DNA origami vaccines program antigen-focused germinal centers
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE305729 | GEO | 2026/08/12
REPOSITORIES: GEO
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Project description:A strategy for improving protective humoral immunity against infectious diseases is to directly modulate the germinal center (GC) through immunogen design, such as germline targeting. However, there remains a critical need for next generation vaccine approaches to elicit improved GC responses resulting in increased antibody specificity, diversity, and durability. Here, we investigated whether a cytokine could be scaffolded on nanoparticles to enhance antigen-specific GC responses and drive maturation of B cell lineages. We designed a chimeric nanoparticle using the GT8-60mer, a germline-targeting HIV immunogen, as a model to scaffold IL-21, a canonical GC cytokine. Delivered using plasmid DNA, nanoparticle immunoadjuvant complexes (NICs) scaffolding GT8 and IL-21 (GT8-IL-21-NIC) drove improved serum antibody titers, antigen-specific GC B cells, and functional Tfh cell responses relative to antigen-only nanoparticles and to co-delivery of IL-21 monomer. Immunization with the GT8-IL-21-NIC also improve humoral immune response durability, with improved bone marrow plasma cell responses. Transcriptomic analysis of GT8-specific GC B cells from GT8-IL-21-NIC immunized mice demonstrated upregulation of selection-associated gene signatures. Utilizing mice harboring human VRC01-class bnAb precursor heavy and light chain genes, immunization with the GT8-IL-21-NIC led to enhanced GC responses with increased antibody diversity, clonal expansion, and somatic hypermutation, with B cells acquiring an increased number of key VRC01-class broadly neutralizing antibody mutations. Thus, generating NICs using IL-21 may provide value as a tool to improve antigen-specific GC responses and vaccine-induced immunity.
2026-03-18 | GSE311626 | GEO
Project description:An effective prophylactic HIV vaccine will likely need to induce broadly neutralizing antibodies (bnAbs). BnAbs to the Apex region of the HIV envelope glycoprotein (Env) are promising targets for vaccination due to their relatively low somatic hypermutation compared with other bnAbs. Most Apex bnAbs engage Env using an exceptionally long heavy chain complementarity determining region 3 (HCDR3) containing specific binding motifs, which reduces bnAb precursor frequency and makes priming of rare bnAb precursors a likely limiting step in the path to Apex bnAb induction. We found that adjuvanted protein or mRNA-LNP immunization of rhesus macaques with ApexGT6, an Env trimer engineered to bind Apex bnAb precursors, consistently induced Apex bnAb-related precursors with long HCDR3s bearing bnAb-like sequence motifs. Cryo-electron microscopy revealed that elicited Apex bnAb-related HCDR3s possessed structures combining elements of several prototype Apex bnAbs. These results achieve an important HIV vaccine development milestone in outbred primates.
2025-08-25 | GSE304129 | GEO
Project description:Germline-targeting immunogens hold promise for initiating the induction of broadly neutralizing antibodies (bnAbs) to human immunodeficiency virus (HIV) and other pathogens.
However, antibody-antigen recognition is typically dominated by heavy chain complementarity determining region 3 (HCDR3) interactions, and vaccine priming of HCDR3-dominant bnAbs by germline-targeting immunogens has not been demonstrated in humans or outbred animals. We found that immunization with N332-GT5, an HIV envelope trimer designed to target precursors of the HCDR3-dominant bnAb BG18, primed bnAb-precursor B cells in 8 of 8 rhesus macaques to substantial frequencies, and with diverse lineages, in germinal center and memory B cells. We confirmed bnAb-mimicking, HCDR3-dominant, trimer-binding interactions with cryo-electron microscopy. The results demonstrate proof of principle for priming of HCDR3-dominant bnAb precursors in outbred animals, suggest that N332-GT5 has promise to induce similar responses in humans, and encourage application of HCDR3-dominant germline-targeting for other bnAbs to HIV and additional pathogens.
