Antibody landscape of C57BL/6 mice cured of B78 melanoma via immunotherapy

Antibodies can play an important role in innate and adaptive immune responses against cancer, and in preventing infectious disease. Using a Nimble Therapeutics high-density peptide array, we assessed potential protein-targets for antibodies found in sera of immune mice, that were previously cured of their melanoma through a combined immunotherapy regimen with long-term memory. Using flow cytometry, immune sera showed strong antibody-binding against melanoma tumor cell lines. Sera from 6 of these cured mice were analyzed with this high-density, whole-proteome peptide-array to determine specific antibody-binding sites and their linear peptide sequence. We identified thousands of peptides that were targeted by 2 or more of these 6 mice and exhibited strong antibody binding only by immune, not naive sera. Confirmatory studies were done to validate these results using 2 separate ELISA-based systems. This technology may be helpful in studying the “immunome”. of protein-based epitopes that are recognized by immune sera from mice, or possibly patients, cured of cancer via immunotherapy.