scholarly journals Pivotal role of M-DC8+ monocytes from viremic HIV-infected patients in TNFα overproduction in response to microbial products

Blood ◽  
2012 ◽  
Vol 120 (11) ◽  
pp. 2259-2268 ◽  
Author(s):  
Charles-Antoine Dutertre ◽  
Sonia Amraoui ◽  
Annalisa DeRosa ◽  
Jean-Pierre Jourdain ◽  
Lene Vimeux ◽  
...  
Keyword(s):  
Dendritic Cell ◽  
Hiv Infection ◽  
Mononuclear Cells ◽  
Inflammatory Diseases ◽  
Intestinal Epithelial ◽  
Color Flow ◽  
Gm Csf ◽  
Cell Counts

Abstract HIV infects activated CD4+ T cells and induces their depletion. Progressive HIV infection leading to AIDS is fueled by chronic immune hyperactivation, mediated by inflammatory cytokines like TNFα. This has been related to intestinal epithelial damage and microbial LPS translocation into the circulation. Using 11-color flow cytometry, cell sorting, and cell culture, we investigated the numbers and TNFα production of fully defined circulating dendritic cell and monocyte populations during HIV-1 infection. In 15 viremic, untreated patients, compared with 8 treated, virologically suppressed patients or to 13 healthy blood donors, circulating CD141 (BDCA-3)+ and CD1c (BDCA-1)+ dendritic cell counts were reduced. Conversely, CD14+CD16++ monocyte counts were increased, particularly those expressing M-DC8, while classical CD14++CD16−M-DC8− monocyte numbers were unchanged. Blood mononuclear cells from viremic patients produced more TNFα in response to LPS than those from virologically suppressed patients. M-DC8+ monocytes were mostly responsible for this overproduction. Moreover, M-DC8+ monocytes differentiated in vitro from classical monocytes using M-CSF and GM-CSF, which is increased in viremic patient's plasma. This M-DC8+ monocyte population, which is involved in the pathogenesis of chronic inflammatory diseases like Crohn disease, might thus be considered as a major actor in the immune hyperactivation fueling HIV infection progression.

Intracytoplasmic Concentration of GM-CSF and Intensity of the GM-CSF Membrane Receptor Are Significantly Higher in Proliferative Than in Dysplastic Variant of CMML and Could Explain the Higher In Vivo and In Vitro Growth Pattern.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 2602-2602
Author(s):  
Francesco Onida ◽  
Servida Federica ◽  
Soligo Davide ◽  
Ricci Clara ◽  
Pasquini Maria Cristina ◽  
...  
Keyword(s):  
Mononuclear Cells ◽  
Membrane Receptor ◽  
Cytokine Receptor ◽  
Biological Difference ◽  
Gm Csf ◽  
Significant Difference ◽  
Normal Controls

