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Sample records for cell cycle-related regulatory

  1. Andrographolide inhibits hepatoma cells growth and affects the expression of cell cycle related proteins.

    PubMed

    Shen, Kai-Kai; Liu, Tian-Yu; Xu, Chong; Ji, Li-Li; Wang, Zheng-Tao

    2009-09-01

    The present study is aimed to investigate the toxic effects of andrographolide (Andro) on hepatoma cells and elucidate its preliminary mechanisms. After cells were treated with different concentrations of Andro (0-50 micromol x L(-1)) for 24 h, cell viability was evaluated with 3-(4,5-dimethylthiazol-2-yl) 2,5-diphenyltetrazolium bromide (MTT) assay. Furthermore, after hepatoma cells (Hep3B and HepG2) were treated with different concentrations of Andro (0-30 micromol x L(-1)) for 14 d, the number of colony formation was accounted under microscope. Cell cycle related proteins such as Cdc-2, phosphorylated-Cdc-2, Cyclin B and Cyclin D1 were detected with Western blotting assay and the cell cycle was analyzed by flow cytometry using propidium iodide staining. MTT results showed that Andro induced growth inhibition of hepatoma cells in a concentration-dependent manner but had no significant effects on human normal liver L-02 cells. Andro dramatically decreased the colony formation of hepatoma cells in the concentration-dependent manner. Moreover, Andro induced a decrease of Hep3B cells at the G0-G1 phase and a concomitant accumulation of cells at G2-M phase. At the molecular level, Western blotting results showed that Andro decreased the expression of Cdc-2, phosphorylated-Cdc-2, Cyclin D1 and Cyclin B proteins in a time-dependent manner, which are all cell cycle related proteins. Taken together, the results demonstrated that Andro specifically inhibited the growth of hepatoma cells and cellular cell cycle related proteins were possibly involved in this process.

  2. Ubiquitination-mediated degradation of cell cycle-related proteins by F-box proteins.

    PubMed

    Zheng, Nana; Wang, Zhiwei; Wei, Wenyi

    2016-04-01

    F-box proteins, subunits of SKP1-cullin 1-F-box protein (SCF) type of E3 ubiquitin ligase complexes, have been validated to play a crucial role in governing various cellular processes such as cell cycle, cell proliferation, apoptosis, migration, invasion and metastasis. Recently, a wealth of evidence has emerged that F-box proteins is critically involved in tumorigenesis in part through governing the ubiquitination and subsequent degradation of cell cycle proteins, and dysregulation of this process leads to aberrant cell cycle progression and ultimately, tumorigenesis. Therefore, in this review, we describe the critical role of F-box proteins in the timely regulation of cell cycle. Moreover, we discuss how F-box proteins involve in tumorigenesis via targeting cell cycle-related proteins using biochemistry studies, engineered mouse models, and pathological gene alternations. We conclude that inhibitors of F-box proteins could have promising therapeutic potentials in part through controlling of aberrant cell cycle progression for cancer therapies.

  3. Cell cycle-related protein expression in vascular dementia and Alzheimer's disease.

    PubMed

    Smith, M Z; Nagy, Z; Esiri, M M

    1999-08-13

    Recent findings from our and other laboratories indicate that cell cycle-related phenomena may play a key role in the formation of Alzheimer-type pathology and neuronal cell death in both Alzheimer's and cerebro-vascular diseases. In this study we examine the expression patterns of cyclins A, B1, D1 and E in neuronal nuclei in the hippocampus in autopsied healthy elderly individuals, Alzheimer's disease patients and subjects suffering from cerebrovascular disease with and without co-existing Alzheimer's disease. Nuclear cyclin B1 and cyclin E expression was detected in hippocampal neurones in each subject category. However, cyclin B1 expression was significantly elevated in the CA1 of patients suffering from cerebro-vascular disease alone, while cyclin E expression was significantly higher in the CA4 subfield in patients suffering from mixed Alzheimer's and cerebro-vascular diseases compared to subjects in other categories. We hypothesize that cell cycle re-entry may occur in healthy elderly people leading to age-related cell death and mild Alzheimer-type pathology in the hippocampus. However, in pathological conditions, the cell cycle arrest may lead either to the development of severe Alzheimer-related pathology or to excess apoptotic cell death as in vascular dementia.

  4. Cell Cycle Related Differentiation of Bone Marrow Cells into Lung Cells

    SciTech Connect

    Dooner, Mark; Aliotta, Jason M.; Pimental, Jeffrey; Dooner, Gerri J.; Abedi, Mehrdad; Colvin, Gerald; Liu, Qin; Weier, Heinz-Ulli; Dooner, Mark S.; Quesenberry, Peter J.

    2007-12-31

    Green-fluorescent protein (GFP) labeled marrow cells transplanted into lethally irradiated mice can be detected in the lungs of transplanted mice and have been shown to express lung specific proteins while lacking the expression of hematopoietic markers. We have studied marrow cells induced to transit cell cycle by exposure to IL-3, IL-6, IL-11 and steel factor at different times of culture corresponding to different phases of cell cycle. We have found that marrow cells at the G1/S interface have a 3-fold increase in cells which assume a lung phenotype and that this increase is no longer seen in late S/G2. These cells have been characterized as GFP{sup +} CD45{sup -} and GFP{sup +} cytokeratin{sup +}. Thus marrow cells with the capacity to convert into cells with a lung phenotype after transplantation show a reversible increase with cytokine induced cell cycle transit. Previous studies have shown the phenotype of bone marrow stem cells fluctuates reversibly as these cells traverse cell cycle, leading to a continuum model of stem cell regulation. The present studies indicate that marrow stem cell production of nonhematopoietic cells also fluctuates on a continuum.

  5. Quercetin ameliorates Aβ toxicity in Drosophila AD model by modulating cell cycle-related protein expression

    PubMed Central

    Kong, Yan; Li, Ke; Fu, Tingting; Wan, Chao; Zhang, Dongdong; Song, Hang; Zhang, Yao; Liu, Na; Gan, Zhenji; Yuan, Liudi

    2016-01-01

    Alzheimer's disease (AD) is a prevalent neurodegenerative disorder characterized by β amyloid (Aβ) deposition and neurofibril tangles. It has been reported that a bioflavonoid, quercetin, could ameliorate AD phenotypes in C. elegans and mice. However, the mechanism underlying the ameliorative effect of quercetin is not fully understood yet. Drosophila models could recapitulate AD-like phenotypes, such as shortened lifespan, impaired locomotive ability as well as defects in learning and memory. So in this study, we investigated the effects of quercetin on AD in Drosophila model and explored the underlying mechanisms. We found quercetin could effectively intervene in AD pathogenesis in vivo. Mechanism study showed quercetin could restore the expression of genes perturbed by Aβ accumulation, such as those involved in cell cycle and DNA replication. Cyclin B, an important cell cycle protein, was chosen to test whether it participated in the AD ameliorative effects of quercetin. We found that cyclin B RNAi in the brain could alleviate AD phenotypes. Taken together, the current study suggested that the neuroprotective effects of quercetin were mediated at least partially by targeting cell cycle-related proteins. PMID:27626494

  6. Quercetin ameliorates Aβ toxicity in Drosophila AD model by modulating cell cycle-related protein expression.

    PubMed

    Kong, Yan; Li, Ke; Fu, Tingting; Wan, Chao; Zhang, Dongdong; Song, Hang; Zhang, Yao; Liu, Na; Gan, Zhenji; Yuan, Liudi

    2016-10-18

    Alzheimer's disease (AD) is a prevalent neurodegenerative disorder characterized by β amyloid (Aβ) deposition and neurofibril tangles. It has been reported that a bioflavonoid, quercetin, could ameliorate AD phenotypes in C. elegans and mice. However, the mechanism underlying the ameliorative effect of quercetin is not fully understood yet. Drosophila models could recapitulate AD-like phenotypes, such as shortened lifespan, impaired locomotive ability as well as defects in learning and memory. So in this study, we investigated the effects of quercetin on AD in Drosophila model and explored the underlying mechanisms. We found quercetin could effectively intervene in AD pathogenesis in vivo. Mechanism study showed quercetin could restore the expression of genes perturbed by Aβ accumulation, such as those involved in cell cycle and DNA replication. Cyclin B, an important cell cycle protein, was chosen to test whether it participated in the AD ameliorative effects of quercetin. We found that cyclin B RNAi in the brain could alleviate AD phenotypes. Taken together, the current study suggested that the neuroprotective effects of quercetin were mediated at least partially by targeting cell cycle-related proteins.

  7. SCTR regulates cell cycle-related genes toward anti-proliferation in normal breast cells while having pro-proliferation activity in breast cancer cells.

    PubMed

    Kang, Seongeun; Kim, Byungtak; Kang, Han-Sung; Jeong, Gookjoo; Bae, Hansol; Lee, Hyunkyung; Lee, Seungyeon; Kim, Sun Jung

    2015-11-01

    Secretin receptor (SCTR), the G-protein coupled receptor (GPCR) for secretin, has been observed to be upregulated in a few tumor types while downregulated in others, promoting or suppressing the proliferation of tumor cells, respectively. However, little is known about the molecular regulatory mechanism of dysregulation in cancer. In the present study, an analysis of the biological pathways affected by methylation in breast cancer using the methylome databases revealed that GPCRs played a major part in the affected pathway. SCTR, one of the dysregulated GPCRs, showed hypermethylation (p<0.01) and downregulation (p<0.05) in breast cancer tissues. Pathway analysis after the downregulation of SCTR by siRNA in MCF-10A cells identified the G2/M stage checkpoint as the top-scored pathway. Cell cycle-related genes were all upregulated or downregulated suppressing cell proliferation. However, the overexpression of SCTR in MCF-7 cells led to a 35% increase of the cell proliferation index and 2.1-fold increase of cellular migration. Our findings indicate that SCTR suppresses the proliferation of normal breast cells, while the gene stimulates the proliferation and migration of cancer cells being downregulated by promoter methylation.

  8. Cell cycle-related genes p57kip2, Cdk5 and Spin in the pathogenesis of neural tube defects.

    PubMed

    Li, Xinjun; Yang, Zhong; Zeng, Yi; Xu, Hong; Li, Hongli; Han, Yangyun; Long, Xiaodong; You, Chao

    2013-07-15

    In the field of developmental neurobiology, accurate and ordered regulation of the cell cycle and apoptosis are crucial factors contributing to the normal formation of the neural tube. Preliminary studies identified several genes involved in the development of neural tube defects. In this study, we established a model of developmental neural tube defects by administration of retinoic acid to pregnant rats. Gene chip hybridization analysis showed that genes related to the cell cycle and apoptosis, signal transduction, transcription and translation regulation, energy and metabolism, heat shock, and matrix and cytoskeletal proteins were all involved in the formation of developmental neural tube defects. Among these, cell cycle-related genes were predominant. Retinoic acid ment caused differential expression of three cell cycle-related genes p57kip2, Cdk5 and Spin, the expression levels of which were downregulated by retinoic acid and upregulated during normal neural tube formation. The results of this study indicate that cell cycle-related genes play an important role in the formation of neural tube defects. P57kip2, Cdk5 and Spin may be critical genes in the pathogenesis of neural tube defects.

  9. Growth pattern switch of renal cells and expression of cell cycle related proteins at the early stage of diabetic nephropathy

    SciTech Connect

    Zhang Yanling; Shi Yonghong; Liu Yaling; Dong Hui; Liu, Maodong; Li Ying; Duan Huijun

    2007-11-09

    Renal hypertrophy, partly due to cell proliferation and hypertrophy, has been found correlated to renal function deterioration in diabetes mellitus. We screened the up-regulated cell cycle related genes to investigate cell growth and the expression of cell cycle regulating proteins at the early stage of diabetic nephropathy using STZ-induced diabetic rats. Cyclin E, CDK{sub 2} and P{sup 27} were found significantly up-regulated in diabetic kidney. Increased cell proliferation in the kidney was seen at day 3, peaked at day 5, and returned to normal level at day 30. Cyclin E and CDK{sub 2} expression also peeked at day 5 and P{sup 27} activity peaked at day 14. These findings indicate that a hyperplastic growth period of renal cells is followed by a hypertrophic growth period at the early stage of diabetes. The growth pattern switch may be regulated by cell cycle regulating proteins, Cyclin E, CDK{sub 2}, and P{sup 27}.

  10. Regulatory T cell memory

    PubMed Central

    Rosenblum, Michael D.; Way, Sing Sing; Abbas, Abul K.

    2016-01-01

    Memory for antigen is a defining feature of adaptive immunity. Antigen-specific lymphocyte populations show an increase in number and function after antigen encounter and more rapidly re-expand upon subsequent antigen exposure. Studies of immune memory have primarily focused on effector B cells and T cells with microbial specificity, using prime challenge models of infection. However, recent work has also identified persistently expanded populations of antigen-specific regulatory T cells that protect against aberrant immune responses. In this Review, we consider the parallels between memory effector T cells and memory regulatory T cells, along with the functional implications of regulatory memory in autoimmunity, antimicrobial host defence and maternal fetal tolerance. In addition, we discuss emerging evidence for regulatory T cell memory in humans and key unanswered questions in this rapidly evolving field. PMID:26688349

  11. PARP-2 regulates cell cycle-related genes through histone deacetylation and methylation independently of poly(ADP-ribosyl)ation

    SciTech Connect

    Liang, Ya-Chen; Hsu, Chiao-Yu; Yao, Ya-Li; Yang, Wen-Ming

    2013-02-01

    Highlights: ► PARP-2 acts as a transcription co-repressor independently of PARylation activity. ► PARP-2 recruits HDAC5, 7, and G9a and generates repressive chromatin. ► PARP-2 is recruited to the c-MYC promoter by DNA-binding factor YY1. ► PARP-2 represses cell cycle-related genes and alters cell cycle progression. -- Abstract: Poly(ADP-ribose) polymerase-2 (PARP-2) catalyzes poly(ADP-ribosyl)ation (PARylation) and regulates numerous nuclear processes, including transcription. Depletion of PARP-2 alters the activity of transcription factors and global gene expression. However, the molecular action of how PARP-2 controls the transcription of target promoters remains unclear. Here we report that PARP-2 possesses transcriptional repression activity independently of its enzymatic activity. PARP-2 interacts and recruits histone deacetylases HDAC5 and HDAC7, and histone methyltransferase G9a to the promoters of cell cycle-related genes, generating repressive chromatin signatures. Our findings propose a novel mechanism of PARP-2 in transcriptional regulation involving specific protein–protein interactions and highlight the importance of PARP-2 in the regulation of cell cycle progression.

  12. Regulatory T cells.

    PubMed

    Thompson, Claire; Powrie, Fiona

    2004-08-01

    Regulatory T (TR) cells are a subset of T cells that function to control immune responses. Different populations of TR cells have been described, including thymically derived CD4(+)CD25+ TR cells and Tr1 cells induced in the periphery through exposure to antigen. A transcription factor, Foxp3, has been identified that is essential for CD4(+)CD25+ TR cell development and function. There is now evidence that transforming growth factor-beta might play a role in this pathway. CD4(+)CD25+ TR cells proliferate extensively in vivo in an antigen-specific manner, and can respond to both self and foreign peptides. By suppressing excessive immune responses, TR cells play a key role in the maintenance of self-tolerance, thus preventing autoimmune disease, as well as inhibiting harmful inflammatory diseases such as asthma and inflammatory bowel disease.

  13. DNA alkylation and tumor induction in regenerating rat liver after cell cycle-related continuous N-nitrosodimethylamine infusion

    SciTech Connect

    Rabes, H.M.; Kerler, R.; Wilhelm, R.

    1983-01-01

    Synchronized regenerating rat liver after partial hepatectomy was used to study cell cycle-related DNA base alkylation and liver carcinogenesis. A continuous iv infusion of (/sup 14/C)N-nitrosodimethylamine (DMN) at a dose of 0.5 mg/kg/hour was given to inbred male Wistar Af/Han rats over a period of 8 hours either during the G1 phase, hydroxyurea-synchronized DNA synthesis, or the G2+M-phase of regenerating liver or to untreated rats (G0-phase liver--carcinogen dose, 1.5 mg/kg/hour). Two hours after the end of the infusion, the amount of 7-methylguanine was highest in the G0-phase liver, with a decrease in the G1 phase, the S-phase, and the G2+M-phase. After continuous DMN exposure, the O6-methylguanine:7-methylguanine ratio was lower in the S-phase and G2+M-phase livers than in the G0-phase and G1-phase livers, indicating an increased O6-methylguanine repair during DNA synthesis and the G2+M-phase. Liver tumors in rats treated by continuous DMN infusion either during the G0 phase or the S-phase developed only after carcinogen exposure during DNA synthesis.

  14. Targeting regulatory T cells.

    PubMed

    Ménétrier-Caux, Christine; Curiel, Tyler; Faget, Julien; Manuel, Manuarii; Caux, Christophe; Zou, Weiping

    2012-03-01

    Cancers express tumor-associated antigens that should elicit immune response to antagonize the tumor growth, but spontaneous immune rejection of established cancer is rare, suggesting an immunosuppressive environment hindering host antitumor immunity. Among the specific and active tumor-mediated mechanisms, CD4(+)CD25(high) T regulatory cells (Treg) are important mediators of active immune evasion in cancer. In this review, we will discuss Treg subpopulations and the mechanisms of their suppressive functions. Treg depletion improves endogenous antitumor immunity and the efficacy of active immunotherapy in animal models for cancer, suggesting that inhibiting Treg function could also improve the limited successes of human cancer immunotherapy. We will also discuss specific strategies for devising effective cancer immunotherapy targeting Treg.

  15. Demethylation and alterations in the expression level of the cell cycle-related genes as possible mechanisms in arsenic trioxide-induced cell cycle arrest in human breast cancer cells.

    PubMed

    Moghaddaskho, Farima; Eyvani, Haniyeh; Ghadami, Mohsen; Tavakkoly-Bazzaz, Javad; Alimoghaddam, Kamran; Ghavamzadeh, Ardeshir; Ghaffari, Seyed H

    2017-02-01

    Arsenic trioxide (As2O3) has been used clinically as an anti-tumor agent. Its mechanisms are mostly considered to be the induction of apoptosis and cell cycle arrest. However, the detailed molecular mechanisms of its anti-cancer action through cell cycle arrest are poorly known. Furthermore, As2O3 has been shown to be a potential DNA methylation inhibitor, inducing DNA hypomethylation. We hypothesize that As2O3 may affect the expression of cell cycle regulatory genes by interfering with DNA methylation patterns. To explore this, we examined promoter methylation status of 24 cell cycle genes in breast cancer cell lines and in a normal breast tissue sample by methylation-specific polymerase chain reaction and/or restriction enzyme-based methods. Gene expression level and cell cycle distribution were quantified by real-time polymerase chain reaction and flow cytometric analyses, respectively. Our methylation analysis indicates that only promoters of RBL1 (p107), RASSF1A, and cyclin D2 were aberrantly methylated in studied breast cancer cell lines. As2O3 induced CpG island demethylation in promoter regions of these genes and restores their expression correlated with DNA methyltransferase inhibition. As2O3 also induced alterations in messenger RNA expression of several cell cycle-related genes independent of demethylation. Flow cytometric analysis revealed that the cell cycle arrest induced by As2O3 varied depending on cell lines, MCF-7 at G1 phase and both MDA-MB-231 and MDA-MB-468 cells at G2/M phase. These changes at transcriptional level of the cell cycle genes by the molecular mechanisms dependent and independent of demethylation are likely to represent the mechanisms of cell cycle redistribution in breast cancer cells, in response to As2O3 treatment.

  16. Regulatory T cells and COPD.

    PubMed

    Dancer, Rachel; Sansom, David M

    2013-12-01

    While the innate immune system has long been implicated in the pathogenesis of COPD, a role for the acquired immune system is less well studied. The increasing recognition that COPD shares features with autoimmune disease has led to interest in a potential role for regulatory T cells, which are intimately involved in the control of autoimmunity. The suggestion that regulatory T cell numbers are increased in patients with COPD may indicate their dysfunction or resistance to suppression by target cells. Investigation of regulatory T cells may therefore be of importance in understanding the inflammation and tissue damage that occurs in patients with COPD who cease smoking.

  17. Anti-regulatory T cells.

    PubMed

    Andersen, Mads Hald

    2017-04-01

    Our initial understanding of immune-regulatory cells was based on the discovery of suppressor cells that assure peripheral T-cell tolerance and promote immune homeostasis. Research has particularly focused on the importance of regulatory T cells (Tregs) for immune modulation, e.g. directing host responses to tumours or inhibiting autoimmunity development. However, recent studies report the discovery of self-reactive pro-inflammatory T cells-termed anti-regulatory T cells (anti-Tregs)-that target immune-suppressive cells. Thus, regulatory cells can now be defined as both cells that suppress immune reactions as well as effector cells that counteract the effects of suppressor cells and support immune reactions. Self-reactive anti-Tregs have been described that specifically recognize human leukocyte antigen-restricted epitopes derived from proteins that are normally expressed by regulatory immune cells, including indoleamine 2,3-dioxygenase (IDO), tryptophan 2,6-dioxygenase (TDO), programmed death-ligand 1 (PD-L1), and forkhead box P3 (Foxp3). These proteins are highly expressed in professional antigen-presenting cells under various physiological conditions, such as inflammation and stress. Therefore, self-reactive T cells that recognize such targets may be activated due to the strong activation signal given by their cognate targets. The current review describes the existing knowledge regarding these self-reactive anti-Tregs, providing examples of antigen-specific anti-Tregs and discussing their possible roles in immune homeostasis and their potential future clinical applications.

  18. Cellular distribution of cell cycle-related molecules in the renal tubules of rats treated with renal carcinogens for 28 days: relationship between cell cycle aberration and carcinogenesis.

    PubMed

    Taniai, Eriko; Hayashi, Hitomi; Yafune, Atsunori; Watanabe, Maiko; Akane, Hirotoshi; Suzuki, Kazuhiko; Mitsumori, Kunitoshi; Shibutani, Makoto

    2012-09-01

    Some renal carcinogens can induce karyomegaly, which reflects aberrant cell division in the renal tubules, from the early stages of exposure. To clarify the cell cycle-related changes during the early stages of renal carcinogenesis, we performed immunohistochemical analysis of tubular cells in male F344 rats treated with carcinogenic doses of representative renal carcinogens for 28 days. For this purpose, the karyomegaly-inducing carcinogens ochratoxin A (OTA), ferric nitrilotriacetic acid, and monuron, and the non-karyomegaly-inducing carcinogens tris(2-chloroethyl) phosphate and potassium bromate were examined. For comparison, a karyomegaly-inducing non-carcinogen, p-nitrobenzoic acid, and a non-carcinogenic non-karyomegaly-inducing renal toxicant, acetaminophen, were also examined. The outer stripe of the outer medulla (OSOM) and the cortex + OSOM were subjected to morphometric analysis of immunoreactive proximal tubular cells. Renal carcinogens, irrespective of their karyomegaly-inducing potential, increased proximal tubular cell proliferation accompanied by an increase in topoisomerase IIα-immunoreactive cells, suggesting a reflection of cell proliferation. Karyomegaly-inducing carcinogens increased nuclear Cdc2-, γH2AX-, and phosphorylated Chk2-immunoreactive cells in both areas, the former two acting in response to DNA damage and the latter one suggestive of sustained G₂. OTA, an OSOM-targeting carcinogen, could easily be distinguished from untreated controls and non-carcinogens by evaluation of molecules responding to DNA damage and G₂/M transition in the OSOM. Thus, all renal carcinogens examined facilitated proximal tubular proliferation by repeated short-term treatment. Among these, karyomegaly-inducing carcinogens may cause DNA damage and G₂ arrest in the target tubular cells.

  19. Regulatory myeloid cells in transplantation.

    PubMed

    Rosborough, Brian R; Raïch-Regué, Dàlia; Turnquist, Heth R; Thomson, Angus W

    2014-02-27

    Regulatory myeloid cells (RMC) are emerging as novel targets for immunosuppressive (IS) agents and hold considerable promise as cellular therapeutic agents. Herein, we discuss the ability of regulatory macrophages, regulatory dendritic cells, and myeloid-derived suppressor cells to regulate alloimmunity, their potential as cellular therapeutic agents, and the IS agents that target their function. We consider protocols for the generation of RMC and the selection of donor- or recipient-derived cells for adoptive cell therapy. Additionally, the issues of cell trafficking and antigen (Ag) specificity after RMC transfer are discussed. Improved understanding of the immunobiology of these cells has increased the possibility of moving RMC into the clinic to reduce the burden of current IS agents and to promote Ag-specific tolerance. In the second half of this review, we discuss the influence of established and experimental IS agents on myeloid cell populations. IS agents believed historically to act primarily on T cell activation and proliferation are emerging as important regulators of RMC function. Better insights into the influence of IS agents on RMC will enhance our ability to develop cell therapy protocols to promote the function of these cells. Moreover, novel IS agents may be designed to target RMC in situ to promote Ag-specific immune regulation in transplantation and to usher in a new era of immune modulation exploiting cells of myeloid origin.

  20. Elevated O-GlcNAcylation promotes gastric cancer cells proliferation by modulating cell cycle related proteins and ERK 1/2 signaling.

    PubMed

    Jiang, Mingzuo; Qiu, Zhaoyan; Zhang, Song; Fan, Xing; Cai, Xiqiang; Xu, Bing; Li, Xiaowei; Zhou, Jinfeng; Zhang, Xiangyuan; Chu, Yi; Wang, Weijie; Liang, Jie; Horvath, Tamas; Yang, Xiaoyong; Wu, Kaichun; Nie, Yongzhan; Fan, Daiming

    2016-09-20

    O-GlcNAc transferase (OGT) is the only enzyme in mammals that catalyzes the attachment of β-D-N-acetylglucosamine (GlcNAc) to serine or threonine residues of target proteins. Hyper-O-GlcNAcylation is becoming increasingly realized as a general feature of cancer and contributes to rapid proliferation of cancer cells. In this study, we demonstrated that O-GlcNAc and OGT levels were increased in all six gastric cancer (GC) cell lines as compared with immortal gastric epithelial cells. Downregulation of the O-GlcNAcylation level by silencing OGT inhibited cell viability and growth rate via the cdk-2, cyclin D1 and ERK 1/2 pathways. In vivo xenograft assays also demonstrated that the hyper-O-GlcNAc level markedly promoted the proliferation of tumors. Moreover, compared with noncancerous tissues, the O-GlcNAcylation level was increased in cancerous tissues. GC patients with higher levels of O-GlcNAcylation exhibited large tumor sizes (≥5 cm), deep tumor invasion (T3 and T4), high AJCC stages (stage III and IV), more lymph node metastases and lower overall survival. Notably, the phosphorylation level of ERK 1/2 was increased progressively with the increase of O-GlcNAcylation in both SGC 7901 and AGS cells. Consistently, human GC tissue arrays also revealed that ERK 1/2 signaling was positively correlated to O-GlcNAcylation (r = 0.348; P = 0.015). Taken together, here we reported that hyper-O-GlcNAcylation significantly promotes GC cells proliferation by modulating cell cycle related proteins and ERK 1/2 signaling, suggesting that inhibition of OGT may be a potential novel therapeutic target of GC.

  1. Elevated O-GlcNAcylation promotes gastric cancer cells proliferation by modulating cell cycle related proteins and ERK 1/2 signaling

    PubMed Central

    Cai, Xiqiang; Xu, Bing; Li, Xiaowei; Zhou, Jinfeng; Zhang, Xiangyuan; Chu, Yi; Wang, Weijie; Liang, Jie; Horvath, Tamas; Yang, Xiaoyong; Wu, Kaichun; Nie, Yongzhan; Fan, Daiming

    2016-01-01

    O-GlcNAc transferase (OGT) is the only enzyme in mammals that catalyzes the attachment of β-D-N-acetylglucosamine (GlcNAc) to serine or threonine residues of target proteins. Hyper-O-GlcNAcylation is becoming increasingly realized as a general feature of cancer and contributes to rapid proliferation of cancer cells. In this study, we demonstrated that O-GlcNAc and OGT levels were increased in all six gastric cancer (GC) cell lines as compared with immortal gastric epithelial cells. Downregulation of the O-GlcNAcylation level by silencing OGT inhibited cell viability and growth rate via the cdk-2, cyclin D1 and ERK 1/2 pathways. In vivo xenograft assays also demonstrated that the hyper-O-GlcNAc level markedly promoted the proliferation of tumors. Moreover, compared with noncancerous tissues, the O-GlcNAcylation level was increased in cancerous tissues. GC patients with higher levels of O-GlcNAcylation exhibited large tumor sizes (≥5 cm), deep tumor invasion (T3 and T4), high AJCC stages (stage III and IV), more lymph node metastases and lower overall survival. Notably, the phosphorylation level of ERK 1/2 was increased progressively with the increase of O-GlcNAcylation in both SGC 7901 and AGS cells. Consistently, human GC tissue arrays also revealed that ERK 1/2 signaling was positively correlated to O-GlcNAcylation (r = 0.348; P = 0.015). Taken together, here we reported that hyper-O-GlcNAcylation significantly promotes GC cells proliferation by modulating cell cycle related proteins and ERK 1/2 signaling, suggesting that inhibition of OGT may be a potential novel therapeutic target of GC. PMID:27542217

  2. Diel Expression of Cell Cycle-Related Genes in Synchronized Cultures of Prochlorococcus sp. Strain PCC 9511

    PubMed Central

    Holtzendorff, J.; Partensky, F.; Jacquet, S.; Bruyant, F.; Marie, D.; Garczarek, L.; Mary, I.; Vaulot, D.; Hess, W. R.

    2001-01-01

    The cell cycle of the chlorophyll b-possessing marine cyanobacterium Prochlorococcus is highly synchronized under natural conditions. To understand the underlying molecular mechanisms we cloned and sequenced dnaA and ftsZ, two key cell cycle-associated genes, and studied their expression. An axenic culture of Prochlorococcus sp. strain PCC 9511 was grown in a turbidostat with a 12 h–12 h light-dark cycle for 2 weeks. During the light periods, a dynamic light regimen was used in order to simulate the natural conditions found in the upper layers of the world's oceans. This treatment resulted in strong cell cycle synchronization that was monitored by flow cytometry. The steady-state mRNA levels of dnaA and ftsZ were monitored at 4-h intervals during four consecutive division cycles. Both genes exhibited clear diel expression patterns with mRNA maxima during the replication (S) phase. Western blot experiments indicated that the peak of FtsZ concentration occurred at night, i.e., at the time of cell division. Thus, the transcript accumulation of genes involved in replication and division is coordinated in Prochlorococcus sp. strain PCC 9511 and might be crucial for determining the timing of DNA replication and cell division. PMID:11208789

  3. Adipocytes as immune regulatory cells

    PubMed Central

    Vielma, Silvana A.; Klein, Richard L.; Levingston, Corinne A.; Young, M. Rita I.

    2013-01-01

    Obesity is a chronic inflammatory state and adipocytes are capable of contributing to this inflammation by their production of inflammatory mediators. The present study used fibroblast-derived adipocytes and normal spleen cells as a model to determine if adipocytes can also serve as immune regulatory cells by modulating the functions of conventional immune cells. Media conditioned by the adipocytes stimulated release of the Th1-type cytokines IL-2, IFN-γ and GM-CSF from cultures of normal spleen cells. The adipocytes also stimulated spleen cell release of inhibitory cytokines, although to varying degrees. This included IL-10, IL-13 and, to a lesser extent, IL-4. Spleen cell production of the inflammatory cytokines IL-6, TNF-α and IL-9 was stimulated by adipocytes, although production of the Th17-derived cytokine, IL-17, was not stimulated. The adipocyte-conditioned medium did not stimulate production of predominantly monocytes-derived chemokines CXCL9, CCL2, CCL3, CCL4, but stimulated production of the predominantly T-cell-derived chemokine CCL5. In all cases where cytokine/chemokine production from spleen cells was stimulated by adipocytes, it was to a far greater level than was produced by the adipocytes themselves. Studies initiated to determine the identity of the adipocyte-derived mediators showed that the spleen cell modulation could not be attributed to solely adiponectin or leptin. Studies to determine the source of some of the cytokines whose production was stimulated by adipocytes showed that expression of the inflammatory cytokine IL-6 was not increased in either CD4+ or CD8+ T-cell. When the splenic T-cells were examined for IFN-γ, the adipocyte stimulation of IFN-γ was within CD8+ T-cells, not CD4+ T-cells. These studies show that adipocytes may be able to serve as immune regulatory cells to stimulate conventional immune cells to release a spectrum of immune mediators. PMID:23587489

  4. Immunometabolism of regulatory T cells

    PubMed Central

    Newton, Ryan; Priyadharshini, Bhavana; Turka, Laurence A

    2016-01-01

    The bidirectional interaction between the immune system and whole-body metabolism has been well recognized for many years. Via effects on adipocytes and hepatocytes, immune cells can modulate whole-body metabolism (in metabolic syndromes such as type 2 diabetes and obesity) and, reciprocally, host nutrition and commensal-microbiota-derived metabolites modulate immunological homeostasis. Studies demonstrating the metabolic similarities of proliferating immune cells and cancer cells have helped give birth to the new field of immunometabolism, which focuses on how the cell-intrinsic metabolic properties of lymphocytes and macrophages can themselves dictate the fate and function of the cells and eventually shape an immune response. We focus on this aspect here, particularly as it relates to regulatory T cells. PMID:27196520

  5. The core regulatory network in human cells.

    PubMed

    Kim, Man-Sun; Kim, Dongsan; Kang, Nam Sook; Kim, Jeong-Rae

    2017-03-04

    In order to discover the common characteristics of various cell types in the human body, many researches have been conducted to find the set of genes commonly expressed in various cell types and tissues. However, the functional characteristics of a cell is determined by the complex regulatory relationships among the genes rather than by expressed genes themselves. Therefore, it is more important to identify and analyze a core regulatory network where all regulatory relationship between genes are active across all cell types to uncover the common features of various cell types. Here, based on hundreds of tissue-specific gene regulatory networks constructed by recent genome-wide experimental data, we constructed the core regulatory network. Interestingly, we found that the core regulatory network is organized by simple cascade and has few complex regulations such as feedback or feed-forward loops. Moreover, we discovered that the regulatory links from genes in the core regulatory network to genes in the peripheral regulatory network are much more abundant than the reverse direction links. These results suggest that the core regulatory network locates at the top of regulatory network and plays a role as a 'hub' in terms of information flow, and the information that is common to all cells can be modified to achieve the tissue-specific characteristics through various types of feedback and feed-forward loops in the peripheral regulatory networks. We also found that the genes in the core regulatory network are evolutionary conserved, essential and non-disease, non-druggable genes compared to the peripheral genes. Overall, our study provides an insight into how all human cells share a common function and generate tissue-specific functional traits by transmitting and processing information through regulatory network.

  6. Regulatory B cells in autoimmune diseases

    PubMed Central

    Yang, Min; Rui, Ke; Wang, Shengjun; Lu, Liwei

    2013-01-01

    B cells are generally considered to be positive regulators of the immune response because of their capability to produce antibodies, including autoantibodies. The production of antibodies facilitates optimal CD4+ T-cell activation because B cells serve as antigen-presenting cells and exert other modulatory functions in immune responses. However, certain B cells can also negatively regulate the immune response by producing regulatory cytokines and directly interacting with pathogenic T cells via cell-to-cell contact. These types of B cells are defined as regulatory B (Breg) cells. The regulatory function of Breg cells has been demonstrated in mouse models of inflammation, cancer, transplantation, and particularly in autoimmunity. In this review, we focus on the recent advances that lead to the understanding of the development and function of Breg cells and the implications of B cells in human autoimmune diseases. PMID:23292280

  7. Regulatory T cells and vasectomy.

    PubMed

    Rival, Claudia; Wheeler, Karen; Jeffrey, Sarah; Qiao, Hui; Luu, Brian; Tewalt, Eric F; Engelhard, Victor H; Tardif, Stephen; Hardy, Daniel; del Rio, Roxana; Teuscher, Cory; Tung, Kenneth

    2013-11-01

    CD4+ CD25+ regulatory T cells (Tregs) strongly influence the early and late autoimmune responses to meiotic germ cell antigens (MGCA) and the gonadal immunopathology in vasectomized mice. This is supported by the published and recently acquired information presented here. Within 24h of unilateral vasectomy (uni-vx) the ipsilateral epididymis undergoes epithelial cell apoptosis followed by necrosis, severe inflammation, and granuloma formation. Unexpectedly, vasectomy alone induced MGCA-specific tolerance. In contrast, uni-vx plus simultaneous Treg depletion resulted in MGCA-specific autoimmune response and bilateral autoimmune orchitis. Both tolerance and autoimmunity were strictly linked to the early epididymal injury. We now discovered that testicular autoimmunity in uni-vx mice did not occur when Treg depletion was delayed by one week. Remarkably, this delayed Treg depletion also prevented tolerance induction. Therefore, tolerance depends on a rapid de novo Treg response to MGCA exposed after vasectomy. Moreover, tolerance was blunted in mice genetically deficient in PD-1 ligand, suggesting the involvement of induced Treg. We conclude that pre-existing natural Treg prevents post-vasectomy autoimmunity, whereas vasectomy-induced Treg maintains post-vasectomy tolerance. We further discovered that vasectomized mice were still resistant to autoimmune orchitis induction for at least 12-16 months; thus, tolerance is long-lasting. Although significant sperm autoantibodies of low titers became detectable in uni-vx mice at 7 months, the antibody titers fluctuated over time, suggesting a dynamic "balance" between the autoimmune and tolerance states. Finally, we observed severe epididymal fibrosis and hypo-spermatogenesis at 12 months after uni-vx: findings of highly critical clinical significance.

  8. Transcriptional profiling of arbuscular mycorrhizal roots exposed to high levels of phosphate reveals the repression of cell cycle-related genes and secreted protein genes in Rhizophagus irregularis.

    PubMed

    Sugimura, Yusaku; Saito, Katsuharu

    2017-02-01

    The development of arbuscular mycorrhiza (AM) is strongly suppressed under high-phosphate (Pi) conditions. To investigate AM fungal responses during the suppression of AM by high Pi, we performed an RNA-seq analysis of Rhizophagus irregularis colonizing Lotus japonicus roots at different levels of Pi (20, 100, 300, and 500 μM). AM fungal colonization decreased markedly under high-Pi conditions. In total, 163 fungal genes were differentially expressed among the four Pi treatments. Among these genes, a cell cycle-regulatory gene, cyclin-dependent kinase CDK1, and several DNA replication- and mitosis-related genes were repressed under high-Pi conditions. More than 20 genes encoding secreted proteins were also downregulated by high-Pi conditions, including the strigolactone-induced putative secreted protein 1 gene that enhances AM fungal colonization. In contrast, the expression of genes related to aerobic respiration and transport in R. irregularis were largely unaffected. Our data suggest that high Pi suppresses the expression of genes associated with fungal cell cycle progression or that encode secreted proteins that may be required for intercellular hyphal growth and arbuscule formation. However, high Pi has little effect on the transcriptional regulation of the primary metabolism or transport in preformed fungal structures.

  9. Cancer-Associated Myeloid Regulatory Cells

    PubMed Central

    De Vlaeminck, Yannick; González-Rascón, Anna; Goyvaerts, Cleo; Breckpot, Karine

    2016-01-01

    Myeloid cells are critically involved in the pathophysiology of cancers. In the tumor microenvironment (TME), they comprise tumor-associated macrophages (TAMs), neutrophils (TANs), dendritic cells, and myeloid-derived suppressor cells, which are further subdivided into a monocytic subset and a granulocytic subset. Some of these myeloid cells, in particular TAMs and TANs, are divided into type 1 or type 2 cells, according to the paradigm of T helper type 1 or type 2 cells. Type 1-activated cells are generally characterized as cells that aid tumor rejection, while all other myeloid cells are shown to favor tumor progression. Moreover, these cells are often at the basis of resistance to various therapies. Much research has been devoted to study the biology of myeloid cells. This endeavor has proven to be challenging, as the markers used to categorize myeloid cells in the TME are not restricted to particular subsets. Also from a functional and metabolic point of view, myeloid cells share many features. Finally, myeloid cells are endowed with a certain level of plasticity, which further complicates studying them outside their environment. In this article, we challenge the exclusive use of cell markers to unambiguously identify myeloid cell subsets in the TME. We further propose to divide myeloid cells into myeloid regulatory or stimulatory cells according to their pro- or antitumor function, because we contend that for therapeutic purposes it is not targeting the cell subsets but rather targeting their protumor traits; hence, myeloid regulatory cells will push antitumor immunotherapy to the next level. PMID:27065074

  10. Special regulatory T cell review: How I became a T suppressor/regulatory cell maven

    PubMed Central

    Shevach, Ethan M

    2008-01-01

    I have briefly reviewed the factors that motivated me to change my views about the existence and importance of suppressor/regulatory T cells and to devote the majority of my laboratory efforts to this newly revitalized area of immunologic research. I am optimistic that manipulation of regulatory T-cell function will shortly be applicable to the clinic. PMID:18154610

  11. T Regulatory Cells and Transplantation Tolerance

    PubMed Central

    Gorantla, Vijay S.; Schneeberger, Stefan; Brandacher, Gerald; Sucher, Robert; Zhang, Dong; Lee, Andrew; Zheng, Xin Xiao

    2010-01-01

    Despite the development of successful immunosuppression protocols and tremendous improvement in short-term graft survival rates, the problem of chronic graft loss remains the bane of clinical transplantation. The induction and maintenance of transplantation tolerance is the “Holy grail” of transplantation. The recent identification and characterization of regulatory T cells (T regs) has opened up exciting opportunities for tolerance induction, immunotherapy and immunomodulation in transplantation. This review focuses on current understanding of regulatory T cells and their role in transplantation tolerance. PMID:20541385

  12. Mechanisms of T regulatory cell function.

    PubMed

    Askenasy, Nadir; Kaminitz, Ayelet; Yarkoni, Shai

    2008-05-01

    Regulatory T cells (Treg) play a pivotal role in tolerance to self-antigens and tissue grafts, and suppression of autoimmune reactions. These cells modulate the intensity and quality of immune reactions through attenuation of the cytolytic activities of reactive immune cells. Treg cells operate primarily at the site of inflammation where they modulate the immune reaction through three major mechanisms: a) direct killing of cytotoxic cells through cell-to-cell contact, b) inhibition of cytokine production by cytotoxic cells, in particular interleukin-2, c) direct secretion of immunomodulatory cytokines, in particular TGF-beta and interleukin-10. In addition to differential contributions of these mechanisms under variable inflammatory conditions, mechanistic complexity and diversity evolves from the diverse tasks performed by various Treg cell subsets in different stages of the immune reaction. Here we attempt to integrate the current experimental evidence to delineate the major suppressive pathways of Treg cells.

  13. Foxp3(+) regulatory T cells in tuberculosis.

    PubMed

    Larson, Ryan P; Shafiani, Shahin; Urdahl, Kevin B

    2013-01-01

    The immune response to Mycobacterium tuberculosis (Mtb) must be tightly regulated to mount a sufficient response to limit bacterial growth and dissemination while avoiding excessive inflammation that could damage host tissues. A wide variety of cell types, cell surface molecules, and cytokines are likely to contribute to this regulation, but recent studies have revealed that a subset of CD4 T cells expressing the transcription factor Foxp3, called regulatory T (reg) cells, play a critical role [1-3]. Although the first reports of T reg cells in tuberculosis (TB) occurred only recently (i.e., 2006) [4, 5], we have already gained many insights into their activity during TB. While it is likely that T reg cells do play some beneficial roles by preventing inflammation-mediated damage to host tissues during TB, this aspect of their function has not been well studied to date. What is clear, however, is that during the initial T cell response to Mtb infection, Mtb induces the expansions of T reg cells that delay the onset of adaptive immunity, suggesting that Mtb has hijacked T reg cell-mediated immune suppression to allow it to replicate unabated in the lung until T cells finally arrive [6]. In this chapter, we will first provide an overview of the delayed T cell response to Mtb and a brief introduction to regulatory T cells. We will then review what is known about T reg cells from observations in human populations, discuss mechanistic insights revealed in the mouse model, and speculate about the relevance of this understanding for future efforts to prevent and treat TB.

  14. Regulatory T cells and autoimmune disease.

    PubMed

    Paust, Silke; Cantor, Harvey

    2005-04-01

    Although T-cell clones bearing T-cell receptors with high affinity for self-peptide major histocompatibility complex (MHC) products are generally eliminated in the thymus (recessive tolerance), the peripheral T-cell repertoire remains strongly biased toward self-peptide MHC complexes and includes autoreactive T cells. A search for peripheral T cells that might exert dominant inhibitory effects on autoreactivity has implicated a subpopulation of CD4(+)CD25(+) T cells called regulatory T cells (Tregs). Here, we discuss the role of cytokines and costimulatory molecules in the generation, maintenance, and function of Tregs. We also summarize evidence for the involvement of Tregs in controlling autoimmune diseases, including type 1 diabetes, experimental autoimmune encephalomyelitis, and inflammatory bowel disease. Last, we discuss our recent definition of the potential role of B7 expressed on activated T-effector cells as a target molecule for Treg-dependent suppression. These observations suggest that the engagement of B7 on effector T cells transmits an inhibitory signal that blocks or attenuates effector T-cell function. We restrict our comments to the suppression mediated by cells within the CD4 lineage; the impact of the cells within the CD8 lineage that may suppress via engagement of Qa-1 on effector T cells is not addressed in this review.

  15. Harnessing Regulatory T cells to Suppress Asthma

    PubMed Central

    Thorburn, Alison N.; Hansbro, Philip M.

    2010-01-01

    Regulatory T cells (Tregs) play an essential role in maintaining the homeostatic balance of immune responses. Asthma is an inflammatory condition of the airways that is driven by dysregulated immune responses toward normally innocuous antigens. Individuals with asthma have fewer and less functional Tregs, which may lead to uncontrolled effector cell responses and promote proasthmatic responses of T helper type 2, T helper 17, natural killer T, antigen-presenting, and B cells. Tregs have the capacity to either directly or indirectly suppress these responses. Hence, the induced expansion of functional Tregs in predisposed or individuals with asthma is a potential approach for the prevention and treatment of asthma. Infection by a number of micro-organisms has been associated with reduced prevalence of asthma, and many infectious agents have been shown to induce Tregs and reduce allergic airways disease in mouse models. The translation of the regulatory and therapeutic properties of infectious agents for use in asthma requires the identification of key modulatory components and the development and trial of effective immunoregulatory therapies. Further translational and clinical research is required for the induction of Tregs to be harnessed as a therapeutic strategy for asthma. PMID:20097830

  16. Regulatory T cells and skeletal muscle regeneration.

    PubMed

    Schiaffino, Stefano; Pereira, Marcelo G; Ciciliot, Stefano; Rovere-Querini, Patrizia

    2017-02-01

    Skeletal muscle regeneration results from the activation and differentiation of myogenic stem cells, called satellite cells, located beneath the basal lamina of the muscle fibers. Inflammatory and immune cells have a crucial role in the regeneration process. Acute muscle injury causes an immediate transient wave of neutrophils followed by a more persistent infiltration of M1 (proinflammatory) and M2 (anti-inflammatory/proregenerative) macrophages. New studies show that injured muscle is also infiltrated by a specialized population of regulatory T (Treg) cells, which control both the inflammatory response, by promoting the M1-to-M2 switch, and the activation of satellite cells. Treg cells accumulate in injured muscle in response to specific cytokines, such as IL-33, and promote muscle growth by releasing growth factors, such as amphiregulin. Muscle repair during aging is impaired due to reduced number of Treg cells and can be enhanced by IL-33 supplementation. Migration of Treg cells could also contribute to explain the effect of heterochronic parabiosis, whereby muscle regeneration of aged mice can be improved by a parabiotically linked young partners. In mdx dystrophin-deficient mice, a model of human Duchenne muscular dystrophy, muscle injury, and inflammation is mitigated by expansion of the Treg-cell population but exacerbated by Treg-cell depletion. These findings support the notion that immunological mechanisms are not only essential in the response to pathogenic microbes and tumor cells but also have a wider homeostatic role in tissue repair, and open new perspectives for boosting muscle growth in chronic muscle disease and during aging.

  17. Regulatory Circuits Controlling Vascular Cell Calcification

    PubMed Central

    Sallam, Tamer; Cheng, Henry; Demer, Linda L.; Tintut, Yin

    2013-01-01

    Vascular calcification is a common feature of chronic kidney disease, cardiovascular disease, and aging. Such abnormal calcium deposition occurs in medial and/or intimal layers of blood vessels as well as in cardiac valves. Once considered a passive and inconsequential finding, the presence of calcium deposits in the vasculature is widely accepted as a predictor of increased morbidity and mortality. Recognition of the importance of vascular calcification in health is driving research into mechanisms that govern its development, progression, and regression. Diverse, but highly interconnected factors, have been implicated, including disturbances in lipid metabolism, oxidative stress, inflammatory cytokines, and mineral and hormonal balances, which can lead to formation of osteoblast-like cells in the artery wall. A tight balance of procalcific and anticalcific regulators dictates the extent of disease. In this review, we focus on the main regulatory circuits modulating vascular cell calcification. PMID:23269436

  18. Role of Regulatory Cells in Oral Tolerance

    PubMed Central

    Wawrzyniak, Marcin; O'Mahony, Liam

    2017-01-01

    The immune system is continuously exposed to great amounts of different antigens from both food and intestinal microbes. Immune tolerance to these antigens is very important for intestinal and systemic immune homeostasis. Oral tolerance is a specific type of peripheral tolerance induced by exposure to antigen via the oral route. Investigations on the role of intestinal immune system in preventing hypersensitivity reactions to innocuous dietary and microbial antigens have been intensively performed during the last 2 decades. In this review article, we discuss how food allergens are recognized by the intestinal immune system and draw attention to the role of regulatory T (Treg) and B (Breg) cells in the establishment of oral tolerance and tolerogenic features of intestinal dendritic cells. We also emphasize the potential role of tonsils in oral tolerance induction because of their anatomical location, cellular composition, and possible usage to develop novel ways of specific immunotherapy for the treatment of allergic diseases. PMID:28102055

  19. Radiation Enhances Regulatory T Cell Representation

    SciTech Connect

    Kachikwu, Evelyn L.; Iwamoto, Keisuke S.; Liao, Yu-Pei; DeMarco, John J.; Agazaryan, Nzhde; Economou, James S.; McBride, William H.; Schaue, Doerthe

    2011-11-15

    Purpose: Immunotherapy could be a useful adjunct to standard cytotoxic therapies such as radiation in patients with micrometastatic disease, although successful integration of immunotherapy into treatment protocols will require further understanding of how standard therapies affect the generation of antitumor immune responses. This study was undertaken to evaluate the impact of radiation therapy (RT) on immunosuppressive T regulatory (Treg) cells. Methods and Materials: Treg cells were identified as a CD4{sup +}CD25{sup hi}Foxp3{sup +} lymphocyte subset, and their fate was followed in a murine TRAMP C1 model of prostate cancer in mice with and without RT. Results: CD4{sup +}CD25{sup hi}Foxp3{sup +} Treg cells increased in immune organs after local leg or whole-body radiation. A large part, but not all, of this increase after leg-only irradiation could be ascribed to radiation scatter and Treg cells being intrinsically more radiation resistant than other lymphocyte subpopulations, resulting in their selection. Their functional activity on a per-cell basis was not affected by radiation exposure. Similar findings were made with mice receiving local RT to murine prostate tumors growing in the leg. The importance of the Treg cell population in the response to RT was shown by systemic elimination of Treg cells, which greatly enhanced radiation-induced tumor regression. Conclusions: We conclude that Treg cells are more resistant to radiation than other lymphocytes, resulting in their preferential increase. Treg cells may form an important homeostatic mechanism for tissues injured by radiation, and in a tumor context, they may assist in immune evasion during therapy. Targeting this population may allow enhancement of radiotherapeutic benefit through immune modulation.

  20. Cellular immune responses towards regulatory cells.

    PubMed

    Larsen, Stine Kiær

    2016-01-01

    This thesis describes the results from two published papers identifying spontaneous cellular immune responses against the transcription factors Foxp3 and Foxo3. The tumor microenvironment is infiltrated by cells that hinder effective tumor immunity from developing. Two of these cell types, which have been linked to a bad prognosis for patients, are regulatory T cells (Treg) and tolerogenic dendritic cells (DC). Tregs inhibit effector T cells from attacking the tumor through various mechanisms, including secreted factors and cell-to-cell contact. Tregs express the transcription factor Foxp3, which is necessary for their development and suppressive activities. Tolerogenic DCs participate in creating an environment in the tumor where effector T cells become tolerant towards the tumor instead of attacking it. The transcription factor Foxo3 was recently described to be highly expressed by tolerogenic DCs and to programme their tolerogenic influence. This thesis describes for the first time the existence of spontaneous cellular immune responses against peptides derived from Foxp3 and Foxo3. We have detected the presence of cytotoxic T cells that recognise these peptides in an HLA-A2 restricted manner in cancer patients and for Foxp3 in healthy donors as well. In addition, we have demonstrated that the Foxp3- and Foxo3-specific CTLs recognize Foxp3- and Foxo3-expressing cancer cell lines and importantly, suppressive immune cells, namely Tregs and in vitro generated DCs. Cancer immunotherapy is recently emerging as an important treatment modality improving the survival of selected patients. The current progress is largely owing to targeting of the immune suppressive milieu that is dominating the tumor microenvironment. This is being done through immune checkpoint blockade with CTLA-4 and PD-1/PD-L1 antibodies and through lymphodepleting conditioning of patients and ex vivo activation of TILs in adoptive cell transfer. Several strategies are being explored for depletion of

  1. Regulatory Functions of Natural Killer Cells in Multiple Sclerosis

    PubMed Central

    Gross, Catharina C.; Schulte-Mecklenbeck, Andreas; Wiendl, Heinz; Marcenaro, Emanuela; Kerlero de Rosbo, Nicole; Uccelli, Antonio; Laroni, Alice

    2016-01-01

    There is increasing evidence that natural killer (NK) cells exhibit regulatory features. Among them, CD56bright NK cells have been suggested to play a major role in controlling T cell responses and maintaining homeostasis. Dysfunction in NK cell-mediated regulatory features has been recently described in untreated multiple sclerosis (MS), suggesting a contribution to MS pathogenesis. Moreover, biological disease-modifying treatments effective in MS apparently enhance the frequencies and/or regulatory function of NK cells, further pointing toward an immunoprotective role of NK cells in MS. Here, we summarize the current knowledge on the regulatory functions of NK cells, based on their interactions with other cells belonging to the innate compartment, as well as with adaptive effector cells. We review the more recent data reporting disruption of NK cell/T cell interactions in MS and discuss how disease-modifying treatments for MS affect NK cells. PMID:28066417

  2. PDGF upregulates CLEC-2 to induce T regulatory cells.

    PubMed

    Agrawal, Sudhanshu; Ganguly, Sreerupa; Hajian, Pega; Cao, Jia-Ning; Agrawal, Anshu

    2015-10-06

    The effect of platelet derived growth factor (PDGF) on immune cells is not elucidated. Here, we demonstrate PDGF inhibited the maturation of human DCs and induced IL-10 secretion. Culture of PDGF-DCs with T cells induced the polarization of T cells towards FoxP3 expressing T regulatory cells that secreted IL-10. Gene expression studies revealed that PDGF induced the expression of C-type lectin like receptor member 2, (CLEC-2) receptor on DCs. Furthermore, DCs transfected with CLEC-2 induced T regulatory cells in DC-T cell co-culture. CLEC-2 is naturally expressed on platelets. Therefore, to confirm whether CLEC-2 is responsible for inducing the T regulatory cells, T cells were cultured with either CLEC-2 expressing platelets or soluble CLEC-2. Both conditions resulted in the induction of regulatory T cells. The generation of T regulatory cells was probably due to the binding of CLEC-2 with its ligand podoplanin on T cells, since crosslinking of podoplanin on the T cells also resulted in the induction of T regulatory cells. These data demonstrate that PDGF upregulates the expression of CLEC-2 on cells to induce T regulatory cells.

  3. Immunopathogenesis In Autism: Regulatory T Cells and Autoimmunity In Neurodevelopment

    DTIC Science & Technology

    2011-07-01

    exogenous agents, such as environmental pollutants, play a role in causing or triggering dysfunctional development that may culminate in an autism diagnosis...1-0484 TITLE: Immunopathogenesis in Autism : Regulatory T Cells and Autoimmunity in Neurodevelopment PRINCIPAL INVESTIGATOR: Jamie C...1 July 2010 – 30 June 2011 4. TITLE AND SUBTITLE Immunopathogenesis in Autism : 5a. CONTRACT NUMBER Regulatory T Cells and Autoimmunity in

  4. Radiation Enhances Regulatory T Cell Representation

    PubMed Central

    Kachikwu, Evelyn L.; Iwamoto, Keisuke S.; Liao, Yu-Pei; DeMarco, John J.; Agazaryan, Nzhde; Economou, James S.; McBride, William H.; Schaue, Dörthe

    2010-01-01

    PURPOSE Immunotherapy (IT) could be a useful adjunct to standard cytotoxic therapies such as radiation in patients with micrometastatic disease although successful integration of IT into treatment protocols will require further understanding of how standard therapies affect the generation of anti-tumor immune responses. This study was undertaken to evaluate the impact of radiation therapy on immunosuppressive T regulatory (Treg) cells. MATERIALS and METHODS Tregs were identified as a CD4+CD25hiFoxp3+ lymphocyte subset and their fate followed in a murine TRAMP-C1 model of prostate cancer in mice with and without radiation therapy. RESULTS CD4+CD25hiFoxp3+ Treg cells increased in immune organs following local leg or whole body radiation. A large part, but not all, of this increase following leg-only irradiation could be ascribed to radiation scatter and Tregs being intrinsically more radiation resistant than other lymphocyte subpopulations resulting in their selection. Their functional activity on a per cell basis was not affected by radiation exposure. Similar findings were made with mice receiving local RT to murine prostate tumors growing in the leg. The importance of the Treg population in the response to RT was shown by systemic elimination of Tregs, which greatly enhanced radiation-induced tumor regression. CONCLUSIONS We conclude that Tregs are more resistant to radiation than other lymphocytes resulting in their preferential increase. Treg cells may form an important homeostatic mechanism for tissues injured by radiation, and in a tumor context may assist in immune evasion during therapy. Targeting this population may allow enhancement of radiotherapeutic benefit through immune modulation. PMID:21093169

  5. Regulatory T Cell Immunotherapy in Immune-Mediated Diseases

    PubMed Central

    Pierini, Antonio; Schneidawind, Dominik; Nishikii, Hidekazu; Negrin, Robert S.

    2015-01-01

    Broad clinical interest rapidly followed the recent discovery of different subpopulations of T cells that have immune regulatory properties and a number of studies have been conducted aiming to dissect the translational potential of these promising cells. In this review we will focus on forkhead box P3 (FoxP3) positive regulatory T cells, T regulatory type 1 cells and invariant natural killer T cells (iNKT). We will analyze their ability to correct immune dysregulation in animal models of immune mediated diseases and we will examine the first clinical approaches where these cells have been directly or indirectly employed. We will discuss successes, challenges and limitations that rose in the road to the clinical use of regulatory T cells. PMID:26779417

  6. Regulatory T Cells and Their Role in Animal Disease.

    PubMed

    Veiga-Parga, T

    2016-07-01

    In humans and mouse models, Foxp3(+) regulatory T cells are known to control all aspects of immune responses. However, only limited information exists on these cells' role in diseases of other animals. In this review, we cover the most important features and different types of regulatory T cells, which include those that are thymus-derived and peripherally induced, the mechanisms by which they control immune responses by targeting effector T cells and antigen-presenting cells, and most important, their role in animal health and diseases including cancer, infections, and other conditions such as hypersensitivities and autoimmunity. Although the literature regarding regulatory T cells in domestic animal species is still limited, multiple articles have recently emerged and are discussed. Moreover, we also discuss the evidence suggesting that regulatory T cells might limit the magnitude of effector responses, which can have either a positive or negative result, depending on the context of animal and human disease. In addition, the issue of plasticity is discussed because plasticity in regulatory T cells can result in the loss of their protective function in some microenvironments during disease. Lastly, the manipulation of regulatory T cells is discussed in assessing the possibility of their use as a treatment in the future.

  7. Generation of regulatory dendritic cells after treatment with paeoniflorin.

    PubMed

    Chen, Dan; Li, Yingxi; Wang, Xiaodong; Li, Keqiu; Jing, Yaqing; He, Jinghua; Qiang, Zhaoyan; Tong, Jingzhi; Sun, Ke; Ding, Wen; Kang, Yi; Li, Guang

    2016-08-01

    Regulatory dendritic cells are a potential therapeutic tool for assessing a variety of immune overreaction diseases. Paeoniflorin, a bioactive glucoside extracted from the Chinese herb white paeony root, has been shown to be effective at inhibiting the maturation and immunostimulatory function of murine bone marrow-derived dendritic cells. However, whether paeoniflorin can program conventional dendritic cells toward regulatory dendritic cells and the underlying mechanism remain unknown. Here, our study demonstrates that paeoniflorin can induce the production of regulatory dendritic cells from human peripheral blood monocyte-derived immature dendritic cells in the absence or presence of lipopolysaccharide (LPS) but not from mature dendritic cells, thereby demonstrating the potential of paeoniflorin as a specific immunosuppressive drug with fewer complications and side effects. These regulatory dendritic cells treated with paeoniflorin exhibited high CD11b/c and low CD80, CD86 and CD40 expression levels as well as enhanced abilities to capture antigen and promote the proliferation of CD4(+)CD25(+) T cells and reduced abilities to migrate and promote the proliferation of CD4(+) T cells, which is associated with the upregulation of endogenous transforming growth factor (TGF)-β-mediated indoleamine 2,3-dioxygenase (IDO) expression. Collectively, paeoniflorin could program immature dendritic cells (imDCs) and imDCs stimulated with LPS toward a regulatory DC fate by upregulating the endogenous TGF-β-mediated IDO expression level, thereby demonstrating its potential as a specific immunosuppressive drug.

  8. How tolerogenic dendritic cells induce regulatory T cells

    PubMed Central

    Maldonado, Roberto A.; von Andrian, Ulrich H.

    2010-01-01

    Since their discovery by Steinman and Cohn in 1973, dendritic cells (DCs) have become increasingly recognized for their crucial role as regulators of innate and adaptive immunity. DCs are exquisitely adept at acquiring, processing and presenting antigens to T cells. They also adjust the context (and hence the outcome) of antigen presentation in response to a plethora of environmental inputs that signal the occurence of pathogens or tissue damage. Such signals generally boost DC maturation, which promotes their migration from peripheral tissues into and within secondary lymphoid organs and their capacity to induce and regulate effector T cell responses. Conversely, more recent observations indicate that DCs are also crucial to ensure immunological peace. Indeed, DCs constantly present innocuous self and non-self antigens in a fashion that promotes tolerance, at least in part, through the control of regulatory T cells (Tregs). Tregs are specialized T cells that exert their immuno-suppressive function through a variety of mechanisms affecting both DCs and effector cells. Here, we review recent advances in our understanding of the relationship between tolerogenic DCs and Tregs. PMID:21056730

  9. Extracellular NAD(+): a danger signal hindering regulatory T cells.

    PubMed

    Adriouch, Sahil; Haag, Friedrich; Boyer, Olivier; Seman, Michel; Koch-Nolte, Friedrich

    2012-11-01

    Endogenous danger signals released during cell damage contribute to alert the immune system. Typically, their release results in the activation and maturation of innate immune cells, and the production of pro-inflammatory cytokines. In addition, extracellular NAD(+) stimulates immune responses by hindering regulatory T cells (Tregs), and could, therefore, represent the prototype of a new category of danger signals.

  10. Introduction: characterization and functions of human T regulatory cells.

    PubMed

    Romagnani, Sergio

    2005-06-01

    The field of human T regulatory (Treg) cells is a rapidly progressing, but still confused field of immunology. The effects of dendritic cell (DC) manipulation in Treg generation and the main features of human "natural" Treg cells, as well as of different populations of adaptive Treg subsets, are still partially unclear. However, it is clear that Treg cells play an important role in human diseases, such as autoimmune disorders, allergy, HIV infection, tumors and graft-versus-host disease.

  11. The Role of Regulatory T Cells in Cancer

    PubMed Central

    2009-01-01

    There has been an explosion of literature focusing on the role of regulatory T (Treg) cells in cancer immunity. It is becoming increasingly clear that Treg cells play an active and significant role in the progression of cancer, and have an important role in suppressing tumor-specific immunity. Thus, there is a clear rationale for developing clinical strategies to diminish their regulatory influences, with the ultimate goal of augmenting antitimor immunity. Therefore, manipulation of Treg cells represent new strategies for cancer treatment. In this Review, I will summarize and review the explosive recent studies demonstrating that Treg cells are increased in patients with malignancies and restoration of antitumor immunity in mice and humans by depletion or reduction of Treg cells. In addition, I will discuss both the prognostic value of Treg cells in tumor progression in tumor-bearing hosts and the rationale for strategies for therapeutic vaccination and immunotherapeutic targeting of Treg cells with drugs and microRNA. PMID:20157609

  12. Emerging role of regulatory T cells in gene transfer.

    PubMed

    Cao, Ou; Furlan-Freguia, Christian; Arruda, Valder R; Herzog, Roland W

    2007-10-01

    Induction and maintenance of immune tolerance to therapeutic transgene products are key requirements for successful gene replacement therapies. Gene transfer may also be used to specifically induce immune tolerance and thereby augment other types of therapies. Similarly, gene therapies for treatment of autoimmune diseases are being developed in order to restore tolerance to self-antigens. Regulatory T cells have emerged as key players in many aspects of immune tolerance, and a rapidly increasing body of work documents induction and/or activation of regulatory T cells by gene transfer. Regulatory T cells may suppress antibody formation and cytotoxic T cell responses and may be critical for immune tolerance to therapeutic proteins. In this regard, CD4(+)CD25(+) regulatory T cells have been identified as important components of tolerance in several gene transfer protocols, including hepatic in vivo gene transfer. Augmentation of regulatory T cell responses should be a promising new tool to achieve tolerance and avoid immune-mediated rejection of gene therapy. During the past decade, it has become obvious that immune regulation is an important and integral component of tolerance to self-antigens and of many forms of induced tolerance. Gene therapy can only be successful if the immune system does not reject the therapeutic transgene product. Recent studies provide a rapidly growing body of evidence that regulatory T cells (T(reg)) are involved and often play a crucial role in tolerance to proteins expressed by means of gene transfer. This review seeks to provide an overview of these data and their implications for gene therapy.

  13. Critical evaluation of regulatory T cells in autoimmunity: are the most potent regulatory specificities being ignored?

    PubMed

    Vandenbark, Arthur A; Offner, Halina

    2008-09-01

    The identification of CD4+ CD25+ Foxp3+ regulatory T (Treg) cells as natural regulators of immunity in the periphery and tissues has stimulated tremendous interest in developing therapeutic strategies for autoimmune diseases. In this review, the site of origin, antigen specificity, homing markers and cytokine profiles of Treg cells were evaluated in autoimmune colitis and type 1 diabetes, two examples in which Treg cells were effective as therapy. These studies were compared with studies of Treg cells in experimental autoimmune encephalomyelitis and multiple sclerosis, where successful therapy has not yet been achieved. Antigen-specific Treg cells appear to have more potent activity than polyclonal Treg cells and therefore hold more promise as therapeutic agents. However, Treg cells specific for the pathogenic T effector cells themselves have largely been overlooked and deserve consideration in future studies.

  14. B cells with regulatory properties in transplantation tolerance

    PubMed Central

    Durand, Justine; Chiffoleau, Elise

    2015-01-01

    Induction of tolerance remains a major goal in transplantation. Indeed, despite potent immunosuppression, chronic rejection is still a real problem in transplantation. The humoral response is an important mediator of chronic rejection, and numerous strategies have been developed to target either B cells or plasma cells. However, the use of anti-CD20 therapy has highlighted the beneficial role of subpopulation of B cells, termed regulatory B cells. These cells have been characterized mainly in mice models of auto-immune diseases but emerging literature suggests their role in graft tolerance in transplantation. Regulatory B cells seem to be induced following inflammation to restrain excessive response. Different phenotypes of regulatory B cells have been described and are functional at various differentiation steps from immature to plasma cells. These cells act by multiple mechanisms such as secretion of immuno-suppressive cytokines interleukin-10 (IL-10) or IL-35, cytotoxicity, expression of inhibitory receptors or by secretion of non-inflammatory antibodies. Better characterization of the development, phenotype and mode of action of these cells seems urgent to develop novel approaches to manipulate the different B cell subsets and the response to the graft in a clinical setting. PMID:26722647

  15. Regulatory T Cells in Hepatitis B and C Virus Infections

    PubMed Central

    2016-01-01

    Hepatitis B virus (HBV) and hepatitis C virus (HCV) are hepatotropic viruses that establish chronic persistent infection by effectively escaping the host immune response and can cause immune-mediated liver injury. It has recently become apparent that regulatory T (Treg) cells, specifically CD4+CD25+Foxp3+ Treg cells, modulate viral diseases by suppressing antiviral immune responses and regulating inflammatory host injury. The roles of Treg cells in HBV and HCV infections range from suppressing antiviral T cell responses to protecting the liver from immune-mediated damage. This review describes Treg cells and subpopulations and focuses on the roles of these cells in HBV and HCV infections. PMID:28035208

  16. Movement of regulatory RNA between animal cells

    PubMed Central

    Jose, Antony M.

    2015-01-01

    Summary Recent studies suggest that RNA can move from one cell to another and regulate genes through specific base-pairing. Mechanisms that modify or select RNA for secretion from a cell are unclear. Secreted RNA can be stable enough to be detected in the extracellular environment and can enter the cytosol of distant cells to regulate genes. Mechanisms that import RNA into the cytosol of an animal cell can enable uptake of RNA from many sources including other organisms. This role of RNA is akin to that of steroid hormones, which cross cell membranes to regulate genes. The potential diagnostic use of RNA in human extracellular fluids has ignited interest in understanding mechanisms that enable the movement of RNA between animal cells. Genetic model systems will be essential to gain more confidence in proposed mechanisms of RNA transport and to connect an extracellular RNA with a specific biological function. Studies in the worm C. elegans and in other animals have begun to reveal parts of this novel mechanism of cell-to-cell communication. Here, I summarize the current state of this nascent field, highlight the many unknowns, and suggest future directions. PMID:26138457

  17. Finding Balance: T cell Regulatory Receptor Expression during Aging.

    PubMed

    Cavanagh, Mary M; Qi, Qian; Weyand, Cornelia M; Goronzy, Jörg J

    2011-10-01

    Aging is associated with a variety of changes to immune responsiveness. Reduced protection against infection, reduced responses to vaccination and increased risk of autoimmunity are all hallmarks of advanced age. Here we consider how changes in the expression of regulatory receptors on the T cell surface contribute to altered immunity during aging.

  18. The expanding universe of regulatory T cell subsets in cancer.

    PubMed

    Gajewski, Thomas F

    2007-08-01

    Evidence has indicated that failed antitumor immunity is dominated by immunosuppressive mechanisms within the tumor microenvironment. In this issue of Immunity, Peng et al. (2007) add to this list by describing tumor-infiltrating gammadelta T cells that have regulatory function.

  19. The two faces of regulatory T cells in cancer

    PubMed Central

    Blatner, Nichole R; Gounari, Fotini; Khazaie, Khashayarsha

    2013-01-01

    Regulatory T cells (Tregs) that expand in human colon cancer express retinoid-related orphan receptor γt (RORγt) and exert potent T-cell suppressive functions while mediating pro-inflammatory effects. Similar Tregs expand and drive a vicious cycle of inflammation in murine polyposis. Targeting RORγt in Tregs interrupts such a cycle and protects mice against polyposis, suggesting that a similar intervention may provide therapeutic benefits to colon cancer patients. PMID:23762787

  20. Minocycline promotes the generation of dendritic cells with regulatory properties

    PubMed Central

    Im, Sun-A; Kim, Ji-Wan; Lee, Jae-Hee; Park, Young-Jun; Song, Sukgil; Lee, Chong-Kil

    2016-01-01

    Minocycline, which has long been used as a broad-spectrum antibiotic, also exhibits non-antibiotic properties such as inhibition of inflammation and angiogenesis. In this study, we show that minocycline significantly enhances the generation of dendritic cells (DCs) from mouse bone marrow (BM) cells when used together with GM-CSF and IL-4. DCs generated from BM cells in the presence of minocycline (Mino-DCs) demonstrate the characteristics of regulatory DCs. Compared with control DCs, Mino-DCs are resistant to subsequent maturation stimuli, impaired in MHC class II-restricted exogenous Ag presentation, and show decreased cytokine secretion. Mino-DCs also show decreased ability to prime allogeneic-specific T cells, while increasing the expansion of CD4+CD25+Foxp3+ T regulatory cells both in vitro and in vivo. In addition, pretreatment with MOG35-55 peptide-pulsed Mino-DCs ameliorates clinical signs of experimental autoimmune encephalitis induced by MOG peptide injection. Our study identifies minocycline as a new pharmacological agent that could be potentially used to increase the production of regulatory DCs for cell therapy to treat autoimmune disorders, allergy, and transplant rejection. PMID:27463004

  1. Regulatory immune cells and functions in autoimmunity and transplantation immunology.

    PubMed

    Papp, Gabor; Boros, Peter; Nakken, Britt; Szodoray, Peter; Zeher, Margit

    2017-03-07

    In physiological circumstances, various tolerogenic mechanisms support the protection of self-structures during immune responses. However, quantitative and/or qualitative changes in regulatory immune cells and mediators can evoke auto-reactive immune responses, and upon susceptible genetic background, along with the presence of other concomitant etiological factors, autoimmune disease may develop. In transplant immunology, tolerogenic mechanisms are also critical, since the balance between of alloantigen-reactive effector cells and the regulatory immune cells will ultimately determine whether a graft is accepted or rejected. Better understanding of the immunological tolerance and the potential modulations of immune regulatory processes are crucial for developing effective therapies in autoimmune diseases as well as in organ transplantation. In this review, we focus on the novel insights regarding the impaired immune regulation and other relevant factors contributing to the development of auto-reactive and graft-reactive immune responses in autoimmune diseases and transplant rejection, respectively. We also address some promising approaches for modification of immune-regulatory processes and tolerogenic mechanisms in autoimmunity and solid organ transplantation, which may be beneficial in future therapeutic strategies.

  2. Direct-to-consumer stem cell marketing and regulatory responses.

    PubMed

    Sipp, Douglas

    2013-09-01

    There is a large, poorly regulated international market of putative stem cell products, including transplants of processed autologous stem cells from various tissues, cell processing devices, cosmetics, and nutritional supplements. Despite the absence of rigorous scientific research in the form of randomized clinical trials to support the routine use of such products, the market appears to be growing and diversifying. Very few stem cell biologics have passed regulatory scrutiny, and authorities in many countries, including the United States, have begun to step up their enforcement activities to protect patients and the integrity of health care markets.

