Background: Vertical transmission (VT) is generally considered to be the leading route of pediatric acquisition of Hepatitis C Virus (HCV). However, the mechanism of HCV VT has never been satisfactorily illustrated. Moreover, CD81, scavenger receptor class B type I (SR-B1), claudin 1 (CLDN1) and occludin (OCLN) were four necessary receptors for HCV cell infection. The expression of the essential receptors may explain the reason of HCV VT.
Objective: To investigate the probable mechanism of HCV VT.
Methods: We isolated trophoblasts from human term placental samples with approval from the Institutional Review Board at the Tongji Hospital of Tongji University and cultured the cells in vitro. Flow cytometry and Western blotting were used to detect the expression of the essential receptors for HCV infection on trophoblasts. Then we generated HCV pseudoparticle (HCVpp) and cell culture-produced HCV (HCVcc) to infect HEK-293T cells and trophoblasts,.At 72 h post-infection, HCVpp and HCVcc were determined in the infected cells.
Results: Trophoblasts expressed CD81, SR-B1, CLDN1 and OCLN, which were essential for HCV cell entry. However, trophoblasts were not infected by HCVpp or HCVcc.
Conclusion: Primary human trophoblasts possess the receptors necessary for HCV infection but resistant to infection in vitro.