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Updated: Oct 16, 2025
A BW Reporter System for Studying Receptor-Ligand Interactions
Published on: January 7, 2019
Development of a reporter gene method to measure the bioactivity of anti-CD38 × CD3 bispecific antibody
Hui Xiong1, Fengyan Luo1, Pengfei Zhou1
1Wuhan YZY Biopharma Co., Ltd, Biolake City C2-1, No. 666 Gaoxin Road, Wuhan, Hubei 430075, China.
Background:
A T cell-redirecting bispecific antibody (bsAb) consisting of a tumor-binding unit and a T cell-binding unit is a large group of antibody-based biologics against death-causing cancer diseases. The anti-CD38 × anti-CD3 bsAb (Y150) is potential for treating multiple myeloma (MM). When developing a cell-based reporter gene bioassay to assess the activities of Y150, it was found that the expression of CD38 on the human T lymphocyte cells (Jurkat) caused the nonspecific activation, which interfered with the specific T cells activation of mediated by the Y150 and CD38(+) tumor cells.
Methods:
Here, we first knocked-out the CD38 expression on Jurkat T cell line by CRISPR-Cas9 technology, then developed a stable monoclonal CD38(-) Jurkat T cell line with an NFAT-RE driving luciferase expressing system. Further based on the CD38(-) Jurkat cell, we developed a reporter gene method to assess the bioactivity of the anti-CD38 × anti-CD3 bsAb.
Results:
Knocking out CD38 expression abolished the nonspecific self-activation of the Jurkat cells. The selected stable monoclonal CD38(-) Jurkat T cell line assured the robustness of the report genes assay for the anti-CD38 × anti-CD3 bsAb. The relative potencies of the Y150 measured by the developed reporter gene assay were correlated with those by the flow-cytometry-based cell cytotoxicity assay and by the ELISA-based binding assay.
Conclusions:
The developed reporter gene assay was mechanism of action-reflective for the bioactivity of anti-CD38 × anti-CD3 antibody, and suitable for the quality control for the bsAb product.
