Detection of antigens associated with Epstein-Barr virus replication in extracts from biopsy specimens of nasopharyngeal carcinomas.

By using monoclonal antibodies to different Epstein-Barr virus (EBV) polypeptides in combination with immunoblotting, we detected antigens associated with EBV replication in extracts from nasopharyngeal carcinoma (NPC) biopsy specimens. Major polypeptides associated with both the diffuse and the restricted components of the early antigen (EA) complex were found in extracts from nine of nine NPC biopsy specimens. Cells from an additional NPC biopsy specimen, passaged repeatedly in nude mice, were found to be positive for the major EA (restricted) polypeptide. This approach revealed that extracts from three of 14 biopsy specimens form other benign and malignant diseases also expressed these viral polypeptides. Therefore, for the first time, these results conclusively demonstrate the presence of EA polypeptides in extracts from NPC biopsy specimens. This finding provides at least a partial explanation for the reported prognostic value of antibodies to this antigen in patients with this disease.