scholarly journals RSV Vaccine Based on Rhabdoviral Vector Protects after Single Immunization

Vaccines ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 59 ◽  
Author(s):  
Wilmschen ◽  
Schneider ◽  
Peters ◽  
Bayer ◽  
Issmail ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Lymphocytic Choriomeningitis ◽  
Effective Vaccine ◽  
Vector Vaccine ◽  
Viral Loads ◽  
Glycoprotein G ◽  
Infected Cells ◽  
Vesicular Stomatitis ◽  
Syncytial Virus ◽  
Tract Infections

The respiratory syncytial virus (RSV) is one major cause of lower respiratory tract infections in childhood and an effective vaccine is still not available. We previously described a new rhabdoviral vector vaccine, VSV-GP, a variant of the vesicular stomatitis virus (VSV), where the VSV glycoprotein G is exchanged by the glycoprotein GP of the lymphocytic choriomeningitis virus. Here, we evaluated VSV-GP as vaccine vector for RSV with the aim to induce RSV neutralizing antibodies. Wild-type F (Fwt) or a codon optimized version (Fsyn) were introduced at position 5 into the VSV-GP genome. Both F versions were efficiently expressed in VSV-GP-F infected cells and incorporated into VSV-GP particles. In mice, high titers of RSV neutralizing antibodies were induced already after prime and subsequently boosted by a second immunization. After challenge with RSV, viral loads in the lungs of immunized mice were reduced by 2–3 logs with no signs of an enhanced disease induced by the vaccination. Even a single intranasal immunization significantly reduced viral load by a factor of more than 100-fold. RSV neutralizing antibodies were long lasting and mice were still protected when challenged 20 weeks after the boost. Therefore, VSV-GP is a promising candidate for an effective RSV vaccine.

scholarly journals Glycoprotein B switches conformation during murid herpesvirus 4 entry

2008 ◽  
Vol 89 (6) ◽  
pp. 1352-1363 ◽  
Author(s):  
Laurent Gillet ◽  
Susanna Colaco ◽  
Philip G. Stevenson
Keyword(s):  
Neutralizing Antibodies ◽  
Structural Changes ◽  
Glycoprotein B ◽  
Cell Binding ◽  
Glycoprotein G ◽  
Late Endosomes ◽  
Endosomal Acidification ◽  
Infected Cells ◽  
Vesicular Stomatitis ◽  
Herpesvirus 4

Herpesviruses are ancient pathogens that infect all vertebrates. The most conserved component of their entry machinery is glycoprotein B (gB), yet how gB functions is unclear. A striking feature of the murid herpesvirus 4 (MuHV-4) gB is its resistance to neutralization. Here, we show by direct visualization of infected cells that the MuHV-4 gB changes its conformation between extracellular virions and those in late endosomes, where capsids are released. Specifically, epitopes on its N-terminal cell-binding domain become inaccessible, whilst non-N-terminal epitopes are revealed, consistent with structural changes reported for the vesicular stomatitis virus glycoprotein G. Inhibitors of endosomal acidification blocked the gB conformation switch. They also blocked capsid release and the establishment of infection, implying that the gB switch is a key step in entry. Neutralizing antibodies could only partially inhibit the switch. Their need to engage a less vulnerable, upstream form of gB, because its fusion form is revealed only in endosomes, helps to explain why gB-directed MuHV-4 neutralization is so difficult.

scholarly journals Epitope-Specific Serological Assays for RSV: Conformation Matters

Vaccines ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 23 ◽  
Author(s):  
Emily Phung ◽  
Lauren Chang ◽  
Kaitlyn Morabito ◽  
Masaru Kanekiyo ◽  
Man Chen ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Antigenic Site ◽  
Immune Monitoring ◽  
Effective Vaccine ◽  
F Protein ◽  
Correlates Of Protection ◽  
Vaccine Trials ◽  
Antigenic Sites ◽  
Syncytial Virus ◽  
The Impact

