Machine learning reveals sex differences in clinical features of acute exacerbation of chronic obstructive pulmonary disease: A multicenter cross-sectional study.

Introduction: Intrinsically, chronic obstructive pulmonary disease (COPD) is a highly heterogonous disease. Several sex differences in COPD, such as risk factors and prevalence, were identified. However, sex differences in clinical features of acute exacerbation chronic obstructive pulmonary disease (AECOPD) were not well explored. Machine learning showed a promising role in medical practice, including diagnosis prediction and classification. Then, sex differences in clinical manifestations of AECOPD were explored by machine learning approaches in this study. Methods: In this cross-sectional study, 278 male patients and 81 female patients hospitalized with AECOPD were included. Baseline characteristics, clinical symptoms, and laboratory parameters were analyzed. The K-prototype algorithm was used to explore the degree of sex differences. Binary logistic regression, random forest, and XGBoost models were performed to identify sex-associated clinical manifestations in AECOPD. Nomogram and its associated curves were established to visualize and validate binary logistic regression. Results: The predictive accuracy of sex was 83.930% using the k-prototype algorithm. Binary logistic regression revealed that eight variables were independently associated with sex in AECOPD, which was visualized by using a nomogram. The AUC of the ROC curve was 0.945. The DCA curve showed that the nomogram had more clinical benefits, with thresholds from 0.02 to 0.99. The top 15 sex-associated important variables were identified by random forest and XGBoost, respectively. Subsequently, seven clinical features, including smoking, biomass fuel exposure, GOLD stages, PaO2, serum potassium, serum calcium, and blood urea nitrogen (BUN), were concurrently identified by three models. However, CAD was not identified by machine learning models. Conclusions: Overall, our results support that the clinical features differ markedly by sex in AECOPD. Male patients presented worse lung function and oxygenation, less biomass fuel exposure, more smoking, renal dysfunction, and hyperkalemia than female patients with AECOPD. Furthermore, our results also suggest that machine learning is a promising and powerful tool in clinical decision-making.

Prognostic value of circulating tumor DNA using target next-generation sequencing in extensive-stage small-cell lung cancer.

BACKGROUND: Chemotherapy remains the mainstay of treatment for small-cell lung cancer (SCLC). Liquid biopsies provide a convenient and non-invasive detection method for monitoring disease progression in patients with SCLC. METHODS: We performed next-generation sequencing of 159 plasma samples from 69 patients with extensive-stage (ES)-SCLC. Circulating tumor (ct)DNA levels were quantified in haploid genome equivalents per mL (hGE/mL). MuTect2 was used to detect single nucleotide variants and short insertions/deletions. The "enrichKEGG" function in the "clusterProfiler" R package was used to enrich the mutated genes that only appeared during disease progression. RESULTS: In our cohort, 66 of 69 (95.7%) plasma samples at the time of diagnosis had detectable somatic mutations; TP53 (89%) and RB1(56%) were the most frequent mutations, as well as copy number variations in some common SCLC-related genes such as RB1. Combination ctDNA and tissue testing improved the overall detection rate of actionable mutations from 19.4% to 26.9% compared with that of tissue detection alone. In addition, ctDNA levels changed dynamically during the course of treatment and were significantly associated with decreased progression-free survival. Notably, actionable mutations were detected at the time of diagnosis and during disease progression. CONCLUSIONS: Our study revealed a dynamic somatic mutation profile through continuous ctDNA detection and confirmed that ctDNA levels can reflect tumor burden and predict PFS in patients with extensive stage-SCLC. Furthermore, we demonstrated that plasma ctDNA assays can provide real-time information on somatic mutations for potential targeted therapies for SCLC.

Risk Factors for Length of Hospital Stay in Acute Exacerbation Chronic Obstructive Pulmonary Disease: A Multicenter Cross-Sectional Study.

