Immune Checkpoint Inhibitor-Associated Systemic Sclerosis in the Treatment of a Small Cell Lung Cancer Patient with Durvalumab: A Case Report.

As one of the key cancer treatment measures, immune-checkpoint inhibitors (ICIs) have revolutionized the treatment landscape of various cancers, including malignancies previously thought to be untreatable. Immune checkpoint inhibitors work by targeting the dysfunctional immune system, to enhance cancer-cell killing by CD8-positive T cells. Despite the beneficial effects of ICIs, these treatments are also linked to a novel class of side effects, termed immune-related adverse events (irAEs). Immune-related adverse events can affect multiple organ systems, such as endocrine, neurological, gastroenteric, dermatologic, ocular, hepatic, renal, and rheumatic ones. While variable in severity, irAEs can be associated with significant morbidity, mortality, cessation of ICI treatment and can be potentially life-threatening sometimes. Among varieties of irAEs, dermatological manifestations are frequently reported, since they can be easily observed. Here, we present a case of a 74-year-old patient with widespread fibrosis of skin, eventually diagnosed as diffuse cutaneous systemic sclerosis after the treatment with durvalumab for small cell lung cancer (SCLC). Prompt recognition and treatment of immune-checkpoint inhibitors-associated systemic sclerosis may help enhance tolerance to ICIs and ensure better performance in treating tumors.

Value of peripheral blood circulating tumor cell detection in the diagnosis of thoracic diseases and the prediction of severity.

Circulating tumor cell (CTC) detection, as a noninvasive liquid biopsy method, has been used in the diagnosis, prognostic indication, and monitoring of a variety of cancers. In this study, we aimed to investigate whether CTC detection could be used in the early diagnosis and prediction of severity of thoracic diseases. We enrolled 168 thoracic disease patients, all of whom underwent pathological biopsy. Carcinoembryonic antigen (CEA) and neuron-specific enolase (NSE) measurement was also performed in 146 patients. There were 131 cases of malignant thoracic diseases and 37 cases of benign lesions. We detected CTCs in a 5 ml peripheral blood sample with the CTCBiopsy® system and analyzed the value of CTC count for predicting disease severity. Of 131 patients with a diagnosis of thoracic malignancy, CTCs were found in blood samples from 122 patients. However, only 2 out of 37 patients with benign thoracic disease had no detectable CTCs. There was no significant correlation between CTC count and benign and malignant lesions (P = 0.986). However, among 131 patients who had been diagnosed with malignant lesions, 33 had lymph node metastasis or distant metastasis. The presence of CTCs was significantly correlated with metastasis (P = 0.016 OR = 1.14). The area under the receiver operating characteristic (ROC) curve was 0.625 (95% confidence interval (CI), 0.519 to 0.730 P = 0.032). In addition, with stage IA1 as the cutoff, all patients were further divided into an early-stage group and a late-stage group. CTC count was significantly correlated with disease progression (P = 0.031 OR = 1.11), with an area under the curve (AUC) of 0.599 (95% CI, 0.506-0.692 P = 0.47). The sensitivity and specificity of CTC detection for the diagnosis of disease stage were 72.3% and 45.5%, respectively. In addition, the cutoff of 2.5 CTCs was the same when predicting disease metastasis and staging. Furthermore, the combination of CTC count, demographic characteristics and tumor markers had better predictive significance for disease staging. CTC count can effectively indicate the stages and metastasis of thoracic diseases, but it cannot differentiate benign and malignant diseases.

The Role of the Acetylcholine System in Common Respiratory Diseases and COVID-19.

As an indispensable component in human beings, the acetylcholine system regulates multiple physiological processes not only in neuronal tissues but also in nonneuronal tissues. However, since the concept of the "Nonneuronal cholinergic system (NNCS)" has been proposed, the role of the acetylcholine system in nonneuronal tissues has received increasing attention. A growing body of research shows that the acetylcholine system also participates in modulating inflammatory responses, regulating contraction and mucus secretion of respiratory tracts, and influencing the metastasis and invasion of lung cancer. In addition, the susceptibility and severity of respiratory tract infections caused by pathogens such as Mycobacterium Tuberculosis and the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) can also correlate with the regulation of the acetylcholine system. In this review, we summarized the major roles of the acetylcholine system in respiratory diseases. Despite existing achievements in the field of the acetylcholine system, we hope that more in-depth investigations on this topic will be conducted to unearth more possible pharmaceutical applications for the treatment of diverse respiratory diseases.

