NF-κB1 (p50) impairs macrophage driven inflammatory response of the host against Helicobacter pylori infection
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PROVIDER: PRJNA497835 | ENA |
REPOSITORIES: ENA
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Project description:In the present study, we observed spontaneous gastritis in 10-12 week old NF-κB1—/— mice with increased level of pro-inflammatory cytokines in gastric tissues. The NF-κB1—/— bone marrow derived macrophages showed increased level of cytokines which further exacerbated with H. pylori infection. To map the contribution of macrophages in the spontaneous gastritis, we performed comparative transcriptome analysis of NF-κB1—/— mice gastric macrophage and H. pylori treated macrophages. The transcriptome analysis showed an upregulation of innate immune response genes in NF-κB1—/— gastric macrophages, but not in H. pylori activated murine macrophages. Network analysis identified STAT1/TLR7/TLR13 as a key regulator and inhibition of STAT1 activation attenuated exacerbated innate immune response. NF-κB1—/— mice after infection with H. pylori showed increased histological gastritis and reduced level of H. pylori colonization. Our study indicates that H. pylori-mediated up-regulation of NF-κB1 mitigates host immune response and promotes chronic colonization of the pathogen.
2021-08-31 | GSE121583 | GEO
Project description:Pro-inflammatory cytokines were shown to promote growth and survival of cancerous cells. TNF induced RelA:p50 NF-κB dimer via the canonical pathway is thought to link inflammation with cancer. Integrating biochemical and computational studies we identify that deficiency of non-canonical signal transducer p100 triggers a positive autoregulatory loop, which instead perpetuates an alternate RelB:p50 containing NF-κB activity upon TNF treatment. TNF stimulated RelB:p50 dimer is sufficient for mediating NF-κB target gene-expressions and suppressing apoptotic cellular death independent of principal NF-κB subunit RelA. We further demonstrate that activating mutations in non-canonical NF-κB module deplete multiple myeloma cells of p100, thereby, provoking autoregulatory RelB:p50 activation. Finally, autoregulatory control reinforces protracted pro-survival NF-κB response, albeit comprising of RelB:p50, upon TNF priming that protects myeloma cells with dysfunctional p100 from subsequent apoptotic insults. In sum, we present evidence for positive autoregulation mediated through the NF-κB system and its potential involvement in human neoplasm.
2017-06-12 | GSE68615 | GEO
Project description:The five NF-kB family members and three nuclear IkB proteins play diverse biological roles, but the mechanisms by which distinct NF-kB and NF-kB: IkB complexes contribute to selective gene transcription remain poorly understood. Using nascent transcript RNA-seq, we observed considerable overlap between p50-dependent and IkBz-dependent genes in Toll-like receptor 4 (TLR4)-activated macrophages. Key inflammatory and immunoregulatory genes, including Il6, Il1b, Nos2, Lcn2, and Batf, were among the p50-IkBz co-dependent genes. IkBz typically bound genomic sites occupied earlier by NF-kB dimers. However, p50-IkBz co-dependence did not coincide with preferential binding of either protein, as p50, IkBz, and RelA co-occupied thousands of sites. A common feature of p50-IkBz co-dependent genes was close proximity to a p50/RelA/IkBz co-bound site exhibiting p50-dependent binding of RelA and IkBz. This result and others suggest that IkBz function is not restricted to p50 homodimers. Notably, IkBz and the p50-IkBz target genes comprise a high percentage of genes that exhibited the greatest differential expression between TLR4-stimulated and tumor necrosis factor receptor (TNFR)-stimulated macrophages, with ectopic IkBz rescuing a subset of these genes. These results reveal a defined p50-IkBz pathway that selectively activates a set of key inflammatory and immunoregulatory genes and serves as an important contributor to the differential responses to TNFR and TLR4.
2024-04-23 | GSE245681 | GEO
Project description:The five NF-kB family members and three nuclear IkB proteins play diverse biological roles, but the mechanisms by which distinct NF-kB and NF-kB:IkB complexes contribute to selective gene transcription remain poorly understood. Using nascent transcript RNA-seq, we observed considerable overlap between p50-dependent and IkBz-dependent genes in Toll-like receptor 4 (TLR4)-activated macrophages. Key inflammatory and immunoregulatory genes, including Il6, Il1b, Nos2, Lcn2, and Batf, were among the p50-IkBz co-dependent genes. IkBz typically bound genomic sites occupied earlier by NF-kB dimers. However, p50-IkBz co-dependence did not coincide with the preferential binding of either protein, as p50, IkBz, and RelA co-occupied thousands of sites. A common feature of p50-IkBz co-dependent genes was close proximity to a p50/RelA/IkBz co-bound site exhibiting p50-dependent binding of RelA and IkBz. This result and others suggest that IkBz function is not restricted to p50 homodimers. Notably, IkBz and the p50-IkBz target genes comprise a high percentage of genes that exhibited the greatest differential expression between TLR4-stimulated and tumor necrosis factor receptor (TNFR)-stimulated macrophages, with ectopic IkBz rescuing a subset of these genes. These results reveal a defined p50-IkBz pathway that selectively activates a set of key inflammatory and immunoregulatory genes and serves as an important contributor to the differential responses to TNFR and TLR4.