  3. T Regulatory Cell Biology in Health and Disease.

    PubMed

    Alroqi, Fayhan J; Chatila, Talal A

    2016-04-01

    Regulatory T (Treg) cells that express the transcription factor forkhead box protein P3 (FOXP3) play an essential role in enforcing immune tolerance to self tissues, regulating host-commensal flora interaction, and facilitating tissue repair. Their deficiency and/or dysfunction trigger unbridled autoimmunity and inflammation. A growing number of monogenic defects have been recognized that adversely impact Treg cell development, differentiation, and/or function, leading to heritable diseases of immune dysregulation and autoimmunity. In this article, we review recent insights into Treg cell biology and function, with particular attention to lessons learned from newly recognized clinical disorders of Treg cell deficiency.

  4. Regulatory mechanisms of helper T cell differentiation

    PubMed Central

    Pappu, Bhanu P.; Angkasekwinai, Pornpimon; Dong, Chen

    2008-01-01

    Interleukin 17 (IL-17) family consists of six cytokines in mammals. Among them, IL-17 and IL-17F are expressed by a novel subset of CD4+ helper T (Th) cells and play critical function in inflammation and autoimmunity. On the other hand, IL-17E, also called IL-25, has been associated with allergic responses. Here we summarize recent work by us as well as other investigators in understanding the regulation and function of these three cytokines. From these studies, IL-17 family cytokines may serve as novel targets for pharmaceutical intervention of immune and inflammatory diseases. PMID:18280574

  5. Dynamics of gene regulatory networks with cell division cycle

    NASA Astrophysics Data System (ADS)

    Chen, Luonan; Wang, Ruiqi; Kobayashi, Tetsuya J.; Aihara, Kazuyuki

    2004-07-01

    This paper focuses on modeling and analyzing the nonlinear dynamics of gene regulatory networks with the consideration of a cell division cycle with duplication process of DNA , in particular for switches and oscillators of synthetic networks. We derive two models that may correspond to the eukaryotic and prokaryotic cells, respectively. A biologically plausible three-gene model ( lac,tetR , and cI ) and a repressilator as switch and oscillator examples are used to illustrate our theoretical results. We show that the cell cycle may play a significant role in gene regulation due to the nonlinear dynamics of a gene regulatory network although gene expressions are usually tightly controlled by transcriptional factors.

  6. CD4+ regulatory T cell responses induced by T cell vaccination in patients with multiple sclerosis

    PubMed Central

    Hong, Jian; Zang, Ying C. Q.; Nie, Hong; Zhang, Jingwu Z.

    2006-01-01

    Immunization with irradiated autologous T cells (T cell vaccination) is shown to induce regulatory T cell responses that are poorly understood. In this study, CD4+ regulatory T cell lines were generated from patients with multiple sclerosis that received immunization with irradiated autologous myelin basic protein-reactive T cells. The resulting CD4+ regulatory T cell lines had marked inhibition on autologous myelin basic protein-reactive T cells and displayed two distinctive patterns distinguishable by the expression of transcription factor Foxp3 and cytokine profile. The majority of the T cell lines had high Foxp3 expression and secreted both IFN-γ and IL-10 as compared with the other pattern characteristic of low Foxp3 expression and predominant production of IL-10 but not IFN-γ. CD4+ regulatory T cell lines of both patterns expressed CD25 and reacted with activated autologous T cells but not resting T cells, irrespective of antigen specificity of the target T cells. It was evident that they recognized preferentially a synthetic peptide corresponding to residues 61–73 of the IL-2 receptor α chain. T cell vaccination correlated with increased Foxp3 expression and T cell reactivity to peptide 61–73. The findings have important implications in the understanding of the role of CD4+ regulatory T cell response induced by T cell vaccination. PMID:16547138

  7. Generation and Function of Induced Regulatory T Cells

    PubMed Central

    Schmitt, Erica G.; Williams, Calvin B.

    2013-01-01

    CD4+ CD25+ Foxp3+ regulatory T (Treg) cells are essential to the balance between pro- and anti-inflammatory responses. There are two major subsets of Treg cells, “natural” Treg (nTreg) cells that develop in the thymus, and “induced” Treg (iTreg) cells that arise in the periphery from CD4+ Foxp3− conventional T cells and can be generated in vitro. Previous work has established that both subsets are required for immunological tolerance. Additionally, in vitro-derived iTreg cells can reestablish tolerance in situations where Treg cells are decreased or defective. This review will focus on iTreg cells, drawing comparisons to nTreg cells when possible. We discuss the molecular mechanisms of iTreg cell induction, both in vivo and in vitro, review the Foxp3-dependent and -independent transcriptional landscape of iTreg cells, and examine the proposed suppressive mechanisms utilized by each Treg cell subset. We also compare the T cell receptor repertoire of the Treg cell subsets, discuss inflammatory conditions where iTreg cells are generated or have been used for treatment, and address the issue of iTreg cell stability. PMID:23801990

  8. Regulatory T cells as therapeutic targets in rheumatoid arthritis

    PubMed Central

    Esensten, Jonathan H.; Wofsy, David; Bluestone, Jeffrey A.

    2011-01-01

    Regulatory T cells (TREG) are a subset of CD4+ T cells with a critical role in the prevention of autoimmunity. Whether defects in TREG contribute to the pathogenesis of rheumatoid arthritis (RA) is unclear. However, a variety of approved and experimental drugs for RA may work, in part, by promoting the function or increasing numbers of TREG. Furthermore, animal studies demonstrate that direct injection of TREG ameliorates a wide range of experimental models of inflammatory and autoimmune diseases. Thus, cell-based therapy with TREG has the potential to produce durable disease remission in patients with RA. PMID:19798031

  9. Gene regulatory networks governing haematopoietic stem cell development and identity.

    PubMed

    Pimanda, John E; Göttgens, Berthold

    2010-01-01

    Development can be viewed as a dynamic progression through regulatory states which characterise the various cell types within a given differentiation cascade. To understand the progression of regulatory states that define the origin and subsequent development of haematopoietic stem cells, the first imperative is to understand the ontogeny of haematopoiesis. We are fortunate that the ontogeny of blood development is one of the best characterized mammalian developmental systems. However, the field is still in its infancy with regard to the reconstruction of gene regulatory networks and their interactions with cell signalling cascades that drive a mesodermal progenitor to adopt the identity of a haematopoietic stem cell and beyond. Nevertheless, a framework to dissect these networks and comprehend the logic of its circuitry does exist and although they may not as yet be available, a sense for the tools that will be required to achieve this aim is also emerging. In this review we cover the fundamentals of network architecture, methods used to reconstruct networks, current knowledge of haematopoietic and related transcriptional networks, current challenges and future outlook.

  10. Single-cell chromatin accessibility reveals principles of regulatory variation.

    PubMed

    Buenrostro, Jason D; Wu, Beijing; Litzenburger, Ulrike M; Ruff, Dave; Gonzales, Michael L; Snyder, Michael P; Chang, Howard Y; Greenleaf, William J

    2015-07-23

    Cell-to-cell variation is a universal feature of life that affects a wide range of biological phenomena, from developmental plasticity to tumour heterogeneity. Although recent advances have improved our ability to document cellular phenotypic variation, the fundamental mechanisms that generate variability from identical DNA sequences remain elusive. Here we reveal the landscape and principles of mammalian DNA regulatory variation by developing a robust method for mapping the accessible genome of individual cells by assay for transposase-accessible chromatin using sequencing (ATAC-seq) integrated into a programmable microfluidics platform. Single-cell ATAC-seq (scATAC-seq) maps from hundreds of single cells in aggregate closely resemble accessibility profiles from tens of millions of cells and provide insights into cell-to-cell variation. Accessibility variance is systematically associated with specific trans-factors and cis-elements, and we discover combinations of trans-factors associated with either induction or suppression of cell-to-cell variability. We further identify sets of trans-factors associated with cell-type-specific accessibility variance across eight cell types. Targeted perturbations of cell cycle or transcription factor signalling evoke stimulus-specific changes in this observed variability. The pattern of accessibility variation in cis across the genome recapitulates chromosome compartments de novo, linking single-cell accessibility variation to three-dimensional genome organization. Single-cell analysis of DNA accessibility provides new insight into cellular variation of the 'regulome'.

  11. Retinoic acid from retinal pigment epithelium induces T regulatory cells.

    PubMed

    Kawazoe, Yuko; Sugita, Sunao; Keino, Hiroshi; Yamada, Yukiko; Imai, Ayano; Horie, Shintaro; Mochizuki, Manabu

    2012-01-01

    Primary cultured retinal pigment epithelial (RPE) cells can convert T cells into T regulatory cells (Tregs) through inhibitory factor(s) including transforming growth factor β (TGFβ) in vitro. Retinoic acid (RA) enhances induction of CD4(+) Tregs in the presence of TGFβ. We investigated whether RA produced by RPE cells can promote generation of Tregs. We found that in vitro, RA-treated T cells expressed high levels of Foxp3 in the presence of recombinant TGFβ. In GeneChip analysis, cultured RPE cells constitutively expressed RA-associated molecules such as RA-binding proteins, enzymes, and receptors. RPE from normal mice, but not vitamin A-deficient mice, contained significant levels of TGFβ. RPE-induced Tregs from vitamin A-deficient mice failed to suppress activation of target T cells. Only a few Foxp3(+) T cells were found in intraocular cells from vitamin A-deficient experimental autoimmune uveitis (EAU) mice, whereas expression was higher in cells from normal EAU mice. RA receptor antagonist-pretreated or RA-binding protein-siRNA-transfected RPE cells failed to convert CD4(+) T cells into Tregs. Our data support the hypothesis that RPE cells produce RA, thereby enabling bystander T cells to be converted into Tregs through TGFβ promotion, which can then participate in the establishment of immune tolerance in the eye.

  12. The companions: regulatory T cells and gene therapy

    PubMed Central

    Eghtesad, Saman; Morel, Penelope A; Clemens, Paula R

    2009-01-01

    Undesired immunological responses to products of therapeutic gene replacement have been obstacles to successful gene therapy. Understanding such responses of the host immune system to achieve immunological tolerance to a transferred gene product is therefore crucial. In this article, we review relevant studies of immunological responses to gene replacement therapy, the role of immunological tolerance mediated by regulatory T cells in down-regulating the unwanted immune responses, and the interrelationship of the two topics. PMID:19368560

  13. Immune regulatory effects of simvastatin on regulatory T cell-mediated tumour immune tolerance.

    PubMed

    Lee, K J; Moon, J Y; Choi, H K; Kim, H O; Hur, G Y; Jung, K H; Lee, S Y; Kim, J H; Shin, C; Shim, J J; In, K H; Yoo, S H; Kang, K H; Lee, S Y

    2010-08-01

    Statins are potent inhibitors of hydroxyl-3-methylglutaryl co-enzyme A (HMG-CoA) reductase, and have emerged as potential anti-cancer agents based on preclinical evidence. In particular, compelling evidence suggests that statins have a wide range of immunomodulatory properties. However, little is known about the role of statins in tumour immune tolerance. Tumour immune tolerance involves the production of immunosuppressive molecules, such as interleukin (IL)-10, transforming growth factor (TGF)-beta and indoleamine-2,3-dioxygenase (IDO) by tumours, which induce a regulatory T cell (T(reg)) response. In this study, we investigated the effect of simvastatin on the production of IL-10, TGF-beta and IDO production and the proliferation of T(regs) using several cancer cell lines, and Lewis lung cancer (3LL) cells-inoculated mouse tumour model. Simvastatin treatment resulted in a decrease in the number of cancer cells (3LL, A549 and NCI-H292). The production of the immune regulatory markers IL-10, TGF-beta in 3LL and NCI-H292 cells increased after treatment with simvastatin. The expression of IDO and forkhead box P3 (FoxP3) transcription factor was also increased in the presence of simvastatin. In a murine 3LL model, there were no significant differences in tumour growth rate between untreated and simvastatin-treated mice groups. Therefore, while simvastatin had an anti-proliferative effect, it also exhibited immune tolerance-promoting properties during tumour development. Thus, due to these opposing actions, simvastatin had no net effect on tumour growth.

  14. T Cell Receptor Signaling in the Control of Regulatory T Cell Differentiation and Function

    PubMed Central

    Li, Ming O.; Rudensky, Alexander Y.

    2016-01-01

    Regulatory T cells (TReg cells), a specialized T cell lineage, have a pivotal function in the control of self-tolerance and inflammatory responses. Recent studies have revealed a discrete mode of TCR signaling that regulates Treg cell differentiation, maintenance and function and that impacts on gene expression, metabolism, cell adhesion and migration of these cells. Here, we discuss the emerging understanding of TCR-guided differentiation of Treg cells in the context of their function in health and disease. PMID:27026074

  15. Control of experimental inflammatory bowel disease by regulatory T cells.

    PubMed

    Asseman, C; Fowler, S; Powrie, F

    2000-10-01

    A helper T cell type 1-mediated colitis driven by enteric bacteria develops in severe combined immunodeficient mice after transfer of CD45RB(high)CD4(+) T cells. Development of disease can be prevented by cotransfer of the reciprocal CD45RB(low) subset. Analysis of the mechanism of immune suppression transferred by CD45RB(low)CD4(+) cells revealed essential roles for both IL-10 and TGF-beta. These data indicate that a functionally specialized population of regulatory T (Treg) cells exists in normal mice and that these can prevent the development of pathogenic responses toward commensal bacteria. The role of Treg cells in the control of the immune response is discussed.

  16. An Arabidopsis gene regulatory network for secondary cell wall synthesis

    SciTech Connect

    Taylor-Teeples, M.; Lin, L.; de Lucas, M.; Turco, G.; Toal, T. W.; Gaudinier, A.; Young, N. F.; Trabucco, G. M.; Veling, M. T.; Lamothe, R.; Handakumbura, P. P.; Xiong, G.; Wang, C.; Corwin, J.; Tsoukalas, A.; Zhang, L.; Ware, D.; Pauly, M.; Kliebenstein, D. J.; Dehesh, K.; Tagkopoulos, I.; Breton, G.; Pruneda-Paz, J. L.; Ahnert, S. E.; Kay, S. A.; Hazen, S. P.; Brady, S. M.

    2014-12-24

    The plant cell wall is an important factor for determining cell shape, function and response to the environment. Secondary cell walls, such as those found in xylem, are composed of cellulose, hemicelluloses and lignin and account for the bulk of plant biomass. The coordination between transcriptional regulation of synthesis for each polymer is complex and vital to cell function. A regulatory hierarchy of developmental switches has been proposed, although the full complement of regulators remains unknown. In this paper, we present a protein–DNA network between Arabidopsis thaliana transcription factors and secondary cell wall metabolic genes with gene expression regulated by a series of feed-forward loops. This model allowed us to develop and validate new hypotheses about secondary wall gene regulation under abiotic stress. Distinct stresses are able to perturb targeted genes to potentially promote functional adaptation. Finally, these interactions will serve as a foundation for understanding the regulation of a complex, integral plant component.

  17. Oct4 Targets Regulatory Nodes to Modulate Stem Cell Function

    PubMed Central

    Campbell, Pearl A.; Perez-Iratxeta, Carolina; Andrade-Navarro, Miguel A.; Rudnicki, Michael A.

    2007-01-01

    Stem cells are characterized by two defining features, the ability to self-renew and to differentiate into highly specialized cell types. The POU homeodomain transcription factor Oct4 (Pou5f1) is an essential mediator of the embryonic stem cell state and has been implicated in lineage specific differentiation, adult stem cell identity, and cancer. Recent description of the regulatory networks which maintain ‘ES’ have highlighted a dual role for Oct4 in the transcriptional activation of genes required to maintain self-renewal and pluripotency while concomitantly repressing genes which facilitate lineage specific differentiation. However, the molecular mechanism by which Oct4 mediates differential activation or repression at these loci to either maintain stem cell identity or facilitate the emergence of alternate transcriptional programs required for the realization of lineage remains to be elucidated. To further investigate Oct4 function, we employed gene expression profiling together with a robust statistical analysis to identify genes highly correlated to Oct4. Gene Ontology analysis to categorize overrepresented genes has led to the identification of themes which may prove essential to stem cell identity, including chromatin structure, nuclear architecture, cell cycle control, DNA repair, and apoptosis. Our experiments have identified previously unappreciated roles for Oct4 for firstly, regulating chromatin structure in a state consistent with self-renewal and pluripotency, and secondly, facilitating the expression of genes that keeps the cell poised to respond to cues that lead to differentiation. Together, these data define the mechanism by which Oct4 orchestrates cellular regulatory pathways to enforce the stem cell state and provides important insight into stem cell function and cancer. PMID:17579724

  18. Genomic definition of multiple ex vivo regulatory T cell subphenotypes.

    PubMed

    Feuerer, Markus; Hill, Jonathan A; Kretschmer, Karsten; von Boehmer, Harald; Mathis, Diane; Benoist, Christophe

    2010-03-30

    Regulatory T (Treg) cells that express the Foxp3 transcription factor are essential for lymphoid homeostasis and immune tolerance to self. Other nonimmunological functions of Treg cells, such as controlling metabolic function in adipose tissue, are also emerging. Treg cells originate primarily in the thymus, but can also be elicited from conventional T cells by in vivo exposure to low-dose antigen or homeostatic expansion or by activation in the presence of TGFbeta in vitro. Treg cells are characterized by a distinct transcriptional signature controlled in part, but not solely, by Foxp3. For a better perspective on transcriptional control in Treg cells, we compared gene expression profiles of a broad panel of Treg cells from various origins or anatomical locations. Treg cells generated by different means form different subphenotypes and were identifiable by particular combinations of transcripts, none of which fully encompassed the entire Treg signature. Molecules involved in Treg cell effector function, chemokine receptors, and the transcription factors that control them were differentially represented in these subphenotypes. Treg cells from the gut proved dissimilar to cells elicited by exposure to TGFbeta in vitro, but instead they resembled a CD103(+)Klrg1(+) subphenotype preferentially generated in response to lymphopenia.

  19. Diverse Gene Expression in Human Regulatory T Cell Subsets Uncovers Connection between Regulatory T Cell Genes and Suppressive Function.

    PubMed

    Hua, Jing; Davis, Scott P; Hill, Jonathan A; Yamagata, Tetsuya

    2015-10-15

    Regulatory T (Treg) cells have a critical role in the control of immunity, and their diverse subpopulations may allow adaptation to different types of immune responses. In this study, we analyzed human Treg cell subpopulations in the peripheral blood by performing genome-wide expression profiling of 40 Treg cell subsets from healthy donors. We found that the human peripheral blood Treg cell population is comprised of five major genomic subgroups, represented by 16 tractable subsets with a particular cell surface phenotype. These subsets possess a range of suppressive function and cytokine secretion and can exert a genomic footprint on target effector T (Teff) cells. Correlation analysis of variability in gene expression in the subsets identified several cell surface molecules associated with Treg suppressive function, and pharmacological interrogation revealed a set of genes having causative effect. The five genomic subgroups of Treg cells imposed a preserved pattern of gene expression on Teff cells, with a varying degree of genes being suppressed or induced. Notably, there was a cluster of genes induced by Treg cells that bolstered an autoinhibitory effect in Teff cells, and this induction appears to be governed by a different set of genes than ones involved in counteracting Teff activation. Our work shows an example of exploiting the diversity within human Treg cell subpopulations to dissect Treg cell biology.

  20. CNS accumulation of regulatory B cells is VLA-4-dependent

    PubMed Central

    Lehmann-Horn, Klaus; Sagan, Sharon A.; Winger, Ryan C.; Spencer, Collin M.; Bernard, Claude C.A.; Sobel, Raymond A.

    2016-01-01

    Objective: To investigate the role of very late antigen-4 (VLA-4) on regulatory B cells (Breg) in CNS autoimmune disease. Methods: Experimental autoimmune encephalomyelitis (EAE) was induced in mice selectively deficient for VLA-4 on B cells (CD19cre/α4f/f) by immunization with myelin oligodendrocyte glycoprotein (MOG) peptide (p)35–55 or recombinant human (rh) MOG protein. B-cell and T-cell populations were examined by flow cytometry and immunohistochemistry. Breg were evaluated by intracellular IL-10 staining of B cells and, secondly, by coexpression of CD1d and CD5. Results: As previously reported, EAE was less severe in B-cell VLA-4-deficient vs control CD19cre mice when induced by rhMOG, a model that is B-cell-dependent and leads to efficient B-cell activation and antibody production. Paradoxically, B-cell VLA-4-deficient mice developed more severe clinical disease than control mice when EAE was induced with MOG p35-55, a B-cell-independent encephalitogen that does not efficiently activate B cells. Peripheral T-cell and humoral immune responses were not altered in B-cell VLA-4-deficient mice. In MOG p35-55-induced EAE, B-cell VLA-4 deficiency reduced CNS accumulation of B but not T cells. Breg were detected in the CNS of control mice with MOG p35-55-induced EAE. However, more severe EAE in B-cell VLA-4-deficient mice was associated with virtual absence of CNS Breg. Conclusions: Our results demonstrate that CNS accumulation of Breg is VLA-4-dependent and suggest that Breg may contribute to regulation of CNS autoimmunity in situ. These observations underscore the need to choose the appropriate encephalitogen when studying how B cells contribute to pathogenesis or regulation of CNS autoimmunity. PMID:27027096

  1. Hypoxic culture conditions enhance the generation of regulatory T cells

    PubMed Central

    Neildez-Nguyen, Thi My Anh; Bigot, Jérémy; Da Rocha, Sylvie; Corre, Guillaume; Boisgerault, Florence; Paldi, Andràs; Galy, Anne

    2015-01-01

    The generation of large amounts of induced CD4+ CD25+ Foxp3+ regulatory T (iTreg) cells is of great interest for several immunotherapy applications, therefore a better understanding of signals controlling iTreg cell differentiation and expansion is required. There is evidence that oxidative metabolism may regulate several key signalling pathways in T cells. This prompted us to investigate the effects of oxygenation on iTreg cell generation by comparing the effects of atmospheric (21%) or of low (5%) O2 concentrations on the phenotype of bead-stimulated murine splenic CD4+ T cells from Foxp3-KI-GFP T-cell receptor transgenic mice. The production of intracellular reactive oxygen species was shown to play a major role in the generation of iTreg cells, a process characterized by increased levels of Sirt1, PTEN and Glut1 on the committed cells, independently of the level of oxygenation. The suppressive function of iTreg cells generated either in atmospheric or low oxygen levels was equivalent. However, greater yields of iTreg cells were obtained under low oxygenation, resulting from a higher proliferative rate of the committed Treg cells and higher levels of Foxp3, suggesting a better stability of the differentiation process. Higher expression of Glut1 detected on iTreg cells generated under hypoxic culture conditions provides a likely explanation for the enhanced proliferation of these cells as compared to those cultured under ambient oxygen. Such results have important implications for understanding Treg cell homeostasis and developing in vitro protocols for the generation of Treg cells from naive T lymphocytes. PMID:25243909

  2. Regulatory Roles of Anoctamin-6 in Human Trabecular Meshwork Cells

    PubMed Central

    Banerjee, Juni; Leung, Chi-Ting; Li, Ang; Peterson-Yantorno, Kim; Ouyang, Huan; Stamer, W. Daniel; Civan, Mortimer M.

    2017-01-01

    Purpose Trabecular meshwork (TM) cell volume is a determinant of aqueous humor outflow resistance, and thereby IOP. Regulation of TM cell volume depends on chloride ion (Cl−) release through swelling-activated channels (ICl,Swell), whose pore is formed by LRRC8 proteins. Chloride ion release through swelling-activated channels has been reported to be regulated by calcium-activated anoctamins, but this finding is controversial. Particularly uncertain has been the effect of anoctamin Ano6, reported as a Ca2+-activated Cl− (CaCC) or cation channel in other cells. The current study tested whether anoctamin activity modifies volume regulation of primary TM cell cultures and cell lines. Methods Gene expression was studied with quantitative PCR, supplemented by reverse-transcriptase PCR and Western immunoblots. Currents were measured by ruptured whole-cell patch clamping and volume by electronic cell sizing. Results Primary TM cell cultures and the TM5 and GTM3 cell lines expressed Ano6 3 to 4 orders of magnitude higher than the other anoctamin CaCCs (Ano1 and Ano2). Ionomycin increased cell Ca2+ and activated macroscopic currents conforming to CaCCs in other cells, but displayed significantly more positive mean reversal potentials (+5 to +12 mV) than those displayed by ICl,Swell (−14 to −21 mV) in the same cells. Nonselective CaCC inhibitors (tannic acid>CaCCinh−A01) and transient Ano6 knockdown strongly inhibited ionomycin-activated currents, ICl,Swell and the regulatory volume response to hyposmotic swelling. Conclusions Ionomycin activates CaCCs associated with net cation movement in TM cells. These currents, ICl,Swell, and cell volume are regulated by Ano6. The findings suggest a novel clinically-relevant approach for altering cell volume, and thereby outflow resistance, by targeting Ano6. PMID:28125837

  3. The split personality of regulatory T cells in HIV infection.

    PubMed

    Chevalier, Mathieu F; Weiss, Laurence

    2013-01-03

    Natural regulatory T cells (Tregs) participate in responses to various chronic infections including HIV. HIV infection is associated with a progressive CD4 lymphopenia and defective HIV-specific CD8 responses known to play a key role in the control of viral replication. Persistent immune activation is a hallmark of HIV infection and is involved in disease progression independent of viral load. The consequences of Treg expansion, observed in HIV infection, could be either beneficial, by suppressing generalized T-cell activation, or detrimental, by weakening HIV-specific responses and thus contributing to viral persistence. The resulting balance between Tregs contrasting outcomes might have critical implications in pathogenesis. Topics covered in this review include HIV-induced alterations of Tregs, Treg cell dynamics in blood and tissues, Treg-suppressive function, and the relationship between Tregs and immune activation. This review also provides a focus on the role of CD39(+) Tregs and other regulatory cell subsets. All these issues will be explored in different situations including acute and chronic infection, antiretroviral treatment-mediated viral control, and spontaneous viral control. Results must be interpreted with regard to both the Treg definition used in context and to the setting of the disease in an attempt to draw clearer conclusions from the apparently conflicting results.

  4. Regulatory pathways coordinating cell cycle progression in early Xenopus development.

    PubMed

    Gotoh, Tetsuya; Villa, Linda M; Capelluto, Daniel G S; Finkielstein, Carla V

    2011-01-01

    The African clawed frog, Xenopus laevis, is used extensively as a model organism for studying both cell development and cell cycle regulation. For over 20 years now, this model organism has contributed to answering fundamental questions concerning the mechanisms that underlie cell cycle transitions--the cellular components that synthesize, modify, repair, and degrade nucleic acids and proteins, the signaling pathways that allow cells to communicate, and the regulatory pathways that lead to selective expression of subsets of genes. In addition, the remarkable simplicity of the Xenopus early cell cycle allows for tractable manipulation and dissection of the basic components driving each transition. In this organism, early cell divisions are characterized by rapid cycles alternating phases of DNA synthesis and division. The post-blastula stages incorporate gap phases, lengthening progression, and allowing more time for DNA repair. Various cyclin/Cdk complexes are differentially expressed during the early cycles with orderly progression being driven by both the combined action of cyclin synthesis and degradation and the appropriate selection of specific substrates by their Cdk components. Like other multicellular organisms, chief developmental events in early Xenopus embryogenesis coincide with profound remodeling of the cell cycle, suggesting that cell proliferation and differentiation events are linked and coordinated through crosstalk mechanisms acting on signaling pathways involving the expression of cell cycle control genes.

  5. IL-33 induces both regulatory B cells and regulatory T cells in dextran sulfate sodium-induced colitis.

    PubMed

    Zhu, Junfeng; Xu, Ying; Zhu, Chunyu; Zhao, Jian; Meng, Xinrui; Chen, Siyao; Wang, Tianqi; Li, Xue; Zhang, Li; Lu, Changlong; Liu, Hongsheng; Sun, Xun

    2017-05-01

    Interleukin (IL)-33 is a member of the IL-1 family. Serum levels of IL-33 are increased in inflammatory bowel diseases (IBD), suggesting that IL-33 is involved in the pathogenesis of IBD, although its role is not clear. In this study, we investigated the role of IL-33 in the regulation of T-helper (Th) cell and B cell responses in mesenteric lymph nodes (MLN) in mice with dextran sulfate sodium (DSS)-induced colitis. Here, we showed that IL-33-treated mice were susceptible to DSS-induced colitis as compared with PBS-treated mice. The production of spontaneous inflammatory cytokines production by macrophages or dendritic cells (DC) in MLN significantly increased, and the responses of Th2, regulatory T cells (Treg) and regulatory B cells (Breg) were markedly upregulated, while Th1 responses were significantly downregulated in MLN of IL-33-treated mice with DSS-induced colitis. Our results demonstrate that IL-33 contributes to the pathogenesis of DSS-induced colitis in mice by promoting Th2 responses, but suppressing Th1 responses, in MLN. Moreover, IL-33 treatment increased Breg and Treg responses in MLN in mice with DSS-induced colitis. Therefore, modulation of IL-33/ST2 signaling is implicated as a novel biological therapy for inflammatory diseases associated with Th1 responses.

  6. SHARPIN controls the development of regulatory T cells.

    PubMed

    Redecke, Vanessa; Chaturvedi, Vandana; Kuriakose, Jeeba; Häcker, Hans

    2016-06-01

    SHARPIN is an essential component of the linear ubiquitin chain assembly complex (LUBAC) complex that controls signalling pathways of various receptors, including the tumour necrosis factor receptor (TNFR), Toll-like receptor (TLR) and antigen receptor, in part by synthesis of linear, non-degrading ubiquitin chains. Consistent with SHARPIN's function in different receptor pathways, the phenotype of SHARPIN-deficient mice is complex, including the development of inflammatory systemic and skin diseases, the latter of which depend on TNFR signal transduction. Given the established function of SHARPIN in primary and malignant B cells, we hypothesized that SHARPIN might also regulate T-cell receptor (TCR) signalling and thereby control T-cell biology. Here, we focus primarily on the role of SHARPIN in T cells, specifically regulatory T (Treg) cells. We found that SHARPIN-deficient (Sharpin(cpdm/cpdm) ) mice have significantly reduced numbers of FOXP3(+) Treg cells in lymphoid organs and the peripheral blood. Competitive reconstitution of irradiated mice with mixed bone marrow from wild-type and SHARPIN-deficient mice revealed an overall reduced thymus population with SHARPIN-deficient cells with almost complete loss of thymic Treg development. Consistent with this cell-intrinsic function of SHARPIN in Treg development, TCR stimulation of SHARPIN-deficient thymocytes revealed reduced activation of nuclear factor-κB and c-Jun N-terminal kinase, establishing a function of SHARPIN in TCR signalling, which may explain the defective Treg development. In turn, in vitro generation and suppressive activity of mature SHARPIN-deficient Treg cells were comparable to wild-type cells, suggesting that maturation, but not function, of SHARPIN-deficient Treg cells is impaired. Taken together, these findings show that SHARPIN controls TCR signalling and is required for efficient generation of Treg cells in vivo, whereas the inhibitory function of mature Treg cells appears to be

  7. Cutting Edge: Regulatory T Cells Facilitate Cutaneous Wound Healing.

    PubMed

    Nosbaum, Audrey; Prevel, Nicolas; Truong, Hong-An; Mehta, Pooja; Ettinger, Monika; Scharschmidt, Tiffany C; Ali, Niwa H; Pauli, Mariela L; Abbas, Abul K; Rosenblum, Michael D

    2016-03-01

    Foxp3-expressing regulatory T cells (Tregs) reside in tissues where they control inflammation and mediate tissue-specific functions. The skin of mice and humans contain a large number of Tregs; however, the mechanisms of how these cells function in skin remain largely unknown. In this article, we show that Tregs facilitate cutaneous wound healing. Highly activated Tregs accumulated in skin early after wounding, and specific ablation of these cells resulted in delayed wound re-epithelialization and kinetics of wound closure. Tregs in wounded skin attenuated IFN-γ production and proinflammatory macrophage accumulation. Upon wounding, Tregs induce expression of the epidermal growth factor receptor (EGFR). Lineage-specific deletion of EGFR in Tregs resulted in reduced Treg accumulation and activation in wounded skin, delayed wound closure, and increased proinflammatory macrophage accumulation. Taken together, our results reveal a novel role for Tregs in facilitating skin wound repair and suggest that they use the EGFR pathway to mediate these effects.

  8. T regulatory cells distinguish two types of primary hypophysitis.

    PubMed

    Mirocha, S; Elagin, R B; Salamat, S; Jaume, J C

    2009-03-01

    Numerous cases of primary hypophysitis have been described over the past 25 years with, however, little insight into the cause(s) of this disease. In order to guide treatment, a better understanding of the pathogenesis is needed. We studied the pathogenesis of primary hypophysitis by analysing systematically the immune response at the pituitary tissue level of consecutive cases of 'lymphocytic' hypophysitis who underwent pituitary biopsy. In order to investigate further the pathogenesis of their diseases we characterized two cases at clinical, cellular and molecular levels. We show here, for the first time, that lymphocytic hypophysitis probably encompasses at least two separate entities. One entity, in agreement with the classical description of lymphocytic hypophysitis, demonstrates an autoimmune process with T helper 17 cell dominance and lack of T regulatory cells. The other entity represents a process in which T regulatory cells seem to control the immune response, which may not be self- but foreign-targeted. Our data suggest that it may be necessary to biopsy suspected primary hypophysitis and to analyse pituitary tissue with immune markers to guide treatment. Based on our results, hypophysitis driven by an immune homeostatic process should not be treated with immunosuppression, while autoimmune-defined hypophysitis may benefit from it. We show here for the first time two different pathogenic processes classified under one disease type and how to distinguish them. Because of our findings, changes in current diagnostic and therapeutic approaches may need to be considered.

  9. Development and function of Foxp3(+) regulatory T cells.

    PubMed

    Wang, Yuan Min; Ghali, Joanna; Zhang, Geoff Yu; Hu, Min; Wang, Ya; Sawyer, Andrew; Zhou, Jimmy Jianheng; Hapudeniya, Dhanushka A; Wang, Yiping; Cao, Qi; Zheng, Guoping; Harris, David C; Alexander, Stephen I

    2016-02-01

    Regulatory T cells (Tregs) have been recognized as having a major role in maintaining peripheral tolerance and preventing and limiting autoimmune and chronic inflammatory diseases. Tregs derive from the thymus and also develop peripherally. In this review, we discuss recent progress in our understanding of the basic mechanisms involved in Treg development and function in protecting against autoimmunity in the periphery, including thymic selection, peripheral induction and the many mechanisms of Treg suppression. Specifically in kidney disease, Tregs have been shown to play a role in limiting injury and may potentially have a therapeutic role.

  10. Negative transcriptional regulatory element that functions in embryonal carcinoma cells.

    PubMed Central

    Ariizumi, K; Takahashi, H; Nakamura, M; Ariga, H

    1989-01-01

    We have cloned the polyomavirus mutant fPyF9, which persists in an episomal state in F9 embryonal carcinoma cells (K. Ariizumi and H. Ariga, Mol. Cell. Biol. 6:3920-3927, 1986). fPyF9 carries three copies of exogenous sequences, the prototype of which is a 21-base-pair repeat (box DNA), in the region of the enhancer B domain of wild-type polyomavirus DNA. The consensus sequence, GCATTCCATTGTT, is 13 base pairs long. The box DNA inserted into fPyF9 appeared to come from a cellular sequence and was present in many kinds of DNAs, including F9 chromosomal DNA. The biological function of box DNA was analyzed by chloramphenicol acetyltransferase expression assays, using chimeric plasmids containing box DNA conjugated with simian virus 40 promoter elements. The results showed that box DNA repressed the activities both of the simian virus 40 promoter and enhancer only in transfected undifferentiated F9 cells and not in differentiated LTK- cells. Box DNA functioned independently of orientation and position with respect to the promoter in an enhancerlike manner, although the effect of box DNA was opposite that of the enhancer. The XhoI linker insertion into the consensus sequences of box DNA abolished the repression activity, and the protein(s) recognizing the consensus sequences was identified only in F9 cells, not in L cells. These analyses suggest that box DNA may be a negative regulatory element that functions in undifferentiated cells. Images PMID:2550812

  11. Glioma-Derived ADAM10 Induces Regulatory B Cells to Suppress CD8+ T Cells

    PubMed Central

    Li, Wen-sheng; Luo, Lun; Huang, Zhen-chao; Guo, Ying

    2014-01-01

    CD8+ T cells play an important role in the anti-tumor activities of the body. The dysfunction of CD8+ T cells in glioma is unclear. This study aims to elucidate the glioma cell-derived ADAM10 (A Disintegrin and metalloproteinase domain-containing protein 10) in the suppression of CD8+ effector T cells by the induction of regulatory B cells. In this study, glioma cells were isolated from surgically removed glioma tissue and stimulated by Phorbol myristate acetage (PMA) in the culture. The levels of ADAM10 in the culture were determined by enzyme-linked immunosorbent assay. Immune cells were assessed by flow cytometry. The results showed that the isolated glioma cells express ADAM10, which was markedly up regulated after stimulated with PMA. The glioma-derived ADAM10 induced activated B cells to differentiate into regulatory B cells, the later suppressed CD8+ T cell proliferation as well as the induced regulatory T cells, which also showed the immune suppressor effect on CD8+ effector T cell proliferation. In conclusion, glioma cells produce ADAM10 to induce Bregs; the latter suppresses CD8+ T cells and induces Tregs. PMID:25127032

  12. Regulatory T cells inhibit CD34+ cell differentiation into NK cells by blocking their proliferation

    PubMed Central

    Pedroza-Pacheco, Isabela; Shah, Divya; Domogala, Anna; Luevano, Martha; Blundell, Michael; Jackson, Nicola; Thrasher, Adrian; Madrigal, Alejandro; Saudemont, Aurore

    2016-01-01

    Graft versus Host Disease (GvHD) remains one of the main complications after hematopoietic stem cell transplantation (HSCT). Due to their ability to suppress effector cells, regulatory T cells (Tregs) have been proposed as a cellular therapy to prevent GvHD, however they also inhibit the functions of natural killer (NK) cells, key effectors of the Graft versus Leukemia effect. In this study, we have explored whether a Tregs therapy will also impact on NK cell differentiation. Using an in vitro model of hematopoietic stem cell (HSC) differentiation into NK cells, we found that activated Tregs led to a 90% reduction in NK cell numbers when added at the time of commitment to the NK cell lineage. This effect was contact dependent and was reversible upon Tregs depletion. The few NK cells that developed in these cultures were mature and exhibited normal functions. Furthermore, adoptive transfer of activated Tregs in rag-/- γc-/- mice abrogated HSC differentiation into NK cells thus confirming our in vitro findings. Collectively, these results demonstrate for the first time that activated Tregs can inhibit NK cell differentiation from HSC under specific conditions. PMID:26915707

  13. Regulatory T cells inhibit CD34+ cell differentiation into NK cells by blocking their proliferation.

    PubMed

    Pedroza-Pacheco, Isabela; Shah, Divya; Domogala, Anna; Luevano, Martha; Blundell, Michael; Jackson, Nicola; Thrasher, Adrian; Madrigal, Alejandro; Saudemont, Aurore

    2016-02-26

    Graft versus Host Disease (GvHD) remains one of the main complications after hematopoietic stem cell transplantation (HSCT). Due to their ability to suppress effector cells, regulatory T cells (Tregs) have been proposed as a cellular therapy to prevent GvHD, however they also inhibit the functions of natural killer (NK) cells, key effectors of the Graft versus Leukemia effect. In this study, we have explored whether a Tregs therapy will also impact on NK cell differentiation. Using an in vitro model of hematopoietic stem cell (HSC) differentiation into NK cells, we found that activated Tregs led to a 90% reduction in NK cell numbers when added at the time of commitment to the NK cell lineage. This effect was contact dependent and was reversible upon Tregs depletion. The few NK cells that developed in these cultures were mature and exhibited normal functions. Furthermore, adoptive transfer of activated Tregs in rag(-/-) γc(-/-) mice abrogated HSC differentiation into NK cells thus confirming our in vitro findings. Collectively, these results demonstrate for the first time that activated Tregs can inhibit NK cell differentiation from HSC under specific conditions.

  14. The Molecular Mechanisms of Regulatory T Cell Immunosuppression

    PubMed Central

    Pandiyan, Pushpa; Zheng, Lixin; Lenardo, Michael J.

    2011-01-01

    CD4+CD25+Foxp3+ T lymphocytes, known as regulatory T cells or Tregs, have been proposed to be a lineage of professional immune suppressive cells that exclusively counteract the effects of the immunoprotective “helper” and “cytotoxic” lineages of T lymphocytes. Here we discuss new concepts on the mechanisms and functions of Tregs. There are several key points we emphasize: 1. Tregs exert suppressive effects both directly on effector T cells and indirectly through antigen-presenting cells; 2. Regulation can occur through a novel mechanism of cytokine consumption to regulate as opposed to the usual mechanism of cytokine/chemokine production; 3. In cases where CD4+ effector T cells are directly inhibited by Tregs, it is chiefly through a mechanism of lymphokine withdrawal apoptosis leading to polyclonal deletion; and 4. Contrary to the current view, we discuss new evidence that Tregs, similar to other T-cells lineages, can promote protective immune responses in certain infectious contexts (Chen et al., 2011; Pandiyan et al., 2011). Although these points are at variance to varying degrees with the standard model of Treg behavior, we will recount developing findings that support these new concepts. PMID:22566849

  15. Regulatory T cell-based therapies for autoimmunity.

    PubMed

    Arellano, Benjamine; Graber, David J; Sentman, Charles L

    2016-08-01

    Autoimmune disorders are long-term diseases that adversely affect the quality of life for patients, and they are one of the top ten leading causes of death. While each autoimmune disorder is unique, they all are caused by a breakdown of tolerance against endogenous proteins. This leads to auto-inflammatory events that promote the destruction of organs in a humoral and cellular immune mediated manner. Treatment options for autoimmunity can involve the use of chemical and biologic agents that suppress inflammation. While these treatment options for patients have shown to be beneficial in autoimmunity, they can result in patients being vulnerable to opportunistic infections. Newer therapies aim to identify methods to specifically block auto-inflammatory immune cells while allowing for an intact immune response to other antigens. T regulatory (Treg) cells are a subtype of the adoptive immune cell that is capable of suppressing inflammatory events in an antigen-specific manner, but they are often poorly functioning within autoimmune patients. Treg cells have been well characterized for their immune modulating capabilities and preclinical and early clinical studies support their therapeutic potential for antigen-specific immune suppression. This review will examine the current understanding of Treg cell function and the therapeutic potential of enhancing Treg cells in patients with inflammatory disorders.

  16. Regulatory T cells in vitiligo: Implications for pathogenesis and therapeutics.

    PubMed

    Dwivedi, Mitesh; Kemp, E Helen; Laddha, Naresh C; Mansuri, Mohmmad Shoab; Weetman, Anthony P; Begum, Rasheedunnisa

    2015-01-01

    Vitiligo is a hypomelanotic autoimmune skin disease arising from a breakdown in immunological self-tolerance, which leads to aberrant immune responses against melanocytes. Regulatory T cells (Tregs) are crucial to the development of self-tolerance and so are major foci in the study of autoimmune pathogenesis of vitiligo. This review will summarise recent findings concerning the role of Tregs in the pathogenesis of vitiligo. In addition, as antigen-specific Tregs are a potential route for the reinstatement of immune tolerance, new strategies that expand or induce de novo generation of Tregs and which are currently being investigated as therapies for other autoimmune diseases, will be discussed. These approaches will highlight the opportunities for Treg cell-based therapeutics in vitiligo.

  17. Special regulatory T cell review: The suppression problem!

    PubMed

    Waldmann, Herman

    2008-01-01

    The concept of T-cell mediated suppression evolved more than 30 years ago. At that time it spawned many claims that have not stood the test of time. The rediscovery of suppression phenomena and regulatory T cells over the past 15 years created schizophrenic responses amongst immunologists. Some claimed that the new proponents of suppression were, once again, bringing immunology into disrepute, whilst others have embraced the field with great enthusiasm and novel approaches to clarification. Without faithful repetition of the "old" experiments, it is difficult to establish what was right and what was wrong. Nevertheless, immunologists must now accept that a good number of the old claims were overstated, and reflected poor scientific discipline. "I speak not to disprove what Brutus spoke, But here I am to speak what I do know" Shakespeare. Julius Caesar Act 3, Scene 2.

  18. Special regulatory T cell review: The suppression problem!

    PubMed Central

    Waldmann, Herman

    2008-01-01

    The concept of T-cell mediated suppression evolved more than 30 years ago. At that time it spawned many claims that have not stood the test of time. The rediscovery of suppression phenomena and regulatory T cells over the past 15 years created schizophrenic responses amongst immunologists. Some claimed that the new proponents of suppression were, once again, bringing immunology into disrepute, whilst others have embraced the field with great enthusiasm and novel approaches to clarification. Without faithful repetition of the “old” experiments, it is difficult to establish what was right and what was wrong. Nevertheless, immunologists must now accept that a good number of the old claims were overstated, and reflected poor scientific discipline. “I speak not to disprove what Brutus spoke, But here I am to speak what I do know” Shakespeare. Julius Caesar Act 3, Scene 2. PMID:18154612

  19. Rapid regulatory control of plant cell expansion and wall relaxation

    SciTech Connect

    Cosgrove, D.J.

    1991-08-14

    The aim of this project is to elucidate the biophysical and cellular mechanisms that control plant cell expansion. At present we are attempting to characterize the kinetics of the system(s) responsible for regulatory and compensatory behavior of growing cells and tissues. This work is significantly because it indicates that biochemical loosening and biophysical stress relaxation of the wall are part of a feedback loop controlling growth. This report briefly summarizes the efforts and results of the past 12 months. In large part, we have been trying to analyze the nature of growth rate noise,'' i.e. spontaneous and often erratic variations in growth rate. We are obtaining evidence that such noise'' is not random, but rather reveals an underlying growth mechanism with complex dynamics.

  20. Regulatory B cells in human inflammatory and autoimmune diseases: from mouse models to clinical research.

    PubMed

    Miyagaki, Tomomitsu; Fujimoto, Manabu; Sato, Shinichi

    2015-10-01

    B cells have been generally considered to be positive regulators of immune responses because of their ability to produce antigen-specific antibodies and to activate T cells through antigen presentation. Impairment of B cell development and function may cause inflammatory and autoimmune diseases. Recently, specific B cell subsets that can negatively regulate immune responses have been described in mouse models of a wide variety of inflammatory and autoimmune diseases. The concept of those B cells, termed regulatory B cells, is now recognized as important in the murine immune system. Among several regulatory B cell subsets, IL-10-producing regulatory B cells are the most widely investigated. On the basis of discoveries from studies of such mice, human regulatory B cells that produce IL-10 in most cases are becoming an active area of research. There have been emerging data suggesting the importance of human regulatory B cells in various diseases. Revealing the immune regulation mechanisms of human regulatory B cells in human inflammatory and autoimmune diseases could lead to the development of novel B cell targeted therapies. This review highlights the current knowledge on regulatory B cells, mainly IL-10-producing regulatory B cells, in animal models of inflammatory and autoimmune diseases and in clinical research using human samples.

  1. Regulatory T cells in patients with Whipple's disease.

    PubMed

    Schinnerling, Katina; Moos, Verena; Geelhaar, Anika; Allers, Kristina; Loddenkemper, Christoph; Friebel, Julian; Conrad, Kristina; Kühl, Anja A; Erben, Ulrike; Schneider, Thomas

    2011-10-15

    Classical Whipple's disease (CWD) is caused by chronic infection with Tropheryma whipplei that seems to be associated with an underlying immune defect. The pathognomonic hallmark of CWD is a massive infiltration of the duodenal mucosa with T. whipplei-infected macrophages that disperse systemically to many other organ systems. An alleviated inflammatory reaction and the absence of T. whipplei-specific Th1 reactivity support persistence and systemic spread of the pathogen. In this article, we hypothesized that regulatory T cells (T(reg)) are involved in immunomodulation in CWD, and we asked for the distribution, activation, and regulatory capacity of T(reg) in CWD patients. Whereas in the lamina propria of CWD patients before treatment numbers of T(reg) were increased, percentages in the peripheral blood were similar in CWD patients and healthy controls. However, peripheral T(reg) of CWD patients were more activated than those of controls. Elevated secretion of IL-10 and TGF-β in the duodenal mucosa of CWD patients indicated locally enhanced T(reg) activity. Enhanced CD95 expression on peripheral memory CD4(+) T cells combined with reduced expression of IFN-γ and IL-17A upon polyclonal stimulation by CD4(+) cells from untreated CWD patients further hinted to T(reg) activity-related exhaustion of effector CD4(+) T cells. In conclusion, increased numbers of T(reg) can be detected within the duodenal mucosa in untreated CWD, where huge numbers of T. whipplei-infected macrophages are present. Thus, T(reg) might contribute to the chronic infection and systemic spread of T. whipplei in CWD but in contrast prevent mucosal barrier defect by reducing local inflammation.

  2. Regulatory immune cells in regulation of intestinal inflammatory response to microbiota

    PubMed Central

    Cong, Y; Liu, Z

    2015-01-01

    The intestinal lumen harbors nearly 100 trillion commensal bacteria that exert crucial function for health. An elaborate balance between immune responses and tolerance to intestinal microbiota is required to maintain intestinal homeostasis. This process depends on diverse regulatory mechanisms, including both innate and adaptive immunity. Dysregulation of the homeostasis between intestinal immune systems and microbiota has been shown to be associated with the development of inflammatory bowel diseases (IBD) in genetically susceptible populations. In this review, we discuss the recent progress reported in studies of distinct types of regulatory immune cells in the gut, including intestinal intraepithelial lymphocytes, Foxp3+ regulatory T cells, regulatory B cells, alternatively activated macrophages, dendritic cells, and innate lymphoid cells, and how dysfunction of this immune regulatory system contributes to intestinal diseases such as IBD. Moreover, we discuss the manipulation of these regulatory immune cells as a potential therapeutic method for management of intestinal inflammatory disorders. PMID:26080708

  3. Regulatory immune cells in regulation of intestinal inflammatory response to microbiota.

    PubMed

    Sun, M; He, C; Cong, Y; Liu, Z

    2015-09-01

    The intestinal lumen harbors nearly 100 trillion commensal bacteria that exert crucial function for health. An elaborate balance between immune responses and tolerance to intestinal microbiota is required to maintain intestinal homeostasis. This process depends on diverse regulatory mechanisms, including both innate and adaptive immunity. Dysregulation of the homeostasis between intestinal immune systems and microbiota has been shown to be associated with the development of inflammatory bowel diseases (IBD) in genetically susceptible populations. In this review, we discuss the recent progress reported in studies of distinct types of regulatory immune cells in the gut, including intestinal intraepithelial lymphocytes, Foxp3(+) regulatory T cells, regulatory B cells, alternatively activated macrophages, dendritic cells, and innate lymphoid cells, and how dysfunction of this immune regulatory system contributes to intestinal diseases such as IBD. Moreover, we discuss the manipulation of these regulatory immune cells as a potential therapeutic method for management of intestinal inflammatory disorders.

  4. MicroRNAs targeting TGFβ signalling underlie the regulatory T cell defect in multiple sclerosis.

    PubMed

    Severin, Mary E; Lee, Priscilla W; Liu, Yue; Selhorst, Amanda J; Gormley, Matthew G; Pei, Wei; Yang, Yuhong; Guerau-de-Arellano, Mireia; Racke, Michael K; Lovett-Racke, Amy E

    2016-06-01

    Transforming growth factor beta (TGFβ) signalling is critical for regulatory T cell development and function, and regulatory T cell dysregulation is a common observation in autoimmune diseases, including multiple sclerosis. In a comprehensive miRNA profiling study of patients with multiple sclerosis naïve CD4 T cells, 19 differentially expressed miRNAs predicted to target the TGFβ signalling pathway were identified, leading to the hypothesis that miRNAs may be responsible for the regulatory T cell defect observed in patients with multiple sclerosis. Patients with multiple sclerosis had reduced levels of TGFβ signalling components in their naïve CD4 T cells. The differentially expressed miRNAs negatively regulated the TGFβ pathway, resulting in a reduced capacity of naïve CD4 T cells to differentiate into regulatory T cells. Interestingly, the limited number of regulatory T cells, that did develop when these TGFβ-targeting miRNAs were overexpressed, were capable of suppressing effector T cells. As it has previously been demonstrated that compromising TGFβ signalling results in a reduced regulatory T cell repertoire insufficient to control autoimmunity, and patients with multiple sclerosis have a reduced regulatory T cell repertoire, these data indicate that the elevated expression of multiple TGFβ-targeting miRNAs in naïve CD4 T cells of patients with multiple sclerosis impairs TGFβ signalling, and dampens regulatory T cell development, thereby enhancing susceptibility to developing multiple sclerosis.

  5. Type 1 diabetes immunotherapy using polyclonal regulatory T cells

    PubMed Central

    Bluestone, Jeffrey A.; Buckner, Jane H.; Fitch, Mark; Gitelman, Stephen E.; Gupta, Shipra; Hellerstein, Marc K.; Herold, Kevan C.; Lares, Angela; Lee, Michael R.; Li, Kevin; Liu, Weihong; Long, S. Alice; Masiello, Lisa M.; Nguyen, Vinh; Putnam, Amy L.; Rieck, Mary; Sayre, Peter; Tang, Qizhi

    2016-01-01

    Type 1 diabetes (T1D) is an autoimmune disease that occurs in genetically susceptible individuals. Regulatory T cells (Tregs) have been shown to be defective in the autoimmune disease setting. Thus, efforts to repair or replace Tregs in T1D may reverse autoimmunity and protect the remaining insulin-producing β cells. On the basis of this premise, a robust technique has been developed to isolate and expand Tregs from patients with T1D. The expanded Tregs retained their T cell receptor diversity and demonstrated enhanced functional activity. We report on a phase 1 trial to assess safety of Treg adoptive immunotherapy in T1D. Fourteen adult subjects with T1D, in four dosing cohorts, received ex vivo–expanded autologous CD4+CD127lo/−CD25+ polyclonal Tregs (0.05 × 108 to 26 × 108 cells). A subset of the adoptively transferred Tregs was long-lived, with up to 25% of the peak level remaining in the circulation at 1 year after transfer. Immune studies showed transient increases in Tregs in recipients and retained a broad Treg FOXP3+CD4+CD25hiCD127lo phenotype long-term. There were no infusion reactions or cell therapy–related high-grade adverse events. C-peptide levels persisted out to 2+ years after transfer in several individuals. These results support the development of a phase 2 trial to test efficacy of the Treg therapy. PMID:26606968

  6. An Arabidopsis gene regulatory network for secondary cell wall synthesis

    DOE PAGES

    Taylor-Teeples, M.; Lin, L.; de Lucas, M.; ...

    2014-12-24

    The plant cell wall is an important factor for determining cell shape, function and response to the environment. Secondary cell walls, such as those found in xylem, are composed of cellulose, hemicelluloses and lignin and account for the bulk of plant biomass. The coordination between transcriptional regulation of synthesis for each polymer is complex and vital to cell function. A regulatory hierarchy of developmental switches has been proposed, although the full complement of regulators remains unknown. In this paper, we present a protein–DNA network between Arabidopsis thaliana transcription factors and secondary cell wall metabolic genes with gene expression regulated bymore » a series of feed-forward loops. This model allowed us to develop and validate new hypotheses about secondary wall gene regulation under abiotic stress. Distinct stresses are able to perturb targeted genes to potentially promote functional adaptation. Finally, these interactions will serve as a foundation for understanding the regulation of a complex, integral plant component.« less

  7. Purification and stability characterization of a cell regulatory sialoglycopeptide inhibitor

    NASA Technical Reports Server (NTRS)

    Moos, P. J.; Fattaey, H. K.; Johnson, T. C.; Spooner, B. S. (Principal Investigator)

    1995-01-01

    Previous attempts to physically separate the cell cycle inhibitory and protease activities in preparations of a purified cell regulatory sialoglycopeptide (CeReS) inhibitor were largely unsuccessful. Gradient elution of the inhibitor preparation from a DEAE HPLC column separated the cell growth inhibitor from the protease, and the two activities have been shown to be distinct and non-overlapping. The additional purification increased the specific biological activity of the CeReS preparation by approximately two-fold. The major inhibitory fraction that eluted from the DEAE column was further analyzed by tricine-SDS-PAGE and microbore reverse phase HPLC and shown to be homogeneous in nature. Two other fractions separated by DEAE HPLC, also devoid of protease activity, were shown to be inhibitory to cell proliferation and most likely represented modified relatives of the CeReS inhibitor. The highly purified CeReS was chemically characterized for amino acid and carbohydrate composition and the role of the carbohydrate in cell proliferation inhibition, stability, and protease resistance was assessed.

  8. Immunoevasive Pericytes From Human Pluripotent Stem Cells Preferentially Modulate Induction of Allogeneic Regulatory T Cells

    PubMed Central

    Domev, Hagit; Milkov, Irina; Dar, Ayelet

    2014-01-01

    Isolated microvessel-residing pericytes and pericytes from human pluripotent stem cells (hPSCs) exhibit mesenchymal stem cell-like characteristics and therapeutic properties. Despite growing interest in pericyte-based stem cell therapy, their immunogenicity and immunomodulatory effects on nonactivated T cells are still poorly defined, in particular those of vasculogenic hPSC pericytes. We found that tissue-embedded and unstimulated cultured hPSC- or tissue-derived pericytes constitutively expressed major histocompatibility complex (MHC) class I and the inhibitory programmed cell death-ligand 1/2 (PD-L1/2) molecules but not MHC class II or CD80/CD86 costimulatory molecules. Pretreatment with inflammatory mediators failed to induce an antigen-presenting cell-like phenotype in stimulated pericytes. CD146+ pericytes from hPSCs did not induce activation and proliferation of allogeneic resting T cells independent of interferon (IFN)-γ prestimulation, similarly to pericytes from human brain or placenta. Instead, pericytes mediated a significant increase in the frequency of allogeneic CD25highFoxP3+ regulatory T cells when cocultured with nonactivated peripheral blood T cells. Furthermore, when peripheral blood CD25high regulatory T cells (Tregs) were depleted from isolated CD3+ T cells, pericytes preferentially induced de novo formation of CD4+CD25highFoxP3+CD127−, suppressive regulatory T cells. Constitutive expression of PD-L1/2 and secretion of transforming growth factor-β by hPSC pericytes directly regulated generation of pericyte-induced Tregs. Pericytes cotransplanted into immunodeficient mice with allogeneic CD25− T cells maintained a nonimmunogenic phenotype and mediated the development of functional regulatory T cells. Together, these findings reveal a novel feature of pericyte-mediated immunomodulation distinguished from immunosuppression, shared by native tissue pericytes and hPSC pericytes, and support the notion that pericytes can be applied for

  9. Regulatory issues in cell-based therapy for clinical purposes.

    PubMed

    Casaroli-Marano, Ricardo P; Tabera, Jaime; Vilarrodona, Anna; Trias, Esteve

    2014-01-01

    Rapid development in the fields of cellular and molecular biology, biotechnology, and bioengineering medicine has brought new, highly innovative treatments and medicinal products, some of which contain viable cells and tissues associated with scaffolds and devices. These new cell-based therapy approaches in regenerative medicine have great potential for use in the treatment of a number of diseases that at present cannot be managed effectively. Given the unique challenges associated with the development of human cell-based medicinal products, great care is required in the development of procedures, practices, and regulation. In cell therapy, appropriate methodologies in the areas of production, reproducibility, maintenance, and delivery are essential for accurate definition and reliable assurance of the suitability and quality of the final products. Recently, the official European Community agencies (EMA) and the relevant authority in the USA (FDA) have made significant efforts to establish regulatory guidance for use in the application of the cell-based therapies for human patients. The guidelines surrounding cell-based therapy take into account the current legislation, but focus less on the heterogeneity and requirements of individual human cell-based products, including specific combination products and applications. When considering guidelines and regulation, a risk assessment approach is an effective method of identifying priority areas for the development of human cell-based medicinal products. Additionally, effective design and thorough validation of the manufacturing process in line with existing Good Manufacturing Practices (GMPs) and quality control regimes and a program that ensures the traceability and biovigilance of the final products are also all essential elements to consider.

  10. Regulatory T-cell vaccination independent of auto-antigen.

    PubMed

    Pascual, David W; Yang, Xinghong; Holderness, Kathryn; Jun, SangMu; Maddaloni, Massimo; Kochetkova, Irina

    2014-03-14

    To date, efforts to treat autoimmune diseases have primarily focused on the disease symptoms rather than on the cause of the disease. In large part, this is attributed to not knowing the responsible auto-antigens (auto-Ags) for driving the self-reactivity coupled with the poor success of treating autoimmune diseases using oral tolerance methods. Nonetheless, if tolerogenic approaches or methods that stimulate regulatory T (Treg) cells can be devised, these could subdue autoimmune diseases. To forward such efforts, our approach with colonization factor antigen I (CFA/I) fimbriae is to establish bystander immunity to ultimately drive the development of auto-Ag-specific Treg cells. Using an attenuated Salmonella vaccine expressing CFA/I fimbriae, fimbriae-specific Treg cells were induced without compromising the vaccine's capacity to protect against travelers' diarrhea or salmonellosis. By adapting the vaccine's anti-inflammatory properties, it was found that it could also dampen experimental inflammatory diseases resembling multiple sclerosis (MS) and rheumatoid arthritis. Because of this bystander effect, disease-specific Treg cells are eventually induced to resolve disease. Interestingly, this same vaccine could elicit the required Treg cell subset for each disease. For MS-like disease, conventional CD25(+) Treg cells are stimulated, but for arthritis CD39(+) Treg cells are induced instead. This review article will examine the potential of treating autoimmune diseases without having previous knowledge of the auto-Ag using an innocuous antigen to stimulate Treg cells via the production of transforming growth factor-β and interleukin-10.

  11. T Cells: Soldiers and Spies--The Surveillance and Control of Effector T Cells by Regulatory T Cells.

    PubMed

    Hall, Bruce M

    2015-11-06

    Traditionally, T cells were CD4+ helper or CD8+ cytotoxic T cells, and with antibodies, they were the soldiers of immunity. Now, many functionally distinct subsets of activated CD4+ and CD8+ T cells have been described, each with distinct cytokine and transcription factor expression. For CD4+ T cells, these include Th1 cells expressing the transcription factor T-bet and cytokines IL-2, IFN-γ, and TNF-β; Th2 cells expressing GATA-3 and the cytokines IL-4, IL-5, and IL-13; and Th17 cells expressing RORγt and cytokines IL-17A, IL-17F, IL-21, and IL-22. The cytokines produced determine the immune inflammation that they mediate. T cells of the effector lineage can be naïve T cells, recently activated T cells, or memory T cells that can be distinguished by cell surface markers. T regulatory cells or spies were characterized as CD8+ T cells expressing I-J in the 1970s. In the 1980s, suppressor cells fell into disrepute when the gene for I-J was not present in the mouse MHC I region. At that time, a CD4+ T cell expressing CD25, the IL-2 receptor-α, was identified to transfer transplant tolerance. This was the same phenotype of activated CD4+ CD25+ T cells that mediated rejection. Thus, the cells that could induce tolerance and undermine rejection had similar badges and uniforms as the cells effecting rejection. Later, FOXP3, a transcription factor that confers suppressor function, was described and distinguishes T regulatory cells from effector T cells. Many subtypes of T regulatory cells can be characterized by different expressions of cytokines and receptors for cytokines or chemokines. In intense immune inflammation, T regulatory cells express cytokines characteristic of effector cells; for example, Th1-like T regulatory cells express T-bet, and IFN-γ-like Th1 cells and effector T cells can change sides by converting to T regulatory cells. Effector T cells and T regulatory cells use similar molecules to be activated and mediate their function, and thus, it can be

  12. Follicular regulatory T cells impair follicular T helper cells in HIV and SIV infection

    PubMed Central

    Miles, Brodie; Miller, Shannon M.; Folkvord, Joy M.; Kimball, Abigail; Chamanian, Mastooreh; Meditz, Amie L.; Arends, Tessa; McCarter, Martin D.; Levy, David N.; Rakasz, Eva G.; Skinner, Pamela J.; Connick, Elizabeth

    2015-01-01

    Human and simian immunodeficiency viruses (HIV and SIV) exploit follicular lymphoid regions by establishing high levels of viral replication and dysregulating humoral immunity. Follicular regulatory T cells (TFR) are a recently characterized subset of lymphocytes that influence the germinal centre response through interactions with follicular helper T cells (TFH). Here, utilizing both human and rhesus macaque models, we show the impact of HIV and SIV infection on TFR number and function. We find that TFR proportionately and numerically expand during infection through mechanisms involving viral entry and replication, TGF-β signalling, low apoptosis rates and the presence of regulatory dendritic cells. Further, TFR exhibit elevated regulatory phenotypes and impair TFH functions during HIV infection. Thus, TFR contribute to inefficient germinal centre responses and inhibit HIV and SIV clearance. PMID:26482032

  13. Foetal immune programming: hormones, cytokines, microbes and regulatory T cells.

    PubMed

    Hsu, Peter; Nanan, Ralph

    2014-10-01

    In addition to genetic factors, environmental cues play important roles in shaping the immune system. The first environment that the developing foetal immune system encounters is the uterus. Although physically the mother and the foetus are separated by the placental membranes, various factors such as hormones and cytokines may provide "environmental cues" to the foetal immune system. Additionally, increasing evidence suggests that prenatal maternal environmental factors, particularly microbial exposure, might significantly influence the foetal immune system, affecting long-term outcomes, a concept termed foetal immune programming. Here we discuss the potential mediators of foetal immune programming, focusing on the role of pregnancy-related hormones, cytokines and regulatory T cells, which play a critical role in immune tolerance.

  14. Control of Regulatory T Cell Migration, Function, and Homeostasis.

    PubMed

    Campbell, Daniel J

    2015-09-15

    Foxp3(+) regulatory T cells (Tregs) are essential for preventing autoimmunity and uncontrolled inflammation, and they modulate immune responses during infection and the development of cancer. Accomplishing these tasks requires the widespread distribution of Tregs in both lymphoid and nonlymphoid tissues, and the selective recruitment of Tregs to different tissue sites has emerged as a key checkpoint that controls tissue inflammation in autoimmunity, infection, and cancer development, as well as in the context of allograft acceptance or rejection. Additionally, Tregs are functionally diverse, and it has become clear that some of this diversity segregates with Treg localization to particular tissue sites. In this article, I review the progress in understanding the mechanisms of Treg trafficking and discuss factors controlling their homeostatic maintenance and function in distinct tissue sites.

  15. The role of regulatory T cells in cancer immunology.

    PubMed

    Whiteside, Theresa L

    2015-01-01

    Regulatory T cells (Treg) are generally considered to be significant contributors to tumor escape from the host immune system. Emerging evidence suggests, however, that in some human cancers, Treg are necessary to control chronic inflammation, prevent tissue damage, and limit inflammation-associated cancer development. The dual role of Treg in cancer and underpinnings of Treg diversity are not well understood. This review attempts to provide insights into the importance of Treg subsets in cancer development and its progression. It also considers the role of Treg as potential biomarkers of clinical outcome in cancer. The strategies for monitoring Treg in cancer patients are discussed as is the need for caution in the use of therapies which indiscriminately ablate Treg. A greater understanding of molecular pathways operating in various tumor microenvironments is necessary for defining the Treg impact on cancer and for selecting immunotherapies targeting Treg.

  16. Naturally occurring regulatory T cells: markers, mechanisms, and manipulation.

    PubMed

    Schmetterer, Klaus G; Neunkirchner, Alina; Pickl, Winfried F

    2012-06-01

    Naturally occurring CD4(+)CD25(high) forkhead box protein 3 (FOXP3)(+) regulatory T cells (nTregs) are key mediators of immunity, which orchestrate and maintain tolerance to self and foreign antigens. In the recent 1.5 decades, a multitude of studies have aimed to define the phenotype and function of nTregs and to assess their therapeutic potential for modulating immune mediated disorders such as autoimmunity, allergy, and episodes of transplant rejection. In this review, we summarize the current knowledge on the biology of nTregs. We address the exact definition of nTregs by specific markers and combinations thereof, which is a prerequisite for the state-of-the-art isolation of defined nTreg populations. Furthermore, we discuss the mechanism by which nTregs mediate immunosuppression and how this knowledge might translate into novel therapeutic modalities. With first clinical studies of nTreg-based therapies being finished, questions concerning the reliable sources of nTregs are becoming more and more eminent. Consequently, approaches allowing conversion of CD4(+) T cells into nTregs by coculture with antigen-presenting cells, cytokines, and/or pharmacological agents are discussed. In addition, genetic engineering approaches for the generation of antigen-specific nTregs are described.

  17. GITR+ regulatory T cells in the treatment of autoimmune diseases.

    PubMed

    Petrillo, Maria Grazia; Ronchetti, Simona; Ricci, Erika; Alunno, Alessia; Gerli, Roberto; Nocentini, Giuseppe; Riccardi, Carlo

    2015-02-01

    Autoimmune diseases decrease life expectancy and quality of life for millions of women and men. Although treatments can slow disease progression and improve quality of life, all currently available drugs have adverse effects and none of them are curative; therefore, requiring patients to take immunosuppressive drugs for the remainder of their lives. A curative therapy that is safe and effective is urgently needed. We believe that therapies promoting the in vivo expansion of regulatory T cells (Tregs) or injection of in vitro expanded autologous/heterologous Tregs (cellular therapy) can alter the natural history of autoimmune diseases. In this review, we present data from murine and human studies suggesting that 1) glucocorticoid-induced tumor necrosis factor receptor-related protein (GITR) plays a crucial role in thymic Treg (tTreg) differentiation and expansion; 2) GITR plays a crucial role in peripheral Treg (pTreg) expansion; 3) in patients with Sjögren syndrome and systemic lupus erythematosus, CD4(+)GITR(+) pTregs are expanded in patients with milder forms of the disease; and 4) GITR is superior to other cell surface markers to differentiate Tregs from other CD4(+) T cells. In this context, we consider two potential new approaches for treating autoimmune diseases consisting of the in vivo expansion of GITR(+) Tregs by GITR-triggering drugs and in vitro expansion of autologous or heterologous GITR(+) Tregs to be infused in patients. Advantages of such an approach, technical problems, and safety issues are discussed.

  18. Unifying roles for regulatory T cells and inflammation in cancer

    PubMed Central

    Erdman, Susan E.; Rao, Varada P.; Olipitz, Werner; Taylor, Christie L.; Jackson, Erin A.; Levkovich, Tatiana; Lee, Chung-Wei; Horwitz, Bruce H.; Fox, James G.; Ge, Zhongming; Poutahidis, Theofilos

    2014-01-01

    Activities of CD4+ regulatory (TREG) cells restore immune homeostasis during chronic inflammatory disorders. Roles for TREG cells in inflammation-associated cancers, however, are paradoxical. It is widely believed that TREG function in cancer mainly to suppress protective anticancer responses. However, we demonstrate here that TREG cells also function to reduce cancer risk throughout the body by efficiently downregulating inflammation arising from the gastrointestinal (GI) tract. Building on a “hygiene hypothesis” model in which GI infections lead to changes in TREG that reduce immune-mediated diseases, here we show that gut bacteria-triggered TREG may function to inhibit cancer even in extraintestinal sites. Ability of bacteria-stimulated TREG to suppress cancer depends on interleukin (IL)-10, which serves to maintain immune homeostasis within bowel and support a protective antiinflammatory TREG phenotype. However, under proinflammatory conditions, TREG may fail to provide antiinflammatory protection and instead contribute to a T helper (Th)-17-driven procarcinogenic process; a cancer state that is reversible by downregulation of inflammation. Consequently, hygienic individuals with a weakened IL-10 and TREG-mediated inhibitory loop are highly susceptible to the carcinogenic consequences of elevated IL-6 and IL-17 and show more frequent inflammation-associated cancers. Taken together, these data unify seemingly divergent disease processes such as autoimmunity and cancer and help explain the paradox of TREG and inflammation in cancer. Enhancing protective TREG functions may promote healthful longevity and significantly reduce risk of cancer. PMID:19795459

  19. Treating arthritis by immunomodulation: is there a role for regulatory T cells?

    PubMed Central

    van Wijk, Femke; Roord, Sarah T.; Albani, Salvatore; Prakken, Berent J.

    2010-01-01

    The discovery of regulatory T cells almost 15 years ago initiated a new and exciting research area. The growing evidence for a critical role of these cells in controlling autoimmune responses has raised expectations for therapeutic application of regulatory T cells in patients with autoimmune arthritis. Here, we review recent studies investigating the presence, phenotype and function of these cells in patients with RA and juvenile idiopathic arthritis (JIA) and consider their therapeutic potential. Both direct and indirect methods to target these cells will be discussed. Arguably, a therapeutic approach that combines multiple regulatory T-cell-enhancing strategies could be most successful for clinical application. PMID:20463189

  20. MALT1 is an intrinsic regulator of regulatory T cells.

    PubMed

    Brüstle, A; Brenner, D; Knobbe-Thomsen, C B; Cox, M; Lang, P A; Lang, K S; Mak, T W

    2015-09-25

    Regulatory T cells (Tregs) are crucial for the maintenance of immunological self-tolerance and their absence or dysfunction can lead to autoimmunity. However, the molecular pathways that govern Treg biology remain obscure. In this study, we show that the nuclear factor-κB signalling mediator mucosa-associated lymphoid tissue lymphoma translocation protein 1 (MALT1) is an important novel regulator of both Tregs originating in the thymus ('natural' or nTregs) and Tregs induced to differentiate from naive thymocyte helper (Th) cells in the periphery ('induced' or iTregs). Our examination of mice deficient for MALT1 revealed that these mutants have a reduced number of total Tregs. In young Malt1(-/-) mice, nTregs are totally absent and iTreg are diminished in the periphery. Interestingly, total Treg numbers increase in older Malt1(-/-) mice as well as in Malt1(-/-) mice subjected to experimentally induced inflammation. iTregs isolated from WT and Malt1(-/-) mice were indistinguishable with respect to their ability to suppress the activities of effector T cells, but Malt1(-/-) iTregs expressed higher levels of Toll-like receptor (TLR) 2. Treatment of WT and Malt1(-/-) Th cells in vitro with the TLR2 ligand Pam3Cys strongly enhanced the induction and proliferation of Malt1(-/-) iTregs. Our data suggest that MALT1 supports nTreg development in the thymus but suppresses iTreg induction in the periphery during inflammation. Our data position MALT1 as a key molecule that contributes to immune tolerance at steady-state while facilitating immune reactivity under stress conditions.Cell Death and Differentiation advance online publication, 25 September 2015; doi:10.1038/cdd.2015.104.

