Analysis at the single-cell level indicates an important role of heterogeneous global DNA methylation status on the progression of lung adenocarcinoma.

Aberrant DNA modifications affect the tumorigenesis and progression of lung cancer. However, the global methylation status of tumor cells and the heterogeneous methylation status of cells within the same tumor need further study. We used publicly available single-cell RNAseq data to investigate the impact and diversity of global methylation status on lung adenocarcinoma. Clustering cells into subgroups and cell differentiation pseudotime analysis, based on expression profile, demonstrated that the global methylation status was crucial to lung adenocarcinoma function and progression. Hypermethylated tumor cells had increased activity related to the hypoxia response. Hyper- and hypomethylated cells indicated upregulation in pathways involving focal adhesion and cell junctions. Pseudotime analysis showed that cell clusters with unique methylation activities were located at the ends of the putative trajectories, suggesting that DNA methylation and demethylation activities were essential to tumor cell progression. Expression of SPP1 was associated with the global methylation status of tumor cells and with patient prognosis. Our study identified the importance and diversity of global DNA methylation status by analysis at the single-cell level. Our findings provide new information about the global DNA methylation status of tumor cells and suggest new approaches for precision medical treatments for lung adenocarcinoma.

Erythromycin inhibits cigarette smoke-induced inflammation through regulating the PPARγ/NF-κB signaling pathway in macrophages.

Chronic obstructive pulmonary disease is characterized by chronic inflammation of the airway and lungs. Accumulating evidence has suggested that erythromycin (EM) plays a protective role against cigarette smoke-induced oxidative stress and the inflammatory response. However, the underlying mechanisms remain relatively unclear. The present study aimed to investigate the role of EM in inhibiting cigarette smoke-induced inflammation in human macrophages and its potential mechanism. A Cell Counting Kit-8 assay was used to determine the optimum concentration of EM and cigarette smoke extract (CSE) and it was found that 0.1 and 1% CSE and 0.1, 1.0 and 10 µg/ml EM exerted no significant effect on the cell proliferation activity, whereas 2 and 3% CSE exerted a significant inhibitory effect over the cell proliferation activity. We observed that 10 µmol/ml GW9662 (A PPARγ antagonist) and the presence of 1% CSE could promote the expression and activation of NF-κB p65. And this increased the expression of IL-6, IL-8 and reactive oxygen species (ROS). At the same time, 10 µmol/ml GW9662 and 1% CSE was found to inhibit the expression and activation of peroxisome proliferator activated receptors γ (PPARγ); However, 1 µg/ml EM was discovered to reverse these effects. Co-immunoprecipitation subsequently discovered an interaction between PPARγ and NF-κB p65. In conclusion, the present study suggested that EM may reduce the damage of PPARγ by inhibiting oxidative stress and reducing the expression of ROS and finally relieving cigarette smoke-induced inflammation through the PPARγ/NF-κB signaling pathway in macrophages.

Non-tuberculous mycobacterial infection and reactive dermatosis associated with adult-onset immunodeficiency due to anti-interferon-gamma autoantibodies: A case report.

INTRODUCTION: Anti-interferon-gamma (anti-IFN-γ) autoantibody increases susceptibility to lower-virulence pathogens and causes immunodeficiency syndrome in HIV-negative patients. PATIENT CONCERNS: A 69-year-old Chinese man presented with a 2-month history of pruritic skin lesions on his forearms, trunk, and legs. He was diagnosed with 5 opportunistic infections without conventional immunosuppression-associated factors in past. The most conspicuous characteristics were recurrent pulmonary infection, persistent immunoglobulin E elevation and eosinophilia during the whole disease course. DIAGNOSIS: Enzyme-linked immunosorbent assay showed anti-IFN-γ autoantibody positive. The final diagnosis for the patient was adult-onset immunodeficiency due to anti-IFN-γ autoantibody, non-tuberculous mycobacterial (NTM) infection and reactive dermatosis. INTERVENTIONS: The patient underwent long-term anti-NTM and corticosteroid maintenance treatment. OUTCOMES: The patient was followed for 2 years during which opportunistic infection no longer happened, the immunoglobulin E level and eosinophil count reduced, the autoantibody levels remained largely steady and lung lesions absorbed. CONCLUSION: Clinicians should be vigilant for NTM infection in patients with anti-IFN-γ autoantibodies, even when culture results are negative. Long-term anti-non-tuberculous mycobacteria and glucocorticoid regimens were effective.

