Olivier Aurelie, Jeanson-Leh Laurence, Bouma Gerben, Compagno Daniel, Blondeau Johanna, Seye Khalil, Charrier Sabine, Burns Siobhan, Thrasher Adrian J, Danos Olivier, Vainchenker William, Galy Anne
Unité mixte INSERM-Université Paris XI, U362, Institut Gustave Roussy, Villejuif F-94805 and CNRS, UMR 8115, Généthon, 91002 Evry, France.
Mol Ther. 2006 Apr;13(4):729-37. doi: 10.1016/j.ymthe.2005.11.003. Epub 2005 Dec 15.
The Wiskott Aldrich syndrome protein (WASP) is a hematopoietic-specific cytoskeletal regulator that is necessary for induction of normal immunity. In the context of effective gene therapy for WAS, cellular models of human WASP deficiency are important for definition of the threshold of protein expression required for optimal activity. Using lentiviral vector-mediated RNA interference (RNAi), we were able to down-regulate the levels of human WASP in cell lines and primary cells. In dendritic cells (DC), RNAi-induced WASP deficiency did not impair phenotypic maturation but perturbed cytoskeletal organization. As a result, podosomes, which are actin-rich structures present in immature adherent DC, were formed less efficiently and motility was disturbed. Overall, treatment of cells with RNAi recapitulated the phenotype of cells derived from patients or animals with inactivating mutations of the WAS gene. Interestingly, reduction of the levels of WASP to about 60% of normal was sufficient to inhibit the formation of podosomes in DC, implying that this cell type requires near-normal levels of WASP to sustain physiological cytoskeleton-dependent activities.
威斯科特-奥尔德里奇综合征蛋白（WASP）是一种造血特异性细胞骨架调节因子，对诱导正常免疫至关重要。在针对威斯科特-奥尔德里奇综合征（WAS）的有效基因治疗背景下，人类WASP缺乏的细胞模型对于确定最佳活性所需的蛋白表达阈值很重要。利用慢病毒载体介导的RNA干扰（RNAi），我们能够下调细胞系和原代细胞中人类WASP的水平。在树突状细胞（DC）中，RNAi诱导的WASP缺乏并不损害表型成熟，但会扰乱细胞骨架组织。结果，在未成熟贴壁DC中存在的富含肌动蛋白的结构——足体，形成效率降低，迁移能力受到干扰。总体而言，用RNAi处理细胞重现了源自具有WAS基因失活突变的患者或动物的细胞的表型。有趣的是，将WASP水平降低至正常水平的约60%就足以抑制DC中足体的形成，这意味着这种细胞类型需要接近正常水平的WASP来维持依赖细胞骨架的生理活动。
