Domain I and II from newly emerging goose tembusu virus envelope protein functions as a dominant-negative inhibitor of virus infectivity

Flavivirus envelope protein locates at the outermost surface of viral particle and mediates virus entry and fusion infection, and domains I and II of E protein play an important role in this process. In this study, we have expressed and purified goose tembusu virus (GTV) E protein domains I and II (DI/II) from E. coli, and tested conceptual approach that purified protein serves as anti-viral reagent. We found that DI/II inhibited GTV JS804 infection in BHK-21 cells in a dose-dependent manner, and this inhibition activity was achieved by binding to cell membrane specifically. Moreover, JS804 treated with DI/II specific anti-serum decreased its infectivity to BHK-21 cells. Taken together, this is first to show that the purified DI/II domain of tembusu virus expressed in E. coli was able to interfere with virus infection, which opens an avenue to develop novel anti-viral regents to prevent and eventually eradicate GTV infection.