Identification and characterization of monocyte subpopulations from patients with bronchial asthma

Involvement of Transforming Growth Factor-β-Associated Kinase 1 in Fixed Airway Obstruction in Asthmatic Patients with Longer Disease Duration Independent on Airway Eosinophilia

Objective

Transforming growth factor-β-associated kinase 1 (TAK1) mediates non-canonical TGF-β signalling by promoting adhesive, migratory, proliferative and contractile responses of fibroblasts to TGF-β₁. However, TAK1 expression status in asthmatic patients with or without fixed airway obstruction (FAO) is unknown.

Patients and Methods

A total of 60 adult asthmatics with FAO were recruited and compared to 43 those without FAO (nFAO). TGF-β₁ concentrations, and total TAK1 and phosphorylated TAK1 (p-TAK1) levels were determined in sputum supernatants, cytospin, and whole cell lysate by ELISA, immunocytochemistry, and Western blot analysis, respectively, in asthmatics with and without FAO.

Results

Asthmatic patients with FAO had much greater sputum TGF-β₁ concentrations than those without FAO. This was independent of airway eosinophilia as there was no significant difference in TGF-β₁ levels between high and low eosinophil counts within FAO and nFAO groups. In contrast, patients with FAO in the presence of sputum eosinophilia had greater expression of TAK1 and p-TAK1 than those without sputum eosinophilia (P=0.0032 and P=0.0061, respectively). The Western Blot data of total TAK1 and p-TAK1 were consistent with the immunocytochemistry, showing upregulation in all sputum cell types (neutrophils, eosinophils, macrophages, lymphocytes and airway epithelial cells). In addition, total TAK1 expression negatively correlated with pre- and post-bronchodilator FEV₁/FVC ratio.

Conclusion

TAK1 may play a key role in asthmatic patients with fixed airway obstruction, which was independent of eosinophilic airway inflammation. The interruption of TAK1 might have favourable clinical impact.

The synergistic and enhancive effects of IL-6 and M-CSF to expand and differentiate functional dendritic cells from human monocytes under serum-free condition

BACKGROUND

Dendritic cells (DCs) are differentiated from monocytes, and have a strong ability to perform phagocytosis, present antigens and activate T cell immune response. Therefore, DCs are one of the key factors in fighting cancer in immunotherapy, and it is an important issue to develop a serum-free system for DC differentiation and expansion in vitro for clinical application.

RESULTS

In this study, IL-6 and M-CSF were determined and a concentration combination of cytokines was optimized to develop an optimal DC serum-free differentiation medium (SF-DC Optimal) that can effectively differentiate CD14⁺ monocytes into CD40⁺CD209⁺ DCs. After differentiation, the morphology, growth kinetics, surface antigen expression, phagocytosis ability, cytokine secretion, mixed lymphocyte reaction and stimulation for maturation of the differentiated DCs were checked and confirmed. Importantly, this research is the first report finding that the addition an extra low concentration of IL-6 and M-CSF exhibited a synergistic effect with GM-CSF and IL-4 to generate higher numbers and more fully functional DCs than the addition of GM-CSF and IL-4 only under serum-free condition.

CONCLUSION

A large number of functional DCs can be generated by using SF-DC Optimal medium and provide an alternative source of DCs for related basic research and clinical applications.

Association of plasma soluble CD14 level with asthma severity in adults: a case control study in China

Background

Soluble CD14 (sCD14) shedding from CD14 could regulate T lymphocyte activation and function, which has implicated in the pathogenesis of bronchial asthma. The level of sCD14 expression is obviously increased in asthmatic patients during acute asthma attacks. The objective of this study was to investigate the association between plasma sCD14 level and asthma severity in adults.

Methods

The plasma sCD14 level in asthma patients (n = 910) and healthy controls (n = 881) was quantified by commercially available enzyme-linked immunosorbent assay (ELISA) kits. The asthma cases were subdivided into intermittent asthma (n = 537), mild (n = 246), moderate (n = 96) and severe (n = 31) persistent asthma patients. Association between plasma sCD14 level and asthma severity, lung function parameters as well as asthma symptoms and signs in adults were performed using multivariate logistic regression models.

