Our studies examining the interaction of VLPs with DCs indicate that while improvements in VLP uptake mediated by this lipopeptide is minimal, its ability to concomitantly induce the maturation of DCs at very small doses is a feature not observed using VLPs alone or VLPs administered in the presence of alum. Our previous work also demonstrated that association of antigen with charged lipopeptide facilitates trafficking of antigen to lymph Cys. Supernatants were clarified by centrifugation, incubated with Huh7 cells (5610 5 ) in a total volume of (500 ml) for 1 hour. Cells were then harvested and cellular fluorescence levels analysed by flow cytometry. All bar graphs represent the percentage reduction in VLP entry relative to baseline levels obtained using serum from naïve mice. doi:10.1371/journal.pone.0047492.g005 Figure 6 . Cell-mediated responses elicited by vaccination. HLA-A2k b transgenic mice (n = 3 per group) were inoculated (100 ml) subcutaneously at the base of the tail on days 0 and 14 with 30 mg of VLPs alone, emulsified with an equal amount of complete freund's adjuvant (CFA) or pre-mixed with 30 mg of E 8 Pam 2 Cys in saline. Splenocytes were obtained 28 days later and restimulated for 7 days in the presence of 10 mg VLPs or an irrelevant HCV-derived HLA-A2restricted epitope not part of the VLP construct. The frequency of peptide-specific T cells producing IFN-c was determined in an ELISPOT assay. Each bar represents the average number of IFN-c producing T cells and standard deviation in each group after subtracting nonspecific responses from corresponding samples stimulated with the irrelevant peptide. doi:10.1371/journal.pone.0047492.g006