Grant: CIHR Clinician Scientist - Phase 1

Hepatitis B virus (HBV) affects 350 million people worldwide and is a leading cause of liver cancer and liver disease, particularly in HIV co-infected populations. People who develop chronic infection most often become lifelong HBV carriers, with current therapies failing to eradicate the virus in most cases. The reason why the immune system does not clear the infection is unclear, however exhaustion or inhibition of immune cells that act against the virus are possible explanations. In chronic HBV infection, previous studies have shown high levels of an immune system inhibiting receptor, programmed death (PD)-1. We hypothesis that blocking the PD-1 receptor in HBV-infected individuals, whether HIV co-infected or not, will promote more effective cell mediated immune responses, and lead to higher cure rates than current HBV therapies alone. Our study will assess the effect of blocking PD-1 on HBV-specific and non-specific immune responses in HBV mono-infected and HBV/HIV co-infected individuals. In addition to providing further information on immune responses in chronic viral infection, this study will provide vital information about the potential for directly harnessing the immune system to cure HBV.