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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. 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

  3. 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

  4. 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

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

    PubMed

    Campbell, Daniel J

    2015-09-15

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

  6. 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

  7. A rapid diagnostic test for human regulatory T-cell function to enable regulatory T-cell therapy

    PubMed Central

    Canavan, James B.; Afzali, Behdad; Scottà, Cristiano; Fazekasova, Henrieta; Edozie, Francis C.; Macdonald, Thomas T.; Hernandez-Fuentes, Maria P.; Lombardi, Giovanna; Lord, Graham M.

    2013-01-01

    Regulatory T cells (CD4+CD25hiCD127lo-FOXP3+ T cells [Tregs]) are a population of lymphocytes involved in the maintenance of self-tolerance. Abnormalities in function or number of Tregs are a feature of autoimmune diseases in humans. The ability to expand functional Tregs ex vivo makes them ideal candidates for autologous cell therapy to treat human autoimmune diseases and to induce tolerance to transplants. Current tests of Treg function typically take up to 120 hours, a kinetic disadvantage as clinical trials of Tregs will be critically dependent on the availability of rapid diagnostic tests before infusion into humans. Here we evaluate a 7-hour flow cytometric assay for assessing Treg function, using suppression of the activation markers CD69 and CD154 on responder T cells (CD4+CD25− [Tresp]), compared with traditional assays involving inhibition of CFSE dilution and cytokine production. In both freshly isolated and ex vivo expanded Tregs, we describe excellent correlation with gold standard suppressor cell assays. We propose that the kinetic advantage of the new assay may place it as the preferred rapid diagnostic test for the evaluation of Treg function in forthcoming clinical trials of cell therapy, enabling the translation of the large body of preclinical data into potentially useful treatments for human diseases. PMID:22219224

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

    PubMed

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

    2016-09-01

    Cells in the body are exposed to irregular mechanical stimuli. Here, we review the so-called fluctuation-driven mechanotransduction in which stresses stretching cells vary on a cycle-by-cycle basis. We argue that such mechanotransduction is an emergent network phenomenon and offer several potential mechanisms of how it regulates cell function. Several examples from the vasculature, the lung, and tissue engineering are discussed. We conclude with a list of important open questions. PMID:27511461

  9. 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

  10. 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.

  11. 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

  12. 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.

  13. 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

  14. Protein phosphatase 2A is requisite for the function of regulatory T cells

    PubMed Central

    Apostolidis, Sokratis A.; Rodríguez-Rodríguez, Noé; Suárez-Fueyo, Abel; Dioufa, Nikolina; Ozcan, Esra; Crispín, José C.; Tsokos, Maria G.; Tsokos, George C.

    2015-01-01

    Immune homeostasis depends on the proper function of regulatory T (Treg) cells. Compromised Treg cell suppressive activity leads to autoimmune disease, graft rejection and promotes anti-tumor immunity. Here we report the previously unrecognized requirement of the serine/threonine phosphatase Protein Phosphatase 2A (PP2A) for the function of Treg cells. Treg cells exhibited high PP2A activity and Treg cell-specific ablation of the PP2A complex resulted in a severe, multi-organ, lymphoproliferative autoimmune disorder. Mass spectrometric analysis revealed that PP2A associates with components of the mTOR pathway and suppresses mTORC1 activity. In the absence of PP2A, Treg cells altered their metabolic and cytokine profile and were unable to suppress effector immune responses. Therefore, PP2A is requisite for the function of Treg cells and the prevention of autoimmunity. PMID:26974206

  15. 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

  16. 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

  17. Proinflammatory cytokines contribute to development and function of regulatory T cells in type 1 diabetes.

    PubMed

    Thomas, Helen E; Graham, Kate L; Chee, Jonathan; Thomas, Ranjeny; Kay, Thomas W; Krishnamurthy, Balasubramanian

    2013-04-01

    Type 1 diabetes is caused by immune-mediated loss of pancreatic beta cells. It has been proposed that inflammatory cytokines play a role in killing beta cells. Expression of interleukin (IL)-1 and tumor necrosis factor (TNF-α) has been detected in islets from patients with type 1 diabetes, and these cytokines can induce beta cell death in vitro. We produced nonobese diabetic (NOD) mice lacking receptors for these cytokines. Islets from mice lacking IL-1RI or TNFR1 were killed when transplanted into wild-type NOD mice, suggesting that cytokine action on beta cells is not required for killing. Mice lacking TNFR1 did not develop diabetes, and mice lacking IL-1R had delayed onset of diabetes, indicating a role for these cytokines in disease development. TNFR1-deficient mice had an increased number of CD4(+) CD25(+) FoxP3(+) regulatory T cells with enhanced suppressive capacity. IL-1 was produced at higher levels in NOD mice and resulted in dilution of suppressor function of CD4(+) CD25(+) FoxP3(+) regulatory T cells. Our data suggest that blocking inflammatory cytokines may increase the capacity of the immune system to suppress type 1 diabetes through regulatory T cells.

  18. Functional regulatory T cells produced by inhibiting cyclic nucleotide phosphodiesterase type 3 prevent allograft rejection

    PubMed Central

    Feng, Gang; Nadig, Satish N.; Bäckdahl, Liselotte; Beck, Stephan; Francis, Ross S.; Schiopu, Alexandru; Whatcott, Andrew; Wood, Kathryn J.; Bushell, Andrew

    2012-01-01

    Regulatory T cells (Tregs) manipulated ex vivo have potential as cellular therapeutics in autoimmunity and transplantation. Although it is possible to expand naturally occurring Tregs, an attractive alternative possibility, particularly suited to solid organ and bone marrow transplantation, is the stimulation of total T cell populations with defined allogeneic antigen presenting cells under conditions that lead to the generation or expansion of donor-reactive, adaptive Tregs. Here we demonstrate that stimulation of mouse CD4+ T cells by immature allogeneic dendritic cells (DCs) combined with pharmacological inhibition of phosphodiesterase 3 (PDEi) results in a functional enrichment of Foxp3+ T cells. Without further manipulation or selection, the resultant population delayed skin allograft rejection mediated by polyclonal CD4+ effectors or donor-reactive CD8+ TCR transgenic T cells and inhibited both effector cell proliferation and T cell priming for IFN-γ production. Notably, PDE inhibition also enhanced the enrichment of human Foxp3+ CD4+ T cells driven by allogeneic APC. These cells inhibited T cell proliferation in a standard in vitro mixed lymphocyte assay and importantly, attenuated the development of vasculopathy mediated by autologous PBMC in a functionally relevant humanized mouse transplant model. These data establish a method for the ex vivo generation of graft-reactive, functional mouse and human Tregs that uses a clinically approved agent, making pharmacological PDE inhibition a potential strategy for Treg-based therapies PMID:21593400

  19. Regular tai chi chuan exercise enhances functional mobility and CD4CD25 regulatory T cells

    PubMed Central

    Yeh, S‐H; Chuang, H; Lin, L‐W; Hsiao, C‐Y; Eng, H L

    2006-01-01

    Background The duration and vigour of physical exercise are widely considered to be critical elements that may positively or negatively affect physical health and immune response. Objectives To investigate the effect of a 12 week programme of regular tai chi chuan exercise (TCC) on functional mobility, beliefs about benefits of exercise on physical and psychological health, and immune regulation in middle aged volunteers. Methods This quasi‐experimental research design involving one group with testing before and after the programme was conducted to measure the effect of 12 weeks of TCC exercise in 14 men and 23 women from the normal community. Results Regular TCC exercise had a highly significant positive effect on functional mobility (p  =  0.001) and beliefs about the health benefits of exercise (p  =  0.013) in the 37 participants. Total white blood cell and red blood cell count did not change significantly, but a highly significant (p<0.001) decrease in monocyte count occurred. A significant (p  =  0.05) increase in the ratio of T helper to suppressor cells (CD4:CD8) was found, along with a significant (p  =  0.015) increase in CD4CD25 regulatory T cells. Production of the regulatory T cell mediators transforming growth factor β and interleukin 10 under specific antigen stimulation (varicella zoster virus) was also significantly increased after this exercise programme. Conclusions A 12 week programme of regular TCC exercise enhances functional mobility, personal health expectations, and regulatory T cell function. PMID:16505081

  20. 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.

  1. 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

  2. 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.

  3. The inhibitory cytokine IL-35 contributes to regulatory T-cell function.

    PubMed

    Collison, Lauren W; Workman, Creg J; Kuo, Timothy T; Boyd, Kelli; Wang, Yao; Vignali, Kate M; Cross, Richard; Sehy, David; Blumberg, Richard S; Vignali, Dario A A

    2007-11-22

    Regulatory T (T(reg)) cells are a critical sub-population of CD4+ T cells that are essential for maintaining self tolerance and preventing autoimmunity, for limiting chronic inflammatory diseases, such as asthma and inflammatory bowel disease, and for regulating homeostatic lymphocyte expansion. However, they also suppress natural immune responses to parasites and viruses as well as anti-tumour immunity induced by therapeutic vaccines. Although the manipulation of T(reg) function is an important goal of immunotherapy, the molecules that mediate their suppressive activity remain largely unknown. Here we demonstrate that Epstein-Barr-virus-induced gene 3 (Ebi3, which encodes IL-27beta) and interleukin-12 alpha (Il12a, which encodes IL-12alpha/p35) are highly expressed by mouse Foxp3+ (forkhead box P3) T(reg) cells but not by resting or activated effector CD4+ T (T(eff)) cells, and that an Ebi3-IL-12alpha heterodimer is constitutively secreted by T(reg) but not T(eff) cells. Both Ebi3 and Il12a messenger RNA are markedly upregulated in T(reg) cells co-cultured with T(eff) cells, thereby boosting Ebi3 and IL-12alpha production in trans. T(reg)-cell restriction of this cytokine occurs because Ebi3 is a downstream target of Foxp3, a transcription factor that is required for T(reg)-cell development and function. Ebi3-/- and Il12a-/- T(reg) cells have significantly reduced regulatory activity in vitro and fail to control homeostatic proliferation and to cure inflammatory bowel disease in vivo. Because these phenotypic characteristics are distinct from those of other IL-12 family members, this novel Ebi3-IL-12alpha heterodimeric cytokine has been designated interleukin-35 (IL-35). Ectopic expression of IL-35 confers regulatory activity on naive T cells, whereas recombinant IL-35 suppresses T-cell proliferation. Taken together, these data identify IL-35 as a novel inhibitory cytokine that may be specifically produced by T(reg) cells and is required for maximal suppressive

  4. Quantitative and functional analysis of CD69(+) NKG2D(+) T regulatory cells in healthy subjects.

    PubMed

    Vitales-Noyola, M; Doníz-Padilla, L; Álvarez-Quiroga, C; Monsiváis-Urenda, A; Portillo-Salazar, H; González-Amaro, R

    2015-07-01

    T regulatory (Treg) cells have a key role in immune homeostasis and the pathogenesis of chronic inflammatory and autoimmune diseases. CD69 is an early leukocyte activation molecule that under steady state conditions is detected in a small proportion of lymphocytes in peripheral blood and lymphoid tissues. Although it has been reported that a subset of CD69(+) T cells behaves as Treg lymphocytes, the possible relationship between CD69(+) Treg cells and CD4(+)NKG2D(+) T lymphocytes, which also exert immunosuppressive activity, has not been explored. In this study, we analyzed the expression of CD69 and NKG2D by T lymphocytes from the peripheral blood of twenty-five healthy subjects by multi-parametric flow cytometry analysis, and their suppressive activity by an assay of inhibition of lymphocyte activation (CD40L expression) and proliferation (carboxyfluorescein partition assay). We found a very small percentage of CD4(+)CD69(+)NKG2D(+) T cells (median 0.002%, Q1-Q3, 0.001-0.004%), which also expressed TGF-β (Latency Associated Peptide or LAP) and IL-10, in all samples analyzed. These cells exerted an important in vitro suppressive effect on both activation and proliferation of T effector cells. Our data suggest that at very small numbers, CD4(+)CD69(+)NKG2D(+) lymphocytes seem to exert a relevant functional immune-regulatory role in healthy subjects.

  5. Interferon Regulatory Factor 4 controls TH1 cell effector function and metabolism

    PubMed Central

    Mahnke, Justus; Schumacher, Valéa; Ahrens, Stefanie; Käding, Nadja; Feldhoff, Lea Marie; Huber, Magdalena; Rupp, Jan; Raczkowski, Friederike; Mittrücker, Hans-Willi

    2016-01-01

    The transcription factor Interferon Regulatory Factor 4 (IRF4) is essential for TH2 and TH17 cell formation and controls peripheral CD8+ T cell differentiation. We used Listeria monocytogenes infection to characterize the function of IRF4 in TH1 responses. IRF4−/− mice generated only marginal numbers of listeria-specific TH1 cells. After transfer into infected mice, IRF4−/− CD4+ T cells failed to differentiate into TH1 cells as indicated by reduced T-bet and IFN-γ expression, and showed limited proliferation. Activated IRF4−/− CD4+ T cells exhibited diminished uptake of the glucose analog 2-NBDG, limited oxidative phosphorylation and strongly reduced aerobic glycolysis. Insufficient metabolic adaptation contributed to the limited proliferation and TH1 differentiation of IRF4−/− CD4+ T cells. Our study identifies IRF4 as central regulator of TH1 responses and cellular metabolism. We propose that this function of IRF4 is fundamental for the initiation and maintenance of all TH cell responses. PMID:27762344

  6. Docosahexaenoic acid reduces suppressive and migratory functions of CD4CD25 regulatory T-cells

    PubMed Central

    Yessoufou, Akadiri; Plé, Aude; Moutairou, Kabirou; Hichami, Aziz; Khan, Naim Akhtar

    2009-01-01

    Immunological tolerance is one of the fundamental aspects of the immune system. The CD4+CD25+ regulatory T (Treg) cells have emerged as key players in the development of tolerance to self and foreign antigens. However, little is known about the endogenous factors and mechanisms controlling their suppressive capacity on immune response. In this study, we observed that docosahexaenoic acid (DHA), an n-3 polyunsaturated fatty acid, diminished, in a dose-dependent manner, the capacity of Treg cells to inhibit the CD4+CD25− effector T-cell proliferation. DHA not only reduced the migration of Treg cells toward chemokines but also downregulated the mRNA expression of CCR-4 and CXCR-4 in Treg cells. DHA also curtailed ERK1/2 and Akt phosphorylation and downregulated the Smad7 levels in these cells. Contradictorily, DHA upregulated the mRNA expression of Foxp3, CTLA-4, TGF-β, and IL-10; nonetheless, this fatty acid increased the expression of p27KIP1 mRNA, known to be involved in Treg cell unresponsiveness. In Foxp3-immunoprepitated nuclear proteins, DHA upregulated histone desacetylase 7 levels that would again participate in the unresposnsiveness of these cells. Finally, a DHA-enriched diet also diminished, ex vivo, the suppressive capacity of Treg cells. Altogether, these results suggest that DHA, by diminishing Treg cell functions, may play a key role in health and disease. PMID:19561360

  7. Docosahexaenoic acid reduces suppressive and migratory functions of CD4+CD25+ regulatory T-cells.

    PubMed

    Yessoufou, Akadiri; Plé, Aude; Moutairou, Kabirou; Hichami, Aziz; Khan, Naim Akhtar

    2009-12-01

    Immunological tolerance is one of the fundamental aspects of the immune system. The CD4(+)CD25(+) regulatory T (Treg) cells have emerged as key players in the development of tolerance to self and foreign antigens. However, little is known about the endogenous factors and mechanisms controlling their suppressive capacity on immune response. In this study, we observed that docosahexaenoic acid (DHA), an n-3 polyunsaturated fatty acid, diminished, in a dose-dependent manner, the capacity of Treg cells to inhibit the CD4(+)CD25(-) effector T-cell proliferation. DHA not only reduced the migration of Treg cells toward chemokines but also downregulated the mRNA expression of CCR-4 and CXCR-4 in Treg cells. DHA also curtailed ERK1/2 and Akt phosphorylation and downregulated the Smad7 levels in these cells. Contradictorily, DHA upregulated the mRNA expression of Foxp3, CTLA-4, TGF-beta, and IL-10; nonetheless, this fatty acid increased the expression of p27(KIP1) mRNA, known to be involved in Treg cell unresponsiveness. In Foxp3-immunoprepitated nuclear proteins, DHA upregulated histone desacetylase 7 levels that would again participate in the unresposnsiveness of these cells. Finally, a DHA-enriched diet also diminished, ex vivo, the suppressive capacity of Treg cells. Altogether, these results suggest that DHA, by diminishing Treg cell functions, may play a key role in health and disease.

  8. Function of a Foxp3 cis-element in protecting regulatory T cell identity.

    PubMed

    Li, Xudong; Liang, Yuqiong; LeBlanc, Mathias; Benner, Chris; Zheng, Ye

    2014-08-14

    The homeostasis of multicellular organisms requires terminally differentiated cells to preserve their lineage specificity. However, it is unclear whether mechanisms exist to actively protect cell identity in response to environmental cues that confer functional plasticity. Regulatory T (Treg) cells, specified by the transcription factor Foxp3, are indispensable for immune system homeostasis. Here, we report that conserved noncoding sequence 2 (CNS2), a CpG-rich Foxp3 intronic cis-element specifically demethylated in mature Tregs, helps maintain immune homeostasis and limit autoimmune disease development by protecting Treg identity in response to signals that shape mature Treg functions and drive their initial differentiation. In activated Tregs, CNS2 helps protect Foxp3 expression from destabilizing cytokine conditions by sensing TCR/NFAT activation, which facilitates the interaction between CNS2 and Foxp3 promoter. Thus, epigenetically marked cis-elements can protect cell identity by sensing key environmental cues central to both cell identity formation and functional plasticity without interfering with initial cell differentiation. PMID:25126782

  9. 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.

  10. Antibodies targeting human OX40 expand effector T cells and block inducible and natural regulatory T cell function

    PubMed Central

    Voo, Kui S.; Bover, Laura; Harline, Megan L.; Vien, Long T.; Facchinetti, Valeria; Arima, Kazuhiko; Kwak, Larry W.; Liu, Yong J.

    2013-01-01

    Current cancer vaccines induce tumor-specific T cell responses without sustained tumor regression because immunosuppressive elements within the tumor induce exhaustion of effector T cells and infiltration of immune-suppressive regulatory T cells (Tregs). Therefore, much effort has been made to generate agonistic Abs targeting members of the TNFR superfamily, such as OX40, 4- 1BB, and GITR, expressed on effector T cells and Tregs, to reinvigorate T cell effector function and block Treg-suppressive function. In this article, we describe the development of a panel of anti-human OX40 agonistic mouse mAbs that could promote effector CD4+ and CD8+ T cell proliferation, inhibit the induction of CD4+ IL-10 -producing type 1 regulatory T cells, inhibit the expansion of ICOS+IL-10+ Tregs, inhibit TGF-b–induced FOXP3 expression on naive CD4+ T cells, and block natural Treg–suppressive function. We humanized two anti–human OX40 mAb clones, and they retained the potency of their parental clones. These Abs should provide broad opportunities for potential combination therapy to treat a wide realm of cancers and preventative vaccines against infectious diseases. PMID:24014877

  11. Antibodies targeting human OX40 expand effector T cells and block inducible and natural regulatory T cell function.

    PubMed

    Voo, Kui S; Bover, Laura; Harline, Megan L; Vien, Long T; Facchinetti, Valeria; Arima, Kazuhiko; Kwak, Larry W; Liu, Yong J

    2013-10-01

    Current cancer vaccines induce tumor-specific T cell responses without sustained tumor regression because immunosuppressive elements within the tumor induce exhaustion of effector T cells and infiltration of immune-suppressive regulatory T cells (Tregs). Therefore, much effort has been made to generate agonistic Abs targeting members of the TNFR superfamily, such as OX40, 4-1BB, and GITR, expressed on effector T cells and Tregs, to reinvigorate T cell effector function and block Treg-suppressive function. In this article, we describe the development of a panel of anti-human OX40 agonistic mouse mAbs that could promote effector CD4(+) and CD8(+) T cell proliferation, inhibit the induction of CD4(+) IL-10 -producing type 1 regulatory T cells, inhibit the expansion of ICOS(+)IL-10(+) Tregs, inhibit TGF-β-induced FOXP3 expression on naive CD4(+) T cells, and block natural Treg-suppressive function. We humanized two anti-human OX40 mAb clones, and they retained the potency of their parental clones. These Abs should provide broad opportunities for potential combination therapy to treat a wide realm of cancers and preventative vaccines against infectious diseases. PMID:24014877

  12. Circulating subsets and CD4(+)CD25(+) regulatory T cell function in chronic inflammatory demyelinating polyradiculoneuropathy.

    PubMed

    Sanvito, Lara; Makowska, Anna; Gregson, Norman; Nemni, Raffaello; Hughes, Richard A C

    2009-01-01

    Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an inflammatory disease of the peripheral nervous system that is probably autoimmune in origin. Different components of the adaptive and innate immunity may be responsible for the aberrant response towards nerve antigens. To investigate this, we examined lymphocyte subsets and regulatory T cell (Treg) function in the blood of CIDP patients, healthy controls (HC) and subjects with non-immune mediated neuropathies (other neuropathies, ON). We used flow cytometry to determine the frequency of monocytes, B cells, natural killer (NK) and NK-T cells, total and activated CD4(+) and CD8(+) T cells, effector memory and central memory CD4(+) and CD8(+) T cells, and CD4(+)CD25(high)Foxp3(+) Tregs. Treg function was studied after polyclonal stimulation and antigen specific stimulation with myelin protein peptides in CIDP and HC. There was an increased frequency of monocytes (p = 0.02) and decreased frequency of NK cells (p = 0.02) in CIDP compared with HC but not ON. There were no significant differences in other populations. Treg function was impaired in CIDP compared to HC (p = 0.02), whilst T cell proliferation to myelin protein peptides before and after depletion of Tregs was not different between patients and controls. This study shows increased circulating monocytes and reduced NK cells in CIDP. Although Treg frequency was not altered, we confirm that Tregs display a defect of suppressive function. Myelin protein peptides were not the target of the altered peripheral regulation of the immune response. The mechanisms of peripheral immune tolerance in CIDP and their relevance to the pathogenesis deserve further exploration.

  13. Generation and immunosuppressive functions of p53-induced human adaptive regulatory T cells

    PubMed Central

    Mandapathil, Magis; Visus, Carmen; Finn, Olivera J; Lang, Stephan; Whiteside, Theresa L

    2013-01-01

    Inducible regulatory T cells (iTregs, also called Tr1 cells) are generated in the periphery (circulation or tissue) of cancer patients upon the encounter of naïve CD4+ T cells with tumor-associated antigens. As p53 is often inactivated by genetic or epigenetic events during oncogenesis, p53-induced Tr1 cells might play a key role in establishing immunosuppressive networks in cancer patients. Tr1 cells were generated by co-culturing circulating CD4+CD25− T cells with autologous immature dendritic cells pulsed with a wild-type (WT) p53-derived peptide or an unrelated peptide derived from mucin 1 (MUC1). The Tr1 phenotype and the specificity for p53 of these cells were confirmed by multicolor flow cytometry. Moreover, the Tr1 cell-mediated suppression of T-cell proliferation was evaluated by CFSE-based flow cytometry, while their ability to alter the T-cell cytokine profile by ELISA and Luminex assays. The capacity of p53-induced Tr1 cells to suppress the generation and function of cytotoxic T lymphcoytes (CTLs) was assessed by flow cytometry and ELISPOT. Of note, low doses of the p53-derived peptide (p53low) induced greater numbers of Tr1 cells than the same peptide employed at high doses (p53high). Moreover, Tr1/p53low cells not secreted higher levels of interleukin-10 and transforming growth factor β1, but also mediated more robust suppressive effects on CTL proliferation than Tr1/p53high cells. Tr1/p53low cells, Tr1/p53high cells, as well as Tr1 cells generated with low doses of an unrelated MUC1-derived peptide were equally effective in suppressing the expansion and antitumor activity of p53-reactive CTLs. p53low induced the expansion of highly suppressive p53-reactive Tr1 cells. However, the capacity of these Tr1 cells to suppress the generation and function of p53-reactive CTLs was independent of their antigen-specificity. PMID:24073385

  14. Imbalanced expression of functional surface molecules in regulatory and effector T cells in systemic lupus erythematosus.

    PubMed

    Mesquita, D; Cruvinel, W M; Araujo, J A P; Salmazi, K C; Kallas, E G; Andrade, L E C

    2014-08-01

    Regulatory T (TREG) cells play an important role in maintaining immune tolerance and avoiding autoimmunity. We analyzed the expression of membrane molecules in TREG and effector T cells in systemic lupus erythematosus (SLE). TREG and effector T cells were analyzed for the expression of CTLA-4, PD1, CD28, CD95, GITR, HLA-DR, OX40, CD40L, and CD45RO in 26 patients with active disease, 31 with inactive disease, and 26 healthy controls. TREG cells were defined as CD25+/high CD127 Ø/low FoxP3+, and effector T cells were defined as CD25+CD127+FoxP3 Ø. The ratio of TREG to effector T cells expressing GITR, PD1, HLA-DR, OX40, CD40L, and CD45RO was determined in the three groups. The frequency of TREG cells was similar in patients with SLE and controls. However, SLE patients had a decreased frequency of CTLA-4+TREG and CD28+TREG cells and an increased frequency of CD40L+TREG cells. There was a decrease in the TREG/effector-T ratio for GITR+, HLA-DR+, OX40+, and CD45RO+ cells, and an increased ratio of TREG/effector-T CD40L+ cells in patients with SLE. In addition, CD40L+TREG cell frequency correlated with the SLE disease activity index (P=0.0163). In conclusion, our findings showed several abnormalities in the expression of functionally critical surface molecules in TREG and effector T cells in SLE that may be relevant to the pathogenesis of this disease. PMID:25098715

  15. Imbalanced expression of functional surface molecules in regulatory and effector T cells in systemic lupus erythematosus

    PubMed Central

    Mesquita Júnior, D.; Cruvinel, W.M.; Araujo, J.A.P.; Salmazi, K.C.; Kallas, E.G.; Andrade, L.E.C.

    2014-01-01

    Regulatory T (TREG) cells play an important role in maintaining immune tolerance and avoiding autoimmunity. We analyzed the expression of membrane molecules in TREG and effector T cells in systemic lupus erythematosus (SLE). TREG and effector T cells were analyzed for the expression of CTLA-4, PD1, CD28, CD95, GITR, HLA-DR, OX40, CD40L, and CD45RO in 26 patients with active disease, 31 with inactive disease, and 26 healthy controls. TREG cells were defined as CD25+/highCD127Ø/lowFoxP3+, and effector T cells were defined as CD25+CD127+FoxP3Ø. The ratio of TREG to effector T cells expressing GITR, PD1, HLA-DR, OX40, CD40L, and CD45RO was determined in the three groups. The frequency of TREG cells was similar in patients with SLE and controls. However, SLE patients had a decreased frequency of CTLA-4+TREG and CD28+TREG cells and an increased frequency of CD40L+TREG cells. There was a decrease in the TREG/effector-T ratio for GITR+, HLA-DR+, OX40+, and CD45RO+ cells, and an increased ratio of TREG/effector-T CD40L+ cells in patients with SLE. In addition, CD40L+TREG cell frequency correlated with the SLE disease activity index (P=0.0163). In conclusion, our findings showed several abnormalities in the expression of functionally critical surface molecules in TREG and effector T cells in SLE that may be relevant to the pathogenesis of this disease. PMID:25098715

  16. 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

  17. 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.

  18. 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.

  19. Restimulation After Cryopreservation and Thawing Preserves the Phenotype and Function of Expanded Baboon Regulatory T Cells

    PubMed Central

    Weiner, Joshua; Duran-Struuck, Raimon; Zitsman, Jonah; Buhler, Leo; Sondermeijer, Hugo; McMurchy, Alicia N.; Levings, Megan K.; Sykes, Megan; Griesemer, Adam

    2015-01-01

    Background Regulatory T cells (Treg) are being explored for their tolerance-inducing capabilities. Freezing and banking Treg for future use makes this strategy more clinically applicable. We aimed to devise an improved method of expanding and cryopreserving Treg to maximize yield, purity, and function for use in xenotransplantation. Methods Baboon peripheral blood mononuclear cells were isolated from whole blood. CD4+/CD25hi cells were isolated by flow cytometric sorting and expanded for 26 days in culture with interleukin (IL)-2, anti-CD3 antibody, artificial antigen presenting cells transfected with human CD58, CD32, and CD80, and rapamycin with weekly restimulations. Expanded Treg were frozen for 2 months then thawed and cultured for 48 hours in medium plus (1) no additives, (2) IL-2, (3) anti-CD3 antibody, (4) IL-2 + anti-CD3 antibody, and (5) IL-2 + anti-CD3 antibody + L cells. Phenotype and suppression were assessed after expansion, immediately after thawing, and after culturing. Results We expanded purified baboon Treg more than 10,000-fold. Expanded Treg exhibited excellent suppression in functional assays. Cryopreservation decreased suppressive function without changing phenotype, but increasing amounts of reactivation after thawing produced significantly better viability and suppressive function with a trend toward greater Treg purity. Conclusions We produced numbers of expanded Tregs consistent with clinical use. In contrast to some previous reports, both Treg phenotype and suppressive function were preserved or even enhanced by increasing amounts of restimulation after thawing. Thus, banking of expanded recipient Tregs for in vivo infusion should be possible. PMID:27019869

  20. Characterization of regulatory T cell (Treg) function in patients infected with Leishmania braziliensis.

    PubMed

    Costa, Diego L; Guimarães, Luiz H; Cardoso, Thiago M; Queiroz, Adriano; Lago, Ednaldo; Roselino, Ana M; Bacellar, Olívia; Carvalho, Edgar M; Silva, João S

    2013-12-01

    Th1 immune responses are crucial for eliminating Leishmania parasites. However, despite strong Th1 responses, cutaneous leishmaniasis (CL) patients infected with Leishmania braziliensis develop the disease, while milder Th1 responses are found in sub-clinical (SC) infections. Therefore, CL patients may experience impaired regulatory T cell (Treg) function, causing excessive Th1 responses and tissue damage. To address this hypothesis, we characterized the function of circulating Tregs in L. braziliensis infected CL patients and compared them to Tregs from uninfected controls (UC) and SC subjects. The frequency of circulating Tregs was similar in CL patients, UC and SC subjects. Moreover, CL patients Tregs suppressed lymphocyte proliferation and PBMC pro-inflammatory cytokine production more efficiently than UC Tregs, and also produced higher levels of IL-10 than UC and SC Tregs. Furthermore, PBMC and mononuclear cells from lesions of CL patients responded normally to Treg-induced suppression. Therefore, the lesion development in CL patients infected with L. braziliensis is not associated with impairment in Treg function or failure of cells to respond to immunomodulation. Rather, the increased Treg activation in CL patients may impair parasite elimination, resulting in establishment of chronic infection. Thus, immunological strategies that interfere with this response may improve leishmaniasis treatment.

  1. Regulatory T cell transfer ameliorates lymphedema and promotes lymphatic vessel function

    PubMed Central

    Gousopoulos, Epameinondas; Proulx, Steven T.; Bachmann, Samia B.; Scholl, Jeannette; Dionyssiou, Dimitris; Demiri, Efterpi; Halin, Cornelia; Dieterich, Lothar C.

    2016-01-01

    Secondary lymphedema is a common postcancer treatment complication, but the underlying pathological processes are poorly understood and no curative treatment exists. To investigate lymphedema pathomechanisms, a top-down approach was applied, using genomic data and validating the role of a single target. RNA sequencing of lymphedematous mouse skin indicated upregulation of many T cell–related networks, and indeed depletion of CD4+ cells attenuated lymphedema. The significant upregulation of Foxp3, a transcription factor specifically expressed by regulatory T cells (Tregs), along with other Treg-related genes, implied a potential role of Tregs in lymphedema. Indeed, increased infiltration of Tregs was identified in mouse lymphedematous skin and in human lymphedema specimens. To investigate the role of Tregs during disease progression, loss-of-function and gain-of-function studies were performed. Depletion of Tregs in transgenic mice with Tregs expressing the primate diphtheria toxin receptor and green fluorescent protein (Foxp3-DTR-GFP) mice led to exacerbated edema, concomitant with increased infiltration of immune cells and a mixed TH1/TH2 cytokine profile. Conversely, expansion of Tregs using IL-2/anti–IL-2 mAb complexes significantly reduced lymphedema development. Therapeutic application of adoptively transferred Tregs upon lymphedema establishment reversed all of the major hallmarks of lymphedema, including edema, inflammation, and fibrosis, and also promoted lymphatic drainage function. Collectively, our results reveal that Treg application constitutes a potential new curative treatment modality for lymphedema. PMID:27734032

  2. 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

  3. Functional analysis of microRNA and transcription factor synergistic regulatory network based on identifying regulatory motifs in non-small cell lung cancer

    PubMed Central

    2013-01-01

    Background Lung cancer, especially non-small cell lung cancer, is a leading cause of malignant tumor death worldwide. Understanding the mechanisms employed by the main regulators, such as microRNAs (miRNAs) and transcription factors (TFs), still remains elusive. The patterns of their cooperation and biological functions in the synergistic regulatory network have rarely been studied. Results Here, we describe the first miRNA-TF synergistic regulation network in human lung cancer. We identified important regulators (MYC, NFKB1, miR-590, and miR-570) and significant miRNA-TF synergistic regulatory motifs by random simulations. The two most significant motifs were the co-regulation of miRNAs and TFs, and TF-mediated cascade regulation. We also developed an algorithm to uncover the biological functions of the human lung cancer miRNA-TF synergistic regulatory network (regulation of apoptosis, cellular protein metabolic process, and cell cycle), and the specific functions of each miRNA-TF synergistic subnetwork. We found that the miR-17 family exerted important effects in the regulation of non-small cell lung cancer, such as in proliferation and cell cycle regulation by targeting the retinoblastoma protein (RB1) and forming a feed forward loop with the E2F1 TF. We proposed a model for the miR-17 family, E2F1, and RB1 to demonstrate their potential roles in the occurrence and development of non-small cell lung cancer. Conclusions This work will provide a framework for constructing miRNA-TF synergistic regulatory networks, function analysis in diseases, and identification of the main regulators and regulatory motifs, which will be useful for understanding the putative regulatory motifs involving miRNAs and TFs, and for predicting new targets for cancer studies. PMID:24200043

  4. Ionizing radiation selectively reduces skin regulatory T cells and alters immune function.

    PubMed

    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.

  5. 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

  6. How antigen specificity directs regulatory T-cell function: self, foreign and engineered specificity.

    PubMed

    Hoeppli, R E; MacDonald, K G; Levings, M K; Cook, L

    2016-07-01

    Regulatory T cells (Tregs) are a suppressive subset of T cells that have important roles in maintaining self-tolerance and preventing immunopathology. The T-cell receptor (TCR) and its antigen specificity play a dominant role in the differentiation of cells to a Treg fate, either in the thymus or in the periphery. This review focuses on the effects of the TCR and its antigen specificity on Treg biology. The role of Tregs with specificity for self-antigen has primarily been studied in the context of autoimmune disease, although recent studies have focused on their role in steady-state conditions. The role of Tregs that are specific for pathogens, dietary antigens and allergens is much less studied, although recent data suggest a significant and previously underappreciated role for Tregs during memory responses to a wide range of foreign antigens. The development of TCR- or chimeric antigen receptor (CAR)-transduced T cells means we are now able to engineer Tregs with disease-relevant antigen specificities, paving the way for ensuring specificity with Treg-based therapies. Understanding the role that antigens play in driving the generation and function of Tregs is critical for defining the pathophysiology of many immune-mediated diseases, and developing new therapeutic interventions. PMID:27256587

  7. Cord Blood Derived CD4+CD25high T Cells Become Functional Regulatory T Cells upon Antigen Encounter

    PubMed Central

    Mayer, Elisabeth; Bannert, Christina; Gruber, Saskia; Klunker, Sven; Spittler, Andreas; Akdis, Cezmi A.

    2012-01-01

    Background: Upon antigen exposure, cord blood derived T cells respond to ubiquitous environmental antigens by high proliferation. To date it remains unclear whether these “excessive” responses relate to different regulatory properties of the putative T regulatory cell (Treg) compartment or even expansion of the Treg compartment itself. Methods: Cord blood (>37 week of gestation) and peripheral blood (healthy controls) were obtained and different Treg cell subsets were isolated. The suppressive potential of Treg populations after antigen exposure was evaluated via functional inhibition assays ([3H]thymidine incorporation assay and CFSE staining) with or without allergen stimulation. The frequency and markers of CD4+CD25highFoxP3+ T cells were characterized by mRNA analysis and flow cytometry. Results: Cord blood derived CD4+CD25high cells did not show substantial suppressor capacity upon TCR activation, in contrast to CD4+CD25high cells freshly purified from adult blood. This could not be explained by a lower frequency of FoxP3+CD4+CD25highcells or FOXP3 mRNA expression. However, after antigen-specific stimulation in vitro, these cells showed strong proliferation and expansion and gained potent suppressive properties. The efficiency of their suppressive capacity can be enhanced in the presence of endotoxins. If T-cells were sorted according to their CD127 expression, a tiny subset of Treg cells (CD4+CD25+CD127low) is highly suppressive even without prior antigen exposure. Conclusion: Cord blood harbors a very small subset of CD4+CD25high Treg cells that requires antigen-stimulation to show expansion and become functional suppressive Tregs. PMID:22272233

  8. 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.

  9. The Macrophage Galactose-Type C-Type Lectin (MGL) Modulates Regulatory T Cell Functions

    PubMed Central

    Zizzari, Ilaria Grazia; Martufi, Paola; Battisti, Federico; Rahimi, Hassan; Caponnetto, Salvatore; Bellati, Filippo; Nuti, Marianna

    2015-01-01

    Regulatory T cells (Tregs) are physiologically designed to prevent autoimmune disease and maintain self-tolerance. In tumour microenvironments, their presence is related to a poor prognosis, and they influence the therapeutic outcome due to their capacity to suppress the immune response by cell-cell contact and to release immunosuppressive cytokines. In this study, we demonstrate that Treg immunosuppressive activity can be modulated by the cross-linking between the CD45RA expressed by Tregs and the C-type lectin MGL. This specific interaction strongly decreases the im-munosuppressive activity of Tregs, restoring the proliferative capacity of co-cultured T lymphocytes. This effect can be attributed to changes in CD45RA and TCR signalling through the inhibition of Lck and inactivation of Zap-70, an increase in the Foxp3 methylation status and, ultimately, the reduced production of suppressive cytokines. These results indicate a role of MGL as an immunomodulator within the tumour microenvironment interfering with Treg functions, suggesting its possible use in the design of anticancer vaccines. PMID:26147970

  10. Functional analysis of highly defined, FACS-isolated populations of human regulatory CD4+ CD25+ T cells.

    PubMed

    Baecher-Allan, Clare; Wolf, Elizabeth; Hafler, David A

    2005-04-01

    The importance of CD4+ CD25+ regulatory T cells (Treg) in maintaining immune homeostasis has been directly demonstrated in vivo by their manipulation in a number of autoimmune disease models in the mouse. In the study of human regulatory cells, we have found that the cells that consistently demonstrate the in vitro regulatory activity most similar to that described for murine cells in vitro are best identified by restricting the isolation of CD25+ CD4 T cells to those cells expressing only the highest levels of CD25, representing approximately 2-3% of total CD4 T cells. Thus, it is the CD4+ CD25high subset that exhibits the in vitro characteristics that are identical to the CD4+ CD25+ regulatory cells initially characterized in mice. Furthermore, the cells expressing medium to low levels of CD25 not only do not exhibit suppressive activity directly ex vivo, but also actually contain a significant proportion of CD62L- CD4 T cells which are believed to be in vivo activated T cells. Due to the inherent difficulties in using CD25 as a marker for the purification of Treg cells, the finding that selection of the CD25high subset of CD4+ CD25+ T cells minimizes the co-isolation of contaminating activated CD4 T cells is important for future studies of these Treg cells in human disease. In order to perform these studies, we first had to establish a highly reproducible 'micro in vitro co-culture' assay system to enable the functional analysis of high-purity, but low-yield regulatory populations derived from FACS sorting. With this system in place, we are poised to dissect the potential heterogeneity of mechanisms employed by highly specific subpopulations of CD4+ CD25+ cells.

