Research ArticleImmunology

PI3Kβ Plays a Critical Role in Neutrophil Activation by Immune Complexes

See allHide authors and affiliations

Sci. Signal.  12 Apr 2011:
Vol. 4, Issue 168, pp. ra23
DOI: 10.1126/scisignal.2001617

You are currently viewing the editor's summary.

View Full Text

Log in to view the full text

Log in through your institution

Log in through your institution

The Integrating Isoform

The class I phosphoinositide 3-kinases (PI3Ks) are implicated in processes such as growth factor signaling and inflammation. PI3Kγ is activated by G protein–coupled receptors (GPCRs), whereas PI3Kα and PI3Kδ are activated by protein tyrosine kinase–coupled receptors. PI3Kβ is unusual in that it appears to respond to signals from both types of receptors, depending on the cellular context. Kulkarni et al. investigated the responses of mouse neutrophils to immune complexes of antibody and antigen, which trigger chronic inflammation in conditions such as autoimmune arthritis. Genetic and pharmacological evidence suggested that immune complexes stimulated PI3Kβ in a process involving activation of FcγR, a tyrosine kinase–coupled low-affinity antibody receptor, and autocrine signaling by a proinflammatory lipid (LTB4) through its GPCR. Mice deficient in PI3Kβ fared better than did controls in models of arthritis and inflammatory skin disease. These data implicate PI3Kβ in the integration of signals from tyrosine kinase–coupled receptors and GPCRs—and suggest that this isoform may be an effective therapeutic target in inflammatory diseases.