Effective omalizumab treatment influenced eosinophil function in severe allergic asthmatics.

Background: Omalizumab is an effective anti-immunoglobulin E (IgE) treatment for allergic asthma. Eosinophil plays a critical role in the pathogenesis of allergic airway inflammation. This study aimed to explore the influence of effective omalizumab treatment on circulating eosinophils. Methods: Allergic asthmatics enrolled in the study were treated with omalizumab for at least 16 weeks and exhibited a good or excellent response according to the global evaluation of treatment effectiveness (GETE) assessed by each patient and specialist physician. For eosinophil functional evaluation, peripheral blood eosinophils were separated; and examined the expression of human leukocyte antigen (HLA)-DR and co-stimulatory molecules cluster of differentiation (CD) 80, CD86 and CD40 by Flow Cytometry and serum were to measure the concentration of eotaxin-1 before and after 16 weeks of omalizumab treatment. Results: Totally 32 allergic asthma patients who responded positively to omalizumab treatment were included. Omalizumab responders showed a significant decline in the expression of co-stimulatory molecules CD40, CD80, and CD86 on peripheral eosinophils and in serum eotaxin-1 concentration after treatment. Negative correlations (r=-0.61, P=0.048) were observed between the change in CD80+ eosinophils and the change in forced expiratory volume in the first second (FEV1)/forced vital capacity (FVC)% predicted and maximal expiratory flow (MEF) 25% after omalizumab treatment. Omalizumab improved FEV1/FVC% predicted (3.88, P=0.033), fractional exhaled nitric oxide (FeNO, -22.24, P=0.028), asthma control test (ACT, 4.22, P<0.001), mini asthma quality of life questionnaire (mini-AQLQ, -14.44, P=0.019), Leicester cough questionnaire (LCQ, 3.03, P=0.009) and visual analogue scale (VAS) for allergic symptoms (-13.00, P=0.001) in patients with severe allergic asthma statistically; reduced mini rhino-conjunctivitis quality of life questionnaire (mini-RQLQ, -8.50, P=0.047), and self-rating anxiety scale (SAS, -5.08, P=0.040) in allergic asthmatics with concomitant allergic rhinitis (AR) or anxiety, respectively. Conclusions: Our findings show a unique role of omalizumab in reducing co-stimulatory molecules expression on eosinophil and serum eotaxin-1 levels in severe allergic asthmatics accompanied by improvement of multiple clinical parameters of allergic diseases.

PTRF-IL33-ZBP1 signaling mediating macrophage necroptosis contributes to HDM-induced airway inflammation.

Polymerase 1 and transcript release factor (PTRF, encoding by Cavin-1) regulates interleukin 33 (IL-33) release, which is implicated in asthma development. Z-DNA binding protein 1 (ZBP1)-sensing Z-RNAs induces necroptosis which causes inflammatory diseases. House dust mite (HDM) is the major source of allergen in house dust and is strongly associated with the development of asthma. Whether PTRF via IL-33 and ZBP1 mediates HDM-induced macrophage necroptosis and airway inflammation remains unclear. Here, we found that deficiency of PTRF could reduce lung IL-33, ZBP1, phosphor-receptor-interacting protein kinase 3 (p-RIPK3), and phosphor-mixed lineage kinase domain-like (p-MLKL) (necroptosis executioner), and airway inflammation in an HDM-induced asthma mouse model. In HDM-treated macrophages, ZBP1, p-RIPK3, and p-MLKL levels were markedly increased, and these changes were reversed by deletion of Cavin-1. Deletion of Il33 also reduced expression of ZBP1, p-RIPK3, and p-MLKL in HDM-challenged lungs. Moreover, IL-33 synergizing with HDM boosted expression of ZBP1, p-RIPK3, and p-MLKL in macrophages. In bronchial epithelial cells rather than macrophages and vascular endothelial cells, PTRF positively regulates IL-33 expression. Therefore, we conclude that PTRF mediates HDM-induced macrophage ZBP1/necroptosis and airway inflammation, and this effect could be boosted by bronchial epithelial cell-derived IL-33. Our findings suggest that PTRF-IL33-ZBP1 signaling pathway might be a promising target for dampening airway inflammation.

