Patent Application
20220333130
1 Field of the Invention
The present invention is in the field of healthcare biotechnology and pertains particularly to a therapeutic gene therapy engendering mRNA, episomal or genomic expression via lentiviral vector integration into genomic DNA of dimeric immunoglobulin A1 (dIgA1), dIgA2 and engineered variants against Viruses, Allergens, Fungi, HIV, H. pylori other bacterial infections, systemic pathologies, IgE, cytokines, cancerous tumors or as anti-biowarfare protection (e.g. protection from purposefully spread natural and unnatural viruses and toxins). This invention includes a method to encode for dimeric immunoglobulin A (dIgA1 or dIgA2) and engineered variants (such as dIgA with modified hinge lengths or other modified constant regions) on a vector as a means to deliver a gene therapy to humans. Specifically, dIgA (dIgA1, dIgA2 or engineered variants) encoded for on a single vector or multiple vectors is the invention. dIgA may be encoded for on a single DNA, or RNA with the use of a furin cleavage site and 2A self-processing peptide between consecutive transgenes. The transgenes that make up dIgA include (1) the immunoglobulin heavy chain, (2) the immunoglobulin light chain and (3) J Chain. These three proteins may be encoded for a on a single genetic element in one or two open reading frames. Where all the transgenes in any one open reading frame will have in the 5′ to 3′ direction a furin cleavage site followed by a 2A self-processing peptide placed between any two adjacent and consecutive transgenes. The use of a 2A self-processing peptide allows for efficient cleavage points between the consecutive transgenes completely removing any trace of the 2A self-processing peptide in the final immunoglobulin. In one embodiment MZB1 may also be encoded for by the vector. In another embodiment mRNA encodes for dIgA (dIgA1, dIgA2 or engineered variants) over one or more mRNA vectors. In an alternative configuration, a 2A self-processing peptide will be used between consecutive transgenes in a single open reading frame in the absence of the furin cleavage site leaving the 2A residue on the C-terminal end of the protein encoded for by the gene that is directly 5′ of the 2A gene. In another configuration mRNA encodes for dIgA (dIgA1, dIgA2 or engineered variants) over one or more mRNA vectors.
In the invention dimeric immunoglobulin A1 (dIgA1), dIgA2 and engineered variants specific against Viruses, Allergens, Fungi, HIV, H. pylori other bacterial infections, systemic pathologies, IgE, cytokines, cancerous tumors or as anti-biowarfare protection may have such binding affinity of dIgA and engineered variants will be based on one or more of individuals affected by such ailments, developed by Phage Display Technology with mutagenesis techniques, discovered and optimized from mice or other animals with humanized immune systems, derived from transgenic mice or derived non-human vertebrate (e.g. mouse or rabbit) intended for fusion with human antibodies giving rise to chimeric antibodies. Further a method to improve the potency of a vaccine is designed by targeted delivery of antigenic proteins or mRNA encoding for antigenic proteins to the lamina propria of the respiratory tract or gastrointestinal tract.
For immunoglobulin encoded vectors the entire immunoglobulin genetic sequence would be derived or identified from one of several sources including plasmablasts, CD27+ memory B-cells—expressing immunoglobulins with binding affinities specific for an antigen, virus antigen, allergen, foreign protein, pathogenic protein or cancer related protein—from humans that have been exposed to such antigens or allergens, mice or other animals with a humanized immune systems, non-human vetebrates (e.g. mouse or rabbit) intended for chimeric antibodies, transgenic mice or combinatorial libraries that may use phage display technology and mutagenesis. Those B-cells would be CD27+ or other CD+ IgG+ and IgA+ memory B-cells or plasmablasts B-cells that bear cell surface immunoglobulins easily allowing for their isolation based on binding affinity for an antigen, allergen, foreign protein, native protein, or pathogen related protein of interest through competitive binding cell sorting methods such as flow cytometry or fluorescence activated cell sorting (FACS) or competitive binding magnetic pull down methods that incorporate magnetic beads biotinylated to an antigen, allergen or foreign protein of interest and a competing protein for the antigen. Plasmids may be created that encode for those immunoglobulins to be further evaluated in addition to subjecting them to targeted mutagenesis. Alternatively, combinatorial libraries may be generated and phage display technology can be used to identify potent single chain variable fragments (scFv) that can be used to identify potent VH and VL pairs of high avidity and binding affinity that can be incorporated into a plasmid expressing a full length immunoglobulin heavy and light chains for evaluation. Other models such as non-human vetebrates (e.g. mouse or rabbit) intended for chimeric antibodies, transgenic mice or mice or other animals with humanized immune systems may be used to identify potent immunoglobulins or potent binding regions. Additionally, the V-region DNA of the heavy (IgH) and light chain (IgL) of the immunoglobulins will be incorporated into a vector construct that could use either the constant region DNA identified in humanized or transgenic mice, filamentous phage or B-cell expressing the identified immunoglobulin of interest or another source of genetic information that may be engineered may replace all or part of the constant region DNA that may also include isotype switching of constant region genetic information, mixes of two constant regions from two isotypes that may be accomplished with combinations of Fab and natural or engineered Fc domains or F(ab′)2 and natural or engineered pFc′ domains. The mRNA, episome, or retroviral incorporation of the DNA via lentivirus delivery system may be delivered to B-cells, muscle cells, liver cells (such as hepatocytes), any human cell, endoscopy based delivery to the lamina propria of the lungs, stomach and/or small intestine destined for memory B-cells in the lamina propria and the supporting lymph nodes as well as other quiescent cells potentially. B-cells targeted to receive the gene therapy may include memory B-cells, Germinal Center B-cells, memory plasma B-cells, a plasma blast, and naïve B-cells The episome may be delivered to the cells of interest via an adeno-associated virus, adenovirus, lentivirus based deliver system or via a vesicle based delivery system such as a lipid nano particle as one of many examples. Additionally, in other embodiments the reinvigoration of an FDA approved antibody or the repurposing of antibodies by placing their V-regions in a vector encoding for dIgA is part of the present invention. Further, in other embodiments a method to improve the potency of a vaccine is designed by targeted delivery of antigenic proteins or protein encoding mRNA to the lamina propria of the respiratory tract or gastrointestinal tract.
The primary mode of infection, carcinogen exposure and allergen entry for the vast majority of carcinogens, allergens, pathogens such as viruses, bacteria affecting the lungs, including gut bacteria, viruses and other disease causing foreign bodies is through our mucosal barriers. Similarly, the primary way that allergens such as fungi, dust mite feces, peanuts, tree nuts and pollen cause allergic reactions is also through our mucosal barriers especially the respiratory tract and in some cases the digestive tracts. Cancer has a specific term for cancers affecting the mucosal or epithelial and exocrine barriers referred to as carcinomas. Carcinomas make up 80%-90% of all cancer diagnosis. Thus, it is safe to say that if mankind had effective means of mucosal protection against infectious agents, allergens or unnatural viruses and toxins that their transmission and thus their allergenic—with respect to but not limited to Type I Hypersensitivity—and pathogenic consequences will be nearly eliminated. With exception to the heart, nearly, every organ is involved in the processing of a liquid or gas that is transported through a lumen or duct Part of or all of these lumens and ducts are aligned with stratified and pseudo stratified columnar epithelial cells that with polymeric immunoglobulin secreting receptor (pIgR) actively transport dimeric immunoglobulin A (dIgA) from the lamina propria to the mucosa or from the surrounding tissue of the exocrine gland to the exocrine duct where upon entering the mucosa or duct of these organs and glands dIgA is converted into secretory immunoglobulin A (SIgA). There may also be some dIgA that is passively diffused to the mucosa and exocrine ducts at relatively low levels in comparison to active transport of dIgA by pIgA. Our mucosal barriers includes but are not limited to our respiratory tract, that is the entirety of the pathways where air flows to the alveoli in the lungs, our digestive tract where food and liquids flow and are absorbed and our reproductive tract, our urinary tract and also our skin.
In order for an individual's immune system to effectively prevent infection from foreign bodies and also avert an allergic reaction to foreign bodies mucosal immunity via immunoglobulins is required. Secretory immunoglobulin A (SIgA1 and SIgA2) is by far the most prevalent of antibodies in the human body and represents a major mode of defense in mucosal immunity. SIgA1 and SIgA2 are made from dimeric immunoglobulin A1 (dIgA1) and dimeric Immunoglobulin A2 (dIgA2) respectively and dIgA1 and dIgA2 is based on Immunoglobulin A1 (IgA1) and Immunoglobulin A2 (IgA2) respectively. Potent IgA1 s and IgA2s as well as IgA variants such as IgAs with varying hinge lengths or modifications to their constant regions can be identified from CD27+ or other CD+ IgA memory B-cells, the V regions of CD27+ or other CD+ IgG memory B cells, other CD memory B-cells, plasmablasts B-cells, from mice or other non-human vertebrates with engineered immune systems or humanized immune systems, from mice or non-human vertebrates B-cells or may have their binding regions discovered via phage display technology such as in the single chain variable fragment or may be discovered from mice or other animals with humanized immune systems.
Expression of dIgA1 and dIgA2 and derivatives of dIgA1 and dIgA2 from mRNA, an episome or genomic DNA via retroviral incorporation of retroviral vector such as one delivered by a lentivirus is claimed in this instant patent. The conversion of dIgA (dIgA1 or dIgA2) to secretory immunoglobulin A (SIgA1 or SIgA2) is a natural process that is part of active transport to the mucosa in humans and is described in
Monoclonal antibodies have enjoyed widespread success in their efficacy against a host of ailments. Monoclonal antibodies further enjoy exquisite specificity to their targets as a result of the virtually limitless possible combinations of amino acids that make up their binding regions especially the CDRs and their large binding region surface area that allow binding specificity to be dependent on a large portion of the target surface topology including Van der Waals interactions, surface charge distribution, dipole-dipole interactions, salt bridges, and surface hydrogen bonding. FDA approved monoclonal antibodies that are fully representative of human immunoglobulins are almost universally based on Immunoglobulin class G (IgG) constant regions (when they have constant regions) as attributed to their long half-life of about 21 days that can be increased through modifications of their fragment crystallizable (Fc) regions. Antibody cocktails that are mixtures of 2 or more antibodies have recently received emergency authorization by the FDA as well for their application against the 2019 novel Coronavirus (COVID-19) and mutant forms. One challenge of direct administration of the antibody is the required repeated administration of such antibodies to sustain any benefit derived from them. In addition they can be very costly to produce making their cost sometimes the factor that prevents their administration in lieu of a lower cost and treatment that may be less effective or have more side effects.
Providing people with the genetic instructions or a gene therapy to make the antibodies with their own molecular machinery overcomes the problem of repeated administration in the case of retroviral insertion of the gene encoding for the antibody or makes administration much more long-lived in the case of episomal or even retroviral integration based administration of the genes encoding for the antibody. Additionally, encoding for antibodies through gene therapy overcomes the high cost associated with manufacturing them. Although, as attributed to their longer half-lives IgG based antibodies have been widely prevalent in absence of a gene therapy encoding for them. IgA and dIgA have half-lives of 6 days making them require frequent administrations in their protein form and has been the reason that life sciences companies have not conducted clinical trials with IgA immunoglobulins. And while IgG can reach the mucosa of the lungs they may only do so via passive transport that results in very low levels of IgG in the mucosa while also being more rapidly degraded at a rate faster than that of SIgA in the harsh mucus environment. On the other hand, IgG does not reach the mucosa of the stomach or small intestine making it impossible to derive any significant benefit from them for purposes of blocking infectious agents or allergens from entering the lamina propria of the stomach or small intestine. Further, IgG does not reach the mucosal linings and ductal linings of exocrine glands at high levels as it relies on passive diffusion to those regions. Gene therapy encoded episomal or genomic expression via integration competent lentivirus delivery systems of dIgA solves the challenged associated with their short half-lives and solves the challenge of achieving therapeutically relevant levels of antibodies in the mucosa. In some cases the time period needed for effective immune protection is rather short and also the speed with which antibodies are need is rather fast as in the case of pneumonia where mRNA based administration of the gene therapy can be effective.
Immunoglobulins may be engineered to extend their half-lives or reduce antibody dependent enhancement of infection (ADE). Typically when IgG binds to its target in the mucosa of the lungs it may result in antibody dependent enhancement of infection (ADE) when either the IgG antibodies lack high binding affinities or when antibodies decline in numbers. Immunoglobulins may be engineered to reduce receptor binding to the fragment crystallizable region (Fc) reducing Antibody Dependent Enhancement (ADE) of infection that can result in a cytokine storm type reaction where the resulting immune reactions could cause damage to the host tissue. (See e.g., Iwasaki, A. & Yang, Y., 2020, Nat. Rev. Immunol. 20:339-341.). Further, IgG and all subclasses are not privileged to enter the mucosa of the stomach and intestines and enter the mucosa of the lungs and other tissues at much lower levels than dIgA1 as a result of their reliance on passive diffusion to those areas where dIgA on the other hand is actively transported to the mucosa via polymeric immunoglobulin secreting receptor (pIgR).
Unquestionably, due to its active transport to the mucosa dIgA that becomes SIgA upon active transport to the mucosal or ductal linings is a privileged immunoglobulin to provide mucosal protection over other immunoglobulins such as immunoglobulin class G (IgG) and its 4 classes (IgG1, IgG2, IgG3 and IgG4) as they offer numerous advantages over IgG. Those advantages include two distinct binding faces that allows dIgA and SIgA to agglutinate foreign bodies together preventing their escape, more potent binding affinities over IgGs with as much as 2 orders of magnitude greater binding affinity than IgGs with the same V regions, active and unidirectional transport to the mucosa via binding to polymeric immunoglobulin secreting receptor (pIgR) at the basolateral face of the epithelium, their high production from localized B-cells in the lamina propria, resistance to degradation in the mucosa as part of the conversion of dIgA to SIgA at the conclusion of active transport to the mucosa, dIgA is specifically and naturally tailored for the mucosa, naturally high levels of production at about 5 grams a day, in its SIgA form it has very low cytotoxicity and anti-inflammatory properties in the mucosa, while having both proinflammatory and anti-inflammatory properties in its dIgA form e.g. in the submucosa (See e.g. Bakema, J., van Egmond, M., 2011, Mucosal Immunol, 4:612-624) protecting against cases of a damaged epithelium in the lamina propria and bloodstream, and SIgA does not cause antibody dependent enhancement of infection that could otherwise result in a cytokine storm in the lungs and thus makes targeted mucosal protection, degradation and clearance of foreign bodies safe and unnoticeable by the host organism (See e.g., Iwasaki, A. & Yang, Y., 2020, Nat. Rev. Immunol. 20:339-341).
This invention primarily relates to a method to encode for dimeric immunoglobulin A (dIgA1 or dIgA2) and engineered variants (such as dIgA with modified hinge lengths or other modified Fc or constant regions) on a vector as a means to deliver a gene therapy to humans. Specifically, dIgA (dIgA1, dIgA2 or engineered variants) encoded for on a single vector or multiple vectors is the invention. dIgA may be encoded for on a single DNA, or RNA with the use of a furin cleavage site and 2A self-processing peptide between consecutive transgenes. The transgenes that make up dIgA include (1) the immunoglobulin heavy chain, (2) the immunoglobulin light chain and (3) J Chain. These three proteins may be encoded for a on a single genetic element in one or two open reading frames. Where all the transgenes in any one open reading frame will have in the 5′ to 3′ direction a furin cleavage site followed by a 2A self-processing peptide placed between any two consecutive transgenes. The use of a furin cleavage site and 2A self-processing peptide allows for efficient cleavage points between the consecutive transgenes completely removing any trace of the 2A self-processing peptide in the final immunoglobulin. In some cases MZB1 may also be encoded for by the vector. In another embodiment a 2A self-processing peptide is used between consecutive transgenes in a single open reading frame in the absence of a furin cleavage site (see
Potent dimeric immunoglobulins of class A1, A2 or variants specific to (1) a virus (s) (2) a systemic ailment such as allergies (3) fungi (4) bacterial infection (4) cancerous tumor (5) biowarfare agent (6) microbial infection, (7) any ailment (8) an allergen or cause of allergies including IgE and cytokines, (9) a target protein or variant may be discovered or have their V regions or CDR regions derived or discovered from one or more sources exposed to the protein or protein source of interest (any of 1 though 9 and variants but not limited to that list) where such sources of antibodies may include B-cells from humans, mice or other animals with humanized immune systems, transgenic mice, non-human vetebrates (e.g. mouse or rabbit) intended for chimeric antibodies or combinatorial libraries using human B-cells to identify immunoglobulin DNA or using phage display technology to identify potent scFv (single chain variable fragments) or even potent antibody binding fragments (Fab) against the protein or pathogen of interest (e.g. any of 1 through 9 or the pathology associated source) or allergen(s) of interest. In the invention one may take the gene sequence encoding for the safest and most potent immunoglobulins or immunoglobulin V-regions, CDR regions, or even binding regions that can be identified or evolved through mutagenesis, use the gene sequence or a redundant sequence that encodes for the same amino acids of those potent immunoglobulins, CDRs and immunoglobulin V-regions that were discovered in mice or other animals with humanized immune systems, non-human vetebrates (e.g. mouse or rabbit) intended for chimeric antibodies, transgenic mice, or derived from phage display technology and deliver to humans via mRNA, episome or lentivirus for retroviral insertion into host genomic DNA the genetic information to produce the antibodies themselves in a dIgA1 or dIgA2 construct encoding for either monoclonal antibodies or an antibody cocktail of 2 or more immunoglobulins all based on those regions responsible for binding the target (e.g. Complementary determining regions, (CDRs)), V-regions, or the entire polypeptide sequence of the potent immunoglobulins they are based on. In humans, mice, animals with humanized immune systems, animals with engineered immune systems such antibodies may be discovered from CD27+ IgG or IgA memory B-cells or CD+ memory B-cells, plasmablasts B-cells, or B-cells from mice or other animals with humanized immune systems exposed to some or all of the pathogen, pathogenic protein, pathogen associated protein or allergen of interest and affinity matured against it, non-human vetebrates (e.g. mouse or rabbit) intended for chimeric antibodies, transgenic mice or other non-human vertebrate with an engineered immune system or derived from phage display technology such as when using the scFv derived from human B-cells. In one embodiment infusion of mRNA, episomes or retroviral incorporation of DNA via integration competent lentiviral vectors will engender humans with the ability to express dimeric immunoglobulin class A subtypes 1 and also subtype 2 (dIgA1 and dIgA2)—potent for the infectious agent, antigen or allergen of interest—that is modified into secretory immunoglobulin A (SIgA) as part of binding to polymeric immunoglobulin secreting receptor (pIgR) at the basal face of epithelial cells (See
When a gene therapy cocktail is used, the infusion of mRNA, episomes or retroviral incorporation of DNA with a lentivirus may also engender humans with the ability to potentially produce any one Immunoglobulin Class G (IgG) subclass 1 (IgG1), subclass 2 (IgG2) and subclass 3 (IgG3), IgA1, IgA2 in addition to dIgA1 and dIgA2. This infusion of mRNA, episomes or retroviral insertion of DNA coding for dIgA1 or dIgA2 engenders humans with two lines of defense against the (1) a virus (s) (2) a systemic ailment such as allergies (3) fungi (4) bacterial infection (4) cancerous tumor (5) biowarfare agent (6) microbial infection, (7) any ailment (8) an allergen or cause of allergies including IgE and cytokines, (9) a target protein or variant.
An additionally benefit of dIgA, which provides SIgA based mucosal immunity is that it is possible to stop foreign bodies and foreign proteins before they breach the epithelial barrier while also avoiding the setting off of destructive inflammatory responses such as allergic reactions or antibody dependent enhancement of infection (ADE). If pathogens are neutralized in the mucus by SIgA1 or SIgA2 or engineered variants it will significantly reduce if not completely eliminate the probability of pathogen or allergen related events that are destructive to human tissue that may be dangerous or life altering to human life. Although, if the pathogen, antigen or allergen did manage to enter the bloodstream by breaching the epithelium a second line of defense dIgA directly beneath the epithelium and a third line of defense dIgA directly beneath the basement membrane would neutralize it and either signal for phagocytosis by neutrophils or macrophages or be transported to the mucosa or duct while dIgA is bound to the target.
