Does a host restriction factor facilitate entry of SARS-CoV-2?


Interferon-induced transmembrane proteins (IFITMs) are a family of host restriction factors that affect the fusion capacity of many enveloped RNA viruses. A preprint by Prelli Bozzo et al. now reports that SARS-CoV-2 appears to hijack IFITMs, and in particular IFITM2, as cofactors for the infection of lung cells. Whereas overexpression of IFITMs impaired SARS-CoV-2 membrane fusion with HEK293T cells in vitro, knockdown studies in the human lung epithelial cell line Calu-3 showed that endogenous levels of IFITM1, IFITM2 and IFITM3, both in the absence or presence of interferon, boost SARS-CoV-2 infection, with IFITM2 showing the strongest effect.


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  1. Prelli Bozzo, C. et al. IFITM proteins promote SARS-CoV-2 infection of human lung cells. Preprint at bioRxiv (2020)

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Correspondence to Ester Gea-Mallorquí.

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Gea-Mallorquí, E. Does a host restriction factor facilitate entry of SARS-CoV-2?. Nat Rev Immunol 20, 648 (2020).

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