Adeno‐associated Viral Vectors in Gene Therapy


Recombinant vectors based on a nonpathogenic human parvovirus, the adeno‐associated virus (AAV), have gained attention as a potentially safe and useful alternative to the more commonly used retroviral and adenoviral vectors. The past decade has witnessed the use of AAV vectors in the potential gene therapy of an ever‐increasing number of human diseases. The safety of AAV vectors in 165 Phase I/II and 1 Phase III clinical trials in humans to date and clinical efficacy in at least 8 human diseases have now been well documented. The availability of a vast repertoire of AAV serotype vectors, both naturally occurring and genetically engineered, and the availability of promising results with animal models of human diseases provide further impetus to the optimism that their use in the potential gene therapy of a wide variety of human diseases, both genetic and acquired, will continue in the foreseeable future.

Key Concepts

  • The first‐generation recombinant AAV vectors have shown efficacy in a number of Phase I/II clinical trials targeting various human diseases.
  • The host immune response to AAV vectors, especially at high doses, remains a challenging problem.
  • The presence of preexisting antibodies to AAV is also a challenge as a significant proportion of the human population is sero‐positive for one or more of the AAV serotypes.
  • The next‐generation AAV vectors have been developed that promise to circumvent most, if not all, of the problems associated with the first generation of AAV vectors.
  • The next generation of AAV vectors, which are more efficacious at lower doses, are likely to prove safe and effective in the potential gene therapy of a wide variety of human diseases in the not‐too‐distant future.

Keywords: AAV; viral vectors; gene expression; gene therapy; human diseases

Figure 1. Schematic structures of a conventional, single‐stranded (ss) and a double‐stranded (ds), self‐complementary AAV vector. The approximate packaging capacity of each vector is also indicated.


Acland GM, Aguirre GD, Ray J, et al. (2001) Gene therapy restores vision in a canine model of childhood blindness. Nature Genetics 28: 92–95.

Bainbridge JW, Smith AJ, Barker SS (2008) Effect of gene therapy on visual function in Leber's congenital amaurosis. New England Journal of Medicine 358: 2231–2239.

Beaty RM, Jackson M, Peterson D, et al. (2001) Delivery of glucose‐6‐phosphatase in a canine model for glycogen storage disease, type Ia, with adeno‐associated virus (AAV) vectors. Gene Therapy 9: 1015–1022.

Carter BJ (2005) Adeno‐associated virus vectors in clinical trials. Human Gene Therapy 16: 541–550.

Chen Y, Luk KD, Cheung KM, et al. (2003) Gene therapy for new bone formation using adeno‐associated viral bone morphogenetic protein‐2 vectors. Gene Therapy 10: 1345–1353.

Chiorini JA, Yang L, Liu Y, Safer B and Kotin RM (1997) Cloning of adeno‐associated virus type 4 (AAV4) and generation of recombinant AAV4 particles. Journal of Virology 71: 6823–6833.

Chiorini JA, Kim F, Yang L and Kotin RM (1999) Cloning and characterization of adeno‐associated virus type 5. Journal of Virology 73: 1309–1319.

Cideciyan AV, Aleman TS, Boye SL (2008) Human gene therapy for RPE65 isomerase deficiency activates the retinoid cycle of vision but with slow rod kinetics. Proceedings of the National Academy of Sciences of the United States of America 105: 15112–15117.

Crystal RG, Sondhi D, Hackett NR, et al. (2004) Clinical protocol. Administration of a replication‐deficient adeno‐associated virus gene transfer vector expressing the human CLN2 cDNA to the brain of children with late infantile neuronal ceroid lipofuscinosis. Human Gene Therapy 15: 1131–1154.

Deodato B, Arsic N, Zentilin L, et al. (2002) Recombinant AAV vector encoding human VEGF165 enhances wound healing. Gene Therapy 9: 777–785.

Dumon KR, Ishii H, Vecchione A, et al. (2001) Fragile histidine triad expression delays tumor development and induces apoptosis in human pancreatic cancer. Cancer Research 61: 4827–4836.

During MJ, Samulski RJ, Elsworth JD, et al. (1998) In vivo expression of therapeutic human genes for dopamine production in the caudates of MPTP‐treated monkeys using an AAV vector. Gene Therapy 5: 820–827.

During MJ, Symes CW, Lawlor PA, et al. (2000) An oral vaccine against NMDAR1 with efficacy in experimental stroke and epilepsy. Science 287: 1453–1460.