Background/Purpose: A patient's length of hospital stay (LHS) is associated with the severity and outcome of acute exacerbation of chronic obstructive pulmonary disease (AECOPD). Therefore, identification of patients with prolonged LHS at an early stage can potentially reduce the risk of adverse events and treatment costs in patients with AECOPD. Therefore, this study aimed to explore the independent predictors of prolonged LHS in AECOPD patients. Patients and Methods: This multicenter cross-sectional study was conducted at two tertiary hospitals between January 2019 and August 2020. Demographic data, underlying diseases, symptoms, and laboratory findings were collected. Univariate analysis was used to identify variables with significant differences. A collinearity diagnostic was applied to the selected variables before the establishment of the regression model. Ordinal logistic regression was performed to explore the independent risk factors for prolonged LHS in patients with AECOPD. Results: In total, 598 patients with AECOPD were screened. Finally, the LHS of 111, 218, and 100 patients was <7, 7-10, and ≥11 days, respectively. Significant differences in the 12 variables were found in the univariate analysis. Because collinearities among white blood cells (WBC), neutrophils (NS), and NS% were observed, WBC and NS% were excluded. Subsequently, an ordinal logistic regression model identified that rates of hypertension and chronic cor pulmonale (CCP), neutrophil-lymphocyte ratio (NLR), and erythrocyte sedimentation rate (ESR) were independent predictors of prolonged LHS in AECOPD patients. Conclusion: Collectively, our results showed that inflammatory status, hypertension, and CCP were independently associated with LHS in patients with AECOPD. These data indicate that early and appropriate administration of antibiotics and anti-inflammatory drugs is essential for reducing LHS. Hypertension and CCP were independent predictors of worse outcomes in patients with AECOPD. Therefore, advanced management and care should be provided to AECOPD patients with hypertension and/or CCP on admission.

ZFHX3 mutation as a protective biomarker for immune checkpoint blockade in non-small cell lung cancer.

To date, immunotherapy has opened a new chapter in the treatment of lung cancer. Precise biomarkers can help to screen subpopulations of lung cancer to provide the best treatment. Multiple studies suggest that specific gene mutations may be predictive markers in guiding non-small cell lung cancer (NSCLC) immune checkpoint inhibitor (ICI) treatment. A published immunotherapy cohort with mutational and survival data for 350 NSCLC patients was used. First, the mutational data of the immunotherapy cohort were used to identify gene mutations related to the prognosis of ICI therapy. The immunotherapy cohort and TCGA-NSCLC cohort were further studied to elucidate the relationships between specific gene mutations and tumor immunogenicity, antitumor immune response capabilities, and immune cell and mutation counts in the DNA damage response (DDR) pathway. In the immunotherapy cohort (N = 350), ZFHX3 mutations were an independent predictive biomarker for NSCLC patients receiving ICI treatment. Significant differences were observed between ZFHX3-mutant (ZFHX3-MT) and ZFHX3-wild type (ZFHX3-WT) patients regarding the overall survival (OS) time (P < 0.001, HR = 0.26, 95% Cl 0.17-0.41). ZFHX3-MT is significantly associated with higher tumor mutation burden (TMB) and neoantigen load (NAL), and ZFHX3-MT positively correlates with known immunotherapy response biomarkers, including T-cell infiltration, immune-related gene expression, and mutation counts in the DDR pathway in NSCLC. ZFHX3-MT is closely related to longer OS in NSCLC patients treated with ICIs, suggesting that ZFHX3 mutations be used as a novel predictive marker in guiding NSCLC ICI treatment.

Clinical Differences between Eosinophilic and Noneosinophilic Acute Exacerbation of Chronic Obstructive Pulmonary Disease: A Multicenter Cross-Sectional Study.

METHODS: A total of 643 AECOPD patients were enrolled in this multicenter cross-sectional study. Finally, 455 were included, 214 in the normal-eosinophil AECOPD (NEOS-AECOPD) group, 63 in the mild increased-eosinophil AECOPD (MEOS-AECOPD) group, and 138 in the severe increased-eosinophil AECOPD (SEOS-AECOPD) group. Demographic data, underlying diseases, symptoms, and laboratory findings were collected. Multiple logistic regression analysis was performed to identify the independent factors associated with blood eosinophils (EOS). Correlations between blood EOS and its associated independent factors were evaluated. RESULTS: The significant differences in 19 factors, including underlying diseases, clinical symptoms, and laboratory parameters, were identified by univariate analysis. Subsequently, multiple logistic regression analysis revealed that lymphocyte%, neutrophil% (NS%), procalcitonin (PCT), and anion gap (AG) were independently associated with blood EOS in AECOPD. Both blood EOS counts and EOS% were significantly correlated with lymphocyte%, NS%, PCT, and AG. CONCLUSIONS: Collectively, blood EOS was independently associated with lymphocyte%, NS%, PCT, and AG in AECOPD patients. Lymphocyte% was lower, and NS%, PCT, and AG were higher in eosinophilic AECOPD. Our results indicate that viral-dominant infections are the probable major etiologies of eosinophilic AECOPD. Noneosinophilic AECOPD is more likely associated with bacterial-dominant infections. The systemic inflammation in noneosinophilic AECOPD was more severe.

