Dendritic Cells Promote the Differentiation of ILCs into NCR-ILC3s in the Lungs of Mice Exposed to Cigarette Smoke.

The involvement of Group 3 innate lymphoid cells (ILC3s) and dendritic cells (DCs) in chronic lung inflammation has been increasingly regarded as the key to understand the inflammatory mechanisms of smoke-related chronic obstructive pulmonary disease (COPD). However, the mechanism underlying the engagement of both remains unclear. Our study aimed to explore NCR-ILC3 differentiation in the lungs of mice exposed to cigarette smoke (CS) and to further investigate whether DCs activated by CS exposure contribute to the differentiation of ILCs into NCR-ILC3s. The study involved both in vivo and in vitro experiments. In the former, the frequencies of lung NCR-ILC3s and NKp46-IL-17A+ ILCs and the expression of DCs, CD40, CD86, IL-23, and IL-1ß quantified by flow cytometry were compared between CS-exposed mice and air-exposed mice. In the latter, NKp46-IL-17A+ ILC frequencies quantified by flow cytometry were compared after two cocultures, one involving lung CD45+Lin-CD127+ ILCs sorted from air-exposed mice and DCs sifted by CD11c magnetic beads from CS-exposed mice and another including identical CD45+Lin-CD127+ ILCs and DCs from air-exposed mice. The results indicated significant increases in the frequencies of NCR-ILC3s and NKp46-IL-17A+ ILCs; in the expression of DCs, CD40, CD86, IL-23, and IL-1ß in CS-exposed mice; and in the frequency of NKp46-IL-17A+ ILCs after the coculture with DCs from CS-exposed mice. In conclusion, CS exposure increases the frequency of lung ILCs and NCR-ILC3s. CS-induced DC activation enhances the differentiation of ILCs into NCR-ILC3s, which likely acts as a mediating step in the involvement of NCR-ILC3s in chronic lung inflammation.

Surgical site wound infection, and other postoperative problems after coronary artery bypass grafting in subjects with chronic obstructive pulmonary disease: A meta-analysis.

We performed a meta-analysis to evaluate the effect of chronic obstructive pulmonary disease on surgical site wound infection, and other postoperative problems after coronary artery bypass grafting. A systematic literature search up to April 2022 was performed and 37 444 subjects with coronary artery bypass grafting at the baseline of the studies; 4320 of them were with the chronic obstructive pulmonary disease, and 33 124 were without chronic obstructive pulmonary disease. Odds ratio (OR), and mean difference (MD) with 95% confidence intervals (CIs) were calculated to assess the effect of chronic obstructive pulmonary disease on surgical site wound infection, and other postoperative problems after coronary artery bypass grafting using the dichotomous, and contentious methods with a random or fixed-effect model. The chronic obstructive pulmonary disease subjects had a significantly higher surgical site wound infection (OR, 1.27; 95% CI, 1.01-1.60, P = 0.04), respiratory failure (OR, 1.84; 95% CI, 1.55-2.18, P < 0.001), mortality (OR, 1.61; 95% CI, 1.37-1.89, P < 0.001), pneumonia (OR, 2.30; 95% CI, 1.97-2.68, P < 0.001), pleural effusion (OR, 1.78; 95% CI, 1.12-2.83, P = 0.02), stroke (OR, 1.99; 95% CI, 1.17-3.36, P = 0.01), and length of intensive care unit stay (MD, 0.73; 95% CI, 0.19-1.26, P = 0.008) after coronary artery bypass grafting compared with subjects without chronic obstructive pulmonary disease. However, chronic obstructive pulmonary disease subjects did not show any significant difference in length of hospital stay (MD, 0.83; 95% CI, -0.01 to 1.67, P = 0.05), and pneumothorax (OR, 1.59; 95% CI, 0.98-2.59, P = 0.06) after coronary artery bypass grafting compared with subjects without chronic obstructive pulmonary disease. The chronic obstructive pulmonary disease subjects had a significantly higher surgical site wound infection, respiratory failure, mortality, pneumonia, pleural effusion, stroke, and length of intensive care unit stay, and no significant difference in length of hospital stay, and pneumothorax after coronary artery bypass grafting compared with subjects without chronic obstructive pulmonary disease. The analysis of outcomes should be with caution because of the low sample size of 1 out of 11 studies in the meta-analysis and a low number of studies in certain comparisons.

