Developing stimulus-responsive adeno-associated virus vectors for cancer-targeted gene therapy
Evans, Annicka Carter
Doctor of Philosophy
The most significant challenge to current gene therapy trials is ensuring delivery to exclusively diseased sites. Both non-viral and viral vectors have broad natural tropisms that elicit off-target side effects when used as a treatment. Adeno-associated virus (AAV) has recently become the most commonly used vector for gene therapy trials because it offers many advantages: it has low pathogenicity in humans, infects most cell types with great efficiency, and can be genetically altered to improve its therapeutic effect. The rapid advancement of viral engineering techniques combined with these innate abilities of AAV serotypes to transduce cells, opens up the possibility for creating recombinant AAV platforms that can act as particles with targeting capabilities. It has therefore been the focus of my research to both understand the innate stimulus-responsive nature of AAV as well as work to develop a cancer-targeted AAV vector through capsid engineering. The designed cancer-targeting platforms utilize known characteristics of the tumor microenvironment and cancer biology - specifically the upregulation of matrix-metalloproteinases and production of reactive oxygen species. The characterization of these stimulus-responsive designs, in combination with the investigation of wild-type n-terminal extrusion in response to temperature and pH, will greatly enhance our understanding of AAV engineering tolerance, and further expand the targeting strategies for the use of this vector for human gene therapy.