Monocyte chemotactic protein-inducing protein 1 negatively regulating asthmatic airway inflammation and mucus hypersecretion involving γ-aminobutyric acid type A receptor signaling pathway in vivo and in vitro.

BACKGROUND: Mounting evidence, consistent with our previous study, showed that γ-aminobutyric acid type A receptor (GABAAR) played an indispensable role in airway inflammation and mucus hypersecretion in asthma. Monocyte chemotactic protein-inducing protein 1 (MCPIP1) was a key negative regulator of inflammation. Recent studies showed that inflammation was largely suppressed by enhanced MCPIP1 expression in many inflammatory diseases. However, the role and potential mechanism of MCPIP1 in airway inflammation and mucus hypersecretion in asthma were still not well studied. This study was to explore the role of MCPIP1 in asthmatic airway inflammation and mucus hypersecretion in both mice and BEAS-2B cells, and its potential mechanism. METHODS: In vivo, mice were sensitized and challenged by ovalbumin (OVA) to induce asthma. Airway inflammation and mucus secretion were analyzed. In vitro, BEAS-2B cells were chosen. Interleukin (IL)-13 was used to stimulate inflammation and mucus hypersecretion in cells. MCPIP1 Lentiviral vector (LA-MCPIP1) and plasmid-MCPIP1 were used to up-regulate MCPIP1 in lung and cells, respectively. MCP-1, thymic stromal lymphopoietin (TSLP), mucin 5AC (MUC5AC), MCPIP1, and GABAARß2 expressions were measured in both lung and BEAS-2B cells. Immunofluorescence staining was performed to observe the expression of GABAARß2 in cells. RESULTS: MCPIP1 was up-regulated by LA-MCPIP1 (P < 0.001) and plasmid-MCPIP1 (P < 0.001) in lung and cells, respectively. OVA-induced airway inflammation and mucus hypersecretion, OVA-enhanced MCP-1, TSLP, MUC5AC, and GABAARß2 expressions, and OVA-reduced MCPIP1 were significantly blunted by LA-MCPIP1 in mice (all P < 0.001). IL-13-enhanced MCP-1, TSLP, MUC5AC, and GABAARß2 expressions, and IL-13-reduced MCPIP1 were markedly abrogated by plasmid-MCPIP1 in BEAS-2B cells (all P < 0.001). CONCLUSION: The results of this study suggested that OVA and IL-13-induced airway inflammation and mucus hypersecretion were negatively regulated by MCPIP1 in both lung and BEAS-2B cells, involving GABAAR signaling pathway.

Pulmonary Cryptococcosis: comparison of Cryptococcal antigen detection and radiography in Immunocompetent and Immunocompromised patients.

BACKGROUND: We compared the cryptococcal antigen detection and imaging findings between immunocompetent and immunocompromised patients in whom pulmonary cryptococcosis had been diagnosed. The aim of our study was to determine whether the patient's immune status and radiography affect the detection of cryptococcal antigen. METHODS: According to whether they took immunosuppressive drugs or not, seventy and eight adult patients with pulmonary cryptococcosis were divided into two groups: the immunocompetent group and the immunocompromised group. According to the detection of CrAg, each group was divided into the CrAg+ group and the CrAg- group. Then, clinical records, laboratory examinations and computed tomography findings were collected and analyzed. RESULTS: No difference was found in baseline characteristics, clinical symptoms, and laboratory investigations. By comparing CrAg detection in these two groups, it was found that the number of CrAg+ cases in the immunocompetent group was more than that in the immunocompromised group. And in the immunocompetent group, diffuse lesions were more common in CrAg+ group and limited lesions were more frequently observed in CrAg- group. CONCLUSIONS: The patient's immune status and radiography would affect the detection of cryptococcal antigen. And serum CrAg could be a useful tool for the diagnosis of pulmonary cryptococcosis in immunocompetent patients with extensive lung involvement.

