Ontology highlight
ABSTRACT:
PROVIDER: PRJNA384879 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:HIV-1 vaccine immunofocusing strategies have the potential to induce broadly reactive nAbs. Here, we engineered a panel of diverse, membrane-resident native HIV-1 trimers vulnerable to two broad targets of neutralizing antibodies (NAbs), the V2 apex and fusion peptide (FP). This dataset contains the raw files used to obtain site-spefific glycan analysis of the membrane-resident HIV-1 trimers
| MSV000088108 | MassIVE
Project description:N-glycans, which represent >50% mass of the HIV-1 envelope (Env) trimer, play important roles for virus-cell entry and immune evasion. How each glycan unit interacts to shape the Env protein-sugar complex and affects Env function is not well understood. Here, high-resolution glycomics analysis of two Env variants from the same donor, with differing functional characteristics and N-glycosylation-site composition, revealed that changes to key N-glycosylation-site not only affected the Env structure at distant locations, but also had a ripple effect on Env-wide glycan processing, virus infectivity, and antibody recognition and virus neutralization. Specifically, the N262 glycan, although not located in the CD4-binding site, controlled Env binding to the CD4 receptor, affected the recognition of Env by several glycan-dependent broadly neutralizing antibodies, and altered heterogeneity of glycosylation at several sites, with N156, N160, and N448 displaying limited glycan processing. Molecular dynamic simulations visualized how specific oligosaccharide positions can move to compensate for loss of a glycan. This study demonstrates how changes in individual glycan units can alter molecular dynamics and processing of the Env-glycan shield and, consequently, Env function.
2021-09-09 | PXD017941 | Pride
Project description:HCoV-NL63 is a coronavirus that can cause severe lower respiratory tract infections requiring hospitalization. Of great interest is understanding the HCoV-NL63 coronavirus spike glycoprotein trimer, which is the conformational machine responsible for entry into host cells and the sole target of neutralizing antibodies during infection. We utilized an electron-transfer/higher energy collision dissociation ion fragmentation scheme (Frese, C. K. et al., 2013.) in combination with cryo-electron microscopy to resolve the extensive glycan shield that obstructs the protein surface. These glycans provide a structural framework to understanding the accessibility of the protein to antibodies.
2016-09-27 | PXD004557 | Pride
Project description:Broadly HIV-1 neutralizing VRC01-class antibodies target the CD4-binding site of Env. They are derived from VH1-2*02 antibody heavy chains paired with rare light chains expressing five amino acid long CDRL3s. They have been isolated from infected subjects but have not yet been elicited by immunization. Env-derived immunogens capable of binding the germline forms of VRC01 B cell receptors on naïve B cells have been designed and evaluated in knock-in mice. However, the elicited antibodies cannot bypass glycans present on the conserved position N276 of Env, which restricts access to the CD4-binding site. Efforts to guide the appropriate maturation of these antibodies by sequential immunization have not yet been successful. Here, we report on a two-step immunization scheme that led to the maturation of VRC01-like antibodies capable of accommodating the N276 glycan and displaying autologous tier 2 neutralizing activities. Our results are relevant to clinical trials aiming to elicit VRC01 antibodies.
2020-05-26 | PXD015168 | Pride
Project description:HIV-1 infection begins with binding of the viral envelope glycoprotein Env to the host receptor CD4, triggering a series of conformational changes that lead to fusion of the virus and cell membranes. Env, a trimer of gp120 and gp41 subunits, occupies a ‘closed’ conformation with contacts between gp120 subunits at the apex, and transitions through an ‘open’ conformation with the gp120 subunits spread apart following CD4 binding. Using deep mutational scanning, sequence-fitness landscapes were mapped for full-length Env from the clade B BaL strain interacting with CD4, and broadly neutralizing antibodies VRC01 and PG16, which preferentially bind closed Env. Contacting residues are conserved for CD4 binding, and glycosylation at N262 is critical for accessing the high-affinity CD4-bound state. By comparison, VRC01 binding is resistant to most single amino acid substitutions, an ideal quality in a broadly neutralizing antibody. Also in contrast to CD4 interaction, Env interfacial residues are under tight selection for PG16 binding to maintain a closed conformation. Screening for mutations that enhanced PG16 binding, we identified several important sites, in particular neutralization of the electropositive apical cavity that we hypothesize promotes trimer opening by electrostatic repulsion. Mutations were combined to generate Quaternary Epitope Stabilized (QES) mutants with enhanced presentation of the PG16 epitope, and the mutations were partially transferable to other HIV-1 strains. These mutational analyses offer insight into Env conformational stabilization that may assist immunogen design.
2019-02-03 | GSE102276 | GEO
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:HCoV-NL63 is a coronavirus that can cause severe lower respiratory tract infections requiring hospitalization. Of great interest is understanding the HCoV-NL63 coronavirus spike glycoprotein trimer, which is the conformational machine responsible for entry into host cells and the sole target of neutralizing antibodies during infection. We utilized an electron-transfer/higher energy collision dissociation ion fragmentation scheme (Frese, C. K. et al., 2013.) in combination with cryo-electron microscopy to resolve the extensive glycan shield that obstructs the protein surface. These glycans provide a structural framework to understanding the accessibility of the protein to antibodies.
2020-03-13 | MSV000085098 | MassIVE
Project description:The COVID-19 pandemic prompted an unprecedented effort to develop effective countermeasures against SARS-CoV-2. While efficacious vaccines and certain therapeutic monoclonal antibodies are available, here, we report the development, cryo-EM structures and functional analyses of distinct potent monoclonal antibodies (mAbs) that neutralize SARS-CoV-2 and its variant B.1.351. We established a platform for rapid identification of highly potent and specific SARS-CoV-2-neutralizing antibodies by high-throughput B cell receptor single cell sequencing of spike receptor binding domain immunized animals. We identified two highly potent and specific SARS-CoV-2 neutralizing mAb clones that have single-digit nanomolar affinity and low-picomolar avidity. We also generated a bispecific antibody of these two lead clones. The lead monospecific and bispecific antibodies showed strong neutralization ability against prototypical SARS-CoV-2 and the highly contagious South African variant B.1.351 that post a further risk of reducing the efficacy of currently available therapeutic antibodies and vaccines. The lead mAbs showed potent in vivo efficacy against authentic SARS-CoV-2 in both prophylactic and therapeutic settings. We solved five cryo-EM structures at ~3 resolution of these neutralizing antibodies in complex with the ectodomain of the prefusion spike trimer, and revealed the molecular epitopes, binding patterns and conformations between the antibodies and spike RBD, which are distinct from existing antibodies. Our recently developed antibodies expand the repertoire of the toolbox of COVID-19 countermeasures against the SARS-CoV-2 pathogen and its emerging variants.
2022-01-11 | GSE174635 | 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