CD8+ T-lymphocytes in peripheral airways of smokers with chronic obstructive pulmonary disease

The Role of Granzyme B Containing Cells in the Progression of Chronic Obstructive Pulmonary Disease

Background

Lung inflammation plays a vital role in the pathogenesis of chronic obstructive pulmonary disease (COPD), but the characteristics of the inflammatory process remain unclear. There is growing interest in the role of granzyme B (GzmB) because CD8⁺ T cells can induce apoptosis of target cells by releasing GzmB, which in turn may cause tissue injury and remodeling. However, GzmB is also expressed by regulatory cells, which are able to suppress CD8⁺ T cell. The role of GzmB⁺ cells needs to be defined in COPD.

Methods

GzmB⁺ and CD8⁺ cells on alveolar wall of surgically resected lungs of microscopically classified 12 nonsmoking control, 12 panlobular emphysema (PLE) and 30 centrilobular emphysema (CLE) subjects were localized by immunohistochemical method. Positively stained cells on alveolar wall were counted and length of corresponding alveolar wall was measured. The results were expressed as mean number of positively stained cells per mm of alveolar wall in each subject.

Results

The number of GzmB⁺ and CD8⁺ cells on alveolar wall of CLE was greater than that of control or PLE subjects (p<0.05 and p<0.001, respectively). There was a positive relationship between the number of alveolar GzmB⁺ cells and forced expiratory volume in 1 second (FEV₁) (r=0.610, p=0.003) in CLE subjects. The number of alveolar GzmB⁺ cells progressively decreased with decline of FEV₁.

Conclusion

Our finding that number of alveolar GzmB⁺ cells was associated with FEV₁ suggests that GzmB⁺ cells might have protective role in the progression of lung destruction and airflow limitation in CLE, which is the predominant emphysema subtype of COPD.

The impact of periodontitis in the course of chronic obstructive pulmonary disease: Pulmonary and systemic effects

AIMS

The aim of this study was to verify the impact of periodontitis in the course of chronic obstructive pulmonary disease (COPD) in C57Bl/6J mice.

MAIN METHODS

The animals were randomly divided into four groups (n = 8): Basal, Periodontitis (P), COPD and COPD+P. COPD was induced by orotracheal instillation of 30 μl of cigarette extract 3 times/week for 7 weeks. Periodontitis was induced by ligation technique for 22 days. Euthanasia was performed on 51st day. The analyzes were total/differential cells and cytokines recovered from bronchoalveolar lavage (BAL), total/differential blood cell count, platelets, total marrow cell count, airway collagen deposition, alveolar enlargement analyzed by mean linear intercept (Lm), mucus and bone crest reabsorption. One-way ANOVA followed by the Student-Newman-Keuls was used.

KEY FINDINGS

The association COPD+P decreased macrophages (p = 0,0351), TNF-α (p = 0,0071) and INF-γ (p = 0,0004) in BAL, when compared to the COPD group maintaining emphysema levels by alveolar enlargement (p < .05) reorganization of collagen fibers (p = .001) and also mean linear intercept (lm) (p = .001) and mucus (p = .0001). The periodontitis group caused TNF-α increase (p = 0, 0001) in BAL.

SIGNIFICANCE

Periodontitis, per se, does not alter any of the parameters analyzed, except for increased TNF-α in BAL. However, its association with COPD caused macrophages TNF-α and INF-γ alterations, when compared to the COPD group maintaining emphysema levels by alveolar enlargement and reorganization of collagen fibers. It seems that periodontitis is influencing the course of Th1 profile cell, and cytokines and pulmonary alterations. Further studies are needed to clarify the regulatory process underlying these two diseases.

T2 Biologics for Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is a significant cause of morbidity and mortality worldwide. In contrast to other chronic diseases, COPD is increasing in prevalence and is projected to be the third leading cause of death and disability worldwide by 2030. Recent advances in understanding the underlying pathophysiology of COPD has led to the development of novel targeted therapies (biologics and small molecules) that address the underlying pathophysiology of the disease. In severe asthma, biologics targeting type 2 (T2)- mediated immunity have been successful and have changed the treatment paradigm. In contrast, no biologics are currently licensed for the treatment of COPD. Those targeting non-T2 pathways have not demonstrated efficacy and in some cases raised concerns related to safety. With the increasing recognition of the eosinophil and perhaps T2-immunity possibly playing a role in a subgroup of patients with COPD, T2 biologics, specifically anti-IL-5(R), have been tested and demonstrated modest reductions in exacerbation frequency. Potential benefit was related to the baseline blood eosinophil count. These benefits were small compared with asthma. Thus, whether a subgroup of COPD sufferers might respond to anti-IL-5 or other T2-directed biologics remains to be fully addressed and requires further investigation.

Cigarette smoke-induced lung inflammation in COPD mediated via CCR1/JAK/STAT /NF-κB pathway

Inflammation is an important cause of chronic obstructive pulmonary disease (COPD) and its acute exacerbation. However, the critical role of C-C chemokine receptor (CCR)1 in progression of cigarette smoke-induced chronic inflammation remains unclear. We studied CCR1 expression using immunohistochemistry, immunofluorescence, and real-time polymerase chain reaction (RT-PCR) in COPD patients and controls. Cytokine levels in peripheral blood were measured by enzyme-linked immunosorbent assay (ELISA). In vitro, we investigated Janus kinase/signal transducers and activators of transcription (JAK/STAT)/nuclear factor-κB (NF-κB) signaling in cigarette smoke extract-induced or CCR1 deficiency/overexpressed mouse macrophage cell line MH-S by RT-PCR and western blot, and measured the cytokine levels in the supernatant with ELISA. We found that CCR1 expression was upregulated in COPD patients and there was a negative correlation between CCR1 mRNA levels and predicted % forced expiratory volume in 1 min. Inflammatory cytokine levels in the peripheral blood were higher in COPD patients than controls, and these were positively correlated with CCR1 levels. CCR1 was shown to play a critical role in regulating smoke-induced inflammation via JAK/STAT3/NF-κB signaling in vitro. CCR1 may play a critical role in airway inflammation in COPD. Additionally, understanding the molecular mechanism may help develop novel methods for the treatment of COPD.

Physiological response to eccentric and concentric cycling in patients with chronic obstructive pulmonary disease

We aimed to compare the cardiorespiratory, metabolic, and perceptual responses to high- and moderate-intensity eccentric cycling versus moderate-intensity concentric cycling in chronic obstructive pulmonary disease (COPD) patients. Ten patients with moderate COPD (forced expiratory volume in 1 s (FEV₁) = 68.6% ± 20.4% of predicted; 68.3 ± 9.1 years) performed 30 min of moderate-intensity concentric (CONC-M: 50% maximum workload; W_max), moderate-intensity eccentric (ECC-M: 50% W_max), and high-intensity eccentric (ECC-H: 100% W_max) cycling. Average power output, oxygen consumption (V̇O₂), minute ventilation (VE), respiratory frequency (f_R), oxygen saturation (SpO₂), heart rate (HR), systolic and diastolic blood pressure (SBP and DBP), rate of perceived exertion (RPE), and dyspnea were measured during cycling. Compared with CONC-M, lower V̇O₂ (-52% ± 14%), VE (-47% ± 16%), f_R (-21% ± 14%), HR (-14% ± 16%), SBP (-73% ± 54%), RPE (-36% ± 26%), and dyspnea (-41% ± 37%) were found during ECC-M. During ECC-H, a similar metabolic demand to CONC-M was found. However, average power output was 117% ± 79% higher during ECC-H. Eccentric cycling can be safely performed by COPD patients and induced lower cardiorespiratory, metabolic, and perceptual responses than concentric exercise when performed at the same workload. Novelty Moderate- and high-intensity eccentric cycling can be performed by COPD patients. Moderate-intensity eccentric cycling showed lower cardiorespiratory, metabolic, and perceptual demand than concentric cycling at the same workload in COPD patients. Even at double workload, eccentric cycling induces lower cardiorespiratory, metabolic, and perceptual demand than moderate-intensity concentric cycling.

