scholarly journals Thymic Regulatory T Cell Development: Role of Signalling Pathways and Transcription Factors

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Mark Engel ◽  
Tom Sidwell ◽  
Ajithkumar Vasanthakumar ◽  
George Grigoriadis ◽  
Ashish Banerjee

Regulatory T cells (Tregs) are a subset of CD4 T cells that are key mediators of immune tolerance. Most Tregs develop in the thymus. In this review we summarise recent findings on the role of diverse signalling pathways and downstream transcription factors in thymic Treg development.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 5172-5172
Author(s):  
Rachel E. Protheroe ◽  
Colin G. Steward ◽  
Graziella Mazza ◽  
David C. Wraith

Abstract Graft versus host disease (GVHD) is the primary cause of transplant related morbidity and mortality, limiting the widespread application of haemopoietic stem cell transplantation (HSCT). Evidence from murine models supports the role of CD4+CD25+ regulatory T cells in the suppression of GVHD. Human evidence regarding the role of regulatory T cells in alloresponses is conflicting and may reflect the difficulty in defining and isolating the regulatory T cell population in humans. We have investigated the use of peripheral blood monocyte-derived dendritic cells (DCs) as stimulator cells in allogeneic mixed lymphocyte reactions (MLRs), as a means of assessing the in vitro suppressive function of regulatory T cells in human alloresponses. Peripheral blood mononuclear cells (PBMCs) were obtained from healthy adult volunteers. Magnetically isolated CD4+CD25+ T cells were combined with 50×103 autologous PBMCs or 20×103 autologous CD4+ T cells as responders, and 5×103 allogeneic irradiated DCs. Proliferation was assessed by tritiated thymidine incorporation. The CD4+CD25+ cells were anergic and demonstrated dose-dependent suppression of responder cell proliferation in the DC-driven allogeneic MLR. Greater than 50% suppression was seen with CD4+CD25+ T cells co-cultured with responder PBMCs at ratios of 1:4 to 1:32. Furthermore, depletion of CD4+CD25+ T cells from whole CD4+ responder cells resulted in enhanced proliferation and an increase in the amplitude of the MLR. Flow cytometry indicated that the majority of the magnetically isolated CD4+CD25+ T cells were FoxP3+ on intracellular staining and demonstrated down-regulation of cell surface expression of the IL-7 receptor (CD127). The potent suppression demonstrated here by CD4+CD25+CD127− T cells at ratios of 1:32 responder cells, suggests that these cells have a potential role for suppressing alloresponses at physiological levels. Moreover, this assay provides the basis for future investigation into regulatory T cell function in patients post-HSCT.


2013 ◽  
Vol 190 (10) ◽  
pp. 4965-4970 ◽  
Author(s):  
Alexander Schwarz ◽  
Marijana Schumacher ◽  
Daniel Pfaff ◽  
Kai Schumacher ◽  
Sven Jarius ◽  
...  

2021 ◽  
pp. 135245852110033
Author(s):  
Quentin Howlett-Prieto ◽  
Xuan Feng ◽  
John F Kramer ◽  
Kevin J Kramer ◽  
Timothy W Houston ◽  
...  

Objective: To determine the effect of long-term anti-CD20 B-cell-depleting treatment on regulatory T cell immune subsets that are subnormal in untreated MS patients. Methods: 30 clinically stable MS patients, before and over 38 months of ocrelizumab treatment, were compared to 13 healthy controls, 29 therapy-naïve MS, 9 interferon-β-treated MS, 3 rituximab-treated MS, and 3 rituximab-treated patients with other autoimmune inflammatory diseases. CD8, CD28, CD4, and FOXP3 expression in peripheral blood mononuclear cells was quantitated with flow cytometry. Results: CD8+ CD28− regulatory cells rose from one-third of healthy control levels before ocrelizumab treatment (2.68% vs 7.98%), normalized by 12 months (13.5%), and rose to 2.4-fold above healthy controls after 18 months of ocrelizumab therapy (19.0%). CD4+ FOXP3+ regulatory cells were lower in MS than in healthy controls (7.98%) and showed slight long-term decreases with ocrelizumab. CD8+ CD28− and CD4+ FOXP3+ regulatory T cell percentages in IFN-β-treated MS patients were between those of untreated MS and healthy controls. Interpretation: Long-term treatment with ocrelizumab markedly enriches CD8+ CD28− regulatory T cells and corrects the low levels seen in MS before treatment, while slightly decreasing CD4+ FOXP3+ regulatory T cells. Homeostatic enrichment of regulatory CD8 T cells provides a mechanism, in addition to B cell depletion, for the benefits of anti-CD20 treatment in MS.


2020 ◽  
Vol 88 (11) ◽  
Author(s):  
Emily M. Siebers ◽  
Elizabeth S. Liedhegner ◽  
Michael W. Lawlor ◽  
Ronald F. Schell ◽  
Dean T. Nardelli

ABSTRACT The symptoms of Lyme disease are caused by inflammation induced by species of the Borrelia burgdorferi sensu lato complex. The various presentations of Lyme disease in the population suggest that differences exist in the intensity and regulation of the host response to the spirochete. Previous work has described correlations between the presence of regulatory T cells and recovery from Lyme arthritis. However, the effects of Foxp3-expressing CD4+ T cells existing prior to, and during, B. burgdorferi infection have not been well characterized. Here, we used C57BL/6 “depletion of regulatory T cell” mice to assess the effects these cells have on the arthritis-resistant phenotype characteristic of this mouse strain. We showed that depletion of regulatory T cells prior to infection with B. burgdorferi resulted in sustained swelling, as well as histopathological changes, of the tibiotarsal joints that were not observed in infected control mice. Additionally, in vitro stimulation of splenocytes from these regulatory T cell-depleted mice resulted in increases in gamma interferon and interleukin-17 production and decreases in interleukin-10 production that were not evident among splenocytes of infected mice in which Treg cells were not depleted. Depletion of regulatory T cells at various times after infection also induced rapid joint swelling. Collectively, these findings provide evidence that regulatory T cells existing at the time of, and possibly after, B. burgdorferi infection may play an important role in limiting the development of arthritis.


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