过继转输扩张型心肌病小鼠淋巴细胞诱导心肌损害

Cardiac impairments induced by adoptive transfer of lymphocytes from the experimental cardiomyopathy in mice

目的探讨扩张型心肌病(DCM)小鼠的自身免疫学机制。方法用人线粒体ADP/ATP载体肽免疫小鼠建立扩张型心肌病模型(DCM组),分别将其以伴刀豆凝集素A(ConA)刺激和未刺激的脾淋巴细胞过继转移给同源近交系小鼠(DCM-T-A组和DCM-T组),以用不含肽的对照液体免疫的小鼠为对照组;观察各组小鼠心肌组织病理学变化,以酶联免疫吸附法检测其血清抗ADP/ATP载体自身抗体水平、实时荧光定量聚合酶链反应检测其心肌细胞因子基因表达。结果在免疫或过继后的第1和第6个月末,DCM组和以ConA刺激的DCM-T-A组小鼠血清抗ADP/ATP载体自身抗体均为阳性;心脏在前期分别出现心肌炎性细胞浸润和轻度心肌纤维化,在后期均出现心脏增大、心肌细胞溶解断裂和弥漫性纤维化;心肌中细胞因子表达均增高,其中干扰素(IFN)-γ(DCM组30d:1486.0±243.0,180d:192.0±38.0;DCM-T-A组30d:357.0±38.6,180d:186.0±19.27)和白细胞介素(IL)-2(DCM组30d:197.0±11.0,180d:103.0±19.0;DCIN-T-A组30d:166.0±13.8,180d:96.0±4.47)表达增高在前期明显,IL-4、IL-6和肿瘤坏死因子(TNF)-α表达增高在后期更为显著。未用ConA刺激的DCM-T组与对照组均无上述改变。结论过继转输DCM小鼠脾淋巴细胞可诱导同源近交系小鼠产生抗ADP/ATP载体自身抗体和T细胞介导的免疫应答,发生过继免疫性心肌损害,且此损害与供体小鼠体内改变相似。

Objective To investigate the autoimmune mechanism in dilated cardiomyopathy (DCM).Methods Thirty-six male Balb/c mice were randomly divided into 2 groups: DCM group to be immunized with human mitochondrion ADP/ATP vector polypeptides and control group (sham immunization group) to be injected with immune fluid without the polypeptide.Before the injection and then every month after the injection serum was collected to examine the ADP/ATP autoantibody level by ELISA.One month after immunization 6 mice of each group were killed and 6 months after the remaining mice were all killed to undergo serologic and histological examination. Lymphocytes from spleen were collected from the mice injected with ADP/ATP vector polypeptides, some of these spleen lymphocytes were co-cultured with concanavalin A (Con A) and some were cultured without stimulation of Con A.Six months after the ADP/ATP vector polypeptide injection another 24 Balb/c mice were randomly divided into 2 groups: DCM-T-A group to be injected with the spleen lymphocytes stimulated by Con A and DCM-T group to be injected with the spleen lymphocytes without Con A stimulation.One month after the transfer 6 mice of each group were killed and 6 months after the remaining mice were all killed to undergo serologic and histological examination.Results One month and 6 months after immunization autoantibody against ADP/ATP vector was positive in the sera of the mice in both DCM and DCM-T-A groups.One month after immunization or transfer the myocardium of both DCM and DCM-T-A groups showed myocarditis-like changes, and 6 months after immunization or transfer the myocardium of both DCM and DCM-T-A groups showed DCM-like changes.Increase of different cytokines was found in the myocardium in both DCM and DCM-T-A groups with predominance of interferon-γ and interleukin (IL)-2 one month after and predominance of IL-4, IL-6, and tumor necrosis factor-α 6 months after immunization or transfer.Such changes were not found in the control group and DCM-T group.Conclusion Human mitochondria ADP/ATP peptides induce autoimmune DCM in mice.T cell-mediated responses play an important role in the development of DCM.