Role of Regulatory T Cells in Disturbed Immune Homeostasis in Patients With Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is a complex chronic disease in which T cell-mediated pulmonary inflammation has been shown to play a key role. Accumulating evidence shows that COPD has many of the characteristics of an autoimmune response. An adaptive immune response directed against lung self-antigens, which are released during the initial innate inflammatory response and are triggered by constant exposure to cigarette smoke and epithelial injury, drives the persistent inflammatory response found in smokers. The development and severity of adaptive inflammation depend on the level of tolerance to self-antigens. For these reasons, the effect of regulatory T (Treg) cells on adaptive immunity in COPD patients is of particular interest and could be targeted therapeutically. The disturbance in immune homeostasis caused by changes in the number or function of Treg cells, which is related to cigarette smoke exposure, may be of importance in understanding the development and progression of COPD.

Bronchial mucosal inflammation and illness severity in response to experimental rhinovirus infection in COPD

Background

Respiratory viral infection causes chronic obstructive pulmonary disease (COPD) exacerbations. We previously reported increased bronchial mucosa eosinophil and neutrophil inflammation in patients with COPD experiencing naturally occurring exacerbations. But it is unclear whether virus per se induces bronchial mucosal inflammation, nor whether this relates to exacerbation severity.

Objectives

We sought to determine the extent and nature of bronchial mucosal inflammation following experimental rhinovirus (RV)-16–induced COPD exacerbations and its relationship to disease severity.

Methods

Bronchial mucosal inflammatory cell phenotypes were determined at preinfection baseline and following experimental RV infection in 17 Global Initiative for Chronic Obstructive Lung Disease stage II subjects with COPD and as controls 20 smokers and 11 nonsmokers with normal lung function. No subject had a history of asthma/allergic rhinitis: all had negative results for aeroallergen skin prick tests.

Results

RV infection increased the numbers of bronchial mucosal eosinophils and neutrophils only in COPD and CD8⁺ T lymphocytes in patients with COPD and nonsmokers. Monocytes/macrophages, CD4⁺ T lymphocytes, and CD20⁺ B lymphocytes were increased in all subjects. At baseline, compared with nonsmokers, subjects with COPD and smokers had increased numbers of bronchial mucosal monocytes/macrophages and CD8⁺ T lymphocytes but fewer numbers of CD4⁺ T lymphocytes and CD20⁺ B lymphocytes. The virus-induced inflammatory cells in patients with COPD were positively associated with virus load, illness severity, and reductions in lung function.

Conclusions

Experimental RV infection induces bronchial mucosal eosinophilia and neutrophilia only in patients with COPD and monocytes/macrophages and lymphocytes in both patients with COPD and control subjects. The virus-induced inflammatory cell phenotypes observed in COPD positively related to virus load and illness severity. Antiviral/anti-inflammatory therapies could attenuate bronchial inflammation and ameliorate virus-induced COPD exacerbations.

The effects of BAFF on T lymphocytes in chronic obstructive pulmonary disease

Background

It has been reported that B cell activating factor belonging to the tumor necrosis factor family (BAFF) expression is increased in chronic obstructive pulmonary disease (COPD). However its role in this chronic inflammatory disease is not fully understood. Previous studies have suggested that BAFF also affects T cell function. We therefore investigated the effects of BAFF on T lymphocytes in COPD.

Methods

BAFF was detected in the cells of sputum and the plasma. Peripheral blood mononuclear cells (PBMCs) were isolated from COPD patients and treated with BAFF or BAFF plus BR3-Fc (BAFF antagonist). The apoptosis of CD4⁺ cells and CD8⁺ cells was analyzed by flow cytometry. CD4⁺ cells and CD8⁺ cells were isolated from peripheral blood of COPD patients respectively and treated with BAFF or BAFF plus BR3-Fc. Interferon-γ (IFN-γ) and interleukin-4 (IL-4) were detected in the CD4⁺ cells, and perforin and granzyme B were detected in the CD8⁺ cells.

Results

BAFF expression was increased in the cells of sputum and the plasma from COPD patients compared with control subjects. The plasma BAFF levels were inversely correlated with FEV₁ percentage of predicted in patients with COPD. BAFF did not significantly alter the apoptosis of CD4⁺ cells, however it significantly inhibited the apoptosis of CD8⁺ cells from COPD patients. BAFF increased IFN-γ expression in the CD4⁺ cells from COPD patients, while it did not significantly alter the expresson of IL-4 in these cells. BAFF increased the expression of perforin and granzyme B in the CD8⁺ cells from COPD patients.

Conclusions

Our findings indicate that BAFF may be involved in the inflammatory response in COPD via affecting T lymphocytes, suggesting a possible role of BAFF in the pathogenesis of COPD.

The Impact of Cigarette Smoking on Risk of Rheumatoid Arthritis: A Narrative Review

Rheumatoid arthritis (RA) is an autoimmune disease characterized by chronic inflammation and subsequent proliferation of synovial tissues, which eventually leads to cartilage and bone destruction without effective treatments. Anti-citrullinated cyclic peptide/protein antibody (ACPA) and rheumatoid factor (RF) are two main characteristic autoantibodies found in RA patients and are associated with unfavorable disease outcomes. Although etiologies and causes of the disease have not been fully clarified yet, it is likely that interactive contributions of genetic and environmental factors play a main role in RA pathology. Previous works have demonstrated several genetic and environmental factors as risks of RA development and/or autoantibody productions. Among these, cigarette smoking and HLA-DRB1 are the well-established environmental and genetic risks, respectively. In this narrative review, we provide a recent update on genetic contributions to RA and the environmental risks of RA with a special focus on cigarette smoking and its impacts on RA pathology. We also describe gene–environmental interaction in RA pathogenesis with an emphasis on cigarette smoking and HLA-DRB1.

COPD: To Be or Not to Be, That is the Question

As our knowledge on the natural history of chronic obstructive pulmonary disease (COPD) progresses, a conceptual model simply based on an accelerated decline of lung function in adult life in response to smoking has become inadequate to capture the complexity of this disease, and increasing attention is being given to possible contributions from events or alterations of developmental processes that take place earlier in life. In addition, a remarkable heterogeneity has emerged among the pathobiological mechanisms that are involved in different phenotypes of COPD, suggesting that an effective disease management will require individualized treatment approaches largely based on the underlying biological mechanisms (endotypes). In this review, we will discuss the many faces of COPD from an epidemiological, pathobiological, and clinical standpoint and argue that airflow limitation encompasses a number of manifestations that are too diverse to be still clustered under the same diagnostic label.

