Department of Molecular Cell Biology, Leiden University Medical Center, Postal Zone S1-P, P.O. Box 9600, 2300 RC, Leiden, The Netherlands.
Biotechnol Lett. 2010 Jun;32(6):749-54. doi: 10.1007/s10529-010-0218-8. Epub 2010 Feb 13.
The archetypical system for regulating heterologous gene expression in mammalian cells involves tetracycline-activated transactivators (rtTA). Binding of such transactivators to tet-operator-controlled promoters induces transcription. Immune responses directed against the transactivator proteins may limit the applicability of this system in immune-competent hosts. To circumvent such immune responses the immune evasion mechanism of the Epstein-Barr virus Nuclear-Antigen 1 was exploited. Our data show that fusion of the rtTA with the EBNA-1 derived Gly-Ala repeat yielded an efficient transactivator with no detectable activity in absence of inducer. Antigenic peptides of the fusion protein were not presented in MHC class I.
用于调节哺乳动物细胞中外源基因表达的典型系统涉及四环素激活的转录激活剂（rtTA）。此类转录激活剂与 tet 操纵子控制的启动子结合可诱导转录。针对转录激活蛋白的免疫反应可能会限制该系统在免疫活性宿主中的适用性。为了规避这种免疫反应，可以利用 Epstein-Barr 病毒核抗原 1 的免疫逃逸机制。我们的数据表明，rtTA 与 EBNA-1 衍生的甘氨酸-丙氨酸重复序列融合产生了一种有效的转录激活剂，在没有诱导剂的情况下检测不到活性。融合蛋白的抗原肽不在 MHC Ⅰ类中呈递。
