Abstract：OBJECTIVE: This study was aimed to investigate the expressions of ICAM-1 and TNF-α in viral myocarditis and the effect of anti-TNF-alpha monoclonal antibody on viral myocarditis in mice. METHODS: Sixty-six male Balb/c mice were randomly assigned into an Infection group (n=30), an Intervention group (n=18) and a Normal control group (n=18). The Infection and Intervention groups were inoculated intraperitoneally with 0.2 mL TCID50 10~ -6/mL coxsackie B_3(CVB_3) solution. Anti-TNF-amAb [0.1 mL/(kg.d)] was additionally administered starting at 1 day before CVB_3 virus inoculation until day 5 in the Intervention group. On the 7th and 14th days after virus inoculation, the changes of histopathology and ultrastructure of myocardium were studied with light and electron microscopy. The expressions of ICAM-1 and TNF-α were detected by immunohistochemical method. RESULTS: Myocardium histopathology of mice in the Normal control group was normal. Myocardial necrosis and cellular infiltration were more prominent in the Infection group than in the Intervention group.ICAM-1 and TNF-α were expressed in the myocardium of Normal control gorup at a very low level, which were significantly lower than those in the Infection and Intervention groups. The expressions of ICAM-1 and TNF-α were dramatically reduced in the Intervention group compared with those in the Infection group.In the Infection group, a positive correlation was found between the expressions of ICAM-1 and TNF-α ( r=0.706, P<0.05); and both ICAM-1 expression and TNF-α expression were positively related to pathological scores of myocardium (r = 0.737, P<0.05;r = 0.693, P<0.05). CONCLUSIONS: ICAM-1 and TNF-α may play important roles in the pathogenesis of viral myocarditis. Anti-TNF-alpha monoclonal antibody has protective effects on myocardial tissues by inhibiting the ICAM-1 and TNF-α expression.
