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posted on 2023-04-28, 15:20 authored by Defne Bayik, Cynthia F. Bartels, Katreya Lovrenert, Dionysios C. Watson, Duo Zhang, Kristen Kay, Juyeun Lee, Adam Lauko, Sadie Johnson, Alice Lo, Daniel J. Silver, Mary McGraw, Matthew Grabowski, Alireza M. Mohammadi, Filippo Veglia, Yi Fan, Michael A. Vogelbaum, Peter Scacheri, Justin D. Lathia Supplementary figures 1-6
Funding
National Institute of Neurological Disorders and Stroke (NINDS)
United States Department of Health and Human Services
Find out more...National Cancer Institute (NCI)
United States Department of Health and Human Services
Find out more...National Heart, Lung, and Blood Institute (NHLBI)
American Heart Association (AHA)
Case Western Reserve University (CWRU)
History
ARTICLE ABSTRACT
In multiple types of cancer, an increased frequency in myeloid-derived suppressor cells (MDSC) is associated with worse outcomes and poor therapeutic response. In the glioblastoma (GBM) microenvironment, monocytic (m) MDSCs represent the predominant subset. However, the molecular basis of mMDSC enrichment in the tumor microenvironment compared with granulocytic (g) MDSCs has yet to be determined. Here we performed the first broad epigenetic profiling of MDSC subsets to define underlying cell-intrinsic differences in behavior and found that enhanced gene accessibility of cell adhesion programs in mMDSCs is linked to their tumor-accelerating ability in GBM models upon adoptive transfer. Mouse and human mMDSCs expressed higher levels of integrin β1 and dipeptidyl peptidase-4 (DPP-4) compared with gMDSCs as part of an enhanced cell adhesion signature. Integrin β1 blockade abrogated the tumor-promoting phenotype of mMDSCs and altered the immune profile in the tumor microenvironment, whereas treatment with a DPP-4 inhibitor extended survival in preclinical GBM models. Targeting DPP-4 in mMDSCs reduced pERK signaling and their migration towards tumor cells. These findings uncover a fundamental difference in the molecular basis of MDSC subsets and suggest that integrin β1 and DPP-4 represent putative immunotherapy targets to attenuate myeloid cell-driven immune suppression in GBM.
Epigenetic profiling uncovers cell adhesion programming as a regulator of the tumor-promoting functions of monocytic myeloid-derived suppressor cells in glioblastoma, identifying therapeutic targets that modulate the immune response and suppress tumor growth.
