Fig. 3.

Increased in vivo FL rescues B-cell commitment in the absence of IL-7 and/or TSLP. (A) In vitro limiting dilution analysis of Ly6D⁺ EPLM B-cell potential. Ly6D⁺ EPLM were sorted from WT, Il7^−/−, Flt3ltg, and Flt3ltg-Il7^−/− mice and plated at the indicated concentrations on OP9 stromal cells together with IL-7. One representative out of four independent experiments is shown. (B) RT-qPCR analysis showing expression of Ebf1, Pax5, and Foxo1 mRNAs in Ly6D⁺ EPLM sorted from the indicated mouse genotypes. Bars show fold expression relative to WT (set as 1). Error bars represent the SEM from three to six independent experiments. (C) Representative FACS plots showing expression of Ebf1 protein within the Ly6D⁺ EPLM of the indicated WT or mutant mice. (D) Percentages of Ebf1-expressing Ly6D⁺ EPLM from WT (n = 7), Il7^−/− (n = 3), Flt3ltg (n = 11), and Flt3ltg-Il7^−/− (n = 6) mice. Bars show mean ± SEM (E) Ly6D⁺ EPLM (Left), and CD19⁺CD117⁺ (Right) numbers from WT (n = 5), Il7^−/− (n = 5), Flt3ltg (n = 3), and Flt3ltg-Il7^−/− (n = 5) mice, as well as from Il7^−/− (n = 5) and Il7rα^−/− (n = 6) mice injected intraperitoneally with 10 daily doses of 10 μg FL each (indicated as +FL) or PBS (+PBS, n = 4). Shown is the mean ± SEM. n.s., not significant, **P ≤ 0.01, ***P ≤ 0.001.