Peste des petits ruminants virus V protein inhibits cellular antiviral response by blocking the secretion of endogenous and exogenous interferons.

Peste des petits ruminants (PPR) is an OIE-listed, acute, and highly contagious viral disease of sheep and goats caused by the PPR virus (PPRV), a morbillivirus within the Paramyxoviridae family. Here, we investigated how the PPRV protein evades the immune response using cellular models of infection. Results indicated that PPRV V protein significantly suppresses both endogenous and exogenous IFN-α- and IFN-β-induced antiviral response with a broad-spectrum effect. The PPRV V protein significantly suppresses the production of IFN-β and its downstream cytokines of interferon-stimulated gene 56 (ISG56), ISG15, C-X-C motif chemokine (CXCL10) as well as the RIG-IN-induced activation of IFN-responsive promoter elements (ISRE). We further found that PPRV V protein inhibits the phosphorylation of IRF3 and STAT1, reducing the production of IFNs to block transduction via JAK-STAT signaling pathway and impairs the host antiviral state.