Theophylline and dexamethasone in combination reduce inflammation and prevent the decrease in HDAC2 expression seen in monocytes exposed to cigarette smoke extract.

Lung and systemic inflammation are associated with impaired lung function and increased mortality in patients with chronic obstructive pulmonary disease (COPD). Theophylline and glucocorticoids have been shown to have an anti-inflammatory effect in some respiratory diseases. However, corticosteroid insensitivity is a major barrier to the anti-inflammatory management of COPD. This study aimed to explore whether a combined treatment of theophylline and dexamethasone (Dex) could decrease cigarette smoke extract (CSE)-induced inflammation via prevention of a reduction in histone deacetylase 2 (HDAC2) expression and through inhibition of the PI3K/Akt pathway, which may be related to corticosteroid sensitivity. The half-maximal inhibitory concentration (IC50) of Dex (IC50-Dex) was used to as a marker of corticosteroid sensitivity. IC50-Dex was determined through observation of Dex inhibition of tumor necrosis factor-α (TNF-α)-induced interleukin (IL)-8 release. Using reverse transcription quantitative PCR and western blotting, U937 cells treated with CSE were assessed for HDAC2 expression levels and phosphorylation levels of Akt. Theophylline and Dex pre-treatment was shown to significantly reduce the CSE-induced release of IL-8 and TNF-α. The combination of theophylline and Dex pretreatment also reversed corticosteroid insensitivity in CSE-induced U937 cells and inhibited the PI3K/AKT pathway to a greater extent than theophylline treatment alone. CSE-treated U937 cells showed a reduction in HDAC2 mRNA and protein expression compared with the control group. However, this effect was reduced after pre-incubation with the combined therapy or theophylline alone. In conclusion, pretreatment with theophylline and Dex decreased CSE-induced inflammation via inhibition of the PI3K/Akt pathway and increase in HDAC2 protein expression.

Richness of sputum microbiome in acute exacerbations of eosinophilic chronic obstructive pulmonary disease.

BACKGROUND: The eosinophilic chronic obstructive pulmonary disease (COPD) is known to be more sensitive to corticosteroid. The sputum microbiome has been shown to affect COPD prognosis, but its role in acute exacerbations of eosinophilic COPD is unclear. This study aimed to investigate the dynamic changes of the airway microbiome in patients with acute exacerbations of eosinophilic COPD. METHODS: Fifty-seven patients with acute exacerbations of COPD from the First Affiliated Hospital of Guangxi Medical University between June 2017 and June 2018 were divided into two groups. Patients with eosinophils ≥300 cells/µL in the peripheral venous blood were assigned to the eosinophilic group (Eos) and the rest to the non-eosinophilic group (Noneos). All patients received similar treatment including inhaled budesonide according to the guidelines. The induced sputum microbiome was analyzed on the 1st and 7th day of treatment using the 16S ribosomal RNA (rRNA) method. The levels of interleukin (IL)-6 and IL-8 were measured in the plasma and the sensitivity to corticosteroids was determined in isolated peripheral blood mononuclear cells. Quantitative data were compared between the two groups using the independent samples t test or Mann-Whitney U test. Categorical data were evaluated using Chi-squared test or Fisher's exact test. RESULTS: Twenty-six patients were classified into Eos group and 31 patients were classified into Noneos group. Prior to treatment, the alpha diversity (Shannon index) (2.65 ±â€Š0.63 vs. 2.56 ±â€Š0.54, t = 0.328, P = 0.747) and the structure of the sputum microbiome were similar in the Eos group and the Noneos group. After 7 days of treatment, alpha diversity increased in both groups, while the microbiome richness (Ace index) was significantly lower in the Eos group (561.87 ±â€Š109.13 vs. 767.88 ±â€Š148.48, t = -3.535, P = 0.002). At the same time, IL-6 (12.09 ±â€Š2.85 pg/mL vs. 15.54 ±â€Š2.45 pg/mL, t = -4.913, P < 0.001) and IL-8 (63.64 ±â€Š21.69 pg/mL vs. 78.97 ±â€Š17.13 pg/mL, t = -2.981, P = 0.004) decreased more significantly in the Eos group, and the percentages of inhibition of IL-8 at dexamethasone concentrations 10 to 10 mol/L were significantly higher in the Eos group than those in the Noneos group (all P < 0.05). CONCLUSIONS: The induced sputum microbiome richness decreased more significantly following treatment in the Eos patients compared to the Noneos patients. The lower plasma inflammatory factor levels and the higher percentage of inhibition of IL-8 might be due to higher corticosteroid sensitivity in Eos patients.