Effect of erythromycin on the ultrastructure of human macrophages exposed to cigarette smoke extract in vitro.

Macrophages serve an active role in the pathophysiology of chronic obstructive pulmonary disease (COPD). Erythromycin (EM) has been verified as an effective treatment for COPD. However, there are few studies on the effect of EM on the ultrastructure of macrophages exposed to cigarette smoke extract (CSE). In the present study, human macrophages were randomly divided into three groups: The control, CSE and the CSE+EM group, using electron microscopy, the effect of EM was evaluated by comparing the ultrastructural changes between these groups. The macrophages were additionally divided into a further four groups: The control, CSE, CSE+EM 24 h and CSE+EM 48 h groups. The generation of reactive oxygen species (ROS) in each group was evaluated by detecting fluorescence intensity. It was observed that the cellular ultrastructure of the CSE group exhibited abnormal changes, though this effect was reversed back to the level of the control in the CSE+EM group. Compared with the control group, the ROS expression level was significantly increased in the CSE group (P < .05); however, compared with the CSE group, the ROS concentration was decreased in the CSE+EM 24 h (P < .05) and CSE+EM 48 h groups (P < .05), though this was more apparent in the EM 48 h group. It was concluded that EM protects human macrophages against CSE. Moreover, it was hypothesized that EM may reduce the symptoms of patients with COPD by protecting the macrophage ultrastructure from the effects of CSE, resulting in the decreased generation of ROS, inhibiting autophagy and reducing endoplasmic reticulum stress.

Theophylline inhibits cigarette smoke-induced inflammation in skeletal muscle by upregulating HDAC2 expression and decreasing NF-κB activation.

Inflammation is associated with skeletal muscle dysfunction and atrophy in patients with chronic obstructive pulmonary disease (COPD). Theophylline has an anti-inflammatory role in COPD. However, the effects of theophylline on inflammation in skeletal muscle in COPD have rarely been reported. The aims of this study were to explore whether theophylline has an anti-inflammatory effect on skeletal muscle in a mouse model of emphysema and to investigate the molecular mechanism underlying this effect. In mice, cigarette smoke (CS) exposure for 28 wk resulted in atrophy of the gastrocnemius muscle. Histone deacetylase 2 (HDAC2) and nuclear factor-κBp65 (NF-κBp65) mRNA and protein levels were significantly decreased and increased, respectively, in gastrocnemius muscle. This effect was revered by aminophylline. The exposure of murine skeletal muscle C2C12 cells to CS extract (CSE) significantly increased IL-8 and TNF-α levels as well as NF-κBp65 mRNA and protein levels and NF-κBp65 activity. This effect was reversed by theophylline. HDAC2 knockdown enhanced the activity of NF-κBp65 and increased IL-8 and TNF-α levels in C2C12 cells. CSE significantly increased the interaction of HDAC2 with NF-κBp65 in C2C12 cells. These data suggest that theophylline has an anti-inflammatory effect on skeletal muscle in a mouse model of emphysema by upregulating HDAC2 expression and decreasing NF-κBp65 activation.

Genomic analysis provides insights into the transmission and pathogenicity of Talaromyces marneffei.

Talaromyces marneffei (T. marneffei) is a medically important opportunistic dimorphic fungus that infects both humans and bamboo rats. However, the mechanisms of transmission and pathogenicity of T. marneffei are poorly understood. In our study, we combined Illumina and PacBio sequencing technologies to sequence and assemble a complete genome of T. marneffei. To elucidate the transmission route and source, we sequenced three additional T. marneffei isolates using Illumina sequencing technology. Variations among isolates were used to develop a multilocus sequence typing (MLST) system comprising five housekeeping genes that can be used to discriminate between isolates derived from different sources. Our analysis revealed that human and bamboo rat share identical genotypes in these five loci. Thus, we hypothesized that T. marneffei is transmitted to humans through inhalation of spores in the surrounding environment into the lungs and that the bamboo rat can serve as an important natural reservoir for pathogens. Furthermore, we also identified temperature-dependent polyketide synthases, non-ribosomal peptide synthetases and secreted proteins as putative pathogenicity-related factors. In addition, we identified antifungal drug targets that can be investigated in future studies to elucidate the mechanisms underlying drug resistance. In summary, our study presents the basic features of the T. marneffei genome and provides insights into the transmission and pathogenicity of T. marneffei, which warrant fundamental experimental research.

