Epstein-Barr virus (EBV) infection by cocultivation of fibroblast-dominant cell line and EBV-transformed lymphocytes.

A long-term cell culture epitheloid cell line (NPC-F/L) was established from the fibroblast-dominant cell line derived from nasopharyngeal carcinoma tissue by cocultivation with an Epstein-Barr virus (EBV)-transformed lymphoblastoid cell line of adenoid origin. The cells were investigated by karyotyping, by immunofluorescent testing for EBV-associated nuclear antigen (EBNA), early antigen (EA), and viral capsid antigen (VCA) and by a light microscopy. The cells were shown to be epithelial not only by morphology but also by immunocytochemical staining with monoclonal antibody to cytokeratins and they expressed EBNA and EA but not VCA. The cells developed histologically undifferentiated squamous cell carcinoma when inoculated subcutaneously into the back of athymic nude BALB/c(nu/nu) mice, which were similar to the human tumors from which the fibroblastoid cell line was established. The presence of EBNA in touch smears prepared both from the biopsy tissue of human and nude mice was demonstrated. Karyotyping analysis indicated an aneuploid chromosome with a model number of 74.