  1. Th17 cells transdifferentiate into regulatory T cells during resolution of inflammation.

    PubMed

    Gagliani, Nicola; Amezcua Vesely, Maria Carolina; Iseppon, Andrea; Brockmann, Leonie; Xu, Hao; Palm, Noah W; de Zoete, Marcel R; Licona-Limón, Paula; Paiva, Ricardo S; Ching, Travers; Weaver, Casey; Zi, Xiaoyuan; Pan, Xinghua; Fan, Rong; Garmire, Lana X; Cotton, Matthew J; Drier, Yotam; Bernstein, Bradley; Geginat, Jens; Stockinger, Brigitta; Esplugues, Enric; Huber, Samuel; Flavell, Richard A

    2015-07-09

    Inflammation is a beneficial host response to infection but can contribute to inflammatory disease if unregulated. The Th17 lineage of T helper (Th) cells can cause severe human inflammatory diseases. These cells exhibit both instability (they can cease to express their signature cytokine, IL-17A) and plasticity (they can start expressing cytokines typical of other lineages) upon in vitro re-stimulation. However, technical limitations have prevented the transcriptional profiling of pre- and post-conversion Th17 cells ex vivo during immune responses. Thus, it is unknown whether Th17 cell plasticity merely reflects change in expression of a few cytokines, or if Th17 cells physiologically undergo global genetic reprogramming driving their conversion from one T helper cell type to another, a process known as transdifferentiation. Furthermore, although Th17 cell instability/plasticity has been associated with pathogenicity, it is unknown whether this could present a therapeutic opportunity, whereby formerly pathogenic Th17 cells could adopt an anti-inflammatory fate. Here we used two new fate-mapping mouse models to track Th17 cells during immune responses to show that CD4(+) T cells that formerly expressed IL-17A go on to acquire an anti-inflammatory phenotype. The transdifferentiation of Th17 into regulatory T cells was illustrated by a change in their signature transcriptional profile and the acquisition of potent regulatory capacity. Comparisons of the transcriptional profiles of pre- and post-conversion Th17 cells also revealed a role for canonical TGF-β signalling and consequently for the aryl hydrocarbon receptor (AhR) in conversion. Thus, Th17 cells transdifferentiate into regulatory cells, and contribute to the resolution of inflammation. Our data suggest that Th17 cell instability and plasticity is a therapeutic opportunity for inflammatory diseases.

  2. Th17 cells transdifferentiate into regulatory T cells during resolution of inflammation

    PubMed Central

    Gagliani, Nicola; Vesely, Maria Carolina Amezcua; Iseppon, Andrea; Brockmann, Leonie; Xu, Hao; Palm, Noah W.; de Zoete, Marcel R.; Licona-Limón, Paula; Paiva, Ricardo S.; Ching, Travers; Weaver, Casey; Zi, Xiaoyuan; Pan, Xinghua; Fan, Rong; Garmire, Lana X.; Cotton, Matthew J.; Drier, Yotam; Bernstein, Bradley; Geginat, Jens; Stockinger, Brigitta; Esplugues, Enric; Huber, Samuel; Flavell, Richard A.

    2015-01-01

    Inflammation is a beneficial host response to infection but can contribute to inflammatory disease if unregulated. The TH17 lineage of T helper (TH) cells can cause severe human inflammatory diseases. These cells exhibit both instability (they can cease to express their signature cytokine, IL-17A)1 and plasticity (they can start expressing cytokines typical of other lineages)1,2 upon in vitro re-stimulation. However, technical limitations have prevented the transcriptional profiling of pre- and post-conversion TH17 cells ex vivo during immune responses. Thus, it is unknown whether TH17 cell plasticity merely reflects change in expression of a few cytokines, or if TH17 cells physiologically undergo global genetic reprogramming driving their conversion from one T helper cell type to another, a process known as transdifferentiation3,4. Furthermore, although TH17 cell instability/plasticity has been associated with pathogenicity1,2,5, it is unknown whether this could present a therapeutic opportunity, whereby formerly pathogenic TH17 cells could adopt an anti-inflammatory fate. Here we used two new fate-mapping mouse models to track TH17 cells during immune responses to show that CD4+ T cells that formerly expressed IL-17A go on to acquire an anti-inflammatory phenotype. The transdifferentiation of TH17 into regulatory T cells was illustrated by a change in their signature transcriptional profile and the acquisition of potent regulatory capacity. Comparisons of the transcriptional profiles of pre- and postconversion TH17 cells also revealed a role for canonical TGF-β signalling and consequently for the aryl hydrocarbon receptor (AhR) in conversion. Thus, TH17 cells transdifferentiate into regulatory cells, and contribute to the resolution of inflammation. Our data suggest that TH17 cell instability and plasticity is a therapeutic opportunity for inflammatory diseases. PMID:25924064

  3. The PDL1-PD1 axis converts human TH1 cells into regulatory T cells.

    PubMed

    Amarnath, Shoba; Mangus, Courtney W; Wang, James C M; Wei, Fang; He, Alice; Kapoor, Veena; Foley, Jason E; Massey, Paul R; Felizardo, Tania C; Riley, James L; Levine, Bruce L; June, Carl H; Medin, Jeffrey A; Fowler, Daniel H

    2011-11-30

    Immune surveillance by T helper type 1 (T(H)1) cells is not only critical for the host response to tumors and infection, but also contributes to autoimmunity and graft-versus-host disease (GVHD) after transplantation. The inhibitory molecule programmed death ligand 1 (PDL1) has been shown to anergize human T(H)1 cells, but other mechanisms of PDL1-mediated T(H)1 inhibition such as the conversion of T(H)1 cells to a regulatory phenotype have not been well characterized. We hypothesized that PDL1 may cause T(H)1 cells to manifest differentiation plasticity. Conventional T cells or irradiated K562 myeloid tumor cells overexpressing PDL1 converted TBET(+) T(H)1 cells into FOXP3(+) regulatory T (T(reg)) cells in vivo, thereby preventing human-into-mouse xenogeneic GVHD (xGVHD). Either blocking PD1 expression on T(H)1 cells by small interfering RNA targeting or abrogation of PD1 signaling by SHP1/2 pharmacologic inhibition stabilized T(H)1 cell differentiation during PDL1 challenge and restored the capacity of T(H)1 cells to mediate lethal xGVHD. PD1 signaling therefore induces human T(H)1 cells to manifest in vivo plasticity, resulting in a T(reg) phenotype that severely impairs cell-mediated immunity. Converting human T(H)1 cells to a regulatory phenotype with PD1 signaling provides a potential way to block GVHD after transplantation. Moreover, because this conversion can be prevented by blocking PD1 expression or pharmacologically inhibiting SHP1/2, this pathway provides a new therapeutic direction for enhancing T cell immunity to cancer and infection.

  4. Cell volume regulatory ion transport in the regulation of cell migration.

    PubMed

    Jakab, M; Ritter, M

    2006-01-01

    Cell migration is typically accomplished by the generation of protrusive mechanical forces and is achieved by repeated spatially and temporally coordinated cycles including the formation of a leading edge, the formation of new and disruption of older adhesions to the substratum, actomyosin based contractions and retraction of the trailing edge. Beside the well-described roles of the cytoskeleton and cell adhesions during these processes, a growing body of evidence indicates that the precise regulation of the cell volume is an indispensable prerequisite for coordinated cell migration. On the one hand during cell migration cell volume is continuously tormented by mechanical and morphological alterations, which pose changes to the intracellular hydrostatic pressure, metabolic changes and the formation or degradation of macromolecules like actin, which distort the osmotic equilibrium and the action of chemoattractants, hormones and transmitters, which frequently alter the electrical properties of a cell and thus cause cell swelling or shrinkage, respectively. On the other hand, a migrating cell actively has to govern cell volume regulatory ion transport mechanisms in order to create the appropriate micro- or even nanoenvironment in the intra- and/or extracellular space, which is necessary to guarantee the correct polarity and hence direction of movement of a migrating cell. This chapter will focus on the role of the cell volume regulatory ion transport mechanisms as they participate in the regulation of cell migration and special emphasis is given to their interplay with the cytoskeleton, their meaning for substrate adhesion and to the polarized fashion of their subcellular distribution.

  5. Dynamics of regulatory networks in gastrin-treated adenocarcinoma cells.

    PubMed

    Doni Jayavelu, Naresh; Bar, Nadav

    2014-01-01

    Understanding gene transcription regulatory networks is critical to deciphering the molecular mechanisms of different cellular states. Most studies focus on static transcriptional networks. In the current study, we used the gastrin-regulated system as a model to understand the dynamics of transcriptional networks composed of transcription factors (TFs) and target genes (TGs). The hormone gastrin activates and stimulates signaling pathways leading to various cellular states through transcriptional programs. Dysregulation of gastrin can result in cancerous tumors, for example. However, the regulatory networks involving gastrin are highly complex, and the roles of most of the components of these networks are unknown. We used time series microarray data of AR42J adenocarcinoma cells treated with gastrin combined with static TF-TG relationships integrated from different sources, and we reconstructed the dynamic activities of TFs using network component analysis (NCA). Based on the peak expression of TGs and activity of TFs, we created active sub-networks at four time ranges after gastrin treatment, namely immediate-early (IE), mid-early (ME), mid-late (ML) and very late (VL). Network analysis revealed that the active sub-networks were topologically different at the early and late time ranges. Gene ontology analysis unveiled that each active sub-network was highly enriched in a particular biological process. Interestingly, network motif patterns were also distinct between the sub-networks. This analysis can be applied to other time series microarray datasets, focusing on smaller sub-networks that are activated in a cascade, allowing better overview of the mechanisms involved at each time range.

  6. Interleukin-2 treatment of tumor patients can expand regulatory T cells.

    PubMed

    Beyer, Marc

    2012-10-01

    Augmented numbers of regulatory T cells contribute to the overall immunosuppression in tumor patients. Interleukin-2 has been widely used in the clinics in anticancer therapy, yet evidence has accumulated that the major drawback, limiting clinical efficacy, is the expansion of regulatory T cells, which aggravates immunosuppression.

  7. Regulatory Elements in Vectors for Efficient Generation of Cell Lines Producing Target Proteins

    PubMed Central

    Maksimenko, O.; Gasanov, N. B.; Georgiev, P.

    2015-01-01

    To date, there has been an increasing number of drugs produced in mammalian cell cultures. In order to enhance the expression level and stability of target recombinant proteins in cell cultures, various regulatory elements with poorly studied mechanisms of action are used. In this review, we summarize and discuss the potential mechanisms of action of such regulatory elements. PMID:26483956

  8. Regulatory T-cell cytokines in patients with nonsegmental vitiligo.

    PubMed

    Kidir, Mehtap; Karabulut, Ayse A; Ercin, Mustafa E; Atasoy, Pınar

    2017-05-01

    In the etiopathogenesis of vitiligo, the role of suppressor cytokines, such as transforming growth factor-β (TGF-β) and interleukin-10 (IL-10), associated with regulatory T-cells (Treg) is not completely known. In this study, the role of Treg-cell functions in the skin of patients with nonsegmental vitiligo was investigated. Lesional and nonlesional skin samples from 30 adult volunteers ranging in age from 18 to 36 years with nonsegmental vitiligo were compared with normal skin area excision specimens of 30 benign melanocytic nevus cases as controls. All samples were evaluated staining for forkhead box P3 (Foxp3), TGF-β, and IL-10 using the standardized streptavidin-biotin immunoperoxidase immunohistochemistry method. Foxp3 expression was lower in lesional vitiligo skin specimens compared to controls; it was also lower in lesional vitiligo specimens than nonlesional vitiligo specimens. IL-10 levels were lower in lesional vitiligo specimens compared to the controls, whereas IL-10 expression was significantly lower in lesional specimens compared with nonlesional specimens. TGF-β expression was higher in both lesional and nonlesional skin specimens of patients with vitiligo compared to controls. TGF-β expression was lower in lesional skin specimens than nonlesional skin specimens. In addition, there was no significant correlation between Foxp3 expression with TGF-β and IL-10 expressions in lesional skin specimens in the vitiligo group. In this study, results supporting the contribution of Treg cells and IL-10 deficiency to the autoimmune process were obtained. Therefore, future studies are necessary to demonstrate the definitive role of Treg-cell functions in the etiopathogenesis of vitiligo.

  9. Regulatory T cells (Tregs) monitoring in environmental diseases.

    PubMed

    Mićović, Vladimir; Vojniković, Bozo; Bulog, Aleksandar; Coklo, Miran; Malatestinić, Dulija; Mrakovcić-Sutić, Ines

    2009-09-01

    The prevalence of environmental diseases is increasing worldwide and these diseases are an onerous burden both to the individual and to the public health. Urban air pollution is a grave problem in majority of metropolises, which contain high levels of traffic congestion generating great amounts of genotoxic substances. The contribution of such environmental exposure to increase prevalence of many allergic, environmental diseases and multiple chemical sensitivity or other related syndromes, as a result of an abnormal immune response based on environmental damage of lymphocyte subsets, is marked. Benzene is one of the most important air pollutants that are emitted by oil industry, since they are involved in almost every refinery process. Volatile organic compounds (VOCs) are a major group of air pollutants and play a crucial role in ecological damages, disturbing the ecosystem and human health. The variability of pollutants is an important factor in determining human exposure to these chemicals. The immune system possess a capacity to distinguish between innocuous and harmful foreign antigens and controls this action by mechanisms of central and peripheral tolerance, where crucial role play regulatory T cells (Tregs). We analyzed the characteristics of human Tregs of inhabitants living near gasoline industry which have assessed moderate spyrometric tests and compared them with those situated in rural areas. Our data demonstrate that the chronic inhalation exposure increases the percentage of Tregs cells, but contrary those of inhabitants with decreased spirometry values have shown diminished number of Tregs, which may contribute to the new therapeutic approach of environmental diseases.

  10. The Cellular and Molecular Mechanisms of Immuno-Suppression by Human Type 1 Regulatory T Cells

    PubMed Central

    Gregori, Silvia; Goudy, Kevin S.; Roncarolo, Maria Grazia

    2011-01-01

    The immuno-regulatory mechanisms of IL-10-producing type 1 regulatory T (Tr1) cells have been widely studied over the years. However, several recent discoveries have shed new light on the cellular and molecular mechanisms that human Tr1 cells use to control immune responses and induce tolerance. In this review we outline the well known and newly discovered regulatory properties of human Tr1 cells and provide an in-depth comparison of the known suppressor mechanisms of Tr1 cells with FOXP3+ Treg. We also highlight the role that Tr1 cells play in promoting and maintaining tolerance in autoimmunity, allergy, and transplantation. PMID:22566914

  11. The impact of regulatory T cells on T-cell immunity following hematopoietic cell transplantation

    PubMed Central

    Nguyen, Vu H.; Shashidhar, Sumana; Chang, Daisy S.; Ho, Lena; Kambham, Neeraja; Bachmann, Michael; Brown, Janice M.

    2008-01-01

    Regulatory T cells (Tregs) prevent graft-versus-host disease (GvHD) by inhibiting the proliferation and function of conventional T cells (Tcons). However, the impact of Tregs on T-cell development and immunity following hematopoietic cell transplantation (HCT) is unknown. Using a murine GvHD model induced by Tcons, we demonstrate that adoptive transfer of Tregs leads to (1) abrogration of GvHD, (2) preservation of thymic and peripheral lymph node architecture, and (3) an accelerated donor lymphoid reconstitution of a diverse TCR-Vβ repertoire. The resultant enhanced lymphoid reconstitution in Treg recipients protects them from lethal cytomegalovirus (MCMV) infection. By contrast, mice that receive Tcons alone have disrupted lymphoid organs from GvHD and remain lymphopenic with a restricted TCR-Vβ repertoire and rapid death on MCMV challenge. Lymphocytes from previously infected Treg recipients generate secondary response specific to MCMV, indicating long-term protective immunity with transferred Tregs. Thymectomy significantly reduces survival after MCMV challenge in Treg recipients compared with euthymic controls. Our results indicate that Tregs enhance immune reconstitution by preventing GvHD-induced damage of the thymic and secondary lymphoid microenvironment. These findings provide new insights into the role of Tregs in affording protection to lymphoid stromal elements important for T-cell immunity. PMID:17916743

  12. T Regulatory Cells Support Plasma Cell Populations in the Bone Marrow.

    PubMed

    Glatman Zaretsky, Arielle; Konradt, Christoph; Dépis, Fabien; Wing, James B; Goenka, Radhika; Atria, Daniela Gomez; Silver, Jonathan S; Cho, Sunglim; Wolf, Amaya I; Quinn, William J; Engiles, Julie B; Brown, Dorothy C; Beiting, Daniel; Erikson, Jan; Allman, David; Cancro, Michael P; Sakaguchi, Shimon; Lu, Li-Fan; Benoist, Christophe O; Hunter, Christopher A

    2017-02-21

    Long-lived plasma cells (PCs) in the bone marrow (BM) are a critical source of antibodies after infection or vaccination, but questions remain about the factors that control PCs. We found that systemic infection alters the BM, greatly reducing PCs and regulatory T (Treg) cells, a population that contributes to immune privilege in the BM. The use of intravital imaging revealed that BM Treg cells display a distinct behavior characterized by sustained co-localization with PCs and CD11c-YFP(+) cells. Gene expression profiling indicated that BM Treg cells express high levels of Treg effector molecules, and CTLA-4 deletion in these cells resulted in elevated PCs. Furthermore, preservation of Treg cells during systemic infection prevents PC loss, while Treg cell depletion in uninfected mice reduced PC populations. These studies suggest a role for Treg cells in PC biology and provide a potential target for the modulation of PCs during vaccine-induced humoral responses or autoimmunity.

  13. CD4+ T cell anergy prevents autoimmunity and generates regulatory T cell precursors

    PubMed Central

    Kalekar, Lokesh A.; Schmiel, Shirdi E.; Nandiwada, Sarada L.; Lam, Wing Y.; Barsness, Laura O.; Zhang, Na; Stritesky, Gretta L.; Malhotra, Deepali; Pauken, Kristen E.; Linehan, Jonathan L.; O’Sullivan, M. Gerard; Fife, Brian T.; Hogquist, Kristin A.; Jenkins, Marc K.; Mueller, Daniel L.

    2015-01-01

    The role that anergy, an acquired state of T cell functional unresponsiveness, plays in natural peripheral tolerance remains unclear. In this study, we demonstrate that anergy is selectively induced in fetal antigen-specific maternal CD4+ T cells during pregnancy. A naturally occurring subpopulation of anergic polyclonal CD4+ T cells, enriched in self antigen-specific T cell receptors, is also observed in healthy hosts. Neuropilin-1 expression in anergic conventional CD4+ T cells is associated with thymic regulatory T cell (Treg cell)-related gene hypomethylation, and this correlates with their capacity to differentiate into Foxp3+ Treg cells that suppress immunopathology. Thus, our data suggest that not only is anergy induction important in preventing autoimmunity, but it also generates the precursors for peripheral Treg cell differentiation. PMID:26829766

  14. The generation and antigen-specificity of CD4+CD25+ regulatory T cells.

    PubMed

    Taams, Leonie S; Curnow, S John; Vukmanovic-Stejic, M; Akbar, Arne N

    2006-09-01

    CD4+CD25+ regulatory T cells are essential components of the immune system. They help to maintain immune tolerance by exerting suppressive effects on cells of the adaptive and innate immune system. In the last few years there has been an abundance of papers addressing the suppressive effects of CD4+CD25+ regulatory T cells and their putative role in various experimental disease models and human diseases. Despite the enormous amounts of data on these cells a number of controversial issues still exists. CD4+CD25+ regulatory T cells were originally described as thymus-derived anergic/suppressive T cells. Recent papers however indicate that these cells might also be generated in the periphery. Due to the thymic development of CD4+CD25+ regulatory T cells it was thought that these cells were specific for self-antigens. Indeed it was shown that CD4+CD25+ regulatory T cells could be positively selected upon high affinity interaction with self-antigens. However, evidence is accumulating that these cells might also interact with non-self antigens. Finally, in the literature there is conflicting evidence regarding the role of soluble factors versus cell-contact in the mechanism of suppression. The aim of this review is to summarize the evidence supporting these opposing viewpoints and to combine them into a general model for the origin, function and antigen-specificity of CD4+CD25+ regulatory T cells.

  15. Caveolin-1 regulates TCR signal strength and regulatory T-cell differentiation into alloreactive T cells.

    PubMed

    Schönle, Anne; Hartl, Frederike A; Mentzel, Jan; Nöltner, Theresa; Rauch, Katharina S; Prestipino, Alessandro; Wohlfeil, Sebastian A; Apostolova, Petya; Hechinger, Anne-Kathrin; Melchinger, Wolfgang; Fehrenbach, Kerstin; Guadamillas, Marta C; Follo, Marie; Prinz, Gabriele; Ruess, Ann-Katrin; Pfeifer, Dietmar; del Pozo, Miguel Angel; Schmitt-Graeff, Annette; Duyster, Justus; Hippen, Keli I; Blazar, Bruce R; Schachtrup, Kristina; Minguet, Susana; Zeiser, Robert

    2016-04-14

    Caveolin-1 (Cav-1) is a key organizer of membrane specializations and a scaffold protein that regulates signaling in multiple cell types. We found increased Cav-1 expression in human and murine T cells after allogeneic hematopoietic cell transplantation. Indeed, Cav-1(-/-)donor T cells caused less severe acute graft-versus-host disease (GVHD) and yielded higher numbers of regulatory T cells (Tregs) compared with controls. Depletion of Tregs from the graft abrogated this protective effect. Correspondingly, Treg frequencies increased when Cav-1(-/-)T cells were exposed to transforming growth factor-β/T-cell receptor (TCR)/CD28 activation or alloantigen stimulation in vitro compared with wild-type T cells. Mechanistically, we found that the phosphorylation of Cav-1 is dispensable for the control of T-cell fate by using a nonphosphorylatable Cav-1 (Y14F/Y14F) point-mutation variant. Moreover, the close proximity of lymphocyte-specific protein tyrosine kinase (Lck) to the TCR induced by TCR-activation was reduced in Cav-1(-/-)T cells. Therefore, less TCR/Lck clustering results in suboptimal activation of the downstream signaling events, which correlates with the preferential development into a Treg phenotype. Overall, we report a novel role for Cav-1 in TCR/Lck spatial distribution upon TCR triggering, which controls T-cell fate toward a regulatory phenotype. This alteration translated into a significant increase in the frequency of Tregs and reduced GVHD in vivo.

  16. Bovine γδ T Cells Are a Major Regulatory T Cell Subset

    PubMed Central

    Hope, Jayne; Taylor, Geraldine; Smith, Adrian L.; Cubillos-Zapata, Carolina; Charleston, Bryan

    2014-01-01

    In humans and mice, γδ T cells represent <5% of the total circulating lymphocytes. In contrast, the γδ T cell compartment in ruminants accounts for 15–60% of the total circulating mononuclear lymphocytes. Despite the existence of CD4+CD25high Foxp3+ T cells in the bovine system, these are neither anergic nor suppressive. We present evidence showing that bovine γδ T cells are the major regulatory T cell subset in peripheral blood. These γδ T cells spontaneously secrete IL-10 and proliferate in response to IL-10, TGF-β, and contact with APCs. IL-10–expressing γδ T cells inhibit Ag-specific and nonspecific proliferation of CD4+ and CD8+ T cells in vitro. APC subsets expressing IL-10 and TFG-β regulate proliferation of γδ T cells producing IL-10. We propose that γδ T cells are a major regulatory T cell population in the bovine system. PMID:24890724

  17. Regulatory T cells require TCR signaling for their suppressive function.

    PubMed

    Schmidt, Amanda M; Lu, Wen; Sindhava, Vishal J; Huang, Yanping; Burkhardt, Janis K; Yang, Enjun; Riese, Matthew J; Maltzman, Jonathan S; Jordan, Martha S; Kambayashi, Taku

    2015-05-01

    Regulatory T cells (Tregs) are a subset of CD4(+) T cells that maintain immune tolerance in part by their ability to inhibit the proliferation of conventional CD4(+) T cells (Tconvs). The role of the TCR and the downstream signaling pathways required for this suppressive function of Tregs are not fully understood. To yield insight into how TCR-mediated signals influence Treg suppressive function, we assessed the ability of Tregs with altered TCR-mediated signaling capacity to inhibit Tconv proliferation. Mature Tregs deficient in Src homology 2 domain containing leukocyte protein of 76 kDa (SLP-76), an adaptor protein that nucleates the proximal signaling complex downstream of the TCR, were unable to inhibit Tconv proliferation, suggesting that TCR signaling is required for Treg suppressive function. Moreover, Tregs with defective phospholipase C γ (PLCγ) activation due to a Y145F mutation of SLP-76 were also defective in their suppressive function. Conversely, enhancement of diacylglycerol-mediated signaling downstream of PLCγ by genetic ablation of a negative regulator of diacylglycerol kinase ζ increased the suppressive ability of Tregs. Because SLP-76 is also important for integrin activation and signaling, we tested the role of integrin activation in Treg-mediated suppression. Tregs lacking the adaptor proteins adhesion and degranulation promoting adapter protein or CT10 regulator of kinase/CT10 regulator of kinase-like, which are required for TCR-mediated integrin activation, inhibited Tconv proliferation to a similar extent as wild-type Tregs. Together, these data suggest that TCR-mediated PLCγ activation, but not integrin activation, is required for Tregs to inhibit Tconv proliferation.

  18. Roles for Inflammation and Regulatory T Cells in Colon Cancer

    PubMed Central

    Erdman, Susan E.; Poutahidis, Theofilos

    2014-01-01

    Risk for developing cancer rises substantially as a result of poorly regulated inflammatory responses to pathogenic bacterial infections. Anti-inflammatory CD4+ regulatory cells (TREG) function to restore immune homeostasis during chronic inflammatory disorders. It seems logical that TREG cells would function to reduce risk of inflammation-associated cancer in the bowel by down-regulating inflammation. It is widely believed, however, that TREG function in cancer mainly to suppress protective anticancer inflammatory responses. Thus roles for inflammation, TREG cells, and gut bacteria in cancer are paradoxical and are the subject of controversy. Our accumulated data build upon the “hygiene hypothesis” model in which gastrointestinal (GI) infections lead to changes in TREG that reduce inflammation-associated diseases. Ability of TREG to inhibit or suppress cancer depends upon gut bacteria and IL-10, which serve to maintain immune balance and a protective anti-inflammatory TREG phenotype. However, under poorly regulated pro-inflammatory conditions, TREG fail to inhibit and may instead contribute to a T helper (Th)-17-driven procarcinogenic process, a cancer state that is reversible by down-regulation of inflammation and interleukin (IL)-6. Consequently, hygienic individuals with a weakened IL-10– and TREG–mediated inhibitory loop are highly susceptible to the carcinogenic consequences of elevated inflammation and show more frequent inflammation-associated cancers. Taken together, these data help explain the paradox of inflammation and TREG in cancer and indicate that targeted stimulation of TREG may promote health and significantly reduce risk of cancer. PMID:20019355

  19. IL-10-producing NKT10 cells are a distinct regulatory invariant NKT cell subset.

    PubMed

    Sag, Duygu; Krause, Petra; Hedrick, Catherine C; Kronenberg, Mitchell; Wingender, Gerhard

    2014-09-01

    Invariant natural killer T (iNKT) cells rapidly produce copious amounts of multiple cytokines after activation, thereby impacting a wide variety of different immune reactions. However, strong activation of iNKT cells with α-galactosylceramide (αGalCer) reportedly induces a hyporeactive state that resembles anergy. In contrast, we determined here that iNKT cells from mice pretreated with αGalCer retain cytotoxic activity and maintain the ability to respond to TCR-dependent as well as TCR-independent cytokine-mediated stimulation. Additionally, αGalCer-pretreated iNKT cells acquired characteristics of regulatory cells, including production and secretion of the immunomodulatory cytokine IL-10. Through the production of IL-10, αGalCer-pretreated iNKT cells impaired antitumor responses and reduced disease in experimental autoimmune encephalomyelitis, a mouse model of autoimmune disease. Furthermore, a subset of iNKT cells with a similar inhibitory phenotype and function were present in mice not exposed to αGalCer and were enriched in mouse adipose tissue and detectable in human PBMCs. These data demonstrate that IL-10-producing iNKT cells with regulatory potential (NKT10 cells) represent a distinct iNKT cell subset.

  20. Mechanisms of Regulatory B cell Function in Autoimmune and Inflammatory Diseases beyond IL-10

    PubMed Central

    Ray, Avijit; Dittel, Bonnie N.

    2017-01-01

    In the past two decades it has become clear that in addition to antigen presentation and antibody production B cells play prominent roles in immune regulation. While B cell-derived IL-10 has garnered much attention, B cells also effectively regulate inflammation by a variety of IL-10-independent mechanisms. B cell regulation has been studied in both autoimmune and inflammatory diseases. While collectively called regulatory B cells (Breg), no definitive phenotype has emerged for B cells with regulatory potential. This has made their study challenging and thus unique B cell regulatory mechanisms have emerged in a disease-dependent manner. Thus to harness the therapeutic potential of Breg, further studies are needed to understand how they emerge and are induced to evoke their regulatory activities. PMID:28124981

  1. Interleukin 10 and dendritic cells are the main suppression mediators of regulatory T cells in human neurocysticercosis.

    PubMed

    Arce-Sillas, A; Álvarez-Luquín, D D; Cárdenas, G; Casanova-Hernández, D; Fragoso, G; Hernández, M; Proaño Narváez, J V; García-Vázquez, F; Fleury, A; Sciutto, E; Adalid-Peralta, L

    2016-02-01

    Neurocysticercosis is caused by the establishment of Taenia solium cysticerci in the central nervous system. It is considered that, during co-evolution, the parasite developed strategies to modulate the host's immune response. The action mechanisms of regulatory T cells in controlling the immune response in neurocysticercosis are studied in this work. Higher blood levels of regulatory T cells with CD4(+) CD45RO(+) forkhead box protein 3 (FoxP3)(high) and CD4(+) CD25(high) FoxP3(+) CD95(high) phenotype and of non-regulatory CD4(+) CD45RO(+) FoxP3(med) T cells were found in neurocysticercosis patients with respect to controls. Interestingly, regulatory T cells express higher levels of cytotoxic T lymphocyte antigen 4 (CTLA-4), lymphocyte-activation gene 3 (LAG-3), programmed death 1 (PD-1) and glucocorticoid-induced tumour necrosis factor receptor (GITR), suggesting a cell-to-cell contact mechanism with dendritic cells. Furthermore, higher IL-10 and regulatory T cell type 1 (Tr1) levels were found in neurocysticercosis patients' peripheral blood, suggesting that the action mechanism of regulatory T cells involves the release of immunomodulatory cytokines. No evidence was found of the regulatory T cell role in inhibiting the proliferative response. Suppressive regulatory T cells from neurocysticercosis patients correlated negatively with late activated lymphocytes (CD4(+) CD38(+) ). Our results suggest that, during neurocysticercosis, regulatory T cells could control the immune response, probably by a cell-to-cell contact with dendritic cells and interleukin (IL)-10 release by Tr1, to create an immunomodulatory environment that may favour the development of T. solium cysticerci and their permanence in the central nervous system.

  2. Regulatory T cells in kidney disease and transplantation.

    PubMed

    Hu, Min; Wang, Yuan Min; Wang, Yiping; Zhang, Geoff Y; Zheng, Guoping; Yi, Shounan; O'Connell, Philip J; Harris, David C H; Alexander, Stephen I

    2016-09-01

    Regulatory T cells (Tregs) have been shown to be important in maintaining immune homeostasis and preventing autoimmune disease, including autoimmune kidney disease. It is also likely that they play a role in limiting kidney transplant rejection and potentially in promoting transplant tolerance. Although other subsets of Tregs exist, the most potent and well-defined Tregs are the Foxp3 expressing CD4(+) Tregs derived from the thymus or generated peripherally. These CD4(+)Foxp3(+) Tregs limit autoimmune renal disease in animal models, especially chronic kidney disease, and kidney transplantation. Furthermore, other subsets of Tregs, including CD8 Tregs, may play a role in immunosuppression in kidney disease. The development and protective mechanisms of Tregs in kidney disease and kidney transplantation involve multiple mechanisms of suppression. Here we review the development and function of CD4(+)Foxp3(+) Tregs. We discuss the specific application of Tregs as a therapeutic strategy to prevent kidney disease and to limit kidney transplant rejection and detail clinical trials in this area of transplantation.

  3. Controlling the fire--tissue-specific mechanisms of effector regulatory T-cell homing.

    PubMed

    Chow, Zachary; Banerjee, Ashish; Hickey, Michael J

    2015-04-01

    Regulatory T cells have essential roles in regulating immune responses and limiting inappropriate inflammation. Evidence now indicates that to achieve this function, regulatory T cells must be able to migrate to the most appropriate locations within both lymphoid and non-lymphoid organs. This function is achieved via the spatiotemporally controlled expression of adhesion molecules and chemokine receptors, varying according to the developmental stage of the regulatory T cell and the location and environment where they undergo activation. In this Review, we summarise information on the roles of adhesion molecules and chemokine receptors in mediating regulatory T-cell migration and function throughout the body under homeostatic and inflammatory conditions. In addition, we review recent studies that have used in vivo imaging to examine the actions of regulatory T cells in vivo, in lymph nodes, in the microvasculature and in the interstitium of peripheral organs. These studies reveal that the capacity of regulatory T cells to undergo selective migration serves a critical role in their ability to suppress immune responses. As such, the cellular and molecular requirements of regulatory T-cell migration need to be completely understood to enable the most effective use of these cells in clinical settings.

  4. Suppression of immune regulatory cells with combined therapy of celecoxib and sunitinib in renal cell carcinoma

    PubMed Central

    Zhao, Qi; Guo, Jianming; Wang, Guomin; Chu, Yiwei; Hu, Xiaoyi

    2017-01-01

    Objective To observe the the potential benefit of sunitinib in combination with cyclooxygenase-2(COX-2) inhibitor in renal cell carcinoma therapy. Methods 769-p cell lines were treated with sunitinib, celecoxib, or in combination at different concentrations respectively. We investigated the expression of granulocyte-macrophage colony stimulating factor (GM-CSF) in 769-p and cell proliferation in vitro. BALB/c mice implanted with Renca cells were divided into 4 groups and administered orally by gavage with sunitinib, COX-2 inhibitor (celecoxib) monotherapy or combination, and PBS respectively. Tumor growth and animal survival were observed. The myeloid-derived suppressor cells (MDSCs) and regulatory T cells (Tregs) in peripheral blood and spleen were determined by flow cytometry. The MDSCs protein was extracted for STAT3 analysis by western blot. Results 769-p cell lines were suppressed in a dose and time-dependent manner. The expression of GM-CSF was substantially inhibited by celecoxib and sunitinib. Combination of sunitinib and celecoxib in vivo could effectively reduce the MDSCs than those in control group. Meanwhile, the CD4+ lymphocytes were strongly increased and the expression of signal transducer and activator of transcription 3 (STAT3) in MDSCs were significantly reduced. Conclusion Combination therapy with sunitinib and celecoxib intensified the curative effects to renal cell carcinoma by suppressing immune regulatory cells. PMID:27926489

  5. Myeloid-derived suppressor cells and myeloid regulatory cells in cancer and autoimmune disorders

    PubMed Central

    Barnie, Prince Amoah; Zhang, Pan; Lv, Hongxiang; Wang, Dan; Su, Xiaolian; Su, Zhaoliang; Xu, Huaxi

    2017-01-01

    Myeloid-derived suppressor cells (MDSCs) were originally described as a heterogeneous population of immature cells derived from myeloid progenitors with immune-suppressive functions in tumor-bearing hosts. In recent years, increasing number of studies have described various populations of myeloid cells with MDSC-like properties in murine models of cancer and autoimmune diseases. These studies have observed that the populations of MDSCs are increased during inflammation and autoimmune conditions. In addition, MDSCs can effectively suppress T cell responses and modulate the activity of natural killer cells and other myeloid cells. MDSCs have also been implicated in the induction of regulatory T cell production. Furthermore, these cells have the potential to suppress the autoimmune response, thereby limiting tissue injury. Myeloid regulatory cells (Mregs) are recently attracting increasing attention, since they function in proinflammatory and immune suppression in autoimmune diseases, as well as in various types of cancer. Currently, research focus is directed from MDSCs to Mregs in cancer and autoimmune diseases. The present study reviewed the suppressive roles of MDSCs in various autoimmune murine models, the immune modulation of MDSCs to T helper 17 lymphocytes, as well as the proinflammatory and immunosuppressive roles of Mregs in various types of cancer and autoimmune diseases. PMID:28352304

  6. MicroRNA-Containing T-Regulatory-Cell-Derived Exosomes Suppress Pathogenic T Helper 1 Cells

    PubMed Central

    Okoye, Isobel S.; Coomes, Stephanie M.; Pelly, Victoria S.; Czieso, Stephanie; Papayannopoulos, Venizelos; Tolmachova, Tanya; Seabra, Miguel C.; Wilson, Mark S.

    2014-01-01

    Summary Foxp3+ T regulatory (Treg) cells prevent inflammatory disease but the mechanistic basis of suppression is not understood completely. Gene silencing by RNA interference can act in a cell-autonomous and non-cell-autonomous manner, providing mechanisms of intercellular regulation. Here, we demonstrate that non-cell-autonomous gene silencing, mediated by miRNA-containing exosomes, is a mechanism employed by Treg cells to suppress T-cell-mediated disease. Treg cells transferred microRNAs (miRNA) to various immune cells, including T helper 1 (Th1) cells, suppressing Th1 cell proliferation and cytokine secretion. Use of Dicer-deficient or Rab27a and Rab27b double-deficient Treg cells to disrupt miRNA biogenesis or the exosomal pathway, respectively, established a requirement for miRNAs and exosomes for Treg-cell-mediated suppression. Transcriptional analysis and miRNA inhibitor studies showed that exosome-mediated transfer of Let-7d from Treg cell to Th1 cells contributed to suppression and prevention of systemic disease. These studies reveal a mechanism of Treg-cell-mediated suppression mediated by miRNA-containing exosomes. PMID:25035954

  7. The role of dendritic cells and regulatory T cells in the pathogenesis of morphea

    PubMed Central

    Teresiak-Mikołajczak, Ewa; Dańczak-Pazdrowska, Aleksandra; Kowalczyk, Michał; Żaba, Ryszard; Adamski, Zygmunt

    2015-01-01

    Morphea is one of diseases characterised by fibrosis of the skin and subcutaneous tissue. It is a chronic disease that does not shorten the life of the patient, yet significantly affects its quality. The group of factors responsible for its pathogenesis is thought to include disturbed functioning of endothelial cells as well as immune disturbances leading to chronic inflammatory conditions, accompanied by increased production of collagen and of other extracellular matrix components. Dendritic cells (DC) are a type of professional antigen-presenting cells and can be found in almost all body tissues. Individual investigations have demonstrated high numbers of plasmacytoid DC (pDC) in morphoeic skin lesions, within deeper dermal layers, around blood vessels, and around collagen fibres in subcutaneous tissue. It appears that DC has a more pronounced role in the development of inflammation and T cell activation in morphea, as compared to systemic sclerosis (SSc). Regulatory T (Treg) cells represent a subpopulation of T cells with immunosuppressive properties. Recent studies have drawn attention to the important role played by Treg in the process of autoimmunisation. Just a few studies have demonstrated a decrease in the number and activity of Treg in patients with SSc, and only such studies involve morphea. This article reviews recent studies on the role of DC and regulatory T cells in the pathogenesis of morphea. Moreover, mechanisms of phototherapy and potential therapeutic targets in the treatment of morphea are discussed in this context. PMID:26155191

  8. Loss of Functionally Redundant p38 Isoforms in T Cells Enhances Regulatory T Cell Induction*

    PubMed Central

    Hayakawa, Morisada; Hayakawa, Hiroko; Petrova, Tsvetana; Ritprajak, Patcharee; Sutavani, Ruhcha V.; Jiménez-Andrade, Guillermina Yanek; Sano, Yasuyo; Choo, Min-Kyung; Seavitt, John; Venigalla, Ram K. C.; Otsu, Kinya; Georgopoulos, Katia; Arthur, J. Simon C.; Park, Jin Mo

    2017-01-01

    The evolutionarily conserved protein kinase p38 mediates innate resistance to environmental stress and microbial infection. Four p38 isoforms exist in mammals and may have been co-opted for new roles in adaptive immunity. Murine T cells deficient in p38α, the ubiquitously expressed p38 isoform, showed no readily apparent cell-autonomous defects while expressing elevated amounts of another isoform, p38β. Mice with T cells simultaneously lacking p38α and p38β displayed lymphoid atrophy and elevated Foxp3+ regulatory T cell frequencies. Double deficiency of p38α and p38β in naïve CD4+ T cells resulted in an attenuation of MAPK-activated protein kinase (MK)-dependent mTOR signaling after T cell receptor engagement, and enhanced their differentiation into regulatory T cells under appropriate inducing conditions. Pharmacological inhibition of the p38-MK-mTOR signaling module produced similar effects, revealing potential for therapeutic applications. PMID:28011639

  9. B Cells with Regulatory Function in Animal Models of Autoimmune and Non-Autoimmune Diseases.

    PubMed

    Lin, Mei; Wang, Zuomin; Han, Xiaozhe

    2015-03-01

    Although the identification of B cell subsets with negative regulatory functions and the definition of their mechanisms of action are recent events, the important negative regulatory roles of B cells in immune responses are now broadly recognized. There is an emerging appreciation for the pivotal role played by B cells in several areas of human diseases including autoimmune diseases and non-autoimmune diseases such as parasite infections and cancer. The recent research advancement of regulatory B cells in human disease coincides with the vastly accelerated pace of research on the bridging of innate and adaptive immune system. Current study and our continued research may provide better understanding of the mechanisms that promote regulatory B10 cell function to counteract exaggerated immune activation in autoimmune as well as non-autoimmune conditions. This review is focused on the current knowledge of BREG functions studied in animal models of autoimmune and non-autoimmune diseases.

  10. A role for the transcription factor Helios in human CD4+CD25+ regulatory T cells

    PubMed Central

    Getnet, Derese; Grosso, Joseph F.; Goldberg, Monica V.; Harris, Timothy J.; Yen, Hung-Rong; Bruno, Tullia C.; Durham, Nicholas M.; Hipkiss, Edward L.; Pyle, Kristin J.; Wada, Satoshi; Pan, Fan; Pardoll, Drew M.; Drake, Charles G.

    2010-01-01

    Relative up-regulation of the Ikaros family transcription factor Helios in natural regulatory T cells (Tregs) has been reported by several groups. However, a role for Helios in regulatory T cells has not yet been described. Here, we show that Helios is upregulated in CD4+CD25+ regulatory T cells. Chromatin Immunoprecipitation (ChIP) experiments indicated that Helios binds to the FoxP3 promoter. These data were further corroborated by experiments showing that knocking-down Helios with siRNA oligonucleotides results in down-regulation of FoxP3. Functionally, we found that suppression of Helios message in CD4+CD25+ T cells significantly attenuates their suppressive function. Taken together, these data suggest that Helios may play an important role in regulatory T cell function and support the concept that Helios may be a novel target to manipulate Treg activity in a clinical setting. PMID:20226531

  11. Accumulation of peripheral autoreactive B cells in the absence of functional human regulatory T cells

    PubMed Central

    Kinnunen, Tuure; Chamberlain, Nicolas; Morbach, Henner; Choi, Jinyoung; Kim, Sangtaek; Craft, Joseph; Mayer, Lloyd; Cancrini, Caterina; Passerini, Laura; Bacchetta, Rosa; Ochs, Hans D.; Torgerson, Troy R.

    2013-01-01

    Regulatory T cells (Tregs) play an essential role in preventing autoimmunity. Mutations in the forkhead box protein 3 (FOXP3) gene, which encodes a transcription factor critical for Treg function, result in a severe autoimmune disorder and the production of various autoantibodies in mice and in IPEX (immune dysregulation, polyendocrinopathy, enteropathy, X-linked) patients. However, it is unknown whether Tregs normally suppress autoreactive B cells. To investigate a role for Tregs in maintaining human B-cell tolerance, we tested the reactivity of recombinant antibodies isolated from single B cells isolated from IPEX patients. Characteristics and reactivity of antibodies expressed by new emigrant/transitional B cells from IPEX patients were similar to those from healthy donors, demonstrating that defective Treg function does not impact central B-cell tolerance. In contrast, mature naive B cells from IPEX patients often expressed autoreactive antibodies, suggesting an important role for Tregs in maintaining peripheral B-cell tolerance. T cells displayed an activated phenotype in IPEX patients, including their Treg-like cells, and showed up-regulation of CD40L, PD-1, and inducibl T-cell costimulator (ICOS), which may favor the accumulation of autoreactive mature naive B cells in these patients. Hence, our data demonstrate an essential role for Tregs in the establishment and the maintenance of peripheral B-cell tolerance in humans. PMID:23223361

  12. THE INITIAL PHASE OF AN IMMUNE RESPONSE FUNCTIONS TO ACTIVATE REGULATORY T CELLS

    PubMed Central

    O’Gorman, William E.; Dooms, Hans; Thorne, Steve H.; Kuswanto, Wilson F.; Simonds, Erin F.; Krutzik, Peter O.; Nolan, Garry P.; Abbas, Abul K.

    2009-01-01

    An early reaction of CD4+ T lymphocytes to antigen is the production of cytokines, notably IL-2. In order to detect cytokine dependent responses, naive antigen-specific T cells were stimulated in vivo and the presence of phosphorylated STAT5 molecules was used to identify the cell populations responding to IL-2. Within hours of T-cell priming, IL-2-dependent STAT5 phosphorylation occurred primarily in Foxp3+ regulatory T cells. In contrast, the antigen-specific T cells received STAT5 signals only after repeated antigen exposure or memory differentiation. Regulatory T cells receiving IL-2 signals proliferated and developed enhanced suppressive activity. These results indicate that one of the earliest events in a T cell response is the activation of endogenous regulatory cells, potentially to prevent autoimmunity. PMID:19542444

  13. Tr1-Like T Cells – An Enigmatic Regulatory T Cell Lineage

    PubMed Central

    White, Anna Malgorzata; Wraith, David C.

    2016-01-01

    The immune system evolved to respond to foreign invaders and prevent autoimmunity to self-antigens. Several types of regulatory T cells facilitate the latter process. These include a subset of Foxp3− CD4+ T cells able to secrete IL-10 in an antigen-specific manner, type 1 regulatory (Tr1) T cells. Although their suppressive function has been confirmed both in vitro and in vivo, their phenotype remains poorly defined. It has been suggested that the surface markers LAG-3 and CD49b are biomarkers for murine and human Tr1 cells. Here, we discuss these findings in the context of our data regarding the expression pattern of inhibitory receptors (IRs) CD49b, TIM-3, PD-1, TIGIT, LAG-3, and ICOS on Tr1-like human T cells generated in vitro from CD4+ memory T cells stimulated with αCD3 and αCD28 antibodies. We found that there were no differences in IR expression between IL-10+ and IL-10− T cells. However, CD4+IL-10+ T cells isolated ex vivo, following a short stimulation and cytokine secretion assay, contained significantly higher proportions of TIM-3+ and PD-1+ cells. They also expressed significantly higher TIGIT mRNA and showed a trend toward increased TIM-3 mRNA levels. These data led us to conclude that large pools of IRs may be stored intracellularly; hence, they may not represent ideal candidates as cell surface biomarkers for Tr1-like T cells. PMID:27683580

  14. Thymic B cells promote thymus-derived regulatory T cell development and proliferation.

    PubMed

    Lu, Fang-Ting; Yang, Wei; Wang, Yin-Hu; Ma, Hong-Di; Tang, Wei; Yang, Jing-Bo; Li, Liang; Ansari, Aftab A; Lian, Zhe-Xiong

    2015-07-01

    Thymic CD4(+) FoxP3(+) regulatory T (Treg) cells are critical for the development of immunological tolerance and immune homeostasis and requires contributions of both thymic dendritic and epithelial cells. Although B cells have been reported to be present within the thymus, there has not hitherto been a definition of their role in immune cell development and, in particular, whether or how they contribute to the Treg cellular thymic compartment. Herein, using both phenotypic and functional approaches, we demonstrate that thymic B cells contribute to the maintenance of thymic Treg cells and, using an in vitro culture system, demonstrate that thymic B cells contribute to the size of the thymic Treg compartment via cell-cell MHC II contact and the involvement of two independent co-stimulatory pathways that include interactions between the CD40/CD80/CD86 co-stimulatory molecules. Our data also suggest that thymic B cells promote the generation of thymic Treg cell precursors (pre-Treg cells), but not the conversion of FoxP3(+) Treg cells from pre-Treg cells. In addition, thymic B cells directly promote the proliferation of thymic Treg cells that is MHC II contact dependent with a minimal if any role for co-stimulatory molecules including CD40/CD80/CD86. Both pathways are independent of TGFβ. In conclusion, we rigorously define the critical role of thymic B cells in the development of thymic Treg cells from non-Treg to precursor stage and in the proliferation of mature thymic Treg cells.

  15. Cell-type-specific enrichment of risk-associated regulatory elements at ovarian cancer susceptibility loci

    PubMed Central

    Coetzee, Simon G.; Shen, Howard C.; Hazelett, Dennis J.; Lawrenson, Kate; Kuchenbaecker, Karoline; Tyrer, Jonathan; Rhie, Suhn K.; Levanon, Keren; Karst, Alison; Drapkin, Ronny; Ramus, Susan J.; Couch, Fergus J.; Offit, Kenneth; Chenevix-Trench, Georgia; Monteiro, Alvaro N.A.; Antoniou, Antonis; Freedman, Matthew; Coetzee, Gerhard A.; Pharoah, Paul D.P.; Noushmehr, Houtan; Gayther, Simon A.

    2015-01-01

    Understanding the regulatory landscape of the human genome is a central question in complex trait genetics. Most single-nucleotide polymorphisms (SNPs) associated with cancer risk lie in non-protein-coding regions, implicating regulatory DNA elements as functional targets of susceptibility variants. Here, we describe genome-wide annotation of regions of open chromatin and histone modification in fallopian tube and ovarian surface epithelial cells (FTSECs, OSECs), the debated cellular origins of high-grade serous ovarian cancers (HGSOCs) and in endometriosis epithelial cells (EECs), the likely precursor of clear cell ovarian carcinomas (CCOCs). The regulatory architecture of these cell types was compared with normal human mammary epithelial cells and LNCaP prostate cancer cells. We observed similar positional patterns of global enhancer signatures across the three different ovarian cancer precursor cell types, and evidence of tissue-specific regulatory signatures compared to non-gynecological cell types. We found significant enrichment for risk-associated SNPs intersecting regulatory biofeatures at 17 known HGSOC susceptibility loci in FTSECs (P = 3.8 × 10−30), OSECs (P = 2.4 × 10−23) and HMECs (P = 6.7 × 10−15) but not for EECs (P = 0.45) or LNCaP cells (P = 0.88). Hierarchical clustering of risk SNPs conditioned on the six different cell types indicates FTSECs and OSECs are highly related (96% of samples using multi-scale bootstrapping) suggesting both cell types may be precursors of HGSOC. These data represent the first description of regulatory catalogues of normal precursor cells for different ovarian cancer subtypes, and provide unique insights into the tissue specific regulatory variation with respect to the likely functional targets of germline genetic susceptibility variants for ovarian cancer. PMID:25804953

  16. Tumor-infiltrating regulatory T cells inhibit endogenous cytotoxic T cell responses to lung adenocarcinoma

    PubMed Central

    Ganesan, Anusha-Preethi; Johansson, Magnus; Ruffell, Brian; Beltran, Adam; Lau, Jonathan; Jablons, David M.; Coussens, Lisa M.

    2013-01-01

    Immune cells comprise a substantial proportion of the tumor mass in human non-small cell lung cancers (NSCLC), but the precise composition and significance of this infiltration is unclear. Herein we examined immune complexity of human NSCLC as well as NSCLC developing in CC10-TAg transgenic mice, and revealed that CD4+ T lymphocytes represent the dominant population of CD45+ immune cells, and relative to normal lung tissue, CD4+FoxP3+ regulatory T cells (Tregs) were significantly increased as a proportion of total CD4+ cells. To assess the functional significance of increased Treg cells, we evaluated CD8+ T cell-deficient/CC10-TAg mice and revealed that CD8+ T cells significantly controlled tumor growth with anti-tumor activity that was partially repressed by Treg cells. However, while treatment with anti-CD25 depleting mAb as monotherapy preferentially depleted Tregs and improved CD8+ T cell-mediated control of tumor progression during early tumor development, similar monotherapy was ineffective at later stages. Since mice bearing early NSCLC treated with anti-CD25 mAb exhibited increased tumor cell death associated with infiltration by CD8+ T cells expressing elevated levels of granzyme A, granzyme B, perforin and interferon-γ, we therefore evaluated carboplatin combination therapy resulting in a significantly extended survival beyond that observed with chemotherapy alone, indicating that Treg depletion in combination with cytotoxic therapy may be beneficial as a treatment strategy for advanced NSCLC. PMID:23851682

  17. A Systematic Analysis of Drosophila Regulatory Peptide Expression in Enteroendocrine Cells.

    PubMed

    Chen, Ji; Kim, Seol-Min; Kwon, Jae Young

    2016-04-30

    The digestive system is gaining interest as a major regulator of various functions including immune defense, nutrient accumulation, and regulation of feeding behavior, aside from its conventional function as a digestive organ. The Drosophila midgut epithelium is completely renewed every 1-2 weeks due to differentiation of pluripotent intestinal stem cells in the midgut. Intestinal stem cells constantly divide and differentiate into enterocytes that secrete digestive enzymes and absorb nutrients, or enteroendocrine cells that secrete regulatory peptides. Regulatory peptides have important roles in development and metabolism, but study has mainly focused on expression and functions in the nervous system, and not much is known about the roles in endocrine functions of enteroendocrine cells. We systemically examined the expression of 45 regulatory peptide genes in the Drosophila midgut, and verified that at least 10 genes are expressed in the midgut enteroendocrine cells through RT-PCR, in situ hybridization, antisera, and 25 regulatory peptide-GAL transgenes. The Drosophila midgut is highly compartmentalized, and individual peptides in enteroendocrine cells were observed to express in specific regions of the midgut. We also confirmed that some peptides expressed in the same region of the midgut are expressed in mutually exclusive enteroendocrine cells. These results indicate that the midgut enteroendocrine cells are functionally differentiated into different subgroups. Through this study, we have established a basis to study regulatory peptide functions in enteroendocrine cells as well as the complex organization of enteroendocrine cells in the Drosophila midgut.

  18. Immunopathogenesis in Autism: Regulatory T-Cells and Autoimmunity in Neurodevelopment

    DTIC Science & Technology

    2011-12-01

    developmental exposure to PFOA of PFOS. However, autism risk cannot be determined from these data alone. Regulatory T cells, immunophenotyping...autoantibodies, CD3+, myelin basic protein, autism 1 JUL 2010 - 30 NOV 2011Final01-12-2011 W81XWH-10-1-0484 Immunopathogenesis in Autism : Regulatory T-Cells...etiology of autism and related neurodevelopmental disorders is largely unknown. Myriad hypotheses have suggested that exogenous agents, such as

  19. Bach2 represses plasma cell gene regulatory network in B cells to promote antibody class switch.

    PubMed

    Muto, Akihiko; Ochiai, Kyoko; Kimura, Yoshitaka; Itoh-Nakadai, Ari; Calame, Kathryn L; Ikebe, Dai; Tashiro, Satoshi; Igarashi, Kazuhiko

    2010-12-01

    Two transcription factors, Pax5 and Blimp-1, form a gene regulatory network (GRN) with a double-negative loop, which defines either B-cell (Pax5 high) or plasma cell (Blimp-1 high) status as a binary switch. However, it is unclear how this B-cell GRN registers class switch DNA recombination (CSR), an event that takes place before the terminal differentiation to plasma cells. In the absence of Bach2 encoding a transcription factor required for CSR, mouse splenic B cells more frequently and rapidly expressed Blimp-1 and differentiated to IgM plasma cells as compared with wild-type cells. Genetic loss of Blimp-1 in Bach2(-/-) B cells was sufficient to restore CSR. These data with mathematical modelling of the GRN indicate that Bach2 achieves a time delay in Blimp-1 induction, which inhibits plasma cell differentiation and promotes CSR (Delay-Driven Diversity model for CSR). Reduction in mature B-cell numbers in Bach2(-/-) mice was not rescued by Blimp-1 ablation, indicating that Bach2 regulates B-cell differentiation and function through Blimp-1-dependent and -independent GRNs.

  20. Bacterial Manipulation of NK Cell Regulatory Activity Increases Susceptibility to Listeria monocytogenes Infection

    PubMed Central

    Guthrie, Brandon S.; Schmidt, Rebecca L.; Jamieson, Amanda; Merkel, Patricia; Knight, Vijaya; Cole, Caroline M.; Raulet, David H.; Lenz, Laurel L.

    2016-01-01

    Natural killer (NK) cells produce interferon (IFN)-γ and thus have been suggested to promote type I immunity during bacterial infections. Yet, Listeria monocytogenes (Lm) and some other pathogens encode proteins that cause increased NK cell activation. Here, we show that stimulation of NK cell activation increases susceptibility during Lm infection despite and independent from robust NK cell production of IFNγ. The increased susceptibility correlated with IL-10 production by responding NK cells. NK cells produced IL-10 as their IFNγ production waned and the Lm virulence protein p60 promoted induction of IL-10 production by mouse and human NK cells. NK cells consequently exerted regulatory effects to suppress accumulation and activation of inflammatory myeloid cells. Our results reveal new dimensions of the role played by NK cells during Lm infection and demonstrate the ability of this bacterial pathogen to exploit the induction of regulatory NK cell activity to increase host susceptibility. PMID:27295349

  1. Identification and clinical relevance of naturally occurring human CD8+HLA-DR+ regulatory T cells.

    PubMed

    Arruvito, Lourdes; Payaslián, Florencia; Baz, Plácida; Podhorzer, Ariel; Billordo, Ariel; Pandolfi, Julieta; Semeniuk, Guillermo; Arribalzaga, Eduardo; Fainboim, Leonardo

    2014-11-01

    The lack of responsiveness to self and non-self Ags is normally maintained by multiple mechanisms, including the suppressive activities of several T cell subsets. In this study, we show that CD8(+) T cells from both adult peripheral blood and umbilical cord blood mononuclear cells constitutively expressing HLA-DR represent a natural human CD8(+) regulatory T cell subset. Their suppressive effect appears to be cell-to-cell contact dependent and may involve CTLA-4 signaling between neighboring T cells. These regulatory T cells can be expanded in vitro and exhibit a suppressive capacity similar to that observed in ex vivo CD8(+)HLA-DR(+) T cells. The high frequency of CD8(+)HLA-DR(+) T cells that we detected in patients with non-small cell lung cancer deserves further work to confirm their putative suppressor effect within the tumor.

  2. CCR6 Recruits Regulatory T Cells and Th17 Cells to the Kidney in Glomerulonephritis

    PubMed Central

    Turner, Jan-Eric; Paust, Hans-Joachim; Steinmetz, Oliver M.; Peters, Anett; Riedel, Jan-Hendrik; Erhardt, Annette; Wegscheid, Claudia; Velden, Joachim; Fehr, Susanne; Mittrücker, Hans-Willi; Tiegs, Gisa; Stahl, Rolf A.K.

    2010-01-01

    T cells recruited to the kidney contribute to tissue damage in crescentic and proliferative glomerulonephritides. Chemokines and their receptors regulate T cell trafficking, but the expression profile and functional importance of chemokine receptors for renal CD4+ T cell subsets are incompletely understood. In this study, we observed that renal FoxP3+CD4+ regulatory T cells (Tregs) and IL-17–producing CD4+ T (Th17) cells express the chemokine receptor CCR6, whereas IFNγ-producing Th1 cells are CCR6−. Induction of experimental glomerulonephritis (nephrotoxic nephritis) in mice resulted in upregulation of the only CCR6 ligand, CCL20, followed by T cell recruitment, renal tissue injury, albuminuria, and loss of renal function. CCR6 deficiency aggravated renal injury and increased mortality (from uremia) among nephritic mice. Compared with wild-type (WT) mice, CCR6 deficiency reduced infiltration of Tregs and Th17 cells but did not affect recruitment of Th1 cells in the setting of glomerulonephritis. Adoptive transfer of WT but not CCR6-deficient Tregs attenuated morphologic and functional renal injury in nephritic mice. Furthermore, reconstitution with WT Tregs protected CCR6−/− mice from aggravated nephritis. Taken together, these data suggest that CCR6 mediates renal recruitment of both Tregs and Th17 cells and that the reduction of anti-inflammatory Tregs in the presence of a fully functional Th1 response aggravates experimental glomerulonephritis. PMID:20299360

  3. Unexpected T cell regulatory activity of anti-histone H1 autoantibody: Its mode of action in regulatory T cell-dependent and -independent manners

    SciTech Connect

    Takaoka, Yuki; Kawamoto, Seiji; Katayama, Akiko; Nakano, Toshiaki; Yamanaka, Yasushi; Takahashi, Miki; Shimada, Yayoi; Chiang, Kuei-Chen; Ohmori, Naoya; Aki, Tsunehiro; Goto, Takeshi; Sato, Shuji; Goto, Shigeru; Chen, Chao-Long; Ono, Kazuhisa

    2013-02-08

    Highlights: ► Anti-histone H1 autoantibody (anti-H1) acts on T cells to inhibit their activation. ► Anti-H1 suppresses T cell activation in Treg cell-dependent and -independent manners. ► Suboptimal dose of anti-H1 enhances suppressor function of Treg cells. ► High dose of anti-H1 directly inhibits T cell receptor signaling. -- Abstract: Induction of anti-nuclear antibodies against DNA or histones is a hallmark of autoimmune disorders, but their actual contribution to disease predisposition remains to be clarified. We have previously reported that autoantibodies against histone H1 work as a critical graft survival factor in a rat model of tolerogeneic liver transplantation. Here we show that an immunosuppressive anti-histone H1 monoclonal antibody (anti-H1 mAb) acts directly on T cells to inhibit their activation in response to T cell receptor (TCR) ligation. Intriguingly, the T cell activation inhibitory activity of anti-H1 mAb under suboptimal dosages required regulatory T (Treg) cells, while high dose stimulation with anti-H1 mAb triggered a Treg cell-independent, direct negative regulation of T cell activation upon TCR cross-linking. In the Treg cell-dependent mode of immunosuppressive action, anti-H1 mAb did not induce the expansion of CD4{sup +}Foxp3{sup +} Treg cells, but rather potentiated their regulatory capacity. These results reveal a previously unappreciated T cell regulatory role of anti-H1 autoantibody, whose overproduction is generally thought to be pathogenic in the autoimmune settings.

  4. A Transcriptional Regulatory Switch Underlying B-Cell Terminal Differentiation and Its Disruption by Dioxin (S)

    EPA Science Inventory

    The terminal differentiation of B cells in lymphoid organs into antibody-secreting plasma cells upon antigen stimulation is a crucial step in the humoral immune response. The architecture of the B-cell transcriptional regulatory network consists of coupled mutually-repressive fee...

  5. Global reorganisation of cis-regulatory units upon lineage commitment of human embryonic stem cells.

    PubMed

    Freire-Pritchett, Paula; Schoenfelder, Stefan; Várnai, Csilla; Wingett, Steven W; Cairns, Jonathan; Collier, Amanda J; García-Vílchez, Raquel; Furlan-Magaril, Mayra; Osborne, Cameron S; Fraser, Peter J; Rugg-Gunn, Peter J; Spivakov, Mikhail

    2017-03-23

    Long-range cis-regulatory elements such as enhancers coordinate cell-specific transcriptional programmes by engaging in DNA looping interactions with target promoters. Deciphering the interplay between the promoter connectivity and activity of cis-regulatory elements during lineage commitment is crucial for understanding developmental transcriptional control. Here, we use Promoter Capture Hi-C to generate a high-resolution atlas of chromosomal interactions involving ~22,000 gene promoters in human pluripotent and lineage-committed cells, identifying putative target genes for known and predicted enhancer elements. We reveal extensive dynamics of cis-regulatory contacts upon lineage commitment, including the acquisition and loss of promoter interactions. This spatial rewiring occurs preferentially with predicted changes in the activity of cis-regulatory elements, and is associated with changes in target gene expression. Our results provide a global and integrated view of promoter interactome dynamics during lineage commitment of human pluripotent cells.

  6. Novel feedback loop between M2 macrophages/microglia and regulatory B cells in estrogen-protected EAE mice.

    PubMed

    Benedek, Gil; Zhang, Jun; Nguyen, Ha; Kent, Gail; Seifert, Hilary; Vandenbark, Arthur A; Offner, Halina

    2017-04-15

    Immunoregulatory sex hormones, including estrogen and estriol, may prevent relapses in multiple sclerosis during pregnancy. Our previous studies have demonstrated that regulatory B cells are crucial for estrogen-mediated protection against experimental autoimmune encephalomyelitis (EAE). Herein, we demonstrate an estrogen-dependent induction of alternatively activated (M2) macrophages/microglia that results in an increased frequency of regulatory B cells in the spinal cord of estrogen treated mice with EAE. We further demonstrate that cultured M2-polarized microglia promote the induction of regulatory B cells. Our study suggests that estrogen neuroprotection induces a regulatory feedback loop between M2 macrophages/microglia and regulatory B cells.

  7. A steganalysis-based approach to comprehensive identification and characterization of functional regulatory elements

    PubMed Central

    Wang, Guandong; Zhang, Weixiong

    2006-01-01

    The comprehensive identification of cis-regulatory elements on a genome scale is a challenging problem. We develop a novel, steganalysis-based approach for genome-wide motif finding, called WordSpy, by viewing regulatory regions as a stegoscript with cis-elements embedded in 'background' sequences. We apply WordSpy to the promoters of cell-cycle-related genes of Saccharomyces cerevisiae and Arabidopsis thaliana, identifying all known cell-cycle motifs with high ranking. WordSpy can discover a complete set of cis-elements and facilitate the systematic study of regulatory networks. PMID:16787547

  8. Human Th17 cells share major trafficking receptors with both polarized effector T cells and FOXP3+ regulatory T cells.

    PubMed

    Lim, Hyung W; Lee, Jeeho; Hillsamer, Peter; Kim, Chang H

    2008-01-01

    It is a question of interest whether Th17 cells express trafficking receptors unique to this Th cell lineage and migrate specifically to certain tissue sites. We found several Th17 cell subsets at different developing stages in a human secondary lymphoid organ (tonsils) and adult, but not in neonatal, blood. These Th17 cell subsets include a novel in vivo-stimulated tonsil IL17+ T cell subset detected without any artificial stimulation in vitro. We investigated in depth the trafficking receptor phenotype of the Th17 cell subsets in tonsils and adult blood. The developing Th17 cells in tonsils highly expressed both Th1- (CCR2, CXCR3, CCR5, and CXCR6) and Th2-associated (CCR4) trafficking receptors. Moreover, Th17 cells share major non-lymphoid tissue trafficking receptors, such as CCR4, CCR5, CCR6, CXCR3, and CXCR6, with FOXP3+ T regulatory cells. In addition, many Th17 cells express homeostatic chemokine receptors (CD62L, CCR6, CCR7, CXCR4, and CXCR5) implicated in T cell migration to and within lymphoid tissues. Expression of CCR6 and CCR4 by some Th17 cells is not a feature unique to Th17 cells but shared with FOXP3+ T cells. Interestingly, the IL17+IFN-gamma+ Th17 cells have the features of both IL17-IFN-gamma+ Th1 and IL17+IFN-gamma- Th17 cells in expression of trafficking receptors. Taken together, our results revealed that Th17 cells are highly heterogeneous, in terms of trafficking receptors, and programmed to share major trafficking receptors with other T cell lineages. These findings have important implications in their distribution in the human body in relation to other regulatory T cell subsets.

  9. Treatment of ongoing autoimmune encephalomyelitis with activated B-cell progenitors maturing into regulatory B cells

    PubMed Central

    Korniotis, Sarantis; Gras, Christophe; Letscher, Hélène; Montandon, Ruddy; Mégret, Jérôme; Siegert, Stefanie; Ezine, Sophie; Fallon, Padraic G.; Luther, Sanjiv A.; Fillatreau, Simon; Zavala, Flora

    2016-01-01

    The influence of signals perceived by immature B cells during their development in bone marrow on their subsequent functions as mature cells are poorly defined. Here, we show that bone marrow cells transiently stimulated in vivo or in vitro through the Toll-like receptor 9 generate proB cells (CpG-proBs) that interrupt experimental autoimmune encephalomyelitis (EAE) when transferred at the onset of clinical symptoms. Protection requires differentiation of CpG-proBs into mature B cells that home to reactive lymph nodes, where they trap T cells by releasing the CCR7 ligand, CCL19, and to inflamed central nervous system, where they locally limit immunopathogenesis through interleukin-10 production, thereby cooperatively inhibiting ongoing EAE. These data demonstrate that a transient inflammation at the environment, where proB cells develop, is sufficient to confer regulatory functions onto their mature B-cell progeny. In addition, these properties of CpG-proBs open interesting perspectives for cell therapy of autoimmune diseases. PMID:27396388

  10. Reciprocity between Regulatory T Cells and Th17 Cells: Relevance to Polarized Immunity in Leprosy.

    PubMed

    Sadhu, Soumi; Khaitan, Binod Kumar; Joshi, Beenu; Sengupta, Utpal; Nautiyal, Arvind Kumar; Mitra, Dipendra Kumar

    2016-01-01

    T cell defect is a common feature in lepromatous or borderline lepromatous leprosy (LL/BL) patients in contrast to tuberculoid or borderline tuberculoid type (TT/BT) patients. Tuberculoid leprosy is characterized by strong Th1-type cell response with localized lesions whereas lepromatous leprosy is hallmarked by its selective Mycobacterium leprae specific T cell anergy leading to disseminated and progressive disease. FoxP3+ Regulatory T cells (Treg) which are essential for maintaining peripheral tolerance, preventing autoimmune diseases and limiting chronic inflammatory diseases also dampen proinflammatory T cells that include T helper 17 (Th17) cells. This study is aimed at evaluating the role of Treg cells in influencing other effector T cells and its relationship with the cytokine polarized state in leprosy patients. Peripheral blood mononuclear cells from of BT/TT (n = 15) and BL/LL (n = 15) patients were stimulated with M. leprae antigen (WCL) in presence of golgi transport inhibitor monensin for FACS based intracellular cytokine estimation. The frequency of Treg cells showed >5-fold increase in BL/LL in comparison to BT/TT and healthy contacts. These cells produced suppressive cytokine, IL-10 in BL/LL as opposed to BT/TT (p = 0.0200) indicating their suppressive function. The frequency of Th17 cells (CD4, CD45RO, IL-17) was, however, higher in BT/TT. Significant negative correlation (r = -0.68, P = 0.03) was also found between IL-10 of Treg cells and IL-17+ T cells in BL/LL. Blocking IL-10/TGF-β restored the IL-17+ T cells in BL/LL patients. Simultaneously, presence of Th17 related cytokines (TGF-β, IL-6, IL-17 and IL-23) decreased the number of FoxP3+ Treg cells concomitantly increasing IL-17 producing CD4+ cells in lepromatous leprosy. Higher frequency of Programmed Death-1/PD-1+ Treg cells and its ligand, PDL-1 in antigen presenting cells (APCs) was found in BL/LL patients. Inhibition of this pathway led to rescue of IFN-γ and IL-17 producing T cells

  11. Toward a complete in silico, multi-layered embryonic stem cell regulatory network

    PubMed Central

    Xu, Huilei; Schaniel, Christoph; Lemischka, Ihor R.; Ma’ayan, Avi

    2010-01-01

    Recent efforts in systematically profiling embryonic stem (ES) cells have yielded a wealth of high-throughput data. Complementarily, emerging databases and computational tools facilitate ES cell studies and further pave the way toward the in silico reconstruction of regulatory networks encompassing multiple molecular layers. Here, we briefly survey databases, algorithms, and software tools used to organize and analyze high-throughput experimental data collected to study mammalian cellular systems with a focus on ES cells. The vision of using heterogeneous data to reconstruct a complete multilayered ES cell regulatory network is discussed. This review also provides an accompanying manually extracted dataset of different types of regulatory interactions from low-throughput experimental ES cell studies available at http://amp.pharm.mssm.edu/iscmid/literature. PMID:20890967

  12. SHARPIN controls regulatory T cells by negatively modulating the T cell antigen receptor complex

    PubMed Central

    Park, Yoon; Jin, Hyung-seung; Lopez, Justine; Lee, Jeeho; Liao, Lujian; Elly, Chris; Liu, Yun-Cai

    2016-01-01

    SHARPIN forms a linear-ubiquitin-chain-assembly complex that promotes signaling via the transcription factor NF-κB. SHARPIN deficiency leads to progressive multi-organ inflammation and immune system malfunction, but how SHARPIN regulates T cell responses is unclear. Here we found that SHARPIN deficiency resulted in a substantial reduction in the number of and defective function of regulatory T cells (Treg cells). Transfer of SHARPIN-sufficient Treg cells into SHARPIN-deficient mice considerably alleviated their systemic inflammation. SHARPIN-deficient T cells displayed enhanced proximal signaling via the T cell antigen receptor (TCR) without an effect on the activation of NF-κB. SHARPIN conjugated with Lys63 (K63)-linked ubiquitin chains, which led to inhibition of the association of TCRζ with the signaling kinase Zap70; this affected the generation of Treg cells. Our study therefore identifies a role for SHARPIN in TCR signaling whereby it maintains immunological homeostasis and tolerance by regulating Treg cells. PMID:26829767

  13. Hepatic Stellate Cells Preferentially Induce Foxp3+ Regulatory T Cells by Production of Retinoic Acid

    PubMed Central

    Dunham, Richard M.; Thapa, Manoj; Velazquez, Victoria M.; Elrod, Elizabeth J.; Denning, Timothy L.; Pulendran, Bali

    2013-01-01

    The liver has long been described as immunosuppressive, although the mechanisms underlying this phenomenon are incompletely understood. Hepatic stellate cells (HSCs), a population of liver nonparenchymal cells, are potent producers of the regulatory T cell (Treg)–polarizing molecules TGF-β1 and all-trans retinoic acid, particularly during states of inflammation. HSCs are activated during hepatitis C virus infection and may therefore play a role in the enrichment of Tregs during infection. We hypothesized that Ag presentation in the context of HSC activation will induce naive T cells to differentiate into Foxp3+ Tregs. To test this hypothesis, we investigated the molecular interactions between murine HSCs, dendritic cells, and naive CD4+ T cells. We found that HSCs alone do not present Ag to naive CD4+ T cells, but in the presence of dendritic cells and TGF-β1, preferentially induce functional Tregs. This Treg induction was associated with retinoid metabolism by HSCs and was dependent on all-trans retinoic acid. Thus, we conclude that HSCs preferentially generate Foxp3+ Tregs and, therefore, may play a role in the tolerogenic nature of the liver. PMID:23359509

  14. Postnatal paucity of regulatory T cells and control of NK cell activation in experimental biliary atresia

    PubMed Central

    Miethke, Alexander G.; Saxena, Vijay; Shivakumar, Pranavkumar; Sabla, Gregg E.; Simmons, Julia; Chougnet, Claire A.