[Efficacy and safety of early physical therapy for acute gastrointestinal injury during mechanical ventilation in patients with sepsis: a randomized controlled pilot trial].

OBJECTIVE: To investigate the therapeutic effect and safety of early physical therapy for acute gastrointestinal injury (AGI) in septic patients receiving mechanical ventilation. METHODS: A randomized controlled trial was conducted in the ICU of a tertiary teaching hospital from May, 2017 to March, 2018. The patients diagnosed with sepsis complicated by AGI during mechanical ventilation were recruited and block-randomized into intervention group and control group. Both groups received standard therapy of sepsis, and the patients in the intervention group also received physical therapy as soon as they were hemodynamically stable. The outcome measures included the recovery of AGI, ICU mortality, duration and outcomes of mechanical ventilation and the length of ICU stay. RESULTS: A total of 60 patients were initially included, and 34 of them completed the study, including 16 in the intervention group and 18 in the control group. After physical rehabilitation, the number of patients with a cure of AGI did not significantly differ between the two group (P > 0.05). Nonetheless, the reduction of AGI scores after the treatments differed significantly between the intervention group and the control group (-1.9±2.1 vs 0.9± 1.6, P < 0.05). No significant differences were found between the two groups in ICU mortality, duration and outcomes of mechanical ventilation, or the length of ICU stay (P > 0.05). In the intervention group, the incidence of exercise-related adverse events was 3.33%, and severe organ injury or death occurred in none of patients. CONCLUSIONS: Early rehabilitation therapy does not reduce the incidence of AGI but can lower AGI scores and alleviate gastrointestinal symptoms in patients with sepsis during mechanical ventilation. The results still await further verification by welldesigned multicenter clinical trials with large sample sizes.

Study on the Mechanism of Curcumin Regulating Lung Injury Induced by Outdoor Fine Particulate Matter (PM2.5).

BACKGROUND: Epidemiological studies have shown that exposure to PM induces oxidative stress, leading to a variety of health problems. In particular, PM2.5 contains a lot of substances harmful to the human body and penetrates into the lungs to induce lung injury. At the same time, there is increasing evidence that oxidative stress also affects the severity of lung injury. However, there is still no good way to reduce or eliminate these hazards. In the future, more experimental research is needed to further confirm the mechanisms of these hazards and formulate effective preventive measures and treatment plans for their hazard mechanisms. Curcumin has been reported to reduce oxidative stress and inflammatory damage and protect organs. OBJECTIVE: To investigate whether curcumin can play a protective role against PM2.5-induced oxidative stress and inflammatory damage by inducing expression of the HO-1/CO/P38 MAPK pathway. METHODS: In this experiment, PM2.5 was dropped into the trachea to establish a lung injury model in mice. 28 SPF-grade male Kunming mice were randomly divided into 4 groups: normal control group, saline control group, PM2.5 treatment group, and curcumin intervention group. Albumin (ALB), lactate dehydrogenase (LDH), and alkaline phosphatase (ALP) were measured in alveolar lavage fluid (BALF) to assess lung tissue damage. Colorimetric detection of oxidative stress indicators such as MDA, GSH-PX, T-AOC, and CAT in the lung tissue was performed. The levels of IL-6 and TNF-α in the lung tissue were determined by ELISA. Histopathological examination was used for the assessment of alveolar epithelial damage. The protein expression of the HO-1/P38 MAPK pathway in the lung tissue was determined by Western blot and immunohistochemistry. Endogenous CO was detected by spectrophotometry. The results showed that the expression of the HO-1/CO/P38 MAPK protein in the lung tissue was significantly increased in the curcumin intervention group compared with the PM2.5 treatment group, and it was statistically significant (P < 0.05). Compared with the PM2.5 treatment group, the curcumin intervention group can reduce the amount of ALB, LDH, and ALP in BALF; reduce the levels of MDA, IL-1, and TNF-α in the lung tissue; and improve GSH-PX, T-AOC, and CAT levels, but there is no statistical difference (P > 0.05). CONCLUSION: We found that PM2.5 can cause lung damage through oxidative stress and inflammatory responses. Oxidative stress and inflammatory responses increase the expression of HO-1/CO/P38 MAPK. The intervention of curcumin can further increase the expression of HO-1/CO/P38 MAPK.

