Boal‐Carvalho I, Mazel‐Sanchez B, Silva F, Garnier L, Yildiz S, Bonifacio JPPL, Niu C, Williams N, Francois P, Schwerk N, Schöning J, Carlens J, Viemann D, Hugues S, Schmolke M. Influenza A viruses limit NLRP3-NEK7-complex formation and pyroptosis in human macrophages.
EMBO Rep 2020;
21:e50421. [PMID:
33180976 PMCID:
PMC7726813 DOI:
10.15252/embr.202050421]
[Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Revised: 10/06/2020] [Accepted: 10/09/2020] [Indexed: 12/20/2022] Open
Abstract
Pyroptosis is a fulminant form of macrophage cell death, contributing to release of pro-inflammatory cytokines. In humans, it depends on caspase 1/4-activation of gasdermin D and is characterized by the release of cytoplasmic content. Pathogens apply strategies to avoid or antagonize this host response. We demonstrate here that a small accessory protein (PB1-F2) of contemporary H5N1 and H3N2 influenza A viruses (IAV) curtails fulminant cell death of infected human macrophages. Infection of macrophages with a PB1-F2-deficient mutant of a contemporary IAV resulted in higher levels of caspase-1 activation, cleavage of gasdermin D, and release of LDH and IL-1β. Mechanistically, PB1-F2 limits transition of NLRP3 from its auto-repressed and closed confirmation into its active state. Consequently, interaction of a recently identified licensing kinase NEK7 with NLRP3 is diminished, which is required to initiate inflammasome assembly.
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