This present invention arises out of a need to neutralize a variety of systemic pathologies and pathology promoting substances and organisms before they have a chance to cross mucosal tissue or spread far from the mucosal barrier. This invention is a gene therapy focused on expressing immunoglobulins that are naturally produced in large concentrations at mucosal and exocrine tissue that is dIgA1m, dIgA2 and engineered variants that becomes SIgA1, SIgA2 and SIgA engineered variant upon being actively transported from the basolateral face of the epithelium to the mucosa or exocrine duct. The present invention is designed to achieve safety and effectiveness by embracing the immunoglobulins that achieve the therapeutic effect or immunological protection against the foreign body, bacteria, virus, antigen, pathogenic body, pathogenic protein, biowarfare agent or allergen of interest that are developed in humans, developed in mice or other animals with humanized immune systems, developed in transgenic animals, developed in mice and intended for chimeric immunoglobulins, developed from phage display technology where single chain variable fragment (scFv) regions from combinatorial libraries and identified in phage display technology to be therapeutically effective against the pathogen, protein of interest or other antigen, or where immunoglobulins are developed in humans exposed to the foreign body, pathogenic body, pathogen associated protein, antigen or allergen of interest all which may be broadly classified for the purposes of this instant patent application as the target of interest. The invention describes the method to identify the DNA sequence and/or polypeptide sequence of high affinity immunoglobulins expressed in individuals that were exposed to the target of interest. The invention further describes the method to design vectors expressing those immunoglobulins and also dimeric immunoglobulins class A (dIgA1 and dIgA2) necessary for mucosal immunity that encode at a minimum part of the binding regions, V-regions as identified from phage display technology or non-human vetebrates (e.g. mouse or rabbit) intended for chimeric antibodies using some or all of the CDR regions, but more generally at least the Fab regions if not the entire polypeptide sequence of the potent immunoglobulins identified from mice or other animal with humanized immune systems, transgenic mice or the CD27+ IgG memory B-cells, CD27+ IgA memory B-cells from persons that were exposed to or were exposed to and recovered from the foreign body, bacteria, virus, micro-organism, antigen, pathogenic body, pathogenic protein, biowarfare agent or allergen of interest. Delivery systems are also described, which include AAV, adenovirus, lentivirus, lipid nanoparticles and vesicle based delivery systems. While dIgA is privileged to reach the mucosa it can also function effectively in the tissue with increased binding affinities over IgG counterparts. Thus, dIgA1 and dIgA2 may be considered in multiple different regions of the body to provide a therapeutic benefit.
Blood will be collected from any of an individual, a transgenic animal, a mouse with humanized immune system, or a mouse that was infected with, exposed to and ideally has undergone affinity maturation, or lives with any of (1) a virus (s) (2) a systemic ailment such as allergies (3) fungi (4) bacterial infection (4) cancerous tumor (5) biowarfare agent (6) microbial infection, (7) any ailment (8) an allergen or cause of allergies, (9) a target protein or variant. Memory B-cells will be collected from the buffy coat layer (layer that contains white blood cells) of fractionated blood. From humans the Immunoglobulin class A (IgA) CD27+ and class G (IgG) CD27+ memory B-cells or other B-cells with cell surface immunoglobulins will be subsequently isolated. Memory B-cells and plasmablasts are the only B-cells that have both undergone some affinity maturation and bear cell surface immunoglobulins in any appreciable quantity that is required for investigation. Thus, the process of separating cells—that have undergone affinity maturation—based on the affinity of their immunoglobulins for a target of interest can most reliably take place with memory B-cells but is also possible with other B-cells bearing a cell-surface immunoglobulin. There is always the possibility that an IgM B-cell that bears the IgM cell surface immunoglobulin will have high binding affinity and that will be considered as well. Additionally, there is always the possibility that one may isolate a plasma B-cell or memory plasma B-cells that produces immunoglobulins with potent binding affinity for the target of interest. A technique known as B-cell Elispot may be used to identify plasma B-cells or memory plasma B-cells secreting antibodies with potent binding affinity for the target of interest. (See e.g., Crotty, S., Aubert, R. D., Glidewell, J., & Ahmed, R., 2004, J Immunol Methods., 286:111-122.) Generally, B-cell Ellispot may involve using memory B-cells and stimulating them to differentiate into plasma secreting B-cells to detect for secreted antibodies potent for the target of interest. The plasma secreting B-cells are placed in proximity to a plate coated with the antigen of interest (whether self-antigen, foreign antigen or allergen is irrespective of the procedure) where after some time period the cells are washed away and biotinylated detection antibodies are added to the plate to detect for the presence of the secreted antibody bound to the antigen on the plate. Thus, this instant patent contemplates the use of memory B-cells, plasmablast B-cells, memory plasma B-cells and plasma B-cells to identify immunoglobulins, immunoglobulin V-regions with potent binding affinity for the target of interest.
Alternatively, phage display technology that collectively expresses a combinatorial library of scFv with the use of mutagenesis as a means of in vitro affinity maturation of repeated cycles of scFv evolution and bio panning techniques to achieve increasing binding affinities for the target of interest may be used to identify the cDNA encoding for the potent binding affinity. The source of the immunoglobulin cDNA encoding for the scFv may or may not be from persons that were exposed to the target of interest. Another possibility is the use of mice or other animals with humanized immune system or transgenic mice as a means to affinity mature human immunoglobulins in these animals by exposure to the target of interest or part of the V regions may be identified with the use of non-human vetebrates (e.g. mouse or rabbit) intended for chimeric antibodies.
In the invention the genetic information that encodes for that potent binding affinity or the polypeptide sequence that results in that immunity will be determined, evaluated for safety, coupled with constant regions potentially engineered and then incorporated into an mRNA vector, episomal expression vector for expression in muscle cells, B-cells including memory B-cells, Germinal Center B-cells, memory plasma B-cells, a plasma blast, and naïve B-cells), liver cells (such as hepatocytes), splenocytes, and other potential cells or retroviral incorporation into genomic DNA via a lentivirus. In the invention those episomes would be delivered as via an adeno-associated-virus (AAV) vehicle as single-stranded DNA that would be converted into double-stranded DNA by the host genetic machinery, adenovirus vehicle, mRNA, lentivirus as RNA that would be reverse transcribed into double-stranded DNA in the host by reverse transcriptase contained in the lentivirus capsid. In the invention if human donors or mice or other animals with humanized immune systems, transgenic mice or non-human vetebrates (e.g. mouse or rabbit) intended for chimeric antibodies are used as the source of potent immunoglobulins or potent binding affinity episomes that encodes for at a minimum immunoglobulins with V regions if not the Fab (See
The various compositions and methods of the invention are described below. Although particular compositions and methods are exemplified herein, it is understood that any of a number of alternative compositions and methods are applicable and suitable for use in practicing the invention. It is understood that vector constructs may include additional DNA, such as a 5′ Untranslated Region (5′ UTR) and 3′ UTR between or preceding cis-acting signals and transgenes as well as spacer DNA between or before cis-acting signals and viral signals such as LTRs, ITRs, psi, cPPT/CTS, etc. It is also understood that evaluation of the immunoglobulin expression constructs for the vectors specified in this invention can be implemented using methods standard in the art. New vector constructs are also proposed to enable the expression of dimeric immunoglobulin A (dIgA), which becomes secretory immunoglobulin A (SIgA) as part of crossing an epithelial cell from the basal to apical face. Additionally, it is understood that there may be a number of methods and assay modifications that can be used to isolated memory B-cells based on relative affinity for antigens of interest by a flow cytometry or Fluorescence activated cell-sorting (FACS) technique. This should not attenuate the value of any particular cited method. Additionally, the value is further justified by the incorporation of genetic information to expression all or part of those high affinity immunoglobulins Fab, V-region, scFv or partial binding element from non-human vetebrates (e.g. mouse or rabbit) intended for chimeric antibodies, in the context of complete immunoglobulin a mRNA, non-viral, viral or retroviral vector construct.
The methods of this invention will utilize unless specified otherwise modern techniques of cell molecular biology, chemical biology, microbiology, biochemistry and immunology. Many of such techniques are explained substantially in the publication literature and are well understood to those skilled in the art.
Unless stated otherwise all terms used herein have the same meaning that they would to one skilled in the science, art and practice that is utilized in the present invention which include terms from methods in molecular biology, immunology, microbiology, chemical biology, recombinant DNA technology, biochemistry and virology. These terms are well within the knowledge of those with in depth knowledge or skill of the art.
The term “conserved polypeptide sequence” as used herein refers to polypeptide sequences that have remained evolutionally conserved possibly due to functional constraints. This bears relevance in the innate immune system, which relies on pattern recognition of conserved polypeptide sequences to recognize antigens of pathogens.
The term “affinity maturation” as used herein refers to the maturation of an immature B-cell through both isotype switching and somatic hyper mutation and a memory B-cell through somatic hyper mutation that occurs through CD4+ helper T-cell activation of B-cells that have engulfed and degraded an antigen.
The term “potent” as used herein refers to binding affinity of immunoglobulins. Potent is meant to refer to a binding affinity of the immunoglobulin for the foreign antigen produced by the pathogen where the binding affinity is sufficiently high to warrant further investigation for the purposes of expressing the immunoglobulin or a derivative of that immunoglobulin as intended for episomal expression of immunoglobulins.
The term “coding DNA” or “cDNA” as used herein refers to DNA that encodes for the polypeptide of interest. cDNA is effectively mRNA but in mRNA the thymine in cDNA is replaced with uracil in mRNA. However, for the purposes of this instant patent the cDNA is more concerned with the polypeptide sequence that it codes for. In that sense the degeneracy of the genetic codes considers any codon that codes for the amino acid to be an acceptable replacement for a cDNA codon. This is because the concern is the polypeptide sequence where the cDNA that codes for it does not matter due to the degeneracy of the genetic code. However, it is recognized that the efficiency with which an amino acid can be polymerized onto the protein being synthesized by the ribosome is dependent on the codon specifically even though three different codons may code for the same amino acid they may be polymerized onto the developing protein at different rates in a codon dependent manner.
The term “dissociation constant” or (Kd) as used herein refers to that immunoglobulin relative proportion or ratio of unbound immunoglobulin to the antigen of interest vs. immunoglobulin bound to the antigen of interest at any instantaneous moment or as a portion of time or ratio that an immunoglobulin is unbound to its antigen vs. bound. Kd is often described as (Koff/Kon).
The term “delivery system” as used refers to any system that contains and delivers molecules to the host cell.
The term “donor” as used refers to a human source of biological material and thus anything derived from the donor. Specifically, the terms donor is used to refer to immunoglobulin polypeptide sequences or the coding DNA (cDNA) that encodes for them that is derived from a single cell from the blood of a person that is infected with or has been exposed to or exposed to and recovered from the virus, pathogen, bacteria, antigen, pathogenic protein, systemic pathogenic ailment, biowarfare agent or allergen of interest. However, the cDNA is not required because of the degeneracy of the genetic code and thus, the polypeptide sequence matters most.
What is meant by a donor based immunoglobulin polypeptide sequence or domain is that the exact sequence is derived from the cell of the donor or human that provided blood and refers to an immunoglobulin or immunoglobulin element with therapeutic binding affinity for its target as per the context.
The term “episome” as used herein refers to DNA that resides in the nucleus of the host cell as an extra-chromosomal DNA and does not integrate into the genomic DNA of the host. The episome is said to be a separate artificial chromosome. Although, an episome can be made to be non-replicating or could be designed to be replicating. When an episome is non-replicating when the cell divides into 2 daughter cells only one of the two daughter cells will contain the episome. The concentration of episomes in the host animal for example will reduce with time that is a function of the lifespan of the different cells where the episomes resides.
The term “therapeutic binding affinity” as used herein refers to the antibody binding to any protein of interest including variants of that protein when specified, as well as other body of interest such as a molecule or macromolecule where the desired therapeutic effect is achieved with that binding affinity in the immunoglobulin of interest. That is the binding affinity that most effectively prevents pathology associated with the antibody's target such as a virus, pathogen, bacteria, microorganism, systemic pathological ailment, cancer, antigen, biowarfare agent or allergen.
The term “J chain” also referred to as “Joining Chain” as used herein refers to a 159 amino acid polypeptide that includes a signaling peptide that is cleaved to a 137 amino acid polypeptide that forms a cysteine bond to (A) 2 immunoglobulin class A subclass 1 through a cysteine bond between the penultimate cysteine on each immunoglobulin heavy chain to each of the C14 and C68 cysteines of J chain. (B) 2 immunoglobulin class A subclass 2 through a cysteine bond between the penultimate cysteine on each immunoglobulin heavy chain to each of the C14 and C68 cysteines of J chain. The resulting immunoglobulin is a tetramer of immunoglobulin heterodimers where each heterodimer is made up of 2 immunoglobulin heavy chains and 2 immunoglobulin light chains that includes J chain as described in this paragraph.
The term “immunogenicity” as used herein refers to the ability of a foreign substance, such as an antigen, molecule, macromolecule or allergen to provoke an immune response in the body of a human and that may result in side effects and health complications.
The term “isotype switching” as used herein refers the changing of an immature IgD or IgM B-cell to an IgG, IgA or IgE B-cell as part of affinity maturation. Isotype switching exclusive of somatic hyper mutation may enhance the specificity of an immunoglobulin for its antigen.
The term “immunocompetent” as used herein refers to individuals that have the ability to produce and further develop an immune response following exposure to an antigen.
The term “pseudotyped” as used herein is the process of producing viruses that is viral or retroviral vectors in combination with foreign viral envelope proteins. A virus that is said to be pseudotyped is also referred to as a pseudovirus.
The term “daughter” cell as used herein refers to any of the cells formed when the cell undergoes cell division by mitosis.
The term “effector functions” refers to the signaling activity of antibodies such as the immunoglobulins. The immunoglobulin heavy chain constant regions specifically the Fc and the pFc′ constant domains are inclusive of effector signaling regions of the immunoglobulin. Different immunoglobulin isotypes and subclasses have different effector functions via different receptors for their Fc regions. Effector functions of immunoglobulins communicate with other cells or soluble proteins in the immune system through receptor mediated processes and signal to them to carry out a function or relay a signal to another type of cell. Effector functions include neutralization, opsonization, sensitization for killing by natural killer cells, activation of the complement system, activation of macrophages or phagocytes and activation of mast cells and basophils, antibody-dependent cellular cytotoxicity and antibody-dependent cellular phagocytosis.
The term “small pre-B-cell” refers to a state in B-cell development while the destined B-cell is in the bone marrow. V to J gene rearrangements of the immunoglobulin light chain on chromosome 2 (Kappa locus) or chromosome 22 (Lamba locus) takes place.
The terms “genomic DNA” refers to chromosomal DNA specific to the organism and thus is expected to be found in most cells of the organism. Genomic DNA represents the bulk of the genetic material of the organism. Other genetic material may be mitochondrial DNA and gamete DNA.
The term “non-viral vector” may refer either to a virus or viral particle containing DNA capable of functioning as an episome in the nucleus but is not contained within a capsid. Non-viral vectors and transfer plasmids contain structural and/or functional genetic elements that are primarily derived from a virus but not part of a viral delivery system.
The term “self-antigen” may refer to a protein, polypeptide of macromolecule that is produced by the organism. Self-antigens are to be distinguished from “antigens” that are proteins, polypeptides or macromolecules produced by an external organism or “viral antigens” that are produced by a virus.
The term “systemic pathologies” may refer to a health disorder whose basis of pathology is due to internal factors related to and encoded for in protein levels, mutations, DNA, RNA or cancer. This is to be distinguished from an “external pathogen” that is a pathogenic protein, virus, fungi or other microorganism that is capable to causing pathology.
The term “pathology” may refer to the specific damage sustained by the host organism as a result of any cause. Pathology is broadly defined and may include tissue damage, tissue compromise, cell loss, cancer, allergic reactions, cell malfunction, organ malfunction, organ malformation, tumors, imbalances in cell levels or imbalances in metabolic levels, as well as the psychological consequences of any imbalance.
The term “retroviral vector” refers to a viral vector or plasmid containing structural and functional genetic elements, or portions thereof, that are primarily derived from a retrovirus that is intended for retroviral incorporation into DNA.
The term “lentiviral vector” refers to a vector or plasmid containing structural and functional genetic elements, or portions thereof, including long terminal repeats (LTRs), psi encapsidation signal, central polypurine tract/central termination sequence (cPPT/CTS), rev response elements (RRE) that are primarily derived from a lentivirus.
The terms “integration-deficient lentiviral vector,” may be used to refer to lentiviral viral vectors that are capable of functioning in the host cell as an episome and cannot integrate into the host genomic DNA or is highly unlikely to integrate into host genomic DNA.
The term “somatic hypermutation” may be used to refer to a process that can occur in B-cells. Where Germinal Center memory B-cell V-regions undergo point mutations to produce variant immunoglobulins some of which may have higher affinity for the antigen that was the cause of the somatic hypermutation process. Somatic hypermutation occurs during many stages of B-cell development and during affinity maturation when germinal center B-cells enter the GC dark zone and undergo proliferation. When memory germinal center B-cells become activated by CD4+ helper T-cells they can assume one of three states of differentiation becoming a memory B-cell, memory plasma secreting B-cell or may re-enter the dark zone and undergo further proliferation where each daughter cell will have undergone different mutations in the V-regions as part of the process of affinity maturation. (See, e.g. Janeway, C., Travers, P., Walport, M., and Shlomchik, M., Janeway's Immunobiology, Ninth Edition. 2016. Garland Science: New York, N.Y. ISBN: (Paperback) 978-0815345053)
The peak affinity of one's immunoglobulins for key antigens or protein targets such as highly conserved cell surface antigens in viruses, bacteria, fungi, microorganisms and other pathogens after affinity maturation has taken place is an important factor in one's ability to fight pathogens that evade the innate immune system. The innate immune system relies in part on evolutionarily conserved polypeptide sequences to detect pathogens. When the peptide sequences of proteins produced and especially presented on the surface of viruses lack a minimal degree of sequence similarity necessary to detect such evolutionarily conserved peptide sequences the participation of the adaptive immune system is required to directly detect such specific pathogens. With an increased number of iterations of exposure to pathogenic proteins and antigens the adaptive immune system can increase its affinity for antigens through a process of affinity maturation. When a B-cell becomes immature it typically starts out as an immunoglobulin class M (IgM) or immunoglobulin class D (IgD) B-cell or expressing both that also bears a cell surface immunoglobulin class M receptor or IgD receptor or both IgD and IgM B-cell receptors (BCRs). Part of the B-cell development process consists of going from the early pro-B-cell to small pre-B-cell stage where immunoglobulin gene element rearrangements occur and are evaluated to ensure productive matches and also the undeveloped B-cell detects in the bone marrow for self-antigens. In the Bone marrow when the affinity for a self-antigen is above a specific threshold the undeveloped B-cell can be rescued by gene rearrangements of gene elements of the V-region and is known as “receptor editing”. If repeated receptor-editing fails to produce an immunoglobulin chain that are not strongly reactive to self-antigens the undeveloped B-cell will undergo apoptosis. Immature B-cells have heightened sensitivity to self-antigens and can continue to undergo receptor editing or antigen-induced apoptosis. (See e.g., Melamed, D., 1998, Cell. 92:173-182) However, about 20% of immature B-cells have some reactivity to self-antigens (See e.g., Wardemann, H., et. al., 2003, Science 301:1374-1377). As without this we would not be able to sufficiently generate an adaptive immune response to a broad range of antigens. Immature B-cells undergo further differentiation into mature naïve B-cells that continue to bear cell surface immunoglobulins of IgM or IgD.
In phase 1 of the primary immune response mature naïve B-cells leave circulation and enter secondary lymph nodes and can engaged in antigen encounter with follicular dendritic cells. B-cells then process antigen and present it on their MHC class II to the T-cell receptor (TCR) of T-helper cells. Upon activation by T-helper cells at the T-cell/B-cell border the B-cell undergoes proliferation in the follicle with three possible fates: a Germinal Center independent memory B-cell bearing an IgM receptor, short lived plasma secreting IgM B-cell with a half-life of a few days or a Germinal Center B-cell that will enter the dark zone and undergo proliferation and somatic hypermutation. A secondary encounter with antigen from a follicular dendritic cell followed by processing presentation on the MHC class II to the TCR of T-follicular-helper cells results in activation of the germinal center B-cell that can undergo isotype switching to IgG(1, 2, 3 or 4) or IgA(1 or 2) and can be dependent on the lymph node. For example, lymph nodes that support the mucosa of any organ tend to cause IgM B-cells to class switch to IgA. They can become a memory B-cell baring the cell surface immunoglobulin, a memory plasma B-cell that can persist for decades depending on the support from the local environment which is often the bone marrow, a plasma blast that is in the process of converting to a memory plasma secreting B-cells or can reenter the dark zone for further proliferation and somatic hypermutation repeating the cycle. IgG and IgA Memory B-cells upon activation can differentiate into a long-lived memory plasma B-cell or can reenter the dark zone for further proliferation and somatic hypermutation. T follicular helper cell (TFH cell) Germinal Center B-cell interactions are important for the generation of germinal center B-cells. (See, e.g. Akkaya, M., Kwak, K. & Pierce, S. K., 2020, Nat Rev Immunol., 20:229-238). The long lived plasma B-cells may migrate to the bone marrow where they can be sustained for decades as a result of the microenvironment in the bone marrow and even potentially the stomach and small intestine. Although, the memory plasma B-cells in the small intestine and stomach may be derived directly from the local lymphnodes supporting the organ or may migrate to the interstitium of the stomach and small intestine while not being supplied from local lymphnodes. (See, e.g. Akkaya, M., Pierce, S. K., 2020, Nat Rev Immunol., 20:229-238; Also see, Landsverk, 0. J., Jahnsen, F. L, et al., 2017, J. Exp. Med. 214:309-317; Khodadadi, L., Hiepe, F., 2019, Frontiers in immunology, 10:721)
The repeated cycle of re-entry into the dark zone allows the affinity maturation process where cell surface immunoglobulin bearing B-cells undergo a repeated cycle of proliferation and somatic hypermutation potentially increasing the affinity for the antigen of interest. Both these processes can potentially result in B-cells with reactivity to self-antigens. Naïve B-cells give rise to both lymphoblasts that secrete antibodies and memory B-cells upon activation from a pathogenic antigen and the activation of CD4+ helper T-cells. Through, repeated cycles of proliferation and somatic hypermutation of germinal center memory B-cells the resulting memory B-cells and the resulting daughter long-lived plasma B-cells can develop a greater affinity for the antigen of interest. (See, e.g. Akkaya, M., Pierce, S. K., 2020, Nat Rev Immunol., 20:229-238; Also See e.g., Ziegner, et. al., 1994, Eur. J. Immunol. 24:2393-2400; Shlomchik, M. J., et. al., 1990, Prog. in Immunol. Proc. 7:415-423; Berek, C., & Milstein, C., 1987, Immunol Rev. 96:23-41; Ochiai, K., Sciammas, R., 2013. Immunity, 38:918-929.). It is through this process that affinity-matured immunoglobulins can be produced by B-cells and memory B-cells can for the most part generally be considered to express immunoglobulins that have high affinity for an antigen of interest. Additionally, during the course of any somatic mutation process that results in memory B-cells the possibility exists that memory B-cells can have a higher affinity for self-antigens. Although, these memory B-cells are unlikely to be activated by CD4+ helper T-cells. There is a panel of assays and additional assays that are used to determine if immunoglobulins have reactivity to self-antigens. Although, it is not comprehensive because of the vast number of proteins produced in the human body. Thus, perhaps the best assay would be based on human bone marrow. (See e.g., Tiller, T., et. al. 2007, Immunity, 26:205-213; Also see e.g., Fsuiji, M., et. al. 2006, The Journal of Experimental Medicine 203:393-400, 2006; Wardemann, H., et. al., 2003, Science 30:1374-1377).
