小鼠病毒性心肌炎慢性期Th细胞分化及清心Ⅱ号的干预作用

目的:初步探讨小鼠病毒性心肌炎(viral myocarditis,VMC)慢性期Th细胞分化的部分调控机制,并观察清心Ⅱ号对这一环节的干预作用。方法:根据预实验20%~40%的死亡率,选用雄性4周龄,体质量12~15 g的BALB/c小鼠100只。正常对照组20只,剩余80只每只在第1天,第14天和第28天分别以1∶2000、1∶1000和1∶500的含柯萨奇B3病毒(coxB3)的生理盐水0.1 ml进行腹腔注射,建立病毒性心肌炎慢性期小鼠模型后,将存活小鼠随机分为模型组和清心Ⅱ号治疗组(简称治疗组),20只/组。从第42天起,正常对照组和模型组给予生理盐水灌胃,治疗组给予清心Ⅱ号水溶液灌胃,疗程45 d。疗程结束后采集血清、脾细胞和心肌标本。光镜观察心肌病理变化;酶联免疫吸附试验检测血清IFN-γ、IL-4和IL-10水平;流式细胞术检测Th细胞分化。结果:在VMC慢性期,光镜观察正常对照组心肌无明显病理改变;模型组小鼠心肌病变明显,心肌细胞排列杂乱,纤维组织增生明显,可见大量钙化灶;治疗组心肌病理改变较模型组明显减轻。与正常对照组相比,慢性期小鼠血清IL-10水平无明显变化(P>0.05);IFN-γ和IL-4水平明显升高(P<0.05);与模型组相比,治疗组小鼠血清中IL-10水平无明显变化(P>0.05);IFN-γ和IL-4水平明显降低(P<0.05,P<0.01)。治疗组小鼠Th1细胞应答水平与模型组相比,差异无统计学意义(P>0.05),Th2应答水平明显受到抑制(P<0.05)。结论:病毒性心肌炎慢性期的免疫应答以Th2细胞应答为主;清心Ⅱ号干预后Th2细胞应答受到抑制,Th1/Th2比例趋于平衡。

Th cell differentiation in chronic stage of viral myocarditis in mice and interference of Qingxin-Ⅱ Recipe

OBJECTIVE: To investigate part mechanisms of Th cell differentiation, and to observe the interference effect of Qingxin-II Recipe in the chronic stage of viral myocarditis (VMC), so as to provide some experimental evidences for illuminating the pathogenesis of VMC and treatment mechanisms of Qingxin-II Recipe. METHODS: According to 20%-40% death rate of experiment in advance, 100 BALB/c male mice (4 weeks old and weighing 12-15 g) were used. Twenty mice were randomly assigned to normal control group, and the other 80 mice were intraperitoneally injected with 0.1 ml normal saline containing coxsackie virus B3 at the 1st, 4th and 28th day (the virus densities were 1:2000, 1:1000 and 1:500 respectively) to induce chronic VMC. At the 42nd day, the surviving mice were randomly divided into untreated group and treatment group, with 20 mice in each group. Mice in the treatment group were orally administered with 0.2 ml Qingxin-II Recipe every day, while mice in the normal control group and the untreated group were administered with 0.2 ml normal saline. All the mice were sacrificed after 45 days, and the sera, heart and spleen cells were collected. Then the myocardial pathological changes were observed by using a light microscope, and the levels of IL-4, IL-10 and IFN-gamma in serum were detected by enzyme linked immunosorbent assay (ELISA). And the Th cell differentiation was observed by flow cytometry. RESULTS: No obvious myocardial pathological changes were observed in mice of the normal control group. Myocardial pathological changes in the treatment group were slighter than those in the untreated group. The difference of serum IL-10 level between the normal control group and the untreated group showed no significance (P>0.05), and the levels of IFN-gamma and IL-4 of the untreated group were higher than those of the normal control group (P<0.05 or P<0.01). There was no statistical difference in IL-10 level between the treatment group and the untreated group (P>0.05), while the serum levels of IL-4 and IFN-gamma of the treatment group were lower than those of the untreated group (P<0.05 or P<0.01). There was no significant difference of the Th1 cell responder between the treatment group and the untreated group (P>0.05), while the Th2 cell responder was inhibited significantly in the treatment group (P<0.05). CONCLUSION: Qingxin-II Recipe can restore the balance of Thl and Th2 cells through inhibiting the reaction of Th2.