Kipp B, Schlaak M, Becker W M
Borstel Research Institute, Division of Allergy, Germany.
Int Arch Allergy Immunol. 1996 Aug;110(4):348-53. doi: 10.1159/000237327.
We have cloned and expressed in bacteria the genes coding for the Fab fragment of the monoclonal antibody (MoAb) M3. M3 is a murine IgG1 antibody reactive with the major allergen Chi t 1-9 of Chironomus thummi thummi. The major allergen Chi t 1-9 is known to be an aggressive inhalant allergen and causes type-I allergy. The immunoglobulin (Ig) fragment genes were cloned as a synthetic dicistronic operon. In this operon each gene is preceded by a bacterial signal sequence to direct the recombinant protein to the periplasmic space of the bacteria. The cloned genes were expressed in Escherichia coli using the strong T7-RNA-polymerase-based system. Sequence analysis revealed that the light and heavy chains of MoAb M3 belong to the V kappa II and V kappa IIC group of the Ig family, respectively. Genes of the V kappa II and V kappa IIC group are known to be used in response to haptens. The apparent affinity constants of the parent antibody M3 and the recombinant Fab fragment are nearly equivalent.
我们已在细菌中克隆并表达了编码单克隆抗体（MoAb）M3 的 Fab 片段的基因。M3 是一种鼠源 IgG1 抗体，可与嗜尸摇蚊主要变应原 Chi t 1-9 发生反应。已知主要变应原 Chi t 1-9 是一种侵袭性吸入变应原，可引发 I 型过敏反应。免疫球蛋白（Ig）片段基因作为合成双顺反子操纵子进行克隆。在该操纵子中，每个基因之前都有一个细菌信号序列，以将重组蛋白导向细菌的周质空间。使用基于强 T7 - RNA 聚合酶的系统在大肠杆菌中表达克隆的基因。序列分析表明，MoAb M3 的轻链和重链分别属于 Ig 家族的 VκII 和 VκIIC 组。已知 VκII 和 VκIIC 组的基因用于对半抗原作出反应。亲本抗体 M3 和重组 Fab 片段的表观亲和常数几乎相等。