Vectors may be created that encode for those immunoglobulins to be evaluated. Other biological sources such as a transgenic animal, a mouse with humanized immune system, or a mouse that was infected with, exposed to, has immune specificity to, or lives with any of (1) a virus (s) (2) a systemic ailment such as allergies (3) fungi (4) bacterial infection (4) cancerous tumor (5) biowarfare agent (6) microbial infection, (7) any ailment (8) an allergen or cause of allergies, (9) a target protein or variant (10) an immune system protein such as IgE or a cytokine. may be used to identify potent immunoglobulins for the target of interest. Additionally, in some embodiments the CDR regions and in other embodiments the V-region polypeptide encoding nucleic acids of the heavy (IgH) and light chain (IgL) of the immunoglobulins may be incorporated into a vector construct that could use either the constant region DNA identified in the B-cell expressing the identified immunoglobulin of interest or another source of genetic information may replace all or part of the constant region DNA that may also include isotype switching of constant region genetic information, mixes of two constant regions from two isotypes that may be accomplished with combinations of Fab (from donor) and natural or engineered Fc domains or F(ab′)2 (from donor) and natural or engineered pFc′ domains. Additionally, the immunoglobulin hinge length may be modified. Central towards this end is the production of dIgA1 and dIIgA2 to enable mucosal immunity against the (1) virus (s) (2) systemic ailment (3) fungi (4) bacterial infection (4) cancerous tumor (5) biowarfare agent (6) microbial infection, (7) any ailment (8) an allergen or cause of allergies such as IgE or cytokines, (9) target protein or variant of interest.
A human (ideally between 21 and 55 years old), a transgenic animal, a mouse or other animal with humanized immune system, or a mouse that was infected with, exposed to, has immune specificity to or lives with any of (1) a virus (s) (2) a systemic ailment such as allergies (3) fungi (4) bacterial infection (4) cancerous tumor (5) biowarfare agent (6) microbial infection, (7) any ailment (8) an allergen (9) a target protein or variant (10) in the case of non-human vertebrates a human immune system protein such as Immunoglobulin class E (IgE) or a cytokine. has their blood drawn. The blood sample will be allowed to separate into its three layers or can be subjected to blood fractionation method such as density gradient centrifugation. The buffy coat layer, which contains the peripheral blood mononuclear cells (PBMCs) that includes memory B-cells is collected.
One method but certainly not only method that could be used to isolate Human CD27+ IgG+ memory B-cells would be with EasySep™ Human IgG+ Memory B-Cell Isolation Kit′.
This kit can be purchased from STEMCELL Technologies in Cambridge, Mass. This kit also includes an option to purchase an additional separation assay to separate out CD27+ IgA+ memory B-cells. In a similar sense all of the memory B-cells could also be isolated and analyzed together. Although, it is preferred to analyze the CD27+ IgG+ and CD27+ IgA memory B-cells with option to analyze separately or together. The separation of different memory B-cell isotypes is achieved through the use of immunoglobulins specific for the heavy chain Fragment crystallizable (Fc) constant regions of a specific memory B-cell isotype. Using the STEMCELL Technologies method primary human CD27+ memory B-cells can be isolated by immunomagnetic bead isolation followed by a depletion cocktail to deplete Human IgM/IgD/IgA B-cell Depletion Cocktail leaving the CD27+ IgG memory B-cells as a pure sample. Also available is a solution to deplete Human IgA B-cells. Thus, both IgG and IgA memory B-cells will be collected. (Catalog #17868, STEMCELL; Website: https://www stemcell.com/easysep-human-igg-memory-b-cell-isolation-kit.html#section-data-and-publications) Patient PBMCs may be stored frozen and thawed before use. (For an alternative method to isolate CD27+B-cells see e.g., Tiller, T., et. al. 2007, Immunity, 26:205-213) Other methods to separate CD+ memory B-cells may be used where such B-cells can be subsequently separated with FACS or magnetic isolation experiments that take advantage of differences in the immunoglobulin constant regions on the cell surface immunoglobulins as a means to separate out IgG from IgA B-cells or plasmablasts. 1 Website: https://www stemcell.com/easysep-human-igg-memory-b-cell-isolation-kit.html#section-data-and-publications
It is difficult to perfectly separate the IgG memory B-cells by their subclasses e.g. IgG1, IgG2, IgG3 etc. IgG1+ memory B-cells generally make up 60%-70% of IgG memory B-cells in healthy donor serum. IgG2+ memory B-cells make up about 25% of IgG memory B-cells and IgG3+ memory B-cells make up about 9% of IgG memory B-cells. This difficulty in separation suggests that the all IgG subclass have heavy chain constant regions that are topographically similar. (See e.g., Tiller, T., et. al. 2007, Immunity, 26:205-213) However, this is not important because downstream steps will address these differences accordingly.
It is understood that there are established methods to isolate memory B-cells from transgenic mice or rabbit, mouse with humanized immune system and from mice that are well known to those familiar with the art. IgG memory B-Cells or IgA memory B-cells will then be separated by relative binding affinity through a flow cytometry technique such as fluorescence activated cell sorting (FACS). The flow cytometry analysis of the relative binding affinities of memory B-cells will be dependent on labeling proteins such as antigens with a fluorescent tag to allow detection of antigen bound B-cells by the FACS that will employ the use of a competing binding protein such as the protein that the target protein binds. (E.g. if the target protein binds the CCR5 receptor, then it could be used as a competing protein in the assay e.g. in a soluble form) There are an extensive number of well-established methods to determine the relative binding affinities of cell surface receptors for the antigen of interest that are well known to those in the art. As an example, one may use in competition with memory B-cells to bind to the CCR5 receptor-binding domain (RBD) of the HIV glycoprotein. Assays may be designed to determine if memory B-cells binding affinities greater than that of CCR5 for the HIV glycoprotein. There are well-established methods for approximate quantification of binding affinity of immunoglobulins using methodology, known to those of skill in the art. (See e.g., Weiss, G. E., et. al., 2012, Journal of immunological methods, 375:68-74.; Hunter, S. A., & Cochran, J. R., 2016, Methods Enzymol. 580:21-44.; Li, P., Selvaraj, P., & Zhu, C., 1999, Biophysical journal, 77:3394-3406.; Amanna, I. J., & Slifka, M. K., 2006, Journal of immunological methods, 317:175-185)
Immunoglobulin DNA sequences of the CD27+ IgG+ and CD27+ IgA+ memory B-cells, CD+ memory B-cells or plasmablasts can be obtained through established methods. (Niu, X., et al.. 2019, Emerging microbes & infections, 8:749-759; Cao, Y., 2020, Cell, 182:73-84) These are well-established methods known to those of skill in the art and also available from a variety of commercial sources with standardized protocols. Further, such a protocol to obtain the DNA encoding for potent immunoglobulins was previously established to allow for efficient isolation and identification of neutralizing monoclonal antibodies (mAbs) in different infectious diseases. (See e.g., Setliff, I., et. al., 2019, Cell, 179:1636-1646; Wu, X., et. al., 2010, Science, 3295:856-861) Alternatively, memory B-cells specific to the antigen can be subjected to an antigen isolation assay where antigen biotinylated to magnetic beads is competed for between memory B-cell surface immunoglobulins such as IgG+ or IgA+ of different memory B-cells. Magnetic pull downs will only capture those memory B-cells with the greatest relative binding affinity for the antigen of interest. B-cells can also compete against a protein of interest that is present in the solution with known binding affinity to the biotinylated antigen. (See e.g., Cao, Y., 2020, Cell, 182:73-84; Niu, X., et al., 2019, Emerging microbes & infections, 8:749-759) These are established methods known to those of skill in the art and also available from a variety of commercial sources with standardized protocols. However, for any particular antigen, assays may have to be developed using established methods known to those of skill in the art. If magnetic beads are used what would result are a cohort of memory B-cells that could then be separated with a subsequent competitive binding flow cytometry assay such as FACS as described herein. Alternatively, the memory B-cells isolated from the magnetic pull down separation can be assessed for binding affinity. Those memory B-cells with among the more desirable affinities may be identified from one or more of (A) the magnetic pull down isolations assay followed by FACS separation (B) magnetic pull down isolations (C) FACS assays. (Niu, X., et al.. 2019, Emerging microbes & infections, 8:749-759)
The Kd threshold for determining which memory B-cells affinity memory B-cells and achieving a mix of IgG1, IgG2, IgG3, IgA1 and IgA2 memory B-cells each that meet a Kd criteria. Preferentially, the Kd criteria for memory B-cell selection would be in the single digit picomolar—if not femtomolar—range. Such dissociation constants can be measured by surface plasmon resonance for the individual immunoglobulin. Although, it is understood that converting an IgG immunoglobulin into an IgA1 recombinant isotype can result in a 1 to 2 order of magnitude increase in binding affinity. Additionally a neutralization titer (NT50) inhibitory dose may be determined to assess the neutralization potential of immunoglobulins of known concentration in solution for an antigen of interest. The NT50 is defined as neutralization titers [50% inhibitory dose (ID50) or the 50% inhibitory concentration (IC50)] that is defined as the reciprocal of the serologic reagent dilution (or concentration for purified reagents) that caused a 50% reduction in relative luminescence (RLU) compared to virus control wells after subtraction of background RLUs. (See e.g., Robbiani, D. F., et al., 2020, Nature, 584:437-442; Antonio, E., et. al., 2020 bioRxiv, 2020.05.21; Sarzotti-Kelsoe, M., et. al., 2014, Journal of immunological methods, 409:147-160).
The DNA sequences that codes for the immunoglobulins expressed by the memory B-cells may be determined by one of several established methods. Such techniques are well established and understood by those that practice the art. Antigen-binding memory B-cells or plasmablasts may be identified after a magnetic pull down isolation experiment and/or flow cytometry. Identification of the immunoglobulin heavy and light chain polypeptide sequences may be used to incorporate such genetic information into a plasmid transfected into e.g. a HEK-293 cell or human hepatocytes for expression and evaluation of the secreted antibody. (see e.g., Setliff, I., et. al., 2019, Cell, 179:1636-1646; Cao, Y., 2020, Cell, 182:73-84;)
Discussed throughout this instant patent application the possibility exists that memory B-cells can have a high affinity for self. There is a panel of assays and additional assays that are used to determine if immunoglobulins have reactivity to self-antigens. There are well-established methods to carry out these panel assays with monoclonal antibodies known to those of skill in the art. (See e.g., Tiller, T., et. al. 2007, Immunity, 26:205-213; Also see e.g., Fsuiji, M., et. al. 2006, The Journal of Experimental Medicine 203:393-400, 2006.; Wardemann, H., et. al., 2003, Science 30:1374-1377). Another described global self-antigen assays can also be used to evaluate immunoglobulin for self-reactivity. (See e.g., Vale, et. al., 2016, Front. Immunol. 7; Nobrega, A., et. al., 1993, Eur J Immunol., 23:2851-2859; Haury, M., et. al., 1997, Scand. J. Immunol. 39:79-87) (See e.g., Weiss, G. E., et. al., 2012, Journal of immunological methods, 375:68-74)
Those immunoglobulins discovered from human B-cells, mice, transgenic mice or mice with humanized immune systems that are deemed to have “therapeutic binding affinity” generally high affinity for antigen of interest while also being at sufficiently low reactivity for self-antigens will have their DNA incorporated into an expression vector for further evaluation. Additionally, high affinity VH and VL regions identified from phage display technology will be incorporated into full length immunoglobulin heavy and light chains for further evaluation. That evaluation of immunoglobulins identified from any of the sources may further include modifying the constant regions of the immunoglobulins using a variety of different sources of human genetic information or through engineering the constant regions to improve effector functions. This approach may include using constant regions of different isotypes or different subclasses and engineering of the constant region that are detected by Fc receptor on macrophages and monocytes as an example to reduce antibody-dependent enhancement of infection. All such immunoglobulins may be evaluated in the battery of tests that include self-reactivity assays and binding assays as described in this document.
Plasmids will be created that encode for immunoglobulins to be evaluated. The V-region and some of the constant region DNA of the heavy (IgH) and light chain (IgL) of the immunoglobulins will be incorporated into a vector construct that could use either the constant region DNA of another isotype and/or subclass or another source of human genetic information may replace all or part of the constant region DNA for the immunoglobulin heavy and/or light chain that may also include (A) class or subclass switching of constant region genetic information (e.g. replacing all of the IgG2 constant region with IgG3 or IgA1), (B) mixes of two constant regions from two isotypes or subclasses (e.g. replacing part of the IgG2 constant region with an IgA1 or IgA2 constant region; although generally at a minimum the Fc or pFc′ region would be derived from IgA1 or IgA2 since the CH3 (Constant Heavy 3) region is responsible for complexing with J Chain (C) replacing the Fc part of the constant region coding DNA (polypeptide sequence) of a particular subclass with the constant region DNA of the subclass from a another source of genetic information with the emphasis of low immunogenicity.
In consideration of human derived immunoglobulins or immunoglobulins derived from mice with humanized or engineered immune systems likely, the immunoglobulin light chain (IgL) constant region would be coded for in the vector as identified. If an CD27+ IgG1+ memory B-cell or other CD+ IgG1 memory B-cell is identified to have potent binding to the target of interest not only will an expression vector encoding an IgG1 immunoglobulin for precisely the same immunoglobulin heavy and light chains as identified in the IgG1+CD27+ memory B-cell. Additionally, the VH-region of the immunoglobulin heavy chain may be paired with the constant domains (CH1, hinge, CH2 and CH3) of another isotype while leaving the immunoglobulin light chain unchanged. With the idea that increased binding affinity can occur simply as a result of an isotype switch from IgM or IgD to IgG, IgA or IgE without changing the amino acid sequence of the V-region. Further, the constant regions of each class and subclass have different effector functions. Additionally, enhanced or reduced signal transfer from Fab to the Fragment crystallizable (Fc) region to the can occur simply as a result of isotype switching (See e.g., Pritsch, O., et al., 1996, J Clin Invest. 98:2235-2243.; Janda, A., et. al., 2016, Front Microbiol., 7:22). Not only will immunoglobulins V-regions be investigated for different isotype functions but they will be investigated for their Fab and F(ab′)2 domains in a variety of ways as described in this instant patent application. Although, the general emphasis is on dIgA1.
In the invention the immunoglobulins identified to both have “therapeutic binding affinity” are intended to be expressed from episomal DNA in the host cells. AAV, lentivirus, vesicle based delivery systems will be used to transport the vector constructs to their target cells with destination of the nucleus of the target cell. In the invention A mix of episomes each of which codes for a unique immunoglobulin and collectively which code for a polyclonal mix of immunoglobulins. As an example, there may be a total of 3 unique immunoglobulins that are coded for by single stranded DNA in an AAV, double stranded DNA in an adenovirus, mRNA or DNA in a vesicle based delivery system, or mRNA in a lentivirus. Those immunoglobulins will include one or more of the following immunoglobulin classes: dIgA1 and dIgA2, IgG1, IgG2, IgG3, IgA1, IgA2, (See
Immunoglobulin constant regions can have isotypic variants known as allotypes which are generally substitutions of one or more amino acids between allotypes. For example the constant region of the IgA2 immunoglobulin heavy chain has two allotyes referred to as A2m(1) and A2m(2). A2m(2) differs from A2m(1) in that there are 23 amino acid substitutions in addition. IgA1 on the other hand does not have allotypes and also unlike both allotypes of IgA2, IgA1 does not have a disulfide bond between the immunoglobulin light and heavy chains. The immunoglobulin Kappa light chain also has three allotypes Km(1), Km(2) and Km(3) that differ by only one or two amino acids between each allotype. Although interestingly Km(3) is the most commonly used allotype in monoclonal antibodies as some reports cite enhanced specificity from Km(3) over Km(2) and Km(1) where Km(3) has alanine at position 153 and valine at position 191. The Lamba light chain also does not have allotypes discovered in nature. There are several reports that speak of potential immunogenicity from using natural allotypes in therapeutics and even in convalescent plasma and blood transfusions. Although, there is definitive reports of anti-allotype responses patients do routinely express anti-therapeutic antibodies. Although, these antitherapeutic antibodies could be the result of the V-regions and even more specifically the CDR regions rather than the constant regions of the immunoglobulin. (See, e.g. Toraño, A., & Putnam, F. W., 1978, Proceedings of the National Academy of Sciences of the United States of America, 75:966-969.; Li, Z., 2013, Exp Hematol Oncol 2:6)
Immunoglobulins are dimers of heterodimeric proteins that consist of light and heavy chain proteins of moderate size linked together through disulfide bonds and thus, they can be difficult to express from adeno-associated virus (AAV) viral vector constructs due to the AAV capsid limited packaging capacity. Reports of the expression of immunoglobulin vector constructs have focused on the expression of immunoglobulins that are dimers of the heterodimers. That is the immunoglobulin consists of two identical heavy chains and two identical light chains linked together through disulfide bonds. One reason immunoglobulins can be difficult to express in vector constructs due to the limited capacity of the vectors. For example, the maximum capacity of an Adeno-Associated Virus (AAV) capsid is typically about 4.9 kilobases of single-stranded DNA. Typically, to express two gene elements from a single vector construct there must be enough room for both DNA sequences, a promoter that includes a ribosome binding site, an intermediate promoter between the two gene elements that includes a ribosome binding site, a polyadenylation element (e.g. Simian Virus 40 polyadenylation element (SV40 polyA) (For an example see SEQ ID NO. 4) or Bovine Growth Hormone polyadenylation element (BGA polyA)) and potentially a post transcriptional regulatory element (e.g. Woodchuck Hepatitis Virus (WHP) Posttranscriptional Regulatory Element (WPRE). In this context collectively, the sum of these elements approaches or exceeds the 4.9 kilobase capacity of the AAV vector or in the case of an IRES the expression of the section transgene is much lower. Although, in addition even if there is enough room to house the two genes with separate promoters and regulatory elements the expression level of one of the two genes if not both genes is often substantially reduced resulting in a substantial excess of one of the two immunoglobulin chains. There have been a few reports and patents that address the challenge associated with obtaining sufficiently high expression of immunoglobulins that are dimers of heterodimers.
There are two major strategies that may be used. The first is to express the immunoglobulin light and heavy chains as a single open reading frame. When two genes of the immunoglobulin light and heavy chains are expressed as a single open reading frame (that is the stop codon of the upstream gene is not encoded) a furin cleavage site and a 2A self-cleaving peptide are used to ensure efficient yields and viable immunoglobulin production. (See e.g., U.S. Pat. Nos. 7,498,024 B2 and 7,709,224 B2 expressly incorporated by reference herein in their entirety). Alternatively, a 2A self-processing peptide placed between two consecutive transgenes encoded for in a single open reading frame may be used in the absence of the furin cleavage site.
