SARS-CoV-2 Disrupts Proximal Elements in the JAK-STAT Pathway

Da-Yuan Chen1,2, Nazimuddin Khan1,2, Brianna J Close2,3

  • 1Department of Biochemistry, Boston Universitygrid.189504.1 School of Medicine, Boston, Massachusetts, USA.

Journal of Virology
|July 14, 2021
PubMed

Insights

SARS-CoV-2 infection universally inhibits interferon signaling by targeting the JAK-STAT pathway. This viral immune evasion strategy allows the virus to replicate across diverse human organs, impacting innate immunity.

Area of Science:

  • Virology and Immunology
  • Cellular Biology
  • Molecular Mechanisms of Viral Infection

Background:

  • SARS-CoV-2 infects multiple human organs, but the molecular mechanisms of viral replication in diverse cellular environments are not fully understood.
  • Understanding how the virus interacts with host cells is crucial for developing effective antiviral strategies against COVID-19.

Purpose of the Study:

  • To identify cellular proteins and pathways broadly affected by SARS-CoV-2 infection across different human cell types.
  • To elucidate the molecular mechanisms by which SARS-CoV-2 evades the host innate immune response, specifically interferon signaling.

Main Methods:

  • Generation of phenotypically diverse, SARS-CoV-2-infectible human cell lines from various organs.
  • Longitudinal analysis of cellular proteins and pathways post-infection.
  • Systematic investigation of the Janus kinase-STAT (JAK-STAT) pathway, including protein analysis and chemical inhibition studies.

Main Results:

  • SARS-CoV-2 infection universally inhibited interferon signaling across all tested cell types.
  • The virus targeted proximal JAK-STAT pathway components (JAK1, Tyk2, IFNAR1), leading to cellular desensitization to type I interferon.
  • IFNAR1 underwent ubiquitination upon infection, and inhibition of JAK kinases enhanced viral infection in stem cell-derived cultures.

Conclusions:

  • Suppression of interferon signaling is a key mechanism employed by SARS-CoV-2 to evade antiviral innate immunity.
  • Targeting viral mediators of immune evasion could be a viable strategy to block SARS-CoV-2 replication in COVID-19 patients.
  • These findings reveal how SARS-CoV-2 propagates in different tissues despite the host's immune response.

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