Results

We observed significant relationships of plasma sCD14 level with asthma severity, lung function parameters as well as asthma symptoms and signs in adults. After adjusting for multiple potential confounders, each one-unit increase in log sCD14 was significantly associated with 67, 82, 79 and 85% reduced ORs for intermittent asthma, mild, moderate and severe persistent asthma, respectively (all P < 0.0001). Compared with the participants of FEV₁/FVC ≥75%, each one-unit increase in log sCD14 was significantly associated with a 37% decreased OR of FEV₁/FVC < 75% (P < 0.0001). However, the adjusted odds ratios (ORs) of severe dyspnea, wheeze and cyanosis in asthma patients were 1.88, 1.46 and 2.20 for each one-unit increase in log sCD14, respectively. In addition, compared with health controls, the adjusted area under the curve (AUC) of sCD14 was 0.814 at a cut-off points of 0.53, and the sensitivity and specificity were 71.0 and 76.8% for predicting asthma in adults. And the adjusted AUC of sCD14 reached 0.786, 0.847, 0.887 and 0.917 in predicting intermittent asthma, mild, moderate and severe persistent asthma, respectively.

Conclusions

Our results indicated that plasma sCD14 level is negatively associated with asthma severity, suggesting a protective role for sCD14 in the development of asthma in adults. And plasma sCD14 level might be a potential biomarker in prediction of asthma severity in adults.

Electronic supplementary material

The online version of this article (10.1186/s12931-019-0987-0) contains supplementary material, which is available to authorized users.

House Dust Mite Allergens and the Induction of Monocyte Interleukin 1β Production That Triggers an IκBζ-Dependent Granulocyte Macrophage Colony-Stimulating Factor Release from Human Lung Epithelial Cells

Asthma is a chronic lung disease characterized by inflammation centered upon bronchial epithelium. House dust mite is one of the most common respiratory allergens that trigger exacerbations of asthma. IκBζ (gene NFKBIZ) is a recently recognized member of the NF-κB family that can be induced in mononuclear phagocytes and lung epithelial cells and has been shown to play a prominent role in epithelial cell function. We therefore analyzed the role of IκBζ in regulating lung epithelial cell cytokine responses to house dust mite mix (HDM). We found that human bronchial epithelial cells express IκBζ and release IL-6 and granulocyte macrophage colony-stimulating factor (GMCSF) when cocultured with human monocytes and HDM. This response is blocked in the presence of IL-1 receptor antagonist (IL-1Ra), indicating that it is IL-1 mediated. Neither HDM-stimulated macrophages nor dendritic cells release IL-1β and subsequently induce cytokine release from the bronchial epithelial cells. Rhodobacter sphaeroides LPS (RS-LPS), a TLR4 antagonist, blocks the ability of HDM to induce IκBζ and release GMCSF from epithelial cells cocultured with monocytes. Additionally, human bronchial epithelial cells show no induction of IκBζ or cytokine responses to direct HDM stimulation. Finally, NFKBIZ small interfering RNA-mediated knockdown in the bronchial epithelial cells suppresses the release of IL-1-induced IL-6 and GMCSF. Our findings indicate a possible role for monocyte recruitment and lung epithelial cell IκBζ in mediating asthma associated inflammation. Thus, IκBζ, IL-1Ra, and RS-LPS deserve future study as potential modulators of house dust mite-induced asthma.

Impact of yoga on biochemical profile of asthmatics: A randomized controlled study

BACKGROUND

Asthma is a chronic inflammatory disorder of the airways. The chronic inflammation causes an associated increase in airway hyperresponsiveness that leads to recurrent episodes of wheezing, breathlessness, chest tightness, and coughing at night or in the early morning. Most of the studies have reported, as the effects of yoga on bronchial asthma, significant improvements in pulmonary functions, quality of life, and decrease in medication use, but none of the studies has attempted to show the effect of yoga on biochemical changes.

OBJECTIVE

To evaluate the effect of yoga on biochemical profile of asthmatics.

