Expression of HCV core protein in Escherichia coli and the establishment of ELISA system

Abstract

Protein encoded by the cDNA of the core region of hepatitis C virus (HCV) was expressed as a fusion protein with β-galactosidase (β-gal) in Escherichia coli, and an ELISA system was established using this fusion protein for diagnosis of HCV infection. Using this ELISA system, a comparative study with anti-C100 antibody ELISA was undertaken in 150 cases of NANB acute hepatitis, chronic hepatitis, liver cirrhosis and hepatocellular carcinoma. Anti-C100 antibody positivity rates with these diseases were 62.5, 71.1, 75.0 and 75.0%, respectively, while anti-JCC antibody positivity rates were as high as 75.0, 85.6, 92.5 and 91.7%, respectively. On average, the positivity rate of anti-C100 antibody was 72.0%, while that of anti-JCC antibody was 87.3%. In the long-term analyses of two clinical cases regarding the antibody responses to these different proteins, anti-JCC antibody had a tendency to be detected earlier than anti-C100 antibody, although the time of detection in relation to ALT peaks was dependent on the case.