Cigarette smoke affects the onco-suppressor DAB2IP expression in bronchial epithelial cells of COPD patients

Cigarette smoke is a risk factor for COPD and lung cancer. In cancer, epigenetic modifications affect the expression of Enhancer of Zester Homolog 2 (EZH2), and silenced disabled homolog 2 interacting protein gene (DAB2IP) (onco-suppressor gene) by Histone H3 tri-methylation in lysine 27 (H3K27me3). In"ex vivo"studies, we assessed EZH2, H3K27me3 and DAB2IP immunoreactivity in bronchial epithelial cells from COPD patients (smokers, ex-smokers), Smoker and control subjects. In"in vitro" experiments we studied the effect of cigarette smoke extract (CSE) on EZH2/H3K27me3/DAB2IP expression, apoptosis, invasiveness, and vimentin expression in 16HBE, primary cells, and lung cancer cell lines (A549) long-term exposed to CSE. Finally, in "in vitro"studies, we tested the effect of GSK343 (selective inhibitor of EZH2). EZH2 and H3K27me3 expression was higher, while DAB2IP was lower levels, in bronchial epithelium from COPD and Smokers than in Controls. CSE increased EZH2, H3K27me3 expression and decreased DAB2IP, cell apoptosis and invasiveness in epithelial cells. GSK343 restored the effects of CSE. Cigarette smoke affects EZH2 expression, and reduced DAB2IP via H3K27me3 in COPD patients. The molecular mechanisms associated with EZH2 expression, generate a dysregulation of cell apoptosis, mesenchymal transition, and cell invasiveness in bronchial epithelial cells, encouraging the progression of airway inflammation toward lung cancer in COPD patients.

Airway inflammation in COPD: progress to precision medicine

Chronic obstructive pulmonary disease (COPD) is a significant cause of morbidity and mortality worldwide, and its prevalence is increasing. Airway inflammation is a consistent feature of COPD and is implicated in the pathogenesis and progression of COPD, but anti-inflammatory therapy is not first-line treatment. The inflammation has many guises and phenotyping this heterogeneity has revealed different patterns. Neutrophil-associated COPD with activation of the inflammasome, T1 and T17 immunity is the most common phenotype with eosinophil-associated T2-mediated immunity in a minority and autoimmunity observed in more severe disease. Biomarkers have enabled targeted anti-inflammatory strategies and revealed that corticosteroids are most effective in those with evidence of eosinophilic inflammation, whereas, in contrast to severe asthma, response to anti-interleukin-5 biologicals in COPD has been disappointing, with smaller benefits for the same intensity of eosinophilic inflammation questioning its role in COPD. Biological therapies beyond T2-mediated inflammation have not demonstrated benefit and in some cases increased risk of infection, suggesting that neutrophilic inflammation and inflammasome activation might be largely driven by bacterial colonisation and dysbiosis. Herein we describe current and future biomarker approaches to assess inflammation in COPD and how this might reveal tractable approaches to precision medicine and unmask important host-environment interactions leading to airway inflammation.

Multi-level immune response network in mild-moderate Chronic Obstructive Pulmonary Disease (COPD)

Background

Chronic Obstructive Pulmonary Disease (COPD) is associated with an abnormal pulmonary and systemic immune response to tobacco smoking. Yet, how do immune cells relate within and between these two biological compartments, how the pulmonary infiltrate influences the lung transcriptome, and what is the role of active smoking vs. presence of disease is unclear.

Methods

To investigate these questions, we simultaneously collected lung tissue and blood from 65 individuals stratified by smoking habit and presence of the disease. The immune cell composition of both tissues was assessed by flow cytometry, whole lung transcriptome was determined with Affymetrix arrays, and we used Weighted Gene Co-expression Network Analysis (WGCNA) to integrate results.

Results

Main results showed that: (1) current smoking and the presence of COPD were both independently associated with a reduction in the proportion of lung T cells and an increase of macrophages, specifically those expressing CD80 + CD163+; (2) changes in the proportion of infiltrating macrophages, smoking status or the level of airflow limitation were associated to different WGCNA modules, which were enriched in iron ion transport, extracellular matrix and cilium organization gene ontologies; and, (3) circulating white blood cells counts were correlated with lung macrophages and T cells.

Conclusions

Mild-moderated COPD lung immune infiltrate is associated with the active smoking status and presence of disease; is associated with changes in whole lung tissue transcriptome and marginally reflected in blood.

Electronic supplementary material

The online version of this article (10.1186/s12931-019-1105-z) contains supplementary material, which is available to authorized users.

Relationship between neutrophil-lymphocyte ratio and short-term prognosis in the chronic obstructive pulmonary patients with acute exacerbation

We retrospectively collected data from a large sample size of population and explore the relationship between neutrophil–lymphocyte ratio (NLR) and adverse outcomes, and assessed the clinical prognostic utility of NLR in patients with chronic obstructive pulmonary patients with acute exacerbation (AECOPD). We reviewed 3 years medical case records, 622 patients were identified including 48 died and 574 alive. Compared with alive group, the died group had significantly elevated neutrophils, lymphocyte, and NLR level (P<0.001). The high-sensitive C-protein level of died group was also higher compared with alive group (7.48 ± 4.2 vs 1.26 ± 0.56, vs P<0.001). The univariate logistic regression indicated that elevated NLR level was associated with the increased of adverse outcome (odds ratio [OR] = 4.59, 95% CI: 2.27–8.94, P<0.001). After adjusted potential confounding factors, the elevated NLR level was still associated with adverse outcomes in the chronic obstructive pulmonary patients with acute exacerbation (OR = 2.05, 95% CI: 1.21–3.48, P=0.008). The area under the receiver operating characteristic curve for death at 90 days was 0.742 (95% CI: 0.554–0.881). NLR cutoff of >4.19 had a sensitivity of 71.4% and specificity of 74.2%. Our results suggested that NLR, as a rapid, inexpensive and easily obtained blood routine index was associated with short-term adverse outcomes in patients with AECOPD. The elevated NLR predicted the increased the risk of 90-day mortality in patients with AECOPD.

The pathology of small airways disease in COPD: historical aspects and future directions

Small airways disease (SAD) is a cardinal feature of chronic obstructive pulmonary disease (COPD) first recognized in the nineteenth century. The diverse histopathological features associated with SAD underpin the heterogeneous nature of COPD. Our understanding of the key molecular mechanisms which drive the pathological changes are not complete. In this article we will provide a historical overview of key histopathological studies which have helped shape our understanding of SAD and discuss the hallmark features of airway remodelling, mucous plugging and inflammation. We focus on the relationship between SAD and emphysema, SAD in the early stages of COPD, and the mechanisms which cause SAD progression, including bacterial colonization and exacerbations. We discuss the need to specifically target SAD to attenuate the progression of COPD.

Immunodeficiency in Patients with Acute Exacerbation of Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD), characterized by progressive airway inflammation and irreversible airflow limitation, leads to serious decline in life quality. The acute exacerbation of COPD (AECOPD) results in high healthcare costs as well as a significant mortality rate. The most common cause of acute exacerbation is infection. Immune deficiency, which induces dysfunction of anti-infection, plays an important role in the pathogenesis of acute exacerbation. As described in this review, the immune dysfunction in patients with AECOPD can be a major focus of efforts to therapeutic strategy.

