YANG, C.D.*; PENG, J.M.; LIANG, S.M.; Institute of BioAgricultural Sciences, Academia Sinica; Institute of Biological Chemistry, Academia Sinica; Institute of BioAgricultural Sciences, Academia Sinica: Cellular effects in host cells induced by recombinant VP1 (rVP1) of foot-and-mouth disease virus (FMDV)

Foot-and-moth disease virus (FMDV) is an etiological agent of foot-and-moth disease (FMD). Capsid protein VP1 of FMDV contains a highly conserved Arg-Gly-Asp (RGD) tripeptide motif that binds to integrins and facilitates the viral internalization into target cells. We have previously purified the recombinant VP1 (rVP1) in aqueous soluble form. In this study, we investigated the cellular effects induced by the rVP1 in virus permissive cell, BHK-21. We found that the rVP1 induced apoptotic signals in BHK-21 cells after binding to integrins. In addition, we also observed that rVP1 reduced the expression of toll-like receptor 9 (TLR9), an immune sensor that recognized bacterial and virus DNA. The effect of rVP1 on the expression of TLR9 was modulated at both translational and transcriptional levels as shown by Western blot and RT-PCR analysis. These results suggest that rVP1 may reduce host defensive response to invading pathogens and trigger apoptosis in host cells.