Diagnostic Efficacy of T-SPOT.TB for Active Tuberculosis in Adult: A Retrospective Study.

Purpose: To explore the diagnostic efficacy and optimal diagnosis threshold of T-SPOT.TB for active tuberculosis in adults and to evaluate the influential factors for T-SPOT.TB results. Patients and Methods: A retrospective study of 1193 adult inpatients from April 2015 to March 2018 in Ruijin Hospital was conducted. All included patients underwent T-SPOT.TB assay, and were divided into two groups, active tuberculosis (ATB) and non-active tuberculosis (non-ATB) groups. Their demographic data, underlying diseases, personal history and laboratory findings were collected to calculate the diagnostic efficacy at different diagnosis thresholds and analyze the impact factors. Symptoms and imaging features of ATB patients were recorded and analyzed. Results: A total of 114 ATB patients and 1079 non-ATB patients were included in the study, and ATB patients had a higher level of T-SPOT.TB than the non-ATB group. Sensitivity and specificity of T-SPOT.TB for diagnosing ATB are 78.95% and 68.58% as the threshold at 6sfu. In the diagnosis accordance curves, ESAT-6, CFP-10, and max (ESAT-6 or CFP-10) reached the plateau at 40sfu, while sum (ESAT-6 and CFP-10) reached the plateau at 70sfu. Multivariate logistic regression analysis showed that obsolescent tuberculosis (p=0.001), smoking history(p=0.005), diabetes(p=0.035) and advanced age (≥65 years old) (p=0.031) were risk factors for false-positive result of T-SPOT.TB. In terms of imaging features, logistic regression analysis suggested that the thin-wall cavitary lesion was the only feature associated with the result of T-SPOT.TB. Conclusion: As for using T-SPOT.TB test to diagnose active tuberculosis, increased threshold could significantly elevate the diagnosis accordance. And we suggest that the threshold of T-SPOT.TB could be increased to 40sfu for diagnosing ATB. Attention should be paid when diagnose ATB in population with obsolescent tuberculosis, smoking history, diabetes and advanced age, for the risk of false-positive.

Inhaled Corticosteroids and Mycobacterial Infection in Patients with Chronic Airway Diseases: A Systematic Review and Meta-Analysis.

BACKGROUND: Inhaled corticosteroids (ICSs) have been widely used in chronic airway diseases, such as asthma, chronic obstructive pulmonary disease (COPD), and bronchiectasis. However, whether ICS use causes mycobacterial infection is uncertain. Some conclusions of published studies were inconsistent. OBJECTIVE: We aimed to investigate the association between the use of ICSs and mycobacterial infections in patients with chronic airway diseases. METHODS: This review was registered on PROSPERO (CRD42021284607). We focused on examining the association between ICS use and mycobacterial infection (nontuberculous mycobacterial [NTM] infection as well as tuberculosis [TB]). We searched PubMed (MEDLINE), Sciencenet, Cochrane, and EMBASE databases for studies up to 2021 to retrieve articles. The enrollment conditions included gender, enrollment diagnosis and ICS use in chronic airway disease patients, and so on. Preclinical studies, review articles, editorials, reviews, conference abstracts, and book chapters were excluded. Methodologically, the study was assessed using the Newcastle Ottawa Scale, and Rev-man5 was used for statistical analysis. RESULTS: Ten studies (including 4 NTM and 6 TB articles) with 517,556 patients met the inclusion criteria and were included in this meta-analysis. From the NTM pooled analyses, ICS use was associated with increased odds of NTM infection in patients with chronic airway diseases (odds ratio [OR] = 3.93, 95% confidence interval [CI] 2.12-7.27), subgroup analysis showed that high-dose ICS use (OR = 2.27, 95% CI 2.08-2.48) and fluticasone use (OR = 2.42, 95% CI 2.23-2.63) were associated with increased odds of NTM infection risk in patients with chronic respiratory diseases. The TB pooled analyses showed a significant association between ICS use and risk of TB infection in patients with chronic respiratory diseases (OR = 2.01, 95% CI 1.23-3.29). Subgroup analysis showed that in chronic respiratory diseases, ICS use increased odds of TB infection in high-dose ICS use (OR = 1.70, 95% CI 1.56-1.86) and in COPD patients (OR = 1.45, 95% CI 1.29-1.63). CONCLUSION: Our meta-analysis indicated that ICS use may increase the odds of mycobacterial infection in chronic respiratory disease patients, and this conclusion is more applicable to patients with high dose of ICS or fluticasone in NTM infection subgroups. In addition, high-dose ICS use may have higher risk of TB infection in patients with chronic respiratory diseases, especially COPD. Therefore, we should be vigilant about the application of ICS use in chronic respiratory diseases to avoid infection.