In one embodiment A furin cleavage site is used in conjunction with the 2A self-cleaving peptide to eliminate the large polypeptide residue that would otherwise be left on the immunoglobulin C terminal end on the upstream immunoglobulin chain after self-cleavage or self-processing of the 2A self-cleaving peptide. Furin cleavage sites of four amino acids in length have a consensus sequence of (N-terminus)—RXKR—cleavage point—(C-terminus)— where X can be any amino acid—and furin cleavage sites range from 4 to 6 peptides in length and are cleaved by furin or other proteases. If the furin cleavage site is located C-terminus to a transgene as part of a single open reading frame in a nucleic acid vector the expression of the transgene will occur with a 4-6 amino acid furin cleavage site residue on the C-terminal end of the resulting protein. Additionally, a 2A self-processing or self-cleaving polypeptide has a consensus sequence following cleavage of (N-terminus)—D(X)E(X)NPG—cleavage point/ribosomal skip—P—(C-terminus). Thus, if a 2A self-processing peptide is followed by a transgene as part of a single open reading frame the expression of the transgene will occur with a 1 amino acid (Proline) 2A self-processing peptide residue on the N-terminal end of the resulting protein. However, if there is a leader sequence or signaling peptide that is cleaved from the protein as part of processing such as transporting the protein outside the nucleus then there would be no 2A cleavage or ribosomal skip residue left on the N-terminal end of the functioning protein. It has been demonstrated that the cleavage residue of 2A self-cleaving polypeptide are efficiently removed from the C-terminus of the adjoining upstream immunoglobulin chain by placing a furin cleavage site directly upstream of the 2A residue resulting in an immunoglobulin chain with a furin cleavage site on the C-terminus end following by the 2A self-cleaving peptide directly C-terminus to the furin cleavage site. (See e.g., Fang, J., et al., 2005, Nat. Biotechnol., 23: 584-590.; Krysan, D. J., et. al., 1999, J Biol Chem. 274:23229-23234; U.S. Pat. No. 7,498,024).
An alternative and earlier reported strategy utilized a dual-promoter rAAV vector to express immunoglobulins. CMV and SV40 small T-antigen intron was used as the promoter for the first transcriptional unit that was followed by the leader sequence (or signal peptide) and heavy chain sequence. The leader sequence is a 19 amino acid cleavable sequence that is expressed N-terminal on the heavy (Leader Sequence Mouse: MGWSCIFLFLLSVTVGVFS) (Most common Leader Sequence Human: MDWTWRILFLVAAATGAHS) and light chain (Among most common Leader Sequence found on Kappa light chains MDMRVPAQLLGLLLLWLPG) chain immunoglobulins and is necessary for efficient translocation into the endoplasmic reticulum (For a list of Leader sequences found in human see Table 1). A Bovine Growth Hormone (BGH) polyadenylation (polyA) (For an example see SEQ ID NO. 5) site was used as the post-transcriptional regulatory element for the first transcriptional subunit. The second transcriptional unit utilized a human elongation factor 1α (EF1-a) promoter that was modified to improve stability of DNA and RNA that also contained an intron 1117 (SEQ ID NO. 9) 5′Untranslated Region (5′UTR). An SV40 polyadenylation site was used as the post-transcriptional regulatory element for the second transcriptional subunit. (See e.g., Lewis, A. D., et. al., 2002, J. Virol. 76:8769-8775; Huang, M. T., et. al., 1990, Molecular and cellular biology, 10:1805-1810; Wu, C., et. al., 2004, Molecular and cellular biology, 24:2789-2796).
Previously, these two considered vector constructs were used to express immunoglobulins that are dimers of hetero dimers in mammalian models. (See e.g., Fang, J., et al., 2005, Nat. Biotechnol., 23: 584-590; Lewis, A. D., et. al., 2002, J Virol. 76:8769-8775) However, these reports were not concerned with the expression of dimeric immunoglobulins (dIgA), which only exist for isotype A in human. Dimeric immunoglobulins are tetramers of heterodimers and requires J chain for efficient formation. No such reports or patents concerned with the expression of dIgA from a single AAV vector nor multiple AAV vectors have been identified, nor have such reports been identified for the expression of dIgA from a lentiviral vector nor any vector including an mRNA vector.
J chain a 159 amino acid (SEQ ID NO. 11) protein with peptide signaling leader sequence MKNHLLFWGVLAVFIKAVHVKA (SEQ ID No. 27) that is cleaved to a 137 amino acid protein (SEQ ID NO. 7) is shown to be required for efficient production of dIgA. (See e.g., Lycke, N., et. al., 1999, J. Immunol. 163:913-919; Sorensen, V., et. al., 1999, J. Immunol., 162:3448-3455; Schroeder, H., et. al., 2008, Fundamental Immunology (Book) 6th:125-151; Castro, C. et. al., 2014, Journal of Immunology, 193:3248-3255; Koshland, M. E., 1985, Annu Rev Immunol. 3:425-453) Without J chain there is a substantial reduction in the amount of dIgA produced by an organism such as mice. J chain forms 2 disulfide bonds (See
In some embodiments Marginal Zone B1 Cell Specific Protein (MZB1) (SEQ ID NO. 8) is co expressed in the vector not targeting B-cells, where it is naturally expressed in humans, for more efficient formation of some allotypes of dIgA2. MZB1 Double Knockout (MZB1−/−) mice produce significantly lower quantities of dIgA than mice that have a functioning MZB1 gene. (See e.g., Xiong, E., et. al., 2019, Proceedings of the National Academy of Sciences, 116:13480-13489) In mice without the availability of MZB1 and J chain proteins dIgA would form in very small quantities and would fail to convert over to SIgA. MZB1 is proposed to interact with IgA through the α-heavy chain (αHC) tailpiece dependent on the penultimate cysteine residue (where two αHCs form a disulfide bond with J chain cysteine C14 and C68) and prevents intracellular degradation of α-heavy chain—Light chain (αHC-LC) IgA Dimer complexes. MZB1 promotes J chain binding to IgA.
Additionally, this instant patent optionally includes the expression of dIgA with MZB1 (See
Human immunoglobulins are complex proteins with different structural/functional regions.
Engineering the Fc region of immunoglobulins can serve a large variety of functions including altering their half-life, to enhance complement dependent effector function, to enhance or reduce Fc receptor effector functions and to enhance binding affinity of immunoglobulins. Enhancing complement dependent effector functions as enhancing the complement effector functions of an immunoglobulin leads to more rapid response by supporting immune cells and immune signaling proteins allowing the pathogen to be eliminated more rapidly. In cases where antibody cocktails are used and including immunoglobulins other than dIgA there is an inherent probability of cytokine storm with some classes of IgG immunoglobulins binding to some antigens or even potentially allergens as a recent example if the epithelial barrier is not breached. However, should some pathogens breach the epithelial barrier the probably of cytokine storm is significantly higher. In some cases immunoglobulins may target pathogen cell surface proteins and prevent interactions between cell surface proteins and host receptors.
It may be beneficial to reduce or eliminate effector function to prevent cytokine secretions and the secretion of other pro-inflammatory agents that occurs with antibody mediation viral enhancement or antibody dependent enhancement (ADE) where it is possible for pathogen specific antibodies to promote pathology in the lung tissue, urinary tract, reproductive tract and even potentially the stomach without infecting the epithelial lining. Generally, this only occurs when antibody levels specific to the target are low or antibody-binding constants are not high enough and are thus non-neutralizing. This instant patent aims to identify those antibodies developed by humans that are of a high binding affinity. However, in the case where the most potent natural antibodies against the target protein falls below a specific threshold value or below the optimal “therapeutic binding affinity” one may consider engineering Fc fragments and CH1 and CL domains to reduce ADE. ADE occurs mostly due to the interactions between the antibody and Fc gamma receptors (FcγRs) which IgA does not have, rather IgA is detected by Fc alpha receptors (FcαRI) where ADE does not happen as readily as with IgG. ADE may be mediated by the binding of the Fc regions of antigen-bound or allergen-bound antibodies to immune cells. One may also change or engineer the immunoglobulin constant light (CL) domains by adding a furin cleavage site or 2A self-processing peptide to their C-terminal end. These changes might interfere with Fcγ receptor binding to the immunoglobulin CH2 constant region. (See e.g., Lu, J., Sun, P. D., et al. 2015, Proceedings of the National Academy of Sciences of the United States of America, vol. 112, pp. 833-838.) When an immunoglobulin binds to an antigen there is a conformational change in the immunoglobulin that causes the CH1 and CL domains of the Fab to undergo a conformational change and engage the Fc region. (See e.g., Pritsch, O., et al., 1996, J Clin Invest. 98:2235-2243; Janda, A., et. al., 2016, Front Microbiol., 7:22; Iwasaki, A. & Yang, Y., 2020, Nat. Rev. Immunol. 20:339-341;.). ADE occurs due to the interactions between the antibody and Fc receptors including Fc gamma receptors (FcγRs). ADE may also be mediated by the binding of the Fc regions of protein-bound antibodies to immune cells. ADE may occur in the lumen of the lungs without the pathogen breaching the epithelial lining. Internalization of the antibody bound to its target in the lungs has the potential to promote inflammation and tissue damage through increased levels of pro-inflammatory chemokines CCL2 and CCL3 and reduced levels of decreased levels of the anti-inflammatory cytokines IL-10 and TGFβ. CC chemokines such as CCL2 and CCL3 promote the migration of monocytes to the lung. CCL2 and CCL3 attract monocytes through the receptor CCR2B, inducing their migration from the bloodstream to become tissue macrophages. SIgA1 and SIgA2 are not efficient activators of the complement cascade that is involved in cytokine storm nor are they efficient activators of proinflammatory responses but rather are anti-inflammatory in nature. This is a result of partial blockage of the FcαRI by secretory component preventing efficient access by resident macrophages, monocytes, neutrophils and eosinophils of the myeloid lineage that are often resident innate immune cells in the mucosa and exocrine lumen that decreases the chance of activating the complement cascade and initiating damaging inflammation. For example, opsonic activity of SIgA is poor compared with dIgA or IgA this is due to partial blockage of the FcαRI binding site by secretory component. This is consistent with the more anti-inflammatory role of SIgA. In contrast dIgA and IgA have a dual role in immunity providing both anti-inflammatory and proinflammatory roles. (See e.g., F. et al., 2008, J. Immunol., 181:6337-6348; Iwasaki, A. & Yang, Y., 2020, Nat. Rev. Immunol. 20:339-341.; Yip, M. S. et al.; 2016, Hong Kong Med. J. 22:25-31; Wang, S. F. et al., 2014, Biochem. Biophys. Res. Commun. 451:208-214; Mak, T., 2014, Primer to the Immune Response 2nd Ed:269-292; Bakema, J., van Egmond, M., 2011, Mucosal Immunol., 4:612-624)
IgA, dIgA and SIgA all variants of IgA are unique in that they each are capable of a different role in inflammation including antibody mediated cellular cytotoxicity, proinflammatory, anti-inflammatory responses. Crystallographic studies have established that one IgA can simultaneously bind to two FcαRI molecules on the surface of the myeloid derived innate immune cell. Crosslinking of FcαRI by an IgA immune complex induces FcRγ-chain independent redistribution of FcαRI to plasma membrane rafts (glycosphingolipids and cholesterol. These domains, termed membrane “rafts,” have estimated average sizes ranging from 70 nm). Monomeric IgA in unbound form inhibits the activation of heterologous receptors (e.g. other FcRs, cytokine receptors, chemotactic receptors and TLRs) For example, experiments with eosinophils, monocytes and transfectants demonstrated that FcαRI shows low capacity to interact with IgA immune complexes in a resting state, but ligand binding capacity increases profoundly after stimulation with cytokines such as granulocyte-macrophage-colony stimulating factor (GM-CSF) and IL-4 or IL-5. The ambivalent functions of IgA in human cells are regulated by the CD-89 associated FcRγ chain. dIgA while involved in proinflammatory responses on the other hand is not capable of crosslinking two receptors on an innate immune cell with FcαRI thus is not able to promote the same level of inflammatory response as a crosslinked IgA1 in an immune complex. dIgA like IgA1 has a fully exposed region to bind to FcαRI receptors found on myeloid lineage monocytes, macrophages, neutrophils and eosinophils. When in an immune complex dIgA triggers proinflammatory responses in these cells with the FcαRI receptors it can trigger opsonization and phagocytosis in innate immune cells such as neutrophils with an FcαRI receptor. Tissue distribution of FcαRI is mostly defined by the presence of neutrophils and some macrophages SIgA has partial blockage of FcαRI by secretory component this dampens the proinflammatory response and favors an anti-inflammatory response. Additionally, only a few FcαRI positive cells are observed in mucosal areas in homeostatic conditions. For instance, intestinal macrophages lack FcαRI expression which is consistent with an anti-inflammatory role of SIgA to protect mucosal immunity. Langerhans cells (tissue resident macrophages of the skin) do not express FcαRI. The role of SIgA is to preserve the epithelium in the mucosa and ducts. SIgA binding by FcαRI is increased when complement receptor 3 (CR3) functions as a coreceptor. (See, e.g. Bakema, J., van Egmond, M., 2011, Mucosal Immunol, 4:612-624; Ben Mkaddem, S., Benhamou, M., & Monteiro, R. C., 2019, Frontiers in immunology, 10:811.)
The introduction of foreign oligopeptides greater than 8 amino acids is capable of eliciting an immune response in individuals. Most nucleated non-lymphocyte cells express the major histocompatibility complex class I (MHCI) which primarily bind oligopeptides 8-14 amino acids in length generated from degradation of cytosolic proteins. B-cells and T-cells on the other hand present major histocompatibility complex class II (MHCII) that present 13-25 amino acid oligopeptides where there is an increasing affinity between the MHCII and a 16-20 amino acid oligo peptide where there is an order of magnitude reduction in binding affinity for the oligopeptide to the MHCII for each amino acid reduction in oligopeptide length below a 16 amino acid oligopeptide. (See, e.g. O'Brien, C., Flower, D. R., & Feighery, C., 2008, Immunome research, 4:6.) T-cell receptors (TCR) on CD8+ Cytotoxic T-cells detect the oligopeptides presented in MHCI to determine if they are self-antigens or not. Although TCR on CD4+ helper T cells detect the oligopeptides presented in MHCII to determine if they are foreign in nature and if they are determined foreign the B-cell is activated. Thus, B-cells which do not have a CD8+ cytotoxic T-cell mechanism are quite well suited to express the integration competent lentiviral gene therapy. Hepatocytes present MHCI but virally infected hepatocytes are largely resistant to perforin/granzyme-mediated killing by CD8+ cytotoxic T-cells. In mouse and chimpanzee models of Hepatitis B (HBV) infection IFN-γ produced by virus specific CD8+ T-cells correlates with a profound reduction in serum and liver HBV DNA by disrupting viral capsid integrity and helps to reduce hepatocyte damage by inducing cyto-protective proteins that confer resistance to granzyme B-mediated killing. (See, e.g. Gehring, A. J., Sun, D., M., Bertoletti, A., et al., 2007, J Virol., 81:2940-9.) Thus, hepatocyte expression of the gene therapy will be short lived if CD8+ T-cells recognizes non-self antigen peptide sequences. The potential sequences in the antibody gene therapy that could be recognized by T-cells include 2A self-processing peptide fragments. There is there is research that demonstrates that E2A peptide fragments will not elicit a CD8+ cytotoxic T-cell response. In an ex vivo research T-cells from 16 immunocompetent human donors were subjected to an ex vivo culture system to measure whether an ex vivo T-cell response could be elicited against the Thosea Asigna Virus (TAV) 2A self-processing peptide (T2A) or 2A-equine rhinitis virus (ERAV) E2A. The ex vivo culture system was one that was previously validated to induce T cell responses even against weakly immunogenic antigens. Of the 16 donors tested ex vivo 5 released very low levers of IFN-γ in response to T2A peptide mixtures and none produced cytotoxic activity or responded to E2A. (See, e.g. Arber, C., Savoldo, B., et al. 2013, Gene therapy, 20:958-962) This, research supports for the use of hepatocytes to express dIgA.
MKNHLLFWGVL
AVFIKAVHVKA
MDWTWRILFLV
AAATGAHS
MDMRVPAQLLG
LLLLWLPG
Skeletal muscle cells do not constitutively express or display WIC class I molecules, although they can possibly be induced to do so by proinflammatory cytokines such as IFN-γ and tumor necrosis factor α (TNFα). Although, muscle cells themselves cannot be made to produce IFN-γ nor TNFα under stimulating conditions consistent with gene therapy production of proteins and DNA based immunizations. Also, it was shown that overexpression of MHCI in muscle cells that is observed in some muscular and neuromuscular disorders may be the event that leads to autoimmune disorders of the skeletal muscle such as idiopathic inflammatory myopathies. Muscle has proved resistant to the development of inflammation caused by immunization with heterologous muscle, and inflammation does not persist long after acute viral injury. Although, research has shown that sufficient proinflammatory stimuli in muscles cells of mice induces the expression of other cytokines such as IL-6, transforming growth factor-beta (TGF-β), and granulocyte-macrophage colony-stimulating factor (GM-CSF) by muscle cells themselves, as well as the up-regulation of MHCI and MHCII. Although, none of IL-1α, IL-4, IL-10, IL-12 or IFN-γ synthesis by human skeletal myoblasts was detected in reports. Further, Cytokine proteins for IFN-α, TNF-α, MIP-1α were not detected to be expressed by muscle cells in studies. Consequently, muscle is considered an attractive target for gene therapy and for the administration of DNA based immunizations speaking to their robustness for their purpose for most individuals in the population. Thus, administering the mRNA, AAV and non-integrating DNA based gene therapies into skeletal muscle cells for the expression of dIgA is an attractive target for individuals that do not have neuromuscular disorders, muscular disorders nor constitutively high levels of inflammation in their skeletal muscle or from immune cells acting on the skeletal muscle. (See, e.g. Nagaraju, K., Plotz, P., 2000, Proceedings of the National Academy of Sciences of the United States of America, 97:9209-9214.)
There is the potential that differences in the leader sequences could elicit an immune response I expressed in MHCI presenting cells. Although, for J Chain the leader sequence (seq ID No. 27) in consistent across the human population. Additionally for the immunoglobulin heavy chain the predominate leader sequence found in the human population is MDWTWRILFLVAAATGAHS (seq ID No. 28). For the immunoglobulin light chain the Kappa light chain has high sequence similarity across most if not all of the human population where the small differences in the sequences are insufficient to elicit an immune response for this reason alone. Kappa light chain leader sequences are less likely to elicit an immune response that lambda light chain leader sequences. Kappa light chain is expressed in 60% of B-cells making it the predominate light chain expressed.
Selecting for random recombination of VH and VL regions or Fab regions of immunoglobulin coding DNA (cDNA) through the generation of combinatorial libraries and the use of phage display technology.
In cases where isolated B-cells does not express immunoglobulins with “therapeutic binding affinity” that is may be required for broad neutralization or mitigation of the effect of allergens it may be necessary to randomly recombine VH and VL regions expressed by different B-cells and also to potentially use mutagenesis to further increase binding affinity. This instant patent contemplates the design of vectors of dIgA1 and dIgA2 from libraries that selected for high affinity pairs of randomly and even purposefully recombined VH and VL immunoglobulin regions from different B-cells and even developed in other animals such as transgenic mice or mice or other animals with humanized immune systems. One of the basic principles is to use single chain variable fragments (scFv) in phage display technology to select for highly potent immunoglobulins. One may assemble large libraries of plasmids that code for the random recombination of VH and VL immunoglobulin regions from different B-cells to select for high avidity and high affinity immunoglobulins where VH and VL regions are linked together with a short flexible peptide linker between the VH and VL fragments may occur by either N-terminus—VH-linker-VL—C-terminus or N-terminus—VL-linker-VH—C-terminus where both orientations have been applied but where N-terminus—VH-linker-VL—C-terminus is more common. This linked protein may be linked by a short peptide chain to the N-terminal end of a protein that is displayed on the surface of a filamentous phage for example.
Combinatorial libraries may be assembled in Escherichia coli as one typical example where E. coli contains a plasmid containing the gene encoding for the VH gene and antibiotic resistance from one type of antibiotic may be transfected with a phagemid containing the VL gene where both plasmids may be cleaved at a restriction site resulting in cleaved DNA where sticky ends undergo homologous recombination between the two cleaved plasmids to generate one larger circular plasmid combined that can result in productive expression of a phage that may be positively selected with the co-expression of a gene coding for antibiotic resistance from a different antibiotic that requires the other part of an antibiotic resistant gene found on the phagemid. One restriction site would be located in the region of the gene encoding for the linker that would be expressed between the VH and VL genes or VL and VH genes depending on the intended relative locations of VH and VL to that of the phage cell surface fusion protein. The resulting phagemid expressed a randomly recombined VH and VL gene that is now expressed as a fusion protein to a phage cell surface protein with the configuration N-terminal—VH—linker—VL—linker—phage cell surface protein—C terminal.
