Fig. 1

Outcome of GFP⁺ BM transplantation at 3 or 12 months of age followed by identification of GFP⁺ cells at 15 months of age. A GFP⁺ BM was transplanted into Tg2576 mice or WT littermates at 3 months and GFP⁺ cell identity determined at 15 months of age (See Fig. S1 for WT groups). In Tg2576 mice, GFP⁺ cells were seen surrounding cerebral blood vessels, which were also positive for the BAM marker CD206, as well in the parenchyma, which had the morphology of microglia and were strongly Iba1⁺. B GFP⁺ BM was transplanted in Tg2576 mice or WT littermates at 12 months and GFP⁺ cell identity determined at 15 months of age. In Tg2576 mice, GFP⁺/CD206⁺ cells were seen surrounding cerebral blood vessels, no GFP⁺/Iba1⁺ were observed in the brain parenchyma. In A,B, arrows indicate co-localization and arrowheads no co-localization. C Number of GFP⁺ and CD206⁺ cells, % GFP⁺CD206⁺ cells, number of Iba1⁺ cells, and % GFP⁺/Iba1⁺ cells at 15 months of age after BM transplant at 3 or 12 months. Of note, in agreement with a previous study [58] we did not observe an increase in microglial cels in Tg2576 mice transplanted at 12 months of age. N = 4–5/group; Two-way ANOVA with Tukey’s test; mean ± SEM; scale bars in A and B, 200 µm and 50 µm; data presented as mean ± SEM