Mus
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA1284875 | ENA |
REPOSITORIES: ENA
Similar Datasets
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: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: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: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: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: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:Interventions to induce lasting HIV remission are needed to obviate the requirement for lifelong antiretroviral therapy (ART). Durable post-intervention control (PIC) of viremia has been achieved in a subset of individuals following broadly neutralizing anti-HIV-1 antibody (bNAb) administration and analytical treatment interruption (ATI)1-4. Prior studies support a role for CD8+ T cells5-9 but the precise features of CD8+ T cells involved in PIC remain unclear. Here we mapped and functionally profiled CD8+ T cell responses to autologous HIV epitopes using longitudinal samples from four ATI trials in bNAb recipients. PIC was associated with superior pre-intervention HIV-specific CD8+ T cell proliferative capacity, stem cell-like memory phenotype, and recall cytotoxicity against autologous HIV peptide-pulsed CD4+ T cells. CD8+ T cell stemness was further increased following bNAb administration without emergence of new clonotypes targeting defined HLA-optimal epitopes. Multimodal single-cell analyses revealed molecular features associated with PIC and HIV-specific CD8+ T cell stemness, including signatures of metabolic fitness and reduced T cell exhaustion. These results identify immune features that precede subsequent PIC to inform the development of combination immunotherapies that will elicit durable HIV remission.
2025-10-10 | GSE294440 | 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
Project description:HIV-1-specific broadly-neutralizing antibodies (bnAb) typically develop in individuals with continuous high-level viral replication and increased immune activation, conditions that cannot be reproduced during prophylactic immunization. Understanding mechanisms supporting bnAb development in the absence of high-level viremia may be important for designing bnAb-inducing immunogens. Here, we show that the breadth of neutralizing antibody responses in HIV-1 controllers was associated with a relative enrichment of circulating CXCR5+ CXCR3+ PD-1Lo CD4 T cells. These CXCR3+ PD-1Lo Tfh-like cells were preferentially induced in vitro by functionally superior dendritic cells from controller neutralizers, and able to secrete IL-21 and support B cells. In addition, these CXCR3+ PD-1Lo Tfh-like cells contain higher proportions of stem cell-like memory T cells, and upon antigenic stimulation differentiated into PD-1Hi Tfh-like cells in a Notch-dependent manner. Together, these data suggest that CXCR5+ CXCR3+ PD-1Lo cells represent a dendritic cell-primed precursor cell population for PD-1Hi Tfh-like cells that may contribute to the generation of bnAbs in the absence of high–level viremia.
2017-02-01 | GSE90897 | GEO
Project description:Peptides generated by proteasome-catalyzed splicing of non-contiguous amino acid sequences have been shown to constitute a source of non-templated human leukocyte antigen class I (HLA-I) epitopes, but their role in pathogen-specific immunity remains unknown. CD8+ T cells are key mediators of human immunodeficiency virus type 1 (HIV-1) control, and identification of novel epitopes to enhance targeting of infected cells is a priority for prophylactic and therapeutic strategies. To explore the contribution of proteasome-catalyzed peptide splicing (PCPS) to HIV-1 epitope generation, we developed a broadly-applicable mass spectrometry-based discovery workflow that we employed to identify spliced HLA-I-bound peptides on HIV-infected cells. We demonstrate that HIV-1-derived spliced peptides comprise a novel, but relatively minor, component of the HLA-I-bound viral immunopeptidome. Although spliced HIV-1 peptides may elicit CD8+ T cell responses relatively infrequently during infection, CD8+ T cells primed by partially-overlapping contiguous epitopes in HIV-infected individuals were able to cross-recognize spliced viral peptides, suggesting a potential role for PCPS in restricting HIV-1 escape pathways. Vaccine-mediated priming of responses to spliced HIV-1 epitopes could thus provide a novel means of exploiting epitope targets typically under-utilized during natural infection.
2019-11-25 | PXD015489 | Pride