Myeloid cell HIF-1α regulates asthma airway resistance and eosinophil function

Hypoxia-inducible factor (HIF)-1α is a master regulator of inflammatory activities of myeloid cells, including neutrophils and macrophages. These studies examine the role of myeloid cell HIF-1α in regulating asthma induction and pathogenesis, and for the first time, evaluate the roles of HIF-1α and HIF-2α in the chemotactic properties of eosinophils, the myeloid cells most associated with asthma. Wild-type (WT) and myeloid cell-specific HIF-1α knockout (KO) C57BL/6 mice were studied in an ovalbumin (OVA) model of asthma. Administration of the pharmacological HIF-1α antagonist YC-1 was used to corroborate findings from the genetic model. WT, HIF-1α, and HIF-2α KO eosinophils underwent in vitro chemotaxis assays. We found that deletion of HIF-1α in myeloid cells and systemic treatment with YC-1 during asthma induction decreased airway hyperresponsiveness (AHR). Deletion of HIF-1α in myeloid cells in OVA-induced asthma also reduced eosinophil infiltration, goblet cell hyperplasia, and levels of cytokines IL-4, IL-5, and IL-13 in the lung. HIF-1α inhibition with YC-1 during asthma induction decreased eosinophilia in bronchoalveolar lavage, lung parenchyma, and blood, as well as decreased total lung inflammation, IL-5, and serum OVA-specific IgE levels. Deletion of HIF-1α in eosinophils decreased their chemotaxis, while deletion of the isoform HIF-2α led to increased chemotaxis. This work demonstrates that HIF-1α in myeloid cells plays a role in asthma pathogenesis, particularly in AHR development. Additionally, treatment with HIF-1α inhibitors during asthma induction decreases AHR and eosinophilia. Finally, we show that HIF-1α and HIF-2α regulate eosinophil migration in opposing ways.     

Elevated chemokine levels during adult but not pediatric Crimean–Congo hemorrhagic fever

BackgroundCrimean–Congo hemorrhagic fever (CCHF) is a tick-borne viral zoonosis. Clinical reports indicate the severity of CCHF is milder in children than adults. The chemokines are important chemo-attractant mediators of the host immune system.ObjectivesThe main aim of the study was to identify whether or not there were any differences in chemokine levels between the pediatric and adult patients and control groups, and whether there was any correlation with disease severity.Study designThe serum levels of select chemokines including chemokine (C-C) ligand 2 (CCL2), CCL3, CCL4, chemokine (C-X-C) ligand 8 (CXCL8), CXCL9, and granulocyte-colony stimulating factor (G-CSF) in 29 adult and 32 pediatric CCHF patients and in 35 healthy children and 40 healthy adult control groups were studied by flow cytometric bead immunoassay method.ResultsGreat variability was detected in the serum levels of the chemokines for both the adult and pediatric patients and controls. With the exception of G-CSF, the median serum levels of CCL2, CCL3, CCL4, CXCL8, and CXCL9 were found to be significantly higher in the adult patients compared to adult controls (2364.7 vs. 761 pg/ml; 714.1 vs. 75.2 pg/ml; 88.6 vs. 25.5 pg/ml; 217.9 vs. 18.3 pg/ml; 875 vs. 352.2 pg/ml, respectively, p < 0.0001 for all comparisons). Among the chemokines the median CCL4 and G-CSF levels were significantly higher in the pediatric patients compared to pediatric controls (40.3 vs. 7.1 pg/ml, p < 0.0001; 0.1 vs. 0.1 pg/ml, p = 0.049, respectively).ConclusionThe results of this study showed prominent chemokine raising in adult CCHF patients compared to children CCHF patients.     

Fibronectin regulates proteoglycan production balance in transforming growth factor-β1-induced chondrogenesis

Transforming growth factor (TGF)-β and bone morphogenetic protein (BMP) induce a cartilage-specific extracellular matrix (ECM) gene, aggrecan, in a chondrogenic cell line, ATDC5. The results of our recent study show that TGF-β1, but not BMP-4, strongly induces an ECM gene, fibronectin, during chondrogenesis. However, the role of fibronectin in chondrogenesis is unclear. In the current study, our results showed that TGF-β1, but not BMP-4, led to versican-dominant proteoglycan production during chondrogenesis of ATDC5 cells. siRNA-mediated reduction of fibronectin and interference in the liaison between fibronectin and integrins by the Arg-Gly-Asp-Ser (RGDS) peptide increased aggrecan expression, and decreased versican expression by TGF-β1 stimulation. These data suggest that fibronectin is a critical mediator for TGF-β-specific production balance of 2 major proteoglycans, aggrecan and versican, during chondrogenesis.     