Effect of inhaled corticosteroids on microbiome and microbial correlations in asthma over a 9-month period.

The effect of inhaled corticosteroids (ICS) on the airway microbiome requires longitudinal research for corroboration. Asthma patients, not undergoing ICS treatment (baseline), were enrolled and prescribed ICS; all these patients were followed up with regular visits at 3 months (visit 1) and 9 months (visit 2). Induced sputum was collected, and fungal microbiota (mycobiome) and bacterial microbiota (bacteriome) were estimated using 16S rRNA and internal transcribed spacer (ITS) sequencing. Bacterial α diversity indices were not significantly different between baseline, visit 1, and visit 2. Visit 1 showed lower fungal evenness than the baseline, and visit 2 showed lower fungal diversity and evenness than the baseline. Fungal, but not bacterial, community compositions differed significantly between the baseline, visit 1, and visit 2. The most abundant bacterial phyla and genera did not differ significantly between the baseline, visit 1, and visit 2. Compared with the baseline, visit 1 showed significantly increased frequency of the fungal phylum Ascomycota and lower frequency of Basidiomycota. We found sharply decreased fungal genera Wallemia, Cladosporium, Penicillium, and Alternaria at visit 1 and visit 2 compared with the baseline, although the differences were not statistically significant. We also found the proportion of Basidiomycota was positively correlated with percentages of sputum eosinophils and neutrophils. The proportions of Saccharomyces, Wallemia, and Aplosporella were positively correlated with percentage of sputum eosinophils. Moreover, we identified distinct inter- and intra-kingdom interactions in baseline, visit 1, and visit 2. Therefore, ICS use altered the airway microbial diversity, evenness, community composition, and microbial connections.

The effect of short-chain fatty acids on M2 macrophages polarization in vitro and in vivo.

Alternatively activated macrophages (M2 polarization) play an important role in asthma. Short-chain fatty acids (SCFAs) possessed immune-regulatory functions, but their effects on M2 polarization of alveolar macrophages and its underlying mechanisms are still unclear. In our study, murine alveolar macrophage MH-S cell line and human monocyte-derived macrophages were used to polarize to M2 subset with interleukin-4 (IL-4) treatment. The underlying mechanisms involved were investigated using molecule inhibitors/agonists. In vivo, female C57BL/6 mice were divided into five groups: CON group, ovalbumin (OVA) asthma group, OVA+Acetate group, OVA+Butyrate group, and OVA+Propionate group. Mice were fed with or without SCFAs (Acetate, Butyrate, Propionate) in drinking water for 20 days before developing OVA-induced asthma model. In MH-S, SCFAs inhibited IL-4-incuced protein or mRNA expressions of M2-associated genes in a dose-dependent manner. G-protein-coupled receptor 43 (GPR43) agonist 4-CMTB and histone deacetylase (HDAC) inhibitor (trichostatin A, TSA), but not GPR41 agonist AR420626 could inhibit the protein or mRNA expressions M2-associated genes. 4-CMTB, but not TSA, had no synergistic role in the inhibitory effect of SCFAs on M2 polarization. In vivo study indicated Butyrate and Propionate, but not Acetate, attenuated OVA-induced M2 polarization in the lung and airway inflammation. We also found the inhibitory effect of SCFAs on M2 polarization in human-derived macrophages. Therefore, SCFAs inhibited M2 polarization in MH-S likely through GPR43 activation and/or HDAC inhibition. Butyrate and Propionate but not Acetate could inhibit M2 polarization and airway inflammation in asthma model. SCFAs also abrogated M2 polarization in human-derived macrophages.

