Figure 1. Identification of Langerhans cells and dermal DC subsets in human skin.

(A) Top: Expression of CD1a and CD14 on purified skin DCs defines epidermal CD1a⁺ LCs, dermal CD1a^dim DCs, and dermal CD14⁺ DCs subpopulations. Bottom: Expression of CD5 defines subpopulations of CD1a^hiLangerin⁺ LCs and dermal CD1a^dimCD141^– DCs. (B) Relative representation of each human DC subset in normal skin (n = 33). The percentage of individual DC subsets mean ± SD ± SEM of the total migrating DCs (HLA-DR⁺CD3/19/56^–) cells is plotted. Epidermal CD5⁺ LCs: 6.0% ± 6.15% ± 1.05%; CD5^– LCs: 26.9% ± 20.4% ± 3.4%; dermal CD1a^dim DCs, CD5⁺: 15.8% ± 12.6% ± 2.16%; CD5^–: 37.6% ± 18.9% ± 3.2%; CD141⁺: 1.09% ± 2% ± 0.3%; dermal CD14⁺ DCs: 10.2% ± 7.6% ± 1.3%. (C) Morphology of sorted skin CD5⁺ LCs, CD5^– LCs, dermal CD1a^dimCD5⁺ DCs, CD1a^dimCD5^– DCs, CD1a^dimCD141⁺ DCs, and CD14⁺ DCs visualized by GIEMSA staining. Scale bar: 10 μM. (D) HLA-DR⁺CD11c⁺CD14^–CD1c⁺CD5⁺ and CD5^– DCs from skin epidermis, dermis, blood, and in vitro–differentiated cultures were analyzed for the expression of CD1a, CD11b, Langerin, CD83, CD86, CCR7, and HLA-DR. The plot shows GeoMean intensity, with values of the background staining subtracted. The mean values obtained for 2–4 donors are plotted. (E) Dermal CD1a^dimCD5⁺ and CD5^– DCs were sorted and stimulated as indicated. Histograms show expression of CD5 on the cells after 6 days of stimulation (red histograms). One representative of 3 donors is shown.