A novel regulatory B-cell population in sheep Peyer's patches spontaneously secretes IL-10 and downregulates TLR9-induced IFNα responses

Peyer's patches (PPs) play an important role in the induction of immune responses in the intestine, but regulation of Toll-like receptor (TLR)-induced innate immune responses in PPs is not well understood. We investigated the responses of PPs and other immune cells to the TLR9 agonist, CpG oligodeoxynucleotide (ODN). Peripheral blood mononuclear cells and lymph node cells secreted significant amounts of interferon (IFN)-α, IFNγ, and interleukin (IL)-12 following stimulation with CpG ODN. In contrast, PP cells exhibited poor cytokine responses, despite abundant expression of TLR9 mRNA. PP cells spontaneously secreted high levels of IL-10, and the primary source of the IL-10 was resting CD5⁻CD11c⁻CD21⁺ B cells. Neutralization of the IL-10 or depletion of CD21⁺ B cells resulted in a significant increase in CpG-induced IFNα-response in PPs, suggesting that IL-10 from B cells regulate innate responses in PPs. These IL-10-secreting PP B cells may represent a novel subset of the recently proposed regulatory B cells (B_regs) in the intestine.     

IL-4Rα expression by airway epithelium and smooth muscle accounts for nearly all airway hyperresponsiveness in murine allergic airway disease

Airway hyperresponsiveness (AHR) often defines asthma. Murine allergic airway disease (AAD), like human eosinophilic asthma, is characterized by AHR, eosinophilia, goblet cell metaplasia (GCM), smooth muscle hypercontractility, and increased production of IL-4 and IL-13—cytokines that induce these characteristics by binding to the IL-4Rα chain. We evaluated the epithelial and smooth muscle IL-4Rα-dependent contributions to AHR of BALB/c mice that possessed 0–2 functional IL-4Rα alleles and had airway disease induced by house dust mite extract (HDM) or exogenous IL-13. Two functional IL-4Rα alleles were required for maximal AHR, while only one functional allele was required for maximal GCM and systemic IL-4/IL-13 levels. Deletion of IL-4Rα from both smooth muscle and epithelial cells inhibited AHR >83% in mice with two functional IL-4Rα alleles. In mice with one functional IL-4Rα allele, selective epithelial cell IL-4Rα deletion maximally inhibited AHR, while selective smooth muscle IL-4Rα deletion decreased IL-13-induced, but not HDM-induced, AHR. Less IL-4Rα signaling is required to maximize the epithelial cell contribution to AHR compared to the smooth muscle contribution to AHR. In addition, epithelial cell responses to IL-4/IL-13 can increase the IL-4Rα-dependent smooth muscle contribution to AHR. These findings carry increasing relevance as IL-4Rα-targeted therapy is administered to human asthmatics.     

BLCA-4 expression is related to MMP-9, VEGF, IL-1α and IL-8 in bladder cancer but not to PEDF, TNF-α or angiogenesis

Aim

BLCA-4 is a specific nuclear matrix protein found in bladder cancer and there is a dearth of study on functional analysis upon this factor. We aimed to discover whether BLCA-4 is related to angiogenesis in bladder cancer.

Methods

Fifty-three bladder cancer samples were included for immunohistochemical staining of BLCA-4, matrix metalloproteinase-9 (MMP-9), vascular endothelial growth factor (VEGF), interleukin-1α (IL-1α), IL-8, pigment epithelium-derived factor (PEDF), tumour necrosis factor-α (TNF-α) and von Willebrand factor (vWF) for microvessel density (MVD). Expressional levels were scored and grouped by clinicopathological parametres for statistical analysis for correlations.

Results

Positive correlations were identified between expression of BLCA-4 and IL-1α (p = 0.038), IL-8 (p = 0.001), VEGF (p = 0.002), and MMP-9 (p = 0.013). No correlation was found for PEDF (p = 0.182), TNF-α (p = 0.531) or MVD (p = 0.932). Positive correlations were also obtained in cases of advanced grade or stage, larger, recurrent and multiple tumours. Positive correlation between BLCA-4 and MMP-9 was also found in papillary urothelial neoplasm of low malignant potential (PUNLMP).

Conclusion

BLCA-4 may not effect pro-angiogenic pathways in bladder cancer, it can however interact with IL-1α, IL-8, VEGF and MMP-9 to enhance tumourigenesis and tumour invasiveness.     

Cyclosporin A and tacrolimus reduce T-cell polyfunctionality but not interferon-γ responses directed at cytomegalovirus

Cytomegalovirus (CMV) -specific immunity is often estimated by the number of in vitro CMV antigen-inducible interferon-γ-positive (IFN-γ(+) ) T cells. However, recent work indicates that simultaneous production of IFN-γ, tumour necrosis factor-α (TNF-α) and interleukin-2 (IL-2) (referred to as 'polyfunctionality') is more relevant for anti-viral protection. Here, we compared polyfunctionality of CMV-specific T cells (pp65 and IE-1 proteins) in 23 solid-organ transplant patients and seven healthy controls by flow cytometry. The proportions of TNF-α(+) /IFN-γ(+) /IL-2 cells among the activated cells were significantly reduced in transplant patients but not the frequencies of IFN-γ(+) CD8(+) T cells. Immunosuppression reduces polyfunctionality, which reflects the increased infection risk in this patient group.     

Inhibition of IL-4 but not IFN-γ production by splenocytes of mice immunized with ovalbumin after oral administration of 5-hydroxymethylfurfural

5-Hydroxymethylfurfural (5-HMF) is one of the most important products of maillard reaction. This study sought to elucidate the immunomodulatory effect of 5-HMF by evaluating IFN-γ and IL-4 production in BALB/c mice sensitized with ovalbumin (OVA). Four groups of BALB/c mice (n?=?5 for each group) including control, vehicle and two 5-HMF (188 and 750?mg/kg?bw) treatment groups were studied. Interleukin-4(IL-4) and interferon gamma (IFN-γ) levels were measured in culture supernatants of spleen cells using enzyme-linked immunosorbent assay. It was found that the IL-4 level was significantly suppressed in 5-HMF treatment groups compared with the vehicle group (P?P?相似文献   

Phosphorylation of Carma1, but not Bcl10, by Akt regulates TCR/CD28-mediated NF-κB induction and cytokine production

Previous studies from our group and others have shown that the Akt kinase can contribute to induction of NF-κB by antigen receptor signaling. However, the direct targets of Akt in this pathway are not known. Here we show that Akt-mediated NF-κB activation is mediated at least in part through direct phosphorylation of the adaptor protein Carma1, which we previously demonstrated could interact with Akt in a TCR ligation-dependent manner. The putative Akt phosphorylation sites in Carma1 are distinct from known PKC consensus sites. Mutation of S551, S637 and S645 in Carma1 to non-phosphorylatable residues decreased phosphorylation of GST-Carma1-linker construct by Akt in vitro. In addition, Carma1 S637A/S645A mutants were significantly impaired in their ability to restore TCR-mediated NF-κB activation and IL-2 expression in Carma1-deficient T cells. Thus, our data reveal Carma1 as a novel target for Akt phosphorylation and suggest that Akt-mediated phosphorylation of Carma1 is an additional regulatory mechanism tuning the NF-κB response downstream of antigen receptor and co-stimulatory signaling.     

Membrane interleukin-18 revisits membrane IL-1α in T-helper type 1 responses

Although all structural studies on cytokine-cytokine receptor interactions are based on a crystallized cytokine binding to its specific receptor, there is no dearth of evidence that membrane-embedded cytokines are biologically active by virtue of cell-cell contact. Clearly the orientation of the membrane cytokine is such that it allows binding to the receptor, as takes place with the soluble form of the cytokine. In this issue, Bellora et al. [Eur. J. Immunol. 2012. 42: 1618-1626] report that interleukin-18 (IL-18) exists as an integral membrane protein on M-CSF-differentiated human macrophages and that upon LPS stimulation, IL-18 induces IFN-γ from NK cells in a caspase-1-dependent fashion. The immunological and inflammatory implications for this finding are considerable because of the role of IL-18 as the primary IFN-γ inducing cytokine in promoting Th1 responses.     

