The saponin monophosphoryl lipid A nanoparticle adjuvant induces dose-dependent HIV vaccine responses in non-human primates
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ABSTRACT:
ORGANISM(S): Macaca mulatta
PROVIDER: GSE291681 | GEO | 2025/03/11
REPOSITORIES: GEO
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Project description:Saponin-based vaccine adjuvants are potent in preclinical animal models and humans, but their mechanisms of action remain poorly understood. Using a stabilized HIV envelope trimer as a model immunogen, we carried out studies in non-human primates (NHPs), comparing the most common clinical adjuvant alum and Saponin/MPLA Nanoparticles (SMNP), a novel ISCOMs-like adjuvant. SMNP elicited substantially stronger humoral immune responses than alum and induced strong type I interferon transcriptional signatures, expansion of innate immune cells, and increased antigen presenting cell activation in LNs. These findings indicate that SMNP promotes multiple facets of the early immune response relevant for enhanced immunity to vaccination.
2024-07-01 | GSE264685 | GEO
Project description:Generating durable humoral immunity through vaccination depends upon effective interaction of follicular helper T cells (Tfh) with germinal center (GC) B cells. Th1 polarization of Tfh cells is an important process shaping the success of Tfh-GC B cell interactions by influencing co-stimulatory and cytokine-dependent Tfh help to B cells. However, the question remains whether adjuvant-dependent modulation of Tfh cells enhances HIV-1 vaccine-induced anti-Envelope (Env) antibody responses. We investigated whether an HIV-1 vaccine platform designed to increase the number of Th1-polarized Tfh cells enhances the magnitude and quality of anti-Env antibodies. Utilizing a novel interferon-induced protein (IP)-10-adjuvanted HIV-1 DNA prime, followed by an MPLA+QS-21-adjuvanted Env protein boost in macaques (DIP-10 PALFQ), we observed higher anti-Env serum IgG titers with greater cross-clade reactivity, specificity to V1V2, and effector functions when compared to macaques primed with DNA lacking IP-10 and boosted with MPLA+alum-adjuvanted Env protein (DPALFA) The DIP-10 PALFQ vaccine regimen elicited higher anti-Env IgG1 and lower IgG4 antibodies in serum, showing for the first time that adjuvants can dramatically impact the IgG subclass profile in macaques. The DIP-10 PALFQ regimen also increased vaginal and rectal IgA antibodies to a greater extent. Within lymph nodes, we observed augmented GC B cell responses and promotion of Th1 gene expression profiles in GC Tfh cells. The frequency of GC Tfh cells correlated with both the magnitude and avidity of anti-Env serum IgG. Together, these data suggest that adjuvant-induced stimulation of Th1-Tfh cells is an effective strategy for enhancing the magnitude and quality of anti-Env antibody response.
2019-12-10 | GSE141707 | GEO
Project description:CD4 T follicular helper cells (Tfh) are essential for establishing serological memory and have distinct helper attributes that impact both the quantity and quality of the antibody response. Therefore, gaining insights into Tfh subsets promoting antibody persistence and functional capacity is crucial for vaccine design. We investigated the potential of inducing a mixed Tfh1/17 response to enhance HIV-1 Envelope (Env) antibodies to a DNA-prime/protein boost platform, utilizing rhesus macaques as our experimental model. Following immunization with Clade C gp140 protein formulated with cationic liposome-based formulation (CAF01), we successfully generated germinal center (GC) Tfh1/17 cells, in contrast to the predominance of GC Tfh1 cells induced with gp140 formulated in monophosphoryl lipid A+QS-21 (MPLA). Analysis of lymph nodes, employing proteomic and transcriptional approaches, demonstrated robust induction of GC responses across vaccine platforms with distinct qualitative and quantitative effects elicited by MPLA versus CAF01. While the induction of GC Tfh1 cells with MPLA and GC Tfh1/17 cells with CAF01 resulted in comparable peak HIV-Env antibody levels, there was a notable difference in antibody persistence. The MPLA group demonstrated significantly greater antibody persistence at week 8 and up to 30 weeks after final immunization compared to CAF01. Inducing GC Tfh1 cells with MPLA furthermore enhanced tier 1 neutralization titers, antibody functions, and Env-specific IgG in the rectal mucosa. Notably, IFNγ+ Env-specific Tfh responses, both in blood and lymph nodes, were higher with MPLA and correlated with Env antibody persistence. These findings suggest that vaccine platforms maximizing GC Tfh1 induction may confer protective immunity against HIV.
