Development of a robust reporter gene assay for measuring the bioactivity of OX40‐targeted therapeutic antibodies. (5th March 2021)

• Record Type: Journal Article
• Authors: Li, Meng; Wang, Lan; Yu, Chuanfei; Wang, Junzhi
• Is Part Of: Luminescence. Volume 36:Number 4(2021)
• Page Start: 885
• Page End: 893
• Publication Date: 2021-03-05
• Subjects: anti‐OX40 monoclonal antibody -- bioactivity -- reporter gene assay -- validation; Luminescence -- Periodicals; Bioluminescence -- Periodicals; Chemiluminescence -- Periodicals; Luminescence -- Periodicals; 535.35
• DOI: 10.1002/bio.4004
• Languages: English
• ISSNs: 1522-7235

Abstract

Abstract: OX40 plays a prominent role in the onset and development of solid tumors, and OX40‐targeted monoclonal antibodies (mAbs) have entered clinical trials for various tumors. Bioactivity determination of therapeutic mAbs is of great significance in product quality, however, mechanism of action‐based bioassays to determine the bioactivity of anti‐OX40 mAbs is still lacking. Here, we established a reporter gene assay system based on two cell lines, namely Jurkat‐OX40‐NFκB‐Luc which stably expresses NFκB‐controlled luciferase, and Raji cells which inherently express FcγRs. In the model, FcγRs on Raji cells could crosslink the Fc of anti‐OX40 mAbs, which leads to the further crosslinking between Fab of anti‐OX40 mAbs and OX40 on Jurkat‐OX40‐NFκB‐Luc cells. OX40 crosslinking could activate Jurkat‐OX40‐NFκB‐Luc cells, and induce the expression of NFκB‐controlled luciferase, the extent of which could reflect the bioactivity of anti‐OX40 mAbs in a dose‐dependent manner. After the optimization of various assay conditions, the validation of the cell‐based bioassay showed good assay performance characteristics, including specificity, accuracy, precision, linearity, and stability. This innovative assay that is based on the OX40‐NFκB pathway can be a powerful pool to measure the bioactivity of OX40‐targeted mAbs. Abstract : FcγRs on Raji cells could crosslink the Fc of anti‐OX40 monoclonal antibodies (mAbs), which leads to the further crosslinking between Fab of anti‐OX40 mAbs and OX40 on Jurkat‐OX40‐NFκB‐Luc cells. OX40 crosslinking could activate Jurkat‐OX40‐NFκB‐Luc cells, and induce the expression of NFκB‐controlled luciferase, the extent of which could reflect the bioactivity of anti‐OX40 mAbs in a dose‐dependent manner.