Abstract Chronic myelomonocytic leukemia (CMML) is a heterogeneous hematological malignancy, which has been included in a new category of MDS/MPD disorders in the last WHO classification of myeloid malignancies. An arbitrarily chosen leukocyte count has been proposed by the FAB group to differentiate between a “dysplastic” type (MD-CMML, with ≤12 x 109 WBC/L) and a “proliferative” type (MP-CMML, with >12 x 109 WBC/L) of CMML. However, apart from the WBC count, no biological difference has been identified to support distinction between these two disease-entities. Among factors that have been implicated in pathogenesis of CMML, GM-CSF produced by either autocrine or paracrine mechanisms has been shown to be a major growth determinant. In this study, peripheral blood samples from normal controls and from patients affected by proliferative and dysplastic variants of CMML were used to investigate expression of intracytoplasmic GM-CSF and expression of GM-CSF membrane receptor. Briefly, mononuclear cells (MNC) were isolated on Ficoll-Paque density gradient and cryopreserved in FCS 10% DMSO. In a first set of experiments samples from 5 healthy controls, 11 MP-CMML and 8 MD-CMML were thawed, permeabilized and stained with GM-CSF PE (Caltag) to evaluate expression of the intracytoplasmic cytokine by FACSCalibur flow cytometer (BD). Mean percentage of GM-CSF expression was 0.1 (range 0–0.5) in normal controls, 59.8 (range 14.5–90.7) in MP-CMML and 2.27 (range 0–9.3) in MD-CMML. The difference between MP and MD disease was statistically significant. To further investigate the possible role of GM-CSF cytokine in the pathogenesis of CMML, in a second set of experiments, MNC from 8 normal controls, 14 MP-CMML and 11 MD-CMML samples were thawed and stained with GM-CSFR (CD116 Pharmingen) and then with Goat Anti-Mouse FITC (BD) to evaluate the expression of the cytokine receptor. Mean percentage of expression of GM-CSFR was significantly higher in CMML samples (41.3, range 9.5–69) than in normal controls (20.3, range 16.4–27.3). No difference was detected between subtypes of MP-CMML and MD-CMML. When we considered median intensity of GM-CSFR expression, we observed a significantly higher values in MP-CMML than in MD-CMML (123.2 and 51.4, respectively), whereas no significant difference was detected between normal samples and MD-CMML. In this study, we also assessed "in vitro" spontaneous colony growth of PB-MNC from patients with both variants of CMML. The number of CFU-GM was higher in the MP-CMML than in MD-CMML (57 vs 17/5x10e5 cells plated) and a significant correlation with intracytoplasmic GM-CSF expression was observed (p <0.05). The higher levels of intracytoplasmic GM-CSF and the increased density of the cytokine receptor in MP-CMML suggest a possible role of GM-CSF in malignant cell proliferation of CMML patients. If our results will be confirmed, these findings could be utilized as a possible biological marker to distinguish proliferative and dysplastic variants of the disease. Further studies are warranted to investigate possible therapeutic applications.

scholarly journals TLR4-dependent GM-CSF protects against lung injury in Gram-negative bacterial pneumonia

2012 ◽  
Vol 302 (5) ◽  
pp. L447-L454 ◽  
Author(s):  
Louis R. Standiford ◽  
Theodore J. Standiford ◽  
Michael J. Newstead ◽  
Xianying Zeng ◽  
Megan N. Ballinger ◽  
...  
Keyword(s):  
Lung Injury ◽  
Bacterial Pneumonia ◽  
Lavage Fluid ◽  
Alveolar Epithelial Cells ◽  
Intratracheal Administration ◽  
Bacterial Colony ◽  
Gram Negative ◽  
Gm Csf

Toll-like receptors (TLRs) are required for protective host defense against bacterial pathogens. However, the role of TLRs in regulating lung injury during Gram-negative bacterial pneumonia has not been thoroughly investigated. In this study, experiments were performed to evaluate the role of TLR4 in pulmonary responses against Klebsiella pneumoniae (Kp). Compared with wild-type (WT) (Balb/c) mice, mice with defective TLR4 signaling (TLR4lps-d mice) had substantially higher lung bacterial colony-forming units after intratracheal challenge with Kp, which was associated with considerably greater lung permeability and lung cell death. Reduced expression of granulocyte-macrophage colony-stimulating factor (GM-CSF) mRNA and protein was noted in lungs and bronchoalveolar lavage fluid of TLR4 mutant mice postintratracheal Kp compared with WT mice, and primary alveolar epithelial cells (AEC) harvested from TLR4lps-d mice produced significantly less GM-CSF in vitro in response to heat-killed Kp compared with WT AEC. TLR4lps-d AEC underwent significantly more apoptosis in response to heat-killed Kp in vitro, and treatment with GM-CSF protected these cells from apoptosis in response to Kp. Finally, intratracheal administration of GM-CSF in TLR4lps-d mice significantly decreased albumin leak, lung cell apoptosis, and bacteremia in Kp-infected mice. Based on these observations, we conclude that TLR4 plays a protective role on lung epithelium during Gram-negative bacterial pneumonia, an effect that is partially mediated by GM-CSF.

scholarly journals Neuropeptide Y (NPY) promotes inflammation-induced tumorigenesis by enhancing epithelial cell proliferation

