title: Phosphoinositide 3-kinase gamma participates in T cell receptor-induced T cell activation.
abstract: Class I phosphoinositide 3-kinases (PI3Ks) constitute a family of enzymes that generates 3-phosphorylated polyphosphoinositides at the cell membrane after stimulation of protein tyrosine (Tyr) kinase-associated receptors or G protein-coupled receptors (GPCRs). The class I PI3Ks are divided into two types: class I(A) p85/p110 heterodimers, which are activated by Tyr kinases, and the class I(B) p110gamma isoform, which is activated by GPCR. Although the T cell receptor (TCR) is a protein Tyr kinase-associated receptor, p110gamma deletion affects TCR-induced T cell stimulation. We examined whether the TCR activates p110gamma, as well as the consequences of interfering with p110gamma expression or function for T cell activation. We found that after TCR ligation, p110gamma interacts with G alpha(q/11), lymphocyte-specific Tyr kinase, and zeta-associated protein. TCR stimulation activates p110gamma, which affects 3-phosphorylated polyphosphoinositide levels at the immunological synapse. We show that TCR-stimulated p110gamma controls RAS-related C3 botulinum substrate 1 activity, F-actin polarization, and the interaction between T cells and antigen-presenting cells, illustrating a crucial role for p110gamma in TCR-induced T cell activation.
authors.affiliation: Department of Immunology and Oncology, Centro Nacional de Biotecnología/Consejo Superior de Investigaciones Cientificas, Madrid 28049, Spain.
authors.forename: Isabela
authors.initials: I
authors.lastname: Alcázar
authors.forename: Miriam
authors.initials: M
authors.lastname: Marqués
authors.forename: Amit
authors.initials: A
authors.lastname: Kumar
authors.forename: Emilio
authors.initials: E
authors.lastname: Hirsch
authors.forename: Matthias
authors.initials: M
authors.lastname: Wymann
authors.forename: Ana C
authors.initials: AC
authors.lastname: Carrera
authors.forename: Domingo F
authors.initials: DF
authors.lastname: Barber
mesh_terms: D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000201:enzymology / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000201:enzymology / Q000276:immunology; D017930:Genes, Reporter; D008213:Lymphocyte Activation; D051379:Mice; D018345:Mice, Knockout; D019869:Phosphatidylinositol 3-Kinases / Q000145:classification / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D011948:Receptors, Antigen, T-Cell / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D011948:Receptors, Antigen, T-Cell; D019869:Phosphatidylinositol 3-Kinases