Composite recombinant antigens were constructed from diagnostically relevant antigenic regions derived from the hepatitis C virus (HCV) core, NS3, NS4 and NS5 proteins. Antigenic properties of each antigenic region included into these composite antigens were preliminary evaluated by testing recombinant proteins containing the HCV protein fragments of different sizes encoded by overlapping PCR fragments. Immunoreactive recombinant proteins were tested by EIA against a large panel of anti-HCV positive and negative serum specimens to identify the most immunoreactive and specific proteins. Three composite antigens were designed based on this analysis. The fist composite protein was composed of one antigenic region from core, NS3 and NS4. The second protein contained an additional NS4 region, while the third protein contained all immunodominant antigenic regions identified in this study. After EIA analysis for the detection of anti-HCV, each composite protein showed almost identical results compared to combining each of the corresponding individual proteins.
hepatitis C ; antigens ; viruses