Publisher Correction: A glycoprotein B-neutralizing antibody structure at 2.8 Å uncovers a critical domain for herpesvirus fusion initiation

Human cytomegalovirus (HCMV) is an important pathogen in transplant patients and in congenital infection. Previously, we demonstrated that vaccination with a recombinant viral glycoprotein B (gB)/MF59 adjuvant formulation before solid organ transplant reduced viral load parameters post transplant. Reduced posttransplant viremia was directly correlated with antibody titers against gB consistent with a humoral response against gB being important. Here we show that sera from the vaccinated seronegative patients displayed little evidence of a neutralizing antibody response against cell-free HCMV in vitro. Additionally, sera from seronegative vaccine recipients had minimal effect on the replication of a strain of HCMV engineered to be cell-associated in a viral spread assay. Furthermore, although natural infection can induce antibody-dependent cellular cytotoxicity (ADCC) responses, serological analysis of seronegative vaccinees again presented no evidence of a substantial ADCC-promoting antibody response being generated de novo. Finally, analyses for responses against major antigenic domains of gB following vaccination were variable, and their pattern was distinct compared with natural infection. Taken together, these data argue that the protective effect elicited by the gB vaccine is via a mechanism of action in seronegative vaccinees that cannot be explained by neutralization or the induction of ADCC. More generally, these data, which are derived from a human challenge model that demonstrated that the gB vaccine is protective, highlight the need for more sophisticated analyses of new HCMV vaccines over and above the quantification of an ability to induce potent neutralizing antibody responses in vitro.

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Trypanosoma cruzi trans-Sialidase in Complex with a Neutralizing Antibody: Structure/Function Studies towards the Rational Design of Inhibitors

PLoS Pathogens ◽

10.1371/journal.ppat.1002474 ◽

2012 ◽

Vol 8 (1) ◽

pp. e1002474 ◽

Cited By ~ 29

Author(s):

Alejandro Buschiazzo ◽

Romina Muiá ◽

Nicole Larrieux ◽

Tamara Pitcovsky ◽

Juan Mucci ◽

...

Keyword(s):

Trypanosoma Cruzi ◽

Structure Function ◽

Rational Design ◽

Neutralizing Antibody ◽

Antibody Structure

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Induction of Neutralizing Antibody against Human Cytomegalovirus (HCMV) with DNA-Mediated Immunization of HCMV Glycoprotein B in Mice

Microbiology and Immunology ◽

10.1111/j.1348-0421.1999.tb02409.x ◽

1999 ◽

Vol 43 (3) ◽

pp. 307-310 ◽

Cited By ~ 10

Author(s):

Eung-soo Hwang ◽

Kyung-bae Kwon ◽

Jae-won Park ◽

Dae-joong Kim ◽

Chung-gyu Park ◽

...

Keyword(s):

Human Cytomegalovirus ◽

Neutralizing Antibody ◽

Glycoprotein B

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Potent Bispecific Neutralizing Antibody Targeting Glycoprotein B and the gH/gL/pUL128/130/131 Complex of Human Cytomegalovirus

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.02422-20 ◽

2020 ◽

Vol 65 (3) ◽

Cited By ~ 1

Author(s):

Hang Su ◽

Xiaohua Ye ◽

Daniel C. Freed ◽

Leike Li ◽

Zhiqiang Ku ◽

...

Keyword(s):

Human Cytomegalovirus ◽

Neutralizing Antibodies ◽

Developmental Disorders ◽

Bispecific Antibody ◽

Hcmv Infection ◽

Rhesus Macaques ◽

Congenital Infection ◽

Neutralizing Antibody ◽

Glycoprotein B ◽

Single Chain

ABSTRACT Human cytomegalovirus (HCMV) is a ubiquitous pathogen that can cause developmental disorders following congenital infection and life-threatening complications among transplant patients. Potent neutralizing monoclonal antibodies (MAbs) are promising drug candidates against HCMV infection. HCMV can infect a broad range of cell types. Therefore, single neutralizing antibodies targeting one HCMV glycoprotein often lack either potency or broad cell-type coverage. We previously characterized two human-derived HCMV neutralizing MAbs. One was the broadly neutralizing MAb 3-25, which targets the antigenic domain 2 of glycoprotein B (gB). The other was the highly potent MAb 2-18, which specifically recognizes the gH/gL/pUL128/130/131 complex (pentamer). To combine the strengths of gB- and pentamer-targeting MAbs, we developed an IgG–single-chain variable fragment (scFv) bispecific antibody by fusing the 2-18 scFv to the heavy-chain C terminus of MAb 3-25. The resulting bispecific antibody showed high-affinity binding to both gB and pentamer. Functionally, the bispecific antibody demonstrated a combined neutralization breadth and potency of the parental MAbs in multiple cell lines and inhibited postinfection viral spreading. Furthermore, the bispecific antibody was easily produced in CHO cells at a yield above 1 g/liter and showed a single-dose pharmacokinetic profile comparable to that of parental MAb 3-25 in rhesus macaques. Importantly, the bispecific antibody retained broadly and potent neutralizing activity after 21 days in circulation. Taken together, our research provides a proof-of-concept study for developing bispecific neutralizing antibody therapies against HCMV infection.

