Project description:Gliomas are incurable malignancies notable for an immunosuppressive microenvironment with abundant myeloid cells whose immunomodulatory properties remain poorly defined. Here, utilizing scRNA-seq data for 183,062 myeloid cells from 85 human tumors, we discover that nearly all glioma-associated myeloid cells express at least one of four immunomodulatory activity programs: Scavenger Immunosuppressive, C1Q Immunosuppressive, CXCR4 Inflammatory, and IL1B Inflammatory. All four programs are present in IDH1 mutant and wild-type gliomas and are expressed in macrophages, monocytes, and microglia whether of blood or resident myeloid cell origins. Integrating our scRNA-seq data with mitochondrial DNA-based lineage tracing, spatial transcriptomics, and organoid explant systems that model peripheral monocyte infiltration, we show that these programs are driven by microenvironmental cues and therapies rather than myeloid cell type, origin, or mutation status. The C1Q Immunosuppressive program is driven by routinely administered dexamethasone. The Scavenger Immunosuppressive program includes ligands with established roles in T-cell suppression, is induced in hypoxic regions, and is associated with immunotherapy resistance. Both immunosuppressive programs are less prevalent in lower-grade gliomas, which are instead enriched for the CXCR4 Inflammatory program. Our study provides a framework to understand immunomodulatory myeloid cells in glioma, and a foundation to develop more effective immunotherapies.
Project description:Tissue resident macrophages can arise from either embryonic or adult hematopoiesis and play important roles in a wide range of biological processes, such as tissue remodeling during organogenesis, tissue homeostasis in the steady state, tissue repair following injury, and immune response to pathogens. Although the origins and tissue-specific functions of resident macrophages have been extensively studied in many other tissues, they are not well characterized in skeletal muscle. In the present study, we have characterized for the first time the ontogeny of skeletal muscle resident macrophages, showing evidence that they arise from both embryonic hematopoietic progenitors, including yolk sac primitive macrophages and fetal liver monocytes, and adult bone marrow hematopoietic stem cells. Single cell-based transcriptome analysis revealed that skeletal muscle resident macrophages were highly distinctive from resident macrophages in other tissues, expressing a specific set of transcription factors and containing functionally diverse subsets correlating to their origins. They appear more active in maintaining tissue homeostasis and promoting muscle growth and regeneration.
Project description:This phase I trial studies the side effects and best dose of pembrolizumab and to see how well it works in treating younger patients with high-grade gliomas (brain tumors that are generally expected to be fast growing and aggressive), diffuse intrinsic pontine gliomas (brain stem tumors), brain tumors with a high number of genetic mutations, ependymoma or medulloblastoma that have come back (recurrent), progressed, or have not responded to previous treatment (refractory). Immunotherapy with monoclonal antibodies, such as pembrolizumab, may induce changes in the body’s immune system, and may interfere with the ability of tumor cells to grow and spread.
Project description:We carried out the analyses of chromosome variations between low-grade and high-grade gliomas in Chinese population. We found out the differences in chromosomes, cytobands, genes, pathways and GO functions. To identify the glioma tissue-specific genomic alterations and compare the genomic variations between low-grade and high-grade gliomas.
Project description:The transcription factor IRF4 is crucial for the fate determination of pro-inflammatory T helper (Th)17 and the functionally opposing group of immunomodulatory regulatory T (Treg) cells. However, molecular mechanisms of how IRF4 steers diverse transcriptional programs in Th17 and Treg cells are far from being definitive. To unveil IRF4-driven lineage determination, we integrated data derived from affinity-purification and full mass spectrometry-based proteome analysis with chromatin immune precipitation sequencing. This allowed the characterization of subtype-specific molecular programs and the identification of IRF4 interactors in the Th17/Treg context. Our data reveal that IRF4-interacting transcription factors are recruited to IRF composite elements for the regulation of cell type-specific transcriptional programs as exemplarily demonstrated for FLI1, which in cooperation with IRF4 promotes Th17-specific gene expression. Inhibition of FLI1 markedly impaired Th17-differentiation. The present ‘omics’ dataset provides a valuable resource for studying IRF4-mediated gene regulatory programs in pro- and anti-inflammatory immune responses.
Project description:We have used Illumina Infinium HumanMethylation450 BeadChip array profiling to profile paediatric high grade gliomas and diffuse intrinsic pontine gliomas. The 450K methylation array is being used to separate brain tumour samples on the basis of their methylation profiles which represent the cell of origin the time and place in which tumours arise. Methylation arrays provide data for an integrated molecular diagnosis of brain tumours and define specific molecular subgroups and subtypes of high grade gliomas carrying distinct driver mutations and patterns of somatic alterations. These data form part of an integrated meta-analysis of high grade gliomas in children combining DNA copy number, methylation and high throughput sequencing datasets.