Decreased interferon-α production in response to CpG DNA dysregulates cytokine responses in patients with multiple sclerosis

Type I interferons (IFNs), represented by IFN-α and β, activate immune effector cells belonging to the innate and adaptive immune systems. Plasmacytoid dendritic cells (pDCs) produce IFN-α in response to CpG DNA. We aimed to examine the impact of pDC-produced IFN-α on the adaptive immune system in Multiple Sclerosis (MS). Our results demonstrated that CpG DNA-induced IFN-α production was significantly decreased in PBMCs from MS patients. Decreased levels of IL-12 p70, IFN-γ, and IL-17 and increased level of IL-10 were found in CpG DNA-treated PBMCs of healthy subjects unlike in those from MS patients. In samples pre-treated with IFN-α and IFN-β, decreased levels of IL-12 p70, IFN-γ, and IL-17 and increased level of IL-10 were detected in PBMCs from MS patients. These results suggest that CpG DNA-induced decreased IFN-α production causes pro-inflammatory cytokine secretion, and either IFN-α or IFN-β induces anti-inflammatory cytokine secretion in the adaptive immune system in MS.     

Triptolide inhibits transforming growth factor-β1-induced proliferation and migration of rat airway smooth muscle cells by suppressing nuclear factor-κB but not extracellular signal-regulated kinase 1/2

Airway remodelling contributes to increased mortality in asthma. We have reported that triptolide can inhibit airway remodelling in a mouse asthma model. In this study, we aimed to investigate the effect of triptolide on proliferation and migration of airway smooth muscle cells (ASMC), and the possible mechanism. Rat ASMC were cultured and synchronized, then pre-treated with different concentrations of triptolide before being stimulated by transforming growth factor-β₁ (TGF-β₁). Cell proliferation was evaluated by cell counting and MTT assay. Flow cytometry was used to study the influence of triptolide on the cell cycle. Migration was measured by Transwell analysis. Signal proteins [nuclear factor-κB (NF-κB) p65 and extracellular signal-regulated kinase 1/2 (ERK1/2)] were detected by Western blotting. A lactate dehydrogenase releasing test and flow cytometry analysis of apoptosis were also performed to explore the potential cytotoxic or pro-apoptotic effects of triptolide. Triptolide significantly inhibited TGF-β₁-induced ASMC proliferation and migration (P < 0·05). The cell cycle was dose-dependently blocked at G1/S-interphase by triptolide. Western blotting analysis showed that TGF-β₁-induced NF-κB p65 phosphorylation was inhibited by triptolide pre-treatment, but ERK1/2 was not affected. No cytotoxic or pro-apoptotic effects were detected under the concentration of triptolide that was used. Triptolide may function as an inhibitor of asthma airway remodelling by suppressing ASMC proliferation and migration through inactivation of the NF-κB pathway.     

Interferon-α induces unabated production of short-lived plasma cells in pre-autoimmune lupus-prone (NZB×NZW)F1 mice but not in BALB/c mice

IFN-α is known to play a critical role in the pathogenesis of systemic lupus erythematosus (SLE), but the mechanisms remain unclear. We previously showed that within weeks, exposure to IFN-α in vivo induces lupus in pre-autoimmune lupus-prone NZB×NZW F1 (NZB/W) but not in BALB/c mice. In the current study, we show that in vivo expression of IFN-α induces sustained B-cell proliferation in both BALB/c and NZB/W mice. In NZB/W but not BALB/c mice, B-cell proliferation was accompanied by a rapid and unabated production of autoantibody-secreting cells (ASCs) in secondary lymphoid organs, suggesting that a B-cell checkpoint is altered in the autoimmune background. The majority (>95%) of ASCs elicited in IFN-α-treated NZB/W mice were short-lived and occurred without the induction of long-lived plasma cells. A short course of cyclophosphamide caused a sharp drop in IFN-α-elicited short-lived plasma cells, but the levels recovered within days following termination of treatment. Thus, our work provides new insights into effectiveness and limitations of the current SLE therapies.     

