Title | MEK inhibition enhances presentation of targetable MHC-I tumor antigens in mutant melanomas. |
Publication Type | Journal Article |
Year of Publication | 2022 |
Authors | Stopfer LE, Rettko NJ, Leddy O, Mesfin JM, Brown E, Winski S, Bryson B, Wells JA, White FM |
Journal | Proc Natl Acad Sci U S A |
Volume | 119 |
Issue | 49 |
Pagination | e2208900119 |
Date Published | 2022 Dec 06 |
ISSN | 1091-6490 |
Keywords | Antigens, Neoplasm, Epitopes, Humans, Melanoma, Mitogen-Activated Protein Kinase Kinases, Proto-Oncogene Proteins B-raf |
Abstract | Combining multiple therapeutic strategies in NRAS/BRAF mutant melanoma-namely MEK/BRAF kinase inhibitors, immune checkpoint inhibitors (ICIs), and targeted immunotherapies-may offer an improved survival benefit by overcoming limitations associated with any individual therapy. Still, optimal combination, order, and timing of administration remains under investigation. Here, we measure how MEK inhibition (MEKi) alters anti-tumor immunity by utilizing quantitative immunopeptidomics to profile changes in the peptide major histocompatibility molecules (pMHC) repertoire. These data reveal a collection of tumor antigens whose presentation levels are selectively augmented following therapy, including several epitopes present at over 1,000 copies per cell. We leveraged the tunable abundance of MEKi-modulated antigens by targeting four epitopes with pMHC-specific T cell engagers and antibody drug conjugates, enhancing cell killing in tumor cells following MEK inhibition. These results highlight drug treatment as a means to enhance immunotherapy efficacy by targeting specific upregulated pMHCs and provide a methodological framework for identifying, quantifying, and therapeutically targeting additional epitopes of interest. |
DOI | 10.1073/pnas.2208900119 |
Alternate Journal | Proc Natl Acad Sci U S A |
PubMed ID | 36454758 |
Grant List | R35 GM122451 / GM / NIGMS NIH HHS / United States R01 CA248323 / CA / NCI NIH HHS / United States U54 CA210180 / CA / NCI NIH HHS / United States U01 CA238720 / CA / NCI NIH HHS / United States T32 ES007020 / ES / NIEHS NIH HHS / United States |