Rapamycin attenuates Tc1 and Tc17 cell responses in cigarette smoke-induced emphysema in mice.

OBJECTIVE AND DESIGN: Chronic exposure to cigarette smoke promotes airway inflammation and emphysema accompanied by enhanced CD8+ interferon (IFN)-γ+ T(Tc1) and CD8+ interleukin (IL)-17+ T(Tc17) cell responses. The mammalian target of rapamycin (mTOR) has been involved in the pathogenesis of emphysema. Inhibiting mTOR by rapamycin has been reported to alleviate emphysema, but the mechanism is not fully understood. We aimed to explore the effect of rapamycin on Tc1 and Tc17 cell responses induced by cigarette smoke exposure. MATERIALS: Male C57BL/6 mice were exposed to cigarette smoke or room air for 24 weeks. Half of the smoke-exposed mice received rapamycin in the last 12 weeks. The severity of emphysema in those mice was evaluated by mean linear intercept (MLI), mean alveolar airspace area (MAA) and destructive index (DI). Bronchoalveolar lavage was collected and analyzed. Phosphorylated (p-) mTOR in CD8+ T cells, Tc1 and Tc17 cells were detected by flow cytometry. The relative expression of p-mTOR in lungs was determined by western blot analysis. IFN-γ and IL-17A levels were detected by enzyme-linked immunosorbent assays. IFN-γ, mTOR and RAR-related orphan receptor (ROR)γt mRNA levels were evaluated by the real-time polymerase chain reaction. RESULTS: Elevated p-mTOR expression in CD8+ T cells and lung tissue was accompanied by the enhanced Tc1 and Tc17 cell responses in lungs of mice exposed to cigarette smoke. Rapamycin reduced inflammatory cells in BALF and decreased MLI, DI and MAA in lungs. Rapamycin decreased p-mTOR expression, and down-regulation of mTOR and RORγt mRNA levels along with the attenuation of Tc1 and Tc17 cell responses in mice with emphysema. CONCLUSIONS: The mTOR was activated in CD8+ T cells accompanied by the enhanced Tc1 and Tc17 cell responses in cigarette smoke-related pulmonary inflammation. Rapamycin ameliorated emphysema and attenuated Tc1 and Tc17 cell responses probably caused by inhibiting mTOR in cigarette smoke-exposed mice.

Erythromycin Regulates Cigarette Smoke-Induced Proinflammatory Mediator Release Through Sirtuin 1-Nuclear Factor κB Axis in Macrophages and Mice Lungs.

BACKGROUND: Macrolides have anti-inflammatory and antioxidative stress function, but their pharmacological regulation remains unclear. Sirtuin 1 (SIRT1) is redox-sensitive protein belongs to class III histone/protein deacetylases, SIRT1 regulates the acetylation/expression of nuclear factor κB (NF-κB) and is involved in the airway inflammation of chronic obstructive pulmonary disease. OBJECTIVES: The present study was designed to examine the effects of erythromycin (EM) on the SIRT1-NF-κB axis and NF-κB-dependent proinflammatory cytokines. METHODS: Human macrophages were preincubated with EM and then treated with cigarette smoke extract (CSE). The mice were treated by injecting drugs to gastric with EM before cigarette smoke exposure. Reactive oxygen species (ROS) released by treated human macrophages were detected using flow cytometry. The expression of SIRT1 and NF-κB was analyzed by western blotting. SIRT1 and the RelA/p65 subunits of NF-κB interaction were detected by coimmunoprecipitation. We found that EM suppressed CSE-induced ROS released in human macrophages, which coincided with increases in SIRT1 protein expression in the macrophages and lungs of mice, resulting in suppressed -NF-κB acetylation and expression correlated with a reduction of inflammatory mediators. CONCLUSION: These findings suggest that EM increased SIRT1, leading to acetylation/expression of NF-κB, and thereby decreasing cigarette smoke-driven NF-κB-dependent proinflammatory cytokine.

