DCs nucleofected with OVA-encoding plasmids activate antigen-specific T cells. At 20 hours after the nucleofection, DCs were collected and used to activate either OT-I (CD8) or OT-II (CD4) T cells. OT-I (A-C) and OT-II (D-F) T-cell activation was measured using thymidine incorporation (panels A and D) or IFN-γ production (panels B and E), respectively. n.d. indicates not detectable. Number of DCs used was 1000, 2500, or 5000, from top to bottom in each panel. (C) In vitro proliferation of CFSE-labeled OT-I T cells was analyzed at day 6. DCs (5000) were nucleofected with pGO (black histogram, top panel) or with psigGOL1tail (black histogram, bottom panel) or with pG (gray open histogram, both panels). (F) In vivo proliferation of CFSE-labeled OT-II T cells at day 6 stimulated by 5000 DCs nucleofected with psigGOL1tail (black histogram) or with pG (gray open histogram) was also analyzed using CFSE dilution assay at day 6. (G) In vivo proliferation of adoptively transferred CFSE-labeled OT-I (top panels) and OT-II (bottom panels) cells 5 days after vaccination with 1 × 106 DCs nucleofected with pGO (left panels) or psigGOL1tail (right panels). In panels A, B, D, and E, results are the mean ± standard error of mean of 3 individual experiments.