Challenges of COPD Patients during the COVID-19 Pandemic.

Coronavirus disease 2019 (COVID-19) is a severe systemic infection that is a major threat to healthcare systems worldwide. According to studies, chronic obstructive pulmonary disease (COPD) patients with COVID-19 usually have a high risk of developing severe symptoms and fatality, but limited research has addressed the poor condition of COPD patients during the pandemic. This review focuses on the underlying risk factors including innate immune dysfunction, angiotensin converting enzyme 2 (ACE2) expression, smoking status, precocious differentiation of T lymphocytes and immunosenescence in COPD patients which might account for their poor outcomes during the COVID-19 crisis. Furthermore, we highlight the role of aging of the immune system, which may be the culprit of COVID-19. In brief, we list the challenges of COPD patients in this national pandemic, aiming to provide immune-related considerations to support critical processes in COPD patients during severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and inspire immune therapy for these patients.

From COPD to Lung Cancer: Mechanisms Linking, Diagnosis, Treatment, and Prognosis.

Many studies have proved that the pathogenesis of the chronic obstructive pulmonary disease (COPD) and lung cancer is related, and may cause and affect each other to a certain extent. In fact, the change of chronic airway obstruction will continue to have an impact on the screening, treatment, and prognosis of lung cancer.In this comprehensive review, we outlined the links and heterogeneity between COPD and lung cancer and finds that factors such as gene expression and genetic susceptibility, epigenetics, smoking, epithelial mesenchymal transformation (EMT), chronic inflammation, and oxidative stress injury may all play a role in the process. Although the relationship between these two diseases have been largely determined, the methods to prevent lung cancer in COPD patients are still limited. Early diagnosis is still the key to a better prognosis. Thus, it is necessary to establish more intuitive screening evaluation criteria and find suitable biomarkers for lung cancer screening in high-risk populations with COPD. Some studies have indicated that COPD may change the efficacy of anti-tumor therapy by affecting the response of lung cancer patients to immune checkpoint inhibitors (ICIs). And for lung cancer patients with COPD, the standardized management of COPD can improve the prognosis. The treatment of lung cancer patients with COPD is an individualized, comprehensive, and precise process. The development of new targets and new strategies of molecular targeted therapy may be the breakthrough for disease treatment in the future.

Inducible Costimulator-C-X-C Motif Chemokine Receptor 3 Signaling is Involved in Chronic Obstructive Pulmonary Disease Pathogenesis.

Background: The role of inducible costimulator (ICOS) signaling in chronic obstructive pulmonary disease (COPD) has not been fully elucidated. Methods: We compared the percentages of ICOS+ T cells and ICOS+ regulatory T (Treg) cells in CD4+ T cells and CD4+CD25+FOXP3+ Tregs, respectively, in the peripheral blood of smokers with or without COPD to those in healthy controls. We further characterized their phenotypes using flow cytometry. To investigate the influence of ICOS signaling on C-X-C motif chemokine receptor 3 (CXCR3) expression in COPD, we evaluated the expression levels of ICOS and CXCR3 in vivo and in vitro. Results: ICOS expression was elevated on peripheral CD4+ T cells and CD4+ Tregs of COPD patients, which positively correlated with the severity of lung function impairment in patients with stable COPD (SCOPD), but not in patients with acute exacerbation of COPD (AECOPD). ICOS+CD4+ Tregs in patients with SCOPD expressed higher levels of coinhibitors, programmed cell death protein 1 (PD-1) and T-cell immunoreceptor with Ig and ITIM domains (TIGIT), than ICOS-CD4+ Tregs, whereas ICOS+CD4+ T cells mostly exhibited a central memory (CD45RA-CCR7+) or effector memory (CD45RA-CCR7-) phenotype, ensuring their superior potential to respond potently and quickly to pathogen invasion. Furthermore, increased percentages of CXCR3+CD4+ T cells and CXCR3+CD4+ Tregs were observed in the peripheral blood of patients with SCOPD, and the expression level of CXCR3 was higher in ICOS+CD4+ T cells than in ICOS-CD4+ T cells. The percentage of CXCR3+CD4+ T cells was even higher in the bronchoalveolar lavage fluid than in matched peripheral blood in SCOPD group. Lastly, in vitro experiments showed that ICOS induced CXCR3 expression on CD4+ T cells. Conclusions: ICOS signaling is upregulated in COPD, which induces CXCR3 expression. This may contribute to increased numbers of CXCR3+ Th1 cells in the lungs of patients with COPD, causing inflammation and tissue damage.

