LYTIC REPLICATION OF EPSTEIN-BARR-VIRUS IN THE PERIPHERAL-BLOOD - ANALYSIS OF VIRAL GENE-EXPRESSION IN B-LYMPHOCYTES DURING INFECTIOUS-MONONUCLEOSIS AND IN THE NORMAL CARRIER STATE

Epstein-Barr virus (EBV) has been shown to establish latency in restin g B lymphocytes of the peripheral blood, This creates a virus reservoi r in contrast to lytic virus replication, which is thought to be restr icted to differentiated epithelial cells in vivo. So far, the route of transmission between B cells and the production of progeny virus in t he epithelial tissue has remained unclear. Reverse transcriptase-polym erase chain reaction (RT-PCR) and immunohistochemistry analysis of 16 patients with acute infectious mononucleosis (IM) and 25 healthy serop ositive donors was performed to detect lytic replication gene products in B lymphocytes of the peripheral blood, Transcriptional activity wa s found in peripheral blood B lymphocytes (PBLs) for BZLF1 in 88%, BAL F2 in 50%, and BcLF1 in 25% of the tested IM patients. All positive re sults were further confirmed in enriched B-cell populations by antigen determination using immunostaining with the APAAP technique. Furtherm ore, we detected transcripts for BZLF1 in 72% and for BALF2 in 16% of peripheral B lymphocytes of healthy seropositive donors. In contrast t o patients with IM, no signals for BcLF1 were ever found in healthy se ropositive donors, In these individuals, lytic replication of EBV is p robably restricted by immunologic and gene regulatory mechanisms, wher eas in the absence of immunologic control, reflected here by IM patien ts, the production of infectious virus becomes visible in PBLs, (C) 19 97 by The American Society of Hematology.