Background: There have been massive efforts on vaccine development against HIV-1 since its discovery.
Various approaches have been taken to attention including rational vaccine design, optimized delivery systems and
heterologous regimen to eradicate the virus. DNA vaccines fundamentally induce host immune responses by genetically
engineered plasmids encoding antigens and expressed in vivo without need of specific delivery system. Therefore, a longterm of endogenous antigen expression could be possible.
Objective: In this study, we aimed at evaluation and comparison of DNA and protein vaccine based on two forms of full and
truncated HIV-1 p24-nef antigens by in silico design in BLALB/c.
Methods: The recombinant pcDNA3.1 harboring two sets of HIV-1 p24 and nef genes in truncated and full forms were
generated and applied to immunize BALB/c along with the corresponding proteins via three different DNA/DNA,
DNA/protein and protein/protein regimens.
Results: The results showed that the applied regimens could elicit strong immune responses in comparison with controls and
the prim-boost DNA/protein regimen reached the highest immune induction (p < 0.05). Moreover, prime-boost approach
was assessed more successful in a qualitatively broad Th1 response induction. The truncated form of the antigens, p24(80-
231 aa)-AAY- Nef (120-150), was evaluated more immunogenic in agreement with the in silico investigation.
Conclusion: The truncated form of p24-Nef was evaluated highly immunogenic specially when applied in prim-boost
DNA/Protein regimen and could be investigated in other delivery systems and a proper animal model to achieve a
therapeutic vaccine candidate against HIV-1.