NZ753155B2 - Promoters, expression cassettes, vectors, kits, and methods for the treatment of achromatopsia and other diseases - Google Patents

Abstract

The present invention provides isolated promoters, transgene expression cassettes, vectors, kits, and methods for treatment of genetic diseases that affect the cone cells of the retina. The present invention features, in a first aspect, a nucleic acid comprising a portion of the cone cell specific promoter PR 2.1, in particular the truncated promoter PR1.7. In one embodiment, the nucleic acid comprises the sequence SEQ ID NO: 4. In another embodiment, PR2. l is truncated at the 5' or the 3' end. In one embodiment of the above aspects, the promoter is capable of promoting CNGB3 expression in S-cone cells, M-cone cells, and L-cone cells. In another embodiment of the above aspects, the promoter is capable of promoting CNGA3 expression in S-cone cells, M-cone cells, and L-cone cells. In yet another em­bodiment of the above aspects, the promoter is capable of promoting GNAT2 expression in S-cone cells, M-cone cells, and L-cone cells. romoter PR 2.1, in particular the truncated promoter PR1.7. In one embodiment, the nucleic acid comprises the sequence SEQ ID NO: 4. In another embodiment, PR2. l is truncated at the 5' or the 3' end. In one embodiment of the above aspects, the promoter is capable of promoting CNGB3 expression in S-cone cells, M-cone cells, and L-cone cells. In another embodiment of the above aspects, the promoter is capable of promoting CNGA3 expression in S-cone cells, M-cone cells, and L-cone cells. In yet another em­bodiment of the above aspects, the promoter is capable of promoting GNAT2 expression in S-cone cells, M-cone cells, and L-cone cells.

Description

PROMOTERS, EXPRESSION CASSETTES, VECTORS, KITS, AND METHODS FOR THE TREATMENT OF ACHROMATOPSIA AND OTHER DISEASES Related Applications This ation claims ty to US Provisional Application 61/824,071, filed on May 16, 2013, the entire contents of which are incorporated by reference in its entirety .

Background of the Invention Achromatopsia is an autosomal recessive retinal disease characterized by markedly reduced visual acuity, nystagmus, severe photophobia under daylight conditions, and reduced or complete loss of color mination (Kohl, S. et al.

Achromatopsia. In: Pagon RA, Bird TC, Dolan CR, Stephens K, editors Gene Reviews [Internet]. Seattle: University of Washington; 2010). It may be partial or complete. See Pang, J .—J . et al. (2010). Achromatopsia as a Potential Candidate for Gene Therapy. In Advances in Experimental Medicine and Biology, Volume 664, Part 6, 6 (2010) (hereinafter Pang et al). Symptoms of achromatopsia include reduced visual acuity, achromatopia (lack of color perception), hemeralopia (reduced visual capacity in bright light accompanied by photoaversion, meaning a dislike or nce of bright light), nystagmus trolled oscillatory nt of the eyes), iris operating abnormalities, and impaired vision (inability to perceive three—dimensional aspects of a scene).

Electroretinograms reveal that in achromatopsia, the function of retinal rod photoreceptors s intact, Whereas retinal cone photoreceptors are not functional.

Mutations in the cone—specific cyclic nucleotide gated channel beta subunit (CNGB3) gene account for about 50% of cases of achromatopsia (Kohl S, et al. Eur J Hum Genet 2005;13:302—8). The rod and cone photoreceptors serve onally different roles in vision. Pang et al. (2010). Cone eceptors are primarily responsible for central, fine resolution and color vision While operating in low to very bright light. They are concentrated in the central macula of the retina and comprise nearly 100% of the fovea.

Rod photoreceptors are responsible for peripheral, low light, and night vision; they are found primarily outside the macula in the peripheral retina.

Approximately 1 in 30,000 individuals s from complete achromatopsia. In complete atopsia, there is total color vision loss, central vision loss, and visual acuity of 20/200 or worse. Thus, most individuals with achromatopsia are legally blind.

The current standard of care consists of limiting retinal light exposure with tinted contact lenses and providing magnification to boost central vision. However, there is no treatment available that corrects cone function in achromatopsia. Pang et al.

There are various genetic causes of congenital achromatopsia. Mutations in the cyclic nucleotide—gated ion channel beta 3 (CNGB3, also known as ACHM3) gene, are one genetic cause of achromatopsia. Recent studies in dogs suggest some promise for the use of recombinant adeno—associated virus (rAAV)—based gene therapy for the treatment of achromatopsia caused by mutations in the CNGB3 gene. Komaromy et al., Gene therapy rescues cone function in congenital achromatopsia. Human Molecular Genetics, 19(13): 2581-2593 (2010) (hereinafter my et al.). In the canine studies, the rAAV vectors that were used packaged a human CNGB3 (hCNGB3) expression cassette that contained elements including a 2.1 kb cone red opsin promoter (PR2.1) and a human CNGB3 (hCNGB3) cDNA. One limitation of the studies is that the hCNGB3 driven by the PR2.1 promoter is expressed only in red and green cones, whereas endogenous hCNGB3 is sed in all three types of cones (red, green and blue cones). Another limitation is that the overall size of the expression cassette ed (5,230 bp) was well beyond the normal packaging capacity (<4.9 kb) of AAV particles; the over—stuffed rAAV particles dramatically impaired the rAAV packaging efficiency, resulting in low yields, a higher empty—to—full particle ratio, and likely a lower infectivity of the vector. Expression cassettes ning a shorter version of the cone red opsin promoter, or a cone arrestin er, were much less effective in ing visual function. The present invention ses these limitations.

The present invention has the advantage of providing promoters that are capable of promoting hCNGB3 expression in all three types of cones. In addition, the promoters of the invention have the advantage that they are short enough to make the hCNGB3 sion te fit well within the normal packaging capacity of rAAV. A promoter that fits within the normal rAAV packaging ty provides benefits, such as improved yields, a lower empty—to—full particle ratio, and higher infectivity of the vector.

The present invention also es expression tes, vectors and kits that utilize these improved promoters, as well as methods for treating atopsia by administering the vectors.

The present invention addresses the need for an effective achromatopsia treatment. y of the Invention The present ion es, in a first aspect, a nucleic acid comprising a n of the cone cell specific promoter PR 2.1.

In one embodiment, the nucleic acid comprises the sequence SEQ ID NO: 4. In another embodiment, PR2.1 is truncated at the 5’ or the 3’ end. In a related ment, the truncation is between about 100 base pairs to 1,500 base pairs. In a further related embodiment, the truncation is about 300 base pairs at the 5’ end. In another further embodiment, the truncation is about 500 base pairs at the 5’ end. In another embodiment, the truncation is about 1,1000 base pairs at the 5’ end. In another further embodiment, the truncation is about 300 base pairs at the 3’ end. In r embodiment, the tion is about 500 base pairs at the 3’ end. In another further embodiment, the truncation is about 1,1000 base pairs at the 3’ end.

In one embodiment, the nucleic acid of the above aspects and embodiments comprises SEQ ID NO:3. In one embodiment, the nucleic acid of the above aspects and embodiments comprises SEQ ID NO:2. In one embodiment, the nucleic acid of the In another aspect, the invention features a nucleic acid comprising the nucleotide sequence of SEQ ID NO:1. In another aspect, the invention features a nucleic acid comprising the nucleotide sequence of SEQ ID NO:2. In another aspect, the invention features a c acid comprising the nucleotide sequence of SEQ ID NO:3.

In another further embodiment, the invention features a nucleic acid comprising a nucleotide sequence which is at least 85% identical to the tide sequence of SEQ ID NO:1.

In one embodiment of the above aspects, the promoter is capable of promoting CNGB3 sion in S—cone cells, M—cone cells, and L—cone cells. In another embodiment of the above aspects, the promoter is capable of promoting CNGA3 expression in S—cone cells, M—cone cells, and L—cone cells. In yet another embodiment of the above aspects, the promoter is capable of promoting GNAT2 sion in S—cone cells, M—cone cells, and L—cone cells.

In another ment, the invention features a recombinant adeno—associated (rAAV) expression vector comprising a target nucleic acid sequence operably linked to the c acid of any one of the above aspects and embodiments. In a related embodiment, the rAAV is serotype 1. In a related embodiments, the rAAV is serotype 2. In another related embodiment, the rAAV is serotype 5. In still another related embodiment, the rAAV is comprised Within an AAV virion.

In one embodiment, the target nucleic acid sequence encodes a cyclic nucleotide— gated channel t B (CNGB3) polypeptide. In a related ment, the CNGB3 is mouse CNGB3. In another related embodiment, the CNGB3 is rat CNGB3. In still another related embodiment, the CNGB3 is human CNGB3.

In one ment, the target nucleic acid sequence encodes a cyclic nucleotide— gated channel subunit A (CNGA3) ptide. In a related embodiment, the CNGA3 is mouse CNGA3. In another related embodiment, the CNGA3 is rat CNGA3. In still another related embodiment, the CNGA3 is human CNGA3.

In one embodiment, the target c acid sequence encodes a Guanine nucleotide—binding protein G(t) subunit 2 (GNAT—Z) polypeptide. In a d embodiment, the GNAT—2 is mouse GNAT—Z. In another related ment, the GNAT—2 is rat GNAT—Z. In still another related embodiment, the GNAT—2 is human In another embodiment, the invention features a mammalian cell comprising the expression vector of any one of the above aspects and embodiments.