Curcumin Attenuates Asthmatic Airway Inflammation and Mucus Hypersecretion Involving a PPARγ-Dependent NF-κB Signaling Pathway In Vivo and In Vitro.

Asthma is characterized by airway inflammation and mucus hypersecretion. Curcumin possessed a potent anti-inflammatory property involved in the PPARγ-dependent NF-κB signaling pathway. Then, the aim of the current study was to explore the value of curcumin in asthmatic airway inflammation and mucus secretion and its underlying mechanism. In vivo, mice were sensitized and challenged by ovalbumin (OVA) to induce chronic asthma. Airway inflammation and mucus secretion were analyzed. In vitro, BEAS-2B cells were obtained. MCP-1, MUC5AC, and PPARγ expression and the phosphorylation of NF-κB p65 and NF-κB p65 DNA-binding activity were measured in both the lungs and BEAS-2B cells. shRNA-PPARγ was used to knock down PPARγ expression. We found that OVA-induced airway inflammation and mucus hypersecretion in mice, OVA and IL-4-induced upregulation of MCP-1 and MUC5AC, suppression of PPARγ, and activation and translocation of NF-κB p65 were notably improved by curcumin both in vivo and in vitro. Our data also showed that these effects of curcumin were significantly abrogated by shRNA-PPARγ. Taken together, our results indicate that curcumin attenuated OVA-induced airway inflammation and mucus hypersecretion in mice and suppressed OVA- and IL-4-induced upregulation of MCP-1 and MUC5AC both in vivo and in vitro, most likely through a PPARγ-dependent NF-κB signaling pathway.

[Curcumin suppresses cigarette smoke extract-induced oxidative stress through PPARγ/ NF-κB pathway in human bronchial epithelial cells in vitro].

OBJECTIVE: To investigate the effect of curcumin against cigarette smoke extract (CSE)- induced oxidative stress in human bronchial epithelial cells and explore the underlying mechanism. METHODS: Human bronchial epithelial cell line 16HBE was treated for 24 h with curcumin, CSE, CSE + curcumin, and CSE + curcumin with transfection by a short hairpin RNA targeting PPARγ (shPPARγ). MTT assay was used to observe the changes in the cell viability after the treatments. Quantitative real-time PCR was performed to detect the mRNA expressions of tumor necrosis factor-α (TNF-α), iNOS and PPARγ in the cells, and the protein expressions of iNOS, PPARγ and the phosphorylation of NF-κB p65 were detected using Western blotting. RESULTS: The treatments did not cause significant changes in the cell viability. Exposure to CSE for 24 h significantly lowered PPARγ expression and increased TNF-α and iNOS expressions and phosphorylation of NF-κB p65 in the cells. The effects of CSE were significantly suppressed by curcumin, but transfection of the cells with shRNA-PPARγ obviously abrogated the suppressive effects of curcumin. CONCLUSIONS: Curcumin suppresses CSE-induced oxidative stress and inflammation via the PPARγ/NF-κB signaling pathway in 16HBE cells, suggesting the potential of curcumin in the treatment of chronic obstructive pulmonary disease.

Extent of Lung Involvement and Serum Cryptococcal Antigen Test in Non-Human Immunodeficiency Virus Adult Patients with Pulmonary Cryptococcosis.

