Abstract: Objective To assess the antibody-dependent enhancement of infection（ADE） when the cultured trophoblastic cells were infected by hepatitis C virus（HCV）. Methods We incubated the cytotrophoblasts with HCV by four different methods. Under the immunoelectron microscopy,we observed the HCV viral particles. RT-PCR method and immunohistochemistry were employed to assay the expressions of HCV NS5 and NS3 and HCV-C antigen and HCV RNA in cells or supernatant. Results The HCV viral particles were observed in the cultured cytotrophoblasts. The HCV RNA and reverse RNA and HCV NS5 and NS3 and HCV-C antigen were only intermittently detected in the culture medium or the cells incubated with HCV RNA positive serum. Conclusion The HCV viral particles can replicate in the cultured cytotrophoblasts. The ADE plays an important role when HCV viral particles enter the cultured cytotrophoblasts. Anti-HCV and/or complement probably enhanced the infection of viral particles.

Key words: Hepatitis C virus, Cytotrophoblasts, In vitro