Respiratory syncytial virus (RSV) causes substantial morbidity and mortality in children and older adults. An effective vaccine must elicit neutralizing antibodies targeting the RSV fusion (F) protein, which exists in two major conformations, pre-fusion (pre-F) and post-fusion (post-F). Although 50% of the surface is shared, pre-F contains highly neutralization-sensitive antigenic sites not present on post-F. Recent advancement of several subunit F-based vaccine trials has spurred interest in quantifying and understanding the protective potential of antibodies directed to individual antigenic sites. Monoclonal antibody competition ELISAs are being used to measure these endpoints, but the impact of F conformation and competition from antibodies binding to adjacent antigenic sites has not been thoroughly investigated. Since this information is critical for interpreting clinical trial outcomes and defining serological correlates of protection, we optimized assays to evaluate D25-competing antibodies (DCA) to antigenic site Ø on pre-F, and compared readouts of palivizumab-competing antibodies (PCA) to site II on both pre-F and post-F. We show that antibodies to adjacent antigenic sites can contribute to DCA and PCA readouts, and that cross-competition from non-targeted sites is especially confounding when PCA is measured using a post-F substrate. While measuring DCA and PCA levels may be useful to delineate the role of antibodies targeting the apex and side of the F protein, respectively, the assay limitations and caveats should be considered when conducting immune monitoring during vaccine trials and defining correlates of protection.

scholarly journals Deficient Incorporation of Rabies Virus Glycoprotein into Virions Enhances Virus-Induced Immune Evasion and Viral Pathogenicity

Viruses ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 218 ◽  
Author(s):  
Chunfu Li ◽  
Hongliang Zhang ◽  
Lina Ji ◽  
Xiao Wang ◽  
Yongjun Wen ◽  
...  
Keyword(s):  
Immune Response ◽  
Rabies Virus ◽  
Recombinant Virus ◽  
Neutralizing Antibodies ◽  
Single Copy ◽  
Wild Type ◽  
Antiviral Immune Response ◽  
Glycoprotein G ◽  
Lethal Infection ◽  
Infected Cells

Previous studies have shown that wild-type (wt) rabies virus (RABV) evades the host immune response by restricting expression of glycoprotein (G), which blocks activation of dendritic cells (DCs) and induces production of virus-neutralizing antibodies (VNAs). In the present study, wt RABVs not only restricted G expression but also reduced incorporation of G into mature virions compared with laboratory-adapted viruses. A recombinant RABV expressing triple G was used to further determine whether G expression relates to incorporation. The recombinant virus showed higher expression and incorporation of G and activated more DCs than the virus that expressed a single copy of G. Removal of G from viruses using subtilisin or Dithiothreitol (DTT)/ Nonidet P-40 (NP40) almost completely abolishes DC activation and VNA production. Consequently, these G-depleted viruses cause lethal infection in mice. Thus, wt RABVs can subvert DC-induced antiviral immune response and maintain pathogenicity by decreasing G expression in infected cells and G incorporation into virions.

scholarly journals A Vaccine Based on the Rhesus Cytomegalovirus UL128 Complex Induces Broadly Neutralizing Antibodies in Rhesus Macaques

2012 ◽  
Vol 87 (3) ◽  
pp. 1322-1332 ◽  
Author(s):  
Felix Wussow ◽  
Yujuan Yue ◽  
Joy Martinez ◽  
Jesse D. Deere ◽  
Jeff Longmate ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Rhesus Macaques ◽  
Horizontal Transmission ◽  
Artificial Chromosome ◽  
Cell Types ◽  
Effective Vaccine ◽  
Broadly Neutralizing Antibodies ◽  
Viral Loads ◽  
Novel Approach ◽  
Congenital Hcmv Infection

