Science.gov

Sample records for cell regulatory function

  1. Regulatory T Cells: Differentiation and Function.

    PubMed

    Plitas, George; Rudensky, Alexander Y

    2016-09-01

    The immune system of vertebrate animals has evolved to mount an effective defense against a diverse set of pathogens while minimizing transient or lasting impairment in tissue function that could result from the inflammation caused by immune responses to infectious agents. In addition, misguided immune responses to "self" and dietary antigens, as well as to commensal microorganisms, can lead to a variety of inflammatory disorders, including autoimmunity, metabolic syndrome, allergies, and cancer. Regulatory T cells expressing the X chromosome-linked transcription factor Foxp3 suppress inflammatory responses in diverse biological settings and serve as a vital mechanism of negative regulation of immune-mediated inflammation. Cancer Immunol Res; 4(9); 721-5. ©2016 AACR. PMID:27590281

  2. Metabolic Regulation of Regulatory T Cell Development and Function

    PubMed Central

    Coe, David John; Kishore, Madhav; Marelli-Berg, Federica

    2014-01-01

    It is now well established that the effector T cell (Teff) response is regulated by a series of metabolic switches. Quiescent T cells predominantly require adenosine triphosphate-generating processes, whereas proliferating Teff require high metabolic flux through growth-promoting pathways, such as glycolysis. Pathways that control metabolism and immune cell function are intimately linked, and changes in cell metabolism at both the cell and system levels have been shown to enhance or suppress specific T cell effector functions. Furthermore, functionally distinct T cell subsets require distinct energetic and biosynthetic pathways to support their specific functional needs. In particular, naturally occurring regulatory T cells (Treg) are characterized by a unique metabolic signature distinct to that of conventional Teff cells. We here briefly review the signaling pathways that control Treg metabolism and how this metabolic phenotype integrates their differentiation and function. Ultimately, these metabolic features may provide new opportunities for the therapeutic modulation of unwanted immune responses. PMID:25477880

  3. Helios Controls a Limited Subset of Regulatory T Cell Functions.

    PubMed

    Sebastian, Mathew; Lopez-Ocasio, Maria; Metidji, Amina; Rieder, Sadiye Amcaoglu; Shevach, Ethan M; Thornton, Angela M

    2016-01-01

    A subpopulation (60-70%) of Foxp3(+) regulatory T cells (Tregs) in both mouse and man expresses the transcription factor Helios, but its role in Treg function is still unknown. We generated Treg-specific Helios-deficient mice to examine the function of Helios in Tregs. We show that the selective deletion of Helios in Tregs leads to slow, progressive systemic immune activation, hypergammaglobulinemia, and enhanced germinal center formation in the absence of organ-specific autoimmunity. Helios-deficient Treg suppressor function was normal in vitro, as well as in an in vivo inflammatory bowel disease model. However, Helios-deficient Tregs failed to control the expansion of pathogenic T cells derived from scurfy mice, failed to mediate T follicular regulatory cell function, and failed to control both T follicular helper cell and Th1 effector cell responses. In competitive settings, Helios-deficient Tregs, particularly effector Tregs, were at a disadvantage, indicating that Helios regulates effector Treg fitness. Thus, we demonstrate that Helios controls certain aspects of Treg-suppressive function, differentiation, and survival. PMID:26582951

  4. T Cell Signaling Targets for Enhancing Regulatory or Effector Function

    PubMed Central

    Pan, Fan; Fan, Huimin; Liu, Zhongmin; Jiang, Shuiping

    2015-01-01

    To respond to infection, resting or naïve T cells must undergo activation, clonal expansion, and differentiation into specialized functional subsets of effector T cells. However, to prevent excessive or self-destructive immune responses, regulatory T cells (Tregs) are instrumental in suppressing the activation and function of effector cells, including effector T cells. The transcription factor Forkhead box P3 (Foxp3) regulates the expression of genes involved in the development and function of Tregs. Foxp3 interacts with other transcription factors and with epigenetic elements such as histone deacetylases (HDACs) and histone acetyltransferases. Treg suppressive function can be increased by exposure to HDAC inhibitors. The individual contributions of different HDAC family members to Treg function and their respective mechanisms of action, however, remain unclear. A study showed that HDAC6, HDAC9, and Sirtuin-1 had distinct effects on Foxp3 expression and function, suggesting that selectively targeting HDACs individually or in combination may enhance Treg stability and suppressive function. Another study showed that the receptor programmed death 1 (PD-1), a well-known inhibitor of T cell activation, halted cell cycle progression in effector T cells by inhibiting the transcription of the gene encoding the substrate-recognition component (Skp2) of the ubiquitin ligase SCFSkp2. Together, these findings reveal new signaling targets for enhancing Treg or effector T cell function that may be helpful in designing future therapies, either to increase Treg suppressive function in transplantation and autoimmune diseases or to block PD-1 function, thus increasing the magnitude of antiviral or antitumor immune responses of effector T cells. PMID:22855503

  5. CTLA-4 control over Foxp3+ regulatory T cell function.

    PubMed

    Wing, Kajsa; Onishi, Yasushi; Prieto-Martin, Paz; Yamaguchi, Tomoyuki; Miyara, Makoto; Fehervari, Zoltan; Nomura, Takashi; Sakaguchi, Shimon

    2008-10-10

    Naturally occurring Foxp3+CD4+ regulatory T cells (Tregs) are essential for maintaining immunological self-tolerance and immune homeostasis. Here, we show that a specific deficiency of cytotoxic T lymphocyte antigen 4 (CTLA-4) in Tregs results in spontaneous development of systemic lymphoproliferation, fatal T cell-mediated autoimmune disease, and hyperproduction of immunoglobulin E in mice, and it also produces potent tumor immunity. Treg-specific CTLA-4 deficiency impairs in vivo and in vitro suppressive function of Tregs-in particular, Treg-mediated down-regulation of CD80 and CD86 expression on dendritic cells. Thus, natural Tregs may critically require CTLA-4 to suppress immune responses by affecting the potency of antigen-presenting cells to activate other T cells. PMID:18845758

  6. Foxo transcription factors control regulatory T cell development and function

    PubMed Central

    Kerdiles, Yann M.; Stone, Erica L.; Beisner, Daniel L.; McGargill, Maureen A.; Ch'en, Irene L.; Stockmann, Christian; Katayama, Carol D.; Hedrick, Stephen M.

    2010-01-01

    SUMMARY Foxo transcription factors integrate extrinsic signals to regulate cell division, differentiation and survival, and specific functions of lymphoid and myeloid cells. Here we showed the absence of Foxo1 severely curtailed the development of Foxp3+ regulatory T (Treg) cells, and those that developed were nonfunctional in vivo. The loss of function included diminished CTLA-4 receptor expression as the Ctla4 gene was a direct target of Foxo1. T cell specific loss of Foxo1 resulted in exocrine pancreatitis, hind limb paralysis, multi-organ lymphocyte infiltration, anti-nuclear antibodies and expanded germinal centers. Foxo-mediated control over Treg cell specification was further revealed by the inability of TGF-β cytokine to suppress T-bet transcription factor in the absence of Foxo1, resulting in IFN-γ-secretion. In addition the absence of Foxo3 exacerbated the effects of the loss of Foxo1. Thus, Foxo transcription factors guide the contingencies of T cell differentiation and specific functions of effector cell populations. PMID:21167754

  7. 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

  8. Metabolic control of regulatory T cell development and function.

    PubMed

    Zeng, Hu; Chi, Hongbo

    2015-01-01

    Foxp3(+) regulatory T cells (Tregs) maintain immune tolerance and play an important role in immunological diseases and cancers. Recent studies have revealed an intricate relationship between Treg biology and host and microbial metabolism. Various metabolites or nutrients produced by host and commensal microbes, such as vitamins and short-chain fatty acids (SCFAs), regulate Treg generation, trafficking, and function. Furthermore, cell intrinsic metabolic programs, orchestrated by mTOR and other metabolic sensors, modulate Foxp3 induction and Treg suppressive activity. Conversely, Tregs are crucial in regulating obesity-associated inflammation and host metabolic balance, and in shaping homeostasis of gut microbiota. We review here the interplay between Tregs and metabolism, with a particular focus on how host, commensal, and cellular metabolism impinge upon Treg homeostasis and function. PMID:25248463

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

    PubMed Central

    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

    2015-01-01

    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 T cell receptor (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 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 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. Since 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 ADAP or Crk/CrkL, which are required for TCR-mediated integrin activation, inhibited Tconv proliferation to a similar extent as wildtype Tregs. Together, these data suggest that TCR-mediated PLCγ activation but not integrin activation is required for Tregs to inhibit Tconv proliferation. PMID:25821220

  10. 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. PMID:26371251

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

    PubMed Central

    Lin, Mei; Wang, Zuomin; Han, Xiaozhe

    2015-01-01

    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. PMID:26236565

  12. Cell Cycle Regulatory Functions of the KSHV Oncoprotein LANA

    PubMed Central

    Wei, Fang; Gan, Jin; Wang, Chong; Zhu, Caixia; Cai, Qiliang

    2016-01-01

    Manipulation of cell cycle is a commonly employed strategy of viruses for achieving a favorable cellular environment during infection. Kaposi’s sarcoma-associated herpesvirus (KSHV), the primary etiological agent of several human malignancies including Kaposi’s sarcoma, and primary effusion lymphoma, encodes several oncoproteins that deregulate normal physiology of cell cycle machinery to persist with endothelial cells and B cells and subsequently establish a latent infection. During latency, only a small subset of viral proteins is expressed. Latency-associated nuclear antigen (LANA) is one of the latent antigens shown to be essential for transformation of endothelial cells in vitro. It has been well demonstrated that LANA is critical for the maintenance of latency, episome DNA replication, segregation and gene transcription. In this review, we summarize recent studies and address how LANA functions as an oncoprotein to steer host cell cycle-related events including proliferation and apoptosis by interacting with various cellular and viral factors, and highlight the potential therapeutic strategy of disrupting LANA-dependent signaling as targets in KSHV-associated cancers. PMID:27065950

  13. Characterization of Dendritic Cell and Regulatory T Cell Functions against Mycobacterium tuberculosis Infection

    PubMed Central

    Morris, Devin; Gonzalez, Brenda; Khurasany, Melissa; Kassissa, Christine; Luong, Jennifer; Kasko, Sarah; Pandya, Shalin; Chu, Michael; Chi, Po-Ting; Bui, Steven; Guerra, Carlos; Chan, John; Venketaraman, Vishwanath

    2013-01-01

    Glutathione (GSH) is a tripeptide that regulates intracellular redox and other vital aspects of cellular functions. GSH plays a major role in enhancing the immune system. Dendritic cells (DCs) are potent antigen presenting cells that participate in both innate and acquired immune responses against microbial infections. Regulatory T cells (Tregs) play a significant role in immune homeostasis. In this study, we investigated the effects of GSH in enhancing the innate and adaptive immune functions of DCs against Mycobacterium tuberculosis (M. tb) infection. We also characterized the functions of the sub-populations of CD4+T cells such as Tregs and non-Tregs in modulating the ability of monocytes to control the intracellular M. tb infection. Our results indicate that GSH by its direct antimycobacterial activity inhibits the growth of intracellular M. tb inside DCs. GSH also increases the expressions of costimulatory molecules such as HLA-DR, CD80 and CD86 on the cell surface of DCs. Furthermore, GSH-enhanced DCs induced a higher level of T-cell proliferation. We also observed that enhancing the levels of GSH in Tregs resulted in downregulation in the levels of IL-10 and TGF-β and reduction in the fold growth of M. tb inside monocytes. Our studies demonstrate novel regulatory mechanisms that favor both innate and adaptive control of M. tb infection. PMID:23762843

  14. Functional role of regulatory T cells in B cell lymphoma and related mechanisms.

    PubMed

    Wu, Wei; Wan, Jun; Xia, Ruixiang; Huang, Zhenqi; Ni, Jing; Yang, Mingzhen

    2015-01-01

    B cell lymphoma (BCL) has a higher degree of malignancy and complicated pathogenic mechanism. Regulatory T cells (Treg cells) are known to exert certain immune suppression functions, in addition to immune mediating effects. Recent studies have revealed the role of Treg cells in pathogenesis and progression of multiple malignant tumors. This study therefore investigated the functional role and related mechanism of Treg cells in BCL. A cohort of thirty patients who were diagnosed with BCL in our hospital between January 2013 and December 2014. Another thirty healthy individuals were recruited. Peripheral blood mononuclear cells (PBMCs) were separated and analyzed for the ratio of CD4+/CD25+ Treg cells. The mRNA expression levels of Foxp3, transforming growth factor (TGF)-β1 and interleukin (IL)-10 genes were quantified by real-time PCR, while their serum levels were determined by enzyme-linked immunosorbent assay (ELISA). Meanwhile all laboratory indexes for patients were monitored during the complete remission (CR) stage. BCL patients significantly elevated ratio of CD4+/CD25+ Treg cells, which were decreased at CR stage. mRNA levels of Foxp3, TGF-β1 and IL-10, in addition to protein levels of TGF-β1 and IL-10 were potentiated in lymphoma patients but decreased in CR patients (P<0.05 in all cases). CD4+/CD25+ Treg cells exert immune suppressing functions in BCL via regulating cytokines, thereby facilitating the pathogenesis and progression of lymphoma. PMID:26464657

  15. Regulatory T cells in atherosclerosis: critical immune regulatory function and therapeutic potential.

    PubMed

    Spitz, Charlotte; Winkels, Holger; Bürger, Christina; Weber, Christian; Lutgens, Esther; Hansson, Göran K; Gerdes, Norbert

    2016-03-01

    Atherosclerosis is a chronic inflammatory disease that is mediated by innate and adaptive immune responses. The disease is characterized by sub-endothelial accumulation and modification of lipids in the artery wall triggering an inflammatory reaction which promotes lesion progression and eventual plaque rupture, thrombus formation, and the respective clinical sequelae such as myocardial infarction or stroke. During the past decade, T-cell-mediated immune responses, especially control of pro-inflammatory signals by regulatory T cells (Tregs), have increasingly attracted the interest of experimental and clinical researchers. By suppression of T cell proliferation and secretion of anti-inflammatory cytokines, such as interleukin-10 (IL-10) and transforming growth factor-β, Tregs exert their atheroprotective properties. Atherosclerosis-prone, hyperlipidemic mice harbor systemically less Tregs compared to wild-type mice, suggesting an imbalance of immune cells which affects local and systemic inflammatory and potentially metabolic processes leading to atherogenesis. Restoring or increasing Treg frequency and enhancing their suppressive capacity by various modulations may pose a promising approach for treating inflammatory conditions such as cardiovascular diseases. In this review, we briefly summarize the immunological basics of atherosclerosis and introduce the role and contribution of different subsets of T cells. We then discuss experimental data and current knowledge pertaining to Tregs in atherosclerosis and perspectives on manipulating the adaptive immune system to alleviate atherosclerosis and cardiovascular disease. PMID:26518635

  16. 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. PMID:26359290

  17. Amphiregulin enhances regulatory T cell-suppressive function via the epidermal growth factor receptor.

    PubMed

    Zaiss, Dietmar M W; van Loosdregt, Jorg; Gorlani, Andrea; Bekker, Cornelis P J; Gröne, Andrea; Sibilia, Maria; van Bergen en Henegouwen, Paul M P; Roovers, Rob C; Coffer, Paul J; Sijts, Alice J A M

    2013-02-21

    Epidermal growth factor receptor (EGFR) is known to be critically involved in tissue development and homeostasis as well as in the pathogenesis of cancer. Here we showed that Foxp3(+) regulatory T (Treg) cells express EGFR under inflammatory conditions. Stimulation with the EGF-like growth factor Amphiregulin (AREG) markedly enhanced Treg cell function in vitro, and in a colitis and tumor vaccination model we showed that AREG was critical for efficient Treg cell function in vivo. In addition, mast cell-derived AREG fully restored optimal Treg cell function. These findings reveal EGFR as a component in the regulation of local immune responses and establish a link between mast cells and Treg cells. Targeting of this immune regulatory mechanism may contribute to the therapeutic successes of EGFR-targeting treatments in cancer patients. PMID:23333074

  18. The Ets-1 transcription factor controls the development and function of natural regulatory T cells.

    PubMed

    Mouly, Enguerran; Chemin, Karine; Nguyen, Hai Vu; Chopin, Martine; Mesnard, Laurent; Leite-de-Moraes, Maria; Burlen-defranoux, Odile; Bandeira, Antonio; Bories, Jean-Christophe

    2010-09-27

    Regulatory T cells (T reg cells) constitute a population of CD4(+) T cells that limits immune responses. The transcription factor Foxp3 is important for determining the development and function of T reg cells; however, the molecular mechanisms that trigger and maintain its expression remain incompletely understood. In this study, we show that mice deficient for the Ets-1 transcription factor (Ets-1(-/-)) developed T cell-mediated splenomegaly and systemic autoimmunity that can be blocked by functional wild-type T reg cells. Spleens of Ets-1(-/-) mice contained mostly activated T cells, including Th2-polarized CD4(+) cells and had reduced percentages of T reg cells. Splenic and thymic Ets-1(-/-) T reg cells expressed low levels of Foxp3 and displayed the CD103 marker that characterizes antigen-experienced T reg cells. Thymic development of Ets-1(-/-) T reg cells appeared intrinsically altered as Foxp3-expressing cells differentiate poorly in mixed fetal liver reconstituted chimera and fetal thymic organ culture. Ets-1(-/-) T reg cells showed decreased in vitro suppression activity and did not protect Rag2(-/-) hosts from naive T cell-induced inflammatory bowel disease. Furthermore, in T reg cells, Ets-1 interacted with the Foxp3 intronic enhancer and was required for demethylation of this regulatory sequence. These data demonstrate that Ets-1 is required for the development of natural T reg cells and suggest a role for this transcription factor in the regulation of Foxp3 expression. PMID:20855499

  19. Bone marrow-resident NK cells prime monocytes for regulatory function during infection

    PubMed Central

    Askenase, Michael H.; Han, Seong-Ji; Byrd, Allyson L.; da Fonseca, Denise Morais; Bouladoux, Nicolas; Wilhelm, Christoph; Konkel, Joanne E.; Hand, Timothy W.; Lacerda-Queiroz, Norinne; Su, Xin-Zhuan; Trinchieri, Giorgio; Grainger, John R.; Belkaid, Yasmine

    2015-01-01

    SUMMARY Tissue-infiltrating Ly6Chi monocytes play diverse roles in immunity, ranging from pathogen killing to immune regulation. How and where this diversity of function is imposed remains poorly understood. Here we show that during acute gastrointestinal infection, priming of monocytes for regulatory function preceded systemic inflammation and was initiated prior to bone marrow egress. Notably, natural killer (NK) cell-derived IFN-γ promoted a regulatory program in monocyte progenitors during development. Early bone marrow NK cell activation was controlled by systemic interleukin-12 (IL-12) produced by Batf3-dependent dendritic cells (DC) in the mucosal-associated lymphoid tissue (MALT). This work challenges the paradigm that monocyte function is dominantly imposed by local signals following tissue recruitment, and instead proposes a sequential model of differentiation in which monocytes are pre-emptively educated during development in the bone marrow to promote their tissue-specific function. PMID:26070484

  20. Protein SUMOylation Is Required for Regulatory T Cell Expansion and Function.

    PubMed

    Ding, Xiao; Wang, Aibo; Ma, Xiaopeng; Demarque, Maud; Jin, Wei; Xin, Huawei; Dejean, Anne; Dong, Chen

    2016-07-26

    Foxp3-expressing regulatory T (Treg) cells are essential for immune tolerance; however, the molecular mechanisms underlying Treg cell expansion and function are still not well understood. SUMOylation is a protein post-translational modification characterized by covalent attachment of SUMO moieties to lysines. UBC9 is the only E2 conjugating enzyme involved in this process, and loss of UBC9 completely abolishes the SUMOylation pathway. Here, we report that selective deletion of Ubc9 within the Treg lineage results in fatal early-onset autoimmunity similar to Foxp3 mutant mice. Ubc9-deficient Treg cells exhibit severe defects in TCR-driven homeostatic proliferation, accompanied by impaired activation and compromised suppressor function. Importantly, TCR ligation enhanced SUMOylation of IRF4, a critical regulator of Treg cell function downstream of TCR signals, which regulates its stability in Treg cells. Our data thus have demonstrated an essential role of SUMOylation in the expansion and function of Treg cells. PMID:27425617

  1. Autophagy enforces functional integrity of regulatory T cells by coupling environmental cues and metabolic homeostasis

    PubMed Central

    Wei, Jun; Long, Lingyun; Yang, Kai; Guy, Cliff; Shrestha, Sharad; Chen, Zuojia; Wu, Chuan; Vogel, Peter; Neale, Geoffrey; Green, Douglas R; Chi, Hongbo

    2015-01-01

    Regulatory T (Treg) cells respond to immune and inflammatory signals to mediate immunosuppression, but how functional integrity of Treg cells is maintained under activating environments remains elusive. Here we found that autophagy was active in Treg cells and supported their lineage stability and survival fitness. Treg cell-specific deletion of the essential autophagy gene Atg7 or Atg5 led to loss of Treg cells, increased tumor resistance, and development of inflammatory disorders. Atg7-deficient Treg cells had increased apoptosis and readily lost Foxp3 expression, especially after activation. Mechanistically, autophagy deficiency upregulated mTORC1 and c-Myc function and glycolytic metabolism that contributed to defective Treg function. Therefore, autophagy couples environmental signals and metabolic homeostasis to protect lineage and survival integrity of Treg cells in activating contexts. PMID:26808230

  2. The Special Relationship in the Development and Function of T Helper 17 and Regulatory T Cells.

    PubMed

    Lochner, Matthias; Wang, Zuobai; Sparwasser, Tim

    2015-01-01

    T helper 17 (Th17) cells play an essential role in the clearance of extracellular pathogenic bacteria and fungi. However, this subset is critically involved in the pathology of many autoimmune diseases, e.g., psoriasis, multiple sclerosis, allergy, rheumatoid arthritis, and inflammatory bowel diseases in humans. Therefore, Th17 responses need to be tightly regulated in vivo to mediate effective host defenses against pathogens without causing excessive host tissue damage. Foxp3(+) regulatory T (Treg) cells play an important role in maintaining peripheral tolerance to self-antigens and in counteracting the inflammatory activity of effector T helper cell subsets. Although Th17 and Treg cells represent two CD4(+) T cell subsets with opposing principal functions, these cell types are functionally connected. In this review, we will first give an overview on the biology of Th17 cells and describe their development and in vivo function, followed by an account on the special developmental relationship between Th17 and Treg cells. We will describe the identification of Treg/Th17 intermediates and consider their lineage stability and function in vivo. Finally, we will discuss how Treg cells may regulate the Th17 cell response in the context of infection and inflammation, and elude on findings demonstrating that Treg cells can also have a prominent function in promoting the differentiation of Th17 cells. PMID:26615094

  3. FIREWACh: High-throughput Functional Detection of Transcriptional Regulatory Modules in Mammalian Cells

    PubMed Central

    Murtha, Matthew; Tokcaer-Keskin, Zeynep; Tang, Zuojian; Strino, Francesco; Chen, Xi; Wang, Yatong; Xi, Xiangmei; Basilico, Claudio; Brown, Stuart; Bonneau, Richard; Kluger, Yuval; Dailey, Lisa

    2014-01-01

    Promoters and enhancers establish precise gene transcription patterns. The development of functional approaches for their identification in mammalian cells has been complicated by the size of these genomes. Here we report a new method called FIREWACh (Functional Identification of Regulatory Elements Within Accessible Chromatin), a high-throughput functional assay for directly identifying active promoter and enhancer elements. FIREWACh simultaneously assessed over 80,000 DNA fragments derived from “nucleosome-free regions” within embryonic stem cell (ESC) chromatin to identify 6,364 new active regulatory elements. Many FIREWACh DNAs represent newly discovered ESC-specific enhancers and their analyses identified enriched binding site motifs for ESC transcription factors including SOX2, OCT4 (POU5f1), and KLF4. Thus FIREWACh identifies endogenous regulators of gene expression and can be used for the discovery of key cell-specific transcription factors. The application of FIREWACh to additional cultured cell types will facilitate functional annotation of the genome and expand our view of transcriptional network dynamics. PMID:24658142

  4. 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.

  5. Marine organism cell biology and regulatory sequence discoveryin comparative functional genomics.

    PubMed

    Barnes, David W; Mattingly, Carolyn J; Parton, Angela; Dowell, Lori M; Bayne, Christopher J; Forrest, John N

    2004-10-01

    The use of bioinformatics to integrate phenotypic and genomic data from mammalian models is well established as a means of understanding human biology and disease. Beyond direct biomedical applications of these approaches in predicting structure-function relationships between coding sequences and protein activities, comparative studies also promote understanding of molecular evolution and the relationship between genomic sequence and morphological and physiological specialization. Recently recognized is the potential of comparative studies to identify functionally significant regulatory regions and to generate experimentally testable hypotheses that contribute to understanding mechanisms that regulate gene expression, including transcriptional activity, alternative splicing and transcript stability. Functional tests of hypotheses generated by computational approaches require experimentally tractable in vitro systems, including cell cultures. Comparative sequence analysis strategies that use genomic sequences from a variety of evolutionarily diverse organisms are critical for identifying conserved regulatory motifs in the 5'-upstream, 3'-downstream and introns of genes. Genomic sequences and gene orthologues in the first aquatic vertebrate and protovertebrate organisms to be fully sequenced (Fugu rubripes, Ciona intestinalis, Tetraodon nigroviridis, Danio rerio) as well as in the elasmobranchs, spiny dogfish shark (Squalus acanthias) and little skate (Raja erinacea), and marine invertebrate models such as the sea urchin (Strongylocentrotus purpuratus) are valuable in the prediction of putative genomic regulatory regions. Cell cultures have been derived for these and other model species. Data and tools resulting from these kinds of studies will contribute to understanding transcriptional regulation of biomedically important genes and provide new avenues for medical therapeutics and disease prevention. PMID:19003267

  6. Functional Improvement of Regulatory T Cells from Rheumatoid Arthritis Subjects Induced by Capsular Polysaccharide Glucuronoxylomannogalactan

    PubMed Central

    Alunno, Alessia; Bartoloni Bocci, Elena; Perito, Stefano; Chow, Siu-Kei; Cenci, Elio; Casadevall, Arturo; Gerli, Roberto; Vecchiarelli, Anna

    2014-01-01

    Objective Regulatory T cells (Treg) play a critical role in the prevention of autoimmunity, and the suppressive activity of these cells is impaired in rheumatoid arthritis (RA). The aim of the present study was to investigate function and properties of Treg of RA patients in response to purified polysaccharide glucuronoxylomannogalactan (GXMGal). Methods Flow cytometry and western blot analysis were used to investigate the frequency, function and properties of Treg cells. Results GXMGal was able to: i) induce strong increase of FOXP3 on CD4+ T cells without affecting the number of CD4+CD25+FOXP3+ Treg cells with parallel increase in the percentage of non-conventional CD4+CD25−FOXP3+ Treg cells; ii) increase intracellular levels of TGF-β1 in CD4+CD25−FOXP3+ Treg cells and of IL-10 in both CD4+CD25+FOXP3+ and CD4+CD25−FOXP3+ Treg cells; iii) enhance the suppressive activity of CD4+CD25+FOXP3+ and CD4+CD25−FOXP3+ Treg cells in terms of inhibition of effector T cell activity and increased secretion of IL-10; iv) decrease Th1 response as demonstrated by inhibition of T-bet activation and down-regulation of IFN-γ and IL-12p70 production; v) decrease Th17 differentiation by down-regulating pSTAT3 activation and IL-17A, IL-23, IL-21, IL-22 and IL-6 production. Conclusion These data show that GXMGal improves Treg functions and increases the number and function of CD4+CD25−FOXP3+ Treg cells of RA patients. It is suggested that GXMGal may be potentially useful for restoring impaired Treg functions in autoimmune disorders and for developing Treg cell-based strategies for the treatment of these diseases. PMID:25338013

  7. Origin and functions of pro-inflammatory cytokine producing Foxp3+ regulatory T cells

    PubMed Central

    Pandiyan, Pushpa; Zhu, Jinfang

    2016-01-01

    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. PMID:26165923

  8. 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. PMID:26165923

  9. 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

  10. Functional changes in regulatory T cells during an experimental infection with sparganum (plerocercofid of Spirometra mansoni).

    PubMed

    Kim, Hyung-Ran; Lee, Su-Min; Won, Jong-Wha; Lim, Woosung; Moon, Byung-In; Yang, Hyun-Jong; Seoh, Ju-Young

    2013-01-01

    Regulatory T (Treg) cells are important in the regulation of immune response, but the exact regulation of Treg-cell function in vivo is still not well known. In the present study, we investigated the functional activity of CD4(+) CD25(+) Treg cells as well as the frequency and number of CD4(+) CD25(+) FoxP3(+) Treg cells in the spleens of experimentally infected mice with a tissue-migrating parasite, sparganum (plerocercoid of Spirometra mansoni) for 3 weeks. The results demonstrated fluctuations in the Treg-cell function during the parasite infection, being up-regulated at day 3, down-regulated until day 14, and thereafter up-regulated again at day 21. We also investigated the cytokine-producing capability of the splenocytes to study the pattern of immune response of the mice to the parasite. The results showed decreased capabilities of interleukin-2 (IL-2), interferon-γ (IFN-γ) and IL-17α production, whereas IL-4-producing and IL-10-producing capabilities were increased along with the parasitic infection. Meanwhile, IL-6-producing capability was increased to reach a peak at week 2, and thereafter was decreased to the baseline level. As a regulatory mechanism, we found that Treg-cell function was attenuated in the presence of the crude extracts of sparganum, but was enhanced in the presence of the excretory-secretory products, suggesting that sparganum products were involved in the triggering and regulation of immune response in the acute and chronic phases, respectively. Results show that Treg cells are central in the immune homeostasis in vivo that is maintained by host-parasite interactions during the parasitic infection. PMID:23078673

  11. Stem cell regulatory function mediated by expression of a novel mouse Oct4 pseudogene

    SciTech Connect

    Lin, Huey; Shabbir, Arsalan; Molnar, Merced; Lee, Techung . E-mail: chunglee@buffalo.edu

    2007-03-30

    Multiple pseudogenes have been proposed for embryonic stem (ES) cell-specific genes, and their abundance suggests that some of these potential pseudogenes may be functional. ES cell-specific expression of Oct4 regulates stem cell pluripotency and self-renewing state. Although Oct4 expression has been reported in adult tissues during gene reprogramming, the detected Oct4 signal might be contributed by Oct4 pseudogenes. Among the multiple Oct4 transcripts characterized here is a {approx}1 kb clone derived from P19 embryonal carcinoma stem cells, which shares a {approx}87% sequence homology with the parent Oct4 gene, and has the potential of encoding an 80-amino acid product (designated as Oct4P1). Adenoviral expression of Oct4P1 in mesenchymal stem cells promotes their proliferation and inhibits their osteochondral differentiation. These dual effects of Oct4P1 are reminiscent of the stem cell regulatory function of the parent Oct4, and suggest that Oct4P1 may be a functional pseudogene or a novel Oct4-related gene with a unique function in stem cells.

  12. HDAC5 controls the functions of Foxp3(+) T-regulatory and CD8(+) T cells.

    PubMed

    Xiao, Haiyan; Jiao, Jing; Wang, Liqing; O'Brien, Shaun; Newick, Kheng; Wang, Liang-Chuan S; Falkensammer, Eva; Liu, Yujie; Han, Rongxiang; Kapoor, Veena; Hansen, Finn K; Kurz, Thomas; Hancock, Wayne W; Beier, Ulf H

    2016-05-15

    Histone/protein deacetylases (HDACs) are frequently upregulated in human malignancies and have therefore become therapeutic targets in cancer therapy. However, inhibiting certain HDAC isoforms can have protolerogenic effects on the immune system, which could make it easier for tumor cells to evade the host immune system. Therefore, a better understanding of how each HDAC isoform affects immune biology is needed to develop targeted cancer therapy. Here, we studied the immune phenotype of HDAC5(-/-) mice on a C57BL/6 background. While HDAC5(-/-) mice replicate at expected Mendelian ratios and do not develop overt autoimmune disease, their T-regulatory (Treg) cells show reduced suppressive function in vitro and in vivo. Likewise, CD4(+) T-cells lacking HDAC5 convert poorly to Tregs under appropriately polarizing conditions. To test if this attenuated Treg formation and suppressive function translated into improved anticancer immunity, we inoculated HDAC5(-/-) mice and littermate controls with a lung adenocarcinoma cell line. Cumulatively, lack of HDAC5 did not lead to better anticancer immunity. We found that CD8(+) T cells missing HDAC5 had a reduced ability to produce the cytokine, IFN-γ, in vitro and in vivo, which may offset the benefit of weakened Treg function and formation. Taken together, targeting HDAC5 weakens suppressive function and de-novo induction of Tregs, but also reduces the ability of CD8(+) T cells to produce IFN-γ. PMID:26704363

  13. APC Activation Restores Functional CD4+CD25+ Regulatory T Cells in NOD Mice that Can Prevent Diabetes Development

    PubMed Central

    Manirarora, Jean N.; Kosiewicz, Michele M.; Parnell, Sarah A.; Alard, Pascale

    2008-01-01

    Background Defects in APC and regulatory cells are associated with diabetes development in NOD mice. We have shown previously that NOD APC are not effective at stimulating CD4+CD25+ regulatory cell function in vitro. We hypothesize that failure of NOD APC to properly activate CD4+CD25+ regulatory cells in vivo could compromise their ability to control pathogenic cells, and activation of NOD APC could restore this defect, thereby preventing disease. Methodology/Principal Findings To test these hypotheses, we used the well-documented ability of complete Freund's adjuvant (CFA), an APC activator, to prevent disease in NOD mice. Phenotype and function of CD4+CD25+ regulatory cells from untreated and CFA-treated NOD mice were determined by FACS, and in vitro and in vivo assays. APC from these mice were also evaluated for their ability to activate regulatory cells in vitro. We have found that sick NOD CD4+CD25+ cells expressed Foxp3 at the same percentages, but decreased levels per cell, compared to young NOD or non-NOD controls. Treatment with CFA increased Foxp3 expression in NOD cells, and also increased the percentages of CD4+CD25+Foxp3+ cells infiltrating the pancreas compared to untreated NOD mice. Moreover, CD4+CD25+ cells from pancreatic LN of CFA-treated, but not untreated, NOD mice transferred protection from diabetes. Finally, APC isolated from CFA-treated mice increased Foxp3 and granzyme B expression as well as regulatory function by NOD CD4+CD25+ cells in vitro compared to APC from untreated NOD mice. Conclusions/Significance These data suggest that regulatory T cell function and ability to control pathogenic cells can be enhanced in NOD mice by activating NOD APC. PMID:19011680

  14. Dynamic Behavior and Function of Foxp3+ Regulatory T Cells in Tumor Bearing Host

    PubMed Central

    Qin, F Xiao-Feng

    2009-01-01

    Regulatory T cells (Tregs) expressing forkhead/winged-helix transcription factor Foxp3 represent a distinct lineage of lymphocytes which play a central role in protecting the host from autoimmune diseases. However, Tregs also pose a major problem to anti-tumor immunity. Growing body of evidence from both laboratory and clinical investigations has demonstrated that expansion and accumulation of these immunosuppressive cells correlates with advanced tumor growth and predicts poor disease prognosis. How tumor development subverts normal self-tolerance function of Tregs thereby thwarts host anti-tumor immunity remains elusive. This review will discuss our current knowledge in understanding the dynamics and plasticity of Foxp3+ Treg activation and induction in tumor bearing hosts and their interaction with various antigen presenting cells (APCs) in tumor microenvironment leading to the establishment of active local and systemic immune suppression. PMID:19254475

  15. Impairment of Regulatory T-Cell Function in Autoimmune Thyroid Disease

    PubMed Central

    Glick, Abigail B.; Wodzinski, Alaina; Fu, Pingfu

    2013-01-01

    Background Autoimmune thyroid disease (AITD) pathogenesis may result from a loss of immune tolerance to thyroid antigens. Regulatory T cells (Tregs) control immune responses, prevent excessive inflammation, and may be dysfunctional in AITD. We investigated the role of Tregs in Hashimoto's thyroiditis (HT) and Graves' disease (GD), complicated by Down syndrome (DS). Our goal was to identify differences in CD4+CD25high Treg function or number in patients with GD and HT, compared to healthy controls (HC). Methods Treg number was assessed by flow cytometric analysis in samples from 20 AITD patients (seven GD, 13 HT), nine HC, and seven individuals with DS, a genetic disorder associated with multiple autoimmune disorders including AITD. Treg function was assessed by the inhibition of proliferation (radioactive thymidine incorporation into DNA) of blood-derived T effector (Teff) cells by Tregs in a coculture. Various methods of stimulation were contrasted. Cytokine levels were determined in conditioned media from the co-cultures. Results No differences were found in the frequency of Tregs as a percentage of CD4+ cells between AITD and HC. AITD Tregs were less capable of inhibiting the proliferation of Teff cells when compared to HC; however, the impairment was dependent on the type of stimulation used. DS patients without AITD exhibited normal Treg function. We observed few differences in cytokine production between HC and AITD patients. Conclusions Tregs from AITD patients are partly dysfunctional, possibly explaining their autoimmunity. Future work will elucidate the diagnostic potential and pathophysiology of Tregs in AITD. PMID:23379353

  16. The alarmin IL-33 promotes regulatory T-cell function in the intestine.

    PubMed

    Schiering, Chris; Krausgruber, Thomas; Chomka, Agnieszka; Fröhlich, Anja; Adelmann, Krista; Wohlfert, Elizabeth A; Pott, Johanna; Griseri, Thibault; Bollrath, Julia; Hegazy, Ahmed N; Harrison, Oliver J; Owens, Benjamin M J; Löhning, Max; Belkaid, Yasmine; Fallon, Padraic G; Powrie, Fiona

    2014-09-25

    FOXP3(+) regulatory T cells (Treg cells) are abundant in the intestine, where they prevent dysregulated inflammatory responses to self and environmental stimuli. It is now appreciated that Treg cells acquire tissue-specific adaptations that facilitate their survival and function; however, key host factors controlling the Treg response in the intestine are poorly understood. The interleukin (IL)-1 family member IL-33 is constitutively expressed in epithelial cells at barrier sites, where it functions as an endogenous danger signal, or alarmin, in response to tissue damage. Recent studies in humans have described high levels of IL-33 in inflamed lesions of inflammatory bowel disease patients, suggesting a role for this cytokine in disease pathogenesis. In the intestine, both protective and pathological roles for IL-33 have been described in murine models of acute colitis, but its contribution to chronic inflammation remains ill defined. Here we show in mice that the IL-33 receptor ST2 is preferentially expressed on colonic Treg cells, where it promotes Treg function and adaptation to the inflammatory environment. IL-33 signalling in T cells stimulates Treg responses in several ways. First, it enhances transforming growth factor (TGF)-β1-mediated differentiation of Treg cells and, second, it provides a necessary signal for Treg-cell accumulation and maintenance in inflamed tissues. Strikingly, IL-23, a key pro-inflammatory cytokine in the pathogenesis of inflammatory bowel disease, restrained Treg responses through inhibition of IL-33 responsiveness. These results demonstrate a hitherto unrecognized link between an endogenous mediator of tissue damage and a major anti-inflammatory pathway, and suggest that the balance between IL-33 and IL-23 may be a key controller of intestinal immune responses. PMID:25043027

  17. Impaired function of regulatory T-cells in patients with chronic obstructive pulmonary disease (COPD).

    PubMed

    Tan, Dino B A; Fernandez, Sonia; Price, Patricia; French, Martyn A; Thompson, Philip J; Moodley, Yuben P

    2014-12-01

    Anti-inflammatory pathways affecting chronic obstructive pulmonary disease (COPD) are poorly understood. Regulatory T-cells (Tregs) are important negative regulators of T-cell activity and hence were investigated in COPD patients in this study. We hypothesised that functional defects in Tregs may promote increased inflammation contributing to the pathogenesis of COPD. Peripheral blood mononuclear cells (PBMC) were isolated from patients with stable COPD and age-matched non-smoking controls. Treg-mediated suppression of memory non-Treg (Foxp3(-)CD45RO(+)) CD4(+) T-cell activation was analysed by comparing PBMC responses to staphylococcal enterotoxin-B (SEB) pre- and post-depletion of Tregs (CD25(+)CD127(low)CD4(+) T-cells) by fluorescence-activated cell sorting (FACS). Activation of T-cells was assessed by HLA-DR expression. Levels of secreted cytokines were measured by ELISA. Depletion of Tregs increased SEB-induced activation of Foxp3(-)CD45RO(+) CD4(+) T-cells in samples from 15/15 healthy controls (demonstrating Treg-mediated suppression) and 9/14 COPD patients (Fisher's test, p=0.017). A screen of clinical data associated a failure of Treg-mediated suppression in the remaining five COPD patients with a higher body mass index (BMI) (33-38 kg/m(2)) compared to patients with unimpaired Treg function (20-32 kg/m(2)). In conclusion, we demonstrate impaired Treg-mediated suppression of CD4(+) T-cell activation in a subset of COPD patients, all of whom had high BMI. Obesity and/or perturbed homeostasis of Treg subsets may explain this defect and therefore contribute to increased inflammation observed in COPD. PMID:25097153

  18. 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

  19. Reduced Numbers and Impaired Function of Regulatory T Cells in Peripheral Blood of Ischemic Stroke Patients.

    PubMed

    Ruhnau, Johanna; Schulze, Juliane; von Sarnowski, Bettina; Heinrich, Marie; Langner, Sönke; Pötschke, Christian; Wilden, Anika; Kessler, Christof; Bröker, Barbara M; Vogelgesang, Antje; Dressel, Alexander

    2016-01-01

    Background and Purpose. Regulatory T cells (Tregs) have been suggested to modulate stroke-induced immune responses. However, analyses of Tregs in patients and in experimental stroke have yielded contradictory findings. We performed the current study to assess the regulation and function of Tregs in peripheral blood of stroke patients. Age dependent expression of CD39 on Tregs was quantified in mice and men. Methods. Total FoxP3(+) Tregs and CD39(+)FoxP3(+) Tregs were quantified by flow cytometry in controls and stroke patients on admission and on days 1, 3, 5, and 7 thereafter. Treg function was assessed by quantifying the inhibition of activation-induced expression of CD69 and CD154 on T effector cells (Teffs). Results. Total Tregs accounted for 5.0% of CD4(+) T cells in controls and <2.8% in stroke patients on admission. They remained below control values until day 7. CD39(+) Tregs were most strongly reduced in stroke patients. On day 3 the Treg-mediated inhibition of CD154 upregulation on CD4(+) Teff was impaired in stroke patients. CD39 expression on Treg increased with age in peripheral blood of mice and men. Conclusion. We demonstrate a loss of active FoxP3(+)CD39(+) Tregs from stroke patient's peripheral blood. The suppressive Treg function of remaining Tregs is impaired after stroke. PMID:27073295

  20. Reduced Numbers and Impaired Function of Regulatory T Cells in Peripheral Blood of Ischemic Stroke Patients

    PubMed Central

    Ruhnau, Johanna; Schulze, Juliane; von Sarnowski, Bettina; Heinrich, Marie; Langner, Sönke; Wilden, Anika; Kessler, Christof; Bröker, Barbara M.

    2016-01-01

    Background and Purpose. Regulatory T cells (Tregs) have been suggested to modulate stroke-induced immune responses. However, analyses of Tregs in patients and in experimental stroke have yielded contradictory findings. We performed the current study to assess the regulation and function of Tregs in peripheral blood of stroke patients. Age dependent expression of CD39 on Tregs was quantified in mice and men. Methods. Total FoxP3+ Tregs and CD39+FoxP3+ Tregs were quantified by flow cytometry in controls and stroke patients on admission and on days 1, 3, 5, and 7 thereafter. Treg function was assessed by quantifying the inhibition of activation-induced expression of CD69 and CD154 on T effector cells (Teffs). Results. Total Tregs accounted for 5.0% of CD4+ T cells in controls and <2.8% in stroke patients on admission. They remained below control values until day 7. CD39+ Tregs were most strongly reduced in stroke patients. On day 3 the Treg-mediated inhibition of CD154 upregulation on CD4+ Teff was impaired in stroke patients. CD39 expression on Treg increased with age in peripheral blood of mice and men. Conclusion. We demonstrate a loss of active FoxP3+CD39+ Tregs from stroke patient's peripheral blood. The suppressive Treg function of remaining Tregs is impaired after stroke. PMID:27073295

  1. Ionizing Radiation Selectively Reduces Skin Regulatory T Cells and Alters Immune Function

    PubMed Central

    Zhou, Yu; Ni, Houping; Balint, Klara; Sanzari, Jenine K.; Dentchev, Tzvete; Diffenderfer, Eric S.; Wilson, Jolaine M.; Cengel, Keith A.; Weissman, Drew

    2014-01-01

    The skin serves multiple functions that are critical for life. The protection from pathogens is achieved by a complicated interaction between aggressive effectors and controlling functions that limit damage. Inhomogeneous radiation with limited penetration is used in certain types of therapeutics and is experienced with exposure to solar particle events outside the protection of the Earth’s magnetic field. This study explores the effect of ionizing radiation on skin immune function. We demonstrate that radiation, both homogeneous and inhomogeneous, induces inflammation with resultant specific loss of regulatory T cells from the skin. This results in a hyper-responsive state with increased delayed type hypersensitivity in vivo and CD4+ T cell proliferation in vitro. The effects of inhomogeneous radiation to the skin of astronauts or as part of a therapeutic approach could result in an unexpected enhancement in skin immune function. The effects of this need to be considered in the design of radiation therapy protocols and in the development of countermeasures for extended space travel. PMID:24959865

  2. Successful expansion of functional and stable regulatory T cells for immunotherapy in liver transplantation

    PubMed Central

    Safinia, Niloufar; Vaikunthanathan, Trishan; Fraser, Henrieta; Thirkell, Sarah; Lowe, Katie; Blackmore, Laura; Whitehouse, Gavin; Martinez-Llordella, Marc; Jassem, Wayel; Sanchez-Fueyo, Alberto; Lechler, Robert I.; Lombardi, Giovanna

    2016-01-01

    Strategies to prevent organ transplant rejection whilst minimizing long-term immunosuppression are currently under intense investigation with regulatory T cells (Tregs) nearing clinical application. The clinical trial, ThRIL, recently commenced at King's College London, proposes to use Treg cell therapy to induce tolerance in liver transplant recipients, the success of which has the potential to revolutionize the management of these patients and enable a future of drug-free transplants. This is the first report of the manufacture of clinical grade Tregs from prospective liver transplant recipients via a CliniMACS-based GMP isolation technique and expanded using anti-CD3/CD28 beads, IL-2 and rapamycin. We report the enrichment of a pure, stable population of Tregs (>95% CD4+CD25+FOXP3+), reaching adequate numbers for their clinical application. Our protocol proved successful in, influencing the expansion of superior functional Tregs, as compared to freshly isolated cells, whilst also preventing their conversion to Th17 cells under pro-inflammatory conditions. We conclude with the manufacture of the final Treg product in the clinical research facility (CRF), a prerequisite for the clinical application of these cells. The data presented in this manuscript together with the much-anticipated clinical results from ThRIL, will undoubtedly inform the improved management of the liver transplant recipient. PMID:26788992

  3. Identifying Functional Gene Regulatory Network Phenotypes Underlying Single Cell Transcriptional Variability

    PubMed Central

    Park, James; Ogunnaike, Babatunde; Schwaber, James; Vadigepalli, Rajanikanth

    2014-01-01

    Summary/abstract Recent analysis of single-cell transcriptomic data has revealed a surprising organization of the transcriptional variability pervasive across individual neurons. In response to distinct combinations of synaptic input-type, a new organization of neuronal subtypes emerged based on transcriptional states that were aligned along a gradient of correlated gene expression. Individual neurons traverse across these transcriptional states in response to cellular inputs. However, the regulatory network interactions driving these changes remain unclear. Here we present a novel fuzzy logic-based approach to infer quantitative gene regulatory network models from highly variable single-cell gene expression data. Our approach involves developing an a priori regulatory network that is then trained against in vivo single-cell gene expression data in order to identify causal gene interactions and corresponding quantitative model parameters. Simulations of the inferred gene regulatory network response to experimentally observed stimuli levels mirrored the pattern and quantitative range of gene expression across individual neurons remarkably well. In addition, the network identification results revealed that distinct regulatory interactions, coupled with differences in the regulatory network stimuli, drive the variable gene expression patterns observed across the neuronal subtypes. We also identified a key difference between the neuronal subtype-specific networks with respect to negative feedback regulation, with the catecholaminergic subtype network lacking such interactions. Furthermore, by varying regulatory network stimuli over a wide range, we identified several cases in which divergent neuronal subtypes could be driven towards similar transcriptional states by distinct stimuli operating on subtype-specific regulatory networks. Based on these results, we conclude that heterogeneous single-cell gene expression profiles should be interpreted through a regulatory

  4. T follicular regulatory cells.

    PubMed

    Sage, Peter T; Sharpe, Arlene H

    2016-05-01

    Pathogen exposure elicits production of high-affinity antibodies stimulated by T follicular helper (Tfh) cells in the germinal center reaction. Tfh cells provide both costimulation and stimulatory cytokines to B cells to facilitate affinity maturation, class switch recombination, and plasma cell differentiation within the germinal center. Under normal circumstances, the germinal center reaction results in antibodies that precisely target foreign pathogens while limiting autoimmunity and excessive inflammation. In order to have this degree of control, the immune system ensures Tfh-mediated B-cell help is regulated locally in the germinal center. The recently identified T follicular regulatory (Tfr) cell subset can migrate to the germinal center and inhibit Tfh-mediated B-cell activation and antibody production. Although many aspects of Tfr cell biology are still unclear, recent data have begun to delineate the specialized roles of Tfr cells in controlling the germinal center reaction. Here we discuss the current understanding of Tfr-cell differentiation and function and how this knowledge is providing new insights into the dynamic regulation of germinal centers, and suggesting more efficacious vaccine strategies and ways to treat antibody-mediated diseases. PMID:27088919

  5. Functional and genomic analyses of FOXP3-transduced Jurkat-T cells as regulatory T (Treg)-like cells

    SciTech Connect

    Kim, Joon-Young Kim, Han-Jong; Hurt, Elaine M.; Chen, Xin; Howard, O.M. Zack; Farrar, William L.

    2007-10-12

    FOXP3, a forkhead transcription factor is essential for the development and function of CD4{sup +}CD25{sup +} regulatory T cells (Tregs). In contrast to conversion of murine naive T cells to Tregs by transduction of Foxp3, it is controversial whether ectopic expression of FOXP3 in human CD4{sup +} T cells is sufficient for acquisition of suppressive activity. Here, we show that retroviral transduction of FOXP3 induces a Treg phenotype in human leukemic CD4{sup +} Jurkat-T cells, evidenced by increased expression of Treg-associated cell surface markers as well as inhibition of cytokine production. Furthermore, FOXP3-transduced Jurkat-T cells suppress the proliferation of human CD4{sup +}CD25{sup -} T cells. Additionally, DNA microarray analysis identifies Treg-related genes regulated by FOXP3. Our study demonstrates that enforced expression of FOXP3 confers Treg-like properties on Jurkat-T cells, which can be a convenient and efficient Treg-like cell model for further study to identify Treg cell surface markers and target genes regulated by FOXP3.

  6. Toll-like receptor 2-mediated modulation of growth and functions of regulatory T cells by oral streptococci.

    PubMed

    Saeki, A; Segawa, T; Abe, T; Sugiyama, M; Arimoto, T; Hara, H; Hasebe, A; Ohtani, M; Tanizume, N; Ohuchi, M; Kataoka, H; Kawanami, M; Yokoyama, A; Shibata, K

    2013-08-01

    This study was designed to determine whether oral streptococci modulate the growth and functions of regulatory T cells. Heat-killed cells of wild-type strains of Streptococcus gordonii and Streptococcus mutans induced the Toll-like receptor 2 (TLR2) -mediated nuclear factor-κB (NF-κB) activation, but their lipoprotein-deficient strains did not. Stimulation with these streptococci resulted in a significant increase in the frequency of CD4(+) CD25(+) Foxp3(+) regulatory T cells in splenocytes derived from both TLR2(+/+) and TLR2(-/-) mice, but the level of increase in TLR2(+/+) splenocytes was stronger than that in TLR2(-/-) splenocytes. Both strains of S. gordonii enhanced the proliferation of CD4(+) CD25(+) Foxp3(+) regulatory T cells isolated from TLR2(+/+) mice at the same level as those from TLR2(-/-) mice in an interleukin-2-independent manner. However, wild-type and lipoprotein-deficient strains of both streptococci did not enhance the suppressive activity of the isolated regulatory T cells in vitro, but rather inhibited it. TLR ligands also inhibited the suppressive activity of the regulatory T cells. Inhibition of the suppressive activity was recovered by the addition of anti-IL-6 antibody. Pretreatment of antigen-presenting cells with the NF-κB inhibitor BAY11-7082 enhanced the suppressive activity of the regulatory T cells. These results suggested that interleukin-6 produced by antigen-presenting cells inhibits the suppressive activity of the regulatory T cells. Wild-type strain, but not lipoprotein-deficient strain, of S. gordonii reduced the frequency of CD4(+)  CD25(+)  Foxp3(+) regulatory T cells in the acute infection model, whereas both strains of S. gordonii increased it in the chronic infection model mice. Hence, this study suggests that oral streptococci are capable of modulating the growth and functions of regulatory T cells in vitro and in vivo. PMID:23413817

  7. Structure-function analysis of the beta regulatory subunit of protein kinase CK2 by targeting embryonic stem cell.

    PubMed

    Ziercher, Léa; Filhol, Odile; Laudet, Béatrice; Prudent, Renaud; Cochet, Claude; Buchou, Thierry

    2011-10-01

    Programs that govern stem cell maintenance and pluripotency are dependent on extracellular factors and of intrinsic cell modulators. Embryonic stem (ES) cells with a specific depletion of the gene encoding the regulatory subunit of protein kinase CK2 (CK2β) revealed a viability defect. However, analysis of CK2β functions along the neural lineage established CK2β as a positive regulator for neural stem/progenitor cell (NSC) proliferation and multipotency. By using an in vitro genetic conditional approach, we demonstrate in this work that specific domains of CK2β involved in the regulatory function towards CK2 catalytic subunits are crucial structural determinants for ES cell homeostasis. PMID:21861102

  8. Homeostasis and function of regulatory T cells (Tregs) in vivo: lessons from TCR-transgenic Tregs

    PubMed Central

    Attridge, Kesley; Walker, Lucy S K

    2014-01-01

    The identification of CD25 and subsequently Forkhead box protein 3 (Foxp3) as markers for regulatory T cells (Tregs) has revolutionized our ability to explore this population experimentally. In a similar vein, our understanding of antigen-specific Treg responses in vivo owes much to the fortuitous generation of T-cell receptor (TCR)-transgenic Tregs. This has permitted tracking of Tregs with a defined specificity in vivo, facilitating analysis of how encounter with cognate antigen shapes Treg homeostasis and function. Here, we review the key lessons learned from a decade of analysis of TCR-transgenic Tregs and set this in the broader context of general progress in the field. Use of TCR-transgenic Tregs has led to an appreciation that Tregs are a highly dynamic proliferative population in vivo, rather than an anergic population as they were initially portrayed. It is now clear that Treg homeostasis is positively regulated by encounter with self-antigen expressed on peripheral tissues, which is likely to be relevant to the phenomenon of peripheral repertoire reshaping that has been described for Tregs and the observation that the Treg TCR specificities vary by anatomical location. Substantial evidence has also accumulated to support the role of CD28 costimulation and interleukin-2 in Treg homeostasis. The availability of TCR-transgenic Tregs has enabled analysis of Treg populations that are sufficient or deficient in particular genes, without the comparison being confounded by repertoire alterations. This approach has yielded insights into genes required for Treg function in vivo, with particular progress being made on the role of ctla-4 in this context. As the prospect of manipulating Treg populations in the clinic becomes reality, a full appreciation of the rules governing their homeostasis will prove increasingly important. PMID:24712457

  9. 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

  10. Decreased Numbers of Blood Dendritic Cells and Defective Function of Regulatory T Cells in Antineutrophil Cytoplasmic Antibody-Associated Vasculitis

    PubMed Central

    Rimbert, Marie; Hamidou, Mohamed; Braudeau, Cécile; Puéchal, Xavier; Teixeira, Luis; Caillon, Hélène; Néel, Antoine; Audrain, Marie; Guillevin, Loic; Josien, Régis

    2011-01-01

    Background Dendritic cells (DC) and regulatory cells (Treg) play pivotal roles in controlling both normal and autoimmune adaptive immune responses. DC are the main antigen-presenting cells to T cells, and they also control Treg functions. In this study, we examined the frequency and phenotype of DC subsets, and the frequency and function of Treg from patients with ANCA-associated vasculitis (AAV). Methodology/Principal Findings Blood samples from 19 untreated patients with AAV during flares and before any immunosuppressive treatment were analyzed, along with 15 AAV patients in remission and 18 age-matched healthy controls. DC and Treg numbers, and phenotypes were assessed by flow cytometry, and in vitro suppressive function of Treg was determined by co-culture assay. When compared to healthy volunteers, absolute numbers of conventional and plasmacytoid DC were decreased in AAV patients. During the acute phase this decrease was significantly more pronounced and was associated with an increased DC expression of CD62L. Absolute numbers of Treg (CD4+CD25highCD127low/− Tcells) were moderately decreased in patients. FOXP3 and CD39 were expressed at similar levels on Treg from patients as compared to controls. The suppressive function of Treg from AAV patients was dramatically decreased as compared to controls, and this defect was more pronounced during flares than remission. This Treg functional deficiency occurred in the absence of obvious Th17 deviation. Conclusion In conclusion, these data show that AAV flares are associated with both a decrease number and altered phenotype of circulating DC and point to a role for Treg functional deficiency in the pathogenesis of AAV. PMID:21494636

  11. YY1 inhibits differentiation and function of regulatory T cells by blocking Foxp3 expression and activity

    PubMed Central

    Hwang, Soo Seok; Jang, Sung Woong; Kim, Min Kyung; Kim, Lark Kyun; Kim, Bong-Sung; Kim, Hyeong Su; Kim, Kiwan; Lee, Wonyong; Flavell, Richard A.; Lee, Gap Ryol

    2016-01-01

    Regulatory T (Treg) cells are essential for maintenance of immune homeostasis. Foxp3 is the key transcription factor for Treg-cell differentiation and function; however, molecular mechanisms for its negative regulation are poorly understood. Here we show that YY1 expression is lower in Treg cells than Tconv cells, and its overexpression causes a marked reduction of Foxp3 expression and abrogation of suppressive function of Treg cells. YY1 is increased in Treg cells under inflammatory conditions with concomitant decrease of suppressor activity in dextran sulfate-induced colitis model. YY1 inhibits Smad3/4 binding to and chromatin remodelling of the Foxp3 locus. In addition, YY1 interrupts Foxp3-dependent target gene expression by physically interacting with Foxp3 and by directly binding to the Foxp3 target genes. Thus, YY1 inhibits differentiation and function of Treg cells by blocking Foxp3. PMID:26892542

  12. YY1 inhibits differentiation and function of regulatory T cells by blocking Foxp3 expression and activity.

    PubMed

    Hwang, Soo Seok; Jang, Sung Woong; Kim, Min Kyung; Kim, Lark Kyun; Kim, Bong-Sung; Kim, Hyeong Su; Kim, Kiwan; Lee, Wonyong; Flavell, Richard A; Lee, Gap Ryol

    2016-01-01

    Regulatory T (T(reg)) cells are essential for maintenance of immune homeostasis. Foxp3 is the key transcription factor for T(reg)-cell differentiation and function; however, molecular mechanisms for its negative regulation are poorly understood. Here we show that YY1 expression is lower in T(reg) cells than T(conv) cells, and its overexpression causes a marked reduction of Foxp3 expression and abrogation of suppressive function of Treg cells. YY1 is increased in T(reg) cells under inflammatory conditions with concomitant decrease of suppressor activity in dextran sulfate-induced colitis model. YY1 inhibits Smad3/4 binding to and chromatin remodelling of the Foxp3 locus. In addition, YY1 interrupts Foxp3-dependent target gene expression by physically interacting with Foxp3 and by directly binding to the Foxp3 target genes. Thus, YY1 inhibits differentiation and function of T(reg) cells by blocking Foxp3. PMID:26892542

  13. TGF-β1 maintains suppressor function and Foxp3 expression in CD4+CD25+ regulatory T cells

    PubMed Central

    Marie, Julien C.; Letterio, John J.; Gavin, Marc; Rudensky, Alexander Y.

    2005-01-01

    Transforming growth factor (TGF)-β1 is a major pluripotential cytokine with a pronounced immunosuppressive effect and its deficiency results in lethal autoimmunity in mice. However, mechanisms of its immunosuppressive action are not completely understood. Here, we report that TGF-β1 supports the maintenance of Foxp3 expression, regulatory function, and homeostasis in peripheral CD4+CD25+ regulatory T (T reg) cells, but is not required for their thymic development. We found that in 8–10-d-old TGF-β1–deficient mice, peripheral, but not thymic, T reg cells are significantly reduced in numbers. Moreover, our experiments suggest that a defect in TGF-β–mediated signaling in T reg cells is associated with a decrease in Foxp3 expression and suppressor activity. Thus, our results establish an essential link between TGF-β1 signaling in peripheral T reg cells and T reg cell maintenance in vivo. PMID:15809351

  14. Phenotypic and Functional Analysis of Activated Regulatory T Cells Isolated from Chronic Lymphocytic Choriomeningitis Virus-infected Mice.

