DNA vaccines encoding retrovirus-based virus-like particles induce efficient immune responses without adjuvant

Fusion of HBsAg and prime/boosting augment Th1 and CTL responses to HCV polytope DNA vaccine

“…3A). Absence of detectable responses against irrelevant CTL peptides (H-2 d ; core [16][17][18][19][20][21][22][23][24][25] and HLA-A2; E 6 and N) in both CTL and ELISpot assays indicated the specificity of the responses against HCVspecific C, E 4 and CE 4 E 6 N (IFN--ELISpot only) peptides. Results of IFN--ELISpot assay ( Fig.…”

“…Peptides corresponding to CD8 + -epitopic peptides (C, E 4, E 6 , N) and an irrelevant H-2 drestricted epitope (core [16][17][18][19][20][21][22][23][24][25] ; NRRPQDVKFP), besides the synthetic CE 4 E 6 N long polytopic peptide were synthesized by solid phase Fmoc chemistry with 97% purity (Institute de Biochimie, Universite de Lausanne, Swiss). In this study, HLA-A2-restricted CD8 + -epitopic peptides (E 6 and N) were also used as irrelevant (negative control) peptides for all assays in BALB/c mice.…”

“…To this end, different strategies such as prime/boost [15;16] and particle-based immunizations have been employed. Chimeric viruslike particle (VLP)-forming DNA vaccines, which encode viral structural proteins capable of assembling into particulate repeated arrays (such as hepatitis B surface antigen; HBsAg), are recently considered as a promising approach for the efficient delivery of antigenic targets [17][18][19]. This so called "plasmo-VLP" strategy combines the ease of production of plasmid DNA and the improved immunogenicity of VLPs [17].…”

Antigen Localization Controls T Cell-Mediated Tumor Immunity

“…Particulate Ag in a cell-associated form was shown to result in increased T cell activation compared with soluble Ag (12,13). Also, virus-like particles, which contain Ags, were shown to result in a stronger T cell response compared with soluble proteins (14). Because tumors continuously secrete membrane vesicles, such as exosomes, providing another source of particulate Ag, we wondered whether this source of Ag in vivo leads to a more profound T cell-mediated immune response compared with secreted soluble or nonsecreted cell-associated Ags.…”

Hepatitis B Surface Antigen-based Vaccines for Human Neoplastic Disease

“…DNA vaccines can be exploited to express VLP-forming antigens, which are amenable to secretion from cells to elicit VLP-targeting immune responses (Bellier et al, 2006;Jin et al, 2007;Chege et al, 2008). The inclusion of localisation signals can be used to enhance the immunogenicity of antigens encoded within DNA vaccines to target proteins to the proteasome for degradation and generate a Th1 type CTL response (Drew et al, 2000;Xu et al, 2005b;Imai et al, 2008;Shen et al, 2008;Starodubova et al, 2008).…”