  11. Pim-2 Kinase Influences Regulatory T Cell Function and Stability by Mediating Foxp3 Protein N-terminal Phosphorylation.

    PubMed

    Deng, Guoping; Nagai, Yasuhiro; Xiao, Yan; Li, Zhiyuan; Dai, Shujia; Ohtani, Takuya; Banham, Alison; Li, Bin; Wu, Shiaw-Lin; Hancock, Wayne; Samanta, Arabinda; Zhang, Hongtao; Greene, Mark I

    2015-08-14

    Regulation of the extent of immune responses is a requirement to maintain self-tolerance and limit inflammatory processes. CD4(+)CD25(+)Foxp3(+) regulatory T (Treg) cells play a role in regulation. The Foxp3 transcription factor is considered a dominant regulator for Treg cell development and function. Foxp3 function itself is directly regulated by multiple posttranslational modifications that occur in response to various external stimuli. The Foxp3 protein is a component of several dynamic macromolecular regulatory complexes. The complexes change constituents over time and through different signals to regulate the development and function of regulatory T cells. Here we identified a mechanism regulating Foxp3 level and activity that operates through discrete phosphorylation. The Pim-2 kinase can phosphorylate Foxp3, leading to decreased suppressive functions of Treg cells. The amino-terminal domain of Foxp3 is modified at several sites by Pim-2 kinase. This modification leads to altered expression of proteins related to Treg cell functions and increased Treg cell lineage stability. Treg cell suppressive function can be up-regulated by either pharmacologically inhibiting Pim-2 kinase activity or by genetically knocking out Pim-2 in rodent Treg cells. Deficiency of Pim-2 activity increases murine host resistance to dextran sodium sulfate-induced colitis in vivo, and a Pim-2 small molecule kinase inhibitor also modified Treg cell functions. Our studies define a pathway for limiting the regulation of Foxp3 function because the Pim-2 kinase represents a potential therapeutic target for modulating the Treg cell suppressive activities in controlling immune responses. PMID:25987564

  12. 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

  13. 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

  14. 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

  15. Phenotypical and functional alterations of CD8 regulatory T cells in primary biliary cirrhosis

    PubMed Central

    Bernuzzi, Francesca; Fenoglio, Daniela; Battaglia, Florinda; Fravega, Marco; Gershwin, M. Eric; Indiveri, Francesco; Ansari, Aftab A.; Podda, Mauro; Invernizzi, Pietro; Filaci, Gilberto

    2011-01-01

    The mechanisms that lead to loss of tolerance in autoimmune disease have remained both elusive and diverse, including both genetic predisposition and generic dysregulation of critical mononuclear cell subsets. In primary biliary cirrhosis (PBC), patients exhibit a multilineage response to the E2 component of pyruvate dehydrogenase involving antibody as well as autoreactive CD4 and CD8 responses. Recent data from murine models of PBC have suggested that a critical mechanism of biliary destruction is mediated by liver-infiltrating CD8 cells. Further, the number of autoreactive liver-infiltrating CD4 and CD8 cells is significantly higher in liver than blood in patients with PBC. Based on this data, we have studied the frequencies and phenotypic characterization of both CD4 and CD8 regulatory T cell components in both patients with PBC and age–sex matched controls. Our data is striking and indicate that CD8 Treg populations from PBC patients, but not controls, have significant phenotypic alterations, including increased expression of CD127 and reduced CD39. Furthermore, in vitro induction of CD8 Tregs by incubation with IL10 is significantly reduced in PBC patients. Importantly, the frequencies of circulating CD4+CD25+ and CD8+ and CD28− T cell subpopulations are not significantly different between patients and controls. In conclusion, these data identify the CD8 Treg subset as a regulatory T cell subpopulation altered in patients with PBC. PMID:20638239

  16. 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

  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. 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

  19. 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

  20. 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

  1. Functional deficit of T regulatory cells in Fulani, an ethnic group with low susceptibility to Plasmodium falciparum malaria

    PubMed Central

    Torcia, Maria G.; Santarlasci, Veronica; Cosmi, Lorenzo; Clemente, AnnMaria; Maggi, Laura; Mangano, Valentina D.; Verra, Federica; Bancone, Germana; Nebie, Issa; Sirima, Bienvenu Sodiomon; Liotta, Francesco; Frosali, Francesca; Angeli, Roberta; Severini, Carlo; Sannella, Anna R.; Bonini, Paolo; Lucibello, Maria; Maggi, Enrico; Garaci, Enrico; Coluzzi, Mario; Cozzolino, Federico; Annunziato, Francesco; Romagnani, Sergio; Modiano, David

    2008-01-01

    Previous interethnic comparative studies on the susceptibility to malaria performed in West Africa showed that Fulani are more resistant to Plasmodium falciparum malaria than are sympatric ethnic groups. This lower susceptibility is not associated to classic malaria-resistance genes, and the analysis of the immune response to P. falciparum sporozoite and blood stage antigens, as well as non-malaria antigens, revealed higher immune reactivity in Fulani. In the present study we compared the expression profile of a panel of genes involved in immune response in peripheral blood mononuclear cells (PBMC) from Fulani and sympatric Mossi from Burkina Faso. An increased expression of T helper 1 (TH1)-related genes (IL-18, IFNγ, and TBX21) and TH2-related genes (IL-4 and GATA3) and a reduced expression of genes distinctive of T regulatory activity (CTLA4 and FOXP3) were observed in Fulani. Microarray analysis on RNA from CD4+CD25+ (T regulatory) cells, performed with a panel of cDNA probes specific for 96 genes involved in immune modulation, indicated obvious differences between the two ethnic groups with 23% of genes, including TGFβ, TGFβRs, CTLA4, and FOXP3, less expressed in Fulani compared with Mossi and European donors not exposed to malaria. As further indications of a low T regulatory cell activity, Fulani showed lower serum levels of TGFβ and higher concentrations of the proinflammatory chemokines CXCL10 and CCL22 compared with Mossi; moreover, the proliferative response of Fulani to malaria antigens was not affected by the depletion of CD25+ regulatory cells whereas that of Mossi was significantly increased. The results suggest that the higher resistance to malaria of the Fulani could derive from a functional deficit of T regulatory cells. PMID:18174328

  2. 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

  3. 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.

  4. A SET-domain-independent role of WRAD complex in cell-cycle regulatory function of mixed lineage leukemia

    PubMed Central

    Ali, Aamir; Veeranki, Sailaja Naga; Tyagi, Shweta

    2014-01-01

    MLL, the trithorax ortholog, is a well-characterized histone 3 lysine 4 methyltransferase that is crucial for proper regulation of the Hox genes during embryonic development. Chromosomal translocations, disrupting the Mll gene, lead to aggressive leukemia with poor prognosis. However, the functions of MLL in cellular processes like cell-cycle regulation are not well studied. Here we show that the MLL has a regulatory role during multiple phases of the cell cycle. RNAi-mediated knockdown reveals that MLL regulates S-phase progression and, proper segregation and cytokinesis during M phase. Using deletions and mutations, we narrow the cell-cycle regulatory role to the C subunit of MLL. Our analysis reveals that the transactivation domain and not the SET domain is important for the S-phase function of MLL. Surprisingly, disruption of MLL–WRAD interaction is sufficient to disrupt proper mitotic progression. These mitotic functions of WRAD are independent of SET domain of MLL and, therefore, define a new role of WRAD in subset of MLL functions. Finally, we address the overlapping and unique roles of the different SET family members in the cell cycle. PMID:24880690

  5. A SET-domain-independent role of WRAD complex in cell-cycle regulatory function of mixed lineage leukemia.

    PubMed

    Ali, Aamir; Veeranki, Sailaja Naga; Tyagi, Shweta

    2014-07-01

    MLL, the trithorax ortholog, is a well-characterized histone 3 lysine 4 methyltransferase that is crucial for proper regulation of the Hox genes during embryonic development. Chromosomal translocations, disrupting the Mll gene, lead to aggressive leukemia with poor prognosis. However, the functions of MLL in cellular processes like cell-cycle regulation are not well studied. Here we show that the MLL has a regulatory role during multiple phases of the cell cycle. RNAi-mediated knockdown reveals that MLL regulates S-phase progression and, proper segregation and cytokinesis during M phase. Using deletions and mutations, we narrow the cell-cycle regulatory role to the C subunit of MLL. Our analysis reveals that the transactivation domain and not the SET domain is important for the S-phase function of MLL. Surprisingly, disruption of MLL-WRAD interaction is sufficient to disrupt proper mitotic progression. These mitotic functions of WRAD are independent of SET domain of MLL and, therefore, define a new role of WRAD in subset of MLL functions. Finally, we address the overlapping and unique roles of the different SET family members in the cell cycle. PMID:24880690

  6. Binding of Hepatitis A Virus to its Cellular Receptor 1 Inhibits T-Regulatory Cell Functions in Humans

    PubMed Central

    Manangeeswaran, Mohanraj; Jacques, Jérôme; Tami, Cecilia; Konduru, Krishnamurthy; Amharref, Nadia; Perrella, Oreste; Casasnovas, Jose M.; Umetsu, Dale T.; DeKruyff, Rosemarie H.; Freeman, Gordon J.; Perrella, Alessandro; Kaplan, Gerardo G.

    2012-01-01

    Background & Aims CD4+ T regulatory (Treg) cells suppress immune responses and control self-tolerance and immunity to pathogens, cancer, and alloantigens. Most pathogens activate Treg cells to minimize immune-mediated tissue damage and prevent clearance, which promotes chronic infections. However, hepatitis A virus (HAV) temporarily inhibits Treg-cell functions. We investigated whether the interaction of HAV with its cellular receptor 1 (HAVCR1), a T-cell co-stimulatory molecule, inhibits the function of Treg cells to control HAV infection. Methods We studied the effects of HAV interaction with HAVCR1 on human T cells using binding, signal transduction, apoptosis, activation, suppression, cytokine production, and confocal microscopy analyses. Cytokines were analyzed in sera from 14 patients with HAV infection using bead arrays. Results Human Treg cells constitutively express HAVCR1. Binding of HAV to HAVCR1 blocked phosphorylation of Akt, prevented activation of the T-cell receptor, and inhibited function of Treg cells. At the peak viremia, patients with acute HAV infection had no Treg-cell suppression function, produced low levels of transforming growth factor-β (TGF–β), which limited leukocyte recruitment and survival, and high levels of interleukin-22, which prevented liver damage. Conclusions Interaction between HAV and its receptor HAVCR1 inhibits Treg cell function, resulting in an immune imbalance that allows viral expansion with limited hepatocellular damage during early stages of infection—a characteristic of HAV pathogenesis. The mechanism by which HAV is cleared in the absence of Treg-cell function could be used as a model to develop anti-cancer therapies, modulate autoimmune and allergic responses, and prevent transplant rejection. PMID:22430395

  7. 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

  8. Deacetylase inhibition increases regulatory T cell function and decreases incidence and severity of collagen-induced arthritis.

    PubMed

    Saouaf, Sandra J; Li, Bin; Zhang, Geng; Shen, Yuan; Furuuchi, Narumi; Hancock, Wayne W; Greene, Mark I

    2009-10-01

    Collagen-induced arthritis (CIA) is an established mouse model of disease with hallmarks of clinical rheumatoid arthritis. Histone/protein deacetylase inhibitors (HDACi) are known to inhibit the pathogenesis of CIA and other models of autoimmune disease, although the mechanisms responsible are unclear. Regulatory T cell (Treg) function is defective in rheumatoid arthritis. FOXP3 proteins in Tregs are present in a dynamic protein complex containing histone acetyltransferase and HDAC enzymes, and FOXP3 itself is acetylated on lysine residues. We therefore investigated the effects of HDACi therapy on regulatory T cell function in the CIA model. Administration of an HDACi, valproic acid (VPA), significantly decreased disease incidence (p<0.005) and severity (p<0.03) in CIA. In addition, VPA treatment increased both the suppressive function of CD4(+)CD25(+) Tregs (p<0.04) and the numbers of CD25(+)FOXP3(+) Tregs in vivo. Hence, clinically approved HDACi such as VPA may limit autoimmune disease in vivo through effects on the production and function of FOXP3(+) Treg cells. PMID:19577564

  9. Deacetylase Inhibition Increases Regulatory T Cell Function and Decreases Incidence and Severity of Collagen-induced Arthritis

    PubMed Central

    Saouaf, Sandra J.; Li, Bin; Zhang, Geng; Shen, Yuan; Furuuchi, Narumi; Hancock, Wayne W.; Greene, Mark I.

    2009-01-01

    Collagen-induced arthritis (CIA) is an established mouse model of disease with hallmarks of clinical rheumatoid arthritis. Histone/protein deacetylase inhibitors (HDACi) are known to inhibit the pathogenesis of CIA and other models of autoimmune disease, although the mechanisms responsible are unclear. Regulatory T cell (Treg) function is defective in rheumatoid arthritis. FOXP3 proteins in Tregs are present in a dynamic protein complex containing histone acetyltransferase and HDAC enzymes, and FOXP3 itself is acetylated on lysine residues. We therefore investigated the effects of HDACi therapy on regulatory T cell function in the CIA model. Administration of an HDACi, valproic acid (VPA), significantly decreased disease incidence (p<0.005) and severity (p<0.03) in CIA. In addition, VPA treatment increased both the suppressive function of CD4+CD25+ Tregs (p<0.04) and the numbers of CD25+FOXP3+ Tregs in vivo. Hence, clinically approved HDACi such as VPA may limit autoimmune disease in vivo through effects on the production and function of FOXP3+ Treg cells. PMID:19577564

  10. 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

  11. Functional analysis of membrane-bound complement regulatory protein on T-cell immune response in ginbuna crucian carp.

    PubMed

    Nur, Indriyani; Abdelkhalek, Nevien K; Motobe, Shiori; Nakamura, Ryota; Tsujikura, Masakazu; Somamoto, Tomonori; Nakao, Miki

    2016-02-01

    Complements have long been considered to be a pivotal component in innate immunity. Recent researches, however, highlight novel roles of complements in T-cell-mediated adaptive immunity. Membrane-bound complement regulatory protein CD46, a costimulatory protein for T cells, is a key molecule for T-cell immunomodulation. Teleost CD46-like molecule, termed Tecrem, has been newly identified in common carp and shown to function as a complement regulator. However, it remains unclear whether Tecrem is involved in T-cell immune response. We investigated Tecrem function related to T-cell responses in ginbuna crucian carp. Ginbuna Tecrem (gTecrem) proteins were detected by immunoprecipitation using anti-common carp Tecrem monoclonal antibody (mAb) and were ubiquitously expressed on blood cells including CD8α(+) and CD4(+) lymphocytes. gTecrem expression on leucocyte surface was enhanced after stimulation with the T-cell mitogen, phytohaemagglutinin (PHA). Coculture with the anti-Tecrem mAb significantly inhibited the proliferative activity of PHA-stimulated peripheral blood lymphocytes, suggesting that cross-linking of Tecrems on T-cells interferes with a signal transduction pathway for T-cell activation. These findings indicate that Tecrem may act as a T-cell moderator and imply that the complement system in teleost, as well as mammals, plays an important role for linking adaptive and innate immunity.

  12. Prolactin down-regulates CD4+CD25hiCD127low/- regulatory T cell function in humans.

    PubMed

    Legorreta-Haquet, M V; Chávez-Rueda, K; Montoya-Díaz, E; Arriaga-Pizano, L; Silva-García, R; Chávez-Sánchez, L; Moreno-Lafont, M; Zenteno-Galindo, E; Blanco-Favela, F

    2012-02-01

    Among its many functions, prolactin (PRL) participates in immune responses and promotes the activation, differentiation and proliferation of T cells. However, the mechanisms by which PRL regulates regulatory T (T(reg)) cells are still unknown. Our goal was to determine whether PRL plays a role in T(reg) function. We measured the expression of PRL and its receptor in T(reg) and effector T (T(eff)) cells from 15 healthy individuals. We also evaluated the functional activity of T(reg) cells by examining proliferation and cytokine secretion in cells activated with anti-CD3/CD28 in the presence or absence of PRL. We report that T(reg) cells constitutively expressed PRL receptor, whereas T(eff) cells required stimulation with anti-CD3/CD28 to induce PRL receptor expression. Expression of PRL was constitutive in both populations. We found that the addition of PRL inhibited the suppressor effect (proliferation) mediated by T(reg) cells in vitro, reducing suppression from 37.4 to 13% when PRL was added to co-cultures of T(reg) and T(eff) cells (P<0.05). Cultures treated with PRL favoured a Th1 cytokine profile, with increased production of TNF and IFNγ. We report for the first time that PRL receptor expression was constitutive in T(reg) cells but not in T(eff) cells, which require stimulation to induce PRL receptor expression. PRL inhibited the suppressive function of T(reg) cells, apparently through the induced secretion of Th1 cytokines.

  13. 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

  14. 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

  15. [Regulatory B cells in human autoimmune diseases].

    PubMed

    Miyagaki, Tomomitsu

    2015-01-01

    B cells have been generally considered to be positive regulators of immune responses because of their ability to produce antigen-specific antibodies and to activate T cells through antigen presentation. Impairment of B cell development and function may cause autoimmune diseases. Recently, specific B cell subsets that can negatively regulate immune responses have been described in mouse models of a wide variety of autoimmune diseases. The concept of those B cells, termed regulatory B cells, is now recognized as important in the murine immune system. Among several regulatory B cell subsets, IL-10-producing regulatory B cells are the most widely investigated. On the basis of discoveries from studies of such mice, human regulatory B cells that produce IL-10 in most cases are becoming an active area of research. There have been emerging data suggesting the importance of human regulatory B cells in various diseases. Revealing the immune regulation mechanisms of human regulatory B cells in human autoimmune diseases could lead to the development of novel B cell targeted therapies. This review highlights the current knowledge on regulatory B cells, mainly IL-10-producing regulatory B cells, in clinical research using human samples. PMID:26725860

  16. A Transendocytosis model of CTLA-4 function predicts its suppressive behaviour on regulatory T cells

    PubMed Central

    Hou, Tie Zheng; Qureshi, Omar S.; Wang, Chun Jing; Baker, Jennifer; Young, Stephen P.; Walker, Lucy S.K.; Sansom, David M.

    2015-01-01

    Manipulation of the CD28/CTLA-4 pathway is at the heart of a number of immunomodulatory approaches used in both autoimmunity and cancer. Whilst it is clear that CTLA-4 is a critical regulator of T cell responses, the immunological contexts in which CTLA-4 controls immune responses are not well defined. Here we show that whilst CD80/CD86-dependent activation of resting human T cells caused extensive T cell proliferation and robust CTLA-4 expression, in this context CTLA-4 blocking antibodies had no impact on the response. In contrast, in settings where CTLA-4+ cells were present as “regulators”, inhibition of resting T cell responses was dependent on CTLA-4 expression and specifically related to the number of antigen presenting cells. At low numbers of APC or low levels of ligand, CTLA-4-dependent suppression was highly effective whereas at higher APC numbers or high levels of ligand, inhibition was lost. Accordingly, the degree of suppression correlated with the level of CD86 expression remaining on the antigen presenting cells. These data reveal clear rules for the inhibitory function of CTLA-4 on Treg which are predicted by its ability to remove ligands from antigen presenting cells. PMID:25632005

  17. Oestradiol potentiates the suppressive function of human CD4+ CD25+ regulatory T cells by promoting their proliferation

    PubMed Central

    Prieto, G Aleph; Rosenstein, Yvonne

    2006-01-01

    CD4+ CD25+ regulatory T (Treg) cells play an important role in the control of the immune system by suppressing the proliferation of effector cells, thereby preventing autoreactive, unnecessary or inconvenient responses. Recently, it has been shown that the number of Treg cells increases during pregnancy, a period with high serum levels of female sex hormones. Oestrogen replacement therapy has been reported to alleviate the symptoms of autoimmune diseases, yet the cellular and molecular mechanisms involved are not fully understood. Here, we show that physiological doses of oestradiol (E2) found during pregnancy, combined with activation through CD3/CD28 engagement, promoted the proliferation of Treg cells without altering their suppressive phenotype. Enhanced suppression was detected when Treg cells were pretreated with the hormone as well as when both cell subpopulations (Treg and T effector) were exposed to E2 throughout the experiment. Together, these data suggest that when combined with an activating stimulus, E2 can modulate the function of human Treg cells by regulating their numbers, and highlight a potential use of E2, or its analogs, to manipulate Treg function. PMID:16630023

  18. 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

  19. IL-12 Converts Foxp3+ Regulatory T Cells to Foxp3+IFN-γ+ T Cells with Inhibitory Functions During Induction of Colitis

    PubMed Central

    Feng, Ting; Cao, Anthony T.; Weaver, Casey T.; Elson, Charles O.; Cong, Yingzi

    2011-01-01

    Regulatory T (Treg) cells are plastic, but the in vivo mechanisms by which they are converted into Foxp3+interferon (IFN)-γ+ T cells, and whether these converted cells retain the ability to inhibit colitis, are not clear. Methods Foxp3+ Treg cells were generated by culture of naïve CD4+ T cells from Foxp3GFP CBir1 T-cell receptor (TCR) transgenic (CBir1-Tg) mice, which are specific for CBir1 flagellin (an immunodominant microbiota antigen), with transforming growth factor (TGF)-β. Foxp3GFP+ CBir1-Tg Treg cells were isolated by fluorescence-activated cell sorting and transferred into TCRβxδ−/− mice. Colitis was induced by transfer of naïve CBir1-Tg CD4+ T cells into immunodeficient mice. Results Microbiota antigen-specific Foxp3+ Treg cells were converted, in the intestine, to IFN-γ+ T-helper (Th)1 cells, interleukin (IL)-17+ Th17 cells, and Foxp3+ T cells that coexpress IFN-γ and/or IL-17. Conversion of Treg cells into IFN-γ-producing Th1 cells and Foxp3+IFN-γ+ T cells required innate cell production of IL-12 in the intestine; blocking IL-12 with an antibody inhibited their conversion to Th1 and Foxp3+IFN-γ+ T cells in the intestines of mice that were recipients of Treg cells. Addition of IL-12, but not IL-23, promoted conversion of Treg cells into Th1 and Foxp3+IFN-γ+ T cells, in vitro. Foxp3+IFN-γ+ T cells had regulatory activity, because they suppressed proliferation of naïve T cells, in vitro, and inhibited induction of colitis by microbiota antigen-specific T cells. IFN-γ+ Th1 cells were not converted into Treg cells; Foxp3+IFN-γ+ T cells differentiated into IFN-γ+ but not Foxp3+ T cells. Conclusions IL-12 promotes conversion of Treg cells into IFN-γ-expressing cells; Foxp3+IFN-γ+ T cells retain their regulatory functions and develop during the transition of Foxp3+ Treg cells into IFN-γ+ Th1 cells. PMID:21419767

  20. Transcription factors RUNX1 and RUNX3 in the induction and suppressive function of Foxp3+ inducible regulatory T cells

    PubMed Central

    Klunker, Sven; Chong, Mark M.W.; Mantel, Pierre-Yves; Palomares, Oscar; Bassin, Claudio; Ziegler, Mario; Rückert, Beate; Meiler, Flurina; Akdis, Mübeccel; Littman, Dan R.

    2009-01-01

    Forkhead box P3 (FOXP3)+CD4+CD25+ inducible regulatory T (iT reg) cells play an important role in immune tolerance and homeostasis. In this study, we show that the transforming growth factor-β (TGF-β) induces the expression of the Runt-related transcription factors RUNX1 and RUNX3 in CD4+ T cells. This induction seems to be a prerequisite for the binding of RUNX1 and RUNX3 to three putative RUNX binding sites in the FOXP3 promoter. Inactivation of the gene encoding RUNX cofactor core-binding factor-β (CBFβ) in mice and small interfering RNA (siRNA)-mediated suppression of RUNX1 and RUNX3 in human T cells resulted in reduced expression of Foxp3. The in vivo conversion of naive CD4+ T cells into Foxp3+ iT reg cells was significantly decreased in adoptively transferred CbfbF/F CD4-cre naive T cells into Rag2−/− mice. Both RUNX1 and RUNX3 siRNA silenced human T reg cells and CbfbF/F CD4-cre mouse T reg cells showed diminished suppressive function in vitro. Circulating human CD4+ CD25high CD127− T reg cells significantly expressed higher levels of RUNX3, FOXP3, and TGF-β mRNA compared with CD4+CD25− cells. Furthermore, FOXP3 and RUNX3 were colocalized in human tonsil T reg cells. These data demonstrate Runx transcription factors as a molecular link in TGF-β–induced Foxp3 expression in iT reg cell differentiation and function. PMID:19917773

  1. 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

  2. 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

  3. Mesenchymal stem cells alleviate atherosclerosis by elevating number and function of CD4(+)CD25 (+)FOXP3 (+) regulatory T-cells and inhibiting macrophage foam cell formation.

    PubMed

    Wang, Zhi Xiao; Wang, Chong Quan; Li, Xiao Yan; Feng, Gao Ke; Zhu, Hong Ling; Ding, Yan; Jiang, Xue Jun

    2015-02-01

    Atherosclerosis is a chronic inflammatory disease characterized by the formation of plaques inside arteries, leading to narrowing and blockage. Potential therapeutic strategies include expanding the population of regulatory T-cells (Tregs) to enhance atheroprotective immunity, and inhibiting the formation of macrophage foam cells. Here, we studied the effect of bone marrow-derived mesenchymal stem cells (BM-MSCs) on atherosclerotic plaque formation in Apolipoprotein E(-/-) (ApoE-KO) mice, and elucidated the underlying mechanism. BM-MSCs isolated from 4 week-old ApoE-KO mice were evaluated by flow cytometry for expression of MSC-specific markers. Thirty eight week-old ApoE-KO mice were randomly divided into three experimental groups (n = 10 per group): 1. MSC group-received BM-MSCs intravenously; 2. Vehicle group-received DMEM; 3. Control group-did not receive any treatment. Administration of MSCs resulted in a marked decrease in the size of atherosclerotic plaques 3 months after treatment. In addition, the number and function of CD4(+)CD25(+)FOXP3(+) regulatory T-cells (Tregs) in cultured splenocytes, and the expression of FOXP3 at both mRNA and protein levels, was significantly increased in the MSC group. In vitro experiments further indicated that the formation of macrophage foam cells was inhibited by treatment with MSCs, accompanied by a significant downregulation in CD36 and scavenger receptor A (SRA). Our findings suggest that MSCs play an atheroprotective role by enhancing the number and function of Tregs and inhibiting the formation of macrophage foam cells. Hence, administration of MSCs to atherosclerotic patients might have significant clinical benefits.

  4. Sodium chloride inhibits the suppressive function of FOXP3+ regulatory T cells.

    PubMed

    Hernandez, Amanda L; Kitz, Alexandra; Wu, Chuan; Lowther, Daniel E; Rodriguez, Donald M; Vudattu, Nalini; Deng, Songyan; Herold, Kevan C; Kuchroo, Vijay K; Kleinewietfeld, Markus; Hafler, David A

    2015-11-01

    FOXP3+ Tregs are central for the maintenance of self-tolerance and can be defective in autoimmunity. In multiple sclerosis and type-1 diabetes, dysfunctional self-tolerance is partially mediated by a population of IFNγ-secreting Tregs. It was previously reported that increased NaCl concentrations promote the induction of proinflammatory Th17 cells and that high-salt diets exacerbate experimental models of autoimmunity. Here, we have shown that increasing NaCl, either in vitro or in murine models via diet, markedly impairs Treg function. NaCl increased IFNγ secretion in Tregs, and reducing IFNγ - either by neutralization with anti-IFNγ antibodies or shRNA-mediated knockdown - restored suppressive activity in Tregs. The heightened IFNγ secretion and loss of Treg function were mediated by the serum/glucocorticoid-regulated kinase (SGK1). A high-salt diet also impaired human Treg function and was associated with the induction of IFNγ-secreting Tregs in a xenogeneic graft-versus-host disease model and in adoptive transfer models of experimental colitis. Our results demonstrate a putative role for an environmental factor that promotes autoimmunity by inducing proinflammatory responses in CD4 effector cells and Treg pathways.

  5. 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

  6. Programmable chemical reaction networks: emulating regulatory functions in living cells using a bottom-up approach.

    PubMed

    van Roekel, Hendrik W H; Rosier, Bas J H M; Meijer, Lenny H H; Hilbers, Peter A J; Markvoort, Albert J; Huck, Wilhelm T S; de Greef, Tom F A

    2015-11-01

    Living cells are able to produce a wide variety of biological responses when subjected to biochemical stimuli. It has become apparent that these biological responses are regulated by complex chemical reaction networks (CRNs). Unravelling the function of these circuits is a key topic of both systems biology and synthetic biology. Recent progress at the interface of chemistry and biology together with the realisation that current experimental tools are insufficient to quantitatively understand the molecular logic of pathways inside living cells has triggered renewed interest in the bottom-up development of CRNs. This builds upon earlier work of physical chemists who extensively studied inorganic CRNs and showed how a system of chemical reactions can give rise to complex spatiotemporal responses such as oscillations and pattern formation. Using purified biochemical components, in vitro synthetic biologists have started to engineer simplified model systems with the goal of mimicking biological responses of intracellular circuits. Emulation and reconstruction of system-level properties of intracellular networks using simplified circuits are able to reveal key design principles and molecular programs that underlie the biological function of interest. In this Tutorial Review, we present an accessible overview of this emerging field starting with key studies on inorganic CRNs followed by a discussion of recent work involving purified biochemical components. Finally, we review recent work showing the versatility of programmable biochemical reaction networks (BRNs) in analytical and diagnostic applications.

  7. 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

  8. Regulatory cells and transplantation tolerance.

    PubMed

    Cobbold, Stephen P; Waldmann, Herman

    2013-06-01

    Transplantation tolerance is a continuing therapeutic goal, and it is now clear that a subpopulation of T cells with regulatory activity (Treg) that express the transcription factor foxp3 are crucial to this aspiration. Although reprogramming of the immune system to donor-specific transplantation tolerance can be readily achieved in adult mouse models, it has yet to be successfully translated in human clinical practice. This requires that we understand the fundamental mechanisms by which donor antigen-specific Treg are induced and function to maintain tolerance, so that we can target therapies to enhance rather than impede these regulatory processes. Our current understanding is that Treg act via numerous molecular mechanisms, and critical underlying components such as mTOR inhibition, are only now emerging. PMID:23732858

  9. T Regulatory Cell Numbers and Function in Patients with Antibiotic-Refractory or Antibiotic-Responsive Lyme Arthritis

    PubMed Central

    Shen, Shiqian; Shin, Junghee J.; Strle, Klemen; McHugh, Gail; Li, Xin; Glickstein, Lisa J.; Drouin, Elise E.; Steere, Allen C.

    2010-01-01

    Objective In a murine model of antibiotic-refractory Lyme arthritis, the numbers of T regulatory cells (Treg) are dramatically reduced. Our goal was to examine Treg numbers and function in human patients with antibiotic-refractory Lyme arthritis. Methods CD4+ T cell subsets were enumerated in peripheral blood (PB) and synovial fluid (SF) in 12 patients with antibiotic-refractory arthritis and 6 with antibiotic-responsive arthritis. Treg function was examined using Borrelia-specific and non-specific Treg proliferation assays. Results In both patient groups, IFN-γ+ TH1 cells in SF were abundant and enriched (~50% of CD4+ T cells). In patients with antibiotic-refractory arthritis, the median percentages of FoxP3+ Treg were significantly higher in SF than PB (12% versus 6%) (P<0.01) or in SF in patients with antibiotic-responsive arthritis (12% versus 5%) (P=0.04). Moreover, in the refractory group, a higher percentage of Treg in SF correlated with a shorter duration to resolution of arthritis (r = −0.74, P = 0.006). In contrast, patients with fewer Treg had suboptimal responses to DMARDs and longer duration of arthritis after antibiotics, and they often required synovectomies for arthritis resolution. In each group, Treg in SF dampened B. burgdorferi-specific proliferative responses, and in 2 patients with refractory arthritis, Treg were functional in non-specific suppression assays. Conclusions Treg were functional in patients with antibiotic-refractory arthritis, and in some patients, large numbers of these cells in SF appeared to participate in arthritis resolution. However, as in the murine model, patients with refractory arthritis and low numbers of Treg seemed unable to resolve synovial inflammation. PMID:20506317

  10. Bcl6 Controls the Th2 Inflammatory Activity of Regulatory T Cells by Repressing Gata3 Function

    PubMed Central

    Sawant, Deepali V.; Sehra, Sarita; Nguyen, Evelyn T.; Jadhav, Rohit; Englert, Kate; Shinnakasu, Ryo; Hangoc, Giao; Broxmeyer, Hal E.; Nakayama, Toshinori; Perumal, Narayanan B.; Kaplan, Mark H.; Dent, Alexander L.

    2012-01-01

    The transcriptional repressor Bcl6 is a critical arbiter of T helper cell fate, promoting the follicular helper (Tfh) lineage while repressing other T helper cell lineages. Bcl6-deficient (Bcl6-/-) mice develop a spontaneous and severe Th2-type inflammatory disease, thus warranting assessment of Bcl6 in Treg cell function. Bcl6-/- Tregs were competent at suppressing T cell proliferation in vitro and Th1-type colitogenic T cell responses in vivo. In contrast, Bcl6-/- Treg cells strongly exacerbated lung inflammation in a model of allergic airway disease, and promoted higher Th2 responses, including systemic up-regulation of microRNA-21. Further, Bcl6-/- Tregs were selectively impaired at controlling Th2 responses but not Th1 and Th17 responses, in mixed chimeras of Bcl6-/- bone marrow with Foxp3-/- bone marrow. Bcl6-/- Tregs displayed increased levels of the Th2 transcription factor Gata3 and other Th2 and Treg genes. Bcl6 potently repressed Gata3 transcriptional transactivation, providing a mechanism for the increased expression of Th2 genes by Bcl6-/- Tregs. Gata3 has a critical role in regulating Foxp3 expression and functional fitness of Tregs, however, the signal that regulates Gata3 and restricts its transactivation of Th2 cytokines in Tregs has remained unexplored. Our results identify Bcl6 as an essential transcription factor regulating Gata3 activity in Tregs. Thus, Bcl6 represents a crucial regulatory layer in the Treg functional program, required for specific suppression of Gata3 and Th2 effector responses by Tregs. PMID:23053511

  11. 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

  12. 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

  13. 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.

  14. 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

  15. 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

  16. 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

  17. Effector and regulatory T-cell function is differentially regulated by RelB within antigen-presenting cells during GVHD.

    PubMed

    MacDonald, Kelli P A; Kuns, Rachel D; Rowe, Vanessa; Morris, Edward S; Banovic, Tatjana; Bofinger, Helen; O'Sullivan, Brendan; Markey, Kate A; Don, Alistair L; Thomas, Ranjeny; Hill, Geoffrey R

    2007-06-01

    Antigen-presenting cells (APCs) are critical for the initiation of graft-versus-host disease (GVHD), although the responsible APC subset and molecular mechanisms remain unclear. Because dendritic cells (DCs) are the most potent APCs and the NF-kB/Rel family member RelB is associated with DC maturation and potent APC function, we examined their role in GVHD. Within 4 hours of total body irradiation, RelB nuclear translocation was increased and restricted to CD11c(hi) DCs within the host APC compartment. Furthermore, the transient depletion of CD11c(hi) donor DCs that reconstitute in the second week after transplantation resulted in a transient decrease in GVHD severity. By using RelB(-/-) bone marrow chimeras as transplant recipients or RelB(-/-) donor bone marrow, we demonstrate that the induction and maintenance of GVHD is critically dependent on this transcription factor within both host and donor APCs. Critically, RelB within APCs was required for the expansion of donor helper T cell type 1 (Th1) effectors and subsequent alloreactivity, but not the peripheral expansion or function of donor FoxP3(+) regulatory T cells. These data suggest that the targeted inhibition of nuclear RelB translocation within APCs represents an attractive therapeutic strategy to dissociate effector and regulatory T-cell function in settings of Th1-mediated tissue injury.

  18. Autologous stem cell transplantation aids autoimmune patients by functional renewal and TCR diversification of regulatory T cells.

    PubMed

    Delemarre, Eveline M; van den Broek, Theo; Mijnheer, Gerdien; Meerding, Jenny; Wehrens, Ellen J; Olek, Sven; Boes, Marianne; van Herwijnen, Martijn J C; Broere, Femke; van Royen, Annet; Wulffraat, Nico M; Prakken, Berent J; Spierings, Eric; van Wijk, Femke

    2016-01-01

    Autologous hematopoietic stem cell transplantation (HSCT) is increasingly considered for patients with severe autoimmune diseases whose prognosis is poor with standard treatments. Regulatory T cells (Tregs) are thought to be important for disease remission after HSCT. However, eliciting the role of donor and host Tregs in autologous HSCT is not possible in humans due to the autologous nature of the intervention. Therefore, we investigated their role during immune reconstitution and re-establishment of immune tolerance and their therapeutic potential following congenic bone marrow transplantation (BMT) in a proteoglycan-induced arthritis (PGIA) mouse model. In addition, we determined Treg T-cell receptor (TCR) CDR3 diversity before and after HSCT in patients with juvenile idiopathic arthritis and juvenile dermatomyositis. In the PGIA BMT model, after an initial predominance of host Tregs, graft-derived Tregs started dominating and displayed a more stable phenotype with better suppressive capacity. Patient samples revealed a striking lack of diversity of the Treg repertoire before HSCT. This ameliorated after HSCT, confirming reset of the Treg compartment following HSCT. In the mouse model, a therapeutic approach was initiated by infusing extra Foxp3(GFP+) Tregs during BMT. Infusion of Foxp3(GFP+) Tregs did not elicit additional clinical improvement but conversely delayed reconstitution of the graft-derived T-cell compartment. These data indicate that HSCT-mediated amelioration of autoimmune disease involves renewal of the Treg pool. In addition, infusion of extra Tregs during BMT results in a delayed reconstitution of T-cell compartments. Therefore, Treg therapy may hamper development of long-term tolerance and should be approached with caution in the clinical autologous setting. PMID:26480932

  19. 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.

