Potentiation of flagellin responses in gut epithelial cells by interferon-γ is associated with STAT-independent regulation of MyD88 expression

2009 ◽  
Vol 423 (1) ◽  
pp. 119-128 ◽  
Author(s):  
Ciara Bannon ◽  
Pam J. Davies ◽  
Andrew Collett ◽  
Geoffrey Warhurst
Keyword(s):  
Epithelial Cells ◽  
Enteric Bacteria ◽  
Interferon Γ ◽  
Janus Kinase ◽  
Cxcl8 Secretion ◽  
Health And Disease ◽  
Toll Like Receptor 5 ◽  
Myeloid Differentiation Factor ◽  
Interfering Rna ◽  
Dose Dependent

Flagellin acting via TLR5 (Toll-like receptor 5) is a key regulator of the host response to the gut microbial flora in both health and disease. The present study has investigated regulation of flagellin–TLR5 signalling in human colonocytes (HT29-19A) by IFNγ (interferon-γ), a cytokine released early in the inflammatory process which has multiple effects on gut epithelial function that may facilitate abnormal responses to enteric bacteria. Flagellin induced a dose-dependent secretion of chemokines CXCL8 and CCL2 in the human colonocyte line, HT29-19A. Exposure to IFNγ did not induce chemokine secretion, but markedly potentiated responses to flagellin, increasing CXL8 gene expression and protein secretion by approx. 4-fold. Potentiation by IFNγ was independent of changes in TLR5 and was associated with a rapid, sustained increase in expression of the downstream adaptor molecule MyD88 (myeloid differentiation factor 88). Knockdown of MyD88 expression using siRNA (small interfering RNA) abolished flagellin-dependent CXCL8 secretion and the potentiating effect of IFNγ. Exposure of non-transformed mouse and human colonocytes to IFNγ also increased MyD88 expression. STAT (signal transducer and activator of transcription) 1 knockdown and use of the broad-spectrum JAK (Janus kinase)-STAT inhibitor AG490 had no effect on IFNγ-mediated up-regulation of MyD88. The findings of the present study suggest that IFNγ sensitizes colonic epithelial cells to bacterial flagellin via a largely STAT-independent up-regulation of MyD88 expression leading to increased secretion of immunomodulatory factors. These results indicate that epithelial responses to flagellin are potentiated by IFNγ, most likely mediated by increased MyD88 expression. The present study adds to our understanding of the spectrum of effects of this cytokine on gut epithelium that may contribute to bacterial-driven inflammation in the gut.

Direct regulation of lipolysis by interleukin-15 in primary pig adipocytes

2004 ◽  
Vol 287 (3) ◽  
pp. R608-R611 ◽  
Author(s):  
Kolapo M. Ajuwon ◽  
Michael E. Spurlock
Keyword(s):  
Protein Kinase ◽  
Muscle Protein ◽  
Interferon Γ ◽  
Janus Kinase ◽  
Dependent Manner ◽  
Kinase C ◽  
Tnf Α ◽  
Interleukin 15 ◽  
Ifn Γ ◽  
Dose Dependent

We recently provided evidence that interleukin-15 (IL-15) is expressed lowly in the pig adipocyte and that interferon-γ (IFN-γ) markedly increases this expression through a pathway regulated in part by protein kinase C (Ajuwon KM, Jacobi SK, Kuske JL, and Spurlock ME. Am J Physiol Regul Integr Comp Physiol 286: R547–R553, 2004). In the present study, we tested the hypothesis that IL-15 acts directly on the adipocyte to regulate lipid accretion by enhancing lipolysis or suppressing lipogenesis. Using recombinant porcine IL-15, we determined that this cytokine stimulates lipolysis in a dose-dependent manner ( P < 0.001). Furthermore, comparative studies with other cytokines showed that IL-15 is more potent in its acute stimulation of lipolysis than either TNF-α, IL-6, or LPS ( P < 0.001). When specific inhibitors of protein kinase A or Janus kinase are present, the lipolytic effect of IL-15 is attenuated ( P < 0.01). These data indicate that, in addition to its regulation of muscle protein accretion and T-cell growth and development, IL-15 also targets the adipocyte directly to alter stimulate lipolysis. Thus, when induced by IFN-γ or other inflammatory mediators, IL-15 may be a significant homeorhetic factor that mobilizes and directs energy away from the adipocyte to other cells during the acute phase of the inflammatory response.

scholarly journals GCN2 drives macrophage and MDSC function and immunosuppression in the tumor microenvironment

