人重组白细胞介素12在CHO细胞中的表达

Expression of Recombinant Human Interleukin 12 in CHO Cell.

将人白细胞介素１２（ｉｎｔｅｒｌｅｕｋｉｎ１２，ＩＬ１２）两条链ｐ３５及ｐ４０全长ｃＤＮＡ分别亚克隆至真核表达载体ｐｃＤＮＡ３中，构建了ｐｃＤＮＡ３／ｐ３５ａ，ｐｃＤＮＡ３／ｐ４０ａ，ｐｃＤＮＡ３／ｐ３５ｂ，ｐｃＤＮＡ３／ｐ４０ｂ四种真核细胞重组表达质粒，利用磷酸钙共沉淀法转染中国苍鼠卵巢（ＣＨＯ）细胞．通过对阳性克隆的筛选鉴定，获得了稳定表达人ＩＬ１２的ＣＨＯ细胞株，活性最高的一株表达量为１０５Ｕ／ｍｌ．此细胞株经半年的传代培养，能够稳定地分泌ＩＬ１２．结果显示：ＩＬ１２在ＣＨＯ细胞中的稳定表达受到重组质粒结构、ＤＮＡ整合、ｍＲＮＡ转录、蛋白质翻译等多因素的影响，ＩＬ１２两个亚基在ＣＨＯ细胞中的共同表达是产生有生物活性ＩＬ１２的基础．

Four kinds of human IL12 expression plasmids pcDNA3/p35a, pcDNA3/p35b, pcDNA3/p40a, pcDNA3/p40b were constructed. These recombinant plasmids were cotransfected into Chinese hamster ovary cells and acquired CHO cell lines that could stably secrete IL12. The highest expressed amount of IL12 in CHO cell is 105 U/ml. The results showed that the expression of human IL12 in CHO cell was affected at several levels such as recombinant plasmid structure, DNA intergration, mRNA transcription and protein transpation etc.