Mucins 3A and 3B Are Expressed in the Epithelium of Human Large Airway.

Aberrant mucus secretion is a hallmark of chronic obstructive pulmonary disease (COPD). Expression of the membrane-tethered mucins 3A and 3B (MUC3A, MUC3B) in human lung is largely unknown. In this observational cross-sectional study, we recruited subjects 45-65 years old from the general population of Stockholm, Sweden, during the years 2007-2011. Bronchial mucosal biopsies, bronchial brushings, and bronchoalveolar lavage fluid (BALF) were retrieved from COPD patients (n = 38), healthy never-smokers (n = 40), and smokers with normal lung function (n = 40). Protein expression of MUC3A and MUC3B in bronchial mucosal biopsies was assessed by immunohistochemical staining. In a subgroup of subjects (n = 28), MUC3A and MUC3B mRNAs were quantified in bronchial brushings using microarray. Non-parametric tests were used to perform correlation and group comparison analyses. A value of p < 0.05 was considered statistically significant. MUC3A and MUC3B immunohistochemical expression was localized to ciliated cells. MUC3B was also expressed in basal cells. MUC3A and MUC3B immunohistochemical expression was equal in all study groups but subjects with emphysema had higher MUC3A expression, compared to those without emphysema. Smokers had higher mRNA levels of MUC3A and MUC3B than non-smokers. MUC3A and MUC3B mRNA were higher in male subjects and correlated negatively with expiratory air flows. MUC3B mRNA correlated positively with total cell concentration and macrophage percentage, and negatively with CD4/CD8 T cell ratio in BALF. We concluded that MUC3A and MUC3B in large airways may be a marker of disease or may play a role in the pathophysiology of airway obstruction.

Gender differences in the T-cell profiles of the airways in COPD patients associated with clinical phenotypes.

T lymphocytes are believed to play an important role in the pathogenesis of chronic obstructive pulmonary disease (COPD). How T cells are recruited to the lungs and contribute to the inflammatory process is largely unknown. COPD is a heterogeneous disease, and discriminating disease phenotypes based on distinct molecular and cellular pathways may provide new approaches for individualized diagnosis and therapies. Bronchoalveolar lavage (BAL) and blood samples were obtained from 40 never-smokers, 40 smokers with normal lung function, and 38 COPD patients. T-cell chemokine receptor expression was analyzed with flow cytometry, and soluble BAL cytokines and chemokines were measured using a cytokine multiplex assay. Correlations with gender and clinical characteristics including lung imaging were investigated using multivariate modeling. Th1/Tc1- and Th2/Tc2-associated soluble analytes and T-cell chemokine receptors were analyzed as cumulative Th1/Tc1 and Th2/Tc2 immune responses. A higher expression of chemokine receptor CCR5 on CD8+ T cells in BAL and higher percentage of CXCR3+CD8+ T cells in blood was found in female smokers with COPD compared to those without COPD. CCR5 expression on CD4+ and CD8+ T cells was lower in BAL from male smokers with COPD compared to those without COPD. Among female smokers with COPD, Th1/Tc1 immune response was linked to BAL macrophage numbers and goblet cell density, and Th2/Tc2 response was associated with the measures of emphysema on high-resolution computed tomography. The highly gender-dependent T-cell profile in COPD indicates different links between cellular events and clinical manifestations in females compared to males. Our findings may reveal mechanisms of importance for the difference in clinical course in female COPD patients compared to males.

Differences in regional air trapping in current smokers with normal spirometry.

We investigated regional air trapping on computed tomography in current smokers with normal spirometry. It was hypothesised that presence of regional air trapping may indicate a specific manifestation of smoking-related changes.40 current smokers, 40 patients with chronic obstructive pulmonary disease (COPD), and 40 healthy never- smokers underwent computed tomography scans. Regional air trapping was assessed on end-expiratory scans and emphysema, micronodules and bronchial wall thickening on inspiratory scans. The ratio of expiratory and inspiratory mean lung attenuation (E/I) was calculated as a measure of static (fixed) air trapping.Regional air trapping was present in 63% of current smokers, in 45% of never smokers and in 8% of COPD patients (p<0.001). Current smokers with and without regional air trapping had E/I ratio of 0.81 and 0.91, respectively (p<0.001). Forced expiratory volume in 1 s (FEV1) was significantly higher and emphysema less frequent in current smokers with regional air trapping.Current smokers with regional air trapping had higher FEV1 and less emphysema on computed tomography. In contrast, current smokers without regional air trapping resembled COPD. Our results highlight heterogeneity among smokers with normal spirometry and may contribute to early detection of smoking related structural changes in the lungs.

Lung density on high resolution computer tomography (HRCT) reflects degree of inflammation in smokers.