ABSTRACTNeutralizing antibodies (NAb) are important for interfering with horizontal transmission of human cytomegalovirus (HCMV) leading to primary and congenital HCMV infection. Recent findings have shown that a pentameric virion complex formed by the glycoproteins gH/gL, UL128, UL130, and UL131A (UL128C) is required for HCMV entry into epithelial/endothelial cells (Epi/EC) and is the target of potent NAb in HCMV-seropositive individuals. Using bacterial artificial chromosome technology, we have generated a modified vaccinia Ankara virus (MVA) that stably coexpresses all 5 rhesus CMV (RhCMV) proteins homologous to HCMV UL128C, termed MVA-RhUL128C. Coimmunoprecipitation confirmed the interaction of RhgH with the other 4 RhCMV subunits of the pentameric complex. All 8 RhCMV-naïve rhesus macaques (RM) vaccinated with MVA-RhUL128C developed NAb that blocked infection of monkey kidney epithelial cells (MKE) and rhesus fibroblasts. NAb titers induced by MVA-RhUL128C measured on both cell types at 2 to 6 weeks postvaccination were comparable to levels observed in naturally infected RM. In contrast, MVA expressing a subset of RhUL128C proteins or RhgB glycoprotein only minimally stimulated NAb that inhibited infection of MKE. In addition, following subcutaneous RhCMV challenge at 8 weeks postvaccination, animals vaccinated with MVA-RhUL128C showed reduced plasma viral loads. These results indicate that MVA expressing the RhUL128C induces NAb inhibiting RhCMV entry into both Epi/EC and fibroblasts and limits RhCMV replication in RM. This novel approach is the first step in developing a prophylactic HCMV vaccine designed to interfere with virus entry into major cell types permissive for viral replication, a required property of an effective vaccine.

scholarly journals 2855. Respiratory Syncytial Virus Neutralizing Antibodies in Cord Blood and Serum from Infants up to 2 Years of Age in a Multinational Prospective Study

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S74-S75
Author(s):  
Joseph B Domachowske ◽  
Veronique Bianco ◽  
Ana Ceballos ◽  
Luis Cousin ◽  
Ulises D’Andrea ◽  
...  
Keyword(s):  
Respiratory Syncytial Virus ◽  
Cord Blood ◽  
Neutralizing Antibodies ◽  
Geometric Mean ◽  
Neutralizing Antibody ◽  
Neutralization Assay ◽  
Entire Cohort ◽  
Syncytial Virus ◽  
Tract Infections

Abstract Background Respiratory syncytial virus (RSV) is the most common cause of lower respiratory tract infections (LRTI) during infancy worldwide. High cord blood (CB) concentrations of anti-RSV neutralizing antibody (nAb) may attenuate, delay, or prevent infant infection. We report RSV A and B nAb concentrations in CB and serum from a birth cohort at different time points through 2 years of age. Methods Between 2013 and 2017, newborns from 8 countries were studied prospectively from birth to 2 years of age (NCT01995175). CB was collected at birth for the entire cohort. A subcohort of children was randomly assigned to have one blood sample collected again at either 2, 4, 6, 12, 18, or 24 months of age. Sera were analyzed for RSV A and B nAb concentrations by serum neutralization assay. Active surveillance was used to identify LRTIs during the 2-year follow-up as previously reported. Results In total, 2,401 newborns were enrolled and followed up. >99% of infants had detectable CB RSV A and B nAb. Geometric mean antibody titers (GMTs) varied by country, but were overall higher for RSV B than for RSV A (327 vs. 251; Figure 1). The lowest GMTs were seen from CB sera collected from South African newborns (197 RSV A, 255 RSV B); Canadian newborns had the highest RSV A GMT (383), while Hondurans had the highest RSV B GMT (460). 1380 infants provided follow-up serum nAb results as part of the subcohort (Figure 2). Dramatic waning of GMTs was evident, with a ~3-fold drop in GMTs at 2 months of age, and an additional ~2-fold drop between 2 and 4 months of age. At 6 and 12 months of age, 71% and 50% of infants had RSV A nAb and GMTs were at a nadir of 14. At 6, 12, and 18 months of age, RSV B nAb was detected in 98%, 69%, and 63% of infants, respectively. The RSV B nAb nadir GMT of 20 was observed at 12 months of age, while the 6- and 18-month RSV B nAb GMTs were 30 and 31, respectively. A total of 1,017 LRTIs were identified during the 2-year study period; of which, 94 (9%) were caused by RSV A and 132 (13%) by RSV B. Associations between CB nAb levels and RSV infection will be presented. Conclusion Neutralizing Ab to RSV A and B was present at birth in infants from 8 countries, and waned over time. GMTs were at a nadir at 6 to 12 months of age. Funding. GlaxoSmithKline Biologicals SA. Disclosures All Authors: No reported Disclosures.

