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Whittaker, G.

Publications and source records attributed to Whittaker, G..

2 recordsLinked to original sources

β-Coronaviruses use lysosomal organelles for cellular egress.

{beta}-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 {beta}-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.

microbiology

FDA approved calcium channel blockers inhibit SARS CoV 2 infectivity in epithelial lung cells

COVID-19 is caused by a novel coronavirus, severe acute respiratory syndrome coronavirus (CoV)-2 (SARS-CoV-2). The virus is responsible for an ongoing pandemic and concomitant public health crisis around the world. While vaccine development is proving to be highly successful, parallel drug development approaches are also critical in the response to SARS-CoV-2 and other emerging viruses. Coronaviruses require Ca2+ ions for host cell entry and we have previously shown that Ca2+ modulates the interaction of the viral fusion peptide with host cell membranes. In an attempt to accelerate drug development, we tested a panel of L-type calcium channel blocker (CCB) drugs currently developed for other conditions, to determine whether they would inhibit SARS-CoV-2 infection in cell culture. All the CCBs tested showed varying degrees of inhibition, with felodipine and nifedipine strongly limiting SARS-CoV-2 entry and infection in epithelial lung cells at concentrations where cell toxicity was minimal. Further studies with pseudo-typed particles displaying the SARS-CoV-2 spike protein suggested that inhibition occurs at the level of virus entry. Overall, our data suggest that certain CCBs have potential to treat SARS-CoV-2 infections and are worthy of further examination for possible treatment of COVID-19.

microbiology