ABSTRACT
T cells are critical effectors of cancer immunotherapies, but little is known about their gene expression programs in diffuse gliomas. Here, we leverage single-cell RNA sequencing (RNA-seq) to chart the gene expression and clonal landscape of tumor-infiltrating T cells across 31 patients with isocitrate dehydrogenase (IDH) wild-type glioblastoma and IDH mutant glioma. We identify potential effectors of anti-tumor immunity in subsets of T cells that co-express cytotoxic programs and several natural killer (NK) cell genes. Analysis of clonally expanded tumor-infiltrating T cells further identifies the NK gene KLRB1 (encoding CD161) as a candidate inhibitory receptor. Accordingly, genetic inactivation of KLRB1 or antibody-mediated CD161 blockade enhances T cell-mediated killing of glioma cells in vitro and their anti-tumor function in vivo. KLRB1 and its associated transcriptional program are also expressed by substantial T cell populations in other human cancers. Our work provides an atlas of T cells in gliomas and highlights CD161 and other NK cell receptors as immunotherapy targets.
Subject(s)
Glioma/immunology , NK Cell Lectin-Like Receptor Subfamily B/genetics , T-Lymphocytes/immunology , Animals , Antigens, Neoplasm , Disease Models, Animal , Gene Expression Profiling , Glioma/genetics , Killer Cells, Natural/immunology , Lectins, C-Type/genetics , Lymphocytes, Tumor-Infiltrating/immunology , Mice , Receptors, Cell Surface/genetics , Single-Cell Analysis , T-Lymphocyte Subsets/immunology , T-Lymphocytes/cytology , Tumor EscapeABSTRACT
Diverse genetic, epigenetic, and developmental programs drive glioblastoma, an incurable and poorly understood tumor, but their precise characterization remains challenging. Here, we use an integrative approach spanning single-cell RNA-sequencing of 28 tumors, bulk genetic and expression analysis of 401 specimens from the The Cancer Genome Atlas (TCGA), functional approaches, and single-cell lineage tracing to derive a unified model of cellular states and genetic diversity in glioblastoma. We find that malignant cells in glioblastoma exist in four main cellular states that recapitulate distinct neural cell types, are influenced by the tumor microenvironment, and exhibit plasticity. The relative frequency of cells in each state varies between glioblastoma samples and is influenced by copy number amplifications of the CDK4, EGFR, and PDGFRA loci and by mutations in the NF1 locus, which each favor a defined state. Our work provides a blueprint for glioblastoma, integrating the malignant cell programs, their plasticity, and their modulation by genetic drivers.
Subject(s)
Brain Neoplasms/genetics , Cell Plasticity/genetics , Glioblastoma/genetics , Adolescent , Aged , Animals , Brain Neoplasms/pathology , Cell Line, Tumor , Cell Lineage/genetics , Child , Cohort Studies , Disease Models, Animal , Female , Genetic Heterogeneity , Glioblastoma/pathology , Heterografts , Humans , Infant , Male , Mice , Mice, Inbred C57BL , Mice, Inbred NOD , Middle Aged , Mutation , RNA-Seq , Single-Cell Analysis/methods , Tumor Microenvironment/geneticsABSTRACT
Gliomas with histone H3 lysine27-to-methionine mutations (H3K27M-glioma) arise primarily in the midline of the central nervous system of young children, suggesting a cooperation between genetics and cellular context in tumorigenesis. Although the genetics of H3K27M-glioma are well characterized, their cellular architecture remains uncharted. We performed single-cell RNA sequencing in 3321 cells from six primary H3K27M-glioma and matched models. We found that H3K27M-glioma primarily contain cells that resemble oligodendrocyte precursor cells (OPC-like), whereas more differentiated malignant cells are a minority. OPC-like cells exhibit greater proliferation and tumor-propagating potential than their more differentiated counterparts and are at least in part sustained by PDGFRA signaling. Our study characterizes oncogenic and developmental programs in H3K27M-glioma at single-cell resolution and across genetic subclones, suggesting potential therapeutic targets in this disease.