During MJ, Kaplitt MG, Stern MB and Eidelberg D (2001) Subthalamic GAD gene transfer in Parkinson' disease patients who are candidates for deep brain stimulation. Human Gene Therapy 12: 1589–1591.

Eaton MJ, Blits B, Ruitenberg MJ, Verhaagen J and Oudega M (2002) Amelioration of chronic neuropathic pain after partial nerve injury by adeno‐associated viral (AAV) vector‐mediated over‐expression of BDNF in the rat spinal cord. Gene Therapy 9: 1387–1395.

Ferrarini M, Arsic N, Recchia FA, et al. (2006) Adeno‐associated virus‐mediated transduction of VEGF165 improves cardiac tissue viability and functional recovery after permanent coronary occlusion in conscious dogs. Circulation Research 98: 954–961.

Feuer WJ, Schiffman JC, Davis JL, et al. (2016) Gene therapy for Leber hereditary optic neuropathy: initial results. Ophthalmology 123: 558–570.

Flotte T, Carter B, Conrad C, et al. (1996) A phase I study of an adeno‐associated virus‐CFTR gene vector in adult CF patients with mild lung disease. Human Gene Therapy 7: 1145–1159.

Flotte TR, Brantly ML, Spencer LT, et al. (2004) Phase I trial of intramuscular injection of a recombinant adeno‐associated virus alpha 1‐antitrypsin (rAAV2‐CB‐hAAT) gene vector to AAT‐deficient adults. Human Gene Therapy 15: 93–128.

Fraites TJ Jr, Schleissing MR, Shanely RA, et al. (2002) Correction of the enzymatic and functional deficits in a model of Pompe disease using adeno‐associated virus vectors. Molecular Therapy 5: 571–578.

Frisella WA, O'Connor LH, Vogler CA, et al. (2001) Intracranial injection of recombinant adeno‐associated virus improves cognitive function in a murine model of mucopolysaccharidosis type VII. Molecular Therapy 3: 351–358.

Gao G, Alvira MR, Wang L, et al. (2002) Novel adeno‐associated viruses from rhesus monkeys as vectors for human gene therapy. Proceedings of the National Academy of Sciences of the United States of America 99: 11854–11859.

Gao G, Vandenberghe LH, Alvira MR, et al. (2004) Clades of adeno‐associated viruses are widely disseminated in human tissues. Journal of Virology 78: 6381–6388.

Gaudet D, Méthot J, Déry S (2013) Efficacy and long-term safety of alipogene tiparvovec (AAV1-LPLS447X) gene therapy for lipoprotein lipase deficiency: an open-label trial. Gene Therapy 20: 361–369.

George LA, Sullivan SK, Giermasz JEJ, et al. (2017) Hemophilia B gene therapy with a high‐specific‐activity factor IX variant. New England Journal of Medicine 377: 2215–2227.

Griffey MA, Wozniak D, Wong M, et al. (2006) CNS‐directed AAV2‐mediated gene therapy ameliorates functional deficits in a murine model of infantile neuronal ceroid lipofuscinosis. Molecular Therapy 13: 538–547.

Guy J, Feuer WJ, Davis JL, et al. (2017) Gene therapy for Leber hereditary optic neuropathy: low‐ and medium‐dose visual results. Ophthalmology 124: 1621–1634.

Haberman RP, Samulski RJ, McCown TJ, et al. (2003) Attenuation of seizures and neuronal death by adeno‐associated virus vector galanin expression and secretion. Nature Medicine 9: 1076–1080.

Hauswirth WW, Aleman TS, Kaushal S (2008) Treatment of Leber congenital amaurosis due to RPE65 mutations by ocular subretinal injection of adeno-associated virus gene vector: short-term results of a phase I trial. Human Gene Therapy 19: 979–990.

Hengge UR and Mirmohammadsadegh A (2000) Adeno‐associated virus expresses transgenes in hair follicles and epidermis. Molecular Therapy 2: 188–194.

Hoshijima M, Ikeda Y, Iwanaga Y, et al. (2002) Chronic suppression of heart‐failure progression by a pseudophosphorylated mutant of phospholamban via in vivo cardiac rAAV gene delivery. Nature Medicine 8: 864–871.

Hwu WL, Muramatsu S, Tseng SH (2012) Gene therapy for aromatic L-amino acid decarboxylase deficiency. Science Translational Medicine 4: 134ra61.

Janson C, McPhee S, Bilaniuk L, et al. (2002) Clinical protocol. Gene therapy of Canavan disease: AAV‐2 vector for neurosurgical delivery of aspartoacylase gene (ASPA) to the human brain. Human Gene Therapy 13: 1391–1412.

