Phenotype of DCs derived in vitro from CD34^hiCD33^lo intrathymic precursors or resident in vivo in the human postnatal thymus.

(A) Representative flow cytometry profile of DCs derived by day 10 from sorted CD34^hiCD33^lo human thymic precursors set up in multicytokine-supported cultures (shaded histograms). (B) Identification of 2 distinct subsets of DCs resident in the human postnatal thymus based on reciprocal expression of CD13 and IL-3Rα. Electronic gates were set on sorted HLA-DR⁺ large-sized thymocytes as shown in the biparametric plot, and then IL-3Rα expression was analyzed on gated Lin⁻CD13⁺(gate I) or Lin⁻CD13⁻(gate II) cells (shaded monoparametric histograms). (C) Representative flow cytometry profile of Lin⁻CD13⁺ IL-3Rα⁻ (shaded histograms) or Lin⁻CD13⁻IL-3Rα⁺ (unshaded histograms) HLA- DR⁺ thymic DCs gated as shown in (B). Background fluorescence (unshaded histograms in A and B, and dashed histograms in C) was determined with isotype-matched irrelevant MoAbs.