Phage expressing single chain variable-fragments (scFv) with high binding affinity to the antigen may be selected for by coating the antigen to a plate which can be accomplished with biotinylation and then submerging the plate in a solution containing the E. coli and phage where following washing the plate with eluting solutions the most strongly binding phage that are not washed away by elution may be identified and have their DNA encoding for the scFv amplified via PCR and sequenced. Such phage may also be used to re-infect E. coli for undergo amplification which being subjected to random mutagenesis of the VH or VL coding regions to create more diversity in the scFv and potentially most strongly binding phage. Random mutagenesis typically occurs at fixed regions along the antibody sequence normally targeted at the complementary-determining regions (CDRs). Site-specific mutagenesis is also employed generally after multiple cycles of random mutagenesis and phage selection based on binding affinity to the antigen biotinylated to the plate. Site-specific mutagenesis selects a defined locus of the VH and/or VL genes or even very specific DNA sequences. Enzyme bases mutagenesis is one form of site specific mutagenesis where a restriction endonuclease cleaves the DNA at a very specific region where oligonucleotide-mediated mutagenesis is widely employed to assist with site-specific mutation by providing internal mismatches that direct point mutations or multiple mutations to the target DNA sequence. Saturation mutagenesis employs the evaluation of substitution of a given residue against the 19 other amino acids at a specific residue.
This patent contemplates an immunization strategy to HIV and potentially a treatment for those infected with HIV. HIV continues to be a top priority to date and no vaccine strategy has induced antibodies with sufficient neutralizing coverage of the quasi-species. Once the host is infected with HIV control of the viral reservoir is significantly dependent on the Fc effector functions of broadly neutralizing antibodies as any loss in Fc effector activity results in the rapid loss of viral control despite potent neutralizing activity. Although, this is not necessarily true prior to infection of the host. As there are other important factors such as agglutination of HIV-1 virions in the mucosa pre infection that may be an equally important part of immune protection against HIV. To the surprise of many researchers, tissue resident natural killer (NK) cells express trivial levels of Fc receptors implying that they are unlikely to contribute to immunoglobulin mediated protection at the site of infection. It was previously reported that FcγRII and FcγRIII expressing macrophages and neutrophils were present in tissues collected from both HIV-seronegative and -seropositive subjects. Additionally, tissue-resident neutrophils while less abundant, mediated more effective phagocytic clearance of immune complexes. It has been suggested that antibody-driven functional activities mediated by cells other than NK cells are more likely to afford protection from infection as well as have therapeutic activity within mucosal and lymphoid tissues. (See e.g. Sips, M., et. al., 2016 Mucosal Immunol., 9:1584-1595.)
Human immunodeficiency virus type-1 (HIV-1) enters the host in virtually all infections through the mucosa of the genital tract or gastrointestinal tract. Once HIV traverses the epithelium in the reproductive tract HIV-1 then may encounter potential target cells such as CD4+ bearing lymphocytes including macrophages, monocytes and CD4+ helper T-cells in the lamina propria. However, it is also possible for HIV-1 to infect CD4+ bearing macrophages, monocytes and helper T-cells in the mucosa of the reproductive tract. In Memory CD4+ T cells and macrophages and monocytes of the myeloid lineage are believed to be an important reservoir for HIV-1. (See e.g. Kruize, Z., 2019, Frontiers in Microbiology, 10:1-17) Although, relatively little is known about HIV-1 infecting macrophages and monocytes in the mucosa as a result of the difficulty associated with isolating macrophages from mucosal tissue. Reproductive tract mucosal macrophages but not intestinal mucosal macrophages support the replication of the R5 HIV-1 strain. Although, intestinal macrophages have been reported to express no detectable, or very low levels of, innate response receptors and HIV-1 receptor/coreceptors and were determined to not support HIV-1 replication. However, these results are not definitive with regard to HIV-1 to infect intestinal tissue macrophages. (See E.g. Shen, R., et. al., 2009. Journal of virology, 83:3258-3267)
One mechanism by which HIV-1 infects CD4+ bearing cells by binding with its HIV-1 envelope glycoproteins which is a trimer of glycoproteins120 (gp120) and gp41. There is a conserved CD4-binding site on the HIV-1 envelope glycoprotein. Additionally, there is a conserved crest on the V3 loop that is necessary for chemokine receptor type 5 (CCR5) or chemokine receptor type 4 (CXCR-4) co-receptor binding that is a key event for HIV envelope fusion with the CD4 bearing T-cell, macrophage or monocyte. Additionally, HIV-1 endocytosis by a micropinocytosis-like mechanism can lead to productive infection in macrophages. In order for micropinocytosis to occur in HIV-1 endocytosis the CCR5 receptor is thought to be present in the engulfed endosome. This pathway specifically requires CCR5 engagement at the cell surface, which in turn suggests that the virus and its coreceptor are present in the endosomal environment simultaneously since the principle of fusion with the endosome membrane is no different than the principle of viral fusion of HIV with an endosome. While HIV undergoes efficient viral degradation following endocytosis, analyses haves supported that HIV-1 transport through the endolysosomal pathway occurs throg in delayed viral degradation following endosomal internalization, possibly allowing the virus to complete its fusion. (See e.g. Gobeil, et. al., 2013, J Virol. 87:735-45, 2013; Carter, G. C., Bernstone, L., Baskaran, D., James, W., 2011, Virology, 409:234-250) This pathway of viral fusion during or after endocytosis is a critical pathway for HIV-1 that must be blocked by antibodies in the mucosal environment for any immunization to be effective. Although, it is generally thought that endocytosis represents a dead end for HIV infection with the caveat of this viral fusion pathway that is thought to require CCR5 or CXCR4 binding to the HIV envelope glycoprotein which occurs at the conserved crest of the V3 loop. In one embodiment a dIgA1 antibody is considered for the conserved crest of the V3 loop is considered.
Although, there are additional sites on the HIV envelope glycoprotein that could be targeted as part of a cocktail strategy to maximize efficacy. Important clues to such a strategy would target conserved regions of the HIV envelop glycoprotein two such conserve regions are the Variable Region 1-Variable Region 2 (V1/V2) regions and the CD4 binding site. A recent HIV-1 clinical trial in Thailand known as RV144 resulted in 31.2% efficacy. (See Tomaras, G. D., et. al., 2013, Proceedings of the National Academy of Sciences of the United States of America, 110:9019-9024.) In this clinical trial the authors reported that “Env-specific plasma IgA/IgG ratios are higher in infected than in uninfected vaccine recipients in RV144.” The report also discussed “Though plasma Env variable region 1 and 2 (V1/V2) IgG correlated with decreased infection risk, high levels of anti-HIV-1 Env plasma IgA correlated with increased infection risk.” That authors attributed this to the difference in effector functions between IgG and IgA. IgG1 for example has FcγRIIIa binding sites for macrophages and neutrophils that IgA does not have where IgA may be less effective at eliciting a pro-inflammatory response from macrophages and neutrophils in the mucosa and also less effective at recruiting natural killer (NK) cells in the bloodstream. The authors reference the following report that stated in the report “the binding of IgG antibodies to variable regions 1 and 2 (V1V2) of HIV-1 envelope proteins (Env) correlated inversely with the rate of HIV-1 infection (estimated odds ratio, 0.57 per 1-SD increase; P=0.02; q=0.08), and the binding of plasma IgA antibodies to Env correlated directly with the rate of infection” (Haynes B F, et al., 2012, N Engl J Med vol. 366:1275-1286). It may be beneficial to incorporate an IgG antibody into an HIV Immunization gene therapy cocktail specific to the V1/V2 regions while having no competing IgA or dIgA specific to the IgG binding site. This is only possible with direct administration of antibodies or a gene therapy based approach. As using a traditional vaccination approach of developing immunity in one immune system from exposure of virus antigens cannot guarantee the ratios of IgG to IgA nor can it guarantee the specificity of the antibodies and their ability to be broadly neutralizing.
The third important binding site is the elusive CD4+ binding site that is typically responsible for HIV's initial binding to the CD4 presenting immune cell. Where a third potential gene therapy antibody cocktail immunoglobulin could be a IgG1 or dIgA1 specific to the HIV CD4 binding site. Such an antibody would block the initiation event of HIV binding to immune cells that precedes the binding to the CCR5 or CXCR-4 binding sites. Although, it is recognized that such binding with the CD4 receptor may not be necessary during HIV-1 endocytosis by a micropinocytosis-like mechanism suggesting that targeting the crest of the V3 loop with dIgA1 is of chief importance and may be sufficient as a stand-alone approach.
In one embodiment an integration competent lentiviral vector or an integration-deficient lentiviral vector encoding for a dIgA1 antibody specific to a conserved target and receptor binding site on the HIV envelope glycoprotein is delivered via a anti CD20+ pseudotyped lentiviral delivery system to B-cells that bears a CD20+ receptor that include naïve B-cells, memory B-cells and germinal center memory B-cells. The vector will be integrated into genomic DNA or be delivered as episomal DNA and will code for a strong promoter that results in a higher level of expression of the vector encoded dIgA1 that the naturally encoded immunoglobulin encoded for by the B-cell resulting in the vector encoded dIgA1 being the major product. After some period following lentivirus administration an mRNA vaccine encoding for the HIV envelop glycoprotein is administered and even a second mRNA booster will be administered some period following. This, will have the effect of activating a large number of B-cells to become memory plasma B-cells potentially persisting for decades to express the dIgA1 specific to the conserved sequence of the envelope glycoprotein. In additional the administration of the mRNA B-cell activator will also result in the development of T follicular helper cells to active Germinal Center B-cells that contain the lentiviral vector.
H. pylori and Other Bacteria
This patent contemplates a strategy to neutralize a variety of bacteria. SIgA is known to neutralize bacterial by binding and agglutinating them preventing the formation of colonies and also binding to their flagella preventing their motility. SIgA also neutralizes bacterial products such as enzymes and toxins. This patent contemplates a strategy to encode for dIgA2 specific to the gram-negative, spiral shaped and microaerophilic bacteria Helicobacter pylori (H. pylori). H. pylori is a leading cause of gastric cancer death worldwide possibly causing over 700,000 deaths yearly and about 15,000 deaths in the U.S. yearly. Additionally, H. pylori is the only bacteria classified by the WHO as a class I carcinogen meaning it is the only bacteria well established to cause cancer. Most bacterial show tropism to specific tissues or cell types and often can use many different adherence mechanisms for attachment. Some speculate, that H. pylori may use as many as 5 different adhesins to attach to gastric epithelial cells. H. pylori has extensive gene variation within its genome that is thought to occur through slipped-strand mispairing within repeats as mechanisms for antigenic variation and adaptive evolution. H. pylori features a genome with high plasticity and high genetic heterogeneity especially in some parts of outer membrane proteins making them difficult targets. Although, there is some sequence identity is observed across some of the H. pylori outer membrane proteins that are thought to be necessary for adherence to the gastric epithelium. A common attachment site on epithelial cells is the Lewis histo-blood group antigens. H. pylori has a large number of sequence-related genes that are expressed on its outer surface. While the exact mechanism related to how H. pylori causes cancer is under investigation there are generally a few requirements for H. pylori to be cancer causing. H. pylori must be able to bind to the gastric epithelium and colonize in addition to burrowing through the epithelium causing stomach or small intestine ulcers in order to cause cancer. Additionally, 50% of H pylori induce vacuolation of epithelial cells that may lead to cancer through the action of vacuolating cytotoxin A (VacA) that is thought to induce apoptosis of epithelial cells that results in vacuoles that have traits of both endosomes and lysosomes. (See e.g., Atherton, J. C., Blaser, M. J., 1995, Cover, T. L., J Biol Chem, Jvol. 270:17771-17777; Kuck, D., Rudi, J., et al. 2001, Infection and immunity, 69:5080-5087) Although, while VacA induces apoptosis in epithelial cells it also disrupts endolysosomal vesicular trafficking and impairs the autophagy pathway. This makes it more difficult for the epithelial cell that has underwent apoptosis to be cleared away and replaced by new epithelial cells. Additionally, the virulence factor cytotoxin associated gene A (CagA) is a known oncoprotein that contributes to the development of gastric cancer. CagA has been shown to be dependent on VacA. It has been shown that in the absence of VacA two different cellular mechanisms proteosome degradation and autophagy degrade CagA. (See e.g., Abdullah, M., Bronte-Tinkew, D. et al., 2019, Sci Rep, vol. 9, pp. 38.; Palframan, S. L., Gabriel, K., 2012, Frontiers in Cellular and Infection Microbiology, 2:1-9) Overall, results suggests that H. pylori may cause stomach cancer through more than one mechanism. Thus, targeting the cancer causing mechanism may not be an effective stand-alone means to mitigate the effects of H. pylori. What is equally important is that H. pylori does not act virulent unless it colonizes. That is the Beta Barrel opening resulting from VacA and resulting cleavage of the virulent peptide does not occur unless H. pylori is adhered to the epithelial cell and colonized and H. pylori does not secrete CagA and other toxins through a membrane channel unless it is colonized. These facts make VacA and CagA difficult targets because they are less likely to present on the outer membrane unless H. pylori is virulent. In order to colonize H. pylori must effectively adhere to epithelial cells. Attachment is mediated through cell surface adhesins. This results in a restricted range of hosts and tissues utilized for colonization. If bacteria are unable to adhere to epithelial cells they tend to be rapidly removed by the shedding of the surface cells and mucus layer. (See, e.g. Borén T, Falk P, Roth K A, Larson G, Normark S., 1993, Science., 262:1892-5) Thus, the most effective preventative measure against H. pylori infection would ideally involve targeting at least one protein that is important in binding to epithelial cells that has a well-conserved sequence on the surface that can be targeted.
The most ideal protein to target would ideally be common among H. pylori strains with a conserved sequence on the outer surface. HopQ I has been reported to be represented in 72.5% of H. pylori strains. HopQ is a porin that facilitates transfer of the CagA. HopQ can exploit the carcinoembryonic antigen-related cell adhesion molecule family (CEACAMs). HopQ binds to the IgV-like domain at the N-terminal of CEACAMs to facilitate the transfer of crucial pathogenic factor CagA to host cells. The HopQ-CEACAM interaction has been measured to be of high affinity (KD from 23 to 268 nM), independent of CEACAM glycosylation. Data has supports that the HopQ-CEACAM interaction contributes to gastric colonization or Hp-induced pathologies. (Koniger, V., Sundberg, E. J., et. al., 2018, The EMBO journal, 37:e98664; Xu, C., Soyfoo, D. M., Wu, Y., & Xu, S., 2020, European journal of clinical microbiology & infectious diseases: official publication of the European Society of Clinical Microbiology, 39:1821-1830) Use of dIgA2 which becomes SIgA2 for this purpose satisfies two requirements first key binding sites can be blocked on H. pylori reducing its ability to bind to epithelial cells. Second, dIgA2 can effectively agglutinate H. pylori facilitating its passage through the digestive system followed by its excretion. For example, it is that cell specific attachment of H. pylori to human gastric surface mucous cells is inhibited by human colostrum secretory immunoglobulin A (SIgA) which is a glycoprotein carrying a highly variable set of N- and O-linked oligosaccharides. The inhibitory activity of SIgA is reduced when it is deglycosylated by digestion with alpha-L-fucosidase. (See, e.g. Boren T, Falk P, Normark S., et al., 1993, Science., 262:1892-5).
This patent contemplates that administration of H. pylori outer membrane proteins and secreted proteins as well as their variants as a vaccine delivered to the lamina propria of the stomach and small intestine. In one embodiment the proteins are administered directly and in another embodiment mRNAs encoding for the proteins are administered via lipid nano particles or other vesicle based deliver vehicles. This patent further contemplates the use of adjuvants administered with the H. pylori proteins to enhance the immune response and the development of memory B-cells sensitive to H. pylori proteins.
This instant patent contemplates the major advantage of dIgA1 and dIgA2 over other immunoglobulins and achieving therapeutically relevant levels of dIgA1 and dIgA2 expression in the regions where they are needed to exert their therapeutic benefit. To achieve therapeutically relevant levels of SIgA1 and SigA2 in the mucosa the underlying interstitium of the lamina propria must reach sufficient concentrations of the therapeutically relevant dIgA1 or dIgA2. Lymph nodes typically align the areas directly outside the smooth muscle tissue (muscularis) of the lamina propria. These lymph nodes supply the interstitium of the lamina propria with plasma B-cells, memory plasma B-cells (that may ultimately migrated to the bone marrow) and some memory B-cells that are specialized in that most of them produce dIgA1 and dIgA2 as opposed to monomeric immunoglobulins more typically found for B-cell in the circulating blood. Thus, typically, dIgA antibodies are supplied right at the site where they undergo transcytosis upon binding with pIgR and the interstitium which is between 1 and 2 mm wide. That is the distance between the smooth muscle and the basal face of the epithelium is the interstitium. Thus, if dIgA1 or dIgA2 is supplied from muscle cells, liver cells or circulating memory B-cells or memory B-cell in the lymph nodes support the lamina propria they must be supplied through the blood stream where their concentration in the lamina propria will be less than the concentration in the blood. Alternatively, they may be ultimately supplied by memory plasma B-cells derived from memory B-cells in the circulating blood or Germinal center memory B-cells that received integration competent or integration-deficient lentiviral vectors. Antibody Levels in organs and interstitial tissues such as those that underlie the mucosal epithelium in the digestive tract, reproductive tract, respiratory tract, kidneys and the skin have been evaluated for Immunoglobulin class G monoclonal antibodies. In the stomach and small intestine the IgG monoclonal antibody concentration in the interstitium of the lamina propria is 2-4% of that of the concentration of the circulating blood after subtracting out the residual plasma in the interstitial vasculature. In the lungs the IgG monoclonal antibody concentration is about 7% of that of the circulating blood after subtracting out the residual plasma in the interstitial vasculature. (See E.g. Eigenmann, M. J., Karlsen, T. V., Krippendorff, B. F., et. al., 2017, J Physiol.; 595:7311-7330) In the skin the IgG monoclonal antibody concentration is about 10% of that of the circulating blood. The unidirectional transport of dIgA1 and dIgA2 from the lamina propria to the mucosa will lead to an overall higher concentration in the lung, digestive and parts of the reproductive tracts in the likely in area of a 50% or greater increase over that of IgG up to some threshold concentration that will unquestionably be therapeutically significant since we must rely on these systems throughout our lives to ensure mucosal protection. Thus, lung lamina propria and mucosa dIgA levels will reach a dIgA concentration in the area of 11% of that of the circulating blood level concentration of dIgA. In the stomach and small intestine circulating antibodies can pass freely through the capillary endothelium in the interstitium that has fenestrations of 60-80 nm allowing for fast equilibration and replacement of any dIgA that is transported to the mucosa. dIgA is 22-26 nm in length. The digestive tract lamina propria and mucosa are likely to see even higher concentration increases in dIgA over that reported for IgG due to the rapid equilibration that occurs between the fenestrated capillary endothelium and the lamina propria thus dIgA concentrations of 4-7% of the circulating blood a level are possible. Although, the capillary endothelium of the lung interstitium are continuous and lack fenestrations. In the kidneys the interstitial concentrations are
Because dIgA is actively and unidirectionally transcytosed across the epithelium with pIgR the dIgA mucosa to blood distribution can be enhanced favorably despite low interstitial concentrations relative to dIgA blood levels. In one embodiment dIgA is supplied from hepatocytes, in another embodiment dIgA is supplied by muscle cells. In another embodiment dIgA is supplied by spleen cells that receive and express the gene therapy vectors. (See E.g. Borrok, M. J., DiGiandomenico, A., Beyaz, N., Marchetti, G. M., Barnes, A. S., Lekstrom, K. J., Phipps, S. S., McCarthy, M. P., Wu, H., Dall'Acqua, W. F., Tsui, P., & Gupta, R., 2018, JCI insight, 3:97844:1-9).
