Figure 6. HSPCs proliferate and give rise to myeloid cells in peripheral tissues particularly in response to TLR ligands.

A-B, Distinct TD- or BM-derived HSPC-enriched populations were implanted under the left kidney capsule of WT mice with medium or LPS with or without preincubation for 12h as indicated. Medium or LPS without cells was injected under the contralateral control kidney capsule. A, Quantitative analysis of the total number of GFP⁺ cells (G) and of GFP⁺ myeloid cells (M) in the left (empty bars and filled circles) and in the right (control, open circles) kidney. ^*P<0.05 vs. control kidney, ^#P<0.05 vs. medium, n=3 experiments, mean±SEM. B, Representative confocal images showing expression of GFP and reactivity with a mixture of mAbs to myeloid markers (CD11c, CD11b, F4/80, Gr-1) 6 days after implantation. Bars represent 50μm. C, Detection of GFP⁺ (donor-derived) CFU-C within the BM (left) and PB (right) after implantation of Lin-c-Kit⁺Sca-1⁺ cells preincubated with medium or LPS for 12h. Mean±SEM, n=3 experiments. D-E, 10⁴ HSPC-enriched Lin⁻c-Kit⁺ GFP⁺ cells were implanted into the left kidney capsule of WT recipient mice together with LPS. D, Representative micrographs showing the expression of GFP, Gr-1, CD11c, or the PDC marker 120G8 in the kidney 6 days later. Bars represent 50μm. E, Relative subset frequencies among GFP⁺ cells in serial kidney sections, n=3 experiments, mean±SEM. F, Representative confocal images showing expression of GFP, incorporation of BrDU and expression of Ki-67 6 days after implantation of the indicated HSPC populations. Bars represent 10μm. Arrows indicate GFP⁺ BrDU⁺ cells, arrow heads show GFP⁻ BrDU⁺ cells.