Objective To investigate the contribution of Th immune bias to Coxsackie virus type B3-induced myocarditis on two different mouse strains.Methods BALB/c and C57BL/6 mice were infected intraperitoneally with Coxsackie virus B3.The incidence of myocarditis was evaluated with serum CK activity,appearance and H.E section of the heart tissue.Virus infection and replication were compared between the two mouse strains both in vitro and in vivo.Th immune bias was determined by cytokine expression pattern,antibody isotype and transcription factor T-bet/Gata-3 expression.Results Coxsackie virus B3 infected myocytes from both BALB/c and C57BL/6 mice both in vitro and in vivo.However,only BALB/c mice developed typical myocarditis after infection.Furthermore,BALB/c mice elicited a Th1 type immune response against CVB3 infection while C57BL/6 mice displayed a Th2 type immune response.Conclusion CVB3 infection induced a different pattern of pathological changes in cardiac muscle tissue in two different strains of mice.This difference was correlated with the different Th immune bias induced in these two mouse strains. if(document.getElementById('ChDivSummary').innerHTML!=""){CutSpan('ChDivSummary',500);DisplaySpanDiv('ChDivSummary');ClearSummaryOnLoad('SummaryLinkChID','SummaryLinkEnID');}else{CutSpan('EnDivSummary',1000);DisplaySpanDiv('EnDivSummary');ClearSummaryOnLoad('SummaryLinkEnID','SummaryLinkChID');}