Generation of immunotoxins with super-targeting mAb in the acute myelocytic leukemia

我们构建了重组融合蛋白DT3C，该融合蛋白含有截短的白喉毒素(DT)的催化和易位结构域以及链球菌蛋白G(3C)的3个免疫球蛋白结合C结构域。Moab的Fc与DT3C结合，形成Moab-DT3C复合体(两个DT3C分子与一个免疫球蛋白分子结合)。Moab-DT3C复合体与表面抗原结合后内化并移位到细胞质中，通过抑制DT的蛋白质合成而产生细胞内效应。通过使用这些，我们开发了一种独特的筛查系统来建立癌症靶向抗原/抗体集。共获得224个对白血病细胞进行细胞免疫毒素标记的单抗克隆。我们的方法为获得用于抗体药物结合(ADC)治疗的优质单抗提供了一个很好的途径。

We generated a recombinant fusion protein DT3C, which contained the catalytic and translocation domain of the truncated diphtheria toxin (DT) as well as the three IgG-binding C domains of streptococcal protein G (3C). Fc of MoAb binds with DT3C, resulting in a MoAb-DT3C complex (two DT3C molecules conjugated with one IgG molecule). The MoAb-DT3C complex binds with the surface Ag, being followed by internalization and translocation into the cytoplasm, leads to the cytocydal effect by protein synthesis inhibition of DT. By using these, we developed a unique screening system to establish cancer-targetable antigens/antibodies sets. In total 224 MoAb clones were obtained which performed immunotoxin cytocydal on leukemic cells. Our method provide an excellent way to obtain promising superior mAbs for antibodies drug conjugation(ADC) therapy.