The effect of TGF-β1 on the generation of mature DCs and the expression of CIITA mRNA in Lin⁻c-kit⁺ HPC cultures stimulated with various combinations of cytokines at day 12. (A) The histogram quads, which were set up on the isotype-matched control dot plot, and (B) the percentage of Ia⁺CD86⁺ cells generated from GM-CSF + SCF + TNF-stimulated Lin⁻c-kit⁺ HPCs. The data represent the mean value ± SD of the percentage of Ia⁺CD86⁺ cells. *P < .05 significance as compared with the cultures without the addition of TGF-β1. The results are representative of more than five experiments. (C) Allogenic MLR induced by Lin⁻c-kit⁺ HPC cultures in the presence of the indicated combination of cytokines at day 12. Results are expressed as the mean ± 1 SD of triplicate cultures and are representative of three independent experiments. (D) The expression of CIITA mRNA in various combination of cytokine-stimulated Lin⁻c-kit⁺ HPCs as indicated at day 12, which represents three independent experiments. (*Lin⁻c-kit⁺ HPCs were cultured in the presence of GM-CSF + SCF + TGF-β1 for 12 days and then recultured in the presence of GM-CSF + TNF for an additional 3 to 5 days.)