2019 ◽  
Vol 4 (42) ◽  
pp. eaax8189 ◽  
Author(s):  
Marie Jo Halaby ◽  
Kebria Hezaveh ◽  
Sara Lamorte ◽  
M. Teresa Ciudad ◽  
Andreas Kloetgen ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Macrophage Polarization ◽  
Suppressor Cells ◽  
Interferon Γ ◽  
Mass Cytometry ◽  
General Control ◽  
Immune Attack ◽  
Environmental Sensor ◽  
Rna Knockdown ◽  
Interfering Rna

General control nonderepressible 2 (GCN2) is an environmental sensor controlling transcription and translation in response to nutrient availability. Although GCN2 is a putative therapeutic target for immuno-oncology, its role in shaping the immune response to tumors is poorly understood. Here, we used mass cytometry, transcriptomics, and transcription factor–binding analysis to determine the functional impact of GCN2 on the myeloid phenotype and immune responses in melanoma. We found that myeloid-lineage deletion of GCN2 drives a shift in the phenotype of tumor-associated macrophages and myeloid-derived suppressor cells (MDSCs) that promotes antitumor immunity. Time-of-flight mass cytometry (CyTOF) and single-cell RNA sequencing showed that this was due to changes in the immune microenvironment with increased proinflammatory activation of macrophages and MDSCs and interferon-γ expression in intratumoral CD8+ T cells. Mechanistically, GCN2 altered myeloid function by promoting increased translation of the transcription factor CREB-2/ATF4, which was required for maturation and polarization of macrophages and MDSCs in both mice and humans, whereas targeting Atf4 by small interfering RNA knockdown reduced tumor growth. Last, analysis of patients with cutaneous melanoma showed that GCN2-dependent transcriptional signatures correlated with macrophage polarization, T cell infiltrates, and overall survival. Thus, these data reveal a previously unknown dependence of tumors on myeloid GCN2 signals for protection from immune attack.

scholarly journals FRI0136 PERIPHERAL PROTEIN BIOMARKER CHANGES FOLLOWING SELECTIVE INHIBITION OF JANUS KINASE 1 (JAK1) BY FILGOTINIB IN ADULTS WITH MODERATELY-TO-SEVERELY ACTIVE RHEUMATOID ARTHRITIS WITH PRIOR INADEQUATE RESPONSE TO METHOTREXATE (FINCH1)

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 650.2-651
Author(s):  
P. C. Taylor ◽  
E. Elboudwarej ◽  
B. Downie ◽  
J. Liu ◽  
R. E. Hawtin ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Cell Migration ◽  
Active Rheumatoid Arthritis ◽  
Immune Cell ◽  
Janus Kinase ◽  
Inadequate Response ◽  
Bone Biology ◽  
Janus Kinase 1 ◽  
Immune Cell Migration ◽  
Dose Dependent

