CBFß is induced by spring viremia of carp virus and promotes virus replication in zebrafish

The core binding factor subunit beta (CBF ss) is a transcription factor that forms a complex with virial proteins to promote viral infection. In this study, we identified a CBF ss homolog from zebrafish (zfCBF ss) and characterized the biological activity. The deduced zfCBF ss protein was highly similar to orthologs from other species. The zfcbf ss gene was constitutively expressed in tissues and was induced in immune tissues after infection with spring viremia carp virus (SVCV) and stimulation with poly(I:C). Interestingly, zfcbf ss is not induced by type I interferons. Overexpression of zfcbf ss induced tnf alpha expression but inhibited isg15 expression. Also, overexpression of zfcbf ss significantly increased SVCV titer in the EPC cells. Co-immunoprecipitation assay revealed that zfCBF ss interacts with SVCV phosphoprotein (SVCVP) and host p53, resulting in the increased stability of zfCBF ss. Our results provide evidence that CBF ss is targeted by virus to suppress host antiviral response.