Enterovirus A71 (EV-A71) is the major pathogen responsible for the severe hand,foot and mouth disease worldwide,for which few effective antiviral drugs are presently available.Interferon-α (IFN-α) has been used in antiviral therapy for decades;it has been reported that EV-A71 antagonizes the antiviral activity of IFN-α based on viral 2Apro-mediated reduction of the interferon-alpha receptor 1 (IFNAR1);however,the mechanism remains unknown.Here,we showed a significant increase in IFNAR1 protein induced by IFN-α in RD cells,whereas EV-A71 infection caused obvious downregulation of the IFNAR1 protein and blockage of IFN-α signaling.Subsequently,we observed that EV-A71 2Apro inhibited IFNAR1 translation by cleavage of the eukaryotic initiation factor 4GI (eIF4GI),without affecting IFNAR1 mRNA levels induced by IFN-α.The inhibition of IFNAR1 translation also occurred in puromycin-induced apoptotic cells when caspase-3 cleaved eIF4GI.Importantly,we verified that 2Apro could activate cellular caspase-3,which was subsequently involved in eIF4GI cleavage mediated by 2Apro.Furthermore,inhibition of caspase-3 activation resulted in the partial restoration of IFNAR1 in cells transfected with 2A or infected with EV-A71,suggesting the pivotal role of both viral 2Apro and caspase-3 activation in the disturbance of IFN-αt signaling.Collectively,we elucidate a novel mechanism by which cellular caspase-3 contributes to viral 2Apro-mediated down-regulation of IFNAR1 at the translation level during EV-A71 infection,indicating that caspase-3 inhibition could be a potential complementary strategy to improve clinical anti-EV-A71 therapy with IFN-α.