scholarly journals Glycoprotein Exchange Vectors Based on Vesicular Stomatitis Virus Allow Effective Boosting and Generation of Neutralizing Antibodies to a Primary Isolate of Human Immunodeficiency Virus Type 1

2000 ◽  
Vol 74 (23) ◽  
pp. 10903-10910 ◽  
Author(s):  
Nina F. Rose ◽  
Anjeanette Roberts ◽  
Linda Buonocore ◽  
John K. Rose
Keyword(s):  
Human Immunodeficiency Virus ◽  
G Protein ◽  
Neutralizing Antibodies ◽  
High Titer ◽  
Primary Isolate ◽  
Effective Vaccine ◽  
Fourfold Increase ◽  
Immunodeficiency Virus ◽  
Vesicular Stomatitis ◽  
Hiv Envelope

ABSTRACT Live recombinant vesicular stomatitis viruses (VSVs) expressing foreign antigens are highly effective vaccine vectors. However, these vectors induce high-titer neutralizing antibody directed at the single VSV glycoprotein (G), and this antibody alone can prevent reinfection and boosting with the same vector. To determine if efficient boosting could be achieved by changing the G protein of the vector, we have developed two new recombinant VSV vectors based on the VSV Indiana serotype but with the G protein gene replaced with G genes from two other VSV serotypes, New Jersey and Chandipura. These G protein exchange vectors grew to titers equivalent to wild-type VSV and induced similar neutralizing titers to themselves but no cross-neutralizing antibodies to the other two serotypes. The effectiveness of these recombinant VSV vectors was illustrated in experiments in which sequential boosting of mice with the three vectors, all encoding the same primary human immunodeficiency virus (HIV) envelope protein, gave a fourfold increase in antibody titer to an oligomeric HIV envelope compared with the response in animals receiving the same vector three times. In addition, only the animals boosted with the exchange vectors produced antibodies neutralizing the autologous HIV primary isolate. These VSV envelope exchange vectors have potential as vaccines in immunizations when boosting of immune responses may be essential.

scholarly journals Vaccination with the RSV fusion protein formulated with a combination adjuvant induces long-lasting protective immunity

2014 ◽  
Vol 95 (5) ◽  
pp. 1043-1054 ◽  
Author(s):  
R. Garg ◽  
L. Latimer ◽  
V. Gerdts ◽  
A. Potter ◽  
S. van Drunen Littel-van den Hurk
Keyword(s):  
T Cells ◽  
Neutralizing Antibodies ◽  
Memory T Cells ◽  
Protective Efficacy ◽  
Affinity Maturation ◽  
Effector Memory ◽  
Polycytidylic Acid ◽  
Syncytial Virus ◽  
One Year ◽  
Tract Infections

Respiratory syncytial virus (RSV) is one of the primary causative agents of upper and lower respiratory tract infections in young children, in particular infants. Recently, we reported the protective efficacy of a RSV vaccine formulation consisting of a truncated version of the fusion (F) protein formulated with a Toll-like receptor (TLR) agonist and an immunostimulatory peptide in a carrier system (ΔF/TriAdj). To evaluate the duration of immunity induced by this vaccine candidate, we carried out long-term trials. The ΔF was formulated with triple adjuvant (TriAdj) containing either polyinosinic : polycytidylic acid (polyI : C) or cytosine-phosphate-guanosine oligodeoxynucleotides (CpG ODNs) and administered intranasally to mice. One year after the second vaccination all mice were challenged with RSV. Both ΔF/TriAdj formulations mediated the induction of high levels of IgG1, IgG2a and virus-neutralizing antibodies, and IgA in the lungs. Based on the numbers of IFN-γ- and IL-5-secreting cells in the spleen, the immune response was slightly T-helper cell type 1 (Th1)-biased. This was confirmed by the presence of F85–93-specific CD8+ effector T cells in the lungs of both ΔF/TriAdj(polyI : C)- and ΔF/TriAdj(CpG)-immunized mice. Both ΔF/TriAdj formulations induced RSV-specific CD8+ T cells. However, ΔF/TriAdj(polyI : C) generated significantly higher IgG affinity maturation and higher numbers of RSV-specific CD8+ effector memory T cells in lungs and CD8+ central memory T cells in spleen and lymph nodes than ΔF/TriAdj(CpG). After RSV challenge, no virus replication and no evidence of vaccine-induced pathology were detected in mice immunized with either of the ΔF/TriAdj formulations, demonstrating that the duration of immunity induced with these vaccines is at least one year.

