IDENTIFICATION OF HCV CORE MIMOTOPES - IMPROVED METHODS FOR THE SELECTION AND USE OF DISEASE-RELATED PHAGE-DISPLAYED PEPTIDES

Disease-specific epitope discovery from random peptide libraries displ ayed on phage using sera from patients involves a number of screening steps with many immune and non-immune sera. To rapidly identify mimoto pes of the human hepatitis C virus (HCV) core protein, we have used an anti-core human monoclonal antibody (mAb; B12.F8) as a probe in scree ning phage that were affinity-selected using a serum from an HCV infec ted patient. Three different positive phage were isolated displaying l ow or no homology with the natural antigen, but which still efficientl y bound to the antigen binding site of the B12.F8 antibody. Testing th e reactivity of these phage with forty-five sera from HCV infected pat ients showed that antibodies recognizing them are present in more than 80% of this population. These antibodies showed distinct fine specifi city, as they bound the selected phage in a mutually exclusive fashion . Co-expression of two mimotopes in the same cells led to chimeric par ticles which were recognized by antibodies of different specificity. T hese data provide novel information on the potential use of the phage display technology for the characterization of antibody specificity as well as disease diagnosis and prevention.