437,649 research outputs found

    Paracrine IL-2 Is Required for Optimal Type 2 Effector Cytokine Production

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    IL-2 is a pleiotropic cytokine that promotes the differentiation of Th cell subsets, including Th1, Th2, and Th9 cells, but it impairs the development of Th17 and T follicular helper cells. Although IL-2 is produced by all polarized Th subsets to some level, how it impacts cytokine production when effector T cells are restimulated is unknown. We show in this article that Golgi transport inhibitors (GTIs) blocked IL-9 production. Mechanistically, GTIs blocked secretion of IL-2 that normally feeds back in a paracrine manner to promote STAT5 activation and IL-9 production. IL-2 feedback had no effect on Th1- or Th17-signature cytokine production, but it promoted Th2- and Th9-associated cytokine expression. These data suggest that the use of GTIs results in an underestimation of the presence of type 2 cytokine-secreting cells and highlight IL-2 as a critical component in optimal cytokine production by Th2 and Th9 cells in vitro and in vivo

    Targeting cellular calcium homeostasis to prevent cytokine-mediated beta cell death

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    AbstractPro-inflammatory cytokines are important mediators of islet inflammation, leading to beta cell death in type 1 diabetes. Although alterations in both endoplasmic reticulum (ER) and cytosolic free calcium levels are known to play a role in cytokine-mediated beta cell death, there are currently no treatments targeting cellular calcium homeostasis to combat type 1 diabetes. Here we show that modulation of cellular calcium homeostasis can mitigate cytokine- and ER stress-mediated beta cell death. The calcium modulating compounds, dantrolene and sitagliptin, both prevent cytokine and ER stress-induced activation of the pro-apoptotic calcium-dependent enzyme, calpain, and partly suppress beta cell death in INS1E cells and human primary islets. These agents are also able to restore cytokine-mediated suppression of functional ER calcium release. In addition, sitagliptin preserves function of the ER calcium pump, sarco-endoplasmic reticulum Ca2+-ATPase (SERCA), and decreases levels of the pro-apoptotic protein thioredoxin-interacting protein (TXNIP). Supporting the role of TXNIP in cytokine-mediated cell death, knock down of TXNIP in INS1-E cells prevents cytokine-mediated beta cell death. Our findings demonstrate that modulation of dynamic cellular calcium homeostasis and TXNIP suppression present viable pharmacologic targets to prevent cytokine-mediated beta cell loss in diabetes.</jats:p

    Global landscape of mouse and human cytokine transcriptional regulation

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    Cytokines are cell-to-cell signaling proteins that play a central role in immune development, pathogen responses, and diseases. Cytokines are highly regulated at the transcriptional level by combinations of transcription factors (TFs) that recruit cofactors and the transcriptional machinery. Here, we mined through three decades of studies to generate a comprehensive database, CytReg, reporting 843 and 647 interactions between TFs and cytokine genes, in human and mouse respectively. By integrating CytReg with other functional datasets, we determined general principles governing the transcriptional regulation of cytokine genes. In particular, we show a correlation between TF connectivity and immune phenotype and disease, we discuss the balance between tissue-specific and pathogen-activated TFs regulating each cytokine gene, and cooperativity and plasticity in cytokine regulation. We also illustrate the use of our database as a blueprint to predict TF–disease associations and identify potential TF–cytokine regulatory axes in autoimmune diseases. Finally, we discuss research biases in cytokine regulation studies, and use CytReg to predict novel interactions based on co-expression and motif analyses which we further validated experimentally. Overall, this resource provides a framework for the rational design of future cytokine gene regulation studies.National Institutes of Health (NIH) [R00 GM114296 and R35 GM128625 to J.I.F.B., 5T32HL007501-34 to J.A.S.]; National Science Foundation [NSF-REU BIO-1659605 to M.M.]. Funding for open access charge: NIH [R35 GM128625]. (R00 GM114296 - National Institutes of Health (NIH); R35 GM128625 - National Institutes of Health (NIH); 5T32HL007501-34 - National Institutes of Health (NIH); NSF-REU BIO-1659605 - National Science Foundation; R35 GM128625 - NIH)Published versio

    Cytokine gene polymorphisms in preterm infants with necrotising enterocolitis: genetic association study

