Fig. 1

Human macrophages survive in vivo for up to two weeks post-injection following brain injection. (a) Schematic of experimental design: primary monocytes were differentiated into macrophages before injection into the zebrafish brain at age 2 days post fertilization (dpf) and imaged at 1, 7 and 14 days post injection (dpi). (b) Micrographs of representative whole larva at 3 dpf (left) and 3D projections showing distribution and survival of human primary macrophages (blue) injected into the hind brain of transgenic mpx:GFP (neutrophils-green)/flk:mCherry (vessels-red) zebrafish larvae at 1 dpi (3 dpf) (right). (c) Micrographs of representative whole larva at 9 dpf (left) and 3D projections showing distribution and survival of human primary macrophages (blue) injected into the hind brain of transgenic mpx:GFP (neutrophils-green)/flk:mCherry (vessels-red) zebrafish larvae at 7 dpi (9 dpf) (right). (d) Micrographs show that cells can persist for up to 2 weeks after injection at 16 dpf. Top panel: representative zebrafish at 16 dpf. Left panel: micrograph shows tiled image of transgenic mpx:GFP (neutrophils-green)/flk:mCherry (vessels-red) 16 dpf zebrafish, white square highlights region of interest in the zebrafish brain. Right panel: micrograph of the inset where the white arrows indicate human cells. Scales are indicated on each image.