Erythromycin reverses cigarette smoke extract-induced corticosteroid insensitivity by inhibition of the JNK/c-Jun pathway.

Corticosteroid insensitivity is a feature of airway inflammation in chronic obstructive pulmonary disease (COPD). Erythromycin exhibits anti-inflammatory activity in COPD, but the concrete mechanism is still unclear. This study aimed to investigate the effects of erythromycin on corticosteroid sensitivity in peripheral blood mononuclear cells (PBMCs) and U937 cells (a human monocytic cell line). PBMCs were collected from non-smokers, healthy smoker volunteers, and COPD subjects. U937 cells were incubated with or without erythromycin and stimulated with TNF-α in the presence or absence of cigarette smoke extract (CSE). The dexamethasone (Dex) concentration required to achieve 50% inhibition of TNF-α-induced interleukin (IL)-8 production was determined and the mitogen-activated protein kinase (MAPK)/Activator protein-1 (AP-1) pathway was also evaluated. Erythromycin improved corticosteroid sensitivity in PBMCs obtained from COPD patients and CSE-treated U937 cells. This improvement in corticosteroid sensitivity was associated with reduced c-Jun expression, which resulted from the inhibition of P38 Mitogen-activated protein kinase (P38MAPK), extracellular signal-regulated protein kinase (ERK)1/2, and c-Jun N-terminal kinase (JNK) phosphorylation. Erythromycin had no effects on the phosphorylated and total protein expression levels of P38MAPK and ERK; however, it induced inhibition of the phosphorylated and total protein expression levels of JNK. This study provides evidence that erythromycin restores corticosteroid sensitivity in PBMCs and U937 cells. JNK inhibition by erythromycin restores corticosteroid sensitivity via the inhibition of c-Jun expression. Thus, JNK/c-Jun is a potential novel therapeutic target for COPD.

Roundabout signaling pathway involved in the pathogenesis of COPD by integrative bioinformatics analysis.