Comparison of pleural effusion features and biomarkers between talaromycosis and tuberculosis in non-human immunodeficiency virus-infected patients.

BACKGROUND: Due to the similar clinical, lung imaging, and pathological characteristics, talaromycosis is most commonly misdiagnosed as tuberculosis. This study aimed to identify the characteristics of talaromycosis pleural effusion (TMPE) and to distinguish TMPE from tuberculosis pleural effusion (TPE). METHODS: We enrolled 19 cases each of TMPE and TPE from Guangxi, China. Patients' clinical records, pleural effusion tests, biomarker test results, and receiver operating characteristic curves were analyzed. RESULTS: In total, 39.8% (65/163) of patients exhibited serous effusion, of whom 61 were non-human immunodeficiency virus (HIV)-infected patients; 68.85% of the non-HIV-infected patients (42/61) had TMPE. Thoracentesis was performed only in 19 patients, all of whom were misdiagnosed with tuberculosis and received long-term anti-tuberculosis treatment. In four of these patients, interleukin (IL)-23, IL-27, and interferon-gamma (IFN-γ) measurements were not performed since pleural effusion samples could not be collected because the effusion had been drained prior to the study. In the remaining 15 patients, pleural effusion samples were collected. Talaromyces marneffei was isolated from the pleural effusion and pleural nodules. Most TMPEs were characterized by yellowish fluid, with marked elevation of protein content and nucleated cell counts. However, neutrophils were predominantly found in TMPEs, and lymphocytes were predominantly found in TPEs (both p < 0.05). Adenosine deaminase (ADA) and IFN-γ levels in TMPEs were significantly lower than those in TPEs (all p < 0.05) and provided similar accuracies for distinguishing TMPEs from TPEs. IL-23 concentration in TMPEs was significantly higher than that in TPEs (p < 0.05), and it provided similar accuracy for diagnosing TMPEs. IL-27 concentrations in TMPEs were significantly lower than those in TPEs (all p < 0.05) but was not useful for distinguishing TMPE from TPE. CONCLUSIONS: Talaromycosis can infringe on the pleural cavity via the translocation of T. marneffei into the pleural space. Nonetheless, this phenomenon is still commonly neglected by clinicians. TMPE is a yellowish fluid with exudative PEs and predominant neutrophils. Higher neutrophil counts and IL-23 may suggest talaromycosis. Higher lymphocyte counts, ADA activity, and IFN-γ concentration may suggest tuberculosis.

Case report: Fever- pneumonia- lymphadenectasis- osteolytic- subcutaneous nodule: Disseminated chromoblastomycosis caused by phialophora.

Chromoblastomycosis (CBM) is a chronic cutaneous and subcutaneous fungal infection caused by certain dematiaceous fungi (usually Fonsecaea, Phialophora, or Cladophialophora). Histologically, CBM is characterized by the presence of medlar bodies. However, the diagnosis is difficult because of the rarity of these pathognomonic presentations and the wide variety of presentations. Treatment of these infections is challenging as it lacks standardization. Herein, we report a case of chromoblastomycosis caused by Phialophora, in a 42-year-old immunocompetent male agriculturist from the humid and subtropical region of southern China. He had a 3-month history of pneumonia with intermittent fever, coughing, and expectoration. The infection subsequently spread to the bone and lymph nodes forming deep lesions and eventually resulting in osteolysis and lymphadenectasis. These subcutaneous nodules were observed after 9 months. Antifungal treatment was administered for 20 months leading to clinical improvement before the patient was lost to follow-up. This case is unique because such deep lesions are rare in immunocompetent individuals and because the initial onset was associated with pneumonia.

Enhanced activation of circulating plasmacytoid dendritic cells in patients with Chronic Obstructive Pulmonary Disease and experimental smoking-induced emphysema.

