Increased secretion of pro-inflammatory cytokines by circulating polymorphonuclear neutrophils and regulation by interleukin 10 during intestinal inflammation.
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ABSTRACT:
SUBMITTER: Nikolaus S
PROVIDER: S-EPMC1727082 | biostudies-other | 1998 Apr
REPOSITORIES: biostudies-other
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Project description:Interleukin-1? (IL-1?), a major pro-inflammatory cytokine, is a leaderless cytosolic protein whose secretion does not follow the classical endoplasmic reticulum-to-Golgi pathway, and for which a canonical mechanism of secretion remains to be established. Neutrophils are essential players against bacterial and fungi infections. These cells are rapidly and massively recruited from the circulation into infected tissues and, beyond of displaying an impressive arsenal of toxic weapons effective to kill pathogens, are also an important source of IL-1? in infectious conditions. Here, we analyzed if an unconventional secretory autophagy mechanism is involved in the exportation of IL-1? by these cells. Our findings indicated that inhibition of autophagy with 3-methyladenine and Wortmannin markedly reduced IL-1? secretion induced by LPS?+?ATP, as did the disruption of the autophagic flux with Bafilomycin A1 and E64d. These compounds did not noticeable affect neutrophil viability ruling out that the effects on IL-1? secretion were due to cell death. Furthermore, VPS34IN-1, a specific autophagy inhibitor, was still able to reduce IL-1? secretion when added after it was synthesized. Moreover, siRNA-mediated knockdown of ATG5 markedly reduced IL-1? secretion in neutrophil-differentiated PLB985 cells. Upon LPS?+?ATP stimulation, IL-1? was incorporated to an autophagic compartment, as was revealed by its colocalization with LC3B by confocal microscopy. Overlapping of IL-1?-LC3B in a vesicular compartment peaked before IL-1? increased in culture supernatants. On the other hand, stimulation of autophagy by cell starvation augmented the colocalization of IL-1? and LC3B and then promoted neutrophil IL-1? secretion. In addition, specific ELISAs indicated that although both IL-1? and pro-IL-1? are released to culture supernatants upon neutrophil stimulation, autophagy only promotes IL-1? secretion. Furthermore, the serine proteases inhibitor AEBSF reduced IL-1? secretion. Moreover, IL-1? could be also found colocalizing with elastase, suggesting both some vesicles containing IL-1? intersect azurophil granules content and that serine proteases also regulate IL-1? secretion. Altogether, our findings indicate that an unconventional autophagy-mediated secretory pathway mediates IL-1? secretion in human neutrophils.
| S-EPMC5825906 | biostudies-literature
Project description:Exposition of neutrophils (polymorphonuclear neutrophils, PMNs) to bacterial products triggers exacerbated activation of these cells, increasing their harmful effects on host tissues. We evaluated the possibility of interfering with the classic immune innate responses of human PMNs exposed to bacterial endotoxin (lipopolysaccharide, LPS), and further stimulated with bacterial formyl peptide (N-formyl-methionine-leucine-phenylalanine, fMLP). We showed that the low- molecular-weight fucoidan (LMW-Fuc), a polysaccharide extracted from brown algae, attenuated the exacerbated activation induced by fMLP on LPS-primed PMNs, in vitro, impairing chemotaxis, NET formation, and the pro-survival and pro-oxidative effects. LMW-Fuc also inhibited the activation of canonical signaling pathways, AKT, bad, p47phox and MLC, activated by the exposition of PMN to bacterial products. The activation of PMN by sequential exposure to LPS and fMLP induced the release of L-selectin+ microparticles, which were able to trigger extracellular reactive oxygen species production by fresh PMNs and macrophages. Furthermore, we observed that LMW-Fuc inhibited microparticle release from activated PMN. In vivo experiments showed that circulating PMN-derived microparticles could be detected in mice exposed to bacterial products (LPS/fMLP), being downregulated in animals treated with LMW-Fuc. The data highlight the autocrine and paracrine role of pro-inflammatory microparticles derived from activated PMN and demonstrate the anti-inflammatory effects of LMW-Fuc on these cells.
