After 4 hours incubation at 37°C, 50 μl of the culture supernatant was harvested and radioactivity counted in a scintillation counter (Beckmann, USA). For controls, maximum chromium
release was achieved by the addition of 10% Triton-X and spontaneous release was assessed with medium alone. Percentage specific lysis was calculated as (Experimental release – spontaneous release)/(Maximum release – spontaneous NU7026 research buy release) × 100. All determinations were made in triplicate. Statistical analysis All statistical analysis was VX-661 price performed using the Statistical Program for Social Sciences (SPSS 14.0 for Windows; HKI-272 datasheet SPSS Inc., Chicago, Illinois, USA), using the Mann-Whitney test for unpaired and the Wilcoxon Signed Ranks test for paired data. A difference between two variables was considered significant when the two-tailed P value was < 0.05. Results Expression of transgenes in monocyte-derived dendritic cells following electroporation of mRNA The yield of each SP6 mMessage Machine reaction was around 20 μg of capped mRNA
from 1 μg of linear DNA template. Transcripts were extracted using RNAeasy columns and the quality of the mRNA confirmed by denaturing agarose gel electrophoresis (Figure 1b). Electroporation of 20 μg eGFP mRNA into monocyte-derived DC resulted
in 64% of DC expressing eGFP at 20 hours after transfection, as assessed by FACS analysis (Figure 1c). Monocyte-derived Unoprostone DC transfected with 20 μg GPC-3 mRNA and matured with LPS were stained with anti GPC-3 antibody (1 μg/ml) and analyzed by flow cytometry but cell surface expression of GPC-3 could not be detected (Figure 1d left panel) until DC were permeabilised, by drop-wise addition of the cells to ice cold 70% ethanol (Figure 1d right panel). These findings demonstrate that transfection of DC with the synthetic mRNA resulted in high levels of expression of GPC-3 or the control protein, eGFP. Figure 1 Expression of transgenes in monocyte-derived dendritic cells following transfection by electroporation of mRNA. a. Diagram of expression vector between SP6 transcription initiation site and SnaB1 restriction enzyme site. b. Denaturing agarose gel showing in vitro transcribed eGFP and GPC-3 mRNA. c. eGFP expression in monocyte-derived DC as determined by flow cytometry, 20 hours after mock transfection (filled area) or transfection with 20 μg eGFP mRNA (open area), when 64% of DC were positive for eGFP. d.