Plasmacytoid dendritic cells (pDCs) are key cells bridging the innate with adaptive immunity. However, the phenotypic characteristics of circulating pDCs and its role in smoking related-Chronic Obstructive Pulmonary Disease (COPD) remain largely unknown. The aim of this study was analyzed the phenotype of circulating pDCs and the expression of IFN-γ producing CD8+T cells and IL-17-producing CD8+T cells in patients with COPD by using multi-colour flow cytometry. The cytokine profiles in peripheral blood from all subjects were measured by ELISA. The influence of cigarette smoke on pDCs was evaluated in an experimental mouse model of emphysema. Circulating pDCs in patients with COPD and in mice exposed to cigarette smoke expressed high levels of co-stimulatory molecules CD40 or CD86 accompanied by exaggerated IFN-γ producing CD8+T cells and IL-17-producing CD8+T cells. In vitro, cigarette smoke directly promoted pDCs maturation and release of IFN-α, IL-6 and IL-12, subsequently inducing differentiation of IFN-γ producing CD8+T cells and IL-17-producing CD8+T cells from mouse naïve CD8+T cells. These data suggested that circulating pDCs display an enhanced activation phenotype in patients with COPD and in experimental smoking mouse model of emphysema, which might contribute to exaggerated IFN-γ producing CD8+T and IL-17-producing CD8+T cell-mediated immune responses.

Identification of key genes in human airway epithelial cells in response to respiratory pathogens using microarray analysis.

BACKGROUND: Airway epithelium is the primary target for pathogens. It functions not only as a mechanical barrier, but also as an important sentinel of the innate immune system. However, the interactions and processes between host airway epithelium and pathogens are not fully understood. RESULTS: In this study, we identified responses of the human airway epithelium cells to respiratory pathogen infection. We retrieved three mRNA expression microarray datasets from the Gene Expression Omnibus database, and identified 116 differentially expressed genes common to all three datasets. Gene functional annotations were performed using Gene Ontology and pathway analyses. Using protein-protein interaction network analysis and text mining, we identified a subset of genes functioned as a group and associated with infection, inflammation, tissue adhesion, and receptor internalization in infected epithelial cells. These genes were further identified in BESE-2B cells in response to Talaromyces marneffei by Real-Time quantitative PCR (qRT-PCR). In addition, we performed an in silico prediction of microRNA-target interactions and examined our findings. CONCLUSIONS: Using bioinformatics analysis, we identified several genes that may serve as biomarkers for the diagnosis or the surveillance of early respiratory tract infection, and identified additional genes and miRNAs that warrant further fundamental experimental research.

Serum magnesium levels and lung cancer risk: a meta-analysis.

BACKGROUND: Whether serum magnesium levels were lower in patients with lung cancer than that in healthy controls is controversial. The aim of this study was to identify and synthesize all citations evaluating the relationship between serum magnesium levels and lung cancer. METHODS: We searched PubMed, WanFang, China National Knowledge Internet (CNKI), and SinoMed databases for relevant studies before December 31, 2017. Two authors independently selected studies, extracted data, and assessed risk of bias. RESULTS: Eleven citations comprising 707 cases with lung cancer and 7595 healthy controls were included in our study. Serum magnesium levels were not significantly lower in patients with lung cancer [summary SMD = 0.193, 95%CI = - 1.504 to 1.890] when compared to health controls, with significant heterogeneity (I2 = 99.6%, P < 0.001) found. Negative associations were found among Asian populations [summary SMD = 0.229, 95%CI = - 1.637 to 2.094] and European populations [summary SMD = - 0.168, 95%CI = - 0.482 to 0.147]. No publication bias was found using the test of Egger and funnel plot. CONCLUSIONS: Our study suggested that serum magnesium levels had no significant association on lung cancer risk.

Neutrophil extracellular traps induced by cigarette smoke activate plasmacytoid dendritic cells.

