Cryo-EM structure of human O-GlcNAcylation enzyme pair OGT-OGA complex.

O-GlcNAcylation is a conserved post-translational modification that attaches N-acetyl glucosamine (GlcNAc) to myriad cellular proteins. In response to nutritional and hormonal signals, O-GlcNAcylation regulates diverse cellular processes by modulating the stability, structure, and function of target proteins. Dysregulation of O-GlcNAcylation has been implicated in the pathogenesis of cancer, diabetes, and neurodegeneration.

Identification of a cross-neutralizing antibody that targets the receptor binding site of H1N1 and H5N1 influenza viruses.

Influenza A viruses pose a significant threat globally each year, underscoring the need for a vaccine- or antiviral-based broad-protection strategy. Here, we describe a chimeric monoclonal antibody, C12H5, that offers neutralization against seasonal and pandemic H1N1 viruses, and cross-protection against some H5N1 viruses. Notably, C12H5 mAb offers broad neutralizing activity against H1N1 and H5N1 viruses by controlling virus entry and egress, and offers protection against H1N1 and H5N1 viral challenge in vivo.

Structural basis for the synergistic neutralization of coxsackievirus B1 by a triple-antibody cocktail.

Coxsackievirus B1 (CVB1) is an emerging pathogen associated with severe neonatal diseases including aseptic meningitis, myocarditis, and pancreatitis and also with the development of type 1 diabetes. We characterize the binding and therapeutic efficacies of three CVB1-specific neutralizing antibodies (nAbs) identified for their ability to inhibit host receptor engagement. High-resolution cryo-EM structures showed that these antibodies recognize different epitopes but with an overlapping region in the capsid VP2 protein and specifically the highly variable EF loop.

Structures of pseudorabies virus capsids.

Pseudorabies virus (PRV) is a major etiological agent of swine infectious diseases and is responsible for significant economic losses in the swine industry. Recent data points to human viral encephalitis caused by PRV infection, suggesting that PRV may be able to overcome the species barrier to infect humans. To date, there is no available therapeutic for PRV infection.

Cryo-EM structures reveal the molecular basis of receptor-initiated coxsackievirus uncoating.

Enterovirus uncoating receptors bind at the surface depression ("canyon") that encircles each capsid vertex causing the release of a host-derived lipid called "pocket factor" that is buried in a hydrophobic pocket formed by the major viral capsid protein, VP1. Coxsackievirus and adenovirus receptor (CAR) is a universal uncoating receptor of group B coxsackieviruses (CVB). Here, we present five high-resolution cryoEM structures of CVB representing different stages of virus infection.

Structural basis for the shared neutralization mechanism of three classes of human papillomavirus type 58 antibodies with disparate modes of binding.

Human papillomavirus type 58 (HPV58) is associated with cervical cancer and poses a significant health burden worldwide. Although the commercial 9-valent HPV vaccine covers HPV58, the structural and molecular-level neutralization sites of the HPV58 complete virion are not fully understood. Here, we report the high-resolution (∼3.

Structural characterization of a neutralizing mAb H16.001, a potent candidate for a common potency assay for various HPV16 VLPs.

With more human papillomavirus (HPV) virus-like particle (VLP) vaccines to hit the market in future, a monoclonal antibody (mAb) with preferably comparable reactivity against vaccines from different expression systems and bioprocesses is urgently needed for the potency characterization. Among all mAbs against HPV16 collected, rabbit mAb H16.001 is potently neutralizing with the highest affinity, recognizes an immune-dominant epitope, and can comparably react with HPV16 vaccines from various sources.

Near-atomic cryo-electron microscopy structures of varicella-zoster virus capsids.

Varicella-zoster virus (VZV) is a medically important human herpesvirus that causes chickenpox and shingles, but its cell-associated nature has hindered structure studies. Here we report the cryo-electron microscopy structures of purified VZV A-capsid and C-capsid, as well as of the DNA-containing capsid inside the virion. Atomic models derived from these structures show that, despite enclosing a genome that is substantially smaller than those of other human herpesviruses, VZV has a similarly sized capsid, consisting of 955 major capsid protein (MCP), 900 small capsid protein (SCP), 640 triplex dimer (Tri2) and 320 triplex monomer (Tri1) subunits.

Rational design of a multi-valent human papillomavirus vaccine by capsomere-hybrid co-assembly of virus-like particles.

The capsid of human papillomavirus (HPV) spontaneously arranges into a T = 7 icosahedral particle with 72 L1 pentameric capsomeres associating via disulfide bonds between Cys175 and Cys428. Here, we design a capsomere-hybrid virus-like particle (chVLP) to accommodate multiple types of L1 pentamers by the reciprocal assembly of single C175A and C428A L1 mutants, either of which alone encumbers L1 pentamer particle self-assembly. We show that co-assembly between any pair of C175A and C428A mutants across at least nine HPV genotypes occurs at a preferred equal molar stoichiometry, irrespective of the type or number of L1 sequences.

Structure guided maturation of a novel humanized anti-HBV antibody and its preclinical development.

We have reported that E6F6, a mouse monoclonal antibody, is a promising treatment option for patients with chronic hepatitis B (CHB). A humanized E6F6 antibody B11 with affinity loss was obtained by CDR-grafting approach. To address this issue, in silico affinity maturation through scanning mutagenesis using CHARMM force field methods was performed on an predicted immune complex model of the B11:HBsAg.