Diffusing capacity in chronic obstructive pulmonary disease assessment: A meta-analysis.

To achieve a multidimensional evaluation of chronic obstructive pulmonary disease (COPD) patients, the spirometry measures are supplemented by assessment of symptoms, risk of exacerbations, and CT imaging. However, the measurement of diffusing capacity of the lung for carbon monoxide (DLCO) is not included in most common used models of COPD assessment. Here, we conducted a meta-analysis to evaluate the role of DLCO in COPD assessment.The studies were identified by searching the terms "diffusing capacity" OR "diffusing capacity for carbon monoxide" or "DLCO" AND "COPD" AND "assessment" in Pubmed, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, Scopus, and Web of Science databases. The mean difference of DLCO % predict was assessed in COPD patient with different severity (according to GOLD stage and GOLD group), between COPD patients with or without with frequent exacerbation, between survivors and non-survivors, between emphysema dominant and non-emphysema dominant COPD patients, and between COPD patients with or without pulmonary hypertension.43 studies were included in the meta-analysis. DLCO % predicted was significantly lower in COPD patients with more severe airflow limitation (stage II/IV), more symptoms (group B/D), and high exacerbation risk (group C/D). Lower DLCO % predicted was also found in exacerbation patients and non-survivors. Low DLCO % predicted was related to emphysema dominant phenotype, and COPD patients with PH.The current meta-analysis suggested that DLCO % predicted might be an important measurement for COPD patients in terms of severity, exacerbation risk, mortality, emphysema domination, and presence of pulmonary hypertension. As diffusion capacity reflects pulmonary ventilation and perfusion at the same time, the predictive value of DLCO or DLCO combined with other criteria worth further exploration.

USP4 is pathogenic in allergic airway inflammation by inhibiting regulatory T cell response.

AIMS: Asthma is characterized by chronic inflammation and airway hyperresponsiveness (AHR). It is controllable, but not curable. Ubiquitin-specific peptidase 4 (USP4) has been verified as a regulator of regulatory T (Treg) cells and Th17 cells in vitro. In this study, we aim to investigate whether USP4 could serve as a therapeutic target for asthma. MAIN METHODS: Age-matched USP4 wild-type and knockout mice received an intraperitoneal injection of 100 µg ovalbumin (OVA) mixed in 2 mg aluminum hydroxide in 1 × PBS on days 0, 7 and 14. On days 21 to 27, the mice were challenged with aerosolized 1% OVA in 1 × PBS for 30 min. Tissue histology, ELISA and flow cytometry were applied 24 h after the last OVA challenge. KEY FINDINGS: USP4 deficiency protected mice from OVA-induced AHR and decreased the production of several inflammatory cytokines in T cells in vivo. Compared to the lung cells isolated from WT mice, Usp4-/- lung cells decreased secretion of IL-4, IL-13 and IL-17A upon stimulation in vitro. Meanwhile, the percentage of CD4+Foxp3+ Treg cells was elevated, with more CCR6+Foxp3+ Treg cells accumulating in the lungs of OVA-challenged USP4 deficient mice than in their wild-type counterparts. Treatment with the USP4 inhibitor, Vialinin A, reduced inflammatory cell infiltration in the lungs of OVA-challenged mice in vivo. SIGNIFICANCE: We found USP4 deficiency contributes to attenuated airway inflammation and AHR in allergen-induced murine asthma, and Vialinin A treatment alleviates asthma pathogenesis and may serve as a promising therapeutic target for asthma.

How does comorbid bronchiectasis affect asthmatic patients? A meta-analysis.

