Entry of the Varicellovirus Canid herpesvirus 1 into Madin–Darby canine kidney epithelial cells is pH‐independent and occurs via a macropinocytosis‐like mechanism but without increase in fluid uptake. (15th November 2021)

• Record Type: Journal Article
• Authors: Eisa, Mohamed; Loucif, Hamza; van Grevenynghe, Julien; Pearson, Angela
• Is Part Of: Cellular microbiology. Volume 23:Number 12(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-11-15
• Subjects: Microbiology -- Periodicals; Cytology -- Periodicals; Host-parasite relationships -- Periodicals; Microbiology -- Periodicals; Cells -- Periodicals; Microbiologie -- Périodiques; Microbiologie; Relation hôte-parasite; Cytologie; Cellule; Réponse cellulaire; Ressource Internet (Descripteur de forme); Périodique électronique (Descripteur de forme); 579.05
• DOI: 10.1111/cmi.13398
• Languages: English
• ISSNs: 1462-5814

Abstract

Abstract: Canid herpesvirus 1 (CHV‐1) is a Varicellovirus that causes self‐limiting infections in adult dogs but morbidity and mortality in puppies. Using a multipronged approach, we discovered the CHV‐1 entry pathway into Madin–Darby canine kidney (MDCK) epithelial cells. We found that CHV‐1 triggered extensive host cell membrane lamellipodial ruffling and rapid internalisation of virions in large, uncoated vacuoles, suggestive of macropinocytosis. Treatment with inhibitors targeting key macropinocytosis factors, including inhibitors of Na + /H + exchangers, F‐actin, myosin light‐chain kinase, protein kinase C, p21‐activated kinase, phosphatidylinositol‐3‐kinase and focal adhesion kinase, significantly reduced viral replication. Moreover, the effect was restricted to exposure to the inhibitors early in infection, confirming a role for the macropinocytic machinery during entry. The profile of inhibitors also suggested a role for signalling via integrins and receptor tyrosine kinases in viral entry. In contrast, inhibitors of clathrin, caveolin, microtubules and endosomal acidification did not affect CHV‐1 entry into MDCK cells. We found that the virus colocalised with the fluid‐phase uptake marker dextran; however, surprisingly, CHV‐1 infection did not enhance the uptake of dextran. Thus, our results indicate that CHV‐1 uses a macropinocytosis‐like, pH‐independent entry pathway into MDCK cells, which nevertheless is not based on stimulation of fluid uptake. Take Aways: CHV‐1 enters epithelial cells via a macropinocytosis‐like mechanism. CHV‐1 induces extensive lamellipodial ruffling. CHV‐1 entry into MDCK cells is pH‐independent. Abstract : The entry pathway of Canid herpesvirus 1 into MDCK cells was shown to be via a macropinocytosis‐like mechanism. CHV‐1 induces membrane ruffles and internalises within large uncoated endocytic vacuoles. Pharmacological inhibitors targeting the macropinocytic machinery blocked virus entry, while in contrast, inhibiting endosomal acidification had no effect on the ability of the virus to infect MDCK cells.