应用RT—PCR方法,体外扩增获得人IL—6、IL—10、IL—13和SCF膜外区蛋白质编码序列.又运用基因重组手段,将这些基因序列分别插入到表达性载体PBV220中,转化大肠肝菌DH5α,经过筛选和鉴定,获得了上述细胞因子膜外区cDNA克隆.SDS—PAGE和生物学活性测定证实:IL—6、IL—10和IL—13已在大肠肝菌中得到表达,尤其是IL—6获得了高效表达,其表达量约占菌体总蛋白质含量的30%左右. The protein coding sequences of human IL-6, IL-10, IL-13 and SCF were obtained by in vitro amplification using RT-PCR method.The gene sequences were inserted into the expression vector PBV220 by gene recombination, The E. coli DH5α was transformed into E. coli DH5α, and the cDNA clone of the extracellular domain of the cytokine was obtained through screening and identification.DS-PAGE and bioassay showed that IL-6, IL-10 and IL-13 have been obtained in E. coli The expression of IL-6, in particular, was highly expressed, accounting for about 30% of the total protein content of the cell body.