Figure 3.

HLA-DR⁺lin⁻IL-3Rα^hi DC are present in peripheral blood. (A and B) PBMC were stained with anti-HLA-DR, anti-IL-3Rα, and lineage markers (not shown) and analyzed by flow cytometry as described in Fig. 1 A–C. R1 and R2 in B represent regions used to sort IL-3Rα^hi blood cells that were positive or negative for HLA-DR, respectively. (C and D) HLA-DR⁺lin⁻IL-3Rα^hi cells sorted from blood according to R1 in B were first cultured separately with IL-3 and GM-CSF for 36 h and then incubated with allogeneic (C) or autologous (D) CD4⁺ T cells. T cell proliferation was measured as total number of CD3⁺BrdU⁺ cells per well at day 6 of coculture with indicated numbers of IL-3Rα^hilin⁻HLA-DR⁺ cells (▪) or CD14^hi monocytes (○) from the same donor (stimulator cells). Individual displays show data that are representative of three experiments. OLS, ortogonal light scatter.