Immunogenicity of candidate DNA vaccine based on subtype A of human immunodeficiency virus type 1 predominant in Russia.

Human immunodeficiency virus (HIV)-1 subtype A strains circulating among the majority of HIVinfected individuals in the former Soviet Union (FSU) countries demonstrate low genetic diversity. The consensus sequence of the FSU region-specific isolate has been used for the candidate DNA vaccine development. We constructed recombinant plasmids with four viral genes: env (gp140), gag, pol (reverse transcriptase), and nef. We immunized BALB/c mice intramuscularly using equimolar mixture of four recombinant plasmids, and observed significant cytotoxic T lymphocyte response and specific CD8(+) cell production against cells presenting HIV-1 peptides. Overall, the Th1 pathway of immune response clearly dominated. Immunological properties of this candidate DNA vaccine against HIV-1 suggest the possibility of its further study in clinical trials.