MATERIALS AND METHODS

In the present study, 276 patients of mild to moderate asthma (FEV 1> 60%) aged between 12 to 60 years were recruited from the Department of Pulmonary Medicine, King George's Medical University, U.P., Lucknow, India. They were randomly divided into two groups: Yoga group (with standard medical treatment and yogic intervention) and control group as standard medical treatment (without yogic intervention). At completion of 6 months of the study period, 35 subjects were dropped out, so out of 276 subjects, only 241 subjects completed the whole study (121 subjects from yoga group and 120 subjects from control group). Biochemical assessment was carried out at baseline and after 6 months of the study period.

RESULTS

In yoga group, there was significant improvement found in the proportion of hemoglobin and antioxidant superoxide dismutase in comparison to control group and significant decrease was found in total leukocyte count (TLC) and differential leukocytes count in comparison to control group. There was no significant change found in TLC, polymorphs, and monocytes in between group comparison.

CONCLUSIONS

Yoga group got significantly better improvement in biochemical variables than control group. Result shows that yoga can be practiced as adjuvant therapy with standard inhalation therapy for better outcome of asthma.

Serum and bronchial lavage fluid concentrations of IL-8, SLPI, sCD14 and sICAM-1 in patients with COPD and asthma

BACKGROUND

Airway inflammation is associated with an increased expression and release of inflammatory reactants that regulate processes of cell migration, activation and degranulation. The purpose of this study was to quantify bronchial lavage (BAL) fluid and serum levels of chemokine (IL-8), secretory leukocyte protease inhibitor (SLPI), soluble intracellular adhesion molecules-1 (sICAM-1) and sCD14, as surrogate markers of inflammatory and immune response in asthma and chronic obstructive pulmonary disease (COPD) patients with similar disease duration time.

METHODS

Biomarkers in serum and BAL fluid from asthma (n=13) and COPD (n=25) patients were measured using commercially available ELISA kits.

RESULTS

We found that in asthma and COPD groups the concentrations of IL-8 and SLPI are significantly higher in BAL fluid than in serum, while levels of sICAM-1 and sCD14 in BAL fluid are significantly lower than in serum. Of these 4 measured biomarkers, only the BAL IL-8 was higher in COPD patients when compared to asthma (P<0.05). In both groups, BAL IL-8 correlated with SLPI (r=0.577, P<0.01 and r=0.589, P<0.05, respectively). In patients with COPD the BAL sICAM-1 correlated with sCD14 (r=0.576, P<0.01), while in asthma patients BAL sICAM-1 correlated with FEV(1)/FVC (r=0.418, P<0.01). Moreover, in asthma patients the serum SLPI correlated with sCD14 (r=0.688, P<0.01) and serum sICAM-1 negatively correlated with FEV(1)/FVC (r=-0.582, P<0.05).

CONCLUSION

Our findings point to the importance of selecting a correct biological fluid when analyzing specific biomarkers, and also show that of 4 measured biomarkers, only the BAL IL-8 was higher in COPD patients when compared to asthma.

IL-1beta induces IL-8 in bronchial cells via NF-kappaB and NF-IL6 transcription factors and can be suppressed by glucocorticoids

IL-1beta may contribute to airway inflammation by inducing pro-inflammatory cytokines and chemokines from bronchial epithelial cells. In the current study, we investigated the cis-acting sites within the IL-8 promoter, and signalling pathways important in IL-8 production from BEAS2B cells following IL-1beta stimulation. IL-1beta treatment (0.1-10 ng/mL) upregulated IL-8 protein production in a dose dependent manner and IL-8 mRNA in a time dependent manner. IL-1beta induced upregulation of IL-8 promoter-reporter constructs, indicating that the mechanism of upregulation was pre-transcriptional. Using IL-8 promoter constructs with mutated cis-acting sites, it was found that both the NF-kappaB and NF-IL6 sites together were required for IL-8 promoter induction following IL-1beta treatment. Using chemical inhibitors or dominant negative mutants, we found that IL-8 promoter activity required IkappaB kinase beta, IkappaB, but not the MAP kinases p38 or c-Jun N-terminal kinase 2. Fluticasone propionate was able to suppress IL-1beta induced IL-8 protein and promoter activation, using both a -1481 bp fragment and a -133 bp fragment, indicating that the glucocorticoid response element found at -330 bp was not required for fluticasone mediated suppression of IL-8 promoter activation.