scholarly journals Safe and effective two-in-one replicon-and-VLP minispike vaccine for COVID-19: Protection of mice after a single immunization

2021 ◽  
Vol 17 (4) ◽  
pp. e1009064
Author(s):  
Alexandru A. Hennrich ◽  
Bevan Sawatsky ◽  
Rosalía Santos-Mandujano ◽  
Dominic H. Banda ◽  
Martina Oberhuber ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Antigen Expression ◽  
Vaccine Platform ◽  
Dna And Rna ◽  
Glycoprotein G ◽  
Virus Like Particle ◽  
Main Target ◽  
Boost Immunization ◽  
Vesicular Stomatitis ◽  
Anchor Sequence

Vaccines of outstanding efficiency, safety, and public acceptance are needed to halt the current SARS-CoV-2 pandemic. Concerns include potential side effects caused by the antigen itself and safety of viral DNA and RNA delivery vectors. The large SARS-CoV-2 spike (S) protein is the main target of current COVID-19 vaccine candidates but can induce non-neutralizing antibodies, which might cause vaccination-induced complications or enhancement of COVID-19 disease. Besides, encoding of a functional S in replication-competent virus vector vaccines may result in the emergence of viruses with altered or expanded tropism. Here, we have developed a safe single round rhabdovirus replicon vaccine platform for enhanced presentation of the S receptor-binding domain (RBD). Structure-guided design was employed to build a chimeric minispike comprising the globular RBD linked to a transmembrane stem-anchor sequence derived from rabies virus (RABV) glycoprotein (G). Vesicular stomatitis virus (VSV) and RABV replicons encoding the minispike not only allowed expression of the antigen at the cell surface but also incorporation into the envelope of secreted non-infectious particles, thus combining classic vector-driven antigen expression and particulate virus-like particle (VLP) presentation. A single dose of a prototype replicon vaccine complemented with VSV G, VSVΔG-minispike-eGFP (G), stimulated high titers of SARS-CoV-2 neutralizing antibodies in mice, equivalent to those found in COVID-19 patients, and protected transgenic K18-hACE2 mice from COVID-19-like disease. Homologous boost immunization further enhanced virus neutralizing activity. The results demonstrate that non-spreading rhabdovirus RNA replicons expressing minispike proteins represent effective and safe alternatives to vaccination approaches using replication-competent viruses and/or the entire S antigen.

scholarly journals Nonglycosylated G-Protein Vaccine Protects against Homologous and Heterologous Respiratory Syncytial Virus (RSV) Challenge, while Glycosylated G Enhances RSV Lung Pathology and Cytokine Levels

2015 ◽  
Vol 89 (16) ◽  
pp. 8193-8205 ◽  
Author(s):  
Sandra Fuentes ◽  
Elizabeth M. Coyle ◽  
Hana Golding ◽  
Surender Khurana
Keyword(s):  
Respiratory Syncytial Virus ◽  
G Protein ◽  
Mammalian Cells ◽  
Neutralizing Antibodies ◽  
Protective Immunity ◽  
Protective Efficacy ◽  
Lung Pathology ◽  
Content Type ◽  
Viral Loads ◽  
Syncytial Virus