    2010-01-01

    Background & Aims Although recent studies have identified important roles for T and NK cells in the pathogenesis of biliary atresia (BA), the mechanisms by which susceptibility to bile duct injury is restricted to the neonatal period are unknown. Methods We characterised hepatic regulatory T cells (Tregs) by flow cytometry in two groups of neonatal mice challenged with rhesus rotavirus (RRV) at day 7 (no ductal injury) or day 1 of life (resulting in BA), determined the functional interaction with effector cells in co-culture assays, and examined the effect of adoptive transfer of CD4+ cells on the BA phenotype. Results While day 7 RRV infection increased hepatic Tregs (Foxp3+ CD4+ CD25+) by 10-fold within 3 days, no increase in Tregs occurred at this time point following infection on day 1. In vitro, Tregs effectively suppressed NK cell activation by hepatic dendritic cells and decreased the production of pro-inflammatory cytokines, including TNFα and IL-15, following RRV infection. In vivo, adoptive transfer of CD4+ cells prior to RRV inoculation led to increased survival, improved weight gain, decreased population of hepatic NK cells, and persistence of donor Tregs in the liver. Conclusions 1) The liver is devoid of Tregs early after perinatal RRV infection; 2) Tregs suppress DC-dependent activation of naive NK cells in vitro, and Treg-containing CD4+ cells inhibit hepatic NK cell expansion in vivo. Thus, the postnatal absence of Tregs may be a key factor that allows hepatic DCs to act unopposed in NK cell activation during the initiation of neonatal bile duct injury. PMID:20347178

  15. Multiple sclerosis associated genetic variants of CD226 impair regulatory T cell function.

    PubMed

    Piédavent-Salomon, Melanie; Willing, Anne; Engler, Jan Broder; Steinbach, Karin; Bauer, Simone; Eggert, Britta; Ufer, Friederike; Kursawe, Nina; Wehrmann, Sabine; Jäger, Jan; Reinhardt, Stefanie; Friese, Manuel A

    2015-11-01

    Recent association studies have linked numerous genetic variants with an increased risk for multiple sclerosis, although their functional relevance remains largely unknown. Here we investigated phenotypical and functional consequences of a genetic variant in the CD226 gene that, among other autoimmune diseases, predisposes to multiple sclerosis. Phenotypically, effector and regulatory CD4(+) memory T cells of healthy individuals carrying the predisposing CD226 genetic variant showed, in comparison to carriers of the protective variant, reduced surface expression of CD226 and an impaired induction of CD226 after stimulation. This haplotype-dependent reduction in CD226 expression on memory T cells was abrogated in patients with multiple sclerosis, as CD226 expression was comparable to healthy risk haplotype carriers irrespective of genetic variant. Functionally, FOXP3-positive regulatory T cells from healthy carriers of the genetic protective variant showed superior suppressive capacity, which was again abrogated in multiple sclerosis patients. Mimicking the phenotype of human CD226 genetic risk variant carriers, regulatory T cells derived from Cd226-deficient mice showed similarly reduced inhibitory activity, eventually resulting in an exacerbated disease course of experimental autoimmune encephalomyelitis, the animal model of multiple sclerosis. Therefore, by combining human and mouse analyses we show that CD226 exhibits an important role in the activation of regulatory T cells, with its genetically imposed dysregulation impairing regulatory T cell function.

  16. Daily subcutaneous injections of peptide induce CD4+ CD25+ T regulatory cells

    PubMed Central

    Dahlberg, P E; Schartner, J M; Timmel, A; Seroogy, C M

    2007-01-01

    Peptide immunotherapy is being explored to modulate varied disease states; however, the mechanism of action remains poorly understood. In this study, we investigated the ability of a subcutaneous peptide immunization schedule to induce of CD4+ CD25+ T regulatory cells. DO11·10 T cell receptor (TCR) transgenic mice on a Rag 2–/– background were injected subcutaneously with varied doses of purified ovalbumin (OVA323−339) peptide daily for 16 days. While these mice have no CD4+ CD25+ T regulatory cells, following this injection schedule up to 30% of the CD4+ cells were found to express CD25. Real-time quantitative polymerase chain reaction (QPCR) analysis of the induced CD4+ CD25+ T cells revealed increased expression of forkhead box P3 (FoxP3), suggesting that these cells may have a regulatory function. Proliferation and suppression assays in vitro utilizing the induced CD4+ CD25+ T cells revealed a profound anergic phenotype in addition to potent suppressive capability. Importantly, co-injection of the induced CD4+ CD25+ T cells with 5,6-carboxy-succinimidyl-fluorescence-ester (CFSE)-labelled naive CD4+ T cells (responder cells) into BALB/c recipient mice reduced proliferation and differentiation of the responder cells in response to challenge with OVA323−339 peptide plus adjuvant. We conclude that repeated subcutaneous exposure to low-dose peptide leads to de novo induction of CD4+ CD25+ FoxP3+ T regulatory cells with potent in vitro and in vivo suppressive capability, thereby suggesting that one mechanism of peptide immunotherapy appears to be induction of CD4+ CD25+ Foxp3+ T regulatory cells. PMID:17490400

  17. Daily subcutaneous injections of peptide induce CD4+ CD25+ T regulatory cells.

    PubMed

    Dahlberg, P E; Schartner, J M; Timmel, A; Seroogy, C M

    2007-08-01

    Peptide immunotherapy is being explored to modulate varied disease states; however, the mechanism of action remains poorly understood. In this study, we investigated the ability of a subcutaneous peptide immunization schedule to induce of CD4(+) CD25(+) T regulatory cells. DO11.10 T cell receptor (TCR) transgenic mice on a Rag 2(-/-) background were injected subcutaneously with varied doses of purified ovalbumin (OVA(323-339)) peptide daily for 16 days. While these mice have no CD4(+) CD25(+) T regulatory cells, following this injection schedule up to 30% of the CD4(+) cells were found to express CD25. Real-time quantitative polymerase chain reaction (QPCR) analysis of the induced CD4(+) CD25(+) T cells revealed increased expression of forkhead box P3 (FoxP3), suggesting that these cells may have a regulatory function. Proliferation and suppression assays in vitro utilizing the induced CD4(+) CD25(+) T cells revealed a profound anergic phenotype in addition to potent suppressive capability. Importantly, co-injection of the induced CD4(+) CD25(+) T cells with 5,6-carboxy-succinimidyl-fluorescence-ester (CFSE)-labelled naive CD4(+) T cells (responder cells) into BALB/c recipient mice reduced proliferation and differentiation of the responder cells in response to challenge with OVA(323-339) peptide plus adjuvant. We conclude that repeated subcutaneous exposure to low-dose peptide leads to de novo induction of CD4(+) CD25(+) FoxP3(+) T regulatory cells with potent in vitro and in vivo suppressive capability, thereby suggesting that one mechanism of peptide immunotherapy appears to be induction of CD4(+) CD25(+) Foxp3(+) T regulatory cells.

  18. T cell receptor repertoires after adoptive transfer of expanded allogeneic regulatory T cells.

    PubMed

    Theil, A; Wilhelm, C; Kuhn, M; Petzold, A; Tuve, S; Oelschlägel, U; Dahl, A; Bornhäuser, M; Bonifacio, E; Eugster, A

    2017-02-01

    Regulatory T cell (Treg ) therapy has been exploited in autoimmune disease, solid organ transplantation and in efforts to prevent or treat graft-versus-host disease (GVHD). However, our knowledge on the in-vivo persistence of transfused Treg is limited. Whether Treg transfusion leads to notable changes in the overall Treg repertoire or whether longevity of Treg in the periphery is restricted to certain clones is unknown. Here we use T cell receptor alpha chain sequencing (TCR-α-NGS) to monitor changes in the repertoire of Treg upon polyclonal expansion and after subsequent adoptive transfer. We applied TCR-α-NGS to samples from two patients with chronic GVHD who received comparable doses of stem cell donor derived expanded Treg . We found that in-vitro polyclonal expansion led to notable repertoire changes in vitro and that Treg cell therapy altered the peripheral Treg repertoire considerably towards that of the infused cell product, to different degrees, in each patient. Clonal changes in the peripheral blood were transient and correlated well with the clinical parameters. We suggest that T cell clonotype analyses using TCR sequencing should be considered as a means to monitor longevity and fate of adoptively transferred T cells.

  19. Type 1 regulatory T cells: a new mechanism of peripheral immune tolerance.

    PubMed

    Zeng, Hanyu; Zhang, Rong; Jin, Boquan; Chen, Lihua

    2015-09-01

    The lack of immune response to an antigen, a process known as immune tolerance, is essential for the preservation of immune homeostasis. To date, two mechanisms that drive immune tolerance have been described extensively: central tolerance and peripheral tolerance. Under the new nomenclature, thymus-derived regulatory T (tT(reg)) cells are the major mediators of central immune tolerance, whereas peripherally derived regulatory T (pT(reg)) cells function to regulate peripheral immune tolerance. A third type of T(reg) cells, termed iT(reg), represents only the in vitro-induced T(reg) cells(1). Depending on whether the cells stably express Foxp3, pT(reg), and iT(reg) cells may be divided into two subsets: the classical CD4(+)Foxp3(+) T(reg) cells and the CD4(+)Foxp3(-) type 1 regulatory T (Tr1) cells(2). This review focuses on the discovery, associated biomarkers, regulatory functions, methods of induction, association with disease, and clinical trials of Tr1 cells.

  20. Regulatory T cell effects in antitumor laser immunotherapy: a mathematical model and analysis

    NASA Astrophysics Data System (ADS)

    Dawkins, Bryan A.; Laverty, Sean M.

    2016-03-01

    Regulatory T cells (Tregs) have tremendous influence on treatment outcomes in patients receiving immunotherapy for cancerous tumors. We present a mathematical model incorporating the primary cellular and molecular components of antitumor laser immunotherapy. We explicitly model developmental classes of dendritic cells (DCs), cytotoxic T cells (CTLs), primary and metastatic tumor cells, and tumor antigen. Regulatory T cells have been shown to kill antigen presenting cells, to influence dendritic cell maturation and migration, to kill activated killer CTLs in the tumor microenvironment, and to influence CTL proliferation. Since Tregs affect explicitly modeled cells, but we do not explicitly model dynamics of Treg themselves, we use model parameters to analyze effects of Treg immunosuppressive activity. We will outline a systematic method for assigning clinical outcomes to model simulations and use this condition to associate simulated patient treatment outcome with Treg activity.

  1. Characterization of peripheral regulatory CD4+ T cells that prevent diabetes onset in nonobese diabetic mice.

    PubMed

    Lepault, F; Gagnerault, M C

    2000-01-01

    The period that precedes onset of insulin-dependent diabetes mellitus corresponds to an active dynamic state in which pathogenic autoreactive T cells are kept from destroying beta cells by regulatory T cells. In prediabetic nonobese diabetic (NOD) mice, CD4+ splenocytes were shown to prevent diabetes transfer in immunodeficient NOD recipients. We now demonstrate that regulatory splenocytes belong to the CD4+ CD62Lhigh T cell subset that comprises a vast majority of naive cells producing low levels of IL-2 and IFN-gamma and no IL-4 and IL-10 upon in vitro stimulation. Consistently, the inhibition of diabetes transfer was not mediated by IL-4 and IL-10. Regulatory cells homed to the pancreas and modified the migration of diabetogenic to the islets, which resulted in a decreased insulitis severity. The efficiency of CD62L+ T cells was dose dependent, independent of sex and disease prevalence. Protection mechanisms did not involve the CD62L molecule, an observation that may relate to the fact that CD4+ CD62Lhigh lymph node cells were less potent than their splenic counterparts. Regulatory T cells were detectable after weaning and persist until disease onset, sustaining the notion that diabetes is a late and abrupt event. Thus, the CD62L molecule appears as a unique marker that can discriminate diabetogenic (previously shown to be CD62L-) from regulatory T cells. The phenotypic and functional characteristics of protective CD4+ CD62L+ cells suggest they are different from Th2-, Tr1-, and NK T-type cells, reported to be implicated in the control of diabetes in NOD mice, and may represent a new immunoregulatory population.

  2. Affinity for self antigen selects regulatory T cells with distinct functional properties

    PubMed Central

    Wyss, Lena; Stadinski, Brian D.; King, Carolyn G.; Schallenberg, Sonja; McCarthy, Nicholas I.; Lee, Jun Young; Kretschmer, Karsten; Terracciano, Luigi M.; Anderson, Graham; Surh, Charles D.; Huseby, Eric S.; Palmer, Ed

    2016-01-01

    How regulatory T cells (Treg cell) control lymphocyte homeostasis is not fully understood. Here we identify two Treg cell populations with differing degrees of self-reactivity and distinct regulatory functions. Triplehi (GITRhiPD-1hiCD25hi) Treg cell are highly self-reactive and control lympho-proliferation in peripheral lymph nodes. Triplelo (GITRloPD-1loCD25lo) Treg cells are less self-reactive and limit development of colitis by promoting conversion of CD4+ Tconv cells into induced Treg cells (iTreg cells). Although Foxp3-deficient (scurfy) mice lack Treg cells, they contain Triplehi-like and Triplelo-like CD4+ T cells with distinct pathological properties. Scurfy TriplehiCD4+T cells infiltrate the skin whereas scurfy TripleloCD4+T cells induce colitis and wasting disease. These findings indicate that T cell receptor affinity for self-antigens drives the differentiation of Tregs into distinct subsets with non-overlapping regulatory activities. PMID:27478940

  3. Cell-type specific cis-regulatory networks: insights from Hox transcription factors.

    PubMed

    Polychronidou, Maria; Lohmann, Ingrid

    2013-01-01

    Hox proteins are a prominent class of transcription factors that specify cell and tissue identities in animal embryos. In sharp contrast to tissue-specifically expressed transcription factors, which coordinate regulatory pathways leading to the differentiation of a selected tissue, Hox proteins are active in many different cell types but are nonetheless able to differentially regulate gene expression in a context-dependent manner. This particular feature makes Hox proteins ideal candidates for elucidating the mechanisms employed by transcription factors to achieve tissue-specific functions in multi-cellular organisms. Here we discuss how the recent genome-wide identification and characterization of Hox cis-regulatory elements has provided insight concerning the molecular mechanisms underlying the high spatiotemporal specificity of Hox proteins. In particular, it was shown that Hox transcriptional outputs depend on the cell-type specific interplay of the different Hox proteins with co-regulatory factors as well as with epigenetic modifiers. Based on these observations it becomes clear that cell-type specific approaches are required for dissecting the tissue-specific Hox regulatory code. Identification and comparative analysis of Hox cis-regulatory elements driving target gene expression in different cell types in combination with analyses on how cofactors, epigenetic modifiers and protein-protein interactions mediate context-dependent Hox function will elucidate the mechanistic basis of tissue-specific gene regulation.

  4. Loss of B cell regulatory function is associated with delayed healing in patients with tibia fracture.

    PubMed

    Yang, Shufeng; Ding, Wei; Feng, Dapeng; Gong, Haiyang; Zhu, Dongmei; Chen, Bin; Chen, Jianmin

    2015-11-01

    The process of bone regeneration after fracture is a complex and well-orchestrated process usually requiring 3-12 weeks. A subset of patients, however, exhibit delayed healing time and even incomplete restoration of the normal bone structure. Although the precise mechanism is unknown, studies have shown that smurf1 may play a role during the process. Here, we sought to determine the involvement of the immune system in impaired bone healing. We found that immediately after fracture, the B-cell composition was shifted toward increased frequency of plasmablasts and decreased frequency of naïve B cells, reflecting higher inflammatory status. The percentage of CD19(+) CD24(+) CD38(+) regulatory B cells was also upregulated in response to bone fracture. The production of IL-10, a pivotal cytokine in regulatory B-cell function, was upregulated in all patients. Interestingly, the increase in IL-10 production was only sustained throughout the healing course in normal healing patients but not in delayed healing patients. Rather, delayed healing patients downregulated B-cell IL-10 secretion early and had reduced level of regulatory B-cell activity. Together, these data revealed a role of regulatory B cells in the endogenous bone regeneration process and an alternation in B-cell-mediated regulation in delayed healing patients.

  5. A Transcriptional Regulatory Switch Underlying B-Cell Terminal Differentiation and its Disruption by Dioxin

    EPA Science Inventory

    The terminal differentiation of B lymphocytes into antibody-secreting plasma cells upon antigen stimulation is a crucial step in the humoral immune response. The mutually-repressive interactions among three key regulatory transcription factors underlying B to plasma cell differe...

  6. Comparison of circulating and intratumoral regulatory T cells in patients with renal cell carcinoma.

    PubMed

    Asma, Gati; Amal, Gorrab; Raja, Marrakchi; Amine, Derouiche; Mohammed, Chebil; Amel, Ben Ammar Elgaaied

    2015-05-01

    The clear evidence that tumor-infiltrating lymphocytes (TIL) exists in the tumor microenvironment raises the question why renal cell carcinoma (RCC) progresses. Numerous studies support the implication of CD4(+)CD25(high) regulatory T (Treg) cells in RCC development. We aimed in this study to characterize the phenotype and function of circulating and intratumoral Treg cells of RCC patient in order to evaluate their implication in the inhibition of the local antitumor immune response. Our results demonstrate that the proportion of Treg in TIL was, in average, similar to that found in circulating CD4(+) T cells of patients or healthy donors. However, intratumoral Treg exhibit a marked different phenotype when compared with the autologous circulating Treg. A higher CD25 mean level, HLA-DR, Fas, and GITR, and a lower CD45RA expression were observed in intratumoral Treg, suggesting therefore that these cells are effector in the tumor microenvironment. Additionally, intratumoral Treg showed a higher inhibitory function on autologous CD4(+)CD25(-) T cells when compared with circulating Treg that may be explained by an overexpression of FoxP3 transcription factor. These findings suggest that intratumoral Treg could be major actors in the impairment of local antitumor immune response for RCC patients.

  7. Breaking Free of Control: How Conventional T Cells Overcome Regulatory T Cell Suppression

    PubMed Central

    Mercadante, Emily R.; Lorenz, Ulrike M.

    2016-01-01

    Conventional T (Tcon) cells are crucial in shaping the immune response, whether it is protection against a pathogen, a cytotoxic attack on tumor cells, or an unwanted response to self-antigens in the context of autoimmunity. In each of these immune settings, regulatory T cells (Tregs) can potentially exert control over the Tcon cell response, resulting in either suppression or activation of the Tcon cells. Under physiological conditions, Tcon cells are able to transiently overcome Treg-imposed restraints to mount a protective response against an infectious threat, achieving clonal expansion, differentiation, and effector function. However, evidence has accumulated in recent years to suggest that Tcon cell resistance to Treg-mediated suppression centrally contributes to the pathogenesis of autoimmune disease. Tipping the balance too far in the other direction, cancerous tumors utilize Tregs to establish an overly suppressive microenvironment, preventing antitumor Tcon cell responses. Given the wide-ranging clinical importance of the Tcon/Treg interaction, this review aims to provide a better understanding of what determines whether a Tcon cell is susceptible to Treg-mediated suppression and how perturbations to this finely tuned balance play a role in pathological conditions. Here, we focus in detail on the complex array of factors that confer Tcon cells with resistance to Treg suppression, which we have divided into two categories: (1) extracellular factor-mediated signaling and (2) intracellular signaling molecules. Further, we explore the therapeutic implications of manipulating the phosphatidylinositol-3 kinase (PI3K)/Akt signaling pathway, which is proposed to be the convergence point of signaling pathways that mediate Tcon resistance to suppression. Finally, we address important unresolved questions on the timing and location of acquisition of resistance, and the stability of the “Treg-resistant” phenotype. PMID:27242798

  8. Regulatory B cells present in lymph nodes draining a murine tumor.

    PubMed

    Maglioco, Andrea; Machuca, Damián G; Camerano, Gabriela; Costa, Héctor A; Ruggiero, Raúl; Dran, Graciela I

    2014-01-01

    In cancer, B cells have been classically associated with antibody secretion, antigen presentation and T cell activation. However, a possible role for B lymphocytes in impairing antitumor response and collaborating with tumor growth has been brought into focus. Recent reports have described the capacity of B cells to negatively affect immune responses in autoimmune diseases. The highly immunogenic mouse tumor MCC loses its immunogenicity and induces systemic immune suppression and tolerance as it grows. We have previously demonstrated that MCC growth induces a distinct and progressive increase in B cell number and proportion in the tumor draining lymph nodes (TDLN), as well as a less prominent increase in T regulatory cells. The aim of this research was to study B cell characteristics and function in the lymph node draining MCC tumor and to analyze whether these cells may be playing a role in suppressing antitumor response and favoring tumor progression. Results indicate that B cells from TDLN expressed increased CD86 and MHCII co-stimulatory molecules indicating activated phenotype, as well as intracellular IL-10, FASL and Granzyme B, molecules with regulatory immunosuppressive properties. Additionally, B cells showed high inhibitory upon T cell proliferation ex vivo, and a mild capacity to secrete antibodies. Our conclusion is that even when evidence of B cell-mediated activity of the immune response is present, B cells from TDLN exhibit regulatory phenotype and inhibitory activity, probably contributing to the state of immunological tolerance characteristic of the advanced tumor condition.

  9. Regulatory B cells preferentially accumulate in tumor-draining lymph nodes and promote tumor growth.

    PubMed

    Ganti, Sheila N; Albershardt, Tina C; Iritani, Brian M; Ruddell, Alanna

    2015-07-20

    Our previous studies found that B16-F10 melanoma growth in the rear footpad of immunocompetent mice induces marked B cell accumulation within tumor-draining popliteal lymph nodes (TDLN). This B cell accumulation drives TDLN remodeling that precedes and promotes metastasis, indicating a tumor-promoting role for TDLN B cells. Here we show that phenotypic characterization of lymphocytes in mice bearing B16-F10 melanomas identifies preferential accumulation of T2-MZP B cells in the TDLN. Comparison of non-draining LNs and spleens of tumor-bearing mice with LNs and spleens from naïve mice determined that this pattern of B cell accumulation was restricted to the TDLN. B cell-deficient and immunocompetent mice reconstituted with T2-MZP B cells but not with other B cell subsets displayed accelerated tumor growth, demonstrating that T2-MZP B cells possess regulatory activity in tumor-bearing mice. Unlike splenic regulatory B cells, however, these TDLN B cells did not exhibit increased IL-10 production, nor did they promote Treg generation in the TDLN. These findings demonstrate that tumors initially signal via the lymphatic drainage to stimulate the preferential accumulation of T2-MZP regulatory B cells. This local response may be an early and critical step in generating an immunosuppressive environment to permit tumor growth and metastasis.

  10. LL-37 Recruits Immunosuppressive Regulatory T Cells to Ovarian Tumors

    DTIC Science & Technology

    2009-11-01

    pro-angiogenic factors, such as MMP-2, IL-6, and VEGF—could increase endothelial cell tubule formation in vitro. Serum-starved human umbilical vein...treated MSC was added to human umbilical vein endothelial cells (HUVECs) then seeded onto Matrigel. Fluorescently labeled cells were monitored were for...tested whether conditioned medium from LL-37-treated MSCs could increase endothelial cell tubule formation in vitro. Serum-starved human umbilical vein

  11. An arabidopsis gene regulatory network for secondary cell wall synthesis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The plant cell wall is an important factor for determining cell shape, function and response to the environment. Secondary cell walls, such as those found in xylem, are composed of cellulose, hemicelluloses and lignin and account for the bulk of plant biomass. The coordination between transcriptiona...

  12. Regulatory System for Stem/Progenitor Cell Niches in the Adult Rodent Pituitary

    PubMed Central

    Yoshida, Saishu; Kato, Takako; Kato, Yukio

    2016-01-01

    The anterior lobe of the pituitary gland is a master endocrine tissue composed of five types of endocrine cells. Although the turnover rate of pituitary endocrine cells is as low as about 1.6% per day, recent studies have demonstrated that Sex-determining region Y-box 2 (SOX2)+-cells exist as pituitary stem/progenitor cells in the adult anterior lobe and contribute to cell regeneration. Notably, SOX2+-pituitary stem/progenitor cells form two types of niches in this tissue: the marginal cell layer (MCL-niche) and the dense cell clusters scattering in the parenchyma (parenchymal-niche). However, little is known about the mechanisms and factors for regulating the pituitary stem/progenitor cell niches, as well as the functional differences between the two types of niches. Elucidation of the regulatory mechanisms in the niches might enable us to understand the cell regeneration system that acts in accordance with physiological demands in the adult pituitary. In this review, so as to reveal the regulatory mechanisms of the two types of niche, we summarize the regulatory factors and their roles in the adult rodent pituitary niches by focusing on three components: soluble factors, cell surface proteins and extracellular matrixes. PMID:26761002

  13. What are the molecules involved in regulatory T-cells induction by dendritic cells in cancer?

    PubMed

    Ramos, Rodrigo Nalio; de Moraes, Cristiano Jacob; Zelante, Bruna; Barbuto, José Alexandre M

    2013-01-01

    Dendritic cells (DCs) are essential for the maintenance of homeostasis in the organism, and they do that by modulating lymphocyte priming, expansion, and response patterns according to signals they receive from the environment. The induction of suppressive lymphocytes by DCs is essential to hinder the development of autoimmune diseases but can be reverted against homeostasis when in the context of neoplasia. In this setting, the induction of suppressive or regulatory T cells contributes to the establishment of a state of tolerance towards the tumor, allowing it to grow unchecked by an otherwise functional immune system. Besides affecting its local environment, tumor also has been described as potent sources of anti-inflammatory/suppressive factors, which may act systemically, generating defects in the differentiation and maturation of immune cells, far beyond the immediate vicinity of the tumor mass. Cytokines, as IL-10 and TGF-beta, as well as cell surface molecules like PD-L1 and ICOS seem to be significantly involved in the redirection of DCs towards tolerance induction, and recent data suggest that tumor cells may, indeed, modulate distinct DCs subpopulations through the involvement of these molecules. It is to be expected that the identification of such molecules should provide molecular targets for more effective immunotherapeutic approaches to cancer.

  14. Immunosuppressive Environment in Basal Cell Carcinoma: The Role of Regulatory T Cells.

    PubMed

    Omland, Silje H; Nielsen, Patricia S; Gjerdrum, Lise M R; Gniadecki, Robert

    2016-11-02

    Interaction between tumour survival tactics and anti-tumour immune response is a major determinant for cancer growth. Regulatory T cells (T-regs) contribute to tumour immune escape, but their role in basal cell carcinoma (BCC) is not understood. The fraction of T-regs among T cells was analysed by immunohistochemistry followed by automated image analysis in facial BCC, peritumoural skin and normal, buttock skin. Quantitative real-time PCR (qRT-PCR) was performed for FOXP3 and cytokines involved in T-reg attraction and T-cell activation. T-regs comprised 45% of CD4-cells surrounding BCC. FOXP3 was highly expressed in BCC, but absent in buttock skin. Unexpectedly, expression of FOXP3 was increased in peritumoural skin, with the FOXP3/CD3 fractions exceeding those of BCC (p?=?0.0065). Transforming growth factor (TGF)-? and T-reg chemokine expression was increased in BCC and peritumoural skin, but not in buttock skin, with expression levels correlating with FOXP3. T-regs are abundantly present both in BCC and in peritumoural skin, mediating an immunosuppressed microenvironment permissive for skin cancer.

  15. Regulatory Oversight of Gene Therapy and Cell Therapy Products in Korea.

    PubMed

    Choi, Minjoung; Han, Euiri; Lee, Sunmi; Kim, Taegyun; Shin, Won

    2015-01-01

    The Ministry of Food and Drug Safety regulates gene therapy and cell therapy products as biological products under the authority of the Pharmaceutical Affairs Act. As with other medicinal products, gene therapy and cell therapy products are subject to approval for use in clinical trials and for a subsequent marketing authorization and to post-market surveillance. Research and development of gene therapy and cell therapy products have been progressing rapidly in Korea with extensive investment, offering great potential for the treatment of various serious diseases. To facilitate development of safe and effective products and provide more opportunities to patients suffering from severe diseases, several regulatory programs, such as the use of investigational products for emergency situations, fast-track approval, prereview of application packages, and intensive regulatory consultation, can be applied to these products. The regulatory approach for these innovative products is case by case and founded on science-based review that is flexible and balances the risks and benefits.

  16. Thymic Versus Induced Regulatory T Cells – Who Regulates the Regulators?

    PubMed Central

    Povoleri, Giovanni Antonio Maria; Scottà, Cristiano; Nova-Lamperti, Estefania Andrea; John, Susan; Lombardi, Giovanna; Afzali, Behdad

    2013-01-01

    Physiological health must balance immunological responsiveness against foreign pathogens with tolerance toward self-components and commensals. Disruption of this balance causes autoimmune diseases/chronic inflammation, in case of excessive immune responses, and persistent infection/immunodeficiency if regulatory components are overactive. This homeostasis occurs at two different levels: at a resting state to prevent autoimmune disease, as autoreactive effector T-cells (Teffs) are only partially deleted in the thymus, and during inflammation to prevent excessive tissue injury, contract the immune response, and enable tissue repair. Adaptive immune cells with regulatory function (“regulatory T-cells”) are essential to control Teffs. Two sets of regulatory T cell are required to achieve the desired control: those emerging de novo from embryonic/neonatal thymus (“thymic” or tTregs), whose function is to control autoreactive Teffs to prevent autoimmune diseases, and those induced in the periphery (“peripheral” or pTregs) to acquire regulatory phenotype in response to pathogens/inflammation. The differentiation mechanisms of these cells determine their commitment to lineage and plasticity toward other phenotypes. tTregs, expressing high levels of IL-2 receptor alpha chain (CD25), and the transcription factor Foxp3, are the most important, since mutations or deletions in these genes cause fatal autoimmune diseases in both mice and men. In the periphery, instead, Foxp3+ pTregs can be induced from naïve precursors in response to environmental signals. Here, we discuss molecular signatures and induction processes, mechanisms and sites of action, lineage stability, and differentiating characteristics of both Foxp3+ and Foxp3− populations of regulatory T cells, derived from the thymus or induced peripherally. We relate these predicates to programs of cell-based therapy for the treatment of autoimmune diseases and induction of tolerance to transplants. PMID

  17. Enhanced suppressor function of TIM-3+ FoxP3+ regulatory T cells.

    PubMed

    Gautron, Anne-Sophie; Dominguez-Villar, Margarita; de Marcken, Marine; Hafler, David A

    2014-09-01

    T-cell immunoglobulin and mucin domain 3 (TIM-3) is an Ig-superfamily member expressed on IFN-γ-secreting Th1 and Tc1 cells and was identified as a negative regulator of immune tolerance. TIM-3 is expressed by a subset of activated CD4(+) T cells, and anti-CD3/anti-CD28 stimulation increases both the level of expression and the number of TIM-3(+) T cells. In mice, TIM-3 is constitutively expressed on natural regulatory T (Treg) cells and has been identified as a regulatory molecule of alloimmunity through its ability to modulate CD4(+) T-cell differentiation. Here, we examined TIM-3 expression on human Treg cells to determine its role in T-cell suppression. In contrast to mice, TIM-3 is not expressed on Treg cells ex vivo but is upregulated after activation. While TIM-3(+) Treg cells with increased gene expression of LAG3, CTLA4, and FOXP3 are highly efficient suppressors of effector T (Teff) cells, TIM-3(-) Treg cells poorly suppressed Th17 cells as compared with their suppression of Th1 cells; this decreased suppression ability was associated with decreased STAT-3 expression and phosphorylation and reduced gene expression of IL10, EBI3, GZMB, PRF1, IL1Rα, and CCR6. Thus, our results suggest that TIM-3 expression on Treg cells identifies a population highly effective in inhibiting pathogenic Th1- and Th17-cell responses.

  18. Fingolimod Increases CD39-Expressing Regulatory T Cells in Multiple Sclerosis Patients

    PubMed Central

    Muls, Nathalie; Dang, Hong Anh; Sindic, Christian J. M.; van Pesch, Vincent

    2014-01-01

    Background Multiple sclerosis (MS) likely results from an imbalance between regulatory and inflammatory immune processes. CD39 is an ectoenzyme that cleaves ATP to AMP and has been suggested as a novel regulatory T cells (Treg) marker. As ATP has numerous proinflammatory effects, its degradation by CD39 has anti-inflammatory influence. The purpose of this study was to explore regulatory and inflammatory mechanisms activated in fingolimod treated MS patients. Methods and Findings Peripheral blood mononuclear cells (PBMCs) were isolated from relapsing-remitting MS patients before starting fingolimod and three months after therapy start. mRNA expression was assessed in ex vivo PBMCs. The proportions of CD8, B cells, CD4 and CD39-expressing cells were analysed by flow cytometry. Treg proportion was quantified by flow cytometry and methylation-specific qPCR. Fingolimod treatment increased mRNA levels of CD39, AHR and CYP1B1 but decreased mRNA expression of IL-17, IL-22 and FOXP3 mRNA in PBMCs. B cells, CD4+ cells and Treg proportions were significantly reduced by this treatment, but remaining CD4+ T cells were enriched in FOXP3+ cells and in CD39-expressing Tregs. Conclusions In addition to the decrease in circulating CD4+ T cells and CD19+ B cells, our findings highlight additional immunoregulatory mechanisms induced by fingolimod. PMID:25411844

  19. Regulatory Roles of Fluctuation-Driven Mechanotransduction in Cell Function.

    PubMed

    Suki, Béla; Parameswaran, Harikrishnan; Imsirovic, Jasmin; Bartolák-Suki, Erzsébet

    2016-09-01

    Cells in the body are exposed to irregular mechanical stimuli. Here, we review the so-called fluctuation-driven mechanotransduction in which stresses stretching cells vary on a cycle-by-cycle basis. We argue that such mechanotransduction is an emergent network phenomenon and offer several potential mechanisms of how it regulates cell function. Several examples from the vasculature, the lung, and tissue engineering are discussed. We conclude with a list of important open questions.

  20. Identification of Regulatory Factors for Mesenchymal Stem Cell-Derived Salivary Epithelial Cells in a Co-Culture System

    PubMed Central

    Park, Yun-Jong; Koh, Jin; Gauna, Adrienne E.; Chen, Sixue; Cha, Seunghee

    2014-01-01

    Patients with Sjögren’s syndrome or head and neck cancer patients who have undergone radiation therapy suffer from severe dry mouth (xerostomia) due to salivary exocrine cell death. Regeneration of the salivary glands requires a better understanding of regulatory mechanisms by which stem cells differentiate into exocrine cells. In our study, bone marrow-derived mesenchymal stem cells were co-cultured with primary salivary epithelial cells from C57BL/6 mice. Co-cultured bone marrow-derived mesenchymal stem cells clearly resembled salivary epithelial cells, as confirmed by strong expression of salivary gland epithelial cell-specific markers, such as alpha-amylase, muscarinic type 3 receptor, aquaporin-5, and cytokeratin 19. To identify regulatory factors involved in this differentiation, transdifferentiated mesenchymal stem cells were analyzed temporarily by two-dimensional-gel-electrophoresis, which detected 58 protein spots (>1.5 fold change, p<0.05) that were further categorized into 12 temporal expression patterns. Of those proteins only induced in differentiated mesenchymal stem cells, ankryin-repeat-domain-containing-protein 56, high-mobility-group-protein 20B, and transcription factor E2a were selected as putative regulatory factors for mesenchymal stem cell transdifferentiation based on putative roles in salivary gland development. Induction of these molecules was confirmed by RT-PCR and western blotting on separate sets of co-cultured mesenchymal stem cells. In conclusion, our study is the first to identify differentially expressed proteins that are implicated in mesenchymal stem cell differentiation into salivary gland epithelial cells. Further investigation to elucidate regulatory roles of these three transcription factors in mesenchymal stem cell reprogramming will provide a critical foundation for a novel cell-based regenerative therapy for patients with xerostomia. PMID:25402494

  1. Complex regulatory pathways coordinate cell cycle progression and development in Caulobacter crescentus

    PubMed Central

    Brown, Pamela J.B.; Hardy, Gail G.; Trimble, Michael J.; Brun, Yves V.

    2008-01-01

    Caulobacter crescentus has become the predominant bacterial model system to study the regulation of cell cycle progression. Stage specific processes such as chromosome replication and segregation, and cell division are coordinated with the development of four polar structures: the flagellum, pili, stalk, and holdfast. The production, activation, localization, and proteolysis of specific regulatory proteins at precise times during the cell cycle culminate in the ability of the cell to produce two physiologically distinct daughter cells. We examine the recent advances that have enhanced our understanding of the mechanisms of temporal and spatial regulation that occur during cell cycle progression. PMID:18929067

  2. NK Cell and CD4+FoxP3+ Regulatory T Cell Based Therapies for Hematopoietic Stem Cell Engraftment

    PubMed Central

    Pierini, Antonio; Alvarez, Maite; Negrin, Robert S.

    2016-01-01

    Allogeneic hematopoietic cell transplantation (HCT) is a powerful therapy to treat multiple hematological diseases. The intensive conditioning regimens used to allow for donor hematopoietic stem cell (HSC) engraftment are often associated with severe toxicity, delayed immune reconstitution, life-threatening infections, and thus higher relapse rates. Additionally, due to the high incidence of graft versus host disease (GvHD), HCT protocols have evolved to prevent such disease that has a detrimental impact on antitumor and antiviral responses. Here, we analyzed the role of host T and natural killer (NK) cells in the rejection of donor HSC engraftment as well as the impact of donor regulatory T cells (Treg) and NK cells on HSC engraftment. We review some of the current strategies that utilize NK or Treg to improve allogeneic HCT therapy in order to accomplish better HSC engraftment and immune reconstitution and achieve a lower incidence of cancer relapse, opportunistic infections, and GvHD. PMID:26880996

  3. Interleukin-35 Induces Regulatory B Cells that Suppress CNS Autoimmune Disease

    PubMed Central

    Wang, Ren-Xi; Yu, Cheng-Rong; Dambuza, Ivy M.; Mahdi, Rashid M.; Dolinska, Monika; Sergeey, Yuri V.; Wingfield, Paul T.; Kim, Sung-Hye; Egwuagu, Charles E.

    2014-01-01

    Interleukin 10-producing regulatory B-cells (Breg-cells) suppress autoimmune diseases while aberrant elevation of Breg-cells prevents sterilizing immunity, promotes carcinogenesis and cancer metastasis by converting resting CD4+ T-cells to regulatory T-cells (Tregs). It is therefore of interest to discover factors that induce Breg-cells. Here we show that IL-35 induces Breg-cells in-vivo and promotes their conversion to a unique Breg subset that produces IL-35 (IL-35+Breg). Treatment of mice with IL-35 conferred protection from uveitis and mice lacking IL-35 or defective in IL-35-signaling produced less Breg-cells and developed severe uveitis. Ex-vivo generated Breg-cells also suppressed uveitis by inhibiting pathogenic Th17/Th1 while promoting Tregs expansion. We further show that IL-35 induced the conversion of human B-cells into Breg-cells and suppressed uveitis by activating STAT1/STAT3 through IL-35-Receptor comprising IL-12Rβ2/IL-27Rα subunits. Discovery that IL-35 converts human B-cells into Breg-cells, allows ex-vivo production of autologous Breg-cells for immunotherapy and investigating Breg/IL-35+Breg cells roles in autoimmune diseases and cancer. PMID:24743305

  4. Zinc Induces Dendritic Cell Tolerogenic Phenotype and Skews Regulatory T Cell-Th17 Balance.

    PubMed

    George, Mariam Mathew; Subramanian Vignesh, Kavitha; Landero Figueroa, Julio A; Caruso, Joseph A; Deepe, George S

    2016-09-01

    Zinc (Zn) is an essential metal for development and maintenance of both the innate and adaptive compartments of the immune system. Zn homeostasis impacts maturation of dendritic cells (DCs) that are important in shaping T cell responses. The mechanisms by which Zn regulates the tolerogenic phenotype of DCs remain largely unknown. In this study, we investigated the effect of Zn on DC phenotype and the generation of Foxp3(+) regulatory T cells (Tregs) using a model of Histoplasma capsulatum fungal infection. Exposure of bone marrow-derived DCs to Zn in vitro induced a tolerogenic phenotype by diminishing surface MHC class II (MHCII) and promoting the tolerogenic markers, programmed death-ligand (PD-L)1, PD-L2, and the tryptophan degrading enzyme, IDO. Zn triggered tryptophan degradation by IDO and kynurenine production by DCs and strongly suppressed the proinflammatory response to stimulation by TLR ligands. In vivo, Zn supplementation and subsequent H. capsulatum infection supressed MHCII on DCs, enhanced PD-L1 and PD-L2 expression on MHCII(lo) DCs, and skewed the Treg-Th17 balance in favor of Foxp3(+) Tregs while decreasing Th17 cells. Thus, Zn shapes the tolerogenic potential of DCs in vitro and in vivo and promotes Tregs during fungal infection.

  5. Stem cell-derived tissue-associated regulatory T cells ameliorate the development of autoimmunity

    PubMed Central

    Haque, Mohammad; Song, Jianyong; Fino, Kristin; Sandhu, Praneet; Song, Xinmeng; Lei, Fengyang; Zheng, Songguo; Ni, Bing; Fang, Deyu; Song, Jianxun

    2016-01-01

    Pluripotent stem cells (PSCs) have the potential to produce almost all of the cells in the body, including regulatory T cells (Tregs). However, the exact conditions required for the development of antigen (Ag)-specific Tregs from PSCs (i.e., PSC-Tregs) are not well delineated. Ag-specific PSC-Tregs can be tissue/organ-associated and migrate to local inflamed tissues/organs to suppress the autoimmune response after adoptive transfer, thereby avoiding potential overall immunosuppression from non-specific Tregs. In this study, we developed a new approach to generate functional Ag-specific Tregs from induced PSCs (iPSCs), i.e., iPSC-Tregs, which had the ability to generate an Ag-specific immunosuppressive response in a murine model of arthritis. We retrovirally transduced murine iPSCs with a construct containing genes of Ag-specific T cell receptor (TCR) and the transcriptional factor FoxP3. We differentiated the iPSCs into Ag-specific iPSC-Tregs using in vitro or in vivo Notch signaling, and demonstrated that adoptive transfer of such Tregs dramatically suppressed autoimmunity in a well-established Ag-induced arthritis model, including the inflammation, joint destruction, cartilage prostaglandin depletion, osteoclast activity, and Th17 production. Our results indicate that PSCs can be used to develop Ag-specific Tregs, which have a therapeutic potential for Treg-based therapies of autoimmune disorders. PMID:26846186

  6. Immunomodulation of mesenchymal stromal cells on regulatory T cells and its possible mechanism.

    PubMed

    Yan, Zhidong; Zhuansun, Yongxun; Chen, Rui; Li, Jianguo; Ran, Pixin

    2014-05-15

    Mesenchymal stromal cells (MSCs) and regulatory T cells (Tregs) have both garnered abundant interests from immunologists worldwide, as both MSCs and Tregs can be considered immunosuppressive in their own right. But a little attention has been paid to the impacts of MSCs on Tregs. To clarify the effects of MSCs on Tregs, we performed the coculture systems within MSCs and Tregs. We confirmed that MSC-exposed Tregs are capable of more immunosuppressive than Tregs without coculturing with MSCs. And this augmenting suppressive capacity was accompanied with an upregulation of programmed cell death 1 receptor (PD-1) on Tregs. Importantly, we found that cell viability of Tregs was excluded from the influences of MSCs. Finally, we showed that PD-1/B7-H1 interactions and IL-10 might be responsible for the enhanced suppressive capability of MSC-exposed Tregs. Further analysis revealed that PD-1/B7-H1 interactions were not responsible for the productions of IL-10 and TGF-β1 in the MSC-Treg coculture systems; in contrast, IL-10 rather than TGF-β1 played a role in the upregualtion of PD-1. Furthermore, this is the first explorative study to evaluate the immunomodulation of MSCs on the suppressive capacity of Tregs in MSC-Treg in vitro coculture setting.

  7. Dendritic Cells in the Periphery Control Antigen-Specific Natural and Induced Regulatory T Cells

    PubMed Central

    Yamazaki, Sayuri; Morita, Akimichi

    2013-01-01

    Dendritic cells (DCs) are specialized antigen-presenting cells that regulate both immunity and tolerance. DCs in the periphery play a key role in expanding naturally occurring Foxp3+ CD25+ CD4+ regulatory T cells (Natural T-regs) and inducing Foxp3 expression (Induced T-regs) in Foxp3− CD4+ T cells. DCs are phenotypically and functionally heterogeneous, and further classified into several subsets depending on distinct marker expression and their location. Recent findings indicate the presence of specialized DC subsets that act to expand Natural T-regs or induce Foxp3+ T-regs from Foxp3− CD4+ T cells. For example, two major subsets of DCs in lymphoid organs act differentially in inducing Foxp3+ T-regs from Foxp3− cells or expanding Natural T-regs with model-antigen delivery by anti-DC subset monoclonal antibodies in vivo. Furthermore, DCs expressing CD103 in the intestine induce Foxp3+ T-regs from Foxp3− CD4+ T cells with endogenous TGF-β and retinoic acid. In addition, antigen-presenting DCs have a capacity to generate Foxp3+ T-regs in the oral cavity where many antigens and commensals exist, similar to intestine and skin. In skin and skin-draining lymph nodes, at least six DC subsets have been identified, suggesting a complex DC-T-reg network. Here, we will review the specific activity of DCs in expanding Natural T-regs and inducing Foxp3+ T-regs from Foxp3− precursors, and further discuss the critical function of DCs in maintaining tolerance at various locations including skin and oral cavity. PMID:23801989

  8. Subcellular localization of proteasomes and their regulatory complexes in mammalian cells.

    PubMed Central

    Brooks, P; Fuertes, G; Murray, R Z; Bose, S; Knecht, E; Rechsteiner, M C; Hendil, K B; Tanaka, K; Dyson, J; Rivett, J

    2000-01-01

    Proteasomes can exist in several different molecular forms in mammalian cells. The core 20S proteasome, containing the proteolytic sites, binds regulatory complexes at the ends of its cylindrical structure. Together with two 19S ATPase regulatory complexes it forms the 26S proteasome, which is involved in ubiquitin-dependent proteolysis. The 20S proteasome can also bind 11S regulatory complexes (REG, PA28) which play a role in antigen processing, as do the three variable gamma-interferon-inducible catalytic beta-subunits (e.g. LMP7). In the present study, we have investigated the subcellular distribution of the different forms of proteasomes using subunit specific antibodies. Both 20S proteasomes and their 19S regulatory complexes are found in nuclear, cytosolic and microsomal preparations isolated from rat liver. LMP7 was enriched approximately two-fold compared with core alpha-type proteasome subunits in the microsomal preparations. 20S proteasomes were more abundant than 26S proteasomes, both in liver and cultured cell lines. Interestingly, some significant differences were observed in the distribution of different subunits of the 19S regulatory complexes. S12, and to a lesser extent p45, were found to be relatively enriched in nuclear fractions from rat liver, and immunofluorescent labelling of cultured cells with anti-p45 antibodies showed stronger labelling in the nucleus than in the cytoplasm. The REG was found to be localized predominantly in the cytoplasm. Three- to six-fold increases in the level of REG were observed following gamma-interferon treatment of cultured cells but gamma-interferon had no obvious effect on its subcellular distribution. These results demonstrate that different regulatory complexes and subpopulations of proteasomes have different distributions within mammalian cells and, therefore, that the distribution is more complex than has been reported for yeast proteasomes. PMID:10657252

  9. [The Role of Regulatory T-cells in Antitumor Immune Response].

    PubMed

    Klabusay, M

    2015-01-01

    Regulatory T-lymphocytes (Treg) are essential for regulation of immune homeostasis and prevention of autoimmune disease development. Regulatory T-cells prevent the onset of autoimmune diseases; they keep immune homeostasis and modulate immune response during infection. Their activity is precisely controlled. Regulatory T-cells belong to one group of immune cells, which can support tumor survival and growth. They realize their function through inhibition of effector T-cells and by regulation of tumor microenvironment through production of various soluble factors. Many publications have proven that the amount of Treg cells is elevated in both solid tumors and in hematologic malignancies. Nevertheless, little is known about mechanisms, which allow increase and maintenance of elevated Treg cells in cancer patients. In this review, we will focus, among others, on the description of function and phenotype of Treg cells, their modulation of humoral immune response and interaction with cancer stem cells. Current development of modern tumor immunotherapy allows new possibilities of influencing Treg cells function.

  10. Biomechanical cell regulatory networks as complex adaptive systems in relation to cancer.

    PubMed

    Feller, Liviu; Khammissa, Razia Abdool Gafaar; Lemmer, Johan

    2017-01-01

    Physiological structure and function of cells are maintained by ongoing complex dynamic adaptive processes in the intracellular molecular pathways controlling the overall profile of gene expression, and by genes in cellular gene regulatory circuits. Cytogenetic mutations and non-genetic factors such as chronic inflammation or repetitive trauma, intrinsic mechanical stresses within extracellular matrix may induce redirection of gene regulatory circuits with abnormal reactivation of embryonic developmental programmes which can now drive cell transformation and cancer initiation, and later cancer progression and metastasis. Some of the non-genetic factors that may also favour cancerization are dysregulation in epithelial-mesenchymal interactions, in cell-to-cell communication, in extracellular matrix turnover, in extracellular matrix-to-cell interactions and in mechanotransduction pathways. Persistent increase in extracellular matrix stiffness, for whatever reason, has been shown to play an important role in cell transformation, and later in cancer cell invasion. In this article we review certain cell regulatory networks driving carcinogenesis, focussing on the role of mechanical stresses modulating structure and function of cells and their extracellular matrices.

  11. Superior Cervical Ganglia Neurons Induce Foxp3+ Regulatory T Cells via Calcitonin Gene-Related Peptide.

    PubMed

    Szklany, Kirsten; Ruiter, Evelyn; Mian, Firoz; Kunze, Wolfgang; Bienenstock, John; Forsythe, Paul; Karimi, Khalil

    2016-01-01

    The nervous and immune systems communicate bidirectionally, utilizing diverse molecular signals including cytokines and neurotransmitters to provide an integrated response to changes in the body's internal and external environment. Although, neuro-immune interactions are becoming better understood under inflammatory circumstances and it has been evidenced that interaction between neurons and T cells results in the conversion of encephalitogenic T cells to T regulatory cells, relatively little is known about the communication between neurons and naïve T cells. Here, we demonstrate that following co-culture of naïve CD4+ T cells with superior cervical ganglion neurons, the percentage of Foxp3 expressing CD4+CD25+ cells significantly increased. This was mediated in part by immune-regulatory cytokines TGF-β and IL-10, as well as the neuropeptide calcitonin gene-related peptide while vasoactive intestinal peptide was shown to play no role in generation of T regulatory cells. Additionally, T cells co-cultured with neurons showed a decrease in the levels of pro-inflammatory cytokine IFN-γ released upon in vitro stimulation. These findings suggest that the generation of Tregs may be promoted by naïve CD4+ T cell: neuron interaction through the release of neuropeptide CGRP.

  12. Adoptive immunotherapy with the use of regulatory T cells and virus-specific T cells derived from cord blood.

    PubMed

    Hanley, Patrick J; Bollard, Catherine M; Brunstein, Claudio G

    2015-06-01

    Cord blood transplantation, an alternative to traditional stem cell transplants (bone marrow or peripheral blood stem cell transplantation), is an attractive option for patients lacking suitable stem cell transplant donors. Cord blood units have also proven to be a valuable donor source for the development of cellular therapeutics. Virus-specific T cells and regulatory T cells are two cord blood-derived products that have shown promise in early-phase clinical trials to prevent and/or treat viral infections and graft-versus-host disease, respectively. We describe how current strategies that use cord blood-derived regulatory T cells and virus-specific T cells have been developed to improve outcomes for cord blood transplant recipients.

  13. The pro-metastatic role of bone marrow-derived cells: a focus on MSCs and regulatory T cells

    PubMed Central

    Koh, Bong Ihn; Kang, Yibin

    2012-01-01

    Several bone marrow-derived cells have been shown to promote tumour growth and progression. These cells can home to the primary tumour and become active components of the tumour microenvironment. Recent studies have also identified bone marrow-derived cells—such as mesenchymal stem cells and regulatory T cells—as contributors to cancer metastasis. The innate versatility of these cells provides diverse functional aid to promote malignancy, ranging from structural support to signal-mediated suppression of the host immune response. Here, we review the role of mesenchymal stem cells and regulatory T cells in cancer metastasis. A better understanding of the bipolar nature of these bone marrow-derived cells in physiological and malignant contexts could pave the way for new therapeutics against metastatic disease. PMID:22473297

  14. TIGIT predominantly regulates the immune response via regulatory T cells

    PubMed Central

    Kurtulus, Sema; Sakuishi, Kaori; Ngiow, Shin-Foong; Joller, Nicole; Tan, Dewar J.; Teng, Michele W.L.; Smyth, Mark J.; Kuchroo, Vijay K.; Anderson, Ana C.

    2015-01-01

    Coinhibitory receptors are critical for the maintenance of immune homeostasis. Upregulation of these receptors on effector T cells terminates T cell responses, while their expression on Tregs promotes their suppressor function. Understanding the function of coinhibitory receptors in effector T cells and Tregs is crucial, as therapies that target coinhibitory receptors are currently at the forefront of treatment strategies for cancer and other chronic diseases. T cell Ig and ITIM domain (TIGIT) is a recently identified coinhibitory receptor that is found on the surface of a variety of lymphoid cells, and its role in immune regulation is just beginning to be elucidated. We examined TIGIT-mediated immune regulation in different murine cancer models and determined that TIGIT marks the most dysfunctional subset of CD8+ T cells in tumor tissue as well as tumor-tissue Tregs with a highly active and suppressive phenotype. We demonstrated that TIGIT signaling in Tregs directs their phenotype and that TIGIT primarily suppresses antitumor immunity via Tregs and not CD8+ T cells. Moreover, TIGIT+ Tregs upregulated expression of the coinhibitory receptor TIM-3 in tumor tissue, and TIM-3 and TIGIT synergized to suppress antitumor immune responses. Our findings provide mechanistic insight into how TIGIT regulates immune responses in chronic disease settings. PMID:26413872

  15. TIGIT predominantly regulates the immune response via regulatory T cells.

    PubMed

    Kurtulus, Sema; Sakuishi, Kaori; Ngiow, Shin-Foong; Joller, Nicole; Tan, Dewar J; Teng, Michele W L; Smyth, Mark J; Kuchroo, Vijay K; Anderson, Ana C

    2015-11-02

    Coinhibitory receptors are critical for the maintenance of immune homeostasis. Upregulation of these receptors on effector T cells terminates T cell responses, while their expression on Tregs promotes their suppressor function. Understanding the function of coinhibitory receptors in effector T cells and Tregs is crucial, as therapies that target coinhibitory receptors are currently at the forefront of treatment strategies for cancer and other chronic diseases. T cell Ig and ITIM domain (TIGIT) is a recently identified coinhibitory receptor that is found on the surface of a variety of lymphoid cells, and its role in immune regulation is just beginning to be elucidated. We examined TIGIT-mediated immune regulation in different murine cancer models and determined that TIGIT marks the most dysfunctional subset of CD8+ T cells in tumor tissue as well as tumor-tissue Tregs with a highly active and suppressive phenotype. We demonstrated that TIGIT signaling in Tregs directs their phenotype and that TIGIT primarily suppresses antitumor immunity via Tregs and not CD8+ T cells. Moreover, TIGIT+ Tregs upregulated expression of the coinhibitory receptor TIM-3 in tumor tissue, and TIM-3 and TIGIT synergized to suppress antitumor immune responses. Our findings provide mechanistic insight into how TIGIT regulates immune responses in chronic disease settings.

  16. Super-enhancers delineate disease-associated regulatory nodes in T cells.

    PubMed

    Vahedi, Golnaz; Kanno, Yuka; Furumoto, Yasuko; Jiang, Kan; Parker, Stephen C J; Erdos, Michael R; Davis, Sean R; Roychoudhuri, Rahul; Restifo, Nicholas P; Gadina, Massimo; Tang, Zhonghui; Ruan, Yijun; Collins, Francis S; Sartorelli, Vittorio; O'Shea, John J

    2015-04-23

    Enhancers regulate spatiotemporal gene expression and impart cell-specific transcriptional outputs that drive cell identity. Super-enhancers (SEs), also known as stretch-enhancers, are a subset of enhancers especially important for genes associated with cell identity and genetic risk of disease. CD4(+) T cells are critical for host defence and autoimmunity. Here we analysed maps of mouse T-cell SEs as a non-biased means of identifying key regulatory nodes involved in cell specification. We found that cytokines and cytokine receptors were the dominant class of genes exhibiting SE architecture in T cells. Nonetheless, the locus encoding Bach2, a key negative regulator of effector differentiation, emerged as the most prominent T-cell SE, revealing a network in which SE-associated genes critical for T-cell biology are repressed by BACH2. Disease-associated single-nucleotide polymorphisms for immune-mediated disorders, including rheumatoid arthritis, were highly enriched for T-cell SEs versus typical enhancers or SEs in other cell lineages. Intriguingly, treatment of T cells with the Janus kinase (JAK) inhibitor tofacitinib disproportionately altered the expression of rheumatoid arthritis risk genes with SE structures. Together, these results indicate that genes with SE architecture in T cells encompass a variety of cytokines and cytokine receptors but are controlled by a 'guardian' transcription factor, itself endowed with an SE. Thus, enumeration of SEs allows the unbiased determination of key regulatory nodes in T cells, which are preferentially modulated by pharmacological intervention.

  17. Cell type-selective disease-association of genes under high regulatory load.

    PubMed

    Galhardo, Mafalda; Berninger, Philipp; Nguyen, Thanh-Phuong; Sauter, Thomas; Sinkkonen, Lasse

    2015-10-15

    We previously showed that disease-linked metabolic genes are often under combinatorial regulation. Using the genome-wide ChIP-Seq binding profiles for 93 transcription factors in nine different cell lines, we show that genes under high regulatory load are significantly enriched for disease-association across cell types. We find that transcription factor load correlates with the enhancer load of the genes and thereby allows the identification of genes under high regulatory load by epigenomic mapping of active enhancers. Identification of the high enhancer load genes across 139 samples from 96 different cell and tissue types reveals a consistent enrichment for disease-associated genes in a cell type-selective manner. The underlying genes are not limited to super-enhancer genes and show several types of disease-association evidence beyond genetic variation (such as biomarkers). Interestingly, the high regulatory load genes are involved in more KEGG pathways than expected by chance, exhibit increased betweenness centrality in the interaction network of liver disease genes, and carry longer 3' UTRs with more microRNA (miRNA) binding sites than genes on average, suggesting a role as hubs integrating signals within regulatory networks. In summary, epigenetic mapping of active enhancers presents a promising and unbiased approach for identification of novel disease genes in a cell type-selective manner.

  18. Cell type-selective disease-association of genes under high regulatory load

    PubMed Central

    Galhardo, Mafalda; Berninger, Philipp; Nguyen, Thanh-Phuong; Sauter, Thomas; Sinkkonen, Lasse

    2015-01-01

    We previously showed that disease-linked metabolic genes are often under combinatorial regulation. Using the genome-wide ChIP-Seq binding profiles for 93 transcription factors in nine different cell lines, we show that genes under high regulatory load are significantly enriched for disease-association across cell types. We find that transcription factor load correlates with the enhancer load of the genes and thereby allows the identification of genes under high regulatory load by epigenomic mapping of active enhancers. Identification of the high enhancer load genes across 139 samples from 96 different cell and tissue types reveals a consistent enrichment for disease-associated genes in a cell type-selective manner. The underlying genes are not limited to super-enhancer genes and show several types of disease-association evidence beyond genetic variation (such as biomarkers). Interestingly, the high regulatory load genes are involved in more KEGG pathways than expected by chance, exhibit increased betweenness centrality in the interaction network of liver disease genes, and carry longer 3′ UTRs with more microRNA (miRNA) binding sites than genes on average, suggesting a role as hubs integrating signals within regulatory networks. In summary, epigenetic mapping of active enhancers presents a promising and unbiased approach for identification of novel disease genes in a cell type-selective manner. PMID:26338775

  19. A predictive modeling approach for cell line-specific long-range regulatory interactions

    PubMed Central

    Roy, Sushmita; Siahpirani, Alireza Fotuhi; Chasman, Deborah; Knaack, Sara; Ay, Ferhat; Stewart, Ron; Wilson, Michael; Sridharan, Rupa

    2015-01-01

    Long range regulatory interactions among distal enhancers and target genes are important for tissue-specific gene expression. Genome-scale identification of these interactions in a cell line-specific manner, especially using the fewest possible datasets, is a significant challenge. We develop a novel computational approach, Regulatory Interaction Prediction for Promoters and Long-range Enhancers (RIPPLE), that integrates published Chromosome Conformation Capture (3C) data sets with a minimal set of regulatory genomic data sets to predict enhancer-promoter interactions in a cell line-specific manner. Our results suggest that CTCF, RAD21, a general transcription factor (TBP) and activating chromatin marks are important determinants of enhancer-promoter interactions. To predict interactions in a new cell line and to generate genome-wide interaction maps, we develop an ensemble version of RIPPLE and apply it to generate interactions in five human cell lines. Computational validation of these predictions using existing ChIA-PET and Hi-C data sets showed that RIPPLE accurately predicts interactions among enhancers and promoters. Enhancer-promoter interactions tend to be organized into subnetworks representing coordinately regulated sets of genes that are enriched for specific biological processes and cis-regulatory elements. Overall, our work provides a systematic approach to predict and interpret enhancer-promoter interactions in a genome-wide cell-type specific manner using a few experimentally tractable measurements. PMID:26338778

  20. (Rapid regulatory control of plant cell expansion and wall relaxation)

    SciTech Connect

    Cosgrove, D.J.

    1990-01-01

    This section presents a brief overview of accomplishments related to this project in the past 3-year period. Our work has focused on the basic mechanisms of plant cell expansion, particularly on the interrelations of water and solute transport with cell wall relaxation and expansion. To study these processes, we have developed new methods and used these methods to analyze the dynamic behavior of growth processes and to examine how various agents (GA, drought, light, genetic lesions) alter the growth machinery of the cell.

  1. Foxp3-transduced polyclonal regulatory T cells protect against chronic renal injury from adriamycin.

    PubMed

    Wang, Yuan Min; Zhang, Geoff Yu; Wang, Yiping; Hu, Min; Wu, Huiling; Watson, Debbie; Hori, Shohei; Alexander, Ian E; Harris, David C H; Alexander, Stephen I

    2006-03-01

    Chronic proteinuric renal injury is a major cause of ESRD. Adriamycin nephropathy is a murine model of chronic proteinuric renal disease whereby chemical injury is followed by immune and structural changes that mimic human disease. Foxp3 is a gene that induces a regulatory T cell (Treg) phenotype. It was hypothesized that Foxp3-transduced Treg could protect against renal injury in Adriamycin nephropathy. CD4+ T cells were transduced with either a Foxp3-containing retrovirus or a control retrovirus. Foxp3-transduced T cells had a regulatory phenotype by functional and phenotypic assays. Adoptive transfer of Foxp3-transduced T cells protected against renal injury. Urinary protein excretion and serum creatinine were reduced (P<0.05), and there was significantly less glomerulosclerosis, tubular damage, and interstitial infiltrates (P<0.01). It is concluded that Foxp3-transduced Treg cells may have a therapeutic role in protecting against immune injury and disease progression in chronic proteinuric renal disease.

  2. The Role of Regulatory T Cells in the Biology of Graft Versus Host Disease

    PubMed Central

    Beres, Amy J.; Drobyski, William R.

    2013-01-01

    Graft versus host disease (GVHD) is the major complication of allogeneic hematopoietic stem cell transplantation. GVHD is characterized by an imbalance between the effector and regulatory arms of the immune system which results in the over production of inflammatory cytokines. Moreover, there is a persistent reduction in the number of regulatory T (Treg) cells which limits the ability of the immune system to re-calibrate this proinflammatory environment. Treg cells are comprised of both natural and induced populations which have unique ontological and developmental characteristics that impact how they function within the context of immune regulation. In this review, we summarize pre-clinical data derived from experimental murine models that have examined the role of both natural and induced Treg cells in the biology of GVHD. We also review the clinical studies which have begun to employ Treg cells as a form of adoptive cellular therapy for the prevention of GVHD in human transplant recipients. PMID:23805140

  3. Modulation of liver tolerance by conventional and nonconventional antigen-presenting cells and regulatory immune cells

    PubMed Central

    Horst, Andrea Kristina; Neumann, Katrin; Diehl, Linda; Tiegs, Gisa

    2016-01-01

    The liver is a tolerogenic organ with exquisite mechanisms of immune regulation that ensure upkeep of local and systemic immune tolerance to self and foreign antigens, but that is also able to mount effective immune responses against pathogens. The immune privilege of liver allografts was recognized first in pigs in spite of major histo-compatibility complex mismatch, and termed the “liver tolerance effect”. Furthermore, liver transplants are spontaneously accepted with only low-dose immunosuppression, and induce tolerance for non-hepatic co-transplanted allografts of the same donor. Although this immunotolerogenic environment is favorable in the setting of organ transplantation, it is detrimental in chronic infectious liver diseases like hepatitis B or C, malaria, schistosomiasis or tumorigenesis, leading to pathogen persistence and weak anti-tumor effects. The liver is a primary site of T-cell activation, but it elicits poor or incomplete activation of T cells, leading to their abortive activation, exhaustion, suppression of their effector function and early death. This is exploited by pathogens and can impair pathogen control and clearance or allow tumor growth. Hepatic priming of T cells is mediated by a number of local conventional and nonconventional antigen-presenting cells (APCs), which promote tolerance by immune deviation, induction of T-cell anergy or apoptosis, and generating and expanding regulatory T cells. This review will focus on the communication between classical and nonclassical APCs and lymphocytes in the liver in tolerance induction and will discuss recent insights into the role of innate lymphocytes in this process. PMID:27041638

  4. Interleukin-35-mediated induction of a novel regulatory T cell population

    PubMed Central

    Collison, Lauren W.; Chaturvedi, Vandana; Henderson, Abigail L.; Giacomin, Paul R.; Guy, Cliff; Bankoti, Jaishree; Finkelstein, David; Forbes, Karen; Workman, Creg J.; Brown, Scott A.; Rehg, Jerold E.; Jones, Michael L.; Ni, Hsiao-Tzu; Artis, David; Turk, Mary Jo; Vignali, Dario A. A.

    2010-01-01

    Regulatory T cells (Tregs) play a critical role in the maintenance of immunological self-tolerance. Naïve human or murine T cell treatment with the inhibitory cytokine IL-35 induces a regulatory population, termed iTR35, that mediates suppression via IL-35, but not IL-10 or TGFβ, neither express nor require Foxp3, are strongly suppressive in five in vivo models, and exhibit in vivo stability. Treg-mediated suppression induces iTR35 generation in an IL-35- and IL-10-dependent manner in vitro, and in inflammatory conditions in vivo in Trichuris-infected intestines and within the tumor microenvironment, where they appear to contribute to the regulatory milieu. iTR35 may constitute a key mediator of infectious tolerance, may contribute to Treg-mediated tumor progression, and ex vivo generated iTR35 may possess therapeutic utility. PMID:20953201

  5. A Dynamic Gene Regulatory Network Model That Recovers the Cyclic Behavior of Arabidopsis thaliana Cell Cycle.

    PubMed

    Ortiz-Gutiérrez, Elizabeth; García-Cruz, Karla; Azpeitia, Eugenio; Castillo, Aaron; Sánchez, María de la Paz; Álvarez-Buylla, Elena R

    2015-09-01

    Cell cycle control is fundamental in eukaryotic development. Several modeling efforts have been used to integrate the complex network of interacting molecular components involved in cell cycle dynamics. In this paper, we aimed at recovering the regulatory logic upstream of previously known components of cell cycle control, with the aim of understanding the mechanisms underlying the emergence of the cyclic behavior of such components. We focus on Arabidopsis thaliana, but given that many components of cell cycle regulation are conserved among eukaryotes, when experimental data for this system was not available, we considered experimental results from yeast and animal systems. We are proposing a Boolean gene regulatory network (GRN) that converges into only one robust limit cycle attractor that closely resembles the cyclic behavior of the key cell-cycle molecular components and other regulators considered here. We validate the model by comparing our in silico configurations with data from loss- and gain-of-function mutants, where the endocyclic behavior also was recovered. Additionally, we approximate a continuous model and recovered the temporal periodic expression profiles of the cell-cycle molecular components involved, thus suggesting that the single limit cycle attractor recovered with the Boolean model is not an artifact of its discrete and synchronous nature, but rather an emergent consequence of the inherent characteristics of the regulatory logic proposed here. This dynamical model, hence provides a novel theoretical framework to address cell cycle regulation in plants, and it can also be used to propose novel predictions regarding cell cycle regulation in other eukaryotes.

  6. Effects of combined radiofrequency radiation exposure on the cell cycle and its regulatory proteins.

    PubMed

    Lee, Kwan-Yong; Kim, Bong Cho; Han, Na-Kyung; Lee, Yun-Sil; Kim, Taehong; Yun, Jae-Hoon; Kim, Nam; Pack, Jeong-Ki; Lee, Jae-Seon

    2011-04-01

    The aim of this study was to investigate whether single or combined radio frequency (RF) radiation exposure has effects on the cell cycle and its regulatory proteins. Exposure of MCF7 cells to either single (837 MHz) or combined (837 and 1950 MHz) RF radiation was conducted at specific absorption rate values of 4 W/kg for 1 h. During the exposure period, the chamber was made isothermal by circulating water through the cavity. After RF radiation exposure, DNA synthesis rate and cell cycle distribution were assessed. The levels of cell cycle regulatory proteins, p53, p21, cyclins, and cyclin-dependent kinases were also examined. The positive control group was exposed to 0.5 and 4 Gy doses of ionizing radiation (IR) and showed changes in DNA synthesis and cell cycle distribution. The levels of p53, p21, cyclin A, cyclin B1, and cyclin D1 were also affected by IR exposure. In contrast to the IR-exposed group, neither the single RF radiation- nor the combined RF radiation-exposed group elicited alterations in DNA synthesis, cell cycle distribution, and levels of cell cycle regulatory proteins. These results indicate that neither single nor combined RF radiation affect cell cycle progression.

  7. Phosphatidylserine Outer Layer Translocation Is Implicated in IL-10 Secretion by Human Regulatory B Cells.

    PubMed

    Audo, Rachel; Hua, Charlotte; Hahne, Michael; Combe, Bernard; Morel, Jacques; Daien, Claire I

    2017-01-01

    B cells can have a regulatory role, mainly mediated by interleukin 10 (IL-10). IL-10 producing B cells (B10 cells) cells remain to be better characterized. Annexin V binds phosphatidylserine (PS), which is externalized during apoptosis. Previous works suggested that B10 cells are apoptotic cells since they bind Annexin V. Others showed that Annexin V binding could also be expressed on viable B cells. We aimed to explore if PS exposure can be a marker of B10 cells and if PS exposure has a functional role on B cell IL-10 production in healthy subjects. We found that B10 cells were significantly more often Annexin V+ than IL-10 non-producing B cells. After CpG activation, Annexin V+ B cells differentiated more often into B10 cells than Annexin Vneg B cells. Cell death and early apoptosis were similar between Annexin V+ and Annexin Vneg B cells. PS blockage, using biotinylated AnV and glyburide, decreased B10 cell differentiation. This study showed that B10 cells have an increased PS exposure independently of any apoptotic state. B cells exposing PS differentiate more into B10 cells whereas PS blockage inhibits B10 cells generation. These results strongly suggest a link between PS exposure and B10 cells.

  8. Phosphatidylserine Outer Layer Translocation Is Implicated in IL-10 Secretion by Human Regulatory B Cells

    PubMed Central

    Hahne, Michael; Combe, Bernard; Morel, Jacques; Daien, Claire I.

    2017-01-01

    B cells can have a regulatory role, mainly mediated by interleukin 10 (IL-10). IL-10 producing B cells (B10 cells) cells remain to be better characterized. Annexin V binds phosphatidylserine (PS), which is externalized during apoptosis. Previous works suggested that B10 cells are apoptotic cells since they bind Annexin V. Others showed that Annexin V binding could also be expressed on viable B cells. We aimed to explore if PS exposure can be a marker of B10 cells and if PS exposure has a functional role on B cell IL-10 production in healthy subjects. We found that B10 cells were significantly more often Annexin V+ than IL-10 non-producing B cells. After CpG activation, Annexin V+ B cells differentiated more often into B10 cells than Annexin Vneg B cells. Cell death and early apoptosis were similar between Annexin V+ and Annexin Vneg B cells. PS blockage, using biotinylated AnV and glyburide, decreased B10 cell differentiation. This study showed that B10 cells have an increased PS exposure independently of any apoptotic state. B cells exposing PS differentiate more into B10 cells whereas PS blockage inhibits B10 cells generation. These results strongly suggest a link between PS exposure and B10 cells. PMID:28072868

  9. IL-2 coordinates IL-2–producing and regulatory T cell interplay

    PubMed Central

    Amado, Inês F.; Berges, Julien; Luther, Rita J.; Mailhé, Marie-Pierre; Garcia, Sylvie; Bandeira, Antonio; Weaver, Casey; Liston, Adrian

    2013-01-01

    Many species of bacteria use quorum sensing to sense the amount of secreted metabolites and to adapt their growth according to their population density. We asked whether similar mechanisms would operate in lymphocyte homeostasis. We investigated the regulation of the size of interleukin-2 (IL-2)–producing CD4+ T cell (IL-2p) pool using different IL-2 reporter mice. We found that in the absence of either IL-2 or regulatory CD4+ T (T reg) cells, the number of IL-2p cells increases. Administration of IL-2 decreases the number of cells of the IL-2p cell subset and, pertinently, abrogates their ability to produce IL-2 upon in vivo cognate stimulation, while increasing T reg cell numbers. We propose that control of the IL-2p cell numbers occurs via a quorum sensing–like feedback loop where the produced IL-2 is sensed by both the activated CD4+ T cell pool and by T reg cells, which reciprocally regulate cells of the IL-2p cell subset. In conclusion, IL-2 acts as a self-regulatory circuit integrating the homeostasis of activated and T reg cells as CD4+ T cells restrain their growth by monitoring IL-2 levels, thereby preventing uncontrolled responses and autoimmunity. PMID:24249704

  10. Interleukin-4 Inhibits Regulatory T Cell Differentiation through Regulating CD103+ Dendritic Cells

    PubMed Central

    Tu, Lei; Chen, Jie; Zhang, Hongwei; Duan, Lihua

    2017-01-01

    CD103+ dendritic cells (DCs) have been shown to play a crucial role in the pathogenesis of inflammatory bowel diseases (IBDs) through educating regulatory T (Treg) cells differentiation. However, the mechanism of CD103+ DCs subsets differentiation remains elusive. Interleukin (IL)-4 is a pleiotropic cytokine that is upregulated in certain types of inflammation, including IBDs and especially ulcerative colitis. However, the precise role of IL-4 in the differentiation of CD103+ DCs subpopulation remains unknown. In this study, we observed a repressive role of IL-4 on the CD103+ DCs differentiation in both mouse and human. High-dose IL-4 inhibited the CD103+ DC differentiation. In comparison to CD103− DCs, CD103+ DCs expressed high levels of the co-stimulatory molecules and indoleamine 2,3-dioxygenase (IDO). Interestingly, IL-4 diminished IDO expression on DCs in a dose-dependent manner. Besides, high-dose IL-4-induced bone marrow-derived DCs, and monocyte-derived DCs revealed mature DCs profiles, characterized by increased co-stimulatory molecules and decreased pinocytotic function. Furthermore, DCs generated under low concentrations of IL-4 favored Treg cells differentiation, which depend on IDO produced by CD103+ DCs. Consistently, IL-4 also reduced the frequency of CD103+ DC in vivo. Thus, we here demonstrated that the cytokine IL-4 involved in certain types of inflammatory diseases by orchestrating the functional phenotype of CD103+ DCs subsets. PMID:28316599

  11. Stem cell transplantation in genetically linked regulatory T-cell disorders.

    PubMed

    Shenoy, Shalini

    2008-01-01

    T-regulatory disorders are a heterogenous group characterized by autoimmune and allergic manifestations of varying onset, severity, and progression. The advent of sophisticated molecular and immunologic diagnostic techniques has resulted in accurate elucidation of etiopathogenesis of many immunoregulatory disorders previously clubbed under the autoimmune umbrella. The severity of presentation and progression, early morbidity and mortality, poor quality of life, and frequent refractoriness to immunosuppressive therapy has prompted studies of stem cell transplantation in many immunoregulatory disorders. The benefits of autologous or allogeneic transplantation are related to either suppression and reprogramming of the immune system (autologous transplant) or replacement of missing elements of immune regulation (allogeneic transplants). Transplant methods have steadily improved through a series of studies and trials to have the benefits of this approach outweigh the risks of procedure-related toxicities. This article summarizes the current status and the future goals of stem cell transplantation for T-cell immunoregulatory disorders and reviews advances in disease detection, targeted transplant strategies and novel approaches, and the pros and cons of transplant in this field.

