Fig. 1

Comparison of T-cell responses after intranodal immunization with NP mRNA or intramuscular immunization with NP DNA. a BALB/c mice were immunized every 2 weeks for a total of three immunizations with 50 µg of intranodally delivered mRNA encoding NP, 100 µg intramuscularly delivered DNA encoding NP or 0.8 RL intranodally (vehicle). Analysis of in vivo cytotoxic T-cell responses (b, c) and ex vivo IFN-γ production (d) was assessed 4 days after the last immunization. b, c In vivo antigen-specific lysis of CellTrace Violet (CTV)-labelled NP peptide-loaded target cells was assessed in lymph nodes (b) and spleens (c). Histograms show the lysis of target cells and are representative for each group. d Ex vivo IFN-γ responses assessed by ELISPOT from splenocytes isolated from vaccinated animals and re-stimulated with NP peptide. Results from each experiment are shown as median ± interquartile range (IQR) with each symbol representing one mouse for a total of 4–8 mice per experiment. Differences between groups were analyzed by Mann–Whitney U test (b), Student’s t test (c), or one-way ANOVA (d)