Figure 2. Dermal CD5⁺ DCs are more efficient than their CD5^– counterparts at priming CTLs.

(A) Allogeneic naive CD8⁺ T cells primed with sorted CD40L-activated skin dermal CD5⁺ or CD5^– CD1a^dim DCs, dermal CD1a^dimCD141⁺ DCs, or dermal CD14⁺ DCs at ratio 1:40 for 7 days. The graph shows the percentage of proliferating (CFSE^lo) CD3⁺CD8⁺ T cells (n = 15). Mean ± SD ± SEM for CD5⁺: 53.7% ± 26.6% ± 6.8%, CD5^–: 36.4% ± 20.7% ± 5.3%, CD141⁺ DCs: 20.2% ± 16.1% ± 5.3%, CD14⁺ DCs: 15.1% ± 17% ± 5.6%. (B) Allogeneic CFSE-labeled naive CD8⁺ T cells primed for 7 days by each dermal skin mDC subset were stained and analyzed by flow cytometry for the expression of granzyme B. The percentage of cells that diluted CFSE and expressed granzyme B is shown. One of 8 experiments is shown. (C) The plot shows the percentage of cells primed by each of the mDC subsets and expressed granzyme B (n = 8). (D) The plots show the expression of IFN-γ and TNF-α by naive CD8⁺ T cells that were primed by either dermal CD5⁺ or CD5^– DCs. CD8⁺ T cells primed by the dermal CD14⁺ DCs are shown as a control. One of 5 experiments is shown. (E) CFSE^loCD8⁺ T cells that were primed by either dermal CD1a^dimCD5⁺ or CD5^– DCs were reactivated by anti-CD3 and anti-CD28 mAbs for 18 hours. IFN-γ was measured in the culture supernatant by a Luminex magnetic bead assay. The graph shows the pooled results of 4 experiments. Data represent mean ± SEM; **P < 0.01, ****P < 0.0001 by paired Student’s t tests (A, C, and E).