Purpose: To explore the potential mechanism underpinning the development of chronic obstructive pulmonary disease (COPD) and to investigate the role of the Roundabout signaling pathway in COPD. Methods: Three microarray datasets (GSE1650, GSE38974 and GSE76925) including 139 cases of severe COPD and 52 cases of normal smokers without carcinoma, were integrated to screen differentially expressed genes (DEGs) using bioinformatics methods. Gene ontology (GO) annotations and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway of the DEGs were performed by a DAVID online tool. Finally, a cigarette smoke (CS)- induced emphysema mice model was established, the lung mRNA expression levels of genes associated with Slit guidance ligand 2 (SLIT2) -Roundabout (ROBO) signaling pathway were detected by reverse transcription quantitative polymerase chain reaction (RT-qPCR), and the protein level of SLIT2 was examined by immunohistochemistry staining. Results: A total of 315 DEGs were identified in three databases. GO and KEGG pathway analyses suggested that the inflammatory response, extracellular matrix disassembly, immune response, the apoptotic signaling pathway, ubiquitination and the Roundabout signaling pathway all together were involved in the development of COPD. The genes SLIT2 and ROBO2 were decreased in patients with COPD and these decreases were significantly negatively correlated with the disease stages of COPD. Consistently, the mRNA expression levels of SLIT2, ROBO1 and ROBO2, and the protein level of SLIT2 were revealed to be lower in the lungs of CS-induced emphysema mice compared with the air-exposed control mice. In addition, the SLIT2 protein level was negatively associated with alveolar mean linear intercept. Conclusion: Integrated bioinformatics analysis may provide novel insights into the complicated pathogenesis of COPD, and to the best of our knowledge, this study is the first to provide evidence to suggest that the Roundabout signaling pathway may be involved in the pathogenesis of COPD.

Erythromycin suppresses neutrophil extracellular traps in smoking-related chronic pulmonary inflammation.

Neutrophil extracellular traps (NETs) may play a critical role in smoking-related chronic airway inflammation. However, the mechanism by which NETs induced by cigarette smoke initiate the adaptive immunity in chronic obstructive pulmonary disease (COPD) is not fully understood. In this study, we explored the effects of NETs induced by cigarette smoke on the myeloid dendritic cells (mDCs) and Th1 and Th17 cells. Additionally, we observed the inhibitory effect of erythromycin on NETs induced by cigarette smoke. We found that elevated NET levels in the sputum of COPD patients were correlated with the circulating Th1 response, mDC activation and airflow limitation. NETs induced by cigarette smoke extract (CSE) could activate monocyte-derived mDCs and promote Th1 and Th17 differentiation in vitro. Erythromycin effectively inhibited NET formation induced by CSE. In vivo, erythromycin decreased NETs in the airway and ameliorated emphysema with Th1 and Th17 cell down-regulation and CD40+ and CD86+ mDCs suppression in mice chronically exposed to cigarette smoke. These findings provide direct evidence that NETs promote the differentiation of Th1 and Th17 and play a role in the adaptive immunity of smoking-related chronic lung inflammation. Erythromycin is a potential therapeutic strategy for NETs inhibition in COPD.

Expression of GR-α and HDAC2 in steroid-Sensitive and steroid-Insensitive interstitial lung disease.

BACKGROUND: Corticosteroid is one of the main treatments for interstitial lung disease (ILD). Cryptogenic-organizing pneumonia (COP) is sensitive to corticosteroid therapy, whereas idiopathic pulmonary fibrosis (IPF) is not. Glucocorticoid receptor-α (GR-α) and histone deacetylase 2 (HDAC2) play critical roles in the sensitivity to corticosteroid therapy; however, it is unclear whether HDAC2 and/or GR-α are expressed in the lung tissues of patients with COP and/or IPF. Possible aberrant expressions of HDAC2 and GR-α in IPF and COP were investigated in the current study. METHODS: Lung tissue samples were obtained from patients with COP (n = 9), IPF (n = 8), pulmonary abscesses (n = 7), or pulmonary inflammatory pseudotumors (n = 6) before corticosteroid treatment, as well as from control subjects (n = 10). The expression of GR-α, HDAC2, PI3K-δ, and NF-κBp65 in the samples was assessed by immunohistochemistry. RESULTS: GR-α expression was the same in lung tissues from COP patients and control subjects, but was significantly lower in lung tissue from IPF. In addition, HDAC2 was significantly higher in lung tissues of COP patients compared to both IPF and control subjects. Furthermore, the transcription factor NF-κBp65 was significantly lower in lung tissues from both COP and control compared to IPF subjects, whereas there was no difference in NF-κBp65 when comparing tissues from COP patients to controls. HDAC2 and GR-α were negatively correlated with NF-κBp65 in COP lung tissue. CONCLUSION: HDAC2 and GR-α expression in lung tissues are potential biomarkers for predicting corticosteroid sensitivity when initially treating COP and IPF, as well as other forms of ILD.