Kaplitt MG, Leone P, Samulski RJ, et al. (1994) Long‐term gene expression and phenotypic correction using adeno‐associated virus vectors in the mammalian brain. Nature Genetics 8: 148–154.

Kaplitt MG, Xiao X, Samulski RJ, et al. (1996) Long‐term gene transfer in porcine myocardium after coronary infusion of an adeno‐associated virus vector. Annals of Thoracic Surgery 62: 1669–1676.

Kay MA, Manno CS, Ragni MV, et al. (2000) Evidence for gene transfer and expression of factor IX in haemophilia B patients treated with an AAV vector. Nature Genetics 24: 257–261.

Kessler PD, Podsakoff GM, Chen X, et al. (1996) Gene delivery to skeletal muscle results in sustained expression and systemic delivery of a therapeutic protein. Proceedings of the National Academy of Sciences of the United States of America 93: 14082–14087.

Kunke D, Grimm D, Denger S, et al. (2000) Preclinical study on gene therapy of cervical carcinoma using adeno‐associated virus vectors. Cancer Gene Therapy 7: 766–777.

Lalani AS, Chang B, Lin J, et al. (2004) Anti‐tumor efficacy of human angiostatin using liver‐mediated adeno‐associated virus gene therapy. Molecular Therapy 9: 56–66.

Lalwani AK, Walsh BJ, Reilly PG, Muzyczka N and Mhatre AN (1996) Development of in vivo gene therapy for hearing disorders: introduction of adeno‐associated virus into the cochlea of the guinea pig. Gene Therapy 3: 588–592.

Lee HC, Kim S‐J, Kim K‐S, Shin H‐C and Yoon J‐W (2000) Remission in models of type 1 diabetes by gene therapy using a single‐chain insulin analogue. Nature 408: 483–488.

Leone P, Janson CG, Bilaniuk L, et al. (2000) Aspartocyclase gene transfer to the mammalian central nervous system with therapeutic implications for Canavan disease. Annals of Neurology 48: 27–38.

Li J, Dressman D, Tsao YP, et al. (1999) Recombinant AAV vector‐mediated sarcoglycan gene transfer in a hamster model for limb girdle muscular dystrophy. Gene Therapy 6: 74–82.

Li S, Ling C, Zhong L, et al. (2015) Efficient and targeted transduction of nonhuman primate liver with systemically delivered optimized AAV3B vectors. Molecular Therapy 23: 1867–1876.

Ma H, Guo P, Li J, et al. (2002) Suppression of intracranial human glioma growth after intramuscular administration of an adeno‐associated viral vector expressing angiostatin. Cancer Research 62: 756–763.

Ma H, Xu R, Cheng H, et al. (2003) Gene transfer into human keloid tissue with adeno‐associated virus vector. Journal of Trauma 54: 569–573.

MacLaren RE, Groppe M, Baranard AR (2014) Retinal gene therapy in patients with choroideremia: initial findings from a phase 1/2 clinical trial. Lancet 383: 1129–1137.

Maguire AM, Simonelli F, Pierce EA (2008) Safety and efficacy of gene transfer for Leber's congenital amaurosis. New England Journal of Medicine 358: 2240–2248.

McBride JL, During MJ, Wuu J, et al. (2003) Structural and functional neuroprotection in a rat model of Huntington's disease by viral gene transfer of GDNF. Experimental Neurology 181: 213–223.

Mease PJ (2003) A phase I dose escalation study of intra‐articular administration of tgAAC94, a recombinant adeno‐associated virus containing the TNFR:Fc fusion gene, in rheumatoid arthritis. NIH Recombinant DNA advisory Committee, Minutes of Meeting of September, 2003. Available at

Mendell JR, Al‐Zaidy R, Shell R, et al. (2017) Single‐dose gene replacement therapy for spinal muscular atrophy. New England Journal of Medicine 377: 1713–1722.

Mori S, Wang L, Takenchi T and Kanda T (2004) Two novel adeno‐associated viruses from cynomolgus monkey pseudotyping characterization of capsid protein. Virology 330: 375–383.

Muramatsu S, Mizukami H, Young NS and Brown KE (1996) Nucleotide sequencing and generation of an infectious clone of adeno‐associated virus 3. Virology 221: 208–217.

Murphy JE, Zhou S, Giese K, et al. (1997) Long‐term correction of obesity and diabetes in genetically obese mice by a single intramuscular injection of recombinant adeno‐associated virus encoding mouse leptin. Proceedings of the National Academy of Sciences of the United States of America 94: 13921–13926.

