The HLA ligandome landscape of chronic myeloid leukemia delineates novel T-cell epitopes for immunotherapy

T Bilich, A Nelde, L Bichmann… - Blood, The Journal …, 2019 - ashpublications.org
T Bilich, A Nelde, L Bichmann, M Roerden, HR Salih, DJ Kowalewski, H Schuster, CC Tsou
Blood, The Journal of the American Society of Hematology, 2019ashpublications.org
Antileukemia immunity plays an important role in disease control and maintenance of
tyrosine kinase inhibitor (TKI)-free remission in chronic myeloid leukemia (CML). Thus,
antigen-specific immunotherapy holds promise for strengthening immune control in CML but
requires the identification of CML-associated targets. In this study, we used a mass
spectrometry–based approach to identify naturally presented HLA class I–and class II–
restricted peptides in primary CML samples. Comparative HLA ligandome profiling using a …
Abstract
Antileukemia immunity plays an important role in disease control and maintenance of tyrosine kinase inhibitor (TKI)-free remission in chronic myeloid leukemia (CML). Thus, antigen-specific immunotherapy holds promise for strengthening immune control in CML but requires the identification of CML-associated targets. In this study, we used a mass spectrometry–based approach to identify naturally presented HLA class I– and class II–restricted peptides in primary CML samples. Comparative HLA ligandome profiling using a comprehensive dataset of different hematological benign specimens and samples from CML patients in deep molecular remission delineated a panel of novel frequently presented CML-exclusive peptides. These nonmutated target antigens are of particular relevance because our extensive data-mining approach suggests the absence of naturally presented BCR-ABL– and ABL-BCR–derived HLA-restricted peptides and the lack of frequent tumor-exclusive presentation of known cancer/testis and leukemia-associated antigens. Functional characterization revealed spontaneous T-cell responses against the newly identified CML-associated peptides in CML patient samples and their ability to induce multifunctional and cytotoxic antigen-specific T cells de novo in samples from healthy volunteers and CML patients. Thus, these antigens are prime candidates for T-cell–based immunotherapeutic approaches that may prolong TKI-free survival and even mediate cure of CML patients.
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