Profiling of SFTS virus and host protein interactions by affinity purification-mass spectrometry.

Severe Fever with Thrombocytopenia Syndrome (SFTS), caused by the novel phlebovirus SFTSV (SFTS bunyavirus), was first identified in 2009 across several Chinese provinces, with a case fatality rate reaching 30 %. Given its compact genome, SFTSV critically depends on host cellular machinery for replication and pathogenesis. In this study, we employed a systematic strategy combining co-immunoprecipitation of viral-host complexes with formaldehyde crosslinking and affinity purification-mass spectrometry (AP-MS) to comprehensively map SFTSV-host interactions. We systematically analyzed protein complexes associated with all five viral structural/non-structural proteins (NP, NSs, Gc, Gn, and L), identifying 432 host proteins as potential viral interactors. Subsequent bioinformatic analysis included Gene Ontology categorization and functional domain/pathway enrichment analysis via KEGG, with interaction networks visualized through Cytoscape. Importantly, we experimentally validated key interactions between NSs and host proteins VDAC1, Vimentin, and HSP90AB1, demonstrating robust consistency with our mass spectrometry findings.