Regression analyses between immunological and virological parameters in infected monkeys during the acute phase of SHIV_SF162P4cy infection.

<p>A significant relationship was detected between: A) IL-10 production and plasma viral load (p = 0.0023); B) α-defensins production and viral RNA (p = 0.0286); C) IFNγ and IL-10 production (p<0.0001). D) AUC: significant relationship between viral load and α-defensins (p = 0.0002).</p

Frequency of MHC class IA, class IB and class II and recombinant haplotypes in animals included in the study.

<p>Animals carrying specific Mhc class I haplotypes. MHC class IA: M1 = 7, M2 = 5, M3 = 9, M4 = 6, M5 = 1, M6 = 2, M7 = 4, rec = 6; frequency of MHC class IB: M1 = 9, M2 = 5, M3 = 11, M4 = 7, M5 = 1, M6 = 3, M7 = 4, rec = 1; frequency of MHC class II: M1 = 9, M2 = 4, M3 = 13, M4 = 6, M5 = 1, M6 = 4, M7 = 3, rec = 2 <i>rec</i> recombinant haplotype.</p

Plasma α-defensin, IL-10 and IFN-γ levels with respect to the pre-infection values in naïve (n = 11) and adjuvant treated monkeys (n = 10) inoculated with SHIV_SF162P4cy.

<p>No significant differences were observed between naive and adjuvant treated monkeys during the observation period. Mean values with standard deviations are connected by dotted lines.</p

Dynamics of viral infection in 21 cynomolgus monkeys inoculated with SHIV_SF162P4cy during acute (2–4 weeks p.i.), post-acute (8–16 weeks p.i.) of infection.

<p>Data represent mean values with standard error of log plasma RNA load, log proviral DNA, IgG anti-Env Ab, and nAb from 0 to 16 weeks p.i. (*) week 4: anti-Env bAb titers correlated positively with viral load (p = 0.0002); (**) week 16: nAb titers correlated positively with anti-Env bAb titers (p = 0.0041); (***) post-acute phase: proviral DNA levels correlated positively with anti-Env bAb (p = 0.0225) and negatively with nAb titers (p = 0.0083).</p

Effects of MHC class I<i>A</i> and II haplotypes on IL-10 and α-defensin production during SHIV_SF162P4cy infection.

<p>Mean values with standard error are depicted for all animals positive or negative for the indicated haplotype: M3 (n = 9) non-M3 (n = 12) class I<i>A</i>; M3 (n = 13) non-M3 (n = 8) class II.</p

Effects of MHC class I<i>A</i> and I<i>B</i> haplotypes on IgG anti-Env antibodies and neutralizing Ab following infection with SHIV_SF162P4cy.

<p>Mean values with standard error are depicted for all animals positive or negative for the indicated haplotype: M4 (n = 6) non-M4 (n = 15) class I<i>A</i>; M4 (n = 7), non-M4 (n = 14) class I<i>B</i>.</p

Biocompatible Anionic Polymeric Microspheres as Priming Delivery System for Effetive HIV/AIDS Tat-Based Vaccines

<div><p>Here we describe a prime-boost regimen of vaccination in <i>Macaca fascicularis</i> that combines priming with novel anionic microspheres designed to deliver the biologically active HIV-1 Tat protein and boosting with Tat in Alum. This regimen of immunization modulated the IgG subclass profile and elicited a balanced Th1-Th2 type of humoral and cellular responses. Remarkably, following intravenous challenge with SHIV89.6P_cy243, vaccinees significantly blunted acute viremia, as compared to control monkeys, and this control was associated with significantly lower CD4⁺ T cell depletion rate during the acute phase of infection and higher ability to resume the CD4⁺ T cell counts in the post-acute and chronic phases of infection. The long lasting control of viremia was associated with the persistence of high titers anti-Tat antibodies whose profile clearly distinguished vaccinees in controllers and viremics. Controllers, as opposed to vaccinated and viremic cynos, exhibited significantly higher pre-challenge antibody responses to peptides spanning the glutamine-rich and the RGD-integrin-binding regions of Tat. Finally, among vaccinees, titers of anti-Tat IgG1, IgG3 and IgG4 subclasses had a significant association with control of viremia in the acute and post-acute phases of infection. Altogether these findings indicate that the Tat/H1D/Alum regimen of immunization holds promise for next generation vaccines with Tat protein or other proteins for which maintenance of the native conformation and activity are critical for optimal immunogenicity. Our results also provide novel information on the role of anti-Tat responses in the prevention of HIV pathogenesis and for the design of new vaccine candidates.</p></div

Lymphoproliferative responses and frequency of cells producing IFN-γ, IL-2 or IL-4 during vaccination.

<p>The proliferative responses of (<b>A</b>) control and vaccinated (<b>B)</b> monkeys are reported as Stimulation Index (S.I). The dotted line indicated the cut-off of the assay. All samples showing a S.I. >3,0 were scored as reactive. In the lower panels the number of Spot Forming Cells (SFC/10⁶ PBMCs) of vaccinated macaques upon in vitro stimulation with Tat peptide pool are reported for the production of (<b>C</b>) IFN-γ, (<b>D</b>) IL-2 and (<b>E</b>) IL-4. None of the control macaques exhibited T cell responses and therefore the data are not presented. Arrows on the top of each panel indicate the time at which the vaccine antigen was given. The dashed line represents the cut-off (SFC/10⁶ PBMCs) of the assay. However, as described in the Material and Methods, were considered positive only samples yielding for IFN-γ ≥80 SFC/10⁶ cells and a fold increase ≥2.5; for IL-2≥30 SFC/10⁶ cells and a fold increase ≥3; for IL-4≥20 SFC/10⁶ cells and a fold increase ≥2.5.</p

Antibody responses against HIV-1 Env and Tat proteins after challenge with SHIV89.6P_cy243.

<p>Anti-Env IgG antibody titers were determined in plasma of control (<b>A</b>) and vaccinated (<b>B</b>) macaques. In the middle panels are reported the anti-Tat IgG antibody titers in (<b>C</b>) controls and (<b>D</b>) vaccinees. In the bottom panels the anti-Tat IgM antibody titers in (<b>E</b>) controls and (<b>F</b>) vaccinees are indicated. The dashed lines indicate the cut-off values (samples showing titers <1∶25 for IgM and <1∶100 for IgG were scored as negative).</p

Absolute numbers of CD4⁺ T cells following challenge with SHIV89.6P_cy243.

<p>The absolute CD4⁺ T cell counts are reported for (<b>A</b>) control and (<b>B</b>) vaccinated monkeys. In the left middle panel (<b>C</b>) the trend line as a LOESS smoothed average of the values of control (dashed line) and vaccinated (continous line) monkeys is shown. (<b>D</b>) Statistical analysis of the changes from baseline of CD4⁺ T cell counts in vaccinated and control macaques during the acute, post-acute and chronic phases of infection. The numbers within the panel indicate the level of statistically significant differences. (<b>E</b>) Analysis of the correlation of plasma viremia and CD4⁺ T cells counts in vaccinated (continuous red line) and control (black line) monkeys is reported.</p