DETECTION OF HUMAN SERUM ANTIBODIES TO THE BFRF3 EPSTEIN-BARR-VIRUS CAPSID COMPONENT BY MEANS OF A DNA-BINDING ASSAY

A novel assay for antibodies to an immunodominant component of the Eps tein-Barr virus (EBV) capsid antigen (VCA) complex was developed by cr eation of a chimeric protein containing the DNA-binding domain of the yeast GAL4 protein fused to the capsid antigen encoded by the BFRF3 ge ne of EBV. GAL4-BFRF3 antigen fusion protein bound specifically to a d uplex DNA oligonucleotide containing GAL4-binding sites. Antibodies to the antigen were revealed by retardation of the electrophoretic mobil ity of the DNA-protein complex. Antibodies to the BFRF3 component of V CA became detectable similar to 2 months after onset of infectious mon onucleosis. Kinetics of the antibody response to BFRFS were identical using supershift or immunoblotting assays. Concordance between the DNA -binding assay and the classical indirect immunofluorescence assay for antibody to VCA was 97%. The GAL4 epitope assay is applicable for det ection of antibodies to many cloned gene products.