| |
|
|
|
|
|
|
|||
|
Blood, 1 April 2008, Vol. 111, No. 7, pp. 3675-3683. Prepublished online as a Blood First Edition Paper on February 4, 2008; DOI 10.1182/blood-2008-01-130146.
IMMUNOBIOLOGY Rabbit ATG but not horse ATG promotes expansion of functional CD4+CD25highFOXP3+ regulatory T cells in vitro1 Hematology Branch, National Heart, Lung, and Blood Institute (NHLBI), National Institutes of Health (NIH), Bethesda, MD; 2 Genomics Core Facility, Pulmonary and Vascular Medicine Branch, NHLBI, NIH, Bethesda, MD; and 3 Mathematical and Statistical Computing Laboratory, Division of Computational Bioscience, Center for Information Technology, NIH, Bethesda, MD
Regulatory T cells (Treg) play important roles in suppressing immune responses and maintaining tolerance. Rabbit antithymocyte globulin (rATG) and horse ATG (hATG) are widely used in the treatment of immune-mediated syndromes, but their effects on Treg are unknown. We show here that in vitro culture of normal human peripheral blood mononuclear cells (PBMCs) with a low-dose rATG resulted in marked expansion of functional Treg by converting CD4+CD25– T cells to CD4+CD25+ T cells. hATG did not expand but rather decreased Treg. Immuno-blot showed increased expression of FOXP3 and NFAT1 in CD4+CD25– and CD4+CD25+ T cells exposed to rATG. PBMCs treated with rATG displayed increased interleukin-10 in culture supernatants than those treated with hATG. Furthermore, rATG and hATG showed differences in their potential to stimulate CD4+ T cells as examined using different activation markers. Microarray revealed that rATG induced markedly different gene-expression patterns in PBMCs, compared with hATG-treated or untreated PBMCs. Our findings indicate that rATG expanded Treg, probably through transcriptional regulation by enhanced NFAT1 expression, in turn conferring CD4+CD25– T cell FOXP3 expression and regulatory activity. The therapeutic effects of rATG may occur not only because of lymphocyte depletion but also enhanced Treg cell number and function.
This article has been cited by other articles:
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Copyright © 2008 by American Society of Hematology Online ISSN: 1528-0020 | |||||||||