In still another embodiment, the invention features a transgene expression te comprising the nucleic acid of any of the above aspects or embodiments, a nucleic acid selected from the group consisting of a CNGB3 nucleic acid, a CNGA3 nucleic acid, and a GNAT2 nucleic acid, and minimal regulatory elements. In one embodiment, the invention features a nucleic acid vector comprising the expression cassette of any one of the above aspects or embodiments. In a related ment, the vector is an adeno—associated viral (AAV) vector.

In another embodiment, the invention features a kit comprising the expression vector of any one of the above aspects or embodiments and instructions for use.

The invention also es in another embodiment, a method of treating an eye disease comprising administering to a subject in need f the expression vector of any one of the above aspects or embodiments, thereby treating the subject.

The invention also features in another embodiment, a method of promoting CNGA3 or CNGB3 expression in the cone cells of a subject comprising administering to the subject the expression vector of any one of the above aspects or embodiments, thereby promoting CNGA3 or CNGB3 expression.

In one embodiment, the eye e is associated with a genetic mutation, substitution, or deletion that affects retinal cone cells. In another embodiment, the eye e affects the retinal t epithelium. In another related embodiment, the eye disease is achromatopsia.

In another embodiment, the sion vector is capable of promoting CNGB3 expression in S—cone cells, M—cone cells, and L—cone cells. In another further embodiment, the expression vector is capable of promoting CNGA3 expression in S— cone cells, M—cone cells, and L—cone cells. In still another further ment, the expression vector is e of promoting GNAT—2 expression in S—cone cells, M—cone cells, and L—cone cells.

In further embodiments, the vector is administered subretinally.

Brief Description of the gs Figure 1: Schematic drawing of the truncated human red/green opsin promoter.

Figure 2: Schematic drawing of the rAAVS—PRZ. l—hCNGB3 vector.

Figure 3: Schematic drawings of four proviral ds that contain variants of the PR2.1 promoter.The PR2.1 promoter (a truncated human red/green opsin promoter) was truncated at its 5’—end by 300 bp, 500 bp, and 1,100 bp to create shorter promoters, designated PR1.7, PR1.5, and PR1.1, respectively. A CMV enhancer was added to the ’ end of the PR1.1 to create a hybrid er. The 500 bp core promoter (shown in gray) and the locus control region (shown in red) of PR2.1 were left intact in each of these constructs. Terminal repeats are ted by the arrows, and the location of SV40 splicing signal sequences is shown.

Figure 4 sets forth SEQ ID NOs: 1—4.

Figure 5 shows the results of ments to assess the efficiency and specificity of PR1.1 and PR1.5 to target cones in mice, using rAAV vectors expressing green fluorescent protein (GFP). PNA is a marker for cone eceptors. DAPI is used to identify nuclei.

Figure 6 shows the results of experiments to assess the ency and specificity of PR1.7 and PR2.1 to target cones in mice, using rAAV vectors expressing green fluorescent protein (GFP). PNA is a marker for cone photoreceptors. DAPI is used to identify nuclei.

Figure 7 shows the results of fundus orescence imaging (FAF) to detect the presence of green cent protein (GFP) in the non—human primate (NHP) eyes received subretinally rAAV2tYF—PR2.1—GFP, rAAV2tYF—PR1.7—GFP, or AAV2tYF— CSP—GFP.

Figure 8 (A—E) shows GFP expression in NHP retinas 3 months after injection of AAV2tYF—GFP vectors. The panels show representative retinal sections from a normal control eye without AAV treatment (panel A), or from eyes inally injected with AAV2tYF—CSP—GFP (panel B), AAV2tYF—PR2.1—GFP (panel C), or AAV2tYF—PR1.7— GFP (panels D & E) stained with DAPI for nuclei (blue) and antibodies to GFP (green), L/M cone opsin (red, panels A, B, C & D) or S cone opsin (red, panel E).

Figure 9 is a graph that shows levels of message RNA (mRNA) of GFP in NHP retinas 3 months after injection of AAV2tYF—GFP vectors. Message RNA (mRNA) of GFP was determined by qRT—PCR, performed in triplicates at 3 different times, and normalized by 18S RNA expression in samples.

Detailed Description of the Invention: I. Overview and Definitions Unless defined otherwise, all cal and scientific terms used herein have the meaning commonly understood by a person d in the art to which this invention belongs. The following references provide one of skill with a general definition of many of the terms used in this invention: Singleton et al., Dictionary of Microbiology and Molecular y (2nd ed. 1994); The Cambridge Dictionary of Science and Technology (Walker ed., 1988); The Glossary of Genetics, 5th Ed., R. Rieger et al. (eds.), Springer Verlag (1991); and Hale & Marham, The Harper Collins Dictionary of Biology (1991). As used herein, the following terms have the gs ascribed to them below, unless ied otherwise.

The articles “a” and “an” are used herein to refer to one or to more than one (i.e. to at least one) of the grammatical object of the e. By way of example, “an element” means one element or more than one element.

The term “including” is used herein to mean, and is used interchangeably with, the phrase “including but not limited to”.

The term “or” is used herein to mean, and is used interchangeably with, the term “and/or,” unless context clearly indicates otherwise.

The term “such as” is used herein to mean, and is used hangeably, with the phrase “such as but not limited to”.

A “subject” or nt” to be treated by the method of the invention can mean either a human or non—human animal. A “nonhuman ” includes any vertebrate or invertebrate organism.

“Achromatopsia” is a color vision disorder. Symptoms of achromatopsia include achromatopia (lack of color tion), amblyopia (reduced visual acuity), hemeralopia (reduced visual capacity in bright light accompanied by photoaversion, meaning a dislike or avoidance of bright light), nystagmus (uncontrolled oscillatory movement of the eyes), iris operating abnormalities, and impaired stereovision lity to perceive three—dimensional aspects of a scene). As used , the term “achromatopsia” refers to a form of achromatopsia caused by c mutations, substitutions, or deletions.

“Treating” a disease (such as, for example, achromatopsia) means alleviating, preventing, or delaying the occurrence of at least one sign or symptom of the disease.

The tric ends of DNA and RNA strands are called the 5’ (five prime) and 3’ (three prime) ends, with the 5' end having a terminal phosphate group and the 3' end a terminal hydroxyl group. The five prime (5’) end has the fifth carbon in the sugar—ring of the deoxyribose or ribose at its terminus. Nucleic acids are synthesized in vivo in the '— to 3'—direction, because the rase used to assemble new strands attaches each new nucleotide to the 3'—hydroxyl (—OH) group via a phosphodiester bond.

A ter” is a region of DNA that facilitates the ription of a ular gene. As part of the process of transcription, the enzyme that synthesizes RNA, known as RNA polymerase, es to the DNA near a gene. Promoters contain specific DNA ces and response elements that e an initial g site for RNA polymerase and for transcription factors that recruit RNA polymerase.

The retina contains three kinds of photoreceptors: rod cells, cone cells, and eceptive ganglion cells. Cone cells are of three types: S—cone cells, M—cone cells, and L—cone cells. S—cone cells respond most strongly to short wavelength light (peak near 420—440 nm) and are also known as blue cones. M—cone cells respond most strongly to medium ngth light (peak near 534—545 nm) and are also known as green cones. L—cone cells respond most strongly to light of long wavelengths (peak near 564—580 nm) and are also known as red cones. The difference in the signals received from the three cone types allows the brain to perceive all possible colors.

A “transgene expression cassette” or “expression cassette” comprises the gene sequences that a nucleic acid vector is to deliver to target cells. These sequences include the gene of st (e. g., a CNGB3 or CNGA3 nucleic acid), one or more promoters, and minimal regulatory elements.

“Minimal regulatory elements” are regulatory elements that are necessary for effective expression of a gene in a target cell and thus should be included in a transgene expression cassette. Such sequences could include, for example, promoter or enhancer sequences, a polylinker sequence facilitating the insertion of a DNA fragment within a plasmid vector, and sequences responsible for intron splicing and polyadenlyation of mRNA transcripts. In a recent example of a gene therapy treatment for achromatopsia, the expression cassette included the minimal regulatory elements of a polyadenylation site, splicing signal ces, and AAV inverted terminal repeats. See, e.g., Komaromy et al.

A “nucleic acid” or “nucleic acid molecule” is a molecule composed of chains of monomeric nucleotides, such as, for example, DNA molecules (e.g., cDNA or c DNA). A nucleic acid may encode, for example, a promoter, the CNGB3 or CNGA3 gene or portion thereof, or regulatory elements. A nucleic acid molecule can be single— stranded or double—stranded. A “CNGB3 nucleic acid” refers to a nucleic acid that comprises the CNGB3 gene or a n thereof, or a functional variant of the CNGB3 gene or a portion thereof. Similarly, a “CNGA3 nucleic acid” refers to a nucleic acid that comprises the CNGA3 gene or a portion f, or a functional variant of the CNGA3 gene or a n thereof, and a “GNAT2 nucleic acid” refers to a nucleic acid that comprises the GNAT2 gene or a portion thereof, or a functional variant of the GNAT2 gene or a portion thereof. A functional variant of a gene includes a variant of the gene with minor variations such as, for example, silent ons, single nucleotide polymorphisms, missense mutations, and other mutations or deletions that do not icantly alter gene on.