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Enveloped Virus-Like Particle Expression of Human Cytomegalovirus Glycoprotein B Antigen Induces Antibodies with Potent and Broad Neutralizing Activity

Clinical and Vaccine Immunology ◽

10.1128/cvi.00662-13 ◽

2013 ◽

Vol 21 (2) ◽

pp. 174-180 ◽

Cited By ~ 40

Author(s):

Marc Kirchmeier ◽

Anne-Catherine Fluckiger ◽

Catalina Soare ◽

Jasminka Bozic ◽

Barthelemy Ontsouka ◽

...

Keyword(s):

Epithelial Cell ◽

Human Cytomegalovirus ◽

Neutralizing Antibodies ◽

Matrix Protein ◽

High Titer ◽

Neutralizing Antibody ◽

Glycoprotein B ◽

Solid Organ ◽

Neutralizing Activity ◽

Enveloped Virus

ABSTRACTA prophylactic vaccine to prevent the congenital transmission of human cytomegalovirus (HCMV) in newborns and to reduce life-threatening disease in immunosuppressed recipients of HCMV-infected solid organ transplants is highly desirable. Neutralizing antibodies against HCMV confer significant protection against infection, and glycoprotein B (gB) is a major target of such neutralizing antibodies. However, one shortcoming of past HCMV vaccines may have been their failure to induce high-titer persistent neutralizing antibody responses that prevent the infection of epithelial cells. We used enveloped virus-like particles (eVLPs), in which particles were produced in cells after the expression of murine leukemia virus (MLV) viral matrix protein Gag, to express either full-length CMV gB (gB eVLPs) or the full extracellular domain of CMV gB fused with the transmembrane and cytoplasmic domains from vesicular stomatitis virus (VSV)-G protein (gB-G eVLPs). gB-G-expressing eVLPs induced potent neutralizing antibodies in mice with a much greater propensity toward epithelial cell-neutralizing activity than that induced with soluble recombinant gB protein. An analysis of gB antibody binding titers and T-helper cell responses demonstrated that high neutralizing antibody titers were not simply due to enhanced immunogenicity of the gB-G eVLPs. The cells transiently transfected with gB-G but not gB plasmid formed syncytia, consistent with a prefusion gB conformation like those of infected cells and viral particles. Two of the five gB-G eVLP-induced monoclonal antibodies we examined in detail had neutralizing activities, one of which possessed particularly potent epithelial cell-neutralizing activity. These data differentiate gB-G eVLPs from gB antigens used in the past and support their use in a CMV vaccine candidate with improved neutralizing activity against epithelial cell infection.

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HCMV glycoprotein B subunit vaccine efficacy was mediated by non-neutralizing antibody effector functions

10.1101/246884 ◽

2018 ◽

Cited By ~ 2

Author(s):

Cody S. Nelson ◽

Tori Huffman ◽

Eduardo Cisneros de la Rosa ◽

Guanhua Xie ◽

Nathan Vandergrift ◽

...

Keyword(s):

Human Cytomegalovirus ◽

Vaccine Efficacy ◽

Subunit Vaccine ◽

Hcmv Infection ◽

Neutralizing Antibody ◽

The United States ◽

Glycoprotein B ◽

Vaccine Platform ◽

Effector Functions ◽

Epitope Specificity

AbstractHuman cytomegalovirus (HCMV) is the most common congenital infection worldwide, frequently causing hearing loss and brain damage in afflicted infants. A vaccine to prevent maternal acquisition of HCMV during pregnancy is necessary to reduce the incidence of infant disease. The glycoprotein B (gB) + MF59 adjuvant subunit vaccine platform is the most successful HCMV vaccine tested to-date, demonstrating approximately 50% efficacy in preventing HCMV acquisition in phase II trials. However, the mechanism of vaccine protection remains unknown. Plasma from 33 gB/MF59 vaccinees at peak immunogenicity was tested for gB epitope specificity as well as neutralizing and non-neutralizing anti-HCMV effector functions, and compared to an HCMV-seropositive cohort. gB/MF59 vaccination elicited IgG responses with gB-binding magnitude and avidity comparable to natural infection. Additionally, IgG subclass distribution was similar with predominant IgG1 and IgG3 responses induced by gB vaccination and HCMV infection. However, vaccine-elicited antibodies exhibited limited neutralization of the autologous virus, negligible neutralization of multiple heterologous strains, and limited binding responses against gB structural motifs targeted by neutralizing antibodies including AD-1, AD-2, and Domain I. Interestingly, vaccinees had high-magnitude IgG responses against AD-3 linear epitopes, demonstrating immunodominance against this non-neutralizing, cytosolic region. Finally, vaccine-elicited IgG robustly bound trimeric, membrane-associated gB on the surface of transfected or HCMV-infected cells and mediated virion phagocytosis, though were poor mediators of NK cell activation. Altogether, these data suggest that non-neutralizing antibody functions, including virion phagocytosis, likely played a role in the observed 50% vaccine-mediated protection against HCMV acquisition.SignificanceThe CDC estimates that every hour, a child is born in the United States with permanent neurologic disability resulting from human cytomegalovirus (HCMV) infection – more than is caused by Down syndrome, fetal alcohol syndrome, and neural tube defects combined. A maternal vaccine to block transmission of HCMV to the developing fetus is a necessary intervention to prevent these adverse outcomes. The gB/MF59 vaccine is the most successful tested clinically to-date, achieving 50% reduction in HCMV acquisition. This manuscript establishes the function and epitope specificity of the humoral response stimulated by this vaccine that may explain the partial vaccine efficacy. Understanding the mechanism of gB/MF59-elicited protective immune responses will guide rational design and evaluation of the next generation of HCMV vaccines.

