This study successfully generated and characterized four novel fully human anti-OX40 monoclonal antibodies that recognize distinct epitopes and exhibit diverse biological activities. Three antibodies demonstrate agonist properties, while one activates lymphocytes through an NK cell-mediated Treg cell killing mechanism, providing new tools for cancer immunotherapy.
Literature Overview
This article, '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 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: three mimic OX40 ligand to activate downstream signaling pathways, while the fourth activates immune responses via NK cell-mediated Treg cell killing. The research further elucidates OX40 expression on NK cells and its interactions with different antibodies, establishing a theoretical foundation for developing novel OX40-targeted immunotherapeutic strategies.
Background Knowledge
OX40 (CD134) is an immune costimulatory receptor primarily expressed on activated T cells, representing a key target for immune checkpoint therapy. Although multiple anti-OX40 agonist antibodies have entered clinical trials, their mechanisms remain incompletely understood. Variations in epitope recognition and functional characteristics among different antibodies limit their therapeutic potential. The role of OX40 on NK cells remains unclear. Developing diverse novel antibodies and analyzing their epitopes and functions could optimize immunotherapy approaches. This study utilized phage display combined with next-generation sequencing (NGS) to screen and generate four fully human anti-OX40 IgG1 antibodies, systematically evaluating their binding properties and biological activities through ELISA, biolayer interferometry, and cell co-culture experiments, providing 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 them into full-length IgG1 antibodies. These were expressed and purified in HEK293 cells. Antibody-OX40 binding was assessed 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 evaluated through co-culture experiments involving human peripheral blood mononuclear cells (hPBMCs) with tumor cells, or NK cells with Treg cells.
Key Conclusions and Perspectives
Research Significance and Prospects
This research provides novel anti-OX40 monoclonal antibodies for cancer immunotherapy while uncovering OX40 expression patterns on NK cells and their binding characteristics with different antibodies, laying the foundation for future combination immunotherapy strategies. Subsequent studies should evaluate these antibodies' anti-tumor efficacy in animal models and investigate synergistic effects with PD-1 or CTLA-4 antibodies to accelerate clinical translation.
Conclusion
This article reports the development and functional characterization of four novel fully human anti-OX40 monoclonal antibodies. These antibodies demonstrate high OX40 binding affinity and exhibit distinct activation mechanisms in hPBMC and NK cell co-culture systems. The study reveals glycosylation heterogeneity 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.
