Unique role of the PI3-Kδ isoform in immunity

Abstract

There is increasing evidence of key roles for the class 1A phosphoinositide 3-kinases (PI-3-Ks) in the immune system. There are three class 1A catalytic subunits – p110α, p110β and p110δ. Particular interest has focused on the δ isoform because this is expressed predominantly in leukocytes, suggesting a unique role in immune signaling. However, the specific role(s) for each of these catalytic isoforms in lymphocyte signaling is undetermined and it is not clear whether the isoforms have overlapping or distinct biological roles. A study by Okkenhaug et al. [ 1. Okkenhaug K. et al. Impaired B- and T-cell-antigen receptor signaling in p110δ PI3-kinase mutant mice. Science. 2002; 297: 1031-1034 PubMed Google Scholar ] has begun to peel away some of the layers of mystery surrounding the function of the individual p110 catalytic isoforms in lymphocytes.