Corrigendum: ICOS+ Tregs: A Functional Subset of Tregs in Immune Diseases.

[This corrects the article DOI: 10.3389/fimmu.2020.02104.].

Rhizopus microsporus lung infection in an immunocompetent patient successfully treated with amphotericin B: A case report.

BACKGROUND: Rhizopus microsporus (R. microsporus) lung infection is an invasive fungal disease with high mortality that is increasingly common in immunocompromised patients. However, it is very rare in immunocompetent patients. Here, we present the case of a 19-year-old girl who developed R. microsporus lung infection without any known immunodeficiency. CASE SUMMARY: The patient presented to our hospital because of hemoptysis and irritative cough without expectoration. She was first treated for community-acquired pneumonia until the detection of R. microsporus in bronchoalveolar lavage fluid by metagenomics next-generation sequencing (mNGS). After a combination therapy of intravenous inhalation and local airway perfusion of amphotericin B, she eventually recovered, with significant absorption of lung infections. CONCLUSION: Early diagnosis and treatment are very important for pulmonary mucormycosis. Compared to fungal culture, mNGS is a relatively precise and convenient method to obtain pathogenic results. A combination therapy of intravenous inhalation and local airway perfusion of amphotericin B may be a promising strategy for the treatment of pulmonary mucormycosis in the future.

Clinicopathologic Features and Molecular Biomarkers as Predictors of Epidermal Growth Factor Receptor Gene Mutation in Non-Small Cell Lung Cancer Patients.

Lung cancer ranks first in the incidence and mortality of cancer in the world, of which more than 80% are non-small cell lung cancer (NSCLC). The majority of NSCLC patients are in stage IIIB~IV when they are admitted to hospital and have no opportunity for surgery. Compared with traditional chemotherapy, specific targeted therapy has a higher selectivity and fewer adverse reactions, providing a new treatment direction for advanced NSCLC patients. Tyrosine kinase inhibitors of epidermal growth factor receptor (EGFR-TKIs) are the widely used targeted therapy for NSCLC patients. Their efficacy and prognosis are closely related to the mutation status of the EGFR gene. Clinically, detecting EGFR gene mutation is often limited by difficulty obtaining tissue specimens, limited detecting technology, and economic conditions, so it is of great clinical significance to find indicators to predict EGFR gene mutation status. Clinicopathological characteristics, tumor markers, liquid biopsy, and other predictors are less invasive, economical, and easier to obtain. They can be monitored in real-time, which is supposed to predict EGFR mutation status and provide guidance for the accurate, individualized diagnosis and therapy of NSCLC patients. This article reviewed the correlation between the clinical indicators and EGFR gene mutation status in NSCLC patients.

ICOS+ Tregs: A Functional Subset of Tregs in Immune Diseases.

Recent studies have reported the pathological effect of ICOS+ T cells, but ICOS signals also widely participate in anti-inflammatory responses, particularly ICOS+ regulatory T (Treg) cells. The ICOS signaling pathway endows Tregs with increased generation, proliferation, and survival abilities. Furthermore, there is enough evidence to suggest a superior capacity of ICOS+ Tregs, which is partly attributable to IL-10 induced by ICOS, yet the associated mechanism needs further investigation. In this review, we discuss the complicated role of ICOS+ Tregs in several classical autoimmune diseases, allergic diseases, and cancers and investigate the related therapeutic applications in these diseases. Moreover, we identify ICOS as a potential biomarker for disease treatment and prognostic prediction. In addition, we believe that anti-ICOS/ICOSL monoclonal antibodies exhibit excellent clinical application potential. A thorough understanding of the effect of ICOS+ Tregs and the holistic role of ICOS toward the immune system will help to improve the therapeutic schedule of diseases.

Whole exome sequencing identifies a rare variant in DAAM2 as a potential candidate in idiopathic pulmonary ossification.

