Proteogenomic approach to immunopeptidomics of ovarian tumors identifies shared peptide vaccine candidates.

Epithelial ovarian cancers are largely comprised of immunogenic tumor sub-types with the degree of CD8+ T cell infiltration being prognostic of clinical outcome. Tumor antigen-specific T cells are identified among these infiltrating T cell populations which has spurred a decade of development towards antigen-specific immunotherapies. Despite these efforts, the success of such immunotherapies has shown to be limited. In this study, we used state-of-the art immunopeptidomics approach and a novel proteogenomic profiling method to identify potential immunogenic human leukocyte antigen class I-presented peptides from patient-derived high-grade serous ovarian cancer. From 11 patients' tumors, we identified promising candidates for their therapeutic potential. Of these, we selected the best 13 candidates and validated their immunogenicity in both healthy donors and cancer patients.