Antigen Receptor Signalling: A Distinctive Role for the p110delta Isoform of PI3K

Trends Immunol. 2007 Feb;28(2):80-7. doi: 10.1016/j.it.2006.12.007. Epub 2007 Jan 5.

Abstract

The activation of antigen receptors triggers two important signalling pathways originating from phosphatidylinositol(4,5)-bisphosphate [PtdIns(4,5)P(2)]. The first is phospholipase Cgamma (PLCgamma)-mediated hydrolysis of PtdIns(4,5)P(2), resulting in the activation of Ras, protein kinase C and Ca(2+) flux. This culminates in profound alterations in gene expression and effector-cell responses, including secretory granule exocytosis and cytokine production. By contrast, phosphoinositide 3-kinases (PI3Ks) phosphorylate PtdIns(4,5)P(2) to yield phosphatidylinositol(3,4,5)-trisphosphate, activating signalling pathways that overlap with PLCgamma or are PI3K-specific. Pathways that are PI3K-specific include Akt-mediated inactivation of Foxo transcription factors and transcription-independent regulation of glucose uptake and metabolism. The p110delta isoform of PI3K is the main source of PI3K activity following antigen recognition by B cells, T cells and mast cells. Here, we review the roles of p110delta in regulating antigen-dependent responses in these cell types.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Cell Differentiation
  • Humans
  • Lymphocytes / cytology
  • Lymphocytes / immunology
  • Phosphatidylinositol 3-Kinases / metabolism*
  • Protein Subunits / metabolism*
  • Receptors, Antigen / immunology*
  • Receptors, Antigen / metabolism*
  • Signal Transduction / immunology*

Substances

  • Protein Subunits
  • Receptors, Antigen
  • Phosphatidylinositol 3-Kinases