Attenuated production of intracellular IL-10 and IL-12 in monocytes from patients with severe asthma

Interleukin (IL)-10 and IL-12 production is decreased in peripheral blood mononuclear cells of patients with mild asthma. Using whole blood culture and flow cytometry we examined whether monocyte heterogeneity influenced IL-10 and IL-12 production in subjects with severe asthma. We demonstrated that IL-10 release in LPS-stimulated whole blood culture was decreased in patients with severe persistent asthma compared to those with mild asthma and controls (P = 0.04 and P < 0.001, respectively). In asthmatic patients, the percentage of CD14(+)CD16(+) cells was higher than that from normal subjects (P = 0.04). Severe asthmatics showed significantly less positive staining for IL-10 and IL-12 (P < 0.001 and P = 0.02, respectively) after stimulation in monocytes, compared to mild asthmatics and controls in both CD14(+)CD16(+) and CD14(+)CD16(minus sign) cells. These results suggest that IL-10 synthesis is attenuated in severe persistent asthma compared to mild asthma and that this cannot be explained by the increase in the CD14(+)CD16(+) monocytes in asthma.

Albuterol does not antagonize the inhibitory effect of dexamethasone on monocyte cytokine release

Beta2-adrenoceptor agonists given by the inhaled route are the most effective bronchodilators known, yet high doses of these drugs may be associated with an increase in asthma mortality and morbidity. One theory for this paradox is that chronic use of beta2-adrenoceptor agonists compromises the anti-inflammatory action of glucocorticosteroids. This hypothesis derives from the ability of albuterol and fenoterol to inhibit the interaction of the glucocorticosteroid receptor (GR) with proinflammatory transcriptional activators acting on the promoter region of certain target genes that encode cytokines such as tumor necrosis factor-alpha (TNF alpha) and granulocyte/macrophage colony-stimulating factor (GM-CSF). However, the functional relevance of these results has not been formally investigated. We have tested the hypothesis that albuterol reduces the ability of dexamethasone to inhibit the generation of TNF alpha and GM-CSF from lipopolysaccharide (LPS)-stimulated human monocytes. Pretreatment of human monocytes with albuterol (1 and 100 microM) for 5 and for 180 min inhibited maximally TNF alpha generation by approximately 25%. However, regardless of the concentration of albuterol, or the time of preincubation, the inhibitory effect of dexamethasone was not significantly affected with respect to the EC50 or the maximal effect produced. Qualitatively identical data were obtained when GM-CSF release was used as an index of monocyte activation. We conclude that high concentrations of albuterol do not compromise the ability of dexamethasone to suppress the generation of TNF alpha and GM-CSF from LPS-stimulated human monocytes.

Functional and phenotypic differences of monocyte-derived dendritic cells from allergic and nonallergic patients

BACKGROUND

Several studies suggest a role for dendritic cell in the pathogenesis of allergic disease.

OBJECTIVE

The purpose of this study was to compare function and phenotype of monocyte-derived dendritic cells (MoDC) from allergic asthmatic patients and healthy control subjects.

METHODS

MoDCs were developed by incubating adherent monocytes for 5 days with IL-4 and granulocyte-macrophage colony-stimulating factor. Phenotype was assessed with flow cytometry, and the antigen-presenting function was assessed with the allogeneic mixed leukocyte reaction and an autologous specific antigen presentation.

RESULTS

The morphology of the MoDCs was characteristic for immature dendritic cells. MoDCs from allergic asthmatic patients showed phenotypic differences in the expression of HLA-DR, CD11b, and the high-affinity receptor for IgE. A clearly enhanced accessory potential of MoDCs from atopic asthmatic patients in the mixed leukocyte reaction was also shown. Moreover, house dust mite-specific T-cell proliferation was increased.

CONCLUSION

This study suggests the involvement of dendritic cells in the pathogenesis of atopic asthma by an increased immunostimulatory capacity of MoDCs.