Structural differences among monoclonal antibodies with distinct fine specificities and kinetic properties
Structural differences among monoclonal antibodies with distinct fine specificities and kinetic properties
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DOI：
10.1016/s0161-5890(99)00130-3
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发表时间：
1999-12-01
影响因子：
3.6
通讯作者：
Smith-Gill, SJ
中科院分区：
文献类型：
--
作者：
Lavoie, TB;Mohan, S;Smith-Gill, SJ
单克隆抗体HyHEL-8、HyHEL-26（分别为HH8和HH26）识别与结构上定义的HH10表位高度重叠的蛋清溶菌酶（HEL）上的表位，而结构上相关的xrp -25是DNP特异性的，不结合HEL。所有四种抗体似乎都使用相同的V(k)23种种系基因，除了HH8外，所有抗体都使用相同的V(H)36-60种系基因。在三种抗mel抗体中，HH26可变区序列与各自种系序列编码的序列最接近。HH8利用V(H)36-60基因家族的不同成员。因此，相同的V-k和V-H基因，结合体细胞衍生的序列差异，被用来识别不相关的Ags HEL和DNP。相反，不同的V(H)36-60种系基因被用来结合相同的抗原（例如HH8 vs HM10和HH26）。虽然HH10、HH8和HH26对HEL的亲和力相差不到10倍，但它们对突变Ag的亲和力相差超过几个数量级。通过对Fab与天然物种变异和溶菌酶定点突变体的结合动力学分析表明，这些交叉反应性差异反映了它们对抗原突变的关联率和解离率的相对敏感性：HH8具有相对突变不敏感的关联率和解离率，HH10具有相对突变敏感的关联率和解离率，HH26具有可变的关联率和解离率。抗体之间只有少数氨基酸差异产生观察到的关联和解离率稳健性差异。我们的研究结果表明，这些比率的关联和解离率以及突变敏感性可能在抗体库开发过程中独立调节。(C) 2000, Elsevier Science Ltd.出版版权所有。
The mAbs HyHEL-8, HyHEL-26 (HH8, and HH26, respectively) recognize epitopes on hen egg-white lysozyme (HEL) highly overlapping with the structurally defined HH10 epitope, while the structurally related XRPC-25 is specific for DNP and does not bind HEL. All four Abs appear to use the same V(k)23 germ line gene, and all but HH8 use the same V(H)36-60 germ line gene. Of the three anti-MEL Abs, the sequences of HH26 variable regions are closest to those encoded by the respective germ line sequences. HH8 utilizes a different member of the V(H)36-60 gene family. Thus, the same V-k and V-H genes, combined with somatically derived sequence differences, are used to recognize the unrelated Ags HEL and DNP. In contrast, different V(H)36-60 germ line genes are used to bind the same antigen (e.g. HH8 vs HM10 and HH26). While the affinities of HH10, HH8, and HH26 for HEL vary by less than 10-fold, their affinities for mutated Ag vary over several orders of magnitude. Analyses of Fab binding kinetics with natural species variants and site-directed mutants of lysozyme indicate that these cross-reactivity differences reflect the relative sensitivities of both the association and dissociation rates to antigenic mutation: HH8 has relatively mutation-insensitive association and dissociation rates, HH10 has a relatively mutation-sensitive association rate but more variable dissociation rates, and HH26 has variable association and dissociation rates. Only a few amino acid differences among the antibodies produce the observed differences in the robustness of the association and dissociation rates. Our results suggest that association and dissociation rates and mutation sensitivity of these rates may be independently modulated during antibody repertoire development. (C) 2000 Published by Elsevier Science Ltd. All rights reserved.