Distinction between Epstein-Barr virus type A (EBNA 2A) and type B (EBNA 2B) isolates extends to the EBNA 3 family of nuclear proteins

作者：Martin Rowe, Lawrence S. Young, Karen A. Cadwallader, Lisa M. Petti, E Kieff, Alan B. Rickinson · 发表于：Journal of Virology · 年份：1989 · DOI：10.1128/jvi.63.3.1031-1039.1989 · 被引用次数：176 · 研究领域：Viral-associated cancers and disorders、Lymphoma Diagnosis and Treatment、Cytomegalovirus and herpesvirus research

The Epstein-Barr virus (EBV) nuclear antigens EBNA 3a, 3b, and 3c have recently been mapped to adjacent reading frames in the BamHI L and E fragments of the B95.8 EBV genome. We studied by immunoblotting the expression of the family of EBNA 3 proteins in a panel of 20 EBV-transformed lymphoblastoid cell lines (LCLs) carrying either type A (EBNA 2A-encoding) or type B (EBNA 2B-encoding) virus isolates. Certain human sera from donors naturally infected with type A isolates detected the EBNA 3a, 3b, and 3c proteins in all type A virus-transformed LCLs (with a single exception in which EBNA 3b was not detected) but detected only EBNA 3a in LCLs carrying type B isolates. These results were confirmed with human and murine antibodies with specific reactivity against sequences of the type A EBNA 3a, 3b, or 3c expressed in bacterial fusion proteins. Conversely, selected human sera from donors naturally infected with type B strains of EBV identified the EBNA 3a encoded by both types of isolates plus two novel EBNAs present only in type B, and not in type A, virus-transformed LCLs; these novel proteins appear to be the type B homologs of EBNA 3b and 3c. The distinction between type A and type B EBV isolates therefore extends beyond the EBNA 2 gene to the EBNA 3 family of proteins. This has important implications with respect to the evolutionary origin of these two EBV types and also places in a new light recent studies which identified differences between type A and type B transformants...