Chapter 5 - Cell-mediated immunity and the outcome of HCV infection in chimpanzees

Abstract

Chronic infection with hepatitis C virus (HCV) is a global public health problem. The common chimpanzee Pan troglodytes is the only animal model for human HCV infection, and emerging data suggest that mechanisms of protective immunity and viral persistence are identical in both species. The few individuals who spontaneously resolve infection have robust cell-mediated immune responses. CD4 + and CD8+ T helper cells targeting multiple class II and class I restricted epitopes, respectively, are found in the peripheral blood and the liver of chimpanzees and humans coincident with the termination of plasma viremia. Lifelong infection in the majority of chimpanzees and humans is characterized by low-frequency T-lymphocyte responses that appear to be largely compartmentalized to the liver. These data suggest that the same lesion in host immunity facilitates the persistence of the virus in both species. Thus, the chimpanzee model is likely to be important for the development of vaccines and other immunotherapies designed to terminate ongoing HCV replication.