tailieunhanh - Báo cáo y học: "A paragon of self-tolerance: CD25+CD4+ regulatory T cells and the control of immune responses"

Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học General Psychiatry cung cấp cho các bạn kiến thức về ngành y đề tài: A paragon of self-tolerance: CD25+CD4+ regulatory T cells and the control of immune responses. | Available online http content 6 1 19 Review A paragon of self-tolerance CD25 CD4 regulatory T cells and the control of immune responses Zoltán Fehérvári and Shimon Sakaguchi Department of Experimental Pathology Kyoto University Kyoto Japan Correspondence Shimon Sakaguchi e-mail shimon@ Received 23 Sep 2003 Accepted 3 Dec 2003 Published 19 Dec 2003 Arthritis Res Ther 2004 6 19-25 DOI ar1037 2004 BioMed Central Ltd Print ISSN 1478-6354 Online ISSN 1478-6362 Abstract The interest in naturally arising regulatory T Tr cells as a paradigm for maintaining immunological selftolerance has undergone an explosive re-emergence in recent years. This renaissance was triggered by several key experimental observations and the identification of specific molecular markers that have enabled the isolation and experimental manipulation of these cells. Although their existence was once controversial a large body of evidence now highlights the critical roles of TR cells in maintaining immunological self-tolerance. Furthermore abnormality of natural TR cells can be a primary cause of autoimmune and other inflammatory diseases in humans. Keywords CD25 CD4 Foxp3 regulatory cells self-tolerance suppression Introduction The random nature of T-cell receptor TCR generation inevitably leads to the appearance of deleterious autoreactive clones but the vast majority of such cells are purged in the thymus during negative selection. However there is abundant evidence showing that significant numbers of autoreactive cells can slip through the net of central tolerance into the periphery and thereby potentially mediate autoimmunity. This phenomenon can be readily demonstrated by the experimental induction of autoimmunity when otherwise normal animals are injected with self proteins plus a strong adjuvant 1 . The fact that healthy animals harbour such destructive cells implies the existence of mechanisms operating in the periphery that are able to .