Chronic Lung Pathologies That Require Repair and Regeneration

Chronic lung diseases, such as chronic obstructive pulmonary disease (COPD) and pulmonary fibrosis, are a major cause of mortality worldwide. With the increasing incidence with ageing, the full impact of these diseases is yet to be realised. For most chronic lung diseases there are limited treatments options, with the existing approaches mainly addressing symptom relief. Little progress has been made, in recent years, in the development of new therapeutic strategies for managing these burdensome pathologies. There is an urgent need to increase our understanding of the mechanisms underlying these diseases. Endogenous progenitor cells (stem cells) have been recognised in many organs, including the lungs where they are suggested to maintain a population of cells that are able to facilitate the endogenous repair processes. Emerging knowledge of how these repair processes are disrupted in chronic lung diseases and the potential to capitalise upon the regenerative capacity of stem cell populations raise the hopes of the field worldwide for innovative treatment approaches for these devastating diseases in the future. This chapter outlines the series of diseases that may benefit from these emerging new therapeutic outlooks.

Cytotoxic lymphocytes in COPD airways: increased NK cells associated with disease, iNKT and NKT-like cells with current smoking

BACKGROUND

Cytotoxic lymphocytes are increased in the airways of COPD patients. Whether this increase is driven primarily by the disease or by smoking is not clear, nor whether it correlates with the rate of decline in lung function.

METHODS

Bronchoscopy with BAL was performed in 52 subjects recruited from the longitudinal OLIN COPD study according to pre-determined criteria; 12 with COPD and a rapid decline in lung function (loss of FEV₁ ≥ 60 ml/year), 10 with COPD and a non-rapid decline in lung function (loss of FEV₁ ≤ 30 ml/year), 15 current and ex-smokers and 15 non-smokers with normal lung function. BAL lymphocyte subsets were determined using flow cytometry.

RESULTS

In BAL fluid, the proportions of NK, iNKT and NKT-like cells all increased with pack-years. Within the COPD group, NK cells - but not iNKT or NKT-like cells - were significantly elevated also in subjects that had quit smoking. In contrast, current smoking was associated with a marked increase in iNKT and NKT-like cells but not in NK cells. Rate of lung function decline did not significantly affect any of the results.

CONCLUSIONS

In summary, increased proportions of NK cells in BAL fluid were associated with COPD; iNKT and NKT-like cells with current smoking but not with COPD. Interestingly, NK cell percentages did not normalize in COPD subjects that had quit smoking, indicating that these cells might play a role in the continued disease progression seen in COPD even after smoking cessation.

TRIAL REGISTRATION

Clinicaltrials.gov identifier NCT02729220 .

Effects of cigarette smoke on immunity, neuroinflammation and multiple sclerosis

Cigarette smoking is the most prominent significant cause of death and morbidity. It is recognised as a risk factor for a number of immune mediated, inflammatory diseases including multiple sclerosis (MS). Here, we review the complex immunological effects of smoking on the immune system, which include enhancement of inflammatory responses with a parallel reduction of some immune defences, resulting in an increased susceptibility to infection and a persistent proinflammatory environment. We discuss the effect of smoking on the susceptibility, clinical course, disability, and mortality in MS, the likely benefits of smoking cessation, and the specific immunological effects of smoking in MS. In conclusion, smoking is an important environmental risk factor for MS occurrence and outcome, and it acts in significant part through immunological mechanisms.

Roles for T/B lymphocytes and ILC2s in experimental chronic obstructive pulmonary disease

Pulmonary inflammation in chronic obstructive pulmonary disease (COPD) is characterized by both innate and adaptive immune responses; however, their specific roles in the pathogenesis of COPD are unclear. Therefore, we investigated the roles of T and B lymphocytes and group 2 innate lymphoid cells (ILC2s) in airway inflammation and remodelling, and lung function in an experimental model of COPD using mice that specifically lack these cells (Rag1^−/− and Rora^fl/flIl7r^Cre [ILC2‐deficient] mice). Wild‐type (WT) C57BL/6 mice, Rag1^−/−, and Rora^fl/flIl7r^Cre mice were exposed to cigarette smoke (CS; 12 cigarettes twice a day, 5 days a week) for up to 12 weeks, and airway inflammation, airway remodelling (collagen deposition and alveolar enlargement), and lung function were assessed. WT, Rag1^−/−, and ILC2‐deficient mice exposed to CS had similar levels of airway inflammation and impaired lung function. CS exposure increased small airway collagen deposition in WT mice. Rag1^−/− normal air‐ and CS‐exposed mice had significantly increased collagen deposition compared to similarly exposed WT mice, which was associated with increases in IL‐33, IL‐13, and ILC2 numbers. CS‐exposed Rora^fl/flIl7r^Cre mice were protected from emphysema, but had increased IL‐33/IL‐13 expression and collagen deposition compared to WT CS‐exposed mice. T/B lymphocytes and ILC2s play roles in airway collagen deposition/fibrosis, but not inflammation, in experimental COPD.

Changes in the expression level of IL-17A and p53-fibrinolytic system in smokers with or without COPD

COPD is a chronic airway inflammatory disease characterized mainly by neutrophil airway infiltrations. The neutrophil airway inflammation is mainly mediated through a key player like the pro-inflammatory cytokine IL-17A which is involved in the modulation of p53-fibrinolytic system. This study was undertaken to examine the molecular changes for the expressions of IL-17A and p53-fibrinolytic system in smokers with or without COPD. Blood and serum samples were collected from ten patients of smokers having COPD and ten samples from smokers without COPD and ten healthy control subjects. Western blot analyses were performed to evaluate the expressions of IL-17A, p53 and PAI-1. Apoptosis was assessed by immunoblot for cleaved caspase-3. In addition, FEV% was also determined of these patients. qRT-PCR was done to detect the gene expression study from the blood samples on p53-fibrinolytic components. A significant difference was found in the expression levels of IL-17A in smokers with COPD patient when compared to smokers without COPD and the control subjects. Similarly the smokers with COPD showed significant increase in the fibrinolytic component PAI-1 as well as in expression levels of p53 when compared to smokers without COPD and normal subjects. Increased cleaved caspase-3 may also promote apoptosis.The expression pattern of the IL-17A in chronic obstructive pulmonary distress syndrome samples was increased as compared of those of normal samples, and their main role in the regulation of and p53-fibrinolytic system makes these components as a predictive prominent component in smokers with COPD.

Differences in prevalence of asthma-COPD overlap according to different criteria

Asthma and chronic obstructive pulmonary disease (COPD) are common chronic airway diseases. Overlap in the clinical features of these 2 diseases is observed in many cases, and thus, the concept of asthma-COPD overlap (ACO) has recently been proposed. However, the definition of ACO and the clinical significance remains to be determined.We evaluated the prevalence and risk of acute exacerbation in ACO among Korean COPD patients as defined by modified Spanish criteria and American Thoracic Society (ATS) Roundtable criteria.The prevalence of ACO was 47.7% (660/1383) by modified Spanish criteria and 1.9% (26/1383) by ATS Roundtable criteria. ACO, regardless of criteria, did not significant affect the exacerbation risk during at least 1-year follow-up period.Substantial discrepancies were found in the prevalence and outcome of ACO according to different diagnostic criteria, which would compromise implementation of ACO before the definition is established.

