白细胞介素7和15对肺结核患者Th1/Th2平衡的调节作用

目的探讨白细胞介素7(IL7)、IL15对肺结核病患者外周血单个核细胞(PBMC)分泌Th1型细胞因子γ干扰素(IFNγ)、肿瘤坏死因子α(TNFα)和Th2型细胞因子IL4、IL10的影响。方法选择2003年1至9月入院的60例肺结核患者和25名健康对照者,用葡聚糖泛影葡胺密度梯度离心法分离PBMC。按加入刺激物的不同,将每份标本分为6组:RPMI1640组、纯化蛋白衍生物(PPD组)、PPD+IL7组、PPD+IL7抗体组、PPD+IL15组、PPD+IL15抗体组。加入相应刺激物后培养72h,收集上清液,采用酶联免疫吸附法(ELISA)检测各组培养上清液中IFNγ、TNFα、IL4、IL10的水平。结果与PPD组相比,加入IL7的患者组PBMC分泌IFNγ和TNFα显著增高,分别为(107±42)～(157±74)ng/L、(460±128)～(887±242)ng/L;显著抑制IL4和IL10的合成,分别为(58±15)～(31±9)ng/L、(153±40)～(112±32)ng/L。健康对照组PBMC分泌IFNγ和TNFα显著增高,分别为(211±57)～(292±92)ng/L、(1203±390)～(1722±503)ng/L;显著抑制IL4和IL10的合成,分别为(43±13)～(36±11)ng/L、(135±37)～(96±36)ng/L。加入IL15患者组PBMC分泌IFNγ和TNFα显著增高,分别为(107±42)～(231±62)ng/L、(460±128)～(843±208)ng/L;显著抑制IL4和IL10的合成,分别为(58±15)～(37±9)ng/L、(153±40)～(116±41)ng/L。健康对照组PBMC分泌IFNγ和TNFα显著增高,分别为(211±57)～(343±108)ng/L、(1203±390)～(1468±235)ng/L;显著抑制IL4和IL10的合成,分别为(43±13)～(36±8)ng/L、(135±37)～(90±35)ng/L。加入IL7抗体或IL15抗体均可抑制IFNγ和TNFα的分泌,促进IL4和IL10的合成。肺结核患者各组IFNγ、TNFα水平均低于健康对照各组,而IL4、IL10水平比较差异无统计学意义。结论IL7和IL15可作为免疫调节剂,诱导IFNγ及TNFα分泌,抑制IL4及IL10合成,从而调节Th1/Th2平衡,发挥对结核分枝杆菌感染患者的免疫保护作用。

The effect of interleulin-7 and interleukin-15 on the production of Th1 and Th2 cytokines by peripheral blood mononuclear cells from patients with tuberculosis

OBJECTIVE: To investigate the effect of interleukin-7 and interleukin-15 on the production of Th1 cytokines interferon-gamma (IFN-gamma), tumor necrosis factor-alpha (TNF-alpha) and Th2 cytokines interleukin-4 (IL-4), IL-10 by peripheral blood mononuclear cells (PBMC) from patients with tuberculosis. METHODS: Peripheral blood was obtained from 60 tuberculosis patients and 25 healthy controls with a positive tuberculin test. PBMCs were isolated by centrifugation on a Ficoll-hypaque density gradient. According to the different stimulators, each sample was divided into six groups: RPMI-1640 group, PPD group, PPD + IL-7 group, PPD + anti-IL-7 group, PPD + IL-15 group, and PPD + anti-IL-15 group. The samples were cultured for 72 h and the supernatants were collected. The levels of IFN-gamma, TNF-alpha, IL-4 and IL-10 in the supernatants were measured by enzyme-linked immunosobent assay (ELISA). RESULTS: Compared with the PPD group, IL-7 increased the production of IFN-gamma and TNF-alpha in the patients (107 +/- 42) ng/L to (157 +/- 74) ng/L, (460 +/- 128) ng/L to (887 +/- 242) ng/L, respectively], but decreased the production of IL-4 and IL-10 (58 +/- 15) ng/L to (31 +/- 9) ng/L, (153 +/- 40) ng/L to (112 +/- 32) ng/L, respectively]; IL-7 also increased the production of IFN-gamma and TNF-alpha in the healthy controls (211 +/- 57) ng/L to (292 +/- 92) ng/L, (1,203 +/- 390) ng/L to (1,722 +/- 503) ng/L, respectively], and decreased the production of IL-4 and IL-10 (43 +/- 13) ng/L to (36 +/- 11) ng/L, (135 +/- 37) ng/L to (96 +/- 36) ng/L, respectively]. IL-15 increased the production of IFN-gamma and TNF-alpha in the patients (107 +/- 42) ng/L to (231 +/- 62) ng/L, (460 +/- 128) ng/L to (843 +/- 208) ng/L, respectively], but decreased the production of IL-4 and IL-10 (58 +/- 15) ng/L to (37 +/- 9) ng/L, (153 +/- 40) ng/L to (116 +/- 41) ng/L, respectively]; IL-15 also increased the production of IFN-gamma and TNF-alpha in the healthy controls (211 +/- 57) ng/L to (343 +/- 108) ng/L, (1,203 +/- 390) ng/L to (1,468 +/- 235) ng/L, respectively], and decreased the production of IL-4 and IL-10 (43 +/- 13) ng/L to (36 +/- 8) ng/L, (135 +/- 37) ng/L to (90 +/- 35) ng/L , respectively]. Anti-IL-7 and anti-IL-15 decreased the production of IFN-gamma and TNF-alpha, but increased the production of IL-4 and IL-10. The levels of IFN-gamma and TNF-alpha were lower in tuberculosis patients than those in the healthy controls (P < 0.05). The levels of IL-4 and IL-10 were not different between the two groups (P > 0.05). CONCLUSION: IL-7 and IL-15 could affect the balance between Th1 and Th2 cytokines by inducing IFN-gamma and TNF-alpha production and inhibiting IL-4 and IL-10 expression. It is suggested that IL-7 and IL-15 may enhance the defense against infection of tuberculosis, and therefore may be useful for the treatment of the disease.