Adjuvant-dependent innate and adaptive immune signatures of risk of SIVmac251 acquisition.
ABSTRACT: A recombinant vaccine containing Aventis Pasteur's canarypox vector (ALVAC)-HIV and gp120 alum decreased the risk of HIV acquisition in the RV144 vaccine trial. The substitution of alum with the more immunogenic MF59 adjuvant is under consideration for the next efficacy human trial. We found here that an ALVAC-simian immunodeficiency virus (SIV) and gp120 alum (ALVAC-SIV + gp120) equivalent vaccine, but not an ALVAC-SIV + gp120 MF59 vaccine, was efficacious in delaying the onset of SIVmac251 in rhesus macaques, despite the higher immunogenicity of the latter adjuvant. Vaccine efficacy was associated with alum-induced, but not with MF59-induced, envelope (Env)-dependent mucosal innate lymphoid cells (ILCs) that produce interleukin (IL)-17, as well as with mucosal IgG to the gp120 variable region 2 (V2) and the expression of 12 genes, ten of which are part of the RAS pathway. The association between RAS activation and vaccine efficacy was also observed in an independent efficacious SIV-vaccine approach. Whether RAS activation, mucosal ILCs and antibodies to V2 are also important hallmarks of HIV-vaccine efficacy in humans will require further studies.
Project description:The Canarypox/gp120/Alum vaccines decreased the risk of HIV acquisition in humans. We demonstrate here the efficacy of this vaccine regimen also in the SIVmac251 macaque model when we used the alum but not the MF59 adjuvant. Analysis of innate and adaptive cell responses, envelope antibodies Fc profiles and glycoforms demonstrated a lower inflammatory response with alum than MF59. Alum elicited mucosal V2 peptide-specific IgG associated with vaccine efficacy whereas the MF59 induced mucosal V2 peptide-specific IgG associated with increased risk of infection. Alum modulated the expression of 12 genes, 7 of which are part of the RAS pathway, that correlates with vaccine efficacy and were linked to innate responses that preserve mucosal integrity and adaptive mucosal antibody response to V2. Thus, activation of the RAS pathway, preservation of mucosal integrity and mucosal antibody to V2 in concert, reduce the risk of SIVmac251 acquisition. Fifty-four (54) rhesus macaques were randomized into two vaccination groups. One group (n=27) was primed twice with ALVAC-SIV (at week 0 and week 4) and boosted twice with ALVAC-SIV/gp120 in MF59 adjuvant (at week 12 and week 24). The second group (n=27) was primed twice with ALVAC-SIV (at week 0 and week 4) and boosted twice with ALVAC-SIV/gp120 in Alum adjuvant (at week 12 and week 24). Blood samples were taken pre-vaccination, 24 hours after the first prime (post-1st imunization at week 0) and 24 hours after the first boost (post-3rd immunization at week 12). All the samples were taken before SIV challenge. Blood samples were conserved in PAXgene tubes. RNA was extracted and hybridized to Illumina beadchips. technical replicate: P162_P382_post1st, P162_P382_post1st_rep1
Project description:The ALVAC-HIV clade B/AE and equivalent SIV-based/gp120 + Alum vaccines successfully decreased the risk of virus acquisition in humans and macaques. Here, we tested the efficacy of HIV clade B/C ALVAC/gp120 vaccine candidates + MF59 or different doses of Aluminum hydroxide (Alum) against SHIV-Cs of varying neutralization sensitivity in macaques. Low doses of Alum induced higher mucosal V2-specific IgA that increased the risk of Tier 2 SHIV-C acquisition. High Alum dosage, in contrast, elicited serum IgG to V2 that correlated with a decreased risk of Tier 1 SHIV-C acquisition. MF59 induced negligible mucosal antibodies to V2 and an inflammatory profile with blood C-reactive Protein (CRP) levels correlating with neutralizing antibody titers. MF59 decreased the risk of Tier 1 SHIV-C acquisition. The relationship between vaccine efficacy and the neutralization profile of the challenge virus appear to be linked to the different immunological spaces created by MF59 and Alum via CXCL10 and IL-1?, respectively.