Proteases and Their Inhibitors in Chronic Obstructive Pulmonary Disease

In the context of respiratory disease, chronic obstructive pulmonary disease (COPD) is the leading cause of mortality worldwide. Despite much development in the area of drug development, currently there are no effective medicines available for the treatment of this disease. An imbalance in the protease: Antiprotease ratio in the COPD lung remains an important aspect of COPD pathophysiology and several studies have shown the efficacy of antiprotease therapy in both in vitro and in vivo COPD models. However more in-depth studies will be required to validate the efficacy of lead drug molecules targeting these proteases. This review discusses the current status of protease-directed drugs used for treating COPD and explores the future prospects of utilizing the potential of antiprotease-based therapeutics as a treatment for this disease.

Small airway inflammation and extrafine inhaled corticosteroids plus long-acting beta2-agonists formulations in chronic obstructive pulmonary disease

OBJECTIVES

To summarize the evidence of small airways involvement in chronic obstructive pulmonary disease (COPD) pathophysiology, and to evaluate the efficacy of extrafine formulations of inhaled corticosteroids (ICS) in combination with long-acting beta₂-agonists (LABAs) in the treatment of COPD.

DATA SOURCE

A search of the PubMed database was conducted using the keywords "COPD", "small airways", "inflammation" and "extrafine formulation." The search was limited to entries published in English before August 2016. Only studies conducted in humans were considered.

STUDY SELECTION

Publications were included on the basis of relevance.

RESULTS

COPD is a common preventable and treatable disease, characterized by persistent and progressive airflow limitation. With improved understanding of COPD pathophysiology, small airways (internal diameter <2 mm), a well-known major site of COPD-associated inflammation and remodeling, have emerged as a potential target for COPD pharmacologic therapies. The ability of extrafine formulations of ICS in combination with LABAs to achieve central and peripheral lung deposition, and the implications of the enhanced efficacy that this may bring, are discussed by examining findings from the development trials plan of the extrafine formulation of beclometasone dipropionate/formoterol fumarate (Foster^®, Chiesi Farmaceutici, Italy) in patients with COPD.

CONCLUSION

There is an urgent need for improved and reliable techniques for small airways assessment in order to detect early damage, disease progression and response to treatment. Evidence from randomized clinical trials supports the benefits of extrafine ICS/LABA formulations in COPD, real world studies are necessary to confirm this.

Cigarette smoke and non-neuronal cholinergic system in the airway epithelium of COPD patients

Acetylcholine (ACh), synthesized by Choline Acetyl-Transferase (ChAT), exerts its physiological effects via mAChRM3 in epithelial cells. We hypothesized that cigarette smoke affects ChAT, ACh, and mAChRM3 expression in the airways from COPD patients promoting airway disease. ChAT, ACh, and mAChRM3 were assessed: "ex vivo" in the epithelium from central and distal airways of COPD patients, Healthy Smoker (S) and Healthy Subjects (C), and "in vitro" in bronchial epithelial cells stimulated with cigarette smoke extract (CSE). In central airways, mAChRM3, ChAT, and ACh immunoreactivity was significantly higher in the epithelium from S and COPD than in C subjects. mAChRM3, ChAT, and ACh score of immunoreactivity was high in the metaplastia area of COPD patients. mAChRM3/ChAT and ACh/ChAT co-localization of immunoreactivity was observed in the bronchial epithelium from COPD. In vitro, CSE stimulation significantly increased mAChRM3, ChAT, and ACh expression and mAChRM3/ChAT and ACh/ChAT co-localization in 16HBE and NHBE, and increased 16HBE proliferation. Cigarette smoke modifies the levels of mAChMR3, ChAT expression, and ACh production in bronchial epithelial cells from COPD patients. Non-neuronal components of cholinergic system may have a role in the mechanism of bronchial epithelial cell proliferation, promoting alteration of normal tissue, and of related pulmonary functions.

Extracellular matrix promotes proliferation, migration and adhesion of airway smooth muscle cells in a rat model of chronic obstructive pulmonary disease via upregulation of the PI3K/AKT signaling pathway

Extracellular matrix (ECM) creates the tissue microenvironment and serves a role in airway wall remodeling in chronic obstructive pulmonary disease (COPD). However, the biological function of ECM in COPD remains to be elucidated. In the present study, 24 healthy Sprague Dawley rats were randomized to normal and COPD groups. COPD was established by intratracheal injection with lipopolysaccharide over 30 days. Subsequently, airway smooth muscle cells (ASMCs) were isolated from rats and served as a model to assess the effects of three ECM components, including collagen type I, laminin and collagen type III (COL‑3). Functional analysis in vitro, using cell counting kit‑8, flow cytometry, wound healing and cell adhesion assays indicated that the ECM components could promote cell proliferation, cell cycle progression, migration and adhesion ability, respectively. Furthermore, as demonstrated by ELISA, treatment with ECM components increased levels of C‑X‑C motif chemokine ligand 1 (CXCL1), CXCL8 and interleukin‑6 in ASMCs. Expression of transforming growth factor β1 (TGFβ1), fibroblast growth factor‑1 (FGF‑1) and tissue inhibitor of metalloproteinase 1 (TIMP1) was increased, and expression of matrix metalloproteinase‑9 (MMP‑9) was decreased following treatment with ECM components, as demonstrated by reverse transcription‑quantitative polymerase chain reaction and western blot analysis. Additionally, specific activation of phosphoinositide 3‑kinase (PI3K) signaling, using insulin‑like growth factor‑1 (IGF‑1), promoted cell proliferation and cell cycle progression, increased expression of TGFβ1, FGF‑1, PI3K, AKT, phospho‑AKT, serine/threonine‑protein kinase mTOR (mTOR), phospho‑mTOR and TIMP1, promoted cell migration capacity and reduced the expression level of MMP‑9 in cells from COPD rats. Consistently, PI3K inhibitor LY294002 exerted the opposite effect to IGF‑1. In conclusion, ECM proteins promoted proliferation, migration and adhesion of ASMCs form rat models of COPD through activation of the PI3K/AKT signaling pathway.

Roles of Myeloid and Lymphoid Cells in the Pathogenesis of Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is currently the third largest cause of human mortality in the world after stroke and heart disease. COPD is characterized by sustained inflammation of the airways, leading to destruction of lung tissue and declining pulmonary function. The main risk factor is known to be cigarette smoke currently. However, the strategies for prevention and treatment have not altered significantly for many years. A growing body of evidences indicates that the immune system plays a pivotal role in the pathogenesis of COPD. The repeated and progressive activation of immune cells is at least in part the source of this chronic inflammation. In this review paper, we have conducted an extensive literature search of the studies of immune cells in COPD patients. The objective is to assess the contributions of different immune cell types, the imbalance of pro/anti-inflammatory immune cells, such as M1/M2 macrophages, Tc1/Tc10, and Th17/Treg, and their mediators in the peripheral blood as well as in the lung to the pathogenesis of COPD. Therefore, understanding their roles in COPD development will help us find the potential target to modify this disease. This review focuses predominantly on data derived from human studies but will refer to animal studies where they help understand the disease in humans.

Inhaled corticosteroids in COPD: Personalising the therapeutic choice

There has been a recent surge in interest in the role of inhaled corticosteroids (ICS) in the treatment of COPD, especially regarding patients with high eosinophil counts. Evidence has shown that despite the increase in localised adverse effects and a small increase in non-fatal pneumonia events with ICS use, ICS still have an important role to play in reducing exacerbation rates and addressing the inflammation that is at the heart of the pathogenesis of COPD. Current international guidelines recommend the use of ICS only in patients with severe disease. This review examines the potential role of ICS in all COPD patients.

