OBJECTIVEINF-lambda has anti-viral and anti-tumor activities. Its application in viral myocarditis (VMC) has not been reported. This study investigated the role of INF-lambda in acute VMC in mice.

METHODSForty mice were randomly divided into three groups: VMC (n=15), IFN-lambda2-treated VMC (n=15) and control (n=10). VMC was induced by an intraperitoneal injection of Coxsackievirus B3 (CVB3).The control group was intraperitoneally injected with 2% PBS. The IFN-lambda2-treated VMC group was administered with 400 ng IFN-lambda2 (0.1 mL) by subcutaneous injections daily, for 5 days. The control and the VMC groups were given equal amount of nomal saline.The surviving mice were sacrificed 9 days after IFN-lambda2 treatment. The pathological changes of heart tissues were examined under a light microscope. Bcl-2 and Bax expression in heart tissues was determined by immunohistochemistry.

RESULTSThe control group presented normal heart tissues. The INF-lambda2-treated VMC group showed significantly a lower pathological score (1.5+/-0.5) than the untreated VMC group (2.8+/-0.8) (P<0.01). Bcl-2 expression decreased (P<0.01), in contrast, Bax expression increased (P<0.01) in the untreated VMC group compared with that in the control group. INF-lambda2 treatment resulted in an increased Bcl-2 expression (P<0.01) and a decreased Bax expression (P<0.01) compared to the untreated VMC group.

CONCLUSIONSINF-lambda2 may alleviate myocardial injuries and inhibit cardiomyocytic apoptosis, thus providing protective effects on myocardial cells in mice with acute VMC.