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

    PubMed Central

    Shevach, Ethan M

    2008-01-01

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

  1. The retinoblastoma family of proteins and their regulatory functions in the mammalian cell division cycle

    PubMed Central

    2012-01-01

    The retinoblastoma (RB) family of proteins are found in organisms as distantly related as humans, plants, and insects. These proteins play a key role in regulating advancement of the cell division cycle from the G1 to S-phases. This is achieved through negative regulation of two important positive regulators of cell cycle entry, E2F transcription factors and cyclin dependent kinases. In growth arrested cells transcriptional activity by E2Fs is repressed by RB proteins. Stimulation of cell cycle entry by growth factor signaling leads to activation of cyclin dependent kinases. They in turn phosphorylate and inactivate the RB family proteins, leading to E2F activation and additional cyclin dependent kinase activity. This propels the cell cycle irreversibly forward leading to DNA synthesis. This review will focus on the basic biochemistry and cell biology governing the regulation and activity of mammalian RB family proteins in cell cycle control. PMID:22417103

  2. CD4+ CD25+ T cells with the phenotypic and functional characteristics of regulatory T cells are enriched in the synovial fluid of patients with rheumatoid arthritis.

    PubMed

    Möttönen, M; Heikkinen, J; Mustonen, L; Isomäki, P; Luukkainen, R; Lassila, O

    2005-05-01

    CD4(+) CD25(+) regulatory T (T(reg)) cells play a critical role in the maintenance of peripheral tolerance and the prevention of autoimmunity. In the present study, we have explored the characteristics of CD4(+) CD25(+) T(reg) cells in patients with rheumatoid arthritis (RA). The frequency and phenotype of CD4(+) CD25(+) T cells in paired samples of synovial fluid (SF) and peripheral blood (PB) from patients with RA and PB from normal controls were analysed. An increased frequency of CD4+ cells T cells expressing CD25 was detected in SF compared to PB from patients with RA. No significant difference was observed in the numbers of CD4(+) CD25(+) T cells in PB from patients and controls. SF CD4(+) CD25(+) T cells expressed high levels of CTLA-4 (both surface and intracellular), GITR and OX40, as well as Foxp3 transcripts. Functionally, SF CD4(+) CD25(+) T cells were impaired in their proliferative responses and could suppress the proliferation of their CD4(+) CD25(-) counterparts. In conclusion, these data demonstrate that CD4(+) CD25(+) T(reg) cells, with the potential to regulate the function of effector T cells and antigen-presenting cells, accumulate in the synovium of patients with RA.

  3. 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

  4. 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

  5. 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

  6. Regulatory roles of tumor-suppressor proteins and noncoding RNA in cancer and normal cell functions.

    PubMed

    Garen, Alan; Song, Xu

    2008-04-15

    We describe a mechanism for reversible regulation of gene transcription, mediated by a family of tumor-suppressor proteins (TSP) containing a DNA-binding domain (DBD) that binds to a gene and represses transcription, and RNA-binding domains (RBDs) that bind RNA, usually a noncoding RNA (ncRNA), forming a TSP/RNA complex that releases the TSP from a gene and reverses repression. This mechanism appears to be involved in the regulation of embryogenesis, oncogenesis, and steroidogenesis. Embryonic cells express high levels of RNA that bind to a TSP and prevent repression of proto-oncogenes that drive cell proliferation. The level of the RNA subsequently decreases in most differentiating cells, enabling a TSP to repress proto-oncogenes and stop cell proliferation. Oncogenesis can result when the level of the RNA fails to decrease in a proliferating cell or increases in a differentiated cell. This mechanism also regulates transcription of P450scc, the first gene in the steroidogenic pathway.

  7. 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.

  8. 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

  9. Evaluation of transcription factor that regulates T helper 17 and regulatory T cells function in periodontal health and disease

    PubMed Central

    Karthikeyan, B.; Talwar; Arun, K. V.; Kalaivani, S.

    2015-01-01

    Background: The differentiation of naοve T helper (Th) cells towards Th17 and regulatory T cells (Treg) is regulated by the transcription factors retinoic acid related orphan receptor gamma transcription (RORYt) and Forkhead box p3 (Foxp3), respectively. An imbalance in the activity of these transcription factors could result in the dysregulation of Th17/Treg response. Materials and Methods: Total RNA was isolated from gingival tissue obtained from 10 patients, each from periodontally healthy and diseased groups. The gene expression of RORYt and Foxp3 was measured by real-time reverse transcription polymerization chain reaction using total RNA isolates from gingival tissues group when compared to the healthy group, while Foxp3 demonstrated a 6.68 ± 0.03 fold decrease of expression in diseased group when compared to healthy group. Conclusion: Our results indicate a functional imbalance in the Th17/Treg response in periodontal disease group when compared to the periodontally healthy group. PMID:26538941

  10. Positive and Negative Regulatory Mechanisms for Fine-Tuning Cellularity and Functions of Medullary Thymic Epithelial Cells

    PubMed Central

    Akiyama, Taishin; Tateishi, Ryosuke; Akiyama, Nobuko; Yoshinaga, Riko; Kobayashi, Tetsuya J.

    2015-01-01

    Self-tolerant T cells and regulatory T cells develop in the thymus. A wide variety of cell–cell interactions in the thymus is required for the differentiation, proliferation, and repertoire selection of T cells. Various secreted and cell surface molecules expressed in thymic epithelial cells (TECs) mediate these processes. Moreover, cytokines expressed by cells of hematopoietic origin regulate the cellularity of TECs. Tumor necrosis factor (TNF) family RANK ligand, lymphotoxin, and CD40 ligand, expressed in T cells and innate lymphoid cells (ILCs), promote the differentiation and proliferation of medullary TECs (mTECs) that play critical roles in the induction of immune tolerance. A recent study suggests that interleukin-22 (IL-22) produced by ILCs promotes regeneration of TECs after irradiation. Intriguingly, tumor growth factor-β and osteoprotegerin limit cellularity of mTECs, thereby attenuating regulatory T cell generation. We will review recent insights into the molecular basis for cell–cell interactions regulating differentiation and proliferation of mTECs and also discuss about a perspective on use of mathematical models for understanding this complicated system. PMID:26441966

  11. Regulatory T cells and tumor immunity.

    PubMed

    Chattopadhyay, Subhasis; Chakraborty, Nitya G; Mukherji, Bijay

    2005-12-01

    Central deletion of "self-reactive" T cells has been the textbook paradigm for inducing "self-tolerance" in the periphery and the concept of a role of T cell-mediated suppression in this process has long been controversial. A decisive shift in the opinion on suppressor T cells has lately occurred with the observations of Sakaguchi's group that linked a class of CD4+CD25+ T cells to the prevention of autoimmunity from neonatal thymectomy in mice. These CD4+CD25+ T cells have been named T regulatory (Treg) cells. They are believed to be selected in the thymus as an anti-self repertoire. Hence they were referred to as natural T regulatory (nTreg) cells. Presently, in addition to their role in autoimmunity, they are believed to exert regulatory function in infection, in transplantation immunity as well as in tumor immunity. In contrast to these nTreg cells, another class of CD4+ Treg cells also exercises regulatory function in the periphery. These Treg cells are also CD4+ T cells and after activation they also become phenotypically CD4+CD25+. They are, however induced in the periphery as Treg cells. Hence, they are termed as induced Treg (iTreg) cells. There are major differences in the biology of these two types of Treg cells. They differ in their requirements for activation and in their mode of action. Nonetheless, evidence indicates that both nTreg cells and iTreg cells are involved in the control of tumor immunity. The question of how to circumvent their regulatory constraints, therefore, has become a major challenge for tumor immunologists. PMID:15868167

  12. 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

  13. Regulatory T cells: balancing protection versus pathology.

    PubMed

    Rakebrandt, Nikolas; Littringer, Katharina; Joller, Nicole

    2016-01-01

    Foxp3+ regulatory T cells (Tregs) maintain immune tolerance, prevent autoimmunity and modulate immune responses during infection and cancer. Recent studies have revealed considerable heterogeneity and plasticity within the Treg compartment, depending on the immunological context, which may result in Tregs losing their suppressive function in inflammatory environments. We review how dysfunctional Tregs contribute to disease pathogenesis in inflammatory conditions and how inappropriate regulatory responses may hamper protective immunity in the context of infection and cancer. We also discuss how Tregs might be targeted therapeutically to re-establish a proper balance between regulatory and effector responses in autoimmunity, infections, and cancer. PMID:27497235

  14. 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

  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. Distinct Effects of IL-18 on the Engraftment and Function of Human Effector CD8+ T Cells and Regulatory T Cells

    PubMed Central

    Danet-Desnoyers, Gwenn; Liu, Ronghua; Jiang, Shuguang; Albelda, Steven M.; Golovina, Tatiana; Coukos, George; Riley, James L.; Jonak, Zdenka L.; June, Carl H.

    2008-01-01

    IL-18 has pleotropic effects on the activation of T cells during antigen presentation. We investigated the effects of human IL-18 on the engraftment and function of human T cell subsets in xenograft mouse models. IL-18 enhanced the engraftment of human CD8+ effector T cells and promoted the development of xenogeneic graft versus host disease (GVHD). In marked contrast, IL-18 had reciprocal effects on the engraftment of CD4+CD25+Foxp3+ regulatory T cells (Tregs) in the xenografted mice. Adoptive transfer experiments indicated that IL-18 prevented the suppressive effects of Tregs on the development of xenogeneic GVHD. The IL-18 results were robust as they were observed in two different mouse strains. In addition, the effects of IL-18 were systemic as IL-18 promoted engraftment and persistence of human effector T cells and decreased Tregs in peripheral blood, peritoneal cavity, spleen and liver. In vitro experiments indicated that the expression of the IL-18Rα was induced on both CD4 and CD8 effector T cells and Tregs, and that the duration of expression was less sustained on Tregs. These preclinical data suggest that human IL-18 may have use as an adjuvant for immune reconstitution after cytotoxic therapies, and to augment adoptive immunotherapy, donor leukocyte infusions, and vaccine strategies. PMID:18818761

  17. Dihydroartemisinin ameliorates inflammatory disease by its reciprocal effects on Th and regulatory T cell function via modulating the mammalian target of rapamycin pathway.

    PubMed

    Zhao, Yan G; Wang, Yunqi; Guo, Zengli; Gu, Ai-di; Dan, Han C; Baldwin, Albert S; Hao, Weidong; Wan, Yisong Y

    2012-11-01

    Dihydroartemisinin (DHA) is an important derivative of the herb medicine Artemisia annua L., used in ancient China. DHA is currently used worldwide to treat malaria by killing malaria-causing parasites. In addition to this prominent effect, DHA is thought to regulate cellular functions, such as angiogenesis, tumor cell growth, and immunity. Nonetheless, how DHA affects T cell function remains poorly understood. We found that DHA potently suppressed Th cell differentiation in vitro. Unexpectedly, however, DHA greatly promoted regulatory T cell (Treg) generation in a manner dependent on the TGF-βR:Smad signal. In addition, DHA treatment effectively reduced onset of experimental autoimmune encephalomyelitis (EAE) and ameliorated ongoing EAE in mice. Administration of DHA significantly decreased Th but increased Tregs in EAE-inflicted mice, without apparent global immune suppression. Moreover, DHA modulated the mammalian target of rapamycin (mTOR) pathway, because mTOR signal was attenuated in T cells upon DHA treatment. Importantly, enhanced Akt activity neutralized DHA-mediated effects on T cells in an mTOR-dependent fashion. This study therefore reveals a novel immune regulatory function of DHA in reciprocally regulating Th and Treg cell generation through the modulating mTOR pathway. It addresses how DHA regulates immune function and suggests a new type of drug for treating diseases in which mTOR activity is to be tempered. PMID:22993204

  18. 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.

  19. Regulatory T Cell Deficiency and Immune dysregulation, Polyendocrinopathy, Enteropathy, X-Linked-Like Disorder Due to Loss of Function Mutations in LRBA

    PubMed Central

    Charbonnier, Louis-Marie; Janssen, Erin; Chou, Janet; Ohsumi, Toshiro K.; Keles, Sevgi; Hsu, Joyce T.; Massaad, Michel J.; Garcia-Lloret, Maria; Hanna-Wakim, Rima; Dbaibo, Ghassan; Alangari, Abdullah A.; Alsultan, Abdulrahman; Al-Zahrani, Daifulah; Geha, Raif S.; Chatila, Talal A.

    2014-01-01

    Background A number of heritable immune dysregulatory diseases result from defects affecting T regulatory (TR) cell development and/or function. They include Immune dysregulation, Polyendocrinopathy, Enteropathy, X-Linked (IPEX), due to mutations in FOXP3, and IPEX-like disorders caused by mutations in IL2RA, STAT5b and STAT1. However, the genetic defects underlying many cases of IPEX-like disorders remain unknown. Objective We sought to identify the genetic abnormalities in subjects with idiopathic IPEX-like disorders. Methods We performed whole exome and targeted gene sequencing, and phenotypic and functional analyses of TR cells. Results A child who presented with an IPEX-like syndrome and severe TR cell deficiency was found to harbor a nonsense mutation in the gene encoding LPS-responsive beige-like anchor (LRBA), previously implicated as cause of common variable immunodeficiency with autoimmunity. Analysis of subjects with LRBA deficiency revealed marked TR cell depletion, profoundly decreased expression of canonical TR cell markers, including FOXP3, CD25, Helios, and CTLA4 and impaired TR cell-mediated suppression. There was skewing in favor of memory T cells and intense autoantibody production with marked expansion of T follicular helper and contraction of T follicular regulatory cells. Whereas the frequency of recent thymic emigrants and the differentiation of induced TR cells were normal, LRBA-deficient T cells exhibited increased apoptosis and reduced activities of the metabolic sensors mammalian target of rapamycin 1 and 2 complexes. Conclusion LRBA deficiency is a novel cause of IPEX-like syndrome and TR cell deficiency associated with metabolic dysfunction and increased apoptosis of TR cells. PMID:25468195

  20. 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

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

    PubMed Central

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

    2015-01-01

    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

  2. PD-1 and Tim-3 pathways are associated with regulatory CD8+ T-cell function in decidua and maintenance of normal pregnancy.

    PubMed

    Wang, S-C; Li, Y-H; Piao, H-L; Hong, X-W; Zhang, D; Xu, Y-Y; Tao, Y; Wang, Y; Yuan, M-M; Li, D-J; Du, M-R

    2015-01-01

    CD8+ T cells are critical in the balance between fetal tolerance and antiviral immunity. T-cell immunoglobulin mucin-3 (Tim-3) and programmed cell death-1 (PD-1) are important negative immune regulatory molecules involved in viral persistence and tumor metastasis. Here, we demonstrate that Tim-3+PD-1+CD8+ T cells from decidua greatly outnumbered those from peripheral blood during human early pregnancy. Co-culture of trophoblasts with CD8+ T cells upregulated PD-1+ and/or Tim-3+ immune cells. Furthermore, the population of CD8+ T cells co-expressing PD-1 and Tim-3 was enriched within the intermediate memory subset in decidua. This population exhibited high proliferative activity and Th2-type cytokine producing capacity. Blockade of Tim-3 and PD-1 resulted in decreased in vitro proliferation and Th2-type cytokine production while increased trophoblast killing and IFN-γ producing capacities of CD8+ T cells. Pregnant CBA/J females challenged with Tim-3 and/or PD-1 blocking antibodies were more susceptible to fetal loss, which was associated with CD8+ T-cell dysfunction. Importantly, the number and function of Tim-3+PD-1+CD8+ T cells in decidua were significantly impaired in miscarriage. These findings underline the important roles of Tim-3 and PD-1 pathways in regulating decidual CD8+ T-cell function and maintaining normal pregnancy.

  3. Phenotypic and functional characterization of a CD4+ CD25high FOXP3high regulatory T-cell population in the dog

    PubMed Central

    Pinheiro, Dammy; Singh, Yogesh; Grant, Charlotte R; Appleton, Richard C; Sacchini, Flavio; Walker, Kate R L; Chadbourne, Alden H; Palmer, Charlotte A; Armitage-Chan, Elizabeth; Thompson, Ian; Williamson, Lina; Cunningham, Fiona; Garden, Oliver A

    2011-01-01

    Relatively little is known about regulatory T (Treg) cells and their functional responses in dogs. We have used the cross-reactive anti-mouse/rat Foxp3 antibody clone FJK-16s to identify a population of canine CD4+ FOXP3high T cells in both the peripheral blood (PB) and popliteal lymph node (LN). FOXP3+ cells in both PB and LN yielded positive staining with the newly developed anti-murine/human Helios antibody clone 22F6, consistent with the notion that they were naturally occurring Treg cells. Stimulation of mononuclear cells of LN origin with concanavalin A (Con A) in vitro yielded increased proportions and median fluorescence intensity of FOXP3 expression by both CD4+ and CD8+ T cells. Removal of the Con A and continued culture disclosed a CD4+ FOXP3high population, distinct from the CD4+ FOXP3intermediate T cells; very few CD8+ FOXP3high T cells were observed, though CD8+ FOXP3intermediate cells were present in equal abundance to CD4+ FOXP3intermediate cells. The CD4+ FOXP3high T cells were thought to represent activated Treg cells, in contrast to the FOXP3intermediate cells, which were thought to be a more heterogeneous population comprising predominantly activated conventional T cells. Co-staining with interferon-γ (IFN-γ) supported this notion, because the FOXP3high T cells were almost exclusively IFN-γ−, whereas the FOXP3intermediate cells expressed a more heterogeneous IFN-γ phenotype. Following activation of mononuclear cells with Con A and interleukin-2, the 5% of CD4+ T cells showing the highest CD25 expression (CD4+ CD25high) were enriched in cells expressing FOXP3. These cells were anergic in vitro, in contrast to the 20% of CD4+ T cells with the lowest CD25 expression (CD4+ CD25−), which proliferated readily. The CD4+ CD25high FOXP3high T cells were able to suppress the proliferation of responder CD4+ T cells in vitro, in contrast to the CD4+ CD25− cells, which showed no regulatory properties. PMID:20880379

  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. 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.

  7. A new effect of IL-4 on human γδ T cells: promoting regulatory Vδ1 T cells via IL-10 production and inhibiting function of Vδ2 T cells

    PubMed Central

    Mao, Yujia; Yin, Shanshan; Zhang, Jianmin; Hu, Yu; Huang, Bo; Cui, Lianxian; Kang, Ning; He, Wei

    2016-01-01

    Interleukin 4 (IL-4) has a variety of immune functions, including helper T-cell (Th-cell) differentiation and innate immune-response processes. However, the impact of IL-4 on gamma delta (γδ) T cells remains unclear. In this study, we investigate the effects of IL-4 on the activation and proliferation of γδ T cells and the balance between variable delta 1 (Vδ1) and Vδ2 T cells in humans. The results show that IL-4 inhibits the activation of γδ T cells in the presence of γδ T-cell receptor (TCR) stimulation in a STAT6-dependent manner. IL-4 promoted the growth of activated γδ T cells and increased the levels of Vδ1 T cells, which in turn inhibited Vδ2 T-cell growth via significant IL-10 secretion. Vδ1 T cells secreted significantly less interferon gamma (IFNγ) and more IL-10 relative to Vδ2. Furthermore, Vδ1 T cells showed relatively low levels of Natural Killer Group 2D (NKG2D) expression in the presence of IL-4, suggesting that Vδ1 T cells weaken the γδ T cell-mediated anti-tumor immune response. For the first time, our findings demonstrate a negative regulatory role of IL-4 in γδ T cell-mediated anti-tumor immunity. PMID:25942601

  8. 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

  9. Genetic polymorphism study of regulatory B cell molecules and cellular immunity function in an adult patient with Common Variable Immunodeficiency

    PubMed Central

    Sarantopoulos, A; Tselios, K; Skendros, P; Bougiouklis, D; Theodorou, I; Boura, P

    2008-01-01

    A 43 year old female patient presented for recurrent bacterial lower respiratory infections. A research for immunodeficiency status revealed total hypogammaglobulinemia, reduced IgG1, IgG2, IgG3 subclass levels, and low number of B lymphocytes (CD19+). Common Variable Immunodeficiency (CVID) 11.2 category was diagnosed according to recent criteria of primary immunodeficiencies (PID). Further immunological study consisting of genetic polymorphism of genes relating to differentiation, activation and function of B cells (ICOS, BAFF receptor BCMA and TACI) was performed, which did not reveal any related mutations. T cell parameters and Th1/Th2 cytokine network did not show any disturbances. It is postulated that probable endstage B cell differentiation defects should be investigated. The patient receives IVIGs replacement thereafter and the rate and severity of infections have significantly improved. PMID:18923749

  10. A Novel Regulatory Function of Sweet Taste-Sensing Receptor in Adipogenic Differentiation of 3T3-L1 Cells

    PubMed Central

    Masubuchi, Yosuke; Nakagawa, Yuko; Ma, Jinhui; Sasaki, Tsutomu; Kitamura, Tadahiro; Yamamoto, Yoritsuna; Kurose, Hitoshi; Kojima, Itaru; Shibata, Hiroshi

    2013-01-01

    Background Sweet taste receptor is expressed not only in taste buds but also in nongustatory organs such as enteroendocrine cells and pancreatic beta-cells, and may play more extensive physiological roles in energy metabolism. Here we examined the expression and function of the sweet taste receptor in 3T3-L1 cells. Methodology/Principal Findings In undifferentiated preadipocytes, both T1R2 and T1R3 were expressed very weakly, whereas the expression of T1R3 but not T1R2 was markedly up-regulated upon induction of differentiation (by 83.0 and 3.8-fold, respectively at Day 6). The α subunits of Gs (Gαs) and G14 (Gα14) but not gustducin were expressed throughout the differentiation process. The addition of sucralose or saccharin during the first 48 hours of differentiation considerably reduced the expression of peroxisome proliferator activated receptor γ (PPARγ and CCAAT/enhancer-binding protein α (C/EBPα at Day 2, the expression of aP2 at Day 4 and triglyceride accumulation at Day 6. These anti-adipogenic effects were attenuated by short hairpin RNA-mediated gene-silencing of T1R3. In addition, overexpression of the dominant-negative mutant of Gαs but not YM-254890, an inhibitor of Gα14, impeded the effects of sweeteners, suggesting a possible coupling of Gs with the putative sweet taste-sensing receptor. In agreement, sucralose and saccharin increased the cyclic AMP concentration in differentiating 3T3-L1 cells and also in HEK293 cells heterologously expressing T1R3. Furthermore, the anti-adipogenic effects of sweeteners were mimicked by Gs activation with cholera toxin but not by adenylate cyclase activation with forskolin, whereas small interfering RNA-mediated knockdown of Gαs had the opposite effects. Conclusions 3T3-L1 cells express a functional sweet taste-sensing receptor presumably as a T1R3 homomer, which mediates the anti-adipogenic signal by a Gs-dependent but cAMP-independent mechanism. PMID:23336004

  11. 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

  12. 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.

  13. REGULATORY T CELLS AND VASECTOMY

    PubMed Central

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

    2013-01-01

    CD4+CD25+ regulatory T cells (Tregs) strongly influence the early and late autoimmune responses to meiotic germ cell antigens (MGCA) and the gonadal immunopathology in vasectomized mice. This is supported by the published and recently acquired information presented here. Within 24 hours of unilateral vasectomy (uni-vx) the ipsilateral epididymis undergoes epithelial cell apoptosis followed by necrosis, severe inflammation, and granuloma formation. Unexpectedly, vasectomy alone induced MGCA-specific tolerance. In contrast, uni-vx plus simultaneous Treg depletion resulted in MGCA-specific autoimmune response and bilateral autoimmune orchitis. Both tolerance and autoimmunity were strictly linked to the early epididymal injury. We now discovered that testicular autoimmunity in uni-vx mice did not occur when Treg depletion was delayed by one week. Remarkably, this delayed Treg depletion also prevented tolerance induction. Therefore, tolerance depends on a rapid de novo Treg response to MGCA exposed after vasectomy. Moreover, tolerance was blunted in mice genetically deficient in PD-1 ligand, suggesting the involvement of induced Treg. We conclude that pre-existing natural Treg prevents post-vasectomy autoimmunity, whereas vasectomy-induced Treg maintains post-vasectomy tolerance. We further discovered that vasectomized mice were still resistant to autoimmune orchitis induction for at least 12–16 months; thus, tolerance is long-lasting. Although significant sperm autoantibodies of low titers became detectable in uni-vx mice at seven months, the antibody titers fluctuated over time, suggesting a dynamic “balance” between the autoimmune and tolerance states. Finally, we observed severe epididymal fibrosis and hypo-spermatogenesis at 12 months after uni-vx: findings of highly critical clinical significance. PMID:24080233

  14. 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

  15. 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

  16. 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

  17. 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.

  18. 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

  19. Regulatory B cell frequency correlates with markers of HIV disease progression and attenuates anti-HIV CD8⁺ T cell function in vitro.

    PubMed

    Siewe, Basile; Stapleton, Jack T; Martinson, Jeffrey; Keshavarzian, Ali; Kazmi, Nazia; Demarais, Patricia M; French, Audrey L; Landay, Alan

    2013-05-01

    HIV infection is associated with elevated expression of IL-10 and PD-L1, contributing to impairment of T cell effector functions. In autoimmunity, tumor immunology, and some viral infections, Bregs modulate T cell function via IL-10 production. In this study, we tested the hypothesis that during HIV infection, Bregs attenuate CD8(+) T cell effector function, contributing to immune dysfunction. We determined that in vitro, TLR2-, TLR9-, and CD40L-costimulated Bregs from HIV(-) individuals exhibited a high frequency of cells expressing IL-10 and PD-L1. Compared with Bregs from HIV(-) individuals, a significantly higher percentage of Bregs from HIV(+) individuals spontaneously expressed IL-10 (P=0.0218). After in vitro stimulation with HIV peptides, Breg-depleted PBMCs from HIV(+) individuals exhibited a heightened frequency of cytotoxic (CD107a(+); P=0.0171) and HIV-specific CD8(+) T cells compared with total PBMCs. Furthermore, Breg depletion led to enhanced proliferation of total CD8(+) and CD107a(+)CD8(+) T cells (P=0.0280, and P=0.0102, respectively). In addition, augmented CD8(+) T cell effector function in vitro was reflected in a 67% increased clearance of infected CD4(+) T cells. The observed Breg suppression of CD8(+) T cell proliferation was IL-10-dependent. In HIV(+) individuals, Breg frequency correlated positively with viral load (r=0.4324; P=0.0095), immune activation (r=0.5978; P=0.0005), and CD8(+) T cell exhaustion (CD8(+)PD-1(+); r=0.5893; P=0.0101). Finally, the frequency of PD-L1-expressing Bregs correlated positively with CD8(+)PD-1(+) T cells (r=0.4791; P=0.0443). Our data indicate that Bregs contribute to HIV-infection associated immune dysfunction by T cell impairment, via IL-10 and possibly PD-L1 expression. PMID:23434518

  20. Regulatory B cell frequency correlates with markers of HIV disease progression and attenuates anti-HIV CD8+ T cell function in vitro

    PubMed Central

    Siewe, Basile; Stapleton, Jack T.; Martinson, Jeffrey; Keshavarzian, Ali; Kazmi, Nazia; Demarais, Patricia M.; French, Audrey L.; Landay, Alan

    2013-01-01

    HIV infection is associated with elevated expression of IL-10 and PD-L1, contributing to impairment of T cell effector functions. In autoimmunity, tumor immunology, and some viral infections, Bregs modulate T cell function via IL-10 production. In this study, we tested the hypothesis that during HIV infection, Bregs attenuate CD8+ T cell effector function, contributing to immune dysfunction. We determined that in vitro, TLR2-, TLR9-, and CD40L-costimulated Bregs from HIV− individuals exhibited a high frequency of cells expressing IL-10 and PD-L1. Compared with Bregs from HIV− individuals, a significantly higher percentage of Bregs from HIV+ individuals spontaneously expressed IL-10 (P=0.0218). After in vitro stimulation with HIV peptides, Breg-depleted PBMCs from HIV+ individuals exhibited a heightened frequency of cytotoxic (CD107a+; P=0.0171) and HIV-specific CD8+ T cells compared with total PBMCs. Furthermore, Breg depletion led to enhanced proliferation of total CD8+ and CD107a+CD8+ T cells (P=0.0280, and P=0.0102, respectively). In addition, augmented CD8+ T cell effector function in vitro was reflected in a 67% increased clearance of infected CD4+ T cells. The observed Breg suppression of CD8+ T cell proliferation was IL-10-dependent. In HIV+ individuals, Breg frequency correlated positively with viral load (r=0.4324; P=0.0095), immune activation (r=0.5978; P=0.0005), and CD8+ T cell exhaustion (CD8+PD-1+; r=0.5893; P=0.0101). Finally, the frequency of PD-L1-expressing Bregs correlated positively with CD8+PD-1+ T cells (r=0.4791; P=0.0443). Our data indicate that Bregs contribute to HIV-infection associated immune dysfunction by T cell impairment, via IL-10 and possibly PD-L1 expression. PMID:23434518

  1. Regulatory B cell frequency correlates with markers of HIV disease progression and attenuates anti-HIV CD8⁺ T cell function in vitro.

    PubMed

    Siewe, Basile; Stapleton, Jack T; Martinson, Jeffrey; Keshavarzian, Ali; Kazmi, Nazia; Demarais, Patricia M; French, Audrey L; Landay, Alan

    2013-05-01

    HIV infection is associated with elevated expression of IL-10 and PD-L1, contributing to impairment of T cell effector functions. In autoimmunity, tumor immunology, and some viral infections, Bregs modulate T cell function via IL-10 production. In this study, we tested the hypothesis that during HIV infection, Bregs attenuate CD8(+) T cell effector function, contributing to immune dysfunction. We determined that in vitro, TLR2-, TLR9-, and CD40L-costimulated Bregs from HIV(-) individuals exhibited a high frequency of cells expressing IL-10 and PD-L1. Compared with Bregs from HIV(-) individuals, a significantly higher percentage of Bregs from HIV(+) individuals spontaneously expressed IL-10 (P=0.0218). After in vitro stimulation with HIV peptides, Breg-depleted PBMCs from HIV(+) individuals exhibited a heightened frequency of cytotoxic (CD107a(+); P=0.0171) and HIV-specific CD8(+) T cells compared with total PBMCs. Furthermore, Breg depletion led to enhanced proliferation of total CD8(+) and CD107a(+)CD8(+) T cells (P=0.0280, and P=0.0102, respectively). In addition, augmented CD8(+) T cell effector function in vitro was reflected in a 67% increased clearance of infected CD4(+) T cells. The observed Breg suppression of CD8(+) T cell proliferation was IL-10-dependent. In HIV(+) individuals, Breg frequency correlated positively with viral load (r=0.4324; P=0.0095), immune activation (r=0.5978; P=0.0005), and CD8(+) T cell exhaustion (CD8(+)PD-1(+); r=0.5893; P=0.0101). Finally, the frequency of PD-L1-expressing Bregs correlated positively with CD8(+)PD-1(+) T cells (r=0.4791; P=0.0443). Our data indicate that Bregs contribute to HIV-infection associated immune dysfunction by T cell impairment, via IL-10 and possibly PD-L1 expression.

  2. 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

  3. 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

  4. 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

  5. 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.

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

    PubMed

    Veiga-Parga, T

    2016-07-01

    In humans and mouse models, Foxp3(+) regulatory T cells are known to control all aspects of immune responses. However, only limited information exists on these cells' role in diseases of other animals. In this review, we cover the most important features and different types of regulatory T cells, which include those that are thymus-derived and peripherally induced, the mechanisms by which they control immune responses by targeting effector T cells and antigen-presenting cells, and most important, their role in animal health and diseases including cancer, infections, and other conditions such as hypersensitivities and autoimmunity. Although the literature regarding regulatory T cells in domestic animal species is still limited, multiple articles have recently emerged and are discussed. Moreover, we also discuss the evidence suggesting that regulatory T cells might limit the magnitude of effector responses, which can have either a positive or negative result, depending on the context of animal and human disease. In addition, the issue of plasticity is discussed because plasticity in regulatory T cells can result in the loss of their protective function in some microenvironments during disease. Lastly, the manipulation of regulatory T cells is discussed in assessing the possibility of their use as a treatment in the future. PMID:26945003

  7. The molecular makeup and function of regulatory and effector synapses.

    PubMed

    Reichardt, Peter; Dornbach, Bastian; Gunzer, Matthias

    2007-08-01

    Physical interactions between T cells and antigen-presenting cells (APCs) form the basis of any specific immune response. Upon cognate contacts, a multimolecular assembly of receptors and adhesion molecules on both cells is created, termed the immunological synapse (IS). Very diverse structures of ISs have been described, yet the functional importance for T-cell differentiation is largely unclear. Here we discuss the principal structure and function of ISs. We then focus on two characteristic T-cell-APC pairs, namely T cells contacting dendritic cells (DCs) or naive B cells, for which extremely different patterns of the IS have been observed as well as fundamentally different effects on the function of the activated T cells. We provide a model on how differences in signaling and the involvement of adhesion molecules might lead to diverse interaction kinetics and, eventually, diverse T-cell differentiation. We hypothesize that the preferred activation of the adhesion molecule leukocyte function-associated antigen-1 (LFA-1) and of the negative regulator for T-cell activation, cytotoxic T-lymphocyte antigen-4 (CTLA-4), through contact with naive B cells, lead to prolonged cell-cell contacts and the generation of T cells with regulatory capacity. In contrast, DCs might have evolved mechanisms to avoid LFA-1 overactivation and CTLA-4 triggering, thereby promoting more dynamic contacts that lead to the preferential generation of effector cells.

  8. Heat shock protein 60 enhances CD4+ CD25+ regulatory T cell function via innate TLR2 signaling.

    PubMed

    Zanin-Zhorov, Alexandra; Cahalon, Liora; Tal, Guy; Margalit, Raanan; Lider, Ofer; Cohen, Irun R

    2006-07-01

    CD4+CD25+ Tregs regulate immunity, but little is known about their own regulation. We now report that the human 60-kDa heat shock protein (HSP60) acts as a costimulator of human Tregs, both CD4+CD25int and CD4+CD25hi. Treatment of Tregs with HSP60, or its peptide p277, before anti-CD3 activation significantly enhanced the ability of relatively low concentrations of the Tregs to downregulate CD4+CD25- or CD8+ target T cells, detected as inhibition of target T cell proliferation and IFN-gamma and TNF-alpha secretion. The enhancing effects of HSP60 costimulation on Tregs involved innate signaling via TLR2, led to activation of PKC, PI3K, and p38, and were further enhanced by inhibition of ERK. HSP60-treated Tregs suppressed target T cells both by cell-to-cell contact and by secretion of TGF-beta and IL-10. In addition, the expression of ERK, NF-kappaB, and T-bet by downregulated target T cells was inhibited. Thus, HSP60, a self-molecule, can downregulate adaptive immune responses by upregulating Tregs innately through TLR2 signaling. PMID:16767222

  9. 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.

  10. 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.

  11. Motifs emerge from function in model gene regulatory networks

    PubMed Central

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

    2011-01-01

    Gene regulatory networks allow the control of gene expression patterns in living cells. The study of network topology has revealed that certain subgraphs of interactions or “motifs” appear at anomalously high frequencies. We ask here whether this phenomenon may emerge because of the functions carried out by these networks. Given a framework for describing regulatory interactions and dynamics, we consider in the space of all regulatory networks those that have prescribed functional capabilities. Markov Chain Monte Carlo sampling is then used to determine how these functional networks lead to specific motif statistics in the interactions. In the case where the regulatory networks are constrained to exhibit multistability, we find a high frequency of gene pairs that are mutually inhibitory and self-activating. In contrast, networks constrained to have periodic gene expression patterns (mimicking for instance the cell cycle) have a high frequency of bifan-like motifs involving four genes with at least one activating and one inhibitory interaction. PMID:21960444

  12. 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

  13. 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

  14. 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.

  15. 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

  16. Additive functions in boolean models of gene regulatory network modules.

    PubMed

    Darabos, Christian; Di Cunto, Ferdinando; Tomassini, Marco; Moore, Jason H; Provero, Paolo; Giacobini, Mario

    2011-01-01

    Gene-on-gene regulations are key components of every living organism. Dynamical abstract models of genetic regulatory networks help explain the genome's evolvability and robustness. These properties can be attributed to the structural topology of the graph formed by genes, as vertices, and regulatory interactions, as edges. Moreover, the actual gene interaction of each gene is believed to play a key role in the stability of the structure. With advances in biology, some effort was deployed to develop update functions in boolean models that include recent knowledge. We combine real-life gene interaction networks with novel update functions in a boolean model. We use two sub-networks of biological organisms, the yeast cell-cycle and the mouse embryonic stem cell, as topological support for our system. On these structures, we substitute the original random update functions by a novel threshold-based dynamic function in which the promoting and repressing effect of each interaction is considered. We use a third real-life regulatory network, along with its inferred boolean update functions to validate the proposed update function. Results of this validation hint to increased biological plausibility of the threshold-based function. To investigate the dynamical behavior of this new model, we visualized the phase transition between order and chaos into the critical regime using Derrida plots. We complement the qualitative nature of Derrida plots with an alternative measure, the criticality distance, that also allows to discriminate between regimes in a quantitative way. Simulation on both real-life genetic regulatory networks show that there exists a set of parameters that allows the systems to operate in the critical region. This new model includes experimentally derived biological information and recent discoveries, which makes it potentially useful to guide experimental research. The update function confers additional realism to the model, while reducing the complexity

  17. Additive Functions in Boolean Models of Gene Regulatory Network Modules

    PubMed Central

    Darabos, Christian; Di Cunto, Ferdinando; Tomassini, Marco; Moore, Jason H.; Provero, Paolo; Giacobini, Mario

    2011-01-01

    Gene-on-gene regulations are key components of every living organism. Dynamical abstract models of genetic regulatory networks help explain the genome's evolvability and robustness. These properties can be attributed to the structural topology of the graph formed by genes, as vertices, and regulatory interactions, as edges. Moreover, the actual gene interaction of each gene is believed to play a key role in the stability of the structure. With advances in biology, some effort was deployed to develop update functions in Boolean models that include recent knowledge. We combine real-life gene interaction networks with novel update functions in a Boolean model. We use two sub-networks of biological organisms, the yeast cell-cycle and the mouse embryonic stem cell, as topological support for our system. On these structures, we substitute the original random update functions by a novel threshold-based dynamic function in which the promoting and repressing effect of each interaction is considered. We use a third real-life regulatory network, along with its inferred Boolean update functions to validate the proposed update function. Results of this validation hint to increased biological plausibility of the threshold-based function. To investigate the dynamical behavior of this new model, we visualized the phase transition between order and chaos into the critical regime using Derrida plots. We complement the qualitative nature of Derrida plots with an alternative measure, the criticality distance, that also allows to discriminate between regimes in a quantitative way. Simulation on both real-life genetic regulatory networks show that there exists a set of parameters that allows the systems to operate in the critical region. This new model includes experimentally derived biological information and recent discoveries, which makes it potentially useful to guide experimental research. The update function confers additional realism to the model, while reducing the complexity

  18. 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

  19. 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

  20. Abatacept (cytotoxic T lymphocyte antigen 4-immunoglobulin) improves B cell function and regulatory T cell inhibitory capacity in rheumatoid arthritis patients non-responding to anti-tumour necrosis factor-α agents

    PubMed Central

    Picchianti Diamanti, A; Rosado, M M; Scarsella, M; Germano, V; Giorda, E; Cascioli, S; Laganà, B; D'Amelio, R; Carsetti, R

    2014-01-01

    The use of biological agents combined with methotrexate (MTX) in rheumatoid arthritis (RA) patients has strongly improved disease outcome. In this study, the effects of abatacept on the size and function of circulating B and T cells in RA patients not responding to anti-tumour necrosis factor (TNF)-α have been analysed, with the aim of identifying immunological parameters helpful to choosing suitable tailored therapies. We analysed the frequency of peripheral B and T cell subsets, B cell function and T regulatory cell (Treg) inhibitory function in 20 moderate/severe RA patients, according to the European League Against Rheumatism (EULAR)/American College of Rheumatology (ACR) criteria, primary non-responders to one TNF-α blocking agent, who received abatacept + MTX. Patients were studied before and 6 months after therapy. We found that abatacept therapy significantly reduced disease activity score on 44 joints (DAS)/erythrocyte sedimentation rate (ESR) values without causing severe side effects. The size of the circulating B and T cell compartments in RA patients was not significantly different from healthy donors, but B cell proliferation and plasma cell differentiation was impaired before therapy and restored by abatacept. While Treg cell frequency was normal, its inhibitory function was absent before therapy and was partially recovered 6 months after abatacept. B and Treg cell function is impaired in RA patients not responding to the first anti-TNF-α agent. Abatacept therapy was able to rescue immune function and led to an effective and safe clinical outcome, suggesting that RA patients, in whom anti-TNF-α failed, are immunologically prone to benefit from an agent targeting a different pathway. PMID:24773026

  1. Regulatory issues for personalized pluripotent cells.

    PubMed

    Condic, Maureen L; Rao, Mahendra

    2008-11-01

    The development of personalized pluripotent stem cells for research and for possible therapies holds out great hope for patients. However, such cells will face significant technical and regulatory challenges before they can be used as therapeutic reagents. Here we consider two possible sources of personalized pluripotent stem cells: embryonic stem cells derived from nuclear transfer (NT-ESCs) and induced pluripotent stem cells (iPSCs) derived from direct reprogramming of adult somatic cells. Both sources of personalized pluripotent stem cells face unique regulatory hurdles that are in some ways significantly higher than those facing stem cells derived from embryos produced by fertilization (ESCs). However, the outstanding long-term potential of iPSCs and their relative freedom from the ethical concerns raised by both ESCs and NT-ESCs makes direct reprogramming an exceptionally promising approach to advancing research and providing therapies in the field of regenerative medicine.

