Zheutlin L M, Ackerman S J, Gleich G J, Thomas L L
J Immunol. 1984 Oct;133(4):2180-5.
Major basic protein (MBP), an arginine-rich basic polypeptide that constitutes the crystalloid core of the large specific eosinophil granule, has previously been shown to stimulate noncytolytic histamine release from human basophils and rat mast cells by an IgE-independent mechanism. Two additional basic polypeptides present in eosinophil granules, eosinophil cationic protein (ECP) and eosinophil-derived neurotoxin (EDN), were examined for similar activity in the present study. Acid-solubilized eosinophil granules were fractionated by chromatography on a Sephadex G-50 column. Incubation of basophil-containing human mononuclear cells with the individual column fractions demonstrated that histamine release occurred only with the fractions that contained MBP. The selectivity of the basophil response for MBP was confirmed by using equimolar concentrations of purified MBP, ECP, and EDN. In contrast, both MBP and ECP, but not EDN, stimulated histamine release from purified rat peritoneal mast cells. Reduction and alkylation of the MBP molecule diminished the response of human basophils to MBP but enhanced the potency of the molecule with rat mast cells. The distinct potency of MBP as a stimulus for histamine secretion from human basophils suggests that eosinophil release of MBP may be a specific event in the augmentation of immediate hypersensitivity reactions and other disorders characterized by eosinophilia.
主要碱性蛋白（MBP）是一种富含精氨酸的碱性多肽，构成了大的特异性嗜酸性粒细胞颗粒的晶体核心，此前已表明它能通过一种不依赖IgE的机制刺激人嗜碱性粒细胞和大鼠肥大细胞释放非细胞溶解性组胺。在本研究中，对嗜酸性粒细胞颗粒中存在的另外两种碱性多肽，即嗜酸性粒细胞阳离子蛋白（ECP）和嗜酸性粒细胞衍生神经毒素（EDN），进行了类似活性的检测。酸溶性嗜酸性粒细胞颗粒通过在Sephadex G - 50柱上进行色谱分离。将含嗜碱性粒细胞的人单核细胞与各个柱层析组分一起孵育，结果表明只有含有MBP的组分才会引起组胺释放。通过使用等摩尔浓度的纯化MBP、ECP和EDN，证实了嗜碱性粒细胞对MBP反应的选择性。相比之下，MBP和ECP都能刺激纯化的大鼠腹膜肥大细胞释放组胺，但EDN不能。MBP分子的还原和烷基化降低了人嗜碱性粒细胞对MBP的反应，但增强了该分子对大鼠肥大细胞的效力。MBP作为人嗜碱性粒细胞组胺分泌刺激物的独特效力表明，嗜酸性粒细胞释放MBP可能是速发型超敏反应增强以及其他以嗜酸性粒细胞增多为特征的疾病中的一个特定事件。