An "isolated" nucleic acid molecule (such as, for example, an ed promoter) is one which is separated from other c acid molecules which are present in the natural source of the nucleic acid. For example, with regard to genomic DNA, the term "isolated" includes nucleic acid molecules which are separated from the chromosome with which the genomic DNA is lly associated. Preferably, an "isolated" nucleic acid molecule is free of ces which naturally flank the nucleic acid molecule in the genomic DNA of the organism from which the nucleic acid molecule is derived. 11. Methods ofthe invention The present invention provides promoters, expression cassettes, vectors, kits, and methods that can be used in the ent of genetic diseases that affect the cone cells of the retina. c diseases that affect the cone cells of the retina include achromatopsia; Leber congenital amaurosis; cone—rod dystrophy; retinitis pigmentosa, ing X—linked retinitis pigmentosa; maculopathies; and age—related macular degeneration. In preferred embodiments, the disease is achromatopsia.

WO 86160 Achromatopsia is a color vision disorder. Autosomal recessive mutations or other types of sequence alterations in three genes are the predominant cause of congenital achromatopsia. See Pang, J .—J . et al. (2010). Achromatopsia as a Potential Candidate for Gene y. In es in Experimental Medicine and Biology, Volume 664, Part 6, 639—646 (2010). Achromatopsia has been associated with mutations in either the alpha or beta subunits of cyclic nucleotide gated channels (CNGs), which are respectively known as CNGA3 and CNGB3. Mutations in the CNGA3 gene that were associated with achromatopsia are reported in Patel KA, et al.

Transmembrane S1 mutations in CNGA3 from achromatopsia 2 patients cause loss of function and impaired cellular trafficking of the cone CNG channel. Invest. Ophthalmol.

Vis. Sci. 46 (7): 2282—90. (2005)., Johnson S, et al. Achromatopsia caused by novel mutations in both CNGA3 and CNGB3. J. Med. Genet. 41 (2): e20. (2004)., Wissinger B, et al. CNGA3 mutations in hereditary cone photoreceptor disorders. Am. J. Hum.

Genet. 69 (4): 722—37.(2001)., and Kohl S, et al. Total colourblindness is caused by mutations in the gene encoding the alpha—subunit of the cone photoreceptor ated cation channel. Nat. Genet. 19 (3): 257—9. (1998). Mutations in CNGB3 gene that were associated with achromatopsia are reported in n S, et al. Achromatopsia caused by novel mutations in both CNGA3 and CNGB3. J. Med. Genet. 41 (2): e20. (2004)., Peng C, et al. Achromatopsia—associated mutation in the human cone photoreceptor cyclic nucleotide—gated channel CNGB3 subunit alters the ligand sensitivity and pore properties of heteromeric ls. J. Biol. Chem. 278 (36): 34533—40 (2003)., Bright SR, et al. Disease—associated ons in CNGB3 produce gain of function alterations in cone cyclic nucleotide—gated channels. Mol. Vis. 11: 1141—50 (2005)., Kohl S, et al.

CNGB3 mutations account for 50% of all cases with autosomal recessive achromatopsia. Eur. J. Hum. Genet. 13 (3): 302—8 (2005)., Rojas CV, et alA frameshift insertion in the cone cyclic tide gated cation channel causes complete achromatopsia in a guineous family from a rural isolate. Eur. J. Hum. Genet. 10 (10): 638—42 (2002)., Kohl S, et al. Mutations in the CNGB3 gene ng the beta— subunit of the cone photoreceptor cGMP—gated channel are responsible for achromatopsia (ACHM3) linked to chromosome 8q21. Hum. Mol. Genet. 9 (14): 2107— 16 (2000)., Sundin OH, et al.. Genetic basis of total colourblindness among the Pingelapese ers. Nat. Genet. 25 (3): 289—93 (2000). Sequence alterations in the gene for cone cell ucin, known as GNAT2, can also cause achromatopsia. See Kohl S, et al., ons in the cone photoreceptor G—protein alpha—subunit gene GNAT2 in patients with achromatopsia. Kokl S, et al. Mutations in the cone photoreceptor G—protein alpha—subunit gene GNAT2 in ts with atopsia. Am J Hum Genet 71 (2): 422—425 (2002) (hereinafter Kohl et al.). The severity of mutations in these proteins correlates with the severity of the achromatopsia phenotype. http://en.wikipedia.org/wiki/Achromatopsia. Mutations in CNGB3 account for about 50% of cases of achromatopsia. Kohl et al. Mutations in CNGA3 account for about 23% of cases, and mutations in GNAT2 account for about 2% of cases.

The “CNGB3 gene” is the gene that encodes the cyclic nucleotide—gated channel beta 3 (CNGB3). The “CNGA3 gene” is the gene that encodes the cyclic nucleotide— gated channel alpha 3 (CNGA3). The CNGB3 and CNGA3 genes are sed in cone cells of the retina. Native l cyclic nucleotide gated channels (CNGs) are critically involoved in phototransduction. CNGs are cation channels that consist of two alpha and two beta ts. In the dark, cones have a relatively high concentration of cyclic guanosine 3'—5' monophosphate , which causes the CNGs to open, resulting in depolarization and continuous glutamate release. Light exposure activates a signal transduction y that breaks down cGMP. The reduction in cGMP concentrarion causes the CNGs to close, preventing the influx of positive ions, hyperpolarizing the cell, and stopping the release of glutamate. ons in either the CNGB3 or CNGA3 genes can cause defects in cone photoreceptor on resulting in achromatopsia. ons in the CNGB3 gene have been associated with other diseases in on to achromatopsia, including progressive cone dystrophy and juvenile macular degeneration.

The GNAT2 gene encodes the alpha—2 subunit of guanine nucleotide binding protein, which is also known as the cone—specific alpha transducin. Guanine nucleotide— binding proteins (G proteins) consist of alpha, beta, and gamma subunits. In photoreceptors, G proteins are critical in the amplification and transduction of visual signals. Various types of sequence alterations in GNAT2 can cause human achromatopsia: nonsense mutations, small deletion and/or insertion mutations, frameshift mutations, and large intragenic deletions. Pang et al.

Currently, there is no effective treatment for achromatopsia. Animal s suggest that it is possible to use gene therapy to treat achromatopsia and other diseases of the retina. For recessive gene s, the goal is to r a wild—type copy of a defective gene to the affected retinal cell type. The ability to r genes to some subsets of cone cells was demonstrated, for example, in Mauck, M. C. et al., Longitudinal evaluation of sion of virally delivered enes in gerbil cone photoreceptors. Visual Neuroscience 25(3): 273—282 (2008). The authors showed that a recombinant AAV vector could be used to achieve long—term expression of a reporter gene encoding green fluorescent protein in specific types of gerbil cone cells. The authors further demonstrated that a human avelength opsin gene could be delivered to specific gerbil cones, resulting in cone responses to long—wavelength light.

Other studies demonstrated that gene therapy with recombinant AAV vectors could be used to convert dichromat monkeys into trichromats by introducing a human L— opsin gene into the squirrel monkey retina. Mancuso, K., et al. Gene therapy for red— green colour ess in adult primates. Nature 461: 784—787 (2009).

Electroretinograms verified that the introduced photopigment was onal, and the monkeys showed improved color vision in a behavioral test.

There are several animal models of achromatopsia for which gene therapy experiments have demonstrated the ability to restore cone function. See Pang et al.

First, the Gnat2CPfl3 mouse has a recessive mutation in the cone— specific alpha transducin gene, resulting in poor visual acuity and little or no cone—specific ERT se.

Treatment of homozygous Pfl3 mice with a single subretinal injection of an AAV pe 5 vector carrying wild type mouse GNAT2 cDNA and a human red cone opsin promoter restored cone— specific ERG responses and visual acuity. Alexander et al. ation of cone vision in a mouse model of achromatopsia. Nat Med 13:685-687 (2007) (hereinafter Alexander et al.). Second, the cpfl5 (Cone Photoreceptor Function Loss 5) mouse has an autosomal recessive missense mutation in the CNGA3 gene with no cone—specific ERG response. Treatment of cpfl5 mice with subretinal injection of an AAV vector carrying the wild type mouse CNGA3 gene and a human blue cone promoter (HB570) resulted in restoration of cone—specific ERG responses. Pang et al.

Third, there is an n Malmute dog that has a naturally occurring CNGB3 mutation causing loss of daytime vision and absence of retinal cone function. In this type of dog, subretinal injection of an AAV5 vector containing human CNGB3 cDNA and a human red cone opsin promoter restored cone—specific ERG responses. See, e.g., my et The prior methods for treatment of achromatopsia using gene therapy were limited by the fact that the promoters used caused expression of transgenes only in certain types of cone cell photoreceptors. The promoters of the present invention can drive gene expression in all three types of cone cells that are present in humans (S—cone cells, M—cone cells, and L—cone cells).

Another limitation of the studies med by Komaromy et al. was that the l size of the expression cassette utilized (5,230 bp) was well beyond the normal packaging ty (<4.9 kb) of AAV particles; the over—stuffed rAAV les dramatically impaired the rAAV packaging efficiency, resulting in low yields, a higher empty—to—full particle ratio, and likely a lower infectivity of the vector. Expression cassettes containing a shorter version of the cone red opsin promoter, or a cone arrestin promoter, were much less effective in restoring visual on. The promoters of the t invention have the advantage that due to their shortened length, they make the hCNGB3 expression cassette efficiently package in an AAV particle. A promoter that fits within the normal rAAV packaging capacity provides benefits, such as improved yields, a lower empty—to—full particle ratio, higher infectivity of the vector, and ultimately, higher cy for treatment of the d condition. 111. ers, Expression Cassettes, Nucleic Acids, and Vectors 0fthe Invention The promoters, CNGB3 nucleic acids, tory elements, and expression cassettes, and vectors of the invention may be produced using methods known in the art.

