抗人BCMA抗体的人源化设计及其体外活性鉴定

Humanization of murine anti-human BCMA antibody and its in vitro activity identification

BCMA高特异地表达于多发性骨髓瘤细胞表面,是多发性骨髓瘤的理想治疗靶点。为了降低鼠源抗体的人抗鼠抗体反应,使其在临床得到更好的应用,本文基于鼠源抗人BCMA抗体序列,获得了靶向人BCMA的人源化抗体,并在体外验证人源化是否影响该抗体的亲和性和特异性。本文将抗人BCMA抗体69G8的可变区序列与人源抗体序列库进行比对,确定人源化抗体模板。利用Discovery Studio软件对抗人BCMA抗体69G8进行人源化设计,获得人源化抗体h69G8,随后利用293T真核表达系统对人源化前后的69G8进行scFv形式的表达并进行亲和力测定。人源化的69G8全抗被合成出来后,对其进行亲和常数、内化特性以及结合特异性等方面的比较,发现其亲和力等特性并无改变。在此基础上,对人源化全抗进行合成,结果亦证明其保留了鼠源抗体的高亲和力、高特异性以及内化特性。本实验对鼠源抗人BCMA抗体69G8进行了人源化,人源化不影响其体外结合活性和亲和力,为69G8未来在临床更好地应用打下了基础。

BCMA is highly specifically expressed on the surface of multiple myeloma cells and is an ideal therapeutic target for the treatment of multiple myeloma.In order to reduce the human anti-mouse antibody response of mouse-derived antibodies and make them more suitable for clinical application,we obtained humanized antibodies targeting human BCMA based on the sequences of mouse-derived anti-human BCMA antibodies,and verified the humanization in vitro.In order to find out whether it affects the affinity and specificity of the antibody,we aligned the variable region sequence of the anti-human BCMA antibody 69G8with the human antibody sequence library to determine the humanized antibody template.The anti-human BCMA antibody 69G8 was designed by Discovery Studio software to obtain the humanized antibody h69G8.And then we used the 293T eukaryotic expression system to express the 69G8 and h69G8 in scFv format and conduct affinity determination.After the humanized 69G8 whole antibody was synthesized,its affinity constant,internalization properties and binding specificity were compared with the mouse-derived anti-human BCMA antibodies.We found that its affinity and other properties did not change.On this basis,the humanized whole antibody was synthesized,and the results also proved that it retained the high affinity,high specificity and internalization properties of the murine antibody.In this experiment,the mouse-derived anti-human BCMA antibody 69G8 was humanized,and humanization did not affect its in vitro binding activity and affinity,which laying a foundation for better clinical application of 69G8 in the future.