CD8α⁺ and CD8α⁻ DCs induce distinct memory responses in vivo. Balb/c mice were either left untreated (I) or were primed with KLH-pulsed CD8α⁺, CD8α⁻, or the combination 14 d earlier, and boosted with unseparated DCs, pulsed with the same antigen. LN cells were harvested 2 d later and cultured with (a) graded doses or (b–f) 10 μg/ml KLH. Proliferation (a) and lymphokine production (b–f) were measured as indicated in Materials and Methods. Figure summarizes the results (mean ± SD) obtained in four independent experiments.