  12. Immunostimulatory conventional dendritic cells evolve into regulatory macrophage-like cells.

    PubMed

    Diao, Jun; Mikhailova, Anastassia; Tang, Michael; Gu, Hongtao; Zhao, Jun; Cattral, Mark S

    2012-05-24

    Dendritic cell (DC) homeostasis in peripheral tissues reflect a balance between DC generation, migration, and death. The current model of DC ontogeny indicates that pre-cDCs are committed to become terminal conventional DCs (cDCs). Here, we report the unexpected finding that proliferating immunostimulatory CD11c(+) MHC class II(+) cDCs derived from pre-cDCs can lose their DC identity and generate progeny that exhibit morphologic, phenotypic, and functional characteristics of regulatory macrophages. DC-derived-macrophages (DC-d-Ms) potently suppress T-cell responses through the production of immunosuppressive molecules including nitric oxide, arginase, and IL-10. Relative deficiency of granulocyte-macrophage colony stimulating factor (GM-CSF) provided a permissive signal for DC-d-M generation. Using a transgenic mouse model that allows tracking of CD11c(+) cells in vivo, we found that DC-d-M development occurs commonly in cancer, but not in lymphoid or nonlymphoid tissues under steady-state conditions. We propose that this developmental pathway serves as an alternative mechanism of regulating DC homeostasis during inflammatory processes.

  13. Role of regulatory T cell in the pathogenesis of inflammatory bowel disease

    PubMed Central

    Yamada, Akiko; Arakaki, Rieko; Saito, Masako; Tsunematsu, Takaaki; Kudo, Yasusei; Ishimaru, Naozumi

    2016-01-01

    Regulatory T (Treg) cells play key roles in various immune responses. For example, Treg cells contribute to the complex pathogenesis of inflammatory bowel disease (IBD), which includes Crohn’s disease and ulcerative colitis during onset or development of that disease. Many animal models of IBD have been used to investigate factors such as pathogenic cytokines, pathogenic bacteria, and T-cell functions, including those of Treg cells. In addition, analyses of patients with IBD facilitate our understanding of the precise mechanism of IBD. This review article focuses on the role of Treg cells and outlines the pathogenesis and therapeutic strategies of IBD based on previous reports. PMID:26900284

  14. The regulatory role of invariant NKT cells in tumor immunity

    PubMed Central

    McEwen-Smith, Rosanna M; Salio, Mariolina; Cerundolo, Vincenzo

    2015-01-01

    Invariant natural killer T (iNKT) cells are a unique population of T lymphocytes, which lie at the interface between the innate and adaptive immune systems, and are important mediators of immune responses and tumor-surveillance. iNKT cells recognize lipid antigens in a CD1d-dependent manner; their subsequent activation results in a rapid and specific downstream response, which enhances both innate and adaptive immunity. The capacity of iNKT cells to modify the immune-microenvironment influences the ability of the host to control tumor growth, making them an important population to be harnessed in the clinic for the development of anti-cancer therapeutics. Indeed, the identification of strong iNKT cell agonists, such as α-galactosylceramide (α-GalCer) and its analogues, has led to the development of synthetic lipids which have shown potential in vaccination and treatment against cancers. In this Masters of Immunology article we discuss these latest findings, and summarise the major discoveries in iNKT cell biology, which have enabled the design of potent strategies for immune-mediated tumor destruction. PMID:25941354

  15. From bench to FDA to bedside: US regulatory trends for new stem cell therapies.

    PubMed

    Knoepfler, Paul S

    2015-03-01

    The phrase "bench-to-bedside" is commonly used to describe the translation of basic discoveries such as those on stem cells to the clinic for therapeutic use in human patients. However, there is a key intermediate step in between the bench and the bedside involving governmental regulatory oversight such as by the Food and Drug Administration (FDA) in the United States (US). Thus, it might be more accurate in most cases to describe the stem cell biological drug development process in this way: from bench to FDA to bedside. The intermediate development and regulatory stage for stem cell-based biological drugs is a multifactorial, continually evolving part of the process of developing a biological drug such as a stem cell-based regenerative medicine product. In some situations, stem cell-related products may not be classified as biological drugs in which case the FDA plays a relatively minor role. However, this middle stage is generally a major element of the process and is often colloquially referred to in an ominous way as "The Valley of Death". This moniker seems appropriate because it is at this point, and in particular in the work that ensues after Phase 1, clinical trials that most drug product development is terminated, often due to lack of funding, diseases being refractory to treatment, or regulatory issues. Not surprisingly, workarounds to deal with or entirely avoid this difficult stage of the process are evolving both inside and outside the domains of official regulatory authorities. In some cases these efforts involve the FDA invoking new mechanisms of accelerating the bench to beside process, but in other cases these new pathways bypass the FDA in part or entirely. Together these rapidly changing stem cell product development and regulatory pathways raise many scientific, ethical, and medical questions. These emerging trends and their potential consequences are reviewed here.

  16. From Bench to FDA to Bedside: US Regulatory Trends for New Stem Cell Therapies

    PubMed Central

    Knoepfler, Paul S.

    2015-01-01

    The phrase “bench to bedside” is commonly used to describe the translation of basic discoveries such as those on stem cells to the clinic for therapeutic use in human patients. However, there is a key intermediate step in between the bench and the bedside involving governmental regulatory oversight such as by the Food and Drug Administration (FDA) in the United States (US). Thus, it might be more accurate in most cases to describe the stem cell biological drug development process in this way: from bench to FDA to bedside. The intermediate development and regulatory stage for stem cell-based biological drugs is a multifactorial, continually evolving part of the process of developing a biological drug such as a stem cell-based regenerative medicine product. In some situations, stem cell-related products may not be classified as biological drugs in which case the FDA plays a relatively minor role. However, this middle stage is generally a major element of the process and is often colloquially referred to in an ominous way as “The Valley of Death”. This moniker seems appropriate because it is at this point and in particular in the work that ensues after Phase 1 clinical trials that most drug product development is terminated, often due to lack of funding, diseases being refractory to treatment, or regulatory issues. Not surprisingly, workarounds to deal with or entirely avoid this difficult stage of the process are evolving both inside and outside the domains of official regulatory authorities. In some cases these efforts involve the FDA invoking new mechanisms of accelerating the bench to beside process, but in other cases these new pathways bypass the FDA in part or entirely. Together these rapidly changing stem cell product development and regulatory pathways raise many scientific, ethical, and medical questions. These emerging trends and their potential consequences are reviewed here. PMID:25489841

  17. Effect of Salmonella infection on cecal tonsil regulatory T cell properties in chickens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two experiments were conducted to study Regulatory T cell (Treg) properties post-Salmonella infection in broiler birds. Four-day-old broiler chicks were orally infected with 5x106 CFU/ml Salmonella enteritidis or sterile PBS (control). Samples were collected at 4, 7, 10, and 14 d post-infection. ...

  18. Contribution of Mesenteric Lymph Nodes and GALT to the Intestinal Foxp3+ Regulatory T-Cell Compartment.

    PubMed

    Geem, Duke; Ngo, Vu; Harusato, Akihito; Chassaing, Benoit; Gewirtz, Andrew T; Newberry, Rodney D; Denning, Timothy L

    2016-05-01

    This study showed that the absence of CCR7 or mesenteric lymph nodes/gut-associated lymphoid tissue did not appreciably impact total intestinal Foxp3+ regulatory T cell representation in the steady-state. However, mesenteric lymph nodes/GALT are required for normal peripherally induced Foxp3+ regulatory T cell differentiation in the small intestine, but not in the large intestine.

  19. Regulatory T Cells Phenotype in Different Clinical Forms of Chagas' Disease

    PubMed Central

    Teixeira-Carvalho, Andréa; Renato Zuquim Antas, Paulo; Assis Silva Gomes, Juliana; Sathler-Avelar, Renato; Otávio Costa Rocha, Manoel; Elói-Santos, Silvana Maria; Pinho, Rosa Teixeira; Correa-Oliveira, Rodrigo; Martins-Filho, Olindo Assis

    2011-01-01

    CD25High CD4+ regulatory T cells (Treg cells) have been described as key players in immune regulation, preventing infection-induced immune pathology and limiting collateral tissue damage caused by vigorous anti-parasite immune response. In this review, we summarize data obtained by the investigation of Treg cells in different clinical forms of Chagas' disease. Ex vivo immunophenotyping of whole blood, as well as after stimulation with Trypanosoma cruzi antigens, demonstrated that individuals in the indeterminate (IND) clinical form of the disease have a higher frequency of Treg cells, suggesting that an expansion of those cells could be beneficial, possibly by limiting strong cytotoxic activity and tissue damage. Additional analysis demonstrated an activated status of Treg cells based on low expression of CD62L and high expression of CD40L, CD69, and CD54 by cells from all chagasic patients after T. cruzi antigenic stimulation. Moreover, there was an increase in the frequency of the population of Foxp3+ CD25HighCD4+ cells that was also IL-10+ in the IND group, whereas in the cardiac (CARD) group, there was an increase in the percentage of Foxp3+ CD25High CD4+ cells that expressed CTLA-4. These data suggest that IL-10 produced by Treg cells is effective in controlling disease development in IND patients. However, in CARD patients, the same regulatory mechanism, mediated by IL-10 and CTLA-4 expression is unlikely to be sufficient to control the progression of the disease. These data suggest that Treg cells may play an important role in controlling the immune response in Chagas' disease and the balance between regulatory and effector T cells may be important for the progression and development of the disease. Additional detailed analysis of the mechanisms on how these cells are activated and exert their function will certainly give insights for the rational design of procedure to achieve the appropriate balance between protection and pathology during parasite

  20. Regulatory T cells play a role in T-cell receptor CDR2 peptide regulation of experimental autoimmune encephalomyelitis.

    PubMed

    Buenafe, Abigail C; Andrew, Shayne; Offner, Halina; Vandenbark, Arthur A

    2012-02-01

    Eliciting T-cell receptor (TCR) -specific responsiveness has been known to provide an effective autoregulatory mechanism for limiting inflammation mediated by T effector cells. Our previous use of TCR peptides derived from the CDR3 regions of a pathogenic TCR effectively reversed ongoing experimental autoimmune encephalomyelitis (EAE) in a humanized TCR transgenic model. In this study, we use the TCR BV8S2 CDR2 peptide in the non-transgenic C57BL/6 EAE model to down-regulate the heterogeneous TCR BV8S2(+)  MOG-35-55-specific pathogenic T-cell population and demonstrate successful treatment of EAE after disease onset. Suppression of disease was associated with reduced MOG-35-55-specific and non-specific T-cell production of interleukin-17a and interferon-γ in the central nervous system, as well as reduced numbers of CD4(+) and Foxp3(+) T cells in the central nervous system. With the use of Foxp3-GFP and Foxp3 conditional knockout mice, we demonstrate that the TCR CDR2 peptide treatment effect is dependent on the presence of Foxp3(+) regulatory T cells and that regulatory T cell numbers are significantly expanded in the periphery of treated mice. Hence, TCR CDR2 peptide therapy is effective in regulating heterogeneous, pathogenic T-cell populations through the activity of the Foxp3(+) regulatory T cell population.

  1. Follicular regulatory T cells control humoral autoimmunity via NFAT2-regulated CXCR5 expression.

    PubMed

    Vaeth, Martin; Müller, Gerd; Stauss, Dennis; Dietz, Lena; Klein-Hessling, Stefan; Serfling, Edgar; Lipp, Martin; Berberich, Ingolf; Berberich-Siebelt, Friederike

    2014-03-10

    Maturation of high-affinity B lymphocytes is precisely controlled during the germinal center reaction. This is dependent on CD4(+)CXCR5(+) follicular helper T cells (TFH) and inhibited by CD4(+)CXCR5(+)Foxp3(+) follicular regulatory T cells (TFR). Because NFAT2 was found to be highly expressed and activated in follicular T cells, we addressed its function herein. Unexpectedly, ablation of NFAT2 in T cells caused an augmented GC reaction upon immunization. Consistently, however, TFR cells were clearly reduced in the follicular T cell population due to impaired homing to B cell follicles. This was TFR-intrinsic because only in these cells NFAT2 was essential to up-regulate CXCR5. The physiological relevance for humoral (auto-)immunity was corroborated by exacerbated lupuslike disease in the presence of NFAT2-deficient TFR cells.

  2. Treatment of Uveitis by In Situ Administration of Ex Vivo-Activated Polyclonal Regulatory T Cells.

    PubMed

    Grégoire, Sylvie; Terrada, Céline; Martin, Gaelle H; Fourcade, Gwladys; Baeyens, Audrey; Marodon, Gilles; Fisson, Sylvain; Billiard, Fabienne; Lucas, Bruno; Tadayoni, Ramin; Béhar-Cohen, Francine; Levacher, Béatrice; Galy, Anne; LeHoang, Phuc; Klatzmann, David; Bodaghi, Bahram; Salomon, Benoît L

    2016-03-01

    CD4(+)CD25(+)Foxp3(+) regulatory T (Treg) cell therapy is a promising approach for the treatment of autoimmune diseases. To be effective, Treg cells should be in an activated state in the target tissue. This can be achieved by systemic administration of Ag-specific Treg cells, which are difficult to produce in conditions that can be translated to the clinic. In this paper, we propose an alternative approach consisting of in situ injection of preactivated polyclonal Treg cells that would exert bystander suppression in the target tissue. We show that polyclonal Treg cells suppressed uveitis in mice as efficiently as Ag-specific Treg cells but only when preactivated and administered in the vitreous. Uveitis control was correlated with an increase of IL-10 and a decrease of reactive oxygen species produced by immune cell infiltrates in the eye. Thus, our results reveal a new mechanism of Treg cell-mediated suppression and a new Treg cell therapy approach.

  3. Blood B Cell and Regulatory Subset Content in Multiple Sclerosis Patients

    PubMed Central

    Habib, Jakob; Deng, Jiusheng; Lava, Neil; Tyor, William; Galipeau, Jacques

    2015-01-01

    Objective B cell targeted therapies have been effective in slowing multiple sclerosis (MS) disease progression suggesting a direct causal link for this lymphoid subset. A small subset of B cells with regulative properties (Bregs) exists in peripheral blood, and induction of Bregs ameliorates experimental autoimmune encephalomyelitis (EAE), the murine model for MS. Therefore the frequency of B cell subsets and regulatory B cells in particular in peripheral blood of MS patients is of interest. Methods The phenotype and frequency of B cell subsets in peripheral blood from 32 MS patients and 34 healthy controls (HC) were examined using flow cytometry. Results We found that there is an increase in CD19+ cell number in MS 1347 ± 159 cells/μL, (average ± SEM) compared to HC, 935 ± 129 cells/μL and no apparent deficiency in B-cells with a regulatory phenotype. In addition, we observed a loss of correlation between CD19+ B cells and total lymphocyte count in MS. Conclusion These findings suggest altered blood B-cell homeostasis in MS patients. PMID:26137596

  4. Model-based control of fuel cells:. (1) Regulatory control

    NASA Astrophysics Data System (ADS)

    Golbert, Joshua; Lewin, Daniel R.

    This paper describes a model-based controller for the regulation of a proton exchange membrane (PEM) fuel cell. The model accounts for spatial dependencies of voltage, current, material flows, and temperatures in the fuel channel. Analysis of the process model shows that the effective gain of the process undergoes a sign change in the normal operating range of the fuel cell, indicating that it cannot be stabilized using a linear controller with integral action. Consequently, a nonlinear model-predictive-controller based on a simplified model has been developed, enabling the use of optimal control to satisfy power demands robustly. The models and controller have been realized in the MATLAB and SIMULINK environment. Initial results indicate improved performance and robustness when using model-based control in comparison with that obtained using an adaptive controller.

  5. FoxP3+ regulatory T cells are not important for rotavirus clearance or the early antibody response to rotavirus.

    PubMed

    Miller, Amber D; Blutt, Sarah E; Conner, Margaret E

    2014-01-01

    Regulatory T cells produce TGF-β that contributes to IgA induction by intestinal commensal bacteria but their importance in IgA responses to pathogens has not been determined. Immunity against the enteropathogen, rotavirus, is dependent on intestinal IgA, but whether FoxP3(+) regulatory T cells contribute to this IgA is unknown. Infection with rotavirus increased the numbers of intestinal FoxP3(+) regulatory T cells. Depletion of FoxP3(+) regulatory T cells altered leukocyte activation but did not significantly alter rotavirus clearance or specific antibody levels. These data suggest FoxP3(+) regulatory T cells are not critical for the early antibody response to rotavirus infection.

  6. Adoptive transfer of hepatic stellate cells ameliorates liver ischemia reperfusion injury through enriching regulatory T cells.

    PubMed

    Feng, Min; Wang, Quanrongzi; Wang, Hao; Wang, Meng; Guan, Wenxian; Lu, Ling

    2014-04-01

    Our previous study indicated that adoptive transferred regulatory T cells (Tregs) attenuated liver ischemia reperfusion injury (IRI). Recent studies demonstrated that hepatic stellate cells (HSCs) were producers of induced Tregs (iTregs) via retinoic acid. This study aimed to investigate the role of adoptive transferred HSCs in liver IRI. Mice were treated with gradient doses of HSCs before surgery at 24h or 72h. The levels of serum aminotransferases and hepatic cytokines were evaluated after reperfusion. Meanwhile, hepatic Tregs and their subsets were analyzed by flow cytometry. We found that adoptive transferred HSCs attenuated liver IRI. Administration of HSCs expanded the number of hepatic iTregs and natural Tregs (nTregs) after reperfusion. In addition, we found that the increased Tregs were almost Helios-Tregs before surgery. These Helios-Tregs were considered as iTregs and protected liver from IRI partially. Furthermore, adoptive transferred HSCs stabilized nTregs and prevented nTregs from reducing after reperfusion. These nTregs also attenuated liver IRI partially. Depletion of Tregs abolished the protective effect of HSCs. Thus, we conclude that adoptive transferred HSCs ameliorate liver IRI in Tregs-dependent manner.

  7. Azacytidine Treatment Inhibits the Progression of Herpes Stromal Keratitis by Enhancing Regulatory T Cell Function.

    PubMed

    Varanasi, Siva Karthik; Reddy, Pradeep B J; Bhela, Siddheshvar; Jaggi, Ujjaldeep; Gimenez, Fernanda; Rouse, Barry T

    2017-04-01

    Ocular infection with herpes simplex virus 1 (HSV-1) sets off an inflammatory reaction in the cornea which leads to both virus clearance and chronic lesions that are orchestrated by CD4 T cells. Approaches that enhance the function of regulatory T cells (Treg) and dampen effector T cells can be effective to limit stromal keratitis (SK) lesion severity. In this report, we explore the novel approach of inhibiting DNA methyltransferase activity using 5-azacytidine (Aza; a cytosine analog) to limit HSV-1-induced ocular lesions. We show that therapy begun after infection when virus was no longer actively replicating resulted in a pronounced reduction in lesion severity, with markedly diminished numbers of T cells and nonlymphoid inflammatory cells, along with reduced cytokine mediators. The remaining inflammatory reactions had a change in the ratio of CD4 Foxp3(+) Treg to effector Th1 CD4 T cells in ocular lesions and lymphoid tissues, with Treg becoming predominant over the effectors. In addition, compared to those from control mice, Treg from Aza-treated mice showed more suppressor activity in vitro and expressed higher levels of activation molecules. Additionally, cells induced in vitro in the presence of Aza showed epigenetic differences in the Treg-specific demethylated region (TSDR) of Foxp3 and were more stable when exposed to inflammatory cytokines. Our results show that therapy with Aza is an effective means of controlling a virus-induced inflammatory reaction and may act mainly by the effects on Treg.IMPORTANCE HSV-1 infection has been shown to initiate an inflammatory reaction in the cornea that leads to tissue damage and loss of vision. The inflammatory reaction is orchestrated by gamma interferon (IFN-γ)-secreting Th1 cells, and regulatory T cells play a protective role. Hence, novel therapeutics that can rebalance the ratio of regulatory T cells to effectors are a relevant issue. This study opens up a new avenue in treating HSV-induced SK lesions by

  8. Conventional and Regulatory CD4+ T Cells That Share Identical TCRs Are Derived from Common Clones.

    PubMed

    Wolf, Kyle J; Emerson, Ryan O; Pingel, Jeanette; Buller, R Mark; DiPaolo, Richard J

    2016-01-01

    Results from studies comparing the diversity and specificity of the TCR repertoires expressed by conventional (Tconv) and regulatory (Treg) CD4+ T cell have varied depending on the experimental system employed. We developed a new model in which T cells express a single fixed TCRα chain, randomly rearranged endogenous TCRβ chains, and a Foxp3-GFP reporter. We purified CD4+Foxp3- and CD4+Foxp3+ cells, then performed biased controlled multiplex PCR and high throughput sequencing of endogenous TCRβ chains. We identified >7,000 different TCRβ sequences in the periphery of 5 individual mice. On average, ~12% of TCR sequences were expressed by both conventional and regulatory populations within individual mice. The CD4+ T cells that expressed shared TCR sequences were present at higher frequencies compared to T cells expressing non-shared TCRs. Furthermore, nearly all (>90%) of the TCR sequences that were shared within mice were identical at the DNA sequence level, indicating that conventional and regulatory T cells that express shared TCRs are derived from common clones. Analysis of TCR repertoire overlap in the thymus reveals that a large proportion of Tconv and Treg sharing observed in the periphery is due to clonal expansion in the thymus. Together these data show that there are a limited number of TCR sequences shared between Tconv and Tregs. Also, Tconv and Tregs sharing identical TCRs are found at relatively high frequencies and are derived from common progenitors, of which a large portion are generated in the thymus.

  9. The Regulatory Effects of Long Noncoding RNA-ANCR on Dental Tissue-Derived Stem Cells

    PubMed Central

    Jia, Qian; Chen, Xiaolin; Jiang, Wenkai; Wang, Wei

    2016-01-01

    Long noncoding RNAs (lncRNA) have been recognized as important regulators in diverse biological processes, such as transcriptional regulation, stem cell proliferation, and differentiation. Previous study has demonstrated that lncRNA-ANCR (antidifferentiation ncRNA) plays a key role in regulating the proliferation and osteogenic differentiation of periodontal ligament stem cells (PDLSCs). However, little is known about the role of ANCR in regulating other types of dental tissue-derived stem cells (DTSCs) behaviours (including proliferation and multiple-potential of differentiation). In this study, we investigated the regulatory effects of lncRNA-ANCR on the proliferation and differentiation (including osteogenic, adipogenic, and neurogenic differentiation) of DTSCs, including dental pulp stem cells (DPSCs), PDLSCs, and stem cells from the apical papilla (SCAP) by downregulation of lncRNA-ANCR. We found that downregulation of ANCR exerted little effect on proliferation of DPSCs and SCAP but promoted the osteogenic, adipogenic, and neurogenic differentiation of DTSCs. These data provide an insight into the regulatory effects of long noncoding RNA-ANCR on DTSCs and indicate that ANCR is a very important regulatory factor in stem cell differentiation. PMID:27648074

  10. T Regulatory Cells Control Susceptibility to Invasive Pneumococcal Pneumonia in Mice

    PubMed Central

    Neill, Daniel R.; Fernandes, Vitor E.; Wisby, Laura; Haynes, Andrew R.; Ferreira, Daniela M.; Laher, Ameera; Strickland, Natalie; Gordon, Stephen B.; Denny, Paul; Kadioglu, Aras; Andrew, Peter W.

    2012-01-01

    Streptococcus pneumoniae is an important human pathogen responsible for a spectrum of diseases including pneumonia. Immunological and pro-inflammatory processes induced in the lung during pneumococcal infection are well documented, but little is known about the role played by immunoregulatory cells and cytokines in the control of such responses. We demonstrate considerable differences in the immunomodulatory cytokine transforming growth factor (TGF)-β between the pneumococcal pneumonia resistant BALB/c and susceptible CBA/Ca mouse strains. Immunohistochemistry and flow cytometry reveal higher levels of TGF-β protein in BALB/c lungs during pneumococcal pneumonia that correlates with a rapid rise in lung Foxp3+Helios+ T regulatory cells. These cells have protective functions during pneumococcal pneumonia, because blocking their induction with an inhibitor of TGF-β impairs BALB/c resistance to infection and aids bacterial dissemination from lungs. Conversely, adoptive transfer of T regulatory cells to CBA/Ca mice, prior to infection, prolongs survival and decreases bacterial dissemination from lungs to blood. Importantly, strong T regulatory cell responses also correlate with disease-resistance in outbred MF1 mice, confirming the importance of immunoregulatory cells in controlling protective responses to the pneumococcus. This study provides exciting new evidence for the importance of immunomodulation during pulmonary pneumococcal infection and suggests that TGF-β signalling is a potential target for immunotherapy or drug design. PMID:22563306

  11. IL-10/TGF-beta-modified macrophages induce regulatory T cells and protect against adriamycin nephrosis.

    PubMed

    Cao, Qi; Wang, Yiping; Zheng, Dong; Sun, Yan; Wang, Ya; Lee, Vincent W S; Zheng, Guoping; Tan, Thian Kui; Ince, Jon; Alexander, Stephen I; Harris, David C H

    2010-06-01

    IL-10/TGF-beta-modified macrophages, a subset of activated macrophages, produce anti-inflammatory cytokines, suggesting that they may protect against inflammation-mediated injury. Here, macrophages modified ex vivo by IL-10/TGF-beta (IL-10/TGF-beta Mu2) significantly attenuated renal inflammation, structural injury, and functional decline in murine adriamycin nephrosis (AN). These cells deactivated effector macrophages and inhibited CD4+ T cell proliferation. IL-10/TGF-beta Mu2 expressed high levels of the regulatory co-stimulatory molecule B7-H4, induced regulatory T cells from CD4+CD25- T cells in vitro, and increased the number of regulatory T cells in lymph nodes draining the kidneys in AN. The phenotype of IL-10/TGF-beta Mu2 did not switch to that of effector macrophages in the inflamed kidney, and these cells did not promote fibrosis. Taken together, these data demonstrate that IL-10/TGF-beta-modified macrophages effectively protect against renal injury in AN and may become part of a therapeutic strategy for chronic inflammatory disease.

  12. Disorders of regulatory T cell function in patients with the Wiskott-Aldrich syndrome.

    PubMed Central

    Zabay, J M; Fontán, G; Campos, A; García-Rodriguez, M C; Pascual-Salcedo, D; Bootello, A; de la Concha, E G

    1984-01-01

    Three patients with the Wiskott-Aldrich syndrome were studied. One of them had no past history of relevant infections. The other two presented different degrees of humoral and cellular immunodeficiency and their T cells in vitro showed a defect in regulatory activity of Ig production in PWM stimulated cultures. This defect was not observed in the third patient. All three had normal numbers of B cells, producing normal amounts of Ig in vitro when co-cultured with normal T cells. It is suggested that the immunoregulatory T cell abnormality might play an important role in the pathogenesis of the humoral immunodeficiency. PMID:6609033

  13. Association Mapping of Cell Wall Synthesis Regulatory Genes and Cell Wall Quality in Switchgrass

    SciTech Connect

    Bartley, Laura; Wu, Y.; Zhu, L.; Brummer, E. C.; Saha, M.

    2016-05-31

    markers might be used to select switchgrass genotypes with improved composition in breeding programs for biofuel and forage production. Because the SSAC continues to be characterized by collaborators in the bioenergy community, the data generated will be used to identify additional markers in higher resolution genotyping data to approach identifying the genes and alleles that cause natural variation in switchgrass cell wall quality. For example, these markers can be surveyed in the 2100-member Oklahoma Southern and Northern Lowland switchgrass collections that this project also characterized. An orthogonal approach to biodiversity studies, using comparative functional genomics permits systematic querying of how much regulatory information is likely to be transferable from dicots to grasses and use of accumulated functional genomics resources for better-characterized grass species, such as rice, itself a biomass source in global agriculture and in certain regions. The project generated and tested a number of specific hypotheses regarding cell wall transcription factors and enzymes of grasses. To aid identification of cell wall regulators, the project assembled a novel, highdepth and -quality gene association network using a general linearized model scoring system to combine rice gene network data. Using known or putative orthologs of Arabidopsis cell wall biosynthesis genes and regulators, the project pulled from this network a cell wall sub-network that includes 96 transcription factors. Reverse genetics of a co-ortholog of the Arabidopsis MYB61 transcription factor in rice revealed that this regulatory node has evolved the ability to regulate grass-specific cell wall synthesis enzymes. A transcription factor with such activity has not been previously characterized to our knowledge, representing a major conclusion of this work. Changes in gene expression in a protoplast-based assay demonstrated positive or negative roles in cell wall regulation for eleven other

  14. Harnessing Regulatory T Cells for the Treatment of Inflammatory Bowel Disease

    PubMed Central

    Geem, Duke; Harusato, Akihito; Flannigan, Kyle

    2015-01-01

    Abstract: Regulatory CD4+ T (Treg) cells are comprised of a heterogeneous population of cells that play a vital role in suppressing inflammation and maintaining immune tolerance. The immunoregulatory function of Treg cells is especially important in the intestine where the mucosa is exposed to a diverse array of foreign antigens—including those derived from food and commensal bacteria. Treg cells are enriched in the intestinal lamina propria and provide a crucial function in promoting tolerance to enteric antigens while modulating tissue inflammation. Correspondingly, Treg cell dysfunction is associated with a breakdown in intestinal tolerance and the induction of aberrant immune responses that may contribute to the pathogenesis of inflammatory bowel disease. This review will provide a brief overview of Treg cell biology with a focus on Foxp3+ Treg and type 1 regulatory (Tr1) cells and summarize the evidence for defective Treg cells in experimental and human inflammatory bowel disease. The potential application of Treg cells as a treatment for inflammatory bowel disease will also be discussed in the context of Treg infusion therapy and the in vivo induction/expansion of intestinal Treg cells. PMID:25793328

  15. Putative cis-regulatory elements in genes highly expressed in rice sperm cells

    PubMed Central

    2011-01-01

    Background The male germ line in flowering plants is initiated within developing pollen grains via asymmetric division. The smaller cell then becomes totally encased within a much larger vegetative cell, forming a unique "cell within a cell structure". The generative cell subsequently divides to give rise to two non-motile diminutive sperm cells, which take part in double fertilization and lead to the seed set. Sperm cells are difficult to investigate because of their presence within the confines of the larger vegetative cell. However, recently developed techniques for the isolation of rice sperm cells and the fully annotated rice genome sequence have allowed for the characterization of the transcriptional repertoire of sperm cells. Microarray gene expression data has identified a subset of rice genes that show unique or highly preferential expression in sperm cells. This information has led to the identification of cis-regulatory elements (CREs), which are conserved in sperm-expressed genes and are putatively associated with the control of cell-specific expression. Findings We aimed to identify the CREs associated with rice sperm cell-specific gene expression data using in silico prediction tools. We analyzed 1-kb upstream regions of the top 40 sperm cell co-expressed genes for over-represented conserved and novel motifs. Analysis of upstream regions with the SIGNALSCAN program with the PLACE database, MEME and the Mclip tool helped to find combinatorial sets of known transcriptional factor-binding sites along with two novel motifs putatively associated with the co-expression of sperm cell-specific genes. Conclusions Our data shows the occurrence of novel motifs, which are putative CREs and are likely targets of transcriptional factors regulating sperm cell gene expression. These motifs can be used to design the experimental verification of regulatory elements and the identification of transcriptional factors that regulate sperm cell-specific gene expression. PMID

  16. Reconstructing differentially co-expressed gene modules and regulatory networks of soybean cells

    PubMed Central

    2012-01-01

    Background Current experimental evidence indicates that functionally related genes show coordinated expression in order to perform their cellular functions. In this way, the cell transcriptional machinery can respond optimally to internal or external stimuli. This provides a research opportunity to identify and study co-expressed gene modules whose transcription is controlled by shared gene regulatory networks. Results We developed and integrated a set of computational methods of differential gene expression analysis, gene clustering, gene network inference, gene function prediction, and DNA motif identification to automatically identify differentially co-expressed gene modules, reconstruct their regulatory networks, and validate their correctness. We tested the methods using microarray data derived from soybean cells grown under various stress conditions. Our methods were able to identify 42 coherent gene modules within which average gene expression correlation coefficients are greater than 0.8 and reconstruct their putative regulatory networks. A total of 32 modules and their regulatory networks were further validated by the coherence of predicted gene functions and the consistency of putative transcription factor binding motifs. Approximately half of the 32 modules were partially supported by the literature, which demonstrates that the bioinformatic methods used can help elucidate the molecular responses of soybean cells upon various environmental stresses. Conclusions The bioinformatics methods and genome-wide data sources for gene expression, clustering, regulation, and function analysis were integrated seamlessly into one modular protocol to systematically analyze and infer modules and networks from only differential expression genes in soybean cells grown under stress conditions. Our approach appears to effectively reduce the complexity of the problem, and is sufficiently robust and accurate to generate a rather complete and detailed view of putative soybean

  17. Cis-regulatory mechanisms governing stem and progenitor cell transitions

    PubMed Central

    Johnson, Kirby D.; Kong, Guangyao; Gao, Xin; Chang, Yuan-I; Hewitt, Kyle J.; Sanalkumar, Rajendran; Prathibha, Rajalekshmi; Ranheim, Erik A.; Dewey, Colin N.; Zhang, Jing; Bresnick, Emery H.

    2015-01-01

    Cis-element encyclopedias provide information on phenotypic diversity and disease mechanisms. Although cis-element polymorphisms and mutations are instructive, deciphering function remains challenging. Mutation of an intronic GATA motif (+9.5) in GATA2, encoding a master regulator of hematopoiesis, underlies an immunodeficiency associated with myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). Whereas an inversion relocalizes another GATA2 cis-element (−77) to the proto-oncogene EVI1, inducing EVI1 expression and AML, whether this reflects ectopic or physiological activity is unknown. We describe a mouse strain that decouples −77 function from proto-oncogene deregulation. The −77−/− mice exhibited a novel phenotypic constellation including late embryonic lethality and anemia. The −77 established a vital sector of the myeloid progenitor transcriptome, conferring multipotentiality. Unlike the +9.5−/− embryos, hematopoietic stem cell genesis was unaffected in −77−/− embryos. These results illustrate a paradigm in which cis-elements in a locus differentially control stem and progenitor cell transitions, and therefore the individual cis-element alterations cause unique and overlapping disease phenotypes. PMID:26601269

  18. PD-1 marks dysfunctional regulatory T cells in malignant gliomas

    PubMed Central

    Lowther, Daniel E.; Goods, Brittany A.; Lucca, Liliana E.; Lerner, Benjamin A.; Raddassi, Khadir; van Dijk, David; Hernandez, Amanda L.; Duan, Xiangguo; Gunel, Murat; Coric, Vlad; Krishnaswamy, Smita; Hafler, David A.

    2016-01-01

    Immunotherapies targeting the immune checkpoint receptor programmed cell death protein 1 (PD-1) have shown remarkable efficacy in treating cancer. CD4+CD25hiFoxP3+ Tregs are critical regulators of immune responses in autoimmunity and malignancies, but the functional status of human Tregs expressing PD-1 remains unclear. We examined functional and molecular features of PD-1hi Tregs in healthy subjects and patients with glioblastoma multiforme (GBM), combining functional assays, RNA sequencing, and cytometry by time of flight (CyTOF). In both patients with GBM and healthy subjects, circulating PD-1hi Tregs displayed reduced suppression of CD4+ effector T cells, production of IFN-γ, and molecular signatures of exhaustion. Transcriptional profiling of tumor-resident Tregs revealed that several genes coexpressed with PD-1 and associated with IFN-γ production and exhaustion as well as enrichment in exhaustion signatures compared with circulating PD-1hi Tregs. CyTOF analysis of circulating and tumor-infiltrating Tregs from patients with GBM treated with PD-1-blocking antibodies revealed that treatment shifts the profile of circulating Tregs toward a more exhausted phenotype reminiscent of that of tumor-infiltrating Tregs, further increasing IFN-γ production. Thus, high PD-1 expression on human Tregs identifies dysfunctional, exhausted Tregs secreting IFN-γ that exist in healthy individuals and are enriched in tumor infiltrates, possibly losing function as they attempt to modulate the antitumoral immune responses. PMID:27182555

  19. Molecular determinants of regulatory T cell development: the essential roles of epigenetic changes.

    PubMed

    Kitagawa, Yohko; Ohkura, Naganari; Sakaguchi, Shimon

    2013-01-01

    Regulatory T (Treg) cells constitute a distinct T cell subset, which plays a key role in immune tolerance and homeostasis. The transcription factor Foxp3 controls a substantial part of Treg cell development and function. Yet its expression alone is insufficient for conferring developmental and functional characteristics of Treg cells. There is accumulating evidence that concurrent induction of Treg-specific epigenetic changes and Foxp3 expression is crucial for lineage specification and functional stability of Treg cells. This review discusses recent progress in our understanding of molecular features of Treg cells, in particular, the molecular basis of how a population of developing T cells is driven to the Treg cell lineage and how its function is stably maintained.

  20. An essential role for IL-2 receptor in regulatory T cell function

    PubMed Central

    Levine, Andrew G; Fan, Xiying; Klein, Ulf; Zheng, Ye; Gasteiger, Georg; Feng, Yongqiang; Fontenot, Jason D.; Rudensky, Alexander Y.

    2016-01-01

    Regulatory T (Treg) cells, expressing abundant amounts of the IL-2 receptor (IL-2R), are reliant on IL-2 produced by activated T cells. This feature implied a key role for a simple network based on IL-2 consumption by Treg cells in their suppressor function. However, congenital deficiency in IL-2R results in reduced expression of the Treg cell lineage specification factor Foxp3, confounding experimental efforts to understand the role of IL-2R expression and signaling in Treg suppressor function. Using genetic gain and loss of function approaches, we demonstrate that IL-2 capture is dispensable for control of CD4+ T cells, but is important for limiting CD8+ T cell activation, and that IL-2R dependent STAT5 transcription factor activation plays an essential role in Treg cell suppressor function separable from T cell receptor signaling. PMID:27595233

  1. Regulatory T cells in tumor-associated tertiary lymphoid structures suppress anti-tumor T cell responses

    PubMed Central

    Joshi, Nikhil S.; Akama-Garren, Elliot H.; Lu, Yisi; Lee, Da-Yae; Chang, Gregory P.; Li, Amy; DuPage, Michel; Tammela, Tuomas; Kerper, Natanya R.; Farago, Anna F.; Robbins, Rebecca; Crowley, Denise M.; Bronson, Roderick T.; Jacks, Tyler

    2016-01-01

    SUMMARY Infiltration of regulatory T (Treg) cells into many tumor types correlates with poor patient prognoses. However, mechanisms of intratumoral Treg cell function remain to be elucidated. We investigated Treg cell function in a genetically-engineered mouse lung adenocarcinoma model and found Treg cells suppress anti-tumor responses in tumor-associated tertiary lymphoid structures (TA-TLS). TA-TLS have been described in human lung cancers, but their function remains to be determined. TLS in this model were spatially associated with >90% of tumors and facilitated interactions between T cells and tumor-antigen presenting dendritic cells (DCs). Costimulatory ligand expression by DCs and T cell proliferation rates increased in TA-TLS upon Treg cell depletion, leading to tumor destruction. Thus, we propose Treg cells in TA-TLS can inhibit endogenous immune responses against tumors, and targeting these cells may provide therapeutic benefit for cancer patients. PMID:26341400

  2. The role of T regulatory cells in immunopathogenesis of myasthenia gravis: implications for therapeutics.

    PubMed

    Alahgholi-Hajibehzad, Mahdi; Kasapoglu, Pinar; Jafari, Reza; Rezaei, Nima

    2015-01-01

    T regulatory cells (Tregs) are crucial for the development of self-tolerance and are the major focus in many studies interpreting the pathogenesis of myasthenia gravis (MG), an autoimmune-based disease. In normal conditions, Tregs regulate the immune responses, while impaired regulatory function of these cells can lead to autoimmunity. Recent studies have confirmed that the thymic and peripheral blood CD4(+)CD25(+) Tregs of MG are defective in functions and/or in numbers, which are associated with disease severity; approaches to correct the defects of these Tregs may be promising in the treatment of MG. This review discusses recent studies on characteristics, quantitative and qualitative changes of Tregs and possible mechanisms that are involved in the impairment of these cells in MG pathogenesis. In addition, new approaches inducing Treg generation that are currently being investigated as therapies for MG, will be discussed as well as proposed approaches for future therapies.

  3. Global regulatory developments for clinical stem cell research: diversification and challenges to collaborations.

    PubMed

    Rosemann, Achim; Bortz, Gabriela; Vasen, Federico; Sleeboom-Faulkner, Margaret

    2016-10-01

    In this article, we explore regulatory developments in stem cell medicine in seven jurisdictions: Japan, China, India, Argentina, Brazil, the USA and the EU. We will show that the research methods, ethical standards and approval procedures for the market use of clinical stem cell interventions are undergoing an important process of global diversification. We will discuss the implications of this process for international harmonization and the conduct of multicountry clinical research collaborations. It will become clear that the increasing heterogeneity of research standards and regulations in the stem cell field presents a significant challenge to international clinical trial partnerships, especially with countries that diverge from the regulatory models that have been developed in the USA and the EU.

  4. [Regulatory requirements regarding cell-based medicinal products for human and veterinary use - a comparison].

    PubMed

    Kuhlmann-Gottke, Johanna; Duchow, Karin

    2015-11-01

    At present, there is no separate regulatory framework for cell-based medicinal products (CBMP) for veterinary use at the European or German level. Current European and national regulations exclusively apply to the corresponding medicinal products for human use. An increasing number of requests for the regulatory classification of CBMP for veterinary use, such as allogeneic stem cell preparations and dendritic cell-based autologous tumour vaccines, and a rise in scientific advice for companies developing these products, illustrate the need for adequate legislation. Currently, advice is given and decisions are made on a case-by-case basis regarding the regulatory classification and authorisation requirements.Since some of the CBMP - in particular in the area of stem-cell products - are developed in parallel for human and veterinary use, there is an urgent need to create specific legal definitions, regulations, and guidelines for these complex innovative products in the veterinary sector as well. Otherwise, there is a risk that that the current legal grey area regarding veterinary medicinal products will impede therapeutic innovations in the long run. A harmonised EU-wide approach is desirable. Currently the European legislation on veterinary medicinal products is under revision. In this context, veterinary therapeutics based on allogeneic cells and tissues will be defined and regulated. Certainly, the legal framework does not have to be as comprehensive as for human CBMP; a leaner solution is conceivable, similar to the special provisions for advanced-therapy medicinal products laid down in the German Medicines Act.

  5. Regulatory B Cells in Pregnancy: Lessons from Autoimmunity, Graft Tolerance, and Cancer

    PubMed Central

    Guzman-Genuino, Ruth Marian; Diener, Kerrilyn R.

    2017-01-01

    The success of pregnancy is contingent on the maternal immune system recognizing and accommodating a growing semi-allogeneic fetus. Specialized subsets of lymphocytes capable of negative regulation are fundamental in this process, and include the regulatory T cells (Tregs) and potentially, regulatory B cells (Bregs). Most of our current understanding of the immune regulatory role of Bregs comes from studies in the fields of autoimmunity, transplantation tolerance, and cancer biology. Bregs control autoimmune diseases and can elicit graft tolerance by inhibiting the differentiation of effector T cells and dendritic cells (DCs), and activating Tregs. Furthermore, in cancer, Bregs are hijacked by neoplastic cells to promote tumorigenesis. Pregnancy therefore represents a condition that reconciles these fields—mechanisms must be in place to ensure maternal immunological tolerance throughout gravidity to allow the semi-allogeneic fetus to grow within. Thus, the mechanisms underlying Breg activities in autoimmune diseases, transplantation tolerance, and cancer may take place during pregnancy as well. In this review, we discuss the potential role of Bregs as guardians of pregnancy and propose an endocrine-modulated feedback loop highlighting the Breg–Treg–tolerogenic DC interface essential for the induction of maternal immune tolerance. PMID:28261223

  6. Effects of royal jelly supplementation on regulatory T cells in children with SLE

    PubMed Central

    Zahran, Asmaa M.; Elsayh, Khalid I.; Saad, Khaled; Eloseily, Esraa M.A.; Osman, Naglaa S.; Alblihed, Mohamd A.; Badr, Gamal; Mahmoud, Mohamed H.

    2016-01-01

    Background and objective To our knowledge, no previous studies have focused on the immunomodulatory effects of fresh royal jelly (RJ) administration on systemic lupus erythematosus (SLE) in humans. Our aim was to study the effect of fresh RJ administration on the disease course in children with SLE with some immunological markers (CD4+ and CD8+ regulatory T cells and T lymphocytes apoptosis). Methods This was an open-label study in which 20 SLE children received 2 g of freshly prepared RJ daily, for 12 weeks. Results The percentages of CD4+ CD25+high FOXP3+cells (CD4+ regulatory T cells) and CD8+CD25+high FOXP3+cells (CD8+ regulatory T cells) were significantly increased after RJ treatment when compared with baseline values. Apoptotic CD4 T lymphocytes were significantly decreased after RJ therapy when compared with baseline values and the control group. Conclusion This is the first human study on the effect of RJ supplementation in children with SLE. Our results showed improvements with 3-month RJ treatment with regard to the clinical severity score and laboratory markers for the disease. At this stage, it is a single study with a small number of patients, and a great deal of additional wide-scale randomized controlled studies are needed to critically validate the efficacy of RJ in SLE. PMID:27887663

  7. Regulatory B Cells in Pregnancy: Lessons from Autoimmunity, Graft Tolerance, and Cancer.

    PubMed

    Guzman-Genuino, Ruth Marian; Diener, Kerrilyn R

    2017-01-01

    The success of pregnancy is contingent on the maternal immune system recognizing and accommodating a growing semi-allogeneic fetus. Specialized subsets of lymphocytes capable of negative regulation are fundamental in this process, and include the regulatory T cells (Tregs) and potentially, regulatory B cells (Bregs). Most of our current understanding of the immune regulatory role of Bregs comes from studies in the fields of autoimmunity, transplantation tolerance, and cancer biology. Bregs control autoimmune diseases and can elicit graft tolerance by inhibiting the differentiation of effector T cells and dendritic cells (DCs), and activating Tregs. Furthermore, in cancer, Bregs are hijacked by neoplastic cells to promote tumorigenesis. Pregnancy therefore represents a condition that reconciles these fields-mechanisms must be in place to ensure maternal immunological tolerance throughout gravidity to allow the semi-allogeneic fetus to grow within. Thus, the mechanisms underlying Breg activities in autoimmune diseases, transplantation tolerance, and cancer may take place during pregnancy as well. In this review, we discuss the potential role of Bregs as guardians of pregnancy and propose an endocrine-modulated feedback loop highlighting the Breg-Treg-tolerogenic DC interface essential for the induction of maternal immune tolerance.

  8. Increased expression of regulatory Tr1 cells in recurrent hepatitis C after liver transplantation.

    PubMed

    Carpentier, A; Conti, F; Stenard, F; Aoudjehane, L; Miroux, C; Podevin, P; Morales, O; Chouzenoux, S; Scatton, O; Groux, H; Auriault, C; Calmus, Y; Pancre, V; Delhem, N

    2009-09-01

    Immune response failure during HCV infection has been associated with the activity of regulatory T cells. Hepatitis C-related cirrhosis is the main reason for liver transplantation. However, 80% of transplanted patients present an accelerated recurrence of the disease. This study assessed the involvement of regulatory T-cell subsets (CD4+CD25+ cells: 'Treg' and CD49b+CD18+ cells: 'T regulatory-1' cells), in the recurrence of HCV after liver transplantation, using transcriptomic analysis, ELISA assays on serum samples and immunohistochemistry on liver biopsies from liver recipients 1 and 5 years after transplantation. Three groups of patients were included: stable HCV-negative recipients and those with mild and severe hepatitis C recurrence. At 5 years, Treg markers were overexpressed in all HCV+ recipients. By contrast, Tr1 markers were only overexpressed in patients with severe recurrence. At 1 year, a trend toward the overexpression of Tr1 was noted in patients evolving toward severe recurrence. IL-10 production, a characteristic of the Tr1 subset, was enhanced in severe recurrence at both 1 and 5 years. These results suggest that Tr1 are enhanced during severe HCV recurrence after liver transplantation and could be predictive of HCV recurrence. High levels of IL-10 at 1 year could be predictive of severe recurrence, and high IL-10 producers might warrant more intensive management.

  9. A Core Regulatory Circuit in Glioblastoma Stem Cells Links MAPK Activation to a Transcriptional Program of Neural Stem Cell Identity.

    PubMed

    Riddick, Gregory; Kotliarova, Svetlana; Rodriguez, Virginia; Kim, H S; Linkous, Amanda; Storaska, Andrew J; Ahn, Susie; Walling, Jennifer; Belova, Galina; Fine, Howard A

    2017-03-03

    Glioblastoma, the most common primary malignant brain tumor, harbors a small population of tumor initiating cells (glioblastoma stem cells) that have many properties similar to neural stem cells. To investigate common regulatory networks in both neural and glioblastoma stem cells, we subjected both cell types to in-vitro differentiation conditions and measured global gene-expression changes using gene expression microarrays. Analysis of enriched transcription factor DNA-binding sites in the promoters of differentially expressed genes was used to reconstruct regulatory networks involved in differentiation. Computational predictions, which were biochemically validated, show an extensive overlap of regulatory circuitry between cell types including a network centered on the transcription factor KLF4. We further demonstrate that EGR1, a transcription factor previously shown to be downstream of the MAPK pathway, regulates KLF4 expression and that KLF4 in turn transcriptionally activates NOTCH as well as SOX2. These results demonstrate how known genomic alterations in glioma that induce constitutive activation of MAPK are transcriptionally linked to master regulators essential for neural stem cell identify.

  10. A Core Regulatory Circuit in Glioblastoma Stem Cells Links MAPK Activation to a Transcriptional Program of Neural Stem Cell Identity

    PubMed Central

    Riddick, Gregory; Kotliarova, Svetlana; Rodriguez, Virginia; Kim, H. S.; Linkous, Amanda; Storaska, Andrew J.; Ahn, Susie; Walling, Jennifer; Belova, Galina; Fine, Howard A.

    2017-01-01

    Glioblastoma, the most common primary malignant brain tumor, harbors a small population of tumor initiating cells (glioblastoma stem cells) that have many properties similar to neural stem cells. To investigate common regulatory networks in both neural and glioblastoma stem cells, we subjected both cell types to in-vitro differentiation conditions and measured global gene-expression changes using gene expression microarrays. Analysis of enriched transcription factor DNA-binding sites in the promoters of differentially expressed genes was used to reconstruct regulatory networks involved in differentiation. Computational predictions, which were biochemically validated, show an extensive overlap of regulatory circuitry between cell types including a network centered on the transcription factor KLF4. We further demonstrate that EGR1, a transcription factor previously shown to be downstream of the MAPK pathway, regulates KLF4 expression and that KLF4 in turn transcriptionally activates NOTCH as well as SOX2. These results demonstrate how known genomic alterations in glioma that induce constitutive activation of MAPK are transcriptionally linked to master regulators essential for neural stem cell identify. PMID:28256619

  11. Arthritis protective regulatory potential of self–heat shock protein cross-reactive T cells

    PubMed Central

    van Eden, Willem; Wendling, Uwe; Paul, Liesbeth; Prakken, Berent; van Kooten, Peter; van der Zee, Ruurd

    2000-01-01

    Immunization with heat shock proteins has protective effects in models of induced arthritis. Analysis has shown a reduced synovial inflammation in such protected animals. Adoptive transfer and immunization with selected T cell epitopes (synthetic peptides) have indicated the protection to be mediated by T cells directed to conserved hsp epitopes. This was shown first for mycobacterial hsp60 and later for mycobacterial hsp70. Fine specificity analysis showed that such T cells were cross-reactive with the homologous self hsp. Therefore protection by microbial hsp reactive T cells can be by cross-recognition of self hsp overexpressed in the inflamed tissue. Preimmunization with hsp leads to a relative expansion of such self hsp cross-responsive T cells. The regulatory nature of such T cells may originate from mucosal tolerance maintained by commensal flora derived hsp or from partial activation through recognition of self hsp as a partial agonist (Altered Peptide Ligand) or in the absence of proper costimulation. Recently, we reported the selective upregulation of B7.2 on microbial hsp60 specific T cells in response to self hsp60. Through a preferred interaction with CTLA-4 on proinflammatory T cells this may constitute an effector mechanism of regulation. Also, regulatory T cells produced IL10. PMID:11189451

  12. Induced and Natural Regulatory T Cells in the Development of Inflammatory Bowel Disease

    PubMed Central

    Mayne, Christopher G.; Williams, Calvin B.

    2013-01-01

    The mucosal immune system mediates contact between the host, and the trillions of microbes that symbiotically colonize the gastrointestinal tract. Failure to tolerate the antigens within this “extended self” can result in inflammatory bowel disease (IBD). Within the adaptive immune system, the most significant cells modulating this interaction are Foxp3+ regulatory T (Treg) cells. Treg cells can be divided into two primary subsets: “natural” Treg (nTreg) cells, and “adaptive” or “induced” Treg (iTreg). Recent research suggests that these subsets serve to play both independent and synergistic roles in mucosal tolerance. Studies from both mouse models and human patients suggest defects in Treg cells can play distinct causative roles in IBD. Numerous genetic, microbial, nutritional, and environmental factors that associate with IBD may also affect Treg cells. In this review we summarize the development and function of Treg cells, and how their regulatory mechanisms may fail, leading to a loss of mucosal tolerance. We discuss both animal models and studies of IBD patients suggesting Treg cell involvement in IBD, and consider how Treg cells may be used in future therapies. PMID:23656897

  13. TRAF3 regulates the effector function of regulatory T cells and humoral immune responses

    PubMed Central

    Chang, Jae-Hoon; Hu, Hongbo; Jin, Jin; Puebla-Osorio, Nahum; Xiao, Yichuan; Gilbert, Brian E.; Brink, Robert; Ullrich, Stephen E.

    2014-01-01

    Regulatory T cells (Treg cells) control different aspects of immune responses, but how the effector functions of Treg cells are regulated is incompletely understood. Here we identified TNF receptor–associated factor 3 (TRAF3) as a regulator of Treg cell function. Treg cell–specific ablation of TRAF3 impaired CD4 T cell homeostasis, characterized by an increase in the Th1 type of effector/memory T cells. Moreover, the ablation of TRAF3 in Treg cells resulted in increased antigen-stimulated activation of follicular T helper cells (TFH cells), coupled with heightened formation of germinal centers and production of high-affinity IgG antibodies. Although the loss of TRAF3 did not reduce the overall frequency of Treg cells, it attenuated the antigen-stimulated production of follicular Treg cells (TFR cells). TRAF3 signaling in Treg cells was required to maintain high level expression of inducible co-stimulator (ICOS), which in turn was required for TFR cell generation and inhibition of antibody responses. These findings establish TRAF3 as a mediator of Treg cell function in the regulation of antibody responses and suggest a role for TRAF3 in mediating ICOS expression in Treg cells. PMID:24378539

  14. Regulatory mechanism of protein metabolic pathway during the differentiation process of chicken male germ cell.

    PubMed

    Li, Dong; Zuo, Qisheng; Lian, Chao; Zhang, Lei; Shi, Qingqing; Zhang, Zhentao; Wang, Yingjie; Ahmed, Mahmoud F; Tang, Beibei; Xiao, Tianrong; Zhang, Yani; Li, Bichun

    2015-08-01

    We explored the regulatory mechanism of protein metabolism during the differentiation process of chicken male germ cells and provide a basis for improving the induction system of embryonic stem cell differentiation to male germ cells in vitro. We sequenced the transcriptome of embryonic stem cells, primordial germ cells, and spermatogonial stem cells with RNA sequencing (RNA-Seq), bioinformatics analysis methods, and detection of the key genes by quantitative reverse transcription PCR (qRT-PCR). Finally, we found 16 amino acid metabolic pathways enriched in the biological metabolism during the differentiation process of embryonic stem cells to primordial germ cells and 15 amino acid metabolic pathways enriched in the differentiation stage of primordial germ cells to spermatogonial stem cells. We found three pathways, arginine-proline metabolic pathway, tyrosine metabolic pathway, and tryptophan metabolic pathway, significantly enriched in the whole differentiation process of embryonic stem cells to spermatogonial stem cells. Moreover, for these three pathways, we screened key genes such as NOS2, ADC, FAH, and IDO. qRT-PCR results showed that the expression trend of these genes were the same to RNA-Seq. Our findings showed that the three pathways and these key genes play an important role in the differentiation process of embryonic stem cells to male germ cells. These results provide basic information for improving the induction system of embryonic stem cell differentiation to male germ cells in vitro.

  15. Regulatory effects on the population dynamics and wave propagation in a cell lineage model.

    PubMed

    Wang, Mao-Xiang; Ma, Yu-Qiang; Lai, Pik-Yin

    2016-03-21

    We consider the interplay of cell proliferation, cell differentiation (and de-differentiation), cell movement, and the effect of feedback regulations on the population and propagation dynamics of different cell types in a cell lineage model. Cells are assumed to secrete and respond to negative feedback molecules which act as a control on the cell lineage. The cell densities are described by coupled reaction-diffusion partial differential equations, and the propagating wave front solutions in one dimension are investigated analytically and by numerical solutions. In particular, wavefront propagation speeds are obtained analytically and verified by numerical solutions of the equations. The emphasis is on the effects of the feedback regulations on different stages in the cell lineage. It is found that when the progenitor cell is negatively regulated, the populations of the cell lineage are strongly down-regulated with the steady growth rate of the progenitor cell being driven to zero beyond a critical regulatory strength. An analytic expression for the critical regulation strength in terms of the model parameters is derived and verified by numerical solutions. On the other hand, if the inhibition is acting on the differentiated cells, the change in the population dynamics and wave propagation speed is small. In addition, it is found that only the propagating speed of the progenitor cells is affected by the regulation when the diffusion of the differentiated cells is large. In the presence of de-differentiation, the effect on down-regulating the progenitor population is weakened and there is no effect on the propagation speed due to regulation, suggesting that the effect of regulatory control is diminished by de-differentiation pathways.

  16. Enhancing gene regulatory network inference through data integration with markov random fields.

    PubMed

    Banf, Michael; Rhee, Seung Y

    2017-02-01

    A gene regulatory network links transcription factors to their target genes and represents a map of transcriptional regulation. Much progress has been made in deciphering gene regulatory networks computationally. However, gene regulatory network inference for most eukaryotic organisms remain challenging. To improve the accuracy of gene regulatory network inference and facilitate candidate selection for experimentation, we developed an algorithm called GRACE (Gene Regulatory network inference ACcuracy Enhancement). GRACE exploits biological a priori and heterogeneous data integration to generate high- confidence network predictions for eukaryotic organisms using Markov Random Fields in a semi-supervised fashion. GRACE uses a novel optimization scheme to integrate regulatory evidence and biological relevance. It is particularly suited for model learning with sparse regulatory gold standard data. We show GRACE's potential to produce high confidence regulatory networks compared to state of the art approaches using Drosophila melanogaster and Arabidopsis thaliana data. In an A. thaliana developmental gene regulatory network, GRACE recovers cell cycle related regulatory mechanisms and further hypothesizes several novel regulatory links, including a putative control mechanism of vascular structure formation due to modifications in cell proliferation.

  17. Enhancing gene regulatory network inference through data integration with markov random fields

    PubMed Central

    Banf, Michael; Rhee, Seung Y.

    2017-01-01

    A gene regulatory network links transcription factors to their target genes and represents a map of transcriptional regulation. Much progress has been made in deciphering gene regulatory networks computationally. However, gene regulatory network inference for most eukaryotic organisms remain challenging. To improve the accuracy of gene regulatory network inference and facilitate candidate selection for experimentation, we developed an algorithm called GRACE (Gene Regulatory network inference ACcuracy Enhancement). GRACE exploits biological a priori and heterogeneous data integration to generate high- confidence network predictions for eukaryotic organisms using Markov Random Fields in a semi-supervised fashion. GRACE uses a novel optimization scheme to integrate regulatory evidence and biological relevance. It is particularly suited for model learning with sparse regulatory gold standard data. We show GRACE’s potential to produce high confidence regulatory networks compared to state of the art approaches using Drosophila melanogaster and Arabidopsis thaliana data. In an A. thaliana developmental gene regulatory network, GRACE recovers cell cycle related regulatory mechanisms and further hypothesizes several novel regulatory links, including a putative control mechanism of vascular structure formation due to modifications in cell proliferation. PMID:28145456

  18. Enhancing gene regulatory network inference through data integration with markov random fields

    DOE PAGES

    Banf, Michael; Rhee, Seung Y.

    2017-02-01

    Here, a gene regulatory network links transcription factors to their target genes and represents a map of transcriptional regulation. Much progress has been made in deciphering gene regulatory networks computationally. However, gene regulatory network inference for most eukaryotic organisms remain challenging. To improve the accuracy of gene regulatory network inference and facilitate candidate selection for experimentation, we developed an algorithm called GRACE (Gene Regulatory network inference ACcuracy Enhancement). GRACE exploits biological a priori and heterogeneous data integration to generate high- confidence network predictions for eukaryotic organisms using Markov Random Fields in a semi-supervised fashion. GRACE uses a novel optimization schememore » to integrate regulatory evidence and biological relevance. It is particularly suited for model learning with sparse regulatory gold standard data. We show GRACE’s potential to produce high confidence regulatory networks compared to state of the art approaches using Drosophila melanogaster and Arabidopsis thaliana data. In an A. thaliana developmental gene regulatory network, GRACE recovers cell cycle related regulatory mechanisms and further hypothesizes several novel regulatory links, including a putative control mechanism of vascular structure formation due to modifications in cell proliferation.« less

  19. Human Gamma Delta T Regulatory Cells in Cancer: Fact or Fiction?

    PubMed Central

    Wesch, Daniela; Peters, Christian; Siegers, Gabrielle Melanie

    2014-01-01

    While gamma delta T cell (γδTc) anticancer immunotherapies are being developed, recent reports suggest a regulatory role for γδTc tumor-infiltrating lymphocytes. This mini-review surveys available evidence, determines strengths and weaknesses thereof and suggest directions for further exploration. We focus on human γδTc, as mouse and human γδTc repertoires differ. Regulatory γδTc are defined and compared to conventional Tregs and their roles in health and disease (focusing in on cancer) are discussed. We contrast the suggested regulatory roles for γδTc in breast and colorectal cancer with their cytotoxic capabilities in other malignancies, emphasizing the context dependence of γδTc functional plasticity. Since γδTc can be induced to exhibit regulatory properties (in some cases reversible), we carefully scrutinize experimental procedures in published reports. As γδTc garner increasing interest for their therapeutic potential, it is critical that we appreciate the full extent of their role(s) and interactions with other cell types in both the circulation and the tumor microenvironment. A comprehensive understanding will enable manipulation of γδTc to improve anti-tumor efficacy and patient outcomes. PMID:25477885

  20. LFA-1 is critical for regulatory T cell homeostasis and function.

    PubMed

    Wohler, Jillian; Bullard, Dan; Schoeb, Trent; Barnum, Scott

    2009-07-01

    Cellular adhesion molecules involved in cell-to-cell mediated suppression by Tregs are not well characterized. We found that the majority of Tregs expressed LFA-1 but most strikingly that the frequency of Tregs in LFA-1(-/-) mice was significantly lower (approximately 50%) in the spleen, lymph nodes, and Peyer's patches compared to wild type controls. The reduction in LFA-1(-/-) Treg cells appears due in part to a reduced capacity of LFA-1(-/-) CD4(+)CD25(-) cells to be induced to become Tregs in the lymph nodes. Importantly, we found that LFA-1(-/-) Tregs fail to suppress T cell responses in vitro and have reduced function in vivo. Treg-mediated suppression does not depend on LFA-1 interactions with ICAM-1 on the surface of responder cells. Our data demonstrate that LFA-1 plays a critical role in regulatory T cell homeostasis and function.

  1. Classical dendritic cells are required for dietary antigen-mediated peripheral regulatory T cell and tolerance induction

    PubMed Central

    Esterházy, Daria; Loschko, Jakob; London, Mariya; Jove, Veronica; Oliveira, Thiago Y.; Mucida, Daniel

    2016-01-01

    Oral tolerance prevents pathological inflammatory responses towards innocuous foreign antigens via peripheral regulatory T cells (pTreg cells). However, whether a particular subset of antigen-presenting cells (APCs) is required during dietary antigen exposure to instruct naïve CD4+ T cells to differentiate into pTreg cells has not been defined. Using myeloid lineage-specific APC depletion in mice, we found that monocyte-derived APCs are dispensable, while classical dendritic cells (cDCs) are critical for pTreg cell induction and oral tolerance. CD11b− cDCs from the gut-draining lymph nodes efficiently induced pTreg cells, and conversely, loss of IRF8-dependent CD11b− cDCs impaired their polarization, although oral tolerance remained intact. These data reveal the hierarchy of cDC subsets in pTreg cell induction and their redundancy during oral tolerance development. PMID:27019226

  2. Interplay between regulatory T cells and PD-1 in modulating T cell exhaustion and viral control during chronic LCMV infection

    PubMed Central

    Penaloza-MacMaster, Pablo; Kamphorst, Alice O.; Wieland, Andreas; Araki, Koichi; Iyer, Smita S.; West, Erin E.; O’Mara, Leigh; Yang, Shu; Konieczny, Bogumila T.; Sharpe, Arlene H.; Freeman, Gordon J.

    2014-01-01

    Regulatory T (T reg) cells are critical for preventing autoimmunity mediated by self-reactive T cells, but their role in modulating immune responses during chronic viral infection is not well defined. To address this question and to investigate a role for T reg cells in exhaustion of virus-specific CD8 T cells, we depleted T reg cells in mice chronically infected with lymphocytic choriomeningitis virus (LCMV). T reg cell ablation resulted in 10–100-fold expansion of functional LCMV-specific CD8 T cells. Rescue of exhausted CD8 T cells was dependent on cognate antigen, B7 costimulation, and conventional CD4 T cells. Despite the striking recovery of LCMV-specific CD8 T cell responses, T reg cell depletion failed to diminish viral load. Interestingly, T reg cell ablation triggered up-regulation of the molecule programmed cell death ligand-1 (PD-L1), which upon binding PD-1 on T cells delivers inhibitory signals. Increased PD-L1 expression was observed especially on LCMV-infected cells, and combining T reg cell depletion with PD-L1 blockade resulted in a significant reduction in viral titers, which was more pronounced than that upon PD-L1 blockade alone. These results suggest that T reg cells effectively maintain CD8 T cell exhaustion, but blockade of the PD-1 inhibitory pathway is critical for elimination of infected cells. PMID:25113973

  3. Regulatory T cell number in multiple sclerosis patients: A meta-analysis.

    PubMed

    Noori-Zadeh, Ali; Mesbah-Namin, Seyed Alireza; Bistoon-Beigloo, Sara; Bakhtiyari, Salar; Abbaszadeh, Hojjat-Allah; Darabi, Shahram; Rajabibazl, Masoumeh; Abdanipour, Alireza

    2016-01-01

    Regulatory T cells (Treg cells), defined as CD4(+) CD25(+) FoxP3(+) T cells by expression of CD4, high-affinity IL-2 receptor and the transcription factor, forkhead box P3 (FoxP3). They play a pivotal role in protecting individuals from autoimmunity and a growing body of evidence suggests their role in the prevention of multiple sclerosis development. However, there are discrepancies about the type of defect in the Treg cells of multiple sclerosis patients and especially whether the Treg number alteration could be contributed to multiple sclerosis pathogenesis. Indeed, whether low number of Treg cells can be a risk factor contributing to multiple sclerosis pathogenesis is the matter of debate and there is not any comprehensive agreement on it. Thus, the objective of this systematic review and meta-analysis was to precisely quantify the nature and magnitude of the association between Treg cell number and the risk ratio/odds ratio (OR) of multiple sclerosis in the case-control studies. Hence, medical databases of Embase, PubMed/Medline, PubMed, PubMed Central and SCOPUS were searched for empirical papers using "Regulatory T cell frequency", "Treg frequency" in combination with "multiple sclerosis". In the case-control studies, papers were reviewed for inclusion/exclusion criteria and 8 publications were included. Under random-effect model meta-analysis the data showed that the frequency of Treg cells was not a risk factor in multiple sclerosis using current laboratory methods.

  4. Correlation between the cord vitamin D levels and regulatory T cells in newborn infants.

    PubMed

    Güven, Ayşegül; Ecevit, Ayşe; Sözer, Oktay; Tarcan, Aytül; Tarcan, Aylin; Ozbek, Namık

    2012-08-01

    Vitamin D is important for calcium homeostasis, muscle, and bone health. It has also immunomodulatory capacities in vivo and in vitro. Regulatory T cells (Treg) have been found to suppress a number of T cell-mediated immune disorders, including allergic responses and autoimmune diseases. This study aimed to investigate the correlation between 25-hydroxyvitamin D (25(OH)D) levels and the regulatory T cells in cord blood. The study group is comprised of 101 full-term newborn infants. Umbilical cord 25(OH)D levels and number and percentage of T lymphocyte, T helper, and Treg cells were measured. Infants were grouped according to 25-hydroxyvitamin D levels (25(OH)D <12 ng/ml and 25(OH)D >12 ng/ml) (converting factor of 25OHD level into SI unit, 2.6). Severe vitamin D deficiency (25(OH)D <12 ng/ml) was observed in 32% of the infants. There was no significant correlation between 25-hydroxyvitamin D levels and T cell number and percentages. There were also no significant differences in white blood cell, total lymphocyte count, T helper, and Treg cell percentage and number between groups. These results suggest that the serum level of 25-hydroxyvitamin D is not crucially involved in the correlation between vitamin D status and T cell regulation in cord blood.

  5. An EAR-Dependent Regulatory Module Promotes Male Germ Cell Division and Sperm Fertility in Arabidopsis.

    PubMed

    Borg, Michael; Rutley, Nicholas; Kagale, Sateesh; Hamamura, Yuki; Gherghinoiu, Mihai; Kumar, Sanjeev; Sari, Ugur; Esparza-Franco, Manuel A; Sakamoto, Wataru; Rozwadowski, Kevin; Higashiyama, Tetsuya; Twell, David

    2014-05-01

    The production of the sperm cells in angiosperms requires coordination of cell division and cell differentiation. In Arabidopsis thaliana, the germline-specific MYB protein DUO1 integrates these processes, but the regulatory hierarchy in which DUO1 functions is unknown. Here, we identify an essential role for two germline-specific DUO1 target genes, DAZ1 and DAZ2, which encode EAR motif-containing C2H2-type zinc finger proteins. We show that DAZ1/DAZ2 are required for germ cell division and for the proper accumulation of mitotic cyclins. Importantly, DAZ1/DAZ2 are sufficient to promote G2- to M-phase transition and germ cell division in the absence of DUO1. DAZ1/DAZ2 are also required for DUO1-dependent cell differentiation and are essential for gamete fusion at fertilization. We demonstrate that the two EAR motifs in DAZ1/DAZ2 mediate their function in the male germline and are required for transcriptional repression and for physical interaction with the corepressor TOPLESS. Our findings uncover an essential module in a regulatory hierarchy that drives mitotic transition in male germ cells and implicates gene repression pathways in sperm cell formation and fertility.