| S-EPMC6738154 | biostudies-literature
Project description:Bronchopulmonary dysplasia (BPD) is one of the most common causes of mortality and morbidity in neonatal intensive care units. Persistent inflammation, with an abnormal influx of polymorphonuclear leukocytes (PMNs) followed by monocytes (MONOs), occurs early in the pathogenesis of BPD. Anti-inflammatory therapy with better efficacy and safety than dexamethasone (DEX) is needed. In the present study we determined cell-specific gene expression and cytokine release in response to glucocorticoids versus interleukin-10 (IL-10). Subsequently, we hypothesized that the insensitivity of MONOs to DEX was associated with a failure of the glucocorticoid receptor to translocate to the nucleus. PMNs and MONOs were isolated from umbilical cord blood at birth, and pretreated with PBS vehicle, IL-10 or glucocorticoids prior to endotoxin (LPS)-stimulation for 4 and 18h. Genome-wide gene expressions were determined by microarray and validated by RT-qPCR. Interleukin 8 release in cell culture supernatant was measured by ELISA. To examine the mechanism of monocyte insensitivity to glucocorticoids, nuclear translocation of the glucocorticoid receptor was determined by Western blots. MONOs had 6 times the number of genes changing expression with IL-10 compared to PMNs at 4h. DEX at the therapeutic level for neonates with BPD had no effect on gene expression in MONOs. The order of potency for inhibition of interleukin-8 release from MONOs was IL-10 >betamethasone >dexamethasone and hydrocortisone. Glucocorticoid potency in MONOs was directly related to glucocorticoid receptor translocation to nucleus. Gene expression profiling for IL-10 versus glucocorticoids indicates there may be major differences in therapeutic efficacy for BPD.
| S-EPMC3560479 | biostudies-literature
Project description:INTRODUCTION: Persistent lung inflammation, with an influx of polymorphonuclear leukocytes and monocytes, occurs early in bronchopulmonary dysplasia. We hypothesized that: 1) that interleukin-10, a potent anti-inflammatory cytokine, would cause a markedly different gene expression profile compared to dexamethasone in these cells, and 2) monocyte insensitivity to dexamethasone was related to glucocorticoid receptor expression. RESULTS: For polymorphonuclear leukocytes, there were <20% of genes changing expression in common between interleukin-10 and dexamethasone. The monocyte had 5 times the number of genes changing expression with interleukin-10 compared to the polymorphonuclear leukocyte. Dexamethasone, in the therapeutic range, had no effect on gene expression in monocytes. The order of potency for inhibition of interleukin-8 release from monocytes was IL-10>betamethasone>> dexamethasone and hydrocortisone. Glucocorticoid potency was directly related to the degree of glucocorticoid receptor translocation to the monocyte nucleus. DISCUSSION: Gene expression profiles by IL-10 versus dexamethasone indicates that there may be major differences in efficacy and adverse effects if interleukin-10 is used for therapy in the future. Betamethasone may be a better therapeutic choice than dexamethasone. METHODS: Isolated cord blood cells were pre-incubated with anti-inflammatory agents prior to endotoxin stimulation. Measurements were made by microarrays, RT-qPCR, ELISA, and Western blots.
2012-02-16 | GSE35683 | GEO
Project description:INTRODUCTION: Persistent lung inflammation, with an influx of polymorphonuclear leukocytes and monocytes, occurs early in bronchopulmonary dysplasia. We hypothesized that: 1) that interleukin-10, a potent anti-inflammatory cytokine, would cause a markedly different gene expression profile compared to dexamethasone in these cells, and 2) monocyte insensitivity to dexamethasone was related to glucocorticoid receptor expression. RESULTS: For polymorphonuclear leukocytes, there were <20% of genes changing expression in common between interleukin-10 and dexamethasone. The monocyte had 5 times the number of genes changing expression with interleukin-10 compared to the polymorphonuclear leukocyte. Dexamethasone, in the therapeutic range, had no effect on gene expression in monocytes. The order of potency for inhibition of interleukin-8 release from monocytes was IL-10>betamethasone>> dexamethasone and hydrocortisone. Glucocorticoid potency was directly related to the degree of glucocorticoid receptor translocation