    PubMed

    Park, Hyo Jin; Oh, Ji Hoon; Ha, Sang-Jun

    2016-01-01

    Regulatory T (Treg) cells, which express Foxp3 as a transcription factor, are subsets of CD4(+) T cells. Treg cells play crucial roles in immune tolerance and homeostasis maintenance by regulating the immune response. The primary role of Treg cells is to suppress the proliferation of effector T (Teff) cells and the production of cytokines such as IFN-γ, TNF-α, and IL-2. It has been demonstrated that Treg cells' ability to inhibit the function of Teff cells is enhanced during persistent pathogen infection and cancer development. To clarify the function of Treg cells under resting or inflamed conditions, a variety of in vitro suppression assays using mouse or human Treg cells have been devised. The main aim of this study is to develop a method to compare the differences in phenotype and suppressive function between resting and activated Treg cells. To isolate activated Treg cells, mice were infected with lymphocytic choriomeningitis virus (LCMV) clone 13 (CL13), a chronic strain of LCMV. Treg cells isolated from the spleen of LCMV CL13-infected mice exhibited both the activated phenotype and enhanced suppressive activity compared with resting Treg cells isolated from naïve mice. Here, we describe the basic protocol for ex vivo phenotype analysis to distinguish activated Treg cells from resting Treg cells. Furthermore, we describe a protocol for the measurement of the suppressive activity of fully activated Treg cells. PMID:27404802

  15. Regulatory IgDhi B Cells Suppress T Cell Function via IL-10 and PD-L1 during Progressive Visceral Leishmaniasis.

    PubMed

    Schaut, Robert G; Lamb, Ian M; Toepp, Angela J; Scott, Benjamin; Mendes-Aguiar, Carolina O; Coutinho, Jose F V; Jeronimo, Selma M B; Wilson, Mary E; Harty, John T; Waldschmidt, Thomas J; Petersen, Christine A

    2016-05-15

    During visceral leishmaniasis (VL), Th1-based inflammation is induced to control intracellular parasites. Inflammation-based pathology was shown to be dampened by IL-10 and eventual programmed death 1-mediated T cell exhaustion. Cell type(s) responsible for the initiation of T cell-produced IL-10 during VL are unknown. CD19(+), CD5(-), CD1d(-), IgD(hi) regulatory B cells from healthy controls produced IL-10 in the absence of infection or stimulation, in contrast to IgD(lo/neg) B cells. IgD(hi) B cells may have a de novo versus induced regulatory program. The population of IgD(hi) B cells increased 3-fold as VL progressed. B cells from VL dogs were necessary and sufficient to suppress Th1 cell effector function. IgD(hi) B cells induced IL-10 production by T cells and IgD(lo) B cells. Blockage of B cell-specific PD-L1 restored Th1 responses. IgD(hi) regulatory B cells represent a novel regulatory B cell that may precipitate T cell exhaustion during VL. PMID:27076677

  16. 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

    2015-03-01

    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 (≥30 ng/mL), 55 were insufficient (20-29 ng/mL) and 80 were deficient (≤19 ng/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

  17. 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

  18. The lysophosphatidylserine receptor GPR174 constrains regulatory T cell development and function

    PubMed Central

    Barnes, Michael J.; Li, Chien-Ming; Xu, Ying; An, Jinping; Huang, Yong

    2015-01-01

    Regulatory T cell (T reg cell) numbers and activities are tightly calibrated to maintain immune homeostasis, but the mechanisms involved are incompletely defined. Here, we report that the lysophosphatidylserine (LysoPS) receptor GPR174 is abundantly expressed in developing and mature T reg cells. In mice that lacked this X-linked gene, T reg cell generation in the thymus was intrinsically favored, and a higher fraction of peripheral T reg cells expressed CD103. LysoPS could act in vitro via GPR174 to suppress T cell proliferation and T reg cell generation. In vivo, LysoPS was detected in lymphoid organ and spinal cord tissues and was abundant in the colon. Gpr174−/Y mice were less susceptible to experimental autoimmune encephalomyelitis than wild-type mice, and GPR174 deficiency in T reg cells contributed to this phenotype. This study provides evidence that a bioactive lipid, LysoPS, negatively influences T reg cell accumulation and activity through GPR174. As such, GPR174 antagonists might have therapeutic potential for promoting immune regulation in the context of autoimmune disease. PMID:26077720

  19. The lysophosphatidylserine receptor GPR174 constrains regulatory T cell development and function.

    PubMed

    Barnes, Michael J; Li, Chien-Ming; Xu, Ying; An, Jinping; Huang, Yong; Cyster, Jason G

    2015-06-29

    Regulatory T cell (T reg cell) numbers and activities are tightly calibrated to maintain immune homeostasis, but the mechanisms involved are incompletely defined. Here, we report that the lysophosphatidylserine (LysoPS) receptor GPR174 is abundantly expressed in developing and mature T reg cells. In mice that lacked this X-linked gene, T reg cell generation in the thymus was intrinsically favored, and a higher fraction of peripheral T reg cells expressed CD103. LysoPS could act in vitro via GPR174 to suppress T cell proliferation and T reg cell generation. In vivo, LysoPS was detected in lymphoid organ and spinal cord tissues and was abundant in the colon. Gpr174(-/Y) mice were less susceptible to experimental autoimmune encephalomyelitis than wild-type mice, and GPR174 deficiency in T reg cells contributed to this phenotype. This study provides evidence that a bioactive lipid, LysoPS, negatively influences T reg cell accumulation and activity through GPR174. As such, GPR174 antagonists might have therapeutic potential for promoting immune regulation in the context of autoimmune disease. PMID:26077720

  20. Early-life compartmentalization of human T cell differentiation and regulatory function in mucosal and lymphoid tissues.

    PubMed

    Thome, Joseph J C; Bickham, Kara L; Ohmura, Yoshiaki; Kubota, Masaru; Matsuoka, Nobuhide; Gordon, Claire; Granot, Tomer; Griesemer, Adam; Lerner, Harvey; Kato, Tomoaki; Farber, Donna L

    2016-01-01

    It is unclear how the immune response in early life becomes appropriately stimulated to provide protection while also avoiding excessive activation as a result of diverse new antigens. T cells are integral to adaptive immunity; mouse studies indicate that tissue localization of T cell subsets is important for both protective immunity and immunoregulation. In humans, however, the early development and function of T cells in tissues remain unexplored. We present here an analysis of lymphoid and mucosal tissue T cells derived from pediatric organ donors in the first two years of life, as compared to adult organ donors, revealing early compartmentalization of T cell differentiation and regulation. Whereas adult tissues contain a predominance of memory T cells, in pediatric blood and tissues the main subset consists of naive recent thymic emigrants, with effector memory T cells (T(EM)) found only in the lungs and small intestine. Additionally, regulatory T (T(reg)) cells comprise a high proportion (30-40%) of CD4(+) T cells in pediatric tissues but are present at much lower frequencies (1-10%) in adult tissues. Pediatric tissue T(reg) cells suppress endogenous T cell activation, and early T cell functionality is confined to the mucosal sites that have the lowest T(reg):T(EM) cell ratios, which suggests control in situ of immune responses in early life. PMID:26657141

  1. Altered connexin 43 expression underlies age-dependent decrease of regulatory T cell suppressor function in nonobese diabetic mice.

    PubMed

    Kuczma, Michal; Wang, Cong-Yi; Ignatowicz, Leszek; Gourdie, Robert; Kraj, Piotr

    2015-06-01

    Type 1 diabetes is one of the most extensively studied autoimmune diseases, but the cellular and molecular mechanisms leading to T cell-mediated destruction of insulin-producing β cells are still not well understood. In this study, we show that regulatory T cells (T(regs)) in NOD mice undergo age-dependent loss of suppressor functions exacerbated by the decreased ability of activated effector T cells to upregulate Foxp3 and generate T(regs) in the peripheral organs. This age-dependent loss is associated with reduced intercellular communication mediated by gap junctions, which is caused by impaired upregulation and decreased expression of connexin 43. Regulatory functions can be corrected, even in T cells isolated from aged, diabetic mice, by a synergistic activity of retinoic acid, TGF-β, and IL-2, which enhance connexin 43 and Foxp3 expression in T(regs) and restore the ability of conventional CD4(+) T cells to upregulate Foxp3 and generate peripherally derived T(regs). Moreover, we demonstrate that suppression mediated by T(regs) from diabetic mice is enhanced by a novel reagent, which facilitates gap junction aggregation. In summary, our report identifies gap junction-mediated intercellular communication as an important component of the T(reg) suppression mechanism compromised in NOD mice and suggests how T(reg) mediated immune regulation can be improved. PMID:25911751

  2. CCR10 regulates balanced maintenance and function of resident regulatory and effector T cells to promote immune homeostasis in skin

    PubMed Central

    Xia, Mingcan; Hu, Shaomin; Fu, Yaoyao; Jin, Wensen; Yi, Qiyi; Matsui, Yurika; Yang, Jie; McDowell, Mary Ann; Sarkar, Surojit; Kalia, Vandana; Xiong, Na

    2014-01-01

    Background CCR10 and CCL27 are the most skin-specific chemokine receptor/ligand pair implicated in skin allergy and inflammatory diseases including atopic dermatitis and psoriasis. This pair is thought to regulate migration and/or maintenance of skin T cells and suggested as therapeutic targets for treatment of skin diseases. However, the functional importance of CCR10/CCL27 in vivo remains elusive. Objective We sought to determine expression and function of CCR10 in different subsets of skin T cells under both homeostatic and inflammatory conditions to gain a mechanistic insight into potential roles of CCR10 during skin inflammation. Methods Using heterozygous and homozygous CCR10-knockout/EGFP-knockin mice, we assessed expression of CCR10 on regulatory and effector T cells of healthy and inflamed skin induced by chemicals, pathogens and auto-reactive T cells. In addition, we assessed the effect of CCR10-knockout on the maintenance and functions of different T cells and inflammatory status in the skin during different phases of the immune response. Results CCR10 expression is preferentially induced on memory-like skin-resident T cells and their progenitors for their maintenance in homeostatic skin but not expressed on most skin-infiltrating effector T cells during inflammation. In CCR10-knockout mice, the imbalanced presence and dysregulated function of resident regulatory and effector T cells result in over-reactive and prolonged innate and memory responses in the skin, leading to increased clearance of Leishmamia infection in the skin. Conclusion CCR10 is a critical regulator of skin immune homeostasis. PMID:24767879

  3. Generation, cryopreservation, function and in vivo persistence of ex vivo expanded cynomolgus monkey regulatory T cells.

    PubMed

    Guo, Hao; Zhang, Hong; Lu, Lien; Ezzelarab, Mohamed B; Thomson, Angus W

    2015-05-01

    We expanded flow-sorted Foxp3(+) cynomolgus monkey regulatory T cells (Treg) >1000-fold after three rounds of stimulation with anti-CD3 mAb-loaded artificial antigen-presenting cells, rapamycin (first round only) and IL-2. The expanded Treg maintained their expression of Treg signature markers, CD25, CD27, CD39, Foxp3, Helios, and CTLA-4, as well as CXCR3, which plays an important role in T cell migration to sites of inflammation. In contrast to expanded effector T cells (Teff), expanded Treg produced minimal IFN-γ and IL-17 and no IL-2 and potently suppressed Teff proliferation. Following cryopreservation, thawed Treg were less viable than their freshly-expanded counterparts, although no significant changes in phenotype or suppressive ability were observed. Additional rounds of stimulation/expansion restored maximal viability. Furthermore, adoptively-transferred autologous Treg expanded from cryopreserved second round stocks and labeled with CFSE or VPD450 were detected in blood and secondary lymphoid tissues of normal or immunosuppressed recipients at least two months after their systemic infusion. PMID:25732601

  4. Loss- and Gain-of-Function Approaches Indicate a Dual Role Exerted by Regulatory T Cells in Pulmonary Paracoccidioidomycosis

    PubMed Central

    Bazan, Silvia B.; Costa, Tania A.; de Araújo, Eliseu Frank; Feriotti, Claudia; Loures, Flávio V.; Pretel, Fernando D.; Calich, Vera L. G.

    2015-01-01

    Paracoccidioidomycosis (PCM), is a pulmonary fungal disease whose severity depends on the adequate development of T cell immunity. Although regulatory T (Treg) cells were shown to control immunity against PCM, deleterious or protective effects were described in different experimental settings. To clarify the function of Treg cells in pulmonary PCM, loss-and gain-of-function approaches were performed with Foxp3GFP knock-in mice and immunodeficient Rag1-/- mice, respectively, which were intratracheally infected with 106 yeast cells. The activity of Foxp3-expressing Treg cells in pulmonary PCM was determined in Foxp3GFP transgenic mice. First, it was verified that natural Treg cells migrate to the lungs of infected mice, where they become activated. Depletion of Treg cells led to reduced fungal load, diminished pathogen dissemination and increased Th1/Th2/Th17 immunity. Further, adoptive transfer of diverse T cell subsets to Rag1-/- mice subsequently infected by the pulmonary route demonstrated that isolated CD4+Foxp3+ Treg cells were able to confer some degree of immunoprotection and that CD4+Foxp3- T cells alone reduced fungal growth and enhanced T cell immunity, but induced vigorous inflammatory reactions in the lungs. Nevertheless, transfer of Treg cells combined with CD4+Foxp3- T cells generated more efficient and balanced immune Th1/Th2/Th17 responses able to limit pathogen growth and excessive tissue inflammation, leading to regressive disease and increased survival rates. Altogether, these loss- and gain-of-function approaches allow us to clearly demonstrate the dual role of Treg cells in pulmonary PCM, their deleterious effects by impairing T cell immunity and pathogen eradication, and their protective role by suppressing exacerbated tissue inflammation. PMID:26512987

  5. Blockade of CTLA-4 on CD4+CD25+ regulatory T cells abrogates their function in vivo.

    PubMed

    Read, Simon; Greenwald, Rebecca; Izcue, Ana; Robinson, Nicholas; Mandelbrot, Didier; Francisco, Loise; Sharpe, Arlene H; Powrie, Fiona

    2006-10-01

    Naturally occurring CD4+ regulatory T cells (T(R)) that express CD25 and the transcription factor FoxP3 play a key role in immune homeostasis, preventing immune pathological responses to self and foreign Ags. CTLA-4 is expressed by a high percentage of these cells, and is often considered as a marker for T(R) in experimental and clinical analysis. However, it has not yet been proven that CTLA-4 has a direct role in T(R) function. In this study, using a T cell-mediated colitis model, we demonstrate that anti-CTLA-4 mAb treatment inhibits T(R) function in vivo via direct effects on CTLA-4-expressing T(R), and not via hyperactivation of colitogenic effector T cells. Although anti-CTLA-4 mAb treatment completely inhibits T(R) function, it does not reduce T(R) numbers or their homing to the GALT, suggesting the Ab mediates its function by blockade of a signal required for T(R) activity. In contrast to the striking effect of the Ab, CTLA-4-deficient mice can produce functional T(R), suggesting that under some circumstances other immune regulatory mechanisms, including the production of IL-10, are able to compensate for the loss of the CTLA-4-mediated pathway. This study provides direct evidence that CTLA-4 has a specific, nonredundant role in the function of normal T(R). This role has to be taken into account when targeting CTLA-4 for therapeutic purposes, as such a strategy will not only boost effector T cell responses, but might also break T(R)-mediated self-tolerance. PMID:16982872

  6. Frequently Increased but Functionally Impaired CD4+CD25+ Regulatory T Cells in Patients with Oral Lichen Planus.

    PubMed

    Zhou, Leilei; Cao, Tianyi; Wang, Yufeng; Yao, Hui; Du, Guanhuan; Chen, Guangjie; Niu, Xiaoyin; Tang, Guoyao

    2016-06-01

    Oral lichen planus (OLP) is a T cell-mediated chronic inflammatory mucosal disease, and CD4(+)CD25(+) regulatory T cells (Tregs) are considered involved in the pathogenesis of OLP. In this study, to investigate whether there are intrinsic factors that might cause functional changes in Tregs in this disease, we evaluated the frequency of Tregs in peripheral blood and oral lesions and the expression levels of function-related transcription factors, forkhead/winged-helix transcription factor box P3 (FOXP3), transforming growth factor β (TGF-β), interleukin 10 (IL-10), and TGF-β receptors (TβRI and TβRII) mRNAs in Tregs of patients with oral lichen planus (OLP). We also investigated the frequency of pro-inflammatory cytokines (IFN-γ and IL-17A) producing Foxp3(+) regulatory cells. Increased proportions of Tregs were found in OLP patients. The expression of FOXP3 on mRNA and protein level was elevated in the Tregs of OLP. The expression of TGF-β was lower both on the mRNA and serum level, whereas the expression of IL-10 showed no significant difference between the OLP patients and normal controls. The percentages of CD4(+)FOXP3(+)IL-17(+) T cells were significantly higher than that of normal controls, whereas the percentages of CD4(+)FOXP3(+)IFN-γ(+) T cells did not differ significantly. Furthermore, impaired suppressive function of CD4(+)CD25(+) T cells was demonstrated in OLP patients by in vitro proliferation assay. These data indicate that Tregs in OLP are frequently expanded but functionally deficient. This could explain, at least in part, why the increased Tregs in OLP fail to control the pathogenesis and development of this autoimmune disease. PMID:27106476

  7. CCR7 is required for the in vivo function of CD4+ CD25+ regulatory T cells

    PubMed Central

    Schneider, Martin A.; Meingassner, Josef G.; Lipp, Martin; Moore, Henrietta D.; Rot, Antal

    2007-01-01

    CCR7-mediated migration of naive T cells into the secondary lymphoid organs is a prerequisite for their encounter with mature dendritic cells, the productive presentation of cognate antigen, and consequent T cell proliferation and effector differentiation. Therefore, CCR7 was suggested to play an important role in the initiation of adaptive immune responses. In this study, we show that primary immunity can also develop in the absence of CCR7. Moreover, CCR7-deficient knockout (KO) mice display augmented immune responses. Our data cumulatively suggest that enhanced immunity in CCR7 KO mice is caused by the defective lymph node (LN) positioning of FoxP3+ CD4+ CD25+ regulatory T cells (T reg cells) and the consequent impediment of their function. The FoxP3+ T reg cells express CCR7 and, after their adoptive transfer, migrate into the LNs of wild-type mice. Here, they proliferate in situ upon antigen stimulation and inhibit the generation of antigen-specific T cells. Conversely, transferred CCR7-deficient T reg cells fail to migrate into the LNs and suppress antigen-induced T cell responses. The transfer of combinations of naive and T reg cells from wild-type and CCR7 KO mice into syngeneic severe combined immunodeficient mice directly demonstrates that CCR7-deficient T reg cells are less effective than their wild-type counterparts in preventing the development of inflammatory bowel disease. PMID:17371928

  8. Inflammation negatively regulates FOXP3 and regulatory T-cell function via DBC1.

    PubMed

    Gao, Yayi; Tang, Jiayou; Chen, Weiqian; Li, Qiang; Nie, Jia; Lin, Fang; Wu, Qingsi; Chen, Zuojia; Gao, Zhimei; Fan, Huimin; Tsun, Andy; Shen, Jijia; Chen, Guihua; Liu, Zhongmin; Lou, Zhenkun; Olsen, Nancy J; Zheng, Song Guo; Li, Bin

    2015-06-23

    Forkhead box P3 (FOXP3)-positive Treg cells are crucial for maintaining immune homeostasis. FOXP3 cooperates with its binding partners to elicit Treg cells' signature and function, but the molecular mechanisms underlying the modulation of the FOXP3 complex remain unclear. Here we report that Deleted in breast cancer 1 (DBC1) is a key subunit of the FOXP3 complex. We found that DBC1 interacts physically with FOXP3, and depletion of DBC1 attenuates FOXP3 degradation in inflammatory conditions. Treg cells from Dbc1-deficient mice were more resistant to inflammation-mediated abrogation of Foxp3 expression and function and delayed the onset and severity of experimental autoimmune encephalomyelitis and colitis in mice. These findings establish a previously unidentified mechanism regulating FOXP3 stability during inflammation and reveal a pathway for potential therapeutic modulation and intervention in inflammatory diseases. PMID:26060310

  9. The Soluble CTLA-4 Splice Variant Protects From Type 1 Diabetes and Potentiates Regulatory T-Cell Function

    PubMed Central

    Gerold, Kay D.; Zheng, Peilin; Rainbow, Daniel B.; Zernecke, Alma; Wicker, Linda S.; Kissler, Stephan

    2011-01-01

    OBJECTIVE CTLA4 gene variation associates with multiple autoimmune disorders, including type 1 diabetes. The CTLA4 susceptibility allele was found to generate decreased levels of mRNA encoding soluble CTLA-4 (sCTLA-4) relative to the full-length isoform, the functional consequence of which is as yet unknown. In this study, we investigated the contribution of sCTLA-4 to immune regulation with the aim to elucidate the functional basis of the disease association of CTLA4. RESEARCH DESIGN AND METHODS To model the disease-associated splicing variation of CTLA4, we generated NOD mice in which sCTLA-4 mRNA is silenced by RNA interference. RESULTS We found that loss of sCTLA-4 impairs the function of regulatory T (Treg) cells. This functional defect could be attributed, at least in part, to the failure of sCTLA-4 knockdown (KD) Treg cells to downregulate dendritic cell costimulation. sCTLA-4 KD Treg cells, in contrast with wild-type Treg cells, failed to inhibit colitis induced by transfer of CD4+CD45RBhi cells into NOD.SCID animals. Furthermore, diminished sCTLA-4 expression accelerated the onset of autoimmune diabetes in transgenic mice. CONCLUSIONS Our results demonstrate that sCTLA-4 participates in immune regulation by potentiating the function of Treg cells. The functional outcome of silencing this splice variant in the NOD model provides an explanation for the association of CTLA4 variation with autoimmunity. Lower sCTLA-4 expression from the susceptibility allele may directly affect the suppressive capacity of Treg cells and thereby modulate disease risk. Our unprecedented approach establishes the feasibility of modeling splicing variations relevant to autoimmunity. PMID:21602513

  10. A transcriptional regulatory role of the THAP11-HCF-1 complex in colon cancer cell function.

    PubMed

    Parker, J Brandon; Palchaudhuri, Santanu; Yin, Hanwei; Wei, Jianjun; Chakravarti, Debabrata

    2012-05-01

    The recently identified Thanatos-associated protein (THAP) domain is an atypical zinc finger motif with sequence-specific DNA-binding activity. Emerging data suggest that THAP proteins may function in chromatin-dependent processes, including transcriptional regulation, but the roles of most THAP proteins in normal and aberrant cellular processes remain largely unknown. In this work, we identify THAP11 as a transcriptional regulator differentially expressed in human colon cancer. Immunohistochemical analysis of human colon cancers revealed increased THAP11 expression in both primary tumors and metastases. Knockdown of THAP11 in SW620 colon cancer cells resulted in a significant decrease in cell proliferation, and profiling of gene expression in these cells identified a novel gene set composed of 80 differentially expressed genes, 70% of which were derepressed by THAP11 knockdown. THAP11 was found to associate physically with the transcriptional coregulator HCF-1 (host cell factor 1) and recruit HCF-1 to target promoters. Importantly, THAP11-mediated gene regulation and its chromatin association require HCF-1, while HCF-1 recruitment at these genes requires THAP11. Collectively, these data provide the first characterization of THAP11-dependent gene expression in human colon cancer cells and suggest that the THAP11-HCF-1 complex may be an important transcriptional and cell growth regulator in human colon cancer. PMID:22371484

  11. Inflammation negatively regulates FOXP3 and regulatory T-cell function via DBC1

    PubMed Central

    Gao, Yayi; Tang, Jiayou; Chen, Weiqian; Li, Qiang; Nie, Jia; Lin, Fang; Wu, Qingsi; Chen, Zuojia; Gao, Zhimei; Fan, Huimin; Tsun, Andy; Shen, Jijia; Chen, Guihua; Liu, Zhongmin; Lou, Zhenkun; Olsen, Nancy J.; Zheng, Song Guo; Li, Bin

    2015-01-01

    Forkhead box P3 (FOXP3)-positive Treg cells are crucial for maintaining immune homeostasis. FOXP3 cooperates with its binding partners to elicit Treg cells’ signature and function, but the molecular mechanisms underlying the modulation of the FOXP3 complex remain unclear. Here we report that Deleted in breast cancer 1 (DBC1) is a key subunit of the FOXP3 complex. We found that DBC1 interacts physically with FOXP3, and depletion of DBC1 attenuates FOXP3 degradation in inflammatory conditions. Treg cells from Dbc1-deficient mice were more resistant to inflammation-mediated abrogation of Foxp3 expression and function and delayed the onset and severity of experimental autoimmune encephalomyelitis and colitis in mice. These findings establish a previously unidentified mechanism regulating FOXP3 stability during inflammation and reveal a pathway for potential therapeutic modulation and intervention in inflammatory diseases. PMID:26060310

  12. FOXP3+ regulatory T cell development and function require histone/protein deacetylase 3

    PubMed Central

    Wang, Liqing; Liu, Yujie; Han, Rongxiang; Beier, Ulf H.; Bhatti, Tricia R.; Akimova, Tatiana; Greene, Mark I.; Hiebert, Scott W.; Hancock, Wayne W.

    2015-01-01

    Treg dysfunction is associated with a variety of inflammatory diseases. Treg populations are defined by expression of the oligomeric transcription factor FOXP3 and inability to produce IL-2, a cytokine required for T cell maintenance and survival. FOXP3 activity is regulated post-translationally by histone/protein acetyltransferases and histone/protein deacetylases (HDACs). Here, we determined that HDAC3 mediates both the development and function of the two main Treg subsets, thymus-derived Tregs and induced Tregs (iTregs). We determined that HDAC3 and FOXP3 physically interact and that HDAC3 expression markedly reduces Il2 promoter activity. In murine models, conditional deletion of Hdac3 during thymic Treg development restored Treg production of IL-2 and blocked the suppressive function of Tregs. HDAC3-deficient mice died from autoimmunity by 4–6 weeks of age; however, injection of WT FOXP3+ Tregs prolonged survival. Adoptive transfer of Hdac3-deficient Tregs, unlike WT Tregs, did not control T cell proliferation in naive mice and did not prevent allograft rejection or colitis. HDAC3 also regulated the development of iTregs, as HDAC3-deficient conventional T cells were not converted into iTregs under polarizing conditions and produced large amounts of IL-2, IL-6, and IL-17. We conclude that HDAC3 is essential for the normal development and suppressive functions of thymic and peripheral FOXP3+ Tregs. PMID:25642770

  13. Characterization and functional studies of forkhead box protein 3(-) lymphocyte activation gene 3(+) CD4(+) regulatory T cells induced by mucosal B cells.

    PubMed

    Chu, K-H; Chiang, B-L

    2015-05-01

    The induction of mucosal tolerance has been demonstrated to be an effective therapeutic approach for the treatment of allergic diseases. Our previous study demonstrated that Peyer's patch B cells could convert naive T cells into regulatory T cells (so-called Treg -of-B(P) cells); however, it is important to characterize this particular subset of Treg -of-B cells for future applications. This study aimed to investigate the role of lymphocyte activating gene 3 (LAG3) in mediating the regulatory function of Treg -of-B(P) cells induced by mucosal follicular B (FOB) cells. Microarray analysis and real-time polymerase chain reaction (PCR) were used to assess the gene expression pattern of Treg -of-B(P) cells. To evaluate the role of LAG3, the in-vitro suppressive function and the alleviation of airway inflammation in a murine model of asthma was assessed. Our data indicated that FOB cells isolated from Peyer's patches had the ability to generate more suppressive Treg -of-B cells with LAG3 expression, compared with CD23(lo) CD21(lo) B cells. LAG3 is not only a marker for Treg -of-B(P) cells, but also participate in the suppressive ability. Moreover, CCR4 and CCR6 could be detected on the LAG3(+) , not LAG3(-) , Treg -of-B(P) cells and would help cells homing to allergic lung. In the murine model of asthma, the adoptive transfer of LAG3(+) Treg -of-B(P) cells was able to sufficiently suppress T helper type 2 (Th2) cytokine production, eosinophil infiltration and alleviate asthmatic symptoms. LAG3 was expressed in Treg -of-B(P) cells and was also involved in the function of Treg -of-B(P) cells. In the future, this particular subset of Treg -of-B cells might be used to alleviate allergic symptoms. PMID:25581421

  14. Immunometabolism of regulatory T cells.

    PubMed

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

    2016-05-19

    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

  15. 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

  16. Functional BCL-2 regulatory genetic variants contribute to susceptibility of esophageal squamous cell carcinoma.

    PubMed

    Pan, Wenting; Yang, Jinyun; Wei, Jinyu; Chen, Hongwei; Ge, Yunxia; Zhang, Jingfeng; Wang, Zhiqiong; Zhou, Changchun; Yuan, Qipeng; Zhou, Liqing; Yang, Ming

    2015-01-01

    B-cell lymphoma-2 (BCL-2) prevents apoptosis and its overexpression could promote cancer cell survival. Multiple functional BCL-2 genetic polymorphisms, such as rs2279115, rs1801018 and rs1564483, have been identified previously and might be involved in cancer development through deregulating BCL-2 expression. Therefore, we examined associations between these three polymorphisms and esophageal squamous cell carcinoma (ESCC) susceptibility as well as its biological function in vivo. Genotypes were determined in two independent case-control sets consisted of 1588 ESCC patients and 1600 controls from two regions of China. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated by logistic regression. The impact of the rs2279115 polymorphism on BCL-2 expression was detected using esophagus tissues. Our results demonstrated that the BCL-2 rs2279115 AA genotype was significantly associated with decreased ESCC risk compared with the CC genotype (OR = 0.72, 95% CI = 0.57-0.90, P = 0.005), especially in nonsmokers (OR = 0.42, 95% CI = 0.29-0.59, P = 0.001) or nondrinkers (OR = 0.44, 95% CI = 0.32-0.62, P =  .002). Genotype-phenotype correlation studies demonstrated that subjects with the rs2279115 CA and AA genotypes had a statistically significant decrease of BCL-2 mRNA expression compared to the CC genotype in both normal and cancerous esophagus tissues. Our results indicate that the BCL-2 rs2279115 polymorphism contributes to ESCC susceptibility in Chinese populations. PMID:26132559

  17. Environmental toxicants perturb human Sertoli cell adhesive function via changes in F-actin organization mediated by actin regulatory proteins

    PubMed Central

    Xiao, Xiang; Mruk, Dolores D.; Tang, Elizabeth I.; Wong, Chris K.C.; Lee, Will M.; John, Constance M.; Turek, Paul J.; Silvestrini, Bruno; Cheng, C. Yan

    2014-01-01

    STUDY QUESTION Can human Sertoli cells cultured in vitro and that have formed an epithelium be used as a model to monitor toxicant-induced junction disruption and to better understand the mechanism(s) by which toxicants disrupt cell adhesion at the Sertoli cell blood–testis barrier (BTB)? SUMMARY ANSWER Our findings illustrate that human Sertoli cells cultured in vitro serve as a reliable system to monitor the impact of environmental toxicants on the BTB function. WHAT IS KNOWN ALREADY Suspicions of a declining trend in semen quality and a concomitant increase in exposures to environmental toxicants over the past decades reveal the need of an in vitro system that efficiently and reliably monitors the impact of toxicants on male reproductive function. Furthermore, studies in rodents have confirmed that environmental toxicants impede Sertoli cell BTB function in vitro and in vivo. STUDY DESIGN, SIZE AND DURATION We examined the effects of two environmental toxicants: cadmium chloride (0.5–20 µM) and bisphenol A (0.4–200 µM) on human Sertoli cell function. Cultured Sertoli cells from three men were used in this study, which spanned an 18-month period. PARTICIPANTS/MATERIALS, SETTING, METHODS Human Sertoli cells from three subjects were cultured in F12/DMEM containing 5% fetal bovine serum. Changes in protein expression were monitored by immunoblotting using specific antibodies. Immunofluorescence analyses were used to assess changes in the distribution of adhesion proteins, F-actin and actin regulatory proteins following exposure to two toxicants: cadmium chloride and bisphenol A (BPA). MAIN RESULTS AND THE ROLE OF CHANCE Human Sertoli cells were sensitive to cadmium and BPA toxicity. Changes in the localization of cell adhesion proteins were mediated by an alteration of the actin-based cytoskeleton. This alteration of F-actin network in Sertoli cells as manifested by truncation and depolymerization of actin microfilaments at the Sertoli cell BTB was caused by

  18. Enforced IL-10 Expression Confers Type 1 Regulatory T Cell (Tr1) Phenotype and Function to Human CD4+ T Cells

    PubMed Central

    Andolfi, Grazia; Fousteri, Georgia; Rossetti, Maura; Magnani, Chiara F; Jofra, Tatiana; Locafaro, Grazia; Bondanza, Attilio; Gregori, Silvia; Roncarolo, Maria-Grazia

    2012-01-01

    Type 1 regulatory T (Tr1) cells are an inducible subset of CD4+ Tr cells characterized by high levels of interleukin (IL)-10 production and regulatory properties. Several protocols to generate human Tr1 cells have been developed in vitro. However, the resulting population includes a significant fraction of contaminating non-Tr1 cells, representing a major bottleneck for clinical application of Tr1 cell therapy. We generated an homogeneous IL-10–producing Tr1 cell population by transducing human CD4+ T cells with a bidirectional lentiviral vector (LV) encoding for human IL-10 and the marker gene, green fluorescent protein (GFP), which are independently coexpressed. The resulting GFP+ LV-IL-10–transduced human CD4+ T (CD4LV-IL-10) cells expressed, upon T-cell receptor (TCR) activation, high levels of IL-10 and concomitant low levels of IL-4, and markers associated with IL-10. Moreover, CD4LV-IL-10 T cells displayed typical Tr1 features: the anergic phenotype, the IL-10, and transforming growth factor (TGF)-β dependent suppression of allogeneic T-cell responses, and the ability to suppress in a cell-to-cell contact independent manner in vitro. CD4LV-IL-10 T cells were able to control xeno graft-versus-host disease (GvHD), demonstrating their suppressive function in vivo. These results show that constitutive over-expression of IL-10 in human CD4+ T cells leads to a stable cell population that recapitulates the phenotype and function of Tr1 cells. PMID:22692497

  19. Conserved regulatory mechanism controls the development of cells with rooting functions in land plants.

    PubMed

    Tam, Thomas Ho Yuen; Catarino, Bruno; Dolan, Liam

    2015-07-21

    Land plants develop filamentous cells-root hairs, rhizoids, and caulonemata-at the interface with the soil. Members of the group XI basic helix-loop-helix (bHLH) transcription factors encoded by LOTUS JAPONICUS ROOTHAIRLESS1-LIKE (LRL) genes positively regulate the development of root hairs in the angiosperms Lotus japonicus, Arabidopsis thaliana, and rice (Oryza sativa). Here we show that auxin promotes rhizoid and caulonema development by positively regulating the expression of PpLRL1 and PpLRL2, the two LRL genes in the Physcomitrella patens genome. Although the group VIII bHLH proteins, AtROOT HAIR DEFECTIVE6 and AtROOT HAIR DEFECTIVE SIX-LIKE1, promote root-hair development by positively regulating the expression of AtLRL3 in A. thaliana, LRL genes promote rhizoid development independently of PpROOT HAIR DEFECTIVE SIX-LIKE1 and PpROOT HAIR DEFECITVE SIX-LIKE2 (PpRSL1 and PpRSL2) gene function in P. patens. Together, these data demonstrate that both LRL and RSL genes are components of an ancient auxin-regulated gene network that controls the development of tip-growing cells with rooting functions among most extant land plants. Although this network has diverged in the moss and the angiosperm lineages, our data demonstrate that the core network acted in the last common ancestor of the mosses and angiosperms that existed sometime before 420 million years ago. PMID:26150509

  20. The Essential Role of Circulating Thyroglobulin in Maintaining Dominance of Natural Regulatory T Cell Function to Prevent Autoimmune Thyroiditis.

    PubMed

    Kong, Y M; Brown, N K; Morris, G P; Flynn, J C

    2015-09-01

    Several key findings from the late 1960s to mid-1970s regarding thyroid hormone metabolism and circulating thyroglobulin composition converged with studies pertaining to the role of T lymphocytes in autoimmune thyroiditis. These studies cemented the foundation for subsequent investigations into the existence and antigenic specificity of thymus-derived natural regulatory T cells (nTregs). These nTregs prevented the development of autoimmune thyroiditis, despite the ever-present genetic predisposition, autoantigen (thyroglobulin), and thyroglobulin-reactive T cells. Guided by the hypothalamus-pituitary-thyroid axis as a fixed set-point regulator in thyroid hormone metabolism, we used a murine model and compared at key junctures the capacity of circulating thyroglobulin level (raised by thyroid-stimulating hormone or exogenous thyroglobulin administration) to strengthen self-tolerance and resist autoimmune thyroiditis. The findings clearly demonstrated an essential role for raised circulating thyroglobulin levels in maintaining the dominance of nTreg function and inhibiting thyroid autoimmunity. Subsequent identification of thyroglobulin-specific nTregs as CD4(+)CD25(+)Foxp3(+) in the early 2000s enabled the examination of probable mechanisms of nTreg function. We observed that whenever nTreg function was perturbed by immunotherapeutic measures, opportunistic autoimmune disorders invariably surfaced. This review highlights the step-wise progression of applying insights from endocrinologic and immunologic studies to advance our understanding of the clonal balance between natural regulatory and autoreactive T cells. Moreover, we focus on how tilting the balance in favor of maintaining peripheral tolerance could be achieved. Thus, murine autoimmune thyroiditis has served as a unique model capable of closely simulating natural physiologic conditions. PMID:26158397

  1. Natural IgM Switches the Function of Lipopolysaccharide-Activated Murine Bone Marrow-Derived Dendritic Cells to a Regulatory Dendritic Cell That Suppresses Innate Inflammation.

    PubMed

    Lobo, Peter I; Schlegel, Kailo H; Bajwa, Amandeep; Huang, Liping; Kurmaeva, Elvira; Wang, Binru; Ye, Hong; Tedder, Thomas F; Kinsey, Gilbert R; Okusa, Mark D

    2015-12-01

    We have previously shown that polyclonal natural IgM protects mice from renal ischemia/reperfusion injury (IRI) by inhibiting the reperfusion inflammatory response. We hypothesized that a potential mechanism involved IgM modulation of dendritic cells (DC), as we observed high IgM binding to splenic DC. To test this hypothesis, we pretreated bone marrow-derived DC (BMDC) with polyclonal murine or human IgM prior to LPS activation and demonstrated that 0.5 × 10(6) IgM/LPS-pretreated BMDC, when injected into wild-type C57BL/6 mice 24 h before renal ischemia, protect mice from developing renal IRI. We show that this switching of LPS-activated BMDC to a regulatory phenotype requires modulation of BMDC function that is mediated by IgM binding to nonapoptotic BMDC receptors. Regulatory BMDC require IL-10 and programmed death 1 as well as downregulation of CD40 and p65 NF-κB phosphorylation to protect in renal IRI. Blocking the programmed death ligand 1 binding site just before i.v. injection of IgM/LPS-pretreated BMDC or using IL-10 knockout BMDC fails to induce protection. Similarly, IgM/LPS-pretreated BMDC are rendered nonprotective by increasing CD40 expression and phosphorylation of p65 NF-κB. How IgM/LPS regulatory BMDC suppress in vivo ischemia-induced innate inflammation remains to be determined. However, we show that suppression is dependent on other in vivo regulatory mechanisms in the host, that is, CD25(+) T cells, B cells, IL-10, and circulating IgM. There was no increase in Foxp3(+) regulatory T cells in the spleen either before or after renal IRI. Collectively, these findings show that natural IgM anti-leukocyte Abs can switch BMDC to a regulatory phenotype despite the presence of LPS that ordinarily induces BMDC maturation. PMID:26519533

  2. The effects of 5-azacytidine on the function and number of regulatory T cells and T-effectors in myelodysplastic syndrome.

    PubMed

    Costantini, Benedetta; Kordasti, Shahram Y; Kulasekararaj, Austin G; Jiang, Jie; Seidl, Thomas; Abellan, Pilar Perez; Mohamedali, Azim; Thomas, Nicolas Shaun B; Farzaneh, Farzin; Mufti, Ghulam J

    2013-08-01

    Expansion of regulatory T cells occurs in high-risk myelodysplastic syndrome and correlates with a poor prognosis. DNA methyltransferase inhibitors, particularly 5-azacytidine, have been shown to increase the survival of patients with high-risk myelodysplastic syndrome. It is not entirely clear whether this improvement in patients' survival is related to the effects of DNA methyltransferase inhibitors on the immune system and/or the direct effect of these drugs on the dysplastic clone. In this study we investigated the effect of 5-azacytidine on the function and proliferation capability of regulatory T cells and T-helper cells. The number and function of CD4(+) T-cell subsets in 68 patients with intermediate-2/high-risk myelodysplastic syndrome were serially assessed at diagnosis and following treatment. The in-vitro effects of 5-azacytidine on CD4(+) T-cell subsets isolated from both healthy donors and patients with myelodysplastic syndrome were also investigated. The number of peripheral blood regulatory T cells was significantly higher in myelodysplastic syndrome patients than in healthy donors and responders to treatment (P=0.01). The absolute numbers of T-helper 1 and T-helper 2, but not T-helper 17, cells were significantly reduced following 12 months of treatment (P=0.03, P=0.03). The in vitro addition of 5-azacytidine to CD4(+) T cells reduced the proliferative capacity of regulatory T cells (P=0.03). In addition, the 5-azacytidine-treated regulatory T cells had reduced suppressive function and produced larger amounts of interleukin-17. The FOXP3 expression in 5-azacyti-dine-treated T-effectors was also increased. Interestingly, these FOXP3(+)/interleukin-17(+) cells originated mainly from effector T cells rather than regulatory T cells. Our data suggest that 5-azacytidine has profound effects on CD4(+) T cells, which correlate with disease status after treatment. Furthermore, despite the demethylation of the FOXP3 promoter and increased FOXP3 expression

  3. The effects of 5-azacytidine on the function and number of regulatory T cells and T-effectors in myelodysplastic syndrome

    PubMed Central

    Costantini, Benedetta; Kordasti, Shahram Y.; Kulasekararaj, Austin G.; Jiang, Jie; Seidl, Thomas; Abellan, Pilar Perez; Mohamedali, Azim; Thomas, Nicolas Shaun B.; Farzaneh, Farzin; Mufti, Ghulam J.

    2013-01-01

    Expansion of regulatory T cells occurs in high-risk myelodysplastic syndrome and correlates with a poor prognosis. DNA methyltransferase inhibitors, particularly 5-azacytidine, have been shown to increase the survival of patients with high-risk myelodysplastic syndrome. It is not entirely clear whether this improvement in patients’ survival is related to the effects of DNA methyltransferase inhibitors on the immune system and/or the direct effect of these drugs on the dysplastic clone. In this study we investigated the effect of 5-azacytidine on the function and proliferation capability of regulatory T cells and T-helper cells. The number and function of CD4+ T-cell subsets in 68 patients with intermediate-2/high-risk myelodysplastic syndrome were serially assessed at diagnosis and following treatment. The in-vitro effects of 5-azacytidine on CD4+ T-cell subsets isolated from both healthy donors and patients with myelodysplastic syndrome were also investigated. The number of peripheral blood regulatory T cells was significantly higher in myelodysplastic syndrome patients than in healthy donors and responders to treatment (P=0.01). The absolute numbers of T-helper 1 and T-helper 2, but not T-helper 17, cells were significantly reduced following 12 months of treatment (P=0.03, P=0.03). The in vitro addition of 5-azacytidine to CD4+ T cells reduced the proliferative capacity of regulatory T cells (P=0.03). In addition, the 5-azacytidine-treated regulatory T cells had reduced suppressive function and produced larger amounts of interleukin-17. The FOXP3 expression in 5-azacyti-dine-treated T-effectors was also increased. Interestingly, these FOXP3+/interleukin-17+ cells originated mainly from effector T cells rather than regulatory T cells. Our data suggest that 5-azacytidine has profound effects on CD4+ T cells, which correlate with disease status after treatment. Furthermore, despite the demethylation of the FOXP3 promoter and increased FOXP3 expression following 5

  4. Exposure to cigarette smoke impacts myeloid-derived regulatory cell function and exacerbates airway hyper-responsiveness

    PubMed Central

    Wang, Yong; Jin, Tong Huan; Farhana, Aisha; Freeman, Jason; Estell, Kim; Zmijewski, Jaroslaw; Gaggar, Amit; Thannickal, Victor J; Schwiebert, Lisa M; Steyn, Adrie JC; Deshane, Jessy S

    2014-01-01

    Cigarette smoking enhances oxidative stress and airway inflammation in asthma, the mechanisms of which are largely unknown. Myeloid-derived regulatory cells (MDRC) are free radical producing immature myeloid cells with immunoregulatory properties which have recently been demonstrated as critical regulators of allergic airway inflammation. NO (nitric oxide)-producing immunosuppressive MDRC suppress T cell proliferation and airway-hyper responsiveness (AHR), while the O2•− (superoxide)-producing MDRC are proinflammatory. We hypothesized that cigarette smoke (CS) exposure may impact MDRC function and contribute to exacerbations in asthma. Exposure of bone marrow (BM) derived NO-producing MDRC to CS reduced the production of NO and its metabolites and inhibited their potential to suppress T cell proliferation. Production of immunoregulatory cytokine IL-10 was significantly inhibited, while proinflammatory cytokines IL-6, IL-1β, TNF-α and IL-33 were enhanced in CS exposed BMMDRC. Additionally, CS exposure increased NF-κB activation and induced BM-MDRC-mediated production of O2•−, via NF-κB dependent pathway. Intratracheal transfer of smoke exposed MDRC producing proinflammatory cytokines increased NF-κB activation, reactive oxygen species and mucin production in vivo and exacerbated AHR in C57BL/6 mice, mice deficient in Type I IFNR and MyD88, both with reduced numbers of endogenous MDRC. Thus, CS exposure modulates MDRC function and contributes to asthma exacerbation and identifies MDRC as potential targets for asthma therapy. PMID:25365203

  5. Exposure to cigarette smoke impacts myeloid-derived regulatory cell function and exacerbates airway hyper-responsiveness.

    PubMed

    Wang, Yong; Jin, Tong Huan; Farhana, Aisha; Freeman, Jason; Estell, Kim; Zmijewski, Jaroslaw W; Gaggar, Amit; Thannickal, Victor J; Schwiebert, Lisa M; Steyn, Adrie J C; Deshane, Jessy S

    2014-12-01

    Cigarette smoking enhances oxidative stress and airway inflammation in asthma, the mechanisms of which are largely unknown. Myeloid-derived regulatory cells (MDRC) are free radical producing immature myeloid cells with immunoregulatory properties that have recently been demonstrated as critical regulators of allergic airway inflammation. NO (nitric oxide)-producing immunosuppressive MDRC suppress T-cell proliferation and airway-hyper responsiveness (AHR), while the O2(•-) (superoxide)-producing MDRC are proinflammatory. We hypothesized that cigarette smoke (CS) exposure may impact MDRC function and contribute to exacerbations in asthma. Exposure of bone marrow (BM)-derived NO-producing MDRC to CS reduced the production of NO and its metabolites and inhibited their potential to suppress T-cell proliferation. Production of immunoregulatory cytokine IL-10 was significantly inhibited, while proinflammatory cytokines IL-6, IL-1β, TNF-α and IL-33 were enhanced in CS-exposed BM-MDRC. Additionally, CS exposure increased NF-κB activation and induced BM-MDRC-mediated production of O2(•-), via NF-κB-dependent pathway. Intratracheal transfer of smoke-exposed MDRC-producing proinflammatory cytokines increased NF-κB activation, reactive oxygen species and mucin production in vivo and exacerbated AHR in C57BL/6 mice, mice deficient in Type I IFNR and MyD88, both with reduced numbers of endogenous MDRC. Thus CS exposure modulates MDRC function and contributes to asthma exacerbation and identifies MDRC as potential targets for asthma therapy. PMID:25365203

  6. CTCF binding site sequence differences are associated with unique regulatory and functional trends during embryonic stem cell differentiation.

    PubMed

    Plasschaert, Robert N; Vigneau, Sébastien; Tempera, Italo; Gupta, Ravi; Maksimoska, Jasna; Everett, Logan; Davuluri, Ramana; Mamorstein, Ronen; Lieberman, Paul M; Schultz, David; Hannenhalli, Sridhar; Bartolomei, Marisa S

    2014-01-01

    CTCF (CCCTC-binding factor) is a highly conserved multifunctional DNA-binding protein with thousands of binding sites genome-wide. Our previous work suggested that differences in CTCF's binding site sequence may affect the regulation of CTCF recruitment and its function. To investigate this possibility, we characterized changes in genome-wide CTCF binding and gene expression during differentiation of mouse embryonic stem cells. After separating CTCF sites into three classes (LowOc, MedOc and HighOc) based on similarity to the consensus motif, we found that developmentally regulated CTCF binding occurs preferentially at LowOc sites, which have lower similarity to the consensus. By measuring the affinity of CTCF for selected sites, we show that sites lost during differentiation are enriched in motifs associated with weaker CTCF binding in vitro. Specifically, enrichment for T at the 18(th) position of the CTCF binding site is associated with regulated binding in the LowOc class and can predictably reduce CTCF affinity for binding sites. Finally, by comparing changes in CTCF binding with changes in gene expression during differentiation, we show that LowOc and HighOc sites are associated with distinct regulatory functions. Our results suggest that the regulatory control of CTCF is dependent in part on specific motifs within its binding site. PMID:24121688

  7. CTCF binding site sequence differences are associated with unique regulatory and functional trends during embryonic stem cell differentiation

    PubMed Central

    Plasschaert, Robert N.; Vigneau, Sébastien; Tempera, Italo; Gupta, Ravi; Maksimoska, Jasna; Everett, Logan; Davuluri, Ramana; Mamorstein, Ronen; Lieberman, Paul M.; Schultz, David; Hannenhalli, Sridhar; Bartolomei, Marisa S.

    2014-01-01

    CTCF (CCCTC-binding factor) is a highly conserved multifunctional DNA-binding protein with thousands of binding sites genome-wide. Our previous work suggested that differences in CTCF’s binding site sequence may affect the regulation of CTCF recruitment and its function. To investigate this possibility, we characterized changes in genome-wide CTCF binding and gene expression during differentiation of mouse embryonic stem cells. After separating CTCF sites into three classes (LowOc, MedOc and HighOc) based on similarity to the consensus motif, we found that developmentally regulated CTCF binding occurs preferentially at LowOc sites, which have lower similarity to the consensus. By measuring the affinity of CTCF for selected sites, we show that sites lost during differentiation are enriched in motifs associated with weaker CTCF binding in vitro. Specifically, enrichment for T at the 18th position of the CTCF binding site is associated with regulated binding in the LowOc class and can predictably reduce CTCF affinity for binding sites. Finally, by comparing changes in CTCF binding with changes in gene expression during differentiation, we show that LowOc and HighOc sites are associated with distinct regulatory functions. Our results suggest that the regulatory control of CTCF is dependent in part on specific motifs within its binding site. PMID:24121688

  8. IFNα/βR Signaling Promotes Regulatory T Cell Development and Function Under Stress Conditions

    PubMed Central

    Metidji, Amina; Rieder, Sadiye Amcaoglu; Glass, Deborah Dacek; Cremer, Isabelle; Punkosdy, George A.; Shevach, Ethan M.

    2015-01-01

    Type I IFNs are a family of cytokines with antiviral and immunomodulatory properties. While the antiviral effects of IFNs are well characterized, their immunomodulatory properties are less clear. To specifically address the effects of type I IFNs on Treg, we studied mixed bone morrow (BM) chimeras between wild-type (WT) and IFNα/βR (IFNAR) knockout (KO) mice, and heterozygous female mice expressing a Treg-specific deletion of the IFNAR. In these two models, IFNAR signaling promotes the development of the Treg lineage in the thymus and their survival in the periphery. IFNAR KO Treg had a higher expression of the pro-apoptotic gene Bim and higher frequency of active caspase positive cells. IFNAR KO Treg from chimeric mice displayed a more naïve phenotype, accompanied by lower levels of CD25 and phosphorylated STAT5. Therefore, in Treg IFNAR signaling may directly or indirectly affect phosphorylation of STAT5. In mixed chimeras with Scurfy fetal liver, Treg derived from IFNAR KO BM were unable to control T effector cell activation and tissue inflammation. Under stress conditions or in a competitive environment, IFNAR signaling may be required to maintain Treg homeostasis and function. PMID:25795758

  9. Conserved regulatory mechanism controls the development of cells with rooting functions in land plants

    PubMed Central

    Tam, Thomas Ho Yuen; Catarino, Bruno; Dolan, Liam

    2015-01-01

    Land plants develop filamentous cells—root hairs, rhizoids, and caulonemata—at the interface with the soil. Members of the group XI basic helix–loop–helix (bHLH) transcription factors encoded by LOTUS JAPONICUS ROOTHAIRLESS1-LIKE (LRL) genes positively regulate the development of root hairs in the angiosperms Lotus japonicus, Arabidopsis thaliana, and rice (Oryza sativa). Here we show that auxin promotes rhizoid and caulonema development by positively regulating the expression of PpLRL1 and PpLRL2, the two LRL genes in the Physcomitrella patens genome. Although the group VIII bHLH proteins, AtROOT HAIR DEFECTIVE6 and AtROOT HAIR DEFECTIVE SIX-LIKE1, promote root-hair development by positively regulating the expression of AtLRL3 in A. thaliana, LRL genes promote rhizoid development independently of PpROOT HAIR DEFECTIVE SIX-LIKE1 and PpROOT HAIR DEFECITVE SIX-LIKE2 (PpRSL1 and PpRSL2) gene function in P. patens. Together, these data demonstrate that both LRL and RSL genes are components of an ancient auxin-regulated gene network that controls the development of tip-growing cells with rooting functions among most extant land plants. Although this network has diverged in the moss and the angiosperm lineages, our data demonstrate that the core network acted in the last common ancestor of the mosses and angiosperms that existed sometime before 420 million years ago. PMID:26150509

  10. Glucocorticoid-Induced Tumour Necrosis Factor Receptor-Related Protein: A Key Marker of Functional Regulatory T Cells

    PubMed Central

    Ronchetti, Simona; Ricci, Erika; Petrillo, Maria Grazia; Cari, Luigi; Migliorati, Graziella; Nocentini, Giuseppe; Riccardi, Carlo

    2015-01-01

    Glucocorticoid-induced tumour necrosis factor receptor-related protein (GITR, TNFRSF18, and CD357) is expressed at high levels in activated T cells and regulatory T cells (Tregs). In this review, we present data from mouse and human studies suggesting that GITR is a crucial player in the differentiation of thymic Tregs (tTregs), and expansion of both tTregs and peripheral Tregs (pTregs). The role of GITR in Treg expansion is confirmed by the association of GITR expression with markers of memory T cells. In this context, it is not surprising that GITR appears to be a marker of active Tregs, as suggested by the association of GITR expression with other markers of Treg activation or cytokines with suppressive activity (e.g., IL-10 and TGF-β), the presence of GITR+ cells in tissues where Tregs are active (e.g., solid tumours), or functional studies on Tregs. Furthermore, some Treg subsets including Tr1 cells express either low or no classical Treg markers (e.g., FoxP3 and CD25) and do express GITR. Therefore, when evaluating changes in the number of Tregs in human diseases, GITR expression must be evaluated. Moreover, GITR should be considered as a marker for isolating Tregs. PMID:25961057

  11. Functional Conservation of the Glide/Gcm Regulatory Network Controlling Glia, Hemocyte, and Tendon Cell Differentiation in Drosophila

    PubMed Central

    Cattenoz, Pierre B.; Popkova, Anna; Southall, Tony D.; Aiello, Giuseppe; Brand, Andrea H.; Giangrande, Angela

    2016-01-01

    High-throughput screens allow us to understand how transcription factors trigger developmental processes, including cell specification. A major challenge is identification of their binding sites because feedback loops and homeostatic interactions may mask the direct impact of those factors in transcriptome analyses. Moreover, this approach dissects the downstream signaling cascades and facilitates identification of conserved transcriptional programs. Here we show the results and the validation of a DNA adenine methyltransferase identification (DamID) genome-wide screen that identifies the direct targets of Glide/Gcm, a potent transcription factor that controls glia, hemocyte, and tendon cell differentiation in Drosophila. The screen identifies many genes that had not been previously associated with Glide/Gcm and highlights three major signaling pathways interacting with Glide/Gcm: Notch, Hedgehog, and JAK/STAT, which all involve feedback loops. Furthermore, the screen identifies effector molecules that are necessary for cell-cell interactions during late developmental processes and/or in ontogeny. Typically, immunoglobulin (Ig) domain–containing proteins control cell adhesion and axonal navigation. This shows that early and transiently expressed fate determinants not only control other transcription factors that, in turn, implement a specific developmental program but also directly affect late developmental events and cell function. Finally, while the mammalian genome contains two orthologous Gcm genes, their function has been demonstrated in vertebrate-specific tissues, placenta, and parathyroid glands, begging questions on the evolutionary conservation of the Gcm cascade in higher organisms. Here we provide the first evidence for the conservation of Gcm direct targets in humans. In sum, this work uncovers novel aspects of cell specification and sets the basis for further understanding of the role of conserved Gcm gene regulatory cascades. PMID:26567182

  12. Functional Conservation of the Glide/Gcm Regulatory Network Controlling Glia, Hemocyte, and Tendon Cell Differentiation in Drosophila.

    PubMed

    Cattenoz, Pierre B; Popkova, Anna; Southall, Tony D; Aiello, Giuseppe; Brand, Andrea H; Giangrande, Angela

    2016-01-01

    High-throughput screens allow us to understand how transcription factors trigger developmental processes, including cell specification. A major challenge is identification of their binding sites because feedback loops and homeostatic interactions may mask the direct impact of those factors in transcriptome analyses. Moreover, this approach dissects the downstream signaling cascades and facilitates identification of conserved transcriptional programs. Here we show the results and the validation of a DNA adenine methyltransferase identification (DamID) genome-wide screen that identifies the direct targets of Glide/Gcm, a potent transcription factor that controls glia, hemocyte, and tendon cell differentiation in Drosophila. The screen identifies many genes that had not been previously associated with Glide/Gcm and highlights three major signaling pathways interacting with Glide/Gcm: Notch, Hedgehog, and JAK/STAT, which all involve feedback loops. Furthermore, the screen identifies effector molecules that are necessary for cell-cell interactions during late developmental processes and/or in ontogeny. Typically, immunoglobulin (Ig) domain-containing proteins control cell adhesion and axonal navigation. This shows that early and transiently expressed fate determinants not only control other transcription factors that, in turn, implement a specific developmental program but also directly affect late developmental events and cell function. Finally, while the mammalian genome contains two orthologous Gcm genes, their function has been demonstrated in vertebrate-specific tissues, placenta, and parathyroid glands, begging questions on the evolutionary conservation of the Gcm cascade in higher organisms. Here we provide the first evidence for the conservation of Gcm direct targets in humans. In sum, this work uncovers novel aspects of cell specification and sets the basis for further understanding of the role of conserved Gcm gene regulatory cascades. PMID:26567182

  13. Functional role of the nicotinic arm of the acetylcholine regulatory axis in human B-cell lines

    PubMed Central

    Arredondo, Juan; Omelchenko, Denys; Chernyavsky, Alexander I; Qian, Jing; Skok, Maryna; Grando, Sergei A

    2009-01-01

    We studied the involvement of nicotinic acetylcholine receptors (nAChRs) in the inflammation-related activity of human B-cell lines. Activation of nAChRs in Daudi cells with epibatidine abolished the pansorbin-dependent upregulation of the pro-inflammatory marker Cox-2 both at the mRNA and protein levels, indicating that the nicotinergic signaling suppresses B-cell activation. While the anti-inflammatory action on B-cells was mediated predominantly through α7 nAChR, as could be judged from abolishing epibatidine effects with methyllycaconitine, both α7 and non-α7 nAChRs, such as α2-containing receptors, were involved in regulation of B-cell apoptosis. The net effect was antiapoptotic. To determine the role of nAChRs in regulating B-cell activation/plasmacytic differentiation, we measured changes in the CD38, CD138 and Bcl-6 gene expression. Epibatidine significantly (P < 0.05) upregulated CD38 at the transcriptional level and CD138 and Bcl-6 – at the translational levels. AR-R17779 significantly (P < 0.05) increased the protein levels of CD38 and CD138. In both cases, the effect of epibatidine was abolished with Mec, and that of AR-R17779 – by MLA, demonstrating a functional role of nAChRs in regulating Daudi cell differentiation. The obtained results revealed distinct contributions of α7 and non-α7 nAChRs to regulation of B-cell activation/differentiation, and suggested that signaling through the nicotinic arm of acetylcholine regulatory axis is important for B-cell involvement in inflammation.

  14. Percentage of Peripheral CD19+CD24hiCD38hi Regulatory B Cells in Neonatal Sepsis Patients and Its Functional Implication

    PubMed Central

    Pan, Xiao; Ji, Zuoquan; Xue, Jiang

    2016-01-01

    Background As a major cause of mortality in neonates, neonatal sepsis is often accompanied by immune dysfunctions, which are frequently caused by dysregulated T cell sub-populations. The role of regulatory B cells in neonatal sepsis, however, remains unknown. Therefore, this study investigated the percentage and functional variation of CD19+CD24hiCD38hi regulatory B cells in peripheral blood of neonatal sepsis patients in an attempt to elucidate the role of these regulatory B cells in pathogenesis of sepsis. Material/Methods Flow cytometry was used to quantify the percentage of CD19+CD24hiCD38hi regulatory B cells from peripheral blood samples. The correlation between B cell percentage and C reactive protein (CRP) level was analyzed. Secretion level of interleukin-10 (IL-10) and effects on the proliferation of naïve CD4+ T cells were further analyzed. Results The percentage of CD19+CD24hiCD38hi regulatory B cells in neonatal sepsis patients was significantly higher compared to healthy controls (p<0.05), and was positively correlated with serum CRP level. The percentage of IL-10+ CD19+CD24hiCD38hi regulatory B cells was also higher in sepsis patients, and also had more potent inhibition on naïve CD4+ T cells (p<0.01). Conclusions The elevation of CD19+CD24hiCD38hi regulatory B cells in neonatal sepsis can inhibit body immune function and thus may participate in the pathogenesis of sepsis. PMID:27389933

  15. Attenuation of experimental colitis in glutathione peroxidase 1 and catalase double knockout mice through enhancing regulatory T cell function.