  6. Expression-Guided In Silico Evaluation of Candidate Cis Regulatory Codes for Drosophila Muscle Founder Cells

    PubMed Central

    Gisselbrecht, Stephen S; He, Fangxue Sherry; Estrada, Beatriz; Michelson, Alan M; Bulyk, Martha L

    2006-01-01

    While combinatorial models of transcriptional regulation can be inferred for metazoan systems from a priori biological knowledge, validation requires extensive and time-consuming experimental work. Thus, there is a need for computational methods that can evaluate hypothesized cis regulatory codes before the difficult task of experimental verification is undertaken. We have developed a novel computational framework (termed “CodeFinder”) that integrates transcription factor binding site and gene expression information to evaluate whether a hypothesized transcriptional regulatory model (TRM; i.e., a set of co-regulating transcription factors) is likely to target a given set of co-expressed genes. Our basic approach is to simultaneously predict cis regulatory modules (CRMs) associated with a given gene set and quantify the enrichment for combinatorial subsets of transcription factor binding site motifs comprising the hypothesized TRM within these predicted CRMs. As a model system, we have examined a TRM experimentally demonstrated to drive the expression of two genes in a sub-population of cells in the developing Drosophila mesoderm, the somatic muscle founder cells. This TRM was previously hypothesized to be a general mode of regulation for genes expressed in this cell population. In contrast, the present analyses suggest that a modified form of this cis regulatory code applies to only a subset of founder cell genes, those whose gene expression responds to specific genetic perturbations in a similar manner to the gene on which the original model was based. We have confirmed this hypothesis by experimentally discovering six (out of 12 tested) new CRMs driving expression in the embryonic mesoderm, four of which drive expression in founder cells. PMID:16733548

  7. The role of pregnancy-associated hormones in the development and function of regulatory B cells.

    PubMed

    Muzzio, Damián; Zygmunt, Marek; Jensen, Federico

    2014-01-01

    During mammalian pregnancy, highly specialized mechanisms of immune tolerance are triggered in order to allow the semi-allogeneic fetus to grow within the maternal uterus in harmony with the maternal immune system. Among other mechanisms, changes in the endocrine status have been proposed to be at least part of the machinery responsible for the induction of immune tolerance during pregnancy. Indeed, pregnancy-associated hormones, estradiol, progesterone, and human chorionic gonadotropin are known to confer immune suppressive capacity to innate as well as adaptive immune cells. Regulatory B cells, a subpopulation of B lymphocytes with strong immunosuppressive functions, were shown to expand during pregnancy. Furthermore, it is well-known that some women suffering from multiple sclerosis, significantly improve their symptoms during pregnancy and this was attributed to the effect of female sex hormones. Accordingly, estradiol protects mice from developing experimental autoimmune encephalomyelitis by triggering the expansion and activation of regulatory B cells. In this review, we discuss different mechanisms associated with the development, activation, and function of regulatory B cells with a special focus on those involving pregnancy-associated hormones.

  8. Regulatory B cells contribute to the impaired antitumor immunity in ovarian cancer patients.

    PubMed

    Wei, Xin; Jin, Yangqiu; Tian, Yinpu; Zhang, Huiyuan; Wu, Jie; Lu, Wei; Lu, Xiaofen

    2016-05-01

    Multiple factors in the tumor microenvironment were found to inhibit antitumor adaptive immune responses, allowing tumor persistence and growth. In this study, ascites from ovarian cancer patients were collected. We observed that a population of interleukin-10(+) B (IL-10(+) B) cells was preferentially enriched in the ascites. This population was associated with naive B cell phenotype or IgM or class-switched memory B cell phenotypes. The frequencies of IL-10(+) B cells were negatively correlated with the frequencies of interferon gamma-producing (IFN-g(+)) CD8(+) T cells and were positively correlated with the frequencies of Foxp3(+) CD4(+) T cells. To examine whether increased IL-10(+) B cells in ascites could directly result in increased suppression of IFN-g production by CD8(+) T cells, we cocultured CD8(+) T cells with autologous blood B cells or ascitic B cells and found that CD8(+) T cells cocultured with ascitic B cells demonstrated significantly suppressed IFN-g production. This suppression was in part mediated by IL-10 as well as low CD80/CD86 expression, since depletion of IL-10 and stimulation of CD28 partially reverted IL-10(+) B cell-mediated suppression. Together, these data demonstrated an additional regulatory mechanism in the tumor microenvironment, which utilizes IL-10(+) B cells.

  9. Regulation in chronic obstructive pulmonary disease: the role of regulatory T-cells and Th17 cells.

    PubMed

    Lane, Nina; Robins, R Adrian; Corne, Jonathan; Fairclough, Lucy

    2010-04-20

    COPD (chronic obstructive pulmonary disease) is an inflammatory disorder of the airways, which is associated with irreversible airway obstruction. The pathological hallmarks of COPD are destruction of the lung parenchyma (pulmonary emphysema), inflammation of the central airways (chronic bronchitis) and inflammation of the peripheral airways (respiratory bronchiolitis). Tobacco smoking is established as the main aetiological factor for COPD. A maladaptive modulation of inflammatory responses to inhalation of noxious particles and gases is generally accepted as being a key central pathogenic process; however, the precise regulatory mechanisms of the disease are poorly understood. Two cell types are known to be important in immune regulation, namely regulatory T-cells and the newly identified Th17 (T-helper 17) cells. Both types of cells are subsets of CD4 T-lymphocytes and modulate the immune response through secretion of cytokines, for example IL (interleukin)-10 and IL-17 respectively. The present review will begin by describing the current understanding of inflammatory cell involvement in the disease process, and then focus on the possible role of subsets of regulatory and helper T-cells in COPD.

  10. A Dynamic Gene Regulatory Network Model That Recovers the Cyclic Behavior of Arabidopsis thaliana Cell Cycle

    PubMed Central

    Ortiz-Gutiérrez, Elizabeth; García-Cruz, Karla; Azpeitia, Eugenio; Castillo, Aaron; Sánchez, María de la Paz; Álvarez-Buylla, Elena R.

    2015-01-01

    Cell cycle control is fundamental in eukaryotic development. Several modeling efforts have been used to integrate the complex network of interacting molecular components involved in cell cycle dynamics. In this paper, we aimed at recovering the regulatory logic upstream of previously known components of cell cycle control, with the aim of understanding the mechanisms underlying the emergence of the cyclic behavior of such components. We focus on Arabidopsis thaliana, but given that many components of cell cycle regulation are conserved among eukaryotes, when experimental data for this system was not available, we considered experimental results from yeast and animal systems. We are proposing a Boolean gene regulatory network (GRN) that converges into only one robust limit cycle attractor that closely resembles the cyclic behavior of the key cell-cycle molecular components and other regulators considered here. We validate the model by comparing our in silico configurations with data from loss- and gain-of-function mutants, where the endocyclic behavior also was recovered. Additionally, we approximate a continuous model and recovered the temporal periodic expression profiles of the cell-cycle molecular components involved, thus suggesting that the single limit cycle attractor recovered with the Boolean model is not an artifact of its discrete and synchronous nature, but rather an emergent consequence of the inherent characteristics of the regulatory logic proposed here. This dynamical model, hence provides a novel theoretical framework to address cell cycle regulation in plants, and it can also be used to propose novel predictions regarding cell cycle regulation in other eukaryotes. PMID:26340681

  11. Hepatic compartmentalization of exhausted and regulatory cells in HIV/HCV-coinfected patients.

    PubMed

    Barrett, L; Trehanpati, N; Poonia, S; Daigh, L; Sarin, S Kumar; Masur, H; Kottilil, S

    2015-03-01

    Accelerated intrahepatic hepatitis C virus (HCV) pathogenesis is likely the result of dysregulation within both the innate and adaptive immune compartments, but the exact contribution of peripheral blood and liver lymphocyte subsets remains unclear. Prolonged activation and expansion of immunoregulatory cells have been thought to play a role. We determined immune cell subset frequency in contemporaneous liver and peripheral blood samples from chronic HCV-infected and HIV/HCV-coinfected individuals. Peripheral blood mononuclear cells (PBMC) and biopsy-derived liver-infiltrating lymphocytes from 26 HIV/HCV-coinfected, 10 chronic HCV-infected and 10 HIV-infected individuals were assessed for various subsets of T and B lymphocytes, dendritic cell, natural killer (NK) cell and NK T-cell frequency by flow cytometry. CD8(+) T cells expressing the exhaustion marker PD-1 were increased in HCV-infected individuals compared with uninfected individuals (P = 0.02), and HIV coinfection enhanced this effect (P = 0.005). In the liver, regulatory CD4(+) CD25(+) Foxp3(+) T cells, as well as CD4(+) CD25(+) PD1(+) T cells, were more frequent in HIV/HCV-coinfected than in HCV-monoinfected samples (P < 0.001). HCV was associated with increased regulatory T cells, PD-1(+) T cells and decreased memory B cells, regardless of HIV infection (P ≤ 0.005 for all). Low CD8(+) expression was observed only in PD-1(+) CD8(+) T cells from HCV-infected individuals and healthy controls (P = 0.002) and was associated with enhanced expansion of exhausted CD8(+) T cells when exposed in vitro to PHA or CMV peptides. In conclusion, in HIV/HCV coinfection, ongoing HCV replication is associated with increased regulatory and exhausted T cells in the periphery and liver that may impact control of HCV. Simultaneous characterization of liver and peripheral blood highlights the disproportionate intrahepatic compartmentalization of immunoregulatory T cells, which may contribute to establishment of chronicity and

  12. Lung-resident tissue macrophages generate Foxp3+ regulatory T cells and promote airway tolerance

    PubMed Central

    Soroosh, Pejman; Doherty, Taylor A.; Duan, Wei; Mehta, Amit Kumar; Choi, Heonsik; Adams, Yan Fei; Mikulski, Zbigniew; Khorram, Naseem; Rosenthal, Peter; Broide, David H.

    2013-01-01

    Airway tolerance is the usual outcome of inhalation of harmless antigens. Although T cell deletion and anergy are likely components of tolerogenic mechanisms in the lung, increasing evidence indicates that antigen-specific regulatory T cells (inducible Treg cells [iTreg cells]) that express Foxp3 are also critical. Several lung antigen-presenting cells have been suggested to contribute to tolerance, including alveolar macrophages (MØs), classical dendritic cells (DCs), and plasmacytoid DCs, but whether these possess the attributes required to directly promote the development of Foxp3+ iTreg cells is unclear. Here, we show that lung-resident tissue MØs coexpress TGF-β and retinal dehydrogenases (RALDH1 and RALDH 2) under steady-state conditions and that their sampling of harmless airborne antigen and presentation to antigen-specific CD4 T cells resulted in the generation of Foxp3+ Treg cells. Treg cell induction in this model depended on both TGF-β and retinoic acid. Transfer of the antigen-pulsed tissue MØs into the airways correspondingly prevented the development of asthmatic lung inflammation upon subsequent challenge with antigen. Moreover, exposure of lung tissue MØs to allergens suppressed their ability to generate iTreg cells coincident with blocking airway tolerance. Suppression of Treg cell generation required proteases and TLR-mediated signals. Therefore, lung-resident tissue MØs have regulatory functions, and strategies to target these cells might hold promise for prevention or treatment of allergic asthma. PMID:23547101

  13. Collagen scaffold microenvironments modulate cell lineage commitment for differentiation of bone marrow cells into regulatory dendritic cells

    PubMed Central

    Fang, Yongxiang; Wang, Bin; Zhao, Yannan; Xiao, Zhifeng; Li, Jing; Cui, Yi; Han, Sufang; Wei, Jianshu; Chen, Bing; Han, Jin; Meng, Qingyuan; Hou, Xianglin; Luo, Jianxun; Dai, Jianwu; Jing, Zhizhong

    2017-01-01

    The microenvironment plays a pivotal role for cell survival and functional regulation, and directs the cell fate determination. The biological functions of DCs have been extensively investigated to date. However, the influences of the microenvironment on the differentiation of bone marrow cells (BMCs) into dendritic cells (DCs) are not well defined. Here, we established a 3D collagen scaffold microenvironment to investigate whether such 3D collagen scaffolds could provide a favourable niche for BMCs to differentiate into specialised DCs. We found that BMCs embedded in the 3D collagen scaffold differentiated into a distinct subset of DC, exhibiting high expression of CD11b and low expression of CD11c, co-stimulator (CD40, CD80, CD83, and CD86) and MHC-II molecules compared to those grown in 2D culture. DCs cultured in the 3D collagen scaffold possessed weak antigen uptake ability and inhibited T-cell proliferation in vitro; in addition, they exhibited potent immunoregulatory function to alleviate allo-delay type hypersensitivity when transferred in vivo. Thus, DCs differentiated in the 3D collagen scaffold were defined as regulatory DCs, indicating that collagen scaffold microenvironments probably play an important role in modulating the lineage commitment of DCs and therefore might be applied as a promising tool for generation of specialised DCs. PMID:28169322

  14. T Cell Receptor CDR3 Sequence but Not Recognition Characteristics Distinguish Autoreactive Effector and Foxp3+ Regulatory T Cells

    PubMed Central

    Liu, Xin; Nguyen, Phuong; Liu, Wei; Cheng, Cheng; Steeves, Meredith; Obenauer, John C.; Ma, Jing; Geiger, Terrence L.

    2010-01-01

    SUMMARY The source, specificity, and plasticity of the forkhead box transcription factor 3 (Foxp3)+ regulatory T (Treg) and conventional T (Tconv) cell populations active at sites of autoimmune pathology are not well characterized. To evaluate this, we combined global repertoire analyses and functional assessments of isolated T cell receptors (TCR) from TCRα retrogenic mice with autoimmune encephalomyelitis. Treg and Tconv cell TCR repertoires were distinct, and autoantigen-specific Treg and Tconv cells were enriched in diseased tissue. Autoantigen sensitivity and fine specificity of these cells intersected, implying that differences in responsiveness were not responsible for lineage specification. Notably, autoreactive Treg and Tconv cells could be fully distinguished by an acidic versus aliphatic variation at a single TCR CDR3 residue. Our results imply that ontogenically distinct Treg and Tconv cell repertoires with convergent specificities for autoantigen respond during autoimmunity and argue against more than limited plasticity between Treg and Tconv cells during autoimmune inflammation. PMID:20005134

  15. Autoimmune Hepatitis: Progress from Global Immunosuppression to Personalised Regulatory T Cell Therapy

    PubMed Central

    Than, Nwe Ni; Jeffery, Hannah C.; Oo, Ye H.

    2016-01-01

    Autoimmune hepatitis (AIH) is an immune mediated liver injury. The precise aetiology of AIH is still unknown but current evidence suggests both genetic and environmental factors are involved. Breakdown in peripheral self-tolerance, and impaired functions of FOXP3+ regulatory T cell along with effector cell resistance to suppression at the tissue level seem to play an important role in AIH immunopathogenesis. AIH is predominantly a T lymphocytes driven disease but B lymphocytes are also involved in the immunopathology. Innate immune cells are crucial in the initial onset of disease and their response is followed by adaptive T (Th1, Th17, and cytotoxic T cells) and B cell responses evidenced by liver histology and peripheral blood serology. Standard treatment regimens involving steroid and immunosuppressive medications lead to global immune suppression requiring life-long therapy with many side effects. Biologic therapies have been attempted but duration of remission is short-lived. Future direction of diagnosis and treatment for AIH should be guided by “omics” and the immunology profile of the individual patient and clinicians should aim to deliver personalised medicine for their patients. Cell therapy such as infusion of autologous, antigen-specific, and liver-homing regulatory T cells to restore hepatic immune tolerance may soon be a potential future treatment for AIH patients. PMID:27446862

  16. Regulatory considerations in production of a cell therapy medicinal product in Europe to clinical research.

    PubMed

    Martín, Patricia Gálvez; Martinez, Adolfina Ruiz; Lara, Visitación Gallardo; Naveros, Beatriz Clares

    2014-02-01

    The development of new drugs using stem cells has become a clinic alternative for the treatment of different diseases such as Alzheimer's, diabetes and myocardial infarction. Similar to conventional medicines, stem cells as new medicinal products for cell therapy are subjected to current legislation concerning their manufacture process. Besides, their legality is determined by the Regulatory Agencies belonging to the Member State of the European Union in which they are being registered. With the evolution of therapy that uses cells as medicines, there is a need to develop the appropriate legislative and regulatory framework capable of ensuring their safety and effectiveness. However, few works have been published regarding the regulations that these products must comply through production and commercialization processes. The present work is focused on the description of key events during clinical development and cell production of stem cells as drugs. Such as the regulations, requirements and directives involved in the production of cell therapy medicinal products, from the clinical design stage to its commercialization in Europe.

  17. A regulatory framework for shoot stem cell control integrating metabolic, transcriptional, and phytohormone signals.

    PubMed

    Schuster, Christoph; Gaillochet, Christophe; Medzihradszky, Anna; Busch, Wolfgang; Daum, Gabor; Krebs, Melanie; Kehle, Andreas; Lohmann, Jan U

    2014-02-24

    Plants continuously maintain pluripotent stem cells embedded in specialized tissues called meristems, which drive long-term growth and organogenesis. Stem cell fate in the shoot apical meristem (SAM) is controlled by the homeodomain transcription factor WUSCHEL (WUS) expressed in the niche adjacent to the stem cells. Here, we demonstrate that the bHLH transcription factor HECATE1 (HEC1) is a target of WUS and that it contributes to SAM function by promoting stem cell proliferation, while antagonizing niche cell activity. HEC1 represses the stem cell regulators WUS and CLAVATA3 (CLV3) and, like WUS, controls genes with functions in metabolism and hormone signaling. Among the targets shared by HEC1 and WUS are phytohormone response regulators, which we show to act as mobile signals in a universal feedback system. Thus, our work sheds light on the mechanisms guiding meristem function and suggests that the underlying regulatory system is far more complex than previously anticipated.

  18. Graded Foxo1 Activity in Regulatory T Cells Differentiates Tumor Immunity from Autoimmunity

    PubMed Central

    Luo, Chong T.; Liao, Will; Dadi, Saida; Toure, Ahmed; Li, Ming O.

    2016-01-01

    Summary Regulatory T (Treg) cells expressing the transcription factor Foxp3 have a pivotal role in maintaining immunological self-tolerance1-5; yet, excessive Treg cell activities suppress anti-tumor immune responses6-8. Compared to resting phenotype Treg (rTreg) cells in the secondary lymphoid organs, Treg cells in non-lymphoid tissues including solid tumors exhibit an activated Treg (aTreg) cell phenotype9-11. However, aTreg cell function and whether its generation can be manipulated to promote tumor immunity without evoking autoimmunity are largely unexplored. Here we show that the transcription factor Foxo1, previously demonstrated to promote Treg cell suppression of lymphoproliferative diseases12,13, has an unexpected function in inhibiting aTreg cell-mediated immune tolerance. We found that aTreg cells turned over at a slower rate than rTreg cells, but were not locally maintained in tissues. Transcriptome analysis revealed that aTreg cell differentiation was associated with repression of Foxo1-dependent gene transcription, concomitant with reduced Foxo1 expression and enhanced Foxo1 phosphorylation at sites of the Akt kinase. Treg cell-specific expression of an Akt-insensitive Foxo1 mutant prevented downregulation of lymphoid organ homing molecules, and depleted aTreg cells, causing CD8+ T cell-mediated autoimmune diseases. Compared to Treg cells from healthy tissues, tumor-infiltrating Treg cells downregulated Foxo1 target genes more substantially. Expression of the Foxo1 mutant at a lower dose was sufficient to deplete tumor-associated Treg cells, activate effector CD8+ T cells, and inhibit tumor growth without inflicting autoimmunity. Thus, Foxo1 inactivation is essential for the generation of aTreg cells that have a crucial function in suppressing CD8+ T cell responses; and the Foxo signaling pathway in Treg cells can be titrated to preferentially break tumor immune tolerance. PMID:26789248

  19. Regulatory mechanism of human vascular smooth muscle cell phenotypic transformation induced by NELIN

    PubMed Central

    PEI, CHANGAN; QIN, SHIYONG; WANG, MINGHAI; ZHANG, SHUGUANG

    2015-01-01

    Vascular disorders, including hypertension, atherosclerosis and restenosis, arise from dysregulation of vascular smooth muscle cell (VSMC) differentiation, which can be controlled by regulatory factors. The present study investigated the regulatory mechanism of the phenotypic transformation of human VSMCs by NELIN in order to evaluate its potential as a preventive and therapeutic of vascular disorders. An in vitro model of NELIN-overexpressing VSMCs was prepared by transfection with a lentiviral (LV) vector (NELIN-VSMCs) and NELIN was slienced using an a lentiviral vector with small interfering (si)RNA in another group (LV-NELIN-siRNA-VSMCs). The effects of NELIN overexpression or knockdown on the phenotypic transformation of human VSMCs were observed, and its regulatory mechanism was studied. Compared with the control group, cells in the NELIN-VSMCs group presented a contractile phenotype with a significant increase of NELIN mRNA, NELIN protein, smooth muscle (SM)α-actin and total Ras homolog gene family member A (RhoA) protein expression. The intra-nuclear translocation of SMα-actin-serum response factor (SMα-actin-SRF) occurred in these cells simultaneously. Following exposure to Rho kinsase inhibitor Y-27632, SRF and SMα-actin expression decreased. However, cells in the LV-NELIN-siRNA-VSMCs group presented a synthetic phenotype, and the expression of NELIN mRNA, NELIN protein, SMα-actin protein and total RhoA protein was decreased. The occurrence of SRF extra-nuclear translocation was observed. In conclusion, the present study suggested that NELIN was able to activate regulatory factors of SMα-actin, RhoA and SRF successively in human VSMCs cultured in vitro. Furthermore, NELIN-induced phenotypic transformation of human VSMCs was regulated via the RhoA/SRF signaling pathway. The results of the present study provide a foundation for the use of NELIN in preventive and therapeutic treatment of vascular remodeling diseases, including varicosity and

  20. 'Hardcore' OX40(+) immunosuppressive regulatory T cells in hepatic cirrhosis and cancer.

    PubMed

    Piconese, Silvia; Timperi, Eleonora; Barnaba, Vincenzo

    2014-01-01

    Human regulatory T cells (Tregs) comprise an array of distinct subsets displaying diverse functions in response to microenvironmental signals. Here, we review our recent findings demonstrating the preferential accumulation of uncommitted, Th1-like and OX40(-) Tregs in non-cirrhotic tissues in contrast to the presence of committed, Th1-suppressing and OX40(+) Tregs in cirrhotic and tumor contexts in human liver affected by chronic hepatitis C.

  1. OX40+ regulatory T cells in cutaneous squamous cell carcinoma suppress effector T cell responses and associate with metastatic potential

    PubMed Central

    Lai, Chester; August, Suzannah; Albibas, Amel; Behar, Ramnik; Cho, Shin-Young; Polak, Marta E; Theaker, Jeff; MacLeod, Amanda S; French, Ruth R; Glennie, Martin J; Al-Shamkhani, Aymen; Healy, Eugene

    2016-01-01

    Purpose Cutaneous squamous cell carcinoma (cSCC) is the most common human cancer with metastatic potential. Despite T cells accumulating around cSCCs, these tumors continue to grow and persist. To investigate reasons for failure of T cells to mount a protective response in cSCC, we focused on regulatory T cells (Tregs) as this suppressive population is well represented among the infiltrating lymphocytes. Experimental Design Flow cytometry was conducted on cSCC lymphocytes and in vitro functional assays were performed using sorted tumoral T cells. Lymphocyte subsets in primary cSCCs were quantified immunohistochemically. Results FOXP3+ Tregs were more frequent in cSCCs than in peripheral blood (p<0.0001, n=86 tumors). Tumoral Tregs suppressed proliferation of tumoral effector CD4+ (p=0.005, n=10 tumors) and CD8+ T cells (p=0.043, n=9 tumors) and inhibited interferon-γ secretion by tumoral effector T cells (p=0.0186, n=11 tumors). The costimulatory molecule OX40 was expressed predominantly on tumoral Tregs (p<0.0001, n=15 tumors) and triggering OX40 with an agonist anti-OX40 antibody overcame the suppression exerted by Tregs, leading to increased tumoral effector CD4+ lymphocyte proliferation (p=0.0098, n=10 tumors). Tregs and OX40+ lymphocytes were more abundant in primary cSCCs which metastasized than in primary cSCCs which had not metastasized (n=48 and n=49 tumors respectively). Conclusions Tregs in cSCCs suppress effector T cell responses and are associated with subsequent metastasis, suggesting a key role for Tregs in cSCC development and progression. OX40 agonism reversed the suppressive effects of Tregs in vitro, suggesting that targeting OX40 could benefit the subset of cSCC patients at high risk of metastasis. PMID:27034329

  2. ECM components guide IL-10 producing regulatory T-cell (TR1) induction from effector memory T-cell precursors.

    PubMed

    Bollyky, Paul L; Wu, Rebecca P; Falk, Ben A; Lord, James D; Long, S Alice; Preisinger, Anton; Teng, Brandon; Holt, Gregory E; Standifer, Nathan E; Braun, Kathleen R; Xie, Cindy Fang; Samuels, Peter L; Vernon, Robert B; Gebe, John A; Wight, Thomas N; Nepom, Gerald T

    2011-05-10

    We describe a role for ECM as a biosensor for inflammatory microenvironments that plays a critical role in peripheral immune tolerance. We show that hyaluronan (HA) promotes induction of Foxp3- IL-10-producing regulatory T cells (TR1) from conventional T-cell precursors in both murine and human systems. This is, to our knowledge, the first description of an ECM component inducing regulatory T cells. Intact HA, characteristic of healing tissues, promotes induction of TR1 capable of abrogating disease in an IL-10-dependent mouse colitis model whereas fragmentary HA, typical of inflamed tissues, does not, indicating a decisive role for tissue integrity in this system. The TR1 precursor cells in this system are CD4(+)CD62L(-)FoxP3(-), suggesting that effector memory cells assume a regulatory phenotype when they encounter their cognate antigen in the context of intact HA. Matrix integrity cues might thereby play a central role in maintaining peripheral tolerance. This TR1 induction is mediated by CD44 cross-linking and signaling through p38 and ERK1/2. This induction is suppressed, also in a CD44-dependent manner, by osteopontin, a component of chronically inflamed ECM, indicating that CD44 signaling serves as a nexus for fate decisions regarding TR1 induction. Finally, we demonstrate that TR1 induction signals can be recapitulated using synthetic matrices. These results reveal important roles for the matrix microenvironment in immune regulation and suggest unique strategies for immunomodulation.

  3. Dissection of Regulatory Elements During Direct Conversion of Somatic Cells into Neurons.

    PubMed

    Soleimani, Tahereh; Falsafi, Nafiseh; Fallahi, Hossein

    2017-02-23

    A revolutionary approach that involves direct conversion of somatic cells into almost any other types of cells showed promising results for regenerative medicine. Currently, producing valuable cell types including neurons, cardiomyocytes and hepatocytes through direct conversion of somatic cells appear to be a feasible option for regenerative medicine. The process involves inducing the cells by chemical cocktails or by expression of different types of transcription factors. In this concept, in vitro neurogenesis considered to be able to produce neuron cells to replace damaged neurons especially in Alzheimer and Parkinson disease. However, early successful experiments followed by major drawbacks such as low differentiation efficiency in producing neurons and detection of various undesirable types of cells in the culture. Therefore, there is not a single optimized common protocol for producing high quality neurons in vitro so far. This is partly due to the lack of our understanding about the precise cellular, genetic, and molecular mechanisms underlying neurogenesis via direct conversion. In the current work, we have employed meta-analysis tools and extensive gene regulatory network analysis on the high through put gene expression data obtained from previous reprogramming protocols to identify central gene regulatory components involved in direct conversion of fibroblasts into neurons. Our results identified miR-9, miR-30 as the most important miRNA and TP53, MYC, JUN, SP1 and SMAD2 considered to be the most important transcription factors. These findings would be useful for direct targeting these hub regulatory elements in order to increase the efficacy and specificity of the conversion protocols. This article is protected by copyright. All rights reserved.

  4. Induction of T helper 3 regulatory cells by dendritic cells infected with porcine reproductive and respiratory syndrome virus

    SciTech Connect

    Silva-Campa, Erika; Flores-Mendoza, Lilian; Resendiz, Monica; Pinelli-Saavedra, Araceli; Mata-Haro, Veronica; Mwangi, Waithaka; Hernandez, Jesus

    2009-05-10

    Delayed development of virus-specific immune response has been observed in pigs infected with the porcine reproductive and respiratory syndrome virus (PRRSV). Several studies support the hypothesis that the PRRSV is capable of modulating porcine immune system, but the mechanisms involved are yet to be defined. In this study, we evaluated the induction of T regulatory cells by PRRSV-infected dendritic cells (DCs). Our results showed that PRRSV-infected DCs significantly increased Foxp3{sup +}CD25{sup +} T cells, an effect that was reversible by IFN-alpha treatment, and this outcome was reproducible using two distinct PRRSV strains. Analysis of the expressed cytokines suggested that the induction of Foxp3{sup +}CD25{sup +} T cells is dependent on TGF-beta but not IL-10. In addition, a significant up-regulation of Foxp3 mRNA, but not TBX21 or GATA3, was detected. Importantly, our results showed that the induced Foxp3{sup +}CD25{sup +} T cells were able to suppress the proliferation of PHA-stimulated PBMCs. The T cells induced by the PRRSV-infected DCs fit the Foxp3{sup +}CD25{sup +} T helper 3 (Th3) regulatory cell phenotype described in the literature. The induction of this cell phenotype depended, at least in part, on PRRSV viability because IFN-alpha treatment or virus inactivation reversed these effects. In conclusion, this data supports the hypothesis that the PRRSV succeeds to establish and replicate in porcine cells early post-infection, in part, by inducing Th3 regulatory cells as a mechanism of modulating the porcine immune system.

  5. Notch signalling suppresses regulatory T-cell function in murine experimental autoimmune uveitis.

    PubMed

    Rong, Hua; Shen, Hongjie; Xu, Yueli; Yang, Hai

    2016-12-01

    Autoimmune uveitis is an intraocular inflammatory disorder in developed countries. Understanding the mechanisms underlying the development and modulation of immune reaction in uveitic eyes is critical for designing therapeutic interventions. Here we investigated the role of Notch signalling in regulatory T-cell (Treg cell) function during experimental autoimmune uveitis (EAU). Using the Foxp3-GFP reporter mouse strain, the significance of Notch signalling for the function of infiltrating Treg cells was characterized in an EAU model. We found that infiltrating Treg cells substantially expressed Notch-1, Notch-2, JAG1 and DLL1 in uveitic eyes. Activation of Notch signalling, represented by expression of HES1 and HES5, was enhanced in infiltrating Treg cells. Treatment with JAG1 and DLL1 down-regulated Foxp3 expression and immunosuppressive activity of isolated infiltrating Treg cells in vitro, whereas neutralizing antibodies against JAG1 and DLL1 diminished Notch ligand-mediated negative effects on Treg cells. To investigate the significance of Notch signalling for Treg cell function in vivo, lentivirus-derived Notch short hairpin RNAs were transduced into in vitro expanded Treg cells before adoptive transfer of Treg cells into EAU mice. Transfer of Notch-1-deficient Treg cells remarkably reduced pro-inflammatory cytokine production and inflammatory cell infiltration in uveitic eyes. Taken together, Notch signalling negatively modulates the immunosuppressive function of infiltrating Treg cells in mouse EAU.

  6. De novo fatty acid synthesis controls the fate between regulatory T and T helper 17 cells.

    PubMed

    Berod, Luciana; Friedrich, Christin; Nandan, Amrita; Freitag, Jenny; Hagemann, Stefanie; Harmrolfs, Kirsten; Sandouk, Aline; Hesse, Christina; Castro, Carla N; Bähre, Heike; Tschirner, Sarah K; Gorinski, Nataliya; Gohmert, Melanie; Mayer, Christian T; Huehn, Jochen; Ponimaskin, Evgeni; Abraham, Wolf-Rainer; Müller, Rolf; Lochner, Matthias; Sparwasser, Tim

    2014-11-01

    Interleukin-17 (IL-17)-secreting T cells of the T helper 17 (TH17) lineage play a pathogenic role in multiple inflammatory and autoimmune conditions and thus represent a highly attractive target for therapeutic intervention. We report that inhibition of acetyl-CoA carboxylase 1 (ACC1) restrains the formation of human and mouse TH17 cells and promotes the development of anti-inflammatory Foxp3(+) regulatory T (Treg) cells. We show that TH17 cells, but not Treg cells, depend on ACC1-mediated de novo fatty acid synthesis and the underlying glycolytic-lipogenic metabolic pathway for their development. Although TH17 cells use this pathway to produce phospholipids for cellular membranes, Treg cells readily take up exogenous fatty acids for this purpose. Notably, pharmacologic inhibition or T cell-specific deletion of ACC1 not only blocks de novo fatty acid synthesis but also interferes with the metabolic flux of glucose-derived carbon via glycolysis and the tricarboxylic acid cycle. In vivo, treatment with the ACC-specific inhibitor soraphen A or T cell-specific deletion of ACC1 in mice attenuates TH17 cell-mediated autoimmune disease. Our results indicate fundamental differences between TH17 cells and Treg cells regarding their dependency on ACC1-mediated de novo fatty acid synthesis, which might be exploited as a new strategy for metabolic immune modulation of TH17 cell-mediated inflammatory diseases.

  7. Identification of Cell Wall Synthesis Regulatory Genes Controlling Biomass Characteristics and Yield in Rice (Oryza Sativa)

    SciTech Connect

    Peng, Zhaohua PEng; Ronald, Palmela; Wang, Guo-Liang

    2013-04-26

    This project aims to identify the regulatory genes of rice cell wall synthesis pathways using a cell wall removal and regeneration system. We completed the gene expression profiling studies following the time course from cell wall removal to cell wall regeneration in rice suspension cells. We also completed, total proteome, nuclear subproteome and histone modification studies following the course from cell wall removal and cell wall regeneration process. A large number of differentially expressed regulatory genes and proteins were identified. Meanwhile, we generated RNAi and over-expression transgenic rice for 45 genes with at least 10 independent transgenic lines for each gene. In addition, we ordered T-DNA and transposon insertion mutants for 60 genes from Korea, Japan, and France and characterized the mutants. Overall, we have mutants and transgenic lines for over 90 genes, exceeded our proposed goal of generating mutants for 50 genes. Interesting Discoveries a) Cell wall re-synthesis in protoplasts may involve a novel cell wall synthesis mechanism. The synthesis of the primary cell wall is initiated in late cytokinesis with further modification during cell expansion. Phragmoplast plays an essential role in cell wall synthesis. It services as a scaffold for building the cell plate and formation of a new cell wall. Only one phragmoplast and one new cell wall is produced for each dividing cell. When the cell wall was removed enzymatically, we found that cell wall re-synthesis started from multiple locations simultaneously, suggesting that a novel mechanism is involved in cell wall re-synthesis. This observation raised many interesting questions, such as how the starting sites of cell wall synthesis are determined, whether phragmoplast and cell plate like structures are involved in cell wall re-synthesis, and more importantly whether the same set of enzymes and apparatus are used in cell wall re-synthesis as during cytokinesis. Given that many known cell wall

  8. Interleukin-6 controls uterine Th9 cells and CD8(+) T regulatory cells to accelerate parturition in mice.

    PubMed

    Gomez-Lopez, Nardhy; Olson, David M; Robertson, Sarah A

    2016-01-01

    Interleukin-6 (IL6) is a determinant of the timing of parturition and birth in mice. We previously demonstrated that genetic IL6 deficiency delays parturition by ~24 h, and this is restored by administration of exogenous IL6. In this study, we have investigated whether IL6 influences the number or phenotypes of T cells or other leukocytes in uterine decidual tissue at the maternal-fetal interface. In late gestation, decidual leukocytes in Il6 null mutant (Il6(-/-)) mice exhibit an altered profile, characterized by reduced numbers of cells expressing the monocyte/macrophage marker F4/80 or the T-cell marker CD4, increased cells expressing the natural killer (NK) cell marker CD49b or the dendritic cell marker CD11c, but no change in cells expressing the neutrophil marker Ly6G. These changes are specific to late pregnancy, as similar differences in decidual leukocytes were not evident in mid-gestation Il6(-/-) mice. The IL6-regulated changes in decidual NK and dendritic cells appear secondary to local recruitment, as no comparable changes occurred in peripheral blood of Il6(-/-) mice. When exogenous IL6 was administered to restore normal timing of parturition, a partial reversal of the altered leukocyte profile was observed, with a 10% increase in the proportion of decidual CD4(+) T cells, a notable 60% increase in CD8(+) T cells including CD8(+)CD25(+)Foxp3(+) regulatory T cells and a 60% reduction in CD4(+)IL9(+) Th9 cells. Together these findings suggest that IL6-controlled accumulation of decidual CD4(+) T cells and CD8(+) regulatory T cells, with an associated decline in decidual Th9 cells, is instrumental for progressing parturition in mice.

  9. TIM-1 signaling is required for maintenance and induction of regulatory B cells.

    PubMed

    Yeung, M Y; Ding, Q; Brooks, C R; Xiao, S; Workman, C J; Vignali, D A A; Ueno, T; Padera, R F; Kuchroo, V K; Najafian, N; Rothstein, D M

    2015-04-01

    Apart from their role in humoral immunity, B cells can exhibit IL-10-dependent regulatory activity (Bregs). These regulatory subpopulations have been shown to inhibit inflammation and allograft rejection. However, our understanding of Bregs has been hampered by their rarity, lack of a specific marker, and poor insight into their induction and maintenance. We previously demonstrated that T cell immunoglobulin mucin domain-1 (TIM-1) identifies over 70% of IL-10-producing B cells, irrespective of other markers. We now show that TIM-1 is the primary receptor responsible for Breg induction by apoptotic cells (ACs). However, B cells that express a mutant form of TIM-1 lacking the mucin domain (TIM-1(Δmucin) ) exhibit decreased phosphatidylserine binding and are unable to produce IL-10 in response to ACs or by specific ligation with anti-TIM-1. TIM-1(Δmucin) mice also exhibit accelerated allograft rejection, which appears to be due in part to their defect in both baseline and induced IL-10(+) Bregs, since a single transfer of WT TIM-1(+) B cells can restore long-term graft survival. These data suggest that TIM-1 signaling plays a direct role in Breg maintenance and induction both under physiological conditions (in response to ACs) and in response to therapy through TIM-1 ligation. Moreover, they directly demonstrate that the mucin domain regulates TIM-1 signaling.

  10. The Role of Different Subsets of Regulatory T Cells in Immunopathogenesis of Rheumatoid Arthritis

    PubMed Central

    Gol-Ara, Maryam; Jadidi-Niaragh, Farhad; Sadria, Reza; Azizi, Gholamreza; Mirshafiey, Abbas

    2012-01-01

    Rheumatoid arthritis (RA) is a common autoimmune disease and a systemic inflammatory disease which is characterized by chronic joint inflammation and variable degrees of bone and cartilage erosion and hyperplasia of synovial tissues. Considering the role of autoreactive T cells (particularly Th1 and Th17 cells) in pathophysiology of RA, it might be assumed that the regulatory T cells (Tregs) will be able to control the initiation and progression of disease. The frequency, function, and properties of various subsets of Tregs including natural Tregs (nTregs), IL-10-producing type 1 Tregs (Tr1 cells), TGF-β-producing Th3 cells, CD8+ Tregs, and NKT regulatory cells have been investigated in various studies associated with RA and collagen-induced arthritis (CIA) as experimental model of this disease. In this paper, we intend to submit the comprehensive information about the immunobiology of various subsets of Tregs and their roles and function in immunopathophysiology of RA and its animal model, CIA. PMID:23133752

  11. Removal of regulatory T cell activity reverses hyporesponsiveness and leads to filarial parasite clearance in vivo.

    PubMed

    Taylor, Matthew D; LeGoff, Laetitia; Harris, Anjanette; Malone, Eva; Allen, Judith E; Maizels, Rick M

    2005-04-15

    Human filarial parasites cause chronic infection associated with long-term down-regulation of the host's immune response. We show here that CD4+ T cell regulation is the main determinant of parasite survival. In a laboratory model of infection, using Litomosoides sigmodontis in BALB/c mice, parasites establish for >60 days in the thoracic cavity. During infection, CD4+ T cells at this site express increasing levels of CD25, CTLA-4, and glucocorticoid-induced TNF receptor family-related gene (GITR), and by day 60, up to 70% are CTLA-4(+)GITR(high), with a lesser fraction coexpressing CD25. Upon Ag stimulation, CD4(+)CTLA-4(+)GITR(high) cells are hyporesponsive for proliferation and cytokine production. To test the hypothesis that regulatory T cell activity maintains hyporesponsiveness and prolongs infection, we treated mice with Abs to CD25 and GITR. Combined Ab treatment was able to overcome an established infection, resulting in a 73% reduction in parasite numbers (p < 0.01). Parasite killing was accompanied by increased Ag-specific immune responses and markedly reduced levels of CTLA-4 expression. The action of the CD25(+)GITR+ cells was IL-10 independent as in vivo neutralization of IL-10R did not restore the ability of the immune system to kill parasites. These data suggest that regulatory T cells act, in an IL-10-independent manner, to suppress host immunity to filariasis.

  12. Strategies to direct the enrichment, expansion, and recruitment of regulatory cells for the treatment of disease

    PubMed Central

    Glowacki, Andrew J.; Gottardi, Riccardo; Yoshizawa, Sayuri; Cavalla, Franco; Garlet, Gustavo P.; Sfeir, Charles; Little, Steven R.

    2014-01-01

    Disease and injury perturb the balance of processes associated with inflammation and tissue remodeling, resulting in positive feedback loops, exacerbation of disease and compromised tissue repair. Conversely, under homeostatic healthy conditions, these processes are tightly regulated through the expansion and/or recruitment of specific cell populations, promoting a balanced steady-state. Better understanding of these regulatory processes and recent advances in biomaterials and biotechnology have prompted strategies to utilize cells for the treatment and prevention of disease through regulation of inflammation and promotion of tissue repair. Herein, we describe how cells that regulate these processes can be increased in prevalence at a site of disease or injury. We review several relevant cell therapy approaches as well as new strategies for directing endogenous regulatory cells capable of promoting environmental homeostasis and even the establishment of a pro-regenerative micro-environment. Collectively, these examples may provide a blueprint for next-generation “medicine” that spurs the body’s own cells to action and replaces conventional drugs. PMID:25245220

  13. Phenotypical and functional alterations of CD8 regulatory T cells in primary biliary cirrhosis

    PubMed Central

    Bernuzzi, Francesca; Fenoglio, Daniela; Battaglia, Florinda; Fravega, Marco; Gershwin, M. Eric; Indiveri, Francesco; Ansari, Aftab A.; Podda, Mauro; Invernizzi, Pietro; Filaci, Gilberto

    2011-01-01

    The mechanisms that lead to loss of tolerance in autoimmune disease have remained both elusive and diverse, including both genetic predisposition and generic dysregulation of critical mononuclear cell subsets. In primary biliary cirrhosis (PBC), patients exhibit a multilineage response to the E2 component of pyruvate dehydrogenase involving antibody as well as autoreactive CD4 and CD8 responses. Recent data from murine models of PBC have suggested that a critical mechanism of biliary destruction is mediated by liver-infiltrating CD8 cells. Further, the number of autoreactive liver-infiltrating CD4 and CD8 cells is significantly higher in liver than blood in patients with PBC. Based on this data, we have studied the frequencies and phenotypic characterization of both CD4 and CD8 regulatory T cell components in both patients with PBC and age–sex matched controls. Our data is striking and indicate that CD8 Treg populations from PBC patients, but not controls, have significant phenotypic alterations, including increased expression of CD127 and reduced CD39. Furthermore, in vitro induction of CD8 Tregs by incubation with IL10 is significantly reduced in PBC patients. Importantly, the frequencies of circulating CD4+CD25+ and CD8+ and CD28− T cell subpopulations are not significantly different between patients and controls. In conclusion, these data identify the CD8 Treg subset as a regulatory T cell subpopulation altered in patients with PBC. PMID:20638239

  14. Involvement of IL-2 in homeostasis of regulatory T cells: the IL-2 cycle.

    PubMed

    Yarkoni, Shai; Kaminitz, Ayelet; Sagiv, Yuval; Yaniv, Isaac; Askenasy, Nadir

    2008-09-01

    A large body of evidence on the activity of regulatory T (Treg) cells was gathered during the last decade, and a similar number of reviews and opinion papers attempted to integrate the experimental findings. The abundant literature clearly delineates an exciting area of research but also underlines some major controversies. A linear cause-result interpretation of experimental maneuvers often ignores the fact that the activity of Treg cells is orchestrated with the effector T (Teff) cells within an intricate network of physiological immune homeostasis. Every modulation of the activity of the effector (cytotoxic) immune system revolves to affect the activity of regulatory (suppressive) cells through elaborate feedback loops of negative and positive regulation. The lack of IL-2 production by innate Treg cells makes this cytokine a prime coupler of the effector and suppressive mechanisms. Here we attempt to integrate evidence that delineates the involvement of IL-2 in primary and secondary feedback loops that regulate the activity of suppressive cells within the elaborate network of physiological immune homeostasis.

  15. Identification of two regulatory elements controlling Fucosyltransferase 7 transcription in murine CD4+ T cells.

    PubMed

    Pink, Matthias; Ratsch, Boris A; Mardahl, Maibritt; Schröter, Micha F; Engelbert, Dirk; Triebus, Julia; Hamann, Alf; Syrbe, Uta

    2014-11-01

    Fucosyltransferase VII encoded by the gene Fut7 is essential in CD4(+) T cells for the generation of E- and P-selectin ligands (E- and P-lig) which facilitate recruitment of lymphocytes into inflamed tissues and into the skin. This study aimed to identify regulatory elements controlling the inducible Fut7 expression in CD4(+) T cells that occurs upon activation and differentiation of naive T cells into effector cells. Comparative analysis of the histone modification pattern in non-hematopoetic cells and CD4(+) T cell subsets revealed a differential histone modification pattern within the Fut7 locus including a conserved non-coding sequence (CNS) identified by cross-species conservation comparison suggesting that regulatory elements are confined to this region. Cloning of the CNS located about 500 bp upstream of the Fut7 locus, into a luciferase reporter vector elicited reporter activity after transfection of the αβ-WT T cell line, but not after transfection of primary murine CD4(+) Th1 cells. As quantification of different Fut7 transcripts revealed a predominance of transcripts lacking the first exons in primary Th1 cells we searched for an alternative promoter. Cloning of an intragenic region spanning a 1kb region upstream of exon 4 into an enhancer-containing vector indeed elicited promoter activity. Interestingly, also the CNS enhanced activity of this intragenic minimal promoter in reporter assays in primary Th1 cells suggesting that both elements interact in primary CD4(+) T cells to induce Fut7 transcription.

  16. Suppression of HIV Replication by CD8+ Regulatory T-Cells in Elite Controllers

    PubMed Central

    Lu, Wei; Chen, Song; Lai, Chunhui; Lai, Mingyue; Fang, Hua; Dao, Hong; Kang, Jun; Fan, Jianhua; Guo, Weizhong; Fu, Linchun; Andrieu, Jean-Marie

    2016-01-01

    We previously demonstrated in the Chinese macaque model that an oral vaccine made of inactivated SIV and Lactobacillus plantarum induced CD8+ regulatory T-cells, which suppressed the activation of SIV+CD4+ T-cells, prevented SIV replication, and protected macaques from SIV challenges. Here, we sought whether a similar population of CD8+ T-regs would induce the suppression of HIV replication in elite controllers (ECs), a small population (3‰) of HIV-infected patients with undetectable HIV replication. For that purpose, we investigated the in vitro antiviral activity of fresh CD8+ T-cells on HIV-infected CD4+ T-cells taken from 10 ECs. The 10 ECs had a classical genomic profile: all of them carried the KIR3DL1 gene and 9 carried at least 1 allele of HLA-B:Bw4-80Ile (i.e., with an isoleucine residue at position 80). In the nine HLA-B:Bw4-80Ile-positive patients, we demonstrated a strong viral suppression by KIR3DL1-expressing CD8+ T-cells that required cell-to-cell contact to switch off the activation signals in infected CD4+ T-cells. KIR3DL1-expressing CD8+ T-cells withdrawal and KIR3DL1 neutralization by a specific anti-killer cell immunoglobulin-like receptor (KIR) antibody inhibited the suppression of viral replication. Our findings provide the first evidence for an instrumental role of KIR-expressing CD8+ regulatory T-cells in the natural control of HIV-1 infection. PMID:27148256

  17. Regulatory T cells, especially ICOS+ FOXP3+ regulatory T cells, are increased in the hepatocellular carcinoma microenvironment and predict reduced survival

    PubMed Central

    Tu, Jian-Fei; Ding, Ya-Hui; Ying, Xi-Hui; Wu, Fa-Zong; Zhou, Xin-Mu; Zhang, Deng-Ke; Zou, Hai; Ji, Jian-Song

    2016-01-01

    Hepatocellular carcinoma (HCC) is a common malignant tumour, especially in Asia. Its prognosis is poor, and there are limited methods for predicting patient survival. This study was carried out to analyse the prognostic value of tumour-infiltrating lymphocytes (TILs), especially regulatory T cells (Tregs), in HCC patients. TILs were analysed in 57 randomly selected HCC patients. The prognostic effects of groups with high and low numbers were evaluated by the Kaplan-Meier and Cox model analyses. Although higher densities of CD3+, CD4+, and CD8+ cytotoxic lymphocytes (CTLs) as well as CD56+ NK cells and CD68+ macrophages were observed in peritumoural tissue, increased numbers of forkhead/winged helix transcription factor P3+ (FOXP3+) Tregs were found in intratumoural tissue. Additionally, regarding ICOS+ FOXP3+ Tregs, an increased prevalence in carcinoma was not only associated with the absolute number but also with the percentage of FOXP3+ cells. Higher Treg levels in tumour tissues indicated a worse prognosis, and the FOXP3+ Tregs/CD4+ T cells ratio was an independent prognostic factor for OS. Therefore, FOXP3+ Tregs, especially ICOS+ FOXP3+ Tregs, contribute to the immunosuppressive HCC microenvironment. High tumour-infiltrating Tregs are thought to be an unfavourable prognostic indicator of HCC. PMID:27725696

  18. Suppression of lethal autoimmunity by regulatory T cells with a single TCR specificity.

    PubMed

    Levine, Andrew G; Hemmers, Saskia; Baptista, Antonio P; Schizas, Michail; Faire, Mehlika B; Moltedo, Bruno; Konopacki, Catherine; Schmidt-Supprian, Marc; Germain, Ronald N; Treuting, Piper M; Rudensky, Alexander Y

    2017-03-06

    The regulatory T cell (T reg cell) T cell receptor (TCR) repertoire is highly diverse and skewed toward recognition of self-antigens. TCR expression by T reg cells is continuously required for maintenance of immune tolerance and for a major part of their characteristic gene expression signature; however, it remains unknown to what degree diverse TCR-mediated interactions with cognate self-antigens are required for these processes. In this study, by experimentally switching the T reg cell TCR repertoire to a single T reg cell TCR, we demonstrate that T reg cell function and gene expression can be partially uncoupled from TCR diversity. An induced switch of the T reg cell TCR repertoire to a random repertoire also preserved, albeit to a limited degree, the ability to suppress lymphadenopathy and T helper cell type 2 activation. At the same time, these perturbations of the T reg cell TCR repertoire led to marked immune cell activation, tissue inflammation, and an ultimately severe autoimmunity, indicating the importance of diversity and specificity for optimal T reg cell function.

  19. Regulatory T cells modulate inflammation and reduce infarct volume in experimental brain ischaemia

    PubMed Central

    Brea, David; Agulla, Jesús; Rodríguez-Yáñez, Manuel; Barral, David; Ramos-Cabrer, Pedro; Campos, Francisco; Almeida, Angeles; Dávalos, Antoni; Castillo, José

    2014-01-01

    Brain ischaemia (stroke) triggers an intense inflammatory response predominately mediated by the accumulation of inflammatory cells and mediators in the ischaemic brain. In this context, regulatory T (Treg) cells, a subpopulation of CD4+ T cells with immunosuppressive and anti-inflammatory properties, are activated in the late stages of the disease. To date, the potential therapeutic usefulness of Treg cells has not been tested. In this study, we aimed to investigate whether Treg cells exert protection/repair following stroke. Both the adoptive transfer of Treg cells into ischaemic rats and the stimulation of endogenous T-cell proliferation using a CD28 superagonist reduced the infarct size at 3–28 days following the ischaemic insult. Moreover, T cell-treated animals had higher levels of FoxP3 and lower levels of IL-1β, CD11b+ and CD68+ cells in the infarcted hemisphere when compared with control animals. However, T-cell treatment did not alter the rate of proliferation of NeuN-, NCAM- or CD31-positive cells, thereby ruling out neurogenesis and angiogenesis in protection. These results suggest that adoptive transfer of T cells is a promising therapeutic strategy against the neurological consequences of stroke. PMID:24889329

  20. Haspin has Multiple Functions in the Plant Cell Division Regulatory Network.

    PubMed

    Kozgunova, Elena; Suzuki, Takamasa; Ito, Masaki; Higashiyama, Tetsuya; Kurihara, Daisuke

    2016-04-01

    Progression of cell division is controlled by various mitotic kinases. In animal cells, phosphorylation of histone H3 at Thr3 by the kinase Haspin (haploid germ cell-specific nuclear protein kinase) promotes centromeric Aurora B localization to regulate chromosome segregation. However, less is known about the function of Haspin in regulatory networks in plant cells. Here, we show that inhibition of Haspin with 5-iodotubercidin (5-ITu) in Bright Yellow-2 (BY-2) cells delayed chromosome alignment. Haspin inhibition also prevented the centromeric localization of Aurora3 kinase (AUR3) and disrupted its function. This suggested that Haspin plays a role in the specific positioning of AUR3 on chromosomes in plant cells, a function conserved in animals. The results also indicated that Haspin and AUR3 are involved in the same pathway, which regulates chromosome alignment during prometaphase/metaphase. Remarkably, Haspin inhibition by 5-ITu also led to a severe cytokinesis defect, resulting in binuclear cells with a partially formed cell plate. The 5-ITu treatment did not affect microtubules, AUR1/2 or the NACK-PQR pathway; however, it did alter the distribution of actin filaments on the cell plate. Together, these results suggested that Haspin has several functions in regulating cell division in plant cells: in the localization of AUR3 on centromeres and in regulating late cell plate expansion during cytokinesis.

  1. Deletion of CTLA-4 on regulatory T cells during adulthood leads to resistance to autoimmunity

    PubMed Central

    Paterson, Alison M.; Lovitch, Scott B.; Sage, Peter T.; Juneja, Vikram R.; Lee, Youjin; Trombley, Justin D.; Arancibia-Cárcamo, Carolina V.; Sobel, Raymond A.; Rudensky, Alexander Y.; Kuchroo, Vijay K.; Freeman, Gordon J.

    2015-01-01

    Cytotoxic T lymphocyte antigen-4 (CTLA-4) is an essential negative regulator of T cell responses. Germline Ctla4 deficiency is lethal, making investigation of the function of CTLA-4 on mature T cells challenging. To elucidate the function of CTLA-4 on mature T cells, we have conditionally ablated Ctla4 in adult mice. We show that, in contrast to germline knockout mice, deletion of Ctla4 during adulthood does not precipitate systemic autoimmunity, but surprisingly confers protection from experimental autoimmune encephalomyelitis (EAE) and does not lead to increased resistance to MC38 tumors. Deletion of Ctla4 during adulthood was accompanied by activation and expansion of both conventional CD4+Foxp3− (T conv) and regulatory Foxp3+ (T reg cells) T cell subsets; however, deletion of CTLA-4 on T reg cells was necessary and sufficient for protection from EAE. CTLA-4 deleted T reg cells remained functionally suppressive. Deletion of Ctla4 on T reg cells alone or on all adult T cells led to major changes in the Ctla4 sufficient T conv cell compartment, including up-regulation of immunoinhibitory molecules IL-10, LAG-3 and PD-1, thereby providing a compensatory immunosuppressive mechanism. Collectively, our findings point to a profound role for CTLA-4 on T reg cells in limiting their peripheral expansion and activation, thereby regulating the phenotype and function of T conv cells. PMID:26371185

  2. Expansion and function of Foxp3-expressing T regulatory cells during tuberculosis.

    PubMed

    Scott-Browne, James P; Shafiani, Shahin; Tucker-Heard, Glady's; Ishida-Tsubota, Kumiko; Fontenot, Jason D; Rudensky, Alexander Y; Bevan, Michael J; Urdahl, Kevin B

    2007-09-03

    Mycobacterium tuberculosis (Mtb) frequently establishes persistent infections that may be facilitated by mechanisms that dampen immunity. T regulatory (T reg) cells, a subset of CD4(+) T cells that are essential for preventing autoimmunity, can also suppress antimicrobial immune responses. We use Foxp3-GFP mice to track the activity of T reg cells after aerosol infection with Mtb. We report that during tuberculosis, T reg cells proliferate in the pulmonary lymph nodes (pLNs), change their cell surface phenotype, and accumulate in the pLNs and lung at a rate parallel to the accumulation of effector T cells. In the Mtb-infected lung, T reg cells accumulate in high numbers in all sites where CD4(+) T cells are found, including perivascular/peribronchiolar regions and within lymphoid aggregates of granulomas. To determine the role of T reg cells in the immune response to tuberculosis, we generated mixed bone marrow chimeric mice in which all cells capable of expressing Foxp3 expressed Thy1.1. When T reg cells were depleted by administration of anti-Thy1.1 before aerosol infection with Mtb, we observed approximately 1 log less of colony-forming units of Mtb in the lungs. Thus, after aerosol infection, T reg cells proliferate and accumulate at sites of infection, and have the capacity to suppress immune responses that contribute to the control of Mtb.

  3. Clinical Potential of Regulatory T Cell Therapy in Liver Diseases: An Overview and Current Perspectives

    PubMed Central

    Jeffery, Hannah C.; Braitch, Manjit Kaur; Brown, Solomon; Oo, Ye Htun

    2016-01-01

    The increasing demand for liver transplantation and the decline in donor organs has highlighted the need for alternative novel therapies to prevent chronic active hepatitis, which eventually leads to liver cirrhosis and liver cancer. Liver histology of chronic hepatitis is composed of both effector and regulatory lymphocytes. The human liver contains different subsets of effector lymphocytes that are kept in check by a subpopulation of T cells known as Regulatory T cells (Treg). The balance of effector and regulatory lymphocytes generally determines the outcome of hepatic inflammation: resolution, fulminant hepatitis, or chronic active hepatitis. Thus, maintaining and adjusting this balance is crucial in immunological manipulation of liver diseases. One of the options to restore this balance is to enrich Treg in the liver disease patients. Advances in the knowledge of Treg biology and development of clinical grade isolation reagents, cell sorting equipment, and good manufacturing practice facilities have paved the way to apply Treg cells as a potential therapy to restore peripheral self-tolerance in autoimmune liver diseases (AILD), chronic rejection, and posttransplantation. Past and on-going studies have applied Treg in type-1 diabetes mellitus, systemic lupus erythematosus, graft versus host diseases, and solid organ transplantations. There have not been any new therapies for the AILD for more than three decades; thus, the clinical potential for the application of autologous Treg cell therapy to treat autoimmune liver disease is an attractive and novel option. However, it is fundamental to understand the deep immunology, genetic profiles, biology, homing behavior, and microenvironment of Treg before applying the cells to the patients. PMID:27656181

  4. Inflammation-associated genes: risks and benefits to Foxp3+ regulatory T-cell function.

    PubMed

    O'Connor, Richard A; Anderton, Stephen M

    2015-10-01

    Foxp3(+) regulatory T (Treg) cells prevent the development of autoimmunity and immunopathology, as well as maintaining homeostasis and tolerance to commensal microorganisms. The suppressive activity of Treg cells is their defining characteristic, generating great interest in their therapeutic potential. However, suppressive and effector functions are not entirely exclusive. Considerable evidence points to the ability of supposedly anti-inflammatory Foxp3-expressing Treg cells to also express transcription factors that have been characterized as cardinal drivers of T effector cell function. We will consider the mounting evidence that Treg cells can function in non-suppressive capacities and review the impetus for this functional change, its relevance to developing immune and autoimmune responses and its significance to the development of Treg-based therapies.

  5. Short-Circuiting Gene Regulatory Networks: Origins of B Cell Lymphoma

    PubMed Central

    Koues, Olivia I.; Oltz, Eugene M.; Payton, Jacqueline E.

    2015-01-01

    B cell lymphomas (BCL) are characterized by widespread deregulation of gene expression when compared with their normal B cell counterparts. Recent epigenomic studies defined cis-regulatory elements (REs) whose activities are altered in BCL to drive some of these pathogenic expression changes. During transformation, multiple mechanisms are employed to alter RE activities, including perturbations in the function of chromatin modifiers, which can lead to revision of the B cell epigenome. Inherited and somatic variants also alter RE function via disruption of TF binding. Aberrant expression of non-coding RNAs deregulates genes involved in B cell differentiation via direct repression and post-transcriptional targeting. These discoveries have established epigenetic etiologies for B cell transformation that are being exploited by novel therapeutic approaches. PMID:26604030

  6. Gene regulatory networks in differentiation and direct reprogramming of hepatic cells.

    PubMed

    Gérard, Claude; Tys, Janne; Lemaigre, Frédéric P

    2016-12-12

    Liver development proceeds by sequential steps during which gene regulatory networks (GRNs) determine differentiation and maturation of hepatic cells. Characterizing the architecture and dynamics of these networks is essential for understanding how cell fate decisions are made during development, and for recapitulating these processes during in vitro production of liver cells for toxicology studies, disease modelling and regenerative therapy. Here we review the GRNs that control key steps of liver development and lead to differentiation of hepatocytes and cholangiocytes in mammals. We focus on GRNs determining cell fate decisions and analyse subcircuitry motifs that may confer specific dynamic properties to the networks. Finally, we put our analysis in the perspective of recent attempts to directly reprogram cells to hepatocytes by forced expression of transcription factors.

  7. Lymphopenia is detrimental to therapeutic approaches to type 1 diabetes using regulatory T cells.

    PubMed

    Ash, Shifra; Yarkoni, Shai; Askenasy, Nadir

    2014-01-01

    One of the therapeutic approaches to type 1 diabetes (T1D) focuses on enhancement of regulatory T cell (Treg) activity, either by adoptive transfer or supplementation of supporting cytokines such as interleukin-2 (IL-2). In principle, this therapeutic design would greatly benefit of concomitant reduction in pathogenic cell burden. Experimental evidence indicates that physiological recovery from lymphopenia is dominated by evolution of effector and cytotoxic cells, which abolishes the therapeutic efficacy of Treg cells. Targeted and selective depletion of effector T cells has been achieved with killer Treg using Fas ligand protein and a fusion protein composed of IL-2 and caspase-3, which showed remarkable efficacy in modulating the course of inflammatory insulitis in NOD mice. We emphasize a critical consideration in design of therapeutic approaches to T1D, immunomodulation without lymphoreduction to avoid the detrimental consequences of rebound recovery from lymphopenia.

  8. Mechanisms by Which B Cells and Regulatory T Cells Influence Development of Murine Organ-Specific Autoimmune Diseases

    PubMed Central

    Ellis, Jason S.; Braley-Mullen, Helen

    2017-01-01

    Experiments with B cell-deficient (B−/−) mice indicate that a number of autoimmune diseases require B cells in addition to T cells for their development. Using B−/− Non-obese diabetic (NOD) and NOD.H-2h4 mice, we demonstrated that development of spontaneous autoimmune thyroiditis (SAT), Sjogren’s syndrome and diabetes do not develop in B−/− mice, whereas all three diseases develop in B cell-positive wild-type (WT) mice. B cells are required early in life, since reconstitution of adult mice with B cells or autoantibodies did not restore their ability to develop disease. B cells function as important antigen presenting cells (APC) to initiate activation of autoreactive CD4+ effector T cells. If B cells are absent or greatly reduced in number, other APC will present the antigen, such that Treg are preferentially activated and effector T cells are not activated. In these situations, B−/− or B cell-depleted mice develop the autoimmune disease when T regulatory cells (Treg) are transiently depleted. This review focuses on how B cells influence Treg activation and function, and briefly considers factors that influence the effectiveness of B cell depletion for treatment of autoimmune diseases. PMID:28134752

  9. Evolution of New cis-Regulatory Motifs Required for Cell-Specific Gene Expression in Caenorhabditis

    PubMed Central

    Félix, Marie-Anne

    2016-01-01

    Patterning of C. elegans vulval cell fates relies on inductive signaling. In this induction event, a single cell, the gonadal anchor cell, secretes LIN-3/EGF and induces three out of six competent precursor cells to acquire a vulval fate. We previously showed that this developmental system is robust to a four-fold variation in lin-3/EGF genetic dose. Here using single-molecule FISH, we find that the mean level of expression of lin-3 in the anchor cell is remarkably conserved. No change in lin-3 expression level could be detected among C. elegans wild isolates and only a low level of change—less than 30%—in the Caenorhabditis genus and in Oscheius tipulae. In C. elegans, lin-3 expression in the anchor cell is known to require three transcription factor binding sites, specifically two E-boxes and a nuclear-hormone-receptor (NHR) binding site. Mutation of any of these three elements in C. elegans results in a dramatic decrease in lin-3 expression. Yet only a single E-box is found in the Drosophilae supergroup of Caenorhabditis species, including C. angaria, while the NHR-binding site likely only evolved at the base of the Elegans group. We find that a transgene from C. angaria bearing a single E-box is sufficient for normal expression in C. elegans. Even a short 58 bp cis-regulatory fragment from C. angaria with this single E-box is able to replace the three transcription factor binding sites at the endogenous C. elegans lin-3 locus, resulting in the wild-type expression level. Thus, regulatory evolution occurring in cis within a 58 bp lin-3 fragment, results in a strict requirement for the NHR binding site and a second E-box in C. elegans. This single-cell, single-molecule, quantitative and functional evo-devo study demonstrates that conserved expression levels can hide extensive change in cis-regulatory site requirements and highlights the evolution of new cis-regulatory elements required for cell-specific gene expression. PMID:27588814

  10. The immunology of pregnancy: regulatory T cells control maternal immune tolerance toward the fetus.

    PubMed

    La Rocca, Claudia; Carbone, Fortunata; Longobardi, Salvatore; Matarese, Giuseppe

    2014-11-01

    Establishment and maintenance of pregnancy represents a challenge for the maternal immune system since it has to defend against pathogens and tolerate paternal alloantigens expressed in fetal tissues. Regulatory T (Treg) cells, a subset of suppressor CD4(+) T cells, play a dominant role in the maintenance of immunological self-tolerance by preventing immune and autoimmune responses against self-antigens. Although localized mechanisms contribute to fetal evasion from immune attack, in the last few years it has been observed that Treg cells are essential in promoting fetal survival avoiding the recognition of paternal semi-allogeneic tissues by maternal immune system. Several functional studies have shown that unexplained infertility, miscarriage and pre-clampsia are often associated with deficit in Treg cell number and function while normal pregnancy selectively stimulates the accumulation of maternal forkhead-box-P3(+) (FoxP3(+)) CD4(+) Treg cells with fetal specificity. Some papers have been reported that the number of Treg cells persists at elevated levels long after delivery developing an immune regulatory memory against father's antigens, moreover these memory Treg cells rapidly proliferate during subsequent pregnancies, however, on the other hand, there are several evidence suggesting a clear decline of Treg cells number after delivery. Different factors such as cytokines, adipokines, pregnancy hormones and seminal fluid have immunoregulatory activity and influence the success of pregnancy by increasing Treg cell number and activity. The development of strategies capable of modulating immune responses toward fetal antigens through Treg cell manipulation, could have an impact on the induction of tolerance against fetal antigens during immune-mediated recurrent abortion.

  11. Chloroquine Treatment Enhances Regulatory T Cells and Reduces the Severity of Experimental Autoimmune Encephalomyelitis

    PubMed Central

    Thomé, Rodolfo; Moraes, Adriel S.; Bombeiro, André Luis; Farias, Alessandro dos Santos; Francelin, Carolina; da Costa, Thiago Alves; Di Gangi, Rosária; dos Santos, Leonilda Maria Barbosa; de Oliveira, Alexandre Leite Rodrigues; Verinaud, Liana

    2013-01-01

    Background The modulation of inflammatory processes is a necessary step, mostly orchestrated by regulatory T (Treg) cells and suppressive Dendritic Cells (DCs), to prevent the development of deleterious responses and autoimmune diseases. Therapies that focused on adoptive transfer of Treg cells or their expansion in vivo achieved great success in controlling inflammation in several experimental models. Chloroquine (CQ), an anti-malarial drug, was shown to reduce inflammation, although the mechanisms are still obscure. In this context, we aimed to access whether chloroquine treatment alters the frequency of Treg cells and DCs in normal mice. In addition, the effects of the prophylactic and therapeutic treatment with CQ on Experimental Autoimmune Encephalomyelitis (EAE), an experimental model for human Multiple Sclerosis, was investigated as well. Methodology/Principal Findings EAE was induced in C57BL/6 mice by immunization with myelin oligodendrocyte glycoprotein (MOG35–55) peptide. C57BL/6 mice were intraperitoneally treated with chloroquine. Results show that the CQ treatment provoked an increase in Treg cells frequency as well as a decrease in DCs. We next evaluated whether prophylactic CQ administration is capable of reducing the clinical and histopathological signs of EAE. Our results demonstrated that CQ-treated mice developed mild EAE compared to controls that was associated with lower infiltration of inflammatory cells in the central nervous system CNS) and increased frequency of Treg cells. Also, proliferation of MOG35–55-reactive T cells was significantly inhibited by chloroquine treatment. Similar results were observed when chloroquine was administrated after disease onset. Conclusion We show for the first time that CQ treatment promotes the expansion of Treg cells, corroborating previous reports indicating that chloroquine has immunomodulatory properties. Our results also show that CQ treatment suppress the inflammation in the CNS of EAE

  12. CD8+CD122+CD49dlow regulatory T cells maintain T-cell homeostasis by killing activated T cells via Fas/FasL-mediated cytotoxicity.

    PubMed

    Akane, Kazuyuki; Kojima, Seiji; Mak, Tak W; Shiku, Hiroshi; Suzuki, Haruhiko

    2016-03-01

    The Fas/FasL (CD95/CD178) system is required for immune regulation; however, it is unclear in which cells, when, and where Fas/FasL molecules act in the immune system. We found that CD8(+)CD122(+) cells, which are mostly composed of memory T cells in comparison with naïve cells in the CD8(+)CD122(-) population, were previously shown to include cells with regulatory activity and could be separated into CD49d(low) cells and CD49d(high) cells. We established in vitro and in vivo experimental systems to evaluate the regulatory activity of CD122(+) cells. Regulatory activity was observed in CD8(+)CD122(+)CD49d(low) but not in CD8(+)CD122(+)CD49d(high) cells, indicating that the regulatory cells in the CD8(+)CD122(+) population could be narrowed down to CD49d(low) cells. CD8(+)CD122(-) cells taken from lymphoproliferation (lpr) mice were resistant to regulation by normal CD122(+) Tregs. CD122(+) Tregs taken from generalized lymphoproliferative disease (gld) mice did not regulate wild-type CD8(+)CD122(-) cells, indicating that the regulation by CD122(+) Tregs is Fas/FasL-dependent. CD122(+) Tregs taken from IL-10-deficient mice could regulate CD8(+)CD122(-) cells as equally as wild-type CD122(+) Tregs both in vitro and in vivo. MHC class I-missing T cells were not regulated by CD122(+) Tregs in vitro. CD122(+) Tregs also regulated CD4(+) cells in a Fas/FasL-dependent manner in vitro. These results suggest an essential role of Fas/FasL as a terminal effector of the CD122(+) Tregs that kill activated T cells to maintain immune homeostasis.

  13. Blockade of TNF-α signaling benefits cancer therapy by suppressing effector regulatory T cell expansion.

    PubMed

    Chang, Li-Yuan; Lin, Yung-Chang; Chiang, Jy-Ming; Mahalingam, Jayashri; Su, Shih-Huan; Huang, Ching-Tai; Chen, Wei-Ting; Huang, Chien-Hao; Jeng, Wen-Juei; Chen, Yi-Cheng; Lin, Shi-Ming; Sheen, I-Shyan; Lin, Chun-Yen

    2015-10-01

    Effector but not naive regulatory T cells (Treg cells) can accumulate in the peripheral blood as well as the tumor microenvironment, expand during tumor progression and be one of the main suppressors for antitumor immunity. However, the underlying mechanisms for effector Treg cell expansion in tumor are still unknown. We demonstrate that effector Treg cell-mediated suppression of antitumor CD8(+) T cells is tumor-nonspecific. Furthermore, TNFR2 expression is increased in these Treg cells by Affymetrix chip analysis which was confirmed by monoclonal antibody staining in both hepatocellular carcinoma (HCC) and colorectal cancer (CRC) patients and murine models. Correspondingly, increased levels of TNF-α in both tissue and serum were also demonstrated. Interestingly, TNF-α could not only expand effector Treg cells through TNFR2 signaling, but also enhanced their suppressive activity against antitumor immunity of CD8(+) T cells. Furthermore, targeting TNFR2 signaling with a TNF-α inhibitor could selectively reduce rapid resurgence of effector Treg cells after cyclophosphamide-induced lymphodepletion and markedly inhibit the growth of established tumors. Herein, we propose a novel mechanism in which TNF-α could promote tumor-associated effector Treg cell expansion and suggest a new cancer immunotherapy strategy using TNF-α inhibitors to reduce effector Treg cells expansion after cyclophosphamide-induced lymphodepletion.

  14. Tumor-suppressor Genes, Cell Cycle Regulatory Checkpoints, and the Skin

    PubMed Central

    Velez, Ana Maria Abreu; Howard, Michael S.

    2015-01-01

    The cell cycle (or cell-division cycle) is a series of events that take place in a cell, leading to its division and duplication. Cell division requires cell cycle checkpoints (CPs) that are used by the cell to both monitor and regulate the progress of the cell cycle. Tumor-suppressor genes (TSGs) or antioncogenes are genes that protect the cell from a single event or multiple events leading to cancer. When these genes mutate, the cell can progress to a cancerous state. We aimed to perform a narrative review, based on evaluation of the manuscripts published in MEDLINE-indexed journals using the Medical Subject Headings (MeSH) terms “tumor suppressor's genes,” “skin,” and “cell cycle regulatory checkpoints.” We aimed to review the current concepts regarding TSGs, CPs, and their association with selected cutaneous diseases. It is important to take into account that in some cell cycle disorders, multiple genetic abnormalities may occur simultaneously. These abnormalities may include intrachromosomal insertions, unbalanced division products, recombinations, reciprocal deletions, and/or duplication of the inserted segments or genes; thus, these presentations usually involve several genes. Due to their complexity, these disorders require specialized expertise for proper diagnosis, counseling, personal and family support, and genetic studies. Alterations in the TSGs or CP regulators may occur in many benign skin proliferative disorders, neoplastic processes, and genodermatoses. PMID:26110128

  15. Regulatory T cells participate in CD39-mediated protection from renal injury.

    PubMed

    Wang, Yuan Min; McRae, Jennifer L; Robson, Simon C; Cowan, Peter J; Zhang, Geoff Yu; Hu, Min; Polhill, Tania; Wang, Yiping; Zheng, Guoping; Wang, Ya; Lee, Vincent W S; Unwin, Robert J; Harris, David C H; Dwyer, Karen M; Alexander, Stephen I

    2012-09-01

    CD39 is an ecto-enzyme that degrades extracellular nucleotides, such as ATP, and is highly expressed on by the vasculature and circulating cells including Foxp3+ regulatory T (Treg) cells. To study the role of purinergic regulation in renal disease, we used the adriamycin nephropathy (AN) mouse model of chronic renal injury, using human CD39-transgenic (hCD39Tg) and wild-type (WT) BALB/c mice. Effects of CD39 expression by Treg cells were assessed in AN by adoptive transfer of CD4(+) CD25(+) and CD4(+) CD25(-) T cells isolated from hCD39Tg and WT mice. hCD39Tg mice were protected from renal injury in AN with decreased urinary protein and serum creatinine, and significantly less renal injury compared with WT mice. While WT CD25(+) and hCD39Tg CD25(-) T cells conferred some protection against AN, hCD39Tg CD25(+) Treg cells offered greater protection. In vitro studies showed direct pro-apoptotic effects of ATP on renal tubular cells. In conclusion, hCD39 expressed by circulating leukocytes and intrinsic renal cells limits innate AN injury. Specifically, CD39 expression by Treg cells contributes to its protective role in renal injury. These findings suggest that extracellular nucleotides mediate AN kidney injury and that CD39, expressed by Treg cells and other cells, is protective in this model.