Background:Filgotinib (FIL), an oral selective Janus kinase 1 (JAK1) inhibitor has shown efficacy and safety in multiple phase 3 studies in adults with moderately-to-severely active rheumatoid arthritis (RA), including those with prior inadequate response to methotrexate (MTX) therapy (FINCH1;NCT02889796).Objectives:A longitudinal study of protein biomarkers related to JAK signaling1, bone biology2, immune cell migration2, and inflammation2was conducted to identify RA-associated markers altered by FIL vs MTX or adalimumab (ADA).Methods:FINCH1 RA patients (pts) were randomized to receive either a stable dose of MTX with placebo (PBO+MTX), ADA+MTX, and either FIL100mg+MTX or FIL200mg+MTX, once daily. Plasma, serum, and urine samples were taken from a subset of pts (~548) at baseline (BL) and weeks (wks) 4 and 12. Twenty-six pre-defined cytokines (biomarkers) were evaluated using ELISA. BL correlation between biomarkers and clinical response measures (DAS28CRP, SJC28, TJC28, CDAI, Patient Assessment and FACIT), were analyzed by Spearman Rank. Multiscale bootstrap resampling evaluated significant intra-cluster biomarker membership. Mean changes in biomarker levels from BL to wks 4 and 12 were compared between arms using PBO-adjusted estimates from a linear mixed effects model. A 5% false-discovery rate was applied for all analyses.Results:At BL, distinct biomarker-based pt clusters (CL) were identified. The strongest intra-group correlations were in bone-cartilage resorption/inflammation (CL1; Rho range 0.37–0.88) and JAK activity (CL2; Rho range 0.41–0.71). Individual BL cytokine levels were significantly associated with DAS28CRP, with unique biomarkers specific to various subcomponents of the score. Eleven biomarkers were associated with DAS28CRP, while 5, 3, and 2 were associated with CDAI, SJC28, and TJC28, respectively. The magnitude of FIL-associated treatment effects was time- and dose-dependent. Significant biomarker changes from BL were observed in FIL pts, relative to PBO+MTX pts. FIL100mg+MTX led to a significant change in 8 biomarkers by either 4 or 12 wks of treatment; FIL200mg+MTX significantly changed these and an additional 4 biomarkers by either time point. The greatest effect of FIL200mg+MTX was at 12 wks for CXCL13 (-38.4%) and IL6 (-53.7%). All treatment arms led to significant reductions in TNFα relative to PBO+MTX. FIL200mg+MTX treatment led to larger reductions of TNFα than ADA+MTX treatment at both wk4 (-24.7% vs -17.9%) and wk12 (-20.5% vs -12.2%), although the differences were not statistically significant.FIL and ADA caused differential patterns of cytokine response at either wks 4 or 12. Of 12 biomarkers with a significant FIL200mg+MTX treatment effect, there was a significantly larger reduction in TNFSF13B and CTX1 relative to ADA+MTX at 12 wks. Of 8 biomarkers with FIL100mg+MTX effects, only 2 (CXCL10 at wk 4; CXCL13 at wks 4 and 12) had significant differences from ADA+MTX. Relative either to FIL200mg+MTX or FIL100mg+MTX, and despite the same direction of effect, ADA+MTX led to a significantly larger reduction in CCL2, CXCL10, CCL4, and CXCL13.Conclusion:Compared with PBO, 12 wks of FIL treatment significantly reduced cytokines associated with JAK activity1, bone biology2, inflammation2, and immune cell migration2in MTX-IR pts. The effects were largely FIL dose-dependent; most cytokines exhibited similar effects regardless of treatment arms, but differential changes between FIL+MTX and ADA+MTX were observed, supportive of the different mechanisms of action of these therapies.References:[1]Majoros A, et al. Front Immunol. 2017;8:29[2]Brennan F, and McInnes I. J Clin Invest. 2008;118:3537-45Acknowledgments:This study was funded by Gilead Sciences, Inc. Editorial support was provided by Fishawack Communications Inc and funded by Gilead Sciences, Inc.Disclosure of Interests:Peter C. Taylor Grant/research support from: Celgene, Eli Lilly and Company, Galapagos, and Gilead, Consultant of: AbbVie, Biogen, Eli Lilly and Company, Fresenius, Galapagos, Gilead, GlaxoSmithKline, Janssen, Nordic Pharma, Pfizer Roche, and UCB, Emon Elboudwarej Shareholder of: Gilead Sciences Inc., Employee of: Gilead Sciences Inc., Bryan Downie Shareholder of: Gilead Sciences Inc., Employee of: Gilead Sciences Inc., Jinfeng Liu Shareholder of: Gilead Sciences Inc., Roche, Employee of: Gilead Sciences Inc., Rachael E. Hawtin Shareholder of: Gilead Sciences Inc., Employee of: Gilead Sciences Inc., Amer M. Mirza Shareholder of: Gilead Sciences Inc., Employee of: Gilead Sciences Inc.

New mimetic peptides of the kinase-inhibitory region (KIR) of SOCS1 through focused peptide libraries

2012 ◽  
Vol 443 (1) ◽  
pp. 231-240 ◽  
Author(s):  
Nunzianna Doti ◽  
Pasqualina L. Scognamiglio ◽  
Stefania Madonna ◽  
Claudia Scarponi ◽  
Menotti Ruvo ◽  
...  
Keyword(s):  
Interferon Γ ◽  
Catalytic Site ◽  
Janus Kinase ◽  
Scanning Method ◽  
Expression Levels ◽  
Interferon Regulatory Factor 1 ◽  
Inhibitory Region ◽  
Inflammatory Processes ◽  
Cytokine Stimulation ◽  
Kinase Inhibitory Region

