激素预处理树突状细胞对哮喘Th2型反应的影响

Effect of glucocorticoid-treated dendritic cells on asthmatic Th2 response

目的:研究激素预处理的树突状细胞(DCs)对哮喘DCs与T细胞共培养上清液中T辅助细胞1(Th1)和Th2型细胞因子的影响及其机制。方法:采集哮喘组和健康组外周血,分别常规培养和加入地塞米松培养至成熟DCs。将2组常规培养和地塞米松预处理的DC-T细胞共培养72h。流式细胞仪测定2组常规培养或地塞米松培养成熟DCs的表型。酶联免疫吸附试验(ELISA)检测DC-T细胞共培养上清液中白细胞介素-5(IL-5)和干扰素-γ(IFN-γ)的含量。结果:哮喘组常规培养的DC-T细胞共培养上清液中IL-5水平高于健康组(P<0.01),其IFN-γ含量较健康组有减少的趋势,但无显著差异(P>0.05);地塞米松预处理的DC-T细胞上清液中IL-5水平低于常规培养组(P<0.01)。无论哮喘组或健康组,地塞米松预处理的DC-T细胞共培养上清液中IFN-γ水平均低于未用地塞米松预处理的DC-T细胞共培养上清液(P<0.01)。2组地塞米松预处理的DCs均部分抑制了肿瘤坏死因子-α(TNF-α)所诱导的DCs表型CD83上调(P<0.01),而上调了CD14的表达(P<0.01)。结论:哮喘患者常规培养的DCs与同种自体T细胞共培养后呈Th2型反应,地塞米松预处理的DCs可使Th2型反应减弱,其机制可能与地塞米松影响DCs的分化、成熟有关。

AIM ： To investigate the effect of dexamethasone - treated dendritic cells （DCs） on Th2 eytokine production from autologous T cells in asthmatic patients and explore the mechanisms by studying the effect of dexamethasone on differentiation, maturation and function of DCs from patients with asthma. METHODS： Human peripheral blood monocyte - derived DCs generated from asthmatic patients and healthy subjects were cultured in the absence or presence of dexamethasone. The phenotypie characterization of DCs was analyzed by flow cytometry. The mature DCs were harvested, washed, and then cocuhured in vitro with autologous T cells purified by a nylon cotton column. The DC -T eocuhure supernatants were collected after 72 h incubation and analyzed for levels of IL - 5 and IFN -γ by ELISA. RESULTS： The concentrations of IL - 5 in the culture supernatants of DC - T cocuhure were significantly up - regulated in patients with asthma compared with that in healthy controls [ （ 145.13±89. 76） ng/L vs （50. 28±22. 37） ng/L, P 〈0. 01 ]. The level of IFN -γ in the DC - T coculture supernatants tended to be decreased in asthmatic patients than that in healthy controls, although this difference did not achieve statistical significance [ （ 197.58 ± 76. 32） ng/L vs （220. 46 ± 65. 34） ng/L, P 〉 0. 05 ） ]. There were significantly decreased levels of IL - 5 by autologous T cells primed by dexamethasone - treated ma- ture DCs from asthmatic patients [ （ 45.39 ± 19.61 ） ng/L vs （ 145.13 ± 89.76 ） ng/L, P 〈0.01 ], alterations not observed from healthy controls （ P 〉 0. 05 ）. IFN -γ production was decreased by autologous T cells primed by dexamethasone- treated mature DCs from both asthmatic patients and healthy controls [ asthma group： （40. 21 ± 22. 89） ng/L vs （ 197.58 ± 76. 32） ng/L, P 〈 0. 01 ; healthy controls： （ 56. 78 ± 20. 37 ） ng/L vs （220. 46 ± 65. 34） ng/L, P 〈 0. 01 ].Dexamethasone - treated DCs exhibited decreased expression of CD83 （P 〈 0. 01 ） and increased expression of CD14 （P 〈 0. 01 ） in both asthmatic patients and healthy controls. CONCLUSION： DCs of asthmatic patients induce a Th2 - skewed eytokine production from autologous T cells. Dexamethasone - treated DCs inhibit the Th2 reactions, and this effect is probably mediated through the pathway that dexamethasone inhibits DCs maturation and skews the macrophage/DC balance towards the rnaerophage side and thus directs the development more towards the maerophage lineage.