How can the cellular immune response control hepatitis B virus replication?

In this review we focus on aspects of the virus-specific cellular immune re sponse, although we should point out that all the components of the innate and adaptive immune response are likely to play a role in successful contro l of hepatitis B virus (HBV) infection. We concentrate particularly on the relevance of the polyclonality and multispecificity of the HBV-specific cyt otoxic T cell response to its antiviral activity. In this context, we discu ss the possible role of viral escape mutations and highlight evidence from other models of the benefit of multispecificity in antiviral responses. We stress the contribution of CD4 help for effective CD8 responses and raise t he possibility that HBV may produce factors inhibiting the antiviral respon se.