2017 ◽  
Vol 312 (2) ◽  
pp. G103-G111 ◽  
Author(s):  
Sabrina Jeppsson ◽  
Shanthi Srinivasan ◽  
Bindu Chandrasekharan
Keyword(s):  
Cell Proliferation ◽  
Epithelial Cell ◽  
Neuropeptide Y ◽  
Intestinal Inflammation ◽  
Enteric Neurons ◽  
Intestinal Epithelial ◽  
Epithelial Proliferation ◽  
Proliferation And Apoptosis

We have demonstrated that neuropeptide Y (NPY), abundantly produced by enteric neurons, is an important regulator of intestinal inflammation. However, the role of NPY in the progression of chronic inflammation to tumorigenesis is unknown. We investigated whether NPY could modulate epithelial cell proliferation and apoptosis, and thus regulate tumorigenesis. Repeated cycles of dextran sodium sulfate (DSS) were used to model inflammation-induced tumorigenesis in wild-type (WT) and NPY knockout ( NPY−/−) mice. Intestinal epithelial cell lines (T84) were used to assess the effects of NPY (0.1 µM) on epithelial proliferation and apoptosis in vitro. DSS-WT mice exhibited enhanced intestinal inflammation, polyp size, and polyp number (7.5 ± 0.8) compared with DSS- NPY−/− mice (4 ± 0.5, P < 0.01). Accordingly, DSS-WT mice also showed increased colonic epithelial proliferation (PCNA, Ki67) and reduced apoptosis (TUNEL) compared with DSS- NPY−/− mice. The apoptosis regulating microRNA, miR-375, was significantly downregulated in the colon of DSS-WT (2-fold, P < 0.01) compared with DSS- NPY−/−-mice. In vitro studies indicated that NPY promotes cell proliferation (increase in PCNA and β-catenin, P < 0.05) via phosphatidyl-inositol-3-kinase (PI3-K)-β-catenin signaling, suppressed miR-375 expression, and reduced apoptosis (increase in phospho-Bad). NPY-treated cells also displayed increased c-Myc and cyclin D1, and reduction in p21 ( P < 0.05). Addition of miR-375 inhibitor to cells already treated with NPY did not further enhance the effects induced by NPY alone. Our findings demonstrate a novel regulation of inflammation-induced tumorigenesis by NPY-epithelial cross talk as mediated by activation of PI3-K signaling and downregulation of miR-375. NEW & NOTEWORTHY Our work exemplifies a novel role of neuropeptide Y (NPY) in regulating inflammation-induced tumorigenesis via two modalities: first by enhanced proliferation (PI3-K/pAkt), and second by downregulation of microRNA-375 (miR-375)-dependent apoptosis in intestinal epithelial cells. Our data establish the existence of a microRNA-mediated cross talk between enteric neurons producing NPY and intestinal epithelial cells, and the potential of neuropeptide-regulated miRNAs as potential therapeutic molecules for the management of inflammation-associated tumors in the gut.

scholarly journals Loss of CXCR4 on non-classical monocytes in participants of the Women’s Interagency HIV Study (WIHS) with subclinical atherosclerosis

2018 ◽  
Vol 115 (6) ◽  
pp. 1029-1040 ◽  
Author(s):  
Karin A L Mueller ◽  
David B Hanna ◽  
Erik Ehinger ◽  
Xiaonan Xue ◽  
Livia Baas ◽  
...  
Keyword(s):  
Hiv Infection ◽  
Mononuclear Cells ◽  
Smoking Status ◽  
Subclinical Atherosclerosis ◽  
Cxcr4 Expression ◽  
Monocyte Subset ◽  
Surface Markers ◽  
Peripheral Blood Mononuclear ◽  
Cell Counts ◽  
Classical Monocytes

