Chen H, Smith P, Ambinder R F, Hayward S D
Molecular Virology Laboratory, the Department of Pharmacology and Molecular Science, and the Department of Oncology, Johns Hopkins School of Medicine, Baltimore, MD, USA.
Blood. 1999 May 1;93(9):3026-32.
In addition to the Epstein-Barr virus (EBV) EBNA and LMP latency genes, there is a family of alternatively spliced BamHI-A rightward transcripts (BARTs). These latency transcripts are highly expressed in the EBV-associated malignancies nasopharyngeal carcinoma and Burkitt's lymphoma, and are expressed at lower levels in latently EBV-infected B-cell lines. The contribution of the BARTs to EBV biology or pathogenesis is unknown. Resting B cells have recently been recognized as a reservoir for EBV persistence in the peripheral blood. In these cells, EBV gene expression is tightly restricted and the only viral gene known to be consistently expressed is LMP2A. We used cell sorting and reverse-transcriptase polymerase chain reaction (RT-PCR) to examine whether BARTs are expressed in the restricted form of in vivo latency. Our results demonstrated that RNAs with splicing diagnostic for transcripts containing the BART RPMS1 and BARFO open-reading frames (ORFs) were expressed in CD19(+) but not in CD23(+) B cells isolated from peripheral blood of healthy individuals. The product of the proximal RPMS1 ORF has not previously been characterized. The RPMS1 ORF was shown to encode a 15-kD protein that localized to the nucleus of transfected cells. Expression of the BARTs in peripheral blood B cells suggests that the proteins encoded by these transcripts are likely to be important for maintenance of in vivo latency.
除了爱泼斯坦-巴尔病毒（EBV）的EBNA和LMP潜伏基因外，还有一个可变剪接的BamHI-A向右转录本（BARTs）家族。这些潜伏转录本在与EBV相关的恶性肿瘤鼻咽癌和伯基特淋巴瘤中高度表达，而在潜伏感染EBV的B细胞系中表达水平较低。BARTs对EBV生物学或发病机制的作用尚不清楚。静息B细胞最近被认为是外周血中EBV持续存在的储存库。在这些细胞中，EBV基因表达受到严格限制，已知持续表达的唯一病毒基因是LMP2A。我们使用细胞分选和逆转录聚合酶链反应（RT-PCR）来检测BARTs是否以体内潜伏的受限形式表达。我们的结果表明，具有包含BART RPMS1和BARFO开放阅读框（ORF）转录本的剪接诊断特征的RNA在从健康个体外周血中分离的CD19(+) B细胞中表达，但在CD23(+) B细胞中不表达。近端RPMS1 ORF的产物以前尚未被鉴定。RPMS1 ORF被证明编码一种定位于转染细胞细胞核的15-kD蛋白。BARTs在外周血B细胞中的表达表明，这些转录本编码的蛋白质可能对维持体内潜伏很重要。