2023-06-16 | GSE234813 | GEO
Project description:Vaccines incorporating slow release, multivalent antigen display, and/or immunomodulation through adjuvants have important roles in shaping the humoral immune response. Here, we analyzed mechanisms of action of a clinically relevant combination adjuvant strategy, where phosphoserine (pSer)-tagged immunogens bound to aluminum hydroxide (alum) adjuvant (promoting prolonged antigen release to draining lymph nodes) are combined with a potent saponin nanoparticle adjuvant termed SMNP (which alters lymph flow and antigen entry into lymph nodes). When employed with a stabilized HIV Env trimer antigen in mice, this combined adjuvant approach promoted substantial enhancements in germinal center (GC) and antibody responses relative to either adjuvant alone. Using scRNA-seq and scBCR-seq, we found that the alum-pSer/SMNP combination augmented the clonal expansion and diversity of GC B cell repertoire, coincident with increased expression of positive selection markers and proportion of S-phase GC B cells. To gain insight into the source of these changes in the GC response, we analyzed antigen biodistribution and structural integrity in draining lymph nodes and found that the combination adjuvant approach, but not alum-pSer delivery or SMNP alone, promoted accumulation of intact antigen on follicular dendritic cells (FDCs), reflecting an integration of the effects by slowing antigen release and altering lymph node uptake. Ablating the Cr1/2 complex on FDCs significantly hampered antigen-specific GC response, corroborating enhanced FDC decoration as the key mechanism of improved vaccine response. These results demonstrate how adjuvants with complementary mechanisms of action impacting vaccine biodistribution and kinetics can synergize to enhance humoral immunity.
2025-02-04 | GSE288450 | GEO
Project description:Broadly neutralizing antibodies (bnAbs) to the HIV envelope (Env) V2-apex region are important leads for HIV vaccine design. Most V2-apex bnAbs engage Env with an uncommonly long heavy chain complementarity-determining region 3 (HCDR3), suggesting that rarity of bnAb precursors poses a challenge for vaccine priming. We created precursor sequence definitions for V2-apex HCDR3-dependent bnAbs and searched for related precursors in human antibody heavy chain ultradeep sequencing data from 14 HIV-unexposed donors. We found potential precursors in a majority of donors for only two long-HCDR3 V2-apex bnAbs, PCT64 and PG9, identifying these bnAbs as priority vaccine targets. We then engineered ApexGT Env trimers that bind inferred germlines for PCT64 and PG9 and have higher affinities for bnAbs; determined cryo-EM structures of ApexGT trimers bound to inferred germline and bnAb forms of PCT64 and PG9; and developed an mRNA-encoded cell-surface trimer for our lead ApexGT candidate. The methods and immunogens developed here have promise to assist the development of an HIV vaccine.
2023-03-11 | PXD033766 | Pride
Project description:The saponin monophosphoryl lipid A nanoparticle adjuvant induces dose-dependent HIV vaccine responses in non-human primates
| PRJNA1234651 | ENA
Project description:Generation of Tier 2 HIV neutralizing antibody (nAb) responses by immunization remains a challenging problem, and the immunological barriers to induction of such responses by Env immunogens remain unclear. We explored these barriers by combining a suite of innovative techniques, including longitudinal lymph node fine needle aspirates, germinal center (GC) B cell lineage tracking, and a new method for detecting and quantifying GC T follicular helper (GC Tfh) cells, in non-human primates immunized with a native-like HIV-1 Env trimer protein (BG505 SOSIP.v5.2). A majority of immunized animals (9/12) developed Tier 2 neutralizing antibodies (nAb). Tier 2 nAb development best correlated with GC B cell magnitude in response to later booster immunizations and the quality of the Tfh help. Notably, these immunological factors distinguished between qualitatively successful and unsuccessful vaccine Ab responses, as they correlated with nAb development but did not correlate with simple Env Ab binding titers. Therefore, direct probing of germinal centers in future vaccine trials is key, as this suite of technically robust approaches provides quantitation of the proximal immune correlates of neutralizing antibody development and could allow redesign of optimal multi-stage vaccination schedules.
