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. 2013 Mar;93(3):437-48.
doi: 10.1189/jlb.0612287. Epub 2012 Dec 27.

Correlates of relative resistance against low-dose rectal simian immunodeficiency virus challenges in peripheral blood mononuclear cells of vaccinated rhesus macaques

Raj Kurupati  1 , Steve Tuyishime, Andrew V Kossenkov, Marina Sazanovich, Larissa H Haut, Marcio O Lasaro, Sarah J Ratcliffe, Steven E Bosinger, Diane G Carnathan, Mark Lewis, Louise C Showe, Guido Silvestri, Hildegund C J Ertl
Affiliations

Correlates of relative resistance against low-dose rectal simian immunodeficiency virus challenges in peripheral blood mononuclear cells of vaccinated rhesus macaques

Raj Kurupati et al. J Leukoc Biol. 2013 Mar.

Abstract

In this study, we compared the immunogenicity and protection from repeated low-dose intrarectal SIVmac251 challenge in two groups of vaccinated RMs. Animals were immunized with live SIVmac239, which had been attenuated by a deletion of the nef sequence, or they were vaccinated twice with an E1-deleted AdHu5, expressing SIVmac239gag. The vaccinated animals and a cohort of unvaccinated control animals were then challenged 10 times in weekly intervals with low doses of SIVmac251 given rectally. Our results confirm previous studies showing that whereas SIVΔnef provides some degree of protection against viral acquisition after repeated low-dose rectal SIVmac251 challenges, vaccination with an AdHu5gag vaccine designed to induce only antiviral T cell responses is ineffective. As immunological analyses of prechallenge, vaccine-induced T and B cell responses failed to reveal correlates of protection that distinguished the more susceptible from the more resistant vaccinated animals, we carried out RNA-Seq studies of paired pre- and postvaccination samples to identify transcriptional patterns that correlated with the differences in response. We show that gene expression signatures associated with the delayed SIV infection seen in some AdHu5gag recipients were largely present in prevaccination samples of those animals. In contrast, the responding SIVΔnef-immunized animals showed a predominance of vaccine-induced changes, thus enabling us to define inherited and vaccine-induced gene expression signatures and their associated pathways that may play a role in preventing SIV acquisition.

