Figure 2

CD8⁺ T-cell responses after priming with DEC-205 targeted DNA vaccines in the presence of costimulatory adjuvants and boosting with an adenoviral vector. Mice were primed with DEC-Ova or Con-Ova in the presence or absence of the indicated adjuvants (Adj.) prior to boosting with adenoviral vectors encoding ovalbumin (Ad-Ova) or GFP (Ad-GFP). The percentage of SIINFEKL/H-2K^b tetramer positive cells (A, C, E, F) and IFN-γ and CD107a double-positive cells after stimulation with the SIINFEKL peptide (B, D) were determined after the boost. Unless stated otherwise, DEC-Ova and Con-Ova were used at a dose of 50 μg. A, B, F) Fifty μg of plasmids encoding a soluble trimer (CD40L¹), a dimeric form (CD40L²) or a tetrameric form of that trimer (CD40L⁴) were co-administered with the DNA vaccine. C, D, F) CpG, Poly I:C or the combination of CpG and Poly I:C (CpI:C) were coinjected with the plasmids as indicated. E) CpI:C was added during DNA priming. Mean percentages with SEM of two independent experiments with a total of eight mice/group are shown (A-D). Mean percentages and SEM of one experiment with four (E) and six (F) mice per group are shown. For reason of clarity, the level of significance in the Bonferroni Multiple Comparison test is only indicated for selected group to group comparisons (* p < 0.05; ** p < 0.01; ***p < 0.001).