Abstract: Objective To investigate the toll-like receptor 2 （TLR2） in livers of mice with murine hepatitis virus-3 （MHV-3）-induced fulminant hepatitis and in peripheral blood mononuclear cell （PBMCs） from patients with mild chronic hepatitis B（CHB）or with HBV-associated acute-on-chronic liver failure （HBV-ACLF）. Methods PBMCs from patients with mild CHB and HBV-ACLF were collected. The TLR2 mRNA in PBMCs were determined by quantitative real-time PCR. Balb/cJ mice were injected intraperitoneally with MHV-3 at dose of 100 pfu to induce fulminant hepatitis. At 0,24,48 and 72 h after injection,the TLR2 mRNA in liver tissues of mice were determined. Results After infection of MHV-3,TLR2 mRNA increased significantly at 48 and 72 h when compared with the baseline at 0 h [（0.39±0.06）% vs.（9.06±1.60）%,P<0.05 and （6.42±2.42）%,P<0.05] and it peaked at 48 h;mRNA levels for TLR2 at 48 and 72 h were positively correlated with the serum ALT and AST（r=0.804,P<0.01;r=0.797,P<0.01,respectively）;mRNA level of TLR2 in PBMCs from patients with HBV-ACLF was significantly higher than patients with mild CHB [（5.92±5.26）% vs.（1.15±1.59）%,P<0.05]. Conclusions TLR2 may take part in the process of liver injury in MHV-3-induced fulminant hepatitis in mice and the pathogenesis of patients with HBV-ACLF.

Key words: Fulminant hepatitis, Acute-on-chronic liver failure, Murine hepatitis virus-3, Toll-like receptor 2, Mouse