Regulation of nuclear factor-kappa B and activator protein-1 activities after stimulation of T cells via glycosylphosphatidylinositol-anchored Ly-6A/E.
Cross-linking of glycosylphosphatidylinositol-anchored proteins, including mouse Ly-6A/E, leads to IL-2 secretion and T cell activation, whereas engagement of Ly-6A/E uniquely inhibits IL-2 production induced via TCR. However, little is known concerning the molecular mechanism by which glycosylphosphatidylinositol-anchored proteins regulate IL-2 expression. In this study, we have examined the ability of an anti-Ly-6A/E mAb to regulate transcription factors controlling IL-2 expression. Stimulation of EL4J(Ly-6E).A4 cells with anti-CD3 epsilon or anti-Ly6A/E mAbs induced nuclear factor (NF)-kappa B p65-p50 (RelA/p50) and AP-1 (Fos/Jun) binding activities and increased nuclear factor of activated T cells (NF-AT) activity, whereas octamer-binding factor and NF-Y levels were stable. Cyclic AMP response element binding protein and T cell-specific factor-1 (alpha) activities were selectively enhanced by anti-CD3 epsilon, but not by anti-Ly6A/E, which suggests that signaling via the TCR and Ly-6 were not identical. Costimulation of these cells with both mAbs produced substantially reduced levels of AP-1, NF-AT, and, especially, NF-kappa B p65-p50 whereas cyclic AMP response element binding protein and T cell-specific factor-1(alpha) were induced to a level seen after stimulation by anti-CD3 epsilon. The inducibility of the IL-2 enhancer in vivo and the contribution of individual transcription factors for this induction were assessed with use of reporter chloramphenicol acetyltransferase constructs containing the IL-2 enhancer or oligomerized binding sites for transcription factors. These experiments also demonstrated a key role for NF-kappa B and AP-1 in the transcriptional regulation of the IL-2 gene by TCR- and Ly6A/E-mediated signaling. By using the 2B4.11 T cell hybridoma and a mutated variant, were revealed a crucial role for the zeta-chain in Ly6A/E-mediated activation of NF-kappa B.
Ivanov
V
V
Department of Microbiology and Immunology, University of Miami School of Medicine, FL 33101.
Fleming
T J
TJ
Malek
T R
TR
D000911:Antibodies, Monoclonal; D000950:Antigens, Ly / Q000276:immunology*; D000954:Antigens, Surface / Q000276:immunology; D001483:Base Sequence; D017252:CD3 Complex / Q000276:immunology; D002460:Cell Line; D017261:Glycosylphosphatidylinositols / Q000378:metabolism; D006825:Hybridomas; D007376:Interleukin-2; D008562:Membrane Glycoproteins / Q000276:immunology; D008565:Membrane Proteins / Q000276:immunology*; D008969:Molecular Sequence Data; D016328:NF-kappa B / Q000378:metabolism*; D016755:Proto-Oncogene Proteins c-jun / Q000378:metabolism*; D011948:Receptors, Antigen, T-Cell / Q000276:immunology; D015398:Signal Transduction / Q000502:physiology; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D018800:Thy-1 Antigens; D014157:Transcription Factors / Q000378:metabolism; D014162:Transfection
D000911:Antibodies, Monoclonal; D000950:Antigens, Ly; D000954:Antigens, Surface; D017252:CD3 Complex; D017261:Glycosylphosphatidylinositols; D007376:Interleukin-2; C074650:Ly6a protein, mouse; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D016328:NF-kappa B; D016755:Proto-Oncogene Proteins c-jun; D011948:Receptors, Antigen, T-Cell; D018800:Thy-1 Antigens; D014157:Transcription Factors; C054979:antigen T cell receptor, zeta chain