The XBB.1.5 COVID-19 vaccine elicits a durable antibody response to ancestral and XBB.1.5 SARS-CoV-2 spike proteins.

The rapid emergence of divergent SARS-CoV-2 variants led to a 2023-2024 update of the COVID-19 mRNA vaccine to a monovalent version containing the XBB.1.5 SARS-CoV-2 spike antigen.

Systemic and Mucosal Humoral Immune Responses to Lumazine Synthase 60-mer Nanoparticle SARS-CoV-2 Vaccines.

Vaccines that stimulate systemic and mucosal immunity to a level required to prevent SARS-CoV-2 infection and transmission are an unmet need. Highly protective hepatitis B and human papillomavirus nanoparticle vaccines highlight the potential of multivalent nanoparticle vaccine platforms to provide enhanced immunity. Here, we report the construction and characterization of self-assembling 60-subunit icosahedral nanoparticle SARS-CoV-2 vaccines using the bacterial enzyme lumazine synthase (LuS).

First-generation N-terminal domain supersite public antibodies retain activity against Omicron-derived lineages and protect mice against Omicron BA.5 challenge.

Unlabelled: Monoclonal antibodies to SARS-CoV-2 can offer prophylactic and therapeutic protection against severe disease, with particular utility for immunosuppressed and vulnerable populations. With the constant emergence of new variants, understanding the neutralizing potency of monoclonal antibodies to dynamic spike protein epitopes is crucial. We show that a set of VH1-24-derived N-terminal domain (NTD)-directed antibodies, isolated from a convalescent donor early in the pandemic, displayed remarkable neutralization resilience against many Omicron SARS-CoV-2 variants, including BA.

Fostemsavir analog BMS-818251 has enhanced viral neutralization potency and similar escape mutation profile.

BMS-818251, a fostemsavir analog, is a next-generation HIV-1 attachment inhibitor with enhanced potency and a similar resistance profile. By using viral outgrowth assays with HIV+ donor samples, we demonstrate here that BMS-818251 exhibits superior viral suppression compared to temsavir, the active form of fostemsavir. To map potential resistance pathways, we employed deep mutational scanning and pseudotyped virus neutralization assays to identify escape mutations within the HIV-1 envelope glycoprotein (Env).

Structural and genetic basis of HIV-1 envelope V2 apex recognition by rhesus broadly neutralizing antibodies.

Broadly neutralizing antibodies targeting the V2 apex of HIV-1 envelope are desired as vaccine design templates, but few have been described. Here, we report 11 lineages of V2 apex-neutralizing antibodies from simian-human immunodeficiency virus (SHIV)-infected rhesus macaques and determine cryo-EM structures for 9. A single V2 apex-neutralizing lineage accounted for cross-clade breadth in most macaques, and somatic hypermutation relative to breadth was generally low, exemplified by antibody V033-a.

The N terminus of H3-influenza hemagglutinin as a site-of-vulnerability to neutralizing antibody.

The N terminus of the H3 subtype of influenza virus hemagglutinin is ∼10 residues longer than the N termini of most other hemagglutinins. As conserved, exposed, and linear regions may be good vaccine targets, we investigated the vaccine utility of the extended H3-N terminus. First, we identified antibody 5E10, for which structure and binding analyses revealed recognition of the H3-N terminus.

improvement of affinity for highly protective anti-malarial antibodies.

The monoclonal antibody CIS43 preferentially binds the junctional region of circumsporozoite protein (PfCSP) and is highly protective in humans. Here, we develop an pipeline to improve antigen-antibody interaction energies and apply it to CIS43 variants elicited in CIS43-germline knock-in mice. Improved binding of CIS43 variants to the CIS43 junctional epitope (PfCSP peptide 21) was achieved by introducing single and double amino acid substitutions in the peptide 21-proximal heavy- and light-chain-variable regions.

Rapid acquisition of HIV-1 neutralization breadth in a rhesus V2 apex germline antibody mouse model after a single bolus immunization.

Current vaccine strategies to elicit broadly neutralizing antibodies (bnAbs) against HIV-1 generally propose complex, multi-boost immunization regimens. In rhesus macaques, SHIV infection has been observed to rapidly drive the development of some classes of bnAbs that share structural similarities with those in humans. Here, we generated a knockin mouse model with B cells bearing the unmutated common ancestor (UCA) of the V2 apex-targeted bnAb lineage, V033-a.

