免疫活性地龙肽的制备及其对小鼠NK细胞活性的影响

目的:提取低分子量免疫活性地龙肽,并就其对自然杀伤(NK)细胞活性的影响进行体外研究。方法:采用粗分离、凝胶过滤层析和阴离子交换层析等方法分离纯化地龙肽;采用乳酸脱氢酶法测定NK细胞活性。结果:用凝胶过滤层析分离得到地龙肽T(分子量8000～20000,含有7种蛋白)。用离子交换层析又将地龙肽T分为A、B两部分,地龙肽A由5种蛋白组成,其中有4种分子量在13000以下;地龙肽B仅由一种蛋白构成,分子量约11000;地龙肽A和T可明显提高NK细胞的活性;地龙肽A、B和T皆可减弱环磷酰胺和地塞米松的免疫抑制作用,提高NK细胞的杀伤率。结论:地龙肽T、A单独应用即可以增强NK细胞的活性,并与IL-2具有协同作用;地龙肽T、A和B还可以拮抗地塞米松、环磷酰胺等免疫抑制剂。

Preparation of immuno-active earthworm peptides and its effect on the activity of natural killer cell in mice

Objective:To extract and purify low molecular weight immuno-active earthworm peptides,and to study its effects on the activity of natural killer cell(NK) cells in vitro.Methods:The immuno-active earthworm peptides were separated and purified through crude separation,gel filtration chromatography and DEAE-sephadex A-25 anion exchange chromatography.The activity of NK cells was determined with Lactate dehydrogenase method.Results:The earthworm peptides T(containing seven proteins with molecular weight 20 000) were prepared through Sephadex G-25 gel filtration chromatography,and then were divided into two parts,earthworm peptides A and earthworm peptides B,by DEAE-sephadex A-25 anion exchange chromatography.Earthworm peptides A was composed of five components,including four proteins whose molecular weights were smaller than 13 000.Earthworm peptides B was a single protein,whose molecular weight was 11 000.Conclusion:The earthworm peptides can not only activate NK cells and enhance NK cytotoxicity,but also cooperate with IL-2 to improve the activity of NK cells and antagonize the immunodeppression of Cyclophosphamide and Dexmethason.