抗L3T4单抗早期干预对心肌病小鼠细胞因子的影响

Expression of cytokine in mice with experimental cardiomyopathy after early treating with anti-L3T4 monoclonal antibody

目的研究早期应用抗L3T4单抗对心肌病小鼠血清和心肌组织中细胞因子的影响,探讨抗L3T4单抗治疗自身免疫性心肌病的机制。方法用含有人线粒体ADP/ATP载体肽的免疫液免疫近交系Balb/C小鼠建立类扩张型心肌病模型(心肌病组);以不含肽免疫液免疫小鼠作为对照组;在同时用含有ADP/ATP载体肽的免疫液免疫小鼠的前1d连续3d以400μg抗L3T4单抗免疫小鼠获得单抗组。采用流式细胞术检测小鼠脾脏中CD4+T细胞内IFN-γ/IL-4的表达;以ELISA法检测其血清中IFN-γ、IL-2、IL-4、IL-6和TNF-α水平;实时荧光定量PCR法检测其心肌细胞因子基因表达。结果心肌病组小鼠血清IFN-γ和IL-4水平明显高于对照组,而单抗早期干预使其生成受到抑制,此结果与流式细胞仪检测到的T细胞内IFN-γ和IL-4水平相一致;血清中IL-2含量在3组小鼠差异均无显著性;TNF-α则在单抗组显著高于对照组和心肌病组。从心肌组织中细胞因子表达情况来看,心肌病组各种细胞因子合成均增多,而早期应用单抗能够抑制其基因表达。结论抗L3T4单抗能够阻断绝大部分细胞因子的生成,从而能够治疗实验鼠自身免疫性心肌病。

[Objective] The mechanisms of anti-L3T4 monoclonal antibody on treating autoimmune cardiomyopathy remain unclear. To clarify these mechanisms, the study focused on T helper-1 （Th1）/T helper-2 （Th2） subsets balance of splenic T cells and serum eytokine levels and myocardial eytokine mRNA expression in mice with experi- mental autoimmune cardiomyopathy. [Methods] Mice （n=6） immunized with the human mitochondria ADP/ATP peptides were served as eardiomyopathy group, and the sham-immunized mice （n=6） were regarded as the controls. Mice in the anti-L3T4 treated group （n=6） immunized with the peptides in the same manners with the eardiomyopa-thy group and injected with 400 μg anti-L3T4 monoclonal antibody on the 0, 1st and 2nd days through the tail veins. We examined percentages of interferon （IFN-γ） and interleukin-4 （IL-4） producing cells in splenic CD4-positire lymphocytes using flow cytometry analysis. Serum IFN-γ, IL-2, IL-4, IL-6 and TNF-α levels were measured by enzyme-linked immunosorbent assay （ELISA） and the expression of myocardial cytokines were detected by realtime PCR. [Results] Serum IFN-γ and IL-4 significantly increased in the cardiomyopathy group but dramatically inhibited by anti-L3T4 antibody, which is consistent with the result from flow cytometry analysis. Serum IL-2 levels had no significant difference among three groups and TNF-α levels were significantly increased in anti-L3T4 group as compared to control group and cardiomyopathy group. Cytokine production in myocardium was significantly correlated with anti-L3T4, which was dramatically inhibited in anti-L3T4 group. [Conclusion] These results suggest that the production of cytokines in cardiomyopathy mice may be repressed by anti-L3T4 antibody and it was one of the mechanisms for the treatment of experimental autoimmune cardiomyopathy.