Studies On Design And Construction Of Recombinant Epitope Vaccine Against HIV-1

The AIDS epidemic threatens the maintenance and development of the whole world. A prophylactic vaccine against HIV, the pathogen of AIDS, is deadly needed to stop the epidemic. Chen et al suggested epitope vaccine as a new strategy for developing an effective vaccine against HIV. Here, we have focused on the design and construction of the recombinant epitope vaccine against HIV.It is difficult to combine a short oligonucleotide that encodes one epitope into an artificial gene for a recombinant epitope vaccine. We developed a universal method, which made it feasible to construct such genes harboring discretionary copy of predefined epitopes. This method resolved the key problem in the realization of recombinant epitope vaccine strategy against HIV. Whether repeated epitope in the recombinant vaccine could enhance the immune response or not is a basic scientific issue. We found that the titre of epitope specific antibody in the antisera was enhanced with increased copies of epitopes. This supported our hypothesis that immune response could be upgraded by involving repeated epitope in epitope vaccines.We also investigated the impact of different epitope spacers on the recombinant vaccine. The results indicated that epitope spacer was important for a good immunogen. Because immunogen harboring spacer GS and GSGGGGS could induce epitope specific antibodies, whereas immunogen harboring spacer RS could not. This may be attributed to the (-helix-tropic of RS and (-sheet-tropic of the other two.Mutated epitope should be involved into an epitope vaccine against HIV mutation. However, one restricted mutation in an epitope might cause immune evasion. We found that antibodies specific for restricted mutant epitopes could be induced with the immunogen harboring these epitopes, which suggested a way to overcome this kind of variation. All the results above will contribute to a successful epitope vaccine against HIV.