Meningiomas are common brain tumors that are treated with surgery and occasional post-operative radiation, with no effective adjuvant therapies for patients with refractory disease. Recent efforts have identified a surprising degree of cellular heterogeneity within meningiomas, including unique immunological populations with potential therapeutic implications. However, the functional role of these cells in shaping meningioma biology remains poorly understood, preventing selection of rationale treatment approaches and translation into clinical trials. In this study, we extend immunological analyses from recent single-cell RNA sequencing of meningiomas, including spatial interrogation of key markers and cell populations using multi-protein immunofluorescence. By inferring cell functional states and local molecular interactions, we identify phagocytic macrophages as a crucial immuno-suppressive population in meningiomas, associated with expression of LAIR-1 and TIM3. Additionally, we observed wide distribution of the immune-activating STING protein across meningioma tissues, suggesting an additional therapeutic approach that may trigger local adaptive responses. Our work offers future directions for immunotherapy research and clinical translation in these common tumors.
