过继转输的胚胎抗原耐受T细胞在妊娠小鼠体内细胞因子及协同刺激分子的表达特征

The expression characteristics of intracellular cytokines and surface costimulatory molecules in embryo antigen-tolerant T cells transferred in pregnant mice

目的 :分析过继转输的小鼠胚胎抗原耐受T细胞内细胞因子及细胞表面协同刺激分子的表达特征。方法 :以♀CBA/J×♂DBA/ 2为自然流产模型 ,将自然流产模型CBA/J孕鼠于孕 4天 (着床期 )分别腹腔注射大鼠抗小鼠CD80和CD86mAb或大鼠同型IgG。于孕 9天 ,应用免疫磁珠阴性分选两组孕鼠的脾脏T细胞 ,将T细胞进行碳氧氢化荧光素双乙酸盐琥珀酰亚胺酯 (CFSE)体外荧光标记 ,再分别过继转输至孕 4天的CBA/J×DBA/ 2孕鼠。在宿主孕鼠孕第 9天 ,处死小鼠取脾细胞 ,用流式细胞术分析在DBA/ 2父系抗原刺激下过继转输的T细胞细胞因子IL 2、IL 4、IL 10和IFN γ及协同刺激分子CD2 8和CTLA 4的表达。结果 :与过继转输的胚胎抗原非耐受T细胞相比 ,过继转输的胚胎抗原耐受T细胞IL 10的表达显著增加 ,IL 2和IFN γ的表达则显著下降 (P <0 0 5 ) ,IL 4的表达无明显改变 (P >0 0 5 ) ;细胞表面CD2 8的表达显著下降 ,而CTLA 4的表达却显著增加 (P <0 0 5 )。结论 :过继转输的小鼠胚胎抗原耐受T细胞内Th2型细胞因子和表面CTLA 4表达上调 ,而Th1型细胞因子和表面CD2 8的表达则下降。胚胎抗原耐受T细胞通过Th2型细胞因子表达优势和协同刺激信号降调节 ,在母 胎免疫耐受的维持中发挥着重要作用。

Objective:To explore the expression characteristics of intracellular cytokines and surface costimulatory molecules in embryo antigen tolerant T cells transferred in pregnant mice.Methods:Using CBA/J×DBA/2 matings as the abortion prone model, the abortion prone CBA/J females mated with DBA/2 males were injected intraperitoneally with rat anti mouse CD80 and CD86 monoclonal antibody (mAb) or rat isotype IgG at day 4 of gestation (window of implantation). Purified T cells were isolated from spleen of the CBA/J females using magnetic beads at day 9 of gestation and labeled with 5 (and 6) carboxyfluorescein diacatate succinimidyl ester (CFSE) in vitro. The CFSE labeled T cells were intravenously injected into other CBA/J females mated with DBA/2 males at day 4 of gestation. At day 9 of gestation, host splenocytes were stimulated with DBA/2 splenocytes for 4 days in vitro, then the expression of intracellular cytokines and costimulatory molecules in the transferred embryo antigen tolerant T cells was analyzed by flow cytometry.Results:Compared with the transferred T cells from isotype IgG treated CBA/J mice, the transferred T cells from anti B7 mAbs treated CBA/J mice showed lower frequency of cells positive for IL 2, IFN γ, CD28 and higher frequency of IL 10, CTLA 4 producing cells in CFSE + population, whereas the frequency of IL 4 producing cells did not appear to significant change.Conclusion:The down regulated expression of Th1 cytokines and CD28, and up regulated expression of Th2 and CTLA 4 in embryo antigen tolerant T cells transferred in the host may play an important role in the maintenance of materno fetal tolerance. [