2024-02-26 | MSV000094174 | MassIVE
Project description:Germline-targeting (GT) HIV vaccine strategies are predicated on deriving broadly neutralizing antibodies (bnAbs) through multiple boost immunogens. However, as the recruitment of memory B cells (MBCs) to germinal centers (GCs) is inefficient and may be derailed by serum antibody-induced epitope masking, driving further B cell receptor (BCR) modification in GC-experienced B cells after boosting poses a challenge. Using humanized Ig knockin mice, we found that GT protein trimer immunogen N332-GT5 could prime inferred-germline precursors to the V3-glycan-targeted bnAb BG18, and that B cells primed by N332-GT5 were effectively boosted by either of two novel protein immunogens designed to have minimum cross-reactivity with the off target V1-binding responses. The delivery of the prime and boost immunogens as mRNA-LNPs generated long-lasting GCs, somatic hypermutation, and affinity maturation, and may, therefore, be an effective tool in HIV vaccine development.
2024-02-26 | MSV000094176 | MassIVE
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:Inducing broadly neutralizing antibodies (bnAbs) against HIV remains a key challenge in vaccine development. Germline targeting immunogens have successfully primed bnAb B cell lineages to individual HIV envelope epitopes in humans and non-human primates. However, eliciting consistent breadth will require the induction of multiple bnAb classes. We investigated whether immunization with a combination of germline-targeting immunogens could concurrently prime multiple bnAb lineages in non-human primates. Animals were immunized with three immunogens, targeting distinct epitopes: the V3-glycan/N332 supersite, the V2 Apex region and the membrane-proximal external region (MPER), either individually or in combinations of two or all three. Triple combination immunization transiently reduced V2 Apex and V3-glycan responses, but by 8 weeks post-boost bnAb-precursor lineages were observed to all three epitopes. Similar somatic hypermutation was observed across groups, indicative of permissive germinal center responses. These findings support combination germline-targeting immunization as a viable strategy to prime multiple bnAb lineages simultaneously.
2025-12-17 | GSE306570 | GEO
Project description:Germinal centers (GCs) are the engines of antibody evolution. Using HIV Env protein immunogen priming in rhesus monkeys (RM) followed by a long period without further immunization, we demonstrate GC B cells (BGC) lasted at least 6 months. A 186-fold BGC cell increase was present by week 10 compared to a conventional immunization. Single cell transcriptional profiling revealed both light and dark zone GC states were sustained. Antibody somatic hypermutation (SHM) of BGC cells continued to accumulate throughout the 29-week priming period, with evidence of selective pressure. Env-binding BGC cells were still 49-fold above baseline at 29 weeks, suggesting they could be active for even longer periods of time. High HIV neutralizing antibody titers were generated after a single booster immunization. Fully glycosylated HIV trimer protein is a complex antigen, posing significant immunodominance challenges for B cells. Memory B cells (BMem) generated under these long priming conditions had higher levels of SHM, and both BMem cells and antibodies were more likely to recognize non-immunodominant epitopes. Numerous BGC cell lineage phylogenies spanning the >6-month GC period were identified, demonstrating continuous GC activity and selection for at least 191 days with no additional antigen exposure. A long prime, slow delivery (12-day) immunization approach holds promise for difficult vaccine targets, and suggests that patience can have great value for tuning GCs to maximize antibody responses.
2022-09-15 | GSE209904 | GEO
Project description:An alluring strategy for improving protective humoral immunity against infectious diseases would be to directly target the germinal center (GC). There remains a critical need for next generation vaccine approaches to elicit more potent GC responses and durable humoral immunity. Here, we investigated whether cytokines could be scaffolded on nanoparticles to further enhance antigen-specific GC responses. We designed a chimeric nanoparticle using the GT8-60mer, a germline-targeting HIV immunogen, as a model to scaffold IL-21. Nanoparticle immunoadjuvant complexes (NICs) scaffolding GT8 and IL-21 (GT8-IL-21-NIC) drove improved serum antibody titers, antigen-specific GC B cells, and functional Tfh cell responses relative to antigen-only nanoparticles and to co-delivery of IL-21 monomer. Single-cell RNA sequencing of antigen-specific GC B cells from GT8-IL-21-NIC immunized mice demonstrated upregulation of LZ and selection-associated gene signatures. The NIC platform was versatile and could support changes to both the antigen and cytokine domains utilizing numerous GC-associated cytokines. Thus, NICs may provide value as a tool to improve antigen-specific vaccine-induced immunity.