  2. 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

  3. 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.

  4. Autoimmunity: regulatory B cells--IL-35 and IL-21 regulate the regulators.

    PubMed

    Tedder, Thomas F; Leonard, Warren J

    2014-08-01

    IL-21 regulates the activity and number of IL-10-producing regulatory B cells (B10 cells) that modulate immune responses and limit diverse autoimmune diseases. A new study demonstrates that IL-35 has a similar function. Identifying regulatory circuits that control B10-cell function in vivo might open the door to future treatments for autoimmune diseases.

  5. Synergistic roles of BMP15 and GDF9 in the development and function of the oocyte-cumulus cell complex in mice: genetic evidence for an oocyte-granulosa cell regulatory loop.

    PubMed

    Su, You-Qiang; Wu, Xuemei; O'Brien, Marilyn J; Pendola, Frank L; Denegre, James N; Matzuk, Martin M; Eppig, John J

    2004-12-01

    Bone morphogenetic protein 15 (BMP15) and growth differentiation factor 9 (GDF9) are oocyte-specific growth factors that appear to play key roles in granulosa cell development and fertility in most mammalian species. We have evaluated the role(s) of these paracrine factors in the development and function of both the cumulus cells and oocytes by assessing cumulus expansion, oocyte maturation, fertilization, and preimplantation embryogenesis in Gdf9+/-Bmp15-/- [hereafter, double mutant (DM)] mice. We found that cumulus expansion, as well as the expression of hyaluronon synthase 2 (Has2) mRNA was impaired in DM oocyte-cumulus cell complexes. This aberrant cumulus expansion was not remedied by coculture with normal wild-type (WT) oocytes, indicating that the development and/or differentiation of cumulus cells in the DM, up to the stage of the preovulatory luteinizing hormone (LH) surge, is impaired. In addition, DM oocytes failed to enable FSH to induce cumulus expansion in WT oocytectomized (OOX) cumulus. Moreover, LH-induced oocyte meiotic resumption was significantly delayed in vivo, and this delayed resumption of meiosis was correlated with the reduced activation of mitogen-activated protein kinase (MAPK) in the cumulus cells, thus suggesting that GDF9 and BMP15 also regulate the function of cumulus cells after the preovulatory LH surge. Although spontaneous in vitro oocyte maturation occurred normally, oocyte fertilization and preimplantation embryogenesis were significantly altered in the DM, suggesting that the full complement of both GDF9 and BMP15 are essential for the development and function of oocytes. Because receptors for GDF9 and BMP15 have not yet been identified in mouse oocytes, the effects of the mutations in the Bmp15 and Gdf9 genes on oocyte development and functions must be produced indirectly by first affecting the granulosa cells and then the oocyte. Therefore, this study provides further evidence for the existence and functioning of an oocyte

  6. T regulatory cells and allergy.

    PubMed

    Taylor, Alison; Verhagen, Johan; Akdis, Cezmi A; Akdis, Mübeccel

    2005-06-01

    Anergy, tolerance and active suppression may not be independent events, but rather involve similar mechanisms and cell types in immune regulation. Induction of allergen-specific T(Reg) cells seems essential for maintaining a healthy immune response towards allergens. By utilizing multiple secreted cytokines and surface molecules, antigen-specific T(Reg) cells may re-direct an inappropriate immune response against allergens or auto-antigens.

  7. Special regulatory T-cell review: FOXP3 biochemistry in regulatory T cells – how diverse signals regulate suppression

    PubMed Central

    Li, Bin; Greene, Mark I

    2008-01-01

    FOXP3 is an acetylated and phosphorylated protein active in human regulatory T cells and forms oligomers which then associate with an even larger molecular complex. FOXP3 actively regulates transcription by recruiting enzymatic co-repressors and/or co-activators. FOXP3 complex ensembles are dynamically regulated by physiological stimuli such as T-cell receptor, IL-2 and proinflammation cytokine signals. Understanding the post-translational modifications of FOXP3 regulated by diverse signals and the biochemistry and structural chemistry of enzymatic proteins in the FOXP3 complex is critical for therapeutically modulating regulatory T cell function. PMID:18154614

  8. 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

  9. 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.

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

    PubMed

    Gajewski, Thomas F

    2007-08-01

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

  11. Regulatory T-cell compartmentalization and trafficking

    PubMed Central

    Wei, Shuang; Kryczek, Ilona; Zou, Weiping

    2006-01-01

    CD4+CD25+FOXP3+ regulatory T cells (CD4+ Treg cells) are thought to differentiate in the thymus and immigrate from the thymus to the periphery. Treg cells can regulate both acquired and innate immunity through multiple modes of suppression. The cross-talk between Treg cells and targeted cells, such as antigen-presenting cells (APCs) and T cells, is crucial for ensuring suppression by Treg cells in the appropriate microenvironment. Emerging evidence suggests that Treg compartmentalization and trafficking may be tissue or/and organ specific and that distinct chemokine receptor and integrin expression may contribute to selective retention and trafficking of Treg cells at sites where regulation is required. In this review, the cellular and molecular signals that control specialized migration and retention of Treg cells are discussed. PMID:16537800

  12. Radiation Enhances Regulatory T Cell Representation

    PubMed Central

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

    2010-01-01

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

  13. 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

  14. 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.

  15. Shaping of the autoreactive regulatory T cell repertoire by thymic cortical positive selection

    PubMed Central

    Ribot, Julie; Enault, Geneviève; Pilipenko, Sylvie; Huchenq, Anne; Calise, Maryline; Hudrisier, Denis; Romagnoli, Paola; van Meerwijk, Joost PM

    2007-01-01

    The main function of regulatory T lymphocytes is to keep autoimmune responses at bay. Accordingly, it has been firmly established that the repertoire of CD4+CD25+Foxp3+ regulatory T cells is enriched in autospecific cells. Differences in thymic positive and/or negative selection may account for selection of the qualitatively distinct regulatory and conventional T cell repertoires. It has previously been shown that precursors for regulatory T cells are less sensitive to negative selection than conventional T cell-precursors. Studies with TCR/ligand doubly transgenic mice suggested that agonist ligand might induce positive selection of regulatory (but not conventional) T cells. However, massive deletion of conventional (but not regulatory) T cell precursors observed in these mice renders interpretation of such data problematic and a potential role for positive selection in generation of the autospecific regulatory T cell-repertoire has remained therefore incompletely understood. To study this important unresolved issue and circumvent use of TCR/ligand transgenic mice, we have developed transgenic mice expressing a single MHC class II/peptide ligand on positively selecting thymic cortical epithelial cells. We found that functional regulatory (but not conventional) T cells specific for the single ligand were preferentially selected from the naturally diverse repertoire of immature precursors. Our data therefore demonstrate that thymic cortical positive selection of regulatory and conventional T cell precursors is governed by distinct rules and that it plays an important role in shaping the autoreactive regulatory T cell repertoire. PMID:17982064

  16. Role of Metabolism in the Immunobiology of Regulatory T Cells.

    PubMed

    Galgani, Mario; De Rosa, Veronica; La Cava, Antonio; Matarese, Giuseppe

    2016-10-01

    Intracellular metabolism is central to cell activity and function. CD4(+)CD25(+) regulatory T cells (Tregs) that express the transcription factor FOXP3 play a pivotal role in the maintenance of immune tolerance to self. Recent studies showed that the metabolism and function of Tregs are influenced significantly by local environmental conditions and the availability of certain metabolites. It also was reported that defined metabolic programs associate with Treg differentiation, expression of FOXP3, and phenotype stabilization. This article reviews how metabolism modulates FOXP3 expression and Treg function, what environmental factors are involved, and how metabolic manipulation could alter Treg frequency and function in physiopathologic conditions. PMID:27638939

  17. The miR-146b-3p/PAX8/NIS Regulatory Circuit Modulates the Differentiation Phenotype and Function of Thyroid Cells during Carcinogenesis.

    PubMed

    Riesco-Eizaguirre, Garcilaso; Wert-Lamas, León; Perales-Patón, Javier; Sastre-Perona, Ana; Fernández, Lara P; Santisteban, Pilar

    2015-10-01

    The presence of differentiated thyroid cells in thyroid cancer is critical for the antitumor response to radioactive iodide treatment, and loss of the differentiated phenotype is a key hallmark of iodide-refractory metastatic disease. The role of microRNAs (miRNA) in fine-tuning gene expression has become a major regulatory mechanism by which developmental and pathologic processes occur. In this study, we performed next-generation sequencing and expression analysis of eight papillary thyroid carcinomas (PTC) to comprehensively characterize miRNAs involved in loss of differentiation. We found that only a small set of abundant miRNAs is differentially expressed between PTC tissue and normal tissue from the same patient. In addition, we integrated computational prediction of potential targets and mRNA sequencing and identified a master miRNA regulatory network involved in essential biologic processes such as thyroid differentiation. Both mature products of mir-146b (miR-146b-5p and -3p) were among the most abundantly expressed miRNAs in tumors. Specifically, we found that miR-146b-3p binds to the 3'-untranslated region of PAX8 and sodium/iodide symporter (NIS), leading to impaired protein translation and a subsequent reduction in iodide uptake. Furthermore, our findings show that miR-146b and PAX8 regulate each other and share common target genes, thus highlighting a novel regulatory circuit that governs the differentiated phenotype of PTC. In conclusion, our study has uncovered the existence of a miR-146b-3p/PAX8/NIS regulatory circuit that may be exploited therapeutically to modulate thyroid cell differentiation and iodide uptake for improved treatment of advanced thyroid cancer.

  18. 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

  19. 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

  20. 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

  1. Dietary Vitamin D Increases Percentages and Function of Regulatory T Cells in the Skin-Draining Lymph Nodes and Suppresses Dermal Inflammation

    PubMed Central

    Geldenhuys, Sian; Judge, Melinda; Weeden, Clare E.; Waithman, Jason

    2016-01-01

    Skin inflammatory responses in individuals with allergic dermatitis may be suppressed by dietary vitamin D through induction and upregulation of the suppressive activity of regulatory T (TReg) cells. Vitamin D may also promote TReg cell tropism to dermal sites. In the current study, we examined the capacity of dietary vitamin D3 to modulate skin inflammation and the numbers and activity of TReg cells in skin and other sites including lungs, spleen, and blood. In female BALB/c mice, dietary vitamin D3 suppressed the effector phase of a biphasic ear swelling response induced by dinitrofluorobenzene in comparison vitamin D3-deficient female BALB/c mice. Vitamin D3 increased the percentage of TReg (CD3+CD4+CD25+Foxp3+) cells in the skin-draining lymph nodes (SDLN). The suppressive activity of TReg cells in the SDLN, mesenteric lymph nodes, spleen, and blood was upregulated by vitamin D3. However, there was no difference in the expression of the naturally occurring TReg cell marker, neuropilin, nor the expression of CCR4 or CCR10 (skin-tropic chemokine receptors) on TReg cells in skin, SDLN, lungs, and airway-draining lymph nodes. These data suggest that dietary vitamin D3 increased the percentages and suppressive activity of TReg cells in the SDLN, which are poised to suppress dermal inflammation. PMID:27672666

  2. Dietary Vitamin D Increases Percentages and Function of Regulatory T Cells in the Skin-Draining Lymph Nodes and Suppresses Dermal Inflammation

    PubMed Central

    Geldenhuys, Sian; Judge, Melinda; Weeden, Clare E.; Waithman, Jason

    2016-01-01

    Skin inflammatory responses in individuals with allergic dermatitis may be suppressed by dietary vitamin D through induction and upregulation of the suppressive activity of regulatory T (TReg) cells. Vitamin D may also promote TReg cell tropism to dermal sites. In the current study, we examined the capacity of dietary vitamin D3 to modulate skin inflammation and the numbers and activity of TReg cells in skin and other sites including lungs, spleen, and blood. In female BALB/c mice, dietary vitamin D3 suppressed the effector phase of a biphasic ear swelling response induced by dinitrofluorobenzene in comparison vitamin D3-deficient female BALB/c mice. Vitamin D3 increased the percentage of TReg (CD3+CD4+CD25+Foxp3+) cells in the skin-draining lymph nodes (SDLN). The suppressive activity of TReg cells in the SDLN, mesenteric lymph nodes, spleen, and blood was upregulated by vitamin D3. However, there was no difference in the expression of the naturally occurring TReg cell marker, neuropilin, nor the expression of CCR4 or CCR10 (skin-tropic chemokine receptors) on TReg cells in skin, SDLN, lungs, and airway-draining lymph nodes. These data suggest that dietary vitamin D3 increased the percentages and suppressive activity of TReg cells in the SDLN, which are poised to suppress dermal inflammation.

  3. 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

  4. 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.

  5. 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

  6. Therapeutic Immunization with HIV-1 Tat Reduces Immune Activation and Loss of Regulatory T-Cells and Improves Immune Function in Subjects on HAART

    PubMed Central

    Ensoli, Barbara; Bellino, Stefania; Tripiciano, Antonella; Longo, Olimpia; Francavilla, Vittorio; Marcotullio, Simone; Cafaro, Aurelio; Picconi, Orietta; Paniccia, Giovanni; Scoglio, Arianna; Arancio, Angela; Ariola, Cristina; Ruiz Alvarez, Maria J.; Campagna, Massimo; Scaramuzzi, Donato; Iori, Cristina; Esposito, Roberto; Mussini, Cristina; Ghinelli, Florio; Sighinolfi, Laura; Palamara, Guido; Latini, Alessandra; Angarano, Gioacchino; Ladisa, Nicoletta; Soscia, Fabrizio; Mercurio, Vito S.; Lazzarin, Adriano; Tambussi, Giuseppe; Visintini, Raffaele; Mazzotta, Francesco; Di Pietro, Massimo; Galli, Massimo; Rusconi, Stefano; Carosi, Giampiero; Torti, Carlo; Di Perri, Giovanni; Bonora, Stefano; Ensoli, Fabrizio; Garaci, Enrico

    2010-01-01

    Although HAART suppresses HIV replication, it is often unable to restore immune homeostasis. Consequently, non-AIDS-defining diseases are increasingly seen in treated individuals. This is attributed to persistent virus expression in reservoirs and to cell activation. Of note, in CD4+ T cells and monocyte-macrophages of virologically-suppressed individuals, there is continued expression of multi-spliced transcripts encoding HIV regulatory proteins. Among them, Tat is essential for virus gene expression and replication, either in primary infection or for virus reactivation during HAART, when Tat is expressed, released extracellularly and exerts, on both the virus and the immune system, effects that contribute to disease maintenance. Here we report results of an ad hoc exploratory interim analysis (up to 48 weeks) on 87 virologically-suppressed HAART-treated individuals enrolled in a phase II randomized open-label multicentric clinical trial of therapeutic immunization with Tat (ISS T-002). Eighty-eight virologically-suppressed HAART-treated individuals, enrolled in a parallel prospective observational study at the same sites (ISS OBS T-002), served for intergroup comparison. Immunization with Tat was safe, induced durable immune responses, and modified the pattern of CD4+ and CD8+ cellular activation (CD38 and HLA-DR) together with reduction of biochemical activation markers and persistent increases of regulatory T cells. This was accompanied by a progressive increment of CD4+ T cells and B cells with reduction of CD8+ T cells and NK cells, which were independent from the type of antiretroviral regimen. Increase in central and effector memory and reduction in terminally-differentiated effector memory CD4+ and CD8+ T cells were accompanied by increases of CD4+ and CD8+ T cell responses against Env and recall antigens. Of note, more immune-compromised individuals experienced greater therapeutic effects. In contrast, these changes were opposite, absent or partial in the

  7. 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.

  8. 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

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

    PubMed Central

    Cong, Y; Liu, Z

    2015-01-01

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

  10. Regulatory role of rpL3 in cell response to nucleolar stress induced by Act D in tumor cells lacking functional p53.

    PubMed

    Russo, Annapina; Pagliara, Valentina; Albano, Francesco; Esposito, Davide; Sagar, Vinay; Loreni, Fabrizio; Irace, Carlo; Santamaria, Rita; Russo, Giulia

    2016-01-01

    Many chemotherapeutic drugs cause nucleolar stress and p53-independent pathways mediating the nucleolar stress response are emerging. Here, we demonstrate that ribosomal stress induced by Actinomycin D (Act D) is associated to the up-regulation of ribosomal protein L3 (rpL3) and its accumulation as ribosome-free form in lung and colon cancer cell lines devoid of p53. Free rpL3 regulates p21 expression at transcriptional and post-translational levels through a molecular mechanism involving extracellular-signal-regulated kinases1/2 (ERK1/2) and mouse double minute-2 homolog (MDM2). Our data reveal that rpL3 participates to cell response acting as a critical regulator of apoptosis and cell migration. It is noteworthy that silencing of rpL3 abolishes the cytotoxic effects of Act D suggesting that the loss of rpL3 makes chemotherapy drugs ineffective while rpL3 overexpression associates to a strong increase of Act D-mediated inhibition of cell migration. Taking together our results show that the efficacy of Act D chemotherapy depends on rpL3 status revealing new specific targets involved in the molecular pathways activated by Act D in cancers lacking of p53. Hence, the development of treatments aimed at upregulating rpL3 may be beneficial for the treatment of these cancers.

  11. Regulatory T cells and transplantation tolerance.

    PubMed

    Cobbold, S P

    2008-01-01

    Rodent models of transplantation have demonstrated that it is possible to induce specific immunological tolerance of donor antigens and indefinite graft survival in the absence of any continued immunosuppression. If this situation could be achieved clinically it would avoid many of the longer term complications of organ grafting, such as the increased risk of infection and cancer and the nephrotoxicity of many immunosuppressive agents. In this review we shall consider the interplay between regulatory T cells, dendritic cells and the graft itself and the resulting local protective mechanisms that are coordinated to maintain the tolerant state. We will discuss how both anti-inflammatory cytokines and negative costimulatory interactions can elicit a number of interrelated mechanisms to regulate both T cell and antigen-presenting cell activity. The induction and maintenance of tolerance via acquired local immune privilege has implications for the design of therapeutic regimens and the monitoring of the tolerant status of patients being weaned off immunosuppression. PMID:18651537

  12. Immunomodulation by mesenchymal stem cells: Interplay between mesenchymal stem cells and regulatory lymphocytes

    PubMed Central

    Ma, Oscar Ka-Fai; Chan, Koon Ho

    2016-01-01

    Mesenchymal stem cells (MSCs) possess immunomodulatory properties, which confer enormous potential for clinical application. Considerable evidence revealed their efficacy on various animal models of autoimmune diseases, such as multiple sclerosis, systemic lupus erythematosus and uveitis. MSCs elicit their immunomodulatory effects by inhibiting lymphocyte activation and proliferation, forbidding the secretion of proinflammatory cytokines, limiting the function of antigen presenting cells, and inducing regulatory T (Treg) and B (Breg) cells. The induction of Treg and Breg cells is of particular interest since Treg and Breg cells have significant roles in maintaining immune tolerance. Several mechanisms have been proposed regarding to the MSCs-mediated induction of Treg and Breg cells. Accordingly, MSCs induce regulatory lymphocytes through secretion of multiple pleiotropic cytokines, cell-to-cell contact with target cells and modulation of antigen-presenting cells. Here, we summarized how MSCs induce Treg and Breg cells to provoke immunosuppression. PMID:27679683

  13. Immunomodulation by mesenchymal stem cells: Interplay between mesenchymal stem cells and regulatory lymphocytes.

    PubMed

    Ma, Oscar Ka-Fai; Chan, Koon Ho

    2016-09-26

    Mesenchymal stem cells (MSCs) possess immunomodulatory properties, which confer enormous potential for clinical application. Considerable evidence revealed their efficacy on various animal models of autoimmune diseases, such as multiple sclerosis, systemic lupus erythematosus and uveitis. MSCs elicit their immunomodulatory effects by inhibiting lymphocyte activation and proliferation, forbidding the secretion of proinflammatory cytokines, limiting the function of antigen presenting cells, and inducing regulatory T (Treg) and B (Breg) cells. The induction of Treg and Breg cells is of particular interest since Treg and Breg cells have significant roles in maintaining immune tolerance. Several mechanisms have been proposed regarding to the MSCs-mediated induction of Treg and Breg cells. Accordingly, MSCs induce regulatory lymphocytes through secretion of multiple pleiotropic cytokines, cell-to-cell contact with target cells and modulation of antigen-presenting cells. Here, we summarized how MSCs induce Treg and Breg cells to provoke immunosuppression. PMID:27679683

  14. Immunomodulation by mesenchymal stem cells: Interplay between mesenchymal stem cells and regulatory lymphocytes

    PubMed Central

    Ma, Oscar Ka-Fai; Chan, Koon Ho

    2016-01-01

    Mesenchymal stem cells (MSCs) possess immunomodulatory properties, which confer enormous potential for clinical application. Considerable evidence revealed their efficacy on various animal models of autoimmune diseases, such as multiple sclerosis, systemic lupus erythematosus and uveitis. MSCs elicit their immunomodulatory effects by inhibiting lymphocyte activation and proliferation, forbidding the secretion of proinflammatory cytokines, limiting the function of antigen presenting cells, and inducing regulatory T (Treg) and B (Breg) cells. The induction of Treg and Breg cells is of particular interest since Treg and Breg cells have significant roles in maintaining immune tolerance. Several mechanisms have been proposed regarding to the MSCs-mediated induction of Treg and Breg cells. Accordingly, MSCs induce regulatory lymphocytes through secretion of multiple pleiotropic cytokines, cell-to-cell contact with target cells and modulation of antigen-presenting cells. Here, we summarized how MSCs induce Treg and Breg cells to provoke immunosuppression.

  15. [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.

  16. Regulatory non-coding RNAs in pluripotent stem cells.

    PubMed

    Rosa, Alessandro; Brivanlou, Ali H

    2013-01-01

    The most part of our genome encodes for RNA transcripts are never translated into proteins. These include families of RNA molecules with a regulatory function, which can be arbitrarily subdivided in short (less than 200 nucleotides) and long non-coding RNAs (ncRNAs). MicroRNAs, which act post-transcriptionally to repress the function of target mRNAs, belong to the first group. Included in the second group are multi-exonic and polyadenylated long ncRNAs (lncRNAs), localized either in the nucleus, where they can associate with chromatin remodeling complexes to regulate transcription, or in the cytoplasm, acting as post-transcriptional regulators. Pluripotent stem cells, such as embryonic stem cells (ESCs) or induced pluripotent stem cells (iPSCs), represent useful systems for modeling normal development and human diseases, as well as promising tools for regenerative medicine. To fully explore their potential, however, a deep understanding of the molecular basis of stemness is crucial. In recent years, increasing evidence of the importance of regulation by ncRNAs in pluripotent cells is accumulating. In this review, we will discuss recent findings pointing to multiple roles played by regulatory ncRNAs in ESC and iPSCs, where they act in concert with signaling pathways, transcriptional regulatory circuitries and epigenetic factors to modulate the balance between pluripotency and differentiation.

  17. Functional evolution of a cis-regulatory module.

    PubMed

    Ludwig, Michael Z; Palsson, Arnar; Alekseeva, Elena; Bergman, Casey M; Nathan, Janaki; Kreitman, Martin

    2005-04-01

    Lack of knowledge about how regulatory regions evolve in relation to their structure-function may limit the utility of comparative sequence analysis in deciphering cis-regulatory sequences. To address this we applied reverse genetics to carry out a functional genetic complementation analysis of a eukaryotic cis-regulatory module-the even-skipped stripe 2 enhancer-from four Drosophila species. The evolution of this enhancer is non-clock-like, with important functional differences between closely related species and functional convergence between distantly related species. Functional divergence is attributable to differences in activation levels rather than spatiotemporal control of gene expression. Our findings have implications for understanding enhancer structure-function, mechanisms of speciation and computational identification of regulatory modules.

  18. 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.

  19. Extra-cell cycle regulatory functions of cyclin-dependent kinases (CDK) and CDK inhibitor proteins contribute to brain development and neurological disorders

    PubMed Central

    Kawauchi, Takeshi; Shikanai, Mima; Kosodo, Yoichi

    2013-01-01

    In developing brains, neural progenitors exhibit cell cycle-dependent nuclear movement within the ventricular zone [interkinetic nuclear migration (INM)] and actively proliferate to produce daughter progenitors and/or neurons, whereas newly generated neurons exit from the cell cycle and begin pial surface-directed migration and maturation. Dysregulation of the balance between the proliferation and the cell cycle exit in neural progenitors is one of the major causes of microcephaly (small brain). Recent studies indicate that cell cycle machinery influences not only the proliferation but also INM in neural progenitors. Furthermore, several cell cycle-related proteins, including p27kip1, p57kip2, Cdk5, and Rb, regulate the migration of neurons in the postmitotic state, suggesting that the growth arrest confers dual functions on cell cycle regulators. Consistently, several types of microcephaly occur in conjunction with neuronal migration disorders, such as periventricular heterotopia and lissencephaly. However, cell cycle re-entry by disturbance of growth arrest in mature neurons is thought to trigger neuronal cell death in Alzheimer's disease. In this review, we introduce the cell cycle protein-mediated regulation of two types of nuclear movement, INM and neuronal migration, during cerebral cortical development, and discuss the roles of growth arrest in cortical development and neurological disorders. PMID:23294285

  20. 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

  1. 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

  2. Ptpn22 Modifies Regulatory T Cell Homeostasis via GITR Upregulation.

    PubMed

    Nowakowska, Dominika J; Kissler, Stephan

    2016-03-01

    PTPN22 gene variation associates with multiple autoimmune diseases, including type 1 diabetes and rheumatoid arthritis. Loss of function studies have demonstrated that PTPN22 impinges on the homeostatic behavior of regulatory T (Treg) cells, a lineage critical for immune tolerance. The frequency and absolute number of Treg cells is increased in Ptpn22-deficient mice, but the mechanism driving this increase is unknown. In this study, we show that Ptpn22 knockdown (KD) promoted the expansion of the Treg cell compartment by upregulating the glucocorticoid-induced TNFR family-related protein (GITR) and increasing GITR signaling. Ptpn22 KD did not accelerate cell division but instead prolonged Treg cell survival, as measured by a decrease in the frequency of apoptotic Treg cells. Loss of Ptpn22 caused a concomitant increase in the proportion of CD44(hi)CD62L(lo) effector Treg cells, at the expense of CD44(lo)CD62L(hi) central Treg cells. The increase in Treg cell numbers, but not their differentiation toward an effector phenotype, was dependent on GITR signaling, because blockade of GITR ligand prevented Treg cell expansion caused by Ptpn22 KD. These findings indicate that GITR plays a key role in regulating the overall size of the Treg cell pool. Our results suggest that the size and composition of the Treg cell compartment are independently controlled and have implications for the design of immunotherapies that seek to improve Treg cell function. PMID:26810223

  3. Regulatory T cells and dendritic cells in transplantation tolerance: molecular markers and mechanisms.

    PubMed

    Cobbold, Stephen P; Nolan, Kathleen F; Graca, Luis; Castejon, Raquel; Le Moine, Alain; Frewin, Mark; Humm, Susan; Adams, Elizabeth; Thompson, Sara; Zelenika, Diana; Paterson, Alison; Yates, Stephen; Fairchild, Paul J; Waldmann, Herman

    2003-12-01

    Transplantation tolerance can be induced in adult rodents using monoclonal antibodies against coreceptor or costimulation molecules on the surface of T cells. There are currently two well-characterized populations of T cells, demonstrating regulatory capacity: the "natural" CD4+CD25+ T cells and the interleukin (IL)-10-producing Tr1 cells. Although both types of regulatory T cells can induce transplantation tolerance under appropriate conditions, it is not clear whether either one plays any role in drug-induced dominant tolerance, primarily due to a lack of clear-cut molecular or functional markers. Similarly, although dendritic cells (DCs) can be pharmacologically manipulated to promote tolerance, the phenotype of such populations remains poorly defined. We have used serial analysis of gene expression (SAGE) with 29 different T-cell and antigen-presenting cell libraries to identify gene-expression signatures associated with immune regulation. We found that independently derived, regulatory Tr1-like clones were highly concordant in their patterns of gene expression but were quite distinct from CD4+CD25+ regulatory T cells from the spleen. DCs that were treated with the tolerance-enhancing agents IL-10 or vitamin D3 expressed a gene signature reflecting a functional specification in common with the most immature DCs derived from embryonic stem cells. PMID:14617201

  4. 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

  5. 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

  6. 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

    Hippen, Keli L; 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; Blazar, Bruce R

    2008-10-01

    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 beta (TGF-beta) 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

  7. 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

  8. Evolution of cis-regulatory sequence and function in Diptera.

    PubMed

    Wittkopp, P J

    2006-09-01

    Cis-regulatory sequences direct patterns of gene expression essential for development and physiology. Evolutionary changes in these sequences contribute to phenotypic divergence. Despite their importance, cis-regulatory regions remain one of the most enigmatic features of the genome. Patterns of sequence evolution can be used to identify cis-regulatory elements, but the power of this approach depends upon the relationship between sequence and function. Comparative studies of gene regulation among Diptera reveal that divergent sequences can underlie conserved expression, and that expression differences can evolve despite largely similar sequences. This complex structure-function relationship is the primary impediment for computational identification and interpretation of cis-regulatory sequences. Biochemical characterization and in vivo assays of cis-regulatory sequences on a genomic-scale will relieve this barrier.

  9. Islet distribution of Peptide YY and its regulatory role in primary mouse islets and immortalised rodent and human beta-cell function and survival.

    PubMed

    Khan, Dawood; Vasu, Srividya; Moffett, R Charlotte; Irwin, Nigel; Flatt, Peter R

    2016-11-15

    Recent evidence suggests that the classic gut peptide, Peptide YY (PYY), could play a fundamental role in endocrine pancreatic function. In the present study expression of PYY and its NPY receptors on mouse islets and immortalised rodent and human beta-cells was examined together with the effects of both major circulating forms of PYY, namely PYY(1-36) and PYY(3-36), on beta-cell function, murine islet adaptions to insulin deficiency/resistance, as well as direct effects on cultured beta-cell proliferation and apoptosis. In vivo administration of PYY(3-36), but not PYY(1-36), markedly (p < 0.05) decreased food intake in overnight fasted mice. Neither form of PYY affected glucose disposal or insulin secretion following an i.p. glucose challenge. However, in vitro, PYY(1-36) and PYY(3-36) inhibited (p < 0.05 to p < 0.001) glucose, alanine and GLP-1 stimulated insulin secretion from immortalised rodent and human beta-cells, as well as isolated mouse islets, by impeding alterations in membrane potential, [Ca(2+)]i and elevations of cAMP. Mice treated with multiple low dose streptozotocin presented with severe (p < 0.01) loss of beta-cell mass accompanied by notable increases (p < 0.001) in alpha and PP cell numbers. In contrast, hydrocortisone-induced insulin resistance increased islet number (p < 0.01) and beta-cell mass (p < 0.001). PYY expression was consistently observed in alpha-, PP- and delta-, but not beta-cells. Streptozotocin decreased islet PYY co-localisation with PP (p < 0.05) and somatostatin (p < 0.001), whilst hydrocortisone increased PYY co-localisation with glucagon (p < 0.05) in mice. More detailed in vitro investigations revealed that both forms of PYY augmented (p < 0.05 to p < 0.01) immortalised human and rodent beta-cell proliferation and protected against streptozotocin-induced cytotoxicity, to a similar or superior extent as the well characterised beta-cell proliferative and anti-apoptotic agent GLP-1. Taken together

  10. 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.

  11. 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

  12. 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

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

    PubMed

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

    2015-10-01

    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.

  14. 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

  15. 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

  16. Age-associated reduction of the count and functional activity of stromal precursor cells can be caused by both true reduction (exhaustion) of cell pool and regulatory effects of the organism.

    PubMed

    Gorskaya, Yu F; Danilova, T A; Nesterenko, V G

    2011-06-01

    The study was carried out on CBA mice using the method of heterotopic transplantation. A fragment of the femoral bone marrow (1/2) or spleen (1/5 of the organ) was transplanted under the renal capsule of a recipient. The following donor-recipient cross-transplantation variants were studied: young-young (Y-Y), young-old (Y-O), old-old (O-O), and old-young (O-Y). Cell suspensions were prepared from 2-month transplants inoculated in monolayer cultures and the cloning efficiency (ECF-F) of stromal precursor cells (CFC-F) was evaluated. The bone marrow transplant ECF-F and the count of CFC-F in the O-O group were 8-fold lower than in the Y-Y group. In the O-Y group, ECF-F was 3-fold higher than in the O-O group, but by 2.5 times lower than in the Y-Y group. ECF-F in Y-O group was 2-fold lower than in Y-Y group. The ECF-F and CFC-F count in spleen transplants in the O-O group were 4- and 6-fold lower, respectively, than in Y-Y group. However, in O-Y group ECF-F was 7-fold higher than in O-O group and higher than even in Y-Y group. The weight of induced ectopic bone tissue after transplantation of the osteoinductor (fragments of the allogenic urinary bladder mucosa) was 2-fold lower in the O-O vs. Y-Y group. However, comparison of the ectopic bone tissue weights in different experimental groups showed that osteoinductor activity of the bladder epithelium did not decrease, but increased 3-fold with age (O-Y:Y-Y). A 5-fold reduction of this proportion in groups where the osteoinductor was transplanted from old donors to old and young recipients (O-Y:O-O) could be attributed to age-specific reduction of the count of inducible osteogenic precursor cells (IOPC). The data in general suggest that age-specific reduction of the stromal precursor count and functional activity could be caused by the true reduction (exhaustion) of cell pool (bone marrow CFC-F; presumably, IOPC) and by the regulatory effects of the organism (bone marrow and splenic CFC-F, IOPC). These data seem to be

  17. 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

  18. Prediction of functional regulatory SNPs in monogenic and complex disease

    PubMed Central

    Zhao, Yiqiang; Clark, Wyatt T.; Mort, Matthew; Cooper, David N.; Radivojac, Predrag; Mooney, Sean D.

    2013-01-01

    Next-Generation Sequencing (NGS) technologies are yielding ever-higher volumes of human genome sequence data. Given this large amount of data, it has become both a possibility and a priority to determine how disease-causing single nucleotide polymorphisms (SNPs) detected within gene regulatory regions (rSNPs) exert their effects on gene expression. Recently, several studies have explored whether disease-causing polymorphisms have attributes that can distinguish them from those that are neutral, attaining moderate success at discriminating between functional and putatively neutral regulatory SNPs. Here, we have extended this work by assessing the utility of both SNP-based features (those associated only with the polymorphism site and the surrounding DNA) and Gene-based features (those derived from the associated gene in whose regulatory region the SNP lies) in the identification of functional regulatory polymorphisms involved in either monogenic or complex disease. Gene-based features were found to be capable of both augmenting and enhancing the utility of SNP-based features in the prediction of known regulatory mutations. Adopting this approach, we achieved an AUC of 0.903 for predicting regulatory SNPs. Finally, our tool predicted 225 new regulatory SNPs with a high degree of confidence, with 105 of the 225 falling into linkage disequilibrium blocks of reported disease-associated GWAS SNPs. PMID:21796725

  19. 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

  20. Functional cis-regulatory genomics for systems biology

    PubMed Central

    Nam, Jongmin; Dong, Ping; Tarpine, Ryan; Istrail, Sorin; Davidson, Eric H.

    2010-01-01

    Gene expression is controlled by interactions between trans-regulatory factors and cis-regulatory DNA sequences, and these interactions constitute the essential functional linkages of gene regulatory networks (GRNs). Validation of GRN models requires experimental cis-regulatory tests of predicted linkages to authenticate their identities and proposed functions. However, cis-regulatory analysis is, at present, at a severe bottleneck in genomic system biology because of the demanding experimental methodologies currently in use for discovering cis-regulatory modules (CRMs), in the genome, and for measuring their activities. Here we demonstrate a high-throughput approach to both discovery and quantitative characterization of CRMs. The unique aspect is use of DNA sequence tags to “barcode” CRM expression constructs, which can then be mixed, injected together into sea urchin eggs, and subsequently deconvolved. This method has increased the rate of cis-regulatory analysis by >100-fold compared with conventional one-by-one reporter assays. The utility of the DNA-tag reporters was demonstrated by the rapid discovery of 81 active CRMs from 37 previously unexplored sea urchin genes. We then obtained simultaneous high-resolution temporal characterization of the regulatory activities of more than 80 CRMs. On average 2–3 CRMs were discovered per gene. Comparison of endogenous gene expression profiles with those of the CRMs recovered from each gene showed that, for most cases, at least one CRM is active in each phase of endogenous expression, suggesting that CRM recovery was comprehensive. This approach will qualitatively alter the practice of GRN construction as well as validation, and will impact many additional areas of regulatory system biology. PMID:20142491

  1. 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.

