The expression of nuclear factor (NF)-κB is an indicator of cellular activation and of inflammatory mediator production. The aim of the present study was to characterise the expression and localisation of p65, the major subunit of NF-κB, in the bronchial mucosa of patients with chronic obstructive pulmonary disease (COPD), and to examine the relationship between p65 expression and disease status.Bronchial biopsies were obtained from 14 smokers with COPD, 17 smokers with normal lung function and 12 nonsmokers with normal lung function. The number of p65 positive (+) cells was quantified by immunohistochemistry and the expression of p65 in bronchial biopsies from the three groups was examined by Western blotting (WB).Smokers with normal lung function and patients with COPD had increased numbers of p65+ cells in the epithelium and increased p65 nuclear expression. In COPD patients the number of epithelial p65+ cells correlated with the degree of airflow limitation. WB analysis showed an increase in p65 in smokers with normal lung function and COPD patients (p<0.05).Bronchial biopsies in smokers with normal lung function and chronic obstructive pulmonary disease patients show increased expression of p65 protein, predominantly in the bronchial epithelium. Disease severity is associated with an increased epithelial expression of nuclear factor-κB.

There are increased numbers of activated T lymphocytes in the bronchial mucosa of stable chronic obstructive pulmonary disease (COPD) patients. T helper type 17 (Th17) cells release interleukin (IL)‐17 as their effector cytokine under the control of IL‐22 and IL‐23. Furthermore, Th17 numbers are increased in some chronic inflammatory conditions. To investigate the expression of interleukin (IL)‐17A, IL‐17F, IL‐21, IL‐22 and IL‐23 and of retinoic orphan receptor RORC2, a marker of Th17 cells, in bronchial biopsies from patients with stable COPD of different severity compared with age‐matched control subjects. The expression of IL‐17A, IL‐17F, IL‐21, IL‐22, IL‐23 and RORC2 was measured in the bronchial mucosa using immunohistochemistry and/or quantitative polymerase chain reaction. The number of IL‐22⁺ and IL‐23⁺ immunoreactive cells is increased in the bronchial epithelium of stable COPD compared with control groups. In addition, the number of IL‐17A⁺ and IL‐22⁺ immunoreactive cells is increased in the bronchial submucosa of stable COPD compared with control non‐smokers. In all smokers, with and without disease, and in patients with COPD alone, the number of IL‐22⁺ cells correlated significantly with the number of both CD4⁺ and CD8⁺ cells in the bronchial mucosa. RORC2 mRNA expression in the bronchial mucosa was not significantly different between smokers with normal lung function and COPD. Further, we report that endothelial cells express high levels of IL‐17A and IL‐22. Increased expression of the Th17‐related cytokines IL‐17A, IL‐22 and IL‐23 in COPD patients may reflect their involvement, and that of specific IL‐17‐producing cells, in driving the chronic inflammation seen in COPD.

CC-chemokines are chemotactic factors expressed in a wide range of cell types and tissues. The aim of this study was to evaluate the involvement of CC-chemokines in the airways inflammation of patients affected by chronic bronchitis. The study evaluated, with an immunoassay, the concentrations of monocyte chemotactic protein-1 (MCP-1), macrophage inflammatory protein-1alpha (MIP-1alpha) and macrophage inflammatory protein-1beta (MIP-1beta), in the bronchoalveolar lavage fluid (BALF) of 12 smokers affected by chronic bronchitis and 14 smoking, 15 nonsmoking and six exsmoking healthy subjects. MCP-1 was significantly increased in patients with chronic bronchitis ((mean+/-SD) 10.75+/-4.04 pg x mL(-1)) and in the smoker control group (12.39+/-5.87 pg x mL(-1)) compared with healthy exsmokers: (7.12+/-1.60 pg x mL(-1), p=0.035 and p=0.045, respectively) and nonsmokers (6.41+/-3.87 pg x mL(-1), p=0.003 and p=0.006, respectively). MIP-1alpha concentrations were undetectable. A significant difference was observed in MIP-1-beta levels in BALF of chronic bronchitics (8.11+/-5.97 pg x mL(-1)) compared to smoker (3.57+/-2.90 pg x mL(-1), p=0.018), exsmoker (3.43+/-0.68 pg x mL(-1), p=0.025) and nonsmoker (3.39+/-3.73 pg x mL(-1), p=0.008) control groups. A negative correlation was observed between MIP-1beta levels and forced expiratory volume in one second values (p=-0.64, p=0.035) in chronic bronchitics. An increase of monocyte chemotactic protein-1 is related to smoking habit and seems consistent with a lung inflammatory reaction. On the contrary, an increase in macrophage inflammatory protein-1beta levels is restricted to smokers developing chronic obstructive pulmonary disease. These data suggest a role of CC-chemokines in the pathogenesis of chronic bronchitis.

