Tetraspanin CD9 is a conserved receptor for rhabdoviruses across multiple genera

Rhabdoviruses exhibit a broad host range, yet the cellular receptors underlying their cross-species tropism remain poorly defined. Here, we identified tetraspanin CD9 as a common entry receptor for diverse rhabdoviruses across genera, including viral hemorrhagic septicemia virus (VHSV) ( Novirhabdovirus ), Siniperca chuatsi rhabdovirus (SCRV) ( Siniperhavirus ), and vesicular stomatitis virus (VSV) ( Vesiculovirus ). We demonstrated that the domain IV of VHSV glycoprotein G directly interacted with the large extracellular loop domain of Lateolabrax japonicus CD9 (LjCD9). CD9 knockout, CD9 protein, or CD9 antibody significantly reduced VHSV infection in vivo and in vitro , while LjCD9 overexpression rendered nonsusceptible HEK293T cells susceptible to VHSV infection, suggesting that LjCD9 is a receptor for VHSV. We further confirmed that LjCD9 functions as a functional receptor of SCRV. Importantly, the human CD9 orthologue can serve as a receptor of VSV. Our findings also revealed that LjCD9 mediated VHSV entry via clathrin- and caveolae-mediated endocytosis. Notably, we identified the FDA-approved drug nitazoxanide (NTZ) as a broad-spectrum inhibitor of VHSV, SCRV, and VSV by disrupting CD9-G interaction. This study establishes CD9 as a cross-species receptor for rhabdoviruses and highlights NTZ as a promising broad-spectrum antiviral agent.