Cigarette smoke exposure worsens acute lung injury in antibiotic-treated bacterial pneumonia in mice

Evidence is accumulating that exposure to cigarette smoke (CS) increases the risk of developing acute respiratory distress syndrome (ARDS). Streptococcus pneumoniae is the most common cause of bacterial pneumonia, which in turn is the leading cause of ARDS. Chronic smokers have increased rates of pneumococcal colonization and develop more severe pneumococcal pneumonia than nonsmokers; yet mechanistic connections between CS exposure, bacterial pneumonia, and ARDS pathogenesis remain relatively unexplored. We exposed mice to 3 wk of moderate whole body CS or air, followed by intranasal inoculation with an invasive serotype of S. pneumoniae. CS exposure alone caused no detectable lung injury or bronchoalveolar lavage (BAL) inflammation. During pneumococcal infection, CS-exposed mice had greater survival than air-exposed mice, in association with reduced systemic spread of bacteria from the lungs. However, when mice were treated with antibiotics after infection to improve clinical relevance, the survival benefit was lost, and CS-exposed mice had more pulmonary edema, increased numbers of BAL monocytes, and elevated monocyte and lymphocyte chemokines. CS-exposed antibiotic-treated mice also had higher serum surfactant protein D and angiopoietin-2, consistent with more severe lung epithelial and endothelial injury. The results indicate that acute CS exposure enhances the recruitment of immune cells to the lung during bacterial pneumonia, an effect that may provide microbiological benefit but simultaneously exposes the mice to more severe inflammatory lung injury. The inclusion of antibiotic treatment in preclinical studies of acute lung injury in bacterial pneumonia may enhance clinical relevance, particularly for future studies of current or emerging tobacco products.

Immune cell response to strenuous resistive breathing: comparison with whole body exercise and the effects of antioxidants

Background/hypothesis

Whole body exercise (WBE) changes lymphocyte subset percentages in peripheral blood. Resistive breathing, a hallmark of diseases of airway obstruction, is a form of exercise for the inspiratory muscles. Strenuous muscle contractions induce oxidative stress that may mediate immune alterations following exercise. We hypothesized that inspiratory resistive breathing (IRB) alters peripheral blood lymphocyte subsets and that oxidative stress mediates lymphocyte subpopulation alterations following both WBE and IRB.

Patients and methods

Six healthy nonathletes performed two WBE and two IRB sessions for 45 minutes at 70% of VO₂ maximum and 70% of maximum inspiratory pressure (Pi_max), respectively, before and after the administration of antioxidants (vitamins E, A, and C for 75 days, allopurinol for 30 days, and N-acetylcysteine for 3 days). Blood was drawn at baseline, at the end of each session, and 2 hours into recovery. Lymphocyte subsets were determined by flow cytometry.

Results

Before antioxidant supplementation at both WBE end and IRB end, the natural killer cell percentage increased, the T helper cell (CD3+ CD4+) percentage was reduced, and the CD4/CD8 ratio was depressed, a response which was abolished by antioxidants only after IRB. Furthermore, at IRB end, antioxidants promoted CD8+ CD38+ and blunted cytotoxic T-cell percentage increase. CD8+ CD45RA+ cell percentage changes were blunted after antioxidant supplementation in both WBE and IRB.

Conclusion

We conclude that IRB produces (as WBE) changes in peripheral blood lymphocyte subsets and that oxidative stress is a major stimulus predominantly for IRB-induced lymphocyte subset alterations.

An Increased Proportion of Apoptosis in CD4⁺ T Lymphocytes Isolated from the Peripheral Blood in Patients with Stable Chronic Obstructive Pulmonary Disease

BACKGROUND

The pathophysiology of chronic obstructive pulmonary disease (COPD) includes inflammation, oxidative stress, an imbalance of proteases and antiproteases and apoptosis which has been focused on lately. Abnormal apoptotic events have been demonstrated in both epithelial and endothelial cells, as well as in inflammatory cells including neutrophils and lymphocytes in the lungs of COPD patients. An increased propensity of activated T lymphocytes to undergo apoptosis has been observed in the peripheral blood of COPD patients. Therefore, the apoptosis of T lymphocytes without activating them was investigated in this study.

METHODS

Twelve control subjects, 21 stable COPD patients and 15 exacerbated COPD patients were recruited in the study. The T lymphocytes were isolated from the peripheral blood using magnetically activated cell sorting. Apoptosis of the T lymphocytes was assessed with flow cytometry using Annexin V and 7-aminoactinomycin D. Apoptosis of T lymphocytes at 24 hours after the cell culture was measured so that the T lymphocyte apoptosis among the control and the COPD patients could be compared.

RESULTS

Stable COPD patients had increased rates of CD4⁺ T lymphocyte apoptosis at 24 hours after the cell culture, more than the CD4⁺ T lymphocyte apoptosis which appeared in the control group, while the COPD patients with acute exacerbation had an amplified response of CD4⁺ T lymphocyte apoptosis as well as of CD8⁺ T lymphocyte apoptosis at 24 hours after the cell culture.

CONCLUSION

Stable COPD patients have more apoptosis of CD4⁺ T lymphocytes, which can be associated with the pathophysiology of COPD in stable conditions.

COPD as an endothelial disorder: endothelial injury linking lesions in the lungs and other organs? (2017 Grover Conference Series)

Chronic obstructive pulmonary disease (COPD) is characterized by chronic expiratory airflow obstruction that is not fully reversible. COPD patients develop varying degrees of emphysema, small and large airway disease, and various co-morbidities. It has not been clear whether these co-morbidities share common underlying pathogenic processes with the pulmonary lesions. Early research into the pathogenesis of COPD focused on the contributions of injury to the extracellular matrix and pulmonary epithelial cells. More recently, cigarette smoke-induced endothelial dysfunction/injury have been linked to the pulmonary lesions in COPD (especially emphysema) and systemic co-morbidities including atherosclerosis, pulmonary hypertension, and chronic renal injury. Herein, we review the evidence linking endothelial injury to COPD, and the pathways underlying endothelial injury and the "vascular COPD phenotype" including: (1) direct toxic effects of cigarette smoke on endothelial cells; (2) generation of auto-antibodies directed against endothelial cells; (3) vascular inflammation; (4) increased oxidative stress levels in vessels inducing increases in lipid peroxidation and increased activation of the receptor for advanced glycation end-products (RAGE); (5) reduced activation of the anti-oxidant pathways in endothelial cells; (6) increased endothelial cell release of mediators with vasoconstrictor, pro-inflammatory, and remodeling activities (endothelin-1) and reduced endothelial cell expression of mediators that promote vasodilation and homeostasis of endothelial cells (nitric oxide synthase and prostacyclin); and (7) increased endoplasmic reticular stress and the unfolded protein response in endothelial cells. We also review the literature on studies of drugs that inhibit RAGE signaling in other diseases (angiotensin-converting enzyme inhibitors and angiotensin receptor blockers), or vasodilators developed for idiopathic pulmonary arterial hypertension that have been tested on cell culture systems, animal models of COPD, and/or smokers and COPD patients.

