Virus-cell interactions in a natural killer-like cell line from a patient with lymphoblastic lymphoma

Lymphoproliferative disorders involving Epstein-Barr virus (EBV) infected natural killer (NK) cells are reported with increasing frequency, but the nature and role of EBV infection in these cells remains undefined. In this study, we have investigated virus-cell interactions in the EBV-positive YTN10 cell line, an NK-like cell line established from a patient with lymphoblastic lymphoma. Low level expression of the EBV receptor CD21 molecule was detected by FACS and reverse transcriptase polymerase chain reaction (RT-PCR) analysis. Immunoblotting and RT-PCR analysis identified a latency II pattern of EBV gene expression, consisting of EBNA-1 transcription from the Qp promoter, in the absence of other EBNA gene expression, and accompanied by LMP-1 and LMP-2A expression. The EBV genome was present in episomal form and there was evidence for lytic viral replication. This latency pattern is typical of EBV gene expression in nasopharyngeal carcinoma and Hodgkin's disease, and differs from the full spectrum of EBV latent gene expression in most posttransplant lymphoproliferative disorders and from the restricted EBNA-1 expression in Burkitt's lymphoma tissues. The interaction between EBV and NK cells described here has important implications for the pathogenesis and treatment of EBV-infected NK malignancies.