GLYCO-2: a Tool to Quantify Glycan Shielding of Glycosylated Proteins with Improved Data Processing and Computation Speed.

Motivation: Glycans bound to glycoproteins mediate immune response, including antibody recognition and immune evasion. Previously, we developed an tool GLYCO (GLYcan COverage) to quantify the glycan shielding of a protein surface, applying it to various studies. However, GLYCO lacks sufficient computational efficiency when analyzing larger datasets.

Transient glycan shield reduction induces CD4-binding site broadly neutralizing antibodies in SHIV-infected macaques.

Broadly neutralizing antibodies (bNAbs) targeting the HIV-1 CD4-binding site (CD4bs) occur infrequently in macaques and humans and have not been reproducibly elicited in any outbred animal model. To address this challenge, we first isolated RHA10, an infection-induced rhesus bNAb with 51% breadth. The cryoelectron microscopy (cryo-EM) structure of RHA10 with the HIV-1 envelope (Env) resembled prototypic human CD4bs bNAbs with CDR-H3-dominated binding.

Env-antibody coevolution identifies B cell priming as the principal bottleneck to HIV-1 V2 apex broadly neutralizing antibody development.

Broadly neutralizing antibodies (bNAbs) are rarely elicited during HIV-1 infection. To identify obstacles to bNAb development, we longitudinally studied 122 rhesus macaques infected by one of 16 different simian-human immunodeficiency viruses (SHIVs). We identified V2 apex as the most common bNAb target and a subset of Envs that preferentially elicited these antibodies.

Structural insights from vaccine candidates for EV-D68.

Enterovirus D68 (EV-D68), a member of the Picornaviridae family, causes respiratory illness and can lead to acute flaccid myelitis in children. No specific treatment or vaccine is available. Here, we determine cryo-EM structures of EV-D68 virus-like particles (VLPs), inactivated virus particles (InVPs), and altered virus particles (A-particles) from B3 and A2 subclades.

Antigen persistence and TLR stimulation contribute to induction of a durable HIV-1-specific neutralizing antibody response.

HIV-1 Env glycoprotein (Env) immunogenicity is limited in part by structural instability and extensive glycan shielding and is likely the greatest obstacle to an HIV-1 vaccine. Stabilized Env trimers can elicit serum neutralizing antibodies, but the response is short-lived. Here we use Newcastle Disease Virus-like particle (NDV-VLP) platform to present stabilized versions of HIV-1 Env at high valency and in the context of varied conformational stability, adjuvants, dose, and antigen persistence.

Safety and pharmacokinetics of N6LS, a broadly neutralising monoclonal antibody for HIV: a phase 1, open-label, dose-escalation study in healthy adults.

Background: Broadly neutralising antibodies (bNAbs) have shown promise as both prevention and treatment strategies against HIV-1. The clinical effectiveness of bNAbs depends on enhancing their neutralisation breadth and extending their serum half-lives. In this study, we aimed to assess the safety, tolerability, pharmacokinetic profile, and neutralisation activity in serum of N6LS, a HIV-1 bNAb.

Conformational trajectory of the HIV-1 fusion peptide during CD4-induced envelope opening.

The hydrophobic fusion peptide (FP), a critical component of the HIV-1 entry machinery, is located at the N terminus of the envelope (Env) gp41 subunit. The receptor-binding gp120 subunit of Env forms a heterodimer with gp41. The gp120/gp41 heterodimer assembles into a homotrimer, in which FP is accessible for antibody binding.

Snake venom protection by a cocktail of varespladib and broadly neutralizing human antibodies.

Snake envenomation is a neglected tropical disease, with 600 species causing over 100,000 deaths and 300,000 permanent disabilities in humans annually. Broadly neutralizing antibodies and broad chemical inhibitors have been proposed as solutions, but how to develop a therapeutically effective cocktail and the number of required components have been unclear. To address this gap, we iteratively recovered two broadly neutralizing antivenom antibodies from the memory B cells of a hyperimmune human donor with extensive snake venom exposure.

Intranasal parainfluenza virus-vectored vaccine expressing SARS-CoV-2 spike protein of Delta or Omicron B.1.1.529 induces mucosal and systemic immunity and protects hamsters against homologous and heterologous challenge.

The continuous emergence of new SARS-CoV-2 variants requires that COVID vaccines be updated to match circulating strains. We generated B/HPIV3-vectored vaccines expressing 6P-stabilized S protein of the ancestral, B.1.