    PubMed

    Kim, Hyung-Ran; Lee, Anbok; Choi, Eun-Jeong; Kie, Jeong-Hae; Lim, Woosung; Lee, Hyeon Kook; Moon, Byung-In; Seoh, Ju-Young

    2014-01-01

    Reactive oxygen species (ROS) have been implicated in the progression of inflammatory diseases including inflammatory bowel diseases (IBD). Meanwhile, several studies suggested the protective role of ROS in immune-mediated inflammatory diseases, and it was recently reported that dextran sodium sulfate (DSS)-induced colitis was attenuated in mice with an elevated level of ROS due to deficiency of peroxiredoxin II. Regulatory T cells (Tregs) are critical in the prevention of IBD and Treg function was reported to be closely associated with ROS level, but it has been investigated only in lowered levels of ROS so far. In the present study, in order to clarify the relationship between ROS level and Treg function, and their role in the pathogenesis of IBD, we investigated mice with an elevated level of ROS due to deficiency of both glutathione peroxidase (GPx)-1 and catalase (Cat) for the susceptibility of DSS-induced colitis in association with Treg function. The results showed that DSS-induced colitis was attenuated and Tregs were hyperfunctional in GPx1-/- × Cat-/- mice. In vivo administration of N-acetylcysteine (NAC) aggravated DSS-induced colitis and decreased Treg function to the level comparable to WT mice. Attenuated Th17 cell differentiation from naïve CD4+ cells as well as impaired production of IL-6 and IL-17A by splenocytes upon stimulation suggested anti-inflammatory tendency of GPx1-/- × Cat-/- mice. Suppression of Stat3 activation in association with enhancement of indoleamine 2,3-dioxygenase and FoxP3 expression might be involved in the immunosuppressive mechanism of GPx1-/- × Cat-/- mice. Taken together, it is implied that ROS level is critical in the regulation of Treg function, and IBD may be attenuated in appropriately elevated levels of ROS. PMID:24743300

  16. Abdominal {gamma}-Radiation Induces an Accumulation of Function-Impaired Regulatory T Cells in the Small Intestine

    SciTech Connect

    Billiard, Fabienne; Buard, Valerie; Benderitter, Marc; Linard, Christine

    2011-07-01

    Purpose: To assess the frequency and the functional characteristics of one major component of immune tolerance, the CD4{sup +}FoxP3{sup +} regulatory T cells (Tregs) in a mouse model of abdominal irradiation. Methods and Materials: Mice were exposed to a single abdominal dose of {gamma}-radiation (10 Gy). We evaluated small intestine Treg infiltration by Foxp3 immunostaining and the functional suppressive activity of Tregs isolated from mesenteric lymph nodes. Results: Foxp3 immunostaining showed that radiation induced a long-term infiltration of the intestine by Tregs (levels 5.5 times greater than in controls). Co-culture of Tregs from mesenteric lymph nodes with CD4{sup +} effector cells showed that the Tregs had lost their suppressive function. This loss was associated with a significant decrease in the levels of Foxp3, TGF-{beta}, and CTLA-4 mRNA, all required for optimal Treg function. At Day 90 after irradiation, Tregs regained their suppressive activity as forkhead box P3 (Foxp3), transforming growth factor beta (TGF-{beta}), and cytotoxic T-lymphocyte antigen 4 (CTLA-4) expression returned to normal. Analysis of the secretory function of mesenteric lymph node Tregs, activated in vitro with anti-CD3/anti-CD28 Abs, showed that this dysfunction was independent of a defect in interleukin-10 secretion. Conclusion: Radiation caused a long-term accumulation of function-impaired Foxp3{sup +}CD4{sup +} Tregs in the intestine. Our study provides new insights into how radiation affects the immune tolerance in peripheral tissues.

  17. Interleukin-10 deficiency impairs regulatory T cell-derived neuropilin-1 functions and promotes Th1 and Th17 immunity

    PubMed Central

    Wang, Shimin; Gao, Xiang; Shen, Guobo; Wang, Wei; Li, Jingyu; Zhao, Jingyi; Wei, Yu-Quan; Edwards, Carl K.

    2016-01-01

    Regulatory T cells (Tregs) expand in peripheral lymphoid organs and can produce immunosuppressive cytokines to support tumor growth. IL-10 abrogation efficiently induces Treg formation but dampens tumoral neuropilin-1 (Nrp-1) Treg signaling, which simultaneously augments Th1 and Th17 immunity. These effects are associated with the plasticity and stability of Tregs and effector T cell functions that can limit tumorigenesis. Within the tumor microenvironment, there appears to be a “mutual antagonism” between immunoenhancement and immunosuppression mechanisms, eventually leading to decreased metastasis. In contrast, tumor progression is paralleled by a reduction in Nrp-1-producing Tregs controlled by the IL-10 and TGF-β1 levels. However, Th1, Th17 and Treg immunity is primarily regulated by IL-10 or Nrp-1 and not TGF-β1 except when combined with IL-10. These results emphasize the important implications for the therapeutic use of Tregs. The number of Treg cells must be maintained in a healthy and dynamic homeostatic range to prevent malignant diseases. Moreover, Treg-mediated immunosuppression can be limited by reducing tumor-derived Treg Nrp-1 levels. PMID:27075020

  18. Regulatory T cells: a review.

    PubMed

    Dasgupta, Alakananda; Saxena, Renu

    2012-01-01

    Regulatory T cells (Tregs) play a pivotal role in the homeostasis of the immune system and in the modulation of the immune response. Tregs have emerged as key players in the development and maintenance of peripheral immune tolerance. Broadly speaking, CD4+ T cells possessing the ability to suppress immune responses can be divided into two types: naturally occurring (nTreg) and inducible (iTreg) or adaptive regulatory cells. Naturally occurring thymus-derived CD4+CD25+ Tregs are a subset of T cells which have immunosuppressive properties and are 5%-10% of the total peripheral CD4+ T cells. In normal conditions, Tregs regulate ongoing immune responses and prevent autoimmunity. Imbalanced function or number of these cells, either enhanced or decreased, might lead to tumour development and autoimmunity, respectively. These cells thus play a major role in autoimmune diseases, transplantation tolerance, infectious diseases, allergic disease and tumour immunity. These natural properties make Tregs attractive tools for novel immunotherapeutic approaches. The in vivo manipulation or depletion of Tregs may help devise effective immunotherapy for patients with cancer, autoimmunity, graftversus-host disease, infectious diseases and allergic diseases. It is crucial to understand the biology of Tregs before attempting therapies, including (i) the injection of expanded Tregs to cure autoimmune disease or prevent graft-versus-host disease or (ii) the depletion or inhibition of Tregs in cancer therapy. Recent findings in murine models and studies in humans have opened new avenues to study the biology of Tregs and their therapeutic potential. This overview provides a framework for integrating these concepts of basic and translational research. PMID:23998865

  19. Eos is redundant for T regulatory cell function, but plays an important role in IL-2 and Th17 production by CD4+ T conventional cells

    PubMed Central

    Rieder, Sadiye Amcaoglu; Metidji, Amina; Glass, Deborah Dacek; Thornton, Angela M.; Ikeda, Tohru; Morgan, Bruce A.; Shevach, Ethan M.

    2015-01-01

    Eos is a transcription factor that belongs to the Ikaros family of transcription factors. Eos has been reported to be a T regulatory cell (Treg) signature gene, to play a critical role in Treg suppressor functions, and to maintain Treg stability. We have utilized mice with a global deficiency of Eos to re-examine the role of Eos expression in both Treg and T conventional (Tconv) cells. Treg from Eos deficient (Eos−/−) mice developed normally, displayed a normal Treg phenotype, and exhibited normal suppressor function in vitro. Eos−/− Treg were as effective as Treg from wild type (WT) mice in suppression of inflammation in a model of inflammatory bowel disease. Bone marrow (BM) from Eos−/− mice was as effective as BM from WT mice in controlling T cell activation when used to reconstitute immunodeficient mice in the presence of Scurfy fetal liver cells. Surprisingly, Eos was expressed in activated Tconv cells and was required for IL-2 production, CD25 expression and proliferation in vitro by CD4+ Tconv cells. Eos−/− mice developed more severe Experimental Autoimmune Encephalomyelitis than WT mice, displayed increased numbers of effector T cells in the periphery and CNS, and amplified IL-17 production. In conclusion, our studies are not consistent with a role for Eos in Treg development and function, but demonstrate that Eos plays an important role in the activation and differentiation of Tconv cells. PMID:26062998

  20. Signal transducer and activator of transcription 5 (STAT5) paralog dose governs T cell effector and regulatory functions

    PubMed Central

    Villarino, Alejandro; Laurence, Arian; Robinson, Gertraud W; Bonelli, Michael; Dema, Barbara; Afzali, Behdad; Shih, Han-Yu; Sun, Hong-Wei; Brooks, Stephen R; Hennighausen, Lothar; Kanno, Yuka; O'Shea, John J

    2016-01-01

    The transcription factor STAT5 is fundamental to the mammalian immune system. However, the relationship between its two paralogs, STAT5A and STAT5B, and the extent to which they are functionally distinct, remain uncertain. Using mouse models of paralog deficiency, we demonstrate that they are not equivalent for CD4+ 'helper' T cells, the principal orchestrators of adaptive immunity. Instead, we find that STAT5B is dominant for both effector and regulatory (Treg) responses and, therefore, uniquely necessary for immunological tolerance. Comparative analysis of genomic distribution and transcriptomic output confirm that STAT5B has fargreater impact but, surprisingly, the data point towards asymmetric expression (i.e. paralog dose), rather than distinct functional properties, as the key distinguishing feature. Thus, we propose a quantitative model of STAT5 paralog activity whereby relative abundance imposes functional specificity (or dominance) in the face of widespread structural homology. DOI: http://dx.doi.org/10.7554/eLife.08384.001 PMID:26999798

  1. MAR binding protein SMAR1 favors IL-10 mediated regulatory T cell function in acute colitis

    SciTech Connect

    Mirlekar, Bhalchandra; Patil, Sachin; Bopanna, Ramanamurthy; Chattopadhyay, Samit

    2015-08-21

    T{sub reg} cells are not only crucial for controlling immune responses to autoantigens but also prevent those directed towards commensal pathogens. Control of effector immune responses by T{sub reg} cells depend on their capacity to accumulate at inflammatory site and accordingly accommodate to inflammatory environment. Till date, the factors associated with maintaining these aspects of T{sub reg} phenotype is not understood properly. Here we have shown that a known nuclear matrix binding protein SMAR1 is selectively expressed more in colonic T{sub reg} cells and is required for their ability to accumulate at inflammatory site and to sustain high levels of Foxp3 and IL-10 expression during acute colitis. Elimination of anti-inflammatory subsets revealed a protective role for IL-10 producing T{sub reg} cells in SMAR1{sup −/−} mice. Moreover, a combined action of Foxp3 and SMAR1 restricts effector cytokine production and enhance the production of IL-10 by colonic T{sub reg} cells that controls acute colitis. This data highlights a critical role of SMAR1 in maintaining T{sub reg} physiology during inflammatory disorders. - Highlights: • SMAR1 is essential to sustain high level of Foxp3 and IL-10 in T{sub reg} cells. • SMAR1{sup −/−} T{sub reg} cells produce pro-inflammatory cytokine IL-17 leads to inflammation. • IL-10 administration can control the inflammation in SMAR1{sup −/−} mice. • Both Foxp3 and SMAR1 maintain T{sub reg} phenotype that controls colitis.

  2. MAR binding protein SMAR1 favors IL-10 mediated regulatory T cell function in acute colitis.

    PubMed

    Mirlekar, Bhalchandra; Patil, Sachin; Bopanna, Ramanamurthy; Chattopadhyay, Samit

    2015-08-21

    Treg cells are not only crucial for controlling immune responses to autoantigens but also prevent those directed towards commensal pathogens. Control of effector immune responses by Treg cells depend on their capacity to accumulate at inflammatory site and accordingly accommodate to inflammatory environment. Till date, the factors associated with maintaining these aspects of Treg phenotype is not understood properly. Here we have shown that a known nuclear matrix binding protein SMAR1 is selectively expressed more in colonic Treg cells and is required for their ability to accumulate at inflammatory site and to sustain high levels of Foxp3 and IL-10 expression during acute colitis. Elimination of anti-inflammatory subsets revealed a protective role for IL-10 producing Treg cells in SMAR1(-/-) mice. Moreover, a combined action of Foxp3 and SMAR1 restricts effector cytokine production and enhance the production of IL-10 by colonic Treg cells that controls acute colitis. This data highlights a critical role of SMAR1 in maintaining Treg physiology during inflammatory disorders. PMID:26168735

  3. CD4⁺ T cells from IPEX patients convert into functional and stable regulatory T cells by FOXP3 gene transfer.

    PubMed

    Passerini, Laura; Rossi Mel, Eva; Sartirana, Claudia; Fousteri, Georgia; Bondanza, Attilio; Naldini, Luigi; Roncarolo, Maria Grazia; Bacchetta, Rosa

    2013-12-11

    In humans, mutations in the gene encoding for forkhead box P3 (FOXP3), a critically important transcription factor for CD4⁺CD25⁺ regulatory T (T(reg)) cell function, lead to a life-threatening systemic poly-autoimmune disease, known as immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome. Severe autoimmunity results from the inborn dysfunction and instability of FOXP3-mutated T(reg) cells. Hematopoietic stem cell transplantation is the only current curative option for affected patients. We show here that when CD4⁺ T cells are converted into T(reg) cells after lentivirus-mediated FOXP3 gene transfer, the resulting CD4(FOXP3) T cell population displays stable phenotype and suppressive function, especially when naïve T cells are converted. We further demonstrate that CD4(FOXP3) T cells are stable in inflammatory conditions not only in vitro but also in vivo in a model of xenogeneic graft-versus-host disease. We therefore applied this FOXP3 gene transfer strategy for the development of a T(reg) cell-based therapeutic approach to restore tolerance in IPEX syndrome. IPEX-derived CD4(FOXP3) T cells mirrored T(reg) cells from healthy donors in terms of cellular markers, anergic phenotype, cytokine production, and suppressive function. These findings pave the way for the treatment of IPEX patients by adoptive cell therapy with genetically engineered T(reg) cells and are seminal for future potential application in patients with autoimmune disorders of different origin. PMID:24337481

  4. Ultra-low Dose Interleukin-2 Promotes Immune-modulating Function of Regulatory T Cells and Natural Killer Cells in Healthy Volunteers

    PubMed Central

    Ito, Sawa; Bollard, Catherine M; Carlsten, Mattias; Melenhorst, Jan Joseph; Biancotto, Angélique; Wang, Ena; Chen, Jinguo; Kotliarov, Yuri; Cheung, Foo; Xie, Zhi; Marincola, Francesco; Tanimoto, Kazushi; Battiwalla, Minoo; Olnes, Matthew J; Perl, Shira; Schum, Paula; Hughes, Thomas E; Keyvanfar, Keyvan; Hensel, Nancy; Muranski, Pawel; Young, Neal S; Barrett, A John

    2014-01-01

    Low-dose interleukin-2 (IL-2) expands regulatory T cells (Tregs) and natural killer (NK) cells after stem cell transplantation (SCT) and may reduce graft-versus-host disease (GVHD). We hypothesized that ultra-low dose (ULD) IL-2 could serve as an immune-modulating agent for stem cell donors to prevent GVHD following SCT. However, the safety, dose level, and immune signatures of ULD IL-2 in immune-competent healthy subjects remain unknown. Here, we have characterized the phenotype and function of Tregs and NK cells as well as the gene expression and cytokine profiles of 21 healthy volunteers receiving 50,000 to 200,000 units/m2/day IL-2 for 5 days. ULD IL-2 was well tolerated and induced a significant increase in the frequency of Tregs with increased suppressive function. There was a marked expansion of CD56bright NK cells with enhanced interferon-γ (IFN-γ) production. Serum cytokine profiling demonstrated increase of IFN-γ induced protein 10 (IP-10). Gene expression analysis revealed significant changes in a highly restricted set of genes, including FOXP3, IL-2RA, and CISH. This is the first study to evaluate global immune-modulating function of ULD IL-2 in healthy subjects and to support the future studies administrating ULD IL-2 to stem cell donors. PMID:24686272

  5. CNS myelin induces regulatory functions of DC-SIGN-expressing, antigen-presenting cells via cognate interaction with MOG.

    PubMed

    García-Vallejo, J J; Ilarregui, J M; Kalay, H; Chamorro, S; Koning, N; Unger, W W; Ambrosini, M; Montserrat, V; Fernandes, R J; Bruijns, S C M; van Weering, J R T; Paauw, N J; O'Toole, T; van Horssen, J; van der Valk, P; Nazmi, K; Bolscher, J G M; Bajramovic, J; Dijkstra, C D; 't Hart, B A; van Kooyk, Y

    2014-06-30

    Myelin oligodendrocyte glycoprotein (MOG), a constituent of central nervous system myelin, is an important autoantigen in the neuroinflammatory disease multiple sclerosis (MS). However, its function remains unknown. Here, we show that, in healthy human myelin, MOG is decorated with fucosylated N-glycans that support recognition by the C-type lectin receptor (CLR) DC-specific intercellular adhesion molecule-3-grabbing nonintegrin (DC-SIGN) on microglia and DCs. The interaction of MOG with DC-SIGN in the context of simultaneous TLR4 activation resulted in enhanced IL-10 secretion and decreased T cell proliferation in a DC-SIGN-, glycosylation-, and Raf1-dependent manner. Exposure of oligodendrocytes to proinflammatory factors resulted in the down-regulation of fucosyltransferase expression, reflected by altered glycosylation at the MS lesion site. Indeed, removal of fucose on myelin reduced DC-SIGN-dependent homeostatic control, and resulted in inflammasome activation, increased T cell proliferation, and differentiation toward a Th17-prone phenotype. These data demonstrate a new role for myelin glycosylation in the control of immune homeostasis in the healthy human brain through the MOG-DC-SIGN homeostatic regulatory axis, which is comprised by inflammatory insults that affect glycosylation. This phenomenon should be considered as a basis to restore immune tolerance in MS. PMID:24935259

  6. Reconstruction of canine diffuse large B-cell lymphoma gene regulatory network: detection of functional modules and hub genes.

    PubMed

    Zamani-Ahmadmahmudi, M; Najafi, A; Nassiri, S M

    2015-01-01

    Lymphoma is one of the most common malignancies in dogs. Canine lymphoma is similar to human non-Hodgkin's lymphoma (NHL) with shared clinical presentation and histopathological features. This study reports the construction of a comprehensive gene regulatory network (GRN) for canine diffuse large B-cell lymphoma (DLBCL), the most common type of canine lymphoma, and performs analysis for detection of major functional modules and hub genes (the most important genes in a GRN). The canine DLBCL GRN was reconstructed from gene expression data (NCBI GEO dataset: GSE30881) using the STRING and MiMI interaction databases. Reconstructed GRNs were then assessed, using various bioinformatics programmes, in order to analyze network topology and identify major pathways and hub genes. The resultant network from both interaction databases had a logically scale-free pattern. Gene ontology (GO) analysis revealed cell activation, cell cycle phase, immune effector process, immune system development, immune system process, integrin-mediated signalling pathway, intracellular protein kinase cascade, intracellular signal transduction, leucocyte activation and differentiation, lymphocyte activation and differentiation as major GO terms in the biological processes of the networks. Moreover, bioinformatics analysis showed E2F1, E2F4, PTEN, CDKN1A, PCNA, DKC1, MNAT1, NDUFB4, ATP5J, PRKDC, BRCA1, MYCN, RFC4 and POLA1 as the most important hub genes. The phosphatidyl inositol signalling system, P53 signalling pathway, Rac CycD pathway, G1/S checkpoint, chemokine signalling pathway and telomere maintenance were the main signalling pathways in which the protein products of the hub genes are involved. PMID:25678421

  7. IL-15 renders conventional lymphocytes resistant to suppressive functions of regulatory T cells through activation of the phosphatidylinositol 3-kinase pathway.

    PubMed

    Ben Ahmed, Mélika; Belhadj Hmida, Nadia; Moes, Nicolette; Buyse, Sophie; Abdeladhim, Maha; Louzir, Hechmi; Cerf-Bensussan, Nadine

    2009-06-01

    IL-15 drives chronic inflammation in several human diseases. We have recently shown that IL-15 inhibits the immunosuppressive effects of TGF-beta through blockage of the Smad3-signaling pathway. Data pointing to reciprocal interactions between TGF-beta and CD4(+) regulatory T cells led us to investigate the impact of IL-15 on the de novo generation and function of regulatory T cells in humans. Our data indicate that IL-15 does not counteract, but rather promotes the effect of TGF-beta on the de novo generation of regulatory T cells (Treg). Thus, in the presence of TGF-beta, IL-15 enhanced the acquisition of regulatory functions by CD4(+)CD25(-) T cells stimulated by anti-CD3 and anti-CD28 Abs. In contrast, IL-15 impaired the functions of Tregs by acting on effector CD4 and CD8 T cells. Accordingly, in the presence of IL-15, proliferation and IFN-gamma production by peripheral CD4 and CD8 T cells could not be efficiently inhibited by Tregs. IL-15-induced resistance of effector T cells to Tregs resulted from activation of the PI3K signaling pathway but did not involve the rescue of effector T cells from apoptosis. Altogether, these data point to the ambiguous role of IL-15 in the control of Treg functions. This dual role may be instrumental to mount rapid but transient proinflammatory immune responses against pathogens but may become deleterious in situations associated with protracted IL-15 over-expression. PMID:19454671

  8. Regulatory T cells in spontaneous autoimmune encephalomyelitis.

    PubMed

    Furtado, G C; Olivares-Villagómez, D; Curotto de Lafaille, M A; Wensky, A K; Latkowski, J A; Lafaille, J J

    2001-08-01

    Spontaneous experimental autoimmune encephalomyelitis (EAE) develops in 100% of mice harboring a monoclonal myelin basic protein (MBP)-specific CD4+ alphabeta T-cell repertoire. Monoclonality of the alphabeta T-cell repertoire can be achieved by crossing MBP-specific T-cell receptor (TCR) transgenic mice with either RAG-/- mice or TCR alpha-/-/TCR beta-/- double knockout mice. Spontaneous EAE can be prevented by a single administration of purified CD4+ splenocytes or thymocytes obtained from wild-type syngeneic mice. The regulatory T cells (T-reg) that protect from spontaneous EAE need not express the CD25 marker, as effective protection can be attained with populations depleted of CD25+ T cells. Although the specificity of the regulatory T cells is important for their generation or regulatory function, T cells that protect from spontaneous EAE can have a diverse TCR alpha and beta chain composition. T-reg cells expand poorly in vivo, and appear to be long lived. Finally, precursors for T-reg are present in fetal liver as well as in the bone marrow of aging mice. We propose that protection of healthy individuals from autoimmune diseases involves several layers of regulation, which consist of CD4+CD25+ regulatory T cells, CD4+CD25- T-reg cells, and anti-TCR T cells, with each layer potentially operating at different stages of T-helper cell-mediated immune responses. PMID:11722629

  9. Cancer-Associated Myeloid Regulatory Cells.

    PubMed

    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. 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

  11. Human intrahepatic regulatory T cells are functional, require IL‐2 from effector cells for survival, and are susceptible to Fas ligand‐mediated apoptosis

    PubMed Central

    Chen, Yung‐Yi; Jeffery, Hannah C.; Hunter, Stuart; Bhogal, Ricky; Birtwistle, Jane; Braitch, Manjit Kaur; Roberts, Sheree; Ming, Mikaela; Hannah, Jack; Thomas, Clare; Adali, Gupse; Hübscher, Stefan G.; Syn, Wing‐Kin; Afford, Simon; Lalor, Patricia F.; Adams, David H.

    2016-01-01

    Regulatory T cells (Treg) suppress T effector cell proliferation and maintain immune homeostasis. Autoimmune liver diseases persist despite high frequencies of Treg in the liver, suggesting that the local hepatic microenvironment might affect Treg stability, survival, and function. We hypothesized that interactions between Treg and endothelial cells during recruitment and then with epithelial cells within the liver affect Treg stability, survival, and function. To model this, we explored the function of Treg after migration through human hepatic sinusoidal‐endothelium (postendothelial migrated Treg [PEM Treg]) and the effect of subsequent interactions with cholangiocytes and local proinflammatory cytokines on survival and stability of Treg. Our findings suggest that the intrahepatic microenvironment is highly enriched with proinflammatory cytokines but deficient in the Treg survival cytokine interleukin (IL)‐2. Migration through endothelium into a model mimicking the inflamed liver microenvironment did not affect Treg stability; however, functional capacity was reduced. Furthermore, the addition of exogenous IL‐2 enhanced PEM Treg phosphorylated STAT5 signaling compared with PEMCD8. CD4 and CD8 T cells are the main source of IL‐2 in the inflamed liver. Liver‐infiltrating Treg reside close to bile ducts and coculture with cholangiocytes or their supernatants induced preferential apoptosis of Treg compared with CD8 effector cells. Treg from diseased livers expressed high levels of CD95, and their apoptosis was inhibited by IL‐2 or blockade of CD95. Conclusion: Recruitment through endothelium does not impair Treg stability, but a proinflammatory microenvironment deficient in IL‐2 leads to impaired function and increased susceptibility of Treg to epithelial cell‐induced Fas‐mediated apoptosis. These results provide a mechanism to explain Treg dysfunction in inflamed tissues and suggest that IL‐2 supplementation, particularly if used in conjunction

  12. MicroRNA-17 Modulates Regulatory T Cell Function by Targeting Co-regulators of the Foxp3 Transcription Factor.

    PubMed

    Yang, Huang-Yu; Barbi, Joseph; Wu, Chao-Yi; Zheng, Ying; Vignali, Paolo D A; Wu, Xingmei; Tao, Jin-Hui; Park, Benjamin V; Bandara, Shashika; Novack, Lewis; Ni, Xuhao; Yang, Xiaoping; Chang, Kwang-Yu; Wu, Ren-Chin; Zhang, Junran; Yang, Chih-Wei; Pardoll, Drew M; Li, Huabin; Pan, Fan

    2016-07-19

    Regulatory T (Treg) cells are important in maintaining self-tolerance and immune homeostasis. The Treg cell transcription factor Foxp3 works in concert with other co-regulatory molecules, including Eos, to determine the transcriptional signature and characteristic suppressive phenotype of Treg cells. Here, we report that the inflammatory cytokine interleukin-6 (IL-6) actively repressed Eos expression through microRNA-17 (miR-17). miR-17 expression increased in Treg cells in the presence of IL-6, and its expression negatively correlated with that of Eos. Treg cell suppressive activity was diminished upon overexpression of miR-17 in vitro and in vivo, which was mitigated upon co-expression of an Eos mutant lacking miR-17 target sites. Also, RNAi of miR-17 resulted in enhanced suppressive activity. Ectopic expression of miR-17 imparted effector-T-cell-like characteristics to Treg cells via the de-repression of genes encoding effector cytokines. Thus, miR-17 provides a potent layer of Treg cell control through targeting Eos and additional Foxp3 co-regulators. PMID:27438767

  13. Low-level regulatory T-cell activity is essential for functional type-2 effector immunity to expel gastrointestinal helminths.

    PubMed

    Smith, K A; Filbey, K J; Reynolds, L A; Hewitson, J P; Harcus, Y; Boon, L; Sparwasser, T; Hämmerling, G; Maizels, R M

    2016-03-01

    Helminth infection is frequently associated with the expansion of regulatory T cells (Tregs) and suppression of immune responses to bystander antigens. We show that infection of mice with the chronic gastrointestinal helminth Heligmosomoides polygyrus drives rapid polyclonal expansion of Foxp3(+)Helios(+)CD4(+) thymic (t)Tregs in the lamina propria and mesenteric lymph nodes while Foxp3(+)Helios(-)CD4(+) peripheral (p)Treg expand more slowly. Notably, in partially resistant BALB/c mice parasite survival positively correlates with Foxp3(+)Helios(+)CD4(+) tTreg numbers. Boosting of Foxp3(+)Helios(+)CD4(+) tTreg populations by administration of recombinant interleukin-2 (rIL-2):anti-IL-2 (IL-2C) complex increased worm persistence by diminishing type-2 responsiveness in vivo, including suppression of alternatively activated macrophage and granulomatous responses at the sites of infection. IL-2C also increased innate lymphoid cell (ILC) numbers, indicating that Treg functions dominate over ILC effects in this setting. Surprisingly, complete removal of Tregs in transgenic Foxp3-DTR mice also resulted in increased worm burdens, with "immunological chaos" evident in high levels of the pro-inflammatory cytokines IL-6 and interferon-γ. In contrast, worm clearance could be induced by anti-CD25 antibody-mediated partial depletion of early Treg, alongside increased T helper type 2 responses and without incurring pathology. These findings highlight the overarching importance of the early Treg response to infection and the non-linear association between inflammation and the prevailing Treg frequency. PMID:26286232

  14. Low-level regulatory T-cell activity is essential for functional type-2 effector immunity to expel gastrointestinal helminths

    PubMed Central

    Smith, K A; Filbey, K J; Reynolds, L A; Hewitson, J P; Harcus, Y; Boon, L; Sparwasser, T; Hämmerling, G; Maizels, R M

    2016-01-01

    Helminth infection is frequently associated with the expansion of regulatory T cells (Tregs) and suppression of immune responses to bystander antigens. We show that infection of mice with the chronic gastrointestinal helminth Heligmosomoides polygyrus drives rapid polyclonal expansion of Foxp3+Helios+CD4+ thymic (t)Tregs in the lamina propria and mesenteric lymph nodes while Foxp3+Helios−CD4+ peripheral (p)Treg expand more slowly. Notably, in partially resistant BALB/c mice parasite survival positively correlates with Foxp3+Helios+CD4+ tTreg numbers. Boosting of Foxp3+Helios+CD4+ tTreg populations by administration of recombinant interleukin-2 (rIL-2):anti-IL-2 (IL-2C) complex increased worm persistence by diminishing type-2 responsiveness in vivo, including suppression of alternatively activated macrophage and granulomatous responses at the sites of infection. IL-2C also increased innate lymphoid cell (ILC) numbers, indicating that Treg functions dominate over ILC effects in this setting. Surprisingly, complete removal of Tregs in transgenic Foxp3-DTR mice also resulted in increased worm burdens, with “immunological chaos” evident in high levels of the pro-inflammatory cytokines IL-6 and interferon-γ. In contrast, worm clearance could be induced by anti-CD25 antibody–mediated partial depletion of early Treg, alongside increased T helper type 2 responses and without incurring pathology. These findings highlight the overarching importance of the early Treg response to infection and the non-linear association between inflammation and the prevailing Treg frequency. PMID:26286232

  15. Murine Melanoma-Infiltrating Dendritic Cells Are Defective in Antigen Presenting Function Regardless of the Presence of CD4+CD25+ Regulatory T Cells

    PubMed Central

    Ataera, Haley; Hyde, Evelyn; Price, Kylie M.; Stoitzner, Patrizia; Ronchese, Franca

    2011-01-01

    Tumor-infiltrating dendritic cells are often ineffective at presenting tumor-derived antigen in vivo, a defect usually ascribed to the suppressive tumor environment. We investigated the effects of depleting CD4+CD25+ “natural” regulatory T cells (Treg) on the frequency, phenotype and function of total dendritic cell populations in B16.OVA tumors and in tumor-draining lymph nodes. Intraperitoneal injection of the anti-CD25 monoclonal antibody PC61 reduced Treg frequency in blood and tumors, but did not affect the frequency of tumor-infiltrating dendritic cells, or their expression of CD40, CD86 and MHCII. Tumor-infiltrating dendritic cells from PC61-treated or untreated mice induced the proliferation of allogeneic T cells in vitro, but could not induce proliferation of OVA-specific OTI and OTII T cells unless specific peptide antigen was added in culture. Some proliferation of naïve, OVA-specific OTI T cells, but not OTII T cells, was observed in the tumor-draining LN of mice carrying B16.OVA tumors, however, this was not improved by PC61 treatment. Experiments using RAG1−/− hosts adoptively transferred with OTI and CD25-depleted OTII cells also failed to show improved OTI and OTII T cell proliferation in vivo compared to C57BL/6 hosts. We conclude that the defective presentation of B16.OVA tumor antigen by tumor-infiltrating dendritic cells and in the tumor-draining lymph node is not due to the presence of “natural” CD4+CD25+ Treg. PMID:21390236

  16. The human T-cell leukemia virus type 1 Rex regulatory protein exhibits an impaired functionality in human lymphoblastoid Jurkat T cells.

    PubMed Central

    Hamaia, S; Cassé, H; Gazzolo, L; Duc Dodon, M

    1997-01-01

    The Rex protein of human T-cell leukemia virus type 1 (HTLV-1) intervenes in the posttranscriptional regulation of proviral gene expression. Its binding to the Rex response element (XRE) present in the 3' long terminal repeat ensures the coordinate cytoplasmic accumulation of spliced and unspliced forms of viral messengers. Consequently, synthesis of viral structural and enzymatic proteins is strictly dependent on the Rex posttranscriptional activity. Here we report that synthesis of HTLV-1 envelope glycoproteins by Jurkat T cells could be detected only when they were regulated in a Rex-independent manner. Indeed, Jurkat T cells transfected with a Rex-dependent env expression vector (encompassing both the env and pX open reading frames) do not produce significant levels of envelope glycoproteins despite the production of significant amounts of Rex protein. The analysis of levels and distribution patterns of the unspliced env and of the singly spliced tax/rex transcripts suggests that the failure in envelope glycoprotein synthesis may be ascribed to a deficiency of Rex in mediating the nucleocytoplasmic transport of unspliced env RNAs in these cells. Furthermore, despite the synthesis of regulatory proteins, HTLV-1 structural proteins were not detected in Jurkat T cells transfected with an HTLV-1 infectious provirus. Conversely, and as expected, structural proteins were produced by Jurkat cells transfected by a human immunodeficiency virus type 1 (HIV-1) infectious provirus. This phenotype appeared to be linked to a specific dysfunction of Rex, since the functionally equivalent Rev protein of HIV-1 was shown to be fully efficient in promoting the synthesis of HTLV-1 envelope glycoproteins in Jurkat cells. Therefore, it seems likely that the block to Rex function in these lymphoblastoid T cells is determined by inefficient Rex-XRE interactions. These observations suggest that the acquisition of this Rex-deficient phenotype by in vivo-infected HTLV-1 T cells may

  17. Natural regulatory T cells in autoimmunity

    PubMed Central

    Lourenço, Elaine V.; La Cava, Antonio

    2010-01-01

    The suppressive/immunomodulatory function of CD4+CD25+Foxp+ regulatory T (Treg) cells is crucial for the maintenance of immune homeostasis, which helps to prevent autoimmunity and reduce the inflammation induced by pathogens and environmental insults. This review summarizes the current knowledge on the types and mechanisms of action of Treg cells and their role in the immune tolerance to self antigens, with a particular focus on naturally occurring Treg cells. PMID:21091291

  18. MicroRNA-31 functions as a tumor suppressor by regulating cell cycle and epithelial-mesenchymal transition regulatory proteins in liver cancer

    PubMed Central

    Bae, Hyun Jin; Eun, Jung Woo; Shen, Qingyu; Park, Se Jin; Shin, Woo Chan; Yang, Hee Doo; Park, Mijung; Park, Won Sang; Kang, Yong-Koo; Nam, Suk Woo

    2015-01-01

    MicroRNA-31 (miR-31) is among the most frequently altered microRNAs in human cancers and altered expression of miR-31 has been detected in a large variety of tumor types, but the functional role of miR-31 still hold both tumor suppressive and oncogenic roles in different tumor types. MiR-31 expression was down-regulated in a large cohort of hepatocellular carcinoma (HCC) patients, and low expression of miR-31 was significantly associated with poor prognosis of HCC patients. Ectopic expression of miR-31 mimics suppressed HCC cell growth by transcriptional deregulation of cell cycle proteins. Additional study evidenced miR-31 directly to suppress HDAC2 and CDK2 expression by inhibiting mRNA translation in HCC cells. We also found that ectopic expression of miR-31 mimics reduced metastatic potential of HCC cells by selectively regulating epithelial-mesenchymal transition (EMT) regulatory proteins such as N-cadherin, E-cadherin, vimentin and fibronectin. HCC tissues derived from chemical-induced rat liver cancer models validated that miR-31 expression is significantly down-regulated, and that those cell cycle- and EMT-regulatory proteins are deregulated in rat liver cancer. Overall, we suggest that miR-31 functions as a tumor suppressor by selectively regulating cell cycle and EMT regulatory proteins in human hepatocarcinogenesis providing a novel target for the molecular treatment of liver malignancies. PMID:25797269

  19. From the regulatory functions of B cells to the identification of cytokine-producing plasma cell subsets.

    PubMed

    Dang, Van Duc; Hilgenberg, Ellen; Ries, Stefanie; Shen, Ping; Fillatreau, Simon

    2014-06-01

    B lymphocytes have a unique role as antibody-producing cells. Antibodies are key mediators of humoral immunity against infections, and are thought to account for the protection afforded by successful vaccines. B cells can also secrete cytokines and subsequently regulate immune responses mediated by T and innate cells. Remarkably, recent studies identified plasma blasts/plasma cells as the main types of activated B cells producing the cytokines interleukin (IL)-10, IL-35, tumor necrosis factor (TNF)-α, IL-17, and GM-CSF in various contexts in mice. Here, we discuss these observations, which suggest the existence of various subsets of plasma blast/plasma cells distinguishable through their cytokine expression pattern. PMID:24637161

  20. Similar disturbances in B cell activity and regulatory T cell function in Henoch-Schonlein purpura and systemic lupus erythematosus

    SciTech Connect

    Beale, M.G.; Nash, G.S.; Bertovich, M.J.; MacDermott, R.P.

    1982-01-01

    The immunoglobulin synthesizing activities of peripheral mononuclear cells (MNC) from five patients with Henoch-Schonlein purpura (HSP) and eight patients with active systemic lupus erythematosus (SLE) were compared. Cumulative amounts of IgM, IgG, and IgA synthesized and secreted by unstimulated and PWM-stimulated patient cells over a 12-day period were determied in a solid-phase radioimmunoassay. In unstimulated control cultures mean rates of IgM, IgG, and IgA synthesis were less than 250 ng/ml. The synthetic activities of patient MNC were markedly increased. In HSP cultures IgA was the major immunoglobulin class produced (2810 x/divide 1.33 ng/ml) followed by IgG (1754 x/divide 1.32 ng/ml) and IgM (404 x/divide 1.16 ng/ml). In SLE cultures IgA and IgG syntheses were equally elevated (4427 x/divide 1.20 and 4438 x/divide 1.49 ng/ml, respectively) whereas IgM synthesis averaged 967 x/divide 1.66 ng/ml. PWM stimulation of pateient MNC caused a sharp decline in the synthesis of all three immunoglobulin classes. After T cell depletion B cell-enriched fractions from HSP and SLE patients maintained high levels of IgA and IgG synthesis that were inhibited by PWM and by normal allogeneic but not autologous T cells. In PWM-stimulted co-cultures, patient T cells nonspecifically suppressed the synthetic activities of autologous and control B cells. in contrast patient B cells achieved normal levels of immunoglobulin synthesis when cultured with control T cells plus PWM. In longitudinal studies patient B and T cell disturbances persisted despite clinical improvement.

  1. Regulatory T cells in allergic diseases.

    PubMed

    Noval Rivas, Magali; Chatila, Talal A

    2016-09-01

    The pathogenesis of allergic diseases entails an ineffective tolerogenic immune response to allergens. Regulatory T (Treg) cells play a key role in sustaining immune tolerance to allergens, yet mechanisms by which Treg cells fail to maintain tolerance in patients with allergic diseases are not well understood. We review current concepts and established mechanisms regarding how Treg cells regulate different components of allergen-triggered immune responses to promote and maintain tolerance. We will also discuss more recent advances that emphasize the "dual" functionality of Treg cells in patients with allergic diseases: how Treg cells are essential in promoting tolerance to allergens but also how a proallergic inflammatory environment can skew Treg cells toward a pathogenic phenotype that aggravates and perpetuates disease. These advances highlight opportunities for novel therapeutic strategies that aim to re-establish tolerance in patients with chronic allergic diseases by promoting Treg cell stability and function. PMID:27596705

  2. Regulatory T cells: stability revisited

    PubMed Central

    Bailey-Bucktrout, Samantha L.; Bluestone, Jeffrey A.

    2011-01-01

    Breakdown in self-tolerance is due, in part, to a loss of regulatory T (Treg) cells. Recently, a controversy has surfaced about whether Treg cells are overwhelmingly stable, or if they can be reprogrammed in inflammatory and autoimmune environments. Those in the instability “camp” have shown that a fraction of Treg cells lose Foxp3 and acquire effector arm activities. Instability is coupled with IL-2 insufficiency and the inflammatory milieu that promote reprogramming. Here, we highlight the basic tenets of each viewpoint and discuss technical, biological and environmental differences in the models that may help yield a unifying hypothesis. Also considered is how Treg cell instability could link to development of autoimmune disease and the implications for Treg cell-based cellular therapy trials. PMID:21620768

  3. Thymus-Derived Regulatory T Cells Are Positively Selected on Natural Self-Antigen through Cognate Interactions of High Functional Avidity.

    PubMed

    Kieback, Elisa; Hilgenberg, Ellen; Stervbo, Ulrik; Lampropoulou, Vicky; Shen, Ping; Bunse, Mario; Jaimes, Yarua; Boudinot, Pierre; Radbruch, Andreas; Klemm, Uwe; Kühl, Anja A; Liblau, Roland; Hoevelmeyer, Nadine; Anderton, Stephen M; Uckert, Wolfgang; Fillatreau, Simon

    2016-05-17

    Regulatory T (Treg) cells expressing Foxp3 transcripton factor are essential for immune homeostasis. They arise in the thymus as a separate lineage from conventional CD4(+)Foxp3(-) T (Tconv) cells. Here, we show that the thymic development of Treg cells depends on the expression of their endogenous cognate self-antigen. The formation of these cells was impaired in mice lacking this self-antigen, while Tconv cell development was not negatively affected. Thymus-derived Treg cells were selected by self-antigens in a specific manner, while autoreactive Tconv cells were produced through degenerate recognition of distinct antigens. These distinct modes of development were associated with the expression of T cell receptor of higher functional avidity for self-antigen by Treg cells than Tconv cells, a difference subsequently essential for the control of autoimmunity. Our study documents how self-antigens define the repertoire of thymus-derived Treg cells to subsequently endow this cell type with the capacity to undermine autoimmune attack. PMID:27192577

  4. Human regulatory T cells control TCR signaling and susceptibility to suppression in CD4+ T cells.

    PubMed

    Chellappa, Stalin; Lieske, Nora V; Hagness, Morten; Line, Pål D; Taskén, Kjetil; Aandahl, Einar M

    2016-07-01

    Human CD4(+)CD25(hi)FOXP3(+) regulatory T cells maintain immunologic tolerance and prevent autoimmune and inflammatory immune responses. Regulatory T cells undergo a similar activation cycle as conventional CD4(+) T cells upon antigen stimulation. Here, we demonstrate that T cell receptors and costimulation are required to activate the regulatory T cell suppressive function. Regulatory T cells suppressed the T cell receptor signaling in effector T cells in a time-dependent manner that corresponded with inhibition of cytokine production and proliferation. Modulation of the activation level and thereby the suppressive capacity of regulatory T cells imposed distinct T cell receptor signaling signatures and hyporesponsiveness in suppressed and proliferating effector T cells and established a threshold for effector T cell proliferation. The immune suppression of effector T cells was completely reversible upon removal of regulatory T cells. However, the strength of prior immune suppression by regulatory T cells and corresponding T cell receptor signaling in effector T cells determined the susceptibility to suppression upon later reexposure to regulatory T cells. These findings demonstrate how the strength of the regulatory T cell suppressive function determines intracellular signaling, immune responsiveness, and the later susceptibility of effector T cells to immune suppression and contribute to unveiling the complex interactions between regulatory T cells and effector T cells. PMID:26715685

  5. Regulatory function of cytomegalovirus-specific CD4{sup +}CD27{sup -}CD28{sup -} T cells

    SciTech Connect

    Tovar-Salazar, Adriana; Patterson-Bartlett, Julie; Jesser, Renee; Weinberg, Adriana

    2010-03-15

    CMV infection is characterized by high of frequencies of CD27{sup -}CD28{sup -} T cells. Here we demonstrate that CMV-specific CD4{sup +}CD27{sup -}CD28{sup -} cells are regulatory T cells (T{sub R}). CD4{sup +}CD27{sup -}CD28{sup -} cells sorted from CMV-stimulated PBMC of CMV-seropositive donors inhibited de novo CMV-specific proliferation of autologous PBMC in a dose-dependent fashion. Compared with the entire CMV-stimulated CD4{sup +} T-cell population, higher proportions of CD4{sup +}CD27{sup -}CD28{sup -} T{sub R} expressed FoxP3, TGFbeta, granzyme B, perforin, GITR and PD-1, lower proportions expressed CD127 and PD1-L and similar proportions expressed CD25, CTLA4, Fas-L and GITR-L. CMV-CD4{sup +}CD27{sup -}CD28{sup -} T{sub R} expanded in response to IL-2, but not to CMV antigenic restimulation. The anti-proliferative effect of CMV-CD4{sup +}CD27{sup -}CD28{sup -} T{sub R} significantly decreased after granzyme B or TGFbeta inhibition. The CMV-CD4{sup +}CD27{sup -}CD28{sup -} T{sub R} of HIV-infected and uninfected donors had similar phenotypes and anti-proliferative potency, but HIV-infected individuals had higher proportions of CMV-CD4{sup +}CD27{sup -}CD28{sup -} T{sub R}. The CMV-CD4{sup +}CD27{sup -}CD28{sup -} T{sub R} may contribute to the downregulation of CMV-specific and nonspecific immune responses of CMV-infected individuals.

  6. Differential impact of high and low penetrance TNFRSF1A gene mutations on conventional and regulatory CD4+ T cell functions in TNFR1-associated periodic syndrome.

    PubMed

    Pucino, Valentina; Lucherini, Orso Maria; Perna, Francesco; Obici, Laura; Merlini, Giampaolo; Cattalini, Marco; La Torre, Francesco; Maggio, Maria Cristina; Lepore, Maria Teresa; Magnotti, Flora; Galgani, Mario; Galeazzi, Mauro; Marone, Gianni; De Rosa, Veronica; Talarico, Rosaria; Cantarini, Luca; Matarese, Giuseppe

    2016-05-01

    TNFR-associated periodic syndrome is an autoinflammatory disorder caused by autosomal-dominant mutations in TNFRSF1A, the gene encoding for TNFR superfamily 1A. The lack of knowledge in the field of TNFR-associated periodic syndrome biology is clear, particularly in the context of control of immune self-tolerance. We investigated how TNF-α/TNFR superfamily 1A signaling can affect T cell biology, focusing on conventional CD4(+)CD25(-) and regulatory CD4(+)CD25(+) T cell functions in patients with TNFR-associated periodic syndrome carrying either high or low penetrance TNFRSF1A mutations. Specifically, we observed that in high penetrance TNFR-associated periodic syndrome, at the molecular level, these alterations were secondary to a hyperactivation of the ERK1/2, STAT1/3/5, mammalian target of rapamycin, and NF-κB pathways in conventional T cells. In addition, these patients had a lower frequency of peripheral regulatory T cells, which also displayed a defective suppressive phenotype. These alterations were partially found in low penetrance TNFR-associated periodic syndrome, suggesting a specific link between the penetrance of the TNFRSF1A mutation and the observed T cell phenotype. Taken together, our data envision a novel role for adaptive immunity in the pathogenesis of TNFR-associated periodic syndrome involving both CD4(+) conventional T cells and Tregs, suggesting a novel mechanism of inflammation in the context of autoinflammatory disorders. PMID:26598380

  7. T regulatory cells in allergy.

    PubMed

    Braga, M; Quecchia, C; Cavallucci, E; Di Giampaolo, L; Schiavone, C; Petrarca, C; Di Gioacchino, M

    2011-01-01

    The progressive understanding of the nature and mechanisms of T regulatory (Treg) cells in the last decade has changed the concept of immune tolerance, that is no longer considered as a mere lack of immune reactivity but as a finely regulated process that requires specific activity of cells, adhesion and secreted molecules. Tregs play a key role in maintenance of self-tolerance and induction of tolerance against ubiquitous innocuous non-self antigens, so preventing the onset of autoimmune diseases and allergies. This review will focus on the Treg response in allergy that is characterized by a down-regulation of allergen specific T cell proliferation and inhibition of both Th1 and Th2 cytokines production. Hence, Treg cells suppress allergen-specific Th1 and Th2 cell responses playing an important role in the physiological immune response to allergens. Further, Treg cells are able to suppress IgE production by B lymphocytes and directly or indirectly inhibit the activity of allergic inflammation effector cells, namely eosinophils, basophils and mastcells. Finally, increasing evidence suggests that Treg cells are also implicated in chronicity development of inflammatory diseases. This appears to happen through a fine interaction they entertain with resident tissue cells and has been particularly highlighted in the study of airways remodeling in asthma. The understanding of the mechanisms underlying allergen tolerance has brought new interest in the development of new allergy treatment, able to target Treg cells, both in allergy prevention and in the therapy of established allergy. PMID:21329567

  8. Regulatory and effector functions of gamma-delta (γδ) T cells and their therapeutic potential in adoptive cellular therapy for cancer.

    PubMed

    Paul, Sourav; Lal, Girdhari

    2016-09-01

    γδ T cells are an important innate immune component of the tumor microenvironment and are known to affect the immune response in a wide variety of tumors. Unlike αβ T cells, γδ T cells are capable of spontaneous secretion of IL-17A and IFN-γ without undergoing clonal expansion. Although γδ T cells do not require self-MHC-restricted priming, they can distinguish "foreign" or transformed cells from healthy self-cells by using activating and inhibitory killer Ig-like receptors. γδ T cells were used in several clinical trials to treat cancer patient due to their MHC-unrestricted cytotoxicity, ability to distinguish transformed cells from normal cells, the capacity to secrete inflammatory cytokines and also their ability to enhance the generation of antigen-specific CD8(+) and CD4(+) T cell response. In this review, we discuss the effector and regulatory function of γδ T cells in the tumor microenvironment with special emphasis on the potential for their use in adoptive cellular immunotherapy. PMID:27012367

  9. The NF-κB transcription factor RelA is required for the tolerogenic function of Foxp3(+) regulatory T cells.

    PubMed

    Messina, Nicole; Fulford, Thomas; O'Reilly, Lorraine; Loh, Wen Xian; Motyer, Jessica M; Ellis, Darcy; McLean, Catriona; Naeem, Haroon; Lin, Ann; Gugasyan, Raffi; Slattery, Robyn M; Grumont, Raelene J; Gerondakis, Steve

    2016-06-01

    The properties of CD4(+) regulatory T cell (Treg) subsets are dictated by distinct patterns of gene expression determined by FOXP3 and different combinations of various transcription factors. Here we show the NF-κB transcription factor RelA is constitutively active in naïve and effector Tregs. The conditional inactivation of Rela in murine FOXP3(+) cells induces a rapid onset, multi-focal autoimmune disease that depends on RelA being expressed in conventional T cells. In addition to promoting Treg lineage stability, RelA determines the size of the effector Treg population, a function influenced by the presence or absence of RelA in conventional T cells. These findings showing that RelA controls Treg stability and promotes the competitive fitness of effector Tregs highlight the importance of RelA activity in peripheral Treg induced tolerance. PMID:27068879

  10. Functional CD25- and CD25+ mucosal regulatory T cells are induced in gut-draining lymphoid tissue within 48 h after oral antigen application.

    PubMed

    Hauet-Broere, Femke; Unger, Wendy W J; Garssen, Johan; Hoijer, Maarten A; Kraal, Georg; Samsom, Janneke N

    2003-10-01

    Oral antigen application induces tolerance, leading to suppression of a subsequent systemic challenge with this antigen. The suppression is mediated by mucosal regulatory T (Tr) cells that may differentiate from naive peripheral T cells in the gut-draining lymphoid tissue. However, little is known about the initial steps of this differentiation process. In this study we show that 48 h after oral OVA treatment, antigen-specific T cells in mesenteric lymph nodes (MLN) and Peyer's Patches (PP) were activated and had divided up to four times. The first division was already seen in PP after 24 h. Analysis of surface marker expression and cytokine secretion of the dividing antigen-specific T cells revealed that they sequentially obtained an activation- and memory-like phenotype. These cells secreted IL-2 in most stages of division but only transiently IFN-gamma whereas no IL-4 or IL-10 secretion was detected. Remarkably, 48 h after antigen application, isolated dividing cells were suppressive, as they transferred tolerance to naive mice. Even though CD25 was expressed heterogeneously, both CD25(+) and CD25(-) OVA-specific T cells from MLN could transfer tolerance. Together these findings show that differentiation of functional Tr cells occurs in the MLN and PP within 2 days after antigen ingestion and involves the generation of CD25(+) and CD25(-) antigen-specific T cells. PMID:14515264

  11. CD28/CTLA-4/B7 costimulatory pathway blockade affects regulatory T-cell function in autoimmunity.

    PubMed

    Vogel, Isabel; Kasran, Ahmad; Cremer, Jonathan; Kim, Yoo-Jin; Boon, Louis; Van Gool, Stefaan W; Ceuppens, Jan L

    2015-06-01

    Naïve T cells require B7/CD28 costimulation in order to be fully activated. Attempts to block this pathway have been effective in preventing unwanted immune reactions. As B7 blockade might also affect Treg cells and interfere with negative signaling through membrane CTLA-4 on effector T (Teff) cells, its immune-modulatory effects are potentially more complex. Here, we used the mouse model of multiple sclerosis (MS), EAE, to study the effect of B7 blockade. An effective therapy for MS patients has to interfere with ongoing inflammation, and therefore we injected CTLA-4Ig at day 7 and 9 after immunization, when myelin-reactive T cells have been primed and start migrating toward the CNS. Surprisingly, B7 blockade exacerbated disease signs and resulted in more severe CNS inflammation and demyelination, and was associated with an enhanced production of the inflammatory cytokines IL-17 and IFN-γ. Importantly, CTLA-4Ig treatment resulted in a transient reduction of Ki67 and CTLA-4 expression and function of peripheral Treg cells. Taken together, B7 blockade at a particular stage of the autoimmune response can result in the suppression of Treg cells, leading to a more severe disease. PMID:25727069

  12. A Transcriptional Regulatory Role of the THAP11–HCF-1 Complex in Colon Cancer Cell Function

    PubMed Central

    Parker, J. Brandon; Palchaudhuri, Santanu; Yin, Hanwei; Wei, Jianjun

    2012-01-01

    The recently identified Thanatos-associated protein (THAP) domain is an atypical zinc finger motif with sequence-specific DNA-binding activity. Emerging data suggest that THAP proteins may function in chromatin-dependent processes, including transcriptional regulation, but the roles of most THAP proteins in normal and aberrant cellular processes remain largely unknown. In this work, we identify THAP11 as a transcriptional regulator differentially expressed in human colon cancer. Immunohistochemical analysis of human colon cancers revealed increased THAP11 expression in both primary tumors and metastases. Knockdown of THAP11 in SW620 colon cancer cells resulted in a significant decrease in cell proliferation, and profiling of gene expression in these cells identified a novel gene set composed of 80 differentially expressed genes, 70% of which were derepressed by THAP11 knockdown. THAP11 was found to associate physically with the transcriptional coregulator HCF-1 (host cell factor 1) and recruit HCF-1 to target promoters. Importantly, THAP11-mediated gene regulation and its chromatin association require HCF-1, while HCF-1 recruitment at these genes requires THAP11. Collectively, these data provide the first characterization of THAP11-dependent gene expression in human colon cancer cells and suggest that the THAP11–HCF-1 complex may be an important transcriptional and cell growth regulator in human colon cancer. PMID:22371484

  13. Regulatory T cells in allergy and asthma.

    PubMed

    Larché, Mark

    2007-09-01

    Allergic diseases including asthma have risen considerably in prevalence in the last 50 years. A concomitant rise in autoimmune disease suggests a defect in immunoregulation, rather than a reduction in T-helper type 1 immunity. Immune responses to innocuous environmental antigens in health are characterized by dominant regulation through the production of interleukin-10 and transforming growth factor-beta. Recent studies suggest that diverse populations of regulatory T cells (Treg) play an important role in regulating T-helper type 2 (Th2) responses to allergens, maintaining functional tolerance. Regulatory responses appear to be compromised in allergic individuals but may be reconstituted to some extent with specific allergen immunotherapy. In experimental models, Treg can suppress Th2 responses to allergen, airway eosinophilia, mucous hypersecretion, and airway hyperresponsiveness. Further studies are required to precisely define the mechanisms of development and action of these cells, and to identify and evaluate novel targets for the treatment of allergic diseases. PMID:17873195

  14. Immunoregulatory changes induced by total lymphoid irradiation. II. Development of thymus-leukemia antigen-positive and -negative suppressor T cells that differ in their regulatory function

    SciTech Connect

    King, D.P.; Strober, S.

    1981-07-01

    BALB/c mice treated with total lymphoid irradiation (TLI) develop non-antigen-specific suppressor cells of the adoptive secondary antibody response and of the mixed leukocyte reaction. Suppressors of the adoptive anti-DNP response were eliminated by incubation of spleen cells with anti-Thy-1.2 or anti-thymus-leukemia (TL) antiserum and complement before cell transfer. Thymectomy before TLI prevented the appearance of the latter suppressor cells. On the other hand, suppressors of the MLR were eliminated by incubation of spleen cells with anti-Thy-1.2 but not anti-TL antiserum and complement. Thymectomy before TLI did not prevent their subsequent development. Thus, two subpopulations of suppressor T cells that differ in the expression of the TL surface antigen, dependence on the presence of the thymus, and in regulatory functions develop after TLI. The TL+, thymus-dependent cell suppresses the adoptive antibody response, and the TL-, thymus-independent cell suppresses the MLR.

  15. T regulatory cells in childhood asthma.

    PubMed

    Strickland, Deborah H; Holt, Patrick G

    2011-09-01

    Asthma is a chronic disease of the airways, most commonly driven by immuno-inflammatory responses to ubiquitous airborne antigens. Epidemiological studies have shown that disease is initiated early in life when the immune and respiratory systems are functionally immature and less able to maintain homeostasis in the face of continuous antigen challenge. Here, we examine the cellular and molecular mechanisms that underlie initial aeroallergen sensitization and the ensuing regulation of secondary responses to inhaled allergens in the airway mucosa. In particular, we focus on how T-regulatory (Treg) cells influence early asthma initiation and the potential of Treg cells as therapeutic targets for drug development in asthma. PMID:21798806

  16. Interleukin 35-Producing B Cells (i35-Breg): A New Mediator of Regulatory B-Cell Functions in CNS Autoimmune Diseases.

    PubMed

    Egwuagu, Charles E; Yu, Cheng-Rong

    2015-01-01

    Neuroinflammation contributes to neuronal deficits in neurodegenerative CNS (central nervous system) autoimmune diseases, such as multiple sclerosis and uveitis. The major goal of most treatment modalities for CNS autoimmune diseases is to limit inflammatory responses in the CNS; immune-suppressive drugs are the therapy of choice. However, lifelong immunosuppression increases the occurrence of infections, nephrotoxicity, malignancies, cataractogenesis, and glaucoma, which can greatly impair quality of life for the patient. Biologics that target pathogenic T cells is an alternative approach that is gaining wide acceptance as indicated by the popularity of a variety of Food and Drug Administration (FDA)-approved anti-inflammatory compounds and humanized antibodies such as Zenapax, Etanercept, Remicade, anti-ICAM, rapamycin, or tacrolimus. B cells are also potential therapeutic targets because they provide costimulatory signals that activate pathogenic T cells and secrete cytokines that promote autoimmune pathology. B cells also produce autoreactive antibodies implicated in several organ-specific and systemic autoimmune diseases including lupus erythematosus, Graves' disease, and Hashimoto's thyroiditis. On the other hand, recent studies have led to the discovery of several regulatory B-cell (Breg) populations that suppress immune responses and autoimmune diseases. In this review, we present a brief overview of Breg phenotypes and in particular, the newly discovered IL35-producing regulatory B cell (i35-Breg). We discuss the critical roles played by i35-Bregs in regulating autoimmune diseases and the potential use of adoptive Breg therapy in CNS autoimmune diseases. PMID:25746047

  17. Increased CD45RA+FoxP3low Regulatory T Cells with Impaired Suppressive Function in Patients with Systemic Lupus Erythematosus

    PubMed Central

    Wang, Weiwei; Shan, Jianping; Lin, Fujun; Jiang, Gengru; Yang, Yuan H.; Wang, Die; Xu, Dakang; Shen, Lisong

    2012-01-01

    Background The role of naturally occurring regulatory T cells (Treg) in the control of the development of systemic lupus erythematosus (SLE) has not been well defined. Therefore, we dissect the phenotypically heterogeneous CD4+FoxP3+ T cells into subpopulations during the dynamic SLE development. Methodlogy/Principal Findings To evaluate the proliferative and suppressive capacities of different CD4+ T cell subgroups between active SLE patients and healthy donors, we employed CD45RA and CD25 as surface markers and carboxyfluorescein diacetatesuccinimidyl ester (CFSE) dilution assay. In addition, multiplex cytokines expression in active SLE patients was assessed using Luminex assay. Here, we showed a significant increase in the frequency of CD45RA+FoxP3low naive Treg cells (nTreg cells) and CD45RA−FoxP3low (non-Treg) cells in patients with active SLE. In active SLE patients, the increased proportions of CD45RA+FoxP3low nTreg cells were positively correlated with the disease based on SLE disease activity index (SLEDAI) and the status of serum anti-dsDNA antibodies. We found that the surface marker combination of CD25+CD45RA+ can be used to defined CD45RA+FoxP3low nTreg cells for functional assays, wherein nTreg cells from active SLE patients demonstrated defective suppression function. A significant correlation was observed between inflammatory cytokines, such as IL-6, IL-12 and TNFα, and the frequency of nTreg cells. Furthermore, the CD45RA+FoxP3low nTreg cell subset increased when cultured with SLE serum compared to healthy donor serum, suggesting that the elevated inflammatory cytokines of SLE serum may promote nTreg cell proliferation/expansion. Conclusions/Significance Our results indicate that impaired numbers of functional CD45RA+FoxP3low naive Treg cell and CD45RA−FoxP3low non-suppressive T cell subsets in inflammatory conditions may contribute to SLE development. Therefore, analysis of subsets of FoxP3+ T cells, using a combination of FoxP3, CD25 and CD

  18. Transcriptomic and Proteomic Data Integration and Two-Dimensional Molecular Maps with Regulatory and Functional Linkages: Application to Cell Proliferation and Invasion Networks in Glioblastoma.

    PubMed

    Gupta, Manoj Kumar; Jayaram, Savita; Reddy, Divijendra Natha; Polisetty, Ravindra Varma; Sirdeshmukh, Ravi

    2015-12-01

    Glioblastoma multiforme (GBM), the most aggressive primary brain tumor, is characterized by high rates of cell proliferation, migration, and invasion. New therapeutic strategies and targets are being continuously explored with the hope for better outcome. By overlaying transcriptomic and proteomic data from GBM clinical tissues, we identified 317 differentially expressed proteins to be concordant with the messenger RNAs (mRNAs). We used these entities to generate integrated regulatory information at the level of microRNAs (miRNAs) and their mRNA and protein targets using prediction programs or experimentally verified miRNA target mode in the miRWalk database. We observed 60% or even more of the miRNA-target pairs to be consistent with experimentally observed inverse expression of these molecules in GBM. The integrated view of these regulatory cascades in the contexts of cell proliferation and invasion networks revealed two-dimensional molecular interactions with regulatory and functional linkages (miRNAs and their mRNA-protein targets in one dimension; multiple miRNAs associated in a functional network in the second dimension). A total of 28 of the 35 differentially expressed concordant mRNA-protein entities represented in the proliferation network, and 51 of the 59 such entities represented in the invasion network, mapped to altered miRNAs from GBM and conformed to an inverse relationship in their expression. We believe the two-dimensional maps of gene expression changes enhance the strength of the discovery datasets derived from omics-based studies for their applications in GBM as well as tumors in general. PMID:26464075

  19. A novel function of interferon regulatory factor-1: inhibition of Th2 cells by down-regulating the Il4 gene during Listeria infection.

