The genome of Epstein-Barr virus (EBV) encodes 86 proteins, but only a limited set is expressed in EBV-growth transformed B cells, termed lymphoblastoid cell lines (LCLs). These cells proliferate via the concerted action of EBV nuclear antigens (EBNAs) and latent membrane proteins (LMPs), some of which are rate limiting to establish a stable homeostasis of growth promoting and anti-apoptotic ac...

AIM To determine EBNA-1 expression in the tissue of patients with diffuse large B-cell lymphoma and its relationship to bcl-2 expression. METHODS Paraffin-embedded tissue from 24 cases of diffuse large B-cell lymphoma were stained immunohisto chemically with monoclonal antibody anti-EBNA-1 and anti-bcl-2 using Streptavidin Biotin Complex method. The bcl-2 expression was measured as negative (...

Since deletion of region 3 (amino acids [aa] 333 to 425) of Epstein-Barr virus nuclear protein 2 (EBNA-2) results in EBV recombinants which cannot transform primary B lymphocytes (J. I. Cohen, F. Wang, and E. Kieff, J. Virol. 65:2545-2554, 1991), the role of domains of region 3 was investigated. Deletion of the Arg-Gly repeat domain, R-337GQSRGRGRGRGRGRGKG354, results in EBV recombinants that t...

Self-association of viral proteins is important for many of their functions, including enzymatic, transcriptional, and transformational activities. Epstein-Barr virus (EBV) nuclear antigen leader protein (EBNA-LP) contains various numbers of W1W2 repeats and a unique carboxyl-terminal Y1Y2 domain. It was reported that EBNA-LP associates with a variety of cellular proteins and plays a critical r...

We read with great interest the report by Murray et al.' We have analyzed 3 1 posttransplantation lymphoproliferative disorders (PTLDs; 18 renal and 13 heartheart-lung cases) for bcl-2, EpsteinBarr virus-latent membrane protein (EBV-LMP), EBNA-l, and EBNA-2.2.5 We used the same antibodies as Murray et al.' All cases were EBV-LMP-l -positive. In more than 90% of cases, 80% of the neoplastic popu...

These experiments evaluate the role of the Epstein-Barr virus (EBV) nuclear antigen leader protein (EBNA-LP) in B-lymphocyte growth transformation by using a recombinant EBV molecular genetic approach. Recombinant viruses encoding for a mutant EBNA-LP lacking the carboxy-terminal 45 amino acids were markedly impaired in their ability to transform primary B lymphocytes compared with EBNA-LP wild...

Expression of EBNA-1 protein is required for the establishment and maintenance of the Epstein-Barr virus (EBV) genome during latent infection. During type I latency, the BamHI Q promoter (Qp) gives rise to EBNA-1 expression. The dominant regulatory mechanism for Qp appears to be mediated through the Q locus, located immediately downstream of the transcription start site. Binding of EBNA-1 to th...

Epstein-Barr virus (EBV) has been causally associated with at least five human malignancies. The exact contributions made by EBV to these cancers remain unknown. We demonstrate that one viral protein found in all EBV-associated malignancies, Epstein-Barr nuclear antigen 1 (EBNA-1), is required for survival of one of these cancers, EBV-positive Burkitt's lymphoma. Inhibition of EBNA-1 decreases ...

Epstein-Barr virus (EBV) EBNA-1 is the only EBV-encoded protein that is essential for the once-per-cell-cycle replication and maintenance of EBV plasmids in latently infected cells. EBNA-1 binds to the oriP region of latent EBV plasmids and cellular metaphase chromosomes. In the absence of oriP-containing plasmids, EBNA-1 was highly colocalized with cellular DNA replication foci that were ident...

The Epstein-Barr virus nuclear antigen 2 (EBNA 2) shows serotype variation and two serologically distinct groups of viruses have been identified. These correspond to the two hybridization groups of viruses (A and B) that are distinguished by a highly substituted nucleic acid sequence in the middle of the open reading frame of the EBNA 2 gene. An epitope survey of the EBNA 2-coding region was ca...