Lung ageing and COPD: is there a role for ageing in abnormal tissue repair?

Chronic obstructive pulmonary disease (COPD) is the fourth leading cause of death worldwide, with increasing prevalence, in particular in the elderly. COPD is characterised by abnormal tissue repair resulting in (small) airways disease and emphysema. There is accumulating evidence that ageing hallmarks are prominent features of COPD. These ageing hallmarks have been described in different subsets of COPD patients, in different lung compartments and also in a variety of cell types, and thus might contribute to different COPD phenotypes. A better understanding of the main differences and similarities between normal lung ageing and the pathology of COPD may improve our understanding of the mechanisms driving COPD pathology, in particular in those patients that develop the most severe form of COPD at a relatively young age, i.e. severe early-onset COPD patients.In this review, after introducing the main concepts of lung ageing and COPD pathology, we focus on the role of (abnormal) ageing in lung remodelling and repair in COPD. We discuss the current evidence for the involvement of ageing hallmarks in these pathological features of COPD. We also highlight potential novel treatment strategies and opportunities for future research based on our current knowledge of abnormal lung ageing in COPD.

What do polymorphisms tell us about the mechanisms of COPD?

COPD (chronic obstructive pulmonary disease) is characterized by irreversible lung airflow obstruction. Cigarette smoke is the major risk factor for COPD development. However, only a minority number of smokers develop COPD, and there are substantial variations in lung function among smokers, suggesting that genetic determinants in COPD susceptibility. During the past decade, genome-wide association studies and exome sequencing have been instrumental to identify the genetic determinants of complex traits, including COPD. Focused studies have revealed mechanisms by which genetic variants contribute to COPD and have led to novel insights in COPD pathogenesis. Through functional investigations of causal variants in COPD, from the proteinase-antiproteinase theory to emerging roles of developmental pathways (such as Hedgehog and Wnt pathways) in COPD, we have greatly expanded our understanding on this complex pulmonary disease. In this review, we critically review functional investigations on roles of genetic polymorphisms in COPD, and discuss future challenges and opportunities in discovering novel mechanisms of functional variants.

Factors associated with pulmonary impairment in HIV-infected South African adults

Background

HIV-infected individuals have increased risk of developing obstructive lung disease (OLD). Studies from developed countries report high viral load, low CD4 counts, and anti-retroviral therapy (ART) to be associated with OLD; but these findings may not be generalizable to populations in resource-limited settings.

Methods

We conducted a prospective cohort study of lung function in 730 HIV-infected black South African adults. Pre-bronchodilator spirometry was performed at enrollment and repeated annually for three years. Logistic regression models were used to identify factors associated with OLD, defined as FEV1/FVC<0.70, at enrollment. Excess annual declines in FEV1 and FVC were modelled as the product-term of follow-up time and exposures using random effects regression.

Results

Median (IQR) age at enrollment was 36 (32–41) years, 85% were female and 30% ever-smoked with a median (IQR) exposure of 3 (1–6) pack-years. Median (IQR) CD4 count and viral load at enrollment were 372 (261–518) cells/mm³ and 2655 (91–13,548) copies/mL respectively. Overall, 25% were receiving ART at enrollment, 16% of whom reported at least 6 months of ART receipt. OLD was found in 35 (5%) at enrollment. Increasing age (aOR = 2.08 per 10-years [95%CI 1.22–3.57], p = 0.007), current smoking (aOR = 3.55 [95%CI 1.20–10.53], p = 0.02), and CRP (aOR = 1.01 per unit-increase [95%CI 1.00–1.03], p = 0.04) were significantly associated with OLD at enrollment; while increasing CD4 count (aOR = 1.02 per-100 cells/mm³ [95%CI 0.85–1.22], p = 0.82), viral load (aOR = 0.67 per log-increase [95%CI 0.43–1.10], p = 0.12) and receipt of ART (aOR = 0.57 [95%CI 0.18–1.75], p = 0.32) were not. The median (IQR) follow-up time was 18 (12–24) months. Participants with a history of tuberculosis (TB) had a 35 mL (95%CI 2–68, p = 0.03) and 57 mL (95%CI 19–96, p = 0.003) per year excess loss of FEV1 and FVC respectively.

Conclusion

Prevalent OLD was associated with older age, current smoking and higher CRP levels, but not CD4 counts and ART, in HIV-infected South African adults. Better understanding of the long-term effects of TB, smoking and inflammation on lung function in HIV-infected populations is urgently needed.

Cellular and molecular mechanisms of asthma and COPD

Asthma and chronic obstructive pulmonary disease (COPD) both cause airway obstruction and are associated with chronic inflammation of the airways. However, the nature and sites of the inflammation differ between these diseases, resulting in different pathology, clinical manifestations and response to therapy. In this review, the inflammatory and cellular mechanisms of asthma and COPD are compared and the differences in inflammatory cells and profile of inflammatory mediators are highlighted. These differences account for the differences in clinical manifestations of asthma and COPD and their response to therapy. Although asthma and COPD are usually distinct, there are some patients who show an overlap of features, which may be explained by the coincidence of two common diseases or distinct phenotypes of each disease. It is important to better understand the underlying cellular and molecular mechanisms of asthma and COPD in order to develop new treatments in areas of unmet need, such as severe asthma, curative therapy for asthma and effective anti-inflammatory treatments for COPD.

The Relationship between Airway Inflammation and Exacerbation in Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is associated with abnormal inflammatory response and airflow limitation. Acute exacerbation involves increased inflammatory burden leading to worsening respiratory symptoms, including dyspnea and sputum production. Some COPD patients have frequent exacerbations (two or more exacerbations per year). A substantial proportion of COPD patients may remain stable without exacerbation. Bacterial and viral infections are the most common causative factors that breach airway stability and lead to exacerbation. The increasing prevalence of exacerbation is associated with deteriorating lung function, hospitalization, and risk of death. In this review, we summarize the mechanisms of airway inflammation in COPD and discuss how bacterial or viral infection, temperature, air pollution, eosinophilic inflammation, and concomitant chronic diseases increase airway inflammation and the risk of exacerbation.

Elastin receptor (S-gal) occupancy by elastin peptides modulates T-cell response during murine emphysema

Chronic obstructive pulmonary disease and emphysema are associated with increased elastin peptides (EP) production because of excessive breakdown of lung connective tissue. We recently reported that exposure of mice to EP elicited hallmark features of emphysema. EP effects are largely mediated through a receptor complex that includes the elastin-binding protein spliced-galactosidase (S-gal). In previous studies, we established a correlation between cytokine production and S-gal protein expression in EP-treated immune cells. In this study, we investigated the S-gal-dependent EP effects on T-helper (Th) and T-cytotoxic (Tc) responses during murine EP-triggered pulmonary inflammation. C57BL/6J mice were endotracheally instilled with the valine-glycine-valine-alanine-proline-glycine (VGVAPG) elastin peptide, and, 21 days after treatment, local and systemic T-lymphocyte phenotypes were analyzed at cytokine and transcription factor expression levels by multicolor flow cytometry. Exposure of mice to the VGVAPG peptide resulted in a significant increase in the proportion of the CD4+ and CD8+ T cells expressing the cytokines IFN-γ or IL-17a and the transcription factors T-box expressed in T cells or retinoic acid-related orphan receptor-γt (RORγt) without effects on IL-4 and Gata-binding protein 3 to DNA sequence [A/T]GATA[A/G] expression. These effects were maximized when each T-cell subpopulation was challenged ex vivo with EP, and they were inhibited in vivo when an analogous peptide antagonizing the EP/S-gal interactions was instilled together with the VGVAPG peptide. This study demonstrates that, during murine emphysema, EP-S-gal interactions contribute to a Th-1 and Th-17 proinflammatory T-cell response combined with a Tc-1 response. Our study also highlights the S-gal receptor as a putative pharmacological target to modulate such an immune response.

