Wang F, Gregory C D, Rowe M, Rickinson A B, Wang D, Birkenbach M, Kikutani H, Kishimoto T, Kieff E
Proc Natl Acad Sci U S A. 1987 May;84(10):3452-6. doi: 10.1073/pnas.84.10.3452.
Epstein-Barr virus (EBV) infection of EBV-negative Burkitt lymphoma (BL) cells induces some changes similar to those seen in normal B lymphocytes that have been growth transformed by EBV. The role of individual EBV genes in this process was evaluated by introducing each of the viral genes that are normally expressed in EBV growth-transformed and latently infected lymphoblasts into an EBV-negative BL cell line, using recombinant retrovirus-mediated transfer. Clones of cells were derived that stably express the EBV nuclear antigen 1 (EBNA-1), EBNA-2, EBNA-3, EBNA-leader protein, or EBV latent membrane protein (LMP). These were compared with control clones infected with the retrovirus vector. All 10 clones converted to EBNA-2 expression differed from control clones or clones expressing other EBV proteins by growth in tight clumps and by markedly increased expression of one particular surface marker of B-cell activation, CD23. Other activation antigens were unaffected by EBNA-2 expression, as were markers already expressed on the parent BL cell line, including BL markers (cALLA and BLA), proliferation markers (transferrin receptor and BK19.9), and cell adhesion-related molecules (LFA-1 and LFA-3). Increased CD23 expression in cells expressing EBNA-2 was apparent from monoclonal anti-CD23 antibody binding to the cell surface, from immunoprecipitation of the 45-kDa and 90-kDa CD23 proteins with monoclonal antibody, and from RNA blots probed with labeled CD23 DNA. The results indicate that EBNA-2 is a specific direct or indirect trans-activator of CD23. This establishes a link between an EBV gene and cell gene expression. Since CD23 has been implicated in the transduction of B-cell growth signals, its specific induction by EBNA-2 could be important in EBV induction of B-lymphocyte transformation.
EB病毒（EBV）对EBV阴性的伯基特淋巴瘤（BL）细胞的感染会诱导一些变化，这些变化类似于在被EBV生长转化的正常B淋巴细胞中所见到的变化。通过使用重组逆转录病毒介导的转移方法，将在EBV生长转化和潜伏感染的淋巴母细胞中正常表达的每个病毒基因导入一个EBV阴性的BL细胞系，以此来评估单个EBV基因在此过程中的作用。获得了稳定表达EBV核抗原1（EBNA-1）、EBNA-2、EBNA-3、EBNA前导蛋白或EBV潜伏膜蛋白（LMP）的细胞克隆。将这些克隆与感染逆转录病毒载体的对照克隆进行比较。所有转化为表达EBNA-2的10个克隆与对照克隆或表达其他EBV蛋白的克隆不同，它们紧密聚集生长，并且B细胞活化的一种特定表面标志物CD23的表达明显增加。其他活化抗原不受EBNA-2表达的影响，亲本BL细胞系上已表达的标志物也不受影响，这些标志物包括BL标志物（普通急性淋巴细胞白血病抗原和BLA）、增殖标志物（转铁蛋白受体和BK19.9）以及细胞黏附相关分子（淋巴细胞功能相关抗原1和淋巴细胞功能相关抗原3）。从单克隆抗CD23抗体与细胞表面的结合、用单克隆抗体对45 kDa和90 kDa CD23蛋白的免疫沉淀以及用标记的CD23 DNA探测的RNA印迹中可以明显看出，表达EBNA-2的细胞中CD23表达增加。结果表明，EBNA-2是CD23的特异性直接或间接反式激活因子。这在一个EBV基因与细胞基因表达之间建立了联系。由于CD23与B细胞生长信号的转导有关，EBNA-2对其的特异性诱导在EBV诱导B淋巴细胞转化过程中可能很重要。
