Research of gene therapy for liver cirrhosis and fibrosis, using solble TGF-beta receptor.

利用RT-PCR技术从小鼠基因文库中获得了转化生长因子-βII型受体胞外区的全长基因。并将其导入COS细胞，在培养上清中表达了4OkD蛋白。通过与转化生长因子-β结合，以及对转化生长因子-β功能的抑制试验，证实该40kD蛋白为转化生长因子-βII型受体蛋白，而将该基因导入大肠杆菌，由于其长度过长，未能获得大量的转化生长因子-β2型受体蛋白。因此，我们利用杆状病毒，获得了4okD蛋白。接下来，我们尝试通过添加干扰素信号肽和加入免疫球蛋白Fc区来改进cDNAs。从COS细胞培养上清液中获得3倍可利用的4OkD蛋白。现在我们将对蛋白质进行柱层析纯化，并将其应用于肝硬变模型大鼠。

We obtained cDNA of extra cellular domain of TGF-beta type II receptor using RT-PCR from mouse cDNA library. And it was introduced to COS cells and 4OkD protein was expressed in culture supernatant. We confirmed that this 40kD protein was TGF-beta type II receptor protein by binding to TGF-beta , and by inhibition test of TGF-beta function.And we failed to earn much TGF-beta type II receptor protein by introducinig cDNA to E.coli, because that cDNA was too long for F.coil. So we used Baculovirus, and obtained 4OkD protein. But it was not available in function.Next we tried to improve cDNA by adding signal peptide of Interferon and adding Immunoglobulin Fc region. We obtained three times degree of available 4OkD protein from COS cells culture supernatant. Now we are going to purify protein by column, and should like to use it in model rat of liver cirrhosis.