{ "abstract": "Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to cause significant respiratory disease, particularly in vulnerable populations. Although ACE2 is the primary receptor for viral entry, previous studies have identified a naturally occurring, ACE2-independent entry pathway that depends on cell surface heparan sulfates and the E484D substitution within the receptor-binding domain of Spike (S). In this study, we expand the panel of airway-derived cell lines that support ACE2-independent, S-E484D-dependent entry and identify the host lysosomal transmembrane protein TMEM106B as the alternative receptor for infection. Specifically, we show that knockout of TMEM106B completely abolishes infection by SARS-CoV-2 SE484D in NCI-H522 and NCI-H661 cells. Ectopic expression of the luminal C-terminal domain (CTD) of TMEM106B-either alone or redirected to the plasma membrane - is sufficient to enable viral entry largely independent of cell surface heparan sulfates in non-permissive cells. We show that S-E484D is required for TMEM106B utilization, whereas other Variants of Concern substitutions at S-E484 are unable to mediate entry. Fc-TMEM106B-CTD fusion protein binds to a chimeric VSV-SARS-CoV-2 SE484D with a higher affinity than WT virus and blocks infection by SARS-CoV-2 SE484D, supporting a direct interaction between S-E484D and TMEM106B-CTD. Serial passaging experiments with VSV-SARS-CoV-2 SE484D identify a V951A mutation within the heptad repeat 1 region that enhances viral spread and fusogenicity in the ACE2-independent cell models. Together, these findings demonstrate that TMEM106B is a key mediator of a naturally occurring ACE2-independent pathway in multiple airway-derived cell lines and suggest that variation in the S protein can expand receptor usage by SARS-CoV-2.", "abstract_shown": true, "affiliations": [ "Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, USA", "Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO, USA", "Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA", "Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USA", "Department of Medicine, Division of Infectious Diseases, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.", "Department of Psychiatry, Washington University School of Medicine, St. Louis, MO, USA", "Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO, USA", "Center for Pathogen Genomics and Microbial Evolution, Havey Institute for Global Health, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.", "Andrew M. and Jane M. Bursky Center for Human Immunology and Immunotherapy Programs, Washington University School of Medicine, St. Louis, MO USA.", "Center for Vaccines and Immunity to Microbial Pathogens, Washington University School of Medicine, St. Louis, MO, USA.", "Department of Otolaryngology, Washington University School of Medicine, St. Louis, MO, USA", "Institute for Informatics, Data Science & Biostatistics, Washington University School of Medicine, St. Louis, MO, USA." ], "article_type": "research article", "arxiv": null, "author_total": 20, "authors": [ { "affs": [ 0 ], "name": "Ming Xia" }, { "affs": [ 0 ], "name": "Qibo Wang" }, { "affs": [ 0 ], "name": "Maritza Puray-Chavez" }, { "affs": [ 1 ], "name": "Kyle LaPak" }, { "affs": [ 0 ], "name": "Zhuoming Liu" }, { "affs": [ 2 ], "name": "Sathvik Palakurty" }, { "affs": [ 0 ], "name": "Paul Rothlauf" }, { "affs": [ 3 ], "name": "Sean Hui", "orcid": "0000-0002-9870-6823" }, { "affs": [ 4 ], "name": "Natalie Stegman" }, { "affs": [ 0 ], "name": "Marjorie Cornejo Pontelli" }, { "affs": [ 5 ], "name": "Jacob Marsh" }, { "affs": [ 0 ], "name": "Anayat Bhat" }, { "affs": [ 5 ], "name": "Celeste M. Karch", "orcid": "0000-0002-6854-5547" }, { "affs": [ 0, 3, 6 ], "name": "Daved H. Fremont", "orcid": "0000-0002-8544-2689" }, { "affs": [ 4, 7 ], "name": "Ramon Lorenzo-Redondo" }, { "affs": [ 0, 2, 3, 8, 9 ], "name": "Michael S. Diamond", "orcid": "0000-0002-8791-3165" }, { "affs": [ 0 ], "name": "Sean P.J. Whelan", "orcid": "0000-0003-1564-8590" }, { "affs": [ 1, 10 ], "name": "Michael B. Major", "orcid": "0000-0002-6753-8513" }, { "affs": [ 1, 11 ], "name": "Dennis Goldfarb" }, { "affs": [ 0 ], "name": "Sebla B. Kutluay" } ], "bibtex": "https://research.draconitic.com/paper/an1yf2vxmv3dg.bib", "cited_by": 0, "doi": "10.64898/2026.03.14.711762", "fulltext_url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC13733688/", "id": "an1yf2vxmv3dg", "issns": [ "2692-8205" ], "landing_url": "https://doi.org/10.64898/2026.03.14.711762", "language": "en", "licence": "CC-BY-NC-ND-4.0", "licence_label": "CC BY-NC-ND 4.0", "licence_source": "article", "licence_url": "https://creativecommons.org/licenses/by-nc-nd/4.0/", "metadata_licence": null, "native_subjects": [ [ "heading", "Article" ], [ "openalex", "2725|SARS-CoV-2 and COVID-19 Research" ] ], "openalex": "W7136038544", "pdf_url": null, "pmcid": "PMC13733688", "pmid": "42990160", "published": "2026-10-30", "publisher": "Cold Spring Harbor Laboratory Preprints", "ris": "https://research.draconitic.com/paper/an1yf2vxmv3dg.ris", "sources": [ { "first_seen": "2026-11-08T12:23:24Z", "native_id": "PMC13733688", "source": "pmc", "url": "https://doi.org/10.64898/2026.03.14.711762" } ], "subjects": [ { "field": "medicine", "origin": "openalex:2725|SARS-CoV-2 and COVID-19 Research", "subfield": "infectious-disease" } ], "title": "TMEM106B mediates ACE2-independent replication of the SARS-CoV-2 SE484D variant in airway-derived cell models", "title_text": "TMEM106B mediates ACE2-independent replication of the SARS-CoV-2 SE484D variant in airway-derived cell models", "type": "preprint", "updated_at": "2026-11-08T12:23:24Z", "url": "https://research.draconitic.com/paper/an1yf2vxmv3dg", "venue": "bioRxiv", "versions": [] }