阻断单核细胞趋化蛋白-1可缓解病毒性心肌炎心肌病变

Blocking Monocyte Chemoattractant Protein-1(MCP-1) Alleviates Cardiac Lesion of Viral Myocarditis

目的 研究单核细胞趋化蛋白 1(MCP 1)在B3型柯萨奇病毒 (CVB3)诱导病毒性心肌炎 (VMC)发病中的作用及其机制。方法 CVB3腹腔注射BALB/c小鼠 ,随机分 3组 :VMC组 (A组 )、抗体阻断组 (B组 )、羊IgG对照组 (C组 ) ,并设未感染生理盐水对照组 (D组 )。比较各组小鼠心脏重量和体重的比值 (HW/BW )、心肌组织病理学积分 (PS)、心肌组织病毒载量、血清CK MB水平和心肌浸润的单个核细胞变化。流式细胞术分析单个核细胞表面CCR2 ,趋化试验分析病毒性心肌炎小鼠外周血单个核细胞对MCP 1的趋化性。结果 与A组相比 ,B组血清CK MB水平降低 (P <0 .0 1)、PS减少 (P <0 .0 5 ) ,但是HW /BW和CVB3载量未呈明显改变 (P>0 .0 5 ) ;B组小鼠心肌浸润的单个核细胞减少 ,下降 2 2 %～ 5 6 % ,平均下降 39% ;与D组相比 ,B组CK MB、PS、HW /BW和CVB3载量均明显升高。而与A组相比 ,C组CVB3载量、血清CK MB水平、HW/BW和心肌组织病理学积分均未呈明显改变。同时发现 ,A组小鼠心肌组织浸润的单个核细胞中CCR2 + 细胞为 70 .2 9% ,外周血单个核细胞中CCR2 + 的细胞占 33.76 % ;B组小鼠心肌组织浸润的单个核细胞中CCR2 + 细胞下降 ,为 4 4 .37%。体外经MCP 1趋化的病毒性心肌炎外周血单个核细胞中CCR2 + 细胞占 86 .5 5 % 。

Purpose: To investigate the role of monocyte chemoattractant protein-1 (MCP-1) in viral myocarditis (VMC) induced by coxsackievirus group B type 3 (CVB3) and its mechanism in pathogenesis of VMC. Methods: BALB/c mice inoculated intraperitoneally with CVB3 were divided into three groups including VMC group infected alone with CVB3 (group A), intervention group with anti-MCP-1 (group B), control group with goat IgG (group C). And the normal control group inoculated intraperitoneally with saline was designed. Ratio of mouse heart weight to body weight (HW/BW), myocardial tissue pathological score (PS) of cardiac tissue, the level of CK -MB in serum and CVB3 loading of myocardial tissue were analyzed. Chemokine receptor CCR2 on peripheral blood mononuclear cells (PMNC) and the infiltrating mononuclear cells (IMNC) in myocardium were detected by flow cytometry, and chemotaxis of PMNC in VMC to MCP-1 was detected by chemotaxis assay. Results (1) Compared with group A, the level of creatine kinase-MB fraction(CK-MB) in group B decreased (P0.05). And there was much difference between group B and group D in the level of CK-MB, PS and CVB3 loading of myocardial tissue. Compared with group A, group C's CVB3 loading in myocardial tissue, CK-MB level in serum, HW/ BW and PS all did not alter markedly (P>0.05). (2) The infiltration of the mononuclear cells in myocardium of group B intervened with anti-MCP-1 antibody decreased 22%-56% , average 39%, versus that of group A. (3) The CCR2 positive cells of PMNC in VMC were 33.76%, and the CCR2 positive cells of IMNC were 70.29%, much higher than the former. If the anti- MCP-1 antibody was used to intervene with MCP-1, the percentage of the CCR2 positive cells decreased to 44.37%, compared with normal mice. By analyzing the CCR2 positive cells of PMNC induced by MCP-1 in vitro, it was detected that above 86.55% induced cells were CCR2 positive, and in the non-induced cells only 33.81% cells were CCR2 positive. Conclusions: Intervention with MCP-1 could alleviate the cardiac lesion and cardiac injury of viral myocarditis, which was associated with improvement of CCR2+ cell infiltration. It demonstrated that MCP-1 played a partial role in the onset of VMC.