Transfected MDDCs stimulate PBMC T cells ex vivo. PBMCs from an HIV⁺ subject were incubated in an overnight IFNγ ELISpot assay with or without transfected autologous DCs. DCs were transfected with 10 μg/10⁶ DCs of consensus nef mRNA or were mock transfected. PBMCs without DCs were incubated with or without a Nef peptide pool matched to the RNA sequence. Each well contained 100 000 PBMCs. The PBMC/DC ratio was 10:1. (A) Digital images of replicate ELISpot wells. (B) Mean response of wells shown in panel A counted with an automated plate reader. Error bars represent 1 standard deviation; SFC, spot-forming cells.