[Expression of CPP32, Fas and Fas ligand and the relationship between their expression and viral antigens in chronic...

To study the significance of Fas-Fas ligand (FasL)-CPP32 mediated hepatocytic apoptosis and the relationship between their expression and hepatitis C virus (HCV) antigens in pathogenesis of chronic hepatitis C (CHC).

The expression of Fas and FasL proteins and CPP32 protease and their mRNAs was detected by immunohistochemistry and in situ hybridization respectively. Meanwhile, HCV core protein and nonstructural protein NS(3) and NS(5) were examined on the sequential liver tissue sections from 65 cases of patients with CHC and 5 cases of normal subjects. The positive staining was quantified by image analysis.

In CHC liver tissues, CPP32 protease, Fas and their mRNAs were mainly expressed in the hepatocytes, especially in the HCV core protein-positive hepatocytes and their surroundings, but FasL protein and its mRNA were expressed dominantly in the infiltrating mononuclear cells in the portal area and hepatic sinusoid. According to the increase of histological activity index (HAI) in the CHC liver tissues, the expression of the three proteins (protease) and their mRNAs were upregrulated obviously.

The results suggest i) that Fas-FasL-CPP32 system is associated with HAI of CHC, ii) that HCV core antigen may affect the expression of CPP32 and Fas hepatocytes apoptosis.