Siglec1 suppresses antiviral innate immune response by inducing TBK1 degradation via the ubiquitin ligase TRIM27

Cell Res. 2015 Oct;25(10):1121-36. doi: 10.1038/cr.2015.108. Epub 2015 Sep 11.

Abstract

Type I interferon (IFN) production plays pivotal roles in host antiviral innate immune responses, but an excessive production of type I IFN leads to the development of immunopathological conditions. Investigations on the regulatory mechanisms underlying host type I IFN production are currently of great interest. Here, we found that the expression of lectin family member Siglec1 was upregulated by viral infection in macrophages, which was dependent on the IFN/JAK/STAT1 signaling pathway. Siglec1 was found to negatively regulate viral infection-triggered type I IFN production. Mechanistically, Siglec1 associates with DAP12 to recruit and activate the scaffolding function of SHP2; SHP2 then recruits E3 ubiquitin ligase TRIM27, which induces TBK1 degradation via K48-linked ubiquitination at Lys251 and Lys372. Therefore, viral infection-induced upregulation of Siglec1 feedback loop inhibits type I IFN production and suppresses antiviral innate immune responses. Our study outlines a novel mechanism of negative regulation of type I IFN production, which may help virus to escape immune elimination.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Line
  • DNA-Binding Proteins / immunology*
  • DNA-Binding Proteins / metabolism
  • HEK293 Cells
  • Humans
  • Immunity, Innate*
  • Interferon Regulatory Factor-3 / immunology
  • Interferon Type I / immunology
  • Macrophages / immunology*
  • Macrophages / virology*
  • Mice, Inbred C57BL
  • Nuclear Proteins / immunology*
  • Nuclear Proteins / metabolism
  • Protein Serine-Threonine Kinases / immunology*
  • Protein Serine-Threonine Kinases / metabolism
  • Proteolysis
  • Sialic Acid Binding Ig-like Lectin 1 / immunology*
  • Signal Transduction
  • Ubiquitin-Protein Ligases
  • Ubiquitination
  • Virus Diseases / immunology
  • Virus Diseases / metabolism

Substances

  • DNA-Binding Proteins
  • Interferon Regulatory Factor-3
  • Interferon Type I
  • Irf3 protein, mouse
  • Nuclear Proteins
  • Sialic Acid Binding Ig-like Lectin 1
  • Siglec1 protein, mouse
  • Trim27 protein, mouse
  • Ubiquitin-Protein Ligases
  • Tbk1 protein, mouse
  • Protein Serine-Threonine Kinases