a Department of Biotherapeutic and Medicinal Sciences , Biogen , Cambridge , MA , USA.
MAbs. 2018 Nov-Dec;10(8):1248-1259. doi: 10.1080/19420862.2018.1519631. Epub 2018 Sep 20.
Bispecific antibody therapeutics can expand the functionality of a conventional monoclonal antibody drug because they can bind multiple antigens. However, their great potential is counterbalanced by the challenges faced in their production. The classic asymmetric bispecific containing an Fc requires the expression of four unique chains - two light chains and two heavy chains; each light chain must pair with its correct heavy chain, which then must heterodimerize to form the full bispecific. The light-chain pairing problem has several solutions, some of which require engineering and optimization for each bispecific pair. Here, we introduce a technology called EFab Domain Substitution, which replaces the Cε2 of IgE for one of the CL/CH1 domains into one arm of an asymmetric bispecific to encourage the correct pairing of the light chains. EFab Domain Substitution provides very robust correct pairing while maintaining antibody function and is effective for many variable domains. We report its effect on the biophysical properties of an antibody and the crystal structure of the EFab domain substituted into the adalimumab Fab (PDB ID 6CR1).
双特异性抗体疗法可以扩展传统单克隆抗体药物的功能，因为它们可以结合多种抗原。然而，它们在生产中面临的挑战也抵消了它们的巨大潜力。经典的不对称双特异性抗体含有 Fc 区，需要表达四种独特的链——两条轻链和两条重链；每条轻链必须与其正确的重链配对，然后重链必须异二聚化形成完整的双特异性抗体。轻链配对问题有几种解决方案，其中一些需要针对每个双特异性抗体对进行工程和优化。在这里，我们介绍一种称为 EFab 结构域取代的技术，该技术将 IgE 的 Cε2 替换为不对称双特异性抗体的一个臂中的 CL/CH1 结构域之一，以鼓励轻链的正确配对。EFab 结构域取代提供了非常稳健的正确配对，同时保持了抗体的功能，并且对许多可变结构域有效。我们报告了它对抗体的物理性质和 EFab 结构域取代到阿达木单抗 Fab 中的晶体结构（PDB ID 6CR1）的影响。
