Fetal bovine serum inhibits hepatitis C virus attachment to host cells

Fetal bovine serum (FBS), used normally as a basic cell culture supplement, inhibits influenza virus growth. However, the role of FBS in the regulation of hepatitis C virus (HCV) infection has not been studied extensively and remains largely unclear. We adopted the established cell-cultured HCV (HCVcc) isolated from the JFH-1 strain and two sets of solutions (cDMEM7.4 and cDMEM6.8; RHMNB6.8 and RHMN6.8) to investigate the effect of FBS on HCV infection. Our data indicate that FBS blocks HCV infection in a dose-dependent manner. The infectivity of HCV diluted in the RHMNB solution was more susceptible to the addition of FBS than that diluted in the cDMEM solution. In addition, FBS-mediated blocking of HCV infection occurred at the step of virus attachment to the target cells, suggesting that FBS contains factors that interfere with the early steps in HCV infection.