Rusznak C, Sapsford R J, Devalia J L, Justin John R, Hewitt E L, Lamont A G, Wood A J, Shah S S, Davies R J, Lozewicz S
Academic Department of Respiratory Medicine, St. Bartholomew's and the Royal London School of Medicine and Dentistry, London, United Kingdom.
Am J Respir Cell Mol Biol. 1999 Jun;20(6):1238-50. doi: 10.1165/ajrcmb.20.6.3226.
Although studies have suggested that exposure to cigarette smoke (CS) may be associated with the development of atopy, the mechanisms underlying this are not clearly understood. It has been suggested that CS impairs the barrier function of the airway epithelium, leading to increased access of allergens such as those of the house dust mite (HDM) Dermatophagoides pteronyssinus (Der p) to antigen-presenting cells, with subsequent allergic sensitization. In order to test this hypothesis, we established primary explant cultures of human bronchial epithelial cells (HBEC) in cell culture inserts, and exposed these for 20 min, 1 h, 3 h, and 6 h to CS or air in the absence or presence of 300 ng/ml Der p, and then further incubated the cultures over a period of 24 h. The HBEC cultures were assessed for changes in permeability as measured by changes in: (1) electrical resistance (ER); and (2) passage of 14C-labeled bovine serum albumin (14C-BSA) and Der p allergens across the HBEC cultures. We also assessed the effects of protease inhibitors and the antioxidant glutathione (GSH) in this experimental system. Damage to HBEC cultures was assessed by the release of [51Cr]sodium chromate from prelabeled cells, and by release of lactate dehydrogenase (LDH). Twenty minutes of exposure to CS as compared with exposure to air did not significantly alter either the ER or passage of 14C-BSA across the HBEC cultures. In contrast, incubation with Der p led to a significant increase in the permeability of HBEC cultures, an effect that was enhanced by exposure to CS but was abrogated by the specific protease inhibitors and GSH. Passage of Der p was also increased by exposure to CS. Exposure of HBEC cultures to CS led to a significant release of 51Cr and LDH from these cells as compared with cells exposed to air. This effect was augmented further when HBEC cultures were incubated with Der p. Exposure of HBEC cultures for 1 h, 3 h, and 6 h to CS led to a markedly significant dose- and time-dependent increase in the permeability of these cells. These results suggest that exposure to CS significantly enhances Der p-induced decreases in electrical resistance and the increased passage across HBEC cultures of 14C-BSA and of the Der p allergen itself.
尽管研究表明，暴露于香烟烟雾（CS）可能与特应性疾病的发生有关，但其潜在机制尚不清楚。有人提出，CS会损害气道上皮的屏障功能，导致屋尘螨（HDM）过敏原如粉尘螨（Der p）更容易接触抗原呈递细胞，进而引发过敏致敏。为了验证这一假设，我们在细胞培养插入物中建立了人支气管上皮细胞（HBEC）的原代外植体培养物，并在不存在或存在300 ng/ml Der p的情况下，将这些培养物分别暴露于CS或空气中20分钟、1小时、3小时和6小时，然后再将培养物进一步孵育24小时。通过以下指标的变化来评估HBEC培养物的通透性变化：（1）电阻（ER）；（2）14C标记的牛血清白蛋白（14C-BSA）和Der p过敏原穿过HBEC培养物的情况。我们还评估了蛋白酶抑制剂和抗氧化剂谷胱甘肽（GSH）在该实验系统中的作用。通过预标记细胞中[51Cr]铬酸钠的释放以及乳酸脱氢酶（LDH）的释放来评估HBEC培养物的损伤情况。与暴露于空气相比，暴露于CS 20分钟并未显著改变HBEC培养物的ER或14C-BSA的穿过情况。相反，与Der p孵育会导致HBEC培养物的通透性显著增加，暴露于CS会增强这种作用，但特异性蛋白酶抑制剂和GSH可消除这种作用。暴露于CS也会增加Der p的穿过。与暴露于空气的细胞相比，将HBEC培养物暴露于CS会导致这些细胞中51Cr和LDH的显著释放。当HBEC培养物与Der p一起孵育时，这种作用会进一步增强。将HBEC培养物暴露于CS 1小时、3小时和6小时会导致这些细胞的通透性显著增加，且呈剂量和时间依赖性。这些结果表明，暴露于CS会显著增强Der p诱导的电阻降低以及14C-BSA和Der p过敏原本身穿过HBEC培养物的增加。
