Appearance of Epstein-Barr virus nuclear antigen in human cordblood lymphocytes

Transformation and induction of EBV-specified EBNA was studied in human umbilical cord-blood lymphocytes infected with EBV, HVS or HVA. Transformation of human umbilical umbilical cord-blood lymphocytes into continuous lymphoblastoid cell lines was successful with EBV derived from five of seven human or simian cell lines but not with HVS or HVA derived from simian lymphoblastoid cell lines. EBNA induction was studied using B95-8 virus for infection of lymphocytes; as early as 24 hours after infection, a few EBNA-positive cells were identified in 10 of 12 samples studied. Thereafter, the number of EBNA-positive cells increased progressively and by day 12, 50% of cells contained EBNA; after 18-20 days, approximately 85-90% of cells were EBNA-positive.