BACKGROUND: Diffuse pulmonary ossification (DPO) is a rare disease characterized by bone tissue formation in the lung. DPO can be classified into idiopathic pulmonary ossification (IPO) and secondary pulmonary ossification. Cases with no identified etiology are classified as IPO. Variants of dishevelled associated activator of morphogenesis 2 (DAAM2) have been reported to be involved in the bone-resorption of osteoclasts. METHODS: Whole exome sequencing (WES) was used on samples from a patient with IPO and his healthy parents. The effects of all variants were determined using functional predictors (PolyPhen-2, SIFT, FATHMM and MutationTaster); variants existing only in the patient were further screened compared with his healthy parents. RESULTS: Forty deleterious variants, including 25 single nucleotide variants (SNVs) and 15 insertions and deletions (indels), were identified by WES. Finally, DAAM2 (c.G2960T:p.R987L) was screened by pathway analysis. CONCLUSIONS: We identified a novel variant of DAAM2 (c.G2960T:p.R987L) that might participate in the disease process of IPO.

Peripheral blood CD4+ T cell populations by CD25 and Foxp3 expression as a potential biomarker: reflecting inflammatory activity in chronic obstructive pulmonary disease.

Background: The temporally dynamic changes of CD25 and Foxp3 expression in CD4+ T cells are initiated by T cell receptor (TCR) signals strength or frequency. There is a deficiency of peripheral markers for assessing COPD activity, and the current study was conducted to explore whether peripheral CD4+ T cell populations based on CD25 and Foxp3 expression could serve as an indicator for COPD inflammatory activity. Methods: The distribution and phenotypic characteristics of CD4+CD25±Foxp3± T cells from peripheral blood in different populations were determined by flow cytometry. The model for the differentiation of CD4+ T cells populations by CD25 and Foxp3 expression was explored in vitro. Results: The frequencies of peripheral CD4+CD25+Foxp3- T cells and CD4+CD25+Foxp3+ T cells were increased in AECOPD patients, whereas the frequency of CD4+CD25-Foxp3+ T cells was increased in SCOPD patients without receiving systemic treatment. Phenotypic analysis revealed that CD4+CD25+Foxp3- T cells, CD4+CD25+Foxp3+ T cells and CD4+CD25-Foxp3+ T cells had received antigenic stimulation and resembled central memory or effector memory T cells. The differentiation of CD4+ T cells populations by CD25 and Foxp3 expression was dictated by TCR signals. The paired study indicated that the frequencies of CD4+CD25+Foxp3- T cells, CD4+CD25+Foxp3+ T cells and CD4+CD25- Foxp3+ T cells were decreased while the frequency of CD4+CD25-Foxp3- T cells were increased in the same patients from AECOPD to convalescence. Conclusions: Collectively, we propose that the dynamic changes of CD4+ T cell populations by CD25 and Foxp3 expression could function as potential biomarkers for reflecting inflammatory activity in COPD.

Generation and Immune Regulation of CD4+CD25-Foxp3+ T Cells in Chronic Obstructive Pulmonary Disease.

The imbalance of CD4+Foxp3+ T cell subsets is reportedly involved in abnormal inflammatory immune responses in patients with chronic obstructive pulmonary disease (COPD). However, the possible role of CD4+CD25-Foxp3+ T cells in immune regulation in COPD remains to be investigated. In the current study, distribution and phenotypic characteristics of CD4+CD25-Foxp3+ T cells from peripheral blood were determined by flow cytometry; the origin, immune function and ultimate fate of CD4+CD25-Foxp3+ T cells were further explored in vitro. It was observed that circulating CD4+CD25-Foxp3+ T cells were significantly increased in stable COPD patients (SCOPD) and resembled central memory or effector memory T cells. Compared with peripheral CD4+CD25+Foxp3+ T cells, peripheral CD4+CD25-Foxp3+ T cells showed a lower expression of Foxp3, CTLA-4, HELIOS, and TIGIT, but a higher expression of CD127 and KI-67, suggesting that CD4+CD25-Foxp3+ T cells lost the expression of Tregs-associated molecules following the reduction in CD25. Unexpectedly, our study found that transforming growth factor-ß1 (TGFß1) decreased CD25 expression and played a critical role in the generation of CD4+CD25-Foxp3+ T cells from CD4+CD25+Foxp3+ T cells. Phenotypic analysis further revealed that both inducible and peripheral CD4+CD25-Foxp3+ T cells exhibited the features of activated conventional T cells. Importantly, memory CD4+CD25-Foxp3+ T cells facilitated the proliferation and differentiation of naïve CD4+ T cells into Th17 cells in the presence of IL-1ß, IL-6, IL-23, and TGFß1. Finally, a fraction of CD4+CD25-Foxp3+ T cells, exhibiting instability and plasticity, were converted to Th17 cells when subjected to Th17 cell-polarizing condition. Taken together, we propose that TGFß1 is responsible for the generation of CD4+CD25-Foxp3+ T cells, and these cells functionally exert an auxiliary effect on Th17 cells generation and might perpetuate chronic inflammation in COPD.