OBJECTIVE: Asthma and bronchiectasis are known to be two distinct diseases with different etiology, pathophysiology, management, and prognosis. However, a high prevalence of bronchiectasis has been reported in patients with severe asthma. Thus, it is of great importance to identify the impact of bronchiectasis on asthmatic patients. DATA SOURCES: Databases including PubMed, Embase, Cochrane, Web of Science were searched comprehensively to identify relevant human clinical studies published until February 2020. STUDY SELECTIONS: Two investigators (Gelei Lan and Guochao Shi) independently obtained the potentially eligible articles based on their titles and abstracts. When opinions differed between the investigators, discussions were made to reach an agreement. The authors of the included studies were contacted for inquiry when necessary. RESULTS: Six observational studies with 1004 patients were included in the meta-analysis. The mean prevalence of bronchiectasis in patients with asthma was 35.2% (ranging from 2.2% to 47%). Asthmatic patients with bronchiectasis were older, had a longer disease duration, exhibited greater severity, and showed more frequent exacerbations and hospitalization, and poorer lung function, compared with the patients without bronchiectasis. CONCLUSION: Despite of the heterogeneity between included studies and detectable publication bias, this meta-analysis demonstrated the impact of comorbid bronchiectasis on asthmatic patients. Thus, coexistence of bronchiectasis should be considered a clinical phenotype of asthma, which may have associations with exacerbation and hospitalization.

Indoor PM2.5, tobacco smoking and chronic lung diseases: A narrative review.

The lung is one of the most important organs exposed to environmental agents. People spend approximately 90% of their time indoors, and risks to health may thus be greater from exposure to poor air quality indoors than outdoors. Multiple indoor pollutants have been linked to chronic respiratory diseases. Environmental tobacco smoke (ETS) is known as an important source of multiple pollutants, especially in indoor environments. Indoor PM2.5 (particulate matter with aerodynamic diameter < 2.5 µm) was reported to be the most reliable marker of the presence of tobacco smoke. Recent studies have demonstrated that PM2.5 is closely correlated with chronic lung diseases. In this paper, we reviewed the relationship of tobacco smoking and indoor PM2.5 and the mechanism that underpin the link of tobacco smoke, indoor PM2.5 and chronic lung diseases.

Oscillatory positive expiratory pressure treatment in lower respiratory tract infection.

Oscillatory positive expiratory pressure (OPEP) devices have been utilized as an adjunct therapy to conventional chest physiotherapy (CPT) to promote the clearance of respiratory secretions in individuals with impaired ability to cough, particularly in chronic diseases. However, few studies have focused on the effectiveness of OPEP in lower respiratory tract infection. In the present study, all patients with lower respiratory tract infections hospitalized in the Department of Pulmonary and Critical Care Medicine, Ruijin Hospital (Shanghai, China) between February 2016 and July 2017 were analyzed. Daily sputum quantity and purulence were recorded on the first 7 days of physiotherapy. Oxygenation index, partial pressure carbon dioxide, white blood cell count, neutrophil percentage, C reactive protein (CRP) and procalcitonin (PCT) levels before and after CPT were compared between patients who received OPEP and patients who received mechanical percussion (MP). Sputum was collected prior to and following CPT. A total of 17 patients received OPEP, while 10 received MP. The OPEP group exhibited improved postural drainage compared with the MP group after 7 days of physiotherapy. After 7 days of CPT, patients who received OPEP also exhibited a significantly improved oxygenation index, while the oxygenation index in the MP group did not improve. The improvement of partial pressure carbon dioxide was not significantly different between groups. The OPEP group also exhibited a greater decrease in white blood cell count, neutrophil percentage and CRP levels, compared with the MP group. However, the decrease in PCT level was similar in the OPEP and MP groups. Sputum culture results revealed that the rate of negative conversion was very low in both groups. There was no difference between the two groups in terms of hospitalization outcomes. In conclusion, OPEP exhibited a greater effectiveness in draining sputum, improving oxygenation and reducing inflammatory status in patients with lower respiratory tract infections compared with MP; however, it did not promote the elimination of microbes.

Intratracheal administration of adipose derived mesenchymal stem cells alleviates chronic asthma in a mouse model.

