β-Coronaviruses Use Lysosomes for Egress Instead of the Biosynthetic Secretory Pathway
- Cell. 2020 Dec 10;183(6):1520-1535.e14. doi: 10.1016/j.cell.2020.10.039.
- 1. Laboratory of Host-Pathogen Dynamics, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD, USA.
- 2. Federated Department of Biological Sciences, Rutgers-State University of New Jersey, Newark, NJ, USA.
- 3. Electron Microscopy Core Facility, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD, USA.
- 4. Division of Rheumatology, Inflammation and Immunity, Brigham and Women's Hospital, Department of Medicine, Harvard Medical School, Boston, MA, USA.
- 5. Department of Microbiology and Immunology, University of Iowa, Iowa City, IA, USA.
- 6. lmmunodynamics Group - Laboratory of Integrative Cancer Immunology, National Cancer Institute, Bethesda, MD, USA.
- 7. Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA.
- 8. Department of Biomolecular Health Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, the Netherlands.
- 9. B-Cell Molecular Immunology Section, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA.
- 10. lmmunodynamics Group - Laboratory of Integrative Cancer Immunology, National Cancer Institute, Bethesda, MD, USA. Electronic address: [email protected].
- 11. Laboratory of Host-Pathogen Dynamics, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD, USA. Electronic address: [email protected].
β-Coronaviruses are a family of positive-strand enveloped RNA viruses that includes the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Much is known regarding their cellular entry and replication pathways, but their mode of egress remains uncertain. Using imaging methodologies and virus-specific reporters, we demonstrate that β-coronaviruses utilize lysosomal trafficking for egress rather than the biosynthetic secretory pathway more commonly used by Other enveloped viruses. This unconventional egress is regulated by the Arf-like small GTPase Arl8b and can be blocked by the Rab7 GTPase competitive inhibitor CID1067700. Such non-lytic release of β-coronaviruses results in lysosome deacidification, inactivation of lysosomal degradation Enzymes, and disruption of antigen presentation pathways. β-Coronavirus-induced exploitation of lysosomal organelles for egress provides insights into the cellular and immunological abnormalities observed in patients and suggests new therapeutic modalities.