Muzyczka N (1992) Use of adeno‐associated virus as a general transduction vector for mammalian cells. Current Topics in Microbiology and Immunology 158: 97–129.

Narfstrom K, Bragadottir R, Redmond TM, et al. (2003) Functional and structural evaluation after AAV.RPE65 gene transfer in the canine model of Leber's congenital amaurosis. Advances in Experimental Medicine and Biology 533: 423–430.

Nathwani AC, Tuddenham EG, Rangarajan S, et al. (2011) Adenovirus‐associated virus vector–mediated gene transfer in hemophilia B. New England Journal of Medicine 365: 2357–2365.

Nathwani AC, Reiss UM, Tuddenham EG, et al. (2014) Long‐term safety and efficacy of factor IX gene therapy in hemophilia B. New England Journal of Medicine 371: 1994–2004.

Pan RY, Xiao X, Chen SL, et al. (1999) Disease‐inducible transgene expression from a recombinant adeno‐associated virus vector in a rat arthritis model. Journal of Virology 73: 3410–3417.

Ponnazhagan S, Mukherjee P, Yoder MC, et al. (1997) Adeno associated virus 2‐mediated gene transfer in vivo: organ‐tropism and expression of transduced sequences in mice. Gene 190: 203–210.

Rangarajan S, Walsh L, Lester W, et al. (2017) AAV5‐Factor VIII gene transfer in severe hemophilia A. New England Journal of Medicine. 377: 2519–2530.

Rehman KK, Wang Z, Bottino R, et al. (2005) Efficient gene delivery to human and rodent islets with double‐stranded (ds) AAV‐based vectors. Gene Therapy 12: 1313–1323.

Ross CJ, Twisk J, Meulenberg JM, et al. (2004) Long‐term correction of murine lipoprotein lipase deficiency with AAV1‐mediated gene transfer of the naturally occurring LPL(S447X) beneficial mutation. Human Gene Therapy 15: 906–919.

Ruitenberg MJ, Blits B, Dijkhuizen PA, et al. (2004) Adeno‐associated viral vector‐mediated gene transfer of brain‐derived neurotrophic factor reverses atrophy of rubrospinal neurons following both acute and chronic spinal cord injury. Neurobiology of Disease 15: 394–406.

Rutledge EA, Halbert CL and Russell DW (1998) Infectious clones and vectors derived from adeno‐associated virus (AAV) serotypes other than AAV type 2. Journal of Virology 72: 309–319.

Sarkar R, Xiao W and Kazazian HH Jr (2003) A single adeno‐associated virus (AAV)‐murine factor VIII vector partially corrects the hemophilia A phenotype. Journal of Thrombosis and Haemostasis 1: 220–226.

Schmidt M, Voutetakis A, Afione S, Zheng C and Chiorini JA (2006) AAV12, isolated from vervet monkey, has unique tropism and biological as well as neutralization properties. Molecular Therapy 13: S288.

Song S, Morgan M, Ellis T, et al. (1998) Sustained secretion of human α‐1‐antitrypsin from murine muscle transduced with adeno‐associated virus vectors. Proceedings of the National Academy of Sciences of the United States of America 95: 14384–14388.

Song L, Kauss MA, Chandra M, et al. (2013a) Optimizing the transduction efficiency of capsid‐modified AAV6 vectors in primary human hematopoietic stem cells in vitro and in a xenograft mouse model in vivo. Cytotherapy 15: 986–998.

Song L, Li X and Jayandharan GR (2013b) High‐efficiency transduction of primary human hematopoietic stem cells and erythroid lineage‐restricted expression by optimized AAV6 serotype vectors in vitro and in a murine xenograft model in vivo. PLoS One 8 (e58757): 2013.

Srivastava A (2016a) Advances and challenges in the use of recombinant adeno‐associated virus vectors for human gene therapy. Cell & Gene Therapy Insights 2: 553–575.

Srivastava A and Carter BJ (2017) AAV infection: protection from cancer. Human Gene Therapy 28: 323–327.

Stedman H, Mendell J, Wilson JM, Finke R and Kleckner A‐L (2000) Phase I clinical trial utilizing gene therapy for limb girdle muscular dystrophy: α‐, β‐, γ‐, or Δ‐sarcoglycan gene delivered with intramuscular instillations of adeno‐associated vectors. Human Gene Therapy 11: 777–790.

Su H, Chang JC, Xu SM and Kan YW (1996) Selective killing of AFP‐positive hepatocellular carcinoma cells by adenoassociated virus transfer of the herpes simplex virus thymidine kinase gene. Human Gene Therapy 7: 463–470.