This patent contemplates direct administration of the gene therapy via endoscopic injection or absorption into the lamina propria. The presence of SIgA in mucosal surfaces is locally produced as dIgA by antibody secreting B-cells and memory plasma B-cells in the lamina propria directly beneath the epithelial cells. The source of these dIgA B-cells is the local lymph nodes for the organ. As an example, the stomach has 4 supporting groups of lymph nodes support 4 distinct regions of the stomach. The small intestine also has a supporting lymph nodes in addition to Payer's patches that are sometimes located in the upper duodenum but more often found in the mid to lower duodenum and in other regions of the small intestine. Nutrient and fluid absorption in the Gastrointestinal tract requires lymphatic networks to both regulate interstitial fluid balance and transport lipids. Lymphatic flow in the stomach begins within the initial lymphatic sinuses near the pyloric glands. These fuse to link lymphatic networks between the muscularis mucosa and the submucosa. (See, e.g., Spencer, J., Sollid, L., 2016, The human intestinal B-cell response. Mucosal Immunol 9, 1113-1124.; Lycke, N., Bemark, M., 2017, Mucosal Immunol, 10:1361-1374; Eichmann, A., 2019, Cellular and Molecular Gastroenterology and Hepatology, 7:503-513)
The embodiment of the invention related to gene therapy delivery to memory B-cells in lymph nodes supporting an organ with a mucosa is achieved through the initial lymphatics in the lamina propria which contain button like openings that allow for flow from the fluid filled interstitum into the lymph vessels into the afferent lymphatic vessels that carry unfiltered lymph fluid passing through local lymph nodes to be filtered. Such initial lymphatics are found in the lungs and GI tract. At the initial lymphatics there are distinct leaf shaped endothelial cells that are the general locations of fluid entry into the lymphatic system. The borders of these epithelial cells have been thought to be the primary valves that permit unidirectional flow of fluid into lymphatics. In the trachea and thought to be the case for the stomach and small intestine the borders of these epithelial cells are thought to contain discontinuous tight junctions made by VE-cadherin that is consistent with their function as connection points along the sides of flaps that are effectively the borders for the button like openings for fluid passage without junctional disassembly. Fluid entry into the button like openings is driven by muscle contraction. The buttons can be thought of as linear segments that are parallel to each other with openings of about 3.2 μm (micrometers) or 3,200 nm (nanometers) that were spaced about 2.9 μm apart in the trachea. (See, e.g., Baluk, P., et. al., The Journal of experimental medicine, vol. 204, pp. 2349-2362, 2007; Eichmann, A., 2019, Cellular and Molecular Gastroenterology and Hepatology, 7:503-513)
When a lymphangion, the functional unit of a lymph vessel, has contractile force exerted on it e.g. as due to muscle contraction of smooth muscle linking lymph vessels lymph can be propelled forward in a unidirectional manner. The semilunar valves are directed towards the flow of the lymph and open when the pressure in the first lymphangion is greater than the pressure in the next lymphangion. Pressure in the first lymphangion may increase because of smooth muscle contraction (in lymph vessel) or because of pressure on the walls from outside. Once the lymph flows into the next lymphangion, it cannot return to the previous lymphangion, as the semilunar valves close tightly. (See, e.g. Venugopal, A. M., Stewart, R. H., Laine, G. A., Dongaonkar, R. M., Quick, C. M., 2007, Am J Physiol Heart Circ., 293: H1183-9)
In the stomach and small intestine, lymphatic capillaries, or lacteals, are located exclusively in intestinal villi. Spontaneous lacteal contraction, in concert with adjacent smooth muscles, is essential for drainage into lymph nodes. Lacteal contraction is regulated by the autonomic nervous system, and to be increased by acetylcholine and decreased by norepinephrine. Additionally, such drainage can be accomplished with massaging the stomach in humans. The lacteals lead to lymph nodes supporting the organ. (See e.g., Cifarelli, V., Eichmann, A., 2019, Cellular and Molecular Gastroenterology and Hepatology, 7:503-513) In one embodiment those lymph nodes that house germinal center memory B-cells will receive the gene therapy delivery vehicle such as a Lentivirus that is known to be absorbed by memory B-cells via a pseudotyped lentivirus that can target the CD receptors such as CD19, CD20 or CD27 on the memory B-cell (See
This patent further contemplates the use of proteins or mRNA encoding for proteins delivered to the lamina propria of the at risk organ identifiable as or derived from the (1) virus (s) (2) systemic ailment (3) fungi (4) bacterial infection (4) cancerous tumor (5) biowarfare agent (6) microbial infection, (7) any ailment (8) target protein or variant of interest. This patent targets the lamina propria and underlying interstitium as a means to reach the lymph nodes supporting the organ of interest. In one embodiment the gastrointestinal tract such as stomach and small intestine is targeted. In another embodiment the lungs are targeted. The lymph nodes would be reached by the vaccine traveling though the underlying lymph vessels in the underlying organ.
There is currently an FDA approved endoscopic injection therapy dextranomer/hyaluronic acid copolymer (Deflux) for the treatment of vesicoureteral reflux. The endoscopic injection treatment associated with this approach is considered minimally invasive, performed on an outpatient basis, and technically straightforward, with a relatively short learning curve and low complication rate. These advantages have led to its widespread use in last 2 decades. In extrapolating from this endoscopy based injection to the lamina propria there is a clear precedent that could be extrapolated to a similar procedure for administering the dIgA1 or dIgA2 gene therapy on one or more of the stomach, upper duodenum, esophagus, the trachea and bronchi.
Important elements of RNA are the 5′ UTR that is upstream of the beneficial gene and the 3′ UTR that is downstream of the beneficial gene. UTRs serve a variety of roles including enhancing the amount of protein that is produced from a single RNA, efficient transport outside the nucleus, stability of the mRNA increasing the mRNA half-life and the ability to control the rate of gene translation.
The 5′ UTR is also known as the leader sequence (not to be confused with the immunoglobulin leader sequence or signal peptide) and is the region of mRNA directly upstream of the initiation codon. 5′ UTRs can form complex secondary structures to regulate translation on two levels by preventing translation or as a tertiary structure necessary for binding and recognition by translation factors. Regulatory elements in the 5′ UTR are also linked to mRNA export outside the nucleus. 5′ UTRs that allow for efficient translation are short, have a low GC content, do not contain upstream AUG codons and are relatively unstructured. A major aim of gene therapy is to minimize the dosage necessary to achieve a therapeutically relevant amount of the protein that is being encoded for which this instant patent contemplates to ensure high expression of vector encoded immunoglobulin in this instant patent. In general it has been shown that shorter 5′ UTR sequences are responsible for higher levels of protein expression when the same 3′ UTR is used to express the same protein. (See e.g., Trepotec, Z., et. al., 2019, Tissue Eng Part A., 1-2:69-79; Leppek, K., Das, R. & Barna, M., 2018, Nat Rev Mol Cell Biol, 19:158-174.; Calvo, S. E., Pagliarini, D. J., et. al., 2009, PNAS, 18:7507-7512; Babendure, J. R., et. al., 2006, RNA, 12:851-861.; Barrett, L. W., et. al., 2012, Cellular and molecular life sciences: CMLS, 69:3613-3634)
Within eukaryotic genes the 5′ UTR is located downstream of the TATA box. The TATA box is the transcription initiation site. Although, there is spacer DNA between the 5′ UTR and the TATA box that is typically about 20 bases. This spacer DNA is necessary for the transcriptional machinery to assemble and begin transcription about 20 bases downstream from the TATA box. For example, TATA box binding protein binding the TATA box with other cofactors followed by RNA polymerase which pushes the transcription start site downstream from the TATA box.
5′ UTRs for proteins intended for high expression typically are very short in the area of 20 to 30 bases including the (−1 through −6 position on the Kozak consensus sequence). For example the protein J chain that is expressed in a dIgA plasma B-cell and in a dIgA memory plasma B-cell at a rate high enough to support 500 dIgA1 immunoglobulins per second (requiring 250 J Chains per second) is has a 5′ UTR of 18 bases including the Kozak consensus sequence. (For a list of 5′ UTRs found in immunoglobulins and selected highly expressed genes see Table 2)
The 3′ UTR is located downstream of the protein coding sequence is involved in numerous regulatory processes including transcript cleavage, stability, translation and mRNA localization. 3′ UTRs effectively determine the fate of mRNA. Sequence constrains are more relaxed in the 3′ UTR allowing for a higher degree of regulation. Although, there are regions of high conservation within the mammalian genome. (Barrett, L. W., et. al., 2012, Cellular and molecular life sciences: CMLS, 69:3613-3634; Siepel, A., et. al., 2005, Genome research, 15:1034-1050). In contrary to promoter regions motifs within the 3′ UTR are conserved on one strand as regulatory proteins regulate translation and even localization by engaging with the conserved motifs. In addition, microRNA binding sites are found in the 3′ UTR that allow miRNAs to decrease the level of expression of the mRNA by the ribosome, blocking regulatory proteins from binding and marking the mRNA for degradation. In addition there are silencer regions within the 3′ UTR that repressor proteins may bind to and inhibit expression.
Recently, it was shown that in human cell lines that 3′ UTRs allow for differentially regulated localization of some proteins to membranes. As an example, the long 3′UTR of the mRNA of CD47 enables efficient transport to the cell surface where it is localized on the surface on the cell. Alternatively the short 3′ UTR of the mRNA of CD47 localizes to the endoplasmic reticulum. The authors of this study concluded that the long 3′UTRs contain additional regulatory elements that can regulate localization and protein abundance. Although, the localization step occurs at the protein level where the mRNA with both the long 3′ UTRs and short 3′ UTRs of CD47 have a similar distribution at the perinuclear endoplasmic reticulum. Thus, the localization of the protein is independent of the localization of mRNA. (See, e.g. Berkovits, B., Mayr, C., 2015, Nature 522:363-367). Immunoglobulins that are expressed on the cell surface likewise have a 3′ UTR that is much longer than the 3′ UTR of the same class and subclass of immunoglobulins that are expressed for secretion. Although, both these immunoglobulins must ultimately reach the surface of the cell. Although, through different pathways. (For a list of 3′ UTRs found in immunoglobulins and selected highly expressed genes see Table 3)
B-Cell Differentiation into Plasma Secreting Cells
The differentiation of B cells into Ig-secreting plasma cells (both memory plasma B-cells and short lived plasma B-cells) requires the expansion of secretory organelles to cope with the increased cargo load. When any B-cells differentiates into a short-lived plasma B-cell or a memory plasma B-cell the cell increases in size significantly while the endoplasmic reticulum (ER) continues to remain close to the nucleus of the cell. Later during interphase the ER fills the entire cell for efficient secretion of immunoglobulins via the extension of ER tubules under the plasma membrane. At the same time the Golgi remains near the nucleus while expanding to 6.5 fold in linear volume mostly linearly while remaining close to the nucleus. Immunoglobulin secretion rate increases dramatically by day 4 following B-cell activation as by day 3 ER proliferation is quite significant and can more readily support high expression rates of immunoglobulins. From this it is evident that without an unusually relatively large dedication to the ER and Golgi plasma secreting B-cells would secrete immunoglobulins at a much lower rate as was empirically observed. (See e.g. Kirk, S. J., Cliff, J. M., Thomas, J. A., Ward, T. H., 2010, J Leukoc Biol. 87:245-255).
This patent contemplates the delivery of gene therapy vectors encoding for immunoglobulins to cells with a large dedication to production of proteins and secretion of proteins as evident by extensive resources dedicated to the ER and Golgi in addition to a large ER and Golgi. For example liver cells or hepatocytes secrete a large amount of albumin and fibrinogen, alpha-1-globulin, alpha-2-globulin and beta globulin. (See e.g. Feldmann, G., Penaud-Laurencin, J., Crassous, J., Benhamou, J. P., 1972, Gastroenterology, 63:1036-1049; Woo, D. H., et. al., 2012, Gastroenterology. 142:602-11; Sharma, N. S., Nagrath, D., & Yarmush, M. L., 2011, PloS one, 6:e20137) Muscle cells must produce large amounts of actin and myosin necessary to support the muscular-skeletal structure. For this reason muscle cells and hepatocytes are able to produce and immunoglobulins at therapeutically relevant levels. (See e.g. Lei, Y., Huang, T., Su, M. et al., 2014, Lab Invest 94:1283-1295; also see Perez, N., et. al., 2005, Genetic vaccines and therapy, 2:1-5) For a similar reason, memory B-cells are also well suited for genomic integration of lentiviral DNA or episomal addition of lentiviral DNA coding for immunoglobulins as upon their differentiation into memory plasma B-cells will have ample resources dedicated to producing and secreting antibodies. (See, e.g. Cascalho, M., et al., 2018, Sci Rep, 8:11143) This patent contemplates targeting memory B-cells for integration-competent lenviral vectors and integration deficient lentiviral vectors encoding for dIgA. In one embodiments (See
In some instances plasma B-cells and memory plasma B-cells may code for truncated immunoglobulin heavy or light chains through somatic hypermutations nonsense mutations and would then still produce the vector encoded dIgA and in other instances the cell will undergo apoptosis. Although, it is important to point out that even with the presence of the naturally encoded immunoglobulins by the cell by using a strong promoter in the vector encoded immunoglobulin the major product of a memory plasma B-cell with the vector encoded immunoglobulin will be the vector encoded dIgA1 immunoglobulin. In contrast to the immunoglobulin Heavy chain that has a large 3′ UTR when it is expressed as a cell surface receptor because the immunoglobulin light chain has the same 3′ UTR whether it is expressed as part of a B-cell receptor or secreted it will serve as an adequate substitute for the immunoglobulin light chain that is endogenously encoded for by the cell.
mRNA Production
mRNA intended for gene therapy may be synthesized in vitro as part of template directed synthesis. Common methods include the T #, T7 and SP6 systems. The T7 system derived from the T7 phage of E. Coli is the most common method. The sequence of interest is placed downstream of the T7 promoter which covers the sequence from −17 to +6 (the first 6 RNA nucleotides to be synthesized) Thus, the first 6 RNA nucleotides do not have full flexibility of choice in the T7 system. One such class III T7 promoter is 5′-TAATACGACTCACTATAGGGAGA-3′. Transcription termination occurs at terminator sites called Rho-independent terminators. Here the 3′ end of mRNA forms a hairpin loop structure about 7-20 base pairs in length directly following the U heavy stretch. This hairpin loop formation results in pausing of RNA polymerase and disrupts the transcription complex. Alternatively, the termination of transcription may occur by the RNA polymerase running off at the end of the template where the formation of a hairpin structure is not necessary.
This patent contemplates the use of dIgA1, dIgA2 and engineered variants of dIgA gene therapy to mitigate allergies. In one embodiment allergies of the respiratory tract are targeted with dIgA1. In another embodiment allergies of the gastrointestinal tract are targeted with dIgA1 or dIgA2. Type I hypersensitivity (or immediate hypersensitivity) is an allergic reaction provoked by re-exposure to a specific type of antigen referred to as an allergen. When an antigen is not associated with a pathogen or infectious agent causes hypersensitivity to those exposed to such antigens the hypersensitivity is referred to as an allergic reaction and the antigen is referred to as an allergen. Allergic reactions can be caused by allergens binding 2 adjacent Immunoglobulin class E (IgE) antibodies bound to adjacent IgE receptors (FcεRI) on mast cells.
In many allergic reactions humans become sensitized to the innocuous antigen and produce IgE antibodies against it. Future exposure to the antigen causes the activation of IgE binding cells mainly mast cells and basophils. Allergies may occur when the allergens cross the mucus membrane of the nasal cavity, eyes, lungs or skin as examples. And genetic factors are thought to play a role in allergies. For those with allergies to an allergen IgE specific to that antigen tends to be highly elevated in the interstitium lining airways and thus, the most effective combat to prevent the allergen from binding IgE would be dIgA1 that is present both in the interstitium and at the mucus barrier in its SIgA form. There are other allergies such as forms of asthma that are due to cytokines including interleukins (IL) and do not have a causal link to IgE.
Allergen induced allergies occur through contact with the mucosa of the respiratory tract, digestive tract, through skin absorption or through blood circulation in some cases such as a bee sting. In the respiratory tract common allergies include pollen, birch, dust mite feces, and cat dandruff causing asthma. About half of the U.S. population is sensitive to at least one innocuous antigen or allergen. The most common allergies in developed countries are from airborne allergens resulting in symptoms mainly affecting the nasal passage and lower airways including the lungs which is classified as asthma. In some cases people are sensitive to one specific allergen and in other cases have nonspecific sensitivity to a range of allergens. When people are sensitive to specific allergens or allergen classes strategies that employ neutralization and degradation of the antigens respectively with SIgA and dIgA may effectively be used. Allergens that are ingested such as proteins found in specific foods that result in allergies are sometimes but not always limited to the gastrointestinal tract that has its own lymphatic support system.
Mast cells have high affinity IgE receptors (FcεRI) that tightly bind to IgE and when an allergen the individual is sensitized to crosses the epithelial cells mast cells can detect them generally via two adjacent IgE bound to the FcεRI. Thus, allergens generally have to have more than one identical or nearly identical binding faces (as far as the immunoglobulin is able to detect) to result in an allergic reaction. When an antigen is bound to IgEs bound to FcεR on mast cells it results in the mast cell to release granules containing cytokines, histamine, tryptase, Platelet-activating factor that causes allergic symptoms and in individuals with asthma cause smooth muscle contraction and mucosal edema and can cause anaphylaxis. Eosinophils are also activated by Mast cells with IgE bound to antigens with IL-5 and can result in eczema and deadly anaphylaxis. There are two phases of sensitization to allergens: The induction phase and the effector phase. The induction phase involves many different cells and proteins including epithelial cells, chemokine ligand 27 (CCL27), immature dendritic cells, antigen presenting dendritic cells, TH2 T-helper cells, cytokines, such as interleukin (IL)-4, IL-5 and IL-13, class switching of B cells to IgE secreting B-cells, IgE secretion and binding to the high-affinity IgE receptor (FcεRI) on the membrane of mast cells and basophils, forming sensitized mast cells and basophils. When immature dendric cells respond via pattern recognition receptors to danger signals they mature into competent antigen-presenting myeloid-type dendritic cells. Generally, allergen detection occurs when these mature dendritic cells subsequently bind and processes the allergen presenting a polypeptide fragment of the allergen via the major histocompatibility complex class II (MHCII) receptor where the dendritic cell subsequently migrates to the local lymph node where they interact with naïve T-cells (TN) through their T-cell receptor (TCR) via MHCII and co-stimulatory molecules that results in TH2 T-helper cells maturation and migration to the local tissue such as the lungs interstitium subsequent interactions as a result of the same or sufficiently similar allergen between the MHCII of dendritic cells and the TCR of TH2 T-helper cells results in the secretion of IL-4 and IL-13. IL-4 and IL-13 stimulate immature IgM or IgD B-cells bound to the allergen to class-switch into IgE B-cells and secrete IgE that can bind IgE FcεRI receptors on mast cells. (See, e.g. He, S. H., Zhang, H., Yang, P. C., 2013, Acta pharmacologica Sinica, 34:1270-1283)
The effector phase begins when the same or a sufficiently similar allergen cross-link two adjacent IgEs on sensitized mast cells or basophils. Activated mast cells or basophils subsequently degranulate releasing granules housing proinflammatory mediators and cytokines including histamine, tryptase LTC4, PGD2 thereby causing the clinical manifestations of allergy. Soluble allergens, sIgEs and mast cells or basophils are three key factors in the patho-physiological process of allergic inflammation, representing causative factors, messengers and primary effector cells, respectively. In contrast to primary effector cells, eosinophils and neutrophils are secondary effector cells, which can be accumulated and activated through the mediators released from mast cells or basophils. (See, e.g. He, S. H., Yang, P. C., et al., 2013, Acta pharmacologica Sinica, 34:1270-1283.) A similar sensitization response to that of respiratory allergies occurs when allergens bind to IgE bound mast cells in the gastrointestinal tract where there is an outflow of fluid across the gut epithelium induces vomiting and diarrhea. (See, e.g. Renz, H., Allen, K., Sicherer, S. et al., 2018, Nat Rev Dis Primers vol. 4, pp. 17098)
The immune response that leads to an excess of IgE production in response to an allergen is caused by two processes. One process signals cause naïve T cells to differentiate into TH2 T-helper cells that produce cytokines that are specialized for promoting responses against parasites or extracellular bacteria. The second comprises TH2 cells to stimulate B-cells to class switch to produce IgE. This results in higher levels of IgE in the interstitium of the lungs for example and the mast cells in the lung are subsequently heavily bound to IgE through the FcεRI receptor making the individual highly sensitive to that antigen the IgE is specific to making an individual asthmatic or results in GI disorders when the stomach is affected by the allergen. This instant patent contemplates blocking allergens from binding IgE by targeting the allergens. In one embodiment dIgA1 would provide mucosal protection in its SIgA1 form by binding to allergens in the respiratory mucosa and also in its dIgA1 form in the interstitium above and below the basement membrane providing three lines of protection against allergens binding IgE bound mast cells and one or two lines of protection—depending if the dendritic cell is sampling the mucosal environment—against allergens binding IgE bound dendritic cells (see
In some embodiments dIgA1 encoded gene therapy specific to the allergen of interest is the therapeutic approach that prevents allergic reactions. Because dIgA (dIgA1 and dIgA2) is actively transported to the mucosa of the lungs and gastrointestinal tract with it becomes SIgA it can bind to allergens before they have a chance to bind to dendritic cell extensions in the mucosa or cross the mucosa and reach IgE bound mast cells that are largely responsible for the allergic response in asthma (See
This patent contemplates the use of dIgA (dIgA1, dIgA2 and engineered variants) and even bispecific dIgA to target cancer. Cancer is a complex pathology that is made up of many different forms. Key characteristics of cancer are abnormal and nonspecific cell growth taking the place of healthy cells while not supporting organ function. The most common types of cancer in males include lung cancer, colorectal cancer, prostate cancer and stomach cancer. In females the most common types of cancer include breast cancer (80% invasive ductal carcinomas), lung cancer, colorectal cancer and cervical cancer. In other words most of the more common types of cancer involve mucosal or exocrine tissue and is often referred to as a carcinoma which makes up 80%-90% of all cancer cases. Thus, dIgA has privileged access to the malignancy in the mucosal lumen or exocrine duct to a greater degree than other immunoglobulins as a result of its active transport by polymeric immunoglobulin secreting receptor (pIgR) to the apical face of the epithelial cells lining the mucosal or exocrine tissue. A further benefit of dIgA and its SIgA counterpart over other immunoglobulins is that it can prevent “metathesis” or the spread of cancers cells to other areas of the body because of its two binding faces. When a cancer cell departs from the malignant tumor dIgA or SIgA in the mucosa or exocrine duct can capture the escaping tumor cell(s) by binding the cell on the immunoglobulin face that is opposite the immunoglobulin face bound to the malignancy (see
The epidermal growth factor receptor (EGFR) is a transmembrane protein that is implicated in cancer. Mutations that cause EGFR overexpression have been associated with a number of cancers including Adenocarcinoma of the lung is the most common type of lung cancer, colon cancer, epithelium tumors of the head and neck at about 80-100% of cases. Somatic mutations involving EGFR lead to its constant activation, which produces uncontrolled cell division. In a wide variety of tissues EGFR expression is at a low level. Excessive expression or activation of EGFR can induce malignancies or malignant transformations. EGFR is observed in 45-75% of non-small cell lung cancer (LSCLC) and is associated with aggressive clinical behavior including increased metastatic rate, high tumor proliferation and advanced stages of cancer. (See, e.g. Zhang, X., & Chang, A., 2007, Journal of medical genetics, vol. 44, pp. 166-172.) Non-small cell lung cancer remains the leading cause of cancer death in the U.S. and accounts for 85% of lung cancer cases in the U.S. The 5-year overall survival rate for patients with metastatic non-small cell lung cancer is 24%.
