104. A Novel Deletion in the FVIII B-Domain That Reduces Transgene Size While Preserving FVIII Activity

Abstract

Infection with the Hepatitis C virus (HCV) represents a major world-wide alth problem. RNAi based treatments have been proposed as a new therapeutic modality. We have focused on the expression of short-hairpin RNAs that can elicit an RNAi response against the HCV genome. We have used standard and custom algorithms to saturate regions of HCV sequences across multiple genotypes to locate optimal RNAi targets resulting in the identification of over 30 potential target sequences that will be evaluated for their efficacy. Because HCV does not replicate efficiently in cell culture or animal model systems, we have synthesized two independent HCV replicons, one of which is derived of patient material, which will be used as viral surrogates to quantify the degree of inhibition of viral replication in cells. Strategies which encompass the utilization of single or combinatorial short hairpin sequences are being compared in order to maximize the inhibition of viral replication as well as decrease the probability for the selection of escape mutants. To further this goal, we have designed novel expression cassettes that will lead to the expression (from bona-fide AAV gene therapy vectors) one or more short hairpin RNA sequences in vitro or in vivo. Taken together these new technologies represent a novel and robust method for the inhibition of HCV replication in cells and paves the way for a clinical trial for the use of RNAI in the treatment of HCV infection.