Comparative characterization of two monoclonal antibodies targeting canine PD-1
Mikolaj Kocikowski1,2, Katarzyna Dziubek1, Katarzyna Węgrzyn3
1International Centre for Cancer Vaccine Science, University of Gdansk, Gdansk, Poland.
Abstract:
Monoclonal antibodies targeting immune checkpoints have revolutionized oncology. Yet, the effectiveness of these treatments varies significantly among patients, and they are associated with unexpected adverse events, including hyperprogression. The murine research model used in drug development fails to recapitulate both the functional human immune system and the population heterogeneity. Hence, a novel model is urgently needed to study the consequences of immune checkpoint blockade. Dogs appear to be uniquely suited for this role. Approximately 1 in 4 companion dogs dies from cancer, yet no antibodies are commercially available for use in veterinary oncology. Here we characterize two novel antibodies that bind canine PD-1 with sub-nanomolar affinity as measured by SPR. Both antibodies block the clinically crucial PD-1/PD-L1 interaction in a competitive ELISA assay. Additionally, the antibodies were tested with a broad range of assays including Western Blot, ELISA, flow cytometry, immunofluorescence and immunohistochemistry. The antibodies appear to bind two distinct epitopes as predicted by molecular modeling and peptide phage display. Our study provides new tools for canine oncology research and a potential veterinary therapeutic.
Insights
New antibodies targeting canine PD-1 offer promising tools for cancer research. These novel antibodies could advance veterinary oncology and improve understanding of immune checkpoint blockade in dogs.
Area of Science:
- Immunology
- Veterinary Oncology
- Drug Development
Background:
- Immune checkpoint inhibitors have transformed cancer treatment but show variable efficacy and adverse effects.
- Current preclinical models do not fully represent human immune responses or patient diversity.
- A suitable model is needed to study immune checkpoint blockade consequences.
Purpose of the Study:
- To characterize novel antibodies targeting canine programmed cell death protein 1 (PD-1).
- To evaluate these antibodies as potential tools for canine oncology research and therapy.
Main Methods:
- Surface Plasmon Resonance (SPR) to measure antibody affinity.
- Competitive Enzyme-Linked Immunosorbent Assay (ELISA) to assess PD-1/PD-L1 interaction blocking.
- Western Blot, flow cytometry, immunofluorescence, and immunohistochemistry assays.
- Molecular modeling and peptide phage display for epitope mapping.
Main Results:
- Two novel antibodies demonstrated sub-nanomolar binding affinity to canine PD-1.
- Both antibodies effectively blocked the PD-1/PD-L1 interaction.
- Antibodies likely bind to distinct epitopes, supported by modeling and phage display.
Conclusions:
- The characterized antibodies are valuable new reagents for canine cancer research.
- These antibodies represent potential therapeutic candidates for veterinary oncology.
- The study highlights the utility of companion dogs as a model for immuno-oncology research.
