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 Effect of Previous Respiratory Syncytial Virus Infection on Murine Immune Responses to F and G Protein-Containing Virus-Like Particles

2019 ◽  
Vol 93 (9) ◽  
Author(s):  
Lori McGinnes Cullen ◽  
Madelyn R. Schmidt ◽  
Trudy G. Morrison
Keyword(s):  
Respiratory Syncytial Virus ◽  
G Protein ◽  
Neutralizing Antibodies ◽  
Protective Immunity ◽  
Immune Memory ◽  
Effective Vaccine ◽  
F Protein ◽  
Virus Like Particles ◽  
Rsv Infection ◽  
Syncytial Virus

ABSTRACTMost individuals are infected with respiratory syncytial virus (RSV) by age two, but infection does not result in long-term protective immunity to subsequent infections. Previous RSV infection may, however, impact responses to an RSV vaccine. The goal of these studies was to explore the effect of previous RSV infection on murine antibody responses to RSV F and G protein-containing virus-like particles (VLP), comparing responses to those resulting from VLP immunization of RSV-naive animals. These studies showed that after RSV infection, immunization with a single dose of VLPs containing a conformation-stabilized prefusion F protein stimulated high titers of neutralizing antibodies (NA), while an immunization with post-F-containing VLPs or a second RSV infection only weakly stimulated NA, even though total anti-F protein IgG antibody levels in both VLP-immunized animals were similar. Furthermore, single pre-F or post-F VLP immunization of animals previously infected (primed) with RSV resulted in total anti-F antibody titers that were 10- to 12-fold higher than titers after a VLP prime and boost of RSV-naive animals or after two consecutive RSV infections. The avidities of serum antibodies as well as numbers of splenic B cells and bone marrow cells after different immunization protocols were also assessed. The combined results show that RSV infection can quite effectively prime animals for the production of protective antibodies that can be efficiently activated by a pre-F VLP boost but not by a post-F VLP boost or a second RSV infection.IMPORTANCEHumans may experience repeated infections caused by the same serotype of respiratory syncytial virus (RSV), in contrast to infections with most other viruses, indicating that immune memory responses to RSV are defective. However, the effects of any residual but nonprotective immunity on responses to RSV vaccines are not clear. This study demonstrates that a VLP vaccine candidate containing a stabilized prefusion F protein can robustly stimulate protective immunity in animals previously infected with RSV, while a second RSV infection or a postfusion F-containing VLP cannot. This result shows that a properly constructed immunogen can be an effective vaccine in animals previously infected with RSV. The results also suggest that the defect in RSV memory is not in the induction of that memory but rather in its activation by a subsequent RSV infection.

scholarly journals Effects of Alterations to the CX3C Motif and Secreted Form of Human Respiratory Syncytial Virus (RSV) G Protein on Immune Responses to a Parainfluenza Virus Vector Expressing the RSV G Protein

2019 ◽  
Vol 93 (7) ◽  
Author(s):  
Bo Liang ◽  
Barbora Kabatova ◽  
Juraj Kabat ◽  
David W. Dorward ◽  
Xiang Liu ◽  
...  
Keyword(s):  
Respiratory Syncytial Virus ◽  
Immune Responses ◽  
G Protein ◽  
Protective Efficacy ◽  
Parainfluenza Virus ◽  
Host Immune Responses ◽  
Syncytial Virus ◽  
Human Parainfluenza Virus ◽  
Type 3 ◽  
Modified Forms

ABSTRACTHuman respiratory syncytial virus (RSV) is a major pediatric respiratory pathogen. The attachment (G) and fusion (F) glycoproteins are major neutralization and protective antigens. RSV G is expressed as membrane-anchored (mG) and -secreted (sG) forms, both containing a central fractalkine-like CX3C motif. The CX3C motif and sG are thought to interfere with host immune responses and have been suggested to be omitted from a vaccine. We used a chimeric bovine/human parainfluenza virus type 3 (rB/HPIV3) vector to express RSV wild-type (wt) G and modified forms, including sG alone, mG alone, mutants with ablated CX3C, and G with enhanced packaging into vector virions. In hamsters, these viruses replicated to similar titers. When assayed with a complement-enhanced neutralization assay in Vero cells, sG did not reduce the serum RSV- or PIV3-neutralizing antibody (NAb) responses, whereas ablating CX3C drastically reduced the RSV NAb response. Protective efficacy against RSV challenge was not reduced by sG but was strongly dependent on the CX3C motif. In ciliated human airway epithelial (HAE) cells, NAbs induced by wt G, but not by wt F, completely blocked RSV infection in the absence of added complement. This activity was dependent on the integrity of the CX3C motif. In hamsters, the rB/HPIV3 expressing wt G conferred better protection against RSV challenge than that expressing wt F. Codon optimization of the wt G further increased its immunogenicity and protective efficacy. This study showed that ablation of the CX3C motif or sG in an RSV vaccine, as has been suggested previously, would be ill advised.IMPORTANCEHuman RSV is the leading viral cause of severe pediatric respiratory illness. An RSV vaccine is not yet available. The RSV attachment protein G is an important protective and neutralization antigen. G contains a conserved fractalkine-like CX3C motif and is expressed in mG and sG forms. sG and the CX3C motif are thought to interfere with host immune responses, but this remains poorly characterized. Here, we used an attenuated chimeric bovine/human parainfluenza virus type 3 (rB/HPIV3) vector to express various modified forms of RSV G. We demonstrated that strong antibody and protective responses could be induