What is the role of regulatory T cells in transplantation tolerance?
There has been considerable recent progress in the characterization of the regulatory T cells that mediate tolerance in a number of transplantation models. The conditions that facilitate the generation of regulatory T cells point to the thymus, the nature of immune suppression and the dose of immunosuppressive agent(s) being important. Putative mechanisms of immune regulation by regulatory T cells, particularly in the 'infectious' tolerance pathway, include Th2-type cytokines (IL-4, IL-10 and transforming growth factor beta) that may play a direct role as an indispensable requirement or may contribute indirectly as a favorable milieu for acquisition of tolerance. Anergic T cells may suppress immune responses via either cytokine competition or antigen-presenting cells. Models of autoimmune disease, in which regulatory T cells were shown to represent a distinct thymus-derived T cell subset, also suggest the role of antigen-presenting cells in mediating immune suppression. Progress has also been made in generating and characterizing regulatory T cells in vitro.
Zhai
Y
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The Dumont-UCLA Transplant Center, University of California (Los Angeles) School of Medicine, Department of Surgery, Room 77-120, Center for Health Science, 10833 Le Conte Avenue, Los Angeles, CA 90095, USA.
Kupiec-Weglinski
J W
JW
D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D017635:Clonal Anergy; D016377:Organ Transplantation; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D013950:Thymus Gland / Q000166:cytology / Q000276:immunology; D014181:Transplantation Immunology