Randall Division of Cell and Molecular Biophysics, King's College London, London, United Kingdom.
MRC & Asthma UK Centre in Allergic Mechanisms of Asthma, London, United Kingdom.
Sci Rep. 2017 Aug 15;7(1):8164. doi: 10.1038/s41598-017-08212-6.
Degranulation of mast cells and basophils, with release of agents of the allergic response, ensues when multivalent antigens bind to and cross-link the cells' receptor-bound IgE antibodies. A widely used commercial monoclonal IgE antibody, SPE-7 IgE from Sigma, was found to possess the radically anomalous property, termed "cytokinergic", of inducing basophil degranulation without the intervention of an antigen. We show here that the IgE monomer, freed of protein contaminants, is devoid of this activity, and that the source of the anomaly is a trace impurity, identified as a dissociation-resistant IgE trimer. Possible models for the formation of IgE trimers and the manner in which they cross-link cell surface receptors are suggested herein.
当多价抗原与细胞结合的 IgE 抗体结合并交联时，肥大细胞和嗜碱性粒细胞脱颗粒，释放过敏反应的介质。西格玛公司的一种广泛使用的商业单克隆 IgE 抗体 SPE-7 IgE 被发现具有一种称为“细胞激活性”的异常性质，即无需抗原干预即可诱导嗜碱性粒细胞脱颗粒。我们在这里表明，IgE 单体，去除了蛋白质污染物，没有这种活性，异常的来源是一种痕量杂质，鉴定为一种不易解离的 IgE 三聚体。本文提出了 IgE 三聚体形成的可能模型以及它们交联细胞表面受体的方式。
