Kymab Ltd., Babraham Research Campus, Cambridge, UK.
Wellcome Trust Sanger Institute, Hinxton, Cambridge, UK.
Nat Biotechnol. 2014 Apr;32(4):356-63. doi: 10.1038/nbt.2825. Epub 2014 Mar 16.
If immunized with an antigen of interest, transgenic mice with large portions of unrearranged human immunoglobulin loci can produce fully human antigen-specific antibodies; several such antibodies are in clinical use. However, technical limitations inherent to conventional transgenic technology and sequence divergence between the human and mouse immunoglobulin constant regions limit the utility of these mice. Here, using repetitive cycles of genome engineering in embryonic stem cells, we have inserted the entire human immunoglobulin variable-gene repertoire (2.7 Mb) into the mouse genome, leaving the mouse constant regions intact. These transgenic mice are viable and fertile, with an immune system resembling that of wild-type mice. Antigen immunization results in production of high-affinity antibodies with long human-like complementarity-determining region 3 (CDR3H), broad epitope coverage and strong signatures of somatic hypermutation. These mice provide a robust system for the discovery of therapeutic human monoclonal antibodies; as a surrogate readout of the human antibody response, they may also aid vaccine design efforts.
如果用感兴趣的抗原进行免疫，带有大量未重排人免疫球蛋白基因座的转基因小鼠可以产生完全人源的抗原特异性抗体；有几种这样的抗体正在临床使用。然而，传统转基因技术固有的技术限制和人源与鼠源免疫球蛋白恒定区之间的序列差异限制了这些小鼠的应用。在这里，我们使用胚胎干细胞中的基因组工程重复循环，将整个人类免疫球蛋白可变基因库（2.7 Mb）插入到小鼠基因组中，而保持小鼠恒定区完整。这些转基因小鼠具有活力和生育能力，其免疫系统类似于野生型小鼠。抗原免疫导致产生具有长的类似人源的互补决定区 3（CDR3H）、广泛的表位覆盖和强烈的体细胞超突变特征的高亲和力抗体。这些小鼠为发现治疗性人源单克隆抗体提供了一个强大的系统；作为人抗体反应的替代读出，它们也可能有助于疫苗设计工作。