2025-10-01 | GSE278580 | GEO
Project description:The high antigenic diversity of HIV has been a major obstacle to development of a broadly protective vaccine. Nevertheless, protective HIV broadly neutralizing antibodies (bnAbs) exist and have been proposed as templates for vaccine development1-6. Germline-targeting is a conceptually radical vaccine design approach to elicit bnAbs, aiming to prime rare bnAb-precursor B cells possessing pre-determined human genetic and structural features shared with template bnAbs, and then guide B cell affinity maturation to potent bnAb evolution with heterologous boosters7-11. Although the approach has shown promise in clinical12-17 and pre-clinical18-34 studies, it faces many immunological challenges and, to date, has not succeeded in generating bnAbs in humans or nontransgenic animals. Here, we report an adjuvanted protein germline-targeting vaccine tested in outbred nonhuman primates that successfully generated bnAb-class memory B cells and sera capable of neutralizing diverse HIV clinical isolates. bnAb clonal lineages were generated in ≥50% of animals, achieving up to 46% neutralization breadth compared to the reference bnAb. Vaccine-induced bnAbs exhibited precise structural mimicry of human bnAb interactions with HIV envelope (Env), matching the germline-targeting predictions. Furthermore, serum bnAb activity developed in 44% of animals; in the most striking instance serum bnAb titers reached levels expected to confer protection against diverse HIV isolates. These results demonstrate proof of principle that germline-targeting vaccines can reproducibly elicit prespecified classes of bnAbs to prespecified epitopes under endogenous conditions, supporting further optimization of this approach for HIV vaccine development.
2026-06-24 | GSE326649 | GEO
Project description:Antibody heavy chain (HC) and light chain (LC) variable region exons are assembled by V(D)J recombination. V(D)J junctional regions encode complementarity-determining-region 3 (CDR3), an antigen-contact region immensely diversified through non-templated nucleotide additions ("N-regions") by terminal deoxynucleotidyl transferase (TdT). HIV-1 vaccine strategies seek to elicit human HIV-1 broadly neutralizing antibodies (bnAbs), such as the potent CD4-binding site VRC01-class bnAbs. Mice with primary B cells that express receptors (BCRs) representing bnAb precursors are used as vaccination models. VRC01-class bnAbs uniformly use human HC VH1-2 and commonly use human LCs Vk3-20 or Vk1-33 associated with an exceptionally short 5-amino-acid (5-aa) CDR3. Prior VRC01-class models had non-physiological precursor levels and/or limited precursor diversity. Here, we describe VRC01-class rearranging mice that generate more physiological primary VRC01-class BCR repertoires via rearrangement of VH1-2, as well as Vk1-33 and/or Vk3-20 in association with diverse CDR3s. Human-like TdT expression in mouse precursor B cells increased LC CDR3 length and diversity and also promoted generation of shorter LC CDR3s via N-region suppression of dominant microhomology-mediated Vk-to-Jk joins. Priming immunization with eOD-GT8 60mer, which strongly engages VRC01 precursors, induced robust VRC01-class germinal center (GC) B cell responses. Vk3-20-based responses were enhanced by N-region addition, which generates Vk3-20-to-Jk junctional sequence combinations that encode VRC01-class 5-aa CDR3s with a critical E residue. VRC01-class-rearranging models should facilitate further evaluation of VRC01-class prime and boost immunogens. These new VRC01-class mouse models establish a prototype for generation of vaccine-testing mouse models for other HIV-1 bnAb lineages that employ different HC or LC Vs.
2022-12-01 | GSE214884 | GEO