BACKGROUND: Smokers have increased cell concentration in the lower respiratory tract indicating a chronic inflammatory state, which in some individuals may lead to development of chronic obstructive pulmonary disease (COPD). Computer tomography (CT) imaging provides means of quantifying pulmonary structure and early signs of disease. We investigated whether lung density on high resolution CT differs between smokers and never-smokers and if this were associated to intensity of inflammation. METHODS: Forty smoking volunteers with normal pulmonary function, 40 healthy never-smokers and 40 patients with COPD of GOLD stage I-II, were included. Mean lung attenuation and percentage of pixels in the lung with attenuation between -750 and -900 HU (percentage higher density spectrum (%HDS)) were calculated on inspiratory CT-scans. Markers of systemic inflammation in blood and cell counts in bronchoalveolar lavage (BAL) fluid were recorded. RESULTS: Lung density expressed as %HDS was increased in smokers (44.0 ± 5.8%) compared to both never-smokers (38.3 ± 5.8%) and patients with COPD (39.1 ± 5.8%), (p < 0.001, for both). Females had denser lungs than males, which was dependent on body height. Cell concentration in BAL were correlated to lung density in smokers (r = 0.50, p < 0.001). CONCLUSIONS: Lung density on CT is associated with cell concentration in BAL in smokers and may mirror an inflammatory response in the lung. Gender difference in lung density is dependent on height. In COPD with emphysema, loss of lung tissue may counterbalance the expected increase in density due to inflammation. The findings may help to interpret high resolution CT in the context of smoking and gender and highlight the heterogeneity of structural changes in COPD.

Distribution of T-cell subsets in BAL fluid of patients with mild to moderate COPD depends on current smoking status and not airway obstruction.

BACKGROUND: COPD is characterized by chronic inflammation. CD8+ T cells and CD4+ T cells have both been implicated in the inflammatory response. We investigated whether the lymphocyte and T-cell subpopulations in BAL differ between patients with COPD who are current smokers and those who are ex-smokers. METHODS: Forty never smokers, 40 smokers with normal lung function, and 38 patients with COPD, GOLD (Global Initiative for Chronic Obstructive Pulmonary Disease) stage I-II (27 smokers and 11 ex-smokers) underwent BAL. Using flow cytometry, cells were analyzed from BAL and blood for T-cell subsets, B cells, natural killer cells, and natural killer T (NKT)-like cells. The differentiation status of CD4+ T cells was also determined. RESULTS: Smokers with or without COPD had higher percentages of CD8+ T cells and NKT-like cells in BAL than did never smokers and ex-smokers with COPD. Most of the NKT-like cells were CD8+. In contrast, the percentages of CD4+ T cells were lower in the smoking than in the nonsmoking groups. In blood, the frequency of CD4+ T cells was increased in the two smoking groups. Current smokers also had increased numbers of activated (CD69+) naive and effector CD4+ T cells in BAL compared with nonsmokers, particularly in patients with COPD. In male smokers with COPD, the percentage of CD8+ T cells in BAL positively correlated with the number of cigarettes per day. CONCLUSIONS: Current smoking status has a greater impact than airway obstruction on the distribution of T-cell subsets in BAL of patients with mild to moderate COPD. This fact must be considered when the role of T cells in COPD is evaluated. Our results stress the importance of subgrouping patients with COPD in terms of smoking.

Hypoxia but not cigarette smoke modulates VEGF secretion from human T cells.

Vascular endothelial growth factor (VEGF) is an important mitogen with multiple functions. In the present study we investigated whether T cell secreted VEGF and inflammatory cytokines were modulated by cigarette smoke and by a hypoxic microenvironment. T cells from peripheral blood of healthy donors were activated under normoxia (21% O(2)) or hypoxia (1-2% O(2)) with or without exposure to cigarette smoke extract. T cells were also obtained from patients with chronic obstructive pulmonary disease (COPD), a smoking-related disease characterized by accumulation of both CD4+ and CD8+T cells. Hypoxia stimulated VEGF secretion from activated T cells, whereas the release of IL-4, IL-6, IL-10, IL-13, IFN-gamma and tumour necrosis factor were not altered. Cigarette smoke extract did not affect VEGF secretion neither in hypoxia nor in normoxia, whereas the secretion of all cytokines was inhibited by the extract in both conditions. When recombinant VEGF was added the smoke-induced inhibition of the IFN-gamma and IL-13 was not observed. Activated T cells from COPD-patients secreted significantly (p < 0.05) more VEGF compared to T cells from healthy individuals. Our data suggest that both cigarette smoke extract and hypoxia modulate the T cell response. This may be of importance in diseases characterized by T cell accumulation, such as COPD.

Serum protein pattern in sarcoidosis analysed by a proteomics approach.

BACKGROUND: An altered protein expression in bronchoalveolar lavage fluid (BALF) of sarcoidosis patients has previously been reported. As this disease is systemic, involving not only the lungs, a change in the serum components is also to be expected. In the present study we therefore analysed the total serum protein profile of the patients earlier reported, with active sarcoidosis. METHODS: We used a proteomics approach to assess overall changes in the protein content of serum in patients with acute sarcoidosis (n = 6) compared to healthy controls (n = 4). RESULTS: Our results show a significantly higher number of protein-spots in serum of the patients compared to the healthy individuals in the pH range 4.5-6.7 (median 886 vs. 742, p < 0.05). The total protein concentrations of the patients' sera were also significantly higher compared to the controls (median 62 vs. 56 mg/mL, p < 0.05). Measurement of the optical densities of the protein-spots from two-dimensional electrophoresis gels, covering pH interval 4.5-6.7, showed varying levels of expression of 22 different serum proteins in the patients compared to the controls. These proteins are involved in immune responses and some are known markers of inflammation. We found three proteins, which were changed concomitantly in the BALF as described in a previous report, and sera of the same patients. CONCLUSIONS: Our results are of importance in order to identify biochemical markers in blood of sarcoidosis patients. Ideally, a combination of markers in BALF and serum may turn out to be disease specific.