Project description:We contrasted innate and adaptive immune responses of HIV vaccine candidates of varying efficacy in macaques that shared the ALVAC+gp120 protein boost with an ALVAC, DNA or Ad26 prime modality. The vaccine efficacies of the DNA/ALVAC+gp120 and ALVAC/ALVAC+gp120 vaccine regimens, both protective, were associated with qualitative temporal-spatial differences in the innate CD14+ and CD16+ cells in blood and tissues. The activation of hypoxia and the inflammasome in CD14+ DR+ CD16- classical monocytes and CD4+ Th2 responses correlated with a decreased risk of SIVmac251 acquisition. CD4+ Th2 cells, in turn, correlated with mucosal NKp44+ cells and mucosal protective antibodies to V2. In contrast, the Ad26/ALVAC+gp120 vaccine resulted in increased de novo differentiated CX3CR1+ CD163+ macrophages in lymph nodes, increased CD4+ Th17 cells in blood and rectal mucosa, and a lack vaccine efficacy. These data posit that the engagement of classical monocytes and inflammasome activation is central for the elicitation of protective innate and adaptive responses by the ALVAC-based HIV vaccine platform. Overall design: Twenty four (24) rhesus macaques were randomized to two vaccination groups. One group (n=12) was primed once with Ad26 (at week 0) and boosted twice with ALVAC-SIV/gp120 in Alum adjuvant (at week 12 and week 24). The second group (n=12) was primed twice with DNA (at week 0 and week 4) and boosted twice with ALVAC-SIV/gp120 in Alum adjuvant (at week 12 and week 24). Blood samples were taken pre-vaccination, 24 hours after the first boost (week 12), 2 weeks after the first boost (week 14), 24 hours after the second boost (week 24) and 1 week after the second boost (week 15). All the samples were taken before SIV challenge. One animal (R270) who received the Ad26/ALVAC+gp120 vaccine was not included in the transcriptomic study because of a lack of blood samples. Blood samples were conserved in PAXgene tubes. RNA was extracted and hybridized to Illumina beadchips.
Project description:We compare the immunogenicity of ALVAC- or NYVAC- based SIVmac251 vaccine regimens combined with gp120/alum boosts and their relative efficacy in a cohort of 65 female rhesus macaques. Both NYVAC- and ALVAC-based regimens induced equivalent titers of serum binding antibodies to gp120, whereas NYVAC elicited significantly higher envelope specific T cell responses. Surprisingly, however, only the ALVAC-based regimen was able to significantly decrease the risk of SIVmac251 acquisition following repeated low-dose intravaginal challenges. The risk of virus acquisition was associated negatively with the frequency of classical monocytes and positively with non-classical. The systems biology approach used to investigate the molecular basis of the different vaccine efficacies demonstrated specific expression profiles elicited by the ALVAC-based regimen that correlate with efficacy. Overall design: A total of 65 female rhesus macaques were randomized into five groups: ALVAC-SIV/gp120 (20 animals), NYVAC-SIV/gp120 (20 animals), ALVAC-control (10 animals), NYVAC-control (10 animals), and naïve (5 animals). The animals in the ALVAC-SIV/gp120 and NYVAC-SIV/gp120 groups were immunized at weeks 0, 4, 12, and 24 with ALVAC-SIV (vCP180) or NYVAC-SIV (VP1071) carrying the identical Env-Gag-Pol genes, respectively. At weeks 12 and 24, the animals from these groups received an alum-formulated gp120 protein boost. The animals in the ALVAC-control and NYVAC-control groups were immunized at weeks 0, 4, 12, and 24 with empty ALVAC-SIV (vCP180) or NYVAC-SIV (VP1071) vectors, respectively. At weeks 12 and 24, the animals from these groups received alum. technical replicate: P168_A06015_w0.6h, P168_A06015_w0.6h_rep1 technical replicate: P168_A06028_w0.6h_rep1, P168_A06028_w0.6h_rep2 technical replicate: P168_A06082_w0.0h, P168_A06082_w0.0h_rep1 technical replicate: P168_A06083_w0.24h, P168_A06083_w0.24h_rep1
Project description:The recombinant ALVAC vaccine coupled with the monomeric gp120/alum protein have decreased the risk of HIV and SIV acquisition. Ab responses to the V1/V2 regions have correlated with a decreased risk of virus acquisition in both humans and macaques. We hypothesized that the breadth and functional profile of Abs induced by an ALVAC/envelope protein regimen could be improved by substituting the monomeric gp120 boost, with the full-length single-chain (FLSC) protein. FLSC is a CD4-gp120 fusion immunogen that exposes cryptic gp120 epitopes to the immune system. We compared the immunogenicity and relative efficiency of an ALVAC-SIV vaccine boosted either with bivalent FLSC proteins or with monomeric gp120 in alum. FLSC was superior to monomeric gp120 in directing Abs to the C3 ?2 helix, the V5 loop, and the V3 region that contains the putative CCR5 binding site. In addition, FLSC boosting elicited significantly higher binding Abs to V2 and increased both the Ab-dependent cellular cytotoxicity activity and the breadth of neutralizing Abs. However, the FLSC vaccine regimen demonstrated only a trend in vaccine efficacy, whereas the monomeric gp120 regimen significantly decreased the risk of SIVmac251 acquisition. In both vaccine regimens, anti-V2 Abs correlated with a decreased risk of virus acquisition but differed with regard to systemic or mucosal origin. In the FLSC regimen, serum Abs to V2 correlated, whereas in the monomeric gp120 regimen, V2 Abs in rectal secretions, the site of viral challenge, were associated with efficacy.