Tan MQ, Qing KY, Zhou SZ, Yoder MC and Srivastava A (2001) Adeno‐associated virus 2‐mediated transduction and erythroid lineage‐restricted long‐term expression of the human β‐globin gene in hematopoietic cells from homozygous β‐thalassemic mice. Molecular Therapy 3: 940–946.

Tuszynski MH, Thal L, Pay M, et al. (2005) A phase 1 clinical trial of nerve growth factor gene therapy for Alzheimer disease. Nature Medicine 11: 551–555.

Wagner J, Reynolds T, Moran ML, et al. (1998) Efficient and persistent gene transfer of AAV‐CFTR in maxillary sinus. Lancet 351: 1702–1703.

Wang B, Li J and Xiao X (2000) Adeno‐associated virus vector carrying human minidystrophin genes effectively ameliorates muscular dystrophy in mdx mouse model. Proceedings of the National Academy of Sciences of the United States of America 97: 13714–13719.

Wang LJ, Lu YY, Muramatsu S, et al. (2002) Neuroprotective effects of glial cell line‐derived neurotrophic factor mediated by an adeno‐associated virus vector in a transgenic animal model of amyotrophic lateral sclerosis. The Journal of Neuroscience 22: 6920–6928.

Watanabe M, Nasu Y, Kashiwakura Y, et al. (2005) Adeno‐associated virus 2‐mediated intratumoral prostate cancer gene therapy: long‐term maspin expression efficiently suppresses tumor growth. Human Gene Therapy 16: 699–710.

Wei X, Zhao C, Jiang J, et al. (2005) Adrenomedullin gene delivery alleviates hypertension and its secondary injuries of cardiovascular system. Human Gene Therapy 16: 372–380.

Xiao W, Chirmule N, Berta SC, et al. (1999) Gene therapy vectors based on adeno‐associated virus type 1. Journal of Virology 73: 3994–4003.

Xin K‐Q, Urabe M, Yang J, et al. (2001) A novel recombinant adeno‐associated virus vaccine induces a long‐term humoral immune response to human immunodeficiency virus. Human Gene Therapy 12: 1047–1061.

Yasukawa H, Yajima T, Duplain H, et al. (2003) The suppressor of cytokine signaling‐1 (SOCS1) is a novel therapeutic target for enterovirus‐induced cardiac injury. The Journal of Clinical Investigation 111: 469–478.

Yoshioka T, Okada T, Maeda Y, et al. (2004) Adeno‐associated virus vector‐mediated interleukin‐10 gene transfer inhibits atherosclerosis in apolipoprotein E‐deficient mice. Gene Therapy 11: 1772–1779.

Zhang J, Wu X, Qin C, et al. (2003) A novel recombinant adeno‐associated virus vaccine reduces behavioral impairment and beta‐amyloid plaques in a mouse model of Alzheimer's disease. Neurobiology of Disease 14: 365–379.

Further Reading

Asokan A, Schaffer DV and Samulski RJ (2012) The AAV vector toolkit: poised at the clinical crossroads. Molecular Therapy 20: 699–708.

Berns KI and Muzyczka N (2017) AAV: an overview of unanswered questions. Human Gene Therapy 28: 308–313.

Gaj T, Epstein BE and Schaffer DV (2016) Genome engineering using adeno‐associated virus: basic and clinical research applications. Molecular Therapy 24: 458–464.

Grimm D and Zolotukhin S (2015) E pluribus unum: 50 years of research, millions of viruses, and one goal – tailored acceleration of AAV evolution. Molecular Therapy 23: 1819–1831.

Hastie E and Samulski RJ (2015) Adeno‐associated virus at 50: a golden anniversary of discovery, research, and gene therapy success‐a personal perspective. Human Gene Therapy 26: 257–265.

Kotterman MA and Schaffer DV (2014) Engineering adeno‐associated viruses for clinical gene therapy. Nature Reviews Genetics 15: 445–451.

Tse LV, Moller‐Tank S and Asokan A (2015) Strategies to circumvent humoral immunity to adeno‐associated viral vectors. Expert Opinion on Biological Therapy 15: 845–855.

Srivastava A (2016b) In vivo tissue‐tropism of adeno‐associated viral vectors. Current Opinion in Virology 21: 75–80.

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Ling, Chen, Zhong, Li, and Srivastava, Arun(May 2018) Adeno‐associated Viral Vectors in Gene Therapy. In: eLS. John Wiley & Sons Ltd, Chichester. [doi: 10.1002/9780470015902.a0005738.pub3]