The methods described below are provided as non—limiting examples of such methods.

Promoters The present invention provides isolated and/or truncated promoters. In some aspects, these promoters include a segment of the PR 2.1 promoter. In one embodiment, the promoter is a truncated PR2.l promoter.

In some embodiments of the promoters of the invention, the promoter is capable of promoting expression of a transgene in , M—cone, and L—cone cells. A “transgene” refers to a segment of DNA containing a gene sequence that has been isolated from one organism and is introduced into a ent organism. For example, to treat an individual who has achromatopsia caused by a mutation of the human CNGB3 gene, a ype (i.e., non—mutated, or functional variant) human CNGB3 gene may be administered using an appropriate vector. The Wild—type gene is referred to as a “transgene.” In preferred embodiments, the ene is a Wild—type version of a gene that encodes a protein that is normally expressed in cone cells of the retina. In one such embodiment, the transgene is derived from a human gene. In a first specific embodiment, the promoter is capable of promoting expression of a CNGB3 nucleic acid in S—cone, M—cone, and L—cone cells. In a second specific embodiment, the promoter is capable of promoting expression of a CNGA3 nucleic acid in S—cone, M—cone, and L— cone cells. In a third specific embodiment, the promoter is capable of ing expression of a GNAT2 nucleic acid in , M—cone, and L—cone cells. In these three specific embodiments, the CNGB3, CNGA3, or GNAT2 is preferably human CNGB3, CNGA3, or GNATZ.

In another aspect, the present invention provides promoters that are shortened versions of the PR2.1 promoter. Such promoters have the advantage that they fit better Within the packaging capacity of AAV particles and therefore e advantages such as, for example, improved yields, a lower empty—to—full particle ratio, and higher infectivity of the vector. In some ments, these promoters are created by truncating the 5’—end of PR2.1 or the 3’—end of PR 2.1. In some such embodiments, the lengths of the truncations are selected from the group consisting of approximately 300bp, 500bp, and 1,100 bp (see, e.g., PR1.7, PR1.5, and PR1.1, tively).

Expression Cassettes In another aspect, the t invention es a transgene expression cassette that es (a) a promoter of the invention; (b) a nucleic acid selected from the group consisting of a CNGB3 nucleic acid, a CNGA3 c acid, and a GNAT2 c acid; and (c) minimal regulatory elements. A promoter of the invention includes the promoters discussed supra.

A “CNGB3 nucleic acid” refers to a nucleic acid that comprises the CNGB3 gene or a portion thereof, or a functional variant of the CNGB3 gene or a portion thereof. Similarly, a “CNGA3 nucleic acid” refers to a nucleic acid that comprises the CNGA3 gene or a portion thereof, or a functional variant of the CNGA3 gene or a n thereof, and a “GNAT2 nucleic acid” refers to a nucleic acid that comprises the GNAT2 gene or a portion thereof, or a functional variant of the GNAT2 gene or a portion thereof. A onal variant of a gene includes a variant of the gene with minor variations such as, for example, silent mutations, single nucleotide polymorphisms, se mutations, and other mutations or deletions that do not significantly alter gene function.

In n embodiments, the nucleic acid is a human nucleic acid (i.e., a c acid that is derived from a human CNGB3, CNGA3, or GNAT2 gene). In other embodiments, the c acid is a non—human c acid (i.e., a nucleic acid that is derived from a non—human CNGB3, CNGA3, or GNAT2 gene). al tory elements” are regulatory elements that are necessary for effective expression of a gene in a target cell. Such regulatory elements could include, for example, er or enhancer sequences, a polylinker sequence tating the insertion of a DNA fragment Within a plasmid vector, and sequences responsible for intron splicing and polyadenlyation of mRNA transcripts. In a recent example of a gene therapy treatment for achromatopsia, the expression cassette included the minimal regulatory elements of a polyadenylation site, splicing signal sequences, and AAV inverted al repeats. See, e. g., Komaromy et al.. The expression cassettes of the ion may also optionally include additional regulatory elements that are not necessary for effective incorporation of a gene into a target cell.

Vectors The present invention also provides vectors that include any one of the expression cassettes discussed in the preceding section. In some embodiments, the vector is an oligonucleotide that comprises the sequences of the expression cassette. In specific embodiments, delivery of the oligonucleotide may be accomplished by in vivo electroporation (see, e.g., Chalberg, TW, et al. phiC3l integrase confers genomic integration and long—term transgene expression in rat retina. Investigative Ophthalmology &Visual Science, 46, 2140—2146 (2005) (hereinafter Chalberg et al., 2005)) or electron che transfection (see, e.g., Chalberg, TW, et al. Gene transfer to rabbit retina with electron avalanche transfection. Investigative Ophthalmology &Visual Science, 47, 4083—4090 (2006) (hereinafter Chalberg et al., 2006)). In further embodiments, the vector is a mpacting peptide (see, e. g., Farjo, R, et al.

Efficient non—viral ocular gene transfer with ted DNA nanoparticles. PLoS ONE, 1, e38 (2006) (hereinafter Farjo et al., 2006), where CK30, a peptide containing a cystein residue coupled to polyethylene glycol followed by 30 lysines, was used for gene transfer to eceptors), a peptide with cell penetrating properties (see Johnson, LN, et al., Cell—penetrating peptide for enhanced delivery of nucleic acids and drugs to ocular tissues including retina and cornea. lar Therapy, 16(1), 107—1 14 (2007) nafter Johnson et al., 2007), Barnett, EM, et al. Selective cell uptake of modified Tat peptide—fluorophore conjugates in rat retina in ex vivo and in vivo models.

Investigative Ophthalmology & Visual Science, 47, 2589—2595 (2006) (hereinafter Barnett et al., 2006), Cashman, SM, et al. Evidence of protein transduction but not intercellular transport by proteins fused to HIV tat in retinal cell culture and in vivo.

Molecular Therapy, 8, 130—142 (2003) (hereinafter Cashman et al., 2003), Schorderet, DF, et al. D—TAT transporter as an ocular peptide delivery system. al and Experimental Ophthalmology, 33, 628—635 (2005)(hereinafter Schorderet et al., 2005), Kretz, A, et al.. HSV—l VP22 augments adenoviral gene er to CNS neurons in the retina and striatum in vivo. Molecular Therapy, 7, 9 (2003)(hereinafter Kretz et al. 2003) for examples of peptide delivery to ocular cells), or a DNA—encapsulating lipoplex, polyplex, liposome, or immunoliposome (see e.g., Zhang, Y, et al. Organspecific gene expression in the rhesus monkey eye following intravenous nonviral gene transfer. Molecular Vision, 9, 465—472 (2003) (hereinafter Zhang et al. 2003), Zhu, C, et al. Widespread expression of an exogenous gene in the eye after intravenous administration. Investigative Ophthalmology & Visual Science, 43, 3075—3080 (2002) (hereinafter Zhu et al. 2002), Zhu, C., et al. Organ—specific expression of the lacZ gene controlled by the opsin promoter after enous gene administration in adult mice.

Journal of Gene Medicine, 6, 906—912. (2004) nafter Zhu et al. 2004)).

In red embodiments, the vector is a viral vector, such as a vector d from an adeno—associated virus, an adenovirus, a retrovirus, a lentivirus, a vaccinia/poxvirus, or a herpesvirus (e. g., herpes simplex virus (HSV)). See e.g., —l6- Howarth. In the most preferred embodiments, the vector is an adeno—associated viral (AAV) vector.

Multiple pes of adeno—associated virus (AAV), including 12 human serotypes (AAVl, AAV2, AAV3, AAV4, AAVS, AAV6, AAV7, AAVS, AAV9, AAV10, AAVl 1, and AAV12) and more than 100 pes from nonhuman es have now been identified. Howarth JL et al., Using viral vectors as gene transfer tools.

Cell Biol l 26: 1—10 (2010) (hereinafter Howarth et al.). In embodiments of the present invention wherein the vector is an AAV vector, the serotype of the inverted terminal repeats (ITRs) of the AAV vector may be selected from any known human or nonhuman AAV serotype. In preferred embodiments, the serotype of the AAV ITRs of the AAV vector is selected from the group consisting of AAVl, AAV2, AAV3, AAV4, AAVS, AAV6, AAV7, AAVS, AAV9, AAV10, AAVl 1, and AAV12. Moreover, in ments of the present invention wherein the vector is an AAV , the serotype of the capsid sequence of the AAV vector may be selected from any known human or animal AAV pe. In some embodiments, the pe of the capsid sequence of the AAV vector is selected from the group consisting of AAVl, AAV2, AAV3, AAV4, AAVS, AAV6, AAV7, AAVS, AAV9, AAV10, AAVl 1, and AAV12. In preferred embodiments, the serotype of the capsid sequence is AAVS. In some embodiments wherein the vector is an AAV vector, a pseudotyping ch is employed, wherein the genome of one ITR serotype is packaged into a different serotype capsid. See e.g., Zolutuhkin S. et al. Production and purification of serotype 1,2, and 5 recombinant adeno—associated viral vectors. Methods 28(2): 158—67 (2002). In preferred embodiments, the serotype of the AAV ITRs of the AAV vector and the serotype of the capsid sequence of the AAV vector are independently selected from the group consisting of AAVl, AAV2, AAV3, AAV4, AAVS, AAV6, AAV7, AAVS, AAV9, AAV10, AAVl 1, and AAV12.