BAMBI regulates macrophages inducing the differentiation of Treg through the TGF-ß pathway in chronic obstructive pulmonary disease.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is characterized by continuous flow limitation and the immune system including macrophages and regulatory T lymphocytes (Tregs) is involved in COPD pathogenesis. In our previous study, we investigated that TGF-ß/BAMBI pathway was associated with COPD by regulating the balance of Th17/Treg. However, the role of bone morphogenetic protein and activin membrane-bound inhibitor (BAMBI), a pseudoreceptor of TGF-ß signalling pathway, in regulating the immune system of COPD patients has not been fully studied. Hence, we speculate that the pseudoreceptor BAMBI may play roles in the regulation of M2 macrophages to induce the differentiation of CD4+ naïve T cells into Tregs and influence the immune response in COPD. METHODS: Peripheral blood mononuclear cells (PBMCs) were isolated from healthy nonsmokers (n = 12), healthy smokers (n = 10) and COPD patients (n = 20). Naïve CD4+ T cells and monocytes-induced macrophages were used for coculture assays. The phenotypic characteristics of macrophages and Tregs were determined by flow cytometry. The expression levels of BAMBI and the TGF-ß/Smad pathway members in M2 macrophages were measured by a Western blot analysis. The monocyte-derived macrophages were stimulated with cigarette smoke extract (CSE, concentration of 0.02%) to simulate the smoking process in humans. pCMV-BAMBI was transfected into monocyte-derived M2 macrophages for subsequent co-culture assays and signalling pathway analysis. RESULTS: Our results showed that M2 macrophages could induce the differentiation of Tregs through the TGF-ß/Smad signalling pathway. In addition, monocyte-derived macrophages from COPD patients highly expressed BAMBI, and had a low capacity to induce Tregs differentiation. The expression of BAMBI and the forced expiratory volume in 1 second (FEV1%) were negatively correlated in COPD. Furthermore, overexpression of BAMBI promoted the conversion of M2 macrophages to M1 macrophages via the TGF-ß/Smad pathway. CONCLUSIONS: We demonstrated that BAMBI could promote the polarization process of M2 macrophages to M1 macrophages via the TGF-ß/Smad signalling pathway and that overexpression of BAMBI could decrease the ability of M2 macrophages to induce Treg differentiation. These findings may provide a potential mechanism by which blocking BAMBI could improve immune function to regulate COPD inflammatory conditions.

Cytokine-induced alterations of BAMBI mediate the reciprocal regulation of human Th17/Treg cells in response to cigarette smoke extract.

In CD4+ T helper (Th) cells, transforming growth factor ß (TGF­ß) is indispensable for the induction of both regulatory T (Treg) and interleukin­17­producing effector T helper (Th17) cells. Although BMP and activin membrane­bound inhibitor (BAMBI) is part of a rheostat­like mechanism for the regulation of TGF­ß signalling and autoimmune arthritis in mouse models, the underlying activity of BAMBI on the human Th17/Treg cell axis, particularly during exposure to cigarette smoke, remains to be elucidated. The present study aimed to further characterize BAMBI expression in human CD4+ cells, as well as immune imbalance during activation and cigarette smoke exposure. Results from the present study indicated that exposure to cigarette smoke extract partially suppressed Treg differentiation and promoted Th17 cell generation under stimulation by anti­CD3/28 antibodies and TGF­ß1. Additionally, exposure to cigarette smoke induced an inhibition of phosphorylated­Smad2/Smad3, which may have arisen from a concomitant enhancement of BAMBI expression. In conclusion, human BAMBI may function as a molecular switch to control TGF­ß signalling strength and the Th17/Treg cell balance, which may be used not only as a biomarker but also as a target of new treatment strategies for maintaining immune tolerance and for the treatment of smoking­induced immune disorders.

