Coronaviruses: Innate Immunity, Inflammasome Activation, Inflammatory Cell Death, and Cytokines

Trends Immunol. 2020 Dec;41(12):1083-1099. doi: 10.1016/ Epub 2020 Oct 15.


The innate immune system acts as the first line of defense against pathogens, including coronaviruses (CoVs). Severe acute respiratory syndrome (SARS)-CoV and Middle East respiratory syndrome (MERS)-CoV are epidemic zoonotic CoVs that emerged at the beginning of the 21st century. The recently emerged virus SARS-CoV-2 is a novel strain of CoV that has caused the coronavirus 2019 (COVID-19) pandemic. Scientific advancements made by studying the SARS-CoV and MERS-CoV outbreaks have provided a foundation for understanding pathogenesis and innate immunity against SARS-CoV-2. In this review, we focus on our present understanding of innate immune responses, inflammasome activation, inflammatory cell death pathways, and cytokine secretion during SARS-CoV, MERS-CoV, and SARS-CoV-2 infection. We also discuss how the pathogenesis of these viruses influences these biological processes.

Keywords: COVID-19; MERS-CoV; MHV; PANoptosis; PANoptosome; RNA virus; SARS-CoV; SARS-CoV-2; cell death; coronavirus; cytokines; inflammasome; inflammation; innate immunity.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • COVID-19 / immunology*
  • Cell Death / immunology*
  • Cytokines / immunology*
  • Humans
  • Immunity, Innate / immunology*
  • Inflammasomes / immunology*
  • SARS-CoV-2 / immunology*


  • Cytokines
  • Inflammasomes