Identification of Antibodies with Non-overlapping Neutralization Sites that Target Coxsackievirus A16.

Hand, foot, and mouth disease is a common childhood illness primarily caused by coxsackievirus A16 (CVA16), for which there are no current vaccines or treatments. We identify three CVA16-specific neutralizing monoclonal antibodies (nAbs) with therapeutic potential: 18A7, 14B10, and NA9D7. We present atomic structures of these nAbs bound to all three viral particle forms-the mature virion, A-particle, and empty particle-and show that each Fab can simultaneously occupy the mature virion.

Viral neutralization by antibody-imposed physical disruption.

In adaptive immunity, organisms produce neutralizing antibodies (nAbs) to eliminate invading pathogens. Here, we explored whether viral neutralization could be attained through the physical disruption of a virus upon nAb binding. We report the neutralization mechanism of a potent nAb 8C11 against the hepatitis E virus (HEV), a nonenveloped positive-sense single-stranded RNA virus associated with abundant acute hepatitis.

Neutralization sites of human papillomavirus-6 relate to virus attachment and entry phase in viral infection.

Human papillomavirus type 6 (HPV6) is the major etiologic agent of genital warts and recurrent respiratory papillomatosis. Although the commercial HPV vaccines cover HPV6, the neutralization sites and mode for HPV6 are poorly understood. Here, we identify the HPV6 neutralization sites and discriminate the inhibition of virus attachment and entry by three potent neutralizing antibodies (nAbs), 5D3, 17D5, and 15F7.

T = 4 Icosahedral HIV-1 Capsid As an Immunogenic Vector for HIV-1 V3 Loop Epitope Display.

The HIV-1 mature capsid (CA) assumes an amorphous, fullerene conical configuration due to its high flexibility. How native CA self-assembles is still unclear despite having well-defined structures of its pentamer and hexamer building blocks. Here we explored the self-assembly of an engineered capsid protein built through artificial disulfide bonding (CA N21C/A22C) and determined the structure of one fraction of the globular particles.

Atomic structures of enterovirus D68 in complex with two monoclonal antibodies define distinct mechanisms of viral neutralization.

Enterovirus D68 (EV-D68) undergoes structural transformation between mature, cell-entry intermediate (A-particle) and empty forms throughout its life cycle. Structural information for the various forms and antibody-bound capsids will facilitate the development of effective vaccines and therapeutics against EV-D68 infection, which causes childhood respiratory and paralytic diseases worldwide. Here, we report the structures of three EV-D68 capsid states representing the virus at major phases.

Discovery and structural characterization of a therapeutic antibody against coxsackievirus A10.

Coxsackievirus A10 (CVA10) recently emerged as a major pathogen of hand, foot, and mouth disease and herpangina in children worldwide, and lack of a vaccine or a cure against CVA10 infections has made therapeutic antibody identification a public health priority. By targeting a local isolate, CVA10-FJ-01, we obtained a potent antibody, 2G8, against all three capsid forms of CVA10. We show that 2G8 exhibited both 100% preventive and 100% therapeutic efficacy against CVA10 infection in mice.

N-terminal truncations on L1 proteins of human papillomaviruses promote their soluble expression in Escherichia coli and self-assembly in vitro.

Human papillomavirus (HPV) is the causative agent in genital warts and nearly all cervical, anogenital, and oropharyngeal cancers. Nine HPV types (6, 11, 16, 18, 31, 33, 45, 52, and 58) are associated with about 90% of cervical cancers and 90% of genital warts. HPV neutralization by vaccine-elicited neutralizing antibodies can block viral infection and prevent HPV-associated diseases.

Crystal Structures of Two Immune Complexes Identify Determinants for Viral Infectivity and Type-Specific Neutralization of Human Papillomavirus.

Persistent, high-risk human papillomavirus (HPV) infection is the primary cause of cervical cancer. Neutralizing antibodies elicited by L1-only virus-like particles (VLPs) can block HPV infection; however, the lack of high-resolution structures has limited our understanding of the mode of virus infection and the requirement for type specificity at the molecular level. Here, we describe two antibodies, A12A3 and 28F10, that specifically bind to and neutralize HPV58 and HPV59, respectively, through two distinct binding stoichiometries.

Atomic structures of Coxsackievirus A6 and its complex with a neutralizing antibody.

Coxsackievirus A6 (CVA6) has recently emerged as a major cause of hand, foot and mouth disease in children worldwide but no vaccine is available against CVA6 infections. Here, we demonstrate the isolation of two forms of stable CVA6 particles-procapsid and A-particle-with excellent biochemical stability and natural antigenicity to serve as vaccine candidates. Despite the presence (in A-particle) or absence (in procapsid) of capsid-RNA interactions, the two CVA6 particles have essentially identical atomic capsid structures resembling the uncoating intermediates of other enteroviruses.

Stop codon mutagenesis for homogenous expression of human papillomavirus L1 protein in Escherichia coli.

Human papillomavirus (HPV) is widely accepted to be the major causative pathogen of cervical cancer, warts, and other epithelial tumors. Virus infection and subsequent disease development can be prevented by vaccination with HPV vaccines derived from eukaryotic expression systems. Here, we report the soluble expression of the major capsid protein L1 of HPV31, a dominant carcinogenic HPV genotype, in Escherichia coli.