SOCS (suppressor of cytokine signalling) proteins are negative-feedback regulators of the JAK (Janus kinase)/STAT (signal transducer and activator of transcription) pathway. Their expression levels are low under physiological conditions, but they are up-regulated in response to cytokine stimulation in many immune and inflammatory processes. Overexpression of SOCS1 in keratinocyte clones abrogates the IFNγ (interferon γ)-induced expression of many pro-inflammatory genes and the release of related chemokines by blocking the JAK/STAT pathway. SOCS1 inhibits JAK2 kinase activity by binding the catalytic site of JAK2, with its KIR (kinase-inhibitory region) acting as a pseudo-substrate of the enzyme. In the present study, we screened a focused combinatorial peptide library of KIR to identify new peptides able to mimic its function with an improved affinity towards the JAK2 catalytic site. Using an alanine-scanning method, KIR residues that are crucial for the interaction with JAK2 were unveiled. In this way, the KIR sequence was restricted to a shorter segment and ‘non-essential’ residues were replaced by different amino acids following a simplified combinatorial approach. We selected a new unnatural sequence able to bind to JAK2 with Kd values in the nanomolar range. This peptide was tested in human keratinocyte cultures and reduced the phosphorylation of STAT1 and the expression levels of IRF-1 (interferon regulatory factor-1).

Intranasal Toxicity of BMS-181885, A Novel 5-HT1 Agonist

1999 ◽  
Vol 18 (5) ◽  
pp. 285-296
Author(s):  
Gene E. Schulze ◽  
Jim E. Proctor ◽  
Mark A. Dominick ◽  
Amy E. Weiss ◽  
Oliver P. Flint ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Nasal Mucosa ◽  
Olfactory Epithelium ◽  
Mucosal Injury ◽  
Separate Experiment ◽  
Toxic Metabolite ◽  
Respiratory Epithelial Cells ◽  
Nasal Injury ◽  
Respiratory Epithelial ◽  
Dose Dependent

One-month intranasal toxicity studies were conducted with BMS-181885 at doses of 1.5, 9, or 15 mg/animal/day in rats and 4, 24, or 40 mg/animal/day in monkeys. A 1-month intermittent intranasal toxicity study was also conducted in monkeys at doses of 3, 6, and 12 mg/animal 3 days per week. BMS-181885 was generally well tolerated in rats but resulted in dose-dependent nasal mucosal injury, primarily characterized by subacute inflammation of the nasal mucosa, and degeneration, single-cell necrosis, and/or erosion of the olfactory epithelium and, to a lesser extent, the respiratory epithelium. In monkeys, daily BMS-181885 administration was well tolerated and produced similar dose-dependent nasal injury primarily characterized by subacute inflammation of the nasal mucosa with degeneration and erosion of the olfactory epithelium. In a separate experiment, intermittent administration also resulted in dose-dependent nasal injury. In cultured rat nasal mucosal cells, BMS-181885 was toxic to olfactory epithelial cells with a range of mean IC50s between 44 and 291 μM. In contrast, BMS-181885 had no effect on respiratory epithelial cells up to its maximum solubility. Cytochrome P450 inhibition had no effect on the toxicity of BMS-181885 in olfactory epithelial cells but produced dose-dependent toxicity in respiratory epithelial cells, which was not present previously. The in vitro data suggest that parent drug, rather than a toxic metabolite, caused the drug-associated nasal mucosal injury.

scholarly journals microRNA-29a-3p, Up-Regulated in Human Gastric Cells and Tissues with H.Pylori Infection, Promotes the Migration of GES-1 Cells via A20-Mediated EMT Pathway

2018 ◽  
Vol 51 (3) ◽  
pp. 1250-1263 ◽  
Author(s):  
Fengying Sun ◽  
Ying Ni ◽  
Hong Zhu ◽  
Jian Fang ◽  
Hua Wang ◽  
...  
Keyword(s):  
Gastric Mucosa ◽  
Epithelial Cells ◽  
Western Blotting ◽  
Molecular Mechanisms ◽  
Luciferase Reporter ◽  
Human Gastric Mucosa ◽  
Gastric Epithelial Cells ◽  
Migration Ability ◽  
Gastric Cells ◽  
Dose Dependent

