All animal procedures were performed in accordance with NIH and University of California guidelines approved IAUC protocols (IAUC #2011-3004). MITRG mice were purchased from Jax (The Jackson Laboratory, #017711) and have been previously characterized (Rongvaux et al., 2014). MITRG mice allow for xenotransplantation and is designed to support human myeloid engraftment. iMGLs were harvested at day 38 and suspended in injection buffer: 1X HBSS with M-CSF (10 ng/ml), IL-34 (50 ng/ml), and TGFβ-1 (25 ng/ml). iMGLs were delivered using stereotactic surgery as previously described (Blurton-Jones, et al, 2009) using the following coordinates; AP: −0.6, ML: ± 2.0, DV: −1.65. Brains were collected from mice at day 60 post-transplantation per established protocols (Blurton-Jones, et al, 2009). Rag5xfAD mice were generated in this lab and previously characterized (Marsh et al., 2016). Rag5xfAD mice display robust beta-amyloid pathology and allow for xenotransplantation of human cells. iMGLs were transplanted into the hippocampi using the following coordinates; AP: −2.06, ML: ± 1.75, DV: −1.95. After transplantation mice were killed and brains collected using previously established protocol. Briefly, mice were anesthetized using sodium-barbiturate and perfused through
