580. Gene Therapy of Chronic Hepatitis B Infection Using a High-Capacity Adenovirus Expressing Interleukin 12 under the Control of a Liver Specific Mifepristone-Inducible Promoter

Three hundred fifty millions people are estimated to be infected by the hepatitis B virus (HBV). Eighty-seven millions of them would develop HBV-related liver cancer or cirrhosis. In this study we developed a high-capacity adenovirus (HC-Ad), characterized by its low toxicity and long-term expression, encoding for the murine interleukin 12 (mIL12) directed by a liver-specific promoter and inducible by the administration of mifepristone (HC-RU-mIL12). We assayed its antiviral effect using two animal models of chronic HBV infection: transgenic mice for the HBV genome and woodchucks chronically infected by the woodchuck hepatitis virus (WHV).