HPCs from Notch-1–deficient mice had reduced capacity to differentiate into DCs. (A-B) HPCs were isolated from control or Notch-1–deficient Notch-AS-Tg mice and incubated with 200 ng/mL FL and 10% splenocyte-conditioned medium for 10 days. LPS (1 μg/mL) was added 24 hours before cell phenotype analysis. Cells were labeled with APC-conjugated anti-CD11c, PE-conjugated anti-CD11b, and FITC-conjugated anti-IA^b, anti–B7-2, or CD40 antibodies. Proportions of IA^b+, B7-2⁺, or CD40⁺ cells were calculated within the populations of CD11c⁺CD11b+ myeloid DCs and CD11c+CD11b-lymphoid DCs. Results of 3 performed experiments are shown. Differences between control and Notch-As-Tg mice within populations of lymphoid and myeloid DCs were statistically significant (P < .05). (C-D) DCs were generated from HPCs as described. The same 2 populations of DCs were sorted using FACSVantage SE cell sorter, irradiated at 150 Gy, and cultured with lymph node (LN) cells isolated from control allogeneic BALB/c mice. Cell proliferation was measured in triplicate. Values are the average ± SE from 3 experiments. Differences between values in control and Notch-AS-Tg mice were statistically significant at all LN cell/DC ratios (P < .05).