BACKGROUND: Adipose-derived mesenchymal stem cell (ASCs) exerts immunomodulatory roles in asthma. However, the underlying mechanism remains unclear. The present study aimed to explore the effects and mechanisms of ASCs on chronic asthma using an ovalbumin (OVA)-sensitized asthmatic mouse model. METHODS: Murine ASCs (mASCs) were isolated from male Balb/c mice and identified by the expression of surface markers using flow cytometry. The OVA-sensitized asthmatic mouse model was established and then animals were treated with the mASCs through intratracheal delivery. The therapy effects were assessed by measuring airway responsiveness, performing immuohistochemical analysis, and examining bronchoalveolar lavage fluid (BALF). Additionally, the expression of inflammatory cytokines and lgE was detected by CHIP and ELISA, respectively. The mRNA levels of serum indices were detected using qRT-PCR. RESULTS: The mASCs grew by adherence with fibroblast-like morphology, and showed the positive expression of CD90, CD44, and CD29 as well as the negative expression of CD45 and CD34, indicating that the mASCs were successfully isolated. Administering mASCs to asthmatic model animals through intratracheal delivery reduced airway responsiveness, the number of lymphocytes (P < 0.01) and the expression of lgE (P < 0.01), IL-1ß (P < 0.05), IL-4 (P < 0.001), and IL-17F (P < 0.001), as well as increased the serum levels of IL-10 and Foxp3, and the percentage of CD4 + CD25 + Foxp3+ Tregs in the spleen, and reduced the expression of IL-17 (P < 0.05) and RORγ. CONCLUSIONS: Intratracheal administration of mASCs alleviated airway inflammation, improved airway remodeling, and relieved airway hyperresponsiveness in an OVA-sensitized asthma model, which might be associated with the restoration of Th1/Th2 cell balance by mASCs.

The Imbalance of FOXP3/GATA3 in Regulatory T Cells from the Peripheral Blood of Asthmatic Patients.

BACKGROUND: Treg cells play an important role in the pathogenic progress of asthma. OBJECTIVE: To address the alterations of Treg cells in asthma. METHODS: Proliferation-and function-associated markers of Treg cells along with the percentage of Treg cells producing some cytokine from asthmatics and healthy subjects were analyzed by flow cytometry. Besides, the expressions of USP21 and PIM2 in Treg cells were measured by cell immunochemistry after Treg cells were sorted. RESULTS: Treg cells from asthmatic patients showed lower proliferation activity and were more likely to be apoptotic. These cells expressed lower levels of GITR, CTLA-4, Nrp-1, and IL-10 compared to those from the healthy control. Th2-like Treg cells increased in asthmatic patients, while the percentage of IFN-r+ Treg cells was similar between two groups. Moreover, the percentage of IL-4+ Treg cells is related to the asthma control. Treg cells from asthmatic patients expressed more FOXP3 as well as GATA3; the expression level of GATA3 negatively correlated with FEV1%pred. Increased expressions of USP21 and PIM2 in Treg cells from asthmatic patients were found. CONCLUSION: Treg cells decreased in asthmatic patients, with an impaired immunosupression function and a Th2-like phenotype, which may be due to overexpression of GATA3 and FOXP3, regulated by USP21 and PIM2, respectively.

Dephosphorylated Polymerase I and Transcript Release Factor Prevents Allergic Asthma Exacerbations by Limiting IL-33 Release.

