Fig 3. Arginase 1 expression in chimeric mice.

Bone marrow cross transplant experiments were performed between donor wild-type (WT) and recipient CX₃CR₁^GFP mice. After recovery, mice were implanted with intracranial GL261 tumors and analyzed by A) flow cytometry and B) histochemistry 10 days later. Tumor-associated microglia (MG), identified as CD11b⁺/CD45^low (A) and GFP⁺ cells (B), were located around tumor periphery and were mostly Arg1^-. In the reverse transplantation experiments, WT recipient mice were transplanted with CX₃CR₁^GFP bone marrow prior to tumor implantation. C) Glioma-associated macrophages (MP) were identified as CD11b⁺/CD45^high and D) as GFP⁺ cells and were mostly Arg1⁺. n = 3 mice/group ± SD.