Specific and efficient transduction of cochlear inner hair cells with recombinant adeno-associated virus type 3 vector

Abstract

Recombinant adeno-associated virus (AAV) vectors are of interest for cochlear gene therapy because of their ability to mediate the efficient transfer and long-term stable expression of therapeutic genes in a wide variety of postmitotic tissues with minimal vector-related cytotoxicity. In the present study, seven AAV serotypes (AAV1-5, 7, 8) were used to construct vectors. The expression of EGFP by the chicken beta-actin promoter associated with the cytomegalovirus immediate-early enhancer in cochlear cells showed that each of these serotypes successfully targets distinct cochlear cell types. In contrast to the other serotypes, the AAV3 vector specifically transduced cochlear inner hair cells with high efficiency in vivo, while the AAV1, 2, 5, 7, and 8 vectors also transduced these and other cell types, including spiral ganglion and spiral ligament cells. There was no loss of cochlear function with respect to evoked auditory brain-stem responses over the range of frequencies tested after the injection of AAV vectors. These findings are of value for further molecular studies of cochlear inner hair cells and for gene replacement strategies to correct recessive genetic hearing loss due to monogenic mutations in these cells.

Optogenetic stimulation of the auditory pathway

“…Thus far, viral and nonviral approaches have been reported (53)(54)(55)(56)(57)(58)(59). Here, we focused on using AAVs, which are good candidates, because they were successfully used to transduce murine SGNs (53, 54, 60) and do not compromise hearing (60)(61)(62). We used transuterine virus injections into the left otocyst of 8 to 14 available embryos 11.5 dpc (refs.…”

Serotype-dependent packaging of large genes in adeno-associated viral vectors results in effective gene delivery in mice

“…An advantage of retinal (or cochlear; ref. 33) gene delivery is the target size of the tissue, which is orders of magnitude smaller than that of other organs, such as liver or lung. We and others have previously demonstrated that vectors with AAV5 capsids efficiently transduce RPE and photoreceptors of several species (25,26,34,35) as well as murine cochlear inner hair cells (33), the appropriate targets for gene therapy of rSTGD and USH.…”

“…33) gene delivery is the target size of the tissue, which is orders of magnitude smaller than that of other organs, such as liver or lung. We and others have previously demonstrated that vectors with AAV5 capsids efficiently transduce RPE and photoreceptors of several species (25,26,34,35) as well as murine cochlear inner hair cells (33), the appropriate targets for gene therapy of rSTGD and USH. The possibility of efficiently packaging MYO7A or CEP290 in a single rAAV2/5 vector opens new therapeutic perspectives for USH1B, the most frequent cause of hereditary deafness and blindness in humans (14), and LCA, the most common inherited cause of blindness in infancy.…”

Neurotrophic Factors and Neural Prostheses: Potential Clinical Applications Based Upon Findings in the Auditory System

“…Five main types of vectors, or vehicles, have been used to drive gene expression in the cochlea; adeno-associated virus, adenovirus, herpes simplex virus, vaccinia virus and liposomes, the latter being the only non-viral vector tested [80,81]. Reporter gene expression studies have demonstrated that, amongst other cells and tissues, transgene expression in SGNs and the organ of Corti is commonly obtained [62,[82][83][84][85]. Persistence of transgene expression depends greatly on the mode of delivery and can range from days to months [84,[86][87][88].…”