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    BACKGROUND The inflammatory cytokine cascade is implicated in the pathogenesis of necrotising enterocolitis (NEC). Genetic association studies of cytokine polymorphisms may help to detect molecular mechanisms that are causally related to the disease process. AIM To examine associations between the common genetic variants in candidate inflammatory cytokine genes and NEC in preterm infants. METHODS Multi-centre case-control and genetic association study. DNA samples were collected from 50 preterm infants with NEC and 50 controls matched for gestational age and ethnic group recruited to a multi-centre case-control study. Ten candidate single-nucleotide polymorphisms in cytokines previously associated with infectious or inflammatory diseases were genotyped. The findings were included in random-effects meta-analyses with data from previous genetic association studies. RESULTS All allele distributions were in Hardy-Weinberg equilibrium. None of the studied cytokine polymorphisms was significantly associated with NEC. Four previous genetic association studies of cytokine polymorphisms and NEC in preterm infants were found. Meta-analyses were possible for several single-nucleotide polymorphisms. These increased the precision of the estimates of effect size but did not reveal any significant associations. CONCLUSIONS The available data are not consistent with more than modest associations between these candidate cytokine variant alleles and NEC in preterm infants. Data from future association studies of these polymorphisms may be added to the meta-analyses to obtain more precise estimates of effects sizes.The study was funded by Tenovus (Scotland)

    Influence of Cytokines and Autologous Lymphokine-Activated Killer Cells on Leukemic Bone Marrow Cells and Colonies in AML

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    We have already shown that cytokine cocktails (IL-1 beta, IL-3, IL-6, SCF, GM-CSF) and/or lymphokine-activated killer (LAK) cells can reduce the amounts of clonal, CD34-positive mononuclear bone marrow cells (BM-MNC) in acute myeloid leukemia (AML). In addition, the influence of those cocktails and/or LAK cells on the clonogenic potential of AML BM-MNC was investigated. BM colonies cultured in agar during different stages of the disease were immunophenotyped in situ: 17 patients at diagnosis, 14 patients in complete remission, 8 patients at relapse, 8 healthy donors. A significant reduction in leukemic cells and colonies positive for CD34 after in vitro culture of BM-MNC with cytokine cocktails was achieved with all samples obtained at diagnosis (n = 8, p < 0.01), in 6 of 8 cases in complete remission but only in 2 of 6 cases at relapse. Cytokine cocktails stimulated granulopoiesis as well as B and T lymphopoiesis. Colonies with leukemic phenotype could never be detected in healthy BM. A significant reduction in leukemic colonies was achieved by coculture of BM-MNC (uncultured or cytokine precultured) with autologous LAK cells in all 4 cases at diagnosis and in 1 case at relapse. An additive effect of in vitro cytokine preincubation of BM samples on the leukemia-reducing effect of LAK cells could be demonstrated in all samples studied (p <0.001; diagnosis: n = 10, relapse: n = 3, complete remission: n = 7). Patients had a better prognosis if CD34-positive colonies in AML could be reduced by cytokine incubation (p = 0.03) or coculture with autologous LAK cells in vitro (p = 0.04). Our data show that cytokines as well as LAK cells alone and in combination can reduce, however not eliminate clonogenic AML cells. Such mechanisms might be responsible for maintaining stable remissions in AML. Copyright (C) 2001 S. Karger AG, Basel

    IL-21 receptor expression in human tendinopathy

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    The pathogenetic mechanisms underlying tendinopathy remain unclear, with much debate as to whether inflammation or degradation has the prominent role. Increasing evidence points toward and early inflammatory infiltrate and associated inflammatory cytokine production in human and animal models of tendon disease. The IL-21/IL-21R axis is a proinflammatory cytokine complex that has been associated with chronic inflammatory diseases including rheumatoid arthritis and inflammatory bowel disease. This project aimed to investigate the role and expression of the cytokine/receptor pair IL-21/IL-21R in human tendinopathy. We found significantly elevated expression of IL-21 receptor message and protein in human tendon samples but found no convincing evidence of the presence of IL-21 at message or protein level. The level of expression of IL-21R message/protein in human tenocytes was significantly up regulated by proinflammatory cytokines (TNFα/IL-1β) in vitro. These findings demonstrate that IL-21R is present in early human tendinopathy mainly expressed by tenocytes and macrophages. Despite a lack of IL-21 expression these data again suggest that early tendinopathy has an inflammatory/cytokine phenotype, which may provide novel translational targets in the treatment of tendinopathy