Lumpy skin disease virus enters into host cells via dynamin-mediated endocytosis and macropinocytosis

Lumpy skin disease virus (LSDV), a ruminant poxvirus of the Capripoxvirus genus, is the etiologic agent of an economically important cattle disease categorized as a notifiable disease by the World Organization for Animal Health. However, the endocytic pathway and their regulatory molecules have not been characterized for LSDV. In the present study, specific pharmacological inhibitors were used to analyze the mechanism of LSDV entry into Mardin-Darby Bovine Kidney cell (MDBK) and bovine mammary epithelial cell (BMEC). The results showed that LSDV entered MDBK and BMEC cells depends on low-pH conditions and dynamin. However, the inhibitor of caveolae- and clathrin-mediated endocytosis cann't inhibit LSDV entry into MDBK and BMEC cells. Furthermore, treatment with specific inhibitors demonstrated that LSDV entry into MDBK and BMEC cells via macropinocytosis depended on the Na1/H1 exchanger (NHE) but not phosphatidylinositol 3-kinase (PI3K). In addition, results demonstrated that these inhibitors inhibited LSDV entry but did not have effect on LSDV binding. Taken together, our study demonstrated that LSDV enters MDBK and BMEC cells through macropinocytosis pathway in a low-PH- and dynamin-dependent manner while independent on PI3K. Results presented in this study potentially provides insight into the entry mechanisms of LSDV, and it may facilitate the development of therapeutic interventions.