Preparation of a novel tri-specific T cell engager targeting CD19 antigen and its anti-leukemia effect exploration
10.3760/cma.j.issn.0253-2727.2021.03.007
- VernacularTitle:一种新的靶向CD19抗原的三特异性T细胞衔接器的制备及其抗白血病作用研究
- Author:
Manling CHEN
1
;
Nan PENG
;
Xiaoyu LIU
;
Ting ZHANG
;
Yingxi XU
;
Zheng TIAN
;
Haiyan XING
;
Kejing TANG
;
Qing RAO
;
Jianxiang WANG
;
Min WANG
Author Information
1. 中国医学科学院、北京协和医学院血液病医院（中国医学科学院血液学研究所），实验血液学国家重点实验室，国家血液系统疾病临床医学研究中心，天津 300020
- Keywords:
Leukemia, lymphoblastic, acute;
CD19;
T cell engager, tri-specific;
Fusion protein;
Immunotherapy
- From:
Chinese Journal of Hematology
2021;42(3):217-223
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To prepare a novel tri-specific T cell engager (19TriTE) targeting CD19 antigen, and to investigate its immunotherapeutic effect on CD19-positive hematological malignancies.Methods:19TriTE was constructed by molecular cloning technology and successfully expressed through the eukaryotic expressing system. The effects of 19TriTE on the proliferation and activation of T cells, as well as the specific cytotoxicity against CD19 positive tumor cell lines were verified.Results:①19TriTE expressing plasmid was constructed and successfully expressed through the eukaryotic expressing system. ②19TriTE can specifically bind to T cells and Nalm6 cells, with equilibrium dissociation constants of 19.21 nmol/L and 11.67 nmol/L, respectively. ③The expression rates of CD69 positive T cells and CD25 positive T cells were 35.4% and 49.8% respectively, when 2 nmol/L 19TriTE were added in the co-culture system, which were significantly higher than those in the control group. ④19TriTE can significantly promote the proliferation of T cells. The absolute count of T cells expanded from the initial one million to 74 million with an 74 fold increase at the concentration of 1 nmol/L on day 12. ⑤19TriTE can significantly mediate T cells killing of CD19 positive target cells in a dose-dependent manner. At the concentration of 10 nmol/L, the target cells lysis reached 50%. ⑥Degranulation experiment verified that 19TriTE can activate T cells in the presence of CD19 positive target cells, and the activation of T cells positively correlated with the dose of 19TriTE. ⑦When 19TriTE fusion protein co-cultured with T cells and target cells overexpression RFP and luciferase genes respectively, 19TriTE can notably mediate T cells killing of CD19 positive target cells through fluorescent microscope or bioluminescence imaging technology.Conclusion:In this study, we successfully constructed and expressed 19TriTE fusion protein and verified that it can effectively activate T cells and promote their proliferation in vitro. At the same time, it can bind to CD19 positive target cells and T cells, as well as enhance T cells anti-leukemia effect in vitro, providing the foundation for further clinical research.