  2. Regulatory Dendritic Cells for Immunotherapy in Immunologic Diseases

    PubMed Central

    Gordon, John R.; Ma, Yanna; Churchman, Laura; Gordon, Sara A.; Dawicki, Wojciech

    2013-01-01

    We recognize well the abilities of dendritic cells to activate effector T cell (Teff cell) responses to an array of antigens and think of these cells in this context as pre-eminent antigen-presenting cells, but dendritic cells are also critical to the induction of immunologic tolerance. Herein, we review our knowledge on the different kinds of tolerogenic or regulatory dendritic cells that are present or can be induced in experimental settings and humans, how they operate, and the diseases in which they are effective, from allergic to autoimmune diseases and transplant tolerance. The primary conclusions that arise from these cumulative studies clearly indicate that the agent(s) used to induce the tolerogenic phenotype and the status of the dendritic cell at the time of induction influence not only the phenotype of the dendritic cell, but also that of the regulatory T cell responses that they in turn mobilize. For example, while many, if not most, types of induced regulatory dendritic cells lead CD4+ naïve or Teff cells to adopt a CD25+Foxp3+ Treg phenotype, exposure of Langerhans cells or dermal dendritic cells to vitamin D leads in one case to the downstream induction of CD25+Foxp3+ regulatory T cell responses, while in the other to Foxp3− type 1 regulatory T cells (Tr1) responses. Similarly, exposure of human immature versus semi-mature dendritic cells to IL-10 leads to distinct regulatory T cell outcomes. Thus, it should be possible to shape our dendritic cell immunotherapy approaches for selective induction of different types of T cell tolerance or to simultaneously induce multiple types of regulatory T cell responses. This may prove to be an important option as we target diseases in different anatomic compartments or with divergent pathologies in the clinic. Finally, we provide an overview of the use and potential use of these cells clinically, highlighting their potential as tools in an array of settings. PMID:24550907

  3. 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.

  4. 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

  5. Movement of regulatory RNA between animal cells.

    PubMed

    Jose, Antony M

    2015-07-01

    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.

  6. 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

  7. miR clusters target cellular functional complexes by defining their degree of regulatory freedom.

    PubMed

    Haier, Jörg; Ströse, Anda; Matuszcak, Christiane; Hummel, Richard

    2016-06-01

    Using the two paralog miR-23∼27∼24 clusters as an example and combining experimental and clinical data in a systematical approach to microRNA (miR) function and dysregulation, a complex picture of their roles in cancer is drawn. Various findings appear to be contradictory to a larger extent and cannot be fully explained by the classical regulatory network models and feedback loops that are mainly considered by one-to-one regulatory interactions of the involved molecules. Here, we propose an extended model of the regulatory role of miRs that, at least, supplements the usually considered single/oligo-target regulation of certain miRs. The cellular availability of the participating miR members in this model reflects an upper hierarchy level of intracellular and extracellular environmental influences, such as neighboring cells, soluble factors, hypoxia, chemotherapeutic drugs, and irradiation, among others. The novel model is based on the understanding of cellular functional complexes, such as for apoptosis, migration, and proliferation. These complexes consist of many regulatory components that can be targeted by miR cluster members to a different extent but may affect the functional complex in different ways. We propose that the final miR-related effect is a result of the possible degree of regulatory freedom provided by the miR effects on the whole functional complex structure. This degree of regulatory freedom defines to which extent the cellular functional complex can react in response to regulatory triggers, also understood as sensitization (more regulatory response options) or de-sensitization (less regulatory response options) of the system rather than single molecules.

  8. The architectural organization of human stem cell cycle regulatory machinery.

    PubMed

    Stein, Gary S; Stein, Janet L; van J Wijnen, Andre; Lian, Jane B; Montecino, Martin; Medina, Ricardo; Kapinas, Kristie; Ghule, Prachi; Grandy, Rodrigo; Zaidi, Sayyed K; Becker, Klaus A

    2012-01-01

    Two striking features of human embryonic stem cells that support biological activity are an abbreviated cell cycle and reduced complexity to nuclear organization. The potential implications for rapid proliferation of human embryonic stem cells within the context of sustaining pluripotency, suppressing phenotypic gene expression and linkage to simplicity in the architectural compartmentalization of regulatory machinery in nuclear microenvironments is explored. Characterization of the molecular and architectural commitment steps that license human embryonic stem cells to initiate histone gene expression is providing understanding of the principal regulatory mechanisms that control the G1/S phase transition in primitive pluripotent cells. From both fundamental regulatory and clinical perspectives, further understanding of the pluripotent cell cycle in relation to compartmentalization of regulatory machinery in nuclear microenvironments is relevant to applications of stem cells for regenerative medicine and new dimensions to therapy where traditional drug discovery strategies have been minimally effective.

  9. 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

  10. 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

  11. 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

  12. Alterations in regulatory T cell subpopulations seen in preterm infants.

    PubMed

    Luciano, Angel A; Arbona-Ramirez, Ileana M; Ruiz, Rene; Llorens-Bonilla, Braulio J; Martinez-Lopez, Denise G; Funderburg, Nicholas; Dorsey, Morna J

    2014-01-01

    Regulatory T cells are a population of CD4+ T cells that play a critical role in peripheral tolerance and control of immune responses to pathogens. The purpose of this study was to measure the percentages of two different regulatory T cells subpopulations, identified by the presence or absence of CD31 (Recent thymic emigrants and peripherally induced naïve regulatory T cells), in term and preterm infant cord blood. We report the association of prenatal factors, intrauterine exposure to lipopolysaccharide and inflammation and the percentages of these regulatory T cell subpopulations in term and preterm infants. Cord blood samples were collected from both term and preterm infants and mononuclear cells isolated over a Ficoll-Hypaque cushion. Cells were then stained with fluorochrome-labeled antibodies to characterize regulatory T cell populations and analyzed with multi-color flow cytometry. Cord blood plasma C-reactive protein, and lipopolysaccharide were also measured. Placental pathology was also examined. We report a gestational age-dependent difference in the percentage of total regulatory T cells, in which preterm infants of lower gestational ages have an increased percentage of regulatory T cells. We report the presence of two populations of regulatory T cells (CD31+ and CD31-) in cord blood of term and preterm infants and their association with different maternal and fetal characteristics. Factors associated with differences in the percentage of CD31- Tregs included the use of prenatal antibiotics, steroids and magnesium sulfate. In addition, the percentage of CD31- Tregs was significantly higher in cord blood of preterm pregnancies associated with inflammation and prenatal lipopolysaccharide exposure. The peripheral Treg pool of preterm infants could be altered by prenatal exposure to inflammation and chorioamnionitis; however, the clinical implications of this finding are not yet understood.

  13. 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

  14. Proceedings: international regulatory considerations on development pathways for cell therapies.

    PubMed

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

    2014-08-01

    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.

  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. 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

  17. 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.

  18. 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

  19. Regulatory dendritic cells: there is more than just immune activation

    PubMed Central

    Schmidt, Susanne V.; Nino-Castro, Andrea C.; Schultze, Joachim L.

    2012-01-01

    The immune system exists in a delicate equilibrium between inflammatory responses and tolerance. This unique feature allows the immune system to recognize and respond to potential threats in a controlled but normally limited fashion thereby preventing a destructive overreaction against healthy tissues. While the adaptive immune system was the major research focus concerning activation vs. tolerance in the immune system more recent findings suggest that cells of the innate immune system are important players in the decision between effective immunity and induction of tolerance or immune inhibition. Among immune cells of the innate immune system dendritic cells (DCs) have a special function linking innate immune functions with the induction of adaptive immunity. DCs are the primary professional antigen presenting cells (APCs) initiating adaptive immune responses. They belong to the hematopoietic system and arise from CD34+ stem cells in the bone marrow. Particularly in the murine system two major subgroups of DCs, namely myeloid DCs (mDCs) and plasmacytoid DCs (pDCs) can be distinguished. DCs are important mediators of innate and adaptive immunity mostly due to their remarkable capacity to present processed antigens via major histocompatibility complexes (MHC) to T cells and B cells in secondary lymphoid organs. A large body of literature has been accumulated during the last two decades describing which role DCs play during activation of T cell responses but also during the establishment and maintenance of central tolerance (Steinman et al., 2003). While the concept of peripheral tolerance has been clearly established during the last years, the role of different sets of DCs and their particular molecular mechanisms of immune deviation has not yet fully been appreciated. In this review we summarize accumulating evidence about the role of regulatory DCs in situations where the balance between tolerance and immunogenicity has been altered leading to pathologic

  20. MicroRNA Profile of Circulating CD4-positive Regulatory T Cells in Human Adults and Impact of Differentially Expressed MicroRNAs on Expression of Two Genes Essential to Their Function*

    PubMed Central

    Fayyad-Kazan, Hussein; Rouas, Redouane; Fayyad-Kazan, Mohammad; Badran, Rabih; El Zein, Nabil; Lewalle, Philippe; Najar, Medhi; Hamade, Eva; Jebbawi, Fadi; Merimi, Makram; Romero, Pedro; Burny, Arsène; Badran, Bassam; Martiat, Philippe

    2012-01-01

    Regulatory T cells (Tregs) are characterized by a high expression of IL-2 receptor α chain (CD25) and of forkhead box P3 (FOXP3), the latter being essential for their development and function. Another major player in the regulatory function is the cytotoxic T-lymphocyte associated molecule-4 (CTLA-4) that inhibits cytotoxic responses. However, the regulation of CTLA-4 expression remains less well explored. We therefore studied the microRNA signature of circulating CD4+ Tregs isolated from adult healthy donors and identified a signature composed of 15 differentially expressed microRNAs. Among those, miR-24, miR-145, and miR-210 were down-regulated in Tregs compared with controls and were found to have potential target sites in the 3′-UTR of FOXP3 and CTLA-4; miR-24 and miR-210 negatively regulated FOXP3 expression by directly binding to their two target sites in its 3′-UTR. On the other hand, miR-95, which is highly expressed in adult peripheral blood Tregs, positively regulated FOXP3 expression via an indirect mechanism yet to be identified. Finally, we showed that miR-145 negatively regulated CTLA-4 expression in human CD4+ adult peripheral blood Tregs by binding to its target site in CTLA-4 transcript 3′-UTR. To our knowledge, this is the first identification of a human adult peripheral blood CD4+ Treg microRNA signature. Moreover, unveiling one mechanism regulating CTLA-4 expression is novel and may lead to a better understanding of the regulation of this crucial gene. PMID:22294691

  1. 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

  2. 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.

  3. 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

  4. Type 1 diabetes immunotherapy using polyclonal regulatory T cells.

    PubMed

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

    2015-11-25

    Type 1 diabetes (T1D) is an autoimmune disease that occurs in genetically susceptible individuals. Regulatory T cells (Tregs) have been shown to be defective in the autoimmune disease setting. Thus, efforts to repair or replace Tregs in T1D may reverse autoimmunity and protect the remaining insulin-producing β cells. On the basis of this premise, a robust technique has been developed to isolate and expand Tregs from patients with T1D. The expanded Tregs retained their T cell receptor diversity and demonstrated enhanced functional activity. We report on a phase 1 trial to assess safety of Treg adoptive immunotherapy in T1D. Fourteen adult subjects with T1D, in four dosing cohorts, received ex vivo-expanded autologous CD4(+)CD127(lo/-)CD25(+) polyclonal Tregs (0.05 × 10(8) to 26 × 10(8) cells). A subset of the adoptively transferred Tregs was long-lived, with up to 25% of the peak level remaining in the circulation at 1 year after transfer. Immune studies showed transient increases in Tregs in recipients and retained a broad Treg FOXP3(+)CD4(+)CD25(hi)CD127(lo) phenotype long-term. There were no infusion reactions or cell therapy-related high-grade adverse events. C-peptide levels persisted out to 2+ years after transfer in several individuals. These results support the development of a phase 2 trial to test efficacy of the Treg therapy. PMID:26606968

  5. Cell cycle control by oscillating regulatory proteins in Caulobacter crescentus.

    PubMed

    Holtzendorff, Julia; Reinhardt, Jens; Viollier, Patrick H

    2006-04-01

    Significant strides have been made in recent years towards understanding the molecular basis of cell cycle progression in the model bacterium Caulobacter crescentus. At the heart of cell cycle regulation is a multicomponent transcriptional feedback loop, governing the production of successive regulatory waves or pulses of at least three master regulatory proteins. These oscillating master regulators direct the execution of phase-specific events and, importantly, through intrinsic genetic switches not only determine the length of a given phase, but also provide the driving force that catapults the cell into the next stage of the cell cycle. The genetic switches act as fail safe mechanisms that prevent the cell cycle from relapsing and thus govern the ordered production and the periodicity of these regulatory waves. Here, we detail how the master regulators CtrA, GcrA and DnaA coordinate cell cycle progression and polar development in Caulobacter. PMID:16547950

  6. Cell cycle control by oscillating regulatory proteins in Caulobacter crescentus.

    PubMed

    Holtzendorff, Julia; Reinhardt, Jens; Viollier, Patrick H

    2006-04-01

    Significant strides have been made in recent years towards understanding the molecular basis of cell cycle progression in the model bacterium Caulobacter crescentus. At the heart of cell cycle regulation is a multicomponent transcriptional feedback loop, governing the production of successive regulatory waves or pulses of at least three master regulatory proteins. These oscillating master regulators direct the execution of phase-specific events and, importantly, through intrinsic genetic switches not only determine the length of a given phase, but also provide the driving force that catapults the cell into the next stage of the cell cycle. The genetic switches act as fail safe mechanisms that prevent the cell cycle from relapsing and thus govern the ordered production and the periodicity of these regulatory waves. Here, we detail how the master regulators CtrA, GcrA and DnaA coordinate cell cycle progression and polar development in Caulobacter.

  7. Construction of cis-regulatory input functions of yeast promoters.

    PubMed

    Ratna, Prasuna; Becskei, Attila

    2011-01-01

    Promoters contain a large number of binding sites for transcriptional factors transmitting signals from a variety of cellular pathways. The promoter processes these input signals and sets the level of gene expression, the output of the gene. Here, we describe how to design genetic constructs and measure gene expression to deliver data suitable for quantitative analysis. Synthetic genetic constructs are well suited to precisely control and measure gene expression to construct cis-regulatory input functions. These functions can be used to predict gene expression based on signal intensities transmitted to activators and repressors in the gene regulatory region. Simple models of gene expression are presented for competitive and noncompetitive repressions. Complex phenomena, exemplified by synergistic silencing, are modeled by reaction-diffusion equations.

  8. 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

  9. 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

  10. Immunomodulatory effects of deacetylase inhibitors: therapeutic targeting of FOXP3+ regulatory T cells

    PubMed Central

    Wang, Liqing; de Zoeten, Edwin F.; Greene, Mark I.; Hancock, Wayne W.

    2010-01-01

    Classical zinc-dependent histone deacetylases (HDACs) catalyse the removal of acetyl groups from histone tails and also from many non-histone proteins, including the transcription factor FOXP3, a key regulator of the development and function of regulatory T cells. Many HDAC inhibitors are in cancer clinical trials, but a subset of HDAC inhibitors has important anti-inflammatory or immunosuppressive effects that might be of therapeutic benefit in immuno-inflammatory disorders or post-transplantation. At least some of these effects result from the ability of HDAC inhibitors to enhance the production and suppressive functions of FOXP3+ regulatory T cells. Understanding which HDACs contribute to the regulation of the functions of regulatory T cells may further stimulate the development of new class- or subclass-specific HDAC inhibitors with applications beyond oncology. PMID:19855427

  11. 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

  12. 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

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

    PubMed

    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

  14. 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

  15. Transcriptional regulatory programs underlying barley germination and regulatory functions of Gibberellin and abscisic acid

    PubMed Central

    2011-01-01

    Background Seed germination is a complex multi-stage developmental process, and mainly accomplished through concerted activities of many gene products and biological pathways that are often subjected to strict developmental regulation. Gibberellins (GA) and abscisic acid (ABA) are two key phytohormones regulating seed germination and seedling growth. However, transcriptional regulatory networks underlying seed germination and its associated biological pathways are largely unknown. Results The studies examined transcriptomes of barley representing six distinct and well characterized germination stages and revealed that the transcriptional regulatory program underlying barley germination was composed of early, late, and post-germination phases. Each phase was accompanied with transcriptional up-regulation of distinct biological pathways. Cell wall synthesis and regulatory components including transcription factors, signaling and post-translational modification components were specifically and transiently up-regulated in early germination phase while histone families and many metabolic pathways were up-regulated in late germination phase. Photosynthesis and seed reserve mobilization pathways were up-regulated in post-germination phase. However, stress related pathways and seed storage proteins were suppressed through the entire course of germination. A set of genes were transiently up-regulated within three hours of imbibition, and might play roles in initiating biological pathways involved in seed germination. However, highly abundant transcripts in dry barley and Arabidopsis seeds were significantly conserved. Comparison with transcriptomes of barley aleurone in response to GA and ABA identified three sets of germination responsive genes that were regulated coordinately by GA, antagonistically by ABA, and coordinately by GA but antagonistically by ABA. Major CHO metabolism, cell wall degradation and protein degradation pathways were up-regulated by both GA and seed

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

    PubMed

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

    2015-10-28

    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.

  17. 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

  18. 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

  19. [THE FATTY CELL. THE VISCERAL FATTY TISSUE, EFFECT OF HUMORAL MEDIATOR LEPTIN IN AUTOCRINE WAY AND IN PARACRIN CENOSISES OF CELLS. TWO PHYLOGENETICALLY, FUNCTIONALLY AND REGULATORY DIFFERENT POOLS OF FATTY TISSUE IN VIVO].

    PubMed

    Titov, V N

    2015-08-01

    Every cell reserves fatty acids in cytozol in drops of lipids in the form of non-polar triglycerides for itself andfor oxidation in mitochondria. The specialized visceral fatty cells ofomentum and adipocytes ofsubcutaneous fat are the cells absorbing saturated and mono unsaturated fatty acids in form of triglycerides in apoB-48 chylomicrons, apoB-100 lipoproteins of low and very low density. They deposit their physiological time and liberate fatty acids in intercellular medium in the form ofpolar unesterified fatty acids bound by albumin. According phylogenetic theory of general pathology, in biological function of trophology (nutrition) fatty cells sequentially implement biological reaction of exotrophy (external nutrition), deposition and endotrophy (internal nutrition). The humoral regulator offeedback in visceral fatty cells is leptin acting in autocrine way, in paracrin cenosises of cells and on the level of organism. The biological role of leptin is in preventing a) deposition of surplus amount of non-polar triglycerides in fatty cells; b) formation of endoplasmic "stress"; c) death of fatty cells in apoptosis way, formation of corpuscles of apoptosis and failure of biological function of endoecology; d) formation of biological reaction of inflammation in visceral fatty tissue; e) high level of unsaturated fatty acids in intercellular medium and f) development of metabolic syndrome. The leptin prevents aphysiological deposit ofnon-polar triglycerides in insulin-dependent cells that are not intended to deposit non-polar triglycerides and also in β-cells of islands. The main cause of high level ofleptin in blood plasma is overeating offood physiological by content of nutrients. PMID:26596040

  20. [THE FATTY CELL. THE VISCERAL FATTY TISSUE, EFFECT OF HUMORAL MEDIATOR LEPTIN IN AUTOCRINE WAY AND IN PARACRIN CENOSISES OF CELLS. TWO PHYLOGENETICALLY, FUNCTIONALLY AND REGULATORY DIFFERENT POOLS OF FATTY TISSUE IN VIVO].

    PubMed

    Titov, V N

    2015-08-01

    Every cell reserves fatty acids in cytozol in drops of lipids in the form of non-polar triglycerides for itself andfor oxidation in mitochondria. The specialized visceral fatty cells ofomentum and adipocytes ofsubcutaneous fat are the cells absorbing saturated and mono unsaturated fatty acids in form of triglycerides in apoB-48 chylomicrons, apoB-100 lipoproteins of low and very low density. They deposit their physiological time and liberate fatty acids in intercellular medium in the form ofpolar unesterified fatty acids bound by albumin. According phylogenetic theory of general pathology, in biological function of trophology (nutrition) fatty cells sequentially implement biological reaction of exotrophy (external nutrition), deposition and endotrophy (internal nutrition). The humoral regulator offeedback in visceral fatty cells is leptin acting in autocrine way, in paracrin cenosises of cells and on the level of organism. The biological role of leptin is in preventing a) deposition of surplus amount of non-polar triglycerides in fatty cells; b) formation of endoplasmic "stress"; c) death of fatty cells in apoptosis way, formation of corpuscles of apoptosis and failure of biological function of endoecology; d) formation of biological reaction of inflammation in visceral fatty tissue; e) high level of unsaturated fatty acids in intercellular medium and f) development of metabolic syndrome. The leptin prevents aphysiological deposit ofnon-polar triglycerides in insulin-dependent cells that are not intended to deposit non-polar triglycerides and also in β-cells of islands. The main cause of high level ofleptin in blood plasma is overeating offood physiological by content of nutrients.

  1. Variant human phosphoribosylpyrophosphate synthetase altered in regulatory and catalytic functions.

    PubMed Central

    Becker, M A; Raivio, K O; Bakay, B; Adams, W B; Nyhan, W L

    1980-01-01

    An inherited, structurally abnormal and superactive form of the enzyme 5-phosphoribosyl 1-pyrophosphate (PP-ribose-P) synthetase (EC 2.7.6.1) has been characterized in fibroblasts cultured from a 14-yr-old male (S.M.) with clinical manifestations of uric acid overproduction present since infancy. PP-ribose-P synthetase from the cells of this child showed four- to fivefold greater than normal resistance to purine nucleotide (ADP and GDP) feedback inhibition of enzyme activity and hyperbolic rather than sigmoidal inorganic phosphate (Pi) activation in incompletely dialyzed extracts. Excessive maximal velocity of the enzyme reaction catalyzed by the mutant enzyme was indicated by: enzyme activities twice those of normal at all concentrations of Pi in chromatographed fibroblast extracts; normal affinity constants for substrates and for the activator, Mg2+; and twofold greater than normal activity per immunoreactive enzyme molecule. The mutant enzyme thus possessed deficient regulatory and superactive catalytic properties, two mechanisms previously demonstrated individually to underlie the excessive PPRribose-P and uric acid synthesis of affected members of families with superactive PP-ribose-P synthetases. Increased PP-ribose-P concentration (4-fold) and generation (2.7-fold) and enhanced rates of PP-ribose-P dependent purine synthetic reactions, including purine synthesis de novo, in S.M. fibroblasts confirmed the functional significance of this patient's mutant enzyme. Diminished stability of the variant PP-ribose-P synthetase was manifested in vitro by increased thermal lability and in vivo by deficiency of enzyme activity at Pi concentrations greater than 0.3 mM in hemolysates and by an accelerated, age-related decrement in enzyme activity in lysates of erythrocytes separated by specific density. Despite the diminished amount of PP-ribose-P synthetase in the S.M. erythrocyte population, S.M. erythrocytes had increased PP-ribose-P concentration and increased rates

  2. 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

  3. 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

  4. 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

  5. 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

    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

  6. 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.

  7. 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

  8. 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

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

    PubMed

    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

    2015-07-21

    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.

  10. 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

  11. 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

  12. 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.

  13. 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.

  14. 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

  15. Regulatory T Cells in Tumor-Associated Tertiary Lymphoid Structures Suppress Anti-tumor T Cell Responses.

    PubMed

    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

    2015-09-15

    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 model of lung adenocarcinoma and found that Treg cells suppressed anti-tumor responses in tumor-associated tertiary lymphoid structures (TA-TLSs). TA-TLSs have been described in human lung cancers, but their function remains to be determined. TLSs 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-TLSs upon Treg cell depletion, leading to tumor destruction. Thus, we propose that Treg cells in TA-TLSs can inhibit endogenous immune responses against tumors, and targeting these cells might provide therapeutic benefit for cancer patients.

  16. 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

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed Central

    White, Anna Malgorzata; Wraith, David C.

    2016-01-01

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

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

    PubMed Central

    White, Anna Malgorzata; Wraith, David C.

    2016-01-01

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

  20. Tr1-Like T Cells - An Enigmatic Regulatory T Cell Lineage.

    PubMed

    White, Anna Malgorzata; Wraith, David C

    2016-01-01

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

  1. [Helper T cell paradigm: Th17 and regulatory T cells involved in autoimmune inflammatory disorders, pathogen defense and allergic diseases].

    PubMed

    Noma, Takeshi

    2010-01-01

    The helper T cell paradigm, divided into two distinct subsets, Th1 and Th2 cells, characterized by distinct cytokine and functions, has been expanded to IL-17-producing Th17 cells. Th1 cells producing IFN-γ are involved in delayed-type hypersensitivity, effective in intracellular pathogens defense, while Th2 cells secrete IL-4, IL-5, IL-13 and IL-25 and has a central role in IgE production, eosinophilic inflammation, and the protection for helminthic parasite infection. Th17 cell lineages, expressing IL-17 family of cytokines and IL-23-mediated functions on T cells, plays a role in immune response to fungi and extracellular pathogens and autoimmune inflammatory disorders. Th17 cells are required the combination of IL-6 and TGF-β and the transcription factors, RORC2/RORgt (mice) and STAT3 for differentiation, and produce IL-17, IL-22, IL-17F, IL-21 and CCL20. FOXP3+ regulatory T (Treg) cells produce TGF-β and IL-10, which regulate effector T cells, and thus maintain peripheral tolerance. Four functionally unique CD4+ T cells, including the regulatory T (Treg) cells are now involved in the regulation of immune responses to pathogens, self-antigens and allergens. Any defect in the entire CD4+T cell population might results in human diseases. In this review, the biology of Th17 cells and Treg cells and their role in immune diseases are presented.

  2. Dendritic Cells Coordinate the Development and Homeostasis of Organ-Specific Regulatory T Cells.

    PubMed

    Leventhal, Daniel S; Gilmore, Dana C; Berger, Julian M; Nishi, Saki; Lee, Victoria; Malchow, Sven; Kline, Douglas E; Kline, Justin; Vander Griend, Donald J; Huang, Haochu; Socci, Nicholas D; Savage, Peter A

    2016-04-19

    Although antigen recognition mediated by the T cell receptor (TCR) influences many facets of Foxp3(+) regulatory T (Treg) cell biology, including development and function, the cell types that present antigen to Treg cells in vivo remain largely undefined. By tracking a clonal population of Aire-dependent, prostate-specific Treg cells in mice, we demonstrated an essential role for dendritic cells (DCs) in regulating organ-specific Treg cell biology. We have shown that the thymic development of prostate-specific Treg cells required antigen presentation by DCs. Moreover, Batf3-dependent CD8α(+) DCs were dispensable for the development of this clonotype and had negligible impact on the polyclonal Treg cell repertoire. In the periphery, CCR7-dependent migratory DCs coordinated the activation of organ-specific Treg cells in the prostate-draining lymph nodes. Our results demonstrate that the development and peripheral regulation of organ-specific Treg cells are dependent on antigen presentation by DCs, implicating DCs as key mediators of organ-specific immune tolerance.

  3. 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

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

    PubMed

    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

  5. Xist function: bridging chromatin and stem cells.

    PubMed

    Wutz, Anton

    2007-09-01

    In mammals, dosage compensation is achieved by transcriptional silencing of one of the two female X chromosomes. X inactivation is dynamically regulated in development. The non-coding Xist RNA localizes to the inactive X, initiates gene repression in the early embryo, and later stabilizes the inactive state. Different functions of Xist are observed depending on which epigenetic regulatory pathways are active in a given cell. Because Xist has evolved recently, with the origin of placental mammals, the underlying pathways are also important in regulating developmental control genes. This review emphasizes the opportunity that Xist provides to functionally define epigenetic transitions in development, to understand cell identity, pluripotency and stem cell differentiation.

  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. 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

  8. Regulatory T Cells in Autoimmune Diabetes: Mechanisms of Action and Translational Potential.

    PubMed

    Ovcinnikovs, Vitalijs; Walker, Lucy S K

    2015-01-01

    Since the discovery of specialized T cells with regulatory function, harnessing the power of these cells to ameliorate autoimmunity has been a major goal. Here we collate the evidence that regulatory T cells (Treg) can inhibit Type 1 diabetes in animal models and humans. We discuss the anatomical sites and molecular mechanisms of Treg suppressive function in the Type 1 diabetes setting, citing evidence that Treg can function in both the pancreatic lymph nodes and within the pancreatic lesion. Involvement of the CTLA-4 pathway, as well as TGF-β and IL-2 deprivation will be considered. Finally, we summarize current efforts to manipulate Treg therapeutically in individuals with Type 1 diabetes. The translation of this research area from bench to bedside is still in its infancy, but the remarkable therapeutic potential of successfully manipulating Treg populations is clear to see. PMID:26615100

  9. 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

  10. 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.

  11. Trypanosoma cruzi Induces Regulatory Dendritic Cells In Vitro▿

    PubMed Central

    Poncini, Carolina Verónica; Soto, Catalina Dirney Alba; Batalla, Estela; Solana, Maria Elisa; González Cappa, Stella Maris

    2008-01-01

    A main feature of acute infection with Trypanosoma cruzi is the presence of immunological disorders. A previous study demonstrated that acute infection with the virulent RA strain downregulates the expression of major histocompatibility complex class II (MHC-II) on antigen-presenting cells and impairs the T-cell stimulatory capacity of splenic dendritic cells (DC). In the present work, we assessed the ability of trypomastigotes (Tp) to modulate the differentiation stage and functionality of bone marrow-derived DC in vitro. We observed that the Tp stage of T. cruzi failed to activate DC, which preserved their low expression of MHC-II and costimulatory molecules, as well as their endocytic activity. We also show that Tp induced transforming growth factor β (TGF-β) secretion by DC and enhanced the gap between interleukin-10 (IL-10) and IL-12p70 production, showing a higher IL-10/IL-12p70 ratio upon lipopolysaccharide (LPS) treatment. In addition, we observed that Tp prevented DC full activation induced by LPS, thereby downregulating their MHC-II surface expression and inhibiting their capacity to stimulate lymphocyte proliferation. In vitro IL-10 neutralization during the differentiation process of DC with Tp+LPS showed a reversion of their inhibitory effect during mixed lymphocyte reaction. In contrast, only simultaneous neutralization of IL-10 and TGF-β, after DC differentiation, was involved in the partial restitution of lymphocyte proliferation. Since both TGF-β and IL-10 are immunosuppressive cytokines essential in the modulation of the immune response and important in the induction of tolerance, our results suggest for the first time that Tp are responsible for the generation of regulatory DC in vitro. PMID:18347042

  12. Regulatory T cells in many flavors control asthma.

    PubMed

    Ray, A; Khare, A; Krishnamoorthy, N; Qi, Z; Ray, P

    2010-05-01

    That regulatory T cells (Tregs) have a crucial role in controlling allergic diseases such as asthma is now undisputed. The cytokines most commonly implicated in Treg-mediated suppression of allergic asthma are transforming growth factor-beta (TGF-beta) and interleukin (IL)-10). In addition to naturally occurring Tregs, adaptive Tregs, induced in response to foreign antigens, have been shown in recent studies. The concept of inducible/adaptive Tregs (iTregs) has considerable significance in preventing asthma if generated early enough in life. This is because cytokines such as IL-4 and IL-6 inhibit Foxp3 induction in naive CD4+ T cells and therefore de novo generation of Tregs can be expected to be less efficient when it is concomitant with effector cell development in response to an allergen. However, if iTregs can be induced, the process of infectious tolerance would facilitate expansion of the iTreg pool as suggested in the recent literature. It is tempting to speculate that there is a window of opportunity in early life in the context of a relatively immature immune system that is permissive for the generation of iTregs specific to a spectrum of allergens that would regulate asthma for lifelong. The focus of this review is the relevance of nTregs and iTregs in controlling asthma from early life into adulthood, the mechanisms underlying Treg function, and the prospects for using our current concepts to harness the full potential of Tregs to limit disease development and progression.

  13. A Regulatory Feedback between Plasmacytoid Dendritic Cells and Regulatory B Cells Is Aberrant in Systemic Lupus Erythematosus

    PubMed Central

    Menon, Madhvi; Blair, Paul A.; Isenberg, David A.; Mauri, Claudia

    2016-01-01

    Summary Signals controlling the generation of regulatory B (Breg) cells remain ill-defined. Here we report an “auto”-regulatory feedback mechanism between plasmacytoid dendritic cells (pDCs) and Breg cells. In healthy individuals, pDCs drive the differentiation of CD19+CD24hiCD38hi (immature) B cells into IL-10-producing CD24+CD38hi Breg cells and plasmablasts, via the release of IFN-α and CD40 engagement. CD24+CD38hi Breg cells conversely restrained IFN-α production by pDCs via IL-10 release. In systemic lupus erythematosus (SLE), this cross-talk was compromised; pDCs promoted plasmablast differentiation but failed to induce Breg cells. This defect was recapitulated in healthy B cells upon exposure to a high concentration of IFN-α. Defective pDC-mediated expansion of CD24+CD38hi Breg cell numbers in SLE was associated with altered STAT1 and STAT3 activation. Both altered pDC-CD24+CD38hi Breg cell interactions and STAT1-STAT3 activation were normalized in SLE patients responding to rituximab. We propose that alteration in pDC-CD24+CD38hi Breg cell interaction contributes to the pathogenesis of SLE. PMID:26968426

  14. Characterization of Regulatory B Cells in Graves' Disease and Hashimoto's Thyroiditis.

    PubMed

    Kristensen, Birte; Hegedüs, Laszlo; Lundy, Steven K; Brimnes, Marie K; Smith, Terry J; Nielsen, Claus H

    2015-01-01

    A hallmark of regulatory B cells is IL-10 production, hence their designation as IL-10+ B cells. Little is known about the ability of self-antigens to induce IL-10+ B cells in Graves' disease (GD), Hashimoto's thyroiditis (HT), or other autoimmune disease. Here we pulsed purified B cells from 12 HT patients, 12 GD patients, and 12 healthy donors with the thyroid self-antigen, thyroglobulin (TG) and added the B cells back to the remaining peripheral blood mononuclear cells (PBMCs). This procedure induced IL-10+ B-cell differentiation in GD. A similar tendency was observed in healthy donors, but not in cells from patients with HT. In GD, B cells primed with TG induced IL-10-producing CD4+ T cells. To assess the maximal frequency of inducible IL-10+ B cells in the three donor groups PBMCs were stimulated with PMA/ionomycin. The resulting IL-10+ B-cell frequency was similar in the three groups and correlated with free T3 levels in GD patients. IL-10+ B cells from both patient groups displayed CD25 or TIM-1 more frequently than did those from healthy donors. B-cell expression of two surface marker combinations previously associated with regulatory B-cell functions, CD24hiCD38hi and CD27+CD43+, did not differ between patients and healthy donors. In conclusion, our findings indicate that autoimmune thyroiditis is not associated with reduced frequency of IL-10+ B cells. These results do not rule out regulatory B-cell dysfunction, however. The observed phenotypic differences between IL-10+ B cells from patients and healthy donors are discussed.

  15. T regulatory cells and B cells cooperate to form a regulatory loop that maintains gut homeostasis and suppresses dextran sulfate sodium-induced colitis.

    PubMed

    Wang, L; Ray, A; Jiang, X; Wang, J-y; Basu, S; Liu, X; Qian, T; He, R; Dittel, B N; Chu, Y

    2015-11-01

    Regulatory T cells (Tregs) and B cells present in gut-associated lymphoid tissues (GALT) are both implicated in the resolution of colitis. However, how the functions of these cells are coordinated remains elusive. We used the dextran sulfate sodium (DSS)-induced colitis model combined with gene-modified mice to monitor the progression of colitis, and simultaneously examine the number of Tregs and B cells, and the production of IgA antibodies. We found that DSS-treated mice exhibited more severe colitis in the absence of B cells, and that the adoptive transfer of B cells attenuated the disease. Moreover, the transfer of IL-10(-/-) B cells also attenuated colitis, suggesting that B cells inhibited colitis through an interleukin-10 (IL-10)-independent pathway. Furthermore, antibody depletion of Tregs resulted in exacerbated colitis. Intriguingly, the number of GALT Tregs in B cell-deficient mice was significantly decreased during colitis and the adoptive transfer of B cells into these mice restored the Treg numbers, indicating that B cells contribute to Treg homeostasis. We also found that B cells induced the proliferation of Tregs that in turn promoted B-cell differentiation into IgA-producing plasma cells. These results demonstrate that B cells and Tregs interact and cooperate to prevent excessive immune responses that can lead to colitis.

  16. T regulatory cells and B cells cooperate to form a regulatory loop that maintains gut homeostasis and suppresses dextran sulfate sodium-induced colitis

    PubMed Central

    Wang, L; Ray, A; Jiang, X; Wang, J-y; Basu, S; Liu, X; Qian, T; He, R; Dittel, B N; Chu, Y

    2015-01-01

    Regulatory T cells (Tregs) and B cells present in gut-associated lymphoid tissues (GALT) are both implicated in the resolution of colitis. However, how the functions of these cells are coordinated remains elusive. We used the dextran sulfate sodium (DSS)-induced colitis model combined with gene-modified mice to monitor the progression of colitis, and simultaneously examine the number of Tregs and B cells, and the production of IgA antibodies. We found that DSS-treated mice exhibited more severe colitis in the absence of B cells, and that the adoptive transfer of B cells attenuated the disease. Moreover, the transfer of IL-10−/− B cells also attenuated colitis, suggesting that B cells inhibited colitis through an interleukin-10 (IL-10)-independent pathway. Furthermore, antibody depletion of Tregs resulted in exacerbated colitis. Intriguingly, the number of GALT Tregs in B cell-deficient mice was significantly decreased during colitis and the adoptive transfer of B cells into these mice restored the Treg numbers, indicating that B cells contribute to Treg homeostasis. We also found that B cells induced the proliferation of Tregs that in turn promoted B-cell differentiation into IgA-producing plasma cells. These results demonstrate that B cells and Tregs interact and cooperate to prevent excessive immune responses that can lead to colitis. PMID:25807185

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

    PubMed Central

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

    2015-01-01

    Cell-to-cell variation is a universal feature of life that impacts a wide range of biological phenomena, from developmental plasticity1,2 to tumor heterogeneity3. While recent advances have improved our ability to document cellular phenotypic variation4–8 the fundamental mechanisms that generate variability from identical DNA sequences remain elusive. Here we reveal the landscape and principles of cellular DNA regulatory variation by developing a robust method for mapping the accessible genome of individual cells via assay for transposase-accessible chromatin using sequencing (ATAC-seq). 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 provides 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 8 cell types. Targeted perturbations of cell cycle or transcription factor signaling evoke stimulus-specific changes in this observed variability. The pattern of accessibility variation in cis across the genome recapitulates chromosome topological domains9 de novo, linking single-cell accessibility variation to three-dimensional genome organization. All together, single-cell analysis of DNA accessibility provides new insight into cellular variation of the “regulome.” PMID:26083756

  18. 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'.