ABSTRACTNew efforts are under way to develop a vaccine against respiratory syncytial virus (RSV) that will provide protective immunity without the potential for vaccine-associated disease enhancement such as that observed in infants following vaccination with formalin-inactivated RSV vaccine. In addition to the F fusion protein, the G attachment surface protein is a target for neutralizing antibodies and thus represents an important vaccine candidate. However, glycosylated G protein expressed in mammalian cells has been shown to induce pulmonary eosinophilia upon RSV infection in a mouse model. In the current study, we evaluated in parallel the safety and protective efficacy of the RSV A2 recombinant unglycosylated G protein ectodomain (amino acids 67 to 298) expressed inEscherichia coli(REG) and those of glycosylated G produced in mammalian cells (RMG) in a mouse RSV challenge model. Vaccination with REG generated neutralizing antibodies against RSV A2 in 7/11 BALB/c mice, while RMG did not elicit neutralizing antibodies. Total serum binding antibodies against the recombinant proteins (both REG and RMG) were measured by surface plasmon resonance (SPR) and were found to be >10-fold higher for REG- than for RMG-vaccinated animals. Reduction of lung viral loads to undetectable levels after homologous (RSV-A2) and heterologous (RSV-B1) viral challenge was observed in 7/8 animals vaccinated with REG but not in RMG-vaccinated animals. Furthermore, enhanced lung pathology and elevated Th2 cytokines/chemokines were observed exclusively in animals vaccinated with RMG (but not in those vaccinated with REG or phosphate-buffered saline [PBS]) after homologous or heterologous RSV challenge. This study suggests that bacterially produced unglycosylated G protein could be developed alone or as a component of a protective vaccine against RSV disease.IMPORTANCENew efforts are under way to develop vaccines against RSV that will provide protective immunity without the potential for disease enhancement. The G attachment protein represents an important candidate for inclusion in an effective RSV vaccine. In the current study, we evaluated the safety and protective efficacy of the RSV A2 recombinant unglycosylated G protein ectodomain produced inE. coli(REG) and those of glycosylated G produced in mammalian cells (RMG) in a mouse RSV challenge model (strains A2 and B1). The unglycosylated G generated high protective immunity and no lung pathology, even in animals that lacked anti-RSV neutralizing antibodies prior to RSV challenge. Control of viral loads correlated with antibody binding to the G protein. In contrast, the glycosylated G protein provided poor protection and enhanced lung pathology after RSV challenge. Therefore, bacterially produced unglycosylated G protein holds promise as an economical approach to a protective vaccine against RSV.

scholarly journals Structure of a Major Antigenic Site on the Respiratory Syncytial Virus Fusion Glycoprotein in Complex with Neutralizing Antibody 101F

2010 ◽  
Vol 84 (23) ◽  
pp. 12236-12244 ◽  
Author(s):  
Jason S. McLellan ◽  
Man Chen ◽  
Jung-San Chang ◽  
Yongping Yang ◽  
Albert Kim ◽  
...  
Keyword(s):  
Respiratory Syncytial Virus ◽  
Neutralizing Antibodies ◽  
Antigenic Site ◽  
Neutralizing Antibody ◽  
Structural Basis ◽  
Effective Vaccine ◽  
Linear Epitope ◽  
Peptide Epitope ◽  
Fusion Glycoprotein ◽  
Syncytial Virus

ABSTRACT Respiratory syncytial virus (RSV) is a major cause of pneumonia and bronchiolitis in infants and elderly people. Currently there is no effective vaccine against RSV, but passive prophylaxis with neutralizing antibodies reduces hospitalizations. To investigate the mechanism of antibody-mediated RSV neutralization, we undertook structure-function studies of monoclonal antibody 101F, which binds a linear epitope in the RSV fusion glycoprotein. Crystal structures of the 101F antigen-binding fragment in complex with peptides from the fusion glycoprotein defined both the extent of the linear epitope and the interactions of residues that are mutated in antibody escape variants. The structure allowed for modeling of 101F in complex with trimers of the fusion glycoprotein, and the resulting models suggested that 101F may contact additional surfaces located outside the linear epitope. This hypothesis was supported by surface plasmon resonance experiments that demonstrated 101F bound the peptide epitope ∼16,000-fold more weakly than the fusion glycoprotein. The modeling also showed no substantial clashes between 101F and the fusion glycoprotein in either the pre- or postfusion state, and cell-based assays indicated that 101F neutralization was not associated with blocking virus attachment. Collectively, these results provide a structural basis for RSV neutralization by antibodies that target a major antigenic site on the fusion glycoprotein.

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