Journal of Stem Cell Research & Therapy

Tyrosine-mutant Aav8 efficiency and the effect on mice lung physiology

3^rd International Conference and Exhibition on Cell & Gene Therapy

October 27-29, 2014 Embassy Suites Las Vegas, USA

Sabrina V Martini, Adriana L Silva, Debora Ferreira, Karina Gomes, Felipe Ornellas, Miqu?ias Lopes Pacheco, Emilia Zin, Hilda Petrs-Silva, Patricia R M Rocco and Marcelo M Morales

Accepted Abstracts: J Stem Cell Res Ther

Abstract:

Background/Aims: Vectors derived from adeno-associated viruses (AAVs) have become important gene delivery tools for the treatment of many inherited pulmonary diseases, such as cystic fibrosis and α1-antitrypsin deficiency. Recently, it was shown that phosphorylation of surface-exposed tyrosine residues from AAV2 capsid targets the viral particles for ubiquitination and proteasome-mediated degradation, and mutations of these tyrosine residues lead to highly efficient vector transduction in vitro and in vivo. In this study we evaluated the pulmonary transduction characteristics of AAV8 vectors containing point mutations in surface-exposed capsid tyrosine residues. Methods: Forty-eight male C57BL/6 mice (20-25 g) were randomly assigned into two groups. In control (CTRL) animals, saline was intratracheally (it) instillated (50 μl), whereas the virus group received (it) AAV8s vectors containing the DNA sequence of enhanced green fluorescence protein (eGFP): Wild-type AAV8 (WT-AAV8, 1010 genome copies, vg), mutant Y733F AAV8 (M-AAV8, 1010 vg). Four weeks after the instillation, lung morphometry, mechanical parameters, vector transduction and the inflammatory cytokines and growth factor expression were analyzed. Results: Vectors-containing single-point mutations of capsid surface tyrosines in serotypes AAV8 displayed significantly increased transduction efficiency in the lung compared with their wild-type counterparts. No significant differences in lung mechanics, histologic and morphometric parameters were observed. There was no evidence of inflammatory response in any group. Conclusion: Delivery of tyrosine mutant AAV8 vector to mice lung allows transgene (eGFP) expression, suggesting efficient transduction. AAV8 vectors did not induce an inflammatory process, mechanical or morphometric changes in the lungs. Such novel vector may be useful in developing valuable new therapeutic strategies for the treatment of many pulmonary genetic diseases.