Small Airway Disease in Patients with Chronic Obstructive Pulmonary Disease

Small airway disease (SAD) has been recognized for many years as a central feature of chronic obstructive pulmonary disease (COPD). Histopathology studies have shown that the narrowing and destruction of small airways in COPD combined with inflammatory cell infiltration in the submucosa increases the severity of the disease. SAD is present in the early stages of COPD and becomes more widespread over time as the disease progresses to more severe COPD. The development of inhalers containing extra-fine particles allows the small airways to be pharmacologically targeted. Recent clinical trials have shown the efficacy of extra-fine triple therapy that targets the small airways in patients with COPD. This article reviews the importance and treatment of SAD in COPD.

IL-12 and IL-7 synergize to control mucosal-associated invariant T-cell cytotoxic responses to bacterial infection

BACKGROUND

Bacterial respiratory tract infections and exacerbations of chronic lung diseases are commonly caused by nontypeable Haemophilus influenzae (NTHi). Cell-mediated cytotoxicity might be key to controlling infection, but the responses of NTHi-specific T-cell populations are not well understood. Mucosal-associated invariant T (MAIT) cells are a recently discovered, innate-like subset of T cells with cytotoxic function, the role of which in lung immunity is unclear.

OBJECTIVE

The aim of this study was to determine the mechanisms behind conventional T-cell and MAIT cell cytotoxic responses to NTHi.

METHODS

Human ex vivo lung explants were infected with a clinical strain of NTHi. Monocyte-derived macrophages were also infected with NTHi in vitro and cocultured with autologous T cells. Cytotoxic responses of T-cell subsets were measured by using flow cytometry.

RESULTS

We found significant upregulation of the cytotoxic markers CD107a and granzyme B in lung CD4⁺, CD8⁺, and MAIT cell populations. We show that MAIT cell cytotoxic responses were upregulated by a combination of both time-dependent antigen presentation and a novel mechanism through which IL-12 and IL-7 synergistically control granzyme B through upregulation of the IL-12 receptor.

CONCLUSIONS

Overall, our data provide evidence for a cytotoxic role of MAIT cells in the lung and highlight important differences in the control of adaptive and innate-like T-cell responses. Understanding these mechanisms might lead to new therapeutic opportunities to modulate the antibacterial response and improve clinical outcome.

Experimental animal models for COPD: a methodological review

INTRODUCTION

Chronic obstructive pulmonary disease (COPD) is a progressive disorder that makes the breathing difficult and is characterized by pathological conditions ranging from chronic inflammation to tissue proteolysis. With regard to ethical issues related to the studies on patients with COPD, the use of animal models of COPD is inevitable. Animal models improve our knowledge about the basic mechanisms underlying COPD physiology, pathophysiology and treatment. Although these models are only able to mimic some of the features of the disease, they are valuable for further investigation of mechanisms involved in human COPD.

METHODS

We searched the literature available in Google Scholar, PubMed and ScienceDirect databases for English articles published until November 2015. For this purpose, we used 5 keywords for COPD, 3 for animal models, 4 for exposure methods, 3 for pathophysiological changes and 3 for biomarkers. One hundred and fifty-one studies were considered eligible for inclusion in this review.

RESULTS

According to the reviewed articles, animal models of COPD are mainly induced in mice, guinea pigs and rats. In most of the studies, this model was induced by exposure to cigarette smoke (CS), intra-tracheal lipopolysaccharide (LPS) and intranasal elastase. There were variations in time course and dose of inducers used in different studies. The main measured parameters were lung pathological data and lung inflammation (both inflammatory cells and inflammatory mediators) in most of the studies and tracheal responsiveness (TR) in only few studies.

CONCLUSION

The present review provides various methods used for induction of animal models of COPD, different animals used (mainly mice, guinea pigs and rats) and measured parameters. The information provided in this review is valuable for choosing appropriate animal, method of induction and selecting parameters to be measured in studies concerning COPD.

Crosstalk Between T Lymphocytes and Lung Fibroblasts: Generation of a Hyaluronan-Enriched Extracellular Matrix Adhesive for Monocytes

In immunity and inflammation, T cells are often associated with stromal mesenchymal cells such as fibroblasts. Hyaluronan and proteins that associate with hyaluronan such as versican and tumor necrosis factor-inducible gene-6 (TSG-6) are extracellular matrix (ECM) components that promote leukocyte adhesion, accumulation, and activation. However, the factors responsible for producing this specialized ECM and its impact on inflammatory events are not well understood. In this study, we explored the role of T cells in stimulating lung fibroblasts to produce an ECM that impacts monocyte adhesion. We found that CD3/CD28-activated human CD4+ T cells when co-cultured with human lung fibroblasts stimulated the expression of mRNA for hyaluronan synthase 2 (HAS2) and decreased the expression of hyaluronidase 2 (HYAL2). This led to an increase in the deposition of hyaluronan that formed cable-like structures within the ECM. Co-culturing activated T cells with fibroblasts also led to increased expression and accumulation of TSG-6. Surprisingly, addition of activated CD4+ T cells to the fibroblasts reduced the expression of mRNA for versican, and increased the expression of enzymes that degrade versican, such as ADAMTS4 and ADAMTS9 (a disintegrin and metalloproteinase with a thrombospondin type-1 motif) leading to a decrease in versican in the ECM of the co-cultures. Furthermore, addition of human monocytes to these co-cultures resulted in elevated monocyte adhesion to the cable-like structures in the ECM when compared to controls. These results illustrate the importance of crosstalk between T cells and fibroblasts in promoting the generation of a matrix that is adhesive for monocytes. J. Cell. Biochem. 118: 2118-2130, 2017. © 2016 Wiley Periodicals, Inc.

The Contribution of Small Airway Obstruction to the Pathogenesis of Chronic Obstructive Pulmonary Disease

The hypothesis that the small conducting airways were the major site of obstruction to airflow in normal lungs was introduced by Rohrer in 1915 and prevailed until Weibel introduced a quantitative method of studying lung anatomy in 1963. Green repeated Rohrer's calculations using Weibels new data in 1965 and found that the smaller conducting airways offered very little resistance to airflow. This conflict was resolved by seminal experiments conducted by Macklem and Mead in 1967, which confirmed that a small proportion of the total lower airways resistance is attributable to small airways <2 mm in diameter. Shortly thereafter, Hogg, Macklem, and Thurlbeck used this technique to show that small airways become the major site of obstruction in lungs affected by emphysema. These and other observations led Mead to write a seminal editorial in 1970 that postulated the small airways are a silent zone within normal lungs where disease can accumulate over many years without being noticed. This review provides a progress report since the 1970s on methods for detecting chronic obstructive pulmonary disease, the structural nature of small airways' disease, and the cellular and molecular mechanisms that are thought to underlie its pathogenesis.