A-type and B-type Epstein-Barr virus differ in their ability to spontaneously enter the lytic cycle

In this study replication of A-type and B-type Epstein-Barr virus (EBV) str ains has been assessed. A-type and B-type lymphoblastoid cell lines (LCLs) were established by infecting B lymphocytes, isolated from five EBV-seropos itive donors, with different A-type and B-type virus isolates. The presence of viral capsid antigens (VCA) in these LCLs was determined by immunofluor esence assay and by immunoblotting, All of the B-type EBV strains were capa ble of spontaneously generating virus regardless of the origin of the donor cells. In contrast the A-type strains, other than strain IARC-BL36, did no t readily produce VCA in any of the different donor lymphocytes used. This study demonstrates another biological difference between the two virus type s: their ability to spontaneously enter the lyric cycle.