This study successfully generated and characterized four novel fully human anti-OX40 monoclonal antibodies that recognize distinct epitopes and exhibit diverse bioactivities, including three with agonist properties and one that activates lymphocytes through an NK cell-mediated Treg cell killing mechanism, providing new tools for cancer immunotherapy.
Literature Overview
The article titled 'Generation of novel human anti-OX-40 mAbs endowed with different biological properties as tools for cancer therapy', published in Frontiers in Immunology, reviews the development and functional characterization of four novel human anti-OX40 monoclonal antibodies and their potential applications in cancer therapy. The study demonstrates that these antibodies activate immune cells through distinct mechanisms, with three mimicking OX40 ligand to activate downstream signaling pathways, while the fourth employs an NK cell-mediated Treg cell killing mechanism. The article further elucidates OX40 expression on NK cells and its interactions with different antibodies, establishing a theoretical foundation for developing novel OX40-targeted immunotherapies.
Background Knowledge
OX40 (CD134), an essential co-stimulatory receptor primarily expressed on activated T cells, serves as a critical target for immune checkpoint therapy. While multiple agonistic anti-OX40 antibodies have entered clinical trials, their mechanisms of action remain incompletely understood, and epitope recognition and functional differences among antibodies limit their therapeutic potential. Additionally, the role of OX40 on NK cells remains unclear. Developing diverse novel antibodies and analyzing their epitope-specific functions could optimize immunotherapeutic strategies. This study utilized phage display combined with next-generation sequencing (NGS) to screen and generate four fully human anti-OX40 IgG1 antibodies, which were systematically evaluated for binding properties and bioactivities through ELISA, biolayer interferometry, and cell co-culture assays, offering new molecular tools for cancer immunotherapy.
Research Methods and Experiments
Researchers screened fully human single-chain variable fragments (scFvs) against OX40 using phage display technology, subsequently converting these to full-length IgG1 antibodies. The antibodies were expressed and purified in HEK293 cells. Binding affinities to OX40 were evaluated via ELISA and biolayer interferometry (BLI), with competition experiments against OX40 ligand (OX40L) to analyze epitope recognition. Antibody agonistic properties and immune cell activation capabilities were assessed through co-culture experiments involving human peripheral blood mononuclear cells (hPBMCs) with tumor cells, and NK cells with Treg cells.
Key Conclusions and Perspectives
Research Significance and Prospects
This research not only provides novel anti-OX40 monoclonal antibodies for cancer immunotherapy but also elucidates OX40 expression patterns on NK cells and its epitope-specific binding characteristics, laying the groundwork for future combination immunotherapy strategies. Subsequent studies should evaluate these antibodies' anti-tumor efficacy in animal models and investigate synergies with PD-1 or CTLA-4 antibodies to accelerate clinical translation.
Conclusion
This article reports the development and functional evaluation of four novel fully human anti-OX40 monoclonal antibodies. These antibodies exhibit high-affinity binding to OX40 and demonstrate distinct activation mechanisms in hPBMC and NK cell co-culture systems. The study first reveals glycosylation differences of OX40 across immune cell types and corresponding antibody specificity, providing theoretical support for developing anti-OX40 monoclonal antibodies and combination therapies in cancer immunotherapy, while offering new molecular tools for future clinical translation.