  16. Lineage stability and phenotypic plasticity of Foxp3⁺ regulatory T cells.

    PubMed

    Hori, Shohei

    2014-05-01

    Regulatory T (Treg) cells expressing the transcription factor forkhead box protein 3 (Foxp3) constitute a unique T-cell lineage committed to suppressive functions. While their differentiation state is remarkably stable in the face of various perturbations from the extracellular environment, they are able to adapt to diverse and fluctuating tissue environments by changing their phenotype. The lineage stability and phenotypic plasticity of Treg cells thus ensure the robustness of self-tolerance and tissue homeostasis. Recent studies have suggested, however, that Treg cells may retain lineage plasticity, the ability to switch their cell fate to various effector T-cell types under certain circumstances such as inflammation, a notion that remains highly contentious. While accumulating evidence indicates that some Treg cells can downregulate Foxp3 expression and/or acquire effector T-helper cell-like phenotypes, results from my laboratory have shown that Treg cells retain epigenetic memory of, and thus remain committed to, Foxp3 expression and suppressive functions despite such phenotypic plasticity. It has also become evident that Foxp3 can be promiscuously and transiently expressed in activated T cells. Here, I argue that the current controversy stems partly from the lack of the lineage specificity of Foxp3 expression and also from the confusion between phenotypic plasticity and lineage plasticity, and discuss implications of our findings in Treg cell fate determination and maintenance.

  17. PKC-Theta in Regulatory and Effector T-cell Functions

    PubMed Central

    Brezar, Vedran; Tu, Wen Juan; Seddiki, Nabila

    2015-01-01

    One of the major goals in immunology research is to understand the regulatory mechanisms that underpin the rapid switch on/off of robust and efficient effector (Teffs) or regulatory (Tregs) T-cell responses. Understanding the molecular mechanisms underlying the regulation of such responses is critical for the development of effective therapies. T-cell activation involves the engagement of T-cell receptor and co-stimulatory signals, but the subsequent recruitment of serine/threonine-specific protein Kinase C-theta (PKC-θ) to the immunological synapse (IS) is instrumental for the formation of signaling complexes, which ultimately lead to a transcriptional network in T cells. Recent studies demonstrated that major differences between Teffs and Tregs occurred at the IS where its formation induces altered signaling pathways in Tregs. These pathways are characterized by reduced recruitment of PKC-θ, suggesting that PKC-θ inhibits Tregs suppressive function in a negative feedback loop. As the balance of Teffs and Tregs has been shown to be central in several diseases, it was not surprising that some studies revealed that PKC-θ plays a major role in the regulation of this balance. This review will examine recent knowledge on the role of PKC-θ in T-cell transcriptional responses and how this protein can impact on the function of both Tregs and Teffs. PMID:26528291

  18. Origin and functions of pro-inflammatory cytokine producing Foxp3+ regulatory T cells.

    PubMed

    Pandiyan, Pushpa; Zhu, Jinfang

    2015-11-01

    CD4(+)CD25(+)Foxp3(+) regulatory cells (Tregs) are a special lineage of cells central in the maintenance of immune homeostasis, and are targeted for human immunotherapy. They are conventionally associated with the production of classical anti-inflammatory cytokines such as IL-10, TGF-β and IL-35, consistent to their anti-inflammatory functions. However, emerging evidence show that they also express effector cytokines such as IFN-γ and IL-17A under inflammatory conditions. While some studies reveal that these pro-inflammatory cytokine producing Foxp3(+) regulatory cells retain their suppressive ability, others believe that these cells are dys-regulated and are associated with perpetuation of immunopathology. Therefore the development of these cells may challenge the efficacy of human Treg therapy. Mechanistically, toll-like receptor (TLR) ligands and the pro-inflammatory cytokine milieu have been shown to play important roles in the induction of effector cytokines in Tregs. Here we review the mechanisms of development and the possible functions of pro-inflammatory cytokine producing Foxp3+ Tregs.

  19. Cis-regulatory analysis of the sea urchin pigment cell gene polyketide synthase.

    PubMed

    Calestani, Cristina; Rogers, David J

    2010-04-15

    The Strongylocentrotus purpuratus polyketide synthase gene (SpPks) encodes an enzyme required for the biosynthesis of the larval pigment echinochrome. SpPks is expressed exclusively in pigment cells and their precursors starting at blastula stage. The 7th-9th cleavage Delta-Notch signaling, required for pigment cell development, positively regulates SpPks. In previous studies, the transcription factors glial cell missing (SpGcm), SpGatae and kruppel-like (SpKrl/z13) have been shown to positively regulate SpPks. To uncover the structure of the Gene Regulatory Network (GRN) regulating the specification and differentiation processes of pigment cells, we experimentally analyzed the putative SpPks cis-regulatory region. We established that the -1.5kb region is sufficient to recapitulate the correct spatial and temporal expression of SpPks. Predicted DNA-binding sites for SpGcm, SpGataE and SpKrl are located within this region. The mutagenesis of these DNA-binding sites indicated that SpGcm, SpGataE and SpKrl are direct positive regulators of SpPks. These results demonstrate that the sea urchin GRN for pigment cell development is quite shallow, which is typical of type I embryo development.

  20. A systems biology approach to defining regulatory mechanisms for cartilage and tendon cell phenotypes

    PubMed Central

    Mueller, A. J.; Tew, S. R.; Vasieva, O.; Clegg, P. D.; Canty-Laird, E. G.

    2016-01-01

    Phenotypic plasticity of adult somatic cells has provided emerging avenues for the development of regenerative therapeutics. In musculoskeletal biology the mechanistic regulatory networks of genes governing the phenotypic plasticity of cartilage and tendon cells has not been considered systematically. Additionally, a lack of strategies to effectively reproduce in vitro functional models of cartilage and tendon is retarding progress in this field. De- and redifferentiation represent phenotypic transitions that may contribute to loss of function in ageing musculoskeletal tissues. Applying a systems biology network analysis approach to global gene expression profiles derived from common in vitro culture systems (monolayer and three-dimensional cultures) this study demonstrates common regulatory mechanisms governing de- and redifferentiation transitions in cartilage and tendon cells. Furthermore, evidence of convergence of gene expression profiles during monolayer expansion of cartilage and tendon cells, and the expression of key developmental markers, challenges the physiological relevance of this culture system. The study also suggests that oxidative stress and PI3K signalling pathways are key modulators of in vitro phenotypes for cells of musculoskeletal origin. PMID:27670352

  1. Multiple regulatory systems coordinate DNA replication with cell growth in Bacillus subtilis.

    PubMed

    Murray, Heath; Koh, Alan

    2014-10-01

    In many bacteria the rate of DNA replication is linked with cellular physiology to ensure that genome duplication is coordinated with growth. Nutrient-mediated growth rate control of DNA replication initiation has been appreciated for decades, however the mechanism(s) that connects these cell cycle activities has eluded understanding. In order to help address this fundamental question we have investigated regulation of DNA replication in the model organism Bacillus subtilis. Contrary to the prevailing view we find that changes in DnaA protein level are not sufficient to account for nutrient-mediated growth rate control of DNA replication initiation, although this regulation does require both DnaA and the endogenous replication origin. We go on to report connections between DNA replication and several essential cellular activities required for rapid bacterial growth, including respiration, central carbon metabolism, fatty acid synthesis, phospholipid synthesis, and protein synthesis. Unexpectedly, the results indicate that multiple regulatory systems are involved in coordinating DNA replication with cell physiology, with some of the regulatory systems targeting oriC while others act in a oriC-independent manner. We propose that distinct regulatory systems are utilized to control DNA replication in response to diverse physiological and chemical changes.

  2. IL-17+ regulatory T cells in the microenvironments of chronic inflammation and cancer.

    PubMed

    Kryczek, Ilona; Wu, Ke; Zhao, Ende; Wei, Shuang; Vatan, Linhua; Szeliga, Wojciech; Huang, Emina; Greenson, Joel; Chang, Alfred; Roliński, Jacek; Radwan, Piotr; Fang, Jingyuan; Wang, Guobin; Zou, Weiping

    2011-04-01

    Foxp3(+)CD4(+) regulatory T (Treg) cells inhibit immune responses and temper inflammation. IL-17(+)CD4(+) T (Th17) cells mediate inflammation of autoimmune diseases. A small population of IL-17(+)Foxp3(+)CD4(+) T cells has been observed in peripheral blood in healthy human beings. However, the biology of IL-17(+)Foxp3(+)CD4(+) T cells remains poorly understood in humans. We investigated their phenotype, cytokine profile, generation, and pathological relevance in patients with ulcerative colitis. We observed that high levels of IL-17(+)Foxp3(+)CD4(+) T cells were selectively accumulated in the colitic microenvironment and associated colon carcinoma. The phenotype and cytokine profile of IL-17(+)Foxp3(+)CD4(+) T cells was overlapping with Th17 and Treg cells. Myeloid APCs, IL-2, and TGF-β are essential for their induction from memory CCR6(+) T cells or Treg cells. IL-17(+)Foxp3(+)CD4(+) T cells functionally suppressed T cell activation and stimulated inflammatory cytokine production in the colitic tissues. Our data indicate that IL-17(+)Foxp3(+) cells may be "inflammatory" Treg cells in the pathological microenvironments. These cells may contribute to the pathogenesis of ulcerative colitis through inducing inflammatory cytokines and inhibiting local T cell immunity, and in turn may mechanistically link human chronic inflammation to tumor development. Our data therefore challenge commonly held beliefs of the anti-inflammatory role of Treg cells and suggest a more complex Treg cell biology, at least in the context of human chronic inflammation and associated carcinoma.

  3. IL-10-Producing Regulatory B Cells Are Decreased in Patients with Common Variable Immunodeficiency

    PubMed Central

    Costa, Priscilla Ramos; Barros, Myrthes Toledo; Kalil, Jorge; Kokron, Cristina Maria

    2016-01-01

    Common variable immunodeficiency (CVID) is the most prevalent symptomatic primary immunodeficiency in adults. CVID patients often present changes in the frequency and function of B lymphocytes, reduced number of Treg cells, chronic immune activation, recurrent infections, high incidence of autoimmunity and increased risk for malignancies. We hypothesized that the frequency of B10 cells would be diminished in CVID patients because these cells play an important role in the development of Treg cells and in the control of T cell activation and autoimmunity. Therefore, we evaluated the frequency of B10 cells in CVID patients and correlated it with different clinical and immunological characteristics of this disease. Forty-two CVID patients and 17 healthy controls were recruited for this study. Cryopreserved PBMCs were used for analysis of T cell activation, frequency of Treg cells and characterization of B10 cells by flow cytometry. IL-10 production by sorted B cells culture and plasma sCD14 were determined by ELISA. We found that CVID patients presented decreased frequency of IL-10-producing CD24hiCD38hi B cells in different cell culture conditions and decreased frequency of IL-10-producing CD24hiCD27+ B cells stimulated with CpG+PIB. Moreover, we found that CVID patients presented lower secretion of IL-10 by sorting-purified B cells when compared to healthy controls. The frequency of B10 cells had no correlation with autoimmunity, immune activation and Treg cells in CVID patients. This work suggests that CVID patients have a compromised regulatory B cell compartment which is not correlated with clinical and immunological characteristics presented by these individuals. PMID:26991898

  4. Myogenic-induced mesenchymal stem cells are capable of modulating the immune response by regulatory T cells

    PubMed Central

    Joo, Sunyoung; Lim, Hyun Ju; Jackson, John D; Atala, Anthony

    2014-01-01

    Cell therapy for patients who have intractable muscle disorders may require highly regenerative cells from young, healthy allogeneic donors. Mesenchymal stem cells are currently under clinical investigation because they are known to induce muscle regeneration and believed to be immune privileged, thus making them suitable for allogeneic applications. However, it is unclear whether allogeneic and myogenic-induced mesenchymal stem cells retain their immunomodulatory characteristics. Therefore, our aim was to evaluate the effects of mesenchymal stem cell differentiation on the immune characteristics of cells in vitro. We investigated the immunologic properties of mesenchymal stem cells after myogenic induction. Mesenchymal stem cells were obtained from C57BL/6 mice and the C3H/10T1/2 murine mesenchymal stem cell line. Two different 5-aza-2′-deoxycytidine doses (0.5 and 3 µM) were evaluated for their effects on mesenchymal stem cell skeletal myogenic differentiation potential, immune antigen expression, and mixed lymphocytic reactions. Using a mixed lymphocytic reaction, we determined the optimal splenocyte proliferation inhibition dose. The induction of regulatory T cells was markedly increased by the addition of 3 µM 5-aza-2′-deoxycytidine–treated mesenchymal stem cells. Myogenic-induced mesenchymal stem cells do not elicit alloreactive lymphocyte proliferative responses and are able to modulate immune responses. These findings support the hypothesis that myogenic-induced mesenchymal stem cells may be transplantable across allogeneic barriers. PMID:24555015

  5. Reprint of "Vitamin D deficiency in pregnant women impairs regulatory T cell function".

    PubMed

    Vijayendra Chary, A; Hemalatha, R; Seshacharyulu, M; Vasudeva Murali, M; Jayaprakash, D; Dinesh Kumar, B

    2015-04-01

    Regulatory T cells and IgE receptors (CD23 and CD21) on B cells were assessed in vitamin D deficient pregnant women. For this, 153 pregnant women were recruited from a government hospital and were categorized into three groups based on 25-hydroxyvitamin D3 (25(OH)D3) status. Regulatory T cell population (Treg cells) and CD23/CD21 expression on B cells were quantified by FACS ARIA II in maternal blood at third trimester; and the same parameters were evaluated in cord blood soon after delivery. In addition, TGF β and IL-10 were quantified in maternal and cord blood by using Milliplex kits. In a representative sample of eight women from each group (vitamin D sufficient, insufficient and deficient), placental tissues were processed for mRNA expressions of vitamin D receptor (VDR), retinoic acid receptor (RXR), vitamin D binding protein (VDBP) and vitamin D regulating enzymes. Of the 153 pregnant women, 18 were sufficient (≥30ng/mL), 55 were insufficient (20-29ng/mL) and 80 were deficient (≤19ng/mL) for 25(OH)D3 status. The maternal blood Treg cell population (mean (%)±SE) was lower (p<0.05) in 25(OH)D3 deficient (0.2±0.01) pregnant women compared to insufficient (0.34±0.01) and sufficient (0.45±0.02) pregnant women. Similarly, cord blood Treg cell population (mean (%)±SE) was also lower (p<0.05) in 25(OH)D3 deficient (0.63±0.03) pregnant women when compared to insufficient (1.05±0.04) and sufficient (1.75±0.02) pregnant women. Mean (%)±SE of B cells with CD23 and CD21 in maternal blood was higher (p<0.05) in 25(OH)D3 deficient pregnant women (0.35±0.02; 1.65±0.04) when compared to insufficient (0.22±0.02; 0.55±0.05) and sufficient (0.15±0.02; 0.21±0.01) pregnant women. Similarly, mean (%)±SE of B cell population with CD23 and CD21 in cord blood was also higher (p<0.05) in 25(OH)D3 deficient (0.41±0.02; 1.2±0.03) when compared to insufficient (0.32±0.01; 0.6±0.05) and sufficient (0.2±0.01; 0.4±0.02) pregnant women. Regulatory cytokines, TGF

  6. Soluble factors secreted by glioblastoma cell lines facilitate recruitment, survival, and expansion of regulatory T cells: implications for immunotherapy

    PubMed Central

    Crane, Courtney A.; Ahn, Brian J.; Han, Seunggu J.; Parsa, Andrew T.

    2012-01-01

    In patients with glioma, the tumor microenvironment can significantly impact pro-inflammatory immune cell functions. However, the mechanisms by which this occurs are poorly defined. Because immunosuppressive regulatory T cells (Treg) are over represented in the tumor microenvironment compared with peripheral blood, we hypothesized that the tumor may have an effect on Treg survival, migration, expansion, and/or induction of a regulatory phenotype from non-Treg conventional CD4+ T cells. We defined the impact of soluble factors produced by tumor cells on Treg from healthy patients in vitro to determine mechanisms by which gliomas influence T cell populations. We found that tumor-derived soluble factors allowed for preferential proliferation and increased chemotaxis of Treg, compared with conventional T cells, indicating that these mechanisms may contribute to the increased Treg in the tumor microenvironment. Conventional T cells also exhibited a significantly increased expression of pro-apoptotic transcripts in the presence of tumor-derived factors, indicating that survival of Treg in the tumor site is driven by exposure to soluble factors produced by the tumor. Together, these data suggest that tumor burden may induce increased Treg infiltration, proliferation, and survival, negating productive anti-tumor immune responses in patients treated with immunotherapies. Collectively, our data indicate that several mechanisms of Treg recruitment and retention in the tumor microenvironment exist and may need to be addressed to improve the specificity of immunotherapies seeking to eliminate Treg in patients with glioma. PMID:22406925

  7. The cytokine milieu in the interplay of pathogenic Th1/Th17 cells and regulatory T cells in autoimmune disease

    PubMed Central

    Leung, Stewart; Liu, Xuebin; Fang, Lei; Chen, Xi; Guo, Taylor; Zhang, Jingwu

    2010-01-01

    The propagation and regulation of an immune response is driven by a network of effector and regulatory T (Treg) cells. The interplay of effector T and Treg cells determines the direction of the immune response towards inflammation or its resolution in an autoimmune disease setting. In autoimmune diseases, this interplay shifts the balance in favor of the development of autoreactive effector T cells, resulting in inflammatory pathology. The objective of an effective therapeutic approach for autoimmune disease is to restore this balance. In this review, we describe the characteristics and development of pathogenic T helper 1 (Th1) and Th17 cells and the beneficial Treg cells in autoimmune diseases and the crucial roles of the cytokine milieu in influencing the balance of these T-cell subsets. Given the importance of cytokines, we discuss current immunotherapeutic strategies using cytokine or cytokine receptor antibodies for the treatment of autoimmune diseases. PMID:20383174

  8. Linear ubiquitin chain assembly complex coordinates late thymic T-cell differentiation and regulatory T-cell homeostasis

    PubMed Central

    Teh, Charis E.; Lalaoui, Najoua; Jain, Reema; Policheni, Antonia N.; Heinlein, Melanie; Alvarez-Diaz, Silvia; Sheridan, Julie M.; Rieser, Eva; Deuser, Stefanie; Darding, Maurice; Koay, Hui-Fern; Hu, Yifang; Kupresanin, Fiona; O'Reilly, Lorraine A.; Godfrey, Dale I.; Smyth, Gordon K.; Bouillet, Philippe; Strasser, Andreas; Walczak, Henning; Silke, John; Gray, Daniel H. D.

    2016-01-01

    The linear ubiquitin chain assembly complex (LUBAC) is essential for innate immunity in mice and humans, yet its role in adaptive immunity is unclear. Here we show that the LUBAC components HOIP, HOIL-1 and SHARPIN have essential roles in late thymocyte differentiation, FOXP3+ regulatory T (Treg)-cell development and Treg cell homeostasis. LUBAC activity is not required to prevent TNF-induced apoptosis or necroptosis but is necessary for the transcriptional programme of the penultimate stage of thymocyte differentiation. Treg cell-specific ablation of HOIP causes severe Treg cell deficiency and lethal immune pathology, revealing an ongoing requirement of LUBAC activity for Treg cell homeostasis. These data reveal stage-specific requirements for LUBAC in coordinating the signals required for T-cell differentiation. PMID:27857075

  9. Chaperone-rich tumor cell lysate-mediated activation of antigen-presenting cells resists regulatory T cell suppression.

    PubMed

    Larmonier, Nicolas; Cantrell, Jessica; Lacasse, Collin; Li, Gang; Janikashvili, Nona; Situ, Elaine; Sepassi, Marjan; Andreansky, Samita; Katsanis, Emmanuel

    2008-04-01

    CD4(+)CD25(+) regulatory T lymphocytes (Tregs) critically contribute to the mechanisms of cancer-induced tolerance. These cells suppress anti-tumoral CD8(+) and CD4(+) T lymphocytes and can also restrain the function of APCs. We have previously documented the immunostimulatory effects of a chaperone-rich cell lysate (CRCL) anti-cancer vaccine. Tumor-derived CRCL induces tumor immunity in vivo, partly by promoting dendritic cell (DC) and macrophage activation. In the current study, we evaluated the effects of CD4(+)CD25(+)forkhead box P3(+) Tregs isolated from mice bearing 12B1 bcr-abl(+) leukemia on DC and macrophages that had been activated by 12B1-derived CRCL. CRCL-activated DC and macrophages resisted Treg suppression, as the production of proinflammatory cytokines, the activation of transcription factor NF-kappaB, and their immunostimulatory potential was unaffected by Tregs. Our results thus highlight CRCL as a powerful adjuvant endowed with the capacity to overcome tumor-induced Treg-inhibitory effects on APCs.

  10. Design principles of regulatory networks: searching for the molecular algorithms of the cell.

    PubMed

    Lim, Wendell A; Lee, Connie M; Tang, Chao

    2013-01-24

    A challenge in biology is to understand how complex molecular networks in the cell execute sophisticated regulatory functions. Here we explore the idea that there are common and general principles that link network structures to biological functions, principles that constrain the design solutions that evolution can converge upon for accomplishing a given cellular task. We describe approaches for classifying networks based on abstract architectures and functions, rather than on the specific molecular components of the networks. For any common regulatory task, can we define the space of all possible molecular solutions? Such inverse approaches might ultimately allow the assembly of a design table of core molecular algorithms that could serve as a guide for building synthetic networks and modulating disease networks.

  11. Design Principles of Regulatory Networks: Searching for the Molecular Algorithms of the Cell

    PubMed Central

    Lim, Wendell A.; Lee, Connie M.; Tang, Chao

    2013-01-01

    A challenge in biology is to understand how complex molecular networks in the cell execute sophisticated regulatory functions. Here we explore the idea that there are common and general principles that link network structures to biological functions, principles that constrain the design solutions that evolution can converge upon for accomplishing a given cellular task. We describe approaches for classifying networks based on abstract architectures and functions, rather than on the specific molecular components of the networks. For any common regulatory task, can we define the space of all possible molecular solutions? Such inverse approaches might ultimately allow the assembly of a design table of core molecular algorithms that could serve as a guide for building synthetic networks and modulating disease networks. PMID:23352241

  12. Advances on Non-CD4 + Foxp3+ T Regulatory Cells: CD8+, Type 1, and Double Negative T Regulatory Cells in Organ Transplantation.

    PubMed

    Ligocki, Ann J; Niederkorn, Jerry Y

    2015-08-01

    The overwhelming body of research on T regulatory cells (Treg) has focused on CD4 + CD25 + Foxp3+ T cells. However, recent years have witnessed a resurgence in interest in CD4 - CD8+, CD4 - CD8- (double negative [DN]), and CD4 + Foxp3- type 1 Treg (Tr1) Treg and their role in controlling autoimmune diseases and in promoting the survival of organ allografts and xenografts. CD8+ and DN Treg can arise spontaneously (natural Treg) or can be induced in situ. Both CD8+ and DN Treg have been shown to enhance the survival of organ allografts and xenografts. Additionally, both can suppress alloimmune responses by contact-dependent mechanisms by either inducing apoptosis or mediating direct cytolysis of effector T cells. CD8+, DN, and Tr1 Treg can also act in a contact-independent manner by elaborating soluble immunosuppressive factors, such as TGF-β and IL-10. Applying CD8+, DN, and Tr1 Treg for enhancing the survival of organ allografts and xenografts is still in its infancy but holds significant potential. Furthermore, there is a need for a more comprehensive understanding of how current immunosuppressive therapies applied to organ transplantations affect the wide array of Treg populations.

  13. Monitoring the frequency and function of regulatory T cells and summary of the approaches currently used to inhibit regulatory T cells in cancer patients.

    PubMed

    Camisaschi, Chiara; Tazzari, Marcella; Rivoltini, Licia; Castelli, Chiara

    2014-01-01

    Regulatory T cells (Treg) are a subset of T lymphocytes that in humans represent less than the 10 % of circulating CD4(+) T cells. Treg are specialized in the inhibition of the immune responses and play a crucial role in the maintenance of immunological tolerance. Several lines of evidence clearly documented the role of Treg in restraining antitumor immune responses. For this reason, antitumor immunotherapy approaches have been recently associated with drug treatments aimed at depleting Treg or blocking their functions. A summary of the currently used in vivo approaches to limit Treg expansion in cancer patients is here provided.A comprehensive phenotypic and functional monitoring of Treg is crucial for the precise assessment of the effects that these different drug treatments exert on Treg. In this chapter, we will provide guidelines for an accurate ex vivo identification of human Treg. Due to the phenotypic and functional heterogeneity, intrinsic plasticity, and the lack of a unique marker exclusively expressed by human Treg, the clear-cut identification of this T cell subset requires the expert usage of multiparametric flow cytometry analysis (FACS). In this view, a combination of phenotypic and functional assessment of Treg is mandatory. In this chapter, we will describe the most reliable methods to identify and monitor the modulation of human Treg in patients undergoing immunological or drug-based treatments. Protocols to measure ex vivo the suppressive functions of Treg are also provided.

  14. Regulatory B cell is critical in bone union process through suppressing proinflammatory cytokines and stimulating Foxp3 in Treg cells.

    PubMed

    Sun, Guojing; Wang, Yicun; Ti, Yunfan; Wang, Jun; Zhao, Jianning; Qian, Hongbo

    2017-04-01

    Bone fractures may result in delayed union (DU) or non-union (NU) in some patients. Evidence suggests that the skewing of the immune system toward the proinflammatory type is a contributing factor. Because B cells were previously found to infiltrate the fracture healing site at abundant levels, we examined the regulatory B cells (Bregs) in DU/NU patients. In bone fracture patients with normal healing, the frequency of interleukin (IL)-10-expressing B cells was significantly upregulated in the early healing process (6 weeks post-surgery) and was downregulated later on (18 weeks post-surgery), whereas in DU/NU patients, the early upregulation of IL-10-expressing B cells was missing. The majority of IL-10-expressing B cells were concentrated in the IgM(+) CD27(+) fraction in both controls and patients. IgM(+) CD27(+) B cells effectively suppressed interferon gamma (IFN-γ), tumor necrosis factor alpha (TNF-α), and IL-2 expression from CD4(+) T cells, as well as IFN-γ and TNF-α expression from CD8(+) T cells. The IgM(+) CD27(+) B cell-mediated suppression was restricted to the sample from the early healing time point in controls, as the IgM(+) CD27(+) B cells from normal healing patients later on or from DU/NU patients did not present significant regulatory function. In addition, culturing of CD4(+) CD25(+) Tregs with IgM(+) CD27(+) B cells from controls at early healing time point resulted in higher Foxp3 expression, a function absent in controls at later time point, or in DU/NU patients. In conclusion, our results support a role of B cell-mediated regulation early during the bone healing process.

  15. Heparin affin regulatory peptide/pleiotrophin negatively affects diverse biological activities in C6 glioma cells.

    PubMed

    Parthymou, Anastasia; Lampropoulou, Evgenia; Mikelis, Constantinos; Drosou, Georgia; Papadimitriou, Evangelia

    2008-01-01

    Heparin affin regulatory peptide (HARP) or pleiotrophin seems to be involved in the progression of several tumors of diverse origin. In this study, we tried to determine the role of HARP in rat C6 glioma cells by using an antisense strategy for inhibition of HARP expression. Decrease of the expression of endogenous HARP in C6 cells (AS-C6 cells) significantly increased proliferation, migration, and anchorage-independent growth of cells. Implantation of AS-C6 cells onto chicken embryo chorioallantoic membranes resulted in a significant increase of tumor-induced angiogenesis compared with that induced by non-transfected or C6 cells transfected with the plasmid alone (PC-C6 cells). In the same line, conditioned medium from AS-C6 cells significantly increased endothelial cell proliferation, migration, and tube formation in vitro compared with the effect of conditioned medium from C6 or PC-C6 cells. Interestingly, vascular endothelial growth factor (VEGF) induced C6 cell proliferation and migration, and SU1496, a selective inhibitor of VEGF receptor 2 (VEGFR2), blocked increased glioma cell growth, migration, and angiogenicity observed in AS-C6 cell cultures. The above results seem to be due to a direct interaction between HARP and VEGF in the culture medium of C6 and PC-C6 cells, while AS-C6 cells secreted comparable amounts of VEGF that do not interact with HARP. Collectively, these data suggest that HARP negatively affects diverse biological activities in C6 glioma cells, mainly due to binding of HARP to VEGF, which may sequester secreted VEGF from signalling through VEGFR2.

  16. Assay of Peripheral Regulatory Vδ1 T Cells in Ankylosing Spondylitis and its Significance

    PubMed Central

    Wang, Hongliang; Sun, Na; Li, Ka; Tian, Jiguang; Li, Jianmin

    2016-01-01

    Background Ankylosing spondylitis (AS) involves inflammation at the sacroiliac joint and spine attachment site. This study aimed to observe the ratio and function of peripheral regulatory Vδ1 T cells in AS patients to investigate their roles in AS pathogenesis. Material/Methods Peripheral blood mononuclear cells (PBMC) were separated by density-gradient centrifugation from AS patients and healthy controls. Flow cytometry was used to determine the ratio between Vδ1 and CD4 T cells of PBMC in AS patients and controls. Flow cytometry sorting (FCS) was used to obtain Vδ1 and naïve CD4 T cells with purity higher than 90%. CFSE staining method was used to detect the effect of Vδ1 T cells on proliferation of naïve CD4 T cells. The effect of Vδ1 T cells on secretion of IFN-γ from naïve CD4 T cells and the ability to secrete IL-10 from Vδ1 T cells were determined by flow cytometry. Results AS patients had significantly lower Vδ1 T cell ratio in PBMC compared to controls (p<0.05), but their CD4 T cell ratio was significantly elevated (p<0.05). Functional assay showed suppression of naïve CD4 T cell proliferation and IFN-γ secretion by peripheral Vδ1 T cells in AS patients (p<0.01). AS patients also had lower IL-10 secreting level from peripheral derived Vδ1 T cells (p<0.01). Conclusions The immune suppression of peripheral Vδ1 T cell in AS patient increases the ratio of peripheral CD4 T cells and IFN-γ level, leading to AS pathogenesis. This immune suppression is mainly due to suppressed IL-10 secretion. PMID:27598263

  17. Emerging roles of T helper 17 and regulatory T cells in lung cancer progression and metastasis.

    PubMed

    Marshall, Erin A; Ng, Kevin W; Kung, Sonia H Y; Conway, Emma M; Martinez, Victor D; Halvorsen, Elizabeth C; Rowbotham, David A; Vucic, Emily A; Plumb, Adam W; Becker-Santos, Daiana D; Enfield, Katey S S; Kennett, Jennifer Y; Bennewith, Kevin L; Lockwood, William W; Lam, Stephen; English, John C; Abraham, Ninan; Lam, Wan L

    2016-10-27

    Lung cancer is a leading cause of cancer-related deaths worldwide. Lung cancer risk factors, including smoking and exposure to environmental carcinogens, have been linked to chronic inflammation. An integral feature of inflammation is the activation, expansion and infiltration of diverse immune cell types, including CD4(+) T cells. Within this T cell subset are immunosuppressive regulatory T (Treg) cells and pro-inflammatory T helper 17 (Th17) cells that act in a fine balance to regulate appropriate adaptive immune responses.In the context of lung cancer, evidence suggests that Tregs promote metastasis and metastatic tumor foci development. Additionally, Th17 cells have been shown to be an integral component of the inflammatory milieu in the tumor microenvironment, and potentially involved in promoting distinct lung tumor phenotypes. Studies have shown that the composition of Tregs and Th17 cells are altered in the tumor microenvironment, and that these two CD4(+) T cell subsets play active roles in promoting lung cancer progression and metastasis.We review current knowledge on the influence of Treg and Th17 cells on lung cancer tumorigenesis, progression, metastasis and prognosis. Furthermore, we discuss the potential biological and clinical implications of the balance among Treg/Th17 cells in the context of the lung tumor microenvironment and highlight the potential prognostic function and relationship to metastasis in lung cancer.

  18. Apoptosis as a mechanism of T-regulatory cell homeostasis and suppression.

    PubMed

    Yolcu, Esma S; Ash, Shifra; Kaminitz, Ayelet; Sagiv, Yuval; Askenasy, Nadir; Yarkoni, Shai

    2008-01-01

    Activation-induced cell death is a general mechanism of immune homeostasis through negative regulation of clonal expansion of activated immune cells. This mechanism is involved in the maintenance of self- and transplant tolerance through polarization of the immune responses. The Fas/Fas-ligand interaction is a major common executioner of apoptosis in lymphocytes, with a dual role in regulatory T cell (Treg) function: Treg cell homeostasis and Treg cell-mediated suppression. Sensitivity to apoptosis and the patterns of Treg-cell death are of outmost importance in immune homeostasis that affects the equilibrium between cytolytic and suppressor forces in activation and termination of immune activity. Naive innate (naturally occurring) Treg cells present variable sensitivities to apoptosis, related to their turnover rates in tissue under steady state conditions. Following activation, Treg cells are less sensitive to apoptosis than cytotoxic effector subsets. Their susceptibility to apoptosis is influenced by cytokines within the inflammatory environment (primarily interleukin-2), the mode of antigenic stimulation and the proliferation rates. Here, we attempt to resolve some controversies surrounding the sensitivity of Treg cells to apoptosis under various experimental conditions, to delineate the function of cell death in regulation of immunity.

  19. Regulatory and pro-inflammatory phenotypes of myelin basic protein-autoreactive T cells in multiple sclerosis

    PubMed Central

    Li, Haiyan; Chen, Meiyue; Zang, Ying C. Q.; Skinner, Sheri M.; Killian, James M.; Zhang, Jingwu Z.

    2009-01-01

    MBP-specific autoreactive T cells are considered pro-inflammatory T cells and thought to play an important role in the pathogenesis of multiple sclerosis (MS). Here, we report that MBP83–99-specific T cells generated from MS patients (n = 7) were comprised of pro-inflammatory and regulatory subsets of distinct phenotypes. The pro-inflammatory phenotype was characterized by high production of IFN-γ, IL-6, IL-21 and IL-17 and low expression of FOXP3, whereas the regulatory subset expressed high levels of FOXP3 and exhibited potent regulatory functions. The regulatory subset of MBP-specific T cells appeared to expand from the CD4+CD25− T-cell pool. Their FOXP3 expression was stable, independent of the activation state and it correlated with suppressive function and inversely with the production of IFN-γ, IL-6, IL-21 and IL-17. In contrast, the phenotype and function of FOXP3low MBP-specific T cells were adaptive and dependent on IL-6. The higher frequency of FOXP3high MBP-specific T cells was observed when IL-6 was neutralized in the culture of PBMC with MBP. The study provides new evidence that MBP-specific T cells are susceptible to pro-inflammatory cytokine milieu and act as either pro-inflammatory or regulatory T cells. PMID:19822525

  20. [Advances in ex vivo expansion and immunotherapy application of regulatory T cells].

    PubMed

    Yan, Li; Shao, Zong-Hong

    2015-04-01

    CD4+ CD25+ regulatory T cells (Treg) play a fundamental role in the establishment and maintenance of immune tolerance. In a some of experimental models, it was found that Tregs can quench autoimmune diseases, maintain allogeneic transplants, and prevent allergic diseases. A major obstacle to their clinical application is related to their definitive phenotype and very limited number of these cells in peripheral circulation, no more than 5%-10% of total CD4+ T cells. Recent progress of technologies for Treg sorting with multicolor flow cytometry and immuno-absorbing columns has overcome these obstacles, and opened the doors to the clinical application of Treg. This review highlight the characteristics of Treg, describe the current information of cell sorting and ex vivo expansion techniques, and outline the adoptive transfer experiments and clinical trials of immunotherapy that have been developed in recent years. It is foreseeable that Treg adoptive transfusion will be a promising immunosuppressive therapy.

  1. Breaking immune tolerance by targeting Foxp3+ regulatory T cells mitigates Alzheimer's disease pathology

    PubMed Central

    Baruch, Kuti; Rosenzweig, Neta; Kertser, Alexander; Deczkowska, Aleksandra; Sharif, Alaa Mohammad; Spinrad, Amit; Tsitsou-Kampeli, Afroditi; Sarel, Ayelet; Cahalon, Liora; Schwartz, Michal

    2015-01-01

    Alzheimer's disease (AD) is a neurodegenerative disorder in which chronic neuroinflammation contributes to disease escalation. Nevertheless, while immunosuppressive drugs have repeatedly failed in treating this disease, recruitment of myeloid cells to the CNS was shown to play a reparative role in animal models. Here we show, using the 5XFAD AD mouse model, that transient depletion of Foxp3+ regulatory T cells (Tregs), or pharmacological inhibition of their activity, is followed by amyloid-β plaque clearance, mitigation of the neuroinflammatory response and reversal of cognitive decline. We further show that transient Treg depletion affects the brain's choroid plexus, a selective gateway for immune cell trafficking to the CNS, and is associated with subsequent recruitment of immunoregulatory cells, including monocyte-derived macrophages and Tregs, to cerebral sites of plaque pathology. Our findings suggest targeting Treg-mediated systemic immunosuppression for treating AD. PMID:26284939

  2. Tissue adaptation of regulatory and intraepithelial CD4+ T cells controls gut inflammation

    PubMed Central

    Sujino, Tomohisa; London, Mariya; Hoytema van Konijnenburg, David P.; Rendon, Tomiko; Buch, Thorsten; Silva, Hernandez M.; Lafaille, Juan J.; Reis, Bernardo S.; Mucida, Daniel

    2016-01-01

    Foxp3+ regulatory T cells in peripheral tissues (pTregs) are instrumental in limiting inflammatory responses to non-self antigens. Within the intestine, pTregs are located primarily in the lamina propria, while intraepithelial CD4+ T cells (CD4IELs), which also exhibit anti-inflammatory properties and depend on similar environmental cues, reside in the epithelium. Using intravital microscopy, we show distinct cell dynamics of intestinal Tregs and CD4IELs. Upon migration to the epithelium, Tregs lose Foxp3 and convert to CD4IELs in a microbiota-dependent fashion, an effect attributed to the loss of the transcription factor ThPOK. Finally, we demonstrate that pTregs and CD4IELs perform complementary roles in the regulation of intestinal inflammation. These results reveal intra-tissue specialization of anti-inflammatory T cells shaped by discrete niches of the intestine. PMID:27256884

  3. [The significance of regulatory CD4+CD25+ T cells in the pathogenesis and treatment of kidney disease].

    PubMed

    Krajewska, Magdalena; Weyde, Wacław; Klinger, Marian

    2007-01-01

    Thanks to a precisely regulated response, the immune system works to maintain homeostasis, and one of the significant mechanisms of this regulation is regulatory T cells. This paper presents the latest knowledge concerning the occurrence of natural regulatory T cells of CD4+CD25+ phenotype and their role in the pathogeneses of immune system diseases. Functional and quantitative disorders in this population of cells are found in many diseases which in their course attack the kidney, for instance mixed cryoglobulinemia, rheumatoid arthritis, Sjögren's syndrome, lupus erythematosus, and type 1 diabetes mellitus. The role of T cells and the effectory and regulatory mechanisms dependent on them in the development and progression of glomerulonephritis is presented. The role of regulatory T cells in the development and progression of chronic kidney disease is discussed as well. Qualms whether a decreased number and/or disrupted function of regulatory T cells promote the development of autoimmune diseases or whether they are secondary phenomena are settled by clinical observations in which restoration of the number of the cells prevents further tissue damage. Strengthening or blocking regulatory T-cell functions and obtaining a balance between activation and suppression in the immune system depending on current needs may become the key to the immunotherapy of many diseases. Another problem presented in this paper is the perspective of regulatory T cell therapy; however, attempts to modify their activity and change the number of cells must be carried with the greatest of care because such a procedure may result in dysregulation of the immune system.

  4. Regulatory Mechanisms Underlying the Expression of Prolactin Receptor in Chicken Granulosa Cells

    PubMed Central

    Hu, Shenqiang; Duggavathi, Raj; Zadworny, David

    2017-01-01

    Prolactin (PRL) has both pro- and anti-gonadal roles in the regulation of avian ovarian functions through its interaction with the receptor (PRLR). However, neither the pattern of expression of PRLR nor its regulatory mechanisms during follicle development have been clearly defined. The objective of the present study was to investigate mechanisms of PRLR expression in chicken granulosa cells. Levels of PRLR transcript were highest in the stroma and walls of follicles < 2 mm in diameter and progressively declined with the maturation of follicles. In preovulatory follicles, PRLR was expressed at higher levels in granulosa than theca layers. FSH exerted the greatest stimulatory effect on PRLR and StAR expression in cultured granulosa cells of the 6–8 mm follicles but this effect declined as follicles matured to F1. In contrast, LH did not alter the expression of PRLR in granulosa cells of all follicular classes but increased levels of StAR in F2 and F1 granulosa cells. Both non-glycosylated- (NG-) and glycosylated- (G-) PRL upregulated basal PRLR expression in granulosa cells of the 6–8 mm, F3 or F1 follicles but had little effect in F2 follicles. Furthermore, FSH-stimulated PRLR expression was reduced by the addition of either isoform of PRL especially in F2 granulosa cells. These results indicate that PRLR is differentially distributed and regulated by FSH or PRL variants independently or in combination in the follicular hierarchy. By using activators and inhibitors, we further demonstrated that multiple signaling pathways, including PKA, PKC, PI3K, mTOR and AMPK, are not only directly involved in, but they can also converge to modulate ERK2 activity to regulate FSH-mediated PRLR and StAR expression in undifferentiated granulosa cells. These data provide new insights into the regulatory mechanisms controlling the expression of PRLR in granulosa cells. PMID:28107515

  5. Upregulation of CD47 in Regulatory T Cells in Atopic Dermatitis

    PubMed Central

    Lee, Nara; Shin, Jung U; Jin, Shan; Yun, Ki Na; Kim, Jin Young; Park, Chang Ook; Kim, Seo Hyeong; Noh, Ji Yeon

    2016-01-01

    Purpose Regulatory T (Treg) cells are key modulators in the immune system. Recent studies have shown that atopic dermatitis (AD) patients have higher numbers of Treg cells; however, little is known about the specific phenotype and function of Treg cells in AD. Materials and Methods To identify differentially expressed proteins in peripheral induced Treg cells in AD and naturally derived Treg cells in normal controls, CD4+CD25+ Treg cells were isolated from thymus tissue of normal mice and the spleens of AD mice. Membrane proteins were extracted, and quantitative proteomics labeling with Tandem Mass Tags (TMT) was performed, followed by one-dimensional liquid chromatography/tandem mass spectrometry analysis. Results Using TMT labeling, we identified 510 proteins, including 63 membrane proteins and 16 plasma membrane proteins. CD47 was one of the upregulated proteins in Treg cells in AD spleens. Although CD47 was expressed in all CD4+ and CD8+ T cells, a significantly higher expression of CD47 was observed in the Treg cells of AD mice and AD patients than in those of normal mice and healthy controls. Furthermore, Treg cells from the spleen showed a significantly higher expression of CD47 than those from the thymus. Conclusion We found that CD47 is highly expressed in the Treg cells of AD mice, particularly in the spleen. Based on our results, we propose that CD47high Treg cells are likely induced Treg cells and that upregulated CD47 in the Treg cells of AD patients may play a role in the increased population of Treg cells in AD. PMID:27593872

  6. Future research and therapeutic applications of human stem cells: general, regulatory, and bioethical aspects

    PubMed Central

    2010-01-01

    There is much to be investigated about the specific characteristics of stem cells and about the efficacy and safety of the new drugs based on this type of cells, both embryonic as adult stem cells, for several therapeutic indications (cardiovascular and ischemic diseases, diabetes, hematopoietic diseases, liver diseases). Along with recent progress in transference of nuclei from human somatic cells, as well as iPSC technology, has allowed availability of lineages of all three germ layers genetically identical to those of the donor patient, which permits safe transplantation of organ-tissue-specific adult stem cells with no immune rejection. The main objective is the need for expansion of stem cell characteristics to maximize stem cell efficacy (i.e. the proper selection of a stem cell) and the efficacy (maximum effect) and safety of stem cell derived drugs. Other considerations to take into account in cell therapy will be the suitability of infrastructure and technical staff, biomaterials, production costs, biobanks, biosecurity, and the biotechnological industry. The general objectives in the area of stem cell research in the next few years, are related to identification of therapeutic targets and potential therapeutic tests, studies of cell differentiation and physiological mechanisms, culture conditions of pluripotent stem cells and efficacy and safety tests for stem cell-based drugs or procedures to be performed in both animal and human models in the corresponding clinical trials. A regulatory framework will be required to ensure patient accessibility to products and governmental assistance for their regulation and control. Bioethical aspects will be required related to the scientific and therapeutic relevance and cost of cryopreservation over time, but specially with respect to embryos which may ultimately be used for scientific uses of research as source of embryonic stem cells, in which case the bioethical conflict may be further aggravated. PMID:21143967

  7. Hyperlipidemia Alters Regulatory T Cell Function and Promotes Resistance to Tolerance Induction Through Costimulatory Molecule Blockade

    PubMed Central

    Bagley, J.; Yuan, J.; Chandrakar, A.; Iacomini, J.

    2016-01-01

    Recent work from our laboratory has shown that hyperlipidemia promotes accelerated rejection of vascularized cardiac allografts in mice by inducing anti-donor Th17 reactivity and production of IL-17. Here, we show that hyperlipidemia also affects FoxP3+ regulatory T cells (Tregs). Hyperlipidemia promotes the development of Tregs that express low levels of CD25. Hyperlipidemia also promotes a decrease in central Tregs and an increase in effector Tregs that appears to account for the increase in the frequency of CD25low Tregs. Alterations in Treg subsets also appear to lead to alterations in Treg function. The ability of FoxP3+, CD25high, CD4+ Tregs from hyperlipidemic mice to inhibit proliferation of effector T cells stimulated with anti-CD3 and CD28 was reduced when compared with Tregs from control mice. Regulatory T cells isolated from hyperlipidemic recipients exhibit increased activation of Akt, and a reduction in Bim levels that permits the expansion of FoxP3+CD25lowCD4+ T cells. Hyperlipidemic mice were also resistant to tolerance induction using costimulatory molecule blockade consisting of anti-CD154 and CTLA4Ig, a strategy that requires Tregs. Together, our data suggest that hyperlipidemia profoundly affects Treg subsets and function as well as the ability to induce tolerance. PMID:26079467

  8. Requirements for efficient cell-type proportioning: regulatory timescales, stochasticity and lateral inhibition

    NASA Astrophysics Data System (ADS)

    Pfeuty, B.; Kaneko, K.

    2016-04-01

    The proper functioning of multicellular organisms requires the robust establishment of precise proportions between distinct cell types. This developmental differentiation process typically involves intracellular regulatory and stochastic mechanisms to generate cell-fate diversity as well as intercellular signaling mechanisms to coordinate cell-fate decisions at tissue level. We thus surmise that key insights about the developmental regulation of cell-type proportion can be captured by the modeling study of clustering dynamics in population of inhibitory-coupled noisy bistable systems. This general class of dynamical system is shown to exhibit a very stable two-cluster state, but also metastability, collective oscillations or noise-induced state hopping, which can prevent from timely and reliably reaching a robust and well-proportioned clustered state. To circumvent these obstacles or to avoid fine-tuning, we highlight a general strategy based on dual-time positive feedback loops, such as mediated through transcriptional versus epigenetic mechanisms, which improves proportion regulation by coordinating early and flexible lineage priming with late and firm commitment. This result sheds new light on the respective and cooperative roles of multiple regulatory feedback, stochasticity and lateral inhibition in developmental dynamics.

  9. Induction of regulatory cells by helminth parasites: exploitation for the treatment of inflammatory diseases.

    PubMed

    Finlay, Conor M; Walsh, Kevin P; Mills, Kingston H G

    2014-05-01

    Helminth parasites are highly successful pathogens, chronically infecting a quarter of the world's population, causing significant morbidity but rarely causing death. Protective immunity and expulsion of helminths is mediated by T-helper 2 (Th2) cells, type 2 (M2) macrophages, type 2 innate lymphoid cells, and eosinophils. Failure to mount these type 2 immune responses can result in immunopathology mediated by Th1 or Th17 cells. Helminths have evolved a wide variety of approaches for immune suppression, especially the generation of regulatory T cells and anti-inflammatory cytokines interleukin-10 and transforming growth factor-β. This is a very effective strategy for subverting protective immune responses to prolong their survival in the host but has the bystander effect of modulating immune responses to unrelated antigens. Epidemiological studies in humans have shown that infection with helminth parasites is associated with a low incidence of allergy/asthma and autoimmunity in developing countries. Experimental studies in mice have demonstrated that regulatory immune responses induced by helminth can suppress Th2 and Th1/Th17 responses that mediate allergy and autoimmunity, respectively. This has provided a rational explanation of the 'hygiene hypothesis' and has also led to the exploitation of helminths or their immunomodulatory products in the development of new immunosuppressive therapies for inflammatory diseases in humans.

  10. The cell envelope stress response of Bacillus subtilis: from static signaling devices to dynamic regulatory network.

    PubMed

    Radeck, Jara; Fritz, Georg; Mascher, Thorsten

    2017-02-01

    The cell envelope stress response (CESR) encompasses all regulatory events that enable a cell to protect the integrity of its envelope, an essential structure of any bacterial cell. The underlying signaling network is particularly well understood in the Gram-positive model organism Bacillus subtilis. It consists of a number of two-component systems (2CS) and extracytoplasmic function σ factors that together regulate the production of both specific resistance determinants and general mechanisms to protect the envelope against antimicrobial peptides targeting the biogenesis of the cell wall. Here, we summarize the current picture of the B. subtilis CESR network, from the initial identification of the corresponding signaling devices to unraveling their interdependence and the underlying regulatory hierarchy within the network. In the course of detailed mechanistic studies, a number of novel signaling features could be described for the 2CSs involved in mediating CESR. This includes a novel class of so-called intramembrane-sensing histidine kinases (IM-HKs), which-instead of acting as stress sensors themselves-are activated via interprotein signal transfer. Some of these IM-HKs are involved in sensing the flux of antibiotic resistance transporters, a unique mechanism of responding to extracellular antibiotic challenge.

  11. GITR ligand-costimulation activates effector and regulatory functions of CD4{sup +} T cells

    SciTech Connect

    Igarashi, Hanna; Cao, Yujia; Iwai, Hideyuki; Piao, Jinhua; Kamimura, Yosuke; Hashiguchi, Masaaki; Amagasa, Teruo; Azuma, Miyuki

    2008-05-16

    Engagement of glucocorticoid-induced TNFR-related protein (GITR) enables the costimulation of both CD25{sup -}CD4{sup +} effector (Teff) and CD25{sup +}CD4{sup +} regulatory (Treg) cells; however, the effects of GITR-costimulation on Treg function remain controversial. In this study, we examined the effects of GITR ligand (GITRL) binding on the respective functions of CD4{sup +} T cells. GITRL-P815 transfectants efficiently augmented anti-CD3-induced proliferation and cytokine production by Teff cells. Proliferation and IL-10 production in Treg were also enhanced by GITRL transfectants when exogenous IL-2 and stronger CD3 stimulation was provided. Concomitant GITRL-costimulation of Teff and Treg converted the anergic state of Treg into a proliferating state, maintaining and augmenting their function. Thus, GITRL-costimulation augments both effector and regulatory functions of CD4{sup +} T cells. Our results suggest that highly activated and increased ratios of Treg reverse the immune-enhancing effects of GITRL-costimulation in Teff, which may be problematic for therapeutic applications using strong GITR agonists.

  12. A link between PDL1 and T regulatory cells in fetomaternal tolerance.

    PubMed

    Habicht, Antje; Dada, Shirine; Jurewicz, Mollie; Fife, Brian T; Yagita, Hideo; Azuma, Miyuki; Sayegh, Mohamed H; Guleria, Indira

    2007-10-15

    Acceptance of the fetus expressing allogeneic paternal Ags by the mother is a physiologic model of transplantation tolerance. Various mechanisms contribute to fetal evasion from immune attack by maternal leukocytes. We have recently demonstrated that the inhibitory costimulatory molecule PDL1 plays a critical role in fetomaternal tolerance in that PDL1 blockade or deficiency resulted in decreased allogeneic fetal survival rates. CD4(+)CD25(+) T regulatory cells (Tregs) have also been demonstrated to play an important role in fetomaternal tolerance. Since PDL1 is expressed on Tregs, we explored the interactions between PDL1 and Tregs in vivo in a mouse model of fetomaternal tolerance. Depletion of CD25(+) T cells abrogated the effect of anti-PDL1 Ab indicating that the effect of PDL1 is possibly mediated by CD25(+) Tregs. Adoptive transfer of Tregs from wild-type but not PDL1-deficient mice into PDL1-deficient recipients significantly improved fetal survival. The frequency, phenotype and placental trafficking of Tregs from PDL1-deficient mice were similar to those of wild-type controls, but were defective in inhibiting alloreactive Th1 cells in vitro. This is the first report providing evidence for a link between PDL1 and T regulatory cells in mediating fetomaternal tolerance.

  13. Regulatory T cells: Mechanisms of suppression and impairment in autoimmune liver disease.

    PubMed

    Liberal, Rodrigo; Grant, Charlotte R; Longhi, Maria Serena; Mieli-Vergani, Giorgina; Vergani, Diego

    2015-02-01

    There are three classic liver diseases with probable autoimmune etiology: primary biliary cirrhosis, primary sclerosing cholangitis, and autoimmune hepatitis. The occurrence of these autoimmune conditions is determined by the breakdown of immune-regulatory mechanisms that in health are responsible for maintaining immunological tolerance against self-antigens. Among the multiple T cell subsets with suppressive function, the regulatory T cells (Tregs), defined by the expression of CD4, the IL-2 receptor α chain (CD25), and the transcription factor FOXP3, have emerged as having a central role in maintaining immune-tolerance to autoantigens. Tregs are equipped with an array of mechanisms of suppression, including the modulation of antigen presenting cell maturation and function, the killing of target cells, the disruption of metabolic pathways, and the production of anti-inflammatory cytokines. In all the three autoimmune liver diseases mentioned above, there is evidence pointing for either a reduced frequency and/or function of Tregs. Here, we review the definition, phenotypic characteristics, and mechanisms of suppression employed by Tregs and then we discuss the evidence available pointing to their impairment in patients with autoimmune liver disease.

  14. Adoptive transfer of dendritic cells isolated from helminth-infected mice enhanced T regulatory cell responses in airway allergic inflammation.

    PubMed

    Liu, J-Y; Li, L-Y; Yang, X-Z; Li, J; Zhong, G; Wang, J; Li, L-J; Ji, B; Wu, Z-Q; Liu, H; Yang, X; Liu, P-M

    2011-10-01

    Our and others' previous studies have shown that Schistosoma japonicum (SJ) infection can inhibit allergic reactions. Moreover, we found that adoptive transfer of dendritic cells (DCs) from inhibited mice showed a similar inhibitory effect on allergy, suggesting a critical role of DCs in SJ-infected mediated inhibition of allergy. In this study, we further examined the mechanism by which DCs contribute to inhibition of allergy. Our results showed that DCs from SJ-infected mice (SJDCs) produced significantly higher levels of IL-10 compared to those from naive control mice (NDCs). Adoptive transfer of SJDCs, unlike NDCs, significantly increased CD4+CD25+Foxp3+ T cells and CD4+CD25+IL-10+ T cells regulatory T-cell responses in vivo. This was correlated with significantly reduced production of IL-4 and IL-5 by CD4+ T cells, eotaxin in lung tissues and reduced airway allergic inflammation in the SJDC recipients following allergen sensitization and challenge. These data suggest that helminth infection may induce tolerogenic DCs that can inhibit the development of airway allergic inflammation through enhancing T regulatory cell responses.

  15. The regulatory network of B-cell differentiation: a focused view of early B-cell factor 1 function

    PubMed Central

    Boller, Sören; Grosschedl, Rudolf

    2014-01-01

    During the last decades, many studies have investigated the transcriptional and epigenetic regulation of lineage decision in the hematopoietic system. These efforts led to a model in which extrinsic signals and intrinsic cues establish a permissive chromatin context upon which a regulatory network of transcription factors and epigenetic modifiers act to guide the differentiation of hematopoietic lineages. These networks include lineage-specific factors that further modify the epigenetic landscape and promote the generation of specific cell types. The process of B lymphopoiesis requires a set of transcription factors, including Ikaros, PU.1, E2A, and FoxO1 to ‘prime’ cis-regulatory regions for subsequent activation by the B-lineage-specific transcription factors EBF1 and Pax-5. The expression of EBF1 is initiated by the combined action of E2A and FoxO1, and it is further enhanced and maintained by several positive feedback loops that include Pax-5 and IL-7 signaling. EBF1 acts in concert with Ikaros, PU.1, Runx1, E2A, FoxO1, and Pax-5 to establish the B cell-specific transcription profile. EBF1 and Pax-5 also collaborate to repress alternative cell fates and lock cells into the B-lineage fate. In addition to the functions of EBF1 in establishing and maintaining B-cell identity, EBF1 is required to coordinate differentiation with cell proliferation and survival. PMID:25123279

  16. Circumvention of regulatory CD4(+) T cell activity during cross-priming strongly enhances T cell-mediated immunity.

    PubMed

    Heit, Antje; Gebhardt, Friedemann; Lahl, Katharina; Neuenhahn, Michael; Schmitz, Frank; Anderl, Florian; Wagner, Hermann; Sparwasser, Tim; Busch, Dirk H; Kastenmüller, Kathrin

    2008-06-01

    Immunization with purified antigens is a safe and practical vaccination strategy but is generally unable to induce sustained CD8(+) T cell-mediated protection against intracellular pathogens. Most efforts to improve the CD8(+) T cell immunogenicity of these vaccines have focused on co-administration of adjuvant to support cross-presentation and dendritic cell maturation. In addition, it has been shown that CD4(+) T cell help during the priming phase contributes to the generation of protective CD8(+) memory T cells. In this report we demonstrate that the depletion of CD4(+) T cells paradoxically enhances long-lasting CD8-mediated protective immunity upon protein vaccination. Functional and genetic in vivo inactivation experiments attribute this enhancement primarily to MHC class II-restricted CD4(+) regulatory T cells (Treg), which appear to physiologically suppress the differentiation process towards long-living effector memory T cells. Since, in functional terms, this suppression by Treg largely exceeds the positive effects of conventional CD4(+) T cell help, even the absence of all CD4(+) T cells or lack of MHC class II-mediated interactions on priming dendritic cells result in enhanced CD8(+) T cell immunogenicity. These findings have important implications for the improvement of vaccines against intracellular pathogens or tumors, especially in patients with highly active Treg.

  17. Quiescence of Memory CD8(+) T Cells Is Mediated by Regulatory T Cells through Inhibitory Receptor CTLA-4.

    PubMed

    Kalia, Vandana; Penny, Laura Anne; Yuzefpolskiy, Yevgeniy; Baumann, Florian Martin; Sarkar, Surojit

    2015-06-16

    Immune memory cells are poised to rapidly expand and elaborate effector functions upon reinfection yet exist in a functionally quiescent state. The paradigm is that memory T cells remain inactive due to lack of T cell receptor (TCR) stimuli. Here, we report that regulatory T (Treg) cells orchestrate memory T cell quiescence by suppressing effector and proliferation programs through inhibitory receptor, cytotoxic-T-lymphocyte-associated protein-4 (CTLA-4). Loss of Treg cells resulted in activation of genome-wide transcriptional programs characteristic of effector T cells and drove transitioning as well as established memory CD8(+) T cells toward terminally differentiated KLRG-1(hi)IL-7Rα(lo)GzmB(hi) phenotype, with compromised metabolic fitness, longevity, polyfunctionality, and protective efficacy. CTLA-4 functionally replaced Treg cells in trans to rescue memory T cell defects and restore homeostasis. These studies present the CTLA-4-CD28-CD80/CD86 axis as a potential target to accelerate vaccine-induced immunity and improve T cell memory quality in current cancer immunotherapies proposing transient Treg cell ablation.

  18. The protein tyrosine phosphatase SHP-1 modulates the suppressive activity of regulatory T cells

    PubMed Central

    Iype, Tessy; Sankarshanan, Mohan; Mauldin, Ileana S.; Mullins, David W.; Lorenz, Ulrike

    2010-01-01

    The importance of regulatory T cells (Treg) for immune tolerance is well recognized, yet the signaling molecules influencing their suppressive activity are relatively poorly understood. Here, through in vivo studies and complementary ex vivo studies, we make several important observations. First, we identify the cytoplasmic tyrosine phosphatase SHP-1 as a novel ‘endogenous brake’ and modifier of the suppressive ability of Treg cells; consistent with this notion, loss of SHP-1 expression strongly augments the ability of Treg cells to suppress inflammation in a mouse model. Second, specific pharmacological inhibition of SHP-1 enzymatic activity via the cancer drug sodium stibogluconate (SSG) potently augmented Treg cell suppressor activity both in vivo and ex vivo. Finally, through a quantitative imaging approach, we directly demonstrate that Treg cells prevent the activation of conventional T cells, and that SHP-1-deficient Treg cells are more efficient suppressors. Collectively, our data reveal SHP-1 as a critical modifier of Treg cell function, and a potential therapeutic target for augmenting Treg cell-mediated suppression in certain disease states. PMID:20952680

  19. Regulatory T Cells Are Critical for Clearing Influenza A Virus in Neonatal Mice

    PubMed Central

    Oliphant, Samantha; Lines, J. Louise; Hollifield, Melissa L.

    2015-01-01

    Abstract We previously reported that neonatal mice infected with influenza A virus (IAV) develop interstitial pneumonia characterized by reduced lung cytokine and chemokine responses. The failure of T cells to infiltrate the airways of neonates correlated with delayed clearance of sublethal IAV infections compared to adults. We hypothesized that negative regulators in the neonatal lungs such as cytokines or T regulatory (Treg) cells are responsible for these differences. Neonates either deficient in interleukin-10 (IL-10) or with T cells unresponsive to transforming growth factor-β signaling due to absence of SMAD family member 4 (Smad4) had similar IAV clearance kinetics to wild-type pups and no difference in T-cell responses. In contrast, functional depletion of Treg cells with anti-CD25 monoclonal antibody resulted in increased proportions of activated CD4+ T cells in the lungs, but failure to clear IAV. Similarly, scurfy pups (mutation in forkhead box P3 [Foxp3] rendering them deficient in Treg cells) had increased proportions of activated T cells in the lungs compared to littermate controls. Scurfy pups also had increased proportions of IL-13-producing CD4+ T cells. Interestingly, like anti-CD25-treated pups, scurfy pups had significantly elevated viral loads compared to controls. Based on these data, we conclude that Tregs are critical for clearance of IAV in neonatal mice. PMID:26501792

  20. Transcriptional Landscape of Human Tissue Lymphocytes Unveils Uniqueness of Tumor-Infiltrating T Regulatory Cells.

    PubMed

    De Simone, Marco; Arrigoni, Alberto; Rossetti, Grazisa; Gruarin, Paola; Ranzani, Valeria; Politano, Claudia; Bonnal, Raoul J P; Provasi, Elena; Sarnicola, Maria Lucia; Panzeri, Ilaria; Moro, Monica; Crosti, Mariacristina; Mazzara, Saveria; Vaira, Valentina; Bosari, Silvano; Palleschi, Alessandro; Santambrogio, Luigi; Bovo, Giorgio; Zucchini, Nicola; Totis, Mauro; Gianotti, Luca; Cesana, Giancarlo; Perego, Roberto A; Maroni, Nirvana; Pisani Ceretti, Andrea; Opocher, Enrico; De Francesco, Raffaele; Geginat, Jens; Stunnenberg, Hendrik G; Abrignani, Sergio; Pagani, Massimiliano

    2016-11-15

    Tumor-infiltrating regulatory T lymphocytes (Treg) can suppress effector T cells specific for tumor antigens. Deeper molecular definitions of tumor-infiltrating-lymphocytes could thus offer therapeutic opportunities. Transcriptomes of T helper 1 (Th1), Th17, and Treg cells infiltrating colorectal or non-small-cell lung cancers were compared to transcriptomes of the same subsets from normal tissues and validated at the single-cell level. We found that tumor-infiltrating Treg cells were highly suppressive, upregulated several immune-checkpoints, and expressed on the cell surfaces specific signature molecules such as interleukin-1 receptor 2 (IL1R2), programmed death (PD)-1 Ligand1, PD-1 Ligand2, and CCR8 chemokine, which were not previously described on Treg cells. Remarkably, high expression in whole-tumor samples of Treg cell signature genes, such as LAYN, MAGEH1, or CCR8, correlated with poor prognosis. Our findings provide insights into the molecular identity and functions of human tumor-infiltrating Treg cells and define potential targets for tumor immunotherapy.

  1. Neutrophils induce proangiogenic T cells with a regulatory phenotype in pregnancy

    PubMed Central

    Nadkarni, Suchita; Smith, Joanne; Sferruzzi-Perri, Amanda N.; Ledwozyw, Agata; Kishore, Madhav; Haas, Robert; Mauro, Claudio; Williams, David J.; Farsky, Sandra H. P.; Marelli-Berg, Federica M.; Perretti, Mauro

    2016-01-01

    Although neutrophils are known to be fundamental in controlling innate immune responses, their role in regulating adaptive immunity is just starting to be appreciated. We report that human neutrophils exposed to pregnancy hormones progesterone and estriol promote the establishment of maternal tolerance through the induction of a population of CD4+ T cells displaying a GARP+CD127loFOXP3+ phenotype following antigen activation. Neutrophil-induced T (niT) cells produce IL-10, IL-17, and VEGF and promote vessel growth in vitro. Neutrophil depletion during murine pregnancy leads to abnormal development of the fetal-maternal unit and reduced empbryo development, with placental architecture displaying poor trophoblast invasion and spiral artery development in the maternal decidua, accompanied by significantly attenuated niT cell numbers in draining lymph nodes. Using CD45 congenic cells, we show that induction of niT cells and their regulatory function occurs via transfer of apoptotic neutrophil-derived proteins, including forkhead box protein 1 (FOXO1), to T cells. Unlike in women with healthy pregnancies, neutrophils from blood and placental samples of preeclamptic women fail to induce niT cells as a direct consequence of their inability to transfer FOXO1 to T cells. Finally, neutrophil-selective FOXO1 knockdown leads to defective placentation and compromised embryo development, similar to that resulting from neutrophil depletion. These data define a nonredundant function of neutrophil–T cell interactions in the regulation of vascularization at the maternal–fetal interface. PMID:27956610

  2. Definition of target antigens for naturally occurring CD4(+) CD25(+) regulatory T cells.

    PubMed

    Nishikawa, Hiroyoshi; Kato, Takuma; Tawara, Isao; Saito, Kanako; Ikeda, Hiroaki; Kuribayashi, Kagemasa; Allen, Paul M; Schreiber, Robert D; Sakaguchi, Shimon; Old, Lloyd J; Shiku, Hiroshi

    2005-03-07

    The antigenic targets recognized by naturally occurring CD4(+) CD25(+) regulatory T cells (T reg cells) have been elusive. We have serologically defined a series of broadly expressed self-antigens derived from chemically induced mouse sarcomas by serological identification of antigens by recombinant expression cloning (SEREX). CD4(+) CD25(+) T cells from mice immunized with SEREX-defined self-antigens had strong suppressive activity on peptide-specific proliferation of CD4(+) CD25(-) T cells and CD8(+) T cells. The suppressive effect was observed without in vitro T cell stimulation. Foxp3 expression in these CD4(+) CD25(+) T cells from immunized mice was 5-10 times greater than CD4(+) CD25(+) T cells derived from naive mice. The suppressive effect required cellular contact and was blocked by anti-glucocorticoid-induced tumor necrosis factor receptor family-related gene antibody. In vitro suppressive activity essentially disappeared 8 wk after the last immunization. However, it was regained by in vitro restimulation with cognate self-antigen protein but not with control protein. We propose that SEREX-defined self-antigens such as those used in this study represent self-antigens that elicit naturally occurring CD4(+) CD25(+) T reg cells.

  3. Within-woman change in regulatory T cells from pregnancy to the postpartum period.

    PubMed

    Wegienka, Ganesa; Havstad, Suzanne; Bobbitt, Kevin R; Woodcroft, Kimberley J; Zoratti, Edward M; Ownby, Dennis R; Cole Johnson, Christine

    2011-01-01

    Regulatory T cells (Treg cells) are an important area of investigation in human health and disease. In this study, the trajectory of percentage of Treg cells (defined as CD4+CD25+Foxp3+CD127--lymphocytes) was measured in the blood of 208 women during pregnancy and up to three additional times in the postpartum period (1, 6 and 12 months postpartum). Whether the trajectory was affected by gravidity, parity, neonatal sex, pet exposure, maternal atopic and asthma status, smoking, maternal race or other pregnancy factors was examined. Multilevel models were fit using full maximum likelihood methods and included both random and fixed effects. Overall, percentages of Treg cells increased from the prenatal to the postpartum period. Among women who were not atopic, nulliparous women had lower percentages of Treg cells over time compared with parous women. Atopic women with pets in the home during pregnancy had lower percentages of Treg cells than atopic women who did not have pets. The trajectory was not affected by the other factors investigated. We conclude that within-woman change in percentages of Treg cells may vary by time in relation to delivery, as well as by maternal atopic status and exposure to pets and number of prior births. The data did not indicate an overall decline in Treg cells in the postpartum period. Future work to better identify the role of Treg cells in successful pregnancy would ideally include a set of well characterized women sampled serially starting prior to pregnancy and throughout the postpartum period.

  4. MicroRNA-26a Promotes Regulatory T cells and Suppresses Autoimmune Diabetes in Mice.

    PubMed

    Ma, Hui; Zhang, Shoutao; Shi, Doufei; Mao, Yanhua; Cui, Jianguo

    2016-02-01

    Type-1 diabetes (TID) is an autoimmune disease in which the body's own immune cells attack islet β cells, the cells in the pancreas that produce and release the hormone insulin. Mir-26a has been reported to play functions in cellular differentiation, cell growth, cell apoptosis, and metastasis. However, the role of microRNA-26a (Mir-26a) in autoimmune TID has never been investigated. In our current study, we found that pre-Mir-26a (LV-26a)-treated mice had significantly longer normoglycemic time and lower frequency of autoreactive IFN-γ-producing CD4(+) cells compared with an empty lentiviral vector (LV-Con)-treated non-obese diabetic (NOD) mice. Mir-26a suppresses autoreactive T cells and expands Tregs in vivo and in vitro. Furthermore, in our adoptive transfer study, the groups receiving whole splenocytes and CD25-depleted splenocytes from LV-Con-treated diabetic NOD mice develop diabetes at 3 to 4 weeks of age. In comparison, mice injected with undepleted splenocytes obtained from LV-26a-treated reversal NOD mice develop diabetes after 6-8 weeks. And depletion of CD25(+) cells in the splenocytes of reversed mice abrogates the delay in diabetes onset. In conclusion, Mir-26a suppresses autoimmune diabetes in NOD mice in part through promoted regulatory T cells (Tregs) expression.

  5. Restricted maternal nutrition alters myogenic regulatory factor expression in satellite cells of ovine offspring.

    PubMed

    Raja, J S; Hoffman, M L; Govoni, K E; Zinn, S A; Reed, S A

    2016-07-01

    Poor maternal nutrition inhibits muscle development and postnatal muscle growth. Satellite cells are myogenic precursor cells that contribute to postnatal muscle growth, and their activity can be evaluated by the expression of several transcription factors. Paired-box (Pax)7 is expressed in quiescent and active satellite cells. MyoD is expressed in activated and proliferating satellite cells and myogenin is expressed in terminally differentiating cells. Disruption in the expression pattern or timing of expression of myogenic regulatory factors negatively affects muscle development and growth. We hypothesized that poor maternal nutrition during gestation would alter the in vitro temporal expression of MyoD and myogenin in satellite cells from offspring at birth and 3 months of age. Ewes were fed 100% or 60% of NRC requirements from day 31±1.3 of gestation. Lambs from control-fed (CON) or restricted-fed (RES) ewes were euthanized within 24 h of birth (birth; n=5) or were fed a control diet until 3 months of age (n=5). Satellite cells isolated from the semitendinosus muscle were used for gene expression analysis or cultured for 24, 48 or 72 h and immunostained for Pax7, MyoD or myogenin. Fusion index was calculated from a subset of cells allowed to differentiate. Compared with CON, temporal expression of MyoD and myogenin was altered in cultured satellite cells isolated from RES lambs at birth. The percent of cells expressing MyoD was greater in RES than CON (P=0.03) after 24 h in culture. After 48 h of culture, there was a greater percent of cells expressing myogenin in RES compared with CON (P0.05). In satellite cells from RES lambs at 3 months of age, the percent of cells expressing MyoD and myogenin were greater than CON after 72 h in culture (P<0.05). Fusion index was reduced in RES lambs at 3 months of age compared with CON (P<0.001). Restricted nutrition during gestation alters the temporal expression of myogenic regulatory factors in satellite cells of the

  6. Adaptive immunity to leukemia is inhibited by cross-reactive induced regulatory T cells

    PubMed Central

    Manlove, Luke S.; Berquam-Vrieze, Katherine E.; Pauken, Kristen E.; Williams, Richard T.; Jenkins, Marc K.; Farrar, Michael A.

