Robbins R A, Koyama S, Spurzem J R, Rickard K A, Nelson K J, Gossman G L, Thiele G M, Rennard S I
Research Service, Omaha Veterans Affairs Medical Center, Nebraska.
Am J Respir Cell Mol Biol. 1992 Jul;7(1):19-29. doi: 10.1165/ajrcmb/7.1.19.
Neutrophils and mononuclear cells have been associated with the lower respiratory tract inflammation observed in both acute and chronic bronchitis. In order to transit into and remain within the airways, neutrophils and mononuclear cells would likely need to adhere to bronchial epithelium. To test this hypothesis, bovine bronchial epithelial cells (BBECs) were isolated and cultured on a round coverslip. After 7 to 10 days, 51Cr-labeled neutrophils and mononuclear cells were evaluated for their capacity to adhere to the BBEC monolayer. Both neutrophils and mononuclear cells readily bound to the BBEC monolayer (10.8 +/- 1.2% bound neutrophils; 40.5 +/- 2.8% bound mononuclear cells). Stimulation of the neutrophils and mononuclear cells with phorbol 12-myristate 13-acetate (PMA) increased the adherence (45.8 +/- 10.6% bound neutrophils, P less than 0.01 compared with unstimulated cells; 58.7 +/- 6.2% bound mononuclear cells, P less than 0.01 compared with unstimulated cells). Importantly, stimulating the BBEC monolayer with PMA, bacterial lipopolysaccharide, or a cigarette smoke extract for 4 to 72 h also increased the adherence of both cell types (P less than 0.01, all comparisons at 24 h). The adherence was not decreased by exposure of either the BBEC monolayer, the neutrophils, or the mononuclear cells to cycloheximide or to the anti-CD11/CD18 monoclonal antibody 60.3 (P greater than 0.05). However, exposure of the BBEC monolayer to trypsin before addition of the neutrophils significantly decreased adherence (P less than 0.05). Because neutrophils and mononuclear cells are thought to mediate cell cytotoxicity by adhering to the target cells, BBECs were labeled with 51Cr, and 51Cr release was measured as an index of cytotoxicity. There was a modest increase in 51Cr release by the addition of unstimulated neutrophils and mononuclear cells, and culturing the BBEC monolayer with PMA before the addition of the neutrophils or mononuclear cells resulted in a further modest enhancement of 51Cr release (P less than 0.05). Similar results were obtained using lactate dehydrogenase release as a measure of cytotoxicity. These results demonstrate that inflammatory cells can adhere to BBECs and may be capable of mediating cytotoxicity and adherence and cytotoxicity can be increased by stimulating BBECs.
中性粒细胞和单核细胞与在急性和慢性支气管炎中观察到的下呼吸道炎症有关。为了进入并停留在气道内，中性粒细胞和单核细胞可能需要黏附于支气管上皮。为了验证这一假设，分离牛支气管上皮细胞（BBECs）并将其培养在圆形盖玻片上。7至10天后，评估51Cr标记的中性粒细胞和单核细胞黏附于BBEC单层的能力。中性粒细胞和单核细胞均能轻易地黏附于BBEC单层（10.8±1.2%的中性粒细胞黏附；40.5±2.8%的单核细胞黏附）。用佛波醇12-肉豆蔻酸酯13-乙酸酯（PMA）刺激中性粒细胞和单核细胞可增加黏附率（45.8±10.6%的中性粒细胞黏附，与未刺激细胞相比P<0.01；58.7±6.2%的单核细胞黏附，与未刺激细胞相比P<0.01）。重要的是，用PMA、细菌脂多糖或香烟烟雾提取物刺激BBEC单层4至72小时也会增加两种细胞类型的黏附率（P<0.01，24小时时所有比较）。将BBEC单层、中性粒细胞或单核细胞暴露于环己酰亚胺或抗CD11/CD18单克隆抗体60.3后，黏附率并未降低（P>0.05）。然而，在加入中性粒细胞之前将BBEC单层暴露于胰蛋白酶会显著降低黏附率（P<0.05）。由于中性粒细胞和单核细胞被认为通过黏附于靶细胞来介导细胞毒性，因此用51Cr标记BBECs，并测量51Cr释放作为细胞毒性的指标。加入未刺激的中性粒细胞和单核细胞后，51Cr释放有适度增加，在加入中性粒细胞或单核细胞之前用PMA培养BBEC单层会导致51Cr释放进一步适度增强（P<0.05）。使用乳酸脱氢酶释放作为细胞毒性的指标也获得了类似结果。这些结果表明，炎症细胞能够黏附于BBECs，并且可能能够介导细胞毒性，刺激BBECs可增加黏附性和细胞毒性。
