CD8⁺ T-Lymphocytes in Peripheral Airways of Smokers with Chronic Obstructive Pulmonary Disease

Abstract

To investigate whether the inflammatory process in peripheral airways is different in smokers who develop symptoms of chronic bronchitis and chronic airflow limitation and in asymptomatic smokers who do not develop chronic airflow limitation, we examined surgical specimens obtained from 16 smokers undergoing lung resection for localized pulmonary lesions. Nine had symptoms of chronic bronchitis and chronic airflow limitation and seven were asymptomatic with normal lung function. In peripheral airways, immunohistochemical methods were performed to identify neutrophils, macrophages, CD4+ and CD8+ T-lymphocytes infiltrating the airway wall, and morphometric methods were used to measure the internal perimeter, the airway wall area, and the smooth muscle area. The number of CD8+ T-lymphocytes and the smooth muscle area were increased in smokers with symptoms of chronic bronchitis and chronic airflow limitation as compared with asymptomatic smokers with normal lung function, while the number of neutrophils, macrophages, and CD4+ T-lymphocytes were similar in the two groups of subjects examined. We concluded that smokers who develop symptoms of chronic bronchitis and chronic airflow limitation have an increased number of CD8+ T-lymphocytes and an increased smooth muscle area in the peripheral airways as compared with asymptomatic smokers with normal lung function, supporting the important role of CD8+ T-lymphocytes and airway remodeling in the pathogenesis of chronic obstructive pulmonary disease.

Subepithelial immunopathology of the large airways in smokers with and without chronic obstructive pulmonary disease

“…In addition the data demonstrate that in smokers without COPD there is no increase in the number of CD8+ cells when compared with COPD when compared to a group of nonsmokers and a positive correlation with increasing obstruction. A shift towards CD8+ T-cells in the small airways has previously been demonstrated in smokers [15] and SAETTA et al [18] have previously demonstrated CD8+ infiltration into the small airways in COPD, suggesting that these cells play a role at different levels of airway within the lung.…”

Chronic Obstructive Pulmonary Disease: Evidence for an Autoimmune Component

“…The infiltration of activated T cells, and particularly CD8 + cytotoxic T cells, has long been recognized as a feature of chronic pulmonary inflammation in COPD (31). Oligoclonal CD8 + T cell infiltrates are present in both the lungs of COPD patients and also in mice chronically exposed to cigarette smoke, where they persist even after a sustained period of smoking cessation (32,33).…”

“…Oligoclonal CD8 + T cell infiltrates are present in both the lungs of COPD patients and also in mice chronically exposed to cigarette smoke, where they persist even after a sustained period of smoking cessation (32,33). Furthermore, a number of groups have demonstrated that CD8 + T cell infiltration is positively correlated with airflow limitation and disease progression (31,34). Although such observations implicate T cell responses in COPD pathogenesis, the precise role of particular T cell subsets in disease progression remains ill defined.…”

αEβ7 Expression on CD8+ T-Cells in COPD BAL Fluid and on TGF-β Stimulated T-Cells In Vitro

“…The numbers of macrophages and CD8+ T-cells in the bronchial mucosa and peripheral lung tissue correlate with a decline in lung function, indicating a role for these cells in the pathogenesis of COPD [2][3][4][5][6] . Studies of tissue samples from smokers and COPD patients have shown increased numbers of CD8+ T-cells in comparison to healthy control subjects, yet few studies have described the function of the these cells.…”