ANTITUMOR AND APOPTOTIC EFFECTS OF CUCURBITACIN A IN A-549 LUNG CARCINOMA CELLS IS MEDIATED VIA G2/M CELL CYCLE ARREST AND M-TOR/PI3K/AKT SIGNALLING PATHWAY.

BACKGROUND: The main aim of this study was to demonstrate the antitumor potential of cucurbitacin A on A-549 NSCLC (non-small cell lung cancer cells). The effects of Cucurbitacin A on apoptotic induction, cell physic, cell cycle failure and m-TOR/PI3K/Akt signalling pathway were also investigated in the present study. MATERIALS AND METHODS: MTT assay and clonogenic assay were carried out to study effects of this compound on cell cytotoxicity and colony forming tendency in A-549 cells. Moreover, phase and fluorescence microscopic techniques were used to examine the effects on cell morphology and induction of apoptosis. The effects on cell cycle phase distribution were investigated by flow cytometry and effects on m-TOR/PI3K/Akt signalling proteins were assessed by western blot analysis. RESULTS: Results showed that cucurbitacin A induced dose-dependent cytotoxic effects along with suppressing the colony forming tendency in these cells. Cucurbitacin A also induced morphological changes in these cells featuring chromatin condensation, cell shrinkage and apoptotic body formation. G2/M phase cell cycle collapse was also induced by Cucurbitacin A along with inhibition of expression levels of m-TOR/PI3K/Akt proteins. CONCLUSIONS: In conclusion, cucurbitacin A inhibits cancer growth in A-549 NSCLC cells by inducing apoptosis, targeting m-TOR/PI3K/Akt signalling pathway and G2/M cell cycle.

Imbalance between subsets of CD8(+) peripheral blood T cells in patients with chronic obstructive pulmonary disease.

Background. CD8(+) T lymphocytes are known to play a critical role in the pathogenesis of chronic obstructive pulmonary disease (COPD). However, systematic analyses of CD8(+) T cell (Cytotoxic T cells, Tc) subsets in COPD patients have yet to be well conducted. Methods. The whole Tc subsets, including Tc1/2/10/17, CD8(+) regulatory T cells (Tregs) and CD8(+) α7(+) T cells, were quantified by flow cytometry in peripheral blood from 24 stable COPD subjects (SCOPD), 14 patients during acute exacerbations (AECOPD), and 14 healthy nonsmokers (HN). Results. Acute exacerbations of COPD were accompanied by elevated levels of circulating CD8(+) T cells. Tc1 cells were increased in both SCOPD and AECOPD patients, whereas the percentage of Tc2 cells was decreased in SCOPD patients but remained normal in AECOPD patients. Tc17 cells were increased only in AECOPD patients, and the percentage of Tc10 cells was reduced in both SCOPD and AECOPD patients. The imbalances of pro/anti-inflammatory Tc subsets observed in COPD may be caused by the lack of Tc10 cells and the impaired anti-inflammatory capacity of CD8(+) Tregs. Conclusions. The imbalances between subsets of CD8(+) peripheral blood T cells contribute to the immune response dysfunction in COPD pathogenesis.

TGF-ß/BAMBI pathway dysfunction contributes to peripheral Th17/Treg imbalance in chronic obstructive pulmonary disease.

BMP and activin membrane-bound inhibitor (BAMBI) is postulated to inhibit or modulate transforming growth factor ß (TGF-ß) signaling. Furthermore, strong upregulation of BAMBI expression following in vitro infection of chronic obstructive pulmonary disease (COPD) lung tissue has been demonstrated. In this study, we investigated whether TGF-ß/BAMBI pathway is associated with COPD. Blood samples were obtained from 27 healthy controls (HC), 24 healthy smokers (HS) and 29 COPD patients. Elevated Th17/Treg ratios, and increased levels of BAMBI protein and mRNA (in plasma and CD4(+) T cells respectively), were observed in COPD compared with HC and HS. BAMBI expression was first observed on human CD4(+) T cells, with a typical membrane-bound pattern. The enhanced plasma BAMBI levels in COPD positively correlated with the increased plasma TGF-ß1 levels and Th17/Treg ratio. Together, an impaired TGF-ß/BAMBI pathway may promote the inflammation leading to Th17/Treg imbalance, which is a new mechanism in smokers who develop COPD.