    2015-01-01

    BCR-ABL+ acute lymphoblastic leukemia patients have transient responses to current therapies. However, the fusion of BCR to ABL generates a potential leukemia-specific antigen that could be a target for immunotherapy. We demonstrate that the immune system can limit BCR-ABL+ leukemia progression although ultimately this immune response fails. To address how BCR-ABL+ leukemia escapes immune surveillance, we developed a peptide: MHC-II tetramer that labels endogenous BCR-ABL-specific CD4+ T cells. Naïve mice harbored a small population of BCR-ABL-specific T cells that proliferated modestly upon immunization. The small number of naïve BCR-ABL specific T cells was due to negative selection in the thymus, which depleted BCR-ABL specific T cells. Consistent with this observation, we saw that BCR-ABL specific T cells were cross-reactive with an endogenous peptide derived from ABL. Despite this cross-reactivity, the remaining population of BCR-ABL reactive T cells proliferated upon immunization with the BCR-ABL fusion peptide and adjuvant. In response to BCR-ABL+ leukemia, BCR-ABL specific T cells proliferated and converted into regulatory T cells (Treg cells), a process that was dependent on cross-reactivity with self-antigen, TGFβ1, and MHC-II antigen presentation by leukemic cells. Treg cells were critical for leukemia progression in C57Bl/6 mice, as transient Treg cell ablation led to extended survival of leukemic mice. Thus, BCR-ABL+ leukemia actively suppresses anti-leukemia immune responses by converting cross-reactive leukemia-specific T cells into Treg cells. PMID:26378075

  7. Foxp3+ regulatory T cells, immune stimulation and host defence against infection

    PubMed Central

    Rowe, Jared H; Ertelt, James M; Way, Sing Sing

    2012-01-01

    The immune system is intricately regulated allowing potent effectors to expand and become rapidly mobilized after infection, while simultaneously silencing potentially detrimental responses that averts immune-mediated damage to host tissues. This relies in large part on the delicate interplay between immune suppressive regulatory CD4+ T (Treg) cells and immune effectors that without active suppression by Treg cells cause systemic and organ-specific autoimmunity. Although these beneficial roles have been classically described as counterbalanced by impaired host defence against infection, newfound protective roles for Treg cells against specific viral pathogens (e.g. herpes simplex virus 2, lymphocytic choriomeningitis virus, West Nile virus) have been uncovered using transgenic mice that allow in vivo Treg-cell ablation based on Foxp3 expression. In turn, Foxp3+ Treg cells also provide protection against some parasitic (Plasmodium sp., Toxoplasma gondii) and fungal (Candida albicans) pathogens. By contrast, for bacterial and mycobacterial infections (e.g. Listeria monocytogenes, Salmonella enterica, Mycobacterium tuberculosis), experimental manipulation of Foxp3+ cells continues to indicate detrimental roles for Treg cells in host defence. This variance is probably related to functional plasticity in Treg cell suppression that shifts discordantly following infection with different types of pathogens. Furthermore, the efficiency whereby Treg cells silence immune activation coupled with the plasticity in Foxp3+ cell activity suggest that overriding Treg-mediated suppression represents a prerequisite ‘signal zero’ that together with other stimulation signals [T-cell receptor (signal 1), co-stimulation (signal 2), inflammatory cytokines (signal 3)] are essential for T-cell activation in vivo. Herein, the importance of Foxp3+ Treg cells in host defence against infection, and the significance of infection-induced shifts in Treg-cell suppression are summarized. PMID

  8. Circulating regulatory anti–T cell receptor antibodies in patients with myasthenia gravis

    PubMed Central

    Jambou, Florence; Zhang, Wei; Menestrier, Monique; Klingel-Schmitt, Isabelle; Michel, Olivier; Caillat-Zucman, Sophie; Aissaoui, Abderrahim; Landemarre, Ludovic; Berrih-Aknin, Sonia; Cohen-Kaminsky, Sylvia

    2003-01-01

    Serum anti–T cell receptor (TCR) Ab’s are involved in immune regulation directed against pathogenic T cells in experimental models of autoimmune diseases. Our identification of a dominant T cell population expressing the Vβ5.1 TCR gene (TCRBV5-1), which is responsible for the production of pathogenic anti-acetylcholine receptor (AChR) autoantibodies in HLA-DR3 patients with early-onset myasthenia gravis (EOMG), prompted us to explore the occurrence, reactivity, and regulatory role of anti-TCR Ab’s in EOMG patients and disease controls with clearly defined other autoantibodies. In the absence of prior vaccination against the TCR, EOMG patients had elevated anti-Vβ5.1 Ab’s of the IgG class. This increase was restricted largely to EOMG cases with HLA-DR3 and with less severe disease, and it predicted clinical improvement in follow-up studies. EOMG patient sera containing anti-TCR Ab’s bound specifically the native TCR on intact Vβ5.1-expressing cells and specifically inhibited the proliferation and IFN-γ production of purified Vβ5.1-expressing cells to alloantigens in mixed lymphocyte reaction and the proliferation of a Vβ5.1-expressing T cell clone to an AChR peptide, indicating a regulatory function for these Ab’s. This evidence of spontaneously active anti-Vβ5.1 Ab’s in EOMG patients suggests dynamic protective immune regulation directed against the excess of pathogenic Vβ5.1-expressing T cells. Though not sufficient to prevent a chronic, exacerbated autoimmune process, it might be boosted using a TCR peptide as vaccine. PMID:12865414

  9. Salmon cartilage proteoglycan suppresses mouse experimental colitis through induction of Foxp3{sup +} regulatory T cells

    SciTech Connect

    Mitsui, Toshihito; Sashinami, Hiroshi; Sato, Fuyuki; Kijima, Hiroshi; Ishiguro, Yoh; Fukuda, Shinsaku; Yoshihara, Shuichi; Hakamada, Ken-Ichi; Nakane, Akio

    2010-11-12

    Research highlights: {yields} Salmon proteoglycan suppresses IL-10{sup -/-} cell transfer-induced colitis progression. {yields} Salmon proteoglycan suppresses Th1- and Th17-related factors in colitis mice. {yields} Salmon proteoglycan enhances Foxp3 expression. -- Abstract: Proteoglycans (PGs) are complex glycohydrates which are widely distributed in extracellular matrix (ECM). PGs are involved in the construction of ECM, cell proliferation and differentiation. ECM components are involved in transduction of proinflammatory responses, but it is still unknown whether PGs are involved in inflammatory response. In this study, we investigated the effect of PG extracted from salmon cartilage on the progression of experimental colitis-induced in severe combined immunodeficiency mice by cell transfer from interleukin-10 (IL-10){sup -/-} mice. IL-10{sup -/-} cell-transferred mice showed weight loss, colon shortening and histological appearance of mild colitis. Daily oral administration of PG attenuated the clinical progression of colitis in a dose-dependent manner. Colitis-induced mice showed the elevated expression of IFN-{gamma}, IL-12, TNF-{alpha}, IL-21, IL-23p19, IL-6, IL-17A and retinoic acid-related orphan receptor {gamma}t (ROR{gamma}t) in lamina propria mononuclear cells (LPMCs) and oral administration of PG suppressed the expression of these factors. Conversely, expression of Foxp3 that induces CD4{sup +}CD25{sup +} regulatory T cells in LPMCs was enhanced by PG administration. These findings suggested that salmon PG attenuated the progression of colitis due to suppression of inflammatory response by enhancement of regulatory T cell induction.

  10. Thymus-derived regulatory T cells control tolerance to commensal microbiota

    PubMed Central

    Cebula, Anna; Seweryn, Michal; Rempala, Grzegorz A.; Pabla, Simarjot Singh; McIndoe, Richard A.; Denning, Timothy L.; Bry, Lynn; Kraj, Piotr; Kisielow, Pawel; Ignatowicz, Leszek

    2013-01-01

    Peripheral mechanisms preventing autoimmunity and maintaining tolerance to commensal microbiota involve CD4+Foxp3+ regulatory T cells1,2 generated in the thymus (tTregs) or extrathymically by induction of naive CD4+Foxp3− T cells (iTregs). Prior studies suggested that the T cell receptor (TCR) repertoires of tTregs and iTregs are biased towards self and non-self antigens, respectively 3–6 but their relative contribution in controlling immunopathology, e.g. colitis and other untoward inflammatory responses triggered by different types of antigens, remains unresolved 7. The intestine, and especially the colon, is a particularly suitable organ to study this question, given the variety of self-, microbiota- and food-derived antigens to which Tregs and other T cell populations are exposed. Intestinal environments can enhance conversion to a regulatory lineage 8,9 and favor tolerogenic presentation of antigens to naive CD4+ T cells 10,11, suggesting that intestinal homeostasis depends on microbiota-specific iTregs 12–15. Here, to identify the origin and antigen-specificity of intestinal Tregs, we performed single cell as well as high-throughput (HT) sequencing of the TCR repertoires of CD4+Foxp3+ and CD4+Foxp3− T cells and analyzed their reactivity against specific commensal species. We show that tTregs constitute the majority of Tregs in all lymphoid and intestinal organs, including colon, where their repertoire is heavily influenced by the composition of the microbiota. Our results suggest that tTregs, and not iTregs, dominantly mediate tolerance to antigens produced by intestinal commensals. PMID:23624374

  11. Generation of regulatory dendritic cells and CD4+Foxp3+ T cells by probiotics administration suppresses immune disorders.

    PubMed

    Kwon, Ho-Keun; Lee, Choong-Gu; So, Jae-Seon; Chae, Chang-Suk; Hwang, Ji-Sun; Sahoo, Anupama; Nam, Jong Hee; Rhee, Joon Haeng; Hwang, Ki-Chul; Im, Sin-Hyeog

    2010-02-02

    The beneficial effects of probiotics have been described in many diseases, but the mechanism by which they modulate the immune system is poorly understood. In this study, we identified a mixture of probiotics that up-regulates CD4(+)Foxp3(+) regulatory T cells (Tregs). Administration of the probiotics mixture induced both T-cell and B-cell hyporesponsiveness and down-regulated T helper (Th) 1, Th2, and Th17 cytokines without apoptosis induction. It also induced generation of CD4(+)Foxp3(+) Tregs from the CD4(+)CD25(-) population and increased the suppressor activity of naturally occurring CD4(+)CD25(+) Tregs. Conversion of T cells into Foxp3(+) Tregs is directly mediated by regulatory dendritic cells (rDCs) that express high levels of IL-10, TGF-beta, COX-2, and indoleamine 2,3-dioxygenase. Administration of probiotics had therapeutical effects in experimental inflammatory bowel disease, atopic dermatitis, and rheumatoid arthritis. The therapeutical effect of the probiotics is associated with enrichment of CD4(+)Foxp3(+) Tregs in the inflamed regions. Collectively, the administration of probiotics that enhance the generation of rDCs and Tregs represents an applicable treatment of inflammatory immune disorders.

  12. Impaired function of regulatory T cells in cord blood of children of allergic mothers.

    PubMed

    Hrdý, J; Kocourková, I; Prokešová, L

    2012-10-01

    Allergy is one of the most common diseases with constantly increasing incidence. The identification of prognostic markers pointing to increased risk of allergy development is of importance. Cord blood represents a suitable source of cells for searching for such prognostic markers. In our previous work, we described the increased reactivity of cord blood cells of newborns of allergic mothers in comparison to newborns of healthy mothers, which raised the question of whether or not this was due to the impaired function of regulatory T cells (T(regs)) in high-risk children. Therefore, the proportion and functional properties of T(regs) in cord blood of children of healthy and allergic mothers were estimated by flow cytometry. The proportion of T(regs) [CD4(+)CD25(high)CD127(low) forkhead box protein 3 (FoxP3(+))] in cord blood of children of allergic mothers tends to be higher while, in contrast, the median of fluorescence intensity of FoxP3 was increased significantly in the healthy group. Intracellular presence of regulatory cytokines interleukin (IL)-10 and transforming growth factor (TGF)-beta was also higher in T(regs) of children of healthy mothers. Although we detected an increased proportion of T(regs) in cord blood of children of allergic mothers, the functional indicators (intracellular presence of regulatory cytokines IL-10 and TGF-beta, median of fluorescence intensity of FoxP3) of those T(regs) were lower in comparison to the healthy group. We can conclude that impaired function of T(regs) in cord blood of children of allergic mothers could be compensated partially by their increased number. Insufficient function of T(regs) could facilitate allergen sensitization in high-risk individuals after subsequent allergen encounter.

  13. CD4+CD25+ T Regulatory Cells in Transplantation Tolerance: 25 Years On.

    PubMed

    Hall, Bruce M

    2016-12-01

    In the 1970s, the capacity of T cells to inhibit immunity and those from transplant tolerant hosts to transfer alloantigen-specific suppression to lymphopenic recipients was described. CD4 T suppressor cells that ex vivo reverted to effector cells were described in the 1980s. Their antigen-specific suppressor function could be preserved by stimulation by specific donor alloantigen and cytokines from activated lymphocytes. This led to the finding that alloantigen-specific T suppressor cells express IL-2 receptor (CD25) and that IL-2 in part promotes their survival.Whether these alloantigen-specific CD4CD25FOXP3 regulatory T (Treg) cells are progeny of thymic-derived CD4CD25FOXP3 Treg (tTreg) cells or are induced from peripheral effector CD4CD25FOXP3T cells (iTreg) cells is still debated.In vitro studies of antigen specific Treg has been difficult as they die in the absence of cytokines produced by immune activated cells. The antigen-specific CD4CD25 T cells that control rejection in tolerant hosts differ from the naive tTreg. Thymic-derived Treg cells are not antigen-specific, and very high ratios are required to suppress rejection. Thymic-derived Treg cells can be expanded ex vivo and are currently being tested in trials to control allograft rejection and graft versus host disease.Thymic-derived Treg cells with specific receptors for alloantigen are activated by either IL-2 or IL-4 but rapidly become dependent on other cytokines, respectively, IFN-γ or IL-12 if activated by IL-2, or IL-5 if activated by IL-4. The Th1 and Th2 pathways for activation of tTreg produce more potent antigen-specific Treg that only suppress specific donor rejection. After 25 years, much remains unknown about antigen-specific CD4CD25FOXP3 Treg-mediating transplant tolerance.

  14. Functional implications of regulatory B cells in human IgA nephropathy.

    PubMed

    Wang, Y-Y; Zhang, L; Zhao, P-W; Ma, L; Li, C; Zou, H-B; Jiang, Y-F

    2014-01-01

    IgA nephropathy (IgAN) diagnosis remains largely based upon immunohistologic detection of IgA- and IgG-containing glomerular deposits in renal mesangial cells, and little is known about the underlying pathogenic mechanisms. This study examines the putative contribution of B cell types, including the Breg type, to IgAN pathogenesis. Twenty-four patients with IgAN and proteinuria (Group A: <3.5 g/24 h, n = 13; Group B: >3.5 g/24 h, n = 11) and 10 healthy controls were enrolled. The frequencies of B cell subtypes in venous blood were measured by flow cytometry. Galactose-deficient IgA1 was measurement by ELISA. Needle biopsies were analysed by histology and immunofluorescence microscopy. Correlation between clinical features and B cell subtypes, including the regulatory B (Breg) cells, and Breg cell-derived immunomodulatory cytokine IL-10 was assessed by Spearman's rank correlation test. IgAN patients had significantly higher frequencies of CD27(+) CD19(+) , CD38(+) CD19(+) , CD86(+) CD19(+) and CD5(+) CD19(+) B cells than the healthy controls, but significantly lower levels of Breg cells and intracellular expression of IL-10 protein in the Breg subtype. Serum IgA concentration positively correlated with CD27(+) CD19(+) B cell frequency and negatively correlated with IL-10(+) Breg cell frequency in IgAN patients, and the percentage of CD19(+) CD5(+) CD1d(+) in CD19(+) cells was negatively correlated with the level of serum Gd-IgA1. Furthermore, the frequencies of CD19(+) CD38(+) and CD19(+) CD86(+) in the CD19(+) subpopulation negatively correlated with the estimated glomerular filtration rate of IgAN patients. Several of the CD19(+) B cell subtypes and the IL-10(+) Breg cells are differentially expressed in IgAN patients and may contribute to the disease pathogenesis.

  15. Regulatory effect of monocytes on T cell proliferative responses to oral microbial antigens.

    PubMed Central

    Stashenko, P

    1982-01-01

    Mononuclear cell preparations isolated by Ficoll-Hypaque centrifugation from human peripheral blood were found to vary considerably in the number of monocytes they contained (mean, 20.3%; range, 13 to 33%). The regulatory role of monocytes in T cell proliferative responses to sonic extracts of a panel of oral microorganisms was therefore investigated. T cells were fractionated by anti-immunoglobulin chromatography and depleted of monocytes by treatment with a monoclonal anti-human Ia-like (DR locus antigen) antibody and complement. Purified populations of monocytes were obtained by extensive adherence procedures. The resultant cell populations were greater than 95% pure, as judged by indirect immunofluorescence on a fluorescence-activated cell sorter. Monocyte-depleted T cells failed to respond by proliferation to the nonoral antigen tetanus toxoid, as well as to any oral microorganism, but retained responsiveness to phytohemagglutinin. Readdition of monocytes in final concentrations of from 5 to 15% resulted in the restoration of maximal T cell proliferation. Monocytes in greater numbers suppressed T cell responses to all sonic extracts tested. PMID:6984019

  16. Interferon Regulatory Factor 4 controls TH1 cell effector function and metabolism

    PubMed Central

    Mahnke, Justus; Schumacher, Valéa; Ahrens, Stefanie; Käding, Nadja; Feldhoff, Lea Marie; Huber, Magdalena; Rupp, Jan; Raczkowski, Friederike; Mittrücker, Hans-Willi

    2016-01-01

    The transcription factor Interferon Regulatory Factor 4 (IRF4) is essential for TH2 and TH17 cell formation and controls peripheral CD8+ T cell differentiation. We used Listeria monocytogenes infection to characterize the function of IRF4 in TH1 responses. IRF4−/− mice generated only marginal numbers of listeria-specific TH1 cells. After transfer into infected mice, IRF4−/− CD4+ T cells failed to differentiate into TH1 cells as indicated by reduced T-bet and IFN-γ expression, and showed limited proliferation. Activated IRF4−/− CD4+ T cells exhibited diminished uptake of the glucose analog 2-NBDG, limited oxidative phosphorylation and strongly reduced aerobic glycolysis. Insufficient metabolic adaptation contributed to the limited proliferation and TH1 differentiation of IRF4−/− CD4+ T cells. Our study identifies IRF4 as central regulator of TH1 responses and cellular metabolism. We propose that this function of IRF4 is fundamental for the initiation and maintenance of all TH cell responses. PMID:27762344

  17. Multiple Roles of MYC in Integrating Regulatory Networks of Pluripotent Stem Cells

    PubMed Central

    Fagnocchi, Luca; Zippo, Alessio

    2017-01-01

    Pluripotent stem cells (PSCs) are defined by their self-renewal potential, which permits their unlimited propagation, and their pluripotency, being able to generate cell of the three embryonic lineages. These properties render PSCs a valuable tool for both basic and medical research. To induce and stabilize the pluripotent state, complex circuitries involving signaling pathways, transcription regulators and epigenetic mechanisms converge on a core transcriptional regulatory network of PSCs, thus determining their cell identity. Among the transcription factors, MYC represents a central hub, which modulates and integrates multiple mechanisms involved both in the maintenance of pluripotency and in cell reprogramming. Indeed, it instructs the PSC-specific cell cycle, metabolism and epigenetic landscape, contributes to limit exit from pluripotency and modulates signaling cascades affecting the PSC identity. Moreover, MYC extends its regulation on pluripotency by controlling PSC-specific non-coding RNAs. In this report, we review the MYC-controlled networks, which support the pluripotent state and discuss how their perturbation could affect cell identity. We further discuss recent finding demonstrating a central role of MYC in triggering epigenetic memory in PSCs, which depends on the establishment of a WNT-centered self-reinforcing circuit. Finally, we comment on the therapeutic implications of the role of MYC in affecting PSCs. Indeed, PSCs are used for both disease and cancer modeling and to derive cells for regenerative medicine. For these reasons, unraveling the MYC-mediated mechanism in those cells is fundamental to exploit their full potential and to identify therapeutic targets. PMID:28217689

  18. Immune regulation by T regulatory cells in HBV related Inflammation and cancer.

    PubMed

    Trehanpati, Nirupama; Vyas, Ashish Kumar

    2017-01-21

    Hepatocellular carcinoma (HCC) is the leading cause of cancer death and hepatitis B virus (HBV) infection is one of the commonest causes in Asians countries. India has the second largest pool after China for hepatitis B infected subjects. HBV clearance is T cell dependent and one of the reason for T cells hypo responsiveness is due to mass production of Tregs through activation of Notch signaling, which suppressCD4/CD8 T cells. Regulatory T cells (Tregs) are important to maintain cellular homeostasis; however during viral infection increase of Tregs is inversely proportional to HBV DNA titers. Tregs exert their suppressive effect either via cell to cell contact or through release of IL-2, IL-10, TGF-β, IL-35. In CHBV infection, PD1 pathway also gets activated and is involved in promoting tolerance.However with Tregs induction, virus specific T cell responses also get decreased. Circulatory and intra-tumoral Tregs promote development of HBV specific HCC more by decreasing and impairing the effector functions of CD8 T cells. Anti-viral therapies and PD1 blockade strategy had shown the inhibition of Tregs and reduction in HBV DNA. However, inhibition of HBV specific Tregs is major challenge for future therapies. New cytokine blockade therapies have emerged as potential therapeutic potentials. This article is protected by copyright. All rights reserved.

  19. TARGETING REGULATORY T CELLS IN THE TREATMENT OF TYPE 1 DIABETES MELLITUS

    PubMed Central

    Cabrera, Susanne M.; Rigby, Mark R.; Mirmira, Raghavendra G.

    2013-01-01

    Type 1 diabetes mellitus (T1DM) is a T cell-mediated autoimmune disease resulting in islet β cell destruction, hypoinsulinemia, and severely altered glucose homeostasis. T1DM has classically been attributed to the pathogenic actions of auto-reactive effector T cells (Teffs) on the β cell. Recent literature now suggests that a failure of a second T cell subtype, known as regulatory T cells (Tregs), plays a critical role in the development of T1DM. During immune homeostasis, Tregs counterbalance the actions of autoreactive Teff cells, thereby participating in peripheral tolerance. An imbalance in the activity between Teff and Tregs may be crucial in the breakdown of peripheral tolerance, leading to the development of T1DM. In this review, we summarize our current understanding of Treg function in health and in T1DM, and examine the effect of experimental therapies for T1DM on Treg cell number and function in both mice and humans. PMID:22709273

  20. Galectin-8 Ameliorates Murine Autoimmune Ocular Pathology and Promotes a Regulatory T Cell Response

    PubMed Central

    Sampson, James F.; Hasegawa, Eiichi; Mulki, Lama; Suryawanshi, Amol; Jiang, Shuhong; Chen, Wei-Sheng; Rabinovich, Gabriel A.; Connor, Kip M.; Panjwani, Noorjahan

    2015-01-01

    Galectins have emerged as potent immunoregulatory agents that control chronic inflammation through distinct mechanisms. Here, we report that treatment with Galectin-8 (Gal-8), a tandem-repeat member of the galectin family, reduces retinal pathology and prevents photoreceptor cell damage in a murine model of experimental autoimmune uveitis. Gal-8 treatment increased the number of regulatory T cells (Treg) in both the draining lymph node (dLN) and the inflamed retina. Moreover, a greater percentage of Treg cells in the dLN and retina of Gal-8 treated animals expressed the inhibitory coreceptor cytotoxic T lymphocyte antigen (CTLA)-4, the immunosuppressive cytokine IL-10, and the tissue-homing integrin CD103. Treg cells in the retina of Gal-8-treated mice were primarily inducible Treg cells that lack the expression of neuropilin-1. In addition, Gal-8 treatment blunted production of inflammatory cytokines by retinal T helper type (TH) 1 and TH17 cells. The effect of Gal-8 on T cell differentiation and/or function was specific for tissues undergoing an active immune response, as Gal-8 treatment had no effect on T cell populations in the spleen. Given the need for rational therapies for managing human uveitis, Gal-8 emerges as an attractive therapeutic candidate not only for treating retinal autoimmune diseases, but also for other TH1- and TH17-mediated inflammatory disorders. PMID:26126176

  1. Peripheral blood CD4(+)/CD25(+) regulatory T cells in alcoholic patients with Strongyloides stercoralis infection.

    PubMed

    Ribeiro, Steveen Rios; Covre, Luciana Polaco; Stringari, Lorenzzo Lyrio; da Penha Zago-Gomes, Maria; Gomes, Daniel Cláudio Oliveira; Pereira, Fausto Edmundo Lima

    2017-03-01

    An increased number of regulatory T (Treg) cells has been reported in patients with HTLV-1 and Strongyloides stercoralis co-infection, suggesting the contribution of these cells to worm survival. As Strongyloides infections have been found to be highly prevalent in chronic alcoholics, we investigated the effect of abusive ethanol ingestion on the induction of Treg cells in alcoholic patients with Strongyloides infection. Treg cells were assessed by flow cytometry in the peripheral blood of 12 healthy non-alcoholic (control) and 14 alcoholic patients (alcoholic) without Strongyloides infection and five non-alcoholics (controlSs) and five chronic alcoholics (alcoholSs) with Strongyloides infection. The results showed significantly higher frequencies of Treg cells in the alcoholic, controlSs and alcoholSs group patients than in the control group patients. However, the frequencies of Treg cells did not differ between the alcoholSs and controlSs groups. In conclusion, our results demonstrate that ethanol consumption induced an increase in the number of circulating Treg cells in chronic alcoholics in this study but was unable to potentiate the induction of these cells in alcoholics with Strongyloides infection.

  2. Decoding the Regulatory Network for Blood Development from Single-Cell Gene Expression Measurements

    PubMed Central

    Haghverdi, Laleh; Lilly, Andrew J.; Tanaka, Yosuke; Wilkinson, Adam C.; Buettner, Florian; Macaulay, Iain C.; Jawaid, Wajid; Diamanti, Evangelia; Nishikawa, Shin-Ichi; Piterman, Nir; Kouskoff, Valerie; Theis, Fabian J.; Fisher, Jasmin; Göttgens, Berthold

    2015-01-01

    Here we report the use of diffusion maps and network synthesis from state transition graphs to better understand developmental pathways from single cell gene expression profiling. We map the progression of mesoderm towards blood in the mouse by single-cell expression analysis of 3,934 cells, capturing cells with blood-forming potential at four sequential developmental stages. By adapting the diffusion plot methodology for dimensionality reduction to single-cell data, we reconstruct the developmental journey to blood at single-cell resolution. Using transitions between individual cellular states as input, we develop a single-cell network synthesis toolkit to generate a computationally executable transcriptional regulatory network model that recapitulates blood development. Model predictions were validated by showing that Sox7 inhibits primitive erythropoiesis, and that Sox and Hox factors control early expression of Erg. We therefore demonstrate that single-cell analysis of a developing organ coupled with computational approaches can reveal the transcriptional programs that control organogenesis. PMID:25664528

  3. ECM components guide IL-10 producing regulatory T-cell (TR1) induction from effector memory T-cell precursors

    PubMed Central

    Bollyky, Paul L.; Wu, Rebecca P.; Falk, Ben A.; Lord, James D.; Long, S. Alice; Preisinger, Anton; Teng, Brandon; Holt, Gregory E.; Standifer, Nathan E.; Braun, Kathleen R.; Xie, Cindy Fang; Samuels, Peter L.; Vernon, Robert B.; Gebe, John A.; Wight, Thomas N.; Nepom, Gerald T.

    2011-01-01

    We describe a role for ECM as a biosensor for inflammatory microenvironments that plays a critical role in peripheral immune tolerance. We show that hyaluronan (HA) promotes induction of Foxp3- IL-10–producing regulatory T cells (TR1) from conventional T-cell precursors in both murine and human systems. This is, to our knowledge, the first description of an ECM component inducing regulatory T cells. Intact HA, characteristic of healing tissues, promotes induction of TR1 capable of abrogating disease in an IL-10–dependent mouse colitis model whereas fragmentary HA, typical of inflamed tissues, does not, indicating a decisive role for tissue integrity in this system. The TR1 precursor cells in this system are CD4+CD62L−FoxP3−, suggesting that effector memory cells assume a regulatory phenotype when they encounter their cognate antigen in the context of intact HA. Matrix integrity cues might thereby play a central role in maintaining peripheral tolerance. This TR1 induction is mediated by CD44 cross-linking and signaling through p38 and ERK1/2. This induction is suppressed, also in a CD44-dependent manner, by osteopontin, a component of chronically inflamed ECM, indicating that CD44 signaling serves as a nexus for fate decisions regarding TR1 induction. Finally, we demonstrate that TR1 induction signals can be recapitulated using synthetic matrices. These results reveal important roles for the matrix microenvironment in immune regulation and suggest unique strategies for immunomodulation. PMID:21518860

  4. Glucocorticoid-induced leucine zipper enhanced expression in dendritic cells is sufficient to drive regulatory T cells expansion in vivo.

    PubMed

    Calmette, Joseph; Ellouze, Mehdi; Tran, Thi; Karaki, Soumaya; Ronin, Emilie; Capel, Francis; Pallardy, Marc; Bachelerie, Françoise; Krzysiek, Roman; Emilie, Dominique; Schlecht-Louf, Géraldine; Godot, Véronique

    2014-12-15

    Tolerance induction by dendritic cells (DCs) is, in part, mediated by the activation of regulatory T cells (Tregs). We have previously shown in vitro that human DCs treated with glucocorticoids (GCs), IL-10, or TGF-β upregulate the GC-Induced Leucine Zipper protein (GILZ). GILZ overexpression promotes DC differentiation into regulatory cells that generate IL-10-producing Ag-specific Tregs. To investigate whether these observations extend in vivo, we have generated CD11c-GILZ(hi) transgenic mice. DCs from these mice constitutively overexpress GILZ to levels observed in GC-treated wild-type DCs. In this article, we establish that GILZ(hi) DCs display an accumulation of Foxp3(+) Tregs in the spleens of young CD11c-GILZ(hi) mice. In addition, we show that GILZ(hi) DCs strongly increase the Treg pool in central and peripheral lymphoid organs of aged animals. Upon adoptive transfer to wild-type recipient mice, OVA-loaded GILZ(hi) bone marrow-derived DCs induce a reduced activation and proliferation of OVA-specific T cells as compared with control bone marrow-derived DCs, associated with an expansion of thymus-derived CD25(+)Foxp3(+) CD4 T cells. Transferred OVA-loaded GILZ(hi) DCs produce significantly higher levels of IL-10 and express reduced levels of MHC class II molecules as compared with OVA-loaded control DCs, emphasizing the regulatory phenotype of GILZ(hi) DCs in vivo. Thus, our work demonstrates in vivo that the GILZ overexpression alone is sufficient to promote a tolerogenic mode of function in DCs.

  5. Inhibition of cell adhesion by xARVCF indicates a regulatory function at the plasma membrane.

    PubMed

    Reintsch, Wolfgang E; Mandato, Craig A; McCrea, Pierre D; Fagotto, François

    2008-09-01

    The cytoplasmic tail of cadherins is thought to regulate the strength and dynamics of cell-cell adhesion. Part of its regulatory activity has been attributed to a membrane-proximal region, the juxtamembrane domain (JMD), and its interaction with members of the p120 catenin subfamily. We show that titration of xARVCF, a member of this family, to the plasma membrane disrupts adhesion in the early embryo. Adhesion can be restored by coexpression of constitutively active Rac, suggesting that intracellular signaling is the primary cause in the loss of adhesion phenotype. Our observations suggest that the recruitment of p120 type catenins to the plasma membrane by the cadherin cytoplasmic tail may create protein complexes, which actively modulate the adhesion "status" of embryonic cells.

  6. A wave of regulatory T cells into neonatal skin mediates tolerance to commensal microbes

    PubMed Central

    Scharschmidt, Tiffany C.; Vasquez, Kimberly S.; Truong, Hong-An; Gearty, Sofia V.; Pauli, Mariela L.; Nosbaum, Audrey; Gratz, Iris K.; Otto, Michael; Moon, James J.; Liese, Jan; Abbas, Abul K.; Fischbach, Michael A.; Rosenblum, Michael D.

    2015-01-01

    Summary The skin is a site of constant dialogue between the immune system and commensal bacteria. However, the molecular mechanisms that allow us to tolerate the presence of skin commensals without eliciting destructive inflammation are unknown. Using a model system to study the antigen-specific response to S. epidermidis, we demonstrated that skin colonization during a defined period of neonatal life was required to establish immune tolerance to commensal microbes. This crucial window was characterized by an abrupt influx of highly activated regulatory T (Treg) cells into neonatal skin. Selective inhibition of this Treg cell wave completely abrogated tolerance. Thus, the host-commensal relationship in the skin relied on a unique Treg cell population that mediated tolerance to bacterial antigens during a defined developmental window. This suggests that the cutaneous microbiome composition in neonatal life is crucial in shaping adaptive immune responses to commensals, and disrupting these interactions may have enduring health implications. PMID:26588783

  7. Regulatory T Cells in the Tumor Microenvironment and Cancer Progression: Role and Therapeutic Targeting

    PubMed Central

    Chaudhary, Belal; Elkord, Eyad

    2016-01-01

    Recent years have seen significant efforts in understanding and modulating the immune response in cancer. In this context, immunosuppressive cells, including regulatory T cells (Tregs) and myeloid-derived suppressor cells (MDSCs), have come under intense investigation for their proposed roles in suppressing tumor-specific immune responses and establishing an immunosuppressive tumor microenvironment, thus enabling tumor immune evasion. Additionally, recent evidence indicates that Tregs comprise diverse and heterogeneous subsets; phenotypically and functionally distinct subsets of tumor-infiltrating Tregs could contribute differently to cancer prognosis and clinical outcomes. Understanding Treg biology in the setting of cancer, and specifically the tumor microenvironment, is important for designing effective cancer therapies. In this review, we critically examine the role of Tregs in the tumor microenvironment and in cancer progression focusing on human studies. We also discuss the impact of current therapeutic modalities on Treg biology and the therapeutic opportunities for targeting Tregs to enhance anti-tumor immune responses and clinical benefits. PMID:27509527

  8. Downregulation of key regulatory proteins in androgen dependent prostate tumor cells by oncolytic reovirus.

    PubMed

    Gupta-Saraf, Pooja; Meseke, Tyler; Miller, Cathy L

    2015-11-01

    As prostate tumor cell growth depends on hormones, androgen ablation is an effective therapy for prostate cancer (PCa). However, progression of PCa cells to androgen independent growth (castrate resistant prostate cancer, CRPC) results in relapse and mortality. Hypoxia, a microenvironment of low oxygen that modifies the activity of PCa regulatory proteins including the androgen receptor (AR), plays a critical role in progression to CRPC. Therapies targeting hypoxia and the AR may lengthen the time to CRPC progression thereby increasing survival time of PCa patients. Mammalian Orthoreovirus (MRV) has shown promise for the treatment of prostate tumors in vitro and in vivo. In this study, we found that MRV infection induces downregulation of proteins implicated in CRPC progression, interferes with hypoxia-induced AR activity, and induces apoptosis in androgen dependent cells. This suggests MRV possesses traits that could be exploited to create novel therapies for the inhibition of progression to CRPC.

  9. A Wave of Regulatory T Cells into Neonatal Skin Mediates Tolerance to Commensal Microbes.

    PubMed

    Scharschmidt, Tiffany C; Vasquez, Kimberly S; Truong, Hong-An; Gearty, Sofia V; Pauli, Mariela L; Nosbaum, Audrey; Gratz, Iris K; Otto, Michael; Moon, James J; Liese, Jan; Abbas, Abul K; Fischbach, Michael A; Rosenblum, Michael D

    2015-11-17

    The skin is a site of constant dialog between the immune system and commensal bacteria. However, the molecular mechanisms that allow us to tolerate the presence of skin commensals without eliciting destructive inflammation are unknown. Using a model system to study the antigen-specific response to S. epidermidis, we demonstrated that skin colonization during a defined period of neonatal life was required for establishing immune tolerance to commensal microbes. This crucial window was characterized by an abrupt influx of highly activated regulatory T (Treg) cells into neonatal skin. Selective inhibition of this Treg cell wave completely abrogated tolerance. Thus, the host-commensal relationship in the skin relied on a unique Treg cell population that mediated tolerance to bacterial antigens during a defined developmental window. This suggests that the cutaneous microbiome composition in neonatal life is crucial in shaping adaptive immune responses to commensals, and disrupting these interactions might have enduring health implications.

  10. Regulatory mutations in CHO cells induce expression of the mouse embryonic antigen SSEA-1.

    PubMed

    Campbell, C; Stanley, P

    1983-11-01

    Two rare and dominant mutants of Chinese hamster ovary (CHO) cells, LEC11 and LEC12, express the mouse embryonic antigen SSEA-1. Parental CHO cells and the revertants, LEC11.R9 and LEC12.R10, do not express this antigen as detected by a sensitive radioimmunoassay with a monoclonal antibody to SSEA-1. The presence of the SSEA-1 determinant correlates with the apparent de novo expression of specific N-acetylglucosaminide alpha(1,3)fucosyltransferase activities not detected in parental or revertant cell extracts. Several differences in the enzymes substrate specificities and their products have been identified. The combined data suggest that LEC11 and LEC12 mutants result from regulatory mutations affecting different fucosyltransferase genes.

  11. A quantitative increase in regulatory T cells controls development of vitiligo.

    PubMed

    Chatterjee, Shilpak; Eby, Jonathan M; Al-Khami, Amir A; Soloshchenko, Myroslawa; Kang, Hee-Kap; Kaur, Navtej; Naga, Osama S; Murali, Anuradha; Nishimura, Michael I; Le Poole, I Caroline; Mehrotra, Shikhar

    2014-05-01

    T-cell cytolytic activity targeting epidermal melanocytes is shown to cause progressive depigmentation and autoimmune vitiligo. By using the recently developed transgenic mice h3TA2 that carry T cells with a HLA-A2-restricted human tyrosinase peptide (h-Tyr)-reactive TCR and develop spontaneous vitiligo from an early age, we addressed the mechanism regulating autoimmune vitiligo. Depigmentation was significantly impaired only in IFN-γ-knockout h3TA2 mice but not in TNF-α- or perforin-knockout h3TA2 mouse strains, confirming a central role for IFN-γ in vitiligo development. In addition, regulatory T cells (Tregs) were relatively abundant in h3TA2-IFN-γ(-/-) mice, and depletion of the Treg-engaging anti-CD25 antibody fully restored the depigmentation phenotype in h3TA2-IFN-γ(-/-) mice, mediated in part through the upregulation of proinflammatory cytokines such as IL-17 and IL-22. Further therapeutic potential of Treg abundance in preventing progressive depigmentation was evaluated by adoptively transferring purified Treg or using rapamycin. Both the adoptive transfer of Tregs and the use of rapamycin induced a lasting remission of vitiligo in mice treated at the onset of disease, or in mice with established disease. This leads us to conclude that reduced regulatory responses are pivotal to the development of vitiligo in disease-prone mice, and that a quantitative increase in the Treg population may be therapeutic for vitiligo patients with active disease.

  12. Regulatory requirements for clinical trial and marketing authorisation application for cell-based medicinal products.

    PubMed

    Salmikangas, P; Flory, E; Reinhardt, J; Hinz, T; Maciulaitis, R

    2010-01-01

    The new era of regenerative medicine has led to rapid development of new innovative therapies especially for diseases and tissue/organ defects for which traditional therapies and medicinal products have not provided satisfactory outcome. Although the clinical use and developments of cell-based medicinal products (CBMPs) could be witnessed already for a decade, robust scientific and regulatory provisions for these products have only recently been enacted. The new Regulation for Advanced Therapies (EC) 1394/2007 together with the revised Annex I, Part IV of Directive 2001/83/EC provides the new legal framework for CBMPs. The wide variety of cell-based products and the foreseen limitations (small sample sizes, short shelf life) vs. particular risks (microbiological purity, variability, immunogenicity, tumourigenicity) associated with CBMPs have called for a flexible, case-by-case regulatory approach for these products. Consequently, a risk-based approach has been developed to allow definition of the amount of scientific data needed for a Marketing Authorisation Application (MAA) of each CBMP. The article provides further insight into the initial risk evaluation, as well as to the quality, non-clinical, and clinical requirements of CBMPs. Special somatic cell therapies designed for active immunotherapy are also addressed.

  13. Purified eicosapentaenoic acid induces prolonged survival of cardiac allografts and generates regulatory T cells.

    PubMed

    Iwami, D; Zhang, Q; Aramaki, O; Nonomura, K; Shirasugi, N; Niimi, M

    2009-06-01

    Fish oil, which is rich in eicosapentaenoic acid (EPA), has been found to have immunomodulatory effects. We examined whether administration of purified EPA affected survival of fully mismatched murine cardiac allografts. Hearts from C57BL/10 (H-2(b)) mice were transplanted into CBA (H-2(k)) recipients treated with one intraperitoneal dose of purified EPA the day of transplantation. Untreated CBA recipients and recipients given 0.1 g/kg of EPA rejected C57BL/10 hearts (median survival time [MST], 8 and 13 days, respectively). With a 1.0 g/kg dose of EPA, graft survival was markedly prolonged (MST >100 days). To determine whether regulatory cells were generated, naïve mice (secondary recipients) underwent adoptive transfer of splenocytes from EPA-treated primary recipients and cardiac allograft transplantation. Adoptive transfer of whole, CD4(+) and CD4(+)CD25(+) splenocytes from EPA-treated recipients induced indefinite survival in secondary recipients. Flow cytometry showed that the CD4(+)CD25(+) cells were Foxp3(+). In reverse transcriptase-polymerase chain reaction (RT-PCR) studies, the expression of peroxisome proliferator-activated receptor gamma (PPARgamma) mRNA was upregulated by EPA treatment. A PPARgamma antagonist abrogated the prolongation of graft survival induced by EPA treatment (MST, 13 days). Thus, in our model, purified EPA induced prolonged survival of fully mismatched cardiac allografts and generated regulatory T cells dependent on PPARgamma activation.

  14. Foxp3+ Regulatory T Cells Are Required for Recovery from Severe Sepsis

    PubMed Central

    Schmoeckel, Katrin; Cziupka, Katharina; Nguyen, Huu Hung; Hildebrandt, Petra; Hünig, Thomas; Sparwasser, Tim; Huehn, Jochen; Pötschke, Christian; Bröker, Barbara M.

    2013-01-01

    The role of regulatory T cells (Tregs) in bacterial sepsis remains controversial because antibody-mediated depletion experiments gave conflicting results. We employed DEREG mice (DEpletion of REGulatory T cells) and a caecal ligation and puncture model to elucidate the role of CD4+Foxp3+ Tregs in sepsis. In DEREG mice natural Tregs can be visualized easily and selectively depleted by diphtheria toxin because the animals express the diphtheria toxin receptor and enhanced green fluorescent protein as a fusion protein under the control of the foxp3 locus. We confirmed rapid Treg-activation and an increased ratio of Tregs to Teffs in sepsis. Nevertheless, 24 h after sepsis induction, Treg-depleted and control mice showed equally strong inflammation, immune cell immigration into the peritoneum and bacterial dissemination. During the first 36 h of disease survival was not influenced by Treg-depletion. Later, however, only Treg-competent animals recovered from the insult. We conclude that the suppressive capacity of Tregs is not sufficient to control overwhelming inflammation and early mortality, but is a prerequisite for the recovery from severe sepsis. PMID:23724126

  15. Mesenchymal Stem Cells as Therapeutics Agents: Quality and Environmental Regulatory Aspects

    PubMed Central

    Sabata, Roger; Verges, Josep; Zugaza, José L.; Ruiz, Adolfina; Clares, Beatriz

    2016-01-01

    Mesenchymal stem cells (MSCs) are one of the main stem cells that have been used for advanced therapies and regenerative medicine. To carry out the translational clinical application of MSCs, their manufacturing and administration in human must be controlled; therefore they should be considered as medicine: stem cell-based medicinal products (SCMPs). The development of MSCs as SCMPs represents complicated therapeutics due to their extreme complex nature and rigorous regulatory oversights. The manufacturing process of MSCs needs to be addressed in clean environments in compliance with requirements of Good Manufacturing Practice (GMP). Facilities should maintain these GMP conditions according to international and national medicinal regulatory frameworks that introduce a number of specifications in order to produce MSCs as safe SCMPs. One of these important and complex requirements is the environmental monitoring. Although a number of environmental requirements are clearly defined, some others are provided as recommendations. In this review we aim to outline the current issues with regard to international guidelines which impact environmental monitoring in cleanrooms and clean areas for the manufacturing of MSCs. PMID:27999600

  16. Cell Shape and Negative Links in Regulatory Motifs Together Control Spatial Information Flow in Signaling Networks

    PubMed Central

    Neves, Susana R.; Tsokas, Panayiotis; Sarkar, Anamika; Grace, Elizabeth A.; Rangamani, Padmini; Taubenfeld, Stephen M.; Alberini, Cristina M.; Schaff, James C.; Blitzer, Robert D.; Moraru, Ion I.; Iyengar, Ravi

    2009-01-01

    Summary The role of cell size and shape in controlling local intracellular signaling reactions, and how this spatial information originates and is propagated, is not well understood. We have used partial differential equations to model the flow of spatial information from the β-adrenergic receptor to MAPK1,2 through the cAMP/PKA/B-Raf/MAPK1,2 network in neurons using real geometries. The numerical simulations indicated that cell shape controls the dynamics of local biochemical activity of signal-modulated negative regulators, such as phosphodiesterases and protein phosphatases within regulatory loops to determine the size of microdomains of activated signaling components. The model prediction that negative regulators control the flow of spatial information to downstream components was verified experimentally in rat hippocampal slices. These results suggest a mechanism by which cellular geometry, the presence of regulatory loops with negative regulators, and key reaction rates all together control spatial information transfer and microdomain characteristics within cells. PMID:18485874

  17. Clinical Outlook for Type-1 and FOXP3+ T Regulatory Cell-Based Therapy

    PubMed Central

    Gregori, Silvia; Passerini, Laura; Roncarolo, Maria-Grazia

    2015-01-01

    T regulatory cells (Tregs) are subsets of T lymphocytes specialized in modulating antigen-specific immune responses in vivo. Hence, Tregs represent an ideal therapeutic tool to control detrimental immune reactions. Based on solid pre-clinical results, investigators started testing the safety and efficacy of Treg-based therapies in humans. Despite promising results, a number of issues remain to be solved. We will discuss the results obtained from clinical trials and the challenges and risks we are facing in the further development of Treg-based therapies. PMID:26635807

  18. Regulatory T-Cells in Pregnancy: Historical Perspective, State of the Art, and Burning Questions

    PubMed Central

    Ruocco, Maria Grazia; Chaouat, Gérard; Florez, Laura; Bensussan, Armand; Klatzmann, David

    2014-01-01

    In this review, we first revisit the original concept of “suppressor T-cells” in pregnancy, put it in a historical perspective, and then highlight the main data that licensed its resurrection and revision into the concept of “regulatory T-cells” (Tregs) in pregnancy. We review the evidence for a major role of Tregs in murine and human pregnancy and discuss Treg interactions with dendritic and uterine natural killer cells, other players of maternal–fetal tolerance. Finally, we highlight what we consider as the most important questions in the field. PMID:25191324

  19. Regulatory Networks that Direct the Development of Specialized Cell Types in the Drosophila Heart

    PubMed Central

    Lovato, TyAnna L.; Cripps, Richard M.

    2016-01-01

    The Drosophila cardiac tube was once thought to be a simple linear structure, however research over the past 15 years has revealed significant cellular and molecular complexity to this organ. Prior reviews have focused upon the gene regulatory networks responsible for the specification of the cardiac field and the activation of cardiac muscle structural genes. Here we focus upon highlighting the existence, function, and development of unique cell types within the dorsal vessel, and discuss their correspondence to analogous structures in the vertebrate heart. PMID:27695700

  20. B-cell lymphoma gene regulatory networks: biological consistency among inference methods.

    PubMed

    de Matos Simoes, Ricardo; Dehmer, Matthias; Emmert-Streib, Frank

    2013-01-01

    Despite the development of numerous gene regulatory network (GRN) inference methods in the last years, their application, usage and the biological significance of the resulting GRN remains unclear for our general understanding of large-scale gene expression data in routine practice. In our study, we conduct a structural and a functional analysis of B-cell lymphoma GRNs that were inferred using 3 mutual information-based GRN inference methods: C3Net, BC3Net and Aracne. From a comparative analysis on the global level, we find that the inferred B-cell lymphoma GRNs show major differences. However, on the edge-level and the functional-level-that are more important for our biological understanding-the B-cell lymphoma GRNs were highly similar among each other. Also, the ranks of the degree centrality values and major hub genes in the inferred networks are highly conserved as well. Interestingly, the major hub genes of all GRNs are associated with the G-protein-coupled receptor pathway, cell-cell signaling and cell cycle. This implies that hub genes of the GRNs can be highly consistently inferred with C3Net, BC3Net, and Aracne, representing prominent targets for signaling pathways. Finally, we describe the functional and structural relationship between C3Net, BC3Net and Aracne gene regulatory networks. Our study shows that these GRNs that are inferred from large-scale gene expression data are promising for the identification of novel candidate interactions and pathways that play a key role in the underlying mechanisms driving cancer hallmarks. Overall, our comparative analysis reveals that these GRNs inferred with considerably different inference methods contain large amounts of consistent, method independent, biological information.

  1. The DRE/DREF transcriptional regulatory system: a master key for cell proliferation.

    PubMed

    Matsukage, Akio; Hirose, Fumiko; Yoo, Mi-Ae; Yamaguchi, Masamitsu

    2008-02-01

    The coordinate expression of many cell proliferation-related genes is required for the cellular shift from the resting state into the proliferating state. One regulatory factor involved in this process, the transcription regulatory factor named DREF (DNA replication-related element-binding factor) was discovered in Drosophila and later found to have orthologues in other species including human. Drosophila DREF is a homo-dimer of a polypeptide of 709 amino acid residues, and shares about 22% identity in its amino acid sequence with the human homolog of 694 amino acid residues. The Drosophila DREF homo-dimer binds specifically to the DRE sequence (5'-TATCGATA) in the promoters of many DNA replication/ cell proliferation-related genes to activate their transcription, and the N-terminal region of DREF carries a domain for specific DRE-binding and homo-dimer formation. Ectopic expression of DREF in eye imaginal discs induces abnormal DNA synthesis, apoptosis and failure to differentiate. Conversely, expression of the dominant negative N-terminal region in larval salivary glands reduces endo-replication. Furthermore, RNA interference-mediated knockdown of DREF in vivo demonstrated its requirement for normal progression through the cell cycle and consequently for growth of imaginal discs and the endoreplicating organs. Both Drosophila and human DREF's interact genetically and physically with regulatory factors related to chromatin structures, suggesting that DREF activates the expression of proliferation-related genes through modification of the 3-D conformation of DNA. A search of the Drosophila genome database identified about 150 genes carrying DRE sequences in their promoter regions, many of which are related to reactions required for cell proliferation such as DNA replication, transcriptional regulation, cell cycle regulation, growth signal transduction and protein metabolism. Thus, DREF appears to be a master key-like factor for cell proliferation. Several

  2. Signatures of human regulatory T cells: an encounter with old friends and new players

    PubMed Central

    Pfoertner, Susanne; Jeron, Andreas; Probst-Kepper, Michael; Guzman, Carlos A; Hansen, Wiebke; Westendorf, Astrid M; Toepfer, Tanja; Schrader, Andres J; Franzke, Anke; Buer, Jan; Geffers, Robert

    2006-01-01

    Background Naturally occurring CD4+CD25+ regulatory T cells (TReg) are involved in the control of autoimmune diseases, transplantation tolerance, and anti-tumor immunity. Thus far, genomic studies on TReg cells were restricted to murine systems, and requirements for their development, maintenance, and mode of action in humans are poorly defined. Results To improve characterization of human TReg cells, we compiled a unique microarray consisting of 350 TReg cell associated genes (Human TReg Chip) based on whole genome transcription data from human and mouse TReg cells. TReg cell specific gene signatures were created from 11 individual healthy donors. Statistical analysis identified 62 genes differentially expressed in TReg cells, emphasizing some cross-species differences between mice and humans. Among them, several 'old friends' (including FOXP3, CTLA4, and CCR7) that are known to be involved in TReg cell function were recovered. Strikingly, the vast majority of genes identified had not previously been associated with human TReg cells (including LGALS3, TIAF1, and TRAF1). Most of these 'new players' however, have been described in the pathogenesis of autoimmunity. Real-time RT-PCR of selected genes validated our microarray results. Pathway analysis was applied to extract signaling modules underlying human TReg cell function. Conclusion The comprehensive set of genes reported here provides a defined starting point to unravel the unique characteristics of human TReg cells. The Human TReg Chip constructed and validated here is available to the scientific community and is a useful tool with which to study the molecular mechanisms that orchestrate TReg cells under physiologic and diseased conditions. PMID:16836768

  3. T regulatory cells participate in the control of germinal centre reactions

    PubMed Central

    Alexander, Carla-Maria; Tygrett, Lorraine T; Boyden, Alexander W; Wolniak, Kristy L; Legge, Kevin L; Waldschmidt, Thomas J

    2011-01-01

    Germinal centre (GC) reactions are central features of T-cell-driven B-cell responses, and the site where antibody-producing cells and memory B cells are generated. Within GCs, a range of complex cellular and molecular events occur which are critical for the generation of high affinity antibodies. These processes require exquisite regulation not only to ensure the production of desired antibodies, but to minimize unwanted autoreactive or low affinity antibodies. To assess whether T regulatory (Treg) cells participate in the control of GC responses, immunized mice were treated with an anti-glucocorticoid-induced tumour necrosis factor receptor-related protein (GITR) monoclonal antibody (mAb) to disrupt Treg-cell activity. In anti-GITR-treated mice, the GC B-cell pool was significantly larger compared with control-treated animals, with switched GC B cells composing an abnormally high proportion of the response. Dysregulated GCs were also observed regardless of strain, T helper type 1 or 2 polarizing antigens, and were also seen after anti-CD25 mAb treatment. Within the spleens of immunized mice, CXCR5+ and CCR7− Treg cells were documented by flow cytometry and Foxp3+ cells were found within GCs using immunohistology. Final studies demonstrated administration of either anti-transforming growth factor-β or anti-interleukin-10 receptor blocking mAb to likewise result in dysregulated GCs, suggesting that generation of inducible Treg cells is important in controlling the GC response. Taken together, these findings indicate that Treg cells contribute to the overall size and quality of the humoral response by controlling homeostasis within GCs. PMID:21635248

  4. IL-27 controls the development of inducible regulatory T cells and Th17 cells via differential effects on STAT1.

    PubMed

    Neufert, Clemens; Becker, Christoph; Wirtz, Stefan; Fantini, Massimo C; Weigmann, Benno; Galle, Peter R; Neurath, Markus F

    2007-07-01

    IL-27 is an IL-12-related cytokine frequently present at sites of inflammation that can promote both anti- and pro-inflammatory immune responses. Here, we have analyzed the mechanisms how IL-27 may drive such divergent immune responses. While IL-27 suppressed the development of proinflammatory Th17 cells, a novel role for this cytokine in inhibiting the development of anti-inflammatory, inducible regulatory T cells (iTreg) was identified. In fact, IL-27 suppressed the development of adaptive, TGF-beta-induced Forkhead box transcription factor p3-positive (Foxp3(+)) Treg. Whereas the blockade of Th17 development was dependent on the transcription factor STAT1, the suppression of iTreg development was STAT1 independent, suggesting that IL-27 utilizes different signaling pathways to shape T cell-driven immune responses. Our data thus demonstrate that IL-27 controls the development of Th17 and iTreg cells via differential effects on STAT1.

  5. Regulatory T cells attenuate Th17 cell-mediated nigrostriatal dopaminergic neurodegeneration in a model of Parkinson's disease

    PubMed Central

    Reynolds, Ashley D.; Stone, David K.; Hutter, Jessica A.L.; Benner, Eric J.; Mosley, R. Lee; Gendelman, Howard E.

    2010-01-01

    Nitrated alpha synuclein (N-α-syn) immunization elicits adaptive immune responses to novel antigenic epitopes that exacerbate neuroinflammation and nigrostriatal degeneration in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) model of Parkinson's disease (PD). We show that such neuroimmune degenerative activities, in significant measure, are Th17 cell-mediated with CD4+CD25+ regulatory T cell (Treg) dysfunction seen amongst populations of N-α-syn induced T cells. In contrast, purified vasoactive intestinal peptide (VIP)-induced and natural Treg reversed N-α-syn T cell nigrostriatal degeneration. Combinations of adoptively transferred N-α-syn and VIP immunocytes or natural Treg administered to MPTP mice attenuated microglial inflammatory responses and led to robust nigrostriatal protection. Taken together, these results demonstrate a putative mechanism for Treg control of N-α-syn-induced neurodestructive immunity and as such provide a sound rationale for future PD immunization strategies. PMID:20118279

  6. p38 MAPK-inhibited dendritic cells induce superior antitumor immune responses and overcome regulatory T cell-mediated immunosuppression

    PubMed Central

    Lu, Yong; Zhang, Mingjun; Wang, Siqing; Hong, Bangxing; Wang, Zhiqiang; Li, Haiyan; Zheng, Yuhuan; Yang, Jing; Davis, Richard E.; Qian, Jianfei; Hou, Jian; Yi, Qing

    2014-01-01

    Dendritic cell (DC)-based cancer immunotherapy is a promising method but so far has demonstrated limited clinical benefits. Regulatory T cells (Treg) represent a major obstacle to cancer immunotherapy approaches. Here we show that inhibiting p38 MAPK during DC differentiation enables DCs to activate tumor-specific effector T cells (Teff), inhibiting the conversion of Treg and compromising Treg inhibitory effects on Teff. Inhibition of p38 MAPK in DCs lowers expression of PPARγ, activating p50 and upregulation of OX40L expression in DCs. OX40L/OX40 interactions between DCs and Teff and/or Treg are critical for priming effective and therapeutic antitumor responses. Similarly, p38 MAPK inhibition also augments the T cell-stimulatory capacity of human monocyte-derived DCs in the presence of Treg. These findings contribute to ongoing efforts to improve DC-based immunotherapy in human cancers. PMID:24957461

  7. Deregulation of Regulatory T Cells in Acute-on-Chronic Liver Failure: A Rat Model

    PubMed Central

    Ni, Shunlan; Li, Shanshan; Yang, Naibin; Tang, Xinyue; Zhang, Shengguo; Hu, Danping

    2017-01-01

    Aims. Acute-on-chronic liver failure (ACLF) and acute liver failure (ALF) are similar in many respects during their acute exacerbation; however, ACLF generally has a poorer prognosis. We aimed to investigate the role and dynamic changes of regulatory T cell (Treg) and T helper 17 (Th17) cell proportions during ACLF progress. Methods. All rats were classified into two groups randomly: ACLF group and ALF group (control group). The rat model of ACLF was preestablished by intraperitoneal injection of carbon tetrachloride for 2 months. Then acute liver injury was induced by combined D-galactosamine and lipopolysaccharide. Six time points were examined before or after acute induction. Liver samples were performed with hematoxylin-eosin and Masson staining; circulatory Treg and Th17 cell frequencies were determined using flow cytometry assays; serum levels of alanine aminotransferase, aspartate aminotransferase, interleukin-10 (IL-10), and interferon-γ (IFN-γ) were examined. Results. In group ACLF, both Th17 cell proportion and IFN-γ level presented upgrade firstly and then descend latter tendency; the trends of Treg cell proportion and IL-10 level were observed to gradually decrease and became stable. Conclusion. The Treg cells played an important role in the immunologic mechanism during the process of ACLF. And the function of Treg cells in ACLF was defective. PMID:28194045

  8. Human secondary lymphoid organs typically contain polyclonally-activated proliferating regulatory T cells.

    PubMed

    Peters, Jorieke H; Koenen, Hans J P M; Fasse, Esther; Tijssen, Henk J; Ijzermans, Jan N M; Groenen, Patricia J T A; Schaap, Nicolaas P M; Kwekkeboom, Jaap; Joosten, Irma

    2013-09-26

    Immunomodulating regulatory T-cell (Treg) therapy is a promising strategy in autoimmunity and transplantation. However, to achieve full clinical efficacy, better understanding of in vivo human Treg biology is warranted. Here, we demonstrate that in contrast to blood and bone marrow Tregs, which showed a resting phenotype, the majority of CD4(pos)CD25(pos)CD127(neg)FoxP3(pos) Tregs in secondary lymphoid organs were proliferating activated CD69(pos)CD45RA(neg) cells with a hyperdemethylated FOXP3 gene and a broad T-cell receptor-Vβ repertoire, implying polyclonal activation. Activated CD69(pos) Tregs were distributed over both T-cell and B-cell areas, distant from Aire(pos) and CD11c(pos) cells. In contrast to the anergic peripheral blood Tregs, lymphoid organ Tregs had significant ex vivo proliferative capacity and produced cytokines like interleukin-2, while revealing similar suppressive potential. Also, next to Treg-expressing chemokine receptors important for a prolonged stay in lymphoid organs, a significant part of the cells expressed peripheral tissue-associated, functional homing markers. In conclusion, our data suggest that human secondary lymphoid organs aid in the maintenance and regulation of Treg function and homeostasis. This knowledge may be exploited for further optimization of Treg immunotherapy, for example, by ex vivo selection of Tregs with capacity to migrate to lymphoid organs providing an in vivo platform for further Treg expansion.

  9. In vivo prevention of transplant arteriosclerosis by ex vivo-expanded human regulatory T cells.

    PubMed

    Nadig, Satish N; Wieckiewicz, Joanna; Wu, Douglas C; Warnecke, Gregor; Zhang, Wei; Luo, Shiqiao; Schiopu, Alexandru; Taggart, David P; Wood, Kathryn J

    2010-07-01

    Transplant arteriosclerosis is the hallmark of chronic allograft dysfunction (CAD) affecting transplanted organs in the long term. These fibroproliferative lesions lead to neointimal thickening of arteries in all transplanted allografts. Luminal narrowing then leads to graft ischemia and organ demise. To date, there are no known tolerance induction strategies that prevent transplant arteriosclerosis. Therefore, we designed this study to test the hypothesis that human regulatory T cells (T(reg) cells) expanded ex vivo can prevent transplant arteriosclerosis. Here we show the comparative capacity of T(reg) cells, sorted via two separate strategies, to prevent transplant arteriosclerosis in a clinically relevant chimeric humanized mouse system. We found that the in vivo development of transplant arteriosclerosis in human arteries was prevented by treatment of ex vivo-expanded human T(reg) cells. Additionally, we show that T(reg) cells sorted on the basis of low expression of CD127 provide a more potent therapy to conventional T(reg) cells. Our results demonstrate that human T(reg) cells can inhibit transplant arteriosclerosis by impairing effector function and graft infiltration. We anticipate our findings to serve as a foundation for the clinical development of therapeutics targeting transplant arteriosclerosis in both allograft transplantation and other immune-mediated causes of vasculopathy.

  10. Alterations in CD46-mediated Tr1 regulatory T cells in patients with multiple sclerosis

    PubMed Central

    Astier, Anne L.; Meiffren, Gregory; Freeman, Samuel; Hafler, David A.

    2006-01-01

    Loss of Treg function appears to be a critical factor in the pathogenesis of human autoimmune diseases. Attention has focused on defects of CD4+CD25high Tregs, and techniques have been developed to determine their function. In contrast, the role of Tr1 regulatory T cells, which secrete the antiinflammatory cytokine IL-10, in autoimmune disease has not been well assessed. CD46 is a newly defined costimulatory molecule for T cell activation, and CD46-costimulated human T cells induce a Tr1 Treg phenotype with considerable amounts of IL-10 secretion. Here, we examined the role of Tr1 cells in patients with multiple sclerosis (MS) by stimulating CD4+ T cells with anti-CD3 and -CD46 mAbs and measuring IL-10 secretion. There were striking defects in the induction of Tr1 cells with CD46 costimulation as measured by IL-10 but not IFN-γ secretion in patients with MS compared with healthy subjects. This loss of Tr1 cell–associated IL-10 secretion was specific to CD46 and not CD28 costimulation and was associated with an altered regulation of the CD46-Cy2 isoform that differentially regulates T cell function in a CD46-transgenic murine model. These data demonstrate a second major Treg defect in human autoimmune disease associated with the CD46 pathway. PMID:17099776

  11. Galectin-8 promotes regulatory T cell differentiation by modulating IL-2 and TGFβ signaling

    PubMed Central

    Sampson, James F.; Suryawanshi, Amol; Chen, Wei-Sheng; Rabinovich, Gabriel A.; Panjwani, Noorjahan

    2015-01-01

    Galectins have emerged as potent immunoregulatory molecules that control chronic inflammation through distinct mechanisms. Galectin-8 (Gal-8), a tandem-repeat type galectin with unique preference for α2,3-sialylated glycans, is ubiquitously expressed, but little is known about its role in T cell differentiation. Here, we report that Gal-8 promotes the polyclonal differentiation of primary mouse Treg cells in vitro. We further show that Gal-8 also facilitates antigen-specific differentiation of regulatory T (Treg) cells, and that Treg cells polarized in the presence of Gal-8 express cytotoxic T lymphocyte antigen-4 (CTLA-4) and IL-10 at a higher frequency than control Treg cells, and efficiently inhibit proliferation of activated T cells in vitro. Investigation of the mechanism by which Gal-8 promotes Treg conversion revealed that Gal-8 activates TGFβ signaling and promotes sustained IL-2R signaling. Taken together, these data suggest that Gal-8 promotes the differentiation of highly suppressive Treg cells, which has implications for the treatment of inflammatory and autoimmune diseases. PMID:26282995

  12. Chronic follicular bronchiolitis requires antigen-specific regulatory T cell control to prevent fatal disease progression

    PubMed Central

    Schmitt, Erica G.; Haribhai, Dipica; Jeschke, Jonathan C.; Co, Dominic O.; Ziegelbauer, Jennifer; Yan, Ke; Iwakura, Yoichiro; Mishra, Manoj K.; Simpson, Pippa; Salzman, Nita H.; Williams, Calvin B.

    2014-01-01

    In order to study regulatory T (Treg) cell control of chronic autoimmunity in a lymphoreplete host, we created and characterized a new model of autoimmune lung inflammation that targets the medium and small airways. We generated transgenic mice that express a chimeric membrane protein consisting of hen egg lysozyme (mHEL) and a hemoglobin (Hb) epitope tag under the control of the Clara cell secretory protein (CCSP) promoter, which largely limited transgene expression to the respiratory bronchioles. When CCSP-mHEL/Hb transgenic mice were crossed to N3.L2 TCR transgenic mice that recognize the Hb epitope, the bigenic progeny developed dense, pseudo-follicular lymphocytic peribronchiolar infiltrates that resembled the histological pattern of follicular bronchiolitis. Aggregates of activated IFN-γ- and IL-17A-secreting CD4+ T cells as well as B cells surrounded the airways. Lung pathology was similar in Ifng−/− and Il17a−/− mice, indicating that either cytokine is sufficient to establish chronic disease. A large number of antigen-specific Treg cells accumulated in the lesions and Treg cell-depletion in the affected mice led to an interstitial spread of the disease that ultimately proved fatal. Thus Treg cells act to restrain autoimmune responses, resulting in an organized and controlled chronic pathological process rather than a progressive disease. PMID:24163409

  13. A role for natural regulatory T cells in the pathogenesis of experimental cerebral malaria.

    PubMed

    Amante, Fiona H; Stanley, Amanda C; Randall, Louise M; Zhou, Yonghong; Haque, Ashraful; McSweeney, Karli; Waters, Andrew P; Janse, Chris J; Good, Michael F; Hill, Geoff R; Engwerda, Christian R

    2007-08-01

    Cerebral malaria (CM) is a serious complication of Plasmodium falciparum infection that is responsible for a significant number of deaths in children and nonimmune adults. A failure to control blood parasitemia and subsequent sequestration of parasites to brain microvasculature are thought to be key events in many CM cases. Here, we show for the first time, to our knowledge, that CD4(+)CD25(+)Foxp3(+) natural regulatory T (Treg) cells contribute to pathogenesis by modulating immune responses in P. berghei ANKA (PbA)-infected mice. Depletion of Treg cells with anti-CD25 monoclonal antibody protected mice from experimental CM. The accumulation of parasites in the vasculature and brain was reduced in these animals, resulting in significantly lower parasite burdens compared with control animals. Mice lacking Treg cells had increased numbers of activated CD4(+) and CD8(+) T cells in the spleen and lymph nodes, but CD8(+) T-cell recruitment to the brain was selectively reduced in these mice. Importantly, a non-Treg-cell source of interleukin-10 was critical in preventing experimental CM. Finally, we show that therapeutic administration of anti-CD25 monoclonal antibody, even when blood parasitemia is established, can prevent disease, confirming a critical and paradoxical role for Treg cells in experimental CM pathogenesis.

  14. LFA-1 is Critical for Regulatory T cell Homeostasis and Function

    PubMed Central

    Wohler, Jillian; Bullard, Dan; Schoeb, Trent; Barnum, Scott

    2015-01-01

    Cellular adhesion molecules involved in cell-to-cell mediated suppression by Tregs are not well characterized. We found that the majority of Tregs expressed LFA-1 but most strikingly that the frequency of Tregs in LFA-1−/− mice was significantly lower (~50%) in the spleen, lymph nodes, and Peyer’s Patches compared to wild type controls. The reduction in LFA-1−/− Treg cells appears due in part to a reduced capacity of LFA-1−/− CD4+CD25− cells to be induced to become Tregs in the lymph nodes. Importantly, we found that LFA-1−/− Tregs fail to suppress T cell responses in vitro and have reduced function in vivo. Treg mediated-suppression does not depend on LFA-1 interactions with ICAM-1 on the surface of responder cells. Our data demonstrate that LFA-1 plays a critical role in regulatory T cell homeostasis and function. PMID:19428111

  15. TIM3+FOXP3+ regulatory T cells are tissue-specific promoters of T-cell dysfunction in cancer

    PubMed Central

    Sakuishi, Kaori; Ngiow, Shin Foong; Sullivan, Jenna M.; Teng, Michele W. L.; Kuchroo, Vijay K.; Smyth, Mark J.; Anderson, Ana C.

    2013-01-01

    T-cell immunoglobulin mucin 3 (TIM3) is an inhibitory molecule that has emerged as a key regulator of dysfunctional or exhausted CD8+ T cells arising in chronic diseases such as cancer. In addition to exhausted CD8+ T cells, highly suppressive regulatory T cells (Tregs) represent a significant barrier against the induction of antitumor immunity. We have found that the majority of intratumoral FOXP3+ Tregs express TIM3. TIM3+ Tregs co-express PD-1, are highly suppressive and comprise a specialized subset of tissue Tregs that are rarely observed in the peripheral tissues or blood of tumor-bearing mice. The co-blockade of the TIM3 and PD-1 signaling pathways in vivo results in the downregulation of molecules associated with TIM3+ Treg suppressor functions. This suggests that the potent clinical efficacy of co-blocking TIM3 and PD-1 signal transduction cascades likely stems from the reversal of T-cell exhaustion combined with the inhibition of regulatory T-cell function in tumor tissues. Interestingly, we find that TIM3+ Tregs accumulate in the tumor tissue prior to the appearance of exhausted CD8+ T cells, and that the depletion of Tregs at this stage interferes with the development of the exhausted phenotype by CD8+ T cells. Collectively, our data indicate that TIM3 marks highly suppressive tissue-resident Tregs that play an important role in shaping the antitumor immune response in situ, increasing the value of TIM3-targeting therapeutic strategies against cancer. PMID:23734331

  16. Shape-dependent control of cell growth, differentiation, and apoptosis: switching between attractors in cell regulatory networks

    NASA Technical Reports Server (NTRS)

    Huang, S.; Ingber, D. E.

    2000-01-01

    Development of characteristic tissue patterns requires that individual cells be switched locally between different phenotypes or "fates;" while one cell may proliferate, its neighbors may differentiate or die. Recent studies have revealed that local switching between these different gene programs is controlled through interplay between soluble growth factors, insoluble extracellular matrix molecules, and mechanical forces which produce cell shape distortion. Although the precise molecular basis remains unknown, shape-dependent control of cell growth and function appears to be mediated by tension-dependent changes in the actin cytoskeleton. However, the question remains: how can a generalized physical stimulus, such as cell distortion, activate the same set of genes and signaling proteins that are triggered by molecules which bind to specific cell surface receptors. In this article, we use computer simulations based on dynamic Boolean networks to show that the different cell fates that a particular cell can exhibit may represent a preprogrammed set of common end programs or "attractors" which self-organize within the cell's regulatory networks. In this type of dynamic network model of information processing, generalized stimuli (e.g., mechanical forces) and specific molecular cues elicit signals which follow different trajectories, but eventually converge onto one of a small set of common end programs (growth, quiescence, differentiation, apoptosis, etc.). In other words, if cells use this type of information processing system, then control of cell function would involve selection of preexisting (latent) behavioral modes of the cell, rather than instruction by specific binding molecules. Importantly, the results of the computer simulation closely mimic experimental data obtained with living endothelial cells. The major implication of this finding is that current methods used for analysis of cell function that rely on characterization of linear signaling pathways or

  17. Memory CD4+ T cells are suppressed by CD8+ regulatory T cells in vitro and in vivo

    PubMed Central

    Long, Xin; Cheng, Qi; Liang, Huifang; Zhao, Jianping; Wang, Jian; Wang, Wei; Tomlinson, Stephen; Chen, Lin; Atkinson, Carl; Zhang, Bixiang; Chen, Xiaoping; Zhu, Peng

    2017-01-01

    Background: Acute graft rejection mediated by alloreactive memory CD4+ T cells is a major obstacle to transplantation tolerance. It has been reported that CD8+ T regulatory cells (Tregs) have the ability to induce graft tolerance by restraining the function of activated CD4+ T cells, but not including memory T cells. The aim of this study is to elucidate the effect of CD8+ Tregs on alloreactive memory CD4+ T cells. Methods: We detected Qa-1 expression and performed proliferative assay on memory CD4+ T cells. All memory CD4+ T cells were purified from mice receiving skin allografts. We performed inhibitory and cytotoxic assays on CD8+ Tregs, which were isolated from a T cell vaccination mouse model, and IL-2, IL-4, IL-10 and IFN-γ levels were measured in co-culture supernatants by ELISA. To confirm CD8+ Tregs inhibition of memory CD4+ T cells in-vivo, we utilized a murine model of cardiac allograft transplantation. Results: Memory CD4+ T cells mediated acute allograft rejection, and CD8+ Tregs suppressed the proliferation of memory CD4+ T cells. In vitro, memory CD4+ T cells were inhibited and lysed by CD8+ Tregs. There was a positive correlation between IFN-γ levels, and cell lysis rate induced by CD8+ Tregs. In-vivo studies demonstrated CD8+ Tregs prolonged graft survival times, by inhibiting CD4+ memory T cells, through a Qa-1-peptide-TCR pathway. Conclusions: CD8+ Tregs inhibit CD4+ memory T cell-mediated acute murine cardiac allograft rejection, and further prolong graft survival times. These results provide new insights into immune regulation of organ rejection. PMID:28123634

  18. Immunomodulation in host-protective immune response against murine tuberculosis through regulation of the T regulatory cell function.

    PubMed

    Das, Shibali; Halder, Kuntal; Goswami, Avranil; Chowdhury, Bidisha Paul; Pal, Nishith K; Majumdar, Subrata

    2015-11-01

    Tuberculosis, caused by the bacteria Mycobacterium tuberculosis,