Cell entry of Bovine herpesvirus-1 through clathrin- and caveolin-mediated endocytosis requires activation of PI3K-Akt-NF-?B and Ras-p38 MAPK pathways as well as the interaction of BoHV-1 gD with cellular receptor nectin-1

Jovine h,rp.r.svirus-1 (BoHV -s) can infect all breeds of iota attle and cause ..evere respiratory organ and jen.tal tract diseases however, tike mechanism oi BoHV-1 entedng Me cells temains ttnclear. In this study, we explored tne inecharusm of BOH\ -1 entering MDBK cells. We found that the entry of BoHV-1 was blocked by NH4C1 and bafilomycin Al, indicating that Bol-IV-1 enty is dependent on the acidic environment of endosome. Specific inhibitor dynasore and srnall interfering RNA (siP.NA) knockdown of dynamin-2 inhibited BoHV-1 enty, showing that dynamin is requited in BoHV-1 enty. The tesults of speciflc inhibitor, siRNA knockdown and colocalination indicating clathrin- and caveolin- mediated endocytosis play a role in BoHV-1 enty. BoHV-1 infection was not affected by EIPA which is a specific inhibitor of rnacropinocytosis. In addition, we found that BoHV-1 triggered PI3K-Akt-NF-KB and Ras-p38 MAPK signaling pathways to induce clathrin-mediated and caveolin-mediated endocytosis at the early stage of BoHV-1 infection. BoHV-1 binding was sufficient to activate the endocytic signaling pathways and promote viral entry. These two signaling pathways were activated by transfection of viral gD protein, and were inhibited by deletion of viral gD protein and the siRNA knockdown of cellular receptor nectin-1. The results of co-localisation indicating the entered BoHV-1 is traced to late endosomes via early endosornes. Otu- results suggested the interaction of viral gD protein and cellular receptor nectin1 niggered the PI3K-Akt-NF-KB and Ras-p38 MAPK signaling pathways and induced clathrin-mediated and caveolin-mediated endocytosis to promote BoHV-1 entry ihto MDBK cells at the early stage of BoHV-1 infection.

Automated summary

This study investigated the mechanism of Bovine herpesvirus-1 (BoHV-1) entry into MDBK cells. It was found that BoHV-1 entry is dependent on the acidic environment of endosomes and requires the dynamin protein. Moreover, clathrin-mediated endocytosis and caveolin-mediated endocytosis play a role in promoting BoHV-1 entry.