title: Triggering of OX40 (CD134) on CD4(+)CD25+ T cells blocks their inhibitory activity: a novel regulatory role for OX40 and its comparison with GITR.
abstract: OX40 (CD134) is a member of the tumor necrosis factor (TNF) receptor family that is transiently expressed on T cells after T-cell receptor (TCR) ligation. Both naive and activated CD4(+)CD25+ regulatory T cells (T reg's) express OX40 but its functional role has not been determined. Since glucocorticoid-induced tumor necrosis factor receptor (GITR), a related TNF receptor family member, influences T reg function, we tested whether OX40 might have similar effect. Triggering either GITR or OX40 on T reg's using agonist antibodies inhibited their capacity to suppress and restored effector T-cell proliferation, interleukin-2 (IL-2) gene transcription and cytokine production. OX40 abrogation of T reg suppression was confirmed in vivo in a model of graft-versus-host disease (GVHD). In a fully allogeneic C57BL/6>BALB/c bone marrow transplantation, GVHD was lethal unless T reg's were cotransferred with the bone marrow and effector T cells. Strikingly, T reg suppression of GVHD was abrogated either by intraperitoneal injection of anti-OX40 or anti-GITR monoclonal antibodies (mAbs) immediately after transfer, or by in vitro pretreatment of T reg's with the same mAbs before transfer. Cumulatively, the results suggest that in addition to controlling memory T-cell numbers, OX40 directly controls T reg-mediated suppression.
authors.affiliation: Immunotherapy and Gene Therapy Unit, Department of Experimental Oncology, Istituto Nazionale per lo Studio e la Cura dei Tumori, Via Venezian 1, 20133 Milan, Italy.
authors.forename: Barbara
authors.initials: B
authors.lastname: Valzasina
authors.forename: Cristiana
authors.initials: C
authors.lastname: Guiducci
authors.forename: Heidrun
authors.initials: H
authors.lastname: Dislich
authors.forename: Nigel
authors.initials: N
authors.lastname: Killeen
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Weinberg
authors.forename: Mario P
authors.initials: MP
authors.lastname: Colombo
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D016026:Bone Marrow Transplantation; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism*; D002455:Cell Division / Q000276:immunology; D053450:Glucocorticoid-Induced TNFR-Related Protein; D006086:Graft vs Host Disease / Q000276:immunology / Q000378:metabolism*; D007376:Interleukin-2 / Q000378:metabolism; D008213:Lymphocyte Activation / Q000502:physiology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008817:Mice, Mutant Strains; D051381:Rats; D017208:Rats, Wistar; D015375:Receptors, Interleukin-2 / Q000378:metabolism; D017475:Receptors, Nerve Growth Factor / Q000276:immunology / Q000378:metabolism*; D053262:Receptors, OX40; D018124:Receptors, Tumor Necrosis Factor / Q000235:genetics / Q000276:immunology / Q000378:metabolism*
chemical_list: D000911:Antibodies, Monoclonal; D053450:Glucocorticoid-Induced TNFR-Related Protein; D007376:Interleukin-2; D015375:Receptors, Interleukin-2; D017475:Receptors, Nerve Growth Factor; D053262:Receptors, OX40; D018124:Receptors, Tumor Necrosis Factor; C106544:Tnfrsf18 protein, mouse; C505717:Tnfrsf4 protein, mouse; C505718:Tnfrsf4 protein, rat