title: CD28-specific antibody prevents graft-versus-host disease in mice.
abstract: The costimulatory molecules B7-1 and B7-2 regulate T cell activation by delivering activation signals through CD28 and inhibitory signals through CTLA4. Graft-vs-host disease (GVHD) is caused by activated donor T cells. Previously, we showed that CD28-deficient donor T cells induced less-severe GVHD than wild-type donor T cells, suggesting that CD28 signals exacerbate GVHD. In this paper we demonstrate that CTLA4 signals attenuate the severity of GVHD. Targeting the CD28 receptor with a specific mAb modulates the receptor in vivo, inhibits donor T cell expansion, and prevents GVHD. CTLA4 signaling was necessary for this effect because treatment with a soluble ligand that blocks binding of B7 to both CD28 and CTLA4 did not prevent GVHD as effectively as anti-CD28 mAb. These results support the current model of T cell costimulation in which CD28 signals amplify GVHD while CTLA4 signals inhibit GVHD, providing evidence that selective targeting of CD28 might be a better therapeutic strategy for inducing immunological tolerance than blocking the ligands for both CD28 and CTLA4.
authors.affiliation: Human Immunogenetics Program, Division of Clinical Research, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA.
authors.forename: X Z
authors.initials: XZ
authors.lastname: Yu
authors.forename: S J
authors.initials: SJ
authors.lastname: Bidwell
authors.forename: P J
authors.initials: PJ
authors.lastname: Martin
authors.forename: C
authors.initials: C
authors.lastname: Anasetti
mesh_terms: D000069594:Abatacept; D000818:Animals; D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D000918:Antibody Specificity; D015703:Antigens, CD; D000943:Antigens, Differentiation / Q000096:biosynthesis / Q000276:immunology / Q000502:physiology; D001402:B-Lymphocytes / Q000276:immunology; D018106:CD28 Antigens / Q000276:immunology*; D060908:CTLA-4 Antigen; D003602:Cytotoxicity, Immunologic; D006086:Graft vs Host Disease / Q000276:immunology* / Q000401:mortality / Q000473:pathology / Q000517:prevention & control*; D006131:Growth Inhibitors / Q000627:therapeutic use; D018796:Immunoconjugates; D007074:Immunoglobulin G / Q000627:therapeutic use*; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D008213:Lymphocyte Activation / Q000276:immunology; D008231:Lymphopenia / Q000276:immunology / Q000517:prevention & control; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008822:Mice, Transgenic; D015375:Receptors, Interleukin-2 / Q000037:antagonists & inhibitors / Q000096:biosynthesis; D015398:Signal Transduction / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology / Q000637:transplantation
chemical_list: D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D000943:Antigens, Differentiation; D018106:CD28 Antigens; D060908:CTLA-4 Antigen; C556706:CTLA4 protein, human; C556707:Ctla4 protein, mouse; D006131:Growth Inhibitors; D018796:Immunoconjugates; D007074:Immunoglobulin G; D007166:Immunosuppressive Agents; D015375:Receptors, Interleukin-2; D000069594:Abatacept