Expression of hepatitis C virus envelope protein 2 induces apoptosis in cultured mammalian cells.

AIM To explore the role of hepatitis C virus (HCV) envelope protein 2 (E2) in the induction of apoptosis. METHODS A carboxyterminal truncated E2 (E2-661) was transiently expressed in several cultured mammalian cell lines or stably expressed in Chinese hamster ovary (CHO) cell line. Cell proliferation was assessed by 3H thymidine uptake. Apoptosis was examined by Hoechst 33258 staining, flow cytometry and DNA fragmentation analysis. RESULTS Reduced proliferation was readily observed in the E2-661 expressing cells. These cells manifested the typical features of apoptosis, including cell shrinkage, chromatin condensation and hypodiploid genomic DNA content. Similar apoptotic cell death was observed in an E2-661 stably expressing cell line. CONCLUSION HCV E2 can induce apoptosis in cultured mammalian cells.