Berahovich Robert, Zhou Hua, Xu Shirley, Wei Yuehua, Guan Jasper, Guan Jian, Harto Hizkia, Fu Shuxiang, Yang Kaihuai, Zhu Shuying, Li Le, Wu Lijun, Golubovskaya Vita
ProMab Biotechnologies, 2600 Hilltop Drive, Richmond, CA 94806, USA.
Forevertek Biotechnology Co., Ltd., Building M0, Oversea Graduate Park National High-Tech Industrial Zone, Changsha 410003, China.
Cancers (Basel). 2018 Sep 11;10(9):323. doi: 10.3390/cancers10090323.
The cell-surface protein B cell maturation antigen (BCMA, CD269) has emerged as a promising target for CAR-T cell therapy for multiple myeloma. In order to create a novel BCMA CAR, we generated a new BCMA monoclonal antibody, clone 4C8A. This antibody exhibited strong and selective binding to human BCMA. BCMA CAR-T cells containing the 4C8A scFv were readily detected with recombinant BCMA protein by flow cytometry. The cells were cytolytic for RPMI8226, H929, and MM1S multiple myeloma cells and secreted high levels of IFN-γ in vitro. BCMA-dependent cytotoxicity and IFN-γ secretion were also observed in response to CHO (Chinese Hamster Ovary)-BCMA cells but not to parental CHO cells. In a mouse subcutaneous tumor model, BCMA CAR-T cells significantly blocked RPMI8226 tumor formation. When BCMA CAR-T cells were given to mice with established RPMI8226 tumors, the tumors experienced significant shrinkage due to CAR-T cell activity and tumor cell apoptosis. The same effect was observed with 3 humanized BCMA-CAR-T cells in vivo. These data indicate that novel CAR-T cells utilizing the BCMA 4C8A scFv are effective against multiple myeloma and warrant future clinical development.
细胞表面蛋白B细胞成熟抗原（BCMA，CD269）已成为嵌合抗原受体T细胞（CAR-T）治疗多发性骨髓瘤的一个有前景的靶点。为了构建一种新型的BCMA嵌合抗原受体，我们制备了一种新的BCMA单克隆抗体，克隆号为4C8A。该抗体对人BCMA表现出强而特异的结合。通过流式细胞术，含有4C8A单链抗体片段（scFv）的BCMA CAR-T细胞很容易被重组BCMA蛋白检测到。这些细胞对RPMI8226、H929和MM1S多发性骨髓瘤细胞具有细胞毒性，并在体外分泌高水平的干扰素-γ。对中国仓鼠卵巢细胞（CHO）-BCMA细胞有反应，但对亲本CHO细胞无反应，也观察到了BCMA依赖性细胞毒性和干扰素-γ分泌。在小鼠皮下肿瘤模型中，BCMA CAR-T细胞显著阻断了RPMI8226肿瘤的形成。当将BCMA CAR-T细胞给予已建立RPMI8226肿瘤的小鼠时，由于CAR-T细胞活性和肿瘤细胞凋亡，肿瘤显著缩小。在体内对3种人源化BCMA-CAR-T细胞也观察到了相同的效果。这些数据表明，利用BCMA 4C8A scFv的新型CAR-T细胞对多发性骨髓瘤有效，值得未来进行临床开发。
