Wang F, Gregory C, Sample C, Rowe M, Liebowitz D, Murray R, Rickinson A, Kieff E
Department of Medicine, Harvard Medical School, Boston, Massachusetts 02115.
J Virol. 1990 May;64(5):2309-18. doi: 10.1128/JVI.64.5.2309-2318.1990.
Latent Epstein-Barr virus (EBV) infection and growth transformation of B lymphocytes is characterized by EBV nuclear and membrane protein expression (EBV nuclear antigen [EBNA] and latent membrane protein [LMP], respectively). LMP1 is known to be an oncogene in rodent fibroblasts and to induce B-lymphocyte activation and cellular adhesion molecules in the EBV-negative Burkitt's lymphoma cell line Louckes. EBNA-2 is required for EBV-induced growth transformation; it lowers rodent fibroblast serum dependence and specifically induces the B-lymphocyte activation antigen CD23 in Louckes cells. These initial observations are now extended through an expanded study of EBNA- and LMP1-induced phenotypic effects in a different EBV-negative B-lymphoma cell line, BJAB. LMP1 effects were also evaluated in the EBV-negative B-lymphoma cell line BL41 and the EBV-positive Burkitt's lymphoma cell line, Daudi (Daudi is deleted for EBNA-2 and does not express LMP). Previously described EBNA-2- and LMP1-transfected Louckes cells were studied in parallel. EBNA-2, from EBV-1 strains but not EBV-2, induced CD23 and CD21 expression in transfected BJAB cells. In contrast, EBNA-3C induced CD21 but not CD23, while no changes were evident in vector control-, EBNA-1-, or EBNA-LP-transfected clones. EBNAs did not affect CD10, CD30, CD39, CD40, CD44, or cellular adhesion molecules. LMP1 expression in all cell lines induced growth in large clumps and expression of the cellular adhesion molecules ICAM-1, LFA-1, and LFA-3 in those cell lines which constitutively express low levels. LMP1 expression induced marked homotypic adhesion in the BJAB cell line, despite the fact that there was no significant increase in the high constitutive BJAB LFA-1 and ICAM-1 levels, suggesting that LMP1 also induces an associated functional change in these molecules. LMP1 induction of these cellular adhesion molecules was also associated with increased heterotypic adhesion to T lymphocytes. The Burkitt's lymphoma marker, CALLA (CD10), was uniformly down regulated by LMP1 in all cell lines. In contrast, LMP1 induced unique profiles of B-lymphocyte activation antigens in the various cell lines. LMP1 induced CD23 and CD39 in BJAB; CD23 in Louckes; CD39 and CD40 in BL41; and CD21, CD40, and CD44 in Daudi. In BJAB, CD23 surface and mRNA expression were markedly increased by EBNA-2 and LMP1 coexpression, compared with EBNA-2 or LMP1 alone. This cooperative effect was CD23 specific, since no such effect was observed on another marker, CD21.(ABSTRACT TRUNCATED AT 400 WORDS)
潜伏性爱泼斯坦-巴尔病毒（EBV）感染和B淋巴细胞的生长转化以EBV核蛋白和膜蛋白表达（分别为EBV核抗原[EBNA]和潜伏膜蛋白[LMP]）为特征。已知LMP1在啮齿动物成纤维细胞中是一种癌基因，并能在EBV阴性的伯基特淋巴瘤细胞系Louckes中诱导B淋巴细胞活化和细胞黏附分子。EBNA-2是EBV诱导生长转化所必需的；它降低了啮齿动物成纤维细胞对血清的依赖性，并在Louckes细胞中特异性诱导B淋巴细胞活化抗原CD23。现在，通过对EBNA和LMP1在另一种EBV阴性B淋巴瘤细胞系BJAB中诱导的表型效应进行扩展研究，这些初步观察结果得到了延伸。还在EBV阴性B淋巴瘤细胞系BL41和EBV阳性伯基特淋巴瘤细胞系Daudi（Daudi缺失EBNA-2且不表达LMP）中评估了LMP1的作用。之前描述的转染了EBNA-2和LMP1的Louckes细胞作为平行对照进行研究。来自EBV-1毒株而非EBV-2的EBNA-2在转染的BJAB细胞中诱导了CD23和CD21表达。相比之下，EBNA-3C诱导了CD21但未诱导CD23，而在载体对照、EBNA-1或EBNA-LP转染的克隆中未观察到明显变化。EBNA对CD10、CD30、CD39、CD40、CD44或细胞黏附分子没有影响。LMP1在所有细胞系中的表达均诱导细胞形成大团块生长，并在那些组成性表达水平较低的细胞系中诱导细胞黏附分子ICAM-1、LFA-1和LFA-3的表达。尽管BJAB细胞中高组成性的LFA-1和ICAM-1水平没有显著增加，但LMP1的表达在BJAB细胞系中诱导了明显的同型黏附，这表明LMP1也在这些分子中诱导了相关的功能变化。LMP1对这些细胞黏附分子的诱导也与对T淋巴细胞异型黏附的增加有关。在所有细胞系中，伯基特淋巴瘤标志物CALLA（CD10）均被LMP1一致下调。相比之下，LMP1在不同细胞系中诱导了独特的B淋巴细胞活化抗原谱。LMP1在BJAB中诱导了CD23和CD39；在Louckes中诱导了CD23；在BL41中诱导了CD39和CD40；在Daudi中诱导了CD21、CD40和CD44。在BJAB中，与单独的EBNA-2或LMP1相比，EBNA-2和LMP1共表达显著增加了CD23的表面和mRNA表达。这种协同效应是CD23特异性的，因为在另一个标志物CD21上未观察到这种效应。（摘要截选至400字）