BACKGROUND: Neutrophil extracellular traps (NETs) represent a distinct strategy by which neutrophils trap, confine and eliminate invading microorganisms. Emerging evidence suggests that NETs exert a deleterious effect to the host in the absence of microbial stimuli. However, the role of NETs in smoking-related lung diseases remains to be elucidated. OBJECTIVES: To evaluate the formation of NETs in the context of chronic inflammation induced by cigarette smoking and explore its potential role in an experimental mouse model of emphysema. METHODS: The formation and degradation of NETs in cigarette smoke exposed mice was assessed with a fluorescence microscope. The potential influences of NETs on plasmacytoiddendritic cells were also investigated. RESULTS: NETs were more prone to formation by polymorphonuclearneutrophils but defective in degradation in cigarette smoke exposed mice. Cigarette smoke extract (CSE) served as an important facilitator that triggered neutrophils to undergo NETosis in vitro. Furthermore, CSE-induced NETs were capable of driving plasmacytoiddendritic cell maturation and activation, thereby initiating a T-cell-mediated immune response. CONCLUSIONS: NETs may represent a critical connection between innate and adaptive immune responses under conditions of chronic inflammation induced by cigarette smoke exposure.

Acute Penicillium marneffei infection stimulates host M1/M2a macrophages polarization in BALB/C mice.

BACKGROUND: Penicillium marneffei (P. marneffei) is a thermally dimorphic fungus pathogen that causes fatal infection. Alveolar macrophages are innate immune cells that have critical roles in protection against pulmonary fungal pathogens and the macrophage polarization state has the potential to be a deciding factor in disease progression or resolution. The aim of this study was to investigate mouse alveolar macrophage polarization states during P. marneffei infection. RESULTS: We used enzyme-linked immunosorbent (ELISA) assays, quantitative real-time PCR (qRT-PCR), and Griess, arginase activity to evaluate the phenotypic markers of alveolar macrophages from BALB/C mice infected with P. marneffei. We then treated alveolar macrophages from infected mice with P. marneffei cytoplasmic yeast antigen (CYA) and investigated alveolar macrophage phenotypic markers in order to identify macrophage polarization in response to P. marneffei antigens. Our results showed: i) P. marneffei infection significantly enhanced the expression of classically activated macrophage (M1)-phenotypic markers (inducible nitric oxide synthase [iNOS] mRNA, nitric oxide [NO], interleukin-12 [IL-12], tumor necrosis factor-alpha [TNF-α]) and alternatively activated macrophage (M2a)-phenotypic markers (arginase1 [Arg1] mRNA, urea) during the second week post-infection. This significantly decreased during the fourth week post-infection. ii) During P. marneffei infection, CYA stimulation also significantly enhanced the expression of M1 and M2a-phenotypic markers, consistent with the results for P. marneffei infection and CYA stimulation preferentially induced M1 subtype. CONCLUSIONS: The data from the current study demonstrated that alveolar macrophage M1/M2a subtypes were present in host defense against acute P. marneffei infection and that CYA could mimic P. marneffei to induce a host immune response with enhanced M1 subtype. This could be useful for investigating the enhancement of host anti-P. marneffei immune responses and to provide novel ideas for prevention of P. marneffei-infection.

Expression profile of lncRNA in human bronchial epithelial cells response to Talaromyces marneffei infection: A microarray analysis.

Talaromyces marneffei is an important opportunistic pathogenic fungus capable of causing systemic lethal infection through inhalation of its conidia. However, little is known about the pathogenesis and interactions between Talaromyces marneffei and host. The aim of this study was to identify potential long noncoding RNAs (lncRNAs) and coding genes associated with interactions between airway epithelial cell and Talaromyces marneffei conidia. We carried out a microarray analysis to determine the expression profile of lncRNA and mRNA in human bronchial epithelial cell in response to Talaromyces marneffei infection. Compared to control group, we found that 370 and 149 lncRNAs were up and down regulated, respectively. Meanwhile, the expression level of 269 and 60 mRNAs was increased and decreased, respectively. To understand the potential role of the differentially expressed lncRNAs, we performed functional annotations of the corresponding coding genes using gene ontology and pathway analyses. Our results provide insights into the pathogenesis of early infection by Talaromyces marneffei.

Imbalance between Subpopulations of Regulatory T Cells in Patients with Acute Exacerbation of COPD.