to the monocyte nucleus. DISCUSSION: Gene expression profiles by IL-10 versus dexamethasone indicates that there may be major differences in efficacy and adverse effects if interleukin-10 is used for therapy in the future. Betamethasone may be a better therapeutic choice than dexamethasone. METHODS: Isolated cord blood cells were pre-incubated with anti-inflammatory agents prior to endotoxin stimulation. Measurements were made by microarrays, RT-qPCR, ELISA, and Western blots. Isolation of cord blood polymorphonuclear leukocytes and monocytes separately from 5 subjects. Endotoxin stimulation in cell culture for 4 hours. Comparison of gene expression between endotoxin alone versus endotoxin-stimualted cells pretreated with interleukin-10 or dexamethasone (at equimolar, therapeutic levels, 10-8 M. Cell Types : MONOs, PMNs; Treatments: LPS, LPS+IL-10, LPS+DEX
2012-02-16 | E-GEOD-35683 | biostudies-arrayexpress
Project description:Cytokines may contribute to the severity of CD4 cell depletion with human immunodeficiency virus (HIV) infection, but quantitative relationships are not well defined. Serum and plasma from 181 HIV-infected individuals were tested with Millipore 30-plex Luminex cytokine assays. Within-individual correlations among cytokines were summarized by two-dimensional hierarchical cluster analysis. Associations with age, sex, race, CD4 count, and HIV viral load were determined with linear regression models. Tests for statistical significance were corrected for multiple comparisons, using a false discovery rate of 0.1. African-Americans had significantly higher levels than whites of six cytokines (IL-2, IL-5, IL-7, IL-15, fractalkine, and IFN-?), and lower levels of MCP-1. Females had higher fractalkine levels than males. Age was not associated with levels of any cytokine. Six cytokines, including the T-helper (Th) type 1 cytokine IL-15, the Th2 cytokines IL-1ra and IL-10, the chemokines fractalkine and MCP-1, and the growth factor G-CSF were each inversely associated with CD4 count; no cytokine was directly associated with CD4 count. Fractalkine was directly associated with HIV viral load, adjusted for CD4 count. Cytokines clustered by primary function (e.g., Th1, Th2, proinflammatory, chemokines, or growth factors) whereas individuals clustered according to cytokine levels (generally high, intermediate, or low) had significantly different CD4 counts [medians (interquartile range) of 60 (17-162), 131 (62-321), and 155 (44-467), respectively; p<0.0001]. CD4 deficiency is associated with generalized increases in cytokines of various functions. Racial differences in cytokine response to HIV infection could contribute to disparities in disease progression.
| S-EPMC3399552 | biostudies-literature
Project description:BackgroundSjögren's syndrome antigen B is expressed in the nucleus and surface membrane of human polymorphonuclear neutrophils and is released after cell death. However, its biological role is not clear. This study is aimed to investigate the effect of Sjögren's syndrome antigen B on human polymorphonuclear neutrophils.MethodsHuman recombinant Sjögren's syndrome antigen B (rSSB) purified from E. coli was incubated with human polymorphonuclear neutrophils as well as retinoid acid-induced granulocytic differentiated HL-60 cells, HL-60 (RA). Interleukin (IL)-8 protein production and mRNA expressions were measured by enzyme-linked immunosorbent assay and quantitative-polymerase chain reaction, respectively. Uptake of fluorescein isothiocyanate (FITC)-rSSB was assessed by flow cytometry and fluorescence microscopy. Moreover, mitogen-activated protein kinase (MAPK) pathways and nuclear factor-kappaB activation were investigated.ResultsHuman rSSB stimulated IL-8 production from normal human neutrophils and HL-60 (RA) cells in a time- and dose-dependent manner. This IL-8-stimulated activity was blocked by chloroquine and NH4Cl, indicating that endosomal acidification is important for this effect. We found rSSB activated both MAPK pathway and nuclear factor-kappaB signaling to transcribe the IL-8 gene expression of cells. Furthermore, tumor necrosis factor-? exerted an additive effect and rSSB-anti-SSB immune complex exhibited a synergistic effect on rSSB-induced IL-8 production.ConclusionsSjögren's syndrome antigen B might act as an endogenous danger molecule to enhance IL-8 gene expression in human polymorphonuclear neutrophils.
