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目的研究ｈＴＮＦα的结构与功能。方法比较了野生型 ｈＴＮＦα与其单突变体 Ｒ２Ｋ－、 Ｎ３０Ｓ－、 Ｒ３２Ｗ－和Ｌ１５７Ｆ－ｈＴＮＦα及两种组合突变体Ｒ３２Ｗ－Ｌ１５７Ｆ－ｈＴＮＦα和Ｒ２Ｋ－Ｎ３０Ｓ－Ｒ３２Ｗ－Ｌ１５７Ｆ－ｈＴＮＦα的细胞毒活性、受体结合能力，以及动物体内毒性。结果发现两种组合突变体基本保持了与野生型相当的对人肿瘤细胞的细胞毒活性，但对小鼠Ｌ９２９细胞的活性明显下降；两种组合突变体与ｈＴＲ７５的结合能力的下降程度要大于 ｈＴＲ５５ ；小鼠体内毒性测定实验表明，两种组合突变体的毒性显著降低，其中双突变体的ＬＤ５０为野生型的３００倍左右，而四突变体对小鼠的体内毒性比野生型下降了７００倍以上；四突变体对恒河猴的体内毒性也比野生型ｈＴＮＦα明显降低。结论获得具有潜在应用价值的ＴＮＦ－α四突变体。
Objective To study the structure and function of hTNFα. Methods To compare the cytotoxic activity of wild-type hTNFα with its single mutants R2K-, N30S-, R32W- and L157F-hTNFα and two combination mutants R32W-L157F-hTNFα and R2K-N30S-R32W-L157F-hTNFα, and their receptors. Ability to bind, and toxicity in animals. As a result, it was found that the two combination mutants basically retained the cytotoxic activity against human tumor cells comparable to that of the wild type, but the activity of the mouse L929 cells was significantly decreased; the degree of decline in the binding ability of the two combination mutants and hTR75 was greater than hTR55; In vivo toxicity assay in mice showed that the toxicity of the two combination mutants was significantly reduced, in which the double mutant had an LD50 of about 300 times that of the wild type, and the fourth mutant had a 700-fold lower toxicity in vivo than the wild type. More than doubled; the in vivo toxicity of quadruple mutants to rhesus monkeys was also significantly lower than that of wild-type hTNFα. Conclusions Four potentially interesting TNF-alpha mutants were obtained.