    PubMed

    Maruyama, Saho; Kanoh, Makoto; Matsumoto, Akira; Kuwahara, Makoto; Yamashita, Masakatsu; Asano, Yoshihiro

    2015-03-01

    Infection with certain pathogens induces a shift of the Th subset balance to a Th1 dominant state. This, in turn, results in the suppression of Th2 responses. We focused on the involvement of interferon regulatory factor-1 (IRF-1) in the suppression of Th2 cells during Listeria infection. We found that the inhibition of IL-4 production by Th2 cells is mediated by a soluble factor (LmSN) produced by Listeria-infected antigen-presenting cells. The inhibition is not observed with T cells from Irf1 gene-targeted mice. IRF-1 suppresses transcription of the Il4 gene in Th2 cells. Under the influence of the LmSN, IRF-1 binds to the 3' untranslated region (UTR) region of the Il4 gene and down-regulates Il4 gene transcription. Finally, we identified IL-1α and IL-1β as the mediator of the LmSN activity. Signaling through IL-1R induces the stabilization and/or nuclear translocation of IRF-1. We propose that IRF-1 functions to induce the T-cell subset shift via a novel mechanism. Under the influence of IL-1, IRF-1 translocates into the nucleus and acts on the 3'UTR region of the Il4 gene, thus inhibiting its transcription in Th2 cells. As a result, the immune system shifts predominantly to a Th1 response during Listeria infection, resulting in effective protection of the host. PMID:25280793

  20. Enhancement of regulatory T cell-like suppressive function in MT-2 by long-term and low-dose exposure to asbestos.

    PubMed

    Ying, Chen; Maeda, Megumi; Nishimura, Yasumitsu; Kumagai-Takei, Naoko; Hayashi, Hiroaki; Matsuzaki, Hidenori; Lee, Suni; Yoshitome, Kei; Yamamoto, Shoko; Hatayama, Tamayo; Otsuki, Takemi

    2015-12-01

    Asbestos exposure causes lung fibrosis and various malignant tumors such as lung cancer and malignant mesothelioma. The effects of asbestos on immune cells have not been thoroughly investigated, although our previous reports showed that asbestos exposure reduced anti-tumor immunity. The effects of continuous exposure of regulatory T cells (Treg) to asbestos were examined using the HTLV-1 immortalized human T cell line MT-2, which possesses a suppressive function and expresses the Treg marker protein, Foxp3. Sublines were generated by the continuous exposure to low doses of asbestos fibers for more than one year. The sublines exposed to asbestos showed enhanced suppressive Treg function via cell-cell contact, and increased production of soluble factors such as IL-10 and transforming growth factor (TGF)-β1. These results also indicated that asbestos exposure induced the reduction of anti-tumor immunity, and efforts to develop substances to reverse this reduction may be helpful in preventing the occurrence of asbestos-induced tumors. PMID:26505785

  1. CD4+FoxP3+ Regulatory T Cells from Gαi2−/− Mice Are Functionally Active In Vitro, but Do Not Prevent Colitis

    PubMed Central

    Götlind, Yu-Yuan C.; Raghavan, Sukanya; Bland, Paul W.; Hörnquist, Elisabeth Hultgren

    2011-01-01

    Background Mice deficient in the inhibitory G protein subunit Gαi2 spontaneously develop a T helper 1 dominated colitis. We examined whether a defect in CD4+FoxP3+ regulatory T cells (Treg) underpins the pathogenesis of colitis in the Gαi2−/− (Gαi2-deficient) colitis model. Methodology/Principal Findings Using flow cytometry, we found that thymus and colonic lamina propria, but not spleen and mesenteric lymph nodes, of colitic Gαi2−/− mice contained increased frequencies of Treg, whereas FoxP3 expression intensity was similar in Gαi2−/− compared to Gαi2+/− or Gαi2+/+ wild type (WT) mice. The frequency of CD4+FoxP3+ T cells expressing CD103 was significantly increased in Gαi2−/− compared to WT mice. Treg in colons from WT mice clustered in the T cell areas of colonic lymphoid patches (CLP), with relatively few Treg in the lamina propria, as demonstrated by immunohistochemistry. In Gαi2−/− mice, CLP were not observed but lamina propria Treg were increased in number and frequency within the CD4+ infiltrate, compared to WT mice. Using an in vitro co-culture system and flow cytometric analysis of cell division we could demonstrate that the in vitro suppressive function of WT and Gαi2−/− CD4+FoxP3+ regulatory T cells (WT-Treg and KO-Treg) was indistinguishable, but that T effector cells (CD4+25− T cells) from Gαi2−/− mice were less readily suppressed than WT effectors (WT-Teff) by Treg from either source. However, neither WT nor Gαi2−/− Treg was able to suppress colitis induced by adoptive transfer of Gαi2−/− effector T cells (KO-Teff) to RAG2−/− recipients. The enhanced inflammatory activity of Gαi2−/− effectors was accompanied by increased expression of an effector/memory T cell phenotype and increased cytokine secretion, especially IL-4, IL-6 and IFN-γ. Conclusions There is an increased frequency of Gαi2−/− Treg in the colon, and they demonstrate no endogenous functional defect. However, Gαi2

  2. Regulatory aspects of functional foods.

    PubMed

    Ovesen, L

    1997-10-01

    Functional foods and claims belong together, so that many people would define functional goods as those which are claimed to have health-promoting effects. Within the EU such claims are regulated by the Food Labelling Regulations, which prohibit food labelling or advertising to claim that a particular food has the property of preventing, treating or curing a disease, or any reference to such property. Food Labelling Regulations are obviously interpreted differently within the EU; but whatever the interpretation, allagree that claims must not be misleading, and consequently should be based on sound scientific data. PMID:9466120

  3. Imperatorin exerts antiallergic effects in Th2-mediated allergic asthma via induction of IL-10-producing regulatory T cells by modulating the function of dendritic cells.

    PubMed

    Lin, Chu-Lun; Hsiao, George; Wang, Ching-Chiung; Lee, Yueh-Lun

    2016-08-01

    Imperatorin is a furanocoumarin compound which exists in many medicinal herbs and possesses various biological activities. Herein, we investigated the antiallergic effects of imperatorin in asthmatic mice and explored the immunomodulatory actions of imperatorin on immune cells. We used a murine model of ovalbumin (OVA)-induced asthma to evaluate the therapeutic potential of imperatorin. Additionally, bone marrow-derived dendritic cells (DCs; BMDCs) were used to clarify whether imperatorin exerts an antiallergic effect through altering the ability of DCs to regulate T cells. Oral administration of imperatorin to OVA-sensitized and -challenged mice decreased serum OVA-specific immunoglobulin E (IgE) production, attenuated the airway hyperresponsiveness (AHR), and alleviated airway inflammation in a dose-dependent manner. Notably, secretions of Th2 cytokines and chemokines were reduced, and numbers of interleukin (IL)-10-producing regulatory T cells (Tregs) increased in imperatorin-treated mice. Imperatorin inhibited proinflammatory cytokines and IL-12 production but enhanced IL-10 secretion by lipopolysaccharide (LPS)-stimulated BMDCs. Compared to fully mature DCs, imperatorin-treated DCs expressed high levels of the inducible costimulatory ligand (ICOSL) and Jagged1 molecules, and had the regulatory capacity to promote the generation of IL-10-producing CD4(+) T cells in vitro. Additionally, imperatorin directly suppressed activated CD4(+) T-cell proliferation and cytokine production. Imperatorin may possess therapeutic potential against Th2-mediated allergic asthma not only via stimulating DC induction of Tregs but also via direct inhibition of Th2 cell activation. These findings provide new insights into how imperatorin affects the Th2 immune response and the development of imperatorin as a Treg-type immunomodulatory agent to treat allergic asthma. PMID:27185659

  4. Impact of protective IL-2 allelic variants on CD4+ Foxp3+ regulatory T cell function in situ and resistance to autoimmune diabetes in NOD mice.

    PubMed

    Sgouroudis, Evridiki; Albanese, Alexandre; Piccirillo, Ciriaco A

    2008-11-01

    Type I diabetes (T1D) susceptibility is inherited through multiple insulin-dependent diabetes (Idd) genes. NOD.B6 Idd3 congenic mice, introgressed with an Idd3 allele from T1D-resistant C57BL/6 mice (Idd3(B6)), show a marked resistance to T1D compared with control NOD mice. The protective function of the Idd3 locus is confined to the Il2 gene, whose expression is critical for naturally occurring CD4(+)Foxp3(+) regulatory T (nT(reg)) cell development and function. In this study, we asked whether Idd3(B6) protective alleles in the NOD mouse model confer T1D resistance by promoting the cellular frequency, function, or homeostasis of nT(reg) cells in vivo. We show that resistance to T1D in NOD.B6 Idd3 congenic mice correlates with increased levels of IL-2 mRNA and protein production in Ag-activated diabetogenic CD4(+) T cells. We also observe that protective IL2 allelic variants (Idd3(B6) resistance allele) also favor the expansion and suppressive functions of CD4(+)Foxp3(+) nT(reg) cells in vitro, as well as restrain the proliferation, IL-17 production, and pathogenicity of diabetogenic CD4(+) T cells in vivo more efficiently than control do nT(reg) cells. Lastly, the resistance to T1D in Idd3 congenic mice does not correlate with an augmented systemic frequency of CD4(+)Foxp3(+) nT(reg) cells but more so with the ability of protective IL2 allelic variants to promote the expansion of CD4(+)Foxp3(+) nT(reg) cells directly in the target organ undergoing autoimmune attack. Thus, protective, IL2 allelic variants impinge the development of organ-specific autoimmunity by bolstering the IL-2 producing capacity of self-reactive CD4(+) T cells and, in turn, favor the function and homeostasis of CD4(+)Foxp3(+) nT(reg) cells in vivo. PMID:18941219

  5. Natural variation in IL-2 sensitivity influences regulatory T cell frequency and function in individuals with long-standing type 1 diabetes

    PubMed Central

    Yang, Jennie H.M.; Cutler, Antony J.; Ferreira, Ricardo C.; Reading, James L.; Cooper, Nicholas J.; Wallace, Chris; Clarke, Pamela; Smyth, Deborah J.; Boyce, Christopher S.; Gao, Guo-Jian; Todd, John A.; Wicker, Linda S.; Tree, Timothy I.M.

    2016-01-01

    Defective immune homeostasis in the balance between FOXP3+ regulatory T cells (Tregs) and effector T cells is a likely contributing factor in the loss of self-tolerance observed in type 1 diabetes (T1D). Given the importance of interleukin-2 (IL-2) signaling in the generation and function of Tregs, observations that polymorphisms in genes in the IL-2 pathway associate with T1D and that some individuals with T1D exhibit reduced IL-2 signaling, indicate that impairment of this pathway may play a role in Treg dysfunction and the pathogenesis of T1D. Here, we have examined IL-2 sensitivity in CD4+ T-cell subsets in 70 individuals with long-standing T1D allowing us to investigate the impact of low IL-2 sensitivity on Treg frequency and function. IL-2 responsiveness, measured by STAT5a phosphorylation, was found to be a very stable phenotype within individuals, but exhibited considerable inter-individual variation and was influenced by T1D-associated PTPN2 gene polymorphisms. Tregs from individuals with lower IL-2 signaling were reduced in frequency, were less able to maintain expression of FOXP3 under limiting concentrations of IL-2 and displayed reduced suppressor function. These results suggest that reduced IL-2 signaling may be used to identify patients with highest Treg dysfunction who may benefit most from IL-2 immunotherapy. PMID:26224887

  6. Evaluation of the expression and function of the P2X7 receptor and ART1 in human regulatory T-cell subsets.

    PubMed

    Cortés-Garcia, Juan D; López-López, Cintya; Cortez-Espinosa, Nancy; García-Hernández, Mariana H; Guzmán-Flores, Juan M; Layseca-Espinosa, Esther; Portales-Cervantes, Liliana; Portales-Pérez, Diana P

    2016-01-01

    Regulatory T cells that express CD39 (CD39+ Treg) exhibit specific immunomodulatory properties. Ectonucleotidase CD39 hydrolyses ATP and ADP. ATP is a ligand of the P2X7 receptor and induces the shedding of CD62L and apoptosis. However, the role of ATP in CD39+ Treg cells has not been defined. Furthermore, NAD can activate the P2X7 receptor via ADP-ribosyltransferase (ART) enzymes and cause cell depletion in murine models. We evaluated the expression and function of P2X7 and ART1 in CD39+ Treg and CD39- Treg cells in the presence or absence of ATP and NAD. We isolated peripheral blood mononuclear cells from healthy subjects and purified CD4+ T cells, CD4+ CD25+ T cells and CD4+ CD25+ CD39+ T cells. P2X7 and ART1 expression was assessed by flow cytometry and real-time PCR. Our results showed low P2X7 expression on CD39+ Treg cells and higher levels of ART1 expression in CD4+ CD39+ T cells than the other subtypes studied. Neither shedding of CD62L nor cell death of CD39+ Treg or CD39- Treg cells was observed by 1mM ATP or 60μM NAD. In contrast, P2Xs receptor-dependent proliferation with 300μM ATP, was inhibited by NAD in the different cell types analysed. The NAD proliferation-inhibition was increased with P2Xs and A2a agonist and was reversed with P2Xs and A2a antagonist, therefore NAD inhibits P2Xs-dependent proliferation and A2a activation. In conclusion, our results suggest that the altered function and expression of P2X7 and ART1 in the human CD39+ Treg or CD39- Treg cells could participate in the resistance against cell death induced by ATP or NAD. PMID:26307000

  7. Interleukin-2 Enhances the Regulatory Functions of CD4(+)T Cell-Derived CD4(-)CD8(-) Double Negative T Cells.

    PubMed

    Cong, Min; Liu, Tianhui; Tian, Dan; Guo, Hongbo; Wang, Ping; Liu, Kai; Lin, Jun; Tian, Yue; Shi, Wen; You, Hong; Jia, Jidong; Zhang, Dong

    2016-08-01

    CD4(+) T cells can be converted to CD4(-)CD8(-) double negative T cells (DN T cells) under appropriate conditions, and IL-2 enhanced the conversion. Here, we investigated the effect of IL-2 on the proliferation and function of converted DN T cells in vitro and in vivo. DN T cells were hyporesponsive when restimulated by mature dendritic cells (mDCs), IL-2 completely restored their responsiveness in vitro. In addition, IL-2 increased the resistance of DN T cells to apoptosis in vivo. DN T cells profoundly inhibited the proliferation of CD4(+)CD25(-) T effector cells triggered by mDCs in vitro, and this suppression was further enhanced by IL-2. Adoptively transferring of DN T cells, in combination with IL-2, inhibited the proliferation and enhanced apoptosis of alloreactive CD4(+) T cells, which resulted in significant prolongation of skin allograft survival time. Perforin plays a key role in the enhancement of DN T cells immune regulation by IL-2. In conclusion, we elucidated that IL-2 promoted DN T cell proliferation and suppressive function. The combination of DN T cells and exogenous IL-2 may represent a novel therapy in the clinical setting to prevent allograft rejection and induce immune tolerance. PMID:27135902

  8. IL-25 promotes the function of CD4+CD25+ T regulatory cells and prolongs skin-graft survival in murine models.

    PubMed

    Tang, Jiayou; Zhou, Xiaohui; Liu, Jie; Meng, Qingshu; Han, Yang; Wang, Zhulin; Fan, Huimin; Liu, Zhongmin

    2015-10-01

    Interleukin (IL)-25, also known as IL-17E, belongs to the IL-17 family of cytokines. Unlike other IL-17 family members, IL-25 promotes Th2-type immune responses, stimulating IL-4, IL-5, and IL-13 production. Here, we employed murine models of skin graft to explore the role of IL-25 in suppression of graft rejection. We found that IL-25 expression is increased during allograft rejection, and allograft rejection was enhanced in IL-25 KO mice. IL-25 KO was associated with down-regulation of Foxp3 expression in CD4+ T cells. Further, while adoptive transfer of WT regulatory T cells (Tregs) protected against allograft rejection, adoptive transfer of IL-25 deficient Tregs failed to protect against allograft rejection. Exogenous IL-25 restored Foxp3 expression and Treg function in vitro. Moreover, IL-25 promoted phosphorylation of NFAT2. Thus, IL-25 may enhance Treg function by up-regulating NFAT2 phosphorylation. Our findings suggest that IL-25 can sustain Foxp3 expression, enhance the suppressive function of Tregs, and prolong skin-graft survival. PMID:25864622

  9. In vitro evaluation of γδ T cells regulatory function in Behçet's disease patients and healthy controls.

    PubMed

    Clemente Ximenis, Antonio; Crespí Bestard, Catalina; Cambra Conejero, Ana; Pallarés Ferreres, Lucio; Juan Mas, Antonio; Olea Vallejo, José Luis; Julià Benique, Maria Rosa

    2016-01-01

    CD8-positive γδ T lymphocytes (GDCD8(+)) are specifically increased in peripheral blood of Behçet's disease (BD) patients. GDCD8(+) have shown a T regulatory (Treg) function in autoimmune experimental models, human tumor infiltrates and intestinal intraepithelial lymphocytes from celiac patients. The aim of this study was to evaluate the Treg function of GDCD8(+) and GDCD8(-), freshly isolated from peripheral blood, in comparison to CD4(+)CD25(high) naturally occurring Treg cells (nTreg) in BD and healthy controls (HC). We tested their suppressive activity on CD4(+)CD25(-) T effector cells (Teff) proliferation by a CFSE dilution protocol, after suboptimal activation with anti-CD3, in the absence or presence of IL-2. Furthermore, secreted cytokines and suppressive latency associated peptide (LAP)-TGFβ surface upregulation were determined after GD activation. We found that Vδ1 chains contribution to GDCD8(+) was higher in BD than in HC, but neither GDCD8(+) nor GDCD8(-); (i) suppressed Teff proliferation, (ii) expressed LAP-TGFβ (iii) nor secreted IL-10, in either group. Moreover, GD presented a proinflammatory cytokine profile, mainly producing IFNγ and TNFα, in contrast to nTregs. In conclusion, peripheral GD could contribute more to the dysregulation of TH1 type of cytokines than to exerting a Treg function in BD. PMID:26439770

  10. The Spatiotemporal Pattern of Glis3 Expression Indicates a Regulatory Function in Bipotent and Endocrine Progenitors during Early Pancreatic Development and in Beta, PP and Ductal Cells

    PubMed Central

    Kang, Hong Soon; Takeda, Yukimasa; Jeon, Kilsoo

    2016-01-01

    The transcription factor Glis-similar 3 (Glis3) has been implicated in the development of neonatal, type 1 and type 2 diabetes. In this study, we examined the spatiotemporal expression of Glis3 protein during embryonic and neonatal pancreas development as well as its function in PP cells. To obtain greater insights into the functions of Glis3 in pancreas development, we examined the spatiotemporal expression of Glis3 protein in a knockin mouse strain expressing a Glis3-EGFP fusion protein. Immunohistochemistry showed that Glis3-EGFP was not detectable during early pancreatic development (E11.5 and E12.5) and at E13.5 and 15.5 was not expressed in Ptf1a+ cells in the tip domains indicating that Glis3 is not expressed in multipotent pancreatic progenitors. Glis3 was first detectable at E13.5 in the nucleus of bipotent progenitors in the trunk domains, where it co-localized with Sox9, Hnf6, and Pdx1. It remained expressed in preductal and Ngn3+ endocrine progenitors and at later stages becomes restricted to the nucleus of pancreatic beta and PP cells as well as ductal cells. Glis3-deficiency greatly reduced, whereas exogenous Glis3, induced Ppy expression, as reported for insulin. Collectively, our study demonstrates that Glis3 protein exhibits a temporal and cell type-specific pattern of expression during embryonic and neonatal pancreas development that is consistent with a regulatory role for Glis3 in promoting endocrine progenitor generation, regulating insulin and Ppy expression in beta and PP cells, respectively, and duct morphogenesis. PMID:27270601

  11. The Spatiotemporal Pattern of Glis3 Expression Indicates a Regulatory Function in Bipotent and Endocrine Progenitors during Early Pancreatic Development and in Beta, PP and Ductal Cells.

    PubMed

    Kang, Hong Soon; Takeda, Yukimasa; Jeon, Kilsoo; Jetten, Anton M

    2016-01-01

    The transcription factor Glis-similar 3 (Glis3) has been implicated in the development of neonatal, type 1 and type 2 diabetes. In this study, we examined the spatiotemporal expression of Glis3 protein during embryonic and neonatal pancreas development as well as its function in PP cells. To obtain greater insights into the functions of Glis3 in pancreas development, we examined the spatiotemporal expression of Glis3 protein in a knockin mouse strain expressing a Glis3-EGFP fusion protein. Immunohistochemistry showed that Glis3-EGFP was not detectable during early pancreatic development (E11.5 and E12.5) and at E13.5 and 15.5 was not expressed in Ptf1a+ cells in the tip domains indicating that Glis3 is not expressed in multipotent pancreatic progenitors. Glis3 was first detectable at E13.5 in the nucleus of bipotent progenitors in the trunk domains, where it co-localized with Sox9, Hnf6, and Pdx1. It remained expressed in preductal and Ngn3+ endocrine progenitors and at later stages becomes restricted to the nucleus of pancreatic beta and PP cells as well as ductal cells. Glis3-deficiency greatly reduced, whereas exogenous Glis3, induced Ppy expression, as reported for insulin. Collectively, our study demonstrates that Glis3 protein exhibits a temporal and cell type-specific pattern of expression during embryonic and neonatal pancreas development that is consistent with a regulatory role for Glis3 in promoting endocrine progenitor generation, regulating insulin and Ppy expression in beta and PP cells, respectively, and duct morphogenesis. PMID:27270601

  12. Regulatory T cells: present facts and future hopes.

    PubMed

    Becker, Christian; Stoll, Sabine; Bopp, Tobias; Schmitt, Edgar; Jonuleit, Helmut

    2006-09-01

    Naturally occurring CD4(+)CD25(+)Foxp3(+) regulatory T cells and several subsets of induced suppressor T cells are key players of the immune tolerance network and control the induction and effector phase of our immunological defense system. These T cell populations actively control the properties of other immune cells by suppressing their functional activity to prevent autoimmunity and transplant rejection but also influence the immune response to allergens as well as against tumor cells and pathogens. Even though we are far from completely understanding the molecular and cellular mechanisms that manage the different regulatory T cell populations, increasing evidence exists about their functional importance. The knowledge on their induction and activation opens the possibility for their selective manipulation in vivo as an attractive approach for an immunotherapy of unwanted immune responses. This review summarizes this knowledge and discusses the potential of regulatory T cells for novel immunointervention strategies in the future. PMID:16715254

  13. The regulatory niche of intestinal stem cells.

    PubMed

    Sailaja, Badi Sri; He, Xi C; Li, Linheng

    2016-09-01

    The niche constitutes a unique category of cells that support the microenvironment for the maintenance and self-renewal of stem cells. Intestinal stem cells reside at the base of the crypt, which contains adjacent epithelial cells, stromal cells and smooth muscle cells, and soluble and cell-associated growth and differentiation factors. We summarize here recent advances in our understanding of the crucial role of the niche in regulating stem cells. The stem cell niche maintains a balance among quiescence, proliferation and regeneration of intestinal stem cells after injury. Mesenchymal cells, Paneth cells, immune cells, endothelial cells and neural cells are important regulatory components that secrete niche ligands, growth factors and cytokines. Intestinal homeostasis is regulated by niche signalling pathways, specifically Wnt, bone morphogenetic protein, Notch and epidermal growth factor. These insights into the regulatory stem cell niche during homeostasis and post-injury regeneration offer the potential to accelerate development of therapies for intestine-related disorders. PMID:27060879

  14. Regulatory T cells: regulators of life.

    PubMed

    Schumacher, Anne; Zenclussen, Ana Claudia

    2014-08-01

    Pregnancy still represents one of the most fascinating paradoxical phenomena in science. Immediately after conception, the maternal immune system is challenged by the presence of foreign paternal antigens in the semen. This triggers mechanisms of recognition and tolerance that all together allow the embryo to implant and later the fetus to develop. Tolerance mechanisms to maintain pregnancy are of special interest as they defy the classical immunology rules. Several cell types, soluble factors, and immune regulatory molecules have been proposed to contribute to fetal tolerance. Within these, regulatory T cells (Treg) are one of the most studied immune cell populations lately. They are reportedly involved in fetal acceptance. Here, we summarize several aspects of Treg biology in normal and pathologic pregnancies focusing on Treg frequencies, subtypes, antigen specificity, and activity as well as on factors influencing Treg generation, recruitment, and function. This review also highlights the contribution of fetal Treg in tolerance induction and addresses the role of Treg in autoimmune diseases and infections during gestation. Finally, the potential of Treg as a predictive marker for the success of assisted reproductive techniques and for therapeutic interventions is discussed. PMID:24661545

  15. CD25 signaling regulates the function and stability of peripheral Foxp3+ regulatory T cells derived from the spleen and lymph nodes of mice.

    PubMed

    Wang, Kunpeng; Gu, Jian; Ni, Xuhao; Ding, Zheng; Wang, Qi; Zhou, Haoming; Zheng, SongGuo; Li, Bin; Lu, Ling

    2016-08-01

    Regulatory T cells (Tregs) play a critical role in sustaining immune tolerance and maintaining immune balance to alloantigen after transplatation. However, the functions of peripheral Tregs in different organs have not been fully characterized. Here, we showed that spleen-derived Tregs exhibited higher expression of Foxp3, greater suppressive capacity, and lower levels of IL-17A secretion than lymph node-derived Tregs in vitro in the presence or absence of inflammatory cytokines, such as IL-6. We found a higher percentage of CD25(bright) Tregs among spleen-derived Tregs than among lymph node-derived Tregs. Additionally, in vivo experiments demonstrated that adoptive transfer of spleen-derived Tregs, but not lymph node-derived Tregs, alleviated ischemia-reperfusion injury. These results reveal novel functions of Tregs derived from peripheral organs. In particular, spleen-derived Tregs, primarily consisting of CD25(bright) cells, may provide a more significant contribution to the suppression of immune-mediated autoimmune and inflammatory disease. PMID:27344615

  16. Identification and functional characterization of the miRNA-gene regulatory network in chronic myeloid leukemia lineage negative cells.

    PubMed

    Agatheeswaran, S; Pattnayak, N C; Chakraborty, S

    2016-01-01

    Chronic myeloid leukemia (CML) is maintained by leukemic stem cells (LSCs) which are resistant to the existing TKI therapy. Hence a better understanding of the CML LSCs is necessary to eradicate these cells and achieve complete cure. Using the miRNA-gene interaction networks from the CML lin(-) cells we identified a set of up/down-regulated miRNAs and corresponding target genes. Association studies (Pearson correlation) from the miRNA and gene expression data showed that miR-1469 and miR-1972 have significantly higher number of target genes, 75 and 50 respectively. We observed that miR-1972 induces G2-M cell cycle arrest and miR-1469 moderately arrested G1 cell cycle when overexpressed in KCL22 cells. We have earlier shown that a combination of imatinib and JAK inhibitor I can significantly bring down the proliferation of CML lineage negative cells. Here we observed that imatinib and JAK inhibitor I combination restored the expression pattern of the down-regulated miRNAs in primary CML lin(-) cells. Thus effective manipulation of the deregulated miRNAs can restore the miRNA-mRNA networks that can efficiently inhibit CML stem and progenitor cells and alleviate the disease. PMID:27586591

  17. Identification and functional characterization of the miRNA-gene regulatory network in chronic myeloid leukemia lineage negative cells

    PubMed Central

    Agatheeswaran, S.; Pattnayak, N. C.; Chakraborty, S.

    2016-01-01

    Chronic myeloid leukemia (CML) is maintained by leukemic stem cells (LSCs) which are resistant to the existing TKI therapy. Hence a better understanding of the CML LSCs is necessary to eradicate these cells and achieve complete cure. Using the miRNA-gene interaction networks from the CML lin(−) cells we identified a set of up/down-regulated miRNAs and corresponding target genes. Association studies (Pearson correlation) from the miRNA and gene expression data showed that miR-1469 and miR-1972 have significantly higher number of target genes, 75 and 50 respectively. We observed that miR-1972 induces G2-M cell cycle arrest and miR-1469 moderately arrested G1 cell cycle when overexpressed in KCL22 cells. We have earlier shown that a combination of imatinib and JAK inhibitor I can significantly bring down the proliferation of CML lineage negative cells. Here we observed that imatinib and JAK inhibitor I combination restored the expression pattern of the down-regulated miRNAs in primary CML lin(−) cells. Thus effective manipulation of the deregulated miRNAs can restore the miRNA-mRNA networks that can efficiently inhibit CML stem and progenitor cells and alleviate the disease. PMID:27586591

  18. CD22 expression mediates the regulatory functions of peritoneal B-1a cells during the remission phase of contact hypersensitivity reactions1

    PubMed Central

    Nakashima, Hiroko; Hamaguchi, Yasuhito; Watanabe, Rei; Ishiura, Nobuko; Kuwano, Yoshihiro; Okochi, Hitoshi; Takahashi, Yoshimasa; Tamaki, Kunihiko; Sato, Shinichi; Tedder, Thomas F.; Fujimoto, Manabu

    2013-01-01

    While contact hypersensitivity (CHS) has been considered a prototype of T cell-mediated immune reactions, recently a significant contribution of regulatory B cell subsets in the suppression of CHS has been demonstrated. CD22, one of the Siglecs, is a B cell-specific molecule that negatively regulates B cell receptor signaling. To clarify the roles of B cells in CHS, CHS in CD22-/- mice was investigated. CD22-/- mice showed delayed recovery from CHS reactions compared with wild type mice. Transfer of wild type peritoneal B-1a cells reversed the prolonged CHS reaction seen in CD22-/- mice, and this was blocked by the simultaneous injection with IL-10 receptor Ab. While CD22-/- peritoneal B-1a cells were capable of producing IL-10 at wild type levels, intraperitoneal injection of differentially labeled wild type/CD22-/- B cells demonstrated that a smaller number of CD22-/- B cells resided in lymphoid organs 5 days after CHS elicitation, suggesting a defect in survival or retention in activated CD22-/- peritoneal B-1 cells. Thus, our current study reveals a regulatory role for peritoneal B-1a cells in CHS. Two distinct regulatory B cell subsets cooperatively inhibit CHS responses. While splenic CD1dhiCD5+ B cells have a crucial role in suppressing the acute exacerbating phase of CHS, peritoneal B-1a cells are likely to suppress the late remission phase as “regulatory B cells”. CD22 deficiency results in disturbed CHS remission by impaired retention or survival of peritoneal B-1a cells that migrate into lymphoid organs. PMID:20335532

  19. Differential effects of inhibitors of the PI3K/mTOR pathway on the expansion and functionality of regulatory T cells.

    PubMed

    Huijts, Charlotte M; Santegoets, Saskia J; Quiles Del Rey, Maria; de Haas, Richard R; Verheul, Henk M; de Gruijl, Tanja D; van der Vliet, Hans J

    2016-07-01

    The PI3K/mTOR pathway is commonly deregulated in cancer. mTOR inhibitors are registered for the treatment of several solid tumors and novel inhibitors are explored clinically. Notably, this pathway also plays an important role in immunoregulation. While mTOR inhibitors block cell cycle progression of conventional T cells (Tconv), they also result in the expansion of CD4(+)CD25(hi)FOXP3(+) regulatory T cells (Tregs), and this likely limits their clinical antitumor efficacy. Here, we compared the effects of dual mTOR/PI3K inhibition (using BEZ235) to single PI3K (using BKM120) or mTOR inhibition (using rapamycin and everolimus) on Treg expansion and functionality. Whereas rapamycin, everolimus and BEZ235 effected a relative expansion benefit for Tregs and increased their overall suppressive activity, BKM120 allowed for similar expansion rates of Tregs and Tconv without altering their overall suppressive activity. Therefore, PI3K inhibition alone might offer antitumor efficacy without the detrimental selective expansion of Tregs associated with mTOR inhibition. PMID:27189717

  20. 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. PMID:26945003

  1. Clonorchis sinensis-derived total protein attenuates airway inflammation in murine asthma model by inducing regulatory T cells and modulating dendritic cell functions.

    PubMed

    Jeong, Young-Il; Kim, Seung Hyun; Ju, Jung Won; Cho, Shin Hyeong; Lee, Won Ja; Park, Jin Wook; Park, Yeong-Min; Lee, Sang Eun

    2011-04-22

    Asthma is characterized by Th2-mediated inflammation, resulting in airway hyperresponsiveness (AHR) through airway remodeling. Recent epidemiological and experimental reports have suggested an inverse relationship between the development of allergy and helminth infections. Infection by Clonorchis sinensis, a liver fluke that resides in the bile duct of humans, is endemic predominantly in Asia including Korea and China. Using a murine model for asthma, we investigated the effects of C. sinensis-derived total protein (Cs-TP) on allergen-induced airway inflammation and the mechanism underlying the protective effects of Cs-TP administration on asthma. Treatment with Cs-TP attenuated OVA-induced airway inflammation and methacholine-induced AHR, as well as eosinophilia development, lymphocyte infiltration into the lung, and goblet cell metaplasia. This protective effect of Cs-TP is associated with markedly reduced OVA-specific IgE and Th1/Th2 cytokine production. Moreover, Cs-TP increased the number of CD4(+)CD25(+)Foxp3(+) regulatory T (Treg) cells as well as their suppressive activity. In fact, proliferation of OVA-restimulated splenocytes was suppressed significantly. Cs-TP also inhibited the expression of such co-stimulatory molecules as CD80, CD86, and CD40 in LPS- or OVA-stimulated dendritic cells (DCs), suggesting that Cs-TP could interfere with the capacity of airway DCs to prime naïve T cells. These data demonstrate the capacity of C. sinensis to ameliorate allergic asthma and broaden our understanding of the paradoxical relationship between the allergic immune response and helminth infection. PMID:21440530

  2. 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. PMID:26721806

  3. Detailed map of a cis-regulatory input function

    NASA Astrophysics Data System (ADS)

    Setty, Y.; Mayo, A. E.; Surette, M. G.; Alon, U.

    2003-06-01

    Most genes are regulated by multiple transcription factors that bind specific sites in DNA regulatory regions. These cis-regulatory regions perform a computation: the rate of transcription is a function of the active concentrations of each of the input transcription factors. Here, we used accurate gene expression measurements from living cell cultures, bearing GFP reporters, to map in detail the input function of the classic lacZYA operon of Escherichia coli, as a function of about a hundred combinations of its two inducers, cAMP and isopropyl -D-thiogalactoside (IPTG). We found an unexpectedly intricate function with four plateau levels and four thresholds. This result compares well with a mathematical model of the binding of the regulatory proteins cAMP receptor protein (CRP) and LacI to the lac regulatory region. The model is also used to demonstrate that with few mutations, the same region could encode much purer AND-like or even OR-like functions. This possibility means that the wild-type region is selected to perform an elaborate computation in setting the transcription rate. The present approach can be generally used to map the input functions of other genes.

  4. FTY720 ameliorates Th1-mediated colitis in mice by directly affecting the functional activity of CD4+CD25+ regulatory T cells.

    PubMed

    Daniel, Carolin; Sartory, Nico; Zahn, Nadine; Geisslinger, Gerd; Radeke, Heinfried H; Stein, Juergen M

    2007-02-15

    Following the present concepts, the synthetic sphingosine analog of myriocin FTY720 alters migration and homing of lymphocytes via sphingosine 1-phosphate receptors. However, several studies indicate that the immunosuppressive properties of FTY720 may alternatively be due to tolerogenic activities via modulation of dendritic cell differentiation or based on direct effects on CD4(+)CD25(+) regulatory T cells (Treg). As Treg play an important role for the cure of inflammatory colitis, we used the Th1-mediated 2,4,6-trinitrobenzene sulfonic acid (TNBS) colitis model to address the therapeutic potential of FTY720 in vivo. A rectal enema of TNBS was given to BALB/c mice. FTY720 was administered i.p. from days 0 to 3 or 3 to 5. FTY720 substantially reduced all clinical, histopathologic, macroscopic, and microscopic parameters of colitis analyzed. The therapeutic effects of FTY720 were associated with a down-regulation of IL-12p70 and subsequent Th1 cytokines. Importantly, FTY720 treatment resulted in a prominent up-regulation of FoxP3, IL-10, TGFbeta, and CTLA4. Supporting the hypothesis that FTY720 directly affects functional activity of CD4(+)CD25(+) Treg, we measured a significant increase of CD25 and FoxP3 expression in isolated lamina propria CD4(+) T cells of FTY720-treated mice. The impact of FTY720 on Treg induction was further confirmed by concomitant in vivo blockade of CTLA4 or IL-10R which significantly abrogated its therapeutic activity. In conclusion, our data provide clear evidence that in addition to its well-established effects on migration FTY720 leads to a specific down-regulation of proinflammatory signals while simultaneously inducing functional activity of CD4(+)CD25(+) Treg. Thus, FTY720 may offer a promising new therapeutic strategy for the treatment of IBD. PMID:17277153

  5. Conjugated Bilirubin Differentially Regulates CD4+ T Effector Cells and T Regulatory Cell Function through Outside-In and Inside-Out Mechanisms: The Effects of HAV Cell Surface Receptor and Intracellular Signaling.

    PubMed

    Corral-Jara, Karla F; Trujillo-Ochoa, Jorge L; Realpe, Mauricio; Panduro, Arturo; Gómez-Leyva, Juan F; Rosenstein, Yvonne; Jose-Abrego, Alexis; Roman, Sonia; Fierro, Nora A

    2016-01-01

    We recently reported an immune-modulatory role of conjugated bilirubin (CB) in hepatitis A virus (HAV) infection. During this infection the immune response relies on CD4+ T lymphocytes (TLs) and it may be affected by the interaction of HAV with its cellular receptor (HAVCR1/TIM-1) on T cell surface. How CB might affect T cell function during HAV infection remains to be elucidated. Herein, in vitro stimulation of CD4+ TLs from healthy donors with CB resulted in a decrease in the degree of intracellular tyrosine phosphorylation and an increase in the activity of T regulatory cells (Tregs) expressing HAVCR1/TIM-1. A comparison between CD4+ TLs from healthy donors and HAV-infected patients revealed changes in the TCR signaling pathway relative to changes in CB levels. The proportion of CD4+CD25+ TLs increased in patients with low CB serum levels and an increase in the percentage of Tregs expressing HAVCR1/TIM-1 was found in HAV-infected patients relative to controls. A low frequency of 157insMTTTVP insertion in the viral receptor gene HAVCR1/TIM-1 was found in patients and controls. Our data revealed that, during HAV infection, CB differentially regulates CD4+ TLs and Tregs functions by modulating intracellular pathways and by inducing changes in the proportion of Tregs expressing HAVCR1/TIM-1. PMID:27578921

  6. Conjugated Bilirubin Differentially Regulates CD4+ T Effector Cells and T Regulatory Cell Function through Outside-In and Inside-Out Mechanisms: The Effects of HAV Cell Surface Receptor and Intracellular Signaling

    PubMed Central

    Corral-Jara, Karla F.; Gómez-Leyva, Juan F.; Rosenstein, Yvonne; Jose-Abrego, Alexis; Roman, Sonia

    2016-01-01

    We recently reported an immune-modulatory role of conjugated bilirubin (CB) in hepatitis A virus (HAV) infection. During this infection the immune response relies on CD4+ T lymphocytes (TLs) and it may be affected by the interaction of HAV with its cellular receptor (HAVCR1/TIM-1) on T cell surface. How CB might affect T cell function during HAV infection remains to be elucidated. Herein, in vitro stimulation of CD4+ TLs from healthy donors with CB resulted in a decrease in the degree of intracellular tyrosine phosphorylation and an increase in the activity of T regulatory cells (Tregs) expressing HAVCR1/TIM-1. A comparison between CD4+ TLs from healthy donors and HAV-infected patients revealed changes in the TCR signaling pathway relative to changes in CB levels. The proportion of CD4+CD25+ TLs increased in patients with low CB serum levels and an increase in the percentage of Tregs expressing HAVCR1/TIM-1 was found in HAV-infected patients relative to controls. A low frequency of 157insMTTTVP insertion in the viral receptor gene HAVCR1/TIM-1 was found in patients and controls. Our data revealed that, during HAV infection, CB differentially regulates CD4+ TLs and Tregs functions by modulating intracellular pathways and by inducing changes in the proportion of Tregs expressing HAVCR1/TIM-1. PMID:27578921

  7. 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.

  8. Regulatory T Cells: A Crisis Averted.

    PubMed

    Malhotra, Deepali; Jenkins, Marc K

    2016-05-17

    Although regulatorycells protect people from autoimmunity, two recent papers in Immunity (Malchow et al., 2016; Kieback et al., 2016) demonstrate that these cells are also a crisis averted. Without the proper education in the thymus, these cells will turn on their host and cause autoimmunity. PMID:27192571

  9. Clonorchis sinensis-derived total protein attenuates airway inflammation in murine asthma model by inducing regulatory T cells and modulating dendritic cell functions

    SciTech Connect

    Jeong, Young-Il; Kim, Seung Hyun; Ju, Jung Won; Cho, Shin Hyeong; Lee, Won Ja; Park, Jin Wook; Park, Yeong-Min; Lee, Sang Eun

    2011-04-22

    Highlights: {yields} Treatment with Clonorchis sinensis-derived total protein attenuates OVA-induced airway inflammation and AHR to methacholine. {yields} Induction of CD4{sup +}CD25{sup +}Foxp3{sup +} T cells and IL-10 along with suppression of splenocyte proliferation by C. sinensis-derived total protein. {yields} C. sinensis-derived total protein interferes with the expression of co-stimulatory molecules in DCs. -- Abstract: Asthma is characterized by Th2-mediated inflammation, resulting in airway hyperresponsiveness (AHR) through airway remodeling. Recent epidemiological and experimental reports have suggested an inverse relationship between the development of allergy and helminth infections. Infection by Clonorchis sinensis, a liver fluke that resides in the bile duct of humans, is endemic predominantly in Asia including Korea and China. Using a murine model for asthma, we investigated the effects of C. sinensis-derived total protein (Cs-TP) on allergen-induced airway inflammation and the mechanism underlying the protective effects of Cs-TP administration on asthma. Treatment with Cs-TP attenuated OVA-induced airway inflammation and methacholine-induced AHR, as well as eosinophilia development, lymphocyte infiltration into the lung, and goblet cell metaplasia. This protective effect of Cs-TP is associated with markedly reduced OVA-specific IgE and Th1/Th2 cytokine production. Moreover, Cs-TP increased the number of CD4{sup +}CD25{sup +}Foxp3{sup +} regulatory T (Treg) cells as well as their suppressive activity. In fact, proliferation of OVA-restimulated splenocytes was suppressed significantly. Cs-TP also inhibited the expression of such co-stimulatory molecules as CD80, CD86, and CD40 in LPS- or OVA-stimulated dendritic cells (DCs), suggesting that Cs-TP could interfere with the capacity of airway DCs to prime naive T cells. These data demonstrate the capacity of C. sinensis to ameliorate allergic asthma and broaden our understanding of the paradoxical

  10. Human Adipose-Derived Stromal/Stem Cells Induce Functional CD4+CD25+FoxP3+CD127− Regulatory T Cells Under Low Oxygen Culture Conditions

    PubMed Central

    Frazier, Trivia P.; McLachlan, James B.; Gimble, Jeffrey M.; Tucker, Hugh A.

    2014-01-01

    Human adipose tissue stromal/stem cells (ASCs) are known to induce proliferation of resting T cells under ambient (21%) O2 conditions; however, ASCs exist physiologically under lower oxygen (5% O2) conditions in adipose tissue. The effects of low oxygen levels on ASC immunomodulation of T cells are unknown. In this study, we show that ASCs stimulated proliferation of naive CD4+ T cells and the percentage of CD25+ T cells was significantly increased under both low and ambient O2. Forkhead box P3 (FoxP3) and transforming growth factor beta (TGF-β) mRNA expression were significantly increased when ASCs were cocultured with CD4+ T cells under low compared with ambient O2 conditions. The low O2-induced regulatory T cells (iTregs) exhibited functionality when added to mixed lymphocyte reactions as demonstrated by inhibition of peripheral blood mononuclear cell proliferation, and by >300-fold increase in FoxP3 mRNA, and >2-fold increase in TGF-β mRNA expression. These results demonstrate that under physiologically relevant low O2 conditions, direct contact of human ASCs with naive CD4+ T cells induced functional iTregs. PMID:24405386

  11. A genome-wide analysis of open chromatin in human epididymis epithelial cells reveals candidate regulatory elements for genes coordinating epididymal function.

    PubMed

    Bischof, Jared M; Gillen, Austin E; Song, Lingyun; Gosalia, Nehal; London, Darin; Furey, Terrence S; Crawford, Gregory E; Harris, Ann

    2013-10-01

    The epithelium lining the epididymis has a pivotal role in ensuring a luminal environment that can support normal sperm maturation. Many of the individual genes that encode proteins involved in establishing the epididymal luminal fluid are well characterized. They include ion channels, ion exchangers, transporters, and solute carriers. However, the molecular mechanisms that coordinate expression of these genes and modulate their activities in response to biological stimuli are less well understood. To identify cis-regulatory elements for genes expressed in human epididymis epithelial cells, we generated genome-wide maps of open chromatin by DNase-seq. This analysis identified 33,542 epididymis-selective DNase I hypersensitive sites (DHS), which were not evident in five cell types of different lineages. Identification of genes with epididymis-selective DHS at their promoters revealed gene pathways that are active in immature epididymis epithelial cells. These include processes correlating with epithelial function and also others with specific roles in the epididymis, including retinol metabolism and ascorbate and aldarate metabolism. Peaks of epididymis-selective chromatin were seen in the androgen receptor gene and the cystic fibrosis transmembrane conductance regulator (CFTR) gene, which has a critical role in regulating ion transport across the epididymis epithelium. In silico prediction of transcription factor binding sites that were overrepresented in epididymis-selective DHS identified epithelial transcription factors, including ELF5 and ELF3, the androgen receptor, Pax2, and Sox9, as components of epididymis transcriptional networks. Active genes, which are targets of each transcription factor, reveal important biological processes in the epididymis epithelium. PMID:24006278

  12. Monoclonal regulatory T cells provide insights into T cell suppression

    PubMed Central

    Gubser, Céline; Schmaler, Mathias; Rossi, Simona W.; Palmer, Ed

    2016-01-01

    Regulatory T cells (Tregs) have a crucial role in maintaining lymphocyte homeostasis. However an understanding of how Tregs function at a cellular and molecular level has not yet been fully elucidated. Here, we make use of a T cell receptor (TCR) transgenic, Rag−/− mouse expressing a Forkhead-Box-Protein P3 (Foxp3) transgene. This mouse provides a source of monoclonal CD4+ Foxp3+ T cells with a defined specificity. Here we show that monoclonal B3K506 Tregs are functional in vitro and in vivo and clearly require cognate antigen to be suppressive. We further show that the strength of Treg stimulation determines the strength of Treg mediated suppression. Finally we analysed various suppressive mechanisms used by monoclonal Tregs and found that Treg-Tconv proximity is a parameter, which correlates with enhanced suppression. PMID:27210828

  13. Monoclonal regulatory T cells provide insights into T cell suppression.

    PubMed

    Gubser, Céline; Schmaler, Mathias; Rossi, Simona W; Palmer, Ed

    2016-01-01

    Regulatory T cells (Tregs) have a crucial role in maintaining lymphocyte homeostasis. However an understanding of how Tregs function at a cellular and molecular level has not yet been fully elucidated. Here, we make use of a T cell receptor (TCR) transgenic, Rag(-/-) mouse expressing a Forkhead-Box-Protein P3 (Foxp3) transgene. This mouse provides a source of monoclonal CD4(+) Foxp3(+) T cells with a defined specificity. Here we show that monoclonal B3K506 Tregs are functional in vitro and in vivo and clearly require cognate antigen to be suppressive. We further show that the strength of Treg stimulation determines the strength of Treg mediated suppression. Finally we analysed various suppressive mechanisms used by monoclonal Tregs and found that Treg-Tconv proximity is a parameter, which correlates with enhanced suppression. PMID:27210828

  14. Regulatory T Cells: Molecular Actions on Effector Cells in Immune Regulation

    PubMed Central

    Arce-Sillas, Asiel; Álvarez-Luquín, Diana Denisse; Tamaya-Domínguez, Beatriz; Gomez-Fuentes, Sandra; Trejo-García, Abel; Melo-Salas, Marlene; Cárdenas, Graciela; Rodríguez-Ramírez, Juan; Adalid-Peralta, Laura

    2016-01-01

    T regulatory cells play a key role in the control of the immune response, both in health and during illness. While the mechanisms through which T regulatory cells exert their function have been extensively described, their molecular effects on effector cells have received little attention. Thus, this revision is aimed at summarizing our current knowledge on those regulation mechanisms on the target cells from a molecular perspective. PMID:27298831

  15. Structural and regulatory functions of keratins

    SciTech Connect

    Magin, Thomas M. . E-mail: t.magin@uni-bonn.de; Vijayaraj, Preethi; Leube, Rudolf E. . E-mail: leube@uni-mainz.de

    2007-06-10

    The diversity of epithelial functions is reflected by the expression of distinct keratin pairs that are responsible to protect epithelial cells against mechanical stress and to act as signaling platforms. The keratin cytoskeleton integrates these functions by forming a supracellular scaffold that connects at desmosomal cell-cell adhesions. Multiple human diseases and murine knockouts in which the integrity of this system is destroyed testify to its importance as a mechanical stabilizer in certain epithelia. Yet, surprisingly little is known about the precise mechanisms responsible for assembly and disease pathology. In addition to these structural aspects of keratin function, experimental evidence accumulating in recent years has led to a much more complex view of the keratin cytoskeleton. Distinct keratins emerge as highly dynamic scaffolds in different settings and contribute to cell size determination, translation control, proliferation, cell type-specific organelle transport, malignant transformation and various stress responses. All of these properties are controlled by highly complex patterns of phosphorylation and molecular associations.

  16. Control of regulatory T cell lineage commitment and maintenance

    PubMed Central

    Josefowicz, Steven Z.; Rudensky, Alexander

    2015-01-01

    Foxp3-expressing regulatory T (Treg) cells suppress pathology mediated by immune responses against self and foreign antigens, and commensal microorganisms. Sustained expression of the transcription factor Foxp3, a key distinguishing feature of Treg cells, is required for their differentiation and suppressor function. In addition, Foxp3 expression prevents deviation of Treg cells into effector T cell lineages and confers dependence of Treg cell survival and expansion on growth factors, foremost interleukin-2, provided by activated effector T cells. In this review we discuss Treg cell differentiation and maintenance with a particular emphasis on molecular regulation of Foxp3 expression, arguably a key to mechanistic understanding of biology of regulatory T cells. PMID:19464984

  17. Regulatory T cells vs Th17: differentiation of Th17 versus Treg, are the mutually exclusive?

    PubMed Central

    Zheng, Song Guo

    2013-01-01

    Naive CD4+ cells differentiate into T helper (Th1, Th2, Th9, Th17) and regulatory T (Treg) cells to execute their immunologic function. Whereas TGF-β suppresses Th1 and Th2 cell differentiation, this cytokine promotes Th9, Th17 and Foxp3+ regulatory T cells depending upon the presence of other cytokines. IL-6 promotes Th17, but suppresses regulatory T cell differentiation. Moreover, natural but not TGF-β-induced regulatory T cells convert into Th17 cells in the inflammatory milieu. Here an update of T cell differentiation and conversion, as well as underlying mechanisms are given. PMID:23885327

  18. Lymph node trafficking of regulatory T cells is prerequisite for immune suppression.

    PubMed

    Huang, Miao-Tzu; Lin, Been-Ren; Liu, Wei-Liang; Lu, Chun-Wei; Chiang, Bor-Luen

    2016-04-01

    Regulatory T cells have a crucial role in health and disease because of their immune regulation function. However, the anatomic sites where regulatory T cells exert optimal immune regulation are open to debate. In our current study with the use of a shear-stress flow assay, we found that regulatory T cells exhibited significantly decreased adhesion to either activated endothelial monolayer or intercellular adhesion molecule 1 or E-selectin-coated surfaces compared with activated effector T cells. The less transmigration capacity of the regulatory T cells prompted our speculation of preferential lymph node localization for the regulatory T cells that endowed these cells with immune regulation function in the most efficient manner. To test this hypothesis, the role of lymph node localization in regulatory T cell-mediated immune suppression was evaluated with a footpad inflammation model. We found that adoptively transferred regulatory T cells inhibited the development of footpad inflammation. In addition, although blockage of CCR7 or CD62L had no effect on the immune suppressive function of the regulatory T cells per se, pretreatment of the regulatory T cells with either CCR7 or CD62L blocking antibodies prevented their recruitment into draining lymph nodes and concomitantly abrogated the immune suppressive effects of adoptively transferred regulatory T cells during footpad inflammation. Our data demonstrate the crucial role of lymph node localization in regulatory T cell-mediated immune suppression and suggest a probable hierarchy in the anatomic sites for optimal immune regulation. Elucidating the relationships between the transmigration characteristics of the regulatory T cells and their immune regulation function will provide insightful information for regulatory T cell-based cell therapy. PMID:26543091

  19. Integrating sequence, evolution and functional genomics in regulatory genomics

    PubMed Central

    Vingron, Martin; Brazma, Alvis; Coulson, Richard; van Helden, Jacques; Manke, Thomas; Palin, Kimmo; Sand, Olivier; Ukkonen, Esko

    2009-01-01

    With genome analysis expanding from the study of genes to the study of gene regulation, 'regulatory genomics' utilizes sequence information, evolution and functional genomics measurements to unravel how regulatory information is encoded in the genome. PMID:19226437

  20. Comparison of Regulatory T Cells in Hemodialysis Patients and Healthy Controls: Implications for Cell Therapy in Transplantation

    PubMed Central

    Afzali, Behdad; Edozie, Francis C.; Fazekasova, Henrieta; Scottà, Cristiano; Mitchell, Peter J.; Canavan, James B.; Kordasti, Shahram Y.; Chana, Prabhjoat S.; Ellis, Richard; Lord, Graham M.; John, Susan; Hilton, Rachel; Lechler, Robert I.

    2013-01-01

    Summary Background and objectives Cell-based therapy with natural (CD4+CD25hiCD127lo) regulatory T cells to induce transplant tolerance is now technically feasible. However, regulatory T cells from hemodialysis patients awaiting transplantation may be functionally/numerically defective. Human regulatory T cells are also heterogeneous, and some are able to convert to proinflammatory Th17 cells. This study addresses the suitability of regulatory T cells from hemodialysis patients for cell-based therapy in preparation for the first clinical trials in renal transplant recipients (the ONE Study). Design, setting, participants, & measurements Healthy controls and age- and sex-matched hemodialysis patients without recent illness/autoimmune disease on established, complication-free hemodialysis for a minimum of 6 months were recruited. Circulating regulatory T cells were studied by flow cytometry to compare the regulatory T cell subpopulations. Regulatory T cells from members of each group were compared for suppressive function and plasticity (IL-17–producing capacity) before and after in vitro expansion with and without Rapamycin, using standard assays. Results Both groups had similar total regulatory T cells and subpopulations I and III. In each subpopulation, regulatory T cells expressed similar levels of the function-associated markers CD27, CD39, HLA-DR, and FOXP3. Hemodialysis regulatory T cells were less suppressive, expanded poorly compared with healthy control regulatory T cells, and produced IL-17 in the absence of Rapamycin. However, Rapamycin efficiently expanded hemodialysis regulatory T cells to a functional and stable cell product. Conclusions Rapamycin-based expansion protocols should enable clinical trials of cell-based immunotherapy for the induction of tolerance to renal allografts using hemodialysis regulatory T cells. PMID:23580782

  1. Functional Studies of Regulatory Genes in the Sea Urchin Embryo

    NASA Astrophysics Data System (ADS)

    Cavalieri, Vincenzo; Bernardo, Maria Di; Spinelli, Giovanni

    Sea urchin embryos are characterized by an extremely simple mode of development, rapid cleavage, high transparency, and well-defined cell lineage. Although they are not suitable for genetic studies, other approaches are successfully used to unravel mechanisms and molecules involved in cell fate specification and morphogenesis. Microinjection is the elective method to study gene function in sea urchin embryos. It is used to deliver precise amounts of DNA, RNA, oligonucleotides, peptides, or antibodies into the eggs or even into blastomeres. Here we describe microinjection as it is currently applied in our laboratory and show how it has been used in gene perturbation analyses and dissection of cis-regulatory DNA elements.

  2. 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. PMID:26922942

  3. [Systemic lupus erythematosus and regulatory T cells].

    PubMed

    Miyara, M; Amoura, Z; Piette, J-C; Gorochov, G

    2008-09-01

    A global depletion of FoxP3+ CD25(bright) CD4+ regulatory T cell is observed during lupus flares. This phenomenon is not the consequence of the relocalization of Tregs in diseased organs but could be related to their specific sensitivity to Fas mediated apoptosis. Several therapeutic perspectives can be drawn taking into account these pathophysiological insights. PMID:18538896

  4. 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

  5. FOXP3+ regulatory T cells in the human immune system.

    PubMed

    Sakaguchi, Shimon; Miyara, Makoto; Costantino, Cristina M; Hafler, David A

    2010-07-01

    Forkhead box P3 (FOXP3)(+) regulatory T (T(Reg)) cells are potent mediators of dominant self tolerance in the periphery. But confusion as to the identity, stability and suppressive function of human T(Reg) cells has, to date, impeded the general therapeutic use of these cells. Recent studies have suggested that human T(Reg) cells are functionally and phenotypically diverse. Here we discuss recent findings regarding human T(Reg) cells, including the ontogeny and development of T(Reg) cell subsets that have naive or memory phenotypes, the unique mechanisms of suppression mediated by T(Reg) cell subsets and factors that regulate T(Reg) cell lineage commitment. We discuss future studies that are needed for the successful therapeutic use of human T(Reg) cells. PMID:20559327

  6. INTERFERON REGULATORY FACTOR 4 AND 8 IN B CELL DEVELOPMENT

    PubMed Central

    Lu, Runqing

    2010-01-01

    IRF4 and 8 are members of the interferon regulatory factor family of transcription factors and have been shown to be essential for the development and function of T cells, macrophages and dendritic cells. A series of recent studies have further demonstrated critical functions for IRF4 and 8 at several stages of B cell development including pre-B cell development, receptor editing, germinal center reaction and plasma cell generation. Collectively, these new studies provide molecular insights into the function of IRF4 and 8 and underscore a requirement for IRF4 and 8 throughout B cell development. This review focuses on the recent advances on roles of IRF4 and 8 in B cell development. PMID:18775669

  7. Combinatorial Gene Regulatory Functions Underlie Ultraconserved Elements in Drosophila

    PubMed Central

    Warnefors, Maria; Hartmann, Britta; Thomsen, Stefan; Alonso, Claudio R.

    2016-01-01

    Ultraconserved elements (UCEs) are discrete genomic elements conserved across large evolutionary distances. Although UCEs have been linked to multiple facets of mammalian gene regulation their extreme evolutionary conservation remains largely unexplained. Here, we apply a computational approach to investigate this question in Drosophila, exploring the molecular functions of more than 1,500 UCEs shared across the genomes of 12 Drosophila species. Our data indicate that Drosophila UCEs are hubs for gene regulatory functions and suggest that UCE sequence invariance originates from their combinatorial roles in gene control. We also note that the gene regulatory roles of intronic and intergenic UCEs (iUCEs) are distinct from those found in exonic UCEs (eUCEs). In iUCEs, transcription factor (TF) and epigenetic factor binding data strongly support iUCE roles in transcriptional and epigenetic regulation. In contrast, analyses of eUCEs indicate that they are two orders of magnitude more likely than the expected to simultaneously include protein-coding sequence, TF-binding sites, splice sites, and RNA editing sites but have reduced roles in transcriptional or epigenetic regulation. Furthermore, we use a Drosophila cell culture system and transgenic Drosophila embryos to validate the notion of UCE combinatorial regulatory roles using an eUCE within the Hox gene Ultrabithorax and show that its protein-coding region also contains alternative splicing regulatory information. Taken together our experiments indicate that UCEs emerge as a result of combinatorial gene regulatory roles and highlight common features in mammalian and insect UCEs implying that similar processes might underlie ultraconservation in diverse animal taxa. PMID:27247329

  8. Combinatorial Gene Regulatory Functions Underlie Ultraconserved Elements in Drosophila.

    PubMed

    Warnefors, Maria; Hartmann, Britta; Thomsen, Stefan; Alonso, Claudio R

    2016-09-01

    Ultraconserved elements (UCEs) are discrete genomic elements conserved across large evolutionary distances. Although UCEs have been linked to multiple facets of mammalian gene regulation their extreme evolutionary conservation remains largely unexplained. Here, we apply a computational approach to investigate this question in Drosophila, exploring the molecular functions of more than 1,500 UCEs shared across the genomes of 12 Drosophila species. Our data indicate that Drosophila UCEs are hubs for gene regulatory functions and suggest that UCE sequence invariance originates from their combinatorial roles in gene control. We also note that the gene regulatory roles of intronic and intergenic UCEs (iUCEs) are distinct from those found in exonic UCEs (eUCEs). In iUCEs, transcription factor (TF) and epigenetic factor binding data strongly support iUCE roles in transcriptional and epigenetic regulation. In contrast, analyses of eUCEs indicate that they are two orders of magnitude more likely than the expected to simultaneously include protein-coding sequence, TF-binding sites, splice sites, and RNA editing sites but have reduced roles in transcriptional or epigenetic regulation. Furthermore, we use a Drosophila cell culture system and transgenic Drosophila embryos to validate the notion of UCE combinatorial regulatory roles using an eUCE within the Hox gene Ultrabithorax and show that its protein-coding region also contains alternative splicing regulatory information. Taken together our experiments indicate that UCEs emerge as a result of combinatorial gene regulatory roles and highlight common features in mammalian and insect UCEs implying that similar processes might underlie ultraconservation in diverse animal taxa. PMID:27247329

  9. 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

  10. Targeting regulatory T cells in tumors.

    PubMed

    Liu, Chang; Workman, Creg J; Vignali, Dario A A

    2016-07-01

    Regulatory T (Treg ) cells play a crucial role in maintaining peripheral tolerance and preventing autoimmunity. However, they also represent a major barrier to effective antitumor immunity and immunotherapy. Consequently, there has been considerable interest in developing approaches that can selectively or preferentially target Treg cells in tumors, while not impacting their capacity to maintain peripheral immune homeostasis. In this review, we describe our current understanding of the mechanisms underlying the recruitment, expansion, and suppressive activity of tumor-associated Treg cells, and discuss the approaches used and the challenges encountered in the immunotherapeutic targeting of Treg cells. In addition, we summarize the primary clinical targets and some emerging data on exciting new potential Treg cell-restricted targets. We propose that discovering and understanding mechanisms that are preferentially used by Treg cells within the tumor microenvironment will lead to strategies that selectively target Treg cell-mediated suppression of antitumor immunity while maintaining peripheral immune tolerance. PMID:26787424

  11. Functional Classification of Immune Regulatory Proteins

    SciTech Connect

    Rubinstein, Rotem; Ramagopal, Udupi A.; Nathenson, Stanley G.; Almo, Steven C.; Fiser, Andras

    2013-05-01

    Members of the immunoglobulin superfamily (IgSF) control innate and adaptive immunity and are prime targets for the treatment of autoimmune diseases, infectious diseases, and malignancies. We describe a computational method, termed the Brotherhood algorithm, which utilizes intermediate sequence information to classify proteins into functionally related families. This approach identifies functional relationships within the IgSF and predicts additional receptor-ligand interactions. As a specific example, we examine the nectin/nectin-like family of cell adhesion and signaling proteins and propose receptor-ligand interactions within this family. We were guided by the Brotherhood approach and present the high-resolution structural characterization of a homophilic interaction involving the class-I MHC-restricted T-cell-associated molecule, which we now classify as a nectin-like family member. The Brotherhood algorithm is likely to have a significant impact on structural immunology by identifying those proteins and complexes for which structural characterization will be particularly informative.

