毒性T淋巴细胞相关抗原-4(CTLA-4)在链霉菌中的表达研究

应用两种链霉菌新型信号肽--vsi和gpp在常用工程菌变铅青链霉菌（Streptomyces lividans）中进行了CTLA-4的分泌表达研究，vsi信号肽与CTLA-4的融合片段克隆至链霉素-大肠杆菌穿梭质粒pUWL-219，同时gpp信号肽与CTLA-4片段在质粒pLNSP中融合，分别转化S.lividans TK24，获得重组菌株S.lividans[pUWL219-VC]和S.lividans[pLNSP/CTLA-4]。重组菌株的发酵上清液经SDS-PAGE及Western blotting分析结果表明：应用不同信号肽构建的两株工程菌均能表达分子量为13000重组蛋白，具有免疫活性。

Gene Cloning and Expression of CTLA-4 in Streptomyces lividans

Gene cloning and expression of CTLA 4 was performed in S. lividans with two new types of different signal peptides--vsi and gpp to investigate the secretory expression efficiency of CTLA 4. The hsCTLA 4 gene was fused to the vsi sequences and then inserted into the shuttle vector pUWL 219. At the same time, the hsCTLA 4 was inserted into the downstream of gpp signal peptide in the plasmid pLNSP. Then the recombinant plasmids were transformed into S.lividans TK24 respectivly. The two engineering strains were named as S.lividans [pUWL219 VC] and S.lividans [pLNSP/CTLA 4]. The result of SDS PAGE and Western blotting show that the recombinant strain S.lividans [pUWL219 VC] and S.lividans [pLNSP/CTLA 4] can express CTLA 4 with about MW 13 000 which is similar to those reported earlier and have immunoactivity. It is the first time that CTLA 4 expression in S.lividans is reported.