Effects of different routes of administration on the immunogenicity of the Tat protein and a Tat-derived peptide

Abstract

The use of the Tat protein of HIV in vaccines against AIDS showed promising results in primate and human studies. To characterize the impact of the administration route on the induction of humoral responses at systemic and mucosal levels, we compared intradermal, intramuscular and mucosal immunizations with Tat and a Tat-derived peptide. Mice were immunized with the Tat protein by different routes and the titer and isotype of anti-Tat antibodies were assessed in serum and mucosal lavages. Intramuscular and intradermal administrations showed comparable immunogenicity, while the mucosal administration was unable to induce IgM in serum and IgG at mucosal sites but showed superior immunogenicity in terms of IgA induction. Anti-Tat antibodies were also obtained upon vaccination with the immunodominant Tat 1–20 peptide which was, however, less immunogenic than the whole Tat protein

The Tat Protein of HIV-1 Prevents the Loss of HSV-Specific Memory Adaptive Responses and Favors the Control of Viral Reactivation

“…The difference in disease symptoms was particularly evident between 7 and 9 days after challenge before the disease signs spontaneously healed in both groups (Figure 1C). they are effectively induced after administration of the Tat protein in humans [46][47][48] and animals [49][50][51]. Consistent with this, 100% of Tat-treated mice displayed anti-Tat IgG at both 60 and 108 days p.i.…”

“…Instead, we asked whether anti-Tat specific antibodies (Ab) could recognize and cross-react with HSV-1. Although anti-Tat Ab are detectable in only a fraction of HIV-infected individuals [ 44 , 45 ], they are effectively induced after administration of the Tat protein in humans [ 46 , 47 , 48 ] and animals [ 49 , 50 , 51 ]. Consistent with this, 100% of Tat-treated mice displayed anti-Tat IgG at both 60 and 108 days p.i.…”

Systemic immunodominant CD8 responses with an effector-like phenotype are induced by intravaginal immunization with attenuated HSV vectors expressing HIV Tat and mediate protection against HSV infection

“…Sera and vaginal lavages for antibodies determinations were collected and stored as previously described [11], and the presence and titers of anti-HSV IgG and IgA were assessed by Elisa as previously described [11,16]. Briefly, samples collected from individual mice were assayed in 96well immunoplates (Nunc Maxisorp, Milan Italy) previously coated overnight with 100 ng/well of HSV1 purified viral lysate (MacIntyre Strain, Tebu-bio, Milan, Italy) and blocked for 90 min at 37 °C with PBS containing 0.5% milk and 0.05% NaN3 (IgG) or PBS containing 1% BSA and 0.1% Tween 20 (IgA).…”