  12. Hurdles in therapy with regulatory T cells.

    PubMed

    Trzonkowski, Piotr; Bacchetta, Rosa; Battaglia, Manuela; Berglund, David; Bohnenkamp, Hermann Richard; ten Brinke, Anja; Bushell, Andrew; Cools, Nathalie; Geissler, Edward K; Gregori, Silvia; Marieke van Ham, S; Hilkens, Catharien; Hutchinson, James A; Lombardi, Giovanna; Madrigal, J Alejandro; Marek-Trzonkowska, Natalia; Martinez-Caceres, Eva M; Roncarolo, Maria Grazia; Sanchez-Ramon, Silvia; Saudemont, Aurore; Sawitzki, Birgit

    2015-09-01

    Improper activation of the immune system contributes to a variety of clinical conditions, including autoimmune and allergic diseases as well as solid organ and bone marrow transplantation. One approach to counteract this activation is through adoptive therapy with regulatory T cells (Tregs). Efforts to manufacture these cells have led to good maunfacturing practice-compliant protocols, and Treg products are entering early clinical trials. Here, we report the stance of the European Union Cooperation in Science and Technology Action BM1305, "Action to Focus and Accelerate Cell-based Tolerance-inducing Therapies-A FACTT," which identifies hurdles hindering Treg clinical applications in Europe and provides possible solutions. PMID:26355029

  13. The potential role of functional inhibition of T regulatory cells by anti-TGFβ antibody in photodynamic therapy of renal cancer

    NASA Astrophysics Data System (ADS)

    Mroz, Pawel; Hamblin, Michael R.

    2011-03-01

    Photodynamic therapy (PDT) has been shown to be an effective locally ablative anti-cancer treatment that has the additional advantage of inducing tumor-directed immune response. We hypothesized that PDT could be combined with anti-transforming growth factor (TGF) beta antibody that does not significantly affect the population of cytotoxic T lymphocytes (CTL) but at the same time, has the potential to decrease the immunosuppressive effects of regulatory T-cells (Treg) mediated by TGF beta. This hypothesis was tested with aTGF-beta antibody combined with BPD-mediated PDT in a BALB/c renal cell carcinoma model. Evidence of positive benefits of the combination therapy over individual treatments alone was obtained.

  14. Function does not follow form in gene regulatory circuits

    PubMed Central

    Payne, Joshua L.; Wagner, Andreas

    2015-01-01

    Gene regulatory circuits are to the cell what arithmetic logic units are to the chip: fundamental components of information processing that map an input onto an output. Gene regulatory circuits come in many different forms, distinct structural configurations that determine who regulates whom. Studies that have focused on the gene expression patterns (functions) of circuits with a given structure (form) have examined just a few structures or gene expression patterns. Here, we use a computational model to exhaustively characterize the gene expression patterns of nearly 17 million three-gene circuits in order to systematically explore the relationship between circuit form and function. Three main conclusions emerge. First, function does not follow form. A circuit of any one structure can have between twelve and nearly thirty thousand distinct gene expression patterns. Second, and conversely, form does not follow function. Most gene expression patterns can be realized by more than one circuit structure. And third, multifunctionality severely constrains circuit form. The number of circuit structures able to drive multiple gene expression patterns decreases rapidly with the number of these patterns. These results indicate that it is generally not possible to infer circuit function from circuit form, or vice versa. PMID:26290154

  15. The interplay of effector and regulatory T cells in cancer.

    PubMed

    Roychoudhuri, Rahul; Eil, Robert L; Restifo, Nicholas P

    2015-04-01

    Regulatory T (Treg) cells suppress effector T (Teff) cells and prevent immune-mediated rejection of cancer. Much less appreciated are mechanisms by which Teff cells antagonize Treg cells. Herein, we consider how complex reciprocal interactions between Teff and Treg cells shape their population dynamics within tumors. Under states of tolerance, including during tumor escape, suppressed Teff cells support Treg cell populations through antigen-dependent provision of interleukin (IL)-2. During immune activation, Teff cells can lose this supportive capacity and directly antagonize Treg cell populations to neutralize their immunosuppressive function. While this latter state is rarely achieved spontaneously within tumors, we propose that therapeutic induction of immune activation has the potential to stably disrupt immunosuppressive population states resulting in durable cancer regression. PMID:25728990

  16. Role of regulatory b cells in neuroimmunologic disorders.

    PubMed

    Han, Jinming; Sun, Li; Fan, Xueli; Wang, Zhongkun; Cheng, Yun; Zhu, Jie; Jin, Tao

    2016-08-01

    B lymphocytes augment the immune response by producing antibodies and activating T cells by antigen presentation. Recent studies have highlighted a specific and functionally significant B-cell subset that could downregulate excessive immune and inflammatory responses through a vast array of inhibitory cytokines, such as interleukin (IL)-10 and transforming growth factor-β (TGF-β). This subset of B cells is generally referred to as regulatory B cells (Bregs). In addition, recent studies have shown that IL-35-producing Bregs also play a role in downregulation of immunity. Diverse phenotypes of Bregs have been proposed to underlie human disorders and their animal models. Most studies have focused on the role of different subsets of Bregs and Bregs-associated molecules such as IL-10, TGF-β, and IL-35 in the pathogenesis of neuroimmunologic disorders. Furthermore, Bregs exert regulatory function mainly through suppressing the differentiation of Th1/Th17 cells and promoting regulatory T-cell expansion. Reduced presence of Bregs is reportedly associated with progression of several neuroimmunologic disorders. This Review summarizes the current knowledge on the role of Bregs in neuroimmunologic disorders, including multiple sclerosis, neuromyelitis optica, and myasthenia gravis. © 2016 The Authors. Journal of Neuroscience Research Published by Wiley Periodicals, Inc. PMID:27112131

  17. Pretreatment With Inactivated Bacillus Calmette-Guerin Increases CD4+CD25+ Regulatory T Cell Function and Decreases Functional and Structural Effects of Asthma Induction in a Rat Asthma Model.

    PubMed

    Gong, Ping; Li, Yun; Tan, Yu-Pin; Li, Hong

    2016-04-01

    Bacillus Calmette-Guerin (BCG) has been shown to have therapeutic effects on asthma through CD4+CD25+ regulatory T cells (Tregs). We sought to assess pretreatment with inactivated BCG on CD4+CD25+ Tregs and its functional and structural effects in rat asthma model. The rat asthma model was established using ovalbumin (OVA) sensitization and challenge. Ten rats were pretreated with BCG prior to OVA and received continued BCG injections during OVA challenge (BCG+OVA group), 10 rats were treated with OVA alone (OVA group), and 10 rats were treated with saline (control group). After 9 weeks, histamine dihydrochloride effect on airway resistance was measured. Number of CD4+CD25+ Tregs was measured by flow cytometry, expression of Foxp3 and CTLA-4 mRNA was measured, and serum TGF-β levels were determined. Differential cell count in bronchoalveolar lavage fluid (BALF) was determined, and lung tissue was processed and stained with hematoxylin and eosin, Masson's trichrome, and alcine blue and periodic acid Schiff's reaction to evaluate inflammatory cell infiltration, collagen deposition, and presence of goblet cells, respectively. BCG treatment led to an increase in CD4+CD25+ Tregs, as well as an increase in Foxp3 and CTLA-4 expression and serum TGF-β levels. In addition, we observed a decrease in histamine dihydrochloride-induced airway resistance, a decrease in inflammatory leukocytes in BALF, and a decrease in airway remodeling indicators in BCG+OVA-treated rats compared with OVA-treated rats. Intradermally injected inactivated BCG has the potential to improve airway inflammation, airway resistance, and airway remodeling through a mechanism that may involve CD4+CD25+ Tregs. PMID:26495900

  18. An Arabidopsis Gene Regulatory Network for Secondary Cell Wall Synthesis

    PubMed Central

    Taylor-Teeples, M; Lin, L; de Lucas, M; Turco, G; Toal, TW; Gaudinier, A; Young, NF; Trabucco, GM; Veling, MT; Lamothe, R; Handakumbura, PP; Xiong, G; Wang, C; Corwin, J; Tsoukalas, A; Zhang, L; Ware, D; Pauly, M; Kliebenstein, DJ; Dehesh, K; Tagkopoulos, I; Breton, G; Pruneda-Paz, JL; Ahnert, SE; Kay, SA; Hazen, SP; Brady, SM

    2014-01-01

    Summary 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. Here, we present a protein-DNA network between Arabidopsis 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. These interactions will serve as a foundation for understanding the regulation of a complex, integral plant component. PMID:25533953

  19. Is there a feudal hierarchy amongst regulatory immune cells? More than just Tregs

    PubMed Central

    Mauri, Claudia; Carter, Natalie

    2009-01-01

    Nature has provided the developing immune system with several checkpoints important for the maintenance of tolerance and the prevention of autoimmunity. The regulatory mechanisms operating in the periphery of the system are mediated by subsets of regulatory cells, now considered principal contributors to peripheral tolerance. Regulatory T cells (Tregs) have received titanic interest in the past decade, placing them at the centre of immuno-suppressive reactions. However, it has become clearer that other immune suppressive cells inhibit auto-reactivity as effectively as Tregs. The function of Tregs and other regulatory cells in rheumatoid arthritis will be discussed in this review. PMID:19664198

  20. [Regulatory T cells in chronic obstructive pulmonary disease].

    PubMed

    Limón-Camacho, Leonardo; Solleiro-Villavicencio, Helena; Pupko-Sissa, Ilana; Lascurain, Ricardo; Vargas-Rojas, María Inés

    2013-01-01

    Exposition to tobacco smoke has been established as the main risk factor to develop chronic obstructive pulmonary disease (COPD), by inducing inflammation of the airways. Several cell populations participate in this inflammatory process. It has been accepted that a maladaptive modulation of inflammatory responses plays a critical role in the development of the disease. Regulatory T cells (Treg) are a subset of T CD4(+) lymphocytes that modulate the immune response through secretion of cytokines. The role of the Treg cells in chronic obstructive pulmonary disease is not clearly known, that is why it is important to focus in understanding their participation in the pathogenesis of the disease. To elaborate a systematic review of original articles in which we could describe Treg cells (their ontogeny, mechanisms of action) and their role in COPD, we made a systematic literature search in some data bases (MEDLINE, AMED, PubMed and Scielo) looking through the next keywords: "COPD and Regulatory T cells/EPOC y células T reguladoras", «Inflammation and COPD/Inflamación y EPOC», «Regulatory T cells/Células T reguladoras». We included basic science articles, controlled and non-controlled clinical trials, meta-analysis and guides. From this search we conclude that Treg cells are a subpopulation of T CD4(+) lymphocytes and their major functions are the suppression of immune responses and the maintenance of tolerance to self-antigens. A disruption in the regulatory mechanisms of the Treg cells leads to the development and perpetuation of inflammation in COPD. PMID:23474149

  1. Parameterizing cell-to-cell regulatory heterogeneities via stochastic transcriptional profiles

    PubMed Central

    Bajikar, Sameer S.; Fuchs, Christiane; Roller, Andreas; Theis, Fabian J.; Janes, Kevin A.

    2014-01-01

    Regulated changes in gene expression underlie many biological processes, but globally profiling cell-to-cell variations in transcriptional regulation is problematic when measuring single cells. Transcriptome-wide identification of regulatory heterogeneities can be robustly achieved by randomly collecting small numbers of cells followed by statistical analysis. However, this stochastic-profiling approach blurs out the expression states of the individual cells in each pooled sample. Here, we show that the underlying distribution of single-cell regulatory states can be deconvolved from stochastic-profiling data through maximum-likelihood inference. Guided by the mechanisms of transcriptional regulation, we formulated plausible mixture models for cell-to-cell regulatory heterogeneity and maximized the resulting likelihood functions to infer model parameters. Inferences were validated both computationally and experimentally for different mixture models, which included regulatory states for multicellular function that were occupied by as few as 1 in 40 cells of the population. Importantly, when the method was extended to programs of heterogeneously coexpressed transcripts, we found that population-level inferences were much more accurate with pooled samples than with one-cell samples when the extent of sampling was limited. Our deconvolution method provides a means to quantify the heterogeneous regulation of molecular states efficiently and gain a deeper understanding of the heterogeneous execution of cell decisions. PMID:24449900

  2. 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. PMID:27190026

  3. 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

  4. Stat3 Is Important for Follicular Regulatory T Cell Differentiation

    PubMed Central

    Wu, Hao; Xie, Markus M.; Liu, Hong; Dent, Alexander L.

    2016-01-01

    The production of antibody is precisely controlled during the germinal center (GC) reaction. This process is dependent on the help from follicular T helper (Tfh) cells to germinal center (GC) B cells and is regulated by regulatory follicular T helper (Tfr) cells. How Tfr cells develop and how their suppressive activity functions are not well understood. Here, we found that Stat3 is indispensible for Tfr cell differentiation. After immunization with Sheep Red Blood Cells (SRBC), the loss of Tfr cells caused by deletion of Stat3 in Treg cells does not affect the size of Tfh or GC B cell population, but rather leads to strongly enhanced production of antigen-specific IgG1 and IgG2b. In Peyer’s patches (PPs) in the gut, we found that Stat3 expression in Treg cells is also required for Tfr cell formation to commensal organisms. However, loss of Tfr cells in the gut did not affect the numbers of Tfh cells and GC B cells, nor affect IgG1 or IgA switching by GC B cells. Overall, our study has uncovered unique roles of Stat3 in Tfr cell differentiation and the regulation of the antibody response. PMID:27148746

  5. Role of regulatory dendritic cells in allergy and asthma.

    PubMed

    Akbari, Omid; Umetsu, Dale T

    2005-01-01

    Dendritic cells (DCs) are the most efficient inducers of all immune responses, and are capable of either inducing productive immunity or maintaining the state of tolerance to self antigens and allergens. In this review, we summarize the emerging literature on DCs, with emphasis on the regulatory function of DCs in allergy and asthma. In particular, we summarize recent data regarding the relationship between DC subsets and TH1, TH2, and regulatory T (TReg) cells. The diverse functions of DCs have been attributed to distinct lineages of DCs, which arise from common immature precursor cells that differentiate in response to specific maturation-inducing or local microenvironment conditions. These subsets of DCs induce different lineages of T cells, such as TH1, TH2, and TReg cells, including Th1Reg and Th2Reg cells, which regulate allergic diseases and asthma. Subsets of DCs regulate the induction of a variety of T-cell subtypes, which suppress the development of allergy and asthma, thus providing anti-inflammatory responses and protective immunity. PMID:15659264

  6. Deciphering cis-regulatory control in inflammatory cells.

    PubMed

    Ghisletti, Serena; Natoli, Gioacchino

    2013-01-01

    In innate immune system cells, such as macrophages and dendritic cells, deployment of inducible gene expression programmes in response to microbes and danger signals requires highly precise regulatory mechanisms. The inflammatory response has to be tailored based on both the triggering stimulus and its dose, and it has to be unfolded in a kinetically complex manner that suits the different phases of the inflammatory process. Genomic characterization of regulatory elements in this context indicated that transcriptional regulators involved in macrophage specification act as pioneer transcription factors (TFs) that generate regions of open chromatin that enable the recruitment of TFs activated in response to external inputs. Therefore, competence for responses to a specific stimulus is programmed at an early stage of differentiation by factors involved in lineage commitment and maintenance of cell identity, which are responsible for the organization of a cell-type-specific cis-regulatory repertoire. The basic functional and organizational principles that regulate inflammatory gene expression in professional cells of the innate immune system provide general paradigms on the interplay between differentiation and environmental responses. PMID:23650641

  7. 3D Chromosome Regulatory Landscape of Human Pluripotent Cells.

    PubMed

    Ji, Xiong; Dadon, Daniel B; Powell, Benjamin E; Fan, Zi Peng; Borges-Rivera, Diego; Shachar, Sigal; Weintraub, Abraham S; Hnisz, Denes; Pegoraro, Gianluca; Lee, Tong Ihn; Misteli, Tom; Jaenisch, Rudolf; Young, Richard A

    2016-02-01

    In this study, we describe the 3D chromosome regulatory landscape of human naive and primed embryonic stem cells. To devise this map, we identified transcriptional enhancers and insulators in these cells and placed them within the context of cohesin-associated CTCF-CTCF loops using cohesin ChIA-PET data. The CTCF-CTCF loops we identified form a chromosomal framework of insulated neighborhoods, which in turn form topologically associating domains (TADs) that are largely preserved during the transition between the naive and primed states. Regulatory changes in enhancer-promoter interactions occur within insulated neighborhoods during cell state transition. The CTCF anchor regions we identified are conserved across species, influence gene expression, and are a frequent site of mutations in cancer cells, underscoring their functional importance in cellular regulation. These 3D regulatory maps of human pluripotent cells therefore provide a foundation for future interrogation of the relationships between chromosome structure and gene control in development and disease. PMID:26686465

  8. Umbilical cord blood regulatory T-cell expansion and functional effects of tumor necrosis factor receptor family members OX40 and 4-1BB expressed on artificial antigen-presenting cells

    PubMed Central

    Harker-Murray, Paul; Porter, Stephen B.; Merkel, Sarah C.; Londer, Aryel; Taylor, Dawn K.; Bina, Megan; Panoskaltsis-Mortari, Angela; Rubinstein, Pablo; Van Rooijen, Nico; Golovina, Tatiana N.; Suhoski, Megan M.; Miller, Jeffrey S.; Wagner, John E.; June, Carl H.; Riley, James L.

    2008-01-01

    Previously, we showed that human umbilical cord blood (UCB) regulatory T cells (Tregs) could be expanded approximately 100-fold using anti-CD3/28 monoclonal antibody (mAb)–coated beads to provide T-cell receptor and costimulatory signals. Because Treg numbers from a single UCB unit are limited, we explored the use of cell-based artificial antigen-presenting cells (aAPCs) preloaded with anti-CD3/28 mAbs to achieve higher levels of Treg expansion. Compared with beads, aAPCs had similar expansion properties while significantly increasing transforming growth factor β (TGF-β) secretion and the potency of Treg suppressor function. aAPCs modified to coexpress OX40L or 4-1BBL expanded UCB Tregs to a significantly greater extent than bead- or nonmodified aAPC cultures, reaching mean expansion levels exceeding 1250-fold. Despite the high expansion and in contrast to studies using other Treg sources, neither OX40 nor 4-1BB signaling of UCB Tregs reduced in vitro suppression. UCB Tregs expanded with 4-1BBL expressing aAPCs had decreased levels of proapoptotic bim. UCB Tregs expanded with nonmodified or modified aAPCs versus beads resulted in higher survival associated with increased Treg persistence in a xeno-geneic graft-versus-host disease lethality model. These data offer a novel approach for UCB Treg expansion using aAPCs, including those coexpressing OX40L or 4-1BBL. PMID:18645038

  9. T Cells: Soldiers and Spies—The Surveillance and Control of Effector T Cells by Regulatory T Cells

    PubMed Central

    2015-01-01

    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

  10. 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

  11. Differential influence of the tumour-specific non-human sialic acid containing GM3 ganglioside on CD4+CD25- effector and naturally occurring CD4+CD25+ regulatory T cells function.

    PubMed

    de León, Joel; Fernández, Audry; Clavell, Marilyn; Labrada, Mayrel; Bebelagua, Yanin; Mesa, Circe; Fernández, Luis E

    2008-04-01

    Increasing evidences suggest that the aberrant expression of certain gangliosides on malignant cells could affect host's anti-tumour-specific immune responses. We have recently documented the relevance of the N-glycolylated variant of GM3 ganglioside (NGcGM3), a tumour-specific non-human sialic acid containing ganglioside, for tumour progression. However, evidences about the implication of host's immunity in NGcGM3-promoted cancer progression had not been obtained previously. In this work, we compared tumour growth of X63 myeloma cells pre-treated or not with an inhibitor of the glucosylceramide synthase enzyme, in wild or CD4+ T cell-depleted BALB/c mice. Results clearly showed a relationship between the agonistic effect of NGcGM3 in tumour growth and the presence of CD4+ T lymphocytes. For the first time, a description of a ganglioside-differential effect over purified CD4+CD25- and naturally occurring regulatory CD4+CD25+ T cells is provided. While NGcGM3 similarly down-modulated the CD4 expression in both cell populations, the inhibitory capacity of the CD4+CD25+ lymphocytes and their proliferation, induced by an anti-CD3 mAb and IL2, were not modified. In a different fashion, a reduction in proliferative capacity and a noteworthy secretion of anti-inflammatory cytokines were detected when CD4+CD25- T cells were cultured in the presence of NGcGM3. Considering the relevance of dendritic cells (DC) on primary activation of T cells, the effect of NGcGM3 over DC differentiation and TLR4-mediated maturation was also assessed. Our results indicate that NGcGM3 contributes to cancer progression mainly by influencing DC and CD4+CD25- T lymphocyte functions, rather than increasing the inhibitory capacity of naturally occurring regulatory T cells. PMID:18310617

  12. 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

  13. Regulatory T cells are baby's best friends.

    PubMed

    Teles, Ana; Zenclussen, Ana Claudia; Schumacher, Anne

    2013-04-01

    Regulatory T cells (Treg) are one of the most and best studied immune cell population during human and murine pregnancy, and there is a general consent about their expansion during pregnancy. However, the identification of new and more reliable Treg markers during the last years resulted in some controversies about the kinetics of various Treg subsets at different pregnancy stages. No doubt exists regarding the importance of Treg for a normal pregnancy as pregnancy complications like spontaneous abortion and preeclampsia could be associated with a reduced Treg number and activity. In future, more attention should be paid to bring established data from the bench to the bedside to force the development of adequate therapies for treatment of pregnancy complications. In this article, we summarize previous and recent data on several aspects of Treg biology during human and murine pregnancy. PMID:23289369

  14. Impaired regulatory B cells in myasthenia gravis.

    PubMed

    Sheng, Jian Rong; Rezania, Kourosh; Soliven, Betty

    2016-08-15

    Regulatory B cells (Bregs) attenuate the severity of experimental autoimmune myasthenia gravis (EAMG) in an interleukin-10 (IL-10)-dependent manner. The goal of this study was to investigate the role of human Bregs in MG focusing on CD19(+)CD1d(hi) CD5(+) and CD19(+)CD24(hi)CD38(hi) subsets. We found that MG patients exhibited a decrease in the frequency of both Breg subsets and IL-10 producing B cells within each subset, which correlated with disease severity. In addition, there was impaired suppression of Th1 polarization in MG. These findings, taken together with EAMG data, indicate that Bregs play an important role in regulating the severity of MG. PMID:27397074

  15. Transcriptional Regulatory Network for the Development of Innate Lymphoid Cells

    PubMed Central

    Zhong, Chao; Zhu, Jinfang

    2015-01-01

    Recent studies on innate lymphoid cells (ILCs) have expanded our knowledge about the innate arm of the immune system. Helper-like ILCs share both the “innate” feature of conventional natural killer (cNK) cells and the “helper” feature of CD4+ T helper (Th) cells. With this combination, helper-like ILCs are capable of initiating early immune responses similar to cNK cells, but via secretion of a set of effector cytokines similar to those produced by Th cells. Although many studies have revealed the functional similarity between helper-like ILCs and Th cells, some aspects of ILCs including the development of this lineage remain elusive. It is intriguing that the majority of transcription factors involved in multiple stages of T cell development, differentiation, and function also play critical roles during ILC development. Regulators such as Id2, GATA-3, Nfil3, TOX, and TCF-1 are expressed and function at various stages of ILC development. In this review, we will summarize the expression and functions of these transcription factors shared by ILCs and Th cells. We will also propose a complex transcriptional regulatory network for the lineage commitment of ILCs. PMID:26379372

  16. Regulatory T Cells Control Th2-Dominant Murine Autoimmune Gastritis.

    PubMed

    Harakal, Jessica; Rival, Claudia; Qiao, Hui; Tung, Kenneth S

    2016-07-01

    Pernicious anemia and gastric carcinoma are serious sequelae of autoimmune gastritis (AIG). Our study indicates that in adult C57BL/6-DEREG mice expressing a transgenic diphtheria toxin receptor under the Foxp3 promoter, transient regulatory T cell (Treg) depletion results in long-lasting AIG associated with both H(+)K(+)ATPase and intrinsic factor autoantibody responses. Although functional Tregs emerge over time during AIG occurrence, the effector T cells rapidly become less susceptible to Treg-mediated suppression. Whereas previous studies have implicated dysregulated Th1 cell responses in AIG pathogenesis, eosinophils have been detected in gastric biopsy specimens from patients with AIG. Indeed, AIG in DEREG mice is associated with strong Th2 cell responses, including dominant IgG1 autoantibodies, elevated serum IgE, increased Th2 cytokine production, and eosinophil infiltration in the stomach-draining lymph nodes. In addition, the stomachs exhibit severe mucosal and muscular hypertrophy, parietal cell loss, mucinous epithelial cell metaplasia, and massive eosinophilic inflammation. Notably, the Th2 responses and gastritis severity are significantly ameliorated in IL-4- or eosinophil-deficient mice. Furthermore, expansion of both Th2-promoting IFN regulatory factor 4(+) programmed death ligand 2(+) dendritic cells and ILT3(+) rebounded Tregs was detected after transient Treg depletion. Collectively, these data suggest that Tregs maintain physiological tolerance to clinically relevant gastric autoantigens, and Th2 responses can be a pathogenic mechanism in AIG. PMID:27259856

  17. On the Concept of Cis-regulatory Information: From Sequence Motifs to Logic Functions

    NASA Astrophysics Data System (ADS)

    Tarpine, Ryan; Istrail, Sorin

    The regulatory genome is about the “system level organization of the core genomic regulatory apparatus, and how this is the locus of causality underlying the twin phenomena of animal development and animal evolution” (E.H. Davidson. The Regulatory Genome: Gene Regulatory Networks in Development and Evolution, Academic Press, 2006). Information processing in the regulatory genome is done through regulatory states, defined as sets of transcription factors (sequence-specific DNA binding proteins which determine gene expression) that are expressed and active at the same time. The core information processing machinery consists of modular DNA sequence elements, called cis-modules, that interact with transcription factors. The cis-modules “read” the information contained in the regulatory state of the cell through transcription factor binding, “process” it, and directly or indirectly communicate with the basal transcription apparatus to determine gene expression. This endowment of each gene with the information-receiving capacity through their cis-regulatory modules is essential for the response to every possible regulatory state to which it might be exposed during all phases of the life cycle and in all cell types. We present here a set of challenges addressed by our CYRENE research project aimed at studying the cis-regulatory code of the regulatory genome. The CYRENE Project is devoted to (1) the construction of a database, the cis-Lexicon, containing comprehensive information across species about experimentally validated cis-regulatory modules; and (2) the software development of a next-generation genome browser, the cis-Browser, specialized for the regulatory genome. The presentation is anchored on three main computational challenges: the Gene Naming Problem, the Consensus Sequence Bottleneck Problem, and the Logic Function Inference Problem.

  18. Transcriptional Regulatory Networks for CD4 T Cell Differentiation

    PubMed Central

    Zhu, Jinfang

    2015-01-01

    CD4+ T cells play a central role in controlling the adaptive immune response by secreting cytokines to activate target cells. Naïve CD4+ T cells differentiate into at least four subsets, Th1, Th2, Th17, and inducible regulatory T cells, each with unique functions for pathogen elimination. The differentiation of these subsets is induced in response to cytokine stimulation, which is translated into Stat activation, followed by induction of master regulator transcription factors. In addition to these factors, multiple other transcription factors, both subset specific and shared, are also involved in promoting subset differentiation. This review will focus on the network of transcription factors that control CD4+ T cell differentiation. PMID:24839135

  19. CD4+CD25bright T cells in human intestinal lamina propria as regulatory cells.

    PubMed

    Makita, Shin; Kanai, Takanori; Oshima, Shigeru; Uraushihara, Koji; Totsuka, Teruji; Sawada, Taisuke; Nakamura, Tetsuya; Koganei, Kazutaka; Fukushima, Tsuneo; Watanabe, Mamoru

    2004-09-01

    It is well known that immune responses in the intestine remain in a state of controlled inflammation, suggesting that not only active suppression by regulatory T cells plays an important role in the normal intestinal homeostasis, but also its dysregulation leads to the development of inflammatory bowel disease. In this study, we demonstrate that the CD4(+)CD25(bright) T cells reside in the human intestinal lamina propria (LP) and functionally retain regulatory activities. All human LP CD4(+) T cells regardless of CD25 expression constitutively expressed CTLA-4, glucocorticoid-induced TNFR family-related protein, and Foxp3 and proliferate poorly. Although LP CD4(+)CD25(-) T cells showed an activated and anergic/memory phenotype, they did not retain regulatory activity. In LP CD4(+)CD25(+) T cells, however, cells expressing CD25 at high levels (CD4(+)CD25(bright)) suppressed the proliferation and various cytokine productions of CD4(+)CD25(-) T cells. LP CD4(+)CD25(bright) T cells by themselves produced fewer amounts of IL-2, IFN-gamma, and IL-10. Interestingly, LP CD4(+)CD25(bright) T cells with regulatory T activity were significantly increased in patients with active inflammatory bowel disease. These results suggest that CD4(+)CD25(bright) T cells found in the normal and inflamed intestinal mucosa selectively inhibit the host immune response and therefore may contribute to the intestinal immune homeostasis. PMID:15322172

  20. Functional Annotation of Putative Regulatory Elements at Cancer Susceptibility Loci

    PubMed Central

    Rosse, Stephanie A; Auer, Paul L; Carlson, Christopher S

    2014-01-01

    Most cancer-associated genetic variants identified from genome-wide association studies (GWAS) do not obviously change protein structure, leading to the hypothesis that the associations are attributable to regulatory polymorphisms. Translating genetic associations into mechanistic insights can be facilitated by knowledge of the causal regulatory variant (or variants) responsible for the statistical signal. Experimental validation of candidate functional variants is onerous, making bioinformatic approaches necessary to prioritize candidates for laboratory analysis. Thus, a systematic approach for recognizing functional (and, therefore, likely causal) variants in noncoding regions is an important step toward interpreting cancer risk loci. This review provides a detailed introduction to current regulatory variant annotations, followed by an overview of how to leverage these resources to prioritize candidate functional polymorphisms in regulatory regions. PMID:25288875

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

    PubMed Central

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

    2016-01-01

    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. PMID:27025390

  2. 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. PMID:25582339

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

    PubMed Central

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

    2015-01-01

    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. PMID:26416420

  4. Regulatory multitasking of tolerogenic dendritic cells - lessons taken from vitamin d3-treated tolerogenic dendritic cells.

    PubMed

    Nikolic, Tatjana; Roep, Bart O

    2013-01-01

    Tolerogenic dendritic cells (DCs) work through silencing of differentiated antigen-specific T cells, activation and expansion of naturally occurring T regulatory cells (Tregs), transfer of regulatory properties to T cells, and the differentiation of naïve T cells into Tregs. Due to an operational definition based on T cell activation assays, the identity of tolerogenic DCs has been a matter of debate and it need not represent a specialized DC subset. Human tolerogenic DCs generated in vitro using inhibitory cytokines, growth factors, natural immunomodulators, or genetic manipulation have been effective and several of these tolerogenic DCs are currently being tested for clinical use. Ex vivo generated tolerogenic DCs reduce activation of naïve T cells using various means, promote a variety of regulatory T cells and most importantly, frequently show stable inhibitory phenotypes upon repetitive maturation with inflammatory factors. Yet, tolerogenic DCs differ with respect to the phenotype or the number of regulatory mechanisms they employ to modulate the immune system. In our experience, tolerogenic DCs generated using the biologically active form of vitamin D (VD3-DCs), alone, or combined with dexamethasone are proficient in their immunoregulatory functions. These tolerogenic DCs show a stable maturation-resistant semi-mature phenotype with low expression of activating co-stimulatory molecules, no production of the IL-12 family of cytokines and high expression of inhibitory molecules and IL-10. VD3-DCs induce increased apoptosis of effector T cells and induce antigen-specific regulatory T cells, which work through linked suppression ensuring infectious tolerance. Lessons learned on VD3-DCs help understanding the contribution of different pattern-recognition receptors (PRRs) and secondary signals to the tolerogenic function and how a cross-talk between DCs and T cells translates into immune regulation. PMID:23717310

  5. Regulatory T cells in immune-mediated renal disease.

    PubMed

    Ghali, Joanna R; Wang, Yuan Min; Holdsworth, Stephen R; Kitching, A Richard

    2016-02-01

    Regulatory T cells (Tregs) are CD4+ T cells that can suppress immune responses by effector T cells, B cells and innate immune cells. This review discusses the role that Tregs play in murine models of immune-mediated renal diseases and acute kidney injury and in human autoimmune kidney disease (such as systemic lupus erythematosus, anti-glomerular basement membrane disease, anti-neutrophil cytoplasmic antibody-associated vasculitis). Current research suggests that Tregs may be reduced in number and/or have impaired regulatory function in these diseases. Tregs possess several mechanisms by which they can limit renal and systemic inflammatory immune responses. Potential therapeutic applications involving Tregs include in vivo induction of Tregs or inducing Tregs from naïve CD4+ T cells or expanding natural Tregs ex vivo, to use as a cellular therapy. At present, the optimal method of generating a phenotypically stable pool of Tregs with long-lasting suppressive effects is not established, but human studies in renal transplantation are underway exploring the therapeutic potential of Tregs as a cellular therapy, and if successful may have a role as a novel therapy in immune-mediated renal diseases. PMID:26206106

  6. Identification of a unique double-negative regulatory T-cell population.

    PubMed

    Lee, Byung O; Jones, Joyce E; Peters, Cory J; Whitacre, David; Frelin, Lars; Hughes, Janice; Kim, Won-Keun; Milich, David R

    2011-12-01

    Regulatory T (Treg) cells represent one of the main mechanisms of regulating self-reactive immune cells. Treg cells are thought to play a role in down-regulating immune responses to self or allogeneic antigens in the periphery. Although the function of Treg cells has been demonstrated in many experimental settings, the precise mechanisms and antigen specificity often remain unclear. In a hepatitis B e antigen-T-cell receptor (HBeAg-TCR) double transgenic mouse model, we observed a phenotypically unique (TCR+)  CD4- /CD8-  CD25(+/-)  GITR(high)  PD-1(high)  FoxP3-) HBeAg-specific population that demonstrates immune regulatory function. This HBeAg-specific double-negative regulatory cell population proliferates vigorously in vitro, in contrast to any other known regulatory population, in an interleukin-2-independent manner. PMID:22044159

  7. Identification of a unique double-negative regulatory T-cell population

    PubMed Central

    Lee, Byung O; Jones, Joyce E; Peters, Cory J; Whitacre, David; Frelin, Lars; Hughes, Janice; Kim, Won-Keun; Milich, David R

    2011-01-01

    Regulatory T (Treg) cells represent one of the main mechanisms of regulating self-reactive immune cells. Treg cells are thought to play a role in down-regulating immune responses to self or allogeneic antigens in the periphery. Although the function of Treg cells has been demonstrated in many experimental settings, the precise mechanisms and antigen specificity often remain unclear. In a hepatitis B e antigen–T-cell receptor (HBeAg-TCR) double transgenic mouse model, we observed a phenotypically unique (TCR+ CD4−/CD8− CD25+/− GITRhigh PD-1high FoxP3−) HBeAg-specific population that demonstrates immune regulatory function. This HBeAg-specific double-negative regulatory cell population proliferates vigorously in vitro, in contrast to any other known regulatory population, in an interleukin-2-independent manner. PMID:22044159

  8. 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

    2016-01-01

    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

  9. 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

  10. Regulatory T Cell Dysfunction Acquiesces to BTLA+ Regulatory B Cells Subsequent to Oral Intervention in Experimental Autoimmune Encephalomyelitis.

    PubMed

    Huarte, Eduardo; Jun, SangMu; Rynda-Apple, Agnieszka; Golden, Sara; Jackiw, Larissa; Hoffman, Carol; Maddaloni, Massimo; Pascual, David W

    2016-06-15

    Regulatory T cells (Tregs) induced during autoimmunity often become quiescent and unable to resolve disease, suggesting inadequate activation. Resolution of established experimental autoimmune encephalomyelitis (EAE) can be achieved with myelin oligodendrocyte glycoprotein (MOG) fused to reovirus protein σ1 (MOG-pσ1), which activates Tregs, restoring protection, but requiring other regulatory cells to revitalize them. B cells have a dichotomous role in both the pathogenesis and recovery from EAE. Although inflammatory B cells contribute to EAE's pathogenesis, treatment of EAE mice with MOG-pσ1, but not OVA-pσ1, resulted in an influx of IL-10-producing B220(+)CD5(+) B regulatory cells (Bregs) enabling Tregs to recover their inhibitory activity, and in turn, leading to the rapid amelioration of EAE. These findings implicate direct interactions between Bregs and Tregs to facilitate this recovery. Adoptive transfer of B220(+)CD5(-) B cells from MOG-pσ1-treated EAE or Bregs from PBS-treated EAE mice did not resolve disease, whereas the adoptive transfer of MOG-pσ1-induced B220(+)CD5(+) Bregs greatly ameliorated EAE. MOG-pσ1-, but not OVA-pσ1-induced IL-10-producing Bregs, expressed elevated levels of B and T lymphocyte attenuator (BTLA) relative to CD5(-) B cells, as opposed to Tregs or effector T (Teff) cells, whose BTLA expression was not affected. These induced Bregs restored EAE Treg function in a BTLA-dependent manner. BTLA(-/-) mice showed more pronounced EAE with fewer Tregs, but upon adoptive transfer of MOG-pσ1-induced BTLA(+) Bregs, BTLA(-/-) mice were protected against EAE. Hence, this evidence shows the importance of BTLA in activating Tregs to facilitate recovery from EAE. PMID:27194787

  11. Regulatory T Cells in Post-stroke Immune Homeostasis.

    PubMed

    Liesz, Arthur; Kleinschnitz, Christoph

    2016-08-01

    The secondary neuroinflammatory response has come into focus of experimental stroke research. Immunological mechanisms after acute stroke are being investigated in the hope to identify novel and druggable pathways that contribute to secondary infarct growth after stroke. Among a variety of neuroimmunological events after acute brain ischemia, including microglial activation, brain leukocyte invasion, and secretion of pro-inflammatory factors, lymphocytes have been identified as the key leukocyte subpopulation driving the neuroinflammatory response and contributing to stroke outcome. Several studies have shown that pro-inflammatory lymphocyte subpopulations worsen stroke outcome and that inhibiting their invasion to the injured brain is neuroprotective. In contrast to the effector functions of pro-inflammatory lymphocytes, regulatory T cells (Treg) are critically involved in maintaining immune homeostasis and have been characterized as disease-limiting protective cells in several inflammatory conditions, particularly in primary inflammatory diseases of the central nervous system (CNS). However, due to the complex function of regulatory cells in immune homeostasis and disease, divergent findings have been described for the role of Treg in stroke models. Emerging evidence suggests that this discrepancy arises from potentially differing functions of Treg depending on the predominant site of action within the neurovascular unit and the surrounding inflammatory milieu. This article will provide a comprehensive review of current findings on Treg in brain ischemia models and discuss potential reasons for the observed discrepancies. PMID:27030356

  12. T regulatory cells and their counterparts: masters of immune regulation.

    PubMed

    Ozdemir, C; Akdis, M; Akdis, C A

    2009-05-01

    The interaction of environmental and genetic factors with the immune system can lead to the development of allergic diseases. The essential step in this progress is the generation of allergen-specific CD4(+) T-helper (Th) type 2 cells that mediate several effector functions. The influence of Th2 cytokines leads to the production of allergen-specific IgE antibodies by B cells, development and recruitment of eosinophils, mucus production and bronchial hyperreactivity, as well as tissue homing of other Th2 cells and eosinophils. Meanwhile, Th1 cells may contribute to chronicity and the effector phases. T cells termed T regulatory (Treg) cells, which have immunosuppressive functions and cytokine profiles distinct from that of either Th1 or Th2 cells, have been intensely investigated during the last 13 years. Treg cell response is characterized by an abolished allergen-specific T cell proliferation and the suppressed secretion of Th1 and Th2-type cytokines. Treg cells are able to inhibit the development of allergen-specific Th2 and Th1 cell responses and therefore play an important role in a healthy immune response to allergens. In addition, Treg cells potently suppress IgE production and directly or indirectly suppress the activity of effector cells of allergic inflammation, such as eosinophils, basophils and mast cells. Currently, Treg cells represent an exciting area of research, where understanding the mechanisms of peripheral tolerance to allergens may soon lead to more rational and safer approaches for the prevention and cure of allergic diseases. PMID:19422105

  13. Non-cell-autonomous effects of vector-expressed regulatory RNAs in mammalian heart cells.

    PubMed

    Kizana, E; Cingolani, E; Marbán, E

    2009-09-01

    In mammalian cells, small regulatory RNA molecules are able to modulate gene expression in a cell-autonomous manner. In contrast, this mechanism of gene regulation can occur systemically in plants and nematodes. The existence of similar cell-to-cell transmission in mammalian cells has been explored, but generalizibilty and mechanistic insights have remained elusive. Here, we show that small regulatory RNA molecules are capable of a non-cell-autonomous effect between primary cardiac myocytes through a gap-junction-dependent mechanism. Co-culture experiments showed that both Dicer-processed small-interfering RNAs (siRNAs) and Drosha-processed microRNAs (miRNAs) were capable of target gene knockdown and physiological effects in a non-cell-autonomous manner. Target gene siRNA molecules were detected in recipient cells, indicating transfer of the primary effector molecule. All of these effects were abrogated by dominant-negative molecular suppression of gap junction function. Our results show that both siRNAs and miRNAs are capable of a non-cell-autonomous effect between mammalian cells through gap junctions. The recognition of this biological process raises the novel therapeutic prospect of a bystander effect after gene transfer to tissues bearing gap junctions and for cell engineering with a view to creating regulatory RNA donor cells that exert their influence throughout a syncytium. PMID:19516277

  14. Form, Function, and Information Processing in Stochastic Regulatory Networks

    NASA Astrophysics Data System (ADS)

    Wiggins, Chris

    2009-03-01

    The ability of a biological network to transduce signals, e.g., from chemical information about the abundance of small molecules into regulatory information about the rate of mRNA expression, is thwarted by numerous sources of noise. A great amount has been learned and conjectured in the last decade about the extent to which the form of a network --- specified by the connectivity and sign of regulation --- constrains or guides the networks function --- the particular noisy input-output relation(s) the network is capable of executing. In parallel, a great amount of research has sought to elucidate the role of inescapable or 'intrinsic' noise arising from the finite copy number of the participating molecules, which sets physical limits on information processing in small cells. I'll discuss how information theory may help illuminate these topics by providing a framework for quantifying function which does not rely on specifying the particular task to be performed a priori, as well as by providing a measure for the extent to which form follows function. En route I hope to show how stochastic chemical kinetics, modeled by the (linear) master equation describing the probability of copy counts for all reactants, benefits from the same spectral approaches fundamental to solving the (linear) diffusion equation.

  15. Common variable immunodeficiency, impaired neurological development and reduced numbers of T regulatory cells in a 10-year-old boy with a STAT1 gain-of-function mutation.

    PubMed

    Kobbe, Robin; Kolster, Manuela; Fuchs, Sebastian; Schulze-Sturm, Ulf; Jenderny, Jutta; Kochhan, Lothar; Staab, Julia; Tolosa, Eva; Grimbacher, Bodo; Meyer, Thomas

    2016-07-25

    Recently, gain-of-function (GOF) mutations in the gene encoding signal transducer and activator of transcription 1 (STAT1) have been associated with chronic mucocutaneous candidiasis (CMC). This case report describes a 10-year-old boy presenting with signs of common variable immunodeficiency (CVID), failure to thrive, impaired neurological development, and a history of recurrent mucocutaneous Candida infections. Sequencing of the STAT1 gene identified a heterozygous missense mutation in exon 7 encoding the STAT1 coiled-coil domain (c.514T>C, p.Phe172Leu). In addition to hypogammaglobulinemia with B-cell deficiency, and a low percentage of Th17 cells, immunological analysis of the patient revealed a marked depletion of forkhead-box P3(+)-expressing regulatory T cells (Tregs). In vitro stimulation of T cells from the patient with interferon-α (IFNα) and/or IFNɣ resulted in a significantly increased expression of STAT1-regulated target genes such as MIG1, IRF1, MX1, MCP1/CCL2, IFI-56K, and CXCL10 as compared to IFN-treated cells from a healthy control, while no IFNα/ɣ-mediated up-regulation of the FOXP3 gene was found. These data demonstrate that the STAT1 GOF mutation F172L, which results in impaired stability of the antiparallel STAT1 dimer conformation, is associated with inhibited Treg cell development and neurological symptoms. PMID:27063510

  16. The Importance of the Nurse Cells and Regulatory Cells in the Control of T Lymphocyte Responses

    PubMed Central

    Reyes García, María Guadalupe; García Tamayo, Fernando

    2013-01-01

    T lymphocytes from the immune system are bone marrow-derived cells whose development and activities are carefully supervised by two sets of accessory cells. In the thymus, the immature young T lymphocytes are engulfed by epithelial “nurse cells” and retained in vacuoles, where most of them (95%) are negatively selected and removed when they have an incomplete development or express high affinity autoreactive receptors. The mature T lymphocytes that survive to this selection process leave the thymus and are controlled in the periphery by another subpopulation of accessory cells called “regulatory cells,” which reduce any excessive immune response and the risk of collateral injuries to healthy tissues. By different times and procedures, nurse cells and regulatory cells control both the development and the functions of T lymphocyte subpopulations. Disorders in the T lymphocytes development and migration have been observed in some parasitic diseases, which disrupt the thymic microenvironment of nurse cells. In other cases, parasites stimulate rather than depress the functions of regulatory T cells decreasing T-mediated host damages. This paper is a short review regarding some features of these accessory cells and their main interactions with T immature and mature lymphocytes. The modulatory role that neurotransmitters and hormones play in these interactions is also revised. PMID:23509712

  17. Tumor Progression Locus 2 (Tpl2) Activates the Mammalian Target of Rapamycin (mTOR) Pathway, Inhibits Forkhead Box P3 (FoxP3) Expression, and Limits Regulatory T Cell (Treg) Immunosuppressive Functions.

    PubMed

    Li, Xin; Acuff, Nicole V; Peeks, Angela R; Kirkland, Rebecca; Wyatt, Kara D; Nagy, Tamas; Watford, Wendy T

    2016-08-01

    The serine/threonine kinase tumor progression locus 2 (Tpl2, also known as Map3k8/Cot) is a potent inflammatory mediator that drives the production of TNFα, IL-1β, and IFNγ. We previously demonstrated that Tpl2 regulates T cell receptor (TCR) signaling and modulates T helper cell differentiation. However, very little is known about how Tpl2 modulates the development of regulatory T cells (Tregs). Tregs are a specialized subset of T cells that express FoxP3 and possess immunosuppressive properties to limit excess inflammation. Because of the documented role of Tpl2 in promoting inflammation, we hypothesized that Tpl2 antagonizes Treg development and immunosuppressive function. Here we demonstrate that Tpl2 constrains the development of inducible Tregs. Tpl2(-/-) naïve CD4(+) T cells preferentially develop into FoxP3(+) inducible Tregs in vitro as well as in vivo in a murine model of ovalbumin (OVA)-induced systemic tolerance. Treg biasing of Tpl2(-/-) T cells depended on TCR signal strength and corresponded with reduced activation of the mammalian target of rapamycin (mTOR) pathway. Importantly, Tpl2(-/-) Tregs have basally increased expression of FoxP3 and immunosuppressive molecules, IL-10 and cytotoxic T lymphocyte-associated protein 4 (CTLA-4). Furthermore, they were more immunosuppressive in vivo in a T cell transfer model of colitis, as evidenced by reduced effector T cell accumulation, systemic production of inflammatory cytokines, and colonic inflammation. These results demonstrate that Tpl2 promotes inflammation in part by constraining FoxP3 expression and Treg immunosuppressive functions. Overall, these findings suggest that Tpl2 inhibition could be used to preferentially drive Treg induction and thereby limit inflammation in a variety of autoimmune diseases. PMID:27261457

  18. US Nuclear Regulatory Commission organization charts and functional statements

    SciTech Connect

    1997-11-01

    This document contains organization charts for the U.S. Nuclear Regulatory Commission (NRC) and for the five offices of the NRC. Function statements are provided delineating the major responsibilities and operations of each office. Organization and function are provided to the branch level. The head of each office, division, and branch is also listed.

  19. Regulatory T Cells in Radiotherapeutic Responses

    PubMed Central

    Schaue, Dörthe; Xie, Michael W.; Ratikan, Josephine A.; McBride, William H.

    2012-01-01

    Radiation therapy (RT) can extend its influence in cancer therapy beyond what can be attributed to in-field cytotoxicity by modulating the immune system. While complex, these systemic effects can help tip the therapeutic balance in favor of treatment success or failure. Engagement of the immune system is generally through recognition of damage-associated molecules expressed or released as a result of tumor and normal tissue radiation damage. This system has evolved to discriminate pathological from physiological forms of cell death by signaling “danger.” The multiple mechanisms that can be evoked include a shift toward a pro-inflammatory, pro-oxidant microenvironment that can promote maturation of dendritic cells and, in cancer treatment, the development of effector T cell responses to tumor-associated antigens. Control over these processes is exerted by regulatory T cells (Tregs), suppressor macrophages, and immunosuppressive cytokines that act in consort to maintain tolerance to self, limit tissue damage, and re-establish tissue homeostasis. Unfortunately, by the time RT for cancer is initiated the tumor-host relationship has already been sculpted in favor of tumor growth and against immune-mediated mechanisms for tumor regression. Reversing this situation is a major challenge. However, recent data show that removal of Tregs can tip the balance in favor of the generation of radiation-induced anti-tumor immunity. The clinical challenge is to do so without excessive depletion that might precipitate serious autoimmune reactions and increase the likelihood of normal tissue complications. The selective modulation of Treg biology to maintain immune tolerance and control of normal tissue damage, while releasing the “brakes” on anti-tumor immune responses, is a worthy aim with promise for enhancing the therapeutic benefit of RT for cancer. PMID:22912933

  20. 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

  1. Research Progress on Regulatory T Cells in Acute Kidney Injury

    PubMed Central

    Wang, Yamei; Tao, Yuhong

    2015-01-01

    Immune inflammation is crucial in mediating acute kidney injury (AKI). Immune cells of both the innate and adaptive immune systems substantially contribute to overall renal damage in AKI. Regulatory T cells (Tregs) are key regulator of immunological function and have been demonstrated to ameliorate injury in several murine experimental models of renal inflammation. Recent studies have illuminated the renal-protective function of Tregs in AKI. Tregs appear to exert beneficial effects in both the acute injury phase and the recovery phase of AKI. Additionally, Tregs-based immunotherapy may represent a promising approach to ameliorate AKI and promote recovery from AKI. This review will highlight the recent insights into the role of Tregs and their therapeutic potential in AKI. PMID:26273681

  2. The development and immunosuppressive functions of CD4+ CD25+ FoxP3+ regulatory T cells are under influence of the adenosine-A2A adenosine receptor pathway

    PubMed Central

    Ohta, Akio; Kini, Radhika; Ohta, Akiko; Subramanian, Meenakshi; Madasu, Manasa; Sitkovsky, Michail

    2012-01-01

    The A2A adenosine receptor (A2AR)-mediated immunosuppression is firmly implicated in the life-saving down-regulation of collateral tissue damage during the anti-pathogen immune response and in highly undesirable protection of cancerous tissues during anti-tumor immune response. Therefore, depending on specific clinical situation there is a need to either weaken or strengthen the intensity of A2AR signal. While the A2AR-mediated immunosuppression was shown to be T cell autonomous in studies of effector T cells, it was not clear how A2AR stimulation affects regulatory T cells (Treg). Here we show in parallel assays that while A2AR stimulation on T cells directly inhibits their activation, there is also indirect and longer-lasting T cell inhibitory effect through modulation of Treg. A2AR stimulation expanded CD4+ CD25hi FoxP3+ cells, which also express CD39, CD73, and CTLA-4. Treg cultured with A2AR agonist showed increased expression of CTLA-4 and stronger immunosuppressive activity. There was a significant increase of Treg cell number after A2AR stimulation. The CD4+ FoxP3+ population contained those induced from CD4+ CD25− cells, but CD4+ FoxP3+ cells predominantly derived from CD4+ CD25+ natural Treg. Thus, A2AR stimulation numerically and functionally enhanced Treg-mediated immunosuppressive mechanism. These data suggest that the A2AR-mediated stimulation of lymphocytes using A2AR agonists should be considered in protocols for ex vivo expansion of Treg before the transfer to patients in different medical applications. PMID:22783261

  3. Regulatory B cells control T-cell autoimmunity through IL-21-dependent cognate interactions.

    PubMed

    Yoshizaki, Ayumi; Miyagaki, Tomomitsu; DiLillo, David J; Matsushita, Takashi; Horikawa, Mayuka; Kountikov, Evgueni I; Spolski, Rosanne; Poe, Jonathan C; Leonard, Warren J; Tedder, Thomas F

    2012-11-01

    B cells regulate immune responses by producing antigen-specific antibodies. However, specific B-cell subsets can also negatively regulate T-cell immune responses, and have been termed regulatory B cells. Human and mouse regulatory B cells (B10 cells) with the ability to express the inhibitory cytokine interleukin-10 (IL-10) have been identified. Although rare, B10 cells are potent negative regulators of antigen-specific inflammation and T-cell-dependent autoimmune diseases in mice. How B10-cell IL-10 production and regulation of antigen-specific immune responses are controlled in vivo without inducing systemic immunosuppression is unknown. Using a mouse model for multiple sclerosis, here we show that B10-cell maturation into functional IL-10-secreting effector cells that inhibit in vivo autoimmune disease requires IL-21 and CD40-dependent cognate interactions with T cells. Moreover, the ex vivo provision of CD40 and IL-21 receptor signals can drive B10-cell development and expansion by four-million-fold, and generate B10 effector cells producing IL-10 that markedly inhibit disease symptoms when transferred into mice with established autoimmune disease. The ex vivo expansion and reinfusion of autologous B10 cells may provide a novel and effective in vivo treatment for severe autoimmune diseases that are resistant to current therapies. PMID:23064231

  4. Functional defects of peripheral regulatory T lymphocytes in patients with progressive vitiligo.

    PubMed

    Ben Ahmed, M; Zaraa, I; Rekik, R; Elbeldi-Ferchiou, A; Kourda, N; Belhadj Hmida, N; Abdeladhim, M; Karoui, O; Ben Osman, A; Mokni, M; Louzir, H

    2012-01-01

    Auto-reactive cytotoxic T lymphocytes play a key role in the progressive loss or destruction of melanocytes in vitiligo but the mechanism underlying the loss of self-tolerance is unknown. A deregulation of regulatory T-cell biology has recently been suggested. The analysis of the suppressive effects of peripheral T regulatory cells in vitiligo patients revealed a functional defect in seven of 15 cases. This defect was strongly correlated with disease activity. The evaluation of the percentage of peripheral regulatory T lymphocytes did not reveal any intrinsic quantitative defect. Yet, a decrease in the percentage of such cells was noted in patients with progressive forms, suggesting a recruitment of regulatory T cells from the peripheral blood to the site of injury. This was further corroborated by the significant increase of Forkhead box P3 expression in the vitiliginous skin of patients. Our data support the involvement of a functional defect of peripheral regulatory T cells in the pathogenesis of vitiligo and open new possibilities to advance therapeutic approaches. PMID:21985183

  5. Regulatory T cells and antigen-specific tolerance.

    PubMed

    Kretschmer, Karsten; Apostolou, Irina; Verginis, Panos; von Boehmer, Harald

    2008-01-01

    Foxp3-expressing regulatory T cells (Tregs) have an essential function of preventing autoimmune disease in man and mouse. Foxp3 binds to forkhead motifs of about 1,100 genes and the strength of binding increases upon PMA/ionomycin stimulation. In Foxp3-expressing T-cell hybridomas, Foxp3 promoter binding does not lead to activation or suppression of genes which becomes only visible after T-cell activation. These findings are in line with observations by others that Foxp3 exerts important functions through association with Tcell receptor (TCR)-dependent transcription factors in a DNAbinding complex. Tregs can be generated when developing T cells encounter TCR agonist ligands in the thymus. This pro - cess requires costimulatory signals. In contrast, extra thymic conversion of naive T cells into Tregs is inhibited by costimulation. In fact, DC-derived retinoic acid (RA) helps the conversion process by counteracting the negative impact of costimulation. Since AP-1 is produced after costimulation and appears to interfere with Foxp3-NFAT transcription complexes, it is of interest to note that RA interferes with AP-1-dependent transcription. Thus, RA may interfere with the negative impact of costimulation on Treg conversion by interfering with the generation and/or function of AP-1. PMID:18802332

  6. Metabolic regulation of stem cell function.

    PubMed

    Burgess, R J; Agathocleous, M; Morrison, S J

    2014-07-01

    Stem cell function is regulated by intrinsic mechanisms, such as transcriptional and epigenetic regulators, as well as extrinsic mechanisms, such as short-range signals from the niche and long-range humoral signals. Interactions between these regulatory mechanisms and cellular metabolism are just beginning to be identified. In multiple systems, differentiation is accompanied by changes in glycolysis, oxidative phosphorylation and the levels of reactive oxygen species. Indeed, metabolic pathways regulate proliferation and differentiation by regulating energy production and the generation of substrates for biosynthetic pathways. Some metabolic pathways appear to function differently in stem cells as compared with restricted progenitors and differentiated cells. They also appear to influence stem cell function by regulating signal transduction, epigenetic marks and oxidative stress. Studies to date illustrate the importance of metabolism in the regulation of stem cell function and suggest complex cross-regulation likely exists between metabolism and other stem cell regulatory mechanisms. PMID:24697828

  7. T regulatory cells and the immune aging process

    PubMed Central

    Jagger, Ann Titi; Shimojima, Yasuhiro; Goronzy, Jorg J.; Weyand, Cornelia M.