BACKGROUND: Serum cryptococcal antigen (CrAg) test is the most used noninvasive method to detect cryptococcal infection. However, false-negative CrAg test is not uncommon in clinical practice. Then, the aim of this study was to investigate the factors associated with false-negative CrAg test among non-human immunodeficiency virus (HIV) adult patients with pulmonary cryptococcosis and its clinical features. METHODS: One hundred and fourteen non-HIV adult patients with pulmonary cryptococcosis, proven by biopsy, were retrospectively reviewed. Finally, 85 patients were enrolled; 56 were CrAg positive (CrAg+ group) and 29 were negative (CrAg- group). It was a cross-sectional study. Then, baseline characteristics, underlying diseases, clinical symptoms, laboratory findings, and chest radiological findings were reviewed and analyzed. Chi-square test was used to analyze categorical variable. Odds ratio (OR) was used to measure correlation. Student's t- test was obtained to analyze continuous variable. RESULTS: No difference in baseline characteristics, underlying diseases, clinical symptoms, and laboratory findings were found between two groups (P > 0.05 in all). Nevertheless, diffuse extent lesion was 82.1% in CrAg+ group and 10.3% in CrAg- group (χ2 = 40.34, P < 0.001; OR = 39.87). CONCLUSIONS: Among patients with limited pulmonary involvement, a negative serum CrAg does not preclude the diagnosis of pulmonary cryptococcosis. However, among patients with extensive pulmonary involvement, serum CrAg is a useful diagnostic tool for pulmonary cryptococcosis. Furthermore, we also noticed that the untypical and mild presentations with extensive pulmonary lesion might be the features of pulmonary cryptococcosis, which needs further investigation.

GLP-1 Analogue Liraglutide Enhances SP-A Expression in LPS-Induced Acute Lung Injury through the TTF-1 Signaling Pathway.

The reduction of pulmonary surfactant (PS) is essential for decreased pulmonary compliance and edema in acute lung injury (ALI). Thyroid transcription factor-1 (TTF-1) plays a major role in the regulation of surfactant protein-A (SP-A), the most abundant protein component of PS. Simultaneously, the glucagon-like peptide-1 (GLP-1) analogue can enhance SP-A expression in the lung. However, the underlying mechanism is still unknown. The purpose of this study was to explore whether liraglutide, a GLP-1 analogue, upregulates SP-A expression through the TTF-1 signaling pathway in ALI. In vivo, a murine model of ALI was induced by lipopolysaccharide (LPS). Pulmonary inflammation, edema, insulin level, ultrastructural changes in type II alveolar epithelial (ATII) cells, and SP-A and TTF-1 expression were analyzed. In vitro, rat ATII cells were obtained. SP-A and TTF-1 expression in cells was measured. ShRNA-TTF-1 transfection was performed to knock down TTF-1 expression. Our data showed that LPS-induced lung injury and increase in insulin level, and LPS-induced reduction of SP-A and TTF-1 expression in both the lung and cells, were significantly compromised by liraglutide. Furthermore, we also found that these effects of liraglutide were markedly blunted by shRNA-TTF-1. Taken together, our findings suggest that liraglutide enhances SP-A expression in ATII cells and attenuates pulmonary inflammation in LPS-induced ALI, most likely through the TTF-1 signaling pathway.

Transforming growth factor-ß1 rs1800470 polymorphism is associated with lung cancer risk: a meta-analysis.

BACKGROUND: Transforming growth factor-ß1 is a member of a large class of polypeptides that regulate the proliferation, differentiation, and carcinogenesis of epithelial cells. The rs1800470 polymorphism influences transforming growth factor-ß1 expression and has been associated with lung cancer susceptibility. However, the association between the rs1800470 polymorphism and lung cancer risk remains controversial. Thus, a meta-analysis was conducted. MATERIAL/METHODS: We comprehensively searched PubMed and EMBASE databases. Summary odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were estimated using random-effects models or fixed-effects models. RESULTS: Overall, there was a significant association between rs1800470 polymorphism and lung cancer susceptibility (OR=1.23; 95%CI, 1.03-1.47; P=0.02). In the stratified analysis by ethnicity, we found that this polymorphism was significantly associated with lung cancer in Asians (OR=1.26; 95%CI, 1.01-1.57; P=0.04). However, we did not find any significant association between this polymorphism and lung cancer risk in Caucasians (OR=1.04; 95%CI, 0.60-1.82; P=0.88). In the NSCLC subgroup, we found that rs1800470 polymorphism could increase NSCLC risk (OR=1.36; 95%CI, 1.06-1.74; P=0.02). CONCLUSIONS: This meta-analysis suggested that rs1800470 polymorphism was a risk factor of lung cancer.

[Inhibition of lipopolysaccharide-induced myeloid-derived suppressor cells in the proliferation of spleen T lymphocytes].