Effect of peptide aldehydes with IL-1β converting enzyme inhibitory properties on IL-1α and IL-1β production in vitro

Tripeptide and pentapeptide aldehydes as substrate-base inhibitors of cysteine proteases were designed in our laboratory for the inhibition of interleukin-lβ converting enzyme (ICE), a recently described cysteine protease responsible for the processing of IL-1β. The biological effectivity of the peptide aldehydes was studied in THP-1 cells and human whole blood. The released and cell-associated IL-1α and IL-1β levels were determined by ELISA from the supernatants and cell lysates, respectively. The total IL-1 like bioactivity was assayed by the D₁₀G₄₁ cell proliferation method. The tripeptide aldehyde (Z-Val-His-Asp-H) and pentapeptide aldehyde (Eoc-Ala-Tyr-Val-Ala-Asp-H) significantly reduced IL-1β levels in the supernatants in relatively high concentrations (10–100 μM), but the IL-1α release was unaffected by these peptides. However, a considerable decrease in the cell-associated IL-1β and IL-1α levels was observed. N-terminal extension of the tripeptide aldehyde yielded even more potent inhibitors. Amino acid substitution at the P₂ position did not cause considerable changes in the inhibitory activity. The peptide aldehydes suppressed the IL-1β production in a reversible manner, whereas dexamethasone, a glucocorticoid, had a prolonged inhibitory effect. The inhibitory effect of these peptides and that of dexamethasone appeared to be additive. These findings indicate that these peptide aldehydes might be used as IL-β inhibitory agents in experimental models in which IL-1β is a key mediator or ICE is implicated.     

Smac mimetic enables the anticancer action of BCG-stimulated neutrophils through TNF-α but not through TRAIL and FasL

BCG, the current gold standard immunotherapy for bladder cancer, exerts its activity via recruitment of neutrophils to the tumor microenvironment. Many patients do not respond to BCG therapy, indicating the need to understand the mechanism of action of BCG-stimulated neutrophils and to identify ways to overcome resistance to BCG therapy. Using isolated human neutrophils stimulated with BCG, we found that TNF-α is the key mediator secreted by BCG-stimulated neutrophils. RT4v6 human bladder cancer cells, which express TNFR1, CD95/Fas, CD95 ligand/FasL, DR4, and DR5, were resistant to BCG-stimulated neutrophil conditioned medium but effectively killed by the combination of conditioned medium and Smac mimetic. rhTNF-α and rhFasL, but not rhTRAIL, in combination with Smac mimetic, generated signature molecular events similar to those produced by BCG-stimulated neutrophils in combination with Smac mimetic. However, experiments using neutralizing antibodies to these death ligands showed that TNF-α secreted from BCG-stimulated neutrophils was the key mediator of anticancer action. These findings explain the mechanism of action of BCG and identified Smac mimetics as potential combination therapeutic agents for bladder cancer.     

CD43−, but not CD43+, IL-10-producing CD1dhiCD5+ B cells suppress type 1 immune responses during Chlamydia muridarum genital tract infection

Regulatory B (Breg) cells are known to modulate immune responses through predominantly interleukin-10 (IL-10)-dependent mechanisms and can be hypothetically divided into innate and adaptive subsets based on the nature of their activating signals. However, the specific role of different Breg subsets in modulating immune responses remains ambiguous. Here we have shown that Chlamydia induces IL-10-producing splenic B-cell populations consisting of CD43⁺ and CD43⁻ subsets of IgM^hiIgD^lo innate-like B (ILB) cells in vitro. While CD43⁺IL-10-producing B cells displayed innate type features and were readily induced by Chlamydia via Toll-like-receptor (TLR) signaling, CD43⁻IL-10-producing B cells required additional B-cell activating factor (BAFF)-mediated signals from dendritic cells (DCs) for their differentiation and activation, thereby classifying them as adaptive type Bregs. Importantly, CD43⁻, but not CD43⁺, IL-10-producing ILB cells displayed bona fide Breg activity by potently suppressing interferon-γ (IFN-γ) production in vitro in an IL-10-dependent manner. Furthermore, a novel CD43⁻CD1d^hiCD5⁺ IL-10-producing Breg population was predominantly induced by Chlamydia genital infection in vivo. Correspondingly, mixed bone marrow chimeric mice with B-cell-specific IL-10 deficiency exhibited significantly increased type 1 immune responses, decreased bacterial burden, and reduced oviduct pathology upon infection. Our data demonstrate for the first time a distinct role for CD43⁻CD1d^hiCD5⁺-adaptive Bregs over CD43⁺ innate counterparts in controlling mucosal responses against intracellular bacterial infection.