    2016-01-01

    Constant exposure to new and persisting antigens and the need to replace cellular attrition with newly build cells lead to profound remodeling of the immune system during the second half of life. The impact of the immunosenescence process varies amongst the different functional subsets represented within the immune system, and emerging data suggest that progressive aging significantly affects frequencies, subset distribution and functional competence of regulatory T cells (Treg). Given the central role of Treg cells in immune homeostasis, age-related loss of Treg function would be predicted to render the host susceptible to excessive immunity, encountered in elderly humans as a syndrome of chronic-smoldering inflammation. Conversely, age-dependent gain of Treg activity would expose the host to greater risk of immune failure, such as the rising risk of malignancies and infections in the aging population. Emerging data suggest that some Treg populations, specifically naturally occurring Tregs (nTreg), seem to accumulate with advancing age, whereas inducible Tregs (iTreg) appear to be less available in the older host. More studies are necessary to elucidate functional competence of old Tregs, with emphasis on comparing efficacy of young on old Tregs for defined functional domains. Mechanisms of declining Treg inducibility are not understood, but may provide an opportunity for targeted immunomodulation in the elderly. On the horizon is the potential to develop novel therapeutic interventions that target Tregs to make the elderly more efficient in fighting cancers and infections and dampen the risk for senescence-associated inflammation. PMID:24296590

  8. 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. PMID:27585233

  9. Regulatory T Cells in Allogeneic Stem Cell Transplantation

    PubMed Central

    Nagler, Arnon

    2013-01-01

    Growing evidence suggests that cellular adoptive immunotherapy is becoming an attractive though challenging approach in regulating tumor immunity and alloresponses in clinical transplantation. Naturally arising CD4+CD25+Foxp3+ regulatory T cells (Treg) have emerged as a key component in this regard. Over the last decade, a large body of evidence from preclinical models has demonstrated their crucial role in auto- and tumor immunity and has opened the door to their “first-in-man” clinical application. Initial studies in clinical allogeneic stem cell transplantation are very encouraging and may pave the way for other applications. Further improvements in Treg ex vivo or in vivo expansion technologies will simplify their global clinical application. In this review, we discuss the current knowledge of Treg biology and their potential for cell-based immunotherapy in allogeneic stem cell transplantation. PMID:23737813

  10. The regulatory role of B cells in autoimmunity, infections and cancer: Perspectives beyond IL10 production.

    PubMed

    Gorosito Serrán, Melisa; Fiocca Vernengo, Facundo; Beccaria, Cristian G; Acosta Rodriguez, Eva V; Montes, Carolina L; Gruppi, Adriana

    2015-11-14

    The term regulatory B cells (B regs) is ascribed to a heterogeneous population of B cells with the function of suppressing inflammatory responses. They have been described mainly during the last decade in the context of different immune-mediated diseases. Most of the work on B regs has been focused on IL-10-producing B cells. However, B cells can exert regulatory functions independently of IL-10 production. Here we discuss the phenotypes, development and effector mechanisms of B regs and advances in their role in autoimmunity, infections and cancer. PMID:26424657

  11. Tumor-educated CD11bhighIalow regulatory dendritic cells suppress T cell response through arginase I.

    PubMed

    Liu, Qiuyan; Zhang, Chaoxiong; Sun, Anna; Zheng, Yuanyuan; Wang, Li; Cao, Xuetao

    2009-05-15

    Tumors can induce generation and accumulation of the immunosuppressive cells such as regulatory T cells in the tumor microenvironment, contributing to tumor escape from immunological attack. Although dendritic cell (DC)-based cancer vaccine can initiate antitumor immune response, regulatory DC subsets involved in the tolerance induction attracted much attention recently. Our previous studies demonstrate that the stromal microenvironment of the spleen, lung, and liver can program generation of CD11c(low)CD11b(high)Ia(low) DCs with regulatory function (CD11b(high)Ia(low) regulatory DCs). However, whether and how the tumor microenvironment can program generation of CD11b(high)Ia(low) regulatory DCs remain to be investigated. In this study, we used the freshly isolated tumor cells to mimic tumor microenvironment to coculture DCs and found that the freshly isolated tumor cells could drive DCs to differentiate into regulatory DCs with a CD11c(low)CD11b(high)Ia(low) phenotype and high expression of IL-10, NO, vascular endothelial growth factor, and arginase I. Tumor-educated CD11b(high)Ia(low) regulatory DCs inhibited CD4(+) T cell proliferation both in vitro and in vivo. 3LL lung cancer-derived TGF-beta and PGE(2) were responsible for the generation of regulatory DCs. PGE(2) was the main inducer of arginase I in regulatory DCs. Arginase I played a major role in the suppression of T cell response by regulatory DCs induced by 3LL lung cancer. A natural counterpart of CD11b(high)Ia(low) DCs was identified in tumor tissue, and CD11b(high)Ia(low) DCs sorted from 3LL lung cancer tissue expressed arginase I and inhibited T cell response. Therefore, tumors can educate DCs to differentiate into a regulatory DC subset, which contributes to constitution of the immunosuppressive tumor microenvironment and promotes tumor immune escape. PMID:19414774

  12. 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

  13. 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

  14. Tregalizumab – A Monoclonal Antibody to Target Regulatory T Cells

    PubMed Central

    König, Martin; Rharbaoui, Faiza; Aigner, Silke; Dälken, Benjamin; Schüttrumpf, Jörg

    2016-01-01

    Regulatory T cells (Tregs) represent a subpopulation of CD4+ T cells, which are essential for the maintenance of immunological tolerance. The absence or dysfunction of Tregs can lead to autoimmunity and allergies. The restoration of functional Tregs and/or Treg cell numbers represents a novel and attractive approach for the treatment of autoimmune diseases, e.g., rheumatoid arthritis (RA). The CD4 cell surface receptor is a target for modulation of T cell function. Monoclonal antibodies (mAbs) against CD4 have previously been tested for the treatment of autoimmune diseases, including RA. Furthermore, in model systems, anti-CD4 antibodies are able to induce tolerance and mediate immunomodulatory effects through a variety of mechanisms. Despite the availability of innovative and effective therapies for RA, many patients still have persistently active disease or experience adverse events that can limit use. A growing body of evidence suggests that Treg modulation could offer a new therapeutic strategy in RA and other autoimmune disorders. Here, we describe tregalizumab (BT-061), which is a novel, non-depleting IgG1 mAb that binds to a unique epitope of CD4. Tregalizumab represents the first humanized anti-CD4 mAb that selectively induces Treg activation. PMID:26834751

  15. Proceedings: International Regulatory Considerations on Development Pathways for Cell Therapies

    PubMed Central

    Tsokas, Katherine; Viswanathan, Sowmya; Zhang, Jiwen; Priest, Catherine; Pearce, Jonathan; Mount, Natalie

    2014-01-01

    Regenerative medicine is a rapidly evolving field that faces novel scientific and regulatory challenges. In September 2013, the International Workshop on Regulatory Pathways for Cell Therapies was convened to discuss the nature of these challenges and potential solutions and to highlight opportunities for potential convergence between different regulatory bodies that might assist the field’s development. The workshop discussions generated potentially actionable steps in five main areas that could mitigate cell therapy development pathway risk and accelerate moving promising therapies to patients. These included the need for convergence of regulatory guidelines on donor eligibility and suitability of lines for use in clinical trials and subsequent commercialization for cell therapies to move forward on a global basis; the need to challenge and encourage investigators in the regenerative medicine field to share information and provide examples of comparability studies related to master cell banks; the need for convergence of guidelines across regulatory jurisdictions on requirements for tumorigenicity studies, based on particular cell types and on biodistribution studies; the need to increase transparency in sharing clinical trial information more broadly and disseminating results more rapidly; and the need to establish a forum for sharing the experiences of various approaches being developed to expedite regulatory approvals and access for patients to innovative cell and regenerative therapies in the different regulatory jurisdictions and to assess their potential strengths and weaknesses. PMID:25038248

  16. Human regulatory T cells suppress proliferation of B lymphoma cells.

    PubMed

    Grygorowicz, Monika Anna; Biernacka, Marzena; Bujko, Mateusz; Nowak, Eliza; Rymkiewicz, Grzegorz; Paszkiewicz-Kozik, Ewa; Borycka, Ilona Sara; Bystydzienski, Zbigniew; Walewski, Jan; Markowicz, Sergiusz

    2016-08-01

    Activated regulatory T cells (Tregs) suppress proliferation and differentiation of normal B cells. In our study, allogeneic polyclonal CD4 (+) CD25 (+) Tregs and CD4 (+) CD25 (+) CD127(lo)Tregs expanded in vitro in the presence of rapamycin and low dose IL-2 suppressed proliferation of 11 out of 12 established lymphoma B-cell lines. The effect of expanded CD4 (+) CD25 (+) Tregs on survival of freshly isolated lymphoma B cells maintained in culture with soluble multimeric CD40L and IL-4 was variable across lymphoma entities. The survival of freshly isolated follicular lymphoma cells usually decreased in cocultures with CD4 (+) CD25 (+) Tregs. Treg effect on chronic lymphocytic leukemia/small lymphocytic lymphoma cells ranged from suppression to help in individual patients. CD4 (+) CD25 (+) Tregs or CD4 (+) CD25 (+) CD127(lo)Tregs expanded ex vivo with rapamycin could be used to suppress regrowth of residual lymphoma after autologous hematopoietic cell transplantation (HCT), and to counteract both graft-versus-host disease and lymphoma re-growth after allogeneic HCT in select patients with lymphoma susceptible to the regulation by Tregs. PMID:26758248

  17. 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

  18. 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

  19. Subsets of regulatory T cells and their roles in allergy.

    PubMed

    Zhang, Huiyun; Kong, Hui; Zeng, Xiaoning; Guo, Lianyi; Sun, Xiaoyun; He, Shaoheng

    2014-01-01

    In recent years, it is recognized that acquired immunity is controlled by regulatory T cell (Treg). Since fundamental pathophysiological changes of allergy are mainly caused by hyperresponsiveness of immune system to allergens that acquires after birth, Tregs likely play key roles in the pathogenesis of allergy, particularly during the sensitization phase. However, accumulated information indicate that there are several distinctive subtypes of Tregs in man, and each of them seems to play different role in controlling immune system, which complicates the involvement of Tregs in allergy. The aim of the present study is to attempt to classify subtypes of Tregs and summarize their roles in allergy. Tregs should include natural Tregs (nTreg) including inducible costimulator (ICOS)(+) Tregs, inducible/adaptive Tregs (iTreg), interleukin (IL)-10-producing type 1 Tregs (Tr1 cells), CD8(+) Tregs and IL-17-producing Tregs. These cells share some common features including expression of Foxp3 (except for Tr1 cells), and secretion of inhibitory cytokine IL-10 and/or TGF-β. Furthermore, it is noticeable that Tregs likely contribute to allergic disorders such as dermatitis and airway inflammation, and play a crucial role in the treatment of allergy through their actions on suppression of effector T cells and inhibition of activation of mast cells and basophils. Modulation of functions of Tregs may provide a novel strategy to prevent and treat allergic diseases. PMID:24886492

  20. Subsets of regulatory T cells and their roles in allergy

    PubMed Central

    2014-01-01

    In recent years, it is recognized that acquired immunity is controlled by regulatory T cell (Treg). Since fundamental pathophysiological changes of allergy are mainly caused by hyperresponsiveness of immune system to allergens that acquires after birth, Tregs likely play key roles in the pathogenesis of allergy, particularly during the sensitization phase. However, accumulated information indicate that there are several distinctive subtypes of Tregs in man, and each of them seems to play different role in controlling immune system, which complicates the involvement of Tregs in allergy. The aim of the present study is to attempt to classify subtypes of Tregs and summarize their roles in allergy. Tregs should include natural Tregs (nTreg) including inducible costimulator (ICOS)(+) Tregs, inducible/adaptive Tregs (iTreg), interleukin (IL)-10-producing type 1 Tregs (Tr1 cells), CD8(+) Tregs and IL-17-producing Tregs. These cells share some common features including expression of Foxp3 (except for Tr1 cells), and secretion of inhibitory cytokine IL-10 and/or TGF-β. Furthermore, it is noticeable that Tregs likely contribute to allergic disorders such as dermatitis and airway inflammation, and play a crucial role in the treatment of allergy through their actions on suppression of effector T cells and inhibition of activation of mast cells and basophils. Modulation of functions of Tregs may provide a novel strategy to prevent and treat allergic diseases. PMID:24886492

  1. Generation and characterization of regulatory dendritic cells derived from murine induced pluripotent stem cells

    PubMed Central

    Zhang, Qi; Fujino, Masayuki; Iwasaki, Shizue; Hirano, Hiroshi; Cai, Songjie; Kitajima, Yuya; Xu, Jinhua; Li, Xiao-Kang

    2014-01-01

    Regulatory dendritic cells (DCregs) represent a potential therapeutic tool for assessing a variety of immune overreaction conditions; however, current approaches for generating DCregs for therapeutic purposes are limited. We attempted to generate and characterize DCregs from murine induced pluripotent stem (iPS) cells. The iPS cells co-cultured with OP9 cells displayed mesodermally differentiated flat colonies. GM-CSF drove most of the colonies exhibiting a differentiated morphology. Thereafter, cells became morphologically heterologous under the effects of TGF-β and IL-10. Most of the floating cells developed an irregular shape with areas of protrusion. The generated iPS-DCregs demonstrated high CD11b/c and low CD40, CD80, CD86 and MHC-II expressions with a high antigen uptake ability and poor T-cell stimulatory function. Importantly, iPS-DCregs showed immune responsiveness regulation effects both in vitro and in vivo and the ability to generate regulatory T-cells in vitro. Our result illustrates a feasible approach for generating functional DCregs from murine iPS cells. PMID:24496181

  2. Functional characterization of the CCL25 promoter in small intestinal epithelial cells suggests a regulatory role for caudal-related homeobox (Cdx) transcription factors.

    PubMed

    Ericsson, Anna; Kotarsky, Knut; Svensson, Marcus; Sigvardsson, Mikael; Agace, William

    2006-03-15

    The chemokine CCL25 is selectively and constitutively expressed in the small intestinal epithelium and plays an important role in mediating lymphocyte recruitment to this site. In this study, we demonstrate that CCL25 expression in murine small intestinal epithelial cells is independent of signaling through the lymphotoxin beta receptor and is not enhanced by inflammatory stimuli, pathways involved in driving the expression of most other chemokines. We define a transcriptional start site in the CCL25 gene and a region -141 to -5 proximal of exon 1 that is required for minimal promoter activity in the small intestinal epithelial cell lines, MODE-K and mICc12. These cell lines expressed far less CCL25 mRNA than freshly isolated small intestinal epithelial cells indicating that they are missing important factors driving CCL25 expression. The CCL25 promoter contained putative binding sites for the intestinal epithelial-associated Caudal-related homeobox (Cdx) transcription factors Cdx-1 and Cdx-2, and small intestinal epithelial cells but not MODE-K and mICc12 cells expressed Cdx-1 and Cdx-2. EMSA analysis demonstrated that Cdx proteins were present in nuclear extracts from freshly isolated small intestinal epithelial cells but not in MODE-K or mICcl2 cells, and bound to putative Cdx sites within the CCL25 promoter. Finally, cotransfection of MODE-K cells with Cdx transcription factors significantly increased CCL25 promoter activity as well as endogenous CCL25 mRNA levels. Together these results demonstrate a unique pattern of regulation for CCL25 and suggest a role for Cdx proteins in regulating CCL25 transcription. PMID:16517733

  3. Role of dendritic cells in the induction of regulatory T cells

    PubMed Central

    2011-01-01

    Dendritic cells (DCs) play a key role in initiating immune responses and maintaining immune tolerance. In addition to playing a role in thymic selection, DCs play an active role in tolerance under steady state conditions through several mechanisms which are dependent on IL-10, TGF-β, retinoic acid, indoleamine-2,3,-dioxygenase along with vitamin D. Several of these mechanisms are employed by DCs in induction of regulatory T cells which are comprised of Tr1 regulatory T cells, natural and inducible foxp3+ regulatory T cells, Th3 regulatory T cells and double negative regulatory T cells. It appears that certain DC subsets are highly specialized in inducing regulatory T cell differentiation and in some tissues the local microenvironment plays a role in driving DCs towards a tolerogenic response. In this review we discuss the recent advances in our understanding of the mechanisms underlying DC driven regulatory T cell induction. PMID:21711933

  4. Regulatory T cells delay disease progression in Alzheimer-like pathology.

    PubMed

    Dansokho, Cira; Ait Ahmed, Dylla; Aid, Saba; Toly-Ndour, Cécile; Chaigneau, Thomas; Calle, Vanessa; Cagnard, Nicolas; Holzenberger, Martin; Piaggio, Eliane; Aucouturier, Pierre; Dorothée, Guillaume

    2016-04-01

    Recent studies highlight the implication of innate and adaptive immunity in the pathophysiology of Alzheimer's disease, and foster immunotherapy as a promising strategy for its treatment. Vaccines targeting amyloid-β peptide provided encouraging results in mouse models, but severe side effects attributed to T cell responses in the first clinical trial AN1792 underlined the need for better understanding adaptive immunity in Alzheimer's disease. We previously showed that regulatory T cells critically control amyloid-β-specific CD4(+) T cell responses in both physiological and pathological settings. Here, we analysed the impact of regulatory T cells on spontaneous disease progression in a murine model of Alzheimer's disease. Early transient depletion of regulatory T cells accelerated the onset of cognitive deficits in APPPS1 mice, without altering amyloid-β deposition. Earlier cognitive impairment correlated with reduced recruitment of microglia towards amyloid deposits and altered disease-related gene expression profile. Conversely, amplification of regulatory T cells through peripheral low-dose IL-2 treatment increased numbers of plaque-associated microglia, and restored cognitive functions in APPPS1 mice. These data suggest that regulatory T cells play a beneficial role in the pathophysiology of Alzheimer's disease, by slowing disease progression and modulating microglial response to amyloid-β deposition. Our study highlights the therapeutic potential of repurposed IL-2 for innovative immunotherapy based on modulation of regulatory T cells in Alzheimer's disease. PMID:26912648

  5. A Functional and Regulatory Network Associated with PIP Expression in Human Breast Cancer

    PubMed Central

    Debily, Marie-Anne; Marhomy, Sandrine El; Boulanger, Virginie; Eveno, Eric; Mariage-Samson, Régine; Camarca, Alessandra; Auffray, Charles; Piatier-Tonneau, Dominique; Imbeaud, Sandrine

    2009-01-01

    Background The PIP (prolactin-inducible protein) gene has been shown to be expressed in breast cancers, with contradictory results concerning its implication. As both the physiological role and the molecular pathways in which PIP is involved are poorly understood, we conducted combined gene expression profiling and network analysis studies on selected breast cancer cell lines presenting distinct PIP expression levels and hormonal receptor status, to explore the functional and regulatory network of PIP co-modulated genes. Principal Findings Microarray analysis allowed identification of genes co-modulated with PIP independently of modulations resulting from hormonal treatment or cell line heterogeneity. Relevant clusters of genes that can discriminate between [PIP+] and [PIP−] cells were identified. Functional and regulatory network analyses based on a knowledge database revealed a master network of PIP co-modulated genes, including many interconnecting oncogenes and tumor suppressor genes, half of which were detected as differentially expressed through high-precision measurements. The network identified appears associated with an inhibition of proliferation coupled with an increase of apoptosis and an enhancement of cell adhesion in breast cancer cell lines, and contains many genes with a STAT5 regulatory motif in their promoters. Conclusions Our global exploratory approach identified biological pathways modulated along with PIP expression, providing further support for its good prognostic value of disease-free survival in breast cancer. Moreover, our data pointed to the importance of a regulatory subnetwork associated with PIP expression in which STAT5 appears as a potential transcriptional regulator. PMID:19262752

  6. Ubiquitous points of control over regulatory T cells.

    PubMed

    Pan, Fan; Barbi, Joseph

    2014-06-01

    Posttranslational modification by ubiquitin tagging is crucial for regulating the stability, activity and cellular localization of many target proteins involved in processes including DNA repair, cell cycle progression, protein quality control, and signal transduction. It has long been appreciated that ubiquitin-mediated events are important for certain signaling pathways leading to leukocyte activation and the stimulation of effector function. Now it is clear that the activities of molecules and pathways central to immune regulation are also modified and controlled by ubiquitin tagging. Among the mechanisms of immune control, regulatory T cells (or Tregs) are themselves particularly sensitive to such regulation. E3 ligases and deubiquitinases both influence Tregs through their effects on the signaling pathways pertinent to these cells or through the direct, posttranslational regulation of Foxp3. In this review, we will summarize and discuss several examples of ubiquitin-mediated control over multiple aspects of Treg biology including the generation, function and phenotypic fidelity of these cells. Fully explored and exploited, these potential opportunities for Treg modulation may lead to novel immunotherapies for both positive and negative fine-tuning of immune restraint. PMID:24777637

  7. The regulatory sciences for stem cell-based medicinal products.

    PubMed

    Yuan, Bao-Zhu; Wang, Junzhi

    2014-06-01

    Over the past few years, several new achievements have been made from stem cell studies, many of which have moved up from preclinical stages to early, or from early to middle or late, stages thanks to relatively safe profile and preliminary evidence of effectiveness. Moreover, some stem cell-based products have been approved for marketing by different national regulatory authorities. However, many critical issues associated mainly with incomplete understanding of stem cell biology and the relevant risk factors, and lack of effective regulations still exist and need to be urgently addressed, especially in countries where establishment of appropriate regulatory system just commenced. More relevantly, the stem cell regulatory sciences need to be established or improved to more effectively evaluate quality, safety and efficacy of stem cell products, and for building up the appropriate regulatory framework. In this review, we summarize some new achievements in stem cell studies, especially the preclinical and clinical studies, the existing regulations, and the associated challenges, and we then propose some considerations for improving stem cell regulatory sciences with a goal of promoting the steadfast growth of the well-regulated stem cell therapies abreast of evolvement of stem cell sciences and technologies. PMID:24733351

  8. Tolerogenic Dendritic Cells for Regulatory T Cell Induction in Man

    PubMed Central

    Raker, Verena K.; Domogalla, Matthias P.; Steinbrink, Kerstin

    2015-01-01

    Dendritic cells (DCs) are highly specialized professional antigen-presenting cells that regulate immune responses, maintaining the balance between tolerance and immunity. Mechanisms via which they can promote central and peripheral tolerance include clonal deletion, the inhibition of memory T cell responses, T cell anergy, and induction of regulatory T cells (Tregs). These properties have led to the analysis of human tolerogenic DCs as a therapeutic strategy for the induction or re-establishment of tolerance. In recent years, numerous protocols for the generation of human tolerogenic DCs have been developed and their tolerogenic mechanisms, including induction of Tregs, are relatively well understood. Phase I trials have been conducted in autoimmune disease, with results that emphasize the feasibility and safety of treatments with tolerogenic DCs. Therefore, the scientific rationale for the use of tolerogenic DCs therapy in the fields of transplantation medicine and allergic and autoimmune diseases is strong. This review will give an overview on efforts and protocols to generate human tolerogenic DCs with focus on IL-10-modulated DCs as inducers of Tregs and discuss their clinical applications and challenges faced in further developing this form of immunotherapy. PMID:26617604

  9. 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

  10. EZH2 is crucial for both differentiation of regulatory T cells and T effector cell expansion

    PubMed Central

    Yang, Xiang-Ping; Jiang, Kan; Hirahara, Kiyoshi; Vahedi, Golnaz; Afzali, Behdad; Sciume, Giuseppe; Bonelli, Michael; Sun, Hong-Wei; Jankovic, Dragana; Kanno, Yuka; Sartorelli, Vittorio; O’Shea, John J.; Laurence, Arian

    2015-01-01

    The roles of EZH2 in various subsets of CD4+ T cells are controversial and its mechanisms of action are incompletely understood. FOXP3-positive Treg cells are a critical helper T cell subset, and dysregulation of Treg generation or function results in systemic autoimmunity. FOXP3 associates with EZH2 to mediate gene repression and suppressive function. Herein, we demonstrate that deletion of Ezh2 in CD4 T cells resulted in reduced numbers of Treg cells in vivo and differentiation in vitro and an increased proportion of memory CD4 T cells in part due to exaggerated production of effector cytokines. Furthermore, we found that both Ezh2-deficient Treg cells and T effector cells were functionally impaired in vivo: Tregs failed to constrain autoimmune colitis and T effector cells neither provided a protective response to T. gondii infection nor mediated autoimmune colitis. The dichotomous function of EZH2 in regulating differentiation and senescence in effector and regulatory T cells helps to explain the apparent existing contradictions in literature. PMID:26090605

  11. Manipulation of regulatory T cells and antigen-specific cytotoxic T lymphocyte-based tumour immunotherapy

    PubMed Central

    Karimi, Shirin; Chattopadhyay, Subhasis; Chakraborty, Nitya G

    2015-01-01

    The most potent killing machinery in our immune system is the cytotoxic T lymphocyte (CTL). Since the possibility for self-destruction by these cells is high, many regulatory activities exist to prevent autoimmune destruction by these cells. A tumour (cancer) grows from the cells of the body and is tolerated by the body's immune system. Yet, it has been possible to generate tumour-associated antigen (TAA) -specific CTL that are also self-antigen specific in vivo, to achieve a degree of therapeutic efficacy. Tumour-associated antigen-specific T-cell tolerance through pathways of self-tolerance generation represents a significant challenge to successful immunotherapy. CD4+ CD25+ FoxP3+ T cells, referred to as T regulatory (Treg) cells, are selected in the thymus as controllers of the anti-self repertoire. These cells are referred to as natural T regulatory (nTreg) cells. According to the new consensus (Nature Immunology 2013; 14:307–308) these cells are to be termed as (tTreg). There is another class of CD4+ Treg cells also involved in regulatory function in the periphery, also phenotypically CD4+ CD25±, classified as induced Treg (iTreg) cells. These cells are to be termed as peripherally induced Treg (pTreg) cells. In vitro-induced Treg cells with suppressor function should be termed as iTreg. These different Treg cells differ in their requirements for activation and in their mode of action. The current challenges are to determine the degree of specificity of these Treg cells in recognizing the same TAA as the CTL population and to circumvent their regulatory constraints so as to achieve robust CTL responses against cancer. PMID:25243729

  12. Ubiquitous Points of Control over Regulatory T cells

    PubMed Central

    Pan, Fan; Barbi, Joseph

    2014-01-01

    Posttranslational modification by ubiquitin tagging is crucial for regulating the stability, activity and cellular localization of many target proteins and processes including DNA repair, cell cycle progression, protein quality control and signal transduction. It has long been appreciated that ubiquitin-mediated events are important for certain signaling pathways leading to leukocyte activation and the stimulation of effector function. It is now clear that the activities of molecules and pathways central to immune regulation are also modified and regulated through ubiquitin. Among the mechanisms of immune control, regulatory T cells (or Tregs) are themselves particularly sensitive to such regulation. E3 ligases and deubiquitinases both influence Tregs through their effects on signaling pathways pertinent for these cells or through the direct, posttranslational regulation of Foxp3. In this review we will summarize and discuss several examples of ubiquitin-mediated control over multiple aspects of biology of Tregs including their generation, function and phenotypic fidelity. Fully explored and exploited, these potential opportunities for Treg modulation may lead to novel immunotherapies for both positive and negative fine-tuning of immune restraint. PMID:24777637

  13. First Insight into the Kinome of Human Regulatory T Cells

    PubMed Central

    König, Sebastian; Probst-Kepper, Michael; Reinl, Tobias; Jeron, Andreas; Huehn, Jochen; Schraven, Burkhart; Jänsch, Lothar

    2012-01-01

    Regulatory T cells (Tregs) are essential for controlling peripheral tolerance by the active suppression of various immune cells including conventional T effector cells (Teffs). Downstream of the T cell receptor (TCR), more than 500 protein kinases encoded by the human genome have to be considered in signaling cascades regulating the activation of Tregs and Teffs, respectively. Following TCR engagement, Tregs posses a number of unique attributes, such as constitutive expression of Foxp3, hyporesponsiveness and poor cytokine production. Furthermore, recent studies showed that altered regulation of protein kinases is important for Treg function. These data indicate that signaling pathways in Tregs are distinctly organized and alterations at the level of protein kinases contribute to the unique Treg phenotype. However, kinase-based signaling networks in Tregs are poorly understood and necessitate further systematic characterization. In this study, we analyzed the differential expression of kinases in Tregs and Teffs by using a kinase-selective proteome strategy. In total, we revealed quantitative information on 185 kinases expressed in the human CD4+ T cell subsets. The majority of kinases was equally abundant in both T cell subsets, but 11 kinases were differentially expressed in Tregs. Most strikingly, Tregs showed an altered expression of cell cycle kinases including CDK6. Quantitative proteomics generates first comparative insight into the kinase complements of the CD4+ Teff and Treg subset. Treg-specific expression pattern of 11 protein kinases substantiate the current opinion that TCR-mediated signaling cascades are altered in Tregs and further suggests that Tregs exhibit significant specificities in cell-cycle control and progression. PMID:22815858

  14. Community Structure Reveals Biologically Functional Modules in MEF2C Transcriptional Regulatory Network

    PubMed Central

    Alcalá-Corona, Sergio A.; Velázquez-Caldelas, Tadeo E.; Espinal-Enríquez, Jesús; Hernández-Lemus, Enrique

    2016-01-01

    Gene regulatory networks are useful to understand the activity behind the complex mechanisms in transcriptional regulation. A main goal in contemporary biology is using such networks to understand the systemic regulation of gene expression. In this work, we carried out a systematic study of a transcriptional regulatory network derived from a comprehensive selection of all potential transcription factor interactions downstream from MEF2C, a human transcription factor master regulator. By analyzing the connectivity structure of such network, we were able to find different biologically functional processes and specific biochemical pathways statistically enriched in communities of genes into the network, such processes are related to cell signaling, cell cycle and metabolism. In this way we further support the hypothesis that structural properties of biological networks encode an important part of their functional behavior in eukaryotic cells. PMID:27252657

  15. The Paradox Role of Regulatory T Cells in Ischemic Stroke

    PubMed Central

    Li, Min; Jiang, Yongjun

    2013-01-01

    The underlying mechanism of ischemic stroke is not completely known. Regulatory T cells (Tregs), a subset of T cells, play a pivotal role in the pathophysiological process of ischemic stroke. However, there is also controversy over the role of Tregs in stroke. Hence, the function of Tregs in ischemic stroke has triggered a heated discussion recently. In this paper, we reviewed the current lines of evidence to describe the full view of Tregs in stroke. We would like to introduce the basic concepts of Tregs and then discuss their paradox function in ischemic stroke. On one side, Tregs could protect brain against ischemic injury via modulating the inflammation process. On the other side, they exaggerated the insult by causing microvascular dysfunction. They also interfered with the neurological function recovery. In addition, the reasons for this paradox role would be discussed in the review and the prospective of the clinical application of Tregs was also included. In conclusion, Tregs contributed to the outcome of ischemic stroke, while more lines of evidence are needed to understand how Tregs regulate the immune system and influence the outcome of stroke. PMID:24288462

  16. Influence of Dietary Components on Regulatory T Cells

    PubMed Central

    Issazadeh-Navikas, Shohreh; Teimer, Roman; Bockermann, Robert

    2012-01-01

    Common dietary components including vitamins A and D, omega-3 and probiotics are now widely accepted to be essential to protect against many diseases with an inflammatory nature. On the other hand, high-fat diets are documented to exert multiple deleterious effects, including fatty liver diseases. Here we discuss the effect of dietary components on regulatory T cell (Treg) homeostasis, a central element of the immune system to prevent chronic tissue inflammation. Accordingly, evidence on the impact of dietary components on diseases in which Tregs play an influential role will be discussed. We will review chronic tissue-specific autoimmune and inflammatory conditions such as inflammatory bowel disease, type 1 diabetes mellitus, multiple sclerosis, rheumatoid arthritis and allergies among chronic diseases where dietary factors could have a direct influence via modulation of Tregs homeostasis and functions. PMID:22113499

  17. IL-10-producing type 1 regulatory T cells and allergy.

    PubMed

    Wu, Kui; Bi, Yutian; Sun, Kun; Wang, Changzheng

    2007-08-01

    As an important subset of regulatory T (Treg) cells, IL-10-producing type 1 regulatory T cells (Tr1), have some different features to thymic-derived naturally occurring CD4+CD25+Foxp3+ Treg cells(nTreg cells). Similar to nTreg cells, Tr1 also play important roles in the control of allergic inflammation in several ways. There is a fine balance between Tr1 and Th2 responses in healthy subjects. Skewing of allergic-specific effector T cells to a Tr1 phenotype appears to be a critical event in successful allergen-specific immunotherapy and glucocorticoids and beta2-agonists treatment. Tr1 suppress Th2 cells and effector cells of allergic inflammation, such as eosinophils, mast cells, basophils, through producing IL-10, and perhaps TGF-beta. Understanding of Tr1 may be helpful in developing new strategies for treatment of allergic diseases. PMID:17764617

  18. Novel Foxp3(-) IL-10(-) Regulatory T-cells Induced by B-Cells Alleviate Intestinal Inflammation in Vivo.

    PubMed

    Shao, Tzu-Yu; Hsu, Ling-Hui; Chien, Chien-Hui; Chiang, Bor-Luen

    2016-01-01

    Recent studies have revealed various Foxp3(-) regulatory T (Treg) cell subsets effectively protect mice from colitis. In the present study, we demonstrated that B cells induced a particular subset of regulatory T (Treg-of-B) cells, expressing programmed cell death 1 (PD-1), inducible costimulator (ICOS), lymphocyte-activation gene 3 (LAG3), glucocorticoid-induced tumor necrosis factor receptor (GITR), and OX-40, did not express Foxp3. Treg-of-B cells produced abundant levels of IL-10 and low levels of IL-4 and TGF-β. Adoptive transfer of Treg-of-B cells protected mice from CD4(+)CD45RB(hi) T-cell-induced colitis, including infiltration of leukocytes, depletion of goblet cells, epithelial hyperplasia, and inhibition of Th1 and Th17 cytokines. These features were similar to IL-10-producing type 1 regulatory T (Tr1) cells; however, IL-10-deficient Treg-of-B cells maintained their suppressive function in vitro as well as in vivo, while the regulation of Tr1 cells depended on IL-10. In conclusion, Treg-of-B cells protected against experimental colitis through an IL-10-independent mechanism. We reported a novel subpopulation of regulatory T cells was different from conventional Foxp3(+) Treg and IL-10-producing Tr1 cells. PMID:27581189

  19. Phenotypical characterization of regulatory T cells in humans and rodents.

    PubMed

    Rodríguez-Perea, A L; Arcia, E D; Rueda, C M; Velilla, P A

    2016-09-01

    Regulatory T cells (Tregs ) constitute a fascinating subpopulation of CD4(+) T cells due to their ability to limit the immune response against self and non-self antigens. Murine models and antibodies directed against surface and intracellular molecules have allowed elucidation of the mechanisms that govern their development and function. However, these markers used to their classification lack of specificity, as they can be expressed by activated T cells. Similarly, there are slight differences between animal models, in steady state and pathological conditions, anatomical localization and strategy of analysis by flow cytometry. Here, we revised the most common markers utilized for Treg typification by flow cytometry such as CD25, forkhead box protein 3 (FoxP3) and CD127, along with our data obtained in different body compartments of humans, mice and rats. Furthermore, we revised and determined the expression of other molecules important for the phenotypical characterization of Treg cells. We draw attention to the drawbacks of those markers used in chronic states of inflammation. However, until a specific marker for the identification of Tregs is discovered, the best combination of markers will depend upon the tissue or the degree of inflammation from which Tregs derive. PMID:27124481

  20. Comprehensive identification of arginine methylation in primary T cells reveals regulatory roles in cell signalling

    PubMed Central

    Geoghegan, Vincent; Guo, Ailan; Trudgian, David; Thomas, Benjamin; Acuto, Oreste

    2015-01-01

    The impact of protein arginine methylation on the regulation of immune functions is virtually unknown. Here, we apply a novel method—isomethionine methyl-SILAC—coupled with antibody-mediated arginine-methylated peptide enrichment to identify methylated peptides in human T cells by mass spectrometry. This approach allowed the identification of 2,502 arginine methylation sites from 1,257 tissue-specific and housekeeping proteins. We find that components of T cell antigen receptor signal machinery and several key transcription factors that regulate T cell fate determination are methylated on arginine. Moreover, we demonstrate changes in arginine methylation stoichiometry during cellular stimulation in a subset of proteins critical to T cell differentiation. Our data suggest that protein arginine methyltransferases exert key regulatory roles in T cell activation and differentiation, opening a new field of investigation in T cell biology. PMID:25849564

  1. Regulatory role of estrogen-induced reactive oxygen species in the modulatory function of UCP 2 in papillary thyroid cancer cells.

    PubMed

    Hima, Sithul; Sreeja, Sreeharshan

    2015-11-01

    Oxidative stress is postulated as one of the mechanisms underlying the estrogen's carcinogenic effect in thyroid cancer. But the fundamental mechanisms behind this carcinogenic effect remain elusive. Physiologically attainable concentrations of estrogen or estrogen metabolites have been made known to cause reactive oxygen species (ROS). It is envisioned that estrogen-induced ROS mediated signaling is a key congruent mechanism that drives the modulation of uncoupled proteins in papillary thyroid carcinoma cells. The present study investigates that estrogens may increase mitochondrial ROS production by repressing uncoupling proteins, which offers a new perspective on the understanding of why thyroid cancer occurs three times more often in females than in males, and the occurrence decreases after menopause. PMID:26450681

  2. Genetic and epigenetic variation in the lineage specification of regulatory T cells

    PubMed Central

    Arvey, Aaron; van der Veeken, Joris; Plitas, George; Rich, Stephen S; Concannon, Patrick; Rudensky, Alexander Y

    2015-01-01

    Regulatory T (Treg) cells, which suppress autoimmunity and other inflammatory states, are characterized by a distinct set of genetic elements controlling their gene expression. However, the extent of genetic and associated epigenetic variation in the Treg cell lineage and its possible relation to disease states in humans remain unknown. We explored evolutionary conservation of regulatory elements and natural human inter-individual epigenetic variation in Treg cells to identify the core transcriptional control program of lineage specification. Analysis of single nucleotide polymorphisms in core lineage-specific enhancers revealed disease associations, which were further corroborated by high-resolution genotyping to fine map causal polymorphisms in lineage-specific enhancers. Our findings suggest that a small set of regulatory elements specify the Treg lineage and that genetic variation in Treg cell-specific enhancers may alter Treg cell function contributing to polygenic disease. DOI: http://dx.doi.org/10.7554/eLife.07571.001 PMID:26510014

  3. Induction of Regulatory T Cells by Intravenous Immunoglobulin: A Bridge between Adaptive and Innate Immunity

    PubMed Central

    Kaufman, Gabriel N.; Massoud, Amir H.; Dembele, Marieme; Yona, Madelaine; Piccirillo, Ciriaco A.; Mazer, Bruce D.

    2015-01-01

    Intravenous immunoglobulin (IVIg) is a polyclonal immunoglobulin G preparation with potent immunomodulatory properties. The mode of action of IVIg has been investigated in multiple disease states, with various mechanisms described to account for its benefits. Recent data indicate that IVIg increases both the number and the suppressive capacity of regulatory T cells, a subpopulation of T cells that are essential for immune homeostasis. IVIg alters dendritic cell function, cytokine and chemokine networks, and T lymphocytes, leading to development of regulatory T cells. The ability of IVIg to influence Treg induction has been shown both in animal models and in human diseases. In this review, we discuss data on the potential mechanisms contributing to the interaction between IVIg and the regulatory T-cell compartment. PMID:26441974

  4. 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. PMID:26051475

  5. Regulatory SNPs in complex diseases: their identification and functional validation.

    PubMed

    Prokunina, Ludmila; Alarcón-Riquelme, Marta E

    2004-04-01

    Finding the genetic causes for complex diseases is a challenge. Expression studies have shown that the level of expression of many genes is altered in disease compared with normal conditions, but what lies behind these changes? Linkage studies provide hints as to where in the genome the genetic triggers--the mutations--might be located. Fine-mapping and association studies can give yet more information about which genes, and which changes in the genes, are involved in the disease. Recent examples show that single-nucleotide polymorphisms (SNPs), which are variations at the single-nucleotide level within an individual's DNA, in the regulatory regions of some genes constitute susceptibility factors in many complex diseases. This article discusses the nature of regulatory SNPs (rSNPs) and techniques for their functional validation, and looks towards what rSNPs can tell us about complex diseases. PMID:15122975

  6. Modeling Nonalcoholic Fatty Liver Disease with Human Pluripotent Stem Cell-Derived Immature Hepatocyte-Like Cells Reveals Activation of PLIN2 and Confirms Regulatory Functions of Peroxisome Proliferator-Activated Receptor Alpha

    PubMed Central

    Graffmann, Nina; Ring, Sarah; Kawala, Marie-Ann; Wruck, Wasco; Ncube, Audrey; Trompeter, Hans-Ingo

    2016-01-01

    Nonalcoholic fatty liver disease (NAFLD/steatosis) is a metabolic disease characterized by the incorporation of fat into hepatocytes. In this study, we developed an in vitro model for NAFLD based on hepatocyte-like cells (HLCs) differentiated from human pluripotent stem cells. We induced fat storage in these HLCs and detected major expression changes of metabolism-associated genes, as well as an overall reduction of liver-related microRNAs. We observed an upregulation of the lipid droplet coating protein Perilipin 2 (PLIN2), as well as of numerous genes of the peroxisome proliferator-activated receptor (PPAR) pathway, which constitutes a regulatory hub for metabolic processes. Interference with PLIN2 and PPARα resulted in major alterations in gene expression, especially affecting lipid, glucose, and purine metabolism. Our model recapitulates many metabolic changes that are characteristic for NAFLD. It permits the dissection of disease-promoting molecular pathways and allows us to investigate the influences of distinct genetic backgrounds on disease progression. PMID:27308945

  7. Modeling Nonalcoholic Fatty Liver Disease with Human Pluripotent Stem Cell-Derived Immature Hepatocyte-Like Cells Reveals Activation of PLIN2 and Confirms Regulatory Functions of Peroxisome Proliferator-Activated Receptor Alpha.

    PubMed

    Graffmann, Nina; Ring, Sarah; Kawala, Marie-Ann; Wruck, Wasco; Ncube, Audrey; Trompeter, Hans-Ingo; Adjaye, James

    2016-08-01

    Nonalcoholic fatty liver disease (NAFLD/steatosis) is a metabolic disease characterized by the incorporation of fat into hepatocytes. In this study, we developed an in vitro model for NAFLD based on hepatocyte-like cells (HLCs) differentiated from human pluripotent stem cells. We induced fat storage in these HLCs and detected major expression changes of metabolism-associated genes, as well as an overall reduction of liver-related microRNAs. We observed an upregulation of the lipid droplet coating protein Perilipin 2 (PLIN2), as well as of numerous genes of the peroxisome proliferator-activated receptor (PPAR) pathway, which constitutes a regulatory hub for metabolic processes. Interference with PLIN2 and PPARα resulted in major alterations in gene expression, especially affecting lipid, glucose, and purine metabolism. Our model recapitulates many metabolic changes that are characteristic for NAFLD. It permits the dissection of disease-promoting molecular pathways and allows us to investigate the influences of distinct genetic backgrounds on disease progression. PMID:27308945

  8. Melanoma cells express ICOS ligand to promote the activation and expansion of T-regulatory cells

    PubMed Central

    Martin-Orozco, Natalia; Li, Yufeng; Wang, Yijun; Liu, Shijuan; Hwu, Patrick; Liu, Yong-Jun; Dong, Chen; Radvanyi, Laszlo

    2010-01-01

    CD4+CD25+Foxp3+ T-regulatory cells (Tregs) accumulate in tumors, however little is known about how the tumor environment influences this process. Here we show that human melanomas express ICOS-ligand (ICOS-L/B7H) that can provide costimulation through ICOS for the expansion of activated Tregs maintaining high Foxp3 and CD25 expression as well as suppressive function. Thus, ICOS-L expression by melanoma tumor cells may directly drive Treg activation and expansion in the tumor microenvironment as another mechanism of immune evasion. PMID:21098714

  9. 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

  10. Isolation of Highly Suppressive CD25+FoxP3+ T Regulatory Cells from G-CSF-Mobilized Donors with Retention of Cytotoxic Anti-Viral CTLs: Application for Multi-Functional Immunotherapy Post Stem Cell Transplantation

    PubMed Central

    Samuel, Edward R.; Beloki, Lorea; Newton, Katy; Mackinnon, Stephen; Lowdell, Mark W.

    2014-01-01

    Previous studies have demonstrated the effective control of cytomegalovirus (CMV) infections post haematopoietic stem cell transplant through the adoptive transfer of donor derived CMV-specific T cells (CMV-T). Strategies for manufacturing CMV immunotherapies has involved a second leukapheresis or blood draw from the donor, which in the unrelated donor setting is not always possible. We have investigated the feasibility of using an aliquot of the original G-CSF-mobilized graft as a starting material for manufacture of CMV-T and examined the activation marker CD25 as a targeted approach for identification and isolation following CMVpp65 peptide stimulation. CD25+ cells isolated from G-CSF-mobilized apheresis revealed a significant increase in the proportion of FoxP3 expression when compared with conventional non-mobilized CD25+ cells and showed a superior suppressive capacity in a T cell proliferation assay, demonstrating the emergence of a population of Tregs not present in non-mobilized apheresis collections. The expansion of CD25+ CMV-T in short-term culture resulted in a mixed population of CD4+ and CD8+ T cells with CMV-specificity that secreted cytotoxic effector molecules and lysed CMVpp65 peptide-loaded phytohaemagglutinin-stimulated blasts. Furthermore CD25 expanded cells retained their suppressive capacity but did not maintain FoxP3 expression or secrete IL-10. In summary our data indicates that CD25 enrichment post CMV stimulation in G-CSF-mobilized PBMCs results in the simultaneous generation of both a functional population of anti-viral T cells and Tregs thus illustrating a potential single therapeutic strategy for the treatment of both GvHD and CMV reactivation following allogeneic haematopoietic stem cell transplantation. The use of G-CSF-mobilized cells as a starting material for cell therapy manufacture represents a feasible approach to alleviating the many problems incurred with successive donations and procurement of cells from unrelated donors

  11. Mast Cell Function

    PubMed Central

    da Silva, Elaine Zayas Marcelino; Jamur, Maria Célia

    2014-01-01

    Since first described by Paul Ehrlich in 1878, mast cells have been mostly viewed as effectors of allergy. It has been only in the past two decades that mast cells have gained recognition for their involvement in other physiological and pathological processes. Mast cells have a widespread distribution and are found predominantly at the interface between the host and the external environment. Mast cell maturation, phenotype and function are a direct consequence of the local microenvironment and have a marked influence on their ability to specifically recognize and respond to various stimuli through the release of an array of biologically active mediators. These features enable mast cells to act as both first responders in harmful situations as well as to respond to changes in their environment by communicating with a variety of other cells implicated in physiological and immunological responses. Therefore, the critical role of mast cells in both innate and adaptive immunity, including immune tolerance, has gained increased prominence. Conversely, mast cell dysfunction has pointed to these cells as the main offenders in several chronic allergic/inflammatory disorders, cancer and autoimmune diseases. This review summarizes the current knowledge of mast cell function in both normal and pathological conditions with regards to their regulation, phenotype and role. PMID:25062998

  12. 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

  13. 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

  14. PLZF+ Innate T Cells Support the TGF-β-Dependent Generation of Activated/Memory-Like Regulatory T Cells

    PubMed Central

    Kang, Byung Hyun; Park, Hyo Jin; Park, Hi Jung; Lee, Jae-II; Park, Seong Hoe; Jung, Kyeong Cheon

    2016-01-01

    PLZF-expressing invariant natural killer T cells and CD4 T cells are unique subsets of innate T cells. Both are selected via thymocyte-thymocyte interaction, and they contribute to the generation of activated/memory-like CD4 and CD8 T cells in the thymus via the production of IL-4. Here, we investigated whether PLZF+ innate T cells also affect the development and function of Foxp3+ regulatory CD4 T cells. Flow cytometry analysis of the thymus and spleen from both CIITA transgenic C57BL/6 and wild-type BALB/c mice, which have abundant PLZF+ CD4 T cells and invariant natural killer T cells, respectively, revealed that Foxp3+ T cells in these mice exhibited a CD103+ activated/memory-like phenotype. The frequency of CD103+ regulatory T cells was considerably decreased in PLZF+ cell-deficient CIITATgPlzflu/lu and BALB/c.CD1d−/− mice as well as in an IL-4-deficient background, such as in CIITATgIL-4−/− and BALB/c.lL-4−/− mice, indicating that the acquisition of an activated/memory-like phenotype was dependent on PLZF+ innate T cells and IL-4. Using fetal thymic organ culture, we further demonstrated that IL-4 in concert with TGF-β enhanced the acquisition of the activated/memory-like phenotype of regulatory T cells. In functional aspects, the activated/memory-like phenotype of Treg cells was directly related to their suppressive function; regulatory T cells of CIITATgPIV−/− mice more efficiently suppressed ovalbumin-induced allergic airway inflammation compared with their counterparts from wild-type mice. All of these findings suggest that PLZF+ innate T cells also augmented the generation of activated/memory-like regulation via IL-4 production. PMID:27101876

  15. PLZF(+) Innate T Cells Support the TGF-β-Dependent Generation of Activated/Memory-Like Regulatory T Cells.

    PubMed

    Kang, Byung Hyun; Park, Hyo Jin; Park, Hi Jung; Lee, Jae-Ii; Park, Seong Hoe; Jung, Kyeong Cheon

    2016-06-30

    PLZF-expressing invariant natural killer T cells and CD4 T cells are unique subsets of innate T cells. Both are selected via thymocyte-thymocyte interaction, and they contribute to the generation of activated/memory-like CD4 and CD8 T cells in the thymus via the production of IL-4. Here, we investigated whether PLZF(+) innate T cells also affect the development and function of Foxp3(+) regulatory CD4 T cells. Flow cytometry analysis of the thymus and spleen from both CIITA transgenic C57BL/6 and wild-type BALB/c mice, which have abundant PLZF(+) CD4 T cells and invariant natural killer T cells, respectively, revealed that Foxp3(+) T cells in these mice exhibited a CD103(+) activated/memory-like phenotype. The frequency of CD103(+) regulatory T cells was considerably decreased in PLZF(+) cell-deficient CIITA(Tg)Plzf(lu/lu) and BALB/c.CD1d(-/-) mice as well as in an IL-4-deficient background, such as in CIITA(Tg)IL-4(-/-) and BALB/c.lL-4(-/-) mice, indicating that the acquisition of an activated/memory-like phenotype was dependent on PLZF(+) innate T cells and IL-4. Using fetal thymic organ culture, we further demonstrated that IL-4 in concert with TGF-β enhanced the acquisition of the activated/memory-like phenotype of regulatory T cells. In functional aspects, the activated/memory-like phenotype of Treg cells was directly related to their suppressive function; regulatory T cells of CIITA(Tg)PIV(-/-) mice more efficiently suppressed ovalbumin-induced allergic airway inflammation compared with their counterparts from wild-type mice. All of these findings suggest that PLZF(+) innate T cells also augmented the generation of activated/memory-like regulation via IL-4 production. PMID:27101876

  16. Drivers of structural features in gene regulatory networks: From biophysical constraints to biological function.

    PubMed

    Martin, O C; Krzywicki, A; Zagorski, M

    2016-07-01

    Living cells can maintain their internal states, react to changing environments, grow, differentiate, divide, etc. All these processes are tightly controlled by what can be called a regulatory program. The logic of the underlying control can sometimes be guessed at by examining the network of influences amongst genetic components. Some associated gene regulatory networks have been studied in prokaryotes and eukaryotes, unveiling various structural features ranging from broad distributions of out-degrees to recurrent "motifs", that is small subgraphs having a specific pattern of interactions. To understand what factors may be driving such structuring, a number of groups have introduced frameworks to model the dynamics of gene regulatory networks. In that context, we review here such in silico approaches and show how selection for phenotypes, i.e., network function, can shape network structure. PMID:27365153

  17. Drivers of structural features in gene regulatory networks: From biophysical constraints to biological function

    NASA Astrophysics Data System (ADS)

    Martin, O. C.; Krzywicki, A.; Zagorski, M.

    2016-07-01

    Living cells can maintain their internal states, react to changing environments, grow, differentiate, divide, etc. All these processes are tightly controlled by what can be called a regulatory program. The logic of the underlying control can sometimes be guessed at by examining the network of influences amongst genetic components. Some associated gene regulatory networks have been studied in prokaryotes and eukaryotes, unveiling various structural features ranging from broad distributions of out-degrees to recurrent "motifs", that is small subgraphs having a specific pattern of interactions. To understand what factors may be driving such structuring, a number of groups have introduced frameworks to model the dynamics of gene regulatory networks. In that context, we review here such in silico approaches and show how selection for phenotypes, i.e., network function, can shape network structure.

  18. Molecular Determinants of Regulatory T Cell Development: The Essential Roles of Epigenetic Changes

    PubMed Central

    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. PMID:23675373

  19. Functional genomics identifies negative regulatory nodes controlling phagocyte oxidative burst

    PubMed Central

    Graham, Daniel B.; Becker, Christine E.; Doan, Aivi; Goel, Gautam; Villablanca, Eduardo J.; Knights, Dan; Mok, Amanda; Ng, Aylwin C.Y.; Doench, John G.; Root, David E.; Clish, Clary B.; Xavier, Ramnik J.

    2015-01-01

    The phagocyte oxidative burst, mediated by Nox2 NADPH oxidase-derived reactive oxygen species, confers host defense against a broad spectrum of bacterial and fungal pathogens. Loss-of-function mutations that impair function of the Nox2 complex result in a life-threatening immunodeficiency, and genetic variants of Nox2 subunits have been implicated in pathogenesis of inflammatory bowel disease (IBD). Thus, alterations in the oxidative burst can profoundly impact host defense, yet little is known about regulatory mechanisms that fine-tune this response. Here we report the discovery of regulatory nodes controlling oxidative burst by functional screening of genes within loci linked to human inflammatory disease. Implementing a multi-omics approach, we define transcriptional, metabolic and ubiquitin-cycling nodes controlled by Rbpj, Pfkl and Rnf145, respectively. Furthermore, we implicate Rnf145 in proteostasis of the Nox2 complex by endoplasmic reticulum-associated degradation. Consequently, ablation of Rnf145 in murine macrophages enhances bacterial clearance, and rescues the oxidative burst defects associated with Ncf4 haploinsufficiency. PMID:26194095

  20. Regulatory Insight into the European Human Pluripotent Stem Cell Registry

    PubMed Central

    Kurtz, Andreas; Stacey, Glyn; Kidane, Luam; Seriola, Anna; Stachelscheid, Harald; Veiga, Anna

    2014-01-01

    Abstract The European pluripotent stem cell registry aims at listing qualified pluripotent stem cell (PSC) lines that are available globally together with relevant information for each cell line. Specific emphasis is being put on documenting ethical procurement of the cells and providing evidence of pluripotency. The report discusses the tasks and challenges for a global PSC registry as an instrument to develop collaboration, to access cells from diverse resources and banks, and to implement standards, and as a means to follow up usage of cells and support adherence to regulatory and scientific standards and transparency for stakeholders. PMID:25457963

  1. Regulatory insight into the European human pluripotent stem cell registry.

    PubMed

    Kurtz, Andreas; Stacey, Glyn; Kidane, Luam; Seriola, Anna; Stachelscheid, Harald; Veiga, Anna

    2014-12-01

    The European pluripotent stem cell registry aims at listing qualified pluripotent stem cell (PSC) lines that are available globally together with relevant information for each cell line. Specific emphasis is being put on documenting ethical procurement of the cells and providing evidence of pluripotency. The report discusses the tasks and challenges for a global PSC registry as an instrument to develop collaboration, to access cells from diverse resources and banks, and to implement standards, and as a means to follow up usage of cells and support adherence to regulatory and scientific standards and transparency for stakeholders. PMID:25457963

  2. Moving to tolerance: Clinical Application of T regulatory cells

    PubMed Central

    McMurchy, Alicia N.; Bushell, Andrew; Levings, Megan K.; Wood, Kathryn J.

    2013-01-01

    Decreasing the incidence of chronic rejection and reducing the need for life-long immunosuppression remain important goals in clinical transplantation. In this article, we will review how regulatory T cells (Treg) came to be recognized as an attractive way to prevent or treat allograft rejection, the ways in which Treg can be manipulated or expanded in vivo, and the potential of in vitro expanded/generated Treg for cellular therapy. We will describe the first regulatory T cell therapies that have been or are in the process of being conducted in the clinic as well as the safety concerns of such therapies and how outcomes may be measured. PMID:21620722

  3. 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. PMID:26071985

  4. 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

  5. IL-10-producing regulatory B-cells suppressed effector T-cells but enhanced regulatory T-cells in chronic HBV infection.

    PubMed

    Liu, Yun; Cheng, Li-Sha; Wu, Sheng-di; Wang, Si-Qi; Li, Lei; She, Wei-Min; Li, Jing; Wang, Ji-Yao; Jiang, Wei

    2016-06-01

    Non-specific immune responses to antigens have been demonstrated as being enhanced during chronic hepatitis B virus (HBV) infection. Here, we evaluated the role of interleukin-10 (IL-10)-producing regulatory B-cells (Bregs) in the pathogenesis of HBV-related liver fibrosis (HBV-LF) and assessed their immunoregulatory effects. Sixty-seven patients diagnosed with chronic hepatitis B (CHB) were enrolled in this study. Numbers and frequencies of peripheral B-cells (memory CD19(+)CD24(hi)CD27(+) cells, immature/transitional CD19(+)CD24(hi)CD38(hi) cells, mature CD19(+)CD24(int)CD38(int) cells) were tested and analysed. Flow cytometry-sorted CD4(+)T cells were cultured with autologous Bregs to elucidate the effects of Bregs on CD4(+)T cells, including effector T and regulatory T-cells (Tregs). The potential immunoregulatory mechanism of Bregs was also investigated. The numbers of total B-cells and Bregs were enriched in CHB patients. The frequency of Bregs was negatively correlated with elevated alanine aminotransferase (ALT) and histological inflammation grades (G), but positively correlated with advanced histological fibrosis stages (S) and enhanced HBV replication. The phenotype of Bregs was predominantly characterized as CD19(+)CD24(hi)CD38(hi) In co-culture with Bregs, CD4(+)CD25(-)T cells from CHB patients produced less interferon-γ (IFN-γ) and IL-17 but more IL-4 than CD4(+)CD25(-)T cells alone, whereas their conversions into Tregs and IL-10(+)T cells were enhanced. In addition, Breg depletion in CHB samples dramatically decreased Treg numbers and expression of cytotoxic T-lymphocyte associated antigen-4 (CTLA-4), IL-10 and transforming growth factor-β (TGF-β). Moreover, the observed regulatory effect was partly dependent on IL-10 release and cell-to-cell contact. Elevated Bregs can suppress effector T but enhance Treg functions, which might influence immune tolerance in chronic HBV infection. PMID:26980345

  6. Interstitial Cells: Regulators of Smooth Muscle Function

    PubMed Central

    Sanders, Kenton M.; Ward, Sean M.; Koh, Sang Don

    2014-01-01

    Smooth muscles are complex tissues containing a variety of cells in addition to muscle cells. Interstitial cells of mesenchymal origin interact with and form electrical connectivity with smooth muscle cells in many organs, and these cells provide important regulatory functions. For example, in the gastrointestinal tract, interstitial cells of Cajal (ICC) and PDGFRα+ cells have been described, in detail, and represent distinct classes of cells with unique ultrastructure, molecular phenotypes, and functions. Smooth muscle cells are electrically coupled to ICC and PDGFRα+ cells, forming an integrated unit called the SIP syncytium. SIP cells express a variety of receptors and ion channels, and conductance changes in any type of SIP cell affect the excitability and responses of the syncytium. SIP cells are known to provide pacemaker activity, propagation pathways for slow waves, transduction of inputs from motor neurons, and mechanosensitivity. Loss of interstitial cells has been associated with motor disorders of the gut. Interstitial cells are also found in a variety of other smooth muscles; however, in most cases, the physiological and pathophysiological roles for these cells have not been clearly defined. This review describes structural, functional, and molecular features of interstitial cells and discusses their contributions in determining the behaviors of smooth muscle tissues. PMID:24987007

  7. 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.

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

    PubMed

    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

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

    PubMed Central

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

    2010-01-01

    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. PMID:20953163

  10. Subversion of cell cycle regulatory mechanisms by HIV

    PubMed Central

    Rice, Andrew P.; Kimata, Jason T.

    2015-01-01

    To establish a productive infection, HIV-1 must counteract cellular innate immune mechanisms and redirect cellular process towards viral replication. Recent studies have discovered that HIV-1 and other primate immunodeficiency viruses subvert cell cycle regulatory mechanisms to achieve these ends. The viral Vpr and Vpx proteins target cell cycle controls to counter innate immunity. The cell cycle-related protein Cyclin L2 is also utilized to counter innate immunity. The viral Tat protein utilizes Cyclin T1 to activated proviral transcription, and regulation of Cyclin T1 levels in CD4+ T cells has important consequences for viral replication and latency. This review will summarize this emerging evidence that primate immunodeficiency viruses subvert cell cycle regulatory mechanisms to enhance replication. PMID:26067601

  11. Protein phosphatase 2A regulatory subunits perform distinct functional roles in the maize pathogen Fusarium verticillioides.

    PubMed

    Shin, Joon-Hee; Kim, Jung-Eun; Malapi-Wight, Martha; Choi, Yoon-E; Shaw, Brian D; Shim, Won-Bo

    2013-06-01

    Fusarium verticillioides is a pathogen of maize causing ear rot and stalk rot. The fungus also produces fumonisins, a group of mycotoxins linked to disorders in animals and humans. A cluster of genes, designated FUM genes, plays a key role in the synthesis of fumonisins. However, our understanding of the regulatory mechanism of fumonisin biosynthesis is still incomplete. We have demonstrated previously that Cpp1, a protein phosphatase type 2A (PP2A) catalytic subunit, negatively regulates fumonisin production and is involved in cell shape maintenance. In general, three PP2A subunits, structural A, regulatory B and catalytic C, make up a heterotrimer complex to perform regulatory functions. Significantly, we identified two PP2A regulatory subunits in the F. verticillioides genome, Ppr1 and Ppr2, which are homologous to Saccharomyces cerevisiae Cdc55 and Rts1, respectively. In this study, we hypothesized that Ppr1 and Ppr2 are involved in the regulation of fumonisin biosynthesis and/or cell development in F. verticillioides, and generated a series of mutants to determine the functional role of Ppr1 and Ppr2. The PPR1 deletion strain (Δppr1) resulted in drastic growth defects, but increased microconidia production. The PPR2 deletion mutant strain (Δppr2) showed elevated fumonisin production, similar to the Δcpp1 strain. Germinating Δppr1 conidia formed abnormally swollen cells with a central septation site, whereas Δppr2 showed early hyphal branching during conidia germination. A kernel rot assay showed that the mutants were slow to colonize kernels, but this is probably a result of growth defects rather than a virulence defect. Results from this study suggest that two PP2A regulatory subunits in F. verticillioides carry out distinct roles in the regulation of fumonisin biosynthesis and fungal development. PMID:23452277

  12. Balancing Inflammation: The Link between Th17 and Regulatory T Cells

    PubMed Central

    Diller, Maggie L.; Kudchadkar, Ragini R.; Delman, Keith A.; Lawson, David H.; Ford, Mandy L.

    2016-01-01

    CD4+ T cell compartments in mouse and man are composed of multiple distinct subsets each possessing unique phenotypic and functional characteristics. IL-17-producing CD4+ T cells (Th17 cells) represent a distinct subset of the CD4+ T cell lineage. Recent evidence suggests that Th17 cells carry out effector functions similar to cytotoxic CD8+ T cells and play an important role in the clearance of extracellular pathogens and fungi. Th17 cell differentiation and function are closely related to the development and function of regulatory T cells (TREG). The balance between these two cell populations is essential for immune homeostasis and dysregulation of this balance has been implicated in a variety of inflammatory conditions including autoimmunity, allograft rejection, and tumorigenesis. Emerging evidence reports a significant amount of plasticity between the Th17 and regulatory T cell compartments, and the mechanisms by which these cells communicate and influence each other are just beginning to be understood. In this review, we highlight recent findings detailing the mechanisms driving Th17 and TREG plasticity and discuss the biologic consequences of their unique relationship. PMID:27413254

  13. Regulatory Multitasking of Tolerogenic Dendritic Cells – Lessons Taken from Vitamin D3-Treated Tolerogenic Dendritic Cells

    PubMed Central

    Nikolic, Tatjana; Roep, Bart O.

