Fig. 3.

IL7Rα^−/− and Flk2^−/− HSCs had impaired tissue-resident lymphoid cell reconstitution compared with WT HSCs. (A) Schematic of experimental design: 500 WT, Flk2^−/−, IL7Rα^−/− or FIDKO HSCs were transplanted into sublethally irradiated fluorescent WT recipients (mTmG or UBC-GFP) and donor contribution of TLCs was quantified 16 weeks post transplantation. (B) Reconstitution of peripheral blood B cells was significantly impaired upon transplantation of Flk2^−/− (white bars), IL7Rα^−/− (red bars) or FIDKO HSCs (red/white bars) compared with WT HSCs (gray bars). Quantification of donor chimerism of traditional B cells in the peripheral blood. (C-F) Donor chimerism of TLCs significantly reduced from IL7Rα^−/− (red bars) and FIDKO (red square bars) donor HSCs compared with WT (gray bars) donor HSCs. Quantification of donor chimerism of B1a cells (C), MZBs (D), ILC2s (E) and Tregs (F). (C′-F′) Cellularity of B1a and MZB cells were significantly reduced from Flk2^−/− (white bars), IL7Rα^−/− (red bars) and FIDKO (red/white bars) donor HSCs compared with WT (gray bars) donor HSCs. Cellularity of lung ILC2 and Tregs were significantly reduced from IL7Rα^−/− (red bars) and FIDKO (red/white bars), but not Flk2^−/− (white bars), donor HSCs compared with WT (gray bars) donor HSCs. Quantification of total B1a cells (C′), cells/gram spleen of MZBs (D′), cells/gram lung ILC2s (E′) and cells/gram of lung tissue Tregs (F′). WT n=8 (6 male), Flk2^−/− n=12 (8 male), IL7Rα^−/− n=7 (4 male), FIDKO n=4 (3 male), representing a minimum of four independent experiments, mean±s.e.m. Differences were analyzed with unpaired two-tailed Student's t-test: *P<0.05, **P<0.005, ***P<0.0005.