Deciphering the molecular bases of the biological effects of antibodies against Interleukin-2: A versatile platform for fine epitope mapping
Deciphering the molecular bases of the biological effects of antibodies against Interleukin-2: A versatile platform for fine epitope mapping
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DOI：
10.1016/j.imbio.2012.02.009
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发表时间：
2013-01-01
期刊：
影响因子：
2.8
通讯作者：
Sidhu, Sachdev
中科院分区：
文献类型：
--
作者：
Rojas, Gertrudis;Pupo, Amaury;Sidhu, Sachdev
阐明白介素2建立的相互作用网络是理解其作为免疫系统主要调节因子的作用的关键一步。这种细胞因子与特定抗体的结合可产生不同类别的免疫复合体，增强或抑制免疫反应。这种功能二分法的分子基础可能与识别表位的性质有关，因此有必要进行精细的表位定位研究。目前的工作旨在开发一个多功能的平台来做到这一点。这是通过在丝状噬菌体上展示人和鼠IL-2，以及对这两种抗原的广泛突变和对200多个变异体结合特性的高通量筛选来实现的。因此，为四种抗人或鼠白细胞介素2的抗体描绘了详细的表位分子图，提炼并在某些情况下修正了先前用多肽库绘制图谱研究得出的结论。小鼠白介素2表面重叠的斑块也符合细胞因子和其受体阿尔法链之间的预测界面，被证明是由两个促进免疫反应增强的单抗识别的，这为它们的生物活性的结构基础提供了新的线索。我们的策略足够强大，足以揭示多个结合细节，并可用于绘制其他抗体识别的表位图，并探索涉及IL-2和相关细胞因子的其他相互作用，从而有助于我们理解免疫系统内复杂的结构-功能关系。(C)2012年爱思唯尔股份有限公司。版权所有。
Elucidating the network of interactions established by Interleukin-2 is a key step to understanding its role as a master regulator of the immune system. Binding of this cytokine by specific antibodies gives rise to different classes of immune complexes that boost or inhibit immune responses. The molecular bases of such functional dichotomy are likely related to the nature of the recognized epitopes, making it necessary to perform fine epitope mapping studies. The current work was aimed at developing a versatile platform to do so. This was accomplished by display of human and mouse Interleukin-2 on filamentous phages, together with extensive mutagenesis of both antigens and high throughput screening of binding properties of more than 200 variants. Detailed molecular pictures of the epitopes were thus delineated for four antibodies against either human or mouse Interleukin-2, which refined and, in some cases, modified the conclusions derived from previous mapping studies with peptide libraries. Overlapping surface patches on mouse Interleukin-2 that also coincide with the predicted interface between the cytokine and its receptor alpha chain were shown to be recognized by two monoclonal antibodies that promote enhancement of immune responses, shedding new light on the structural bases of their biological activity. Our strategy was powerful enough to reveal multiple binding details and could be used to map the epitopes recognized by other antibodies and to explore additional interactions involving Interleukin-2 and related cytokines, thus contributing to our understanding of the complex structure-function relationships within the immune system. (C) 2012 Elsevier GmbH. All rights reserved.