title: T cell costimulatory pathways: promising novel targets for immunosuppression and tolerance induction.
abstract: It is now accepted that T cells need two signals for full activation. The first is the foreign antigen itself presented by self-major histocompatibility complex and thus provides antigen specificity to the immune response. The second is a "costimulatory" signal, the best-characterized of which is provided through the T cell accessory molecule CD28. In vitro, the blockade of costimulatory signals inhibits T cell activation and induces a state of antigen-specific unresponsiveness. In vivo, agents that block CD28-mediated costimulation have proved extremely effective in inhibiting the immune response in experimental models of transplantation and autoimmune disease, providing novel strategies for use in clinical trials in the near future.
authors.forename: M H
authors.initials: MH
authors.lastname: Sayegh
authors.forename: L A
authors.initials: LA
authors.lastname: Turka
mesh_terms: D000818:Animals; D001327:Autoimmune Diseases / Q000517:prevention & control; D018106:CD28 Antigens / Q000276:immunology; D006084:Graft Rejection / Q000517:prevention & control; D006801:Humans; D007108:Immune Tolerance; D007165:Immunosuppression Therapy; D008213:Lymphocyte Activation / Q000502:physiology*; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000502:physiology*
chemical_list: D018106:CD28 Antigens