Study Of Immunologic Pathogenesis In Murine For Myocarditis Induced By Murine Cytomegalovirus

Part I To establish experimental murine cytomegalovirus animal myocarditis modelObjective To establish an experimental animal MCMV myocarditis model. Methods BALB/c mice were inoculated intraperitioneally with TCID₅₀10^-4 MCMV viral suspension. Myocardium of murine were detected with virus titer, pathology and electrocardiogram were recorded.Results The incidence of mice viral myocarditis is 69.4%. The peak time of dead is 7^th～14^th day in the postinfection. The mortality of the mice is 11.11%. The survival rate is 88.89%. 44.5% murine in the experiment group suffer from perimyocarditis. Histopathologic changes of myocardium were recorded and observed. There are swollen and denaturation in the cardiac cells. There are a number of inflammatory cells infiltration around the blood vessel in the 7^th day of postinfection. The single cell nuclear condense any lysis. There are focal necrosis and morphonuclear leukocytes and lymphcytes infiltration in the myocardium in the 14^th day of postinfection. The extent of the myocarditis reached to the peak 7-14 days after infection and decreased gradually after 14^th day of postinfection. The pathological change scores are less than 2. Viral myocarditis is mild. 50 % abnormal electrocariograms occurred in the experimental group, while no abnormal electrocardiograms were detected in control group . The virus title of heart were positive at 14^th day of postinfection ,while were negative after 14^th day of postinfection in the experimental group.Conclusion This animal MCMV myocarditis model can be used in the research ofmechanism of myocarditis ,the prognosis and screening certain agents for anti-mcmv inmyocarditis therapy. Part II Effeet of antiheart musele autoantibody on murine cytomegalovirus myoearditisObjective To explore the effect of autoantibody against the myocardial β 1-adrenergicreceptor, muscarinic acetylcholine recepter-2, adenine nucleotide translocator and cardiacmyosin heavy chain on myocarditis for murine cytomegalovirus(MCMV).Methods The autoantibody titer of anti-cardiac β 1-adrenergic receptor, muscarinicacetylcholine recepter-2, adenine nucleotide translocator and cardiac myosin heavy chainin sera of murine were detected by using ELISA assay.Results The autoantibody titer of anti-cardiac β 1-adrenergic receptor, muscarinicacetylcholine recepter-2, adenine nucleotide translocator and cardiac myosin heavy chainof sera in the experiment group were significantly higher than those in the controlgroup(P<0.01).Conclusion The anti-cardiac β 1-adrenergic receptor, muscarinic acetylcholinerecepter-2, adenine nucleotide translocator and cardiac myosin heavy chain autoantibodymight take part in pathogenesis of murine cytomegalovirus myocarditis. Part IIIExpression and role of cytokine in myocardium of myocarditisinduced by MCMVObjective To explore the expression and role of IL-1β, IL-6, IL-10 and TNF-α in myocardium of myocarditis induced by MCMV.Methods The expression of IL-1β, IL-6, IL-10 and TNF-α in myocardium of myocarditis induced by MCMV were detected with immunohistochemistry. The mRNA expression of IL-1β, IL-6, IL-10 and TNF-α in myocardium of myocarditis induced by MCMV were detected with real-time fluorescent quantitative PCR. The protein expression of IL-1β, IL-6, IL-10 and TNF- α in myocardium of myocarditis induced by MCMV were detected with western blotting.Results The immunological reaction positive cells of IL-1β, IL-6, IL-10 and TNF-α in myocardium of myocarditis induced by MCMV were detected with immunohistochemistry in the 3th , 7th and 14th day of postinfection. The immunological reaction positive cells of IL-1β, IL-6, IL-10 and TNF-α in the experiment group were significantly higher than those in the control group, P<0.01(7day and 14 day), P<0.05(3day). The mRNA expression of IL-1β, IL-6, IL-10 and TNF-α in myocardium of myocarditis induced by MCMV were detected with real-time fluorescent quantitative PCR in the 14th day of postinfection. The mRNA expression of IL-1β, IL-6, IL-10 and TNF- α in the experiment group were significantly higher than those in the control group, P<0.01. The protein expression of IL-1β, IL-6, IL-10 and TNF-α in myocardium of myocarditis induced by MCMV were detected with western blotting in the 14th day of postinfection. The protein expression of IL-1β, IL-6, IL-10 and TNF-α in the experiment group were significantly higher than those in the control group, P<0.01. Conclusion The expression of IL-1β,IL-6,IL-10 and TNF-α were all elevated markedly in myocardium of myocarditis induced by MCMV. IL-1β and TNF-α may damage to myocardium, while IL-6 and IL-10 may protect to myocardium. They may participate collectively in pathogenesis of myocarditis induced by MCMV.