Human regulatory T cells (Tregs) have been reported to be not significantly different in the peripheral blood of patients with chronic obstructive pulmonary disease (COPD) and healthy controls. Recent research has identified some new markers for Tregs and indicated that Tregs are composed of distinct subpopulations. The aim of the study was to describe the changing patterns of circulating Treg subpopulations in patients with acute exacerbation of COPD (AECOPD) and healthy controls, and to explore their potential roles in AECOPD pathogenesis. Blood samples were obtained from 30 never-smokers with normal lung function and 30 patients with COPD before and after they had an exacerbation. The proportions of Treg subpopulations were evaluated using flow cytometry. In the peripheral blood, decreased proportions of CD4+CD25+CD127low Tregs, CD4+CD25+CD45RA+ Tregs, and CD4+CD25+CD62L+ Tregs and an increased proportion of CD4+CD25+CD45RO+ Tregs were found in patients with stable COPD compared with non-smokers with normal lung function. The patients showed further changes in Treg subpopulations when they had an AECOPD, with an overall decrease in a suppressive subset, indicating that the immune negative regulatory population of Tregs did not play an effective role. Immune homeostasis favored inflammation, and a negative correlation between the circulating tumor necrosis factor-alpha and the proportions of CD4+CD25+CD62L+ cells (r = -0.698, p < 0.05) in patients with AECOPD was found. The imbalance between the suppressive subsets and the proinflammatory subset of Tregs and the decline of Treg subpopulations with immunosuppressive activity may play important roles in AECOPD progression.

Dendritic cells induce Tc1 cell differentiation via the CD40/CD40L pathway in mice after exposure to cigarette smoke.

Dendritic cells and CD8(+) T cells participate in the pathology of chronic obstructive pulmonary disease, including emphysema, but little is known of the involvement of the CD40/CD40L pathway. We investigated the role of the CD40/CD40L pathway in Tc1 cell differentiation induced by dendritic cells in a mouse model of emphysema, and in vitro. C57BL/6J wild-type and CD40(-/-) mice were exposed to cigarette smoke (CS) or not (control), for 24 wk. In vitro experiments involved wild-type and CD40(-/-) dendritic cells treated with CS extract (CSE) or not. Compared with the control groups, the CS mice (both wild type and CD40(-/-)) had a greater percentage of lung dendritic cells and higher levels of major histocompatability complex (MHC) class I molecules and costimulatory molecules CD40 and CD80. Relative to the CS CD40(-/-) mice, the CS wild type showed greater signs of lung damage and Tc1 cell differentiation. In vitro, the CSE-treated wild-type cells evidenced more cytokine release (IL-12/p70) and Tc1 cell differentiation than did the CSE-treated CD40(-/-) cells. Exposure to cigarette smoke increases the percentage of lung dendritic cells and promotes Tc1 cell differentiation via the CD40/CD40L pathway. Blocking the CD40/CD40L pathway may suppress development of emphysema in mice exposed to cigarette smoke.

Th17 cells and IL-17 promote the skin and lung inflammation and fibrosis process in a bleomycin-induced murine model of systemic sclerosis.

OBJECTIVES: Systemic sclerosis (SSc) is characterised by fibrosis of the skin and internal organs, such as the lungs. Enhanced Th17 responses are associated with skin fibrosis in patients with SSc, however, whether they are associated with lung fibrosis has not been clarified. This study aimed to investigate the potential association of Th17 responses with the skin and pulmonary fibrosis as well as the potential mechanisms in a mouse bleomycin (BLM) model of SSc. METHODS: BALB/c mice were injected subcutaneously with phosphate buffered saline (PBS) (control) or BLM for 28 days and the skin and pulmonary inflammation and fibrosis were characterized by histology. The percentages of circulating, skin and pulmonary infiltrating Th17 cells and the contents of collagen in mice were analysed. The levels of RORγt, IL-17A, IL-6 and TGF-ß1 mRNA transcripts in the skin and lungs were determined by quantitative RTPCR and the levels of serum IL-17A, IL-6 and TGF-ß1 were determined by ELISA. Furthermore, the effect of rIL-17A on the proliferation of pulmonary fibroblasts and their cytokine expression was analysed. The potential association of Th17 responses with the severity of skin and lung fibrosis was analysed. RESULTS: In comparison with the control mice, significantly increased skin and pulmonary inflammation and fibrosis and higher levels of hydroxyproline were detected in the BLM mice. Significantly higher frequency of circulating, skin and lung infiltrating Th17 cells and higher levels of serum, skin and lung IL-17A, TGF-ß1, IL-6 and RORγt were detected in the BLM mice. The concentrations of serum IL-17A were correlated positively with the percentages of Th17 cells and the contents of skin hydroxyproline in the BLM mice. The levels of IL-17A expression were positively correlated with the skin and lung inflammatory scores as well as the skin fibrosis in the BLM mice. In addition, IL-17A significantly enhanced pulmonary fibroblast proliferation and their type I collagen, TGF-ß and IL-6 expression in vitro, which were attenuated by treatment with anti-IL-17A. CONCLUSIONS: Our results indicate that Th17 cells participate in the pathogenesis of skin and lung fibrosis by enhancing fibroblast proliferation and cytokine production in a mouse BLM model of SSc.