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.

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.

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.

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.

Elevated frequencies of CD4(+) IL-21(+) T, CD4(+) IL-21R(+) T and IL-21(+) Th17 cells, and increased levels of IL-21 in bleomycin-induced mice may be associated with dermal and pulmonary inflammation and fibrosis.

AIM: Systemic sclerosis (SSc) is characterized by immune abnormalities, progressive fibrosis of the skin and internal organs, and microvascular injury and damage. Interleukin-21 receptor (IL-21R) is expressed in the epidermis from patients with SSc. However, information describing the role of IL-21 in SSc is limited. METHODS: We established a mouse model of bleomycin (BLM)-induced fibrosis. The frequency of CD4(+) IL-21(+) T, CD4(+) IL-21R(+) T and IL-21(+) Th17 cells in peripheral blood, skin and lungs of BLM-induced mice were detected by flow cytometry; IL-21 levels in the peripheral blood were evaluated by enzyme-linked immunosorbent assay (ELISA). CD4(+) T cells were isolated from the spleen of BLM-induced and control mice and cultured in vitro alone or in the presence of mrIL-21 or mrIL-21 plus transforming growth factor (TGF)-ß1. The frequency of Th17 cells was detected by flow cytometry; levels of IL-17 were evaluated by ELISA, and the expression of IL-17A and retinoic-acid-receptor-related orphan receptors gamma t (RORγt) messenger RNA were analyzed by real-time polymerase chain reaction. RESULTS: Compared to control mice, the frequency of CD4(+) IL-21(+) T, CD4(+) 21R(+) T and IL-21(+) Th17 cells and the levels of IL-21 were significantly increased in BLM-induced mice. The frequency of CD4(+) IL-21(+) T, CD4(+) 21R(+) T and IL-21(+) Th17 cells and the levels of IL-21 were correlated with dermal and pulmonary inflammation and fibrosis. In vitro analyses indicate that IL-21 promoted the differentiation of Th17 cells from CD4(+) cells isolated from the spleen of BLM-induced mice. CONCLUSION: IL-21 may play an important role in the pathogenesis of SSc as a Th17 effector cytokine, and IL-21 may induce the differentiation of Th17 cells in the BLM-induced SSc mouse model.

Combination of erythromycin and dexamethasone improves corticosteroid sensitivity induced by CSE through inhibiting PI3K-δ/Akt pathway and increasing GR expression.

Corticosteroid insensitivity, which is induced by cigarette smoke extract (CSE), is a significant barrier when treating chronic obstructive pulmonary disease (COPD). Erythromycin (EM) has been shown to have an anti-inflammatory role in some chronic airway inflammatory diseases, particularly diffuse panbronchiolitis and cystic fibrosis. Here, we explored whether the combination therapy of EM and dexamethasone (Dex) reverses corticosteroid insensitivity and investigated the molecular mechanism by which this occurs. We demonstrated that the combination of EM and Dex restored corticosteroid sensitivity in peripheral blood mononuclear cells (PBMCs) from COPD patients and U937 cells after CSE exposure. Moreover, pretreatment with 10, 50, or 100 µg/ml EM reversed the HDAC2 protein reduction induced by CSE exposure in a dose-dependent manner. U937 cells exposed to CSE show a reduction in histone deacetylase (HDAC) activity, which was potently reversed by EM or combination treatment. Although 10 and 17.5% CSE increased phosphorylated Akt (PAkt) expression in a concentration-dependent manner, preapplication of EM and the combination treatment in particular blocked this PAkt increase. Total Akt levels were unaffected by CSE or EM treatments. Furthermore, the combination treatment enhanced glucocorticoid receptor (GR)α expression. Our results demonstrate that the combination therapy of EM and Dex can restore corticosteroid sensitivity through inhibition of the PI3K-δ/Akt pathway and enhancing GRα expression.