Background/Aims: Helicobacter pylori (H. pylori) infection is closely related to human gastric mucosa-associated diseases. Several recent studies on miRNAs have expanded our insights on H.pylori pathogenesis. This study aimed to investigate the biological roles and underlying molecular mechanisms of miR-29a-3p in human gastric cells and tissues with H.pylori infection. Methods: miR-29a-3p expression was quantified by quantitative RT-PCR (qRT-PCR). A miR-29a-3p target gene was validated by bioinformatics analysis, western blotting and dual luciferase reporter gene assays. Western blotting and immunohistochemistry (IHC) assay were performed to detect the protein expression. Transwell assay was used to determine the cell migration ability. Results: MiR-29a-3p was up-regulated in H.pylori-positive gastric mucosa tissues and H.pylori-infected gastric cells. The up-regulation of miR-29a-3p was dose-dependent in BGC-823 and GES-1 cells infected with H.pylori. Using gain- and loss-of-function experiments in vitro, we demonstrated that miR-29a-3p promoted the migration of gastric epithelial cells. We further characterized A20 as a direct target of miR-29a-3p. The expression of A20 was decreased in H.pylori-positive gastric mucosa tissues compared with H.pylori-negative gastric mucosa tissues. A20 downregulation was time- and dose-dependent in GES-1 and BGC-823 cells infected with H.pylori. In GES-1 and BGC-823 cells infected with H.pylori, the miR-29a-3p mimic significantly blocked A20 expression, which suggests that H.pylori decreased A20 expression through up-regulating miR-29a-3p in GES-1 and BGC-823 cells infected with H.pylori. The knockdown of A20 by siRNA enhanced the migration of human gastric epithelial cells and promoted the expression of Snail, Vimentin, and N-cadherin and inhibited the expression of E-cadherin. Conclusion: The miR-29a-3p may act as a tumor promotive miRNA by regulating cells migration through directly targeting of A20 gene in human gastric epithelial cells infected with H.pylori.

Co-operation of interleukin-17 and interferon-γ on chemokine secretion in human fetal intestinal epithelial cells

2001 ◽  
Vol 120 (5) ◽  
pp. A189
Author(s):  
Hiroki Takaya ◽  
Akira Andoh ◽  
Jin Makino ◽  
Takashi Okuno ◽  
Kazunori Hata ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Intestinal Epithelial Cells ◽  
Interferon Γ ◽  
Interleukin 17 ◽  
Intestinal Epithelial

scholarly journals Expression of Interferon-γ by a Coronavirus Defective-Interfering RNA Vector and Its Effect on Viral Replication, Spread, and Pathogenicity

Virology ◽  
1997 ◽  
Vol 233 (2) ◽  
pp. 327-338 ◽  
Author(s):  
Xuming Zhang ◽  
David R. Hinton ◽  
Daniel J. Cua ◽  
Stephen A. Stohlman ◽  
Michael M.C. Lai
Keyword(s):  
Viral Replication ◽  
Interferon Γ ◽  
Defective Interfering Rna ◽  
Interfering Rna

Effects of oviductal proteins, including heat shock 70 kDa protein 8, on survival of ram spermatozoa over 48 h in vitro

2009 ◽  
Vol 21 (3) ◽  
pp. 408 ◽  
Author(s):  
R. E. Lloyd ◽  
R. M. A. Elliott ◽  
A. Fazeli ◽  
P. F. Watson ◽  
W. V. Holt
Keyword(s):  
Plasma Membrane ◽  
Heat Shock ◽  
Membrane Proteins ◽  
Epithelial Cells ◽  
Beneficial Effect ◽  
Active Component ◽  
Apical Plasma Membrane ◽  
Series Of Experiments ◽  
Dose Dependent

Following insemination, ram spermatozoa are transported to the isthmus region of the oviduct where they bind to the oviductal epithelial cells (OEC), remaining viable for several hours. The aim of the present study was to begin to decipher which component(s) of the ewe oviduct actively participates in maintaining the viability of ram spermatozoa. A series of experiments was conducted to investigate whether: (1) soluble OEC apical plasma membrane proteins (sAPM) isolated from ewes prolong survival of ram spermatozoa over an extended (48 h) coincubation period at 39°C; (2) a recombinant form of one of these oviductal proteins, namely heat shock 70 kDa protein 8 (HSPA8), prolongs survival of ram spermatozoa; and (3) pretreatment with HSPA8 antibody compromises the ability of sAPM to prolong the survival of ram spermatozoa. Both sAPM and recombinant HSPA8 had a beneficial effect on the viability of ram spermatozoa during coincubation, although both these effects were dose dependent. In contrast, pretreatment with HSPA8 antibody significantly negated the ability of sAPM to maintain the viability of ram spermatozoa. These findings suggest that HSPA8 is an active component of the ewe oviduct that participates in maintaining the viability of ram spermatozoa. This is a potentially valuable observation given that there is a great deal of room for improving existing diluents for storing fresh ram semen.

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