In some embodiments of the present invention wherein the vector is a rAAV , a mutant capsid sequence is employed. Mutant capsid sequences, as well as other ques such as rational mutagenesis, engineering of targeting peptides, generation of chimeric particles, library and directed evolution approaches, and immune evasion modifications, may be employed in the present ion to optimize AAV vectors, for purposes such as achieving immune evasion and enhanced therapeutic output. See e.g., Mitchell AM. et al. AAV’s anatomy: Roadmap for optimizing vectors for ational success. Curr Gene Ther. 10(5): 319—340.

Making the nucleic acids of the invention A nucleic acid molecule (including, for example, a promoter, CNGB3 nucleic acid, CNGA3 nucleic acid, a GNAT2 nucleic acid, or a regulatory element) of the present invention can be ed using standard molecular biology ques. Using all or a portion of a nucleic acid ce of interest as a hybridization probe, nucleic acid molecules can be isolated using standard hybridization and cloning techniques (e.g., as described in Sambrook, J E. F., and Maniatis, T. Molecular Cloning. A ., Fritsh, Laboratory Manual. 2nd, ed., Cold Spring Harbor Laboratory, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y., 1989).

A nucleic acid molecule for use in the methods of the invention can also be isolated by the polymerase chain on (PCR) using synthetic oligonucleotide primers designed based upon the sequence of a c acid molecule of interest. A nucleic acid molecule used in the methods of the invention can be amplified using cDNA, mRNA or, alternatively, genomic DNA as a template and appropriate oligonucleotide primers according to standard PCR amplification techniques.

Furthermore, oligonucleotides corresponding to nucleotide sequences of interest can also be chemically synthesized using rd techniques. us methods of chemically synthesizing polydeoxynucleotides are known, including solid—phase synthesis which has been ted in commercially available DNA synthesizers (See e.g., a et al. US. Patent No. 4,598,049; Caruthers et al. US. Patent No. 4,458,066; and Itakura US. Patent Nos. 4,401,796 and 4,373,071, incorporated by nce ). Automated methods for designing synthetic oligonucleotides are available. See e.g., Hoover, D.M. & Lubowski, J. Nucleic Acids Research, 30(10): e43 (2002).

Many embodiments of the invention involve a CNGB3 c acid, a CNGA3 c acid, or a GNAT2 nucleic acid. Some aspects and embodiments of the invention involve other nucleic acids, such as isolated promoters or regulatory elements. A nucleic acid may be, for example, a cDNA or a chemically synthesized nucleic acid. A cDNA can be obtained, for example, by amplification using the polymerase chain reaction (PCR) or by screening an appropriate cDNA library. Alternatively, a nucleic acid may be chemically synthesized. —18- IV. Methods and Kits 0fthe ion Methods of Treatment The invention provides methods for treating a e associated with a c mutation, substitution, or deletion that affects retinal cone cells, wherein the methods comprise administering to a subject in need of such treatment a vector that includes one of the promoters of the invention, thereby treating the subject. In a red embodiment, the disease is achromatopsia. Other diseases associated with a genetic mutation, substitution, or deletion that affects retinal cone cells include achromatopsia, Leber ital amaurosis, cone—rod dystrophy, maculopathies, age—related macular degeneration and retinitis pigmentosa, including X—linked retinitis pigmento sa.

The ion further provides methods for ng achromatopsia comprising administering any of the vectors of the invention to a subject in need of such treatment, thereby treating the subject.

A “subject” to be treated by the s of the ion can mean either a human or non—human animal. A “nonhuman animal” includes any vertebrate or invertebrate organism. In some embodiments, the nonhuman animal is an animal model of retinal disease, or of achromatopsia in ular. See e.g., Pang et al., Alexander et al., Komaromy et al. Various large animal models are available for the study of AAV— mediated gene—based therapies in the retina. Stieger K. et al. AAV—mediated gene therapy for retinal disorders inlarge animal models. ILAR J. 50(2): 4 (2009).

The promoters of the invention are described supra. “Treating”a e (such as, for example, achromatopsia) means alleviating, preventing, or delaying the occurrence of at least one sign or symptom of the disease. A “sign” of a disease is a manifestation of the disease that can be observed by others or measured by objective methods, such as, e.g., electroretinography or behavioral testing. A “symptom” of a e is a teristic of the disease that is subjectively perceived by the subject.

In either of these two methods of treatment, the vector can be any type of vector known in the art. In some embodiments, the vector is a non—viral vector, such as a naked DNA plasmid, an oligonucleotide (such as, e.g., an antisense ucleotide, a small molecule RNA (siRNA), a double stranded oligodeoxynucleotide, or a single stranded DNA oligonucleotide). In specific embodiments involving oligonucleotide vectors, delivery may be accomplished by in vivo electroporation (see e.g., Chalberg et al., 2005) or electron avalanche transfection (see e.g., Chalberg et al. 2006). In further embodiments, the vector is a dendrimer/DNA x that may optionally be encapsulated in a water soluble polymer, a DNA—compacting peptide (see e.g., Farjo et al. 2006, where CK30, a peptide containing a cystein residue coupled to poly ethylene glycol followed by 30 lysines, was used for gene transfer to photoreceptors), a peptide with cell penetrating ties (see Johnson et al. 2007; Barnett et al., 2006; Cashman et al., 2003; Schorder et al., 2005; Kretz et al. 2003 for examples of peptide delivery to ocular cells), or a DNA—encapsulating lipopleX, eX, liposome, or immunoliposome (see e.g., Zhang et al. 2003; Zhu et al. 2002; Zhu et al. 2004). In many additional embodiments, the vector is a viral vector, such as a vector derived from an adeno— associated virus, an adenovirus, a retrovirus, a irus, a vaccinia/poxvirus, or a herpesvirus (e.g., herpes simpleX virus (HSV)). See e.g., Howarth. In preferred ments, the vector is an adeno—associated viral (AAV) vector.

In the methods of treatment of the present invention, administering of a vector can be lished by any means known in the art. In preferred embodiments, the administration is by subretinal injection. In certain embodiments, the subretinal injection is delivered entially to one or more s where cone density is particularly high (such as e.g., the tapetal zone superior to the optic disc). In other embodiments, the administration is by intraocular ion, intravitreal injection, or intravenous injection. Administration of a vector to the retina may be unilateral or bilateral and may be lished with or without the use of general anesthesia.

In the methods of treatment of the present invention, the volume of vector delivered may be determined based on the characteristics of the subject receiving the treatment, such as the age of the subject and the volume of the area to which the vector is to be delivered. It is known that eye size and the volume of the subretinal space differ among individuals and may change with the age of the subject. In embodiments wherein the vector is administered subretinally, vector volumes may be chosen with the aim of covering all or a certain percentage of the subretinal space, or so that a ular number of vector genomes is red.

In the methods of ent of the present invention, the concentration of vector that is administered may differ depending on production method and may be chosen or 2014/036792 optimized based on concentrations determined to be therapeutically effective for the particular route of administration. In some embodiments, the concentration in vector genomes per milliliter (vg/ml) is selected from the group consisting of about 108 vg/ml, about 109 vg/ml, about 1010 vg/ml, about 1011 vg/ml, about 1012 vg/ml, about 1013 vg/ml, and about 1014 vg/ml. In preferred embodiments, the concentration is in the range of 1010 vg/ml — 1013 vg/ml, delivered by subretinal injection or intravitreal injection in a volume of about 0.1 mL, about 0.2 mL, about 0.4 mL, about 0.6 mL, about 0.8 mL, and about 1.0 mL Kits The present invention also provides kits. In one aspect, a kit of the invention comprises a vector that ses (a) any one of the promoters of the invention and (b) instructions for use f. In another aspect, a kit of the invention comprises (a) any one of the vectors of the invention, and (b) instructions for use thereof. The promoters and vectors of the invention are described supra. In some embodiments, a vector of the invention may be any type of vector known in the art, including a non—viral or viral vector, as described supra. In preferred embodiments, the vector is a viral vector, such as a vector derived from an adeno—associated virus, an adenovirus, a retrovirus, a lentivirus, a vaccinia/poxvirus, or a herpesvirus (e.g., herpes simpleX virus (HSV)). In the most preferred embodiments, the vector is an adeno—associated viral (AAV) vector.

The ctions provided with the kit may describe how the promoter can be incorporated into a vector or how the vector can be administered for eutic purposes, e.g., for treating a disease associated with a genetic mutation, substitution, or on that affects retinal cone cells. In some embodiments wherein the kit is to be used for therapeutic purposes, the instructions include details regarding recommended dosages and routes of administration.