  19. An overview of stem cell research and regulatory issues.

    PubMed

    Cogle, Christopher R; Guthrie, Steven M; Sanders, Ronald C; Allen, William L; Scott, Edward W; Petersen, Bryon E

    2003-08-01

    Stem cells are noted for their ability to self-renew and differentiate into a variety of cell types. Some stem cells, described as totipotent cells, have tremendous capacity to self-renew and differentiate. Embryonic stem cells have pluripotent capacity, able to form tissues of all 3 germ layers but unable to form an entire live being. Research with embryonic stem cells has enabled investigators to make substantial gains in developmental biology, therapeutic tissue engineering, and reproductive cloning. However, with these remarkable opportunities many ethical challenges arise, which are largely based on concerns for safety, efficacy, resource allocation, and methods of harvesting stem cells. Discussing the moral and legal status of the human embryo is critical to the debate on stem cell ethics. Religious perspectives and political events leading to regulation of stem cell research are presented and discussed, with special attention directed toward the use of embryonic stem cells for therapeutic and reproductive cloning. Adult stem cells were previously thought to have a restricted capacity to differentiate; however, several reports have described their plasticity potential. Furthermore, there have been close ties between the behavior of stem cells and cancer cells. True eradication of cancer will require a deeper understanding of stem cell biology. This article was written to inform medical scientists and practicing clinicians across the spectrum of medical education about the research and regulatory issues affecting the future of stem cell therapy.

  20. Distinct regulatory elements mediate similar expression patterns in the excretory cell of Caenorhabditis elegans.

    PubMed

    Zhao, Zhongying; Fang, Li; Chen, Nansheng; Johnsen, Robert C; Stein, Lincoln; Baillie, David L

    2005-11-18

    Identification of cis-regulatory elements and their binding proteins constitutes an important part of understanding gene function and regulation. It is well accepted that co-expressed genes tend to share transcriptional elements. However, recent findings indicate that co-expression data show poor correlation with co-regulation data even in unicellular yeast. This motivates us to experimentally explore whether it is possible that co-expressed genes are subject to differential regulatory control using the excretory cell of Caenorhabditis elegans as an example. Excretory cell is a functional equivalent of human kidney. Transcriptional regulation of gene expression in the cell is largely unknown. We isolated a 10-bp excretory cell-specific cis-element, Ex-1, from a pgp-12 promoter. The significance of the element has been demonstrated by its capacity of converting an intestine-specific promoter into an excretory cell-specific one. We also isolated a cDNA encoding an Ex-1 binding transcription factor, DCP-66, using a yeast one-hybrid screen. Role of the factor in regulation of pgp-12 expression has been demonstrated both in vitro and in vivo. Search for occurrence of Ex-1 reveals that only a small portion of excretory cell-specific promoters contain Ex-1. Two other distinct cis-elements isolated from two different promoters can also dictate the excretory cell-specific expression but are independent of regulation by DCP-66. The results indicate that distinct regulatory elements are able to mediate the similar expression patterns.

  1. 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.

  2. 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

  3. 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.

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

    PubMed

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

    2014-02-24

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

  5. 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

  6. A microfluidic platform reveals differential response of regulatory T cells to micropatterned costimulation arrays.

    PubMed

    Lee, Joung-Hyun; Dustin, Michael L; Kam, Lance C

    2015-11-01

    T cells are key mediators of adaptive immunity. However, the overall immune response is often directed by minor subpopulations of this heterogeneous family of cells, owing to specificity of activation and amplification of functional response. Knowledge of differences in signaling and function between T cell subtypes is far from complete, but is clearly needed for understanding and ultimately leveraging this branch of the adaptive immune response. This report investigates differences in cell response to micropatterned surfaces by conventional and regulatory T cells. Specifically, the ability of cells to respond to the microscale geometry of TCR/CD3 and CD28 engagement is made possible using a magnetic-microfluidic device that overcomes limitations in imaging efficiency associated with conventional microscopy equipment. This device can be readily assembled onto micropatterned surfaces while maintaining the activity of proteins and other biomolecules necessary for such studies. In operation, a target population of cells is tagged using paramagnetic beads, and then trapped in a divergent magnetic field within the chamber. Following washing, the target cells are released to interact with a designated surface. Characterization of this system with mouse CD4(+) T cells demonstrated a 50-fold increase in target-to-background cell purity, with an 80% collection efficiency. Applying this approach to CD4(+)CD25(+) regulatory T cells, it is then demonstrated that these rare cells respond less selectively to micro-scale features of anti-CD3 antibodies than CD4(+)CD25(-) conventional T cells, revealing a difference in balance between TCR/CD3 and LFA-1-based adhesion. PKC-θ localized to the distal pole of regulatory T cells, away from the cell-substrate interface, suggests a mechanism for differential regulation of TCR/LFA-1-based adhesion. Moreover, specificity of cell adhesion to anti-CD3 features was dependent on the relative position of anti-CD28 signaling within the cell

  7. A microfluidic platform reveals differential response of regulatory T cells to micropatterned costimulation arrays.

    PubMed

    Lee, Joung-Hyun; Dustin, Michael L; Kam, Lance C

    2015-11-01

    T cells are key mediators of adaptive immunity. However, the overall immune response is often directed by minor subpopulations of this heterogeneous family of cells, owing to specificity of activation and amplification of functional response. Knowledge of differences in signaling and function between T cell subtypes is far from complete, but is clearly needed for understanding and ultimately leveraging this branch of the adaptive immune response. This report investigates differences in cell response to micropatterned surfaces by conventional and regulatory T cells. Specifically, the ability of cells to respond to the microscale geometry of TCR/CD3 and CD28 engagement is made possible using a magnetic-microfluidic device that overcomes limitations in imaging efficiency associated with conventional microscopy equipment. This device can be readily assembled onto micropatterned surfaces while maintaining the activity of proteins and other biomolecules necessary for such studies. In operation, a target population of cells is tagged using paramagnetic beads, and then trapped in a divergent magnetic field within the chamber. Following washing, the target cells are released to interact with a designated surface. Characterization of this system with mouse CD4(+) T cells demonstrated a 50-fold increase in target-to-background cell purity, with an 80% collection efficiency. Applying this approach to CD4(+)CD25(+) regulatory T cells, it is then demonstrated that these rare cells respond less selectively to micro-scale features of anti-CD3 antibodies than CD4(+)CD25(-) conventional T cells, revealing a difference in balance between TCR/CD3 and LFA-1-based adhesion. PKC-θ localized to the distal pole of regulatory T cells, away from the cell-substrate interface, suggests a mechanism for differential regulation of TCR/LFA-1-based adhesion. Moreover, specificity of cell adhesion to anti-CD3 features was dependent on the relative position of anti-CD28 signaling within the cell

  8. Specificity of regulatory CD4+CD25+ T cells for self-T cell receptor determinants.

    PubMed

    Buenafe, Abigail C; Tsaknaridis, Laura; Spencer, Leslie; Hicks, Kevin S; McMahan, Rachel H; Watson, Lisa; Culbertson, Nicole E; Latocha, Dorian; Wegmann, Keith; Finn, Tom; Bartholomew, Richard; Burrows, Gregory G; Whitham, Ruth; Bourdette, Dennis N; Jones, Richard E; Offner, Halina; Chou, Yuan K; Vandenbark, Arthur A

    2004-04-01

    Although the phenotypic and regulatory properties of the CD4(+)CD25(+) T cell lineage (Treg cells) have been well described, the specificities remain largely unknown. We demonstrate here that the CD4(+)CD25(+) Treg population includes the recognition of a broad spectrum of human TCR CDR2 determinants found in the germline V gene repertoire as well as that of a clonotypic nongermline-encoded CDR3beta sequence present in a recombinant soluble T cell receptor (TCR) protein. Regulatory activity was demonstrated in T cell lines responsive to TCR but not in T cell lines responsive to control antigens. Inhibitory activity of TCR-reactive T cells required cell-cell contact and involved CTLA-4, GITR, IL-10, and IL-17. Thus, the T-T regulatory network includes Treg cells with specificity directed toward self-TCR determinants.

  9. 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

  10. Harnessing FOXP3+ regulatory T cells for transplantation tolerance

    PubMed Central

    Waldmann, Herman; Hilbrands, Robert; Howie, Duncan; Cobbold, Stephen

    2014-01-01

    Early demonstrations that mice could be tolerized to transplanted tissues with short courses of immunosuppressive therapy and that with regard to tolerance to self, CD4+FOXP3+ regulatory T cells (Tregs) appeared to play a critical role, have catalyzed strategies to harness FOXP3-dependent processes to control rejection in human transplantation. This review seeks to examine the scientific underpinning for this new approach to finesse immunosuppression. PMID:24691478

  11. 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

  12. 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.

  13. Epigenetic and transcriptional control of Foxp3+ regulatory T cells.

    PubMed

    Huehn, Jochen; Beyer, Marc

    2015-02-01

    Regulatory T cells (Treg cells) present a unique T-cell lineage that plays a key role for the initiation and maintenance of immunological tolerance. Treg cells are characterized by the expression of the forkhead box transcription factor Foxp3, which acts as a lineage-specifying factor and determines the unique properties of these immunosuppressive cells. Work over the past few years has shown that well-defined and precisely controlled events on transcriptional and epigenetic level are required to ensure stable expression of Foxp3 in Treg cells. More recent work suggested that in addition to stable Foxp3 expression, epigenetic modifications of Treg-cell specific genes contribute to the unique phenotype of Treg cells by imprinting their transcriptional program and stabilizing the expression of molecules being essential for the suppressive properties of Treg cells. In this review, we will highlight how Foxp3 expression itself is epigenetically and transcriptionally controlled, how the Treg-cell specific epigenetic signature is achieved, how Foxp3 as transcription factor influences the gene expression programs in Treg cells and how unique properties of Treg-cell subsets are defined by other transcription factors.

  14. Impaired CD4+CD25+ regulatory T cell activity in the peripheral blood of patients with autoimmune sensorineural hearing loss.

    PubMed

    Xia, Ming; Zhang, Han Bing; Liu, Fang; Yin, Hai Ying; Xu, An Ting

    2008-09-01

    CD4+CD25+ regulatory T cells exert an immune regulatory function and thus play an important role in the control of self-reactivity in the pathogenesis of autoimmune inflammatory conditions. The aim of the study presented here is to perform a quantitative and functional analyses of these cells in patients with autoimmune sensorineural hearing loss (ASNHL). T cell subsets (CD4+CD25+, CD4+CD25(high), CD4+, and CD8+) from the peripheral blood of 17 patients with ASNHL, 16 patients with noise induced hearing loss (NHL), and 100 normal controls were analyzed by flow cytometry. The CD4/CD8 ratio was also analyzed. In addition, the suppressive capability of CD4+CD25+ T cells was tested in vitro by measuring their ability to suppress the proliferation and IFN-gamma secretion of CD4+CD25- T cells. No significant difference was found in the T cell subsets of ASNHL patients compared to normal controls or NHL patients, except that the proportion of CD4+ T cells was elevated in ASNHL patients. However, we did observe defective regulatory function of CD4+CD25+ T cells in patients with ASNHL. Our data supported the idea that CD4+CD25+ regulatory T cells played an immunosuppressive function in the periphery. The impaired suppressive activity of these cells may be an important factor in the pathogenesis of ASNHL.

  15. Mesenchymal stromal cells and immunomodulation: A gathering of regulatory immune cells.

    PubMed

    Najar, Mehdi; Raicevic, Gordana; Fayyad-Kazan, Hussein; Bron, Dominique; Toungouz, Michel; Lagneaux, Laurence

    2016-02-01

    Because of their well-recognized immunomodulatory properties, mesenchymal stromal cells (MSCs) represent an attractive cell population for therapeutic purposes. In particular, there is growing interest in the use of MSCs as cellular immunotherapeutics for tolerance induction in allogeneic transplantations and the treatment of autoimmune diseases. However, multiple mechanisms have been identified to mediate the immunomodulatory effects of MSCs, sometimes with several ambiguities and inconsistencies. Although published studies have mainly reported the role of soluble factors, we believe that a sizeable cellular component plays a critical role in MSC immunomodulation. We refer to these cells as regulatory immune cells, which are generated from both the innate and adaptive responses after co-culture with MSCs. In this review, we discuss the nature and role of these immune regulatory cells as well as the role of different mediators, and, in particular, regulatory immune cell induction by MSCs through interleukin-10. Once induced, immune regulatory cells accumulate and converge their regulatory pathways to create a tolerogenic environment conducive for immunomodulation. Thus, a better understanding of these regulatory immune cells, in terms of how they can be optimally manipulated and induced, would be suitable for improving MSC-based immunomodulatory therapeutic strategies.

  16. 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

  17. Not miR-ly micromanagers: the functions and regulatory networks of microRNAs in mammalian skin.

    PubMed

    Riemondy, Kent; Hoefert, Jaimee E; Yi, Rui

    2014-01-01

    The microRNA (miRNA) pathway is a widespread mechanism of post-transcriptional gene regulation in eukaryotic cells. In animals, each miRNA species can regulate hundreds of protein-coding genes, resulting in pervasive functions for miRNAs in numerous cellular processes. Since the identification of the first mammalian miRNA, the function of miRNAs in mammals has been a topic of great interest, both because of the versatile roles of miRNAs in biological systems, as well as the clinical potential of these regulatory RNAs. With well-defined cell lineages and the availability of versatile tools for both in vivo and in vitro studies, mammalian skin has emerged as an important system in which to examine miRNAs' functions in adult tissues. In this review, we discuss recent insights into the functions and regulatory networks of miRNAs in mammals, with a specific focus on murine skin development as a model system. We first introduce functional analyses of the miRNA biogenesis pathway in the skin, then highlight the functions of individual miRNAs in skin development, followed by an examination of miRNA roles in skin stress responses. We finish with a discussion of miRNA regulatory networks and emphasize future challenges and emerging technologies that permit the genome-wide study of miRNA functions and regulatory mechanisms in mammalian skin.

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

    PubMed

    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

    2016-03-01

    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

  19. 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

  20. 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.

  1. Colorectal cancer risk genes are functionally enriched in regulatory pathways.

    PubMed

    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

  2. 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

  3. 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

  4. 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

  5. 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

  6. 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

  7. 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.

  8. Functional and regulatory interactions between Hox and extradenticle genes

    PubMed Central

    Azpiazu, Natalia; Morata, Ginés

    1998-01-01

    The homeobox gene extradenticle (exd) acts as a cofactor of Hox function both in Drosophila and vertebrates. It has been shown that the distribution of the Exd protein is developmentally regulated at the post-translational level; in the regions where exd is not functional Exd is present only in the cell cytoplasm, whereas it accumulates in the nuclei of cells requiring exd function. We show that the subcellular localization of Exd is regulated by the BX-C genes and that each BX-C gene can prevent or reduce nuclear translocation of Exd to different extents. In spite of this negative regulation, two BX-C genes, Ultrabithorax and abdominal-A, require exd activity for their maintenance and function. We propose that mutual interactions between Exd and BX-C proteins ensure the correct amounts of interacting molecules. As the Hoxd10 gene has the same properties as Drosophila BX-C genes, we suggest that the control mechanism of subcellular distribution of Exd found in Drosophila probably operates in other organisms as well. PMID:9436985

  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. 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

  11. Matrix Formalism to Describe Functional States of Transcriptional Regulatory Systems

    PubMed Central

    Price, Nathan D; Joyce, Andrew R; Palsson, Bernhard O

    2006-01-01

    Complex regulatory networks control the transcription state of a genome. These transcriptional regulatory networks (TRNs) have been mathematically described using a Boolean formalism, in which the state of a gene is represented as either transcribed or not transcribed in response to regulatory signals. The Boolean formalism results in a series of regulatory rules for the individual genes of a TRN that in turn can be used to link environmental cues to the transcription state of a genome, thereby forming a complete transcriptional regulatory system (TRS). Herein, we develop a formalism that represents such a set of regulatory rules in a matrix form. Matrix formalism allows for the systemic characterization of the properties of a TRS and facilitates the computation of the transcriptional state of the genome under any given set of environmental conditions. Additionally, it provides a means to incorporate mechanistic detail of a TRS as it becomes available. In this study, the regulatory network matrix, R, for a prototypic TRS is characterized and the fundamental subspaces of this matrix are described. We illustrate how the matrix representation of a TRS coupled with its environment (R*) allows for a sampling of all possible expression states of a given network, and furthermore, how the fundamental subspaces of the matrix provide a way to study key TRS features and may assist in experimental design. PMID:16895435

  12. Closing the regulatory regress: GMP accreditation in stem cell laboratories.

    PubMed

    Stephens, Neil; Lewis, Jamie; Atkinson, Paul

    2013-03-01

    Contemporary biomedical research is conducted amidst regimes of national and transnational regulation. Regulation, like rules generally, cannot specify all the practicalities of their application. Regulations for biomedical research impose considerable constraints on laboratories and others. In principle, there is a never-ending regress whereby scientists have to provide increasingly more guarantees that protocols have been followed, standards reached and maintained, and rules adhered to. In practice, regulatory regress is not the actual outcome, as actors find ways of establishing closure for all practical purposes. Based on ethnographic case studies of two sites of biomedical work--the UK Stem Cell Bank and an anonymous laboratory working with primary human foetal material--this article documents the possibility of regulatory regress and strategies aimed at its closure.

  13. 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

  14. 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

  15. Regulatory roles for NKT cell ligands in environmentally induced autoimmunity.

    PubMed

    Vas, Jaya; Mattner, Jochen; Richardson, Stewart; Ndonye, Rachel; Gaughan, John P; Howell, Amy; Monestier, Marc

    2008-11-15

    The development of autoimmune diseases is frequently linked to exposure to environmental factors such as chemicals, drugs, or infections. In the experimental model of metal-induced autoimmunity, administration of subtoxic doses of mercury (a common environmental pollutant) to genetically susceptible mice induces an autoimmune syndrome with rapid anti-nucleolar Ab production and immune system activation. Regulatory components of the innate immune system such as NKT cells and TLRs can also modulate the autoimmune process. We examined the interplay among environmental chemicals and NKT cells in the regulation of autoimmunity. Additionally, we studied NKT and TLR ligands in a tolerance model in which preadministration of a low dose of mercury in the steady state renders animals tolerant to metal-induced autoimmunity. We also studied the effect of Sphingomonas capsulata, a bacterial strain that carries both NKT cell and TLR ligands, on metal-induced autoimmunity. Overall, NKT cell activation by synthetic ligands enhanced the manifestations of metal-induced autoimmunity. Exposure to S. capsulata exacerbated autoimmunity elicited by mercury. Although the synthetic NKT cell ligands that we used are reportedly similar in their ability to activate NKT cells, they displayed pronounced differences when coinjected with environmental agents or TLR ligands. Individual NKT ligands differed in their ability to prevent or break tolerance induced by low-dose mercury treatment. Likewise, different NKT ligands either dramatically potentiated or inhibited the ability of TLR9 agonistic oligonucleotides to disrupt tolerance to mercury. Our data suggest that these differences could be mediated by the modification of cytokine profiles and regulatory T cell numbers.

  16. 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

  17. Design Principles of Regulatory Networks: Searching for the Molecular Algorithms of the Cell

    PubMed Central

    Lim, Wendell A.; Lee, Connie M.; Tang, Chao

    2013-01-01

    A challenge in biology is to understand how complex molecular networks in the cell execute sophisticated regulatory functions. Here we explore the idea that there are common and general principles that link network structures to biological functions, principles that constrain the design solutions that evolution can converge upon for accomplishing a given cellular task. We describe approaches for classifying networks based on abstract architectures and functions, rather than on the specific molecular components of the networks. For any common regulatory task, can we define the space of all possible molecular solutions? Such inverse approaches might ultimately allow the assembly of a design table of core molecular algorithms that could serve as a guide for building synthetic networks and modulating disease networks. PMID:23352241

  18. 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...

  19. 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.

  20. 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

  1. 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

  2. Viral Interactions with B-Cells Contribute to Increased Regulatory T-Cells During Chronic HCV Infection

    PubMed Central

    Ayers, Chris L.; Firan, Mihail; Pillai, Vinodh; Lee, William M.

    2011-01-01

    Abstract Hepatitis C virus (HCV) has a propensity to establish chronic infection that is characterized by attenuated virus-specific T-cell responses. Mechanisms leading to T-cell attenuation are poorly understood and likely involve dysfunctional interactions between antigen-presenting cells (APC) and effector/regulatory T-cells. Reports on dendritic cells (DC) have described only minor dysfunction during HCV infection. However, there is a paucity of reports regarding B-cell function, despite clear associations with B-cell-related secondary sequelae. In this study we evaluated the state of B-cells during chronic HCV infection, and observed a diminished ability to respond to mitogenic stimuli, correlating with increased apoptosis. This was in contrast to their ex vivo phenotype, which indicated ongoing chronic activation in vivo. There was a high association of HCV-positive strand RNA with B-cells in a subset of HCV patients. Interestingly, ex-vivo-derived HCV RNA-positive B-cells induced significantly greater proliferation in allogeneic T-cells than in HCV-negative B-cells, correlating with an increased generation of CD4+CD25+FOXP3+ regulatory T-cells (Tregs). In-vitro exposure of healthy peripheral blood mononuclear cells (PBMC) to HCV resulted in robust activation of resting B-cells. These HCV-exposed B-cells also showed an enhanced ability to generate Tregs. Our results provide strong evidence for a novel and paradoxical link between HCV-induced enhanced APC function and the generation of Tregs. PMID:21449722

  3. How microRNA and transcription factor co-regulatory networks affect osteosarcoma cell proliferation.

    PubMed

    Poos, Kathrin; Smida, Jan; Nathrath, Michaela; Maugg, Doris; Baumhoer, Daniel; Korsching, Eberhard

    2013-01-01

    Osteosarcomas (OS) are complex bone tumors with various genomic alterations. These alterations affect the expression and function of several genes due to drastic changes in the underlying gene regulatory network. However, we know little about critical gene regulators and their functional consequences on the pathogenesis of OS. Therefore, we aimed to determine microRNA and transcription factor (TF) co-regulatory networks in OS cell proliferation. Cell proliferation is an essential part in the pathogenesis of OS and deeper understanding of its regulation might help to identify potential therapeutic targets. Based on expression data of OS cell lines divided according to their proliferative activity, we obtained 12 proliferation-related microRNAs and corresponding target genes. Therewith, microRNA and TF co-regulatory networks were generated and analyzed regarding their structure and functional influence. We identified key co-regulators comprising the microRNAs miR-9-5p, miR-138, and miR-214 and the TFs SP1 and MYC in the derived networks. These regulators are implicated in NFKB- and RB1-signaling and focal adhesion processes based on their common or interacting target genes (e.g., CDK6, CTNNB1, E2F4, HES1, ITGA6, NFKB1, NOTCH1, and SIN3A). Thus, we proposed a model of OS cell proliferation which is primarily co-regulated through the interactions of the mentioned microRNA and TF combinations. This study illustrates the benefit of systems biological approaches in the analysis of complex diseases. We integrated experimental data with publicly available information to unravel the coordinated (post)-transcriptional control of microRNAs and TFs to identify potential therapeutic targets in OS. The resulting microRNA and TF co-regulatory networks are publicly available for further exploration to generate or evaluate own hypotheses of the pathogenesis of OS (http://www.complex-systems.uni-muenster.de/co_networks.html).

  4. Promotion of regulatory T cell induction by immunomodulatory herbal medicine licorice and its two constituents.

    PubMed

    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.

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

    PubMed Central

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

    2016-01-01

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

  6. Becoming self-aware: the thymic education of regulatory T cells.

    PubMed

    Lio, Chan-Wang J; Hsieh, Chyi-Song

    2011-04-01

    The generation of Foxp3(+) regulatory T (Treg) cells in the thymus is essential for immune homeostasis. In the past several years, substantial progress has been made in understanding the mechanisms by which a minor portion of developing thymocytes are selected to become Treg cells. Although previously controversial, recent data support the importance of TCR specificity as a primary determinant for selecting self-reactive thymocytes to become Treg cells in a multi-step process involving cytokines, co-stimulatory molecules, and a variety of antigen-presenting cells. Importantly, the antigenic niche for Treg cell development appears to be typically quite small, implying the recognition of tissue-specific, rather than ubiquitous, self-antigens. Finally, it appears that an NF-κB transcription factor, c-Rel, may be the link between TCR recognition and the induction of Foxp3 expression, which is required for the function and stability of the natural Treg cell population.

  7. Cerebral regulatorycells restrain microglia/macrophage-mediated inflammatory responses via IL-10.

    PubMed

    Xie, Luokun; Choudhury, Gourav Roy; Winters, Ali; Yang, Shao-Hua; Jin, Kunlin

    2015-01-01

    Forkhead box P3 (Foxp3)(+) regulatory T (Treg) cells maintain the immune tolerance and prevent inflammatory responses in the periphery. However, the presence of Treg cells in the CNS under steady state has not been studied. Here, for the first time, we show a substantial TCRαβ (+) CD4(+) Foxp3(+) T-cell population (cerebral Treg cells) in the rat cerebrum, constituting more than 15% of the cerebral CD4(+) T-cell compartment. Cerebral Treg cells showed an activated/memory phenotype and expressed many Treg-cell signature genes at higher levels than peripheral Treg cells. Consistent with their activated/memory phenotype, cerebral Treg cells robustly restrained the LPS-induced inflammatory responses of brain microglia/macrophages, suggesting a role in maintaining the cerebral homeostasis by inhibiting the neuroinflammation. In addition, brain astrocytes were the helper cells that sustained Foxp3 expression in Treg cells through IL-2/STAT5 signaling, showing that the interaction between astrocytes and Treg cells contributes to the maintenance of Treg-cell identity in the brain. Taken together, our work represents the first study to characterize the phenotypic and functional features of Treg cells in the rat cerebrum. Our data have provided a novel insight for the contribution of Treg cells to the immunosurveillance and immunomodulation in the cerebrum under steady state.

  8. Quiescence of Memory CD8(+) T Cells Is Mediated by Regulatory T Cells through Inhibitory Receptor CTLA-4.

    PubMed

    Kalia, Vandana; Penny, Laura Anne; Yuzefpolskiy, Yevgeniy; Baumann, Florian Martin; Sarkar, Surojit

    2015-06-16

    Immune memory cells are poised to rapidly expand and elaborate effector functions upon reinfection yet exist in a functionally quiescent state. The paradigm is that memory T cells remain inactive due to lack of T cell receptor (TCR) stimuli. Here, we report that regulatory T (Treg) cells orchestrate memory T cell quiescence by suppressing effector and proliferation programs through inhibitory receptor, cytotoxic-T-lymphocyte-associated protein-4 (CTLA-4). Loss of Treg cells resulted in activation of genome-wide transcriptional programs characteristic of effector T cells and drove transitioning as well as established memory CD8(+) T cells toward terminally differentiated KLRG-1(hi)IL-7Rα(lo)GzmB(hi) phenotype, with compromised metabolic fitness, longevity, polyfunctionality, and protective efficacy. CTLA-4 functionally replaced Treg cells in trans to rescue memory T cell defects and restore homeostasis. These studies present the CTLA-4-CD28-CD80/CD86 axis as a potential target to accelerate vaccine-induced immunity and improve T cell memory quality in current cancer immunotherapies proposing transient Treg cell ablation.

  9. Regulatory T cells and the immune pathogenesis of prenatal infection.

    PubMed

    Rowe, Jared H; Ertelt, James M; Xin, Lijun; Way, Sing Sing

    2013-12-01

    Pregnancy in placental mammals offers exceptional comprehensive benefits of in utero protection, nutrition, and metabolic waste elimination for the developing fetus. However, these benefits also require durable strategies to mitigate maternal rejection of fetal tissues expressing foreign paternal antigens. Since the initial postulate of expanded maternal immune tolerance by Sir Peter Medawar 60 years ago, an amazingly elaborate assortment of molecular and cellular modifications acting both locally at the maternal-placental interface and systemically have been shown to silence potentially detrimental maternal immune responses. In turn, simultaneously maintaining host defense against the infinite array of potential pathogens during pregnancy is equally important. Fortunately, resistance against most infections is preserved seamlessly throughout gestation. On the other hand, recent studies on pathogens with unique predisposition for prenatal infections have uncovered distinctive holes in host defense associated with the reproductive process. Using these infections to probe the response during pregnancy, the immune suppressive regulatory subset of maternal CD4 T cells has been increasingly shown to dictate the inter-workings between prenatal infection susceptibility and pathogenesis of ensuing pregnancy complications. Herein, the recent literature suggesting a necessity for maternal regulatory T cells (Tregs) in pregnancy-induced immunological shifts that sustain fetal tolerance is reviewed. Additional discussion is focused on how expansion of maternal Treg suppression may become exploited by pathogens that cause prenatal infections and the perilous potential of infection-induced immune activation that may mitigate fetal tolerance and inadvertently inject hostility into the protective in utero environment.

  10. Localization of general and regulatory proteolysis in Bacillus subtilis cells.

    PubMed

    Kirstein, Janine; Strahl, Henrik; Molière, Noël; Hamoen, Leendert W; Turgay, Kürşad

    2008-11-01

    Protein degradation mediated by ATP-dependent proteases, such as Hsp100/Clp and related AAA+ proteins, plays an important role in cellular protein homeostasis, protein quality control and the regulation of, e.g. heat shock adaptation and other cellular differentiation processes. ClpCP with its adaptor proteins and other related proteases, such as ClpXP or ClpEP of Bacillus subtilis, are involved in general and regulatory proteolysis. To determine if proteolysis occurs at specific locations in B. subtilis cells, we analysed the subcellular distribution of the Clp system together with adaptor and general and regulatory substrate proteins, under different environmental conditions. We can demonstrate that the ATPase and the proteolytic subunit of the Clp proteases, as well as the adaptor or substrate proteins, form visible foci, representing active protease clusters localized to the polar and to the mid-cell region. These clusters could represent a compartmentalized place for protein degradation positioned at the pole close to where most of the cellular protein biosynthesis and also protein quality control are taking place, thereby spatially separating protein synthesis and degradation.

  11. 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

  12. 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

  13. 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

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

    PubMed

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

    2015-01-01

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

  15. 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.

  16. Regulatory T Cells Are Dispensable for Tolerance to RBC Antigens

    PubMed Central

    Richards, Amanda L.; Kapp, Linda M.; Wang, Xiaohong; Howie, Heather L.; Hudson, Krystalyn E.

    2016-01-01

    Autoimmune hemolytic anemia (AIHA) occurs when pathogenic autoantibodies against red blood cell (RBC) antigens are generated. While the basic disease pathology of AIHA is well studied, the underlying mechanism(s) behind the failure in tolerance to RBC autoantigens are poorly understood. Thus, to investigate the tolerance mechanisms required for the establishment and maintenance of tolerance to RBC antigens, we developed a novel murine model. With this model, we evaluated the role of regulatory T cells (Tregs) in tolerance to RBC-specific antigens. Herein, we show that neither sustained depletion of Tregs nor immunization with RBC-specific proteins in conjunction with Treg depletion led to RBC-specific autoantibody generation. Thus, these studies demonstrate that Tregs are not required to prevent autoantibodies to RBCs and suggest that other tolerance mechanisms are likely involved.

  17. Regulatory T Cells Are Dispensable for Tolerance to RBC Antigens

    PubMed Central

    Richards, Amanda L.; Kapp, Linda M.; Wang, Xiaohong; Howie, Heather L.; Hudson, Krystalyn E.

    2016-01-01

    Autoimmune hemolytic anemia (AIHA) occurs when pathogenic autoantibodies against red blood cell (RBC) antigens are generated. While the basic disease pathology of AIHA is well studied, the underlying mechanism(s) behind the failure in tolerance to RBC autoantigens are poorly understood. Thus, to investigate the tolerance mechanisms required for the establishment and maintenance of tolerance to RBC antigens, we developed a novel murine model. With this model, we evaluated the role of regulatory T cells (Tregs) in tolerance to RBC-specific antigens. Herein, we show that neither sustained depletion of Tregs nor immunization with RBC-specific proteins in conjunction with Treg depletion led to RBC-specific autoantibody generation. Thus, these studies demonstrate that Tregs are not required to prevent autoantibodies to RBCs and suggest that other tolerance mechanisms are likely involved. PMID:27698653

  18. 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

  19. 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

  20. The Motivational Function of Regulatory Focus in Creativity.

    ERIC Educational Resources Information Center

    Lam, Tom Wing-Hong; Chiu, Chi-Yue

    2002-01-01

    A study involving 35 Hong Kong undergraduates tested the Regulatory Focus Theory, which maintains that people may focus on achieving positive outcomes (have a promotion focus) or on avoiding negative ones (have a prevention focus). Results indicate the prevention focus group is more likely to join a competition. (Contains references.) (Author/CR)

  1. Genetic regulatory networks programming hematopoietic stem cells and erythroid lineage specification.

    PubMed

    Swiers, Gemma; Patient, Roger; Loose, Matthew

    2006-06-15

    Erythroid cell production results from passage through cellular hierarchies dependent on differential gene expression under the control of transcription factors responsive to changing niches. We have constructed Genetic Regulatory Networks (GRNs) describing this process, based predominantly on mouse data. Regulatory network motifs identified in E. coli and yeast GRNs are found in combination in these GRNs. Feed-forward motifs with autoregulation generate forward momentum and also control its rate, which is at its lowest in hematopoietic stem cells (HSCs). The simultaneous requirement for multiple regulators in multi-input motifs (MIMs) provides tight control over expression of target genes. Combinations of MIMs, exemplified by the SCL/LMO2 complexes, which have variable content and binding sites, explain how individual regulators can have different targets in HSCs and erythroid cells and possibly also how HSCs maintain stem cell functions while expressing lineage-affiliated genes at low level, so-called multi-lineage priming. MIMs combined with cross-antagonism describe the relationship between PU.1 and GATA-1 and between two of their target genes, Fli-1 and EKLF, with victory for GATA-1 and EKLF leading to erythroid lineage specification. These GRNs are useful repositories for current regulatory information, are accessible in interactive form via the internet, enable the consequences of perturbation to be predicted, and can act as seed networks to organize the rapidly accumulating microarray data.

  2. Orchestration of transplantation tolerance by regulatory dendritic cell therapy or in situ targeting of dendritic cells

    PubMed Central

    Morelli, Adrian E.; Thomson, Angus W.

    2014-01-01

    Purpose of review Extensive research in murine transplant models over the past two decades has convincingly demonstrated the ability of regulatory dendritic cells (DCreg) to promote long-term allograft survival. We review important considerations regarding the source of therapeutic DCreg (donor or recipient) and their mode of action, in situ targeting of DCreg, and optimal therapeutic regimens to promote DCreg function. Recent findings Recent studies have defined protocols and mechanisms whereby ex vivo-generated DCreg of donor or recipient origin subvert allogeneic T cell responses and promote long-term organ transplant survival. Particular interest has focused on how donor antigen (Ag) is acquired, processed and presented by autologous DCs, on the stability of DCreg, and on in situ targeting of DC to promote their tolerogenic function. New evidence of the therapeutic efficacy of DCreg in a clinically-relevant non-human primate organ transplant model and production of clinical grade DCreg support early evaluation of DCreg therapy in human graft recipients. Summary We discuss strategies currently used to promote DC tolerogenicity, including DCreg therapy and in situ targeting of DC, with a view to improved understanding of underlying mechanisms and identification of the most promising strategies for therapeutic application. PMID:24926700

  3. 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.

  4. 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

  5. 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

  6. 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

  7. 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

  8. 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

  9. 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

  10. 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

  11. Differential Responses of Human Regulatory T Cells (Treg) and Effector T Cells to Rapamycin

    PubMed Central

    Strauss, Laura; Czystowska, Malgorzata; Szajnik, Marta; Mandapathil, Magis; Whiteside, Theresa L.

    2009-01-01

    Background The immunosuppressive drug rapamycin (RAPA) promotes the expansion of CD4+ CD25highFoxp3+ regulatory T cells via mechanisms that remain unknown. Here, we studied expansion, IL-2R-γ chain signaling, survival pathways and resistance to apoptosis in human Treg responding to RAPA. Methodology/Principal Findings CD4+CD25+ and CD4+CD25neg T cells were isolated from PBMC of normal controls (n = 21) using AutoMACS. These T cell subsets were cultured in the presence of anti-CD3/CD28 antibodies and 1000 IU/mL IL-2 for 3 to 6 weeks. RAPA (1–100 nM) was added to half of the cultures. After harvest, the cell phenotype, signaling via the PI3K/mTOR and STAT pathways, expression of survival proteins and Annexin V binding were determined and compared to values obtained with freshly-separated CD4+CD25high and CD4+CD25neg T cells. Suppressor function was tested in co-cultures with autologous CFSE-labeled CD4+CD25neg or CD8+CD25neg T-cell responders. The frequency and suppressor activity of Treg were increased after culture of CD4+CD25+ T cells in the presence of 1–100 nM RAPA (p<0.001). RAPA-expanded Treg were largely CD4+CD25highFoxp3+ cells and were resistant to apoptosis, while CD4+CD25neg T cells were sensitive. Only Treg upregulated anti-apoptotic and down-regulated pro-apoptotic proteins. Treg expressed higher levels of the PTEN protein than CD4+CD25neg cells. Activated Treg±RAPA preferentially phosphorylated STAT5 and STAT3 and did not utilize the PI3K/mTOR pathway. Conclusions/Significance RAPA favors Treg expansion and survival by differentially regulating signaling, proliferation and sensitivity to apoptosis of human effector T cells and Treg after TCR/IL-2 activation. PMID:19543393

  12. 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

  13. A systems biology approach to defining regulatory mechanisms for cartilage and tendon cell phenotypes

    PubMed Central

    Mueller, A. J.; Tew, S. R.; Vasieva, O.; Clegg, P. D.; Canty-Laird, E. G.

    2016-01-01

    Phenotypic plasticity of adult somatic cells has provided emerging avenues for the development of regenerative therapeutics. In musculoskeletal biology the mechanistic regulatory networks of genes governing the phenotypic plasticity of cartilage and tendon cells has not been considered systematically. Additionally, a lack of strategies to effectively reproduce in vitro functional models of cartilage and tendon is retarding progress in this field. De- and redifferentiation represent phenotypic transitions that may contribute to loss of function in ageing musculoskeletal tissues. Applying a systems biology network analysis approach to global gene expression profiles derived from common in vitro culture systems (monolayer and three-dimensional cultures) this study demonstrates common regulatory mechanisms governing de- and redifferentiation transitions in cartilage and tendon cells. Furthermore, evidence of convergence of gene expression profiles during monolayer expansion of cartilage and tendon cells, and the expression of key developmental markers, challenges the physiological relevance of this culture system. The study also suggests that oxidative stress and PI3K signalling pathways are key modulators of in vitro phenotypes for cells of musculoskeletal origin. PMID:27670352

  14. Upstream Distal Regulatory Elements Contact the Lmo2 Promoter in Mouse Erythroid Cells

    PubMed Central

    Bhattacharya, Anandi; Chen, Chih-Yu; Ho, Sara; Mitchell, Jennifer A.

