Expression data for tumor-infiltrating CD45+ cells

Regulatory T (Treg) cells are crucial for immune homeostasis but they also contribute to tumor immune evasion by promoting a suppressive tumor microenvironment (TME). Mice with Treg cell-restricted Neuropilin 1 deficiency show tumor resistance while maintaining peripheral immune homeostasis, thereby providing a controlled system to interrogate the impact of intratumoral Treg cells on the TME. Using this and other genetic models, we showed that Treg cells shaped the transcriptional landscape across multiple tumor-infiltrating immune cell types. Treg cells suppressed CD8+ T cell secretion of interferon- (IFN), which would otherwise block the activation of sterol regulatory element-binding protein 1 (SREBP1)-mediated fatty acid synthesis in immunosuppressive (M2-like) tumor-associated macrophages (TAMs). Thus, Treg cells indirectly but selectively sustained M2-like TAM metabolic fitness, mitochondrial integrity and survival. SREBP1 inhibition augmented the efficacy of immune checkpoint blockade, suggesting that targeting Treg cells or their modulation of lipid metabolism in M2-like TAMs could improve cancer immunotherapy. Microarray gene expression assay was performed to interogate the impact of fragile (Nrp1–/–) Tregs on the gloabal transcriptome oftumor immune infiltrates (CD45+ cells) at various time points over the course of tumor growth. B16. F10 or MC38 tumor -infiltrating CD45+ cells isolated from the Foxp3Cre-YFP or Nrp1L/LFoxp3Cre-YFP mice on designated days over the course of tumor growth