Effect of CD8+ lymphocyte depletion on virus containment after simian immunodeficiency virus SIVmac251 challenge of live attenuated SIVmac239delta3-vaccinated rhesus macaques.

Although live attenuated vaccines can provide potent protection against simian immunodeficiency virus (SIV) and simian-human immunodeficiency virus challenges, the specific immune responses that confer this protection have not been determined. To test whether cellular immune responses mediated by CD8+ lymphocytes contribute to this vaccine-induced protection, we depleted rhesus macaques vaccinated with the live attenuated virus SIVmac239Delta3 of CD8+ lymphocytes and then challenged them with SIVmac251 by the intravenous route. While vaccination did not prevent infection with the pathogenic challenge virus, the postchallenge levels of virus in the plasmas of vaccinated control animals were significantly lower than those for unvaccinated animals.

Role of genes that modulate host immune responses in the immunogenicity and pathogenicity of vaccinia virus.

Poxvirus vaccine vectors, although capable of eliciting potent immune responses, pose serious health risks in immunosuppressed individuals. We therefore constructed five novel recombinant vaccinia virus vectors which contained overlapping deletions of coding regions for the B5R, B8R, B12R, B13R, B14R, B16R, B18R, and B19R immunomodulatory gene products and assessed them for both immunogenicity and pathogenicity. All five of these novel vectors elicited both cellular and humoral immunity to the inserted HIV-BH10 env comparable to that induced by the parental Wyeth strain vaccinia virus.

Vaccination with gp120-depleted HIV-1 plus immunostimulatory CpG oligodeoxynucleotides in incomplete Freund's adjuvant stimulates cellular and humoral immunity in rhesus macaques.

Whole killed human immunodeficiency virus type 1 (HIV-1) immunogens contain the more conserved epitopes of HIV-1 and therefore may provide some utility as potential HIV-1 vaccine candidates. Previous studies have shown that synthetic oligodeoxynucleotides (ODN) containing unmethylated cytosine-guanine (CpG) dinucleotides trigger rapid stimulation of both CD4+ and CD8+ T cells. Here, we investigated whether immunization of rhesus macaques with an inactivated gp120-depleted HIV-1 immunogen, emulsified in incomplete Freund's adjuvant (IFA) together with immunostimulatory CpG-containing ODN (ODN 2006), would elicit HIV-specific cellular and humoral immune responses.