stem cell transplantation in children following reduced intensity conditioning: potential predictive value of NK cell chimaerism for late graft rejection. Leukemia. 2003;17:1934-1942. 7. Seidel MG, Ernst U, Printz D, et al. Expression of the putatively regulatory T-cell marker FOXP3 by CD4( )CD25 T cells after pediatric hematopoietic stem cell transplantation. Haematologica. 2006;91:566-569. 8....

CD4+CD25+ regulatory T cells play an important role in peripheral tolerance. These cells have been reported to be capable of suppressing the response of CD4+CD25- T cells in vitro. The depletion of these cells evokes effective immune responses to tumor cells in vivo. In this study, we demonstrate that CD4+CD25+ T cells also suppress all subsets of Valpha24+NKT cells (Valpha24+CD4-CD8- double ne...

Naturally arising CD4+CD25+ regulatory T (T(R)) cells have been shown to prevent and cure murine T cell-mediated colitis. However, their exact mechanism of controlling colitogenic memory CD4+ T cells in in vivo systems excluding the initial process of naive T cell activation and differentiation has not been examined to date. Using the colitogenic effector memory (T(EM)) CD4+ cell-mediated colit...

Thymectomy of BALB/c mice on day 3 of life results in the development of autoimmune gastritis (AIG) due to the absence of CD4(+)CD25(+) regulatory T cells. However, depletion of CD4(+)CD25(+) T cells by treatment with anti-CD25 rarely resulted in AIG. Depletion was efficient, as transfer of splenocytes from depleted mice induced AIG in nu/nu mice. One explanation for this result is that CD4(+)C...

HIV-1 infection is characterized by a progressive decline in CD4(+) T cells leading to a state of profound immunodeficiency. IL-2 therapy has been shown to improve CD4(+) counts beyond that observed with antiretroviral therapy. Recent phase III trials revealed that despite a sustained increase in CD4(+) counts, IL-2-treated patients did not experience a better clinical outcome [Abrams D, et al....

OBJECTIVE The goal of this study was to analyze the role of aryl hydrocarbon receptor in peripheral blood CCR6+ CD4+ and CD4+ CD25+T cells of patients with rheumatoid arthritis. METHODS Flow cytometry was applied to determine the proportion of AhR positive cells in CCR6+ CD4+T, CD4+ CD25+T and peripheral blood peripheral mononuclear cells from each subject. AhR mRNA and CYP1A1 mRNA relative e...

Contact hypersensitivity (CHS) is a CD8+ T cell-mediated, inflammatory response to hapten sensitization and challenge of the skin. During sensitization, the magnitude and duration of hapten-specific CD8+ T cell expansion in the skin-draining lymph nodes (LN) are restricted by CD4+CD25+ T regulatory cells (Treg). The regulation of hapten-specific CD8+ T cell priming in Class II MHC-deficient (MH...

Pancreatic lymph node-derived CD4 CD25 T regulatory (Treg) cells inhibit in situ differentiation of islet-reactive CD8 T cells into cytotoxic T lymphocytes, thereby preventing diabetes progression. The mechanism by which these Treg cells suppress anti-islet CD8 T cells is unknown. Here, we show by using a CD8 T cell-mediated model of type 1 diabetes that transforming growth factor (TGF)–TGFrece...

CD4+CD25+ regulatory T cells (Treg) are instrumental in the maintenance of immunological tolerance. One critical question is whether Treg can only be generated in the thymus or can differentiate from peripheral CD4+CD25- naive T cells. In this paper, we present novel evidence that conversion of naive peripheral CD4+CD25- T cells into anergic/suppressor cells that are CD25+, CD45RB-/low and intr...