2016-12-31 | GSE89148 | GEO
Project description:The HIV-1 envelope glycoprotein (Env) is the sole neutralizing determinant on the surface of the virus. The Env gp120 and gp41 subunits mediate receptor binding and membrane fusion and are generated from the gp160 precursor by cellular furins. This cleavage event is required for viral entry. One approach to generate HIV-1 neutralizing antibodies following immunization is to express membrane-bound Env anchored on the cell-surface by genetic means using the natural HIV gp41 transmembrane (TM) spanning domain. To simplify the process of Env trimer membrane expression we sought to remove the need for Env precursor cleavage while maintaining native-like conformation following genetic expression. To accomplish these objectives, we selected our previously developed 'native flexibly linked' (NFL) stabilized soluble trimers that are both near native in conformation and cleavage-independent. We genetically fused the NFL construct to the HIV TM domain by using a short linker or by restoring the native membrane external proximal region, absent in soluble trimers, to express the full HIV Env ectodomain on the plasma membrane. Both forms of cell-surface NFL trimers, without and with the MPER, displayed favorable antigenic profiles by flow cytometry when expressed from plasmid DNA or mRNA. These results were consistent with the presence of well-ordered cell surface native-like trimeric Env, a necessary requirement to generate neutralizing antibodies by vaccination. Inoculation of rabbits with mRNA lipid nanoparticles (LNP) expressing membrane-bound stabilized HIV Env NFL trimers generated tier 2 neutralizing antibody serum titers in immunized animals. Multiple inoculations of mRNA LNPs generated similar neutralizing antibody titers compared to immunizations of matched NFL soluble proteins in adjuvant. Given the recent success of mRNA vaccines to prevent severe COVID, these are important developments for genetic expression of native-like HIV Env trimers in animals and potentially in humans.
2024-05-31 | MSV000094915 | MassIVE
Project description:The HIV-1 genome gains access to the inside of a cell via the mechanism of the viral spike protein Env, which undergoes a series of major conformational rearrangements after binding target receptors that ultimately drive virus-cell membrane fusion. Env is expressed as a heterogenous ensemble of conformations, which can inappropriately misdirect the host immune response towards the production of non-protective, strain-specific antibodies. Potent, broadly neutralizing antibodies (bnAbs) frequently recognize a ‘closed’ Env conformation, and therefore Env has undergone significant engineering to stabilize the closed state for vaccine incorporation. Previously, we used deep mutational scanning of Env from a prototypical tier 1 clade B strain (BaL) to characterize the sequence-activity landscape for binding to PG16, a bnAb that preferentially binds the closed state. Mutations were identified that increased expression of closed Env and reduced conformational heterogeneity, but these mutations were only partially transferable to Env sequences from other strains. To generate an expanded set of mutations that may be broadly applicable to diverse HIV-1 strains, we present here the deep mutational scanning of Env from the tier 2 clade C strain DU422 for interactions with CD4 and PG16. Residues across the trimerization domain and trimer interface have low mutational tolerance for maintaining PG16 recognition. New mutations are identified that enhance presentation of the closed Env conformation, and these are applied to Env sequences spanning multiple clades and tiers.
2019-02-01 | GSE117328 | GEO
Project description:The 2009 H1N1 influenza pandemic has prompted a significant need for the development of efficient, single-dose, adjuvanted vaccines. Here we investigated the adjuvant potential of CpG oligodeoxynucleotide (ODN) when used with a human seasonal influenza virus vaccine in ferrets. We found that the CpG ODNadjuvanted vaccine effectively increased antibody production and activated type I interferon (IFN) responses compared to vaccine alone. Based on these findings, pegylated IFN- 2b (PEG-IFN) was also evaluated as an adjuvant in comparison to CpG ODN and complete FreundM-bM-^@M-^Ys adjuvant (CFA). Our results showed that all three vaccines with adjuvant added prevented seasonal human A/Brisbane/59/2007 (H1N1) virus replication more effectively than did vaccine alone. Gene expression profiles indicated that, as well as upregulating IFN-stimulated genes (ISGs), CpG ODN enhanced B-cell activation and increased Toll-like receptor 4 (TLR4) and IFN regulatory factor 4 (IRF4) expression, whereas PEG-IFN augmented adaptive immunity by inducing major histocompatibility complex (MHC) transcription and Ras signaling. In contrast, the use of CFA as an adjuvant induced limited ISG expression but increased the transcription of MHC, cell adhesion molecules, and B-cell activation markers. Taken together, our results better characterize the specific molecular pathways leading to adjuvant activity in different adjuvant-mediated influenza virus vaccinations. In this experiment, 3 ferrets in each group immunizied with different adjuvanted human seasonal vaccines of CFA plus vaccine, CpG plus vaccine, pegylated IFN-alpha plus vaccine and vaccine alone (PBS plus vaccine) and 4 ferrets from control group (PBS only) were anesthetized at day 1 post vaccination. The whole blodd was collected for RNA extraction and purification on the scheduled date. The subsequent gene expression analysis was performed with Affymetrix GeneChip Canine Genome 2.0 Array.
2011-02-11 | E-GEOD-27248 | biostudies-arrayexpress