AbstractAimsTo test whether human immunodeficiency virus (HIV) infection and subclinical cardiovascular disease (sCVD) are associated with expression of CXCR4 and other surface markers on classical, intermediate, and non-classical monocytes in women.Methods and resultssCVD was defined as presence of atherosclerotic lesions in the carotid artery in 92 participants of the Women’s Interagency HIV Study (WIHS). Participants were stratified into four sets (n = 23 each) by HIV and sCVD status (HIV−/sCVD−, HIV−/sCVD+, HIV+/sCVD−, and HIV+/sCVD+) matched by age, race/ethnicity, and smoking status. Three subsets of monocytes were determined from archived peripheral blood mononuclear cells. Flow cytometry was used to count and phenotype surface markers. We tested for differences by HIV and sCVD status accounting for multiple comparisons. We found no differences in monocyte subset size among the four groups. Expression of seven surface markers differed significantly across the three monocyte subsets. CXCR4 expression [median fluorescence intensity (MFI)] in non-classical monocytes was highest among HIV−/CVD− [628, interquartile range (IQR) (295–1389)], followed by HIV+/CVD− [486, IQR (248–699)], HIV−/CVD+ (398, IQR (89–901)), and lowest in HIV+/CVD+ women [226, IQR (73–519)), P = 0.006 in ANOVA. After accounting for multiple comparison (Tukey) the difference between HIV−/CVD− vs. HIV+/CVD+ remained significant with P = 0.005 (HIV−/CVD− vs. HIV+/CVD− P = 0.04, HIV−/CVD− vs. HIV−/CVD+ P = 0.06, HIV+/CVD+ vs. HIV+/CVD− P = 0.88, HIV+/CVD+ vs. HIV−/CVD+ P = 0.81, HIV+/CVD− vs. HIV−/CVD+, P = 0.99). All pairwise comparisons with HIV−/CVD− were individually significant (P = 0.050 vs. HIV−/CVD+, P = 0.028 vs. HIV+/CVD−, P = 0.009 vs. HIV+/CVD+). CXCR4 expression on non-classical monocytes was significantly higher in CVD− (501.5, IQR (249.5–887.3)) vs. CVD+ (297, IQR (81.75–626.8) individuals (P = 0.028, n = 46 per group). CXCR4 expression on non-classical monocytes significantly correlated with cardiovascular and HIV−related risk factors including systolic blood pressure, platelet and T cell counts along with duration of antiretroviral therapy (P < 0.05). In regression analyses, adjusted for education level, study site, and injection drug use, presence of HIV infection and sCVD remained significantly associated with lower CXCR4 expression on non-classical monocytes (P = 0.003), but did not differ in classical or intermediate monocytes.ConclusionCXCR4 expression in non-classical monocytes was significantly lower among women with both HIV infection and sCVD, suggesting a potential atheroprotective role of CXCR4 in non-classical monocytes.

Selective toxic effects of tamoxifen on osteoclasts: comparison with the effects of oestrogen

1996 ◽  
Vol 149 (3) ◽  
pp. 503-508 ◽  
Author(s):  
T R Arnett ◽  
R Lindsay ◽  
J M Kilb ◽  
B S Moonga ◽  
M Spowage ◽  
...  
Keyword(s):  
Mononuclear Cells ◽  
Time Lapse ◽  
Bone Cell ◽  
Neonatal Rat ◽  
Pit Formation ◽  
Cell Counts ◽  
Bone Cell Cultures ◽  
Dying Cells

Abstract We investigated the actions of the trans- and cis-isomers of tamoxifen on the function of neonatal rat osteoclasts in vitro. Both compounds inhibited resorption pit formation by osteoclast-containing mixed bone cell cultures incubated for 24 h on cortical bone slices. Cell counts revealed that the inhibition was closely related to a cytotoxic effect, to which osteoclasts appeared particularly sensitive. Partial inhibition of resorption was seen in the presence of 2 μm trans-tamoxifen, whereas complete abolition of resorption and osteoclast viability occurred with 10 μm trans-tamoxifen; survival of mononuclear cells was unimpaired at either concentration. Cis-tamoxifen appeared to be slightly more toxic, with significant inhibitions of osteoclast viability and thus resorption pit formation at a concentration of 2 μm, and also of mononuclear cell numbers at 10 μm. Time-lapse video observations indicated that osteoclast death occurred rapidly (within 2–3 h) following exposure to 10 μm of either trans-tamoxifen or cis-tamoxifen. The morphological appearance of the dying cells was consistent with apoptosis. These results may help to explain the anti-resorptive action of tamoxifen seen in vivo in rats and humans. In contrast, oestradiol-17β consistently exerted no significant effects on resorption pit formation by rat osteoclasts over 24 h, even at grossly supraphysiological concentrations (up to 10 μm). Journal of Endocrinology (1996) 149, 503–508

