Bruton's Tyrosine Kinase Regulates TLR7/8-induced TNF Transcription via Nuclear factor-κB Recruitment

Biochem Biophys Res Commun. 2018 May 5;499(2):260-266. doi: 10.1016/j.bbrc.2018.03.140. Epub 2018 Mar 22.

Abstract

Tumour necrosis factor (TNF) is produced by primary human macrophages in response to stimulation by exogenous pathogen-associated molecular patterns (PAMPs) and endogenous damage-associated molecular patterns (DAMPs) via Toll-like receptor (TLR) signalling. However, uncontrolled TNF production can be deleterious and hence it is tightly controlled at multiple stages. We have previously shown that Bruton's tyrosine kinase (Btk) regulates TLR4-induced TNF production via p38 MAP Kinase by stabilising TNF messenger RNA. Using both gene over-expression and siRNA-mediated knockdown we have examined the role of Btk in TLR7/8 mediated TNF production. Our data shows that Btk acts in the TLR7/8 pathway and mediates Ser-536 phosphorylation of p65 RelA and subsequent nuclear entry in primary human macrophages. These data show an important role for Btk in TLR7/8 mediated TNF production and reveal distinct differences for Btk in TLR4 versus TLR7/8 signalling.

Keywords: Bruton's tyrosine kinase; Macrophages; NFκB; R848; Toll-like receptors-7/8.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3' Untranslated Regions / genetics
  • Agammaglobulinaemia Tyrosine Kinase
  • Base Pairing / genetics
  • Cell Nucleus / metabolism
  • Cytokines / biosynthesis
  • Down-Regulation / genetics
  • Humans
  • NF-kappa B / metabolism*
  • Phosphorylation
  • Promoter Regions, Genetic / genetics
  • Protein-Tyrosine Kinases / metabolism*
  • Toll-Like Receptor 4 / metabolism
  • Toll-Like Receptor 7 / metabolism*
  • Toll-Like Receptor 8 / metabolism*
  • Transcription Factor RelA / metabolism
  • Transcription, Genetic*
  • Tumor Necrosis Factor-alpha / genetics*
  • Tumor Necrosis Factor-alpha / metabolism

Substances

  • 3' Untranslated Regions
  • Cytokines
  • NF-kappa B
  • Toll-Like Receptor 4
  • Toll-Like Receptor 7
  • Toll-Like Receptor 8
  • Transcription Factor RelA
  • Tumor Necrosis Factor-alpha
  • Protein-Tyrosine Kinases
  • Agammaglobulinaemia Tyrosine Kinase
  • BTK protein, human