目的 :检测支气管哮喘小鼠外周血单个核细胞(PBMC)及肺泡灌洗液(BALF)炎性细胞中T细胞免疫球蛋白与黏蛋白域蛋白3(Tim-3)的表达及与Th17/Treg细胞的关系,探讨其在哮喘发病中的作用。方法 :建立小鼠哮喘动物模型,分为哮喘组和对照组。收集各组小鼠PBMC及BALF炎性细胞,应用实时荧光定量PCR检测PBMCs及BALF炎性细胞中的Tim-3 m RNA水平,流式细胞仪检测CD4细胞中IL-17(CD4+IL-17+)比例反映Th17水平,CD4细胞中CD4+CD25+Fox P3+反映Treg细胞水平;酶联免疫吸附法(ELISA)检测PBMCs上清液中IL-10、IL-17、TGF-β水平,分析Tim-3的表达与Th17/Treg水平的相关性。结果:哮喘组PBMCs及BALF炎性细胞中Tim-3 m RNA水平、CD4+IL-17+表达及Th17/Treg比例、IL-17均高于对照组(P<0.05),而CD4+CD25+Fox P3+水平、IL-10显著低于对照组。哮喘组PBMCs及BALF炎性细胞中的Tim-3 m RNA表达分别与CD4+IL-17+表达及Th17/Treg比例呈正相关(r=0.76,r=0.87,r=0.71,r=0.82,P<0.05),而与CD4+CD25+Fox P3+的表达呈负相关(r=-0.84,r=-0.79,P<0.05)。结论:哮喘小鼠PBMCs及BALF炎性细胞中Tim-3 m RNA水平显著升高,Tim-3可能在哮喘发生发展中起着重要作用并与Th17/Treg失衡有关。
Summary： This study investigated the expression of interleukin-17 （IL-17） and T cell immunoglobulin mucin and domain-containing molecule-3 （Tim-3） in bronchoalveolar lavage fluid （BALF） of asthmatic mice and the effect of dexamethasone （DEX） on these factors. Thirty-six mice were randomly divided into three groups： normal group, asthmatic group and DEX group. The mouse model of asthma was es- tablished by sensitization with ovalbumin in both the asthmatic and DEX groups. The levels of IL-6, IL-10, IL-17 and TGF-β were measured in BALF by enzyme-linked immunesorbent assay （ELISA）. The mRNA expression level of Tim-3 was detected by reverse transcription polymerase chain reaction （RT-PCR）. The ratio of Tim-3＋CD4＋ cells to total CD4＋ cells in BALF was determined by flow cy- tometry. Differential inflammatory cells in BALF were detected. The correlations among IL-17, IL-6, IL-10, Tim-3 and inflammatory cells were analyzed. The results showed that the levels of IL-17, IL-6 and Tim-3 were substantially increased and the IL-10 level decreased in BALF in the asthmatic mice, which was significantly reversed by DEX treatment. IL-17 expression was positively correlated with IL-6 and Tim-3 expression and the number of inflammatory cells but negatively with IL-10 expression. These results indicate that the increased expression of IL-17 and Tim-3 in BALF may be implicated in the occurrence and development of asthmatic inflammation; the mechanism by which DEX suppresses asthmatic airway inflammation involves down-regulation of IL-17 and Tim-3 levels.
