Murray R J, Kurilla M G, Griffin H M, Brooks J M, Mackett M, Arrand J R, Rowe M, Burrows S R, Moss D J, Kieff E
Department of Cancer Studies, University of Birmingham, United Kingdom.
Proc Natl Acad Sci U S A. 1990 Apr;87(8):2906-10. doi: 10.1073/pnas.87.8.2906.
The potentially pathogenic effects of infection with Epstein-Barr virus (EBV), a B-lymphotropic agent with cell growth-transforming potential, are contained in healthy virus carriers by virus-specific cytotoxic T-lymphocyte (CTL) surveillance. The target antigens against which such CTL responses are directed are yet undefined, but the antigens probably derived from one or more of the EBV "latent" proteins constitutively expressed in virus-transformed B cells. We have analyzed target specificity of CTL responses from two EBV-immune donors that are preferentially reactive against autologous cells transformed with type A but not with type B virus isolates. Coding sequences for four EBV latent proteins with allelic polymorphism between A and B virus types--namely, the EBV nuclear antigens (EBNAs) EBNA 2, EBNA 3a, EBNA 3c, and EBNA leader protein--have been introduced into vaccinia virus vectors under control of vaccinia promoter P7.5 and used to express relevant EBNA proteins in appropriate target cells. Thus the CTL response from one donor has been mapped to type A EBNA 2 protein and from a second donor to type A EBNA 3a protein. Thereafter, a series of recombinant vaccinia viruses were constructed that carried specific internal deletions within the EBNA 2 type A coding sequence; by using these vectors, the above EBNA 2 type A-specific CTL response was shown to be directed against an epitope within a 100-amino acid fragment near the N terminus of the protein. This work clearly shows human CTL recognition of virus-coded nuclear antigens in the EBV system; moreover, it establishes an experimental approach that can be extended to all EBV latent proteins and to the more common CTL responses that cross-react against type A and type B virus isolates.
爱泼斯坦-巴尔病毒（EBV）是一种具有细胞生长转化潜能的嗜B淋巴细胞病原体，在健康病毒携带者中，其潜在致病作用通过病毒特异性细胞毒性T淋巴细胞（CTL）监测得以控制。此类CTL反应所针对的靶抗原尚未明确，但这些抗原可能来源于病毒转化的B细胞中组成性表达的一种或多种EBV“潜伏”蛋白。我们分析了两名EBV免疫供体的CTL反应的靶标特异性，他们优先对A型而非B型病毒分离株转化的自体细胞产生反应。四种在A型和B型病毒之间具有等位基因多态性的EBV潜伏蛋白的编码序列，即EBV核抗原（EBNAs）EBNA 2、EBNA 3a、EBNA 3c和EBNA前导蛋白，已在痘苗病毒启动子P7.5的控制下导入痘苗病毒载体，并用于在适当的靶细胞中表达相关的EBNA蛋白。因此，一名供体的CTL反应已定位到A型EBNA 2蛋白，另一名供体的CTL反应已定位到A型EBNA 3a蛋白。此后，构建了一系列在EBNA 2型A编码序列内携带特定内部缺失的重组痘苗病毒；通过使用这些载体，上述A型EBNA 2特异性CTL反应被证明针对该蛋白N端附近100个氨基酸片段内的一个表位。这项工作清楚地表明了人类CTL在EBV系统中对病毒编码核抗原的识别；此外，它建立了一种可扩展到所有EBV潜伏蛋白以及对A型和B型病毒分离株产生交叉反应的更常见CTL反应的实验方法。
