Immune cell infiltration into brain tumor microenvironment is mediated by Rab27-regulated vascular wall integrity.

ABSTRACT: Aggressive brain tumors often exhibit immunologically 'cold' microenvironment, where the vascular barrier impedes effective immunotherapy in poorly understood ways. Tumor vasculature also plays a pivotal role in immunoregulation and antitumor immunity. Here, we show that small GTPase Rab27 controls the vascular morphogenesis and permeability for blood content and immune effectors. Thus, in Rab27a/b double knock out (Rab27-dKO) mice, the brain vasculature is abnormally scarce, while the blood vessels become dysmorphic and hyperpermeable in the context of brain tumors, including syngeneic glioblastoma. These defects are reflected in rearrangements of endothelial cell subpopulations with underlying diminution of venous endothelial subtype along with changes in gene and protein expression. Not

SUBMITTER: Adnani L 

PROVIDER: S-EPMC12101492 | biostudies-literature | 2025 May

REPOSITORIES: biostudies-literature