Cellular sialoglycans are differentially required for endosomal and cell-surface entry of SARS-CoV-2 in lung cell lines.

Autor: Siwak KC; Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Canada., LeBlanc EV; Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Canada., Scott HM; Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Canada., Kim Y; Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Canada., Pellizzari-Delano I; Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Canada., Ball AM; Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Canada., Temperton NJ; Viral Pseudotype Unit, Medway School of Pharmacy, University of Kent and Greenwich at Medway, Chatham, United Kingdom., Capicciotti CJ; Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Canada.; Department of Chemistry, Queen's University, Kingston, Canada.; Department of Surgery, Queen's University, Kingston, Canada., Colpitts CC; Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Canada.
Jazyk: angličtina
Zdroj: PLoS pathogens [PLoS Pathog] 2024 Dec 03; Vol. 20 (12), pp. e1012365. Date of Electronic Publication: 2024 Dec 03 (Print Publication: 2024).
DOI: 10.1371/journal.ppat.1012365
Abstrakt: Cell entry of severe acute respiratory coronavirus-2 (SARS-CoV-2) and other CoVs can occur via two distinct routes. Following receptor binding by the spike glycoprotein, membrane fusion can be triggered by spike cleavage either at the cell surface in a transmembrane serine protease 2 (TMPRSS2)-dependent manner or within endosomes in a cathepsin-dependent manner. Cellular sialoglycans have been proposed to aid in CoV attachment and entry, although their functional contributions to each entry pathway are unknown. In this study, we used genetic and enzymatic approaches to deplete sialic acid from cell surfaces and compared the requirement for sialoglycans during endosomal and cell-surface CoV entry using lentiviral particles pseudotyped with the spike proteins of different sarbecoviruses. We show that entry of SARS-CoV-1, WIV1-CoV and WIV16-CoV, like the SARS-CoV-2 omicron variant, depends on endosomal cathepsins and requires cellular sialoglycans for entry. Ancestral SARS-CoV-2 and the delta variant can use either pathway for entry, but only require sialic acid for endosomal entry in cells lacking TMPRSS2. Binding of SARS-CoV-2 spike protein to cells did not require sialic acid, nor was sialic acid required for SARS-CoV-2 entry in TMRPSS2-expressing cells. These findings suggest that cellular sialoglycans are not strictly required for SARS-CoV-2 attachment, receptor binding or fusion, but rather promote endocytic entry of SARS-CoV-2 and related sarbecoviruses. In contrast, the requirement for sialic acid during entry of MERS-CoV pseudoparticles and authentic HCoV-OC43 was not affected by TMPRSS2 expression, consistent with a described role for sialic acid in merbecovirus and embecovirus cell attachment. Overall, these findings clarify the role of sialoglycans in SARS-CoV-2 entry and suggest that cellular sialoglycans mediate endosomal, but not cell-surface, SARS-CoV-2 entry.
Competing Interests: The authors have declared that no competing interests exist.
(Copyright: © 2024 Siwak et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)
Databáze: MEDLINE
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