Overcoming Genetic and Immunological Barriers to the Use of Adeno-Associated Viral Vectors for Ocular Gene Therapy

Abstract

Gene therapy with adeno-associated viral (AAV) vectors has emerged as a promising treatment option for patients with debilitating genetic disorders. Nonetheless, implementation of AAV gene therapy for many conditions still faces substantial challenges, precluding large-scale clinical translation of these vectors. In this thesis, I explore two of the major barriers limiting the use of AAV gene therapy in patients: 1) genetic heterogeneity in diseases, which complicates the development of targeted therapies, and 2) vector-induced immunity and inflammation, which reduce treatment efficacy and, in some cases, may compromise safety. With collaborators, I design and conduct experimental studies addressing these obstacles in the eye, one of the primary sites of ongoing gene therapy trials. These studies result in several advances for the ocular gene therapy field, including 1) the creation of two novel AAV vectors capable of treating a genetically heterogeneous eye disease in mice, 2) the discovery that expression of AAV vectors in specific cell types correlates with ocular inflammation, 3) the successful mitigation of vector-induced inflammation in mice and pigs by “cloaking” AAV genomes from host immune responses, and 4) the development of a fluorescence in situ hybridization-based method that can visualize and quantify individual AAV genomes in transduced cells. This collection of work may improve the safety and efficacy of AAV vectors for a broad range of vision disorders with the potential to vastly expand the number of patients who benefit from gene therapy.