SEARCH:   Advanced

Blood, 15 June 2008, Vol. 111, No. 12, pp. 5629-5636. Prepublished online as a Blood First Edition Paper on April 3, 2008; DOI 10.1182/blood-2008-02-139899. This Article Full Text Full Text (PDF) All Versions of this Article: blood-2008-02-139899v1 blood-2008-02-139899v2 111/12/5629    most recent Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Rights and Permissions Citing Articles Citing Articles via CrossRef Google Scholar Articles by Li, L. Articles by Wu, C.-Y. PubMed PubMed Citation Articles by Li, L. Articles by Wu, C.-Y. Related Collections Immunobiology Social Bookmarking                   What's this?  Previous Article  |  Table of Contents  |  Next Article  IMMUNOBIOLOGY CD4+CD25+ Treg cells inhibit human memory T cells to produce IFN- in response to M tuberculosis antigen ESAT-6 Li Li1, and Chang-You Wu1 1 Department of Immunology, Zhongshan School of Medicine, Key Laboratory of Tropical Disease Control Research of Ministry of Education, Sun Yat-Sen University, Guangzhou, China T cells play an important role in innate immunity against infections; however, the regulation of these cells remains largely unknown. In the present study, we show that ESAT-6, an antigen of Mycobacterium tuberculosis, induces IFN- secretion by human T cells. In addition, ESAT-6 also induces the activation and proliferation of T cells. Phenotypic analysis indicates that IFN-–producing T cells are mainly effector memory cells with the surface phenotype of CD45RA–CD62L–CCR7–. These results were further confirmed by the fact that naive T cells from cord blood did not produce IFN- in response to ESAT-6. Further studies indicated that stimulation with ESAT-6 directly induced purified T cells to produce IFN-, independent of both antigen-presenting cells and CD4+ T cells. Unexpectedly, depletion of CD4+ T cells markedly enhanced IFN- production by T cells, indicating that CD4+ T cells regulate the response of T cells. Importantly, CD4+CD25+ T regulatory (Treg) cells but not CD4+CD25– T cells significantly inhibited IFN- production by T cells. Taken together, these data demonstrate for the first time that Treg cells can play an important role in the regulation of immune responses of antigen-specific human memory T cells. CiteULike    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

	Copyright © 2008 by American Society of Hematology         Online ISSN: 1528-0020