title: Blocking OX-40/OX-40 ligand interaction in vitro and in vivo leads to decreased T cell function and amelioration of experimental allergic encephalomyelitis.
abstract: The OX-40R is a member of the TNF receptor family and is expressed primarily on activated CD4+ T cells. When the OX-40R is engaged by the OX-40 ligand (OX-40L), a potent costimulatory signal occurs. We have identified a population of CD11b+ cells, isolated from the central nervous system (CNS) of mice with actively induced experimental allergic encephalomyelitis (EAE), that expresses OX-40L. Moreover, the expression of OX-40L was found to be associated with paralytic episodes of EAE and was reduced or absent at disease recovery. These CD11b+ cells also coexpressed B7 and MHC class II. Therefore, to address the relative contributions of OX-40R/OX-40L and CD28/B7 to the costimulation of myelin-specific T cells, blocking studies were performed using soluble OX-40R and/or soluble CTLA-4. CD11b+ cells isolated from the CNS of mice with actively induced EAE were able to present Ag to proteolipid protein 139-151-specific T cell lines in vitro. The addition of soluble OX-40R:Ig to CD11b+ brain microglia/macrophages inhibited T cell proliferation by 50-70%. The addition of CTLA-4:Ig inhibited T cell proliferation by 20-30%, and the combination inhibited T cell proliferation by 95%. In vivo administration of soluble OX-40R at the onset of actively induced or adoptively transferred EAE reduced ongoing signs of disease, and the mice recovered more quickly from acute disease. The data imply that OX-40L, expressed by CNS-derived APC, acts to provide an important costimulatory signal to EAE effector T cells found within the inflammatory lesions. Furthermore, the data suggest that agents designed to inhibit the OX-40L/OX-40R complex may be useful for treating autoimmune disease.
authors.affiliation: Earle A. Chiles Research Institute, Robert W. Franz Cancer Research Center, Providence Portland Medical Center, Portland, OR 97213, USA. weinbera@ohsu.edu
authors.forename: A D
authors.initials: AD
authors.lastname: Weinberg
authors.forename: K W
authors.initials: KW
authors.lastname: Wegmann
authors.forename: C
authors.initials: C
authors.lastname: Funatake
authors.forename: R H
authors.initials: RH
authors.lastname: Whitham
mesh_terms: D019264:Adoptive Transfer; D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D004681:Encephalomyelitis, Autoimmune, Experimental / Q000276:immunology* / Q000628:therapy*; D005260:Female; D007700:Kinetics; D008024:Ligands; D008213:Lymphocyte Activation; D016177:Macrophage-1 Antigen / Q000378:metabolism; D008562:Membrane Glycoproteins; D051379:Mice; D053278:OX40 Ligand; D053262:Receptors, OX40; D018124:Receptors, Tumor Necrosis Factor / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000276:immunology / Q000627:therapeutic use; D013601:T-Lymphocytes / Q000276:immunology*; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7 / Q000378:metabolism*; D048069:Tumor Necrosis Factors