DNA-plasmids of HIV-1 induce systemic and mucosal immune responses

DNA-based immunization has been shown to induce protective immunity against several microbial pathogens including HIV-1, Several routes of DNA vaccina tion have been exploited, However, the properties of the immune responses s eem to differ with the different routes used for DNA delivery, ultimately a ffecting the outcome of experimental challenge. We measured the primary imm une response following one vaccination, This report presents differences as sociated with three different DNA delivery routes: intramuscular injection, intranasal application, and gene-gun based immunization. Induction of syst emic humoral immune responses was achieved most efficiently by either intra nasal or gene-gun mediated immunization, followed by intramuscular injectio n. Mucosal IgA was reproducibly induced by intranasal instillation of the D NA, and found in lung washings, faeces, and vaginal washings, Cytotoxic T c ells were not induced by a single immunization, but were observed after thr ee immunizations using intramuscular injections.