    2012-01-01

    The Lim domain only 2 (Lmo2) gene encodes a transcriptional cofactor critical for the development of hematopoietic stem cells. Several distal regulatory elements have been identified upstream of the Lmo2 gene in the human and mouse genomes that are capable of enhancing reporter gene expression in erythroid cells and may be responsible for the high level transcription of Lmo2 in the erythroid lineage. In this study we investigate how these elements regulate transcription of Lmo2 and whether or not they function cooperatively in the endogenous context. Chromosome conformation capture (3C) experiments show that chromatin-chromatin interactions exist between upstream regulatory elements and the Lmo2 promoter in erythroid cells but that these interactions are absent from kidney where Lmo2 is transcribed at twelve fold lower levels. Specifically, long range chromatin-chromatin interactions occur between the Lmo2 proximal promoter and two broad regions, 3–31 and 66–105 kb upstream of Lmo2, which we term the proximal and distal control regions for Lmo2 (pCR and dCR respectively). Each of these regions is bound by several transcription factors suggesting that multiple regulatory elements cooperate in regulating high level transcription of Lmo2 in erythroid cells. Binding of CTCF and cohesin which support chromatin loops at other loci were also found within the dCR and at the Lmo2 proximal promoter. Intergenic transcription occurs throughout the dCR in erythroid cells but not in kidney suggesting a role for these intergenic transcripts in regulating Lmo2, similar to the broad domain of intergenic transcription observed at the human β-globin locus control region. Our data supports a model in which the dCR functions through a chromatin looping mechanism to contact and enhance Lmo2 transcription specifically in erythroid cells. Furthermore, these chromatin loops are supported by the cohesin complex recruited to both CTCF and transcription factor bound regions. PMID

  15. 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

  16. 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

  17. Immune privilege induced by regulatory T cells in transplantation tolerance.

    PubMed

    Cobbold, Stephen P; Adams, Elizabeth; Graca, Luis; Daley, Stephen; Yates, Stephen; Paterson, Alison; Robertson, Nathan J; Nolan, Kathleen F; Fairchild, Paul J; Waldmann, Herman

    2006-10-01

    Immune privilege was originally believed to be associated with particular organs, such as the testes, brain, the anterior chamber of the eye, and the placenta, which need to be protected from any excessive inflammatory activity. It is now becoming clear, however, that immune privilege can be acquired locally in many different tissues in response to inflammation, but particularly due to the action of regulatory T cells (Tregs) induced by the deliberate therapeutic manipulation of the immune system toward tolerance. In this review, we consider the interplay between Tregs, dendritic cells, and the graft itself and the resulting local protective mechanisms that are coordinated to maintain the tolerant state. We discuss how both anti-inflammatory cytokines and negative costimulatory interactions can elicit a number of interrelated mechanisms to regulate both T-cell and antigen-presenting cell activity, for example, by catabolism of the amino acids tryptophan and arginine and the induction of hemoxygenase and carbon monoxide. The induction of local immune privilege has implications for the design of therapeutic regimens and the monitoring of the tolerant status of patients being weaned off immunosuppression. PMID:16972908

  18. 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

  19. 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

  20. 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

  1. Myeloid-derived suppressor cells promote cross-tolerance in B-cell lymphoma by expanding regulatory T cells.

    PubMed

    Serafini, Paolo; Mgebroff, Stephanie; Noonan, Kimberly; Borrello, Ivan

    2008-07-01

    Tumor-induced T-cell tolerance is a major mechanism that facilitates tumor progression and limits the efficacy of immune therapeutic interventions. Regulatory T cells (Treg) play a central role in the induction of tolerance to tumor antigens, yet the precise mechanisms regulating its induction in vivo remain to be elucidated. Using the A20 B-cell lymphoma model, here we identify myeloid-derived suppressor cells (MDSC) as the tolerogenic antigen presenting cells capable of antigen uptake and presentation to tumor-specific Tregs. MDSC-mediated Treg induction requires arginase but is transforming growth factor-beta independent. In vitro and in vivo inhibition of MDSC function, respectively, with NOHA or sildenafil abrogates Treg proliferation and tumor-induced tolerance in antigen-specific T cells. These findings establish a role for MDSCs in antigen-specific tolerance induction through preferential antigen uptake mediating the recruitment and expansion of Tregs. Furthermore, therapeutic interventions, such as in vivo phosphodiesterase 5-inhibition, which effectively abrogate the immunosuppressive role of MDSCs and reduce Treg numbers, may play a critical role in delaying and/or reversing tolerance induction. PMID:18593947

  2. Expansion of Regulatory T Cells in Patients with Langerhans Cell Histiocytosis

    PubMed Central

    Senechal, Brigitte; Elain, Gaelle; Jeziorski, Eric; Grondin, Virginie; Patey-Mariaud de Serre, Natacha; Jaubert, Francis; Beldjord, Kheira; Lellouch, Arielle; Glorion, Christophe; Zerah, Michel; Mary, Pierre; Barkaoui, Mohammed; Emile, Jean Francois; Boccon-Gibod, Liliane; Josset, Patrice; Debré, Marianne; Fischer, Alain; Donadieu, Jean; Geissmann, Frederic

    2007-01-01

    Background Langerhans cell histiocytosis (LCH) is a rare clonal granulomatous disease that affects mainly children. LCH can involve various tissues such as bone, skin, lung, bone marrow, lymph nodes, and the central nervous system, and is frequently responsible for functional sequelae. The pathophysiology of LCH is unclear, but the uncontrolled proliferation of Langerhans cells (LCs) is believed to be the primary event in the formation of granulomas. The present study was designed to further investigate the nature of proliferating cells and the immune mechanisms involved in the LCH granulomas. Methods and Findings Biopsies (n = 24) and/or blood samples (n = 25) from 40 patients aged 0.25 to 13 y (mean 7.8 y), were studied to identify cells that proliferate in blood and granulomas. We found that the proliferating index of LCs was low (∼1.9%), and we did not observe expansion of a monocyte or dendritic cell compartment in patients. We found that LCH lesions were a site of active inflammation, tissue remodeling, and neo-angiogenesis, and the majority of proliferating cells were endothelial cells, fibroblasts, and polyclonal T lymphocytes. Within granulomas, interleukin 10 was abundant, LCs expressed the TNF receptor family member RANK, and CD4+ CD25high FoxP3high regulatory T cells (T-regs) represented 20% of T cells, and were found in close contact with LCs. FoxP3+ T-regs were also expanded compared to controls, in the blood of LCH patients with active disease, among whom seven out of seven tested exhibited an impaired skin delayed-type hypersensitivity response. In contrast, the number of blood T-regs were normal after remission of LCH. Conclusions These findings indicate that LC accumulation in LCH results from survival rather than uncontrolled proliferation, and is associated with the expansion of T-regs. These data suggest that LCs may be involved in the expansion of T-regs in vivo, resulting in the failure of the host immune system to eliminate LCH cells. Thus

  3. 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

  4. Glucocorticosteroids modify Langerhans cells to produce TGF-β and expand regulatory T cells.

    PubMed

    Stary, Georg; Klein, Irene; Bauer, Wolfgang; Koszik, Frieder; Reininger, Bärbel; Kohlhofer, Sabine; Gruber, Kristina; Skvara, Hans; Jung, Thomas; Stingl, Georg

    2011-01-01

    Although glucocorticosteroids (GCSs) have been used for many decades in transplantation and (auto)inflammatory diseases, the exact mechanisms responsible for their immunosuppressive properties are not fully understood. The purpose of this study was to characterize the effects of oral GCSs on the cutaneous immune response. We analyzed, by immunofluorescence staining and quantitative RT-PCR, residual skin biopsy material from a clinical study in which we had used oral GCS as positive control for determining the effects of candidate anti-inflammatory compounds on epicutaneous patch tests of Ni-allergic patients. Expectedly, oral GCS treatment led to a reduction of clinical symptoms and infiltrating leukocytes. Notably, we observed increased numbers of dermal FOXP3(+)CD25(+) T cells and epidermal Langerhans cells (LCs) that were associated with upregulated mRNA expression of TGF-β in lesions of GCS-treated Ni-allergic patients. To investigate this phenomenon further, we exposed purified LCs to GCS. They exhibited, in contrast to GCS-nonexposed LCs, 1) a more immature phenotype, 2) higher intracellular amounts of TGF-β, and 3) increased receptor activator for NF-κB expression, conditions that reportedly favor the expansion of regulatory T cells (Tregs). Indeed, we observed an enhancement of functionally suppressive FOXP3(+) T cells when CD3(+) cells were incubated with GCS-pretreated LCs. The expansion of Tregs was inhibited by TGF-β blockage alone, and their suppressive activity was neutralized by a combination of anti-TGF-β and anti-IL-10 Abs. Our data show that systemically applied GCSs endow LCs with Treg-promoting properties and thus shed new light on the mechanisms of GCS-mediated immunosuppression.

  5. The Spectrum and Regulatory Landscape of Intestinal Innate Lymphoid Cells Are Shaped by the Microbiome.

    PubMed

    Gury-BenAri, Meital; Thaiss, Christoph A; Serafini, Nicolas; Winter, Deborah R; Giladi, Amir; Lara-Astiaso, David; Levy, Maayan; Salame, Tomer Meir; Weiner, Assaf; David, Eyal; Shapiro, Hagit; Dori-Bachash, Mally; Pevsner-Fischer, Meirav; Lorenzo-Vivas, Erika; Keren-Shaul, Hadas; Paul, Franziska; Harmelin, Alon; Eberl, Gérard; Itzkovitz, Shalev; Tanay, Amos; Di Santo, James P; Elinav, Eran; Amit, Ido

    2016-08-25

    Innate lymphoid cells (ILCs) are critical modulators of mucosal immunity, inflammation, and tissue homeostasis, but their full spectrum of cellular states and regulatory landscapes remains elusive. Here, we combine genome-wide RNA-seq, ChIP-seq, and ATAC-seq to compare the transcriptional and epigenetic identity of small intestinal ILCs, identifying thousands of distinct gene profiles and regulatory elements. Single-cell RNA-seq and flow and mass cytometry analyses reveal compartmentalization of cytokine expression and metabolic activity within the three classical ILC subtypes and highlight transcriptional states beyond the current canonical classification. In addition, using antibiotic intervention and germ-free mice, we characterize the effect of the microbiome on the ILC regulatory landscape and determine the response of ILCs to microbial colonization at the single-cell level. Together, our work characterizes the spectrum of transcriptional identities of small intestinal ILCs and describes how ILCs differentially integrate signals from the microbial microenvironment to generate phenotypic and functional plasticity.

  6. Functional characterization of the 5'-regulatory region of the murine apolipoprotein gene.

    PubMed

    Lahiri, D K; Alley, G M; Ge, Y-W; Du, Y

    2002-11-01

    The apolipoprotein E (APOE) gene causes a major risk factor for the development of Alzheimer's disease (AD). To study the transcription control of the mouse (m) APOE gene, we first tested the promoter activity of a 721-base-pair (bp) 5'-flanking region, which is located 771 bp upstream from the translation initiation codon. We cloned the 721-bp region upstream of the reporter chloramphenicol acetyl transferase (CAT) gene into a promoterless vector (pBLCAT3). The mAPOE promoter and vector DNA were separately transfected in rat glial C6 and neuronal PC12 cell lines. The 721-bp APOE region (from position 329 to 1050) is functionally active in different cell lines tested. The serial deletion analysis indicates that the 266-bp promoter region (from 784 to 1050) has the highest and the 67-bp region (from 983 to 1050) the lowest activity on the reporter gene in neuronal and astrocytic cell lines. These studies suggest that the 147-bp region (from 637 to 784) has a negative regulatory effect on the reporter gene. In the gel shift assay, the 67-bp region binds to a specific transcription factor(s) in PC12 nuclear extracts. Our results suggest that mAPOE can also be expressed in neuronal cells in addition to the astrocytic cells. Characterization of mAPOE promoter is important for the AD drug development discovery and APOE transgenic mice studies.

  7. Insights on regulation and function of the iron regulatory protein 1 (IRP1).

    PubMed

    Wang, Jian; Chen, Guohua; Filebeen, Carine; Pantopoulos, Kostas

    2008-01-01

    Iron regulatory protein 1 (IRP1) controls the translation or stability of several mRNAs by binding to iron responsive elements (IREs) within their untranslated regions. Its activity is regulated by an unusual iron-sulfur cluster (ICS) switch. Thus, in iron-replete cells, IRP1 assembles a cubane [4Fe-4S] cluster that prevents RNA-binding activity and renders the protein to cytosolic aconitase. We show that wild type or mutant forms of IRP1 that fail to assemble a [4Fe-4S] cluster are sensitized for iron-dependent degradation by the ubiquitin-proteasome pathway. The regulation of IRP1 abundance poses an alternative mechanism to prevent accumulation of inappropriately high IRE-binding activity when the ICS assembly pathway is impaired. To study functional aspects of IRP1, we overexpressed wild type or mutant forms of the protein in human H1299 lung cancer cells in a tetracycline-inducible fashion, and analyzed how this affects cell growth. While the induction of IRP1 did not affect cell proliferation in culture, it dramatically reduced the capacity of the cells to form solid tumor xenografts in nude mice. These data provide a first link between IRP1 and cancer.

  8. Increased frequencies of CD4+CD25high regulatory T cells in acute dengue infection

    PubMed Central

    Lühn, Kerstin; Simmons, Cameron P.; Moran, Edward; Dung, Nguyen Thi Phuong; Chau, Tran Nguyen Bich; Quyen, Nguyen Than Ha; Thao, Le Thi Thu; Van Ngoc, Tran; Dung, Nguyen Minh; Wills, Bridget; Farrar, Jeremy; McMichael, Andrew J.; Dong, Tao; Rowland-Jones, Sarah

    2007-01-01

    Dengue virus infection is an increasingly important tropical disease, causing 100 million cases each year. Symptoms range from mild febrile illness to severe hemorrhagic fever. The pathogenesis is incompletely understood, but immunopathology is thought to play a part, with antibody-dependent enhancement and massive immune activation of T cells and monocytes/macrophages leading to a disproportionate production of proinflammatory cytokines. We sought to investigate whether a defective population of regulatory T cells (T reg cells) could be contributing to immunopathology in severe dengue disease. CD4+CD25highFoxP3+ T reg cells of patients with acute dengue infection of different severities showed a conventional phenotype. Unexpectedly, their capacity to suppress T cell proliferation and to secrete interleukin-10 was not altered. Moreover, T reg cells suppressed the production of vasoactive cytokines after dengue-specific stimulation. Furthermore, T reg cell frequencies and also T reg cell/effector T cell ratios were increased in patients with acute infection. A strong indication that a relative rise of T reg cell/effector T cell ratios is beneficial for disease outcome comes from patients with mild disease in which this ratio is significantly increased (P < 0.0001) in contrast to severe cases (P = 0.2145). We conclude that although T reg cells expand and function normally in acute dengue infection, their relative frequencies are insufficient to control the immunopathology of severe disease. PMID:17452519

  9. A limited role for regulatory T cells in post-ischemic neovascularization.

    PubMed

    Hellingman, A A; van der Vlugt, L E P M; Lijkwan, M A; Bastiaansen, A J N M; Sparwasser, T; Smits, H H; Hamming, J F; Quax, P H A

    2012-02-01

    Recently, it was demonstrated that arteriogenesis is enhanced in mice deficient in regulatory T cells (CD4(+) CD25(+) FoxP3(+) T cell), which can suppress effector T cell responses. The present study investigates the effects of these regulatory T cells on arteriogenesis in more detail by either specific expanding or depleting regulatory T cells. Hind limb ischemia was induced by electro-coagulation of the femoral artery in mice. Regulatory T cells were either expanded by injecting mice with a complex of interleukin (IL)-2 with the IL-2 monoclonal antibody JES6-1, or depleted by anti-CD25 antibody or diphtheria toxin injections in DEREG mice (depletion of regulatory T cells). Blood flow restoration was monitored using laser Doppler perfusion imaging. Collateral arteries were visualized by immunohistochemistry. Regulatory T cell expansion led to a moderate though significant suppression of blood flow restoration after ischemia induction. Surprisingly, depletion of regulatory T cells resulted in minor increase on blood flow recovery. However, collateral and capillary densities in the post-ischemic skeletal muscle were significantly increased in DEREG mice depleted for regulatory T cells. The presence of regulatory T cells after ischemia induction when analysed in non-depleted DEREG mice could be demonstrated by green fluorescent protein staining only in lymph nodes in the ischemic area, and not in the ischemic muscle tissue. The current study demonstrates that, even under conditions of major changes in regulatory T cell content, the contribution of regulatory T cells to the regulation of the arteriogenic response is only moderate. PMID:21426486

  10. A limited role for regulatory T cells in post-ischemic neovascularization

    PubMed Central

    Hellingman, AA; van der Vlugt, LEPM; Lijkwan, MA; Bastiaansen, AJNM; Sparwasser, T; Smits, HH; Hamming, JF; Quax, PHA

    2012-01-01

    Abstract Recently, it was demonstrated that arteriogenesis is enhanced in mice deficient in regulatory T cells (CD4+CD25+FoxP3+ T cell), which can suppress effector T cell responses. The present study investigates the effects of these regulatory T cells on arteriogenesis in more detail by either specific expanding or depleting regulatory T cells. Hind limb ischemia was induced by electro-coagulation of the femoral artery in mice. Regulatory T cells were either expanded by injecting mice with a complex of interleukin (IL)-2 with the IL-2 monoclonal antibody JES6–1, or depleted by anti-CD25 antibody or diphtheria toxin injections in DEREG mice (depletion of regulatory T cells). Blood flow restoration was monitored using laser Doppler perfusion imaging. Collateral arteries were visualized by immunohistochemistry. Regulatory T cell expansion led to a moderate though significant suppression of blood flow restoration after ischemia induction. Surprisingly, depletion of regulatory T cells resulted in minor increase on blood flow recovery. However, collateral and capillary densities in the post-ischemic skeletal muscle were significantly increased in DEREG mice depleted for regulatory T cells. The presence of regulatory T cells after ischemia induction when analysed in non-depleted DEREG mice could be demonstrated by green fluorescent protein staining only in lymph nodes in the ischemic area, and not in the ischemic muscle tissue. The current study demonstrates that, even under conditions of major changes in regulatory T cell content, the contribution of regulatory T cells to the regulation of the arteriogenic response is only moderate. PMID:21426486

  11. A limited role for regulatory T cells in post-ischemic neovascularization.

    PubMed

    Hellingman, A A; van der Vlugt, L E P M; Lijkwan, M A; Bastiaansen, A J N M; Sparwasser, T; Smits, H H; Hamming, J F; Quax, P H A

    2012-02-01

    Recently, it was demonstrated that arteriogenesis is enhanced in mice deficient in regulatory T cells (CD4(+) CD25(+) FoxP3(+) T cell), which can suppress effector T cell responses. The present study investigates the effects of these regulatory T cells on arteriogenesis in more detail by either specific expanding or depleting regulatory T cells. Hind limb ischemia was induced by electro-coagulation of the femoral artery in mice. Regulatory T cells were either expanded by injecting mice with a complex of interleukin (IL)-2 with the IL-2 monoclonal antibody JES6-1, or depleted by anti-CD25 antibody or diphtheria toxin injections in DEREG mice (depletion of regulatory T cells). Blood flow restoration was monitored using laser Doppler perfusion imaging. Collateral arteries were visualized by immunohistochemistry. Regulatory T cell expansion led to a moderate though significant suppression of blood flow restoration after ischemia induction. Surprisingly, depletion of regulatory T cells resulted in minor increase on blood flow recovery. However, collateral and capillary densities in the post-ischemic skeletal muscle were significantly increased in DEREG mice depleted for regulatory T cells. The presence of regulatory T cells after ischemia induction when analysed in non-depleted DEREG mice could be demonstrated by green fluorescent protein staining only in lymph nodes in the ischemic area, and not in the ischemic muscle tissue. The current study demonstrates that, even under conditions of major changes in regulatory T cell content, the contribution of regulatory T cells to the regulation of the arteriogenic response is only moderate.

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

    PubMed

    Hsu, Peter; Nanan, Ralph

    2014-10-01

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

  13. [Regulatory T cell based transplant tolerance--freedom from immunosuppression].

    PubMed

    Koshiba, Takaaki; Ito, Atsushi; Li, Ying; Wu, Yanling; Takemura, Mami; Sakaguchi, Shimon

    2007-03-01

    Tolerance after clinical transplantation (Tx) is still extremely rare. However, Kyoto elective protocol enabled a substantial number of patients to weaned off immunosuppression after liver Tx. This is referred to as an immunoprivilege. Nevertheless, the operating mechanisms for liver Tx tolerance remain elusive. The authors demonstrated that regulatory T cells (Tregs) are likely to play an important role in liver Tx tolerance. In addition, we found that precursor like Tregs exist in the human peripheral blood. This can propagate upon stimulation with allo-antigen, in contrast to anergic property of Tregs. Thus, the exploitation of precursor like Tregs as a cellular source of ex vivo and in vivo expansion may lead to the widespread clinical use of Tregs for Tx.

  14. Regulatory T-Cells in Chronic Lymphocytic Leukemia and Autoimmune Diseases

    PubMed Central

    D’Arena, Giovanni; Rossi, Giovanni; Vannata, Barbara; Deaglio, Silvia; Mansueto, Giovanna; D’Auria, Fiorella; Statuto, Teodora; Simeon, Vittorio; De Martino, Laura; Marandino, Aurelio; Del Poeta8, Giovanni; De Feo, Vincenzo; Musto, Pellegrino

    2012-01-01

    Regulatory T-cells (Tregs) constitute a small subset of cells that are actively involved in maintaining self-tolerance, in immune homeostasis and in antitumor immunity. They are thought to play a significant role in the progression of cancer and are generally increased in patient with chronic lymphocytic leukemia (CLL). Their number correlates with more aggressive disease status and is predictive of the time to treatment, as well. Moreover, it is now clear that dysregulation in Tregs cell frequency and/or function may result in a plethora of autoimmune diseases, including multiple sclerosis, type 1 diabetes mellitus, myasthenia gravis, systemic lupus erythematosus, autoimmune lymphoproliferative disorders, rheumatoid arthritis, and psoriasis. Efforts are made aiming to develop approaches to deplete Tregs or inhibit their function in cancer and autoimmune disorders, as well. PMID:22973497

  15. Special regulatory T cell review: The resurgence of the concept of contrasuppression in immunoregulation

    PubMed Central

    Lehner, Thomas

    2008-01-01

    The original concept of contrasuppression (CS) is evident in many immunoregulatory mechanisms. Inhibition of suppressor activity – CS – may be critical in microbial infection and autoimmunity. The major cellular interactions involved in suppression are the CD25+ FoxP3+ CD4+ T regulatory cells, programmed death-1 (PD-1) : PD-L1/L2 and cytotoxic T lymphocyte antigen-4 (CTLA-4) : CD80/86 pathways. These cellular functions are affected by dendritic cells (DC) and a complex array of cytokines of which interleukin (IL)-2, IL-10, IL-6 and transforming growth factor-β (TGF-β) are especially significant. Inhibition of regulatory cells, suppressor pathways or cytokines, is consistent with CS and can be attributed to IL-6, IL-2, PD-1 or PD-L-1 antibodies, blockade of CTLA-4 : CD80/86 pathway, inhibition of CD40–CD40L pathways, and TGF-β, IL-10 antibodies. Contrasuppression may regulate innate immunity by Toll-like receptor expressed not only in non-cognate DC, monocytes, natural killer cells and γδ T cells but also in adaptive T cells. Furthermore, cross-talk between innate and adaptive immunity may be facilitated by contrasuppressor activity. ‘‘What’s in a name? That which we call a rose by any other name would smell as sweet.’’ From Romeo and Juliet (II, 47–8) W. Shakespeare PMID:18154618

  16. Special regulatory T cell review: The resurgence of the concept of contrasuppression in immunoregulation.

    PubMed

    Lehner, Thomas

    2008-01-01

    The original concept of contrasuppression (CS) is evident in many immunoregulatory mechanisms. Inhibition of suppressor activity--CS--may be critical in microbial infection and autoimmunity. The major cellular interactions involved in suppression are the CD25+ FoxP3+ CD4+ T regulatory cells, programmed death-1 (PD-1) : PD-L1/L2 and cytotoxic T lymphocyte antigen-4 (CTLA-4) : CD80/86 pathways. These cellular functions are affected by dendritic cells (DC) and a complex array of cytokines of which interleukin (IL)-2, IL-10, IL-6 and transforming growth factor-beta (TGF-beta) are especially significant. Inhibition of regulatory cells, suppressor pathways or cytokines, is consistent with CS and can be attributed to IL-6, IL-2, PD-1 or PD-L-1 antibodies, blockade of CTLA-4 : CD80/86 pathway, inhibition of CD40-CD40L pathways, and TGF-beta, IL-10 antibodies. Contrasuppression may regulate innate immunity by Toll-like receptor expressed not only in non-cognate DC, monocytes, natural killer cells and gammadelta T cells but also in adaptive T cells. Furthermore, cross-talk between innate and adaptive immunity may be facilitated by contrasuppressor activity. ''What's in a name? That which we call a rose by any other name would smell as sweet.'' From Romeo and Juliet (II, 47-8) W. Shakespeare.

  17. Assay of Peripheral Regulatory Vδ1 T Cells in Ankylosing Spondylitis and its Significance

    PubMed Central

    Wang, Hongliang; Sun, Na; Li, Ka; Tian, Jiguang; Li, Jianmin

    2016-01-01

    Background Ankylosing spondylitis (AS) involves inflammation at the sacroiliac joint and spine attachment site. This study aimed to observe the ratio and function of peripheral regulatory Vδ1 T cells in AS patients to investigate their roles in AS pathogenesis. Material/Methods Peripheral blood mononuclear cells (PBMC) were separated by density-gradient centrifugation from AS patients and healthy controls. Flow cytometry was used to determine the ratio between Vδ1 and CD4 T cells of PBMC in AS patients and controls. Flow cytometry sorting (FCS) was used to obtain Vδ1 and naïve CD4 T cells with purity higher than 90%. CFSE staining method was used to detect the effect of Vδ1 T cells on proliferation of naïve CD4 T cells. The effect of Vδ1 T cells on secretion of IFN-γ from naïve CD4 T cells and the ability to secrete IL-10 from Vδ1 T cells were determined by flow cytometry. Results AS patients had significantly lower Vδ1 T cell ratio in PBMC compared to controls (p<0.05), but their CD4 T cell ratio was significantly elevated (p<0.05). Functional assay showed suppression of naïve CD4 T cell proliferation and IFN-γ secretion by peripheral Vδ1 T cells in AS patients (p<0.01). AS patients also had lower IL-10 secreting level from peripheral derived Vδ1 T cells (p<0.01). Conclusions The immune suppression of peripheral Vδ1 T cell in AS patient increases the ratio of peripheral CD4 T cells and IFN-γ level, leading to AS pathogenesis. This immune suppression is mainly due to suppressed IL-10 secretion. PMID:27598263

  18. Assay of Peripheral Regulatory Vδ1 T Cells in Ankylosing Spondylitis and its Significance.

    PubMed

    Wang, Hongliang; Sun, Na; Li, Ka; Tian, Jiguang; Li, Jianmin

    2016-01-01

    BACKGROUND Ankylosing spondylitis (AS) involves inflammation at the sacroiliac joint and spine attachment site. This study aimed to observe the ratio and function of peripheral regulatory Vδ1 T cells in AS patients to investigate their roles in AS pathogenesis. MATERIAL AND METHODS Peripheral blood mononuclear cells (PBMC) were separated by density-gradient centrifugation from AS patients and healthy controls. Flow cytometry was used to determine the ratio between Vδ1 and CD4 T cells of PBMC in AS patients and controls. Flow cytometry sorting (FCS) was used to obtain Vδ1 and naïve CD4 T cells with purity higher than 90%. CFSE staining method was used to detect the effect of Vδ1 T cells on proliferation of naïve CD4 T cells. The effect of Vδ1 T cells on secretion of IFN-γ from naïve CD4 T cells and the ability to secrete IL-10 from Vδ1 T cells were determined by flow cytometry. RESULTS AS patients had significantly lower Vδ1 T cell ratio in PBMC compared to controls (p<0.05), but their CD4 T cell ratio was significantly elevated (p<0.05). Functional assay showed suppression of naïve CD4 T cell proliferation and IFN-γ secretion by peripheral Vδ1 T cells in AS patients (p<0.01). AS patients also had lower IL-10 secreting level from peripheral derived Vδ1 T cells (p<0.01). CONCLUSIONS The immune suppression of peripheral Vδ1 T cell in AS patient increases the ratio of peripheral CD4 T cells and IFN-γ level, leading to AS pathogenesis. This immune suppression is mainly due to suppressed IL-10 secretion. PMID:27598263

  19. Regulatory T Cells in Type 1 Autoimmune Pancreatitis

    PubMed Central

    Uchida, Kazushige; Kusuda, Takeo; Koyabu, Masanori; Miyoshi, Hideaki; Fukata, Norimasa; Sumimoto, Kimi; Fukui, Yuri; Sakaguchi, Yutaku; Ikeura, Tsukasa; Shimatani, Masaaki; Fukui, Toshiro; Matsushita, Mitsunobu; Takaoka, Makoto; Nishio, Akiyoshi; Okazaki, Kazuichi

    2012-01-01

    Autoimmune pancreatitis (AIP) is a newly recognized pancreatic disorder. Recently, International Consensus Diagnostic Criteria for AIP (ICDC) was published. In this ICDC, AIP was classified into Type 1 and Type 2. Patients with Type 1 AIP have several immunologic and histologic abnormalities specific to the disease, including increased levels of serum IgG4 and storiform fibrosis with infiltration of lymphocytes and IgG4-positive plasmacytes in the involved organs. Among the involved organs showing extrapancreatic lesions, the bile duct is the most common, exhibiting sclerosing cholangitis (IgG4-SC). However, the role of IgG4 is unclear. Recently, it has been reported that regulatory T cells (Tregs) are involved in both the development of various autoimmune diseases and the shift of B cells toward IgG4, producing plasmacytes. Our study showed that Tregs were increased in the pancreas with Type 1 AIP and IgG4-SC compared with control. In the patients with Type 1 AIP and IgG4-SC, the numbers of infiltrated Tregs were significantly positively correlated with IgG4-positive plasma cells. In Type 1 AIP, inducible costimulatory molecule (ICOS)+ and IL-10+ Tregs significantly increased compared with control groups. Our data suggest that increased quantities of ICOS+ Tregs may influence IgG4 production via IL-10 in Type 1 AIP. PMID:22536257

  20. Altered Immunoregulation in Rheumatoid Arthritis: The Role of Regulatory T Cells and Proinflammatory Th17 Cells and Therapeutic Implications

    PubMed Central

    Alunno, Alessia; Caterbi, Sara; Ibba-Manneschi, Lidia; Bistoni, Onelia; Bartoloni, Elena; Valentini, Valentina; Terenzi, Riccardo; Gerli, Roberto

    2015-01-01

    In recent years several studies investigated the role of T lymphocyte subpopulations in the pathogenesis of rheumatoid arthritis (RA). Pathogenic Th17 cells mediate pannus growth, osteoclastogenesis, and synovial neoangiogenesis; hence they are key players in the development of the disease. On the other hand, regulatory T (Treg) cells are a T cell subset whose peculiar function is to suppress autoreactive lymphocytes. The imbalance between Th17 and Treg cells has been identified as a crucial event in the pathogenesis of RA. In addition, the effects of currently employed RA therapeutic strategies on these lymphocyte subpopulations have been extensively investigated. This review article aims to discuss current knowledge on Treg and Th17 cells in RA and possible implications of their therapeutic targeting in this disorder. PMID:25918479

  1. S. macrurus myogenic regulatory factors induce mammalian skeletal muscle differentiation: Evidence for functional conservation of MRFs

    PubMed Central

    Kim, Hyun-Jung; Güth, Robert; Jonsson, Colleen B.; Unguez, Graciela A.

    2009-01-01

    The current-producing cells of the electric organ (EO), i.e., electrocytes, in Sternopygus macrurus derive from skeletal muscle fibers. Mature electrocytes are not contractile but they do retain some muscle proteins, are multinucleated, and receive cholinergic innervation. Electrocytes express the myogenic regulatory factors (MRFs) MyoD, myogenin, Myf5 and MRF4 despite their incomplete muscle phenotype. Although S. macrurus MRFs share functional domains that are highly conserved and their expression is confined to the myogenic lineage, their capability to induce the muscle phenotype has not been determined. To test the functional conservation of S. macrurus MRFs to transcriptionally activate skeletal muscle gene expression and induce the myogenic program, we transiently over-expressed S. macrurus MyoD (SmMyoD) and myogenin (SmMyoG) in mouse C3H/10T1/2 and NIH3T3 embryonic cells. RT-PCR and immunolabeling studies showed that SmMyoD and SmMyoG efficiently can convert these two cell lines into multinucleated myotubes that expressed differentiated muscle markers. The levels of myogenic induction by SmMyoD and SmMyoG were comparable to those obtained with mouse MRF homologs. Furthermore, SmMyoD and SmMyoG proteins were able to induce mouse MyoD and myogenin in C3H/10T1/2 cells. We conclude that S. macrurus MRFs are functionally conserved as they can transcriptionally activate skeletal muscle gene expression and induce the myogenic program in mammalian non-muscle cells. Hence, these data suggest that the partial muscle phenotype of electrocytes is not likely due to differences in the MRF-dependent transcriptional program between skeletal muscle and electric organ. PMID:19598116

  2. [Significance of regulatory B cells in nosogenesis of immune thrombocytopenia].

    PubMed

    Li, Xin; Wang, Fang; Ding, Kai Yang; Dai, Lan

    2014-04-01

    This study was aimed to investigate the role of regulatory B cells (Breg) in pathogenesis of immune thrombocytopenia (ITP) and its clinical significance. A total of 35 ITP patients and 20 normal controls were enrolled in this study. The expression of CD19(+)CD24(hi)CD38(hi) B cells was detected by flow cytometry and the expression of IL-10 mRNA and TGF-β1 mRNA was assayed by RT-PCR. The results indicated that the expression level of CD19(+)CD24(hi)CD38(hi) B cells in peripheral blood of newly diagnosed ITP patients was obviously lower than that in normal controls (P < 0.05); the expression level of CD19(+)CD24(hi)CD38(hi) B cells in ITP patients with increased platelet count after treatment was higher than that before treatment (P < 0.05); the expression level of IL-10 mRNA in newly diagnosed ITP patients was significantly lower than that the in normal controls (P < 0.05), the expression level of TGF-β1 mRNA in newly diagnosed ITP patients increases as compared with normal controls (P < 0.05), after treatment with DXM the expression of IL-10 mRNA was enhanced, the expression of TGF-β1 mRNA was reduced as compared with expression level before treatment (P < 0.05). It is concluded that the Breg cells may play an important role in the pathogenesis of ITP via humoral immunity and its regulation of T lymphocytes.

  3. Functional organization of an Mbp enhancer exposes striking transcriptional regulatory diversity within myelinating glia.

    PubMed

    Dionne, Nancy; Dib, Samar; Finsen, Bente; Denarier, Eric; Kuhlmann, Tanja; Drouin, Régen; Kokoeva, Maia; Hudson, Thomas J; Siminovitch, Kathy; Friedman, Hana C; Peterson, Alan C

    2016-01-01

    In mammals, large caliber axons are ensheathed by myelin, a glial specialization supporting axon integrity and conferring accelerated and energy-efficient action potential conduction. Myelin basic protein (MBP) is required for normal myelin elaboration with maximal mbp transcription in oligodendrocytes requiring the upstream M3 enhancer. To further characterize the mechanism regulating mbp transcription, we defined M3 structure/function relationships by evaluating its evolutionary conservation, DNA footprints and the developmental programing conferred in mice by M3 derivatives. Multiple M3 regulatory element combinations were found to drive expression in oligodendrocytes and Schwann cells with a minimal 129 bp sequence conferring expression in oligodendrocytes throughout myelin elaboration, maintenance and repair. Unexpectedly, M3 derivatives conferred markedly different spatial and temporal expression programs thus illuminating striking transcriptional heterogeneity within post-mitotic oligodendrocytes. Finally, one M3 derivative engaged only during primary myelination, not during adult remyelination, demonstrating that transcriptional regulation in the two states is not equivalent. PMID:26507463

  4. Comprehensive analysis of current approaches to inhibit regulatory T cells in cancer

    PubMed Central

    Pere, Helene; Tanchot, Corinne; Bayry, Jagadeesh; Terme, Magali; Taieb, Julien; Badoual, Cecile; Adotevi, Olivier; Merillon, Nathalie; Marcheteau, Elie; Quillien, Ve´ronique; Banissi, Claire; Carpentier, Alain; Sandoval, Federico; Nizard, Mevyn; Quintin-Colonna, Françoise; Kroemer, Guido; Fridman, Wolf H.; Zitvogel, Laurence; Oudard, Ste´phane; Tartour, Eric

    2012-01-01

    CD4+CD25+Foxp3+ regulatory T cells (Treg) have emerged as a dominant T cell population inhibiting anti-tumor effector T cells. Initial strategies used for Treg-depletion (cyclophosphamide, anti-CD25 mAb…) also targeted activated T cells, as they share many phenotypic markers. Current, ameliorated approaches to inhibit Treg aim to either block their function or their migration to lymph nodes and the tumor microenvironment. Various drugs originally developed for other therapeutic indications (anti-angiogenic molecules, tyrosine kinase inhibitors,etc) have recently been discovered to inhibit Treg. These approaches are expected to be rapidly translated to clinical applications for therapeutic use in combination with immunomodulators. PMID:22737608

  5. Coexpression of TIGIT and FCRL3 identifies Helios+ human memory regulatory T cells.

    PubMed

    Bin Dhuban, Khalid; d'Hennezel, Eva; Nashi, Emil; Bar-Or, Amit; Rieder, Sadiye; Shevach, Ethan M; Nagata, Satoshi; Piccirillo, Ciriaco A

    2015-04-15

    Two distinct subsets of CD4(+)Foxp3(+) regulatory T (Treg) cells have been described based on the differential expression of Helios, a transcription factor of the Ikaros family. Efforts to understand the origin and biological roles of these Treg populations in regulating immune responses have, however, been hindered by the lack of reliable surface markers to distinguish and isolate them for subsequent functional studies. Using a single-cell cloning strategy coupled with microarray analysis of different Treg functional subsets in humans, we identify the mRNA and protein expression of TIGIT and FCRL3 as a novel surface marker combination that distinguishes Helios(+)FOXP3(+) from Helios(-)FOXP3(+) memory cells. Unlike conventional markers that are modulated on conventional T cells upon activation, we show that the TIGIT/FCRL3 combination allows reliable identification of Helios(+) Treg cells even in highly activated conditions in vitro as well as in PBMCs of autoimmune patients. We also demonstrate that the Helios(-)FOXP3(+) Treg subpopulation harbors a larger proportion of nonsuppressive clones compared with the Helios(+)FOXP3(+) cell subset, which is highly enriched for suppressive clones. Moreover, we find that Helios(-) cells are exclusively responsible for the productions of the inflammatory cytokines IFN-γ, IL-2, and IL-17 in FOXP3(+) cells ex vivo, highlighting important functional differences between Helios(+) and Helios(-) Treg cells. Thus, we identify novel surface markers for the consistent identification and isolation of Helios(+) and Helios(-) memory Treg cells in health and disease, and we further reveal functional differences between these two populations. These new markers should facilitate further elucidation of the functional roles of Helios-based Treg heterogeneity.

  6. Coexpression of TIGIT and FCRL3 Identifies Helios+ Human Memory Regulatory T Cells

    PubMed Central

    Dhuban, Khalid Bin; d’Hennezel, Eva; Nashi, Emil; Bar-Or, Amit; Rieder, Sadiye; Shevach, Ethan M.; Nagata, Satoshi; Piccirillo, Ciriaco A.

