[Characterization of binding and entry process of Japanese encephalitis virus infection to high-susceptibility and low-susceptibility cell lines].

The binding and entry of Japanese encephalitis virus (JEV) to established cell lines were analyzed using radiolabeled virion. A JEV high-susceptibility cell line, Vero cells, adsorbed and internalized much more JEV than did NRK cells, which is a low-susceptibility cell line. NRK cells injected with viral genomic RNA produced infectious virions in culture medium. Protease treatment of cells reduced the binding of JEV to Vero cells stronger than that to NRK cells. JEV bound to a 74 KD molecule present in membrane fraction of Vero cells and this binding was inhibited by a hemagglutinin-inhibiting monoclonal antibody against JEV (MAb 301). MAb 301 also inhibited the binding of JEV to Vero cells much more strongly than to the NRK cells. The 74 KD molecule was not detected in the membrane fraction of NRK cells. These results suggest that the process of binding and entry of JEV determine the JEV susceptibility of cells at least to a certain extent, and in particular suggest that the 74 KD molecule may be a possible candidate or component of the cellular receptor for JEV.