OBJECTIVE: To explore the effects of lipopolysaccharide (LPS)-induced myeloid-derived suppressor cells (MDSCs) on the proliferation of spleen T lymphocytes. METHODS: BALB/c mice were randomly divided into two groups: LPS group and normal control group. They were injected intraperitoneally with LPS and normal saline solution respectively. MDSCs were separated with CD11b immunomagnetic beads from the spleen extract of mice. The morphological characteristics of MDCSs were observed by Wright-Giemsa staining and the characteristic molecules on cell surface identified by flow cytometry. And the effects of MDSCs on the in vitro proliferation of T cells were determined by methyl-thiazolyl-tetrazolium bromide (MTT). RESULTS: The proportion of MDSCs in the spleen of the LPS group was much more than that of the normal control group (27.4% ± 6.6% vs 5.1% ± 3.8%; t = 5.06, P = 0.007). CD11b(+)Gr-1(+)MDSCs could be separated by CD11b immunomagnetic beads from the spleen of mice injected with LPS at a high purity of 84.0% ± 4.2%. MTT method showed that the proliferation of T cells decreased significantly after a co-cultivation with CD11b(+)MDSCs versus the control group. And it was positively correlated with the number of MDSCs (F = 46.26, P = 0.000). CONCLUSIONS: A high purity of LPS-induced myeloid-derived suppressor cells may be separated with CD11b immunomagnetic beads. And it has dose-dependent inhibitory effects on the proliferation of the spleen T lymphocytes.

[Effect and mechanism of lipopolysaccharides-induced myeloid-derived suppressor cells on airway inflammation in asthmatic mice].

OBJECTIVE: To explore the effect and mechanism of lipopolysaccharides (LPS)-induced CD11b⁺Gr-1⁺ myeloid-derived suppressor cells (MDSCs) on airway inflammation in asthmatic mice. METHODS: A total of 34 female BALB/c mice were selected. Among them, 4 mice received an intraperitoneal injection of LPS for inducing the accumulation of MDSCs. And the MDSCs were separated with CD11b immunomagnetic beads from spleen extract. Another 30 mice were randomly divided into normal control, asthmatic and cell treatment groups. The mice in the asthmatic and cell treatment groups were sensitized with ovalbumin by a combination of intraperitoneal injection and challenges to establish the murine asthmatic model. At Days 14 and 21 post-sensitization, the mice in cell treatment group received an intravenous injection of LPS-induced MDSCs. At 24 hours after the last allergen challenge, the number of inflammatory cells were counted and morphological identification of leucocytes in bronchoalveolar lavage fluid (BALF) was performed to analyze the degree of airway inflammation in conjunctions with pathological sections. The BALF and serum levels of interleukin-13 were measured by enzyme-linked immunosorbent assay (ELISA). The number of CD4⁺CD25⁺Foxp3⁺ regulatory T cells (Tregs) in peripheral blood was measured by flow cytometry. RESULTS: The total number of cells, the percentage of neutrophils and eosinophils of BALF in the cell treatment group [(17.0 ± 8.3)×104/ml, 11.1% ± 2.0%, 9.8% ± 2.9%] were significantly lower than those in the asthmatic group [(36.0 ± 15.9)×104/ml, 20.8% ± 4.0%, 14.1% ± 4.2%] (P = 0.000, 0.000, 0.011). Compared to the asthmatic group, the BALF and serum levels of IL-13 were significantly lower [(34.7 ± 7.1) vs (105.0 ± 9.0) ng/L, (34.0 ± 4.7) vs (48.1 ± 6.1) ng/L] (both P = 0.000) and the number of CD4⁺CD25⁺Foxp3⁺ regulatory T cells increased in peripheral blood (8.0% ± 1.3% vs 5.1% ± 2.1%, P = 0.002) and airway inflammation was significantly relieved in the cell treatment group. CONCLUSION: LPS-induced MDSCs may improve airway inflammation through up-regulating Tregs in peripheral blood and suppressing Th2 effector function in asthmatic mice.

[Pathogenic mechanism of CD8(+)CD28(-)T cell and the effect of dexamethasone in asthmatic mouse].

