DCs sorted by expression of maturation and costimulatory molecules differentially contribute to the frequency and phenotype of the primary Melan-A specific CD8⁺ T-cell response. (A) Frequency of DC subpopulations expressing combinations of the CD83, CD80, and CD86 molecules after maturation with the indicated reagent. DC subpopulations from one representative experiment are shown with DCs gated by FSC/SSC, and the specific populations sorted for subsequent experiments are indicated by the boxes. Similar results were obtained from 5 independent donors. (B-C) Data are from one donor representative of 3 independent sorting experiments showing the mean percentage of CD8⁺/Melan-A pentamer⁺ cells (B) and the absolute number of Melan-A specific CD8⁺ T cells displaying dual expression of CD27 and CD28 (C) after priming by sorted DC subpopulations (± SEM). Quantitation of cell numbers and the phenotype of Melan-A specific cells were determined 9 days after priming. **Statistically significant differences with P values shown.