CHARACTERIZATION OF THE ANTIBODY-RESPONSE TO THE LATENT INFECTION TERMINAL PROTEINS OF EPSTEIN-BARR-VIRUS IN PATIENTS WITH NASOPHARYNGEAL CARCINOMA

Human sera were tested for antibodies against the Epstein-Barr virus ( EBV) latent infection terminal proteins (TPs). Anti-TP IgG and IgA ant ibodies were detected by an indirect immunofluorescence assay of insec t cells expressing a recombinant TPI. Out of 301 human sera of patient s with EBV-related and EBV-unrelated disorders, only sera from patient s with nasopharyngeal carcinoma (NPC) (32/83; 38 %) showed anti-TP ant ibodies. Studies on serial sera from German and Hong Kong NPC patients revealed a decline of anti-TP antibodies during tumour therapy, and n one of these antibodies were identified in patients with early tumour stages or in remission. Comparative studies of TP1-specific polyclonal rabbit antisera and human TP-positive sera showed clear differences i n the TP epitopes recognized by each. Human antisera contained antibod ies only to native epitopes in exons 2 to 7 of TP1 whereas rabbit anti sera reacted only with epitopes located in the first exon and, additio nally, exhibited EBV strain specificities.