Grant: CIHR Fellowship

Approximately 25-30% of the HIV infected individuals are also infected with hepatitis C virus (HCV). The success of the new antiretroviral treatments for HIV has allowed HIV-infected individuals to live longer but have rendered the effects of hepatitis C infection more visible. HCV is a virus that infects the liver and over several years can cause different forms of liver damage including liver cancer. These effects occur faster in HIV-infected individuals and represent an increasing cause of death in this population. Hence, the urgent need to eliminate hepatitis C infection. This effort is hindered by insufficient understanding of the immune response that may control hepatitis C infection in HIV+ individuals and how this relates to the stage of HIV infection. In addition, the only treatment for hepatitis C is a drug known as pegylated interferon (PEG-IFN) which has a very limited rate of success and causes many side effects in particular in HIV-infected individuals. The goal of this proposal is to understand the immunological aspects that can lead to elimination of hepatitis C in HIV-infected individuals and the factors that can enhance the response of PEG-IFN therapy in this population. We hypothesize that spontaneous elimination of the virus and successful response to treatment in co-infected individuals is dictated by the capacity to generate a strong immune response and requires the preservation of high CD4 T cell counts These results will help in decreasing the side effects associated with hepatitis C treatment in HIV-infected individuals and the development of new treatments and treatment strategies.