Meakins-Christie Laboratories, Faculty of Medicine, McGill University, Montreal, Qc, Canada.
Respir Res. 2011 Nov 9;12(1):149. doi: 10.1186/1465-9921-12-149.
Cigarette smoke is a major risk factor for chronic obstructive pulmonary disease (COPD), an inflammatory lung disorder. COPD is characterized by an increase in CD8(+) T cells within the central and peripheral airways. We hypothesized that the CD8(+) T cells in COPD patients have increased Toll-like receptor (TLR) expression compared to control subjects due to the exposure of cigarette smoke in the airways.
Endobronchial biopsies and peripheral blood were obtained from COPD patients and control subjects. TLR4 and TLR9 expression was assessed by immunostaining of lung tissue and flow cytometry of the peripheral blood. CD8(+) T cells isolated from peripheral blood were treated with or without cigarette smoke condensate (CSC) as well as TLR4 and TLR9 inhibitors. PCR and western blotting were used to determine TLR4 and TLR9 expression, while cytokine secretion from these cells was detected using electrochemiluminescence technology.
No difference was observed in the overall expression of TLR4 and TLR9 in the lung tissue and peripheral blood of COPD patients compared to control subjects. However, COPD patients had increased TLR4 and TLR9 expression on lung CD8(+) T cells. Exposure of CD8(+) T cells to CSC resulted in an increase of TLR4 and TLR9 protein expression. CSC exposure also caused the activation of CD8(+) T cells, resulting in the production of IL-1β, IL-6, IL-10, IL-12p70, TNFα and IFNγ. Furthermore, inhibition of TLR4 or TLR9 significantly attenuated the production of TNFα and IL-10.
Our results demonstrate increased expression of TLR4 and TLR9 on lung CD8(+) T cells in COPD. CD8(+) T cells exposed to CSC increased TLR4 and TLR9 levels and increased cytokine production. These results provide a new perspective on the role of CD8(+) T cells in COPD.
香烟烟雾是慢性阻塞性肺疾病（COPD）的主要危险因素，这是一种肺部炎症性疾病。COPD 的特征是中央和外周气道中的 CD8+T 细胞增加。我们假设由于香烟烟雾在气道中的暴露，COPD 患者的 CD8+T 细胞的 Toll 样受体（TLR）表达增加。
从 COPD 患者和对照受试者中获得支气管内活检和外周血。通过肺组织免疫染色和外周血流式细胞术评估 TLR4 和 TLR9 的表达。从外周血中分离出 CD8+T 细胞，用或不用香烟烟雾冷凝物（CSC）以及 TLR4 和 TLR9 抑制剂处理。使用 PCR 和 Western blot 来确定 TLR4 和 TLR9 的表达，同时使用电化学发光技术检测这些细胞的细胞因子分泌。
与对照受试者相比，COPD 患者的肺组织和外周血中 TLR4 和 TLR9 的总体表达没有差异。然而，COPD 患者的肺 CD8+T 细胞上 TLR4 和 TLR9 的表达增加。CD8+T 细胞暴露于 CSC 导致 TLR4 和 TLR9 蛋白表达增加。CSC 暴露还导致 CD8+T 细胞的激活，导致产生 IL-1β、IL-6、IL-10、IL-12p70、TNFα 和 IFNγ。此外，TLR4 或 TLR9 的抑制显著减弱了 TNFα 和 IL-10 的产生。
我们的结果表明，COPD 患者肺 CD8+T 细胞上 TLR4 和 TLR9 的表达增加。暴露于 CSC 的 CD8+T 细胞增加了 TLR4 和 TLR9 水平并增加了细胞因子的产生。这些结果为 CD8+T 细胞在 COPD 中的作用提供了新的视角。
