Viruses. 2022 Feb 28. pii: 496. [Epub ahead of print]14(3):
Shiqian Li,
Dai Xiao,
Yujia Zhao,
Luwen Zhang,
Rui Chen,
Weizhe Liu,
Yimin Wen,
Yijie Liao,
Yiping Wen,
Rui Wu,
Xinfeng Han,
Qin Zhao,
Senyan Du,
Qigui Yan,
Xintian Wen,
Sanjie Cao,
Xiaobo Huang.
(1) Background: Porcine deltacoronavirus (PDCoV) is a newly emerged enteric virus affecting pig breeding industries worldwide, and its pathogenic mechanism remains unclear. (2) Methods: In this study, we preliminarily identified the endocytic pathway of PDCoV in PK-15 cells, using six chemical inhibitors (targeting clathrin-mediated endocytosis, caveolae-mediated endocytosis, macropinocytosis pathway and endosomal acidification), overexpression of dominant-negative (DN) mutants to treat PK-15 cells and proteins knockdown. (3) Results: The results revealed that PDCoV entry was not affected after treatment with chlorpromazine (CPZ), 5-(N-ethyl-N-isopropyl) amiloride (EIPA)or ammonium chloride (NH4Cl), indicating that the entry of PDCoV into PK-15 cells were clathrin-, micropinocytosis-, PH-independent endocytosis. Conversely, PDCoV infection was sensitive to nystatin, dynasore and methyl-β-cyclodextrin (MβCD) with reduced PDCoV internalization, indicating that entry of PDCoV into PK-15 cells was caveolae-mediated endocytosis that required dynamin and cholesterol; indirect immunofluorescence and shRNA interference further validated these results. (4) Conclusions: In conclusion, PDCoV entry into PK-15 cells depends on caveolae-mediated endocytosis, which requires cholesterol and dynamin. Our finding is the first initial identification of the endocytic pathway of PDCoV in PK-15 cells, providing a theoretical basis for an in-depth understanding of the pathogenic mechanism of PDCoV and the design of new antiviral targets.
Keywords: caveolae-mediated endocytosis; cell entry; clathrin-mediated endocytosis; macropinocytosis; porcine deltacoronavirus (PDCoV)