Fang Chih Yeu, Chiang Chen Yi, Pan Yun Ru, Tse Ka Po, Chang Yu Sun, Chang Hwan You
Institute of Molecular Medicine, National Tsing Hua University, Hsin-Chu, Taiwan, ROC.
Intervirology. 2007;50(4):254-63. doi: 10.1159/000101996. Epub 2007 Apr 25.
The Epstein-Barr virus (EBV) has been implicated in the development of many human neoplasias including B lymphoma and nasopharyngeal carcinoma. EBV latent membrane protein 1 (LMP1) is essential to virus-induced B cell immortalization and the downregulation of cell adhesion molecules that increases cell motility. Therefore, identifying LMP1 activity modulation methods may lead to the development of new therapies for LMP1-positive tumors.
This study uses a phage display single-chain variable fragments (scFvs) library to screen recombinant antibodies specific to the LMP1 C terminal region. A total of 45 individual clones were obtained, and these scFvs were cloned as intrabodies and transfected into LMP1-positive cells.
One of the scFv clones, designated H3, was capable of reducing LMP1-mediated NF-kappaB activation in HEK293 cells. Immunofluorescence and co-immunoprecipitation studies show that scFv H3 could interact with LMP1 in vivo. In addition, expression of scFv H3 intrabody could reduce cell motility in MDCK-LMP1 cells in the transwell migration assay.
These data indicate that scFv H3 intrabody can inhibit LMP1 functions in epithelial cells and may be useful for attenuating the LMP1 function in LMP1-positive tumors.
爱泼斯坦-巴尔病毒（EBV）与包括B淋巴瘤和鼻咽癌在内的多种人类肿瘤的发生有关。EBV潜伏膜蛋白1（LMP1）对于病毒诱导的B细胞永生化以及下调增加细胞运动性的细胞粘附分子至关重要。因此，确定LMP1活性调节方法可能会导致开发针对LMP1阳性肿瘤的新疗法。
本研究使用噬菌体展示单链可变片段（scFv）文库筛选针对LMP1 C末端区域的重组抗体。共获得45个单克隆，这些scFv被克隆为胞内抗体并转染到LMP1阳性细胞中。
其中一个scFv克隆，命名为H3，能够降低HEK293细胞中LMP1介导的核因子κB激活。免疫荧光和免疫共沉淀研究表明，scFv H3在体内可与LMP1相互作用。此外，在transwell迁移试验中，scFv H3胞内抗体的表达可降低MDCK-LMP1细胞的运动性。
这些数据表明，scFv H3胞内抗体可抑制上皮细胞中的LMP1功能，可能有助于减弱LMP1阳性肿瘤中LMP1的功能。
