Single-Cell Transcriptomics Revealed Subtype-Specific Tumor Immune Microenvironments in Human Glioblastomas.

Area of Science:

• Oncology
• Immunology
• Genomics

Background:

• Human glioblastoma (GBM) is an aggressive brain tumor with significant cellular heterogeneity.
• The complex interactions within the GBM tumor microenvironment (TME) remain incompletely understood.

Purpose of the Study:

• To systematically characterize the cellular milieu and subtype interactions within the GBM TME.
• To identify the roles of distinct GBM cell subtypes and associated immune cells in shaping the TME.

Main Methods:

• Single-cell transcriptome sequencing of primary GBM tumors from 7 patients.
• Lineage relationship analysis to trace cellular origins and states.
• Identification and characterization of tumor-associated macrophages/microglia (TAMs) subsets.

Main Results:

• Identified neural-progenitor-2-like (NPC2-like) cells associated with tumor origin and high metabolic activity.
• Mesenchymal-like (MES1/MES2-like) GBM cells correlated with immune infiltration and hypoxia.
• Discovered TAM-1 subset linked to hypoxia, angiogenesis, invasion, and poor prognosis.
• All GBM cell states promoted M2-type TAM polarization and immunosuppression via 10 ligand-receptor pathways.

Conclusions:

• GBM cell subtypes differentially influence the tumor immune microenvironment.
• Specific GBM cell states and TAM subsets are critical drivers of tumor progression and immunosuppression.
• Findings offer potential for patient stratification and personalized glioblastoma therapies.