Methods of making recombinant associated viral vectors (AAV vectors) The present invention also es methods of making a recombinant adeno— associated viral (rAAV) vector sing inserting into an adeno—associated viral vector any one of the ers of the invention (described supra) and a nucleic acid selected from the group consisting of a CNGB3 nucleic acid, a CNGA3 nucleic acid, and a GNAT2 nucleic acid (also described supra). In some embodiments, the nucleic acid is a human nucleic acid, i.e., a nucleic acid derived from a human CNGB3, CNGA or GNAT gene, or a functional variant thereof. In alternative embodiments, the nucleic acid is a nucleic acid derived from a non—human gene.

In the methods of making an rAAV vector that are provided by the invention, the serotype of the capsid sequence and the serotype of the ITRs of said AAV vector are independently selected from the group consisting of AAVl, AAV2, AAV3, AAV4, AAV5, AAV6, AAV7, AAV8, AAV9, AAV10, AAVl 1, and AAV12. Thus, the invention encompasses vectors that use a pseudotyping approach, wherein the genomne of one ITR serotype is packaged into a different pe capsid. See e.g., Daya S. and Bems, K.l., Gene therapy using associated virus s. Clinical Microbiology Reviews, 21(4): 583-593 (2008) nafter Daya et al.). Furthermore, in some embodiments, the capsid sequence is a mutant capsid sequence.

AAV Vectors AAV vectors are derived from adeno—associated virus, which has its name because it was originally bed as a contaminant of adenovirus preparations. AAV vectors offer numerous nown advantages over other types of vectors: wildtype strains infect humans and an primates without evidence of disease or adverse effects; the AAV capsid displays very low immunogenicity ed with high chemical and physical stability which permits rigorous methods of virus purification and concentration; AAV vector transduction leads to sustained transgene expression in post— mitotic, nondividing cells and provides long—term gain of function; and the variety of AAV subtypes and variants offers the possibility to target selected tissues and cell types.

Heilbronn R & Weger S, Viral Vectors for Gene Transfer: t Status of Gene Therapeutics, in M. Schafer—Korting (ed.), Drug Delivery, Handbook of Experimental Pharmacology, 197: 143—170 (2010) (hereinafter Heilbronn). A major limitation of AAV vectors is that the AAV offers only a limited ene capacity (<4.9 kb) for a conventional vector containing single—stranded DNA.

AAV is a nonenveloped, small, —stranded DNA—containing virus encapsidated by an icosahedral, 20nm diameter capsid. The human pe AAV2 was used in a majority of early studies of AAV. Heilbronn. It contains a 4.7 kb linear, single—stranded DNA genome with two open reading frames rep and cap (“rep” for replication and “cap” for capsid). Rep codes for four overlapping uctural proteins: Rep78, Rep68, Rep52, and Rep40. Rep78 and Rep69 are required for most steps of the AAV life cycle, including the initiation of AAV DNA replication at the hairpin— structured inverted terminal repeats (ITRs), which is an essential step for AAV vector production. The cap gene codes for three capsid proteins, VPl, VP2, and VP3. Rep and cap are flanked by 145 bp ITRs. The ITRs contain the origins of DNA replication and the packaging signals, and they serve to e chromosomal integration. The ITRs are generally the only AAV elements ined in AAV vector construction.

To achieve replication, AAVs must be coinfected into the target cell with a helper virus. Grieger JC & ki RJ, Adeno—associated virus as a gene therapy vector: Vector development, production, and clinical applications. Adv Biochem Engin/Biotechnol 99: 1 19—145 (2005). Typically, helper viruses are either adenovirus (Ad) or herpes simplex virus (HSV). In the absence of a helper virus, AAV can establish a latent infection by integrating into a site on human some 19. Ad or HSV infection of cells latently infected with AAV will rescue the integrated genome and begin a tive infection. The four Ad proteins required for helper function are ElA, ElB, E4, and E2A. In addition, synthesis of Ad virus—associated (VA) RNAs is required. viruses can also serve as helper viruses for productive AAV replication. Genes encoding the helicase—primase complex (UL5, UL8, and UL52) and the DNA—binding n (UL29) have been found sufficient to mediate the HSV helper effect. In some embodiments of the present invention that employ rAAV vectors, the helper virus is an adenovirus. In other embodiments that employ rAAV vectors, the helper virus is HSV.

Making recombinant AAV (rAAV) vectors The production, purification, and characterization of the rAAV vectors of the present invention may be carried out using any of the many methods known in the art.

For reviews of laboratory—scale production s, see, e. 57., Clark RK, Recent advances in recombinant adeno—associated virus vector production. Kidney Int. 6ls:9—15 (2002); Choi VW et al., Production of recombinant associated viral vectors for in vitro and in vivo use. Current Protocols in Molecular Biology 16.25.1—16.25.24 (2007) (hereinafter Choi et al.); Grieger JC & Samulski RJ, Adeno—associated virus as a gene therapy vector: Vector pment, production, and clinical applications. Adv m Biotechnol 99:119—145 (2005) (hereinafter Grieger & Samulski); Heilbronn R & Weger S, Viral Vectors for Gene Transfer: Current Status of Gene Therapeutics, in M.

Schafer—Korting (ed.), Drug Delivery, Handbook of Experimental Pharmacology, 197: 143—170 (2010) (hereinafter Heilbronn); Howarth JL et al., Using viral s as gene transfer tools. Cell Biol Toxicol 26:1—10 (2010) (hereinafter Howarth). The production methods described below are intended as non—limiting examples.

AAV vector production may be accomplished by cotransfection of packaging plasmids. Heilbronn. The cell line supplies the deleted AAV genes rep and cap and the ed helpervirus functions. The adenovirus helper genes, VA—RNA, E2A and E4 are transfected together with the AAV rep and cap genes, either on two separate plasmids or on a single helper construct. A inant AAV vector plasmid wherein the AAV capsid genes are replaced with a transgene expression cassette ising the gene of interest, e. g., a CNGB3 nucleic acid; a promoter; and minimal regulatory elements) bracketed by lTRs, is also transfected. These packaging plasmids are typically ected into 293 cells, a human cell line that constitutively expresses the ing required Ad helper genes, ElA and ElB. This leads to ication and ing of the AAV vector ng the gene of st.

Multiple serotypes of AAV, including 12 human serotypes and more than 100 serotypes from nonhuman primates have now been identified. Howarth et al. The AAV vectors of the present invention may comprise capsid sequences d from AAVs of any known serotype. As used , a “known serotype” encompasses capsid mutants that can be produced using methods known in the art. Such methods, include, for example, genetic manipulation of the viral capsid sequence, domain swapping of d es of the capsid regions of different serotypes, and generation of AAV chimeras using techniques such as marker rescue. See Bowles et al. Marker rescue of associated virus (AAV) capsid mutants: A novel approach for chimeric AAV production. Journal of Virology, 77(1): 423—432 (2003), as well as references cited therein. Moreover, the AAV vectors of the present invention may comprise ITRs derived from AAVs of any known serotype. Preferentially, the ITRs are derived from one of the human serotypes AAVl—AAV12. In some embodiments of the present invention, a pseudotyping approach is employed, wherein the genome of one ITR serotype is packaged into a different serotype capsid.

Preferentially, the capsid sequences employed in the present invention are derived from one of the human pes AAVl—AAVlZ. Recombinant AAV vectors containing an AAVS serotype capsid ce have been demonstrated to target retinal cells in vivo. See, for example, Komaromy et al. Therefore, in preferred embodiments of the t invention, the serotype of the capsid sequence of the AAV vector is AAVS. In other embodiments, the pe of the capsid sequence of the AAV vector is AAVl, AAV2, AAV3, AAV4, AAV6, AAV7, AAV8, AAV9, AAVlO, AAVl l, or AAV12. Even when the serotype of the capsid sequence does not naturally target retinal cells, other methods of specific tissue targeting may be employed. See Howarth et al.

For example, recombinant AAV vectors can be ly targeted by genetic manipulation of the viral capsid sequence, particularly in the looped out region of the AAV three— dimensional structure, or by domain ng of exposed surfaces of the capsid regions of different serotypes, or by generation of AAV chimeras using techniques such as marker rescue. See Bowles et al. Marker rescue of adeno—associated virus (AAV) capsid mutants: A novel approach for ic AAV production. Journal of Virology, 77(1): 423—432 (2003), as well as references cited therein.

One possible protocol for the production, purification, and characterization of recombinant AAV (rAAV) vectors is provided in Choi et al. Generally, the following steps are involved: design a transgene expression cassette, design a capsid sequence for targeting a specific receptor, te adenovirus—free rAAV vectors, purify and titer.

These steps are summarized below and described in detail in Choi et al.

The ene expression cassette may be a single—stranded AAV (ssAAV) vector or a “dimeric” or self—complementary AAV (scAAV) vector that is packaged as a pseudo—double—stranded transgene. Choi et al.; Heilbronn; Howarth. Using a traditional ssAAV vector generally results in a slow onset of gene expression (from days to weeks until a plateau of transgene expression is reached) due to the required conversion of single—stranded AAV DNA into double—stranded DNA. In contrast, scAAV vectors show an onset of gene expression within hours that plateaus within days after transduction of quiescent cells. Heilbronn. However, the packaging capacity of scAAV vectors is approximately half that of ional ssAAV s. Choi et al.

