EXPRESSION OF THE EPSTEIN-BARR-VIRUS DNA-POLYMERASE IN ESCHERICHIA-COLI FOR USE AS ANTIGEN FOR THE DIAGNOSIS OF NASOPHARYNGEAL CARCINOMA

Epstein-Barr virus (EBV) encoded DNA polymerase (POL) was cloned and o ver-expressed in Escherichia coli. Western blot analysis confirmed the presence of antibody to this POL protein in sera from nasopharyngeal carcinoma (NPC) patients. By Western blot analysis, moderate to high c oncentration of IgG POL-specific antibodies were present in 43 of 48 N PC sera and only 4 of 48 healthy, seropositive controls. The POL-speci fic IgG antibodies appear as early as stage I of NPC, suggesting that the recombinant POL protein can be a useful diagnostic marker for earl y diagnosis of the disease. It was also found that human sera containi ng high titer of cytomegalovirus (CMV) antibodies or herpes simplex vi rus type 1 (HSV-1) antibodies did not cross-react with the recombinant EBV POL, despite the homology shared by DNA polymerase proteins of th ese viruses. (C) 1995 Wiley-Liss, Inc.