Project description:Immunization with recombinant ALVAC/gp120 alum vaccine provided modest protection from human immunodeficiency virus type 1 (HIV-1) and simian immunodeficiency virus (SIV) acquisition in humans and macaques. Vaccine-mediated protection was associated with the elicitation of IgG against the envelope V2 loop and of envelope-specific CD4+ T cell responses. We hypothesized that the simultaneous expression of the costimulatory molecule CD40L (CD154) by the ALVAC-HIV vector could increase both protective humoral and cellular responses. We engineered an ALVAC-SIV coexpressing CD40L with SIVmac251 (ALVAC-SIV/CD40L) gag, pol, and env genes. We compared its immunogenicity in macaques with that of a canonical ALVAC-SIV, with both given as a vector-prime/gp120 in alum boost strategy. The ALVAC-SIV/CD40L was superior to the ALVAC-SIV regimen in inducing binding and tier 1 neutralizing antibodies against the gp120. The increase in humoral responses was associated with the expression of the membrane-bound form of the CD40L by CD4+ T cells in lymph nodes. Unexpectedly, the ALVAC-SIV/CD40L vector had a blunting effect on CD4+ Th1 helper responses and instead favored the induction of myeloid-derived suppressor cells, the immune-suppressive interleukin-10 (IL-10) cytokine, and the down-modulatory tryptophan catabolism. Ultimately, this strategy failed to protect macaques from SIV acquisition. Taken together, these results underlie the importance of balanced vaccine-induced activating versus suppressive immune responses in affording protection from HIV.IMPORTANCE CD40-CD40 ligand (CD40L) interaction is crucial for inducing effective cytotoxic and humoral responses against pathogens. Because of its immunomodulatory function, CD40L has been used to enhance immune responses to vaccines, including candidate vaccines for HIV. The only successful vaccine ever tested in humans utilized a strategy combining canarypox virus-based vector (ALVAC) together with an envelope protein (gp120) adjuvanted in alum. This strategy showed limited efficacy in preventing HIV-1/SIV acquisition in humans and macaques. In both species, protection was associated with vaccine-induced antibodies against the HIV envelope and CD4+ T cell responses, including type 1 antiviral responses. In this study, we tested whether augmenting CD40L expression by coexpressing it with the ALVAC vector could increase the protective immune responses. Although coexpression of CD40L did increase humoral responses, it blunted type 1 CD4+ T cell responses against the SIV envelope protein and failed to protect macaques from viral infection.
Project description:We used the simian immunodeficiency virus mac251 (SIV(mac251)) macaque model to study the effect of the dose of mucosal exposure on vaccine efficacy. We immunized macaques with a DNA prime followed by SIV gp120 protein immunization with ALVAC-SIV and gp120 in alum, and we challenged them with SIV(mac251) at either a single high dose or at two repeated low-dose exposures to a 10-fold-lower dose. Infection was neither prevented nor modified following a single high-dose challenge of the immunized macaques. However, two exposures to a 10-fold-lower dose resulted in protection from SIV(mac251) acquisition in 3 out of 12 macaques. The remaining animals that were infected had a modulated pathogenesis, significant downregulation of interferon responsive genes, and upregulation of genes involved in B- and T-cell responses. Thus, the choice of the experimental model greatly influences the vaccine efficacy of vaccines for human immunodeficiency virus (HIV).
Project description:NK cells are essential for controlling viral infections. We investigated NK cell and innate lymphoid cell (ILC) dynamics and function in rhesus macaque rectal tissue and blood following mucosal priming with replicating adenovirus (Ad)-SIV recombinants, systemic boosting with SIV envelope protein, and subsequent repeated low-dose intravaginal SIV exposures. Mucosal memory-like NK and ILC subsets in rectal and vaginal tissues of chronically infected macaques were also evaluated. No differences in NK cell or ILC frequencies or cytokine production were seen between vaccinated and Ad-empty/alum controls, suggesting responses were due to the Ad-vector and alum vaccine components. Mucosal NKp44+ ILCs increased postvaccination and returned to prelevels postinfection. The vaccine regimen induced mucosal SIV-specific Ab, which mediated Ab-dependent cellular cytotoxicity and was correlated with mucosal NKp44+CD16+ ILCs. Postvaccination NKp44+ and NKp44+IL-17+ ILC frequencies were associated with delayed SIV acquisition and decreased viremia. In chronically SIV-infected animals, NKp44+ ILCs negatively correlated with viral load, further suggesting a protective effect, whereas, NKG2A- NKp44- double-negative ILCs positively correlated with viral load, indicating a pathogenic role. No such associations of circulating NK cells were seen. ?? NK cells in mucosal tissues of chronically infected animals exhibited impaired cytokine production compared with non-?? NK cells but responded to anti-gp120 Ab and Gag peptides, whereas non-?? NK cells did not. Mucosal ?? NKp44+ and ?? DN cells were similarly associated with protection and disease progression, respectively. Thus, the data suggest NKp44+ ILCs and ?? cells contribute to SIV infection outcomes. Vaccines that promote mucosal NKp44+ and suppress double-negative ILCs are likely desirable.
