三氯乙烯致敏小鼠Tc1/Tc2细胞失衡研究

The study on imbalance of Tc1 /Tc2 cells in trichloroethylene sensitized mice

目的检测小鼠经三氯乙烯(TCE)致敏后Tc1、Tc2细胞的变化,探讨Tc1/Tc2细胞失衡在三氯乙烯药疹样皮炎(DMLT)中的可能作用。方法 BALB/c雌性小鼠随机分为空白对照、溶剂对照和TCE处理组,在末次激发后24、48、72h和7 d根据皮肤肿胀程度和病理表现分为致敏组和未致敏组。无菌取出脾脏,用流式细胞术检测Tc1、Tc2细胞数量,实时荧光定量PCR检测T-bet、GATA-3 mRNA转录水平。结果与未致敏组相比,致敏组Tc1细胞数量在24、48、72 h和7 d显著上升(P<0.01),72 h水平最高;致敏组Tc2细胞数量在24、48、72 h显著上升(P<0.01),72 h水平达到峰值,7d较未致敏组差异无统计学意义(P>0.05);致敏组Tc1/Tc2比例于48、72 h和7 d较未致敏组显著上升(P<0.01)。致敏组T-bet、GATA-3 mRNA转录水平在48、72 h和7 d较相应时点未致敏组显著上升(P<0.05,P<0.01),72 h达到峰值。结论 Tc1/Tc2细胞失衡可能参与了TCE致敏小鼠的免疫损伤过程并发挥重要的作用。

Objective To detect the alterations of Tcl and Tc2 cells in trichloroethylene （TCE） sensitized mice and to shed light on the possible role of Tcl/Tc2 imbalance on occupational medicamentosa-like dermatitis induced by trichloroethylene （DMLT）. Methods Female BALB/c mice, randomly separated into blank control, solvent control and TCE group, were sacrificed on 24, 48, 72 h and 7 d after last challenge. Sensitized or non-sensitized mice were identified by cutaneous swelling and histological appearance before sacrifice. Spleens were taken to pre- pare splenocyte suspensions quantifying Tcl and Tc2 by flow cytometry. Tc lineage-specific transcription factors, T- bet and GATA-3, were evaluated by real-time fluorescence quantitative PCR. Results Compared with non-sensi- tized group, the percentages of Tcl cells in sensitized mice were significantly higher at four consecutive timepoints （P 〈0. 01 ）, which peaked at 72 h. Tc2 cell levels in sensitized mice were markedly elevated at 24 and 48 h with reaching the summit at 72 h （P 〈 0.01 ）, whereas the level at 7 d showed no significant difference with non-sensi- tized mice （P 〉 0. 05 ）. Tcl/Tc2 ratios in sensitized group were significantly higher at 48, 72 h and 7 d compared with non-sensitized group. The levels of T-bet and GATA-3 mRNA in sensitized mice were remarkably increased than corresponding non-sensitized mice at 48, 72 h and 7 d （P 〈 0. 05, P 〈 0. 01 ）. Conclusion The imbalance of Tcl/Tc2 cells may play a key role in the immunological damage in TCE sensitized mice.