Enteroviral Replication and Cardiocyte Injury in the Myocardium from patients with Dilated Cardiomyopathy and Perforin Knockout Mice with Viral Myocarditis

(1)穿孔素敲除（pfk）小鼠的实验性柯萨奇病毒B3心肌炎。我们检测了感染柯萨奇病毒B3（CVB3）心肌炎的pfk和野生（C57BL/6）小鼠心肌的光镜和（LM）电镜（EM）变化。接种病毒后第5 ~ 28天处死小鼠。第8天和第14天，许多心肌细胞坏死，淋巴细胞和巨噬细胞浸润。免疫电镜观察到淋巴细胞颗粒中可见穿孔素。淋巴细胞有时与心肌细胞膜紧密接触。pfk小鼠心肌中有大量淋巴细胞浸润，但心肌细胞坏死程度低于野生小鼠。这些发现表明穿孔素在淋巴细胞介导的心肌细胞损伤的发展中起重要作用。(2) 26例扩张型心肌病（DCM）合并难治性心力衰竭的肠病毒RNA复制蛋白研究我们对左心室部分切除术后获得的心肌标本进行了光镜原位杂交（ISH）和病毒学分析。用PCR和ISH检测心肌标本肠病毒RNA在心肌中的存在和定位。PCR研究中，7例（38%）患者心肌同时检测到正义和反义病毒RNA。这些rna的存在表明在心肌中有活跃的病毒复制。在ISH治疗中，3例患者有肠病毒基因组活跃复制的证据。退行性心肌细胞、间质炎性细胞和小血管内皮细胞均可见病毒信号。我们在各种心肌病变中检测到正义和反义肠病毒RNA。我们的研究结果表明，活跃的病毒复制在DCM患者心肌病变的发展中起作用。

(1)Experimental Coxsackievirus B3 Myocarditis in Perforin Knockout (pfk) Mice.We examined light and (LM) electron-microscopic (EM) changes of the myocardium obtained from pfk and wild(C57BL/6) mice with Coxsackievirus B3(CVB3) myocarditis. The mice were sacrificed on days 5-28 after virus inoculation. On days 8 and 14 many cardiocytes underwent necrosis with infiltration of lymphocytes and macrophages. By immuno-EM perforin were often observed in the granules of lymphocytes. The lymphocytes were sometimes in close contact with plasma membrane of cardiocytes. In pfk mice, cardiocyte necrosis was less than in wild mice, although significant number of lymphocytes infiltrated in the myocardium. These findings suggest that perforin plays an important role in the development of lymphcyte-mediated cardiocyte injury.(2)Enteroviral RNA Replicatin in 26 Cases of Dilated Cardiomyopathy (DCM) with Refractory Heart FailureWe performed light microscopic in situ hybridization (ISH) and virological analyses of myocardial specimens obtained by partial left ventriculectomy. Myocardial specimens were tested for the presence and localization of enteroviral RNA in the myocardium by PCR and ISH. In PCR studies, both sense and antisense viral RNA were detected in the myocardium of seven patients(38%). The presence of these RNAs indicates active viral replication in the myocardium. On ISH, 3 patients had evidence of active replication of enteroviral genomes. Viral signals were found in degenerating cardiocytes, interstitial inflammatory cells and endothelial cells of small vessels. We detected both sense and antisense enteroviral RNA in various myhocardial lesions. Our results suggest that active viral replication plays a role in the development of myocardial lesions in DCM patients.