Cigarette Smoke Disturbs the Survival of CD8+ Tc/Tregs Partially through Muscarinic Receptors-Dependent Mechanisms in Chronic Obstructive Pulmonary Disease.

BACKGROUND: CD8+ T cells (Cytotoxic T cells, Tc) are known to play a critical role in the pathogenesis of smoking related airway inflammation including chronic obstructive pulmonary disease (COPD). However, how cigarette smoke directly impacts systematic CD8+ T cell and regulatory T cell (Treg) subsets, especially by modulating muscarinic acetylcholine receptors (MRs), has yet to be well elucidated. METHODS: Circulating CD8+ Tc/Tregs in healthy nonsmokers (n = 15), healthy smokers (n = 15) and COPD patients (n = 18) were evaluated by flow cytometry after incubating with anti-CD3, anti-CD8, anti-CD25, anti-Foxp3 antibodies. Peripheral blood T cells (PBT cells) from healthy nonsmokers were cultured in the presence of cigarette smoke extract (CSE) alone or combined with MRs agonist/antagonist for 5 days. Proliferation and apoptosis were evaluated by flow cytometry using Ki-67/Annexin-V antibodies to measure the effects of CSE on the survival of CD8+ Tc/Tregs. RESULTS: While COPD patients have elevated circulating percentage of CD8+ T cells, healthy smokers have higher frequency of CD8+ Tregs. Elevated percentages of CD8+ T cells correlated inversely with declined FEV1 in COPD. CSE promoted the proliferation and inhibited the apoptosis of CD8+ T cells, while facilitated both the proliferation and apoptosis of CD8+ Tregs. Notably, the effects of CSE on CD8+ Tc/Tregs can be mostly simulated or attenuated by muscarine and atropine, the MR agonist and antagonist, respectively. However, neither muscarine nor atropine influenced the apoptosis of CD8+ Tregs. CONCLUSION: The results imply that cigarette smoking likely facilitates a proinflammatory state in smokers, which is partially mediated by MR dysfunction. The MR antagonist may be a beneficial drug candidate for cigarette smoke-induced chronic airway inflammation.

Cigarette smoking promotes inflammation in patients with COPD by affecting the polarization and survival of Th/Tregs through up-regulation of muscarinic receptor 3 and 5 expression.

BACKGROUND: CD4+ T cells in the lung are involved in the pathogenesis of chronic obstructive pulmonary disease (COPD), although CD4+ T cell subsets and the direct effect of smoking on these cells, especially the expression of MRs, have not been comprehensively examined. METHODS: First, circulating CD4+ T cell subsets in healthy nonsmokers, patients with SCOPD and patients with AECOPD were evaluated by flow cytometry. Then, differentiation experiments were carried out using RT-PCR, and Ki-67/Annexin V antibodies were used to measure proliferation and apoptosis. We also explored the impact of CSE on the differentiation and survival of CD4+Th/Tregs and examined the expression of MRs in healthy nonsmokers and patients with SCOPD. RESULTS: We found the percentages of circulating Th1 and Th17 cells were increased in patients with AECOPD, while the percentage of Th2 cells was decreased in patients with SCOPD. The percentages of Th10 cells were decreased in both patients with SCOPD and patients with AECOPD, while the percentages of Tregs were increased. In addition, the percentages of CD4+α-7+ T cells were decreased in patients with SCOPD and patients with AECOPD. However, only the decrease observed in patients with AECOPD was significant. In vitro studies also revealed MR expression affected the polarization of T cells, with different CD4+ T cell subtypes acquiring different MR expression profiles. The addition of CSE facilitated CD4+ T cell polarization towards pro-inflammatory subsets (Th1 and Th17) and affected the survival of CD4+ T cells and Treg cells by up-regulating the expression of MR3 and 5, resulting in an imbalance of CD4+ T cell subsets. CONCLUSIONS: Our findings suggest an imbalance of circulating CD4+ T cell subsets is involved in COPD pathogenesis in smokers. Cigarette smoking may contribute to this imbalance by affecting the polarization and survival of Th/Tregs through the up-regulation of MR3 and MR5.