BACKGROUND: Asthma is a chronic inflammatory disease characterized by airway inflammation and airway hyperresponsiveness (AHR). IL-33 is considered as one of the most critical molecules in asthma pathogenesis. IL-33 is stored in nucleus and passively released during necrosis. But little is known about whether living cells can release IL-33 and how this process is regulated. OBJECTIVE: We sought to investigate the role of polymerase I and transcript release factor (PTRF) in IL-33 release and asthma pathogenesis. METHODS: Ovalbumin (OVA)-induced asthma model in PTRF+/- mice were employed to dissect the role of PTRF in vivo. Then, further in vitro experiments were carried out to unwind the potential mechanism involved. RESULTS: In OVA asthma model with challenge phase, PTRF+/- mice showed a greater airway hyper-reaction, with an intense airway inflammation and more eosinophils in bronchoalveolar lavage fluid (BALF). Consistently, more acute type 2 immune response in lung and a higher IL-33 level in BALF were found in PTRF+/- mice. In OVA asthma model without challenge phase, airway inflammation and local type 2 immune responses were comparable between control mice and PTRF+/- mice. Knockdown of PTRF in 16HBE led to a significantly increased level of IL-33 in cell culture supernatants in response to LPS or HDM. Immunoprecipitation assay clarified Y158 as the major phosphorylation site of PTRF, which was also critical for the interaction of IL-33 and PTRF. Overexpression of dephosphorylated mutant Y158F of PTRF sequestered IL-33 in nucleus together with PTRF and limited IL-33 extracellular secretion. CONCLUSION: Partial loss of PTRF led to a greater AHR and potent type 2 immune responses during challenge phase of asthma model, without influencing the sensitization phase. PTRF phosphorylation status determined subcellular location of PTRF and, therefore, regulated IL-33 release.

Critical roles of adenosine A2A receptor in regulating the balance of Treg/Th17 cells in allergic asthma.

INTRODUCTION: Deficiency of Treg cells and hyperactivity of Th17 cells together are involved in the immunological pathogenesis of asthma. The adenosine A2A receptor (A2AR) plays a critical role in the increased Foxp3 expression of Treg cells and the decreased Th17 generation. OBJECTIVE: The study aimed to investigate A2AR expression in peripheral blood and its regulatory effect on balance of Treg/Th17 cells in asthma. METHODS: Thirty-one patients with chronic persistent asthma were recruited and divided into 18 intermittent to mild asthma patients, 13 moderate to severe asthma patients. A2AR, Foxp3, and ROR-γt mRNA expression levels in peripheral blood mononuclear cells (PBMCs) were measured by quantitative polymerase chain reaction (qPCR). TGF-ß, IL-17, and IgE in plasma were detected with enzyme-linked immunosorbent assay (ELISA). Forty-two BALB/c mice were randomly, equally assigned to control group, ovalbumin (OVA) group and OVA + CGS (CGS21680, A2AR agonist) group. The infiltration of lung inflammation cells were evaluated by HE, A2AR, Foxp3, and ROR-γt mRNA in lung tissues measured by qPCR, TGF-ß, IL-17, and IgE in plasma measured with ELISA, and IL-17 and TGF-ß protein in lung tissues analyzed with immunohistochemical. RESULTS: Our results showed that expression A2AR mRNA in PBMCs was associated with asthma severity. Foxp3 mRNA, TGF-ß, and FEV1%pred positively correlated with A2AR mRNA in asthma. ROR-γt mRNA and IL-17 negatively correlated with A2AR mRNA in asthma. CGS could promote Foxp3 mRNA expression, TGF-ß, and improve lung function while inhibit ROR-γt mRNA expression, IL-17, and the infiltration of lung inflammation cells. CONCLUSION: A2AR could regulate the balance of Treg/Th17 cells in asthma.

Role of PIM2 in allergic asthma.

