Epitope mapping of a chimeric CD137 mAb: a necessary step for assessing the biologic relevance of non-human primate models.
Epitope mapping of a chimeric CD137 mAb: a necessary step for assessing the biologic relevance of non-human primate models.
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嵌合 CD137 mAb 的表位作图：评估非人类灵长类动物模型的生物学相关性的必要步骤。
DOI：
10.1002/jmr.937
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发表时间：
2009
期刊：
影响因子：
--
通讯作者：
Schulze,DanH
中科院分区：
文献类型：
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作者：
Chan,Siaw-Lin;Voskens,CarolineJ;Lin,Wei;Schindler,DanielG;Azimzadeh,Agnes;Wang,Lai-Xi;Taylor,RodneyJ;Strome,ScottE;Schulze,DanH
基于抗体的CD137(4-1BB)共信号通路的操纵是治疗癌症和自身免疫性疾病的一个有吸引力的选择。我们研制了一种嵌合的抗人CD137单抗(GG)，并对其功能进行了鉴定。作为计划中的临床前研究的一部分，我们评估了GG与食蟹猴和恒河猴外周血单个核细胞(PBMC)的结合情况。有趣的是，GG只识别人CD137，而商品化的抗CD137单抗(4B4-1)识别人和非人灵长类(NHP)激活的PBMCs。随后的分析表明，CD137的氨基酸序列在灵长类物种之间很大程度上是保守的(∼同源性为95%)，胞外区仅相差9-10个氨基酸。基于这些数据，我们在胞外区产生了突变结构，用人CD137序列取代了NHP，并鉴定了3个对GG结合至关重要的氨基酸。这些残基可能是构象表位的一部分，因为跨越该区域的多肽无法阻止mAb结合。这些数据表明，灵长类物种之间定义的共刺激分子的细微序列差异可以作为一种策略，用于定位抗体与构象表位结合所需的残基。版权所有©2009 John Wiley&Sons，Ltd.
Antibody based manipulation of the CD137 (4‐1BB) co‐signaling pathway is an attractive option for the treatment of cancer and autoimmune disease. We developed a chimeric anti‐human CD137 monoclonal antibody (GG) and characterized its function. As a component of planned preclinical studies, we evaluated the binding of GG to activated peripheral blood mononuclear cells (PBMCs) from cynomolgus macaque and baboon against human. Interestingly, GG only recognized human CD137, while a commercial anti‐CD137 mAb (4B4‐1), recognized activated PBMCs from both human and non‐human primates (NHP). Subsequent analysis revealed that the amino acid sequence of CD137 is largely conserved between primate species (∼95% identical), with the extracellular domain differing by only 9–10 amino acids. Based on these data, we generated mutant constructs in the extracellular domain, replacing NHP with human CD137 sequences, and identified 3 amino acids critical for GG binding. These residues are likely part of a conformational epitope, as a peptide spanning this region is unable to block mAb binding. These data demonstrate that subtle sequence variations of defined co‐stimulatory molecules amongst primate species can be employed as a strategy for mapping residues necessary for antibody binding to conformational epitopes. Copyright © 2009 John Wiley & Sons, Ltd.