Peripheral blood monocyte-derived DCs can prime KLH-specific and HIV-1 p24–specific precursors from naive CD4⁺CD45RA⁺ T cells.

(A) Autologous naive CD4⁺CD45RA⁺ T cells (left) or memory CD4⁺CD45RO⁺ T cells (right) freshly isolated from peripheral blood were stimulated with unpulsed DCs (noAg d6 and noAg d7) or with DCs pulsed with KLH, p24, or TT, at various T/DC ratios. [³H]-thymidine incorporation was measured on day 6 for TT and on day 7 for KLH and p24. Each point was done in triplicate. A representative experiment out of 3 with 3 different donors is shown. (B) Secondary stimulation. After 9 days of culture for the first stimulation, T-cell lines RA/p24, RA/KLH, and RO/TT, derived from the same donor shown in panel A, were restimulated for 3 days with DCs pulsed with p24, KLH, or TT, respectively, or with DCs pulsed with an irrelevant Ag (control), ie, KLH for RA/p24, TT for RA/KLH, and KLH for RO/TT. [³H]-thymidine was added for the last 18 hours of the assay. Each point was done in triplicate.