| S-EPMC4411107 | biostudies-literature
Project description:Pneumococcal capsular polysaccharide (PS) vaccines induce type-specific immunoglobulin M (IgM), IgG, and IgA. Type-specific IgG to the PS is sufficient to confer protection against the homologous serotype of the pneumococcus, but the efficacies of type-specific IgM and IgA are less well understood. We examined the in vitro activities and efficacies in mice of two human monoclonal antibodies (MAbs) to type 8 PS, NAD (IgA) and D11 (IgM). MAb-mediated opsonophagocytic killing was evaluated after coculture of type 8 pneumococci with human polymorphonuclear cells (PMNs), type-specific or control MAbs, and human complement sources. The effects of the MAbs on PMN interleukin-8 (IL-8) and IL-6 secretion were determined in supernatants from cocultures containing pneumococci and PMNs by enzyme-linked immunosorbent assay. MAb efficacy was determined in an intratracheal model of type 8 infection in mice with classical complement pathway deficiency. Both MAbs were protective in 100% of infected mice. Neither MAb promoted a significant amount of killing of type 8 pneumococci compared to its isotype control MAb. Both type-specific MAbs mediated complement-dependent modulation of PMN IL-8 secretion, with increased secretion at effector/target (E:T) ratios of 500:1 and 50:1 and reduced secretion at 1:5. Trypan blue staining revealed that PMNs cocultured with D11 were less viable at an E:T ratio of 1:5 than PMNs cocultured with the control MAb. PMN IL-6 secretion was increased by both type-specific and control MAbs. These results suggest that certain type-specific IgM and IgAs might contribute to host defense by modulation of the inflammatory response to pneumococci.
| S-EPMC308885 | biostudies-literature
Project description:BACKGROUND This study aimed to analyze and explore the relationship between the cytokines IL-4 and IL-10 in relation to gene polymorphism and their respective effects on the susceptibility to virus-induced encephalitis. MATERIAL AND METHODS From January 2012 to June 2013, 112 patients with virus-induced encephalitis (the case group and 109 healthy individuals (the control group) were recruited for the purposes of this study. The functional variations that IL-4 and IL-10 genes exhibit were detected through the use of a function analysis and selection tool for single-nucleotide polymorphisms (FASTSNP). The genotypes of IL-4 were rs2227283 and IL-4 rs2227288, and the genotypes of IL-10 were rs1800871 and IL-10 rs1800872. These genotypes were respectively assessed using direct sequencing. RESULTS IL-4 rs2227283 and IL-10 rs1800871 have no correlation in with risk of virus-induced encephalitis (both P>0.05) GA and AA genotypes were related to IL-4 rs2227288 and GT, while TT and GT + TT genotypes were related to IL-10 rs1800872. These were highlighted as being risk factors in virus-induced encephalitis (all P<0.05). However, the duration of fever, white blood cell (WBC) count, C-reactive protein (CRP), neutrophils, and lymphocytes and monocytes of virus-induced encephalitis patients with IL-4 rs2227288 and IL-10 rs1800872 all displayed significant differences (all P<0.05). Frequencies of GAGT and CAGT haplotypes were evaluated and deemed to be of statistical significance and subsequently were highlighted as being risk factors in virus-induced encephalitis (all P<0.05). CONCLUSIONS IL-4 rs2227288 and IL-10 rs1800872 may contribute to an increased risk for virus-induced encephalitis. Through use of direct sequencing, we showed that genotypes of IL-4 rs2227288 and IL-10 rs1800872 may have particular host susceptibility to virus-induced encephalitis.
| S-EPMC5683680 | biostudies-literature
Project description:Neutrophils are implicated in the pathogenesis of tuberculosis (TB), a disease caused by Mycobacterium tuberculosis infection, but the mechanisms by which they promote disease are not fully understood. Neutrophils can express cytokines that influence TB progression, and so we compared neutrophil and T-cell expression of the Th1 cytokines IFN? and TNF, the Th2 cytokine IL-4, and regulatory cytokine IL-10 in M. tuberculosis-infected macaques to determine if neutrophil cytokine expression contributes to dysregulated immunity in TB. We found that peripheral blood neutrophils produced cytokines after stimulation by mycobacterial antigens and inactive and viable M. tuberculosis. M. tuberculosis antigen-stimulated neutrophils inhibited antigen-specific T-cell IFN? production. In lung granulomas, neutrophil cytokine expression resembled T-cell cytokine expression, and although there was histologic evidence for neutrophil interaction with T cells, neutrophil cytokine expression was not correlated with T-cell cytokine expression or bacteria load. There was substantial overlap in the spatial arrangement of cytokine-expressing neutrophils and T cells, but IL-10-expressing neutrophils were also abundant in bacteria-rich areas between caseum and epithelioid macrophages. These results suggest that neutrophils contribute to the cytokine milieu in granulomas and may be important immunoregulatory cells in TB granulomas.
| S-EPMC6824993 | biostudies-literature