    2013-01-01

    Tolerogenic dendritic cells (DCs) work through silencing of differentiated antigen-specific T cells, activation and expansion of naturally occurring T regulatory cells (Tregs), transfer of regulatory properties to T cells, and the differentiation of naïve T cells into Tregs. Due to an operational definition based on T cell activation assays, the identity of tolerogenic DCs has been a matter of debate and it need not represent a specialized DC subset. Human tolerogenic DCs generated in vitro using inhibitory cytokines, growth factors, natural immunomodulators, or genetic manipulation have been effective and several of these tolerogenic DCs are currently being tested for clinical use. Ex vivo generated tolerogenic DCs reduce activation of naïve T cells using various means, promote a variety of regulatory T cells and most importantly, frequently show stable inhibitory phenotypes upon repetitive maturation with inflammatory factors. Yet, tolerogenic DCs differ with respect to the phenotype or the number of regulatory mechanisms they employ to modulate the immune system. In our experience, tolerogenic DCs generated using the biologically active form of vitamin D (VD3-DCs), alone, or combined with dexamethasone are proficient in their immunoregulatory functions. These tolerogenic DCs show a stable maturation-resistant semi-mature phenotype with low expression of activating co-stimulatory molecules, no production of the IL-12 family of cytokines and high expression of inhibitory molecules and IL-10. VD3-DCs induce increased apoptosis of effector T cells and induce antigen-specific regulatory T cells, which work through linked suppression ensuring infectious tolerance. Lessons learned on VD3-DCs help understanding the contribution of different pattern-recognition receptors (PRRs) and secondary signals to the tolerogenic function and how a cross-talk between DCs and T cells translates into immune regulation. PMID:23717310

  14. Generation and identification of tumor-evoked regulatory B cells

    PubMed Central

    Biragyn, Arya; Lee-Chang, Catalina; Bodogai, Monica

    2014-01-01

    The involvement of Bregs in cancer remains poorly understood despite their well-documented regulation of responses to the self and protection from harmful autoimmunity. We recently discovered a unique regulatory B cell subset evoked by breast cancer to mediate protection of metastasizing cancer cells. These results together with the wealth of findings of the last 40 years on B cells in tumorigenesis suggest the existence of additional cancer Bregs modulating anticancer responses. To facilitate the search for them, here we provide our detailed protocol for the characterization and generation of tumor-evoked regulatory B cells. Wherever applicable, we also discuss nuances and uniqueness of a Breg study in cancer to warn potential pitfalls. PMID:25015287

  15. 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

  16. Escape from suppression: tumor-specific effector cells outcompete regulatory T cells following stem-cell transplantation

    PubMed Central

    Mirmonsef, Paria; Tan, Gladys; Zhou, Gang; Morino, Tricia; Noonan, Kimberly; Borrello, Ivan

    2008-01-01

    Immune reconstitution of autologous hematopoietic stem-cell transplant recipients with the progeny of mature T cells in the graft leads to profound changes in the emerging functional T-cell repertoire. In the steady state, the host is frequently tolerant to tumor antigens, reflecting dominant suppression of naive and effector T cells by regulatory T cells (Tregs). We examined the relative frequency and function of these 3 components within the tumor-specific T-cell compartment during immune reconstitution. Grafts from tumor-bearing donors exerted a significant antitumor effect in irradiated, syngeneic tumor-bearing recipients. This was associated with dramatic clonal expansion and interferon-γ (IFNγ) production by previously tolerant tumor-specific T cells. While donor-derived Tregs expanded in recipients, they did not inhibit the antigen-driven expansion of effector T cells in the early posttransplantation period. Indeed, the repopulation of tumor-specific effector T cells significantly exceeded that of Tregs, the expansion of which was limited by IL-2 availability. Although the intrinsic suppressive capacity of Tregs remained intact, their diminished frequency was insufficient to suppress effector cell function. These findings provide an explanation for the reversal of tolerance leading to tumor rejection in transplant recipients and likely contribute to the efficacy of adoptive T-cell therapies in lymphopenic hosts. PMID:18063750

  17. 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

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

    PubMed

    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

  19. Functional splicing network reveals extensive regulatory potential of the core spliceosomal machinery.

    PubMed

    Papasaikas, Panagiotis; Tejedor, J Ramón; Vigevani, Luisa; Valcárcel, Juan

    2015-01-01

    Pre-mRNA splicing relies on the poorly understood dynamic interplay between >150 protein components of the spliceosome. The steps at which splicing can be regulated remain largely unknown. We systematically analyzed the effect of knocking down the components of the splicing machinery on alternative splicing events relevant for cell proliferation and apoptosis and used this information to reconstruct a network of functional interactions. The network accurately captures known physical and functional associations and identifies new ones, revealing remarkable regulatory potential of core spliceosomal components, related to the order and duration of their recruitment during spliceosome assembly. In contrast with standard models of regulation at early steps of splice site recognition, factors involved in catalytic activation of the spliceosome display regulatory properties. The network also sheds light on the antagonism between hnRNP C and U2AF, and on targets of antitumor drugs, and can be widely used to identify mechanisms of splicing regulation. PMID:25482510

  20. 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

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

    PubMed

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

    2016-02-21

    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

  2. Functional and topological characteristics of mammalian regulatory domains

    PubMed Central

    Symmons, Orsolya; Uslu, Veli Vural; Tsujimura, Taro; Ruf, Sandra; Nassari, Sonya; Schwarzer, Wibke; Ettwiller, Laurence; Spitz, François

    2014-01-01

    Long-range regulatory interactions play an important role in shaping gene-expression programs. However, the genomic features that organize these activities are still poorly characterized. We conducted a large operational analysis to chart the distribution of gene regulatory activities along the mouse genome, using hundreds of insertions of a regulatory sensor. We found that enhancers distribute their activities along broad regions and not in a gene-centric manner, defining large regulatory domains. Remarkably, these domains correlate strongly with the recently described TADs, which partition the genome into distinct self-interacting blocks. Different features, including specific repeats and CTCF-binding sites, correlate with the transition zones separating regulatory domains, and may help to further organize promiscuously distributed regulatory influences within large domains. These findings support a model of genomic organization where TADs confine regulatory activities to specific but large regulatory domains, contributing to the establishment of specific gene expression profiles. PMID:24398455

  3. Direct-to-Consumer Stem Cell Marketing and Regulatory Responses

    PubMed Central

    2013-01-01

    Summary 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. PMID:23934911

  4. 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. PMID:23934911

  5. Origin and pharmacological modulation of tumor-associated regulatory dendritic cells

    PubMed Central

    Zhong, Hua; Gutkin, Dmitriy W.; Han, Baohui; Ma, Yang; Keskinov, Anton A.; Shurin, Michael R.; Shurin, Galina V.

    2014-01-01

    Protumorigenic activity of immune regulatory cells has been proven to play a major role in precluding immunosurveillance and limiting the efficacy of anticancer therapies. Although several approaches have been offered to deplete myeloid-derived suppressor cells (MDSC) and regulatory T cells, there are no data on how to control suppressive dendritic cell (DC) accumulation or function in the tumor environment. Although immunosuppressive function of DC in cancer was implicated to immature and plasmacytoid DC, details of how conventional DC (cDC) develop immunosuppressive properties remain less understood. Here, we show that the development of lung cancer in mice was associated with fast accumulation of regulatory DC (regDC) prior to the appearance of MDSC. Using the in vitro and in vivo approaches, we demonstrated that (i)both cDC and MDSC could be polarized into protumor regDC in the lung cancer environment; (ii) cDC → regDC polarization was mediated by the small Rho GTPase signaling, which could be controlled by noncytotoxic doses of paclitaxel; and (iii) prevention of regDC appearance increased the antitumor potential of DC vaccine in lung cancer. These findings not only bring new players to the family of myeloid regulatory cells and provide new targets for cancer therapy, but offer novel insights into the immunomodulatory capacity of chemotherapeutic agents used in low, noncytotoxic doses. PMID:24443321

  6. Mutant KRAS Conversion of Conventional T Cells into Regulatory T Cells.

    PubMed

    Zdanov, Stephanie; Mandapathil, Magis; Abu Eid, Rasha; Adamson-Fadeyi, Saudat; Wilson, Willie; Qian, Jiahua; Carnie, Andrea; Tarasova, Nadya; Mkrtichyan, Mikayel; Berzofsky, Jay A; Whiteside, Theresa L; Khleif, Samir N

    2016-04-01

    Constitutive activation of theKRASoncogene in human malignancies is associated with aggressive tumor growth and poor prognosis. Similar to other oncogenes,KRASacts in a cell-intrinsic manner to affect tumor growth or survival. However, we describe here a different, cell-extrinsic mechanism through which mutant KRAS contributes to tumor development. Tumor cells carrying mutated KRAS induced highly suppressive T cells, and silencing KRAS reversed this effect. Overexpression of the mutantKRAS(G12V)gene in wild-type KRAS tumor cells led to regulatory T-cell (Treg) induction. We also demonstrate that mutant KRAS induces the secretion of IL10 and transforming growth factor-β1 (both required for Treg induction) by tumor cells through the activation of the MEK-ERK-AP1 pathway. Finally, we report that inhibition of KRAS reduces the infiltration of Tregs in KRAS-driven lung tumorigenesis even before tumor formation. This cell-extrinsic mechanism allows tumor cells harboring a mutantKRASoncogene to escape immune recognition. Thus, an oncogene can promote tumor progression independent of its transforming activity by increasing the number and function of Tregs. This has a significant clinical potential, in which targeting KRAS and its downstream signaling pathways could be used as powerful immune modulators in cancer immunotherapy.Cancer Immunol Res; 4(4); 354-65. ©2016 AACR. PMID:26880715

  7. Functional regulatory roles of microRNAs in atherosclerosis.

    PubMed

    Gao, Ya; Peng, Juan; Ren, Zhong; He, Ni-Ya; Li, Qing; Zhao, Xue-Shan; Wang, Mei-Mei; Wen, Hong-Yan; Tang, Zhi-Han; Jiang, Zhi-Sheng; Wang, Gui-Xue; Liu, Lu-Shan

    2016-09-01

    MicroRNAs are a group of endogenously small non-coding RNA molecules that downregulate gene expression at the post-transcriptional level through binding to the 3'UTR of target mRNAs. Recent findings have revealed a key role for microRNAs in the pathophysiological processes of atherosclerosis. As a complex disease, atherosclerosis is influenced by a combination of multiple genes and environmental factors. Both of them play a role in atherogenesis by affecting different types of cells (such as endothelial cell, vascular smooth muscle cell and monocyte/macrophage) function. MicroRNAs control the senescence and dysfunction of endothelial cells, proliferation and migration of vascular smooth muscle cells, and macrophage-driven cytokine production and polarization. By these effects, microRNAs can influence the processes of atherosclerosis and may represent new molecular targets for therapy. PMID:27384386

  8. 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'. PMID:26083756

  9. 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. PMID:25563193

  10. Induction of Human Regulatory T Cells with Bacterial Superantigens.

    PubMed

    Caserta, Stefano; Taylor, Amanda L; Terrazzini, Nadia; Llewelyn, Martin J

    2016-01-01

    Regulatory T cells (Tregs) that suppress the activation of immune effector cells limit immunopathology and are fast emerging as therapeutic targets for autoimmune and cancer disease. Tools enabling Treg in vitro-induction, expansion, and characterization and manipulation will help future clinical developments. In this chapter, we describe in detail how to use bacterial superantigens to induce human Tregs efficiently from peripheral blood mononuclear cells. How to assess human Treg phenotype and suppressive capacity are also described. Technical details, variations, and alternative experimental conditions are provided. PMID:26676048

  11. TGF-β-Induced Regulatory T Cells Directly Suppress B Cell Responses through a Noncytotoxic Mechanism.

    PubMed

    Xu, Anping; Liu, Ya; Chen, Weiqian; Wang, Julie; Xue, Youqiu; Huang, Feng; Rong, Liming; Lin, Jin; Liu, Dahai; Yan, Mei; Li, Quan-Zhen; Li, Bin; Song, Jianxun; Olsen, Nancy; Zheng, Song Guo

    2016-05-01

    Foxp3(+) regulatory T cells (Treg) playing a crucial role in the maintenance of immune tolerance and prevention of autoimmune diseases consist of thymus-derived naturally occurring CD4(+)Foxp3(+) Treg cells (nTreg) and those that can be induced ex vivo with TGF-β (iTreg). Although both Treg subsets share similar phenotypes and functional characteristics, they also have potential biologic differences on their biology. The role of iTreg in regulating B cells remains unclear so far. The suppression assays of Treg subsets on activation, proliferation, and Abs production of B cells were measured using a Treg and B cell coculture system in vitro. Transwell and Ab blockade experiments were performed to assess the roles of cell contact and soluble cytokines. Treg were adoptively transferred to lupus mice to assess in vivo effects on B cells. Like nTreg, iTreg subset also directly suppressed activation and proliferation of B cells. nTreg subset suppressed B cell responses through cytotoxic manner related to expression of granzyme A, granzyme B, and perforin, whereas the role of iTreg subset on B cells did not involve in cytotoxic action but depending on TGF-β signaling. Furthermore, iTreg subset can significantly suppress Ab produced by lupus B cells in vitro. Comparison experiments using autoantibodies microarrays demonstrated that adoptive transfer of iTreg had a superior effect than nTreg subset on suppressing lupus B cell responses in vivo. Our data implicate a role and advantage of iTreg subset in treating B cell-mediated autoimmune diseases, boosting the translational potential of these findings. PMID:27001954

  12. 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

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

    PubMed Central

    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

  14. Prediction of Functionally Important Phospho-Regulatory Events in Xenopus laevis Oocytes

    PubMed Central

    Johnson, Jeffrey R.; Santos, Silvia D.; Johnson, Tasha; Pieper, Ursula; Strumillo, Marta; Wagih, Omar; Sali, Andrej; Krogan, Nevan J.; Beltrao, Pedro

    2015-01-01

    The African clawed frog Xenopus laevis is an important model organism for studies in developmental and cell biology, including cell-signaling. However, our knowledge of X. laevis protein post-translational modifications remains scarce. Here, we used a mass spectrometry-based approach to survey the phosphoproteome of this species, compiling a list of 2636 phosphosites. We used structural information and phosphoproteomic data for 13 other species in order to predict functionally important phospho-regulatory events. We found that the degree of conservation of phosphosites across species is predictive of sites with known molecular function. In addition, we predicted kinase-protein interactions for a set of cell-cycle kinases across all species. The degree of conservation of kinase-protein interactions was found to be predictive of functionally relevant regulatory interactions. Finally, using comparative protein structure models, we find that phosphosites within structured domains tend to be located at positions with high conformational flexibility. Our analysis suggests that a small class of phosphosites occurs in positions that have the potential to regulate protein conformation. PMID:26312481

  15. USP1 deubiquitinase: cellular functions, regulatory mechanisms and emerging potential as target in cancer therapy

    PubMed Central

    2013-01-01

    Reversible protein ubiquitination is emerging as a key process for maintaining cell homeostasis, and the enzymes that participate in this process, in particular E3 ubiquitin ligases and deubiquitinases (DUBs), are increasingly being regarded as candidates for drug discovery. Human DUBs are a group of approximately 100 proteins, whose cellular functions and regulatory mechanisms remain, with some exceptions, poorly characterized. One of the best-characterized human DUBs is ubiquitin-specific protease 1 (USP1), which plays an important role in the cellular response to DNA damage. USP1 levels, localization and activity are modulated through several mechanisms, including protein-protein interactions, autocleavage/degradation and phosphorylation, ensuring that USP1 function is carried out in a properly regulated spatio-temporal manner. Importantly, USP1 expression is deregulated in certain types of human cancer, suggesting that USP1 could represent a valid target in cancer therapy. This view has gained recent support with the finding that USP1 inhibition may contribute to revert cisplatin resistance in an in vitro model of non-small cell lung cancer (NSCLC). Here, we describe the current knowledge on the cellular functions and regulatory mechanisms of USP1. We also summarize USP1 alterations found in cancer, combining data from the literature and public databases with our own data. Finally, we discuss the emerging potential of USP1 as a target, integrating published data with our novel findings on the effects of the USP1 inhibitor pimozide in combination with cisplatin in NSCLC cells. PMID:23937906

  16. Human FoxP3+ regulatory T cells in systemic autoimmune diseases.

    PubMed

    Miyara, Makoto; Gorochov, Guy; Ehrenstein, Michael; Musset, Lucile; Sakaguchi, Shimon; Amoura, Zahir

    2011-10-01

    Since the characterization of CD4(+)CD25(+) regulatory T (Treg) cells in mice, significant progress has been made in the definitions of the phenotype and the function of human Treg cells in health and in pathological conditions. Recent advances in the field leading to a better molecular definition of Treg subsets in humans and the description of the dynamics of differentiation of Treg cells should bring new insights in the understanding of human chronic systemic autoimmune diseases. How Treg cells are compromised in these diseases is a challenging issue because the elucidation of the mechanisms leading to such anomaly might lead to promising novel therapeutic approaches. PMID:21621000

  17. Roles of transcription factors and epigenetic modifications in differentiation and maintenance of regulatory T cells.

    PubMed

    Sekiya, Takashi; Nakatsukasa, Hiroko; Lu, Qianjin; Yoshimura, Akihiko

    2016-06-01

    Regulatory T (Treg) cells are an essential cell subset for the maintenance of immune homeostasis. Treg cells are characterized by a distinct pattern of gene expression, including the upregulation of immune-suppressive genes and the silencing of inflammatory genes. The molecular mechanisms involved in the development and maintenance of Tregs have been extensively investigated. We have identified essential transcription factors NR4a and Smad2/3 in the development of thymic Tregs and induced Tregs, respectively. This article reviews the roles of transcription factors in the differentiation, maintenance, and function of Treg cells. PMID:26970203

  18. Cutting Edge: Integrin α4 Is Required for Regulatory B Cell Control of Experimental Autoimmune Encephalomyelitis.

    PubMed

    Glatigny, Simon; Wagner, Catriona A; Bettelli, Estelle

    2016-05-01

    The neutralization of integrin α4 (Itga4) is currently used as treatment in multiple sclerosis. Although most studies have focused on its function on lymphocyte migration to the CNS, we have uncovered the importance of Itga4 for the generation of regulatory B cells in peripheral immune organs and their control of pathogenic T cell response and CNS pathology. Our study underscores the importance of looking at the dual role of B cells in CNS autoimmunity and provides important perspectives regarding the efficacy and side effects associated with Itga4 neutralization and other B cell-targeting therapies. PMID:27016608

  19. In vitro gene regulatory networks predict in vivo function of liver

    PubMed Central

    2010-01-01

    Background Evolution of toxicity testing is predicated upon using in vitro cell based systems to rapidly screen and predict how a chemical might cause toxicity to an organ in vivo. However, the degree to which we can extend in vitro results to in vivo activity and possible mechanisms of action remains to be fully addressed. Results Here we use the nitroaromatic 2,4,6-trinitrotoluene (TNT) as a model chemical to compare and determine how we might extrapolate from in vitro data to in vivo effects. We found 341 transcripts differentially expressed in common among in vitro and in vivo assays in response to TNT. The major functional term corresponding to these transcripts was cell cycle. Similarly modulated common pathways were identified between in vitro and in vivo. Furthermore, we uncovered the conserved common transcriptional gene regulatory networks between in vitro and in vivo cellular liver systems that responded to TNT exposure, which mainly contain 2 subnetwork modules: PTTG1 and PIR centered networks. Interestingly, all 7 genes in the PTTG1 module were involved in cell cycle and downregulated by TNT both in vitro and in vivo. Conclusions The results of our investigation of TNT effects on gene expression in liver suggest that gene regulatory networks obtained from an in vitro system can predict in vivo function and mechanisms. Inhibiting PTTG1 and its targeted cell cyle related genes could be key machanism for TNT induced liver toxicity. PMID:21073692

  20. Differential effects of rapamycin and retinoic acid on expansion, stability and suppressive qualities of human CD4+CD25+FOXP3+ T regulatory cell subpopulations

    PubMed Central

    Scottà, Cristiano; Esposito, Marianna; Fazekasova, Henrieta; Fanelli, Giorgia; Edozie, Francis C.; Ali, Niwa; Xiao, Fang; Peakman, Mark; Afzali, Behdad; Sagoo, Pervinder; Lechler, Robert I.; Lombardi, Giovanna

    2013-01-01

    Adoptive transfer of ex vivo expanded CD4+CD25+FOXP3+ regulatory T cells is a successful therapy for autoimmune diseases and transplant rejection in experimental models. In man, equivalent manipulations in bone marrow transplant recipients appear safe, but questions regarding the stability of the transferred regulatory T cells during inflammation remain unresolved. In this study, protocols for the expansion of clinically useful numbers of functionally suppressive and stable human regulatory T cells were investigated. Regulatory T cells were expanded in vitro with rapamycin and/or all-trans retinoic acid and then characterized under inflammatory conditions in vitro and in vivo in a humanized mouse model of graft-versus-host disease. Addition of rapamycin to regulatory T-cell cultures confirms the generation of high numbers of suppressive regulatory T cells. Their stability was demonstrated in vitro and substantiated in vivo. In contrast, all-trans retinoic acid treatment generates regulatory T cells that retain the capacity to secrete IL-17. However, combined use of rapamycin and all-trans retinoic acid abolishes IL-17 production and confers a specific chemokine receptor homing profile upon regulatory T cells. The use of purified regulatory T-cell subpopulations provided direct evidence that rapamycin can confer an early selective advantage to CD45RA+ regulatory T cells, while all-trans retinoic acid favors CD45RA− regulatory T-cell subset. Expansion of regulatory T cells using rapamycin and all-trans retinoic acid drug combinations provides a new and refined approach for large-scale generation of functionally potent and phenotypically stable human regulatory T cells, rendering them safe for clinical use in settings associated with inflammation. PMID:23242600

  1. Autoimmunity: from black water fever to regulatory function.

    PubMed

    Chang, Christopher

    2014-01-01

    Autoimmunity is a field that has only been around for a little over a century. Initially, it was thought that autoimmunity could not happen, that the body would never turn on itself (i.e. "horror autotoxicus"). It was only around the First World War that autoimmunity was recognized as the pathogenesis of various diseases, including rheumatoid arthritis. The discovery of Compound E led to successful treatment of patients with autoimmune diseases, but it was not till later that the adverse effects of this class of drugs were elucidated. The "modern" age of autoimmunity began around 1945 with the description of blackwater fever, and most of the subsequent research on hemolytic anemia and the role of an autoantibody in its pathogenesis led to a description of the anti-globulin reaction. The lupus erythematous (LE) cell was recognized in the mid-1940s by Hargreaves. His research carried on into the 1960s. Rheumatoid factor was also first described in the 1940s as yet another serum factor with activity against globulin-coated sheep red blood cells. The concept of autoimmunity really gained a foothold in the 1950s, when autoimmune thyroid disease and idiopathic thrombocytopenia were first described. Much has happened since then, and our understanding of autoimmunity has evolved now to include mechanisms of apoptosis, signaling pathway derangements, and the discovery of subsets of T cells with regulatory activity. The modern day study of autoimmunity is a fascinating area of research, and full understanding of the pathogenesis of autoimmune diseases is far from being completely elucidated. PMID:24491820

  2. Mucosal Regulatory T Cells and T Helper 17 Cells in HIV-Associated Immune Activation

    PubMed Central

    Pandiyan, Pushpa; Younes, Souheil-Antoine; Ribeiro, Susan Pereira; Talla, Aarthi; McDonald, David; Bhaskaran, Natarajan; Levine, Alan D.; Weinberg, Aaron; Sekaly, Rafick P.

    2016-01-01

    Residual mucosal inflammation along with chronic systemic immune activation is an important feature in individuals infected with human immunodeficiency virus (HIV), and has been linked to a wide range of co-morbidities, including malignancy, opportunistic infections, immunopathology, and cardiovascular complications. Although combined antiretroviral therapy (cART) can reduce plasma viral loads to undetectable levels, reservoirs of virus persist, and increased mortality is associated with immune dysbiosis in mucosal lymphoid tissues. Immune-based therapies are pursued with the goal of improving CD4+ T-cell restoration, as well as reducing chronic immune activation in cART-treated patients. However, the majority of research on immune activation has been derived from analysis of circulating T cells. How immune cell alterations in mucosal tissues contribute to HIV immune dysregulation and the associated risk of non-infectious chronic complications is less studied. Given the significant differences between mucosal T cells and circulating T cells, and the immediate interactions of mucosal T cells with the microbiome, more attention should be devoted to mucosal immune cells and their contribution to systemic immune activation in HIV-infected individuals. Here, we will focus on mucosal immune cells with a specific emphasis on CD4+ T lymphocytes, such as T helper 17 cells and CD4+Foxp3+ regulatory T cells (Tregs), which play crucial roles in maintaining mucosal barrier integrity and preventing inflammation, respectively. We hypothesize that pro-inflammatory milieu in cART-treated patients with immune activation significantly contributes to enhanced loss of Th17 cells and increased frequency of dysregulated Tregs in the mucosa, which in turn may exacerbate immune dysfunction in HIV-infected patients. We also present initial evidence to support this hypothesis. A better comprehension of how pro-inflammatory milieu impacts these two types of cells in the mucosa will shed light

  3. Nanoengineering of Immune Cell Function

    PubMed Central

    Shen, Keyue; Milone, Michael C.; Dustin, Michael L.; Kam, Lance C.

    2010-01-01

    T lymphocytes are a key regulatory component of the adaptive immune system. Understanding how the micro- and nano-scale details of the extracellular environment influence T cell activation may have wide impact on the use of T cells for therapeutic purposes. In this article, we examine how the micro- and nano-scale presentation of ligands to cell surface receptors, including microscale organization and nanoscale mobility, influences the activation of T cells. We extend these studies to include the role of cell-generated forces, and the rigidity of the microenvironment, on T cell activation. These approaches enable delivery of defined signals to T cells, a step toward understanding the cell-cell communication in the immune system, and developing micro/nano- and material- engineered systems for tailoring immune responses for adoptive T cell therapies. PMID:21562611

  4. A Lactobacillus rhamnosus Strain Induces a Heme Oxygenase Dependent Increase in Foxp3+ Regulatory T Cells

    PubMed Central

    Karimi, Khalil; Kandiah, Nalaayini; Chau, Jessie; Bienenstock, John; Forsythe, Paul

    2012-01-01

    We investigated the consequences of feeding with a Lactobacillus species on the immune environment in GALT, and the role of dendritic cells and heme oxygenase-1 in mediating these responses. Feeding with a specific strain of Lactobacillus rhamnosus induced a significant increase in CD4+CD25+Foxp3+ functional regulatory T cells in GALT. This increase was greatest in the mesenteric lymph nodes and associated with a marked decrease in TNF and IFNγ production. Dendritic cell regulatory function and HO-1 expression was also increased. The increase in Foxp3+ T cells could be prevented by treatment with a heme oxygenase inhibitor. However, neither inhibition of heme oxygenase nor blockade of IL-10 and TGFβ prevented the inhibition of inflammatory cytokine production. In conclusion Lactobacillus feeding induced a tolerogenic environment in GALT. HO-1 was critical to the enhancement of Foxp3+ regulatory T cells while additional, as yet unknown, pathways were involved in the down-regulation of inflammatory cytokine production by T cells. PMID:23077634

  5. Defective regulatory B-cell compartment in patients with immune thrombocytopenia

    PubMed Central

    Li, Xiaojuan; Zhong, Hui; Bao, Weili; Boulad, Nayla; Evangelista, Jessie; Haider, Muhammad Anis; Bussel, James

    2012-01-01

    B lymphocytes producing antiplatelet autoantibodies play a major role in autoimmune thrombocytopenia (ITP). However, certain B cells, including the human CD19+CD24hiCD38hi subpopulation, possess regulatory functions mediated partly by IL-10. In a cohort of chronic ITP patients with low platelet counts who consisted of patients off treatment, we found a lower frequency of CD19+CD24hiCD38hi in the peripheral compartment of nonsplenectomized patients (P = .03). IL-10 expression after activation was decreased in all ITP circulating CD19+ subpopulations (P < .03), and inhibition of monocyte TNF-α expression by activated B cells was reduced in patients with platelet numbers of < 50 × 109 cells/L (P = .001), indicating that regulatory B cells of patients with ITP are functionally impaired in their ability to dampen monocyte activation. Interestingly, in nonsplenectomized patients whose platelet counts were elevated after treatment with thrombopoietic agents, the frequency of CD19+CD24hiCD38hi B cells was increased compared with those before treatment (P = .02). Altogether, these data indicate a compromised regulatory B-cell com-partment as an additional defect in immune regulation in patients with chronic ITP that may be restored in responders to thrombopoietic treatment. PMID:22859611

  6. Edge usage, motifs, and regulatory logic for cell cycling genetic networks

    NASA Astrophysics Data System (ADS)

    Zagorski, M.; Krzywicki, A.; Martin, O. C.

    2013-01-01

    The cell cycle is a tightly controlled process, yet it shows marked differences across species. Which of its structural features follow solely from the ability to control gene expression? We tackle this question in silico by examining the ensemble of all regulatory networks which satisfy the constraint of producing a given sequence of gene expressions. We focus on three cell cycle profiles coming from baker's yeast, fission yeast, and mammals. First, we show that the networks in each of the ensembles use just a few interactions that are repeatedly reused as building blocks. Second, we find an enrichment in network motifs that is similar in the two yeast cell cycle systems investigated. These motifs do not have autonomous functions, yet they reveal a regulatory logic for cell cycling based on a feed-forward cascade of activating interactions.

  7. Regulatory landscape for cell therapy--EU view.

    PubMed

    McBlane, James W

    2015-09-01

    This article addresses regulation of cell therapies in the European Union (EU), covering cell sourcing and applications for clinical trials and marketing authorisation applications. Regulatory oversight of cell sourcing and review of applications for clinical trials with cell therapies are handled at national level, that is, separately with each country making its own decisions. For clinical trials, this can lead to different decisions in different countries for the same trial. A regulation is soon to come into force that will address this and introduce a more efficient clinical trial application process. However, at the marketing authorisation stage, the process is pan-national: the Committee for Human Medicinal Products (CHMP) is responsible for giving the final scientific opinion on all EU marketing authorisation applications for cell therapies: favourable scientific opinions are passed to the European Commission (EC) for further consultation and, if successful, grant of a marketing authorisation valid in all 28 EU countries. In its review of applications for marketing authorisations (MAAs) for cell therapies, the CHMP is obliged to consult the Committee for Advanced Therapies (CAT), who conduct detailed scientific assessments of these applications, with assessment by staff from national regulatory authorities and specialist advisors to the regulators. PMID:25997566

  8. Control of regulatory T cells and airway tolerance by lung macrophages and dendritic cells.

    PubMed

    Duan, Wei; Croft, Michael

    2014-12-01

    Airway tolerance, a state of immunological surveillance, suppresses the development of lung inflammatory disorders that are driven by various pathological effector cells of the immune system. Tolerance in the lung to inhaled antigens is primarily mediated by regulatory T cells (Treg cells) that can inhibit effector T cells via a myriad of mechanisms. Accumulating evidence suggests that regulatory antigen-presenting cells are critical for generating Treg cells and/or maintaining the suppressive environment in the lung. This review focuses on the control of airway tolerance by Treg cells and the role of regulatory lung tissue and alveolar macrophages, and lung and lymph node dendritic cells, in contributing to airway tolerance that is associated with suppression of allergic asthmatic disease. PMID:25525738

  9. 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. PMID:20491794

  10. Promoting transplantation tolerance; adoptive regulatory T cell therapy

    PubMed Central

    Safinia, N; Leech, J; Hernandez-Fuentes, M; Lechler, R; Lombardi, G

    2013-01-01

    Transplantation is a successful treatment for end-stage organ failure. Despite improvements in short-term outcome, long-term survival remains suboptimal because of the morbidity and mortality associated with long-term use of immunosuppression. There is, therefore, a pressing need to devise protocols that induce tolerance in order to minimize or completely withdraw immunosuppression in transplant recipients. In this review we will discuss how regulatory T cells (Tregs) came to be recognized as an attractive way to promote transplantation tolerance. We will summarize the preclinical data, supporting the importance of these cells in the induction and maintenance of immune tolerance and that provide the rationale for the isolation and expansion of these cells for cellular therapy. We will also describe the data from the first clinical trials, using Tregs to inhibit graft-versus-host disease (GVHD) after haematopoietic stem cell transplantation and will address both the challenges and opportunities in human Treg cell therapy. PMID:23574313

  11. Functional conservation of Pax6 regulatory elements in humans and mice demonstrated with a novel transgenic reporter mouse

    PubMed Central

    Tyas, David A; Simpson, T Ian; Carr, Catherine B; Kleinjan, Dirk A; van Heyningen, Veronica; Mason, John O; Price, David J

    2006-01-01

    Background The Pax6 transcription factor is expressed during development in the eyes and in specific CNS regions, where it is essential for normal cell proliferation and differentiation. Mice lacking one or both copies of the Pax6 gene model closely humans with loss-of-function mutations in the PAX6 locus. The sequence of the Pax6/PAX6 protein is identical in mice and humans and previous studies have shown structural conservation of the gene's regulatory regions. Results We generated a transgenic mouse expressing green fluorescent protein (GFP) and neomycin resistance under the control of the entire complement of human PAX6 regulatory elements using a modified yeast artificial chromosome (YAC). Expression of GFP was studied in embryos from 9.5 days on and was confined to cells known to express Pax6. GFP expression was sufficiently strong that expressing cells could be distinguished from non-expressing cells using flow cytometry. Conclusion This work demonstrates the functional conservation of the regulatory elements controlling Pax6/PAX6 expression in mice and humans. The transgene provides an excellent tool for studying the functions of different Pax6/PAX6 regulatory elements in controlling Pax6 expression in animals that are otherwise normal. It will allow the analysis and isolation of cells in which Pax6 is activated, irrespective of the status of the endogenous locus. PMID:16674807

  12. Current status of IL-10 and regulatory T-cells in cancer

    PubMed Central

    Dennis, Kristen L.; Blatner, Nichole R.; Gounari, Fotini; Khazaie, Khashayarsha

    2014-01-01

    Purpose of review Tumor growth elicits antigen-specific cytotoxic as well as immune suppressive responses. Interleukin-10 (IL-10) is a key immune-suppressive cytokine produced by regulatory T-cells (Tregs) and by helper T-cells (TH). Here we review pleiotropic functions of IL-10 that impact the immune pathology of cancer. Recent findings The role of IL-10 in cancer has become less certain with knowledge of its immune stimulatory functions. IL-10 is needed for T-helper cell functions, T-cell immune surveillance, and suppression of cancer-associated inflammation. By promoting tumor specific immune surveillance and hindering pathogenic inflammation IL-10 is emerging as a key cytokine in the battle of the host against cancer. Summary IL-10 functions at the cross roads of immune stimulation and immune suppression in cancer. Immunological mechanisms of action of IL-10 can be ultimately exploited to develop novel and effective cancer therapies. PMID:24076584

  13. Distinct Gene Regulatory Pathways for Human Innate versus Adaptive Lymphoid Cells.

    PubMed

    Koues, Olivia I; Collins, Patrick L; Cella, Marina; Robinette, Michelle L; Porter, Sofia I; Pyfrom, Sarah C; Payton, Jacqueline E; Colonna, Marco; Oltz, Eugene M

    2016-05-19

    Innate lymphoid cells (ILCs) serve as sentinels in mucosal tissues, sensing release of soluble inflammatory mediators, rapidly communicating danger via cytokine secretion, and functioning as guardians of tissue homeostasis. Although ILCs have been extensively studied in model organisms, little is known about these "first responders" in humans, especially their lineage and functional kinships to cytokine-secreting T helper (Th) cell counterparts. Here, we report gene regulatory circuitries for four human ILC-Th counterparts derived from mucosal environments, revealing that each ILC subset diverges as a distinct lineage from Th and circulating natural killer cells but shares circuitry devoted to functional polarization with their Th counterparts. Super-enhancers demarcate cohorts of cell-identity genes in each lineage, uncovering new modes of regulation for signature cytokines, new molecules that likely impart important functions to ILCs, and potential mechanisms for autoimmune disease SNP associations within ILC-Th subsets. PMID:27156452

  14. 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

  15. Regulatory T cells prevent CD8 T cell maturation by inhibiting CD4 Th cells at tumor sites.

    PubMed

    Chaput, Nathalie; Darrasse-Jèze, Guillaume; Bergot, Anne-Sophie; Cordier, Corinne; Ngo-Abdalla, Stacie; Klatzmann, David; Azogui, Orly

    2007-10-15

    Natural regulatory T cells (Tregs) are present in high frequencies among tumor-infiltrating lymphocytes and in draining lymph nodes, supposedly facilitating tumor development. To investigate their role in controlling local immune responses, we analyzed intratumoral T cell accumulation and function in the presence or absence of Tregs. Tumors that grew in normal BALB/c mice injected with the 4T1 tumor cell line were highly infiltrated by Tregs, CD4 and CD8 cells, all having unique characteristics. Most infiltrating Tregs expressed low levels of CD25Rs and Foxp3. They did not proliferate even in the presence of IL-2 but maintained a strong suppressor activity. CD4 T cells were profoundly anergic and CD8 T cell proliferation and cytotoxicity were severely impaired. Depletion of Tregs modified the characteristics of tumor infiltrates. Tumors were initially invaded by activated CD4(+)CD25(-) T cells, which produced IL-2 and IFN-gamma. This was followed by the recruitment of highly cytotoxic CD8(+) T cells at tumor sites leading to tumor rejection. The beneficial effect of Treg depletion in tumor regression was abrogated when CD4 helper cells were also depleted. These findings indicate that the massive infiltration of tumors by Tregs prevents the development of a successful helper response. The Tregs in our model prevent Th cell activation and subsequent development of efficient CD8 T cell activity required for the control of tumor growth. PMID:17911581

  16. T regulatory cell chemokine production mediates pathogenic T cell attraction and suppression

    PubMed Central

    Patterson, Scott J.; Pesenacker, Anne M.; Wang, Adele Y.; Gillies, Jana; Mojibian, Majid; Morishita, Kim; Tan, Rusung; Kieffer, Timothy J.; Verchere, C. Bruce; Panagiotopoulos, Constadina; Levings, Megan K.

    2016-01-01

    T regulatory cells (Tregs) control immune homeostasis by preventing inappropriate responses to self and nonharmful foreign antigens. Tregs use multiple mechanisms to control immune responses, all of which require these cells to be near their targets of suppression; however, it is not known how Treg-to-target proximity is controlled. Here, we found that Tregs attract CD4+ and CD8+ T cells by producing chemokines. Specifically, Tregs produced both CCL3 and CCL4 in response to stimulation, and production of these chemokines was critical for migration of target T cells, as Tregs from Ccl3–/– mice, which are also deficient for CCL4 production, did not promote migration. Moreover, CCR5 expression by target T cells was required for migration of these cells to supernatants conditioned by Tregs. Tregs deficient for expression of CCL3 and CCL4 were impaired in their ability to suppress experimental autoimmune encephalomyelitis or islet allograft rejection in murine models. Moreover, Tregs from subjects with established type 1 diabetes were impaired in their ability to produce CCL3 and CCL4. Together, these results demonstrate a previously unappreciated facet of Treg function and suggest that chemokine secretion by Tregs is a fundamental aspect of their therapeutic effect in autoimmunity and transplantation. PMID:26854929

  17. Regulatory T cells actively infiltrate metastatic brain tumors.

    PubMed

    Sugihara, Adam Quasar; Rolle, Cleo E; Lesniak, Maciej S

    2009-06-01

    Regulatory T cells (CD4+CD25+FoxP3+, Treg) have been shown to play a major role in suppression of the immune response to malignant gliomas. In this study, we investigated the kinetics of Treg infiltration in metastatic brain tumor models, including melanoma, breast and colon cancers. Our data indicate that both CD4+ and Treg infiltration are significantly increased throughout the time of metastatic tumor progression. These findings were recapitulated in human CNS tumor samples of metastatic melanoma and non-small cell lung carcinoma. Collectively, these data support investigating immunotherapeutic strategies targeting Treg in metastatic CNS tumors. PMID:19424570

  18. Role of regulatory B cells in immune tolerance to allergens and beyond.

    PubMed

    van de Veen, Willem; Stanic, Barbara; Wirz, Oliver F; Jansen, Kirstin; Globinska, Anna; Akdis, Mübeccel

    2016-09-01

    Immune tolerance to both self-antigens and innocuous non-self-antigens is essential to protect the host against chronic inflammatory diseases and tissue damage. A wide range of cell types and suppressive molecules are involved in induction and maintenance of tolerance. In addition to their key function in the production of immunoglobulins, B cells can regulate immune responses through their surface molecules and secretion of cytokines. Regulatory B (Breg) cells are characterized by their immunosuppressive capacity, which is often mediated through IL-10 secretion. However, IL-35 and TGF-β have also been associated with B cell-mediated immunosuppression. Several types of murine and human Breg cells have been described, such as mouse CD5(+)CD1d(hi) B10 cells, CD21(hi)CD23(hi)CD24(hi) transitional stage 2-like B cells, and CD138(+) plasma cells and plasmablasts. Human Breg cell types include CD27(+)CD24(high) B10 cells, CD24(hi)CD38(hi) immature transitional B cells, and CD73(-)CD25(+)CD71(+) BR1 cells and a subset of plasma cells. Support for the in vivo existence of allergen-specific human Breg cells comes from direct detection of their increase during the course of allergen-specific immunotherapy, as well as their increased expression in nonallergic but high-dose allergen-exposed beekeepers. Human BR1 cells selectively upregulate IgG4 antibodies on differentiation to plasma cells. This suggests an additional immune regulatory role because of the noninflammatory and blocking antibody function of IgG4. Taken together, Breg cells appear to be involved in mediating allergen tolerance, but many open questions remain to be answered. PMID:27596706

  19. Immune Regulation and Control of Regulatory T cells by OX40 and 4-1BB

    PubMed Central

    So, Takanori; Lee, Seung-Woo; Croft, Michael

    2008-01-01

    The TNFR family members OX40 (CD134) and 4-1BB (CD137) have been found to play major roles as costimulatory receptors for both CD4 and CD8 T cells. In particular, in many situations, they can control proliferation, survival, and cytokine production, and hence are thought to dictate accumulation of protective T cells during anti-viral and anti-tumor responses and pathogenic T cells during autoimmune reactions. As opposed to simply controlling the activity of naïve, effector, and memory T cells, recent data have suggested that both molecules are also instrumental in controlling the generation and activity of so-called regulatory or suppressor T cells (Treg), perhaps in both positive and negative manners. Part of the action on Treg might function to further promote protective or pathogenic T cells, but alternate activities of OX40 and 4-1BB on Treg are also being described that suggest there might be control by these molecules at multiple levels that will alter the biological outcome when these receptors are ligated. This review specifically focuses on recent studies of regulatory T cells, and regulatory or suppressive activity, that are modulated by OX40 or 4-1BB. PMID:18508403

  20. Colorectal cancer risk genes are functionally enriched in regulatory pathways

    PubMed Central

    Lu, Xi; Cao, Mingming; Han, Su; Yang, Youlin; Zhou, Jin

    2016-01-01

    Colorectal cancer (CRC) is a common complex disease caused by the combination of genetic variants and environmental factors. Genome-wide association studies (GWAS) have been performed and reported some novel CRC susceptibility variants. However, the potential genetic mechanisms for newly identified CRC susceptibility variants are still unclear. Here, we selected 85 CRC susceptibility variants with suggestive association P < 1.00E-05 from the National Human Genome Research Institute GWAS catalog. To investigate the underlying genetic pathways where these newly identified CRC susceptibility genes are significantly enriched, we conducted a functional annotation. Using two kinds of SNP to gene mapping methods including the nearest upstream and downstream gene method and the ProxyGeneLD, we got 128 unique CRC susceptibility genes. We then conducted a pathway analysis in GO database using the corresponding 128 genes. We identified 44 GO categories, 17 of which are regulatory pathways. We believe that our results may provide further insight into the underlying genetic mechanisms for these newly identified CRC susceptibility variants. PMID:27146020

  1. Integrative functional genomics identifies regulatory mechanisms at coronary artery disease loci.

    PubMed

    Miller, Clint L; Pjanic, Milos; Wang, Ting; Nguyen, Trieu; Cohain, Ariella; Lee, Jonathan D; Perisic, Ljubica; Hedin, Ulf; Kundu, Ramendra K; Majmudar, Deshna; Kim, Juyong B; Wang, Oliver; Betsholtz, Christer; Ruusalepp, Arno; Franzén, Oscar; Assimes, Themistocles L; Montgomery, Stephen B; Schadt, Eric E; Björkegren, Johan L M; Quertermous, Thomas

    2016-01-01

    Coronary artery disease (CAD) is the leading cause of mortality and morbidity, driven by both genetic and environmental risk factors. Meta-analyses of genome-wide association studies have identified >150 loci associated with CAD and myocardial infarction susceptibility in humans. A majority of these variants reside in non-coding regions and are co-inherited with hundreds of candidate regulatory variants, presenting a challenge to elucidate their functions. Herein, we use integrative genomic, epigenomic and transcriptomic profiling of perturbed human coronary artery smooth muscle cells and tissues to begin to identify causal regulatory variation and mechanisms responsible for CAD associations. Using these genome-wide maps, we prioritize 64 candidate variants and perform allele-specific binding and expression analyses at seven top candidate loci: 9p21.3, SMAD3, PDGFD, IL6R, BMP1, CCDC97/TGFB1 and LMOD1. We validate our findings in expression quantitative trait loci cohorts, which together reveal new links between CAD associations and regulatory function in the appropriate disease context. PMID:27386823

  2. Integrative functional genomics identifies regulatory mechanisms at coronary artery disease loci

    PubMed Central

    Miller, Clint L.; Pjanic, Milos; Wang, Ting; Nguyen, Trieu; Cohain, Ariella; Lee, Jonathan D.; Perisic, Ljubica; Hedin, Ulf; Kundu, Ramendra K.; Majmudar, Deshna; Kim, Juyong B.; Wang, Oliver; Betsholtz, Christer; Ruusalepp, Arno; Franzén, Oscar; Assimes, Themistocles L.; Montgomery, Stephen B.; Schadt, Eric E.; Björkegren, Johan L.M.; Quertermous, Thomas

    2016-01-01

    Coronary artery disease (CAD) is the leading cause of mortality and morbidity, driven by both genetic and environmental risk factors. Meta-analyses of genome-wide association studies have identified >150 loci associated with CAD and myocardial infarction susceptibility in humans. A majority of these variants reside in non-coding regions and are co-inherited with hundreds of candidate regulatory variants, presenting a challenge to elucidate their functions. Herein, we use integrative genomic, epigenomic and transcriptomic profiling of perturbed human coronary artery smooth muscle cells and tissues to begin to identify causal regulatory variation and mechanisms responsible for CAD associations. Using these genome-wide maps, we prioritize 64 candidate variants and perform allele-specific binding and expression analyses at seven top candidate loci: 9p21.3, SMAD3, PDGFD, IL6R, BMP1, CCDC97/TGFB1 and LMOD1. We validate our findings in expression quantitative trait loci cohorts, which together reveal new links between CAD associations and regulatory function in the appropriate disease context. PMID:27386823

  3. Deletion of CTLA-4 on regulatory T cells during adulthood leads to resistance to autoimmunity.

    PubMed

    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; Sharpe, Arlene H

    2015-09-21

    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

  4. 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

  5. Phylogenetic conservation of the regulatory and functional properties of the Vav oncoprotein family

    SciTech Connect

    Couceiro, Jose R.; Martin-Bermudo, Maria D.; Bustelo, Xose R. . E-mail: xbustelo@usal.es

    2005-08-15

    Vav proteins are phosphorylation-dependent GDP/GTP exchange factors for Rho/Rac GTPases. Despite intense characterization of mammalian Vav proteins both biochemically and genetically, there is little information regarding the conservation of their biological properties in lower organisms. To approach this issue, we have performed a characterization of the regulatory, catalytic, and functional properties of the single Vav family member of Drosophila melanogaster. These analyses have shown that the intramolecular mechanisms controlling the enzyme activity of mammalian Vav proteins are already present in Drosophila, suggesting that such properties have been set up before the divergence between protostomes and deuterostomes during evolution. We also show that Drosophila and mammalian Vav proteins have similar catalytic specificities. As a consequence, Drosophila Vav can trigger oncogenic transformation, morphological change, and enhanced cell motility in mammalian cells. Gain-of-function studies using transgenic flies support the implication of this protein in cytoskeletal-dependent processes such as embryonic dorsal closure, myoblast fusion, tracheal development, and the migration/guidance of different cell types. These results highlight the important roles of Vav proteins in the signal transduction pathways regulating cytoskeletal dynamics. Moreover, they indicate that the foundations for the regulatory and enzymatic activities of this protein family have been set up very early during evolution.

  6. Regulatory T-cell as orchestra leader in immunosuppression process of multiple sclerosis.

    PubMed

    Jadidi-Niaragh, Farhad; Mirshafiey, Abbas

    2011-09-01

    Multiple sclerosis (MS) is a chronic inflammatory autoimmune disease of the central nervous system characterized by perivascular inflammation and demyelination and loss of neurologic function. In this disease and its experimental model (experimental autoimmune encephalomyelitis, EAE), axonal and neuronal loss is thought to play a key role in irreversible loss of function and disability. Regarding the evident role of autoreactive T-cells (particularly Th1 and Th17 cells) in pathophysiology of MS, it might be assumed that the regulatory T-cells (Tregs) can control initiation and progression of disease and even treat it. The frequency, function and properties of various subsets of Tregs including natural Tregs (nTregs), IL-10 producing type 1 Tregs (Tr1 cells), transforming growth factor-β producing Th3 cells, CD8(+) Tregs, and natural killer like T regulatory cells in MS and its model EAE, have been investigated in several experimental studies. In this review, we intend to submit the comprehensive information about the immunobiology of various subsets of Tregs and their roles and function in immunopathophysiology of MS and its animal model, EAE. PMID:21284556

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

    PubMed

    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. γδ T Cell-Dependent Regulatory T Cells Prevent the Development of Autoimmune Keratitis.

    PubMed

    Huang, Yafei; Yang, Zhifang; Huang, Chunjian; McGowan, Jessica; Casper, Tamara; Sun, Deming; Born, Willi K; O'Brien, Rebecca L

    2015-12-15

    To prevent potentially damaging inflammatory responses, the eye actively promotes local immune tolerance via a variety of mechanisms. Owing to trauma, infection, or other ongoing autoimmunity, these mechanisms sometimes fail, and an autoimmune disorder may develop in the eye. In mice of the C57BL/10 (B10) background, autoimmune keratitis often develops spontaneously, particularly in the females. Its incidence is greatly elevated in the absence of γδ T cells, such that ∼80% of female B10.TCRδ(-/-) mice develop keratitis by 18 wk of age. In this article, we show that CD8(+) αβ T cells are the drivers of this disease, because adoptive transfer of CD8(+), but not CD4(+), T cells to keratitis-resistant B10.TCRβ/δ(-/-) hosts induced a high incidence of keratitis. This finding was unexpected because in other autoimmune diseases, more often CD4(+) αβ T cells, or both CD4(+) and CD8(+) αβ T cells, mediate the disease. Compared with wild-type B10 mice, B10.TCRδ(-/-) mice also show increased percentages of peripheral memory phenotype CD8(+) αβ T cells, along with an elevated frequency of CD8(+) αβ T cells biased to produce inflammatory cytokines. In addition, B10.TCRδ-/- mice have fewer peripheral CD4(+) CD25(+) Foxp3(+) αβ regulatory T cells (Tregs), which express lower levels of receptors needed for Treg development and function. Together, these observations suggest that in B10 background mice, γδ T cells are required to generate adequate numbers of CD4(+) CD25(+) Foxp3(+) Tregs, and that in B10.TCRδ(-/-) mice a Treg deficiency allows dysregulated effector or memory CD8(+) αβ T cells to infiltrate the cornea and provoke an autoimmune attack. PMID:26566677

  9. 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

  10. Regulatory Oversight of Cell and Gene Therapy Products in Canada.

    PubMed

    Ridgway, Anthony; Agbanyo, Francisca; Wang, Jian; Rosu-Myles, Michael

    2015-01-01

    Health Canada regulates gene therapy products and many cell therapy products as biological drugs under the Canadian Food and Drugs Act and its attendant regulations. Cellular products that meet certain criteria, including minimal manipulation and homologous use, may be subjected to a standards-based approach under the Safety of Human Cells, Tissues and Organs for Transplantation Regulations. The manufacture and clinical testing of cell and gene therapy products (CGTPs) presents many challenges beyond those for protein biologics. Cells cannot be subjected to pathogen removal or inactivation procedures and must frequently be administered shortly after final formulation. Viral vector design and manufacturing control are critically important to overall product quality and linked to safety and efficacy in patients through concerns such as replication competence, vector integration, and vector shedding. In addition, for many CGTPs, the value of nonclinical studies is largely limited to providing proof of concept, and the first meaningful data relating to appropriate dosing, safety parameters, and validity of surrogate or true determinants of efficacy must come from carefully designed clinical trials in patients. Addressing these numerous challenges requires application of various risk mitigation strategies and meeting regulatory expectations specifically adapted to the product types. Regulatory cooperation and harmonisation at an international level are essential for progress in the development and commercialisation of these products. However, particularly in the area of cell therapy, new regulatory paradigms may be needed to harness the benefits of clinical progress in situations where the resources and motivation to pursue a typical drug product approval pathway may be lacking. PMID:26374212

  11. Alterations in regulatory T-cells: rediscovered pathways in immunotoxicology.

    PubMed

    Corsini, Emanuela; Oukka, Mohamed; Pieters, Raymond; Kerkvliet, Nancy I; Ponce, Rafael; Germolec, Dori R

    2011-01-01

    In addition to the effector T-cells subsets, T-cells can also differentiate into cells that play a suppressive or regulatory role in adaptive immune responses. The cell types currently identified as regulatory T-cells (T(regs)) include natural or thymic-derived T(regs), T-cells which express Foxp3(+)CD25(+)CD4(+) and can suppress immune responses to autoreactive T-cells, as well as inducible T(regs), that are generated from naïve T-cells in the periphery after interaction with antigens presented by dendritic cells. Inducible T(regs) include T(H)3 cells, T(r)1 cells, and Foxp3(+)-inducible T(regs). T(regs) have been shown to be critical in the maintenance of immune responses and T-cell homeostasis. These cells play an important role in suppressing responses to self-antigens and in controlling inappropriate responses to non-self-antigens, such as commensal bacteria or food in the gut. For example, depletion of CD4(+)CD25(+) T(regs) from mice resulted in the development of multi-organ autoimmune diseases. CD4(+)CD25(+) T(regs) and/or IL-10-producing T(r)1 cells are capable of suppressing or attenuating T(H)2 responses to allergens. Moreover, adoptive transfer of CD4(+)CD25(+) T(regs) from healthy to diseased animals resulted in the prevention or cure of certain autoimmune diseases, and was able to induce transplantation tolerance. Clinical improvement seen after allergen immunotherapy for allergic diseases such as rhinitis and asthma is associated with the induction of IL-10- and TGFβ-producing T(r)1 cells as well as FoxP3-expressing IL-10 T-cells, with resulting suppression of the T(H)2 cytokine milieu. Activation, expansion, or suppression of CD4(+)CD25(+) T(regs) in vivo by xenobiotics, including drugs, may therefore represent a relevant mechanism underlying immunotoxicity, including immunosuppression, allergic asthma, and autoimmune diseases. PMID:21848365

  12. 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

  13. Characterization of Regulatory T-Cell Markers in CD4+ T Cells of the Upper Airway Mucosa

    PubMed Central

    Ballke, Christina; Gran, Einar; Baekkevold, Espen S.; Jahnsen, Frode L.

    2016-01-01

    CD4+ T regulatory cells (Tregs) comprise a heterogeneous population of cells the regulate immune responses and prevent autoimmunity. Most reports on human Tregs are derived from studies of peripheral blood, although Tregs mainly exert their functions in the periphery. Here we performed a detailed analysis of Tregs in the human upper airway mucosa under non-inflammatory conditions, and found that 10% of all CD4+ T cells expressed the transcription factor FOXP3 and the memory marker CD45RO, as well as high levels of CTLA-4. The majority of FOXP3+CD4+ T cells co-expressed the transcription factor Helios and produced very little cytokines, compatible with being thymus-derived Tregs. FOXP3+Helios-CD4+ T cells were more heterogeneous. A mean of 24% produced the immunomodulatory cytokine IL-10, whereas a large fraction also produced IL-2, IFN-μ or IL-17. A significant population (6%) of FOXP3-negative T cells also produced IL-10, usually in combination with IFN-μ. Together, we found that CD4+ T cells in the upper airways differed functionally from their counterparts in peripheral blood, including higher expression of IL-10. Moreover, our findings suggest that several subsets of CD4+ T cells with functionally distinct regulatory properties reside in the upper airway mucosa which should be taken into account when targeting Tregs for therapy. PMID:26866695

  14. Regulatory T-Cell-Associated Cytokines in Systemic Lupus Erythematosus

    PubMed Central

    Okamoto, Akiko; Fujio, Keishi; Okamura, Tomohisa; Yamamoto, Kazuhiko

    2011-01-01

    Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by autoantibody production, complement activation, and immune complex deposition, resulting in tissue and organ damage. An understanding of the mechanisms responsible for homeostatic control of inflammation, which involve both innate and adoptive immune responses, will enable the development of novel therapies for SLE. Regulatory T cells (Treg) play critical roles in the induction of peripheral tolerance to self- and foreign antigens. Naturally occurring CD4+CD25+ Treg, which characteristically express the transcription factor forkhead box protein P3 (Foxp3), have been intensively studied because their deficiency abrogates self-tolerance and causes autoimmune disease. Moreover, regulatory cytokines such as interleukin-10 (IL-10) also play a central role in controlling inflammatory processes. This paper focuses on Tregs and Treg-associated cytokines which might regulate the pathogenesis of SLE and, hence, have clinical applications. PMID:22219657

  15. Foxp3 expressing regulatory T-cells in allergic disease.

    PubMed

    Nouri-Aria, Kayhan T

    2009-01-01

    Allergic diseases such as asthma, rhinitis and eczema are increasing in prevalence worldwide, in particular in industrialised countries affecting up to 20% of the population. Regulatory T-cells (Tregs) have been shown to be critical in T-cell homeostasis and in the maintenance of immune responses, such as prevention of autoimmunity and hampering allergic diseases. The so-called 'natural' CD4+CD25+ Tregs and/or IL-10-producing Tr1 cells have been shown to be responsible for the protection of immune tolerance and intact immune reactions following exposure to allergens such as aeroallergens or food allergens. In this regard, both cell-cell contact (through membrane bound TGF-beta or via suppressive molecules such as CLTA-4) and soluble cytokine-(TGF-beta and IL-10) dependent mechanisms have been shown to contribute to the ability of Tregs to operate effectively. The transcription factor Foxp3, a member of the forkhead-winged helix family, appears to be critical in the suppressive abilities of regulatory T-cells. Adoptive transfer of CD4+CD25+ Tregs from healthy to diseased animals corroborated and provided further evidence of the vital role of these populations in the prevention or cure of certain autoimmune conditions. Clinical improvement seen after allergen immunotherapy for allergic diseases such as rhinitis and asthma has also been associated with the induction of IL-10 and TGF-beta producing Trl cells as well as Foxp3 expressing CD4+CD25+ T-cells, resulting in the suppression ofTh2 cytokine milieu. Activation and expansion ofantigen-specific CD4+CD25+ Tregs in vivo using adjuvants such as IL-10 or pharmacological agents such as low dose steroids or vitamin D3 could represent novel approaches to induce antigen-specific tolerance in immune-mediated conditions such as allergic asthma, autoimmune disease and the rejection of transplanted organs in man. PMID:20429425

  16. Tissue resident regulatory T cells: novel therapeutic targets for human disease

    PubMed Central

    Zhou, Xiaohui; Tang, Jiayou; Cao, Hao; Fan, Huimin; Li, Bin

    2015-01-01

    Over the past decade, the ability of regulatory T cells (Tregs) to suppress multiple types of immune cells has received tremendous attention. Mounting evidence has revealed that tissue resident Tregs control non-immunological processes of their target tissues and contribute to a plethora of human diseases. The identification of novel tissue-specific Tregs has highlighted their heterogeneity and complexity. This review summarizes the recent findings for visceral adipose tissue CD4+Foxp3+ regulatory T cells (VAT Tregs), muscle Tregs, bone Tregs and skin memory Tregs, with a focus on their unique functions in local tissues. This interpretation of the roles of tissue-specific Tregs and of their involvement in disease progression provides new insight into the discovery of potential therapeutic targets of human diseases. PMID:25891216

  17. 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. PMID:23762097

  18. 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

  19. 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

  20. Natural and induced T regulatory cells in cancer.

    PubMed

    Adeegbe, Dennis O; Nishikawa, Hiroyoshi

    2013-01-01

    CD4+Foxp3+ T regulatory (Treg) cells control many facets of immune responses ranging from autoimmune diseases, to inflammatory conditions, and cancer in an attempt to maintain immune homeostasis. Natural Treg (nTreg) cells develop in the thymus and constitute a critical arm of active mechanisms of peripheral tolerance particularly to self antigens. A growing body of knowledge now supports the existence of induced Treg (iTreg) cells which may derive from a population of conventional CD4+ T cells. The fork-head transcription factor (Foxp3) typically is expressed by natural CD4+ Treg cells, and thus serves as a marker to definitively identify these cells. On the contrary, there is less consensus on what constitutes iTreg cells as their precise definition has been somewhat elusive. This is in part due to their distinct phenotypes which are shaped by exposure to certain inflammatory or "assault" signals stemming from the underlying immune disorder. The "policing" activity of Treg cells tends to be uni-directional in several pathological conditions. On one end of the spectrum, Treg cell suppressive activity is beneficial by curtailing T cell response against self-antigens and allergens thus preventing autoimmune diseases and allergies. On the other end however, their inhibitory roles in limiting immune response against pseudo-self antigens as in tumors often culminates into negative outcomes. In this review, we focus on this latter aspect of Treg cell immunobiology by highlighting the involvement of nTreg cells in various animal models and human tumors. We further discuss iTreg cells, relationship with their natural counterpart, and potential co-operation between the two in modulating immune response against tumors. Lastly, we discuss studies focusing on these cells as targets for improving anti-tumor immunity. PMID:23874336

  1. Functional effects of a natural polymorphism in the transcriptional regulatory sequence of HLA-DQB1.

    PubMed Central

    Beaty, J S; West, K A; Nepom, G T

    1995-01-01

    DNA sequence polymorphism in the genes encoding HLA class II proteins accounts for allelic diversity in antigen recognition and presentation and, thus, in the role of these cell surface glycoproteins as determinants of the scope of the T-cell repertoire. In addition, sequence polymorphism in the promoter-proximal transcriptional regulatory regions of these genes has been described, particularly for the HLA-DQB1 locus, where these differences may contribute to variation in locus- and allele-specific expression. In this study, we measured the effect of such regulatory sequence polymorphism on the expression of endogenous alleles of DQB1 in heterozygous cells. Quantitative reverse transcriptase-mediated PCR analysis showed that expression of the DQB1*0301 allele responded more rapidly to gamma interferon induction than that of DQB1*0302. We have analyzed functional effects of a prominent allelic polymorphism that consists of a TG dinucleotide present between the W and X1 consensus elements in the DQB1*0302 allele but missing in the DQB1*0301 allele. The dominant effect of this polymorphism was to introduce a variation in the spacing between the W and X1 elements of these two alleles. A secondary compensatory effect was specific for the TG dinucleotide itself, which was essential for the binding of a nuclear protein complex to the *0302 regulatory region immediately 5' of the X1 element. Derivatives of the DQB1 5' regulatory region were used to drive expression of the chloramphenicol acetyltransferase gene in transient transfections of human B-lymphoblastoid and gamma interferon-treated melanoma cell lines, demonstrating that the additional spacing between the W and X1 elements caused by the presence of the TG dinucleotide in the *0302 allele resulted in reduced expression compared with that driven by the *0301 fragment; this difference overshadowed an up-regulating effect on expression which corresponded to the binding of the TG-dependent nuclear protein complex. The

  2. IL-10-producing regulatory B10 cells ameliorate collagen-induced arthritis via suppressing Th17 cell generation.

    PubMed

    Yang, Min; Deng, Jun; Liu, Yang; Ko, King-Hung; Wang, Xiaohui; Jiao, Zhijun; Wang, Shengjun; Hua, Zichun; Sun, Lingyun; Srivastava, Gopesh; Lau, Chak-Sing; Cao, Xuetao; Lu, Liwei

    2012-06-01

    IL-10-producing CD1d(hi)CD5(+) B cells, also known as B10 cells, have been shown to possess a regulatory function in the inhibition of immune responses, but whether and how B10 cells suppress the development of autoimmune arthritis remain largely unclear. In this study, we detected significantly decreased numbers of IL-10-producing B cells, but increased IL-17-producing CD4(+) T (Th17) cells in both spleen and draining lymph nodes of mice during the acute stage of collagen-induced arthritis (CIA) when compared with adjuvant-treated control mice. On adoptive transfer of in vitro expanded B10 cells, collagen-immunized mice showed a marked delay of arthritis onset with reduced severity of both clinical symptoms and joint damage, accompanied by a substantial reduction in the number of Th17 cells. To determine whether B10 cells directly inhibit the generation of Th17 cells in culture, naive CD4(+) T cells labeled with carboxyfluorescein succinimidyl ester (CFSE) were co-cultured with B10 cells. These B10 cells suppressed Th17 cell differentiation via the reduction of STAT3 phosphorylation and retinoid-related orphan receptor γt (RORγt) expression. Moreover, Th17 cells showed significantly decreased proliferation when co-cultured with B10 cells. Although adoptive transfer of Th17 cells triggered the development of collagen-induced arthritis in IL-17(-/-)DBA/1J mice, co-transfer of B10 cells with Th17 cells profoundly delayed the onset of arthritis. Thus, our findings suggest a novel regulatory role of B10 cells in arthritic progression via the suppression of Th17 cell generation. PMID:22538089

  3. 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

  4. Validation of Skeletal Muscle cis-Regulatory Module Predictions Reveals Nucleotide Composition Bias in Functional Enhancers

    PubMed Central

    Kwon, Andrew T.; Chou, Alice Yi; Arenillas, David J.; Wasserman, Wyeth W.

