Peste des petits ruminants virus non-structural V and C proteins interact with the NF-B p65 subunit and modulate pro-inflammatory cytokine gene induction

Peste des petits ruminants virus (PPRV) is known to induce transient immunosuppression in infected small ruminants by modulating several cellular pathways involved in the antiviral immune response. Our study shows that the PPRV-coded non-structural proteins C and V can interact with the cellular NF-kappa B p65 subunit. The PPRV-C protein interacts with the transactivation domain (TAD) while PPRV-V interacts with the Rel homology domain (RHD) of the NF-kappa B p65 subunit. Both viral proteins can suppress the NF-kappa B transcriptional activity and NF-kappa B-mediated transcription of cellular genes. PPRV-V protein expression can significantly inhibit the nuclear translocation of NF-kappa B p65 upon TNF-alpha stimulation, whereas PPRV-C does not affect it. The NF-kappa B-mediated pro-inflammatory cytokine gene expression is significantly downregulated in cells expressing PPRV-C or PPRV-V protein. Our study provides evidence suggesting a role of PPRV non-structural proteins V and C in the modulation of NF-kappa B signalling through interaction with the NF-kappa B p65 subunit.