Recombinant Mouse β-Defensin 3 Protects against Coxsackievirus B3-Induced Myocarditis in Mice.

OBJECTIVES: To investigate the protective effect of recombinant mouse β-defensin 3 (rMBD3) against coxsackievirus B3 (CVB3)-induced myocarditis in mice.

METHODS: CVB3-infected HeLa cells were treated with rMBD3, and the titer of CVB3 and the proliferative activities of the cells were determined. CBV3-infected BALB/c mice were divided into five groups: rMBD3 high (5 mg/kg/day, q.d.), rMBD3 low (2.5 mg/kg/day, q.d.), ribavirin (10 mg/kg/day, q.d.), normal control, and myocarditis control. On days 5 and 12 after treatment, 3 mice from each group were sacrificed and serum lactate dehydrogenase, creatine kinase-MB isozyme, and tumor necrosis factor-α levels were determined. The heart index and the inflammation of myocardial tissue were also assessed. On day 5, the CVB3 50% tissue culture infective dose (TCID50) values of heart tissues were measured.

RESULTS: rMBD3 inhibited the replication of CVB3 and protected HeLa cells from infection. rMBD3 reduced the CVB3 titer markedly and inhibited the pathological reaction of cardiac myocytes to viral myocarditis. Treatment with rMBD3 improved the cell survival rate and reduced the cardiac index.

CONCLUSION: rMBD3 was demonstrated to possess anti-CVB3 activity in vivo and in vitro.