    2015-01-01

    Two distinct subsets of CD4+Foxp3+ regulatory T (Treg) cells have been described based on the differential expression of Helios, a transcription factor of the Ikaros family. Efforts to understand the origin and biological roles of these Treg populations in regulating immune responses have, however, been hindered by the lack of reliable surface markers to distinguish and isolate them for subsequent functional studies. Using a single-cell cloning strategy coupled with microarray analysis of different Treg functional subsets in humans, we identify the mRNA and protein expression of TIGIT and FCRL3 as a novel surface marker combination that distinguishes Helios+FOXP3+ from Helios−FOXP3+ memory cells. Unlike conventional markers that are modulated on conventional T cells upon activation, we show that the TIGIT/FCRL3 combination allows reliable identification of Helios+ Treg cells even in highly activated conditions in vitro as well as in PBMCs of autoimmune patients. We also demonstrate that the Helios−FOXP3+ Treg subpopulation harbors a larger proportion of nonsuppressive clones compared with the Helios+ FOXP3+ cell subset, which is highly enriched for suppressive clones. Moreover, we find that Helios− cells are exclusively responsible for the productions of the inflammatory cytokines IFN-γ, IL-2, and IL-17 in FOXP3+ cells ex vivo, highlighting important functional differences between Helios+ and Helios− Treg cells. Thus, we identify novel surface markers for the consistent identification and isolation of Helios+ and Helios− memory Treg cells in health and disease, and we further reveal functional differences between these two populations. These new markers should facilitate further elucidation of the functional roles of Helios-based Treg heterogeneity. PMID:25762785

  7. A Generalized Gene-Regulatory Network Model of Stem Cell Differentiation for Predicting Lineage Specifiers.

    PubMed

    Okawa, Satoshi; Nicklas, Sarah; Zickenrott, Sascha; Schwamborn, Jens C; Del Sol, Antonio

    2016-09-13

    Identification of cell-fate determinants for directing stem cell differentiation remains a challenge. Moreover, little is known about how cell-fate determinants are regulated in functionally important subnetworks in large gene-regulatory networks (i.e., GRN motifs). Here we propose a model of stem cell differentiation in which cell-fate determinants work synergistically to determine different cellular identities, and reside in a class of GRN motifs known as feedback loops. Based on this model, we develop a computational method that can systematically predict cell-fate determinants and their GRN motifs. The method was able to recapitulate experimentally validated cell-fate determinants, and validation of two predicted cell-fate determinants confirmed that overexpression of ESR1 and RUNX2 in mouse neural stem cells induces neuronal and astrocyte differentiation, respectively. Thus, the presented GRN-based model of stem cell differentiation and computational method can guide differentiation experiments in stem cell research and regenerative medicine. PMID:27546532

  8. Treatment with MOG-DNA vaccines induces CD4+CD25+FoxP3+ regulatory T cells and up-regulates genes with neuroprotective functions in experimental autoimmune encephalomyelitis

    PubMed Central

    2012-01-01

    Background DNA vaccines represent promising therapeutic strategies in autoimmune disorders such as multiple sclerosis (MS). However, the precise mechanisms by which DNA vaccines induce immune regulation remain largely unknown. Here, we aimed to expand previous knowledge existing on the mechanisms of action of DNA vaccines in the animal model of MS, experimental autoimmune encephalomyelitis (EAE), by treating EAE mice with a DNA vaccine encoding the myelin oligodendrocyte glycoprotein (MOG), and exploring the therapeutic effects on the disease-induced inflammatory and neurodegenerative changes. Methods EAE was induced in C57BL6/J mice by immunization with MOG35-55 peptide. Mice were intramuscularly treated with a MOG-DNA vaccine or vehicle in prophylactic and therapeutic approaches. Histological studies were performed in central nervous system (CNS) tissue. Cytokine production and regulatory T cell (Treg) quantification were achieved by flow cytometry. Gene expression patterns were determined using microarrays, and the main findings were validated by real-time PCR. Results MOG-DNA treatment reduced the clinical and histopathological signs of EAE when administered in both prophylactic and therapeutic settings. Suppression of clinical EAE was associated with dampening of antigen (Ag)-specific proinflammatory Th1 and Th17 immune responses and, interestingly, expansion of Treg in the periphery and upregulation in the CNS of genes encoding neurotrophic factors and proteins involved in remyelination. Conclusions These results suggest for the first time that the beneficial effects of DNA vaccines in EAE are not limited to anti-inflammatory mechanisms, and DNA vaccines may also exert positive effects through hitherto unknown neuroprotective mechanisms. PMID:22727044

  9. Shape-dependent control of cell growth, differentiation, and apoptosis: switching between attractors in cell regulatory networks

    NASA Technical Reports Server (NTRS)

    Huang, S.; Ingber, D. E.

    2000-01-01

    Development of characteristic tissue patterns requires that individual cells be switched locally between different phenotypes or "fates;" while one cell may proliferate, its neighbors may differentiate or die. Recent studies have revealed that local switching between these different gene programs is controlled through interplay between soluble growth factors, insoluble extracellular matrix molecules, and mechanical forces which produce cell shape distortion. Although the precise molecular basis remains unknown, shape-dependent control of cell growth and function appears to be mediated by tension-dependent changes in the actin cytoskeleton. However, the question remains: how can a generalized physical stimulus, such as cell distortion, activate the same set of genes and signaling proteins that are triggered by molecules which bind to specific cell surface receptors. In this article, we use computer simulations based on dynamic Boolean networks to show that the different cell fates that a particular cell can exhibit may represent a preprogrammed set of common end programs or "attractors" which self-organize within the cell's regulatory networks. In this type of dynamic network model of information processing, generalized stimuli (e.g., mechanical forces) and specific molecular cues elicit signals which follow different trajectories, but eventually converge onto one of a small set of common end programs (growth, quiescence, differentiation, apoptosis, etc.). In other words, if cells use this type of information processing system, then control of cell function would involve selection of preexisting (latent) behavioral modes of the cell, rather than instruction by specific binding molecules. Importantly, the results of the computer simulation closely mimic experimental data obtained with living endothelial cells. The major implication of this finding is that current methods used for analysis of cell function that rely on characterization of linear signaling pathways or

  10. Gene regulatory networks controlling hematopoietic progenitor niche cell production and differentiation in the Drosophila lymph gland.

    PubMed

    Tokusumi, Yumiko; Tokusumi, Tsuyoshi; Shoue, Douglas A; Schulz, Robert A

    2012-01-01

    Hematopoiesis occurs in two phases in Drosophila, with the first completed during embryogenesis and the second accomplished during larval development. The lymph gland serves as the venue for the final hematopoietic program, with this larval tissue well-studied as to its cellular organization and genetic regulation. While the medullary zone contains stem-like hematopoietic progenitors, the posterior signaling center (PSC) functions as a niche microenvironment essential for controlling the decision between progenitor maintenance versus cellular differentiation. In this report, we utilize a PSC-specific GAL4 driver and UAS-gene RNAi strains, to selectively knockdown individual gene functions in PSC cells. We assessed the effect of abrogating the function of 820 genes as to their requirement for niche cell production and differentiation. 100 genes were shown to be essential for normal niche development, with various loci placed into sub-groups based on the functions of their encoded protein products and known genetic interactions. For members of three of these groups, we characterized loss- and gain-of-function phenotypes. Gene function knockdown of members of the BAP chromatin-remodeling complex resulted in niche cells that do not express the hedgehog (hh) gene and fail to differentiate filopodia believed important for Hh signaling from the niche to progenitors. Abrogating gene function of various members of the insulin-like growth factor and TOR signaling pathways resulted in anomalous PSC cell production, leading to a defective niche organization. Further analysis of the Pten, TSC1, and TSC2 tumor suppressor genes demonstrated their loss-of-function condition resulted in severely altered blood cell homeostasis, including the abundant production of lamellocytes, specialized hemocytes involved in innate immune responses. Together, this cell-specific RNAi knockdown survey and mutant phenotype analyses identified multiple genes and their regulatory networks required for

  11. Immunoregulatory T Cell Function in Multiple Myeloma

    PubMed Central

    Ozer, H.; Han, T.; Henderson, E. S.; Nussbaum, A.; Sheedy, D.

    1981-01-01

    Multiple myeloma is a malignancy characterized by uncontrolled monoclonal B cell differentiation and immunoglobulin production. In most instances, there is concomitant reduction in polyclonal differentiation and immunoglobulin synthesis both in vivo and in vitro. In in vitro pokeweed mitogen-induced B cell differentiation assays, proliferation and polyclonal immunoglobulin secretion optimally requires T cell help and can be inhibited both by monocytes and suppressor T cells. Helper function and monocyte-mediated suppression are relatively radio-resistant whereas T suppressor function is sensitive to 2,000 rad x-irradiation. We have examined myeloma T cell subset function in this assay using recombinations of isolated patient and normal B cells, T cells, and T cell subsets. Monocytes were removed by a carbonyl iron ingestion technique, normal and myeloma T cells were fractionated on the basis of Fc receptors for immunoglobulin (Ig) G (Tγ) or IgM (Tμ or T non-γ), and proliferation and IgG secretion after co-culture determined by [3H]thymidine incorporation and radio-immunoassay, respectively. Myeloma B cells demonstrate quantitatively and qualitatively normal blastogenic responses and are appropriately regulated by either autologous or allogeneic T helper and suppressor subsets. Despite normal proliferation, however, myeloma B cells remain deficient in subsequent differentiation and immunoglobulin secretion even when co-cultured in the absence of monocytes or suppressor T cells and the presence of normal helper cells. Myeloma T cell populations, in contrast, are entirely normal in helper capacity over a range of T:B ratios but are markedly deficient in radiosensitive and concanavalin A-induced suppressor activity. T suppressor cell dysfunction in multiple myeloma is apparently due to a deficit in the T non-γ suppressor subset, whereas Tγ cells, although proportionately reduced, are functionally normal. This unique T suppressor deficit reflects the heterogeneity

  12. Identification of functional elements and regulatory circuits by Drosophila modENCODE

    SciTech Connect

    Roy, Sushmita; Ernst, Jason; Kharchenko, Peter V.; Kheradpour, Pouya; Negre, Nicolas; Eaton, Matthew L.; Landolin, Jane M.; Bristow, Christopher A.; Ma, Lijia; Lin, Michael F.; Washietl, Stefan; Arshinoff, Bradley I.; Ay, Ferhat; Meyer, Patrick E.; Robine, Nicolas; Washington, Nicole L.; Stefano, Luisa Di; Berezikov, Eugene; Brown, Christopher D.; Candeias, Rogerio; Carlson, Joseph W.; Carr, Adrian; Jungreis, Irwin; Marbach, Daniel; Sealfon, Rachel; Tolstorukov, Michael Y.; Will, Sebastian; Alekseyenko, Artyom A.; Artieri, Carlo; Booth, Benjamin W.; Brooks, Angela N.; Dai, Qi; Davis, Carrie A.; Duff, Michael O.; Feng, Xin; Gorchakov, Andrey A.; Gu, Tingting; Henikoff, Jorja G.; Kapranov, Philipp; Li, Renhua; MacAlpine, Heather K.; Malone, John; Minoda, Aki; Nordman, Jared; Okamura, Katsutomo; Perry, Marc; Powell, Sara K.; Riddle, Nicole C.; Sakai, Akiko; Samsonova, Anastasia; Sandler, Jeremy E.; Schwartz, Yuri B.; Sher, Noa; Spokony, Rebecca; Sturgill, David; van Baren, Marijke; Wan, Kenneth H.; Yang, Li; Yu, Charles; Feingold, Elise; Good, Peter; Guyer, Mark; Lowdon, Rebecca; Ahmad, Kami; Andrews, Justen; Berger, Bonnie; Brenner, Steven E.; Brent, Michael R.; Cherbas, Lucy; Elgin, Sarah C. R.; Gingeras, Thomas R.; Grossman, Robert; Hoskins, Roger A.; Kaufman, Thomas C.; Kent, William; Kuroda, Mitzi I.; Orr-Weaver, Terry; Perrimon, Norbert; Pirrotta, Vincenzo; Posakony, James W.; Ren, Bing; Russell, Steven; Cherbas, Peter; Graveley, Brenton R.; Lewis, Suzanna; Micklem, Gos; Oliver, Brian; Park, Peter J.; Celniker, Susan E.; Henikoff, Steven; Karpen, Gary H.; Lai, Eric C.; MacAlpine, David M.; Stein, Lincoln D.; White, Kevin P.; Kellis, Manolis

    2010-12-22

    To gain insight into how genomic information is translated into cellular and developmental programs, the Drosophila model organism Encyclopedia of DNA Elements (modENCODE) project is comprehensively mapping transcripts, histone modifications, chromosomal proteins, transcription factors, replication proteins and intermediates, and nucleosome properties across a developmental time course and in multiple cell lines. We have generated more than 700 data sets and discovered protein-coding, noncoding, RNA regulatory, replication, and chromatin elements, more than tripling the annotated portion of the Drosophila genome. Correlated activity patterns of these elements reveal a functional regulatory network, which predicts putative new functions for genes, reveals stage- and tissue-specific regulators, and enables gene-expression prediction. Our results provide a foundation for directed experimental and computational studies in Drosophila and related species and also a model for systematic data integration toward comprehensive genomic and functional annotation. Several years after the complete genetic sequencing of many species, it is still unclear how to translate genomic information into a functional map of cellular and developmental programs. The Encyclopedia of DNA Elements (ENCODE) (1) and model organism ENCODE (modENCODE) (2) projects use diverse genomic assays to comprehensively annotate the Homo sapiens (human), Drosophila melanogaster (fruit fly), and Caenorhabditis elegans (worm) genomes, through systematic generation and computational integration of functional genomic data sets. Previous genomic studies in flies have made seminal contributions to our understanding of basic biological mechanisms and genome functions, facilitated by genetic, experimental, computational, and manual annotation of the euchromatic and heterochromatic genome (3), small genome size, short life cycle, and a deep knowledge of development, gene function, and chromosome biology. The functions

  13. Role of IL-10-producing regulatory B cells in modulating T-helper cell immune responses during silica-induced lung inflammation and fibrosis

    PubMed Central

    Liu, Fangwei; Dai, Wujing; Li, Chao; Lu, Xiaowei; Chen, Ying; Weng, Dong; Chen, Jie

    2016-01-01

    Silicosis is characterized by chronic lung inflammation and fibrosis, which are seriously harmful to human health. Previous research demonstrated that uncontrolled T-helper (Th) cell immune responses were involved in the pathogenesis of silicosis. Lymphocytes also are reported to have important roles. Existing studies on lymphocyte regulation of Th immune responses were limited to T cells, such as the regulatory T (Treg) cell, which could negatively regulate inflammation and promote the process of silicosis. However, other regulatory subsets in silicosis have not been investigated in detail, and the mechanism of immune homeostasis modulation needs further exploration. Another regulatory lymphocyte, the regulatory B cell, has recently drawn increasing attention. In this study, we comprehensively showed the role of IL-10-producing regulatory B cell (B10) in a silicosis model of mice. B10 was inducible by silica instillation. Insufficient B10 amplified inflammation and attenuated lung fibrosis by promoting the Th1 immune response. Insufficient B10 clearly inhibited Treg and decreased the level of IL-10. Our study indicated that B10 could control lung inflammation and exacerbate lung fibrosis by inhibiting Th1 response and modulating the Th balance. The regulatory function of B10 could be associated with Treg induction and IL-10 secretion. PMID:27354007

  14. Immune homeostasis enforced by co-localized effector and regulatory T cells

    PubMed Central

    Liu, Zhiduo; Gerner, Michael Y.; Van Panhuys, Nicholas; Levine, Andrew G.; Rudensky, Alexander Y.; Germain, Ronald N.

    2015-01-01

    Foxp3+ regulatory T cells (Tregs) play a critical role in preventing autoimmune disease by limiting the effector activity of conventional T cells that have escaped thymic negative selection or cell-autonomous peripheral inactivation1–3. However, despite the substantial information available about the molecular players mediating Treg functional interference with auto-aggressive effector responses4,5, the relevant cellular events in intact tissues remain largely unexplored and the issues of whether Tregs prevent activation of self-specific T cells or function primarily to limit damage from such cells have not been addressed6. Here we have employed multiplex, high-resolution, quantitative imaging to reveal that within most secondary lymphoid tissues, Tregs expressing phosphorylated STAT5 (pSTAT5) and high amounts of the suppressive molecules CD73 and CTLA-4 exist in discrete clusters with rare IL-2 producing effector T cells activated by self-antigens. This local IL-2 production induces the STAT5 phosphorylation in the Tregs and is part of a feedback circuit that augments the suppressive properties of the Tregs to limit further autoimmune responses. Inducible ablation of TCR expression by Tregs reduces their regulatory capacity and disrupts their localization in such clusters, resulting in uncontrolled effector T cell responses. Our data thus reveal that autoreactive T cells reach a state of activation and cytokine gene induction on a regular basis, with physically co-clustering, TCR-stimulated Tregs responding to this activation in a feedback manner to suppress incipient autoimmunity and maintain immune homeostasis. PMID:26605524

  15. An etiologic regulatory mutation in IRF6 with loss- and gain-of-function effects.

    PubMed

    Fakhouri, Walid D; Rahimov, Fedik; Attanasio, Catia; Kouwenhoven, Evelyn N; Ferreira De Lima, Renata L; Felix, Temis Maria; Nitschke, Larissa; Huver, David; Barrons, Julie; Kousa, Youssef A; Leslie, Elizabeth; Pennacchio, Len A; Van Bokhoven, Hans; Visel, Axel; Zhou, Huiqing; Murray, Jeffrey C; Schutte, Brian C

    2014-05-15

    DNA variation in Interferon Regulatory Factor 6 (IRF6) causes Van der Woude syndrome (VWS), the most common syndromic form of cleft lip and palate (CLP). However, an etiologic variant in IRF6 has been found in only 70% of VWS families. To test whether DNA variants in regulatory elements cause VWS, we sequenced three conserved elements near IRF6 in 70 VWS families that lack an etiologic mutation within IRF6 exons. A rare mutation (350dupA) was found in a conserved IRF6 enhancer element (MCS9.7) in a Brazilian family. The 350dupA mutation abrogated the binding of p63 and E47 transcription factors to cis-overlapping motifs, and significantly disrupted enhancer activity in human cell cultures. Moreover, using a transgenic assay in mice, the 350dupA mutation disrupted the activation of MCS9.7 enhancer element and led to failure of lacZ expression in all head and neck pharyngeal arches. Interestingly, disruption of the p63 Motif1 and/or E47 binding sites by nucleotide substitution did not fully recapitulate the effect of the 350dupA mutation. Rather, we recognized that the 350dupA created a CAAAGT motif, a binding site for Lef1 protein. We showed that Lef1 binds to the mutated site and that overexpression of Lef1/β-Catenin chimeric protein repressed MCS9.7-350dupA enhancer activity. In conclusion, our data strongly suggest that 350dupA variant is an etiologic mutation in VWS patients and disrupts enhancer activity by a loss- and gain-of-function mechanism, and thus support the rationale for additional screening for regulatory mutations in patients with CLP. PMID:24442519

  16. Myeloid-Derived Suppressor Cells (MDSC) Protect Islet Transplants via B7-H1 Mediated Enhancement of T Regulatory Cells

    PubMed Central

    Chou, Hong-Shiue; Hsieh, Ching-Chuan; Charles, Ronald; Wang, Lianfu; Wagner, Timothy; Fung, John J.; Qian, Shiguang; L, Lina Lu

    2011-01-01

    Background Side effects of lifetime immunosuppression for cell transplants often outweigh the benefits, therefore, induction of transplant tolerance is needed. We have shown that cotransplantation with myeoid-derived suppressor cells (MDSC) effectively protect islet allografts from rejection without requirement of immunosuppression. This study was to investigate the underlying mechanisms. Methods MDSC were generated by addition of hepatic stellate cells (HpSC) from various stain mice into dendritic cell (DC) culture. The quality of MDSC was monitored by phenotype and function analyses. MDSC mixed with islet allografts were transplanted into diabetic recipients. T cell response was analyzed following transplant by flow and histochemical analyses, and compared to islet alone and islet/DC transplant groups. B7-H1 knockout mice were used to determine the role of B7-H1 on MDSC in regulation of T cell response. Results Cotransplantation with MDSC (not DC) effectively protected islet allografts without requirement of immunosuppression. This is associated with attenuation of CD8 T cells in the grafts and marked expansion of T regulatory (Treg) cells, which contributed to MDSC-induced T cell hyporesponsiveness. Antigen-specific Treg cells were prone to accumulate in lymphoid organs close to the grafts. Both in vitro and in vivo data demonstrated that B7-H1 was absolutely required for MDSC to exert immune regulatory activity and induction of Treg cells. Conclusion The described approach holds great clinical application potential, and may overcome the limitation of requiring chronic administration of immunosuppression in cell transplants. Understanding the underlying mechanisms will facilitate the development of this novel therapeutic strategy. PMID:22179405

  17. The Effect of Traditional Chinese Formula Danchaiheji on the Differentiation of Regulatory Dendritic Cells

    PubMed Central

    Wang, Xiaodong; Tong, Jingzhi; Li, Keqiu; Jing, Yaqing

    2016-01-01

    Recently, regulatory dendritic cells (DCregs), a newly described dendritic cell subset with potent immunomodulatory function, have attracted increased attention for their utility in treating immune response-related diseases, such as graft-versus-host disease, hypersensitivity, and autoimmune diseases. Danchaiheji (DCHJ) is a traditional Chinese formula that has been used for many years in the clinic. However, whether DCHJ can program dendritic cells towards a regulatory phenotype and the underlying mechanism behind this process remain unknown. Herein, we investigate the effects of traditional Chinese DCHJ on DCregs differentiation and a mouse model of skin transplantation. The current study demonstrates that DCHJ can induce dendritic cells to differentiate into DCregs, which are represented by high CD11b and low CD86 and HLA-DR expression as well as the secretion of IL-10 and TGF-β. In addition, DCHJ inhibited DC migration and T cell proliferation, which correlated with increased IDO expression. Furthermore, DCHJ significantly prolonged skin graft survival time in a mouse model of skin transplantation without any liver or kidney toxicity. The traditional Chinese formula DCHJ has the potential to be a potent immunosuppressive agent with high efficiency and nontoxicity. PMID:27525028

  18. Sustained attention in infancy as a longitudinal predictor of self-regulatory functions.

    PubMed

    Johansson, Maria; Marciszko, Carin; Gredebäck, Gustaf; Nyström, Pär; Bohlin, Gunilla

    2015-11-01

    Previous literature suggests that attention processes such as sustained attention would constitute a developmental foundation for the self-regulatory functions executive functioning and effortful control (e.g., Garon, Bryson, & Smith, 2008; Rothbart, Derryberry, & Posner, 1994). Our main aim was to test this hypothesis by studying whether sustained attention at age 1 year can predict individual differences in self-regulatory functions at age 2 years. Longitudinal data from 66 infants and their parents were included in the study. Sustained attention was assessed during free play at age 1 year; executive functioning, measured using an eye-tracking version of the A-not-B task, and effortful control, measured using parental ratings, were assessed at both age 1 and age 2 years. The results did support a longitudinal prediction of individual differences in 2-year-olds' self-regulatory functions as a function of sustained attention at age 1 year. We also found significant improvement in both executive functioning and effortful control over time, and the two self-regulatory constructs were related in toddlerhood but not in infancy. The study helps increase our understanding of the early development of self-regulatory functions necessary for identifying developmental risks and, in the future, for developing new interventions.

  19. Advanced Inverter Functions to Support High Levels of Distributed Solar: Policy and Regulatory Considerations (Brochure)

    SciTech Connect

    Not Available

    2014-11-01

    This paper explains how advanced inverter functions (sometimes called 'smart inverters') contribute to the integration of high levels of solar PV generation onto the electrical grid and covers the contributions of advanced functions to maintaining grid stability. Policy and regulatory considerations associated with the deployment of advanced inverter functions are also introduced.

  20. Maps of cis-Regulatory Nodes in Megabase Long Genome Segments are an Inevitable Intermediate Step Toward Whole Genome Functional Mapping

    PubMed Central

    Nikolaev, Lev G; Akopov, Sergey B; Chernov, Igor P; Sverdlov, Eugene D

    2007-01-01

    The availability of complete human and other metazoan genome sequences has greatly facilitated positioning and analysis of various genomic functional elements, with initial emphasis on coding sequences. However, complete functional maps of sequenced eukaryotic genomes should include also positions of all non-coding regulatory elements. Unfortunately, experimental data on genomic positions of a multitude of regulatory sequences, such as enhancers, silencers, insulators, transcription terminators, and replication origins are very limited, especially at the whole genome level. Since most genomic regulatory elements (e.g. enhancers) are generally gene-, tissue-, or cell-specific, the prediction of these elements by computational methods is difficult and often ambiguous. Therefore, the development of high-throughput experimental approaches for identifying and mapping genomic functional elements is highly desirable. At the same time, the creation of whole-genome map of hundreds of thousands of regulatory elements in several hundreds of tissue/cell types is presently far beyond our capabilities. A possible alternative for the whole genome approach is to concentrate efforts on individual genomic segments and then to integrate the data obtained into a whole genome functional map. Moreover, the maps of polygenic fragments with functional cis-regulatory elements would provide valuable data on complex regulatory systems, including their variability and evolution. Here, we reviewed experimental approaches to the realization of these ideas, including our own developments of experimental techniques for selection of cis-acting functionally active DNA fragments from large (megabase-sized) segments of mammalian genomes. PMID:18660850

  1. Maps of cis-Regulatory Nodes in Megabase Long Genome Segments are an Inevitable Intermediate Step Toward Whole Genome Functional Mapping.

    PubMed

    Nikolaev, Lev G; Akopov, Sergey B; Chernov, Igor P; Sverdlov, Eugene D

    2007-04-01

    The availability of complete human and other metazoan genome sequences has greatly facilitated positioning and analysis of various genomic functional elements, with initial emphasis on coding sequences. However, complete functional maps of sequenced eukaryotic genomes should include also positions of all non-coding regulatory elements. Unfortunately, experimental data on genomic positions of a multitude of regulatory sequences, such as enhancers, silencers, insulators, transcription terminators, and replication origins are very limited, especially at the whole genome level. Since most genomic regulatory elements (e.g. enhancers) are generally gene-, tissue-, or cell-specific, the prediction of these elements by computational methods is difficult and often ambiguous. Therefore, the development of high-throughput experimental approaches for identifying and mapping genomic functional elements is highly desirable. At the same time, the creation of whole-genome map of hundreds of thousands of regulatory elements in several hundreds of tissue/cell types is presently far beyond our capabilities. A possible alternative for the whole genome approach is to concentrate efforts on individual genomic segments and then to integrate the data obtained into a whole genome functional map. Moreover, the maps of polygenic fragments with functional cis-regulatory elements would provide valuable data on complex regulatory systems, including their variability and evolution. Here, we reviewed experimental approaches to the realization of these ideas, including our own developments of experimental techniques for selection of cis-acting functionally active DNA fragments from large (megabase-sized) segments of mammalian genomes. PMID:18660850

  2. Nickel decreases cellular iron level and converts cytosolic aconitase to iron-regulatory protein 1 in A549 cells

    SciTech Connect

    Chen Haobin; Davidson, Todd; Singleton, Steven; Garrick, Michael D.; Costa, Max . E-mail: costam@env.med.nyu.edu

    2005-08-15

    Nickel (Ni) compounds are well-established carcinogens and are known to initiate a hypoxic response in cells via the stabilization and transactivation of hypoxia-inducible factor-1 alpha (HIF-1{alpha}). This change may be the consequence of nickel's interference with the function of several Fe(II)-dependent enzymes. In this study, the effects of soluble nickel exposure on cellular iron homeostasis were investigated. Nickel treatment decreased both mitochondrial and cytosolic aconitase (c-aconitase) activity in A549 cells. Cytosolic aconitase was converted to iron-regulatory protein 1, a form critical for the regulation of cellular iron homeostasis. The increased activity of iron-regulatory protein 1 after nickel exposure stabilized and increased transferrin receptor (Tfr) mRNA and antagonized the iron-induced ferritin light chain protein synthesis. The decrease of aconitase activity after nickel treatment reflected neither direct interference with aconitase function nor obstruction of [4Fe-4S] cluster reconstitution by nickel. Exposure of A549 cells to soluble nickel decreased total cellular iron by about 40%, a decrease that likely caused the observed decrease in aconitase activity and the increase of iron-regulatory protein 1 activity. Iron treatment reversed the effect of nickel on cytosolic aconitase and iron-regulatory protein 1. To assess the mechanism for the observed effects, human embryonic kidney (HEK) cells over expressing divalent metal transporter-1 (DMT1) were compared to A549 cells expressing only endogenous transporters for inhibition of iron uptake by nickel. The inhibition data suggest that nickel can enter via DMT1 and compete with iron for entry into the cell. This disturbance of cellular iron homeostasis by nickel may have a great impact on the ability of the cell to regulate a variety of cell functions, as well as create a state of hypoxia in cells under normal oxygen tension. These effects may be very important in how nickel exerts phenotypic

  3. Ex Vivo Induced Regulatory Human/Murine Mesenchymal Stem Cells as Immune Modulators.

    PubMed

    Hinden, Liad; Shainer, Reut; Almogi-Hazan, Osnat; Or, Reuven

    2015-07-01

    Over the past decade there has been a growing interest in using mesenchymal stem cells (MSCs) as an immune-regulatory agent for prevention and treatment of various immune disorders including graft-versus-host disease (GVHD), transplanted organ rejection, and autoimmune diseases. However, the high diversity in the results from clinical trials using MSCs for such disorders emphasizes the need for MSCs to be "professionalized" ex vivo to a more defined regulatory phenotype before administering to patients. To this aim, we have established an ex vivo immunomodulatory triple combination treatment (TCT) for MSCs, using IFNγ, TGFβ, and kynurenine. We show that pretreated MSCs acquire an immunomodulatory phenotype, have improved regulatory functions, and upregulate the expression of inducible nitric oxide synthase, indoleamine 2,3-dioxygenase, cyclooxygenase-2 (COX2), heme oxygenase 1, leukemia inhibitory factor (LIF), and programmed death ligand 1. We define the pathway of kynurenine induced aryl hydrocarbon receptor activation in MSCs and how it contributes to the upregulation of COX2 expression and IL-6 downregulation. The combination of reduced IL-6 secretion with enhanced LIF expression leads to the inhibition of Th17 differentiation in coculture of TCT MSCs and lymphocytes. To test the immunomodulatory function of TCT MSCs in vivo, we used the cells as GVHD prophylaxis in a GVHD mouse model. TCT MSCs administration significantly decreased GVHD score and improved mouse survival. Importantly, single administration could attenuate disease symptoms for more than 3 weeks. Based on these results, we suggest considering TCT MSCs as an improved cell therapy for systemic diseases with an underlying inflammatory and immunologic etiology. Stem Cells 2015;33:2256-2267.

  4. Kinome Profiling of Regulatory T Cells: A Closer Look into a Complex Intracellular Network

    PubMed Central

    Tuettenberg, Andrea; Hahn, Susanne A.; Mazur, Johanna; Gerhold-Ay, Aslihan; Scholma, Jetse; Marg, Iris; Ulges, Alexander; Satoh, Kazuki; Bopp, Tobias; Joore, Jos; Jonuleit, Helmut

    2016-01-01

    Regulatory T cells (Treg) are essential for T cell homeostasis and maintenance of peripheral tolerance. They prevent activation of auto-reactive T effector cells (Teff) in the context of autoimmunity and allergy. Otherwise, Treg also inhibit effective immune responses against tumors. Besides a number of Treg-associated molecules such as Foxp3, CTLA-4 or GARP, known to play critical roles in Treg differentiation, activation and function, the involvement of additional regulatory elements is suggested. Herein, kinase activities seem to play an important role in Treg fine tuning. Nevertheless, our knowledge regarding the complex intracellular signaling pathways controlling phenotype and function of Treg is still limited and based on single kinase cascades so far. To gain a more comprehensive insight into the pathways determining Treg function we performed kinome profiling using a phosphorylation-based kinome array in human Treg at different activation stages compared to Teff. Here we have determined intriguing quantitative differences in both populations. Resting and activated Treg showed an altered pattern of CD28-dependent kinases as well as of those involved in cell cycle progression. Additionally, significant up-regulation of distinct kinases such as EGFR or CK2 in activated Treg but not in Teff not only resemble data we obtained in previous studies in the murine system but also suggest that those specific molecular activation patterns can be used for definition of the activation and functional state of human Treg. Taken together, detailed investigation of kinome profiles opens the possibility to identify novel molecular mechanisms for a better understanding of Treg biology but also for development of effective immunotherapies against unwanted T cell responses in allergy, autoimmunity and cancer. PMID:26881744

  5. Kinome Profiling of Regulatory T Cells: A Closer Look into a Complex Intracellular Network.

    PubMed

    Tuettenberg, Andrea; Hahn, Susanne A; Mazur, Johanna; Gerhold-Ay, Aslihan; Scholma, Jetse; Marg, Iris; Ulges, Alexander; Satoh, Kazuki; Bopp, Tobias; Joore, Jos; Jonuleit, Helmut

    2016-01-01

    Regulatory T cells (Treg) are essential for T cell homeostasis and maintenance of peripheral tolerance. They prevent activation of auto-reactive T effector cells (Teff) in the context of autoimmunity and allergy. Otherwise, Treg also inhibit effective immune responses against tumors. Besides a number of Treg-associated molecules such as Foxp3, CTLA-4 or GARP, known to play critical roles in Treg differentiation, activation and function, the involvement of additional regulatory elements is suggested. Herein, kinase activities seem to play an important role in Treg fine tuning. Nevertheless, our knowledge regarding the complex intracellular signaling pathways controlling phenotype and function of Treg is still limited and based on single kinase cascades so far. To gain a more comprehensive insight into the pathways determining Treg function we performed kinome profiling using a phosphorylation-based kinome array in human Treg at different activation stages compared to Teff. Here we have determined intriguing quantitative differences in both populations. Resting and activated Treg showed an altered pattern of CD28-dependent kinases as well as of those involved in cell cycle progression. Additionally, significant up-regulation of distinct kinases such as EGFR or CK2 in activated Treg but not in Teff not only resemble data we obtained in previous studies in the murine system but also suggest that those specific molecular activation patterns can be used for definition of the activation and functional state of human Treg. Taken together, detailed investigation of kinome profiles opens the possibility to identify novel molecular mechanisms for a better understanding of Treg biology but also for development of effective immunotherapies against unwanted T cell responses in allergy, autoimmunity and cancer. PMID:26881744

  6. Daratumumab depletes CD38+ immune regulatory cells, promotes T-cell expansion, and skews T-cell repertoire in multiple myeloma

    PubMed Central

    Krejcik, Jakub; Casneuf, Tineke; Nijhof, Inger S.; Verbist, Bie; Bald, Jaime; Plesner, Torben; Syed, Khaja; Liu, Kevin; van de Donk, Niels W. C. J.; Weiss, Brendan M.; Ahmadi, Tahamtan; Lokhorst, Henk M.; Mutis, Tuna

    2016-01-01

    Daratumumab targets CD38-expressing myeloma cells through a variety of immune-mediated mechanisms (complement-dependent cytotoxicity, antibody-dependent cell-mediated cytotoxicity, and antibody-dependent cellular phagocytosis) and direct apoptosis with crosslinking. These mechanisms may also target nonplasma cells that express CD38, which prompted evaluation of daratumumab’s effects on CD38-positive immune subpopulations. Peripheral blood (PB) and bone marrow (BM) from patients with relapsed/refractory myeloma from 2 daratumumab monotherapy studies were analyzed before and during therapy and at relapse. Regulatory B cells and myeloid-derived suppressor cells, previously shown to express CD38, were evaluated for immunosuppressive activity and daratumumab sensitivity in the myeloma setting. A novel subpopulation of regulatory T cells (Tregs) expressing CD38 was identified. These Tregs were more immunosuppressive in vitro than CD38-negative Tregs and were reduced in daratumumab-treated patients. In parallel, daratumumab induced robust increases in helper and cytotoxic T-cell absolute counts. In PB and BM, daratumumab induced significant increases in CD8+:CD4+ and CD8+:Treg ratios, and increased memory T cells while decreasing naïve T cells. The majority of patients demonstrated these broad T-cell changes, although patients with a partial response or better showed greater maximum effector and helper T-cell increases, elevated antiviral and alloreactive functional responses, and significantly greater increases in T-cell clonality as measured by T-cell receptor (TCR) sequencing. Increased TCR clonality positively correlated with increased CD8+ PB T-cell counts. Depletion of CD38+ immunosuppressive cells, which is associated with an increase in T-helper cells, cytotoxic T cells, T-cell functional response, and TCR clonality, represents possible additional mechanisms of action for daratumumab and deserves further exploration. PMID:27222480

  7. Regulatory T cells enhance persistence of the zoonotic pathogen Seoul virus in its reservoir host.

    PubMed

    Easterbrook, Judith D; Zink, M Christine; Klein, Sabra L

    2007-09-25

    Hantaviruses are zoonotic pathogens that maintain a persistent infection in their reservoir hosts, yet the mechanisms mediating persistence remain unknown. Regulatory T cell responses cause persistent infection by suppressing proinflammatory and effector T cell activity; hantaviruses may exploit these responses to cause persistence. To test this hypothesis, male Norway rats were inoculated with Seoul virus and regulatory T cells were monitored during infection. Increased numbers of CD4(+)CD25(+)Forkhead box P3(+) T cells and expression of Forkhead box P3 and TGF-beta were observed in the lungs of male rats during persistent Seoul virus infection. To determine whether regulatory T cells modulate Seoul virus persistence, regulatory T cells were inactivated in male rats by using an anti-rat CD25 monoclonal antibody (NDS-63). Inactivation of regulatory T cells reduced the amount of Seoul virus RNA present in the lungs and the proportion of animals shedding viral RNA in saliva. Because regulatory T cells suppress proinflammatory-induced pathogenesis, pathologic observations in the lungs were evaluated during infection. Subclinical acute multifocal areas of hemorrhage and edema were noted in the lungs during infection; inactivation of regulatory T cells reduced the amount of pathologic foci. Expression of TNF was suppressed during the persistent phase of infection; inactivation of regulatory T cells eliminated the suppression of TNF. Taken together, these data suggest that regulatory T cells mediate Seoul virus persistence, possibly through elevated transcription and synthesis of TGF-beta and suppression of TNF. These data provide evidence of regulatory T cell involvement in the persistence of a zoonotic pathogen in its natural reservoir host.

  8. Regulatory Networks that Direct the Development of Specialized Cell Types in the Drosophila Heart

    PubMed Central

    Lovato, TyAnna L.; Cripps, Richard M.

    2016-01-01

    The Drosophila cardiac tube was once thought to be a simple linear structure, however research over the past 15 years has revealed significant cellular and molecular complexity to this organ. Prior reviews have focused upon the gene regulatory networks responsible for the specification of the cardiac field and the activation of cardiac muscle structural genes. Here we focus upon highlighting the existence, function, and development of unique cell types within the dorsal vessel, and discuss their correspondence to analogous structures in the vertebrate heart. PMID:27695700

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

    PubMed

    Beyer, Marc

    2012-10-01

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

  10. The Cellular and Molecular Mechanisms of Immuno-Sup