Another important receptor class involved in mucosal cancers is the PD-1/PD-L1 pathway which controls the maintenance and induction of immune tolerance within the tumor microenvironment. Programmed cell death protein 1 (PD-1) is a T-cell surface protein that regulates the immune response by down regulating the immune system and promoting self-tolerance. This pathway can thus attenuate the immune response of T cells to cancer cells. PD-1 has been targeted in immunotherapies to block the activity of this receptor in T-cells. Effectively, PD-1 antagonists can enhance the T-cell response against cancer cells and also blocks through competitive inhibition particular cancer cell receptors referred to as Programmed Death Ligand 1 (PD-L1) and PD-L2 from binding PD-1 on T-cells. When PD-L1 and PD-L2 bind T-cells they reduce T-cell survival and proliferation, in addition to reducing their cytokine secretion while making it more difficult for such PD-1 bound T-cells from being activated. It has been shown for example, that mice which lack PD-1 can steadily develop autoimmunity. Anti-PD-1/PD-L1 inhibitors have seen success in reducing cancerous tumor growths a number of mechanisms that including enhancing the T-cell response, activating a series immune system responses that combat tumor cells in addition to inducing infiltration into tumors. Additionally, CTLA-4 (CD152) agonist also controls the proliferation of T-cells and thus binding CTLA-4 with an antagonist enhances T-cell proliferation in the presence of cancer. It has also been shown that CTLA-4 activated T-cells can inhibit the proliferation of other T-cells.
This instant patent contemplates Lipid Nanoparticles as delivery vehicles for mRNA encoding for dIgA1 or dIgA2. Lipid Nanoparticles have seen unprecedented advances in medicine. LNPs have advantages over capsid delivered vectors in that they are not immunogenic, are biodegradable, have an impressive safety profile and can be delivered with adjuvants. In addition, LNPs have control over drug release, facilitate endosomal escape and can be effective scaled up for manufacturing.
LNPs surface features such as the addition of antibodies are typically added after the formation of the LNP with its payload. LNPs range in size from 1 nm to 1000 nm. Although ideally LNPs are less then 150 nm to facilitate their ability to reach their target destination. Lipid nanoparticles can efficiently target liver cells (See e.g. Truong, B., et. al., 2019, PNAS, 116:21150-21159; Kim, M., et. al., 2021, 7:1-12, 2021.) LNPs can effectively be made to target any cell type through adding monoclonal antibodies or other binding proteins on their surface that are specific to the target cell surface receptor or other CD receptor. This can be done in a variety of ways such as modular manner where a (See, e.g. Veiga, N., Goldsmith, M., Granot, Y. et al., 2018, Nat Commun, 9:4493) LNPs are very effective at delivering the payload to the cytosol of the cell but not the nucleus of the cell. In one embodiment when mRNA is intended for translation in the rough ER or other destination that information can effectively be encoded for on the 3′ UTR. In another embodiment using the evolutionary conserved 3′ UTR for the immunoglobulin as an example or other 3′ UTR for example the 3′ UTR of a protein that is heavily expressed by humans or highly expressed and secreted in the target-cell can deliver the mRNA for increased protein yield.
LNPs are generally made up of an aqueous core surrounded by a lipid bilayer shell that can include a number of lipids that serve different functions. LNPs generally rely on cationic lipids to efficiently complex negatively charged RNA. Although, anionic and neutral formulations have proven to be effective. Cationic lipids bearing a permanent positive charge are more toxic. Although, amine groups can be incorporated into LNPs allowing them to maintain a cation surface charge at physiological pH which both reduces nonspecific lipid-protein interactions and also allows for RNA release in the cytosol. The cationic charge on the LNP surface allows for efficient interaction with the negatively charged membranes on cell surfaces. This in turn also facilitates engulfment by the cell where the resulting negatively charged endosome is disrupted by the positively charged LNP that facilitates escape of the mRNA. Phospholipids also contribute to the disruption of the endosome. (See e.g., Reichmuth, A. M., Oberli, M. A., Jaklenec, A., Langer, R., Blankschtein, D., 2016, Therapeutic delivery, 7:319-334) There are an extensive number of methods involved in incorporating mRNA in LNPs. In one of many approaches mRNA molecules self-assemble in ionizable molecules in acidic conditions to form uniform LNPs by combining the ingredients of LNPs with the drug. In another approach preassembled LNPs are combined with the drug through a directed microfluidic integration process. The method used in LNP synthesis influences the LNP size and encapsulation efficiency. One method to form LNPs involves condensing lipids from an ethanol solution in water. Aqueous phase mRNA may be encapsulated during condensation. Lipid rafts may be converted into LNPs in a controlled microfluidic process that can accelerate or decelerated the rate of LNP closure influencing the size of the LNP and in turn the total mRNA packaged within it. (See e.g., Reichmuth, A. M., Oberli, M. A., Jaklenec, A., Langer, R., & Blankschtein, D., 2016, Therapeutic delivery, 7:319-334)
This instant patent contemplates the use of chimeric antibodies in the dIgA1 and dIgA2 gene therapy constructs as an effective means to develop potent affinity for the target of interest. Using the immune system of Mice can be an effective means to develop potent binding affinity against the target of interest. However, attempting to take an antibody discovered in mouse for use in human often results in a human anti-murine antibody response. Although, there is are a few examples of a fully murine FDA approved monoclonal antibody for cancer and kidney transplant rejection. This response can be to the constant region of the mouse antibody or even part of the V-region of the mouse antibody. As a result potent antibodies developed in mice have had all or part of the genetic information coding for the binding region incorporated in a human antibody construct that preferably utilizes all of the constant region from one human antibody heavy chain (IgG1, IgG2, IgG3 and IgG4) and part of the V-region that the binding element of the mouse antibody can tolerate without losing binding affinity to its target. This patent contemplates the same hybridization techniques to be used in IgA1 and IgA2 constructs intendent for chimeric dIgA1 and dIgA2 gene therapy encoded vectors. Further, such hybridization techniques may use any mouse IgG or IgA antibody V region and incorporate the necessary components of the V region into an IgA1 or IgA2 antibody. All antibody heavy chains are based on V-regions derived from the same genetic loci and subjected to the same conditions related to affinity maturation making dIgA1 and dIgA2 highly suitable for any chimeric antibody derived from a mouse or other non-human vertebrate. Additionally, there is no significant different in the principle constructs and function behind IgA1 or IgA2 and that of IgG1, IgG2, IgG3 and IgG4 in their engagement with the V-region. That is a V-region that is effective in one construct is generally effective in all constructs.
In antibodies the residues in the variable domains (V region) in each of the heavy and light chains of the region are partitioned into three hypervariable complementarity-determining regions (CDRs) and four framework regions (FRs). The FRs, which make up about 85% of the V region, are a more stable amino acid sequence and function as the scaffolds for the CDRs that directly contact the antigen. The FRs can influence the orientation, relative conformation, phi an psi angles of the amino acids in the CDRs and thus can ultimately improve or disrupt the binding affinity of the CDR derived from a mouse monoclonal antibody. Thus, some of the mouse FRs may be used in the chimeric antibody with potentially some amino acid substitution in the human FRs or non-human vertebrate derived CDRs may be made to ensure the binding affinity remains potent. In one embodiment the CDRs from a mouse IgG1, IgG2A, IgG2B, IgG2C or IgA antibody are incorporated into an otherwise fully human IgA1 or IgA2 antibody intended to be expressed as dIgA1 or dIgA2 respectively. In another embodiment all the CDRs and one or more of FR1, FR2, FR3 and FR4 from a mouse IgG1, IgG2A, IgG2B, IgG2C or IgA antibody are incorporated into an otherwise fully human IgA1 or IgA2 antibody intended to be expressed as dIgA1 or dIgA2 respectively. In a further embodiment amino acid substitutions, additions or deletions are made into the CDRs or FRs from mice or human in the chimeric dIgA1 or dIgA2 antibodies. In a further embodiment another non-human vertebrate such as a rat or rabbit is used in place of a mouse.
Mice or Other Non-Human Vertebrate with Engineered Immune Systems (Transgenic Mice):
This instant patent contemplates the use of mice with engineered immune systems or other non-human vertebrate with engineered immune systems so that it produces fully human antibodies in place of the murine or non-human vertebrate antibodies is an important for the discovery of antibodies with therapeutic potential. Engineered animals such as mice for this purpose are capable of producing a fully antibody repertoire capable of affinity maturation towards the antigen target. Engineered animals are capable of highly evolved in-vivo mechanisms such as hypermutation in germinal centers resulting in fully human (comprising human variable and constant regions) high affinity antibodies with optimal biophysical properties that because they are developed in vivo in the host non-human vertebrate are less likely to cause immunogenicity in humans. Use of non-human vertebrates with engineered immune systems provides a straight-forward approach to rapidly obtain antigen specific antibodies that have undergone recombination, junctional diversification, affinity maturation and isotype switching in vivo in a non-human vertebrate system. Fully human antibodies avoid the problem of attenuating antibody characteristics when humanizing the constant region of chimeric antibodies and thus can lead to more exquisite specificity for the target with reduced overall effort and cost. The earliest in vivo non-human vertebrate used for this purpose in vivo was Xenomouse™ that used completely human transgenic heavy chain loci which comprise human variable regions (human VH, D and JH gene segments) upstream of human constant regions. Subsequently, it has been discovered that the use of 60 totally human transgenic loci in such in vivo systems is detrimental and B-cell development is hampered, leading to relatively small B-cell compartments and restricted utility for generating antibodies. Later-generation transgenic animals (eg, the Velocimouse™) have been created which have 65 chimeric heavy chain loci in which a human variable region is upstream of endogenous (eg, mouse or rat) constant expression. US2008/0196112A1 (Innate Pharma) discloses transgenic animals comprising a single, predetermined human rearranged VDJ from a lead antibody, together with one or more human constant region genes in a locus. (See e.g. For example, see U.S. Pat. Nos. 10,251,377 B2 and 10,667,501 B2 expressly incorporated by reference herein in their entirety; Also see Lee, E. C., Liang, Q., Ali, H. et al., 2014, Nat. Biotechnol., 32:356-363). These mice with engineered immune systems serve as an efficient means to discover immunoglobulins and immunoglobulin V regions that are potent for the target of interest. Potent antibodies may be discovered through FACS cell sorting or magnetic beads biotinylated to the antigen of interest. In one embodiment the incorporation of such V regions is made into dIgA1 and dIgA2 DNA and mRNA vector constructs.
The instant patent invention contemplates the delivery of an episomally-maintained gene therapy based vaccination/immunization as an intramuscular injection, intravenous injection or injection proximal to lymph nodes that can be an intramuscular injection and administration to the lamina propria via endoscopic injection. AAV vectors (See
The vectors of the invention include heterologous control sequences, which include, but are not limited to, constitutive promoters, such as the human cytomegalovirus (CMV) immediate early enhancer/promoter (SEQ ID NO. 1), Rous sarcoma virus (RSV), simian virus 40 (SV40) and mammalian elongation factor 1α (EF1α), are non-specific promoters and are commonly used in gene therapy vectors. Other promoters that are commonly used in gene therapy include cytomegalovirus enhancer/chicken beta-actin (CAG). Other promoters include mouse phosphoglycerate kinase (mPGK) and human synapsin (hSYN) promoter. Preferred promoters include the EF1-alpha promoter (Kim et al., Gene 91(2): 217-23 (1990)) and Guo et al., Gene Ther. 3(9):802-10 (1996)). Highly preferred promoters include the human cytomegalovirus (CMV) immediate early gene enhancer/promoter, elongation factor 1-alpha (EF1a) promoter, a cytomegalovirus enhancer/chicken beta-actin (CAG) promoter and a simian virus 40 (SV40) promoter. Other promoters include a tetracycline responsive promoter (TRE), a transthyretin promoter (TTR), and a CK6 promoter. The sequences of these and numerous additional promoters are known in the art. The relevant sequences may be readily obtained from public databases and incorporated into vectors for use in practicing the present invention. In some cases the relevant sequences are published in a Journal Article.
Typically, in order to express 2 or more proteins in a vector two or more promoters are required. As an example, an internal ribosome entry site (IRES) sequence is often used to drive expression of individual genes when those genes are located 5′ to at least one gene. Alternatively, an elongation factor 1-alpha promoter (EF1α) may be used where a polyadenylation site may be used to process the mRNA of the preceding gene. When two genes are linked with an IRES sequence, the expression level of the second gene is often significantly weaker than the first gene (Furler et al., Gene Therapy 8:864-873, 2001). However, one may use as will be understood by those of skill in the art, expression vectors typically include a promoter operably linked to the coding sequence or sequences to be expressed, as well as ribosome binding sites, RNA splice sites, a polyadenylation site, and transcriptional terminator sequences, as appropriate to the coding sequence(s) being expressed. Other sequences such as a Kozak sequence (SEQ ID NO: 20) such as “GCCACC” are introduced directly before the transcription start codon to allow for the expression of a transgene. The Kozak sequence is also important for the second transcription start codon that is directly preceded by an IRES or directly preceded by a second promoter. In general the Kozak sequence is important for the translation initiation at any place on the mRNA.
Increased levels of gene expression generally occurs when a Woodchuck hepatitis-virus posttranscriptional regulatory element (WPRE) is incorporated. WPRE is most effective when placed downstream of the transgene, following the 3′ UTR proximal to the polyadenylation signal. Polyadenylation signals and WPRE are incorporated into vectors to ensure high levels of gene expression. In some embodiments WPRE is incorporated into the vectors. In other embodiments two consecutive WPRE regulatory elements are used. Generally, WPRE and a polyadenylation signal can substantially increase gene expression over the vector that only includes the polyadenylation signal.
Episomally maintained vectors with self-replicating elements are capable of long-term episomal persistence in human cells and may be referred to as episomally-maintained self-replicating vectors. Typically, these vectors are based on few designs. One common design contains components derived from either EBV or bovine papilloma virus, where there is a greater emphasis for gene therapy related applications with EBV. EBV is a human herpesvirus that can maintain its genome extra-chromosomally as an episome in dividing mammalian cells. Maintenance is also achieved with the EBV viral latent origin of replication oriP and EBV nuclear antigen 1 (EBNA1) that act together to replicate and retain the viral genome in the nucleus. Thus, inclusion of these sequences allows them to be maintained in dividing cells. (See e.g., Conese, M., et. al., 2004, Gene Ther., 11:1735-1741) Although, there are substantial safety and immunotolerance challenges associated with the EBNA1 protein making it unsuitable for present application.
The present invention contemplates the use of non-viral vectors, viral vectors and retroviral vectors as an efficient and effective means to express immunoglobulins whose polypeptide sequence is derived from humans especially human memory B-cells or plasmablasts, a transgenic animal, a mouse with humanized immune system, or a mouse any of which that was infected with, exposed to, has immune specificity to, or lives with any of (1) a virus (s) (2) a systemic ailment such as allergies (3) fungi (4) bacterial infection (4) cancerous tumor (5) biowarfare agent (6) microbial infection, (7) any ailment 8) an allergen or cause of allergies, (9) a target protein or variant (10) an immune system protein such as Immunoglobulin class E (IgE) or a cytokine. Additionally, scFv or Fab identified from phage display technology may be used to identify such potent immunoglobulin V or Fab regions. In another context only the V-regions (VL and VH), CDR regions or Fab regions may be used from humans B-cells, B-cells from transgenic mice, B-cells from mice or other non-human vertebrate with humanized immune systems and in some cases portions of the constant regions such as CH1 and CL polypeptide sequence are derived from the immunoglobulin polypeptide sequence of memory B-cells or plasmablasts. This strategy provides flexibility to use entire immunoglobulin polypeptide sequences or only V-region sequences in conjunction with other constant region sequences or including isotype switched constant region sequences, engineered constant region sequences that cannot be detected by Fc receptors and even a combination of constant region sequences from two sources. E.g. using the CH1 and optionally the hinge polypeptide sequence and also the CL sequences derived from potent immunoglobulins where the immunoglobulin heavy and light chain genes or polypeptide sequences were identified while using CH2 and CH3 polypeptide sequences from another human source. Additionally, CDRs may be used in conjunction with FR regions from another human or even mouse source. When mice are used to identify potent immunoglobulins for chimeric immunoglobulins will be systematically designed.
This patent contemplates an approach undertaken so that at risk individuals and individuals that may not be able to develop sufficient adaptive immunity quickly enough if at all to any of (1) a virus (s) (2) a systemic ailment such as allergies (3) fungi (4) bacterial infection (4) cancerous tumor (5) biowarfare agent (6) microbial infection, (7) any ailment (8) an allergen or cause of allergies (9) a target protein or variant (10) an immune system protein such as Immunoglobulin class E (IgE) or a cytokine, can be engendered immunity or immune protection in a relatively short time window in a manner that circumvents their adaptive immune system.
In the invention the vector constructs non-viral, viral and retroviral delivery systems then effectively serve as the mechanism to realize that immunoglobulin-based binding affinity that was discovered in humans, transgenic mice or other non-human vertebrate with an engineered immune system, mice with a resulting chimeric antibody, or mice with humanized immune systems when considering the expression of dIgA1 and dIgA2. However, the present invention further considers the use of vector constructs to express dimeric immunoglobulin A1 (dIgA1) and dIgA2 that encode for the immunoglobulin heavy chain, the immunoglobulin light chain (kappa or lambda), J chain and optional use of MZB1 in some embodiments on a single vector construct in order to also engender recipients with a mucosal immunity against the pathogen of interest. In these contexts the present invention considers the use of a variety of vectors to introduce DNA constructs that comprise these coding sequences. The expression of dIgA1 or dIgA2 in a single vector construct is important since a mix of different episomes that encode for a polyclonal mix of immunoglobulins potent against the pathogen of interest and likely to prevent mutated form of the pathogen from infecting the recipient of the episomal gene therapy can be rendered less effective if two such gene elements were used to express dIgA1. If dIgA required two vector constructs for encoding its expression such a strategy would require a disproportionately large titer of the vectors containing J chain and MZB1 to ensure that a sufficient portion of the same cells receive both vectors.