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Figures

Figure 1.
Figure 1.. Schedule of vaccinations, bleeds, and challenges.
The graph shows time-points for vaccination and challenges of animals above the line and for collection of samples for the different types of analyses below the line. IR, intrarectal; ICS, testing PBMCs for T cells by ICS; Ab, testing sera for antibodies by ELISAs; Solexa, testing PBMCs for gene expression profiles; VL, testing plasma for viral loads.
Figure 2.
Figure 2.. Gag-specific CD8+ and CD4+ T cell responses.
PBMCs from vaccinated RMs were tested by ICS for Gag-specific T cells producing IFN-γ, TNF-α, or IL-2. Graphs show T cell frequencies for each animal after subtraction of background for different time-points after priming (i.e., vaccination with SIVΔnef or the first dose of AdHu5). (A) Results for total T cells, (B) Teff, (C) TEM, and (D) TCM. The graphs (a and b) show results for CD8+ T cells and (c and d) CD4+ T cells. (a and c) Results for SIVΔnef-immunized animals; (b and d) results for AdHu5-vaccinated animals.
Figure 3.
Figure 3.. Cytokine profiles of Gag-specific CD8+ and CD4+ T cells subsets.
The graphs show averages for all of the AdHu5gag-vaccinated animals in the top rows, for the four SIVΔnef-vaccinated RMs that became infected in the middle rows, and for the two SIVΔnef-vaccinated RMs that resisted infection in the lower rows. Results were obtained with samples harvested 13 weeks after the first vaccine dose. The different colors of the pie chart reflect the relative percentages of T cells producing cytokines or a combination of cytokines: light purple, cells producing IFN-γ, IL-2, and TNF-α; gray, cells producing IFN-γ and IL-2; yellow, cells producing IFN-γ and TNF-α; light blue, cells producing IFN-γ; magenta, cells producing IL-2 and TNF-α; pink, cells producing IL-2; dark blue, cells producing TNF-α.
Figure 4.
Figure 4.. gp160-Specific antibody responses in SIVΔnef-vaccinated RMs.
(A) Antibody titers: plasma samples were harvested before (×), 26 weeks after vaccination (■), and 6 weeks after completion of challenges (▫) and tested for antibody responses to SIVmac239 Gp160 by an ELISA. Graphs show average results ± sd for each sample for individual animals. (B) Antibody avidity: plasma samples harvested 32 weeks after vaccination and 8 weeks after completion of challenges were diluted in PBS/3% BSA/0.05% Tween-20 and incubated in wells coated with Gp160. Wells were then incubated with various concentrations of NaSCN. Graphs show percent adsorbance (determined by adding an enzyme-labeled secondary antibody and then substrate) of anti-Gp160 antibodies in the presence of different concentrations of NaSCN as compared with binding without NaSCN (the latter normalized to 100%). Symbols identifying samples from specific animals are shown next to the graphs.
Figure 5.
Figure 5.. Time to infection and viral loads upon SIVmac251 challenges.
Vaccinated and control RMs were challenged 10 times with SIVmac251 given rectally. Viral titers were measured, and for SIVΔnef-vaccinated RMs, positive samples were retested by a nef-specific nested PCR. (A) Percent of animals that remained virus-free after each challenge. (B) Viral titers measured after each challenge. Transient viral spikes in SIVΔnef-immunized RMs and low titers at the end in BD20 and 4340 could not be amplified by the nef-specific PCR. The two animals of the SIVΔnef group that resisted infection are shown with dotted lines.
Figure 6.
Figure 6.. PCA performed on pre- and postvaccinated PBMC samples using expression of all 19,062 informative transcripts.
Samples are plotted against first and second principal components and Pc1-captured common differences between effects of vaccines, i.e., differences between pre- and postvaccination samples. Dotted box shows two replicates from the same sample done with different initial RNA concentrations.
Figure 7.
Figure 7.. Expression of transcripts induced by SIVΔnef vaccines and indicative of protection.
(A) Groups of transcripts correlated with weeks of resistance, also listed in Supplemental Table 4. (B) Transcripts differentially expressed between two protected (P) and among four unprotected (U) animals, also listed in Supplemental Table 5. FC, fold change.
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References

    1. Hu S. L., Stamatatos L. (2007) Prospects of HIV Env modification as an approach to HIV vaccine design. Curr. HIV Res. 5, 507–513 - PubMed
    1. Roux K. H., Taylor K. A. (2007) AIDS virus envelope spike structure. Curr. Opin. Struct. Biol. 17, 244–252 - PubMed
    1. Gray E. S., Moore P. L., Choge I. A., Decker J. M., Bibollet-Ruche F., Li H., Leseka N., Treurnicht F., Mlisana K., Shaw G. M.., et al. (2007) Neutralizing antibody responses in acute human immunodeficiency virus type 1 subtype C infection. J. Virol. 81, 6187–6196 - PMC - PubMed
    1. Barouch D. H., Liu J., Li H., Maxfield L. F., Abbink P., Lynch D. M., Iampietro M. J., SanMiguel A., Seaman M. S., Ferrari G.., et al. (2012) Vaccine protection against acquisition of neutralization-resistant SIV challenges in rhesus monkeys. Nature 482, 89–93 - PMC - PubMed
    1. Hansen S. G., Vieville C., Whizin N., Coyne-Johnson L., Siess D. C., Drummond D. D., Legasse A. W., Axthelm M. K., Oswald K., Trubey C. M.., et al. (2009) Effector memory T cell responses are associated with protection of rhesus monkeys from mucosal simian immunodeficiency virus challenge. Nat. Med. 15, 293–299 - PMC - PubMed

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