title: Wortmannin, a phosphatidylinositol 3-kinase inhibitor, blocks antigen-mediated, but not CD3 monoclonal antibody-induced, activation of murine CD4+ T cells.
abstract: Perturbation of several distinct T cell molecules, including the CD3/TCR complex, CD7, and CD28, activates phosphatidylinositol 3-kinase (PI3-K), but a clear consensus on the role of PI3-K in T cell activation has yet to emerge. We report here that CD3 mAb-induced IL-2 production by CD4+ T cells from DO11.10 TCR-alphabeta-transgenic mice is refractory to the potent PI3-K inhibitor, wortmannin, demonstrating that activation under these conditions is independent of PI3-K. In marked contrast, wortmannin substantially inhibits IL-2 production elicited by Ag (OVA(323-339) peptide) presented by appropriate APCs (syngeneic B7+ B cell blasts) and blocks Ag-induced differentiation of naive CD4+ DO11.10 T cells into IL-4-producing cells. Wortmannin inhibits Ag-induced conjugate formation between T cells and B7+ B cell blasts. Because T cell activation by Ag requires stable interactions with APCs, this inhibitory effect on conjugate formation may underlie the ability of wortmannin to block Ag-induced IL-2 production and differentiation.
authors.affiliation: Department of Medicine and San Francisco General Hospital, University of California, 94143, USA.
authors.forename: J
authors.initials: J
authors.lastname: Shi
authors.forename: T
authors.initials: T
authors.lastname: Cinek
authors.forename: K E
authors.initials: KE
authors.lastname: Truitt
authors.forename: J B
authors.initials: JB
authors.lastname: Imboden
mesh_terms: D000730:Androstadienes / Q000494:pharmacology*; D000818:Animals; D018122:B7-1 Antigen / Q000502:physiology; D017252:CD3 Complex / Q000502:physiology*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D002454:Cell Differentiation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D007376:Interleukin-2 / Q000096:biosynthesis; D015847:Interleukin-4 / Q000096:biosynthesis; D008213:Lymphocyte Activation / Q000187:drug effects*; D008211:Lymphocyte Cooperation; D051379:Mice; D008822:Mice, Transgenic; D010047:Ovalbumin / Q000276:immunology; D010455:Peptides / Q000276:immunology; D019869:Phosphatidylinositol 3-Kinases; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000037:antagonists & inhibitors*; D011948:Receptors, Antigen, T-Cell / Q000502:physiology*; D015398:Signal Transduction; D000077191:Wortmannin
chemical_list: D000730:Androstadienes; D018122:B7-1 Antigen; D017252:CD3 Complex; D004791:Enzyme Inhibitors; D007376:Interleukin-2; D010455:Peptides; D011948:Receptors, Antigen, T-Cell; D015847:Interleukin-4; D010047:Ovalbumin; D019869:Phosphatidylinositol 3-Kinases; D017853:Phosphotransferases (Alcohol Group Acceptor); D000077191:Wortmannin