title: Inhibition of T cell activation by a monoclonal antibody reactive against the alpha 3 domain of human MHC class I molecules.
abstract: A long term goal of investigators working in our laboratory has been to develop new mAbs for use as immunosuppressive agents. As a means toward achieving this goal, several new mAbs (hybridomas) have been developed by screening fusions for supernatants that possess T cell-inhibitory properties. Of these new mAbs, one mAb, designated 5H7, has been shown to possess both a unique combination of specificity for a monomorphic determinant of the alpha 3 domain of human class I MHC heavy chains and highly potent T cell inhibitory properties. mAb 5H7 profoundly inhibited T cell proliferation in response to anti-CD3 mAb in primary or secondary allogenic MLR or in primary human anti-mouse xenogenic MLR. mAb 5H7 inhibited expression of an early T cell activation marker, Leu23 (CD69); expression of IL-2Rs; and IL-2 production by both CD4+ and CD8+ T cells. mAb 5H7 inhibited IL-2 release by the Jurkat (E6-1) human T cell leukemia line in response to immobilized anti-CD3 mAb, thus, providing further evidence that 5H7 can inhibit activation directly at the level of the T cell. 5H7 profoundly blocked CD3-dependent (anti-CD3, anti-CD3 plus PMA, or anti-CD3 plus anti-CD28) pathways, but only partially blocked a CD3-independent (anti-CD28 plus PMA) pathway of T cell activation. In conclusion, class I MHC molecules that are expressed on the T cell may regulate early TCR/CD3-dependent signaling events. In addition, 5H7 mAb may provide a reagent for suppression of cellular immunity in vivo.
authors.affiliation: Department of Surgery, University of Chicago Pritzker School of Medicine, IL 60637.
authors.forename: D M
authors.initials: DM
authors.lastname: Smith
authors.forename: J A
authors.initials: JA
authors.lastname: Bluestone
authors.forename: D R
authors.initials: DR
authors.lastname: Jeyarajah
authors.forename: M H
authors.initials: MH
authors.lastname: Newberg
authors.forename: V H
authors.initials: VH
authors.lastname: Engelhard
authors.forename: J R
authors.initials: JR
authors.lastname: Thistlethwaite
authors.forename: E S
authors.initials: ES
authors.lastname: Woodle
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology*; D015703:Antigens, CD / Q000378:metabolism; D000945:Antigens, Differentiation, T-Lymphocyte / Q000378:metabolism; D018106:CD28 Antigens / Q000502:physiology; D017252:CD3 Complex / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D015395:Histocompatibility Antigens Class I / Q000276:immunology*; D006801:Humans; D066298:In Vitro Techniques; D007376:Interleukin-2 / Q000096:biosynthesis; D037181:Lectins, C-Type; D008213:Lymphocyte Activation; D011948:Receptors, Antigen, T-Cell / Q000276:immunology; D015375:Receptors, Interleukin-2 / Q000378:metabolism; D015398:Signal Transduction; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D000099192:CD69 Antigens
chemical_list: D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D018106:CD28 Antigens; D017252:CD3 Complex; D015395:Histocompatibility Antigens Class I; D007376:Interleukin-2; D037181:Lectins, C-Type; D011948:Receptors, Antigen, T-Cell; D015375:Receptors, Interleukin-2; D000099192:CD69 Antigens