Phenotypic heterogeneity defines B cell responses to repeated SARS-CoV-2 exposures through vaccination and infection.

Long-lived humoral memory is key to durable immunity against pathogens yet remains challenging to define due to heterogeneity among antigen-reactive B cells. We addressed this gap through longitudinal sampling over the course of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mRNA vaccinations with or without breakthrough infection. High-dimensional phenotypic profiling performed on ∼72 million B cells showed that receptor-binding domain (RBD) reactivity was associated with five distinct immunoglobulin G (IgG) B cell populations.

A broadly protective human antibody for GI genogroup noroviruses.

Noroviruses infect millions each year, and while effective countermeasures are eagerly sought, none have been reported for the GI genogroup, first described more than 50 years ago. Here, to provide insight into GI norovirus neutralization, we isolated a broad GI antibody, 16E10, from a human blood donor and showed it neutralizes noroviruses in human enteroid cultures and abrogates or reduces infection in rhesus macaques. The cryogenic electron microscopy reconstruction of 16E10 with a norovirus protruding-domain dimer at 2.

Distinct binding modes drive the broad neutralization profile of two persistent influenza hemagglutinin stem-specific antibody lineages.

Elicitation of antibodies to the influenza hemagglutinin stem is a critical part of universal influenza vaccine strategies. While numerous broadly reactive stem antibodies have been isolated, our understanding of how these antibodies mature within the human B cell repertoire is limited. Here, we isolated and tracked two stem-specific antibody lineages over a decade in a single participant that received multiple seasonal and pandemic influenza vaccinations.

Broadly neutralizing antibodies targeting pandemic GII.4 variants or seven GII genotypes of human norovirus.

Human norovirus causes more than 700 million illnesses annually. Extensive genetic diversity and a paucity of information on conserved neutralizing epitopes pose major obstacles to the design of broadly protective norovirus immunogens. Here, we used high-resolution liquid chromatography-tandem mass spectrometry (LC-MS/MS)-driven proteomics to quantitatively characterize the circulating serum IgG repertoire before and after immunization with an experimental monovalent norovirus GII.

Structural basis for complement receptor engagement and virus neutralization through Epstein-Barr virus gp350.

Epstein-Barr virus (EBV) causes infectious mononucleosis and is associated with malignancies in humans. Viral infection of B cells is initiated by the viral glycoprotein 350 (gp350) binding to complement receptor 2 (CR2). Despite decades of effort, no vaccines or curative agents have been developed, partly due to lack of atomic-level understanding of the virus-host interface.

Structure of a zoonotic H5N1 hemagglutinin reveals a receptor-binding site occupied by an auto-glycan.

Highly pathogenic avian influenza has spilled into many mammals, most notably cows and poultry, with several dozen human breakthrough infections. Zoonotic crossovers, with hemagglutinins mutated to enhance viral ability to use human α2-6-linked sialic acid receptors versus avian α2-3-linked ones, highlight the pandemic risk. To gain insight into these crossovers, we determined the cryoelectron microscopy (cryo-EM) structure of the hemagglutinin from the zoonotic H5N1 A/Texas/37/2024 strain (clade 2.

Structural development of the HIV-1 apex-directed PGT145-PGDM1400 antibody lineage.

Broadly neutralizing antibodies (bNAbs) targeting the apex of the HIV-1-envelope (Env) trimer comprise the most potent category of HIV-1 bNAbs and have emerged as promising therapeutics. Here, we investigate the development of the HIV-1 apex-directed PGT145-PGDM1400 antibody lineage and report cryo-EM structures at 3.4 Å resolution of PGDM1400 and of an improved PGT145 variant (PGT145-R100aS), each bound to the BG505 Env trimer.

Transient glycan-shield reduction induces CD4-binding site broadly neutralizing antibodies in SHIV-infected macaques.

Unlabelled: Broadly neutralizing antibodies (bNAbs) targeting the HIV-1 CD4-binding site (CD4bs) occur infrequently in macaques and humans and have not been reproducibly elicited in any outbred animal model. To address this challenge, we first isolated RHA10, an infection-induced rhesus bNAb with 51% breadth. The cryo-EM structure of RHA10 with HIV-1 envelope (Env) resembled prototypic human CD4bs bNAbs with CDR-H3-dominated binding.