title: Ox-40 ligand: a potent costimulatory molecule for sustaining primary CD4 T cell responses.
abstract: Ox-40 and Ox-40 ligand (Ox-40L) are thought to be involved in T cell-APC interactions. However, their exact role in T cell responses is undefined. Using fibroblast transfectants expressing Ox-40L and/or B7-1, and CD4 cells from TCR transgenic mice, we investigated the effect of Ox-40 signaling on primary responses to the Ag pigeon cytochrome c. Ox-40 expression on naive CD4 cells peaked 2 to 3 days after activation, and was lost by 4 to 5 days. APCs with Ox-40L promoted partial activation of naive T cells with some IL-2 secretion, but were unable to enhance proliferation, unlike those with B7-1. APCs coexpressing Ox-40L with B7-1 induced large quantities of IL-2 and promoted proliferative responses that persisted for several days. Effector cells taken 5 days after naive T cell activation reexpressed Ox-40 within 4 h and responded strongly to APCs expressing Ox-40L, whereas B7-1 had little effect. Synergy was also seen between Ox-40L and B7-1, with primarily IL-2 being elevated, although IL-4 and IL-5 were also up-regulated. The most striking action was on effector T cell proliferation, which continued at high levels for up to 4 days, with little proliferation evident at this time in the absence of Ox-40 signals. These data suggest that Ox-40/Ox-40L interactions act after initial activation events to prolong clonal expansion and enhance effector cytokine secretion, and may be involved in promoting long-lived primary CD4 responses.
authors.affiliation: Division of Immunochemistry, La Jolla Institute for Allergy and Immunology, San Diego, CA 92121, USA.
authors.forename: I
authors.initials: I
authors.lastname: Gramaglia
authors.forename: A D
authors.initials: AD
authors.lastname: Weinberg
authors.forename: M
authors.initials: M
authors.lastname: Lemon
authors.forename: M
authors.initials: M
authors.lastname: Croft
mesh_terms: D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology*; D018122:B7-1 Antigen / Q000235:genetics / Q000276:immunology; D018106:CD28 Antigens / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D002478:Cells, Cultured; D010856:Columbidae; D003574:Cytochrome c Group / Q000276:immunology; D005347:Fibroblasts; D007376:Interleukin-2 / Q000378:metabolism; D015847:Interleukin-4 / Q000378:metabolism; D015848:Interleukin-5 / Q000378:metabolism; D008213:Lymphocyte Activation / Q000502:physiology*; D008562:Membrane Glycoproteins; D051379:Mice; D008822:Mice, Transgenic; D053278:OX40 Ligand; D010446:Peptide Fragments / Q000276:immunology; D011948:Receptors, Antigen, T-Cell / Q000235:genetics; D053262:Receptors, OX40; D018124:Receptors, Tumor Necrosis Factor / Q000235:genetics / Q000276:immunology*; D011993:Recombinant Fusion Proteins / Q000276:immunology; D014162:Transfection; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7 / Q000276:immunology*; D048069:Tumor Necrosis Factors
chemical_list: D018122:B7-1 Antigen; D018106:CD28 Antigens; D003574:Cytochrome c Group; D007376:Interleukin-2; D015848:Interleukin-5; D008562:Membrane Glycoproteins; D053278:OX40 Ligand; D010446:Peptide Fragments; D011948:Receptors, Antigen, T-Cell; D053262:Receptors, OX40; D018124:Receptors, Tumor Necrosis Factor; D011993:Recombinant Fusion Proteins; C505717:Tnfrsf4 protein, mouse; C504586:Tnfsf4 protein, mouse; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7; D048069:Tumor Necrosis Factors; D015847:Interleukin-4