ ID NO: 25501), sg19alt (SEQ ID NO: 17213), sg22ref (SEQ ID NO: 15340), sg28 (SEQ ID NO: 35795) or in combination of sg10ref (SEQ ID NO: 24295)+sg28 (SEQ ID NO: 35795), sg19alt (SEQ ID NO: 17213)+sg28 (SEQ ID NO: 35795) and sg22ref (SEQ ID NO: 15340)+sg28 (SEQ ID NO: 35795). Briefly, 2.50×105 cells were mixed with preassembled RNPs composed of 105 pmole SpCas9 and 120 pmole sgRNA then mixed with 100 pmole of electroporation enhancer (IDT-1075916). The cells were then electroporated using P3 primary cell 4D-nucleofector X Kit S (V4XP-3032, Lonza) by applying the DZ100 program. Since the cells are homozygous, the editing and excision are expected to be biallelic. A fraction of cells was harvested 72 h post nucleofection and genomic DNA was extracted to measure on-target activity using NGS analysis. The analysis revealed that more than 85% of the cells were edited in each of the samples treated with an individual guide (
Signal transducer and activator of transcription 1 (STAT1) is an essential mediator of the type I interferon-induced signaling that activates the immune response against various infectious pathogens. Upon IFNγ activation, STAT1 becomes phosphorylated by JAKs, dimerizes via a phosphorylation-dependent interaction and translocates to the nucleus where it drives downstream gene transcription encoding proteins for anti-viral and pro-inflammatory functions (Fujiki et al., 2017).
Monoallelic mutations in STAT1 have been identified in patients with a great diversity of clinical manifestations and immune lesions. Mutations have been predominately associated with chronic mucocutaneous candidiasis (CMC) with or without a variety of autoimmune manifestations. STAT1 mutations have been also associated with a gradual decline in cellular and humoral immunity leading to fatal viral infections. Increased STAT1 phosphorylation and DNA binding found in most CMC patients promoted the notion that a gain-of-function (GOF) mechanism underlies these disorders (Lieu et al., (2011); Ovadia et al., (2016); and Okada et al., (2018)). Due to the high diversity of STAT1 mutations in patients leading to a GOF mechanism driving CMC, inventors identified heterozygous SNP rs2066802 residing in exon 3, which has a ˜20% frequency in the population, as a target for a discriminatory editing strategy to eliminate the mutant allele by inserting indels leading to premature stop codons and abolishment of mutant transcript via nonsense mediated decay (NMD) as described in
To this end, we have established a cellular system harboring both a R274G mutation and a normal allele recapitulating patient cells to study the gene expression GOF effect of mutated STAT1 and validating gene editing strategies for restoration.
Inventors utilized a U3A cell system, which harbors an intrinsic genomic mutation of STAT1 leading to lack of expression and unresponsiveness to interferon-gamma induction, as a model for studying ectopic STAT1 WT and R274G mutated alleles. Three viral based stable lines were established: WT-STAT1-mCherry; Mutant R274G-STAT1-GFP encompassing the alternative form of rs066802 SNP for editing purposes; and WT and R274G-mutant biallelic for GOF evaluation of STAT1 mediated gene expression (
To determine the validity of the inventors' strategy, biallelic U3A cells were electroporated with RNP complexed with a specific guide targeting a SNP located on exon 3 of mutant allele. Briefly, 2.5×105 U3A cells were mixed with preassembled RNPs composed of 105 pmole Cas9-HiFi and 120 pmole sgRNA (See Table 2), then mixed with 100 pmole of electroporation enhancer (IDT-1075916). The cells are then electroporated using SF primary cell 4D-nucleofector X Kit S (V4XP-3032, Lonza) by applying the DS-137 program. Edited cells were cultured for 8 days to ensure degradation of pre-edited STAT1 protein, stimulated for 24 h with IFNγ and subjected to transcriptional restoration of downstream STAT1 mediated genes (
Inventors next investigated the effect of editing the mutated allele on gene expression restoration by comparing STAT1 mediated genes between biallelic, WT, and edited biallelic cells following IFNγ stimulation. For these experiments, qRT-PCR was used to compare STAT1 mediated transcriptional responses to IFN-γ stimulation. As shown in
These results demonstrate that a strategy utilizing SNP-based specific editing of mutant allele leads to transcriptional restoration of the mutant STAT1 GOF phenotype to a WT phenotype.
This application claims the benefit of U.S. Provisional Application No. 62/810,879, filed Feb. 26, 2019, the contents of which is hereby incorporated by reference.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2020/019633 | 2/25/2020 | WO | 00 |
| Number | Date | Country | |
|---|---|---|---|
| 62810879 | Feb 2019 | US |