T cell­associated inflammation, particularly type 2 inflammation, has an important role in asthma pathogenesis, which is suppressed by regulatory T cells (Tregs). Proviral integration site for Moloney murine leukemia virus 2 (PIM2), a member off the serine/threonine kinase family, promotes the growth and survival of T cells and influences the function of Treg cells. However, whether PIM2 affects asthma pathogenesis remains unclear. Peripheral blood mononuclear cells and Treg cells from asthmatic and healthy subjects were obtained, and the expression level of PIM2 was measured by reverse transcription­quantitative polymerase chain reaction and immunocytochemistry. In addition, BALB/c female mice sensitized and challenged by ovalbumin were used as an asthma model, and PIM2 inhibitor was injected during the challenge period to observe the effect of PIM2 on asthma. The asthma symptoms were recorded, and airway hyper­responsiveness (AHR), expression levels of cytokines in the serum or bronchoalveolar lavage fluid (BALF), and the number of BALF leukocytes were evaluated. In addition, hematoxylin and eosin staining and immunohistochemistry of lung tissues was performed. The results demonstrated that PIM2 was overexpressed in patients with asthma in natural Treg cells. Inhibition of PIM2 attenuated asthma symptoms, and improved AHR and airway inflammation compared with asthmatic mice without inhibition of PIM2. In addition, expression levels of interleukin (IL)­10 and forkhead box protein 3 (FOXP3) in BALF were increased following PIM2 inhibition (IL­10, 470.3±21.78 vs. 533.7±25.55 pg/ml, P<0.05; FOXP3, 259±4.68 vs. 279.3±3.68 pg/ml; asthma and PIM2 inhibition groups, respectively; P<0.05). In conclusion, PIM2 may exhibit an important role in asthma pathogenesis and exacerbate AHR, airway inflammation and asthma symptoms. These effects of PIM2 may be dependent on Treg cells and the secretion of IL­10 by Tregs. The results of the present study suggest that PIM2 may be a potential target molecule for asthma treatment.

Inhaled corticosteroids improve lung function, airway hyper-responsiveness and airway inflammation but not symptom control in patients with mild intermittent asthma: A meta-analysis.

It remains controversial whether inhaled corticosteroid (ICS) should be used in patients with intermittent asthma. The present study aimed to assess the effect of ICS compared with placebo or other therapies in patients with intermittent asthma. Medline, Embase and CNKI databases were searched up to June 2016 and a meta-analysis was conducted. The findings demonstrated that in adult patients, when compared with placebo, ICS increased forced expiratory volume in 1 sec FEV1 [standardized mean difference (SMD), 0.51; 95% confidence interval (CI), 0.22-0.80] and alleviated airway hyper-responsiveness, which was indicated as log transformed PC20FEV1 (concentrations of methacholine when there was a fall in FEV1 ≥20%; SMD, 0.87; 95% CI, 0.60 to 1.14). ICS also reduced fractional exhaled nitric oxide (FeNO) levels [weighted mean difference (WMD), -12.57 parts per billion (ppb; a unit of NO concentration in exhaled air); 95% CI -15.88 to -9.25 ppb]. However, symptom scores did not change after ICS treatment (SMD, -0.26; 95% CI, -0.52 to 0). When compared with leukotriene receptor antagonists (LTRA), ICS had no advantage in increasing FEV1 (WMD, 0.04 l; 95% CI, -0.06 to 0.13 l), reducing sputum eosinophil percentage (WMD, -6%; 95% CI, -12.38 to 0.38%) or symptom scores (SMD, 0.44; 95% CI, -0.02 to 0.9). However, in child patients, ICS significantly (P<0.05) increased the possibility of symptom control when compared with placebo [relative risk (RR), 8; 95% CI, 1.04 to 61.52] or LTRA (RR, 2.67; 95% CI, 0.39 to 18.42). In conclusion, ICS improves lung function and alleviates airway hyper-responsiveness and airway inflammation but cannot influence symptom scores, and has no advantage over LTRA in terms of lung function improvement and airway inflammation control in adult patients with mild intermittent asthma. However, in children, the benefit of ICS in symptom control is more significant than with LTRA.

USP21 prevents the generation of T-helper-1-like Treg cells.

FOXP3+ Regulatory T (Treg) cells play a key role in the maintenance of immune homeostasis and tolerance. Disruption of Foxp3 expression results in the generation of instable Treg cells and acquisition of effector T-cell-like function. Here we report that the E3 deubiquitinase USP21 prevents the depletion of FOXP3 at the protein level and restricts the generation of T-helper-1-like Treg cells. Mice depleted of Usp21 specifically in Treg cells display immune disorders characterized by spontaneous T-cell activation and excessive T-helper type 1 (Th1) skewing of Treg cells into Th1-like Treg cells. USP21 stabilizes FOXP3 protein by mediating its deubiquitination and maintains the expression of Treg signature genes. Our results demonstrate how USP21 prevents FOXP3 protein depletion and controls Treg lineage stability in vivo.