Project description:The recombinant Canarypox ALVAC-HIV/gp120/alum vaccine regimen was the first to significantly decrease the risk of HIV acquisition in humans, with equal effectiveness in both males and females. Similarly, an equivalent SIV-based ALVAC vaccine regimen decreased the risk of virus acquisition in Indian rhesus macaques of both sexes following intrarectal exposure to low doses of SIVmac251. Here, we demonstrate that the ALVAC-SIV/gp120/alum vaccine is also efficacious in female Chinese rhesus macaques following intravaginal exposure to low doses of SIVmac251 and we confirm that CD14+ classical monocytes are a strong correlate of decreased risk of virus acquisition. Furthermore, we demonstrate that the frequency of CD14+ cells and/or their gene expression correlates with blood Type 1 CD4+ T helper cells, ?4?7+ plasmablasts, and vaginal cytocidal NKG2A+ cells. To better understand the correlate of protection, we contrasted the ALVAC-SIV vaccine with a NYVAC-based SIV/gp120 regimen that used the identical immunogen. We found that NYVAC-SIV induced higher immune activation via CD4+Ki67+CD38+ and CD4+Ki67+?4?7+ T cells, higher SIV envelope-specific IFN-? producing cells, equivalent ADCC, and did not decrease the risk of SIVmac251 acquisition. Using the systems biology approach, we demonstrate that specific expression profiles of plasmablasts, NKG2A+ cells, and monocytes elicited by the ALVAC-based regimen correlated with decreased risk of virus acquisition.
Project description:Many viral infections, including HIV, exhibit sex-based pathogenic differences. However, few studies have examined vaccine-related sex differences. We compared immunogenicity and protective efficacy of monomeric SIV gp120 with oligomeric SIV gp140 in a pre-clinical rhesus macaque study and explored a subsequent sex bias in vaccine outcome. Each immunization group (16 females, 8 males) was primed twice mucosally with replication-competent Ad-recombinants encoding SIVsmH4env/rev, SIV239gag and SIV239nef?1-13 and boosted twice intramuscularly with SIVmac239 monomeric gp120 or oligomeric gp140 in MF59 adjuvant. Controls (7 females, 5 males) received empty Ad and MF59. Up to 9 weekly intrarectal challenges with low-dose SIVmac251 were administered until macaques became infected. We assessed vaccine-induced binding, neutralizing, and non-neutralizing antibodies, Env-specific memory B cells and plasmablasts/plasma cells (PB/PC) in bone marrow and rectal tissue, mucosal Env-specific antibodies, and Env-specific T-cells. Post-challenge, only one macaque (gp140-immunized) remained uninfected. However, SIV acquisition was significantly delayed in vaccinated females but not males, correlated with Env-specific IgA in rectal secretions, rectal Env-specific memory B cells, and PC in rectal tissue. These results extend previous correlations of mucosal antibodies and memory B cells with protective efficacy. The gp140 regimen was more immunogenic, stimulating elevated gp140 and cyclic V2 binding antibodies, ADCC and ADCP activities, bone marrow Env-specific PB/PC, and rectal gp140-specific IgG. However, immunization with gp120, the form of envelope immunogen used in RV144, the only vaccine trial to show some efficacy, provided more significant acquisition delay. Further over 40 weeks of follow-up, no gp120 immunized macaques met euthanasia criteria in contrast to 7 gp140-immunized and 2 control animals. Although males had higher binding antibodies than females, ADCC and ADCP activities were similar. The complex challenge outcomes may reflect differences in IgG subtypes, Fc glycosylation, Fc-R polymorphisms, and/or the microbiome, key areas for future studies. This first demonstration of a sex-difference in SIV vaccine-induced protection emphasizes the need for sex-balancing in vaccine trials. Our results highlight the importance of mucosal immunity and memory B cells at the SIV exposure site for protection.