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HCMV glycoprotein B nucleoside-modified mRNA vaccine elicits antibody responses with greater durability and breadth than MF59-adjuvanted gB protein immunization

10.1101/797894 ◽

2019 ◽

Author(s):

Cody S. Nelson ◽

Jennifer A. Jenks ◽

Norbert Pardi ◽

Matthew Goodwin ◽

Hunter Roark ◽

...

Keyword(s):

Protein Structure ◽

Human Cytomegalovirus ◽

Neutralizing Antibody ◽

The United States ◽

Antibody Responses ◽

Full Length ◽

Glycoprotein B ◽

Transplant Recipients ◽

Igg Binding ◽

Infant Birth

AbstractA vaccine to prevent maternal acquisition of human cytomegalovirus (HCMV) during pregnancy is a primary strategy to reduce the incidence of congenital disease. Similarly, vaccination of transplant recipients against HCMV has been proposed to prevent transplant-associated HCMV morbidity. The MF59-adjuvanted glycoprotein B protein subunit vaccine (gB/MF59) is the most efficacious tested to-date for both indications. We previously identified that gB/MF59 vaccination elicited poor neutralizing antibody responses and an immunodominant response against gB antigenic domain 3 (AD-3). Thus, we sought to test novel gB vaccines to improve functional antibody responses and reduce AD-3 immunodominance. Groups of juvenile New Zealand White rabbits were administered 3 sequential doses of full-length gB protein with an MF59-like squalene adjuvant (analogous to clinically-tested vaccine), gB ectodomain protein (lacking AD-3) with squalene adjuvant, or lipid nanoparticle (LNP)-packaged nucleoside-modified mRNA encoding full-length gB. The AD-3 immunodominant IgG response following human gB/MF59 vaccination was closely mimicked in rabbits, with 78% of binding antibodies directed against this region in the full-length gB protein group compared to 1% and 46% in the ectodomain and mRNA-LNP-vaccinated groups, respectively. All vaccines were highly immunogenic with similar kinetics and comparable peak gB-binding and functional antibody responses. Although gB ectodomain subunit vaccination reduced targeting of non-neutralizing epitope AD-3, it did not improve vaccine-elicited neutralizing or non-neutralizing antibody functions. gB nucleoside-modified mRNA-LNP-immunized rabbits exhibited enhanced durability of IgG binding to soluble and cell membrane-associated gB protein as well as HCMV-neutralizing function. Furthermore, the gB mRNA-LNP vaccine enhanced breadth of IgG binding responses against discrete gB peptide residues. Finally, low-magnitude gB-specific T cell activity was observed in the full-length gB protein and mRNA-LNP vaccine groups, though not in ectodomain-vaccinated rabbits. Altogether, these data suggest that the gB mRNA-LNP vaccine candidate, aiming to improve upon the partial efficacy of gB/MF59 vaccination, should be further evaluated in preclinical models.Author summaryHuman cytomegalovirus (HCMV) is the most common infectious cause of infant birth defects, resulting in permanent neurologic disability for one newborn child every hour in the United States. Furthermore, this virus causes significant morbidity and mortality in immune-suppressed transplant recipients. After more than a half century of research and development, we remain without a clinically-licensed vaccine or therapeutic to reduce the burden of HCMV-associated disease. In this study, we sought to improve upon the glycoprotein B protein vaccine (gB/MF59), the most efficacious HCMV vaccine evaluated in clinical trial, via targeted modifications to either the protein structure or vaccine formulation. An attempt to alter the protein structure to focus the immune response on vulnerable epitopes (‘gB ectodomain’) had little effect on the quality or function of the vaccine-elicited antibodies. However, a novel vaccine platform, nucleoside-modified mRNA formulated in lipid nanoparticles, increased the durability and breadth of vaccine-elicited immune responses. We propose that an mRNA-based gB vaccine may ultimately prove more efficacious than the gB/MF59 vaccine and should be further evaluated for its ability to elicit antiviral immune factors that can prevent both infant and transplant-associated disease caused by HCMV infection.

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