Cyclophilin A inhibits rotavirus replication by facilitating host IFN-I production.

Rotavirus (RV) infection causes serious dehydrating diarrhoea in infants and newborn animals. Our previous study revealed that cyclophilin A (CYPA), a peptidyl-prolyl cis-trans isomerase (PPIase), could be temporarily upregulated in RV-infected MA104 cells in early stage of infection (unpublished data). To find out the possible roles of CYPA in RV infection, we overexpressed and silenced CYPA in various cell lines by gene transfection and shRNA. We found that transfection of CYPA significantly inhibited RV replication, while silencing the expression of CYPA significantly increased RV replication. Accordingly, overexpression of CYPA significantly increased IFN-β production; while silencing CYPA significantly reduced IFN-β production. This effect of CYPA on IFN-β production was independent of its PPIase activity. Moreover, IFN-β secreted by host cells in RV infection had a critical repressive effect on viral replication. Finally, we found that inhibiting JNK pathway by SP600125 and JNK siRNA abrogated the effect of CYPA on IFN-β transcription in RV-infected MA104 cells. Together, our data suggested that CYPA inhibited RV replication by facilitating host IFN-β production, which was independent on the PPIase activity of CYPA but dependent on the activation of JNK signaling pathway.