Generation and analysis of transgenic mice carrying parvoviral NS gene

细小病毒具有小单链DNA，其非结构蛋白（NS）调控病毒衣壳蛋白（VP）和宿主基因的表达。细小病毒与自身免疫性疾病或因免疫能力改变而怀疑的抗肿瘤发生的相关性。因此，我们试图用细小病毒NS蛋白产生转基因小鼠，以参与自身免疫性疾病的修饰和抗肿瘤发生。由于前病毒NS对小鼠胎儿具有潜在的细胞毒性，首先采用四环素诱导基因表达系统制备过表达前病毒NS的转基因小鼠。我们培育了4只携带逆转录四环素反应因子（rtTA）基因的小鼠和3只携带四环素反应因子（TRE）基因和细小病毒NS基因的融合转基因小鼠。用四环素对这些小鼠进行杂交，获得双转基因过表达NS的小鼠。另一方面，我们还在宿主细胞中检测了NS的细胞毒性和细胞因子与NS的相互作用，以期通过NS的过表达来预测表型。结果表明，NS的细胞毒性与诱导凋亡有关，并且NS与CREB结合蛋白CBP （CREB binding protein）相互作用，CBP是结合多种转录因子的重要共激活因子。

Parvoviruses have small single stranded DNA,its nonstructural (NS) protein regulates viral capsid protein (VP) and host gene expressions. Correlation between parvoviruses and autoimmun diseases or antitumorigenesis suspected because of modification of immunocompetence. Thus, we tried to generate transgenic mice to involve modification of autoimmune disease and anti tumorigenesis with parvoviral NS protein.At first, tetracycline inducible gene expression system was applied to generate transgenic mice overexperssing prvoviral NS,because of potential cytotoxicity of NS to mouse fetus. We generated 4 founder mice carrying reverse tetracycline transactivator (rtTA) gene and 3 founder mice carrying fusion transgene including tetracycline responsive element (TRE) and parvoviral NS genes. These mice are cross breeding to generate dual transgenic mice overexpression NS by administration of tetracycline.On the other hand, we also examined cytotoxicity of NS and cellular factors interact with NS in host cells, to expect phenotypes by overexpression of NS.The results indicate that cytotoxicity of NS is correlated with induction of apoptosis, and that NS interacts to CBP (CREB binding protein) which is an important coactivators to bind several transcriptional factors.