    2011-01-01

    We performed a genome-wide scan for muscle-specific cis-regulatory modules (CRMs) using three computational prediction programs. Based on the predictions, 339 candidate CRMs were tested in cell culture with NIH3T3 fibroblasts and C2C12 myoblasts for capacity to direct selective reporter gene expression to differentiated C2C12 myotubes. A subset of 19 CRMs validated as functional in the assay. The rate of predictive success reveals striking limitations of computational regulatory sequence analysis methods for CRM discovery. Motif-based methods performed no better than predictions based only on sequence conservation. Analysis of the properties of the functional sequences relative to inactive sequences identifies nucleotide sequence composition can be an important characteristic to incorporate in future methods for improved predictive specificity. Muscle-related TFBSs predicted within the functional sequences display greater sequence conservation than non-TFBS flanking regions. Comparison with recent MyoD and histone modification ChIP-Seq data supports the validity of the functional regions. PMID:22144875

  5. Diversification and senescence of Foxp3+ regulatory T cells during experimental autoimmune encephalomyelitis.

    PubMed

    Tauro, Sharyn; Nguyen, Phuong; Li, Bofeng; Geiger, Terrence L

    2013-05-01

    The fate of Foxp3(+) regulatory T (Treg) cells responding during autoimmunity is not well defined. We observed a marked elevation in KLRG1(+) (where KLRG1 stands for killer cell lectin-like receptor G1) CNS-infiltrating Treg cells in experimental autoimmune encephalomyelitis (EAE), and assessed their origin and properties. KLRG1(+) Treg cells showed increased activation marker expression, Foxp3 and CD25 levels, and more rapid cell cycling than KLRG1(-) cells. KLRG1(-) Treg cells converted into KLRG1(+) cells and this was increased in autoimmune inflammation. Conversion was unidirectional; KLRG1(+) Treg cells did not revert to a KLRG1(-) state. KLRG1(+) but notKLRG1(-) Treg cells survived poorly, indicative of terminal differentiation. This was associated with diminished BCL2 and increased apoptosis of isolated cells. KLRG1 was also upregulated on iTreg cells after transfer and EAE induction or on iTreg cells developing spontaneously during EAE. KLRG1(+) Treg cells produced more IL-10 and had altered effector cytokine production compared with their KLRG1(-) counterparts. Despite their differences, KLRG1(+) and KLRG1(-) Treg cells proved similarly potent in suppressing EAE. KLRG1(+) and KLRG1(-) populations were phenotypically heterogeneous, with the extent and pattern of activation marker expression dependent both on cellular location and inflammation. Our results support an extensive diversification of Treg cells during EAE, and associate KLRG1 with altered Treg-cell function and senescence. PMID:23436224

  6. 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...

  7. Hyperglycemia decreases mitochondrial function: The regulatory role of mitochondrial biogenesis

    SciTech Connect

    Palmeira, Carlos M. Rolo, Anabela P.; Berthiaume, Jessica; Bjork, James A.; Wallace, Kendall B.

    2007-12-01

    Increased generation of reactive oxygen species (ROS) is implicated in 'glucose toxicity' in diabetes. However, little is known about the action of glucose on the expression of transcription factors in hepatocytes, especially those involved in mitochondrial DNA (mtDNA) replication and transcription. Since mitochondrial functional capacity is dynamically regulated, we hypothesized that stressful conditions of hyperglycemia induce adaptations in the transcriptional control of cellular energy metabolism, including inhibition of mitochondrial biogenesis and oxidative metabolism. Cell viability, mitochondrial respiration, ROS generation and oxidized proteins were determined in HepG2 cells cultured in the presence of either 5.5 mM (control) or 30 mM glucose (high glucose) for 48 h, 96 h and 7 days. Additionally, mtDNA abundance, plasminogen activator inhibitor-1 (PAI-1), mitochondrial transcription factor A (TFAM) and nuclear respiratory factor-1 (NRF-1) transcripts were evaluated by real time PCR. High glucose induced a progressive increase in ROS generation and accumulation of oxidized proteins, with no changes in cell viability. Increased expression of PAI-1 was observed as early as 96 h of exposure to high glucose. After 7 days in hyperglycemia, HepG2 cells exhibited inhibited uncoupled respiration and decreased MitoTracker Red fluorescence associated with a 25% decrease in mtDNA and 16% decrease in TFAM transcripts. These results indicate that glucose may regulate mtDNA copy number by modulating the transcriptional activity of TFAM in response to hyperglycemia-induced ROS production. The decrease of mtDNA content and inhibition of mitochondrial function may be pathogenic hallmarks in the altered metabolic status associated with diabetes.

  8. Vav family exchange factors: an integrated regulatory and functional view.

    PubMed

    Bustelo, Xosé R

    2014-01-01

    The Vav family is a group of tyrosine phosphorylation-regulated signal transduction molecules hierarchically located downstream of protein tyrosine kinases. The main function of these proteins is to work as guanosine nucleotide exchange factors (GEFs) for members of the Rho GTPase family. In addition, they can exhibit a variety of catalysis-independent roles in specific signaling contexts. Vav proteins play essential signaling roles for both the development and/or effector functions of a large variety of cell lineages, including those belonging to the immune, nervous, and cardiovascular systems. They also contribute to pathological states such as cancer, immune-related dysfunctions, and atherosclerosis. Here, I will provide an integrated view about the evolution, regulation, and effector properties of these signaling molecules. In addition, I will discuss the pros and cons for their potential consideration as therapeutic targets. PMID:25483299

  9. Vav family exchange factors: an integrated regulatory and functional view

    PubMed Central

    Bustelo, Xosé R

    2014-01-01

    The Vav family is a group of tyrosine phosphorylation-regulated signal transduction molecules hierarchically located downstream of protein tyrosine kinases. The main function of these proteins is to work as guanosine nucleotide exchange factors (GEFs) for members of the Rho GTPase family. In addition, they can exhibit a variety of catalysis-independent roles in specific signaling contexts. Vav proteins play essential signaling roles for both the development and/or effector functions of a large variety of cell lineages, including those belonging to the immune, nervous, and cardiovascular systems. They also contribute to pathological states such as cancer, immune-related dysfunctions, and atherosclerosis. Here, I will provide an integrated view about the evolution, regulation, and effector properties of these signaling molecules. In addition, I will discuss the pros and cons for their potential consideration as therapeutic targets. PMID:25483299

  10. Enhanced immunoregulation of mesenchymal stem cells by IL-10-producing type 1 regulatory T cells in collagen-induced arthritis

    PubMed Central

    Lim, Jung-Yeon; Im, Keon-Il; Lee, Eun-Sol; Kim, Nayoun; Nam, Young-Sun; Jeon, Young-Woo; Cho, Seok-Goo

    2016-01-01

    Mesenchymal stem cells (MSCs) possess immunomodulatory properties and have potential, however, there have been conflicting reports regarding their effects in rheumatoid arthritis (RA), which causes inflammation and destruction of the joints. Through a comparative analysis of regulatory T (Treg) and IL-10-producing type 1 regulatory T (Tr1) cells, we hypothesized that Tr1 cells enhance the immunoregulatory functions of MSCs, and that a combinatorial approach to cell therapy may exert synergistic immunomodulatory effects in an experimental animal model of rheumatoid arthritis (RA). A combination of MSCs and Tr1 cells prevented the development of destructive arthritis compared to single cell therapy. These therapeutic effects were associated with an increase in type II collagen (CII)-specific CD4+CD25+Foxp3+ Treg cells and inhibition of CII-specific CD4+IL-17+ T cells. We observed that Tr1 cells produce high levels of IL-10-dependent interferon (IFN)-β, which induces toll-like receptor (TLR) 3 expression in MSCs. Moreover, induction of indoleamine 2,3-dioxygenase (IDO) by TLR3 involved an autocrine IFN-β that was dependent on STAT1 signaling. Furthermore, we observed that production of IFN-β and IL-10 in Tr1 cells synergistically induces IDO in MSCs through the STAT1 pathway. These findings suggest co-administration of MSCs and Tr1 cells to be a novel therapeutic modality for clinical autoimmune diseases. PMID:27246365

  11. Enhanced immunoregulation of mesenchymal stem cells by IL-10-producing type 1 regulatory T cells in collagen-induced arthritis.

    PubMed

    Lim, Jung-Yeon; Im, Keon-Il; Lee, Eun-Sol; Kim, Nayoun; Nam, Young-Sun; Jeon, Young-Woo; Cho, Seok-Goo

    2016-01-01

    Mesenchymal stem cells (MSCs) possess immunomodulatory properties and have potential, however, there have been conflicting reports regarding their effects in rheumatoid arthritis (RA), which causes inflammation and destruction of the joints. Through a comparative analysis of regulatory T (Treg) and IL-10-producing type 1 regulatory T (Tr1) cells, we hypothesized that Tr1 cells enhance the immunoregulatory functions of MSCs, and that a combinatorial approach to cell therapy may exert synergistic immunomodulatory effects in an experimental animal model of rheumatoid arthritis (RA). A combination of MSCs and Tr1 cells prevented the development of destructive arthritis compared to single cell therapy. These therapeutic effects were associated with an increase in type II collagen (CII)-specific CD4+CD25+Foxp3+ Treg cells and inhibition of CII-specific CD4+IL-17+ T cells. We observed that Tr1 cells produce high levels of IL-10-dependent interferon (IFN)-β, which induces toll-like receptor (TLR) 3 expression in MSCs. Moreover, induction of indoleamine 2,3-dioxygenase (IDO) by TLR3 involved an autocrine IFN-β that was dependent on STAT1 signaling. Furthermore, we observed that production of IFN-β and IL-10 in Tr1 cells synergistically induces IDO in MSCs through the STAT1 pathway. These findings suggest co-administration of MSCs and Tr1 cells to be a novel therapeutic modality for clinical autoimmune diseases. PMID:27246365

  12. Upholding the T cell immune-regulatory function of CD31 inhibits the formation of T/B immunological synapses in vitro and attenuates the development of experimental autoimmune arthritis in vivo.

    PubMed

    Clement, Marc; Fornasa, Giulia; Loyau, Stéphane; Morvan, Marion; Andreata, Francesco; Guedj, Kevin; Khallou-Laschet, Jamila; Larghi, Paola; Le Roux, Delphine; Bismuth, Georges; Chiocchia, Gilles; Hivroz, Claire; Newman, Debra K; Nicoletti, Antonino; Caligiuri, Giuseppina

    2015-01-01

    CD31, a trans-homophilic inhibitory receptor expressed on both T- and B-lymphocytes, drives the mutual detachment of interacting leukocytes. Intriguingly, T cell CD31 molecules relocate to the immunological synapse (IS), where the T and B cells establish a stable interaction. Here, we show that intact CD31 molecules, which are able to drive an inhibitory signal, are concentrated at the periphery of the IS but are excluded from the center of the IS. At this site, were the cells establish the closest contact, the CD31 molecules are cleaved, and most of the extracellular portion of the protein, including the trans-homophilic binding sites, is shed from the cell surface. T cells lacking CD31 trans-homophilic binding sites easily establish stable interactions with B cells; at the opposite, CD31 signaling agonists inhibit T/B IS formation as well as the ensuing helper T cell activation and function. Confocal microscopy and flow cytometry analysis of experimental T/B IS shows that the T cell inhibitory effects of CD31 agonists depend on SHP-2 signaling, which reduces the phosphorylation of ZAP70. The analysis of synovial tissue biopsies from patients affected by rheumatoid arthritis showed that T cell CD31 molecules are excluded from the center of the T/B cell synapses in vivo. Interestingly, the administration of CD31 agonists in vivo significantly attenuated the development of the clinical signs of collagen-induced arthritis in DBA1/J mice. Altogether, our data indicate that the T cell co-inhibitory receptor CD31 prevents the formation of functional T/B immunological synapses and that therapeutic strategies aimed at sustaining CD31 signaling will attenuate the development of autoimmune responses in vivo. PMID:25277651

  13. In colorectal cancer mast cells contribute to systemic regulatory T-cell dysfunction.

    PubMed

    Blatner, Nichole R; Bonertz, Andreas; Beckhove, Philipp; Cheon, Eric C; Krantz, Seth B; Strouch, Matthew; Weitz, Juergen; Koch, Moritz; Halverson, Amy L; Bentrem, David J; Khazaie, Khashayarsha

    2010-04-01

    T-regulatory cells (Treg) and mast cells (MC) are abundant in colorectal cancer (CRC) tumors. Interaction between the two is known to promote immune suppression or loss of Treg functions and autoimmunity. Here, we demonstrate that in both human CRC and murine polyposis the outcome of this interaction is the generation of potently immune suppressive but proinflammatory Treg (DeltaTreg). These Treg shut down IL10, gain potential to express IL17, and switch from suppressing to promoting MC expansion and degranulation. This change is also brought about by direct coculture of MC and Treg, or culture of Treg in medium containing IL6 and IL2. IL6 deficiency in the bone marrow of mice susceptible to polyposis eliminated IL17 production by the polyp infiltrating Treg, but did not significantly affect the growth of polyps or the generation of proinflammatory Treg. IL6-deficient MC could generate proinflammatory Treg. Thus, MC induce Treg to switch function and escalate inflammation in CRC without losing T-cell-suppressive properties. IL6 and IL17 are not needed in this process. PMID:20308560

  14. T regulatory cells: Achilles' heel of Mycobacterium tuberculosis infection?

    PubMed

    Parkash, Om; Agrawal, Sonali; Madhan Kumar, M

    2015-07-01

    T regulatory cells (Treg) constitute a specialized subset of T cells that play a pivotal role in preventing the occurrence of autoimmune diseases by suppressing deleterious activities of immune cells. Contrarily, they can have adverse effect on immune response against infectious diseases where Treg weaken the host immunity leading to enhanced microbial load and thereby increase in severity of the disease. Here, we have attempted to review plethora of information documenting prevalence of Treg in tuberculosis (TB) and their involvement in progression and immunopathogenesis of the disease. Further, we have laid emphasis on the possible use of Treg as a biomarker for determining the TB treatment efficacy. Also, we have discussed the probable contribution of Treg in dampening the efficacy of BCG, the anti-TB vaccine. Finally, we have speculated some of the possible strategies which might be explored by exploiting Treg for enhancing the efficacy of TB management. PMID:25948475

  15. Promotion of regulatory T cell induction by immunomodulatory herbal medicine licorice and its two constituents

    PubMed Central

    Guo, Ao; He, Dongming; Xu, Hong-Bo; Geng, Chang-An; Zhao, Jian

    2015-01-01

    Regulatory T cells (Treg) play a critical role to control immune responses and to prevent autoimmunity, thus selective increase of Treg cells in vivo has broad therapeutic implications for autoimmune and inflammatory diseases. Licorice is a well-known herbal medicine used worldwide for over thousands of years, and accumulating evidence has shown its immunomodulatory potential. However, it is not clear whether licorice could regulate the induction and function of Treg cells. Here we found licorice extract could promote Treg cell induction, and then we used a rational approach to isolate its functional fractions and constituents. The results showed that two constituents, isoliquiritigenin and naringenin, promoted Treg cell induction both in vitro and in vivo. The effective fractions and two constituents of licorice also enhanced immune suppression of Treg cells, and they further reduced severity of DSS-induced colitis in mice. This study suggested that promotion of regulatory T cell induction could be an underlying mechanism of the historically and widely used herbal medicine licorice, providing its two effective molecules against autoimmune and inflammatory diseases. PMID:26370586

  16. Disrupted regulatory T cell homeostasis in inflammatory bowel diseases

    PubMed Central

    Pedros, Christophe; Duguet, Fanny; Saoudi, Abdelhadi; Chabod, Marianne

    2016-01-01

    In the gut, where billions of non-self-antigens from the food and the microbiota are present, the immune response must be tightly regulated to ensure both host protection against pathogenic microorganisms and the absence of immune-related pathologies. It has been well documented that regulatory T cells (Tregs) play a pivotal role in this context. Indeed, Tregs are able to prevent excessive inflammation, which can lead to the rupture of intestinal homeostasis observed in inflammatory bowel diseases (IBDs). Both the worldwide incidence and prevalence of such diseases have increased throughout the latter part of the 20th century. Therefore, it is crucial to understand how Tregs suppress the colitogenic immune cells to establish new treatments for patients suffering from IBDs. In this review, we will first summarize the results obtained in animal model studies that highlight the importance of Tregs in maintaining intestinal homeostasis and describe the specific suppressive mechanisms involved. Next, our current knowledge about Tregs contribution to human IBDs will be reviewed, as well as the current therapeutic perspective on using Tregs for clinical IBD treatment and the challenges that remain to be resolved to ensure both the safety and effectiveness of these therapies in targeting this critical immune-regulatory cell population. PMID:26811641

  17. Prospective Clinical Testing of Regulatory Dendritic Cells in Organ Transplantation

    PubMed Central

    Thomson, Angus W.; Zahorchak, Alan F.; Ezzelarab, Mohamed B.; Butterfield, Lisa H.; Lakkis, Fadi G.; Metes, Diana M.

    2016-01-01

    Dendritic cells (DC) are rare, professional antigen-presenting cells with ability to induce or regulate alloimmune responses. Regulatory DC (DCreg) with potential to down-modulate acute and chronic inflammatory conditions that occur in organ transplantation can be generated in vitro under a variety of conditions. Here, we provide a rationale for evaluation of DCreg therapy in clinical organ transplantation with the goal of promoting sustained, donor-specific hyporesponsiveness, while lowering the incidence and severity of rejection and reducing patients’ dependence on anti-rejection drugs. Generation of donor- or recipient-derived DCreg that suppress T cell responses and prolong transplant survival in rodents or non-human primates has been well-described. Recently, good manufacturing practice (GMP)-grade DCreg have been produced at our Institution for prospective use in human organ transplantation. We briefly review experience of regulatory immune therapy in organ transplantation and describe our experience generating and characterizing human monocyte-derived DCreg. We propose a phase I/II safety study in which the influence of donor-derived DCreg combined with conventional immunosuppression on subclinical and clinical rejection and host alloimmune responses will be examined in detail. PMID:26858719

  18. 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

  19. Disturbed T Cell Signaling and Altered Th17 and Regulatory T Cell Subsets in the Pathogenesis of Systemic Lupus Erythematosus

    PubMed Central

    Rother, Nils; van der Vlag, Johan

    2015-01-01

    Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by the presence of autoantibodies against nuclear components. Circulating immune complexes of chromatin and autoantibodies deposit in various tissues leading to inflammation and tissue damage. It has been well documented that autoimmunity in SLE depends on autoreactive T cells. In this review, we summarize the literature that addresses the roles of T cell signaling, and Th17 and regulatory T cells (Tregs) in the development of SLE. T cell receptor (TCR) signaling appears to be aberrant in T cells of patients with SLE. In particular, defects in the TCRζ chain, Syk kinase, and calcium signaling molecules have been associated with SLE, which leads to hyperresponsive autoreactive T cells. Furthermore, in patients with SLE increased numbers of autoreactive Th17 cells have been documented, and Th17 cells appear to be responsible for tissue inflammation and damage. In addition, reduced numbers of Tregs as well as Tregs with an impaired regulatory function have been associated with SLE. The altered balance between the number of Tregs and Th17 cells in SLE may result from changes in the cytokine milieu that favors the development of Th17 cells over Tregs. PMID:26648939

  20. Expansion of regulatory T cells from umbilical cord blood and adult peripheral blood CD4(+)CD25 (+) T cells.

    PubMed

    Lin, Syh-Jae; Lu, Chun-Hao; Yan, Dah-Chin; Lee, Pei-Tzu; Hsiao, Hsiu-Shan; Kuo, Ming-Ling

    2014-10-01

    CD4(+)CD25(+) regulatory T cells (Treg), if properly expanded from umbilical cord blood (UCB), may provide a promising immunotherapeutic tool. Our previous data demonstrated that UCB CD4(+)CD25(+) T cells with 4-day stimulation have comparable phenotypes and suppressive function to that of adult peripheral blood (APB) CD4(+)CD25(+) T cells. We further examined whether 2-week culture would achieve higher expansion levels of Tregs. UCB CD4(+)CD25(+) T cells and their APB counterparts were stimulated with anti-CD3/anti-CD28 in the presence of IL-2 or IL-15 for 2 weeks. The cell proliferation and forkhead box P3 (FoxP3) expression were examined. The function of the expanded cells was then investigated by suppressive assay. IL-21 was applied to study whether it counteracts the function of UCB and APB CD4(+)CD25(+) T cells. The results indicate that UCB CD4(+)CD25(+) T cells expanded much better than their APB counterparts. IL-2 was superior to expand UCB and APB Tregs for 2 weeks than IL-15. FoxP3 expression which peaked on Day 10-14 was comparable. Most importantly, expanded UCB Tregs showed greater suppressive function in allogeneic mixed lymphocyte reaction. The addition of IL-21, however, counteracted the suppressive function of expanded UCB and APB Tregs. The results support using UCB as a source of Treg cells. PMID:24515612

  1. Control of peripheral tolerance by regulatory T cell-intrinsic Notch signaling.

    PubMed

    Charbonnier, Louis-Marie; Wang, Sen; Georgiev, Peter; Sefik, Esen; Chatila, Talal A

    2015-11-01

    Receptors of the Notch family direct the differentiation of helper T cell subsets, but their influence on regulatory T cell (T(reg) cell) responses is obscure. We found here that lineage-specific deletion of components of the Notch pathway enhanced T(reg) cell-mediated suppression of type 1 helper T cell (T(H)1 cell) responses and protected against their T(H)1 skewing and apoptosis. In contrast, expression in T(reg) cells of a gain-of-function transgene encoding the Notch1 intracellular domain resulted in lymphoproliferation, exacerbated T(H)1 responses and autoimmunity. Cell-intrinsic canonical Notch signaling impaired T(reg) cell fitness and promoted the acquisition by T(reg) cells of a T(H)1 cell-like phenotype, whereas non-canonical Notch signaling dependent on the adaptor Rictor activated the kinase AKT-transcription factor Foxo1 axis and impaired the epigenetic stability of Foxp3. Our findings establish a critical role for Notch signaling in controlling peripheral T(reg) cell function. PMID:26437242

  2. T Follicular Helper Cells and Regulatory B Cells Dynamics in Systemic Lupus Erythematosus

    PubMed Central

    Chu, Yiwei; Xue, Yu; Xuan, Dandan; Zheng, Shucong; Zou, Hejian

    2014-01-01

    T follicular helper (Tfh) cells aid effector B cells, and augment autoimmunity, whereas the role of Tfh cells on regulatory B (Breg) cells in systemic lupus erythematosus (SLE) is not known. The aim of this study is to investigate the percentage of Breg cells in SLE, and the role of Tfh cells on Breg cells. First, we demonstrated the presence of Breg cells in SLE peripheral blood mononuclear cells and in involved skins. Both the percentage of circulating Breg cells and the ability to produce interleukin-10 (IL-10) were elevated in SLE patients. The percentage of Breg cells increased during SLE flares and decreased following disease remission. Second, Tfh cell expansion was not only related to autoantibody production but also correlated with the increased percentage of Breg cells. Third, in vitro studies revealed that Tfh cell-derived IL-21 could promote IL-10 production and Breg cell differentiation. In conclusions, these data imply that SLE flares may be linked to the expansion of Tfh cells and that Breg cells are increased in a regulatory feedback manner. Thus, SLE development may be associated with the complex regulation of Tfh cells and diverse B cell subsets. PMID:24551101

  3. Emerging regulatory mechanisms in ubiquitin-dependent cell cycle control

    PubMed Central

    Mocciaro, Annamaria; Rape, Michael

    2012-01-01

    The covalent modification of proteins with ubiquitin is required for accurate cell division in all eukaryotes. Ubiquitylation depends on an enzymatic cascade, in which E3 enzymes recruit specific substrates for modification. Among ~600 human E3s, the SCF (Skp1–cullin1–F-box) and the APC/C (anaphase-promoting complex/cyclosome) are known for driving the degradation of cell cycle regulators to accomplish irreversible cell cycle transitions. The cell cycle machinery reciprocally regulates the SCF and APC/C through various mechanisms, including the modification of these E3s or the binding of specific inhibitors. Recent studies have provided new insight into the intricate relationship between ubiquitylation and the cell division apparatus as they revealed roles for atypical ubiquitin chains, new mechanisms of substrate and E3 regulation, as well as extensive crosstalk between ubiquitylation enzymes. Here, we review these emerging regulatory mechanisms of ubiquitin-dependent cell cycle control and discuss how their manipulation might provide therapeutic benefits in the future. PMID:22357967

  4. 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

  5. Enhancer turnover and conserved regulatory function in vertebrate evolution

    PubMed Central

    Domené, Sabina; Bumaschny, Viviana F.; de Souza, Flávio S. J.; Franchini, Lucía F.; Nasif, Sofía; Low, Malcolm J.; Rubinstein, Marcelo

    2013-01-01

    Mutations in regulatory regions including enhancers are an important source of variation and innovation during evolution. Enhancers can evolve by changes in the sequence, arrangement and repertoire of transcription factor binding sites, but whole enhancers can also be lost or gained in certain lineages in a process of turnover. The proopiomelanocortin gene (Pomc), which encodes a prohormone, is expressed in the pituitary and hypothalamus of all jawed vertebrates. We have previously described that hypothalamic Pomc expression in mammals is controlled by two enhancers—nPE1 and nPE2—that are derived from transposable elements and that presumably replaced the ancestral neuronal Pomc regulatory regions. Here, we show that nPE1 and nPE2, even though they are mammalian novelties with no homologous counterpart in other vertebrates, nevertheless can drive gene expression specifically to POMC neurons in the hypothalamus of larval and adult transgenic zebrafish. This indicates that when neuronal Pomc enhancers originated de novo during early mammalian evolution, the newly created cis- and trans-codes were similar to the ancestral ones. We also identify the neuronal regulatory region of zebrafish pomca and confirm that it is not homologous to the mammalian enhancers. Our work sheds light on the process of gene regulatory evolution by showing how a locus can undergo enhancer turnover and nevertheless maintain the ancestral transcriptional output. PMID:24218639

  6. 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

  7. 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. PMID:18154612

  8. Regulatory Considerations for NK Cells Used in Human Immunotherapy Applications.

    PubMed

    Lee, Dean A

    2016-01-01

    Translating cellular therapy from the laboratory to the clinic is a complicated process that involves scale-up of procedures to generate clinically relevant cell numbers, adaptation to reagents and equipment that are qualified for human use, establishing parameters of safety for reagents and equipment that are not already qualified for human use, codifying these processes into standards of practice and rules of conduct, and obtaining approval from regulatory bodies based on those codified standards and rules. As the laws and regulations that apply to cellular therapy will vary by time and geography, this chapter reviews some common key principles for the manufacturing of NK cells for human use that will need to be considered within the constraints of local policies and regulations. PMID:27177680

  9. 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.

  10. T-cell regulatory mechanisms in specific immunotherapy.

    PubMed

    Jutel, Marek; Akdis, Cezmi A

    2008-01-01

    Allergen-specific immunotherapy (SIT) is the only treatment which leads to a lifelong tolerance against previously disease-causing allergens due to restoration of normal immunity against allergens. The description of T-regulatory (Treg) cells being involved in prevention of sensitization to allergens has led to great interest whether they represent a major target for allergen-SIT and whether it would be possible to manipulate Treg cells to increase its efficacy. Activationinduced cell death, anergy and/or immune response modulation by Treg cells are essential mechanisms of peripheral T-cell tolerance. There is growing evidence that anergy, tolerance and active suppression are not entirely distinct, but rather represent linked mechanisms possibly involving the same cells and multiple suppressor mechanisms. Skewing of allergen-specific effector T cells to Treg cells appears as a crucial event in the control of healthy immune response to allergens and successful allergen-SIT. The Treg cell response is characterized by abolished allergen- induced specific T-cell proliferation and suppressed Thelper (Th)1- and Th2-type cytokine secretion. In addition, mediators of allergic inflammation that trigger cAMP-associated G-protein-coupled receptors, such as histamine receptor-2, may contribute to peripheral tolerance mechanisms. The increased levels of interleukin-10 and transforming growth factor-Beta that are produced by Treg cells potently suppress IgE production, while simultaneously increasing production of non-inflammatory isotypes IgG4 and IgA, respectively. In addition, Treg cells directly or indirectly suppress effector cells of allergic inflammation such as mast cells, basophils and eosinophils. In conclusion, peripheral tolerance to allergens is controlled by multiple active suppression mechanisms. It is associated with regulation of antibody isotypes and effector cells to the direction of a healthy immune response. By the application of the recent knowledge in Treg

  11. Novel Foxp3− IL-10− Regulatory T-cells Induced by B-Cells Alleviate Intestinal Inflammation in Vivo

    PubMed Central

    Shao, Tzu-Yu; Hsu, Ling-Hui; Chien, Chien-Hui; Chiang, Bor-Luen

    2016-01-01

    Recent studies have revealed various Foxp3− regulatory T (Treg) cell subsets effectively protect mice from colitis. In the present study, we demonstrated that B cells induced a particular subset of regulatory T (Treg-of-B) cells, expressing programmed cell death 1 (PD-1), inducible costimulator (ICOS), lymphocyte-activation gene 3 (LAG3), glucocorticoid-induced tumor necrosis factor receptor (GITR), and OX-40, did not express Foxp3. Treg-of-B cells produced abundant levels of IL-10 and low levels of IL-4 and TGF-β. Adoptive transfer of Treg-of-B cells protected mice from CD4+CD45RBhi T-cell-induced colitis, including infiltration of leukocytes, depletion of goblet cells, epithelial hyperplasia, and inhibition of Th1 and Th17 cytokines. These features were similar to IL-10-producing type 1 regulatory T (Tr1) cells; however, IL-10-deficient Treg-of-B cells maintained their suppressive function in vitro as well as in vivo, while the regulation of Tr1 cells depended on IL-10. In conclusion, Treg-of-B cells protected against experimental colitis through an IL-10-independent mechanism. We reported a novel subpopulation of regulatory T cells was different from conventional Foxp3+ Treg and IL-10-producing Tr1 cells. PMID:27581189

  12. Genome-wide Analysis Identifies Bcl6-Controlled Regulatory Networks during T Follicular Helper Cell Differentiation.

    PubMed

    Liu, Xindong; Lu, Huiping; Chen, Tingting; Nallaparaju, Kalyan C; Yan, Xiaowei; Tanaka, Shinya; Ichiyama, Kenji; Zhang, Xia; Zhang, Li; Wen, Xiaofeng; Tian, Qiang; Bian, Xiu-wu; Jin, Wei; Wei, Lai; Dong, Chen

    2016-02-23

    T follicular helper (Tfh) cell is a unique T cell subset specialized in promoting humoral immunity. B-cell lymphoma 6 protein (Bcl6) has been identified as an obligatory transcription factor in Tfh cells; however, the molecular mechanism underlying Bcl6 function remains largely unknown. Here, we defined Bcl6 target genes in Tfh cells by analyzing genome-wide Bcl6 occupancy together with transcriptome profiling. With consensus sequences being different from those in Th9, B cells, and macrophages, Bcl6 binding in Tfh cell was closely associated with a decrease in 5-hydroxymethylcytosine (5hmC). Importantly, Bcl6 promoted Tfh cell differentiation through antagonizing IL-7R (CD127)/signal transducer and activator of transcription (STAT) 5 axis; deletion of the Bcl6 gene in T cells resulted in enhanced IL-7R-STAT5 signaling and substantial expansion of CD127(hi) non-Tfh cells. Thus, our study systemically examines Bcl6-controlled regulatory networks and provides important insights into Bcl6's biological functions in Tfh cells. PMID:26876184

  13. 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

  14. Adoptive Immunotherapy using Regulatory T cells and Virus-specific T cells Derived from Cord Blood

    PubMed Central

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

    2014-01-01

    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 (GvHD), respectively. Here we describe how current strategies utilizing cord blood-derived regulatory T cells and virus-specific T cells have been developed to improve outcomes for cord blood transplant recipients. PMID:25632003

  15. Cholera-like enterotoxins and Regulatory T cells.

    PubMed

    Basset, Christelle; Thiam, Fatou; Martino, Cyrille Di; Holton, John; Clements, John D; Kohli, Evelyne

    2010-07-01

    Cholera toxin (CT) and the heat-labile enterotoxin of E. coli (LT), as well as their non toxic mutants, are potent mucosal adjuvants of immunization eliciting mucosal and systemic responses against unrelated co-administered antigens in experimental models and in humans (non toxic mutants). These enterotoxins are composed of two subunits, the A subunit, responsible for an ADP-ribosyl transferase activity and the B subunit, responsible for cell binding. Paradoxically, whereas the whole toxins have adjuvant properties, the B subunits of CT (CTB) and of LT (LTB) have been shown to induce antigen specific tolerance when administered mucosally with antigens in experimental models as well as, recently, in humans, making them an attractive strategy to prevent or treat autoimmune or allergic disorders. Immunomodulation is a complex process involving many cell types notably antigen presenting cells and regulatory T cells (Tregs). In this review, we focus on Treg cells and cholera-like enterotoxins and their non toxic derivates, with regard to subtype, in vivo/in vitro effects and possible role in the modulation of immune responses to coadministered antigens. PMID:22069660

  16. 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.

  17. Peritoneal cavity regulatory B cells (B10 cells) modulate IFN-γ+CD4+ T cell numbers during colitis development in mice.

    PubMed

    Maseda, Damian; Candando, Kathleen M; Smith, Susan H; Kalampokis, Ioannis; Weaver, Casey T; Plevy, Scott E; Poe, Jonathan C; Tedder, Thomas F

    2013-09-01

    The spleen regulatory B cell subset with the functional capacity to express IL-10 (B10 cells) modulates both immune responses and autoimmune disease severity. However, the peritoneal cavity also contains relatively high frequencies of functionally defined IL-10-competent B10 cells. In this study, peritoneal cavity B10 cells shared similar cell surface phenotypes with their spleen counterparts. However, peritoneal cavity B10 cells were 10-fold more frequent among B cells than occurred within the spleen, intestinal tract, or mesenteric lymph nodes and were present at higher proportions among the phenotypically defined peritoneal B1a > B1b > B2 cell subpopulations. The development or localization of B10 cells within the peritoneal cavity was not dependent on the presence of commensal microbiota, T cells, IL-10 or B10 cell IL-10 production, or differences between their fetal liver or adult bone marrow progenitor cell origins. The BCR repertoire of peritoneal cavity B10 cells was diverse, as occurs in the spleen, and predominantly included germline-encoded VH and VL regions commonly found in either the conventional or B1 B cell compartments. Thereby, the capacity to produce IL-10 appears to be an intrinsic functional property acquired by clonally diverse B cells. Importantly, IL-10 production by peritoneal cavity B cells significantly reduced disease severity in spontaneous and induced models of colitis by regulating neutrophil infiltration, colitogenic CD4(+) T cell activation, and proinflammatory cytokine production during colitis onset. Thus, the numerically small B10 cell subset within the peritoneal cavity has regulatory function and is important for maintaining homeostasis within gastrointestinal tissues and the immune system. PMID:23918988

  18. Large-Scale Depletion of CD25+ Regulatory T Cells from Patient Leukapheresis Samples

    PubMed Central

    Powell, Daniel J.; Parker, Linda L.; Rosenberg, Steven A.

    2006-01-01

    Summary The ability to selectively enrich or deplete T lymphocytes of specific phenotype and function holds significant promise for application in adoptive immunotherapy protocols. Although CD4+ T cells can have an impact on CD8+ T-cell effector function, memory, and maintenance, a subset of CD4+ T cells, CD25+ regulatory T cells (Treg), can regulate peripheral self tolerance and possess the ability to suppress antitumor responses. The authors report the ability to selectively deplete CD25+ Treg cells from patient leukapheresis samples using a clinical-grade, large-scale immunomagnetic system. Using leukapheresis samples containing up to 1.3 × 1010 white blood cells, efficient depletion of Treg cells was measured by flow cytometric analysis of CD25 expression and FOXP3 expression on post-depletion products. Remnant CD25+ cells could not be detected in CD25-depleted products after short-term culture in IL-2 or enriched following secondary immunomagnetic selection for CD25+ cells, confirming that efficient depletion had occurred. In parallel to efficient enrichment of CD25− cells, immunomagnetic selection resulted in the recovery of Treg cells, since CD25+ lymphocytes removed during depletion were primarily composed of CD4+ T cells that expressed high levels of FOXP3 and possessed suppressive activity against autologous TCR-stimulated CD4+ CD25− T cells in vitro. These results show that selective separation of functional CD25+ Treg cells from large-scale samples can be performed in large scale under clinical-grade conditions with sufficient selection, recovery, viability, ability to expand, and function for potential use in adoptive immunotherapy. PMID:16000960

  19. 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. PMID:24732772

  20. 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

  1. [The Regulatory Proteins of β-Adrenergic Receptor and Their Functions].

    PubMed

    Tian, Ai-ju; Li, Zi-jian

    2015-04-01

    Vascular diseases has become a top killer of human health, and cardiovascular receptors are pivotal in the occurrence, development, prevention and treatment of cardiovascular diseases. As for the important member of G protein-coupled receptor, β-adrenergic receptor is undoubtedly a most important target of cardiovascular drugs. Being the hot spot in the cardiovascular research and application, β- adrenergic receptor blocker has been considered as the greatest breakthrough for the prevention and cure of cardiovascular disease after digitalis. The 2012 Nobel Prize in chemistry was awarded again to the researchers on β-adrenergic receptors. Extensive researchs show that β-adrenergic receptors are precisely regulated by different regulatory proteins in cells in the transduction of different physiological and pathological signaling pathways. Based on these findings, function-selective ligands recently arise in the receptor research and will be the new chance of drug discovery. In this article we reviewed the related signal pathways and functions of β-adrenergic receptor regulatory proteins. PMID:26201103

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

    PubMed

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

    2013-04-01

    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

  3. Increased Expression of Regulatory T Cells and Down-Regulatory Molecules in Lepromatous Leprosy

    PubMed Central

    Palermo, Maria L.; Pagliari, Carla; Trindade, Maria Angela B.; Yamashitafuji, Tania M.; Duarte, Alberto José S.; Cacere, Camila R.; Benard, Gil

    2012-01-01

    T regulatory cells (Tregs) play an important role in the mechanism of host's failure to control pathogen dissemination in severe forms of different chronic granulomatous diseases, but their role in leprosy has not yet been elucidated; 28 newly diagnosed patients (16 patients with lepromatous leprosy and 12 patients with tuberculoid leprosy) and 6 healthy Mycobacterium leprae-exposed individuals (contacts) were studied. Tregs were quantified by flow cytometry (CD4+ CD25+ Foxp3+) in peripheral blood mononuclear cells stimulated in vitro with a M. leprae antigenic preparation and phytohemagglutinin as well as in skin lesions by immunohistochemistry. The lymphoproliferative (LPR), interleukin-10 (IL-10), and interferon-γ (IFN-γ) responses of the in vitro-stimulated peripheral blood mononuclear cells and the in situ expression of IL-10, transforming growth factor-β (TGF-β), and cytotoxic T-lymphocyte antigen 4 (CTLA-4) were also determined. We show that M. leprae antigens induced significantly lower LPR but significantly higher Treg numbers in lepromatous than tuberculoid patients and contacts. Mitogen-induced LPR and Treg frequencies were not significantly different among the three groups. Tregs were also more frequent in situ in lepromatous patients, and this finding was paralleled by increased expression of the antiinflammatory molecules IL-10 and CTLA-4 but not TGF-β. In lepromatous patients, Tregs were intermingled with vacuolized hystiocyte infiltrates all over the lesion, whereas in tuberculoid patients, Tregs were rare. Our results suggest that Tregs are present in increased numbers, and they may have a pathogenic role in leprosy patients harboring uncontrolled bacillary multiplication but not in those individuals capable of limiting M. leprae growth. PMID:22556091

  4. Increased expression of regulatory T cells and down-regulatory molecules in lepromatous leprosy.

    PubMed

    Palermo, Maria L; Pagliari, Carla; Trindade, Maria Angela B; Yamashitafuji, Tania M; Duarte, Alberto José S; Cacere, Camila R; Benard, Gil

    2012-05-01

    T regulatory cells (Tregs) play an important role in the mechanism of host's failure to control pathogen dissemination in severe forms of different chronic granulomatous diseases, but their role in leprosy has not yet been elucidated; 28 newly diagnosed patients (16 patients with lepromatous leprosy and 12 patients with tuberculoid leprosy) and 6 healthy Mycobacterium leprae-exposed individuals (contacts) were studied. Tregs were quantified by flow cytometry (CD4+ CD25+ Foxp3+) in peripheral blood mononuclear cells stimulated in vitro with a M. leprae antigenic preparation and phytohemagglutinin as well as in skin lesions by immunohistochemistry. The lymphoproliferative (LPR), interleukin-10 (IL-10), and interferon-γ (IFN-γ) responses of the in vitro-stimulated peripheral blood mononuclear cells and the in situ expression of IL-10, transforming growth factor-β (TGF-β), and cytotoxic T-lymphocyte antigen 4 (CTLA-4) were also determined. We show that M. leprae antigens induced significantly lower LPR but significantly higher Treg numbers in lepromatous than tuberculoid patients and contacts. Mitogen-induced LPR and Treg frequencies were not significantly different among the three groups. Tregs were also more frequent in situ in lepromatous patients, and this finding was paralleled by increased expression of the antiinflammatory molecules IL-10 and CTLA-4 but not TGF-β. In lepromatous patients, Tregs were intermingled with vacuolized hystiocyte infiltrates all over the lesion, whereas in tuberculoid patients, Tregs were rare. Our results suggest that Tregs are present in increased numbers, and they may have a pathogenic role in leprosy patients harboring uncontrolled bacillary multiplication but not in those individuals capable of limiting M. leprae growth. PMID:22556091

  5. 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

  6. 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. PMID:26340681

  7. CD8α+ Dendritic cells prime TCR-peptide-reactive regulatory CD4+FOXP3− T cells

    PubMed Central

    Smith, Trevor R. F.; Maricic, Igor; Ria, Francesco; Schneider, Susan; Kumar, Vipin

    2011-01-01

    Summary CD4+ T cells with immune regulatory function can be either FOXP3+ or FOXP3−. We have previously shown that priming of naturally occurring TCR-peptide-reactive regulatory CD4+FOXP3− T cells (Treg) specifically controls Vβ8.2+CD4+ T cells mediating experimental autoimmune encephalomyelitis (EAE). However, the mechanism by which these Treg are primed to recognize their cognate antigenic determinant, which is derived from the TCRVβ8.2-chain, is not known. In this study we show that antigen presenting cells (APC) derived from splenocytes of naïve mice are able to stimulate cloned CD4+ Treg in the absence of exogenous antigen, and their stimulation capacity is augmented during EAE. Among the APC populations DC were the most efficient in stimulating the Treg. Stimulation of CD4+ Treg was dependent upon processing and presentation of TCR peptides from ingested Vβ8.2TCR+ CD4+ T cells. Additionally, dendritic cells pulsed with TCR peptide or apoptotic Vβ8.2+ T cells are able to prime Treg in vivo and mediate protection from disease in a CD8-dependent fashion. These data highlight a novel mechanism for the priming of CD4+ Treg by CD8α+ DC, and suggest a pathway that can be exploited to prime antigen-specific regulation of T cell-mediated inflammatory disease. PMID:20394075

  8. Orchestration of plasma cell differentiation by Bach2 and its gene regulatory network.

    PubMed

    Igarashi, Kazuhiko; Ochiai, Kyoko; Itoh-Nakadai, Ari; Muto, Akihiko

    2014-09-01

    Bach2 is a basic region-leucine zipper (bZip) transcription factor that forms heterodimers with small Maf oncoproteins and binds to target genes, thus repressing their expression. Bach2 is required for class switch recombination (CSR) and somatic hypermutation (SHM) of immunoglobulin genes in activated B cells. Bach2 represses the expression of Prdm1 encoding Blimp-1 repressor and thereby inhibits terminal differentiation of B cells to plasma cells. This causes a delay in the induction of Prdm1, thereby securing a time window for the expression of Aicda encoding activation-induced cytidine deaminase (AID) required for both CSR and SHM. Based on the characteristics of a gene regulatory network (GRN) involving Bach2 and Prdm1 and its dynamics, a 'delay-driven diversity' model was introduced to explain the responses of activated B cells. Bach2 is also required for the proper differentiation and function of peripheral T cells. In the absence of Bach2, CD4(+) T cells show increased differentiation to effector cells producing higher levels of Th2-related cytokines, such as IL-4 and IL-10, and a reduction in the generation of regulatory T cells. Bach2 represses many genes in T cells, including Prdm1, suggesting that the Bach2-Prdm1 pathway is also important in maintaining the homeostasis of T cells. Furthermore, Bach2 is essential for the function of alveolar macrophages. Therefore, Bach2 orchestrates both acquired and innate immunity at multiple points. Its connection with disease is also reviewed in this report. PMID:25123280

  9. Human regulatory B cells combine phenotypic and genetic hallmarks with a distinct differentiation fate.

    PubMed

    Lin, Wenyu; Cerny, Daniela; Chua, Edmond; Duan, Kaibo; Yi, June Tai Jing; Shadan, Nurhidaya Binte; Lum, Josephine; Maho-Vaillant, Maud; Zolezzi, Francesca; Wong, Siew Cheng; Larbi, Anis; Fink, Katja; Musette, Philippe; Poidinger, Michael; Calbo, Sébastien

    2014-09-01

    Regulatory B cells (B-reg) produce IL-10 and suppress inflammation in both mice and humans, but limited data on the phenotype and function of these cells have precluded detailed assessment of their contribution to host immunity. In this article, we report that human B-reg cannot be defined based on a phenotype composed of conventional B cell markers, and that IL-10 production can be elicited in both the CD27(+) memory population and naive B cell subset after only a brief stimulation in vitro. We therefore sought to obtain a better definition of IL-10-producing human B-regs using a multiparameter analysis of B cell phenotype, function, and gene expression profile. Exposure to CpG and anti-Ig are the most potent stimuli for IL-10 secretion in human B cells, but microarray analysis revealed that human B cells cotreated with these reagents resulted in only ∼0.7% of genes being differentially expressed between IL-10(+) and IL-10(-) cells. Instead, connectivity map analysis revealed that IL-10-secreting B cells are those undergoing specific differentiation toward a germinal center fate, and we identified a CD11c(+) B cell subset that was not capable of producing IL-10 even under optimal conditions. Our findings will assist in the identification of a broader range of human pro-B-reg populations that may represent novel targets for immunotherapy. PMID:25080484

  10. VIP contribution to the decidualization program: regulatory T cell recruitment.

    PubMed

    Grasso, Esteban; Paparini, Daniel; Agüero, Mariana; Mor, Gil; Pérez Leirós, Claudia; Ramhorst, Rosanna

    2014-04-01

    During early pregnancy, the human uterus undergoes profound tissue remodeling characterized by leukocyte invasion and production of proinflammatory cytokines, followed by tissue repair and tolerance maintenance induction. Vasoactive intestinal peptide (VIP) is produced by trophoblast cells and modulates the maternal immune response toward a tolerogenic profile. Here, we evaluated the contribution of the VIP/VPAC to endometrial renewal, inducing decidualization and the recruitment of induced regulatory T cells (iTregs) that accompany the implantation period. For that purpose, we used an in vitro model of decidualization with a human endometrial stromal cell line (HESC) stimulated with progesterone (P4) and lipopolysaccharide (LPS) simulating the inflammatory response during implantation and human iTregs (CD4(+)CD25(+)FOXP3(+)) differentiated from naïve T cells obtained from peripheral blood mononuclear cells of fertile women. We observed that VIP and its receptor VPAC1 are constitutively expressed in HESCs and that P4 increased VIP expression. Moreover, in HESC VIP induced expression of RANTES (CCL5), one of the main chemokines involved in T cell recruitment, and this effect is enhanced by the presence of P4 and LPS. Finally, assays of the migration of iTregs toward conditioned media from HESCs revealed that endogenous VIP production induced by P4 and LPS and RANTES production were involved, as anti-RANTES neutralizing Ab or VIP antagonist prevented their migration. We conclude that VIP may have an active role in the decidualization process, thus contributing to recruitment of iTregs toward endometrial stromal cells by increasing RANTES expression in a P4-dependent manner. PMID:24492467

  11. Sequential activation and distinct functions for distal and proximal modules within the IgH 3′ regulatory region

    PubMed Central

    Garot, Armand; Marquet, Marie; Saintamand, Alexis; Bender, Sébastien; Le Noir, Sandrine; Rouaud, Pauline; Carrion, Claire; Oruc, Zéliha; Bébin, Anne-Gaëlle; Moreau, Jeanne; Lebrigand, Kevin; Denizot, Yves; Alt, Frederick W.; Cogné, Michel; Pinaud, Eric

    2016-01-01

    As a master regulator of functional Ig heavy chain (IgH) expression, the IgH 3′ regulatory region (3′RR) controls multiple transcription events at various stages of B-cell ontogeny, from newly formed B cells until the ultimate plasma cell stage. The IgH 3′RR plays a pivotal role in early B-cell receptor expression, germ-line transcription preceding class switch recombination, interactions between targeted switch (S) regions, variable region transcription before somatic hypermutation, and antibody heavy chain production, but the functional ranking of its different elements is still inaccurate, especially that of its evolutionarily conserved quasi-palindromic structure. By comparing relevant previous knockout (KO) mouse models (3′RR KO and hs3b-4 KO) to a novel mutant devoid of the 3′RR quasi-palindromic region (3′PAL KO), we pinpointed common features and differences that specify two distinct regulatory entities acting sequentially during B-cell ontogeny. Independently of exogenous antigens, the 3′RR distal part, including hs4, fine-tuned B-cell receptor expression in newly formed and naïve B-cell subsets. At mature stages, the 3′RR portion including the quasi-palindrome dictated antigen-dependent locus remodeling (global somatic hypermutation and class switch recombination to major isotypes) in activated B cells and antibody production in plasma cells. PMID:26831080

  12. 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

  13. Clinical perspectives for regulatory T cells in transplantation tolerance.

    PubMed

    Hippen, Keli L; Riley, James L; June, Carl H; Blazar, Bruce R

    2011-12-01

    Three main types of CD4+ regulatory T cells can be distinguished based upon whether they express Foxp3 and differentiate naturally in the thymus (natural Tregs) or are induced in the periphery (inducible Tregs); or whether they are FoxP3 negative but secrete IL-10 in response to antigen (Tregulatory type 1, Tr1 cells). Adoptive transfer of each cell type has proven highly effective in mouse models at preventing graft vs. host disease (GVHD) and autoimmunity. Although clinical application was initially hampered by low Treg frequency and unfavorable ex vivo expansion properties, several phase I trials are now being conducted to assess their effect on GVHD following hematopoietic stem cell transplantation (HSCT) and in type I diabetes. Human Treg trials for HSCT recipients have preceded other indications because GVHD onset is precisely known, the time period needed for prevention relatively short, initial efficacy is likely to provide life-long protection, and complications of GVHD can be lethal. This review will summarize the clinical trials conducted to date that have employed Tregs to prevent GVHD following HSCT and discuss recent advances in Treg cellular therapy. PMID:21820917

  14. Regulatory T cell reprogramming towards a Th2 cell-like lineage impairs oral tolerance and promotes food allergy

    PubMed Central

    Rivas, Magali Noval; Burton, Oliver T.; Wise, Petra; Charbonnier, Louis-Marie; Georgiev, Peter; Oettgen, Hans C.; Rachid, Rima; Chatila, Talal

    2015-01-01

    Summary Oral immunotherapy has had limited success in establishing tolerance in food allergy, reflecting failure to elicit an effective regulatory T (Treg) cell response. We show that disease-susceptible mice (Il4raF709) with enhanced IL-4 receptor (IL-4R) signaling exhibited STAT6-dependent impaired generation and function of mucosal allergen-specific Treg cells. This failure was associated with the acquisition by Treg cells of T helper 2 (Th2) cell-like phenotype, also found in peripheral blood allergen-specific Treg cells of food allergic children. Selective augmentation of IL-4R signaling in Treg cells induced their reprogramming into Th2-like cells and disease susceptibility, whereas Treg cell lineage-specific deletion of Il4 and Il13 was protective. IL-4R signaling impaired the capacity of Treg cells to suppress mast cell activation and expansion, which in turn drove Treg cell Th2 cell reprogramming. Interruption of Treg cell Th2 cell reprogramming may thus provide novel therapeutic strategies in food allergy. PMID:25769611

  15. Regulatory T cell reprogramming toward a Th2-cell-like lineage impairs oral tolerance and promotes food allergy.

    PubMed

    Noval Rivas, Magali; Burton, Oliver T; Wise, Petra; Charbonnier, Louis-Marie; Georgiev, Peter; Oettgen, Hans C; Rachid, Rima; Chatila, Talal A

    2015-03-17

    Oral immunotherapy has had limited success in establishing tolerance in food allergy, reflecting failure to elicit an effective regulatory T (Treg) cell response. We show that disease-susceptible (Il4ra(F709)) mice with enhanced interleukin-4 receptor (IL-4R) signaling exhibited STAT6-dependent impaired generation and function of mucosal allergen-specific Treg cells. This failure was associated with the acquisition by Treg cells of a T helper 2 (Th2)-cell-like phenotype, also found in peripheral-blood allergen-specific Treg cells of food-allergic children. Selective augmentation of IL-4R signaling in Treg cells induced their reprogramming into Th2-like cells and disease susceptibility, whereas Treg-cell-lineage-specific deletion of Il4 and Il13 was protective. IL-4R signaling impaired the capacity of Treg cells to suppress mast cell activation and expansion, which in turn drove Th2 cell reprogramming of Treg cells. Interruption of Th2 cell reprogramming of Treg cells might thus provide candidate therapeutic strategies in food allergy. PMID:25769611

  16. Cognate interaction with iNKT cells expands IL-10-producing B regulatory cells.

    PubMed

    Vomhof-DeKrey, Emilie E; Yates, Jennifer; Hägglöf, Thomas; Lanthier, Paula; Amiel, Eyal; Veerapen, Natacha; Besra, Gurdyal S; Karlsson, Mikael C I; Leadbetter, Elizabeth A

    2015-10-01

    Successful induction of B-cell activation and memory depends on help from CD4+ T cells. Invariant natural killer T (iNKT) cells (glycolipid-specific, CD1d-restricted innate lymphocytes) provide both cognate (direct) and noncognate (indirect) helper signals to enhance B-cell responses. Both forms of iNKT-cell help induce primary humoral immune responses, but only noncognate iNKT-cell help drives humoral memory and plasma cells. Here, we show that iNKT cognate help for B cells is fundamentally different from the help provided by conventional CD4+ T cells. Cognate iNKT-cell help drives an early, unsustained germinal center B-cell expansion, less reduction of T follicular regulatory cells, an expansion of marginal zone B cells, and early increases in regulatory IL-10-producing B-cell numbers compared with noncognate activation. These results are consistent with a mechanism whereby iNKT cells preferentially provide an innate form of help that does not generate humoral memory and has important implications for the application of glycolipid molecules as vaccine adjuvants. PMID:26392556

  17. Cognate interaction with iNKT cells expands IL-10–producing B regulatory cells

    PubMed Central

    Vomhof-DeKrey, Emilie E.; Yates, Jennifer; Hägglöf, Thomas; Lanthier, Paula; Amiel, Eyal; Veerapen, Natacha; Besra, Gurdyal S.; Karlsson, Mikael C. I.; Leadbetter, Elizabeth A.

    2015-01-01

    Successful induction of B-cell activation and memory depends on help from CD4+ T cells. Invariant natural killer T (iNKT) cells (glycolipid-specific, CD1d-restricted innate lymphocytes) provide both cognate (direct) and noncognate (indirect) helper signals to enhance B-cell responses. Both forms of iNKT-cell help induce primary humoral immune responses, but only noncognate iNKT-cell help drives humoral memory and plasma cells. Here, we show that iNKT cognate help for B cells is fundamentally different from the help provided by conventional CD4+ T cells. Cognate iNKT-cell help drives an early, unsustained germinal center B-cell expansion, less reduction of T follicular regulatory cells, an expansion of marginal zone B cells, and early increases in regulatory IL-10–producing B-cell numbers compared with noncognate activation. These results are consistent with a mechanism whereby iNKT cells preferentially provide an innate form of help that does not generate humoral memory and has important implications for the application of glycolipid molecules as vaccine adjuvants. PMID:26392556

  18. The Lupus Susceptibility Gene Pbx1 Regulates the Balance between Follicular Helper T Cell and Regulatory T Cell Differentiation.

    PubMed

    Choi, Seung-Chul; Hutchinson, Tarun E; Titov, Anton A; Seay, Howard R; Li, Shiwu; Brusko, Todd M; Croker, Byron P; Salek-Ardakani, Shahram; Morel, Laurence

    2016-07-15

    Pbx1 controls chromatin accessibility to a large number of genes and is entirely conserved between mice and humans. The Pbx1-d dominant-negative isoform is more frequent in CD4(+) T cells from lupus patients than from healthy controls. Pbx1-d is associated with the production of autoreactive T cells in mice carrying the Sle1a1 lupus-susceptibility locus. Transgenic (Tg) expression of Pbx1-d in CD4(+) T cells reproduced the phenotypes of Sle1a1 mice, with increased inflammatory functions of CD4(+) T cells and impaired Foxp3(+) regulatory T cell (Treg) homeostasis. Pbx1-d-Tg expression also expanded the number of follicular helper T cells (TFHs) in a cell-intrinsic and Ag-specific manner, which was enhanced in recall responses and resulted in Th1-biased Abs. Moreover, Pbx1-d-Tg CD4(+) T cells upregulated the expression of miR-10a, miR-21, and miR-155, which were implicated in Treg and follicular helper T cell homeostasis. Our results suggest that Pbx1-d impacts lupus development by regulating effector T cell differentiation and promoting TFHs at the expense of Tregs. In addition, our results identify Pbx1 as a novel regulator of CD4(+) T cell effector function. PMID:27296664

  19. Prediction and Validation of Gene Regulatory Elements Activated During Retinoic Acid Induced Embryonic Stem Cell Differentiation.

    PubMed

    Simandi, Zoltan; Horvath, Attila; Nagy, Peter; Nagy, Laszlo

    2016-01-01

    Embryonic development is a multistep process involving activation and repression of many genes. Enhancer elements in the genome are known to contribute to tissue and cell-type specific regulation of gene expression during the cellular differentiation. Thus, their identification and further investigation is important in order to understand how cell fate is determined. Integration of gene expression data (e.g., microarray or RNA-seq) and results of chromatin immunoprecipitation (ChIP)-based genome-wide studies (ChIP-seq) allows large-scale identification of these regulatory regions. However, functional validation of cell-type specific enhancers requires further in vitro and in vivo experimental procedures. Here we describe how active enhancers can be identified and validated experimentally. This protocol provides a step-by-step workflow that includes: 1) identification of regulatory regions by ChIP-seq data analysis, 2) cloning and experimental validation of putative regulatory potential of the identified genomic sequences in a reporter assay, and 3) determination of enhancer activity in vivo by measuring enhancer RNA transcript level. The presented protocol is detailed enough to help anyone to set up this workflow in the lab. Importantly, the protocol can be easily adapted to and used in any cellular model system. PMID:27403939

  20. Integrating innate and adaptive immune cells: Mast cells as crossroads between regulatory and effector B and T cells.

    PubMed

    Mekori, Yoseph A; Hershko, Alon Y; Frossi, Barbara; Mion, Francesca; Pucillo, Carlo E

    2016-05-01

    A diversity of immune mechanisms have evolved to protect normal tissues from infection, but from immune damage too. Innate cells, as well as adaptive cells, are critical contributors to the correct development of the immune response and of tissue homeostasis. There is a dynamic "cross-talk" between the innate and adaptive immunomodulatory mechanisms for an integrated control of immune damage as well as the development of the immune response. Mast cells have shown a great plasticity, modifying their behavior at different stages of immune response through interaction with effector and regulatory populations of adaptive immunity. Understanding the interplays among T effectors, regulatory T cells, B cells and regulatory B cells with mast cells will be critical in the future to assist in the development of therapeutic strategies to enhance and synergize physiological immune-modulator and -suppressor elements in the innate and adaptive immune system. PMID:25941086