OBJECTIVE: To explore whether or not CD8(+)CD28(-)T cell play a pathogenic role in asthma and detect the effects of dexamethasone (DXM). METHODS: A total of 30 mice were randomly divided into 3 groups: asthmatic group, DXM group and control group (n = 10 each). The asthmatic and DXM groups were sensitized twice and inhaled ovalbumin. The DXM Group received an intraperitoneal injection of DXM 1mg/kg before inhaling ovalbumin. After successful modeling, 3 mice were selected randomly from each group to measure the airway responsiveness. Also a bronchoalveolar lavage cytological study was performed and lung tissue sections were prepared for histopathologic examination to evaluate the airway inflammation. The content of IgE in bronchoalveolar lavage fluid (BALF) was detected with a murine IgE ELISA kit. And the fractions of CD8(+)CD28(-)T cell of peripheral blood and BALF were tested by flow cytometry to analyze the correlation between IgE, eosinophils (EOS) of BALF and CD8(+)CD28(-)T cell of blood. RESULTS: The airway hyperresponsiveness in asthmatic and DXM groups were significantly higher than that in the control group. The number of total cells and EOS of BALF in the asthmatic group [(5.56 ± 4.06) × 10(2)/L; (3.29 ± 2.23) × 10(2)/L] were significantly higher than that in control group [(0.91 ± 0.65) × 10(2)/L, P = 0.003; (0.43 ± 0.37) × 10(2)/L, P = 0.001] and DXM group [(2.59 ± 1.69) × 10(2)/L, P = 0.044; (1.11 ± 0.73) × 10(2)/L, P = 0.008]; while the DXM group was insignificantly higher than the control group (P = 0.234, P = 0.363). There were significant differences in the contents of IgE of BALF for the asthmatic, DXM and control groups [(23.85 ± 5.97) g/L, (13.15 ± 2.22) g/L, (6.54 ± 1.03) g/L, F = 38.558, P = 0.000]. The percentages of CD8(+)CD28(-)T cell in peripheral blood in asthmatic and DXM groups [(18.68 ± 4.12)% and (13.43 ± 2.91)%] were significantly higher than those in control mice [(8.43 ± 4.60)%, both P < 0.05]. The percentages of CD8(+)CD28(-)T cell of BALF in asthmatic group and DXM group [(1.25 ± 0.40)% and (0.66 ± 0.49)%] were also significantly higher than those in control mice [(0.21 ± 0.19)%, both P < 0.05]. The percentages of CD8(+)CD28(-)T cell of blood and BALF in the DXM mice were significantly lower than those in asthmatic group. The correlations between IgE (r = 0.864, P = 0.012), EOS (r = 0.804, P = 0.029) and CD8(+)CD28(-)T cell were significant. CONCLUSION: The fraction of CD8(+)CD28(-)T cell is closely correlated with the inflammation of asthmatic airway. The airway hyperresponsiveness and inflammation in asthmatic mice may be relieved by DXM through its effect of inhibiting the expression of CD8(+)CD28(-) T cell.

[Expression of interleukin-17A in asthmatic mice and its significance].

OBJECTIVE: To study the serum level of interleukin-17A (IL-17A) and its expressions in the lung, spleen and thymus in asthmatic mice. METHODS: In 14 normal BALB/c female mice and 14 asthmatic mice, the changes in the airway pathology and the cell proportion in the bronchoalveolar lavage fluid (BALF) were observed. The serum level of IL-17A and IL-17A expressions in the tissue homogenates of the lung, spleen and thymus of the mice were detected by sandwich enzyme-linked immunosorbent assay (ELISA). RESULTS: The airway inflammation in the asthmatic mice was characterized mainly by eosinophil and neutrophil infiltration, which was not observed in the normal control group. Serum IL-17A levels and IL-17A expressions in the lung, spleen and thymus of the asthmatic mice were significantly higher than those in the normal control group (P<0.01). In the asthmatic mice, IL-17A expression in the lung tissues was positively correlated with the percentages of neutrophils (r=0.693, P=0.040) and eosinophils (r=0.733, P=0.030) in the BALF. CONCLUSION: IL-17A is highly expressed in the serum, lung, spleen and thymus of asthmatic mice. IL-17A may be one of the major cytokines involved in exacerbation of bronchial asthma, and is probably associated with the recruitment of neutrophils and eosinophils into the airways.