Search results for "Foxp3"
showing 10 items of 140 documents
Human CD25+ regulatory T cells: two subsets defined by the integrins alpha 4 beta 7 or alpha 4 beta 1 confer distinct suppressive properties upon CD4…
2004
Down-regulation of autoreactive T cell responses in vivo includes cell-contact-dependent as well as contact-independent mechanisms. Infectious tolerance is a contact-dependent mechanism used by naturally occurring CD25(+) T regulatory cells (Tregs) to confer suppressive activity upon conventional CD4(+) T cells thereby generating secondary T helper suppressor cells(Th(sup)), which inhibit T cell activation via soluble mediators. Here, we describe two distinct subsets of human Tregs, characterized by expression of either the alpha(4)beta(7) integrin or the alpha(4)beta(1) integrin. Upon activation, both subsets show an enhanced expression of FoxP3, recently described as a key transcription f…
Expansion of intestinal CD4+CD25highTreg cells in patients with ankylosing spondylitis: A putative role for interleukin-10 in preventing intestinal T…
2010
Objective Subclinical gut inflammation has been demonstrated in patients with ankylosing spondylitis (AS). This study was undertaken to determine the frequency of regulatory CD4+CD25high T cells (Treg cells) and to evaluate Treg cell–related cytokines (interleukin-2 [IL-2], transforming growth factor β [TGFβ], and IL-10) and transcription factors (FoxP3 and STAT-5) in the ileum of patients with AS. Methods Quantitative gene expression analysis, by reverse transcriptase–polymerase chain reaction, of Treg-related cytokines (IL-2, TGFβ, and IL-10) and transcription factors (STAT-5 and FoxP3) was performed on ileal biopsy specimens from 18 patients with AS, 15 patients with active Crohn's disea…
Induction of regulatory Tr1 cells and inhibition of TH17 cells by IL-27
2011
Accumulating evidence indicates that IL-27, a member of the IL-12 family of cytokines, alleviates the severity of autoimmune diseases in both mice and men. The IL-27-induced activation of signal transducer and activator of transcription (Stat)1 and Stat3 promotes the generation of IL-10- producing type 1 regulatory T (Tr1) cells that inhibit effector T cells. In addition, IL-27 also suppresses the development of pathogenic IL-17-producing CD4(+) T cells (T(H)17) cells suggesting that pharmacological manipulations of IL-27 signaling pathway could be exploited therapeutically in regulating tissue inflammation. Here, we review how IL-27 controls inflammation through the regulation of Tr1 and T…
Langerhans cells are negative regulators of the anti-Leishmania response
2011
Langerhans cells suppress the immune response to low-dose Leishmania major infection in part by inducing regulatory T cells.
Gram-positive bacteria on grass pollen exhibit adjuvant activity inducing inflammatory T cell responses.
2011
BACKGROUND: Recently, it has been established that pollen grains contain Th2-enhancing activities besides allergens. OBJECTIVE: The aim of this study was to analyse whether pollen carry additional adjuvant factors like microbes and what immunological effects they may exert. METHODS: Timothy pollen grains were collected and disseminated on agar plates, and the growing microorganisms were cultivated and defined. Furthermore, the immunologic effects of microbial products on DC and T cell responses were analysed. RESULTS: A complex mixture of bacteria and moulds was detected on grass pollen. Besides Gram-negative bacteria that are known to favour Th1-directed immune responses, moulds were ident…
Interferon-α Suppresses cAMP to Disarm Human Regulatory T Cells
2013
Abstract IFN-α is an antineoplastic agent in the treatment of several solid and hematologic malignancies that exerts strong immune- and autoimmune-stimulating activity. However, the mechanisms of immune activation by IFN-α remain incompletely understood, particularly with regard to CD4+CD25highFoxp+ regulatory T cells (Treg). Here, we show that IFN-α deactivates the suppressive function of human Treg by downregulating their intracellular cAMP level. IFN-α–mediated Treg inactivation increased CD4+ effector T-cell activation and natural killer cell tumor cytotoxicity. Mechanistically, repression of cAMP in Treg was caused by IFN-α–induced MAP–ERK kinase (MEK)/extracellular signal-regulated ki…
P38 MAP Kinase Signaling Is Required for the Conversion of CD4+CD25− T Cells into iTreg
2008
CD4+CD25+ regulatory T cells (Treg) are important mediators of immune tolerance. A subset of Treg can be generated in the periphery by TGF-beta dependent conversion of conventional CD4+CD25− T cells into induced Treg (iTreg). In chronic viral infection or malignancy, such induced iTreg, which limit the depletion of aberrant or infected cells, may be of pathogenic relevance. To identify potential targets for therapeutic intervention, we investigated the TGF-beta signaling in Treg. In contrast to conventional CD4+ T cells, Treg exhibited marked activation of the p38 MAP kinase pathway. Inhibition of p38 MAP kinase activity prevented the TGF-beta-dependent conversion of CD4+CD25− T cells into …
Fibroblast Growth Factor 21 (FGF21) Protects against High Fat Diet Induced Inflammation and Islet Hyperplasia in Pancreas
2015
Fibroblast growth factor 21 (FGF21) is an important endocrine metabolic regulator expressed in multiple tissues including liver and adipose tissue. Although highest levels of expression are in pancreas, little is known about the function of FGF21 in this tissue. In order to understand the physiology of FGF21 in the pancreas, we analyzed its expression and regulation in both acinar and islet tissues. We found that acinar tissue express 20-fold higher levels than that observed in islets. We also observed that pancreatic FGF21 is nutritionally regulated; a marked reduction in FGF21 expression was noted with fasting while obesity is associated with 3–4 fold higher expression. Acinar and islet c…
Tumor infiltrating T lymphocytes expressing FoxP3, CCR7 or PD-1 predict the outcome of prostate cancer patients subjected to salvage radiotherapy aft…
2016
Tumor immunologic microenvironment is strongly involved in tumor progression and the presence of tumor infiltrating lymphocytes (TIL) with different phenotypes has been demonstrated to be of prognostic relevance in different malignancies. We investigated whether TIL infiltration of tumor tissues could also predict the outcome of prostate cancer patients. To this end, we carried out a retrospective analysis correlating the outcome of locally advanced prostate cancer patients undergone salvage radiotherapy upon relapse after radical surgery with the infiltration by different TIL populations. Twenty-two patients with resectable prostate cancer, with a mean age of 67 (+/−3.93) years, who receiv…
The Genotype of the Donor for the (GT)n Polymorphism in the Promoter/Enhancer of FOXP3 Is Associated with the Development of Severe Acute GVHD but Do…
2015
The FOXP3 gene encodes for a protein (Foxp3) involved in the development and functional activity of regulatory T cells (CD4+/CD25+/Foxp3+), which exert regulatory and suppressive roles over the immune system. After allogeneic stem cell transplantation, regulatory T cells are known to mitigate graft versus host disease while probably maintaining a graft versus leukemia effect. Short alleles (<=(GT)(15)) for the (GT)(n) polymorphism in the promoter/enhancer of FOXP3 are associated with a higher expression of FOXP3, and hypothetically with an increase of regulatory T cell activity. This polymorphism has been related to the development of auto-or alloimmune conditions including type 1 diabetes …