β-Coronaviruses use lysosomal organelles for cellular egress

Ghosh, S; Dellibovi-Ragheb, TA; Pak, E; Qiu, Q; Fisher, M; Takvorian, PM; Bleck, C; Hsu, V; Fehr, AR; Perlman, S; Achar, SR; Straus, MR; Whittaker, GR; de Haan, CAM; Altan-Bonnet, G; Altan-Bonnet, N

β-Coronaviruses are a family of positive-strand enveloped RNA viruses that include the severe acute respiratory syndrome-CoV2 (SARS-CoV2). While much is known regarding their cellular entry and replication pathways, their mode of egress remains uncertain; however, this is assumed to be via the biosynthetic secretory pathway by analogy to other enveloped viruses. Using imaging methodologies in combination with virus-specific reporters, we demonstrate that β-Coronaviruses utilize lysosomal trafficking for egress from cells. This pathway is regulated by the Arf-like small GTPase Arl8b; thus, virus egress is insensitive to inhibitors of the biosynthetic secretory pathway. Coronavirus infection results in lysosome deacidification, inactivation of lysosomal degradation and disruption of antigen presentation pathways. This coronavirus-induced exploitation of lysosomes provides insights into the cellular and immunological abnormalities observed in patients and suggests new therapeutic modalities.