Activation of the transcription factor signal transducer and activator of transcription (STAT)‐4 is critical for the differentiation of T‐helper 1 cells/type‐1 cytotoxic T‐cells and the production of interferon (IFN)‐γ.Expression of STAT4, phospho‐STAT4, IFN‐γ and T‐box expressed in T‐cells (T‐bet) proteins in bronchial biopsies and bronchoalveolar lavage (BAL)‐derived lymphocytes, obtained from 12 smokers with mild/moderate chronic obstructive pulmonary disease (COPD) (forced expiratory volume in one second (FEV₁) 59±16% predicted), 14 smokers with normal lung function (FEV₁106±12% pred) and 12 nonsmoking subjects (FEV₁111±14% pred), was examined by immunohistochemistry and immunocytochemistry.In bronchial biopsies of COPD patients, the number of submucosal phospho‐STAT4+ cells was increased (240 (22–406)versus125 (0–492)versus29 (0–511) cells·mm⁻²) when compared with both healthy smokers and control nonsmokers, respectively. In smokers, phospho‐STAT4+ cells correlated with the degree of airflow obstruction and the number of IFN‐γ+ cells. Similar results were seen in BAL (2.8 (0.2–5.9)versus1.03 (0.09–1.6)versus0.69 (0–2.3) lymphocytes·mL⁻¹×10³). In all smokers who underwent lavage, phospho‐STAT4+ lymphocytes correlated with airflow obstruction and the number of IFNγ+ lymphocytes. T‐bet expression was not altered in bronchial biopsies and BAL‐derived lymphocytes between the three groups.In conclusion, this study suggests that stable mild/moderate chronic obstructive pulmonary disease is associated with an active T‐helper 1 cell/type‐1 cytotoxic T‐cell inflammatory process involving activation of signal transducer and activator of transcription 4 and interferon-gamma production.

Toll-like receptors (TLRs) and nucleotide-binding oligomerisation domain (NOD)-like receptors (NLRs) are two major forms of innate immune sensors but their role in the immunopathology of stable chronic obstructive pulmonary disease (COPD) is incompletely studied. Our objective here was to investigate TLR and NLR signalling pathways in the bronchial mucosa in stable COPD.Using immunohistochemistry, the expression levels of TLR2, TLR4, TLR9, NOD1, NOD2, CD14, myeloid differentiation primary response gene 88 (MyD88), Toll-interleukin-1 receptor domain-containing adaptor protein (TIRAP), and the interleukin-1 receptor-associated kinases phospho-IRAK1 and IRAK4 were measured in the bronchial mucosa of subjects with stable COPD of different severity (n=34), control smokers (n=12) and nonsmokers (n=12). The bronchial bacterial load ofPseudomonas aeruginosa,Haemophilus influenzae,Moraxella catarrhalisandStreptococcus pneumoniaewas measured by quantitative real-time PCR.TLR4 and NOD1 expression was increased in the bronchial mucosa of patients with severe/very severe stable COPD compared with control subjects. TLR4 bronchial epithelial expression correlated positively with CD4⁺and CD8⁺cells and airflow obstruction. NOD1 expression correlated with CD8⁺cells. The bronchial load ofP. aeruginosawas directly correlated, butH. influenzaeinversely correlated, with the degree of airflow obstruction. Bacterial load did not correlate with inflammatory cells.Bronchial epithelial overexpression of TLR4 and NOD1 in severe/very severe stable COPD, associated with increased bronchial inflammation andP. aeruginosabacterial load, may play a role in the pathogenesis of COPD.

Background: Increased numbers of activated neutrophils have been reported in the bronchial mucosa of patients with stable chronic obstructive pulmonary disease (COPD), particularly in severe disease. Objectives: To investigate the expression of neutrophilic chemokines and adhesion molecules in bronchial biopsies from patients with stable COPD of different severity (GOLD stages I–IV) compared with age-matched control subjects, smokers with normal lung function and never smokers. Methods: The expression of CCL5, CXCL1, 5, 6, 7 and 8, CXCR1, CXCR2, CD11b and CD44 was measured in the bronchial mucosa using immunohistochemistry, confocal immunofluorescence, real-time quantitative polymerase chain reaction (RT-QPCR) and Western blotting (WB). Results: The numbers of CCL5+ epithelial cells and CCL5+ and CXCL7+ immunostained cells were increased in the bronchial submucosa of patients with stable severe COPD compared with control never smokers and smokers with normal lung function. This was also confirmed at the level of mRNA expression. The numbers of CCL5+ cells in the submucosa of patients with COPD were 2–15 times higher than any other chemokines. There was no correlation between the number of these cells and the number of neutrophils in the bronchial submucosa. Compared with control smokers, the percentage of neutrophils co-expressing CD11b and CD44 receptors was significantly increased in the submucosa of patients with COPD. Conclusion: The increased expression of CCL5 and CXCL7 in the bronchial mucosa of patients with stable COPD, together with an increased expression of extracellular matrix-binding receptors on neutrophils, may be involved in the pathogenesis of COPD.