Alternatively, the transgene expression te may be split between two AAV vectors, which allows delivery of a longer construct. See e.g., Daya et al. A ssAAV vector can be constructed by digesting an riate plasmid (such as, for example, a plasmid containing the hCNGB3 gene) with restriction endonucleases to remove the rep and cap fragments, and gel purifying the plasmid backbone containing the AAth—ITRs. Choi et al. Subsequently, the desired transgene expression cassette can be inserted between the appropriate restriction sites to construct the single—stranded rAAV vector plasmid. A scAAV vector can be constructed as described in Choi et al.

Then, a large—scale d ation (at least 1 mg) of the rAAV vector and the suitable AAV helper plasmid and pXX6 Ad helper plasmid can be purified by double CsCl gradient onation. Choi et al. A suitable AAV helper plasmid may be selected from the pXR series, pXRl—pXR5, which respectively permit cross—packaging of AAV2 ITR genomes into capsids of AAV serotypes l to 5. The riate capsid may be chosen based on the efficiency of the capsid’s targeting of the cells of interest.

For example, in a preferred ment of the present invention, the serotype of the capsid sequence of the rAAV vector is AAV5, because this type of capsid is known to effectively target retinal cells. Known methods of varying genome (i.e., transgene expression cassette) length and AAV capsids may be employed to improve expression and/or gene transfer to specific cell types (e.g., retinal cone cells). See, e.g., Yang GS, Virus—mediated transduction of murine retina with adeno—associated virus: Effects of viral capsid and genome size. Journal of gy, 76(15): 7651—7660.

Next, 293 cells are transfected with pXX6 helper plasmid, rAAV vector plasmid, and AAV helper plasmid. Choi et al. Subsequently the fractionated cell lysates are subjected to a multistep process of rAAV purification, followed by either CsCl nt purification or heparin sepharose column purification. The production and quantitation of rAAV virions may be determined using a dot—blot assay. In vitro transduction of rAAV in cell culture can be used to verify the infectivity of the virus and functionality of the sion cassette.

In on to the methods described in Choi et al, various other transfection methods for production of AAV may be used in the context of the present invention.

For e, transient ection methods are available, including s that rely on a calcium phosphate precipitation ol.

In addition to the laboratory— scale methods for producing rAAV vectors, the present ion may utilize techniques known in the art for bioreactor— scale manufacturing of AAV vectors, including, for example, Heilbronn; Clement, N. et al. —26- Large—scale adeno—associated viral vector production using a herpesvirus—based system enables manufacturing for clinical studies. Human Gene Therapy, 20: 796—606.

The present ion is further illustrated by the following examples, which should not be construed as further limiting. The contents of all figures and all nces, patents and published patent applications cited throughout this application, as well as the Figures, are expressly incorporated herein by reference in their entirety.

Examples EXAMPLE 1: Creation and Testing of Shorter Versions of the PR2.1 Promoter Materials and Methods Figure 2 shows a schematic drawing of the proviral plasmid containing AAV terminal repeats (TR), the PR2.l promoter and the hCMGB3 transgene. The PR2.l promoter was ned by making truncations starting from the 5’—end of PR2.l. The 500 bp core promoter and the 600 bp locus l region (LCR) of PR2.l were left intact. Three shortened versions of the PR2.l promoter were created: PRl.7, PRl.5, and PRl.l. PRl.7, PRl.5, and PRl.l were created by truncating PR2.l at the 5’—end by approximately 300 bp, 500 bp, and 1,100 bp, respectively.

SEQ ID NO: 1 corresponds to PRl.l promoter SEQ ID NO: 2 corresponds to PRl.5 promoter SEQ ID NO: 3 ponds to PRl.7 promoter SEQ ID NO: 4 corresponds to PR2.l promoter A CMV enhancer was added to the 5’ end of the PRl.l to create a hybrid promoter. al plasmids that contained each of these ers were created, as shown in Figure 3. These proviral plasmids (p) contained AAV terminal repeats (TR), a synthesized promoter (PR2. l—syn) or truncations thereof, with or t a CMV enhancer (CMVenh), and a green fluorescent protein (GFP) ene. The ing four proviral plasmids were constructed and sequenced: ( 1) pTR—PR2.1syn—GFP (2) pTR-PR1.8-GFP (3) pTR-PR1.6-GFP (4) pTR—CMVenh—PR1.1—GFP.

To construct pTR—PR2.1syn—GFP, a parental plasmid pTR—CMVenh—hGFP was first constructed from pTR—CBA—hRSl by replacing the CBA and hRSl sequences with hGFP sequences. The human GFP (hGFP) DNA sequence was PCR amplified from the source with ucleotide primers with endonuclease restriction sites at both ends (Not I and BspHI), ed with Not I /BspHI, and joined into pTR—CBA—hRSl plasmid that had been digested with NotI/NcoI to remove all uncessary DNA sequences including the chicken beta actin promoter and the hRSl (but not the CMV enhancer). The resulting plasmid pTR—CMVenh—hGFP contains the CMV enhancer, the hGFP open reading frame (ORF), and the SV40 poly (A) sequence flanked by AAV2 ITRs. The PR2.1 DNA sequence was synthesized according to the DNA sequence 5’ of the human red cone opsin (Wang Y. et al., A locus control region adjacent to the human red and green visual pigment genes, Neuron, vol 9, pp429—440, 1992). The synthesized PR2.1 was composed of bases spanning —4564 to —3009 joined to bases —496 to 0 and contained a LCR essential for expression of both the L and M opsin genes in humans (Komaromy AM et al., ing gene sion to cones with human cone opsin promoters in inant AAV, Gene Therapy, vol 15, pp1049—1055, 2008). In addition, a 97 base pair SV40 splice donor/splice acceptor (SD/SA) was attached to the end of PR2.1 promoter. sized PR2.1 including the SD/SA sequence was inserted into the p]206 cloning vector to te PR2.1syn. The PR2.1syn DNA sequence, including the SV40 SD/SA sequence, was ed from pJ206—PR2.1syn by HindIII/Acc65l digestion and inserted into pTR—CMVenh—hGFP that had been digested with I/Acc65I to remove the unnecessary CMV enhancer sequence to generate the plasmid pTR—PR2.1syn—hGFP.

To construct plasmids with shorter versions of the PR2.1 promoter, the PR2.1 sequence with truncation of 300 bp, 500 bp or 1,100 bp from the 5’ end of PR2.1 were PCR amplified from pJ206—PR2.1syn. Four oligonucleotide primers were designed: 1) PR right-Hind: 5’- GATTTAAGCTTGCGGCCGCGGGTACAATTCCGCAGCTTTTAGAG—3’ ; —28- 2) PRl . l Left-Hind: 5’ -CTGCAAGCTTGTGGGACCACAAATCAG—3’; 3) PRl.5 Left-Acc65I: 5’- TACCAGCCATCGGCTGTTAG—3’; and 4) PR1.7 left-Acc65I: 5’-GTGGGTACCGGAGGCTGAGGGGTG-3’. Primer PR right- Hind was paired with the other three primers to PCR amplify PRl.l, PRl.5, and PRl.7 respectively. Pfu Ultra HS polymerase mix was used with a thermal cycle of 95 °C for min, and then 35 cycles of 94 °C for l min, 58 °C for 45 sec, and 72 °C for 2 min.

PRl.l was amplified from pJ206—PR2.lsyn using the primer set of PR right—Hind and PRl . l—left—Hind. The amplified DNA was digested with HindIII and inserted into pTR—CMVenh—hGFP that had been digested with HindIII to te plasmid pTR-CMVenh-PRl . l-hGFP.

PRl.5 was amplified from pJ206—PR2.lsyn using the primer set of PR right—Hind and PRl .5—left—Acc65I. The amplified DNAwas digested with HindIII/Acc65l, and inserted into pTR—CMVenh—hGFP that had been ed with I/Acc65l to generate plasmid pTR—PRl .5—hGFP PRl.7 was amplified from pJ206—PR2.lsyn using the primer set of PR right—Hind and PRl .7—left—Acc65l. The amplified DNAwas digested with I/Acc65l, and inserted into pTR—CMVenh—hGFP that had been digested with HindIII/Acc65l to generate plasmid pTR—PRl .7—hGFP.

The DNA sequence of the expression cassette, including the promoter and hGFP, were confirmed by DNA sequencing, and the location of TRs was confirmed by Smal ction mapping.

To examine if the PR2.l promoter is functional for RNA transcription and subesequent n expression, a human retinal pigment epithelia (RPE) cell line, APRE—l9, and human embryonic kidney HEK293 cells were seeded in 6—well plates (5 x105 well) and then transfected with 1 ug of DNA from each of six plasmids: pTR— -PRl . l-GFP, pTR-PRl .5-GFP, pTR-PRl .7-GFP, pTR-PR2. l syn-GFP, pTR- PR2. l—GFP ol), or pTR—smCBA—GFP (positive control). Transfected cells were incubated at 37°C, 5% CO2 incubator for 4 days. During the period of incubation, transfected cells were examined by fluoresecence microscopy for GFP expression.

Results DNA sequencing and restriction mapping of all four plasmids confirmed that the sequence and the TRs of these proviral plasmids are correct.

