Chemokines In Peripheral Blood Mononuclear Cells Research Articles

Activation of Immune and Defense Responses in the Intestinal Mucosa by Outer Membrane Vesicles of Commensal and Probiotic Escherichia coli Strains.

The influence of microbiota in human health is well-known. Imbalances in microbiome structure have been linked to several diseases. Modulation of microbiota composition through probiotic therapy is an attempt to harness the beneficial effects of commensal microbiota. Although, there is wide knowledge of the responses induced by gut microbiota, the microbial factors that mediate these effects are not well-known. Gram-negative bacteria release outer membrane vesicles (OMVs) as a secretion mechanism of microbial factors, which have an important role in intercellular communication. Here, we investigated whether OMVs from the probiotic Escherichia coli strain Nissle 1917 (EcN) or the commensal E. coli strain ECOR12 trigger immune responses in various cellular models: (i) peripheral blood mononuclear cells (PBMCs) as a model of intestinal barrier disruption, (ii) apical stimulation of Caco-2/PMBCs co-culture as a model of intact intestinal mucosa, and (iii) colonic mucosa explants as an ex vivo model. Stimulations with bacterial lysates were also performed. Whereas, both OMVs and lysates activated expression and secretion of several cytokines and chemokines in PBMCs, only OMVs induced basolateral secretion and mRNA upregulation of these mediators in the co-culture model. We provide evidence that OMVs are internalized in polarized Caco-2 cells. The activated epithelial cells elicit a response in the underlying immunocompetent cells. The OMVs effects were corroborated in the ex vivo model. This experimental study shows that OMVs are an effective strategy used by beneficial gut bacteria to communicate with and modulate host responses, activating signaling events through the intestinal epithelial barrier.

Depression and neuroticism in patients with chronic hepatitis C: Correlation with peripheral blood mononuclear cells activation

BackgroundHepatitis C virus (HCV) infection is commonly associated with cognitive dysfunction and depression, which could be related to direct brain infection. Viral sequences and proteins were found in brain macrophage/microglia cells and these cells were reported to be activated. Since blood leukocytes cross blood–brain barrier, activation state of peripheral blood mononuclear cells (PBMC) could reflect the state of brain immune cells. ObjectiveThe aim of the study was to determine whether depression and neuroticism in chronic HCV infection correlates with the expression of key cytokines and chemokines in PBMC. DesignWe studied 24 HCV-positive patients undergoing treatment with interferon and ribavirin. Patients were tested for depression using Beck Depression Inventory (BDI) and Montgomery Åsberg Depression Rating Scale (MADRS), while neuroticism was assessed by the Revised Eysenck Personality Inventory (N/EPO-R). Transcripts representing 28 various cytokines and chemokines were measured by real-time quantitative PCR in PBMC. ResultsPrior to therapy BDI and MADRS positively correlated with viral load while neuroticism correlated with IL-3, IL-8 and M-CSF transcription levels. Six months after therapy there was positive correlation between depression and/or neuroticism scores and the levels of proinflammatory cytokines TNF-α and IL-12 transcripts, as well as IL-8, IL-10, IL-16, MCP-1, MCP-2, MIP-1-alpha, MIP-1-beta, and TGF-beta, and IFN-β transcripts. ConclusionActivation of PBMC, as measured by the level of cytokine and chemokine transcripts, correlates with depression and neuroticism scores. These findings suggest a pivotal role of immune cells activation in depression and possibly neurocognitive dysfunction among chronic hepatitis C patients.

Hev b 6.01 and Hev b 5 induce pro‐inflammatory cytokines and chemokines from peripheral blood mononuclear cells in latex allergy

Hev b 6.01 (prohevein) and Hev b 5 [acidic natural rubber latex (NRL) protein] are major IgE-binding allergens in NRL allergy. To examine allergen-specific cytokine and chemokine responses in NRL-allergic patients. Fourteen NRL-allergic patients and 10 healthy controls participated in the study. Hev b 6.01 and Hev b 5 were purified under non-denaturating conditions by chromatographic methods. Specific IgE antibodies were measured by ELISA and proliferation of peripheral blood mononuclear cells (PBMC) by (3)H-thymidine incorporation assay. Allergen-specific induction of cytokine and chemokine mRNA in PBMC was measured by real-time PCR and protein levels by ELISA. Surface expression of chemokine receptors was analysed by flow cytometry. Twelve (86%) NRL-allergic patients had positive skin prick test reactions and IgE antibodies against Hev b 6.01, but less than 30% responded to Hev b 5. Cell proliferation against Hev b 6.01, but not against Hev b 5, was significantly increased. Both allergens elicited significantly higher expression of pro-inflammatory and T-helper type 2 cytokines (TNF, IL-12p40, IL-13) and chemokines (CCL3, CCL4, CCL20) in the NRL-allergic patients than in controls. Interestingly, mRNA expression of the regulatory cytokine TGF-beta1 was reduced, whereas IL-10 expression was enhanced after allergen stimulations in patients with NRL allergy. Finally, the NRL-allergic patients showed increased CCR4 expression on CD3(+)CD8(-) T cells and decreased CXCR3 expression on CD3(+)CD8(+) T cells. Allergen-specific induction of cytokines and chemokines in PBMC and chemokine receptor expression on circulating T cells may contribute to the pathogenesis of NRL allergy.

Increased expression of chemokines in patients with Wegener's granulomatosis − modulating effects of methylprednisolone in vitro

Chemokines, a group of cytokines that attracts and activates leucocyte subpopulations in inflamed tissue, have been associated with the pathogenesis of a number of inflammatory diseases, and some recent reports have suggested their involvement in Wegener's granulomatosis (WG). To elucidate further the possible role of chemokines in WG we examined serum levels of several CC- and CXC-chemokines in WG patients and assessed the ability of corticosteroids to modulate the expression of these mediators in vitro. Our main findings were: (i) WG patients (n = 14) had elevated serum levels of several inflammatory chemokines [i.e. regulated upon activation normal T cell expressed and secreted (RANTES), monocyte chemoattractant protein (MCP)-1 and interleukin (IL)-8] compared to healthy controls (n = 9), as assessed by enzyme immunoassays (EIAs); (ii) by using EIAs and real-time reverse transcription-polymerase chain reaction (RT-PCR), we demonstrated the ability of methylprednisolone (MP) to down-regulate both the spontaneous and the staphylococcal enterotoxin B (SEB)-induced release of chemokines from peripheral blood mononuclear cells (PBMC) in vitro in both WG patients and controls, possibly involving both transcriptional and post-transcriptional mechanisms; and (iii) the ability of MP to attenuate chemokine secretion was less pronounced in WG patients than in controls, particularly with regard to inhibition of spontaneous release. Our findings suggest a role for chemokines in the pathogenesis of WG. The diminished MP-mediated suppression of chemokines in PBMC from WG patients suggests that more specific modulators of chemokine levels should be investigated in this disorder.