Bhadra Sanchita, Lozano Mary M, Dudley Jaquelin P
Section of Molecular Genetics and Microbiology, The University of Texas at Austin, Austin, TX 78712-0162, USA.
J Virol. 2005 Oct;79(19):12592-6. doi: 10.1128/JVI.79.19.12592-12596.2005.
Type B leukemogenic virus is a variant of mouse mammary tumor virus (MMTV) that causes thymic lymphomas rather than mammary tumors in mice. We demonstrate that conversion of a mammotropic MMTV to a T-cell-tropic virus requires two alterations in the long terminal repeat: (i) acquisition of a T-cell-specific enhancer and (ii) loss of transcriptional repression through deletion of negative regulatory elements (NREs) or by suppression of NRE activity after appropriate positioning of the enhancer.
B型致白血病病毒是小鼠乳腺肿瘤病毒（MMTV）的一种变体，它在小鼠中引发胸腺淋巴瘤而非乳腺肿瘤。我们证明，嗜乳腺性MMTV向嗜T细胞病毒的转变需要长末端重复序列发生两处改变：（i）获得一个T细胞特异性增强子；（ii）通过缺失负调控元件（NRE）或在增强子适当定位后抑制NRE活性来消除转录抑制。
