AAV cis -regulatory sequences are correlated with ocular toxicity

• DOI: 10.1073/pnas.1821000116
• Publication Date: 2019-03-05T01:26:48Z
• Authors: Wenjun Xiong; David M. Wu; Yunlu Xue; Sean K. Wang; Michelle J. Chung; Xuke Ji; Parimal Rana; Sophia R. Zhao; Shuyi Mai; Constance L. Cepko
• Keywords: 0301 basic medicine; Genetic Vectors; Gene Transfer Techniques; Genetic Therapy; Retinal Pigment Epithelium; Dependovirus; Retina; 3. Good health; Mice, Inbred C57BL; Mice; 03 medical and health sciences; PNAS Plus; Transduction, Genetic; Animals; Photoreceptor Cells; Transgenes; Promoter Regions, Genetic; Vision, Ocular

Adeno-associated viral vectors (AAVs) have become popular for gene therapy, given their many advantages, including reduced inflammatory profile compared with that of other viruses. However, even in areas immune privilege such as the eye, AAV are capable eliciting host-cell responses. To investigate effects responses on several ocular cell types, we tested multiple genome structures and capsid types using subretinal injections mice. Assays morphology, inflammation, physiology were performed. Pathological photoreceptors retinal pigment epithelium (RPE) observed. Müller glia microglia activated, proinflammatory cytokines TNF-α IL-1β up-regulated. There was a strong correlation between cis-regulatory sequences toxicity. AAVs any one three broadly active promoters, or an RPE-specific promoter, toxic, while four different photoreceptor-specific promoters not toxic at highest doses tested. little toxicity transgene, type, preparation method, cellular contaminants within preparation. The effect dose-dependent, RPE being more sensitive than photoreceptors. Our results suggest is associated certain and/or activity damage occurs due to by microglia. By applying multiple, assays toxicity, can be designed so they used safely high dose, potentially providing greater therapeutic efficacy.