Isocitrate dehydrogenase mutations suppress STAT1 and CD8+ T cell accumulation in gliomas
Gary Kohanbash ... Joseph F. Costello, Hideho Okada
Gary Kohanbash ... Joseph F. Costello, Hideho Okada
Published April 3, 2017
Citation Information: J Clin Invest. 2017;127(4):1425-1437. doi:10.1172/JCI90644.
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Categories: Research Article Immunology Oncology

Isocitrate dehydrogenase mutations suppress STAT1 and CD8+ T cell accumulation in gliomas

Abstract

Mutations in the isocitrate dehydrogenase genes IDH1 and IDH2 are among the first genetic alterations observed during the development of lower-grade glioma (LGG). LGG-associated IDH mutations confer gain-of-function activity by converting α-ketoglutarate to the oncometabolite R-2-hydroxyglutarate (2HG). Clinical samples and gene expression data from The Cancer Genome Atlas (TCGA) demonstrate reduced expression of cytotoxic T lymphocyte–associated genes and IFN-γ–inducible chemokines, including CXCL10, in IDH-mutated (IDH-MUT) tumors compared with IDH-WT tumors. Given these findings, we have investigated the impact of IDH mutations on the immunological milieu in LGG. In immortalized normal human astrocytes (NHAs) and syngeneic mouse glioma models, the introduction of mutant IDH1 or treatment with 2HG reduced levels of CXCL10, which was associated with decreased production of STAT1, a regulator of CXCL10. Expression of mutant IDH1 also suppressed the accumulation of T cells in tumor sites. Reductions in CXCL10 and T cell accumulation were reversed by IDH-C35, a specific inhibitor of mutant IDH1. Furthermore, IDH-C35 enhanced the efficacy of vaccine immunotherapy in mice bearing IDH-MUT gliomas. Our findings demonstrate a mechanism of immune evasion in IDH-MUT gliomas and suggest that specific inhibitors of mutant IDH may improve the efficacy of immunotherapy in patients with IDH-MUT gliomas.

Authors

Gary Kohanbash, Diego A. Carrera, Shruti Shrivastav, Brian J. Ahn, Naznin Jahan, Tali Mazor, Zinal S. Chheda, Kira M. Downey, Payal B. Watchmaker, Casey Beppler, Rolf Warta, Nduka A. Amankulor, Christel Herold-Mende, Joseph F. Costello, Hideho Okada

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Decreased chemokines and chemotaxis of T cells to IDH-MUT–derived CM com...

Figure 4

Decreased chemokines and chemotaxis of T cells to IDH-MUT–derived CM compared with media derived from IDH-WT cells.

(A and B) GL261-WT or GL261- MUT cells treated with either DMSO (control) or 1 μM IDH-C35 for 3 days were stimulated with 10 ng/ml recombinant murine IFN-γ for 6 hours prior to analysis. (A) RT-PCR analysis of Cxcl9 and Cxcl10 from GL261-WT (WT) and GL261-MUT (MUT) cells treated with or without IDH-C35. Gene expression levels were normalized to Gapdh and are shown relative to levels in WT samples. (B) Chemotaxis of activated CD8+ T cells toward GL261 glioma cell–CM by Transwell assay. CM were diluted 1:1 with fresh media. For CXCL10 conditions, 100 ng/ml recombinant murine CXCL10 (rCXCL10) was added to GL261-MUT–CM. For blockade of CXCR3, T cells were preincubated in 10 μg/ml anti-CXCR3 for 30 minutes prior to use. Results are representative of 3 independent experiments, each performed in triplicate with highly similar results. (C) RT-PCR analysis of OAS2 and CXCL10 gene expression from 4 unique glioma patient–derived neurospheres with IDH1 mutations either untreated (–) or treated with IDH-C35 for 3 days. Each line (and sample name) corresponds to a neurosphere generated from a different patient. Gene expression levels were normalized to GAPDH and are shown relative to expression levels in untreated neurosphere NCH1681. P values were obtained using 1-way ANOVA with a Newman-Keuls multiple comparisons test (A and B) and a 2-tailed, paired t test (C). *P < 0.05, **P < 0.01, ***P < 0.001; NS, P > 0.05.