Any of a variety of vectors for introduction of constructs (See
Reference to a vector as “recombinant” refers to the linkage of DNA sequences which are not known in nature and which come from two or more organisms in nature. Reference to the “transgene” refers to the gene encoding for a polypeptide in the vector that is intended for some function in the organism that is unrelated to the maintenance or support of the vector function. Expression of the transgene is regulated by sequences that are operatively linked to a polypeptide coding sequence when the expression and/or control sequences regulate the transcription and/or translation of the nucleic acid sequence. Thus expression and/or control sequences can include promoters, enhancers, transcription terminators, polyadenylation sites, furin cleavage sites, 2A self-cleaving polypeptides, replicating elements, a start codon (e.g., ATG) 5′ to the coding sequence, Kozak sequences, splicing signals for introns, a 5′UTR, a 3′UTR and stop codons. (For example, see U.S. Pat. Nos. 7,498,024 B2 and 7,709,224 B2 expressly incorporated by reference herein in their entirety)
Recombinant Adeno Associated Virus (rAAV) vectors are established to exhibit strong transient expression with excellent titer and the ability to enter dividing and non-dividing human cells without eliciting an immune response for most—upon first time exposure—to the AAV capsid protein structure. However, multiple exposures to an AAV capsid may elicit an immune response. Although, advances in science may likely overcome the immunogenicity of AAV that are also able to attain the same safety profile as currently clinically approved rAAVs. rAAV vectors delivered via AAV capsids have the ability to enter cells that depends in part on AAV serotype. Further, AAVs are favored for in vivo episomal gene transfer of therapeutic genes because of their low immunogenicity, strong safety record, and high efficiency of transduction of a number of cell types in animal models. (Wu, Z., et. al., 2006, Mol Ther. 14:316-327.) Replication-defective AAV virions encapsulating the recombinant AAV vectors of the instant invention are made by standard techniques known in the art using AAV packaging cells and packaging technology. The coding sequence for two or more polypeptides or proteins of interest is commonly inserted into the adenovirus in the deleted E3 region of the virus genome. The recombinant vectors of this invention comprise the ability to express dimeric Immunoglobulin A (dIgA), which is a tetramer of heterodimers linked together by disulfide bonds between immunoglobulin light and heavy chains and disulfide bonds between the J chain protein and the immunoglobulin heavy chain. Further the recombinant vectors of this invention encode for immunoglobulins that are naturally developed in humans especially human memory B-cells or plasmablasts, discovered from a transgenic animal, a mouse with humanized immune system, or a mouse any of which that was infected with, exposed to, has immune specificity to, or lives with any of (1) a virus (s) (2) a systemic ailment such as allergies (3) fungi (4) bacterial infection (4) cancerous tumor (5) biowarfare agent (6) microbial infection, (7) any ailment 8) an allergen or cause of allergies, (9) a target protein or variant (10) an immune system protein such as Immunoglobulin class E (IgE) or a cytokine. In some embodiments only a portion—that must include one or more of the CDRs and V-region segments of both the immunoglobulin light and heavy chains—of the polypeptide sequence encoding for the potent immunoglobulins will be used in the vector construct. The elements of the recombinant AAV vectors may comprise (A) a packaging site that enables the vector to be placed in replication incompetent AAV virions; (B) the coding sequence for immunoglobulin gene elements e.g. heavy chain (IgH), light chain (IgL), J chain and associated proteins e.g. MZB1; (C) the optional use of the sequence encoding for a 2A self-cleaving peptide site located C-terminal to a furin cleavage site. (D) a modified 2A self-cleaving peptide may be substituted for a full length 2A self-cleaving peptide to minimally contain the consensus sequence (C) in some cases with potentially some loss in efficiency (E) the optional use of a multi-promoter rAAV vector for immunoglobulin expression. (F) the optional use of both (C) and (D) in a single vector. (See
Adeno-associated virus (AAV) is a helper-dependent human parvovirus, which is able to infect cells latently by chromosomal integration or delivery of an episomally maintain gene element to the nucleus. AAV has significant potential as a human gene therapy vector. For use in practicing the present invention rAAV virions may be produced using standard methodology, known to those of skill in the art and are constructed such that they include, as operatively linked components in the direction of transcription, control sequences including transcriptional initiation and termination sequences, and the coding sequence(s) of interest. More specifically, in the invention in one embodiment the recombinant AAV vectors of the instant invention comprise: (1) a packaging site enabling the vector to be incorporated into replication-defective AAV virions; (2) the coding sequence for two or more polypeptides or proteins of interest, e.g., heavy and light chains of an immunoglobulin of interest; (3) the optional use of a sequence encoding a 2A self-processing cleavage site alone or in combination with an additional furin cleavage site. (4) optional use of separate promoters and regulatory elements for each coding sequence (5) Optional use of a combination of (3) and (4). AAV vectors for use in practicing the invention are constructed such that they also include, as operatively linked components in the direction of transcription, control sequences including transcriptional initiation and termination sequences. In another embodiment these components are flanked on the 5′ and 3′ end by functional AAV ITR sequences. By “functional AAV ITR sequences” is meant that the ITR sequences function as intended for the rescue, replication and packaging of the AAV vectors. Further, AAV vectors for use in practicing the invention in one embodiment will code for (A) immunoglobulins that are derived from immunoglobulins identified from the blood of leukocytes from humans especially human B-cells, memory B-cells or plasmablasts, discovered from a transgenic animal, a mouse with humanized immune system, or a mouse any of which that was infected with, exposed to, has immune specificity to, or lives with any of (1) a virus (s) (2) a systemic ailment such as allergies (3) fungi (4) bacterial infection (4) cancerous tumor (5) biowarfare agent (6) microbial infection, (7) any ailment 8) an allergen or cause of allergies, (9) a target protein or variant (10) an immune system protein such as Immunoglobulin class E (IgE) or a cytokine. Or such FVsc identified from Phage Display technology. (B) immunoglobulins whose CDR or V-regions (VL and VH) are derived from immunoglobulins identified in identified from any of the same sources discussed in part (A) of this section. (C) immunoglobulins whose antibody binding fragments (Fab): V-regions (VL and VH) and constant heavy domain 1 CH1 and constant light (CL) chain domain are derived from immunoglobulins identified from any of the same sources discussed in part (A) of this section. (D) immunoglobulins whose antibody binding fragments that results from pepsin cleavage (Fab′)2: V-regions (VL and VH) and constant heavy region 1 CH1, hinge and constant light (CL) chain domain are derived from immunoglobulins identified from any of the same sources discussed in part (A) of this section. (E) Dimeric Immunoglobulin A (dIgA) that requires cDNA coding for or the polypeptide sequence of the immunoglobulin class A immunoglobulin heavy and light chains, J chain with optional use of the signaling peptide (see SEQ IDs 11 and 7) and optional encoding of MZB1. (For similar examples, see U.S. Pat. Nos. U.S. Pat. No. 7,498,024 B2 and U.S. Pat. No. 7,709,224 B2; Also see e.g., Fang, J., et al., 2005, Nat. Biotechnol., 23: 584-590.; Krysan, D. J., et. al., 1999, J Biol Chem. 274:23229-23234)
Recombinant AAV (rAAV) vectors are capable of directing the expression and production of selected recombinant polypeptide or protein products in target cells. Thus, the recombinant vectors comprise at least all of the sequences of AAV essential for encapsidation of the vector and the physical structures or inverted terminal repeats (ITRs) for infection of the recombinant AAV virions. Thus, AAV ITRs for use in the vectors of the invention need not have a wild-type nucleotide sequence (e.g., as described in Kotin, H., 1994, Gene Ther., 5:793-801), and may be altered by the insertion, deletion or substitution of nucleotides or the AAV ITRs may be derived from any of several AAV serotypes. Generally, an AAV vector is a vector derived from an adeno-associated virus serotype, including without limitation, AAV-1, AAV-2, AAV-3, AAV-4, AAV-5, AAV-6, AAV-7, AAV-8, etc. Preferred rAAV vectors have the wild type REP and CAP genes deleted in whole or part, but retain functional flanking ITR sequences that are necessary for the vector to be efficiently encapsidated by the AAV capsid to form the rAAV virion. (For example, see U.S. Pat. Nos. 7,498,024 B2 and 7,709,224 B2 expressly incorporated by reference herein in their entirety)
Among the most widely used platforms for producing rAAV involves transfecting Human Embryonic Kidney 293 (HEK293) cells with either two or three plasmids; one encoding the gene of interest, one carrying the AAV rep/cap genes, and another containing helper genes provided by either adeno or herpes viruses which contains the E4, E2a and VA helper genes that mediate AAV replication (See e.g., Janik, J. E., et. al., 1981, “Proc. Natl. Acad. Sci., 78:1925-1929; Buller, R. M. L., et al., 1981, J, Virol. vol. 40:241-24; Matsushita, T., et. al., 1998, Gene Ther., 5:938-945) The helper construct includes AAV coding regions that are capable of being expressed in the producer cell and which complement the AAV helper function that is absent in the AAV vector. Without such helper genes AAV production is generally reduced by at least a factor of 100. The helper construct may be designed to down regulate the expression of the large Rep proteins (Rep78 and Rep68), typically by mutating the start codon following p5 from ATG to ACG. (See e.g., as described in U.S. Pat. No. 6,548,286 expressly incorporated by reference herein in their entirety.) This is followed by introduction of helper virus and/or additional vectors into the producer cell, wherein the helper virus and/or additional vectors provide accessory functions capable of supporting efficient rAAV virus production. The producer cells are then cultured to produce rAAV. These steps are carried out using standard methodology. Replication-defective AAV virions encapsulating the recombinant AAV vectors of the instant invention are made by Standard techniques known in the art using AAV packaging cells and packaging technology. Examples of these methods may be found, for example, in U.S. Pat. Nos. 5,436,146, 6,040,183, 6,093,570 and 6,548,286, expressly incorporated by reference herein in their entirety. Further compositions and methods for packaging are described in Wang et al. (US 2002/0168342), expressly incorporated by reference herein in its entirety. In practicing the invention, host cells for producing rAAV virions include mammalian cells, insect cells, microorganisms and yeast. HEK293 is a commonly used host cell that has seen significant success and has become among the most preferred host cells of choice for AAV production. Host cells can also be packaging cells in which the AAV rep and cap genes are stably maintained in the host cell or producer cells in which the AAV vector genome is stably maintained and packaged. AAV vectors are purified and formulated using techniques known to those familiar in the art.
Lentiviral Vectors and Lentiviral Design for B-cell Targeting and Potentially other Cell Type Targeting
Lentiviral vectors have been extensively investigated and optimized over the past years (See e.g., Milone, M. C., et al., 2017, Leukemia, 32:1529-1541). Lentiviral vectors may be used in practicing the present invention (See
This patent further contemplates the use of pseudotyped lentivirus to efficiently transduce targeted cells. Lentiviruses have been shown to transduce B-cells of a murine model with persistent expression of the transduced gene. This was accomplished by generating a lentivirus pseudotyped with an anti-CD19 antibody. The lentivirus anti-CD19 antibody targeted the B-cell surface receptor CD19 that mediated viral fusion upon binding the lentivirus to the B-cell, which permitted persistent expression of the transduced gene. (See e.g., Cascalho, M., et al., 2018, Sci Rep, 8:11143). Additionally, B-cells have been effectively targeted with a lentivirus pseudotyped with an envelope glycoprotein derived from the Baboon endogenous virus. (See, e.g., Fusil, F., Cosset, F. L. et. al., 2015, Molecular therapy: the journal of the American Society of Gene Therapy, 23:1734-1747) Lentivirus have seen use in clinical trials and has received FDA approval for immune based gene therapies. (See e.g., Milone, M. C., et al., 2017, Leukemia, 32:1529-1541; Campochiaro, P. A., et al., 2017, Hum Gene Ther. 28: 99-111; Milani, M., et al. 2017, EMBO Mol Med. 9:1558-73). The ability to direct the delivery of lentivirus vectors encoding one or more target protein coding sequences to specific target cells is desirable in practice of the present invention. Pesudotyping Lentivirus is well known to those familiar with the art. In all lentivirus packaging system the envelope protein or alternatively the pseudotyped protein is encoded for in a separate plasmid under the control of a CMV promoter. If the pseudotyped protein involves two separate proteins such as an immunoglobulin two separate promoters are typically used in the plasmid. This instant patent contemplates the use of pseudotyped integration deficient and also integration competent lentivirus to integrate the vector encoding for an immunoglobulin including dIgA1 and dIgA2 into genomic DNA. In one embodiment (See
The light chain is ideally suited for antigen recognition as it tends to play a dominant role in target binding. Thus, the light chain binding the target will be sufficient in most cases to induce the memory B-cell to be activated and differentiate into a memory plasma B-cell or a Germinal center memory B-cell. (See, e.g. Sun, M., Li, L., Sheng Gao, Q., Pad S., 1994, The Journal of Biological Chemistry, 269:734-738; Also see, Hadzidimitriou, A., Darzentas, N., Belessi, C., et. al., 2009, Blood, 113:403-411). Other B-cells that express CD27+ markers would also be targeted including memory plasma B-cells that can survive for decades. If creating a gene therapy for an HIV immunization incorporating the HGN194 recombinant isotype of dIgA1 into a lentiviral vector construct in one embodiment one may consider to first administer the anti-CD20+ pseudotyped lentivirus carrying the lentiviral vector gene therapy to B-cells with a CD20+ marker. This can be followed by a future exposure to the HIV envelope glycoprotein such as through an mRNA based vaccine some period later that will activate the CD20+B-cells containing the dIgA1 vector that would include immature B-cells and memory B-cells that received the integration-competent or optionally integration-deficient lentiviral vector. This will result in long-term persistence of memory plasma B-cells as well as memory B-cells and Germinal Center Cells many that will encode for HGN194 recombinant isotype of dIgA1 in addition to other B-cells specific to other regions of the HIV glycoprotein that resulted from the mRNA administration of the HIV glycoprotein. Vaccine boosters of the envelope glycoprotein can increase the count of memory plasma B-cells and T follicular helper T-cells would be appropriately developed to aid in the formation of memory B-cell from Germinal Center B-cells. A similar strategy could be used in an H. pylori vaccination as well as for other lethal viruses and pathogens. Because memory plasma B-cells both migrate to the bone marrow they can provide an extra layer of protection potentially for decades if not a lifetime. (See, e.g. Akkaya, M., Kwak, K. & Pierce, S. K., 2020, Nat Rev Immunol., 20:229-238; Also see, Landsverk, 0. J., Jahnsen, F. L, et al., 2017, J. Exp. Med. 214:309-317; Khodadadi, L., Cheng, Q., Radbruch, A., & Hiepe, F., 2019, Frontiers in immunology, 10:721.) In another embodiment an anti CD27+ pseudotyped lentivirus (see
The present invention provides integration-deficient replication-incompetent self-inactivating system, integration-competent replication-incompetent self-inactivating system and integration-competent replication incompetent systems where lentiviral vectors comprising one or more transgene sequences and lentiviral packaging vectors comprising one or more packaging elements. Additionally, the present invention provides pseudotyped lentiviral vectors encoding a heterologous or functionally modified envelope protein for producing pseudotyped lentivirus.
The term “vector” can refer to a ribonucleic acid (RNA) or deoxyribonucleic acid (DNA) molecule capable transferring or transporting another nucleic acid molecule. The transferred nucleic acid is generally linked to, e.g., inserted into, the vector nucleic acid molecule. A vector may include sequences that direct autonomous replication in a cell. An RNA vector is packaged into the lentivirus packaging system and is reverse transcribed into DNA following viral fusion with the transduced cell.
As is evident to one of skill in the art, the term “retroviral vector” is widely used to refer either to a nucleic acid molecule (e.g., a transfer plasmid) that includes virus-derived nucleic acid elements that typically facilitate transfer of the nucleic acid molecule by integration into the genome of a cell or to a viral particle that mediates nucleic acid retroviral transfer. Retroviral particles will typically include various viral components and sometimes also host cell components in addition to nucleic acid(s).
Once the virus is integrated into the host genome, it is referred to as a “provirus.”, The provirus serves as a template for RNA polymerase II and directs the expression of RNA molecules, which encode the structural proteins and enzymes needed to produce new viral particles. At each end of the provirus are structures called “long terminal repeats” or “LTRs.”, The term “long terminal repeat (LTR)” refers to domains of base pairs located at the ends of lentiviral vector which, in their natural sequence context, are direct repeats and contain U3, R and U5 regions. LTRs generally provide functions fundamental to the expression of lentiviral genes (e.g., promotion, initiation and polyadenylation of gene transcripts) and to viral replication. The LTR contains numerous regulatory signals including transcriptional control elements, polyadenylation signals and sequences needed for replication and integration of the viral genome. The viral LTR is divided into three regions called U3, R and U5. The U3 region contains the enhancer and promoter elements. The U5 region is the sequence between the primer-binding site and the R region and contains the polyadenylation sequence. The R (repeat) region is flanked by the U3 and U5 regions. Typically, the LTR composed of U3, R and U5 regions and appears at both the 5′ and 3′ ends of the viral genome where in the third generation system the 5′ LTR of the RNA vector has the U3 missing.
The term “packaging signal” or “packaging sequence” refers to sequences located within the lentiviral genome which are required for insertion of the viral RNA into the viral capsid or particle, (See e.g., Clever et al., 1995. J. of Virology, Vol. 69, No. 4; pp. 2101-2109.) Many lentiviral vectors use the minimal packaging signal (referred to as psi (Ψ) or (Ψ+) sequence) needed for encapsidation of the viral genome. Thus, as used in this instant patent, the terms “psi” and the symbol “Ψ′,” are used in reference to the non-coding sequence required for encapsidation of retroviral RNA strands during viral particle formation. Although, in some embodiments additional nucleotides are used at both the 5′ and 3′ ends of the psi signal to maximize efficiency of the lentivirus. “Self-inactivating” vectors refers to replication-defective vectors, e.g., lentiviral vectors, in which the 3′ LTR enhancer-promoter region, known as the U3 region, has been modified (e.g., by deletion and/or substitution) to prevent viral transcription beyond the first round of viral replication this is also a characteristic of the third generation lentiviral packaging system. This is because the 3′ LTR U3 region is used as a template for the left 5′ LTR U3 region during viral replication and, thus, the viral transcript cannot be made without the U3 enhancer-promoter. Thus the U3 of the 5′ LTR is inactivated. To render a lentiviral vector replication deficient a large part of the U3 region of the 3′LTR is deleted or modified which eliminates the viral promoter activity and also allowing for the transgene expression to be controlled by the incorporation of an internal promoter. Additionally, this large deletion of the U3 region has the added benefit of increasing transgene expression. (For example, see e.g., U.S. Pat. No. 2013/0004471 paragraph 82). The U3 region of the 5′ LTR may be replaced with a heterologous promoter to drive transcription of the viral genome during production of viral particles. Examples of heterologous promoters, which can be used include, for example, viral simian virus 40 (SV40) (e.g., early or late), cytomegalovirus (CMV) (e.g., immediate early), Moloney murine leukemia virus (MoMLV), Rous sarcoma virus (RSV), and herpes simplex virus (HSV) (thymidine kinase) promoters. Typical promoters are able to drive high levels of transcription in a Tat-independent manner. This replacement reduces the possibility of recombination to generate replication-competent virus because there is no complete U3 sequence in the virus production system.
In some embodiments for maximum biosafety the 3rd Generation lentiviral packaging systems are preferred. The replication-incompetent 3rd generation lentiviral packaging system splits the viral genome into 4 plasmids: (A) a plasmid containing only the genes necessary for packaging the lentiviral vector which are gag and pol which are operatively linked to a promoter, a rev gene and a polyA site (B) A plasmid that contains only the regulatory gene rev that is operatively linked to a promoter and a polyA site. (C) A plasmid that only contains the envelope gene known as env operatively linked to a promoter and a polyA site. (D) The transgene plasmid that contains the genes whose expression is desired as part of gene therapy. The transgene plasmid also contains modified LTRs at the 5′ and 3′ ends. The LTR includes a deleted or inactivated U3. Also in the LTR are the R and U5 cis-acting signals. The deleted or inactivated U3 enhancer/promoter (known as ΔU3) of the 5′ LTR is replaced with a human cytomegaloviruss (CMV) immediate early enhancer and promoter to eliminate the need for the transcriptional activator tat that has been deleted or inactivated. The viral RNA is stored in the lentivirus delivery system with a 5′LTR as a 5′-cap-R-U5 and the 3′LTR contains the mutated or deleted U3 (ΔU3) and R followed by a poly A tail of about 200 adenosines. That is the 5′ U3 is missing and the 3′ U5 is missing. The provirus that results following reverse transcription in the third generation lentiviral packaging systems contains the ΔU3-R-U5 sequences at the 5′ end and U5-R-ΔU3 sequences at the 3′ end. The first and second generation lentivirus packaging system also store the viral RNA with a 5′LTR as 5′-cap-R-U5 and the 3′LTR as U3-R followed by about 200 adenosines. The provirus that results following reverse transcription in the first and second generation lentiviral packaging systems contains the U3-R-U5 sequences at the 5′ end and U5-R-U3 sequences at the 3′ end. Additional details that describe the transgene plasmid and LTRs are described in later embodiments. The third generation lentiviral packaging system typically employs a heterologous or functionally modified envelope protein for safety. The third generation lentiviral packaging system builds on the first generation packaging system by additionally deleting the accessory genes vif, vpr, vpu and nef. Integration-deficient lentiviral vectors refer to lentiviral vectors that cannot act as retroviruses. They are viral vectors that are episomally-maintained. Both the U5 and U3 regions may be mutated at integrase (IN) attachment (att) sites to eliminate their retroviral function. This occurs through mutating specific recognition sequences necessary for integrase (IN) to attach to the vector and also cut by IN. A common strategy used to generate integration deficient lentiviral vectors is to mutate specific amino acid residues on the integrase, which is found on the pol gene, that are necessary for retroviral function. Such mutations often include either D64 or D116 of the catalytic triad. Mutating RRK (262-264) motif at the C-terminal domain causes IN to fail to bind target genomic DNA. Mutating Lysines at integrase protein positions 264, 266 and 273 impairs target DNA binding and stand transfer. These lysines residues may be acetylated in the target cell where the acetylation is required for strand transfer. Other mutations might occur at N120 or W235 that is necessary for DNA binding and thus either of these mutations block integration. If the gene encoding for the integrase protein is not mutated then the lentivirus would be integration competent and would be expected to integrate the vector into the host genomic DNA, that is also contemplated in some embodiments in this instant patent. The lentivirus (See e.g. Banasik, M. B., McCray, P. B. Jr., 2010, Gene Ther., 17:150-7. See e.g., Apolonia, L., 2009, Ph.D. Thesis, University College London; Yáñez-Muñoz, R. J., et al., 2006, Nat Med. 12:348-353; Conese, M., et. al., 2004, Gene Ther., 11:1735-1741; Karwacz, K., et al., 2009, J. Virol., 83:3094-3103).
This present application claims benefit to U.S. provisional patent application Ser. No. 63/008,844 filed on Apr. 13, 2020 and 63/076,527 filed on Sep. 10, 2020. The entire disclosure is included herein in its entirety at least by reference.
