T helper type 17-related cytokine expression is increased in the bronchial mucosa of stable chronic obstructive pulmonary disease patients.

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.

Chemokines and chemokine receptors blockers as new drugs for the treatment of chronic obstructive pulmonary disease.

Chronic obstructive pulmonary disease (COPD) is characterised by an abnormal inflammatory response of the lung to noxious particles or gases. The cellular inflammatory response in COPD is characterised by an increased number of inflammatory cells in the lungs. Although the molecular and cellular mechanisms responsible for the development of COPD are not well understood; several mediators are assumed to regulate the activation and recruitment of these inflammatory cells into the lung of COPD patients particularly those belonging to the chemokine family. Inhibitors or blockers of chemokine and chemokine receptors are therefore of great interest as potential novel therapies for COPD and many are now in clinical development. A high degree of redundancy exists in the chemokine network and inhibition of a single chemokine or receptor may not be sufficient to block the inflammatory response. Despite this, animal studies suggest a strong rationale for inhibiting the chemokine network in COPD. As such, every leading pharmaceutical company maintains a significant interest in developing agents that regulate leukocyte navigation as potential anti-inflammatory drugs. Drugs and antibodies targeting chemokines and their receptors are generally still in early stages of development and the results of clinical trial are awaited with great interest. These agents may not only provide improved management of COPD but also, importantly, indicate proof-of-concept to further clarify the role of chemokines in the pathophysiology of COPD.

COPD pathology in the small airways.

In the last quarter of century, the analysis of small airways specimens obtained from chronic obstructive pulmonary disease (COPD) patients compared with those from a control group of age-matched smokers with normal lung function has provided novel insights on the potential role of the different inflammatory and structural cells, pro/anti-inflammatory mediators and intracellular signalling pathways, contributing to a better knowledge of the pathogenesis of stable COPD. This also has provided a scientific rationale for new drugs discovery and targeting to the small airways. This review summarizes and discusses the pathology of small airways of stable COPD patients, of different severity, compared with control smokers with normal lung function.

Nuclear localisation of p65 in sputum macrophages but not in sputum neutrophils during COPD exacerbations.

BACKGROUND: Exacerbations represent an important feature of the clinical manifestation and natural history of chronic obstructive pulmonary disease (COPD). Nuclear localisation of p65 is a signal of nuclear factor-kappaB (NF-kappaB) activation. A study was undertaken to evaluate whether NF-kappaB activation is modified in sputum cells during COPD exacerbations. METHODS: Total and nuclear p65 immunoreactivity was measured by immunocytochemistry in the sputum cells of 11 smokers with moderate COPD during an exacerbation and after 6-8 weeks of clinical stability. RESULTS: Total sputum cell count was significantly increased during exacerbations from a median (IQR) of 880 (510-1865) to 1914.5 (1065-3205) x 10(3)/ml (p<0.05). The main inflammatory cells in the sputum were neutrophils (83.2 (75.4-92.3)%) and macrophages (14.7 (2.6-21.6)%) and their relative proportion did not change during exacerbations. Nuclear staining for p65 was absent in sputum neutrophils, both during exacerbations and in the stable phase. In contrast, the percentage of macrophages expressing nuclear p65 increased significantly during exacerbations from a median (IQR) of 16 (7-24)% to 41.4 (6-69)% (p<0.05). CONCLUSIONS: NF-kappaB appears to be activated in sputum macrophages but not in sputum neutrophils during exacerbations of COPD

Mucin expression in peripheral airways of patients with chronic obstructive pulmonary disease.

AIMS: To study the expression of mucins in peripheral airways in patients with chronic obstructive pulmonary disease (COPD). METHODS AND RESULTS: Peripheral lung sections from smokers with COPD (n = 9) and age-matched controls including smokers (n = 11) and lifelong non-smokers with normal lung function (n = 6) were stained with alcian blue, periodic acid-Schiff (PAS) and by immunohistochemistry of mucins (MUC): MUC2, MUC4, MUC5AC, MUC5B and MUC6. Histochemical staining and immunoreactivity of bronchiolar epithelium were graded and the presence or absence of stained mucus in the bronchiolar lumen was evaluated. There were no differences in alcian blue and PAS epithelial staining between the three groups. Intraluminal PAS staining was significantly more frequent among COPD subjects (P < 0.05). The expression of MUC5AC was significantly higher in the bronchiolar epithelium of patients with COPD (P < 0.05). Within the bronchiolar lumen, the predominant mucin was MUC5B. Intraluminal MUC5B was significantly more frequent among COPD patients (P < 0.05). CONCLUSIONS: COPD is specifically associated with increased expression of MUC5B in the bronchiolar lumen and of the mucin MUC5AC in the bronchiolar epithelium. These changes in mucin production in the peripheral airways may contribute to the pathophysiology of COPD.