In vitro analysis using ARPE— l9 and HEK293 cells found that r of these cell lines supported functionality of the PR2.l promoter. At 24 h post transfection, strong GFP—expression was observed in cells ected with DNA from CBA— GFP (positive control). At 48 h post transfection, weak GFP expression was observed in cells transfected with DNA from pTR—CMVenh—PRl.l—GFP. No GFP—expressing cells were observed in all other wells, i.e. those transfected with DNA from pTR—PRl.5—GFP, pTR—PRl.7—GFP, pTR—PR2. FP, or pTR—PR2. l—GFP. Plasmid 2. l—GFP contains the ength PR2.l promoter that is known to be onal for RNA transcription and subesequent GFP expression in vivo (Komaromy AM et al., Targeting gene expression to cones with human cone opsin promoters in recombinant AAV, Gene Therapy, vol 15, pplO49—lO55, 2008). Therefore these results indicate that the ARPE— 19 cell line does not support PR2.l promotor, neither any other shorter versions of PR2.l promoter. Weak sion of GFP from pTR—CMVenh—PRl . l—GFP transfected cells is most likely due to the CMV enhancer, which greatly elevates the th of the PRl.l promoter.

Further studies were d out to te the efficiency and specificity of PRl.l, PRl.5 PRl.7 and PR2.l to target cones in mice, using rAAV vectors expressing green fluorescent protein (GFP).

The constructs are packaged in a rAAV capsid and tested in vivo in a mouse model. As shown in Figures 5 and 6, four rAAV vectors, i.e. rAAV5—CMVenh—PRl.l— GFP, rAAV5—PRl.5—GFP, rAAV5—PRl.7—GFP, and rAAV5—PR2.l—GFP, are produced by a standard plasmid transfection method. The rAAV vectors that have been packaged in transfected cells are harvested by cell lysis and then purified by iodixanol (IDX) gradient followed by Q Sepharose HP column tography, and formulated in Alcon BSS solution. Normal mice are then injected by subretinal injection (1 uL) in both eyes (5 mice per vector). Six weeks post injection, mice are sacrificed, eyes enucleated and retinal sections prepared. Slides are stained with DAPI to identify nuclei and immunostained for GFP and for PNA (a marker for cone photoreceptors). The results are shown in Figures 5 and 6. GFP protein expression was detected in photoreceptors (cones and rods) of eyes received rAAV5—GFP vectors containing one of the four promoters, i.e. PRl.l, PRl.5, PRl.7, or PR2.l. In which, PRl.5 is a relatively weaker promoter, and PRl.l is a strong promoter but has off target GFP expression in RPE cells. Overall, PRl.7 is able to the PR2.l promoter in terms of strength (both score +++ in GFP sion level in cones) and cell type specificity (target to cones and also rods, but not RPE cells).

EXAMPLE 2: Evaluation in non-human primates Further studies were carried out to evaluate three cone— specific promoters and three AAV capsid serotypes by comparing their efficiency and specificity to target L, M and S cones in nonhuman primates (NHP), using rAAV s expressing green fluorescent protein (GFP). In the first study, six cynomolgus macaques received ral subretinal injections of AAV2tYF—GFP containing a PRl.7, CSP, or PR2.l promoter. Each eye received two injections of 0.1 mL of AAV vector at a concentration of 5 x1011 vg/mL (two 0.05 mL blebs/eye, l x 1011 vg/eye). Twelve weeks post treatment, retinal tissue was ed for quantitative reverse riptase PCR (qRT— PCR) and immunohistochemistry. The vector with the PRl .7 promoter was found to result in robust and specific targeting of GFP—reporter gene expression (Grade 3) in all three types of cones in the subretinal bleb areas in all NHP eyes. Figure 7 shows the results of in—life fundus autofluorescence g (FAF) to detect the presence of fluorophores (GFP) in the eye. Variable staining of GFP (Grades 0, l or 2) was seen in the subretinal bleb areas in the PR2.l promoter group and no GFP labeling was present in any of the eyes receiving the CSP promoter group (Grade 0) (Figure 8, Table 1, below). Table l is a summary of the herein described Immunohistochemistry Grading in er Selection Study. In Table l, GFP expression was graded as 0 (no ng), 1 (mild staining), 2 (moderate staining) and 3 (intense staining).

Table 1 Eye Promoter R B1 R B2 Mea Group GFP+R GFP+ G1 G2 n Mean G B |00253 OS None na na 0 0 0 0 na na |M080058 None na na 0 0 0 na na |M083748 None na na 0 0 0 na na |08050 OS AAV2tYF-CSP-GFP 0 0 0 0 0 0 no no |08051 OD AAV2tYF-CSP-GFP 0 0 0 0 0 no no |08053 OD AAV2tYF-CSP-GFP 0 0 0 0 0 no no |08054 OS AAV2tYF-CSP-GFP 0 0 0 0 0 no no |08053 OS AAV2tYF-PR2.1- 1 1 O O 0.5 1.4 yes no |08050 OD F-PR2.1- 1 2 1 1 1.25 yes yes |08052 OD AAV2tYF-PR2.1- 2 2 1 1 1.5 yes no IO8049 OS AAV2tYF-PR2.1- 3 2 2 2 2.25 yes yes |08049 OD AAV2tYF-PR1.7- 3 3 3 3 3 3 yes yes |08051 OS AAV2tYF-PR1.7- 3 3 3 3 3 yes yes |08052 OS AAV2tYF-PR1.7- 3 3 3 3 3 yes yes |08054 OD AAV2tYF-PR1.7- 3 3 3 3 3 yes yes Taken er, the results of these experiments show that the strength and specificity of shortened PR1.7 is comparable to that of PR2.l in mice. It was found that the PR1.7 promoter directed the highest level of expression ni reg/ green and blue cones.

The CNGB3 native promoter has been identified to be a strong RPE—specific promoter in mice. lents Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the invention bed herein. Such equivalents are intended to be encompassed by the following claims.

Claims (35)

1. A nucleic acid comprising a portion of the cone cell specific promoter PR2.1, consisting of the nucleic acid sequence of SEQ ID NO: 3.

2. The c acid of claim 1, wherein the promoter is capable of promoting CNGB3 expression in S-cone cells, M-cone cells, and L-cone cells.

3. The c acid of claim 1, wherein the promoter is capable of promoting CNGA3 expression in S-cone cells, M-cone cells, and L-cone cells.

4. The nucleic acid of claim 1, wherein the promoter is capable of promoting GNAT2 expression in S-cone cells, M-cone cells, and L-cone cells.

5. A recombinant adeno-associated (rAAV) expression vector comprising a target nucleic acid sequence operably linked to the nucleic acid of claim 1.

6. The expression vector of claim 5, wherein rAAV is serotype 1.

7. The expression vector of claim 5, wherein rAAV is serotype 2.

8. The expression vector of claim 5, wherein rAAV is serotype 5.

9. The expression vector of claim 5, wherein rAAV is comprised within an AAV virion.

10. The expression vector of claim 5, wherein the target nucleic acid sequence encodes a cyclic nucleotide-gated channel subunit B (CNGB3) polypeptide.

11. The expression vector of claim 10, n the CNGB3 is mouse CNGB3.

12. The expression vector of claim 10, wherein the CNGB3 is rat CNGB3.

13. The expression vector of claim 10, n the CNGB3 is human CNGB3.

14. The expression vector of claim 5, wherein the target c acid sequence encodes a cyclic tide-gated channel subunit A (CNGA3) polypeptide.

15. The expression vector of claim 14, n the CNGA3 is mouse CNGA3.

16. The expression vector of claim 14, wherein the CNGA3 is rat CNGA3.

17. The expression vector of claim 14, n the CNGA3 is human CNGA3.

18. The expression vector of claim 5, n the target c acid sequence encodes a Guanine nucleotide-binding protein G(t) t alpha-2 (GNAT-2) polypeptide.

19. The expression vector of claim 18, wherein the GNAT-2 is mouse GNAT-2.

20. The sion vector of claim 18, wherein the GNAT-2 is rat GNAT-2.

21. The sion vector of claim 18, wherein the GNAT-2 is human GNAT-2.

22. An isolated ian cell comprising the expression vector of any one of claims 5-

23. A transgene expression cassette comprising: (a) the nucleic acid of claim 1; (b) a nucleic acid selected from the group consisting of a CNGB3 nucleic acid, a CNGA3 nucleic acid, and a GNAT2 nucleic acid; and (c) minimal regulatory elements.

24. A nucleic acid vector comprising the expression cassette of claim 23.

25. The vector of claim 24, wherein the vector is an adeno-associated viral (AAV) vector.

26. A kit comprising the expression vector of any one of claims 5-21 and instructions for use.

27. Use of the expression vector of any one of claims 4-21, in the manufacture of a medicament for treating an eye disease.

28. Use of the expression vector of any one of claims 4-21, in the manufacture of a medicament for promoting CNGA3 or CNGB3 expression in the cone cells of a subject.

29. The use of claim 27, wherein the eye disease is associated with a genetic mutation, substitution, or deletion that affects retinal cone cells.

30. The use of claim 27, wherein the eye disease affects the retinal pigment epithelium.

31. The use of claim 27, wherein the eye disease is achromatopsia.

32. The use of claim 27 or 28, wherein the expression vector is capable of promoting CNGB3 expression in S-cone cells, M-cone cells, and L-cone cells.

33. The use of claim 27 or 28, wherein the expression vector is e of ing CNGA3 expression in S-cone cells, M-cone cells, and L-cone cells.

34. The use of claim 27 or 28, wherein the expression vector is capable of promoting GNAT-2 expression in S-cone cells, M-cone cells, and L-cone cells.

35. The use of claim 27 or 28, wherein the medicament is formulated for subretinal administration.