Isolation of transforming and early antigen-inducing Epstein-Barr virus from nasopharyngeal carcinoma hybrid cells (NPC-KT).

The biologic activities of Epstein-Barr (EB) virus from an epithelioid-nasopharyngeal carcinoma hybrid cell line (NPC-KT) and three subclones from the NPC-KT cells were examined. Much infectious virus was released by treatment with 5-iodo-2'-deoxyuridine. All virus preparations from NPC-KT cells and the subclones were found to possess both transforming and EB virus-induced early antigen (EA)-inducing activities. The lymphoblastoid cell lines, which were established by infection of human cord-blood lymphocytes with the virus, were diploid with normal karyotypes. The cell lines were positive for EB virus-associated nuclear antigen but negative for EA and EB viral capsid antigen.