Effects of Low-Dose and Long-Term Treatment with Erythromycin on Interleukin-17 and Interleukin-23 in Peripheral Blood and Induced Sputum in Patients with Stable Chronic Obstructive Pulmonary Disease.

OBJECTIVE: To study the effects of low-dose and long-term treatment with erythromycin on IL-17 and IL-23, in peripheral blood and induced sputum, in patients with stable chronic obstructive pulmonary disease (COPD). METHODS: Patients were randomly divided into placebo-treated group, group A (12 months of additive treatment with erythromycin, N = 18), and group B (6 months of additive treatment with erythromycin followed by 6 months of follow-up, N = 18). Inflammatory cells in induced sputum, pulmonary function, and the 6-minute walk distance (6MWD) were analyzed. Concentrations of IL-17 and IL-23 in peripheral blood and sputum were measured using enzyme-linked immunosorbent assays. RESULTS: After treatment, sputum and peripheral blood concentrations of IL-17 and IL-23 significantly decreased in groups A and B compared with placebo-treated group. There were no significant differences after erythromycin withdrawal at months 9 and 12 in group B compared with placebo-treated group. An increase in 6MWD was observed after treatment. CONCLUSIONS: Erythromycin was beneficial and reduced airway inflammation in COPD patients. Underlying mechanisms may involve inhibition of IL-17 and IL-23 mediated airway inflammation. COPD patients treated with erythromycin for 6 months experienced improved exercise capacity. Finally, treatment for 12 months may be more effective than treatment for 6 months.

Four SNPs and Systemic Level of FOXP3 in Smokers and Patients with Chronic Obstructive Pulmonary Disease.

Forkhead box P3 (FOXP3) is the essential transcription factor for the function of regulatory T-cell (Treg). However, the gene mutation of FOXP3 in patients with chronic obstructive pulmonary disease (COPD) at different stages has not been reported. We aim to investigate four single nucleotide polymorphisms (SNPs) and the mRNA expression of FOXP3 in smokers with normal lung function and smokers with COPD at different stages. FOXP3 mRNA expression and SNPs in FOXP3 were assessed in nonsmokers with normal lung function (N), smokers with normal lung function (S), smokers with COPD in the Global Initiative for Chronic Obstructive Lung Disease (GOLD) 1 or 2 grade (COPD 1-2), and smokers with COPD in GOLD 3 or 4 grade (COPD 3-4). In peripheral blood sample, FOXP3 mRNA was assessed using real-time quantitative PCR and SNPs were analyzed by TaqMan PCR. FOXP3 mRNA level in peripheral blood sample was decreased when COPD was aggravated. The frequency of FOXP3 rs5902434 genotype del/del and allele del are lower in COPD 1-2 and COPD 3-4 than that in N or S. The rs5902434 genotype del/del and allele del were, respectively, associated with decreased risk of COPD and lung function decline. The rs5902434 genotypic distribution was correlated with FOXP3 mRNA level. In conclusion, both FOXP3 rs5902434 genotypes and alleles were differently distributed in COPD patients and smokers with normal lung function. The distribution of del/del genotype was associated with systemic expression of FOXP3 mRNA. More research is needed to explore the role of FOXP3 gene polymorphism in immunoinflammation of COPD.