IL-21 induction of CD4+ T cell differentiation into Th17 cells contributes to bleomycin-induced fibrosis in mice.

Systemic sclerosis (SSc) is a connective tissue disease characterized by fibrosis of the skin and internal organs. Th17 cells and interleukin-17 (also called IL-17A) have been found to be increased in peripheral blood and skin in patients with SSc. IL-21 is a potent inducer of Th17 differentiation that is produced by activated T cells, and whose relationship with Th17 cells in SSc is unclear. Here, using a bleomycin (BLM)-induced mouse model of skin fibrosis, we detected the frequency of CD4+/IL-17+ (Th17) cells, CD4+/IL-21+ T cells and IL-21+ Th17 cells in peripheral blood, skin and lungs, as well as the serum content of IL-17A and IL-21. In addition, we assessed the differentiation of CD4+ T cells cultured from these mice into Th17 cells in response to treatment with IL-21. Compared with the control mice, Th17 cell counts and IL-17A levels were significantly increased and correlated with inflammatory and fibrotic indices in the skin and lungs of the BLM-induced fibrosis mice. Moreover, serum levels of CD4+/IL-21+ T cells, IL-21+ Th17 cells, and IL-21 were significantly increased in these mice, and correlated positively with serum levels of Th17 cells. In vitro experiments showed that IL-21 treated CD4+ T cells derived from BLM-induced mice differentiated into Th17 cells. Our results indicate that Th17 cells and IL-17A contributes to inflammatory and fibrotic processes in the skin and lungs in a BLM-induced mouse model of SSc. Moreover, the expansion of the Th17 cell population may be subsequent to IL-21 promotion of the differentiation of CD4+ T cells in these mice.

The Treg/Th17 paradigm in lung cancer.

Pathogenic mechanisms underlying the development of lung cancer are very complex and not yet entirely clarified. T lymphocytes and their immune-regulatory cytokines play a pivotal role in controlling tumor growth and metastasis. Following activation by unique cytokines, CD4+ T helper cells differentiate into Th1, Th2, Th17, and regulatory T cells (Tregs). Traditionally, research in lung cancer immunity has focused almost exclusively on Th1/Th2 cell balance. Recently, Th17 cells and Tregs represent an intriguing issue to be addressed in lung cancer pathogenesis. Tregs play an important role in the preservation of self-tolerance and modulation of overall immune responses against tumor cells. Th17 cells directly or via other proinflammatory cytokines modulate antitumor immune responses. Notably, there is a close relation between Tregs and Th17 cells. However, the possible interaction between these subsets in lung cancer remains to be elucidated. In this setting, targeting Treg/Th17 balance for therapeutic purposes may represent a useful tool for lung cancer treatment in the future. The purpose of this review is to discuss recent findings of the role of these novel populations in lung cancer immunity and to highlight the pleiotropic effects of these subsets on the development and regulation of lung cancer.

Penicillium marneffei infection within an osteolytic lesion in an HIV-negative patient.

Penicillium marneffei is a thermally dimorphic pathogenic fungus that causes systemic infection similar to disseminated cryptococcosis. P. marneffei is endemic in Southeast Asia, usually infecting HIV-infected individuals; infection of HIV-negative individuals is extremely rare. Here, we describe a disseminated P. marneffei infection within an osteolytic lesion in an HIV-negative patient. A 40-year-old Chinese woman presented with intermittent fever, generalized lymphadenopathy, and a skin rash. Following a sternum biopsy, the patient was diagnosed with P. marneffei infection. An emission computed tomography bone scan revealed the presence of increased radioactivity in the left clavicle and sternum, indicative of an osteolytic lesion. In addition to reporting this very rare case, we also present a brief review of the literature, highlighting the differences in clinical manifestations between HIV-positive and HIV-negative patients infected with P. marneffei as it applies to our case.