Expression of hepatitis C virus proteins does not interfere with major histocompatibility complex class I processing and presentation in vitro

Hepatitis C virus (HCV) infection takes a chronic course in the majority of patients, The mechanisms underlying the evasion of the host immune respons e and viral persistence are poorly understood. In this context, we investig ated interactions of HCV proteins with major histocompatibility complex (MH C) class T processing and presentation pathways using cell lines that allow the tetracycline-regulated expression of viral structural and nonstructura l proteins. These well-characterized inducible cell lines were found to eff iciently process and present endogenously synthesized HCV proteins via MHC class I. Functional MHC class I cell-surface expression and intracellular p roteasome activity were not affected by the expression of HCV proteins. The se results suggest that viral evasion of the host immune response does not involve interactions of HCV with MHC class I processing and presentation. O ther mechanisms, such as interference with the interferon system, may be op erative in HCV infection, leading to viral persistence.