title: Blockade of CTLA-4 signals inhibits Th2-mediated murine chronic graft-versus-host disease by an enhanced expansion of regulatory CD8+ T cells.
abstract: CTLA-4 (CD152) is thought to be a negative regulator of T cell activation. Little is known about the function of CTLA-4 in Th2-type immune responses. We have investigated the effect of initial treatment with anti-CTLA-4 mAb on murine chronic graft-vs-host disease. Transfer of parental BALB/c splenocytes into C57BL/6 x BALB/c F1 mice induced serum IgE production, IL-4 expression by donor CD4+ T cells, and host allo-Ag-specific IgG1 production at 6-9 wk after transfer. Treatment with anti-CTLA-4 mAb for the initial 2 wk significantly reduced IgE and IgG1 production and IL-4 expression. Analysis of the splenic phenotype revealed the enhancement of donor T cell expansion, especially within the CD8 subset, and the elimination of host cells early after anti-CTLA-4 mAb treatment. This treatment did not affect early IFN-gamma expression by CD4+ and CD8+ T cells and anti-host cytolytic activity. Thus, blockade of CTLA-4 greatly enhanced CD8+ T cell expansion, and this may result in the regulation of consequent Th2-mediated humoral immune responses. These findings suggest a new approach for regulating IgE-mediated allergic immune responses by blockade of CTLA-4 during a critical period of Ag sensitization.
authors.affiliation: Department of Immunology, National Children's Medical Research Center, Tokyo, Japan.
authors.forename: J
authors.initials: J
authors.lastname: Sakurai
authors.forename: J
authors.initials: J
authors.lastname: Ohata
authors.forename: K
authors.initials: K
authors.lastname: Saito
authors.forename: H
authors.initials: H
authors.lastname: Miyajima
authors.forename: T
authors.initials: T
authors.lastname: Hirano
authors.forename: T
authors.initials: T
authors.lastname: Kohsaka
authors.forename: S
authors.initials: S
authors.lastname: Enomoto
authors.forename: K
authors.initials: K
authors.lastname: Okumura
authors.forename: M
authors.initials: M
authors.lastname: Azuma
mesh_terms: D000069594:Abatacept; D000818:Animals; D019138:Antibodies, Blocking / Q000494:pharmacology; D000911:Antibodies, Monoclonal / Q000008:administration & dosage / Q000494:pharmacology; D015703:Antigens, CD; D000943:Antigens, Differentiation / Q000276:immunology* / Q000502:physiology; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology*; D060908:CTLA-4 Antigen; D002908:Chronic Disease; D005260:Female; D006086:Graft vs Host Disease / Q000276:immunology / Q000517:prevention & control*; D018796:Immunoconjugates; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D008213:Lymphocyte Activation / Q000276:immunology*; D008212:Lymphocyte Depletion; D017710:Lymphocyte Transfusion; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D015398:Signal Transduction / Q000276:immunology*; D013154:Spleen / Q000166:cytology / Q000637:transplantation; D018418:Th2 Cells / Q000276:immunology*
chemical_list: D019138:Antibodies, Blocking; D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D000943:Antigens, Differentiation; D060908:CTLA-4 Antigen; C556707:Ctla4 protein, mouse; D018796:Immunoconjugates; D007166:Immunosuppressive Agents; D000069594:Abatacept