Development of a Recombinant Based ELISA using Specific Antibodies to F Protein in HCV Chronically Infected Patients-A Seroprevalence Study

Abstract

Background and Aims: The hepatitis C virus (HCV) F protein is a recently described, frameshift product of HCV core encoding sequence. Its function and antigenic properties are unknown. In order to assess the presence of antibodies specific for F protein we characterized specific anti-F antibodies in patients with chronic HCV infection. Methods: The F protein was cloned from the HCV genome. The recombinant protein was expressed in Escherichia coli and purified by immunoaffinity chromatography. An enzymelinked immunosorbent assay was developed using the purified recombinant HCV F protein. Results: Serum samples were collected from 72 patients with chronic HCV infection and from 30 healthy controls. Eighty-two percent of chronic HCV patients had evidence of anti-F antibodies. 59 samples out of the 72 HCV infected patients exhibited a positive anti-F reaction, showing significant difference from the controls with no HCV infection (P < 0.01). Conclusion: Based on these findings, HCV F protein elicits a specific antibody response, so frameshift could occur in the core-coding sequence in HCV genotype 1a in Iranian patients. As the first report, the prevalence of anti-F antibodies in chronic hepatitis C in Iran is of the order of 82%.