Inactivation of PI3Kgamma and PI3Kdelta distorts T-cell development and causes multiple organ inflammation

Blood. 2007 Oct 15;110(8):2940-7. doi: 10.1182/blood-2007-04-086751. Epub 2007 Jul 12.

Abstract

Mice lacking both the p110gamma and p110delta isoforms display severe impairment of thymocyte development. Here, we show that this phenotype is recapitulated in p110gamma-/-/p110delta(D910A/D910A) (p110gamma(KO)delta(D910A)) mice where the p110delta isoform has been inactivated by a point mutation. Moreover, we have examined the pathological consequences of the p110gammadelta deficiency, which include profound T-cell lymphopenia, T-cell and eosinophil infiltration of mucosal organs, elevated IgE levels, and a skewing toward Th2 immune responses. Using small-molecule selective inhibitors, we demonstrated that in mature T cells, p110delta, but not p110gamma, controls Th1 and Th2 cytokine secretion. Thus, the pathology in the p110gammadelta-deficient mice is likely to be secondary to a developmental block in the thymus that leads to lymphopenia-associated inflammatory responses.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Proliferation
  • Class I Phosphatidylinositol 3-Kinases
  • Class Ib Phosphatidylinositol 3-Kinase
  • Cytokines / biosynthesis
  • Enzyme-Linked Immunosorbent Assay
  • Eosinophils / metabolism
  • Flow Cytometry
  • Fluorescent Antibody Technique
  • Immunoglobulin A / blood
  • Immunoglobulin E / blood
  • Immunoglobulin G / blood
  • Immunoglobulin M / blood
  • Inflammation / etiology
  • Inflammation / immunology*
  • Isoenzymes / deficiency
  • Isoenzymes / immunology
  • Lymphocyte Culture Test, Mixed
  • Lymphopenia / etiology
  • Mice
  • Mice, Mutant Strains
  • Mucous Membrane / immunology
  • Mucous Membrane / pathology
  • Phosphatidylinositol 3-Kinases / deficiency*
  • Phosphatidylinositol 3-Kinases / immunology
  • Salivary Glands / immunology
  • Salivary Glands / pathology
  • Stomach / immunology
  • Stomach / pathology
  • T-Lymphocyte Subsets / cytology
  • T-Lymphocyte Subsets / immunology
  • Th2 Cells / cytology*
  • Th2 Cells / immunology*
  • Thymus Gland / immunology
  • Thymus Gland / pathology

Substances

  • Cytokines
  • Immunoglobulin A
  • Immunoglobulin G
  • Immunoglobulin M
  • Isoenzymes
  • Immunoglobulin E
  • Class I Phosphatidylinositol 3-Kinases
  • Class Ib Phosphatidylinositol 3-Kinase
  • Pik3cd protein, mouse
  • Pik3cg protein, mouse