scholarly journals HLA-E Up-Regulation Induced by HIV Infection May Directly Contribute to CD94-Mediated Impairment of NK Cells

2005 ◽  
Vol 18 (2) ◽  
pp. 269-276 ◽  
Author(s):  
F. Martini ◽  
C. Agrati ◽  
G. D'Offizi ◽  
F. Poccia
Keyword(s):  
T Cells ◽  
Hiv Infection ◽  
Nk Cells ◽  
Cd4 T Cells ◽  
Nk Cell ◽  
Treatment Interruption ◽  
Cell Number ◽  
Hiv Replication

Alterations in NK cell numbers and function have been repeatedly shown during HIV infection. In this study, NK cell number and MHC class I expression on CD4+ T cells were studied in HIV patients at different stages of disease progression. An increased expression of HLA-E was seen on CD4+ T cells. In parallel, a reduced number of CD94+ NK cells was observed in advanced disease stages. Moreover, a decline in CD94 expression on NK cells was observed at the HIV replication peak in patients undergoing antiretroviral treatment interruption, suggesting a role of viral replication on NK cells alterations. In vitro HIV infection induced a rapid down-regulation of HLA-A,B,C expression, paralleled by an increased expression of HLA-E surface molecules, the formal ligands of CD94 NK receptors. HIV-infected HLA-E expressing cells were able to inhibit NK cell cytotoxicity through HLA-E expression, since cytotoxicity was restored by antibody masking experiments. These data indicate that the CD94/HLA-E interaction may contribute to NK cell dysfunction in HIV infection, suggesting a role of HIV replication in this process.

Stabilization but no functional influence of HIF-1α expression in the intestinal epithelium during Salmonella Typhimurium infection

2022 ◽  
Author(s):  
Laura Robrahn ◽  
Aline Dupont ◽  
Sandra Jumpertz ◽  
Kaiyi Zhang ◽  
Christian H. Holland ◽  
...  
Keyword(s):  
Gene Expression ◽  
Intestinal Epithelium ◽  
Bacterial Infections ◽  
Inflammatory Diseases ◽  
Protein Stabilization ◽  
Inflammatory Factors ◽  
Intestinal Epithelial ◽  
Data Set ◽  
The Impact

The hypoxia-inducible transcription factor 1 (HIF-1) has been shown to enhance microbial killing and to ameliorate the course of bacterial infections. While the impact of HIF-1 on inflammatory diseases of the gut has been studied intensively, its function in bacterial infections of the gastrointestinal tract remains largely elusive. With the help of a publicly available gene expression data set, we could infer significant activation of HIF-1 after oral infection of mice with Salmonella Typhimurium. Immunohistochemistry and western blot analysis confirmed marked HIF-1α protein stabilization, especially in the intestinal epithelium. This prompted us to analyze conditional Hif1a -deficient mice to examine cell type-specific functions of HIF-1 in this model. Our results demonstrate enhanced non-canonical induction of HIF-1 activity upon Salmonella infection in the intestinal epithelium as well as in macrophages. Surprisingly, Hif1a deletion in intestinal epithelial cells did not impact on inflammatory gene expression, bacterial spread or disease outcome. In contrast, Hif1a deletion in myeloid cells enhanced intestinal Cxcl2 expression and reduced the cecal Salmonella load. In vitro , HIF-1α-deficient macrophages showed an overall impaired transcription of mRNA encoding pro-inflammatory factors, however, intracellular survival of Salmonella was not impacted by HIF-1α deficiency.