2024-03-14 | GSE249261 | GEO
Project description:Helicobacter pylori is a widespread Gram-negative pathogen involved in a variety of gastrointestinal diseases, including gastritis, ulceration, mucosa-associated lymphoid tissue (MALT) lymphoma and gastric cancer. Immune responses aimed at eradication of H. pylori often prove futile, and paradoxically play a crucial role in the degeneration of epithelial integrity and disease progression. We have previously shown that H. pylori infection of primary human monocytes increases their potential to respond to subsequent bacterial stimuli – a process that may be involved in the generation of exaggerated, yet ineffective immune responses directed against the pathogen. In this study, we show that H. pylori-induced monocyte priming is not a common feature of Gram-negative bacteria, as Acinetobacter lwoffii induces tolerance to subsequent Escherichia coli lipopolysaccharide (LPS) challenge. Although the increased reactivity of H. pylori-infected monocytes seems to be specific to H. pylori, it appears to be independent of its virulence factors Cag pathogenicity island (CagPAI), cytotoxin associated gene A (CagA), vacuolating toxin A (VacA) and g-glutamyl transferase (g-GT). Utilizing whole-cell proteomics complemented with biochemical signaling studies, we show that H. pylori infection of monocytes induces a unique proteomic signature compared to other pro-inflammatory priming stimuli, namely LPS and the pathobiont A. lwoffii. Contrary to these tolerance- inducing stimuli, H. pylori priming leads to accumulation of NF-кB proteins, including p65/RelA, and thus to the acquisition of a monocyte phenotype more responsive to subsequent LPS challenge. The plasticity of pro-inflammatory responses based on abundance and availability of intracellular signaling molecules may be a heretofore underappreciated form of regulating innate immune memory as well as a novel facet of the pathobiology induced by H. pylori
2023-11-10 | PXD045072 | Pride
Project description:Phosphorylation of the NF-ĸB p50 subunit is known to regulate target gene expression. Here, we investigate the role of the novel p50 S80 phosphorylation in regulating TNFα-induced transcription by utilising Wild type (WT) and NFKB1S80A HEK293T cells
2019-09-16 | GSE117279 | GEO
Project description:Myeloid-derived suppressor cells (MDSC) include immature monocytic (M-MDSC) and granulocytic (PMN-MDSC) cells that share the ability to suppress adaptive immunity and hinder the effectiveness of anti-cancer treatments. Of note, in response to interferon-γ (IFNγ) M-MDSC release the tumor-promoting and immunosuppressive molecule nitric oxide (NO), whereas macrophages largely express anti-tumor properties. Investigating these opposing activities, we found that tumor-derived prostaglandin E2 (PGE2) induces nuclear accumulation of p50 NF-κB in M-MDSC, diverting their response to IFNγ towards NO-mediated immunosuppression and reducing TNFα expression. At the genome level, p50 NF-κB promoted binding of STAT1 to regulatory regions of selected IFNγ-dependent genes, including inducible nitric oxide synthase (Nos2). In agreement, ablation of p50 as well as pharmacological inhibition of either the PGE2 receptor EP2 or NO production reprogrammed M-MDSC towards a NOS2low/TNFαhigh phenotype, restoring the in vivo antitumor activity of IFNγ. Our results indicate that inhibition of the PGE2/p50/NO axis prevents MDSC suppressive functions and restores the efficacy of anticancer immunotherapy.
2020-05-15 | GSE84468 | GEO
Project description:Helicobacter pylori (H. pylori) is a human pathogen that infects almost half of the world’s population. Infection with H. pylori is frequently associated with chronic gastritis and can even lead to gastric and duodenal ulcers and gastric cancer. Although the persistent colonization of H. pylori and the development of H. pylori-associated gastritis remain poorly understood, it is believed that, in gastric mucosa, the modulated gastric epithelial cells (GECs) by H. pylori are key contributors. We used microarrays to detail the global programme of gene expression in Helicobacter pylori infected-gastric epithelial cell line AGS cells and identified up-regulated genes induced by Helicobacter pylori infection.
2024-04-18 | GSE264263 | GEO
Project description:Phosphorylation of the NF-ĸB p50 subunit is known to regulate target gene expression. The role of p50 S80 phosphorylation in regulating LPS-induced transcription by utilising wild type (WT) and NFKB1S80A THP-1 cells is investigated.
2020-09-19 | GSE120212 | GEO
Project description:Gastric mucosa responds to the pathogen Helicobacter pylori (H. pylori) by producing and release of pro-inflammatory cytokines that activate the innate immune system mainly through activation of the transcription factor NF-κB. Although NF-κB signaling is well studied for many possible inducers, induction by H. pylori remains poorly understood. Here, we performed a high-throughput genome-wide RNAi screen for genes influencing H. pylori-induced NF-κB activation. In comparison to TNFα or IL‐1β NF‐κB signaling, we identified 21 proteins unique necessary for H. pylori NF-κB pathway and 24 factors that inhibited the activation. Furthermore, we present here the R/Bioconductor package Nested Effect Model for systematic use in high-throughput screens to classify newly identified factors. We identified alpha kinase 1 (ALPK1) as particular important for the H. pylori NF‐κB pathway without affecting TNFα or IL‐1β signaling. ALPK1 silencing inhibits activity of TAK1 and the IκB kinases (IKKs), degradation of the NF‐κB inhibitor IκBα, nuclear translocation of the NF‐κB subunit p65, and transcription of the NF‐κB target genes, e.g. IL‐8. Thus, we identify ALPK1 as a novel inflammatory regulator functioning particularly in the NF‐κB signaling network activated by H. pylori.
2019-09-02 | GSE89613 | GEO