title: Phosphatidylinositol 3-kinase inhibitors prevent mouse cytotoxic T-cell development in vitro.
abstract: To become competent killer cells, CD8(+) T cells require stimulation through signal transduction pathways associated with the T-cell receptor, costimulatory molecules such as CD28, and cytokine receptors such as the interleukin (IL)-2 receptor. We used wortmannin and LY294002, two inhibitors of phosphatidylinositol 3-kinase (PI3-K), to study the role of PI3-K in mouse cytotoxic T-lymphocyte (CTL) induction in response to mitogenic anti-CD3 antibody. Anti-CD3-induced CD8(+) T-cell proliferation and CTL development were inhibited dose dependently by both PI3-K inhibitors. IL-2 synthesis by anti-CD3-activated CD8(+) T cells was also diminished by PI3-K inhibition. PI3-K inhibition resulted in a modest decrease in anti-CD3-induced CD4(+) T-cell proliferation but failed to affect IL-2 expression by anti-CD3-activated CD4(+) T cells. PI3-K inhibition during CTL induction resulted in decreased levels of mRNAs coding for granzyme B, perforin, and Fas ligand. In addition, CTL induced in the presence of PI3-K inhibitors failed to conjugate normally with P815 target cells. Exogenous IL-2 did not reverse the effects of PI3-K inhibition on CD8(+) T-cell proliferation and CTL induction. These results support the conclusion that PI3-K activation is involved in T-cell receptor, CD28, and IL-2 receptor signaling of CD8(+) T cells. PI3-K is, therefore, an important component of multiple signal transduction pathways involved in CTL generation.
authors.affiliation: Department of Microbiology & Immunology, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia B3H 4H7, Canada.
authors.forename: T
authors.initials: T
authors.lastname: Phu
authors.forename: S M
authors.initials: SM
authors.lastname: Haeryfar
authors.forename: B L
authors.initials: BL
authors.lastname: Musgrave
authors.forename: D W
authors.initials: DW
authors.lastname: Hoskin
mesh_terms: D000730:Androstadienes / Q000494:pharmacology; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D018106:CD28 Antigens / Q000276:immunology; D017252:CD3 Complex / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000187:drug effects; D015815:Cell Adhesion Molecules / Q000096:biosynthesis; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D002867:Chromones / Q000494:pharmacology; D003602:Cytotoxicity, Immunologic / Q000276:immunology; D053222:Fas Ligand Protein; D005260:Female; D015870:Gene Expression / Q000187:drug effects; D053804:Granzymes; D007376:Interleukin-2 / Q000096:biosynthesis / Q000235:genetics / Q000494:pharmacology; D008562:Membrane Glycoproteins / Q000235:genetics; D051379:Mice; D008810:Mice, Inbred C57BL; D009025:Morpholines / Q000494:pharmacology; D054353:Perforin; D019869:Phosphatidylinositol 3-Kinases / Q000276:immunology*; D000081082:Phosphoinositide-3 Kinase Inhibitors; D052899:Pore Forming Cytotoxic Proteins; D017260:Receptor-CD3 Complex, Antigen, T-Cell / Q000276:immunology; D015375:Receptors, Interleukin-2 / Q000235:genetics / Q000276:immunology; D012697:Serine Endopeptidases / Q000235:genetics; D015398:Signal Transduction / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D000077191:Wortmannin
chemical_list: D000730:Androstadienes; D000911:Antibodies, Monoclonal; D018106:CD28 Antigens; D017252:CD3 Complex; D015815:Cell Adhesion Molecules; D002867:Chromones; D053222:Fas Ligand Protein; D053804:Granzymes; D007376:Interleukin-2; D008562:Membrane Glycoproteins; D009025:Morpholines; D054353:Perforin; D019869:Phosphatidylinositol 3-Kinases; D000081082:Phosphoinositide-3 Kinase Inhibitors; D052899:Pore Forming Cytotoxic Proteins; D017260:Receptor-CD3 Complex, Antigen, T-Cell; D015375:Receptors, Interleukin-2; D012697:Serine Endopeptidases; D000077191:Wortmannin; C505658:Fasl protein, mouse; C085911:2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one; C509214:Gzmb protein, mouse