scholarly journals High doses of immunoglobulin G attenuate immune aggregate-mediated complement activation by enhancing physiologic cleavage of C3b in C3bn- IgG complexes

Blood ◽  
1996 ◽  
Vol 88 (1) ◽  
pp. 184-193 ◽  
Author(s):  
HU Lutz ◽  
P Stammler ◽  
E Jelezarova ◽  
M Nater ◽  
PJ Spath
Keyword(s):  
Inflammatory Diseases ◽  
Factor H ◽  
Human Igg ◽  
Partial Protection ◽  
Beneficial Effects ◽  
High Concentrations ◽  
High Doses ◽  
Immune Aggregates

Abstract Intravenously applied human IgG has beneficial effects in treating inflammatory diseases, presumably because it has a complement attenuating role. This role of IgG was studied in vitro by following C3 activation and inactivation in sera that were supplemented with exogenous human IgG and incubated with immune aggregates. IgG added at 2 to 10 mg/mL stimulated the physiologic inactivation of C3b-containing complexes twofold to threefold in 20% sera. This, in turn, lowered the overall C3 activation by 28%, as new C3 convertases primarily assembled on C3b-containing complexes. Exogenous IgG (5 mg/mL) also stimulated inactivation of purified C3b2-IgG complexes, whereby their half-life dropped from 3–4 to 1.5 minutes in 20% serum. IgG appeared to act like a modulator of factor H and I because it did not stimulate inactivation of C3b-containing complexes in factor I-deficient serum. Thus, the known partial protection of C3bn-IgG complexes from inactivation by factor H and I was downregulated by high concentrations of IgG. The ability of high doses of IgG to stimulate complement inactivation is a novel regulatory role of IgG. This may be one of the molecular principles for its therapeutic efficacy in treating complement-mediated inflammations.

scholarly journals Absorption of Hemoglobin Iron: The Role of Xanthine Oxidase in the Intestinal Heme-Splitting Reaction

Blood ◽  
1970 ◽  
Vol 35 (1) ◽  
pp. 94-103 ◽  
Author(s):  
R. BEN DAWSON ◽  
SHEILA RAFAL ◽  
LEWIS R. WEINTRAUB
Keyword(s):  
Epithelial Cell ◽  
Xanthine Oxidase ◽  
Intestinal Epithelial Cell ◽  
Oxidase Inhibitor ◽  
Small Intestinal Mucosa ◽  
Intestinal Epithelial ◽  
Sephadex Column ◽  
Xanthine Oxidase Inhibitor

Abstract Heme from ingested hemoglobin—59Fe is taken into the epithelial cell of the small intestinal mucosa of the dog and the 59Fe subsequently appears in the plasma bound to transferrin. A substance was demonstrated in homogenates of the mucosa which releases iron from a hemoglobin substrate in vitro. Thus: (1) The addition of catalase to the mucosal homogenate reduces the "heme-splitting" reaction. In contrast, sodium azide, a catalase inhibitor, potentiates the reaction. This suggests that a peroxide generating system participates in the "heme-splitting" reaction. (2) Xanthine oxidase, an enzyme present in the intestinal epithelial cell, produces H2O2 by oxidation of its substrate. The addition of allopurinol, a xanthine oxidase inhibitor, to the intestinal mucosal homogenate diminishes the "heme-splitting" reaction. (3) Fractionation of the 50,000 Gm. supernatant of the mucosal homogenate on a G-200 Sephadex column shows the "heme-splitting" activity to have the same elution volume as xanthine oxidase, indicating a similar molecular weight. (4) The addition of a mucosal homogenate to a xanthine substrate results in the production of uric acid. These data suggest that xanthine oxidase in the intestinal epithelial cell is important in the release of iron from absorbed heme. The enzyme mediates the "heme-splitting" reaction by the generation of peroxides which, in turn, oxidize the alpha-methene bridge of the heme ring releasing iron and forming biliverdin.

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