IGSF11-VISTA is a critical and targetable immune checkpoint axis in diffuse midline glioma

Diffuse midline glioma (DMG) is an aggressive pediatric brain tumor with no curative treatment, and lacks a comprehensive understanding of immune-tumor cell interactions within their spatial context. Our multi-omics approach, integrating single-nuclei RNA sequencing, spatial transcriptomics, and high-dimensional imaging, utilizes patient samples and an experimental murine DMG model to unveil two spatially distinct regions. MES-patterns are defined by mesenchymal (MES) tumor cells and blood-derived immune cells, whereas AOO-patterns are enriched with astrocyte (AC)-, oligodendrocyte (OC)-, and oligodendrocyte precursor cell (OPC)-like cancer populations, alongside homeostatic-like microglia. The less-studied immune checkpoint, IGSF11, is primarily expressed by AOO-associated cancer cells, while its receptor VISTA is detected mainly in homeostatic microglia. Targeting IGSF11-VISTA results in tumor reduction and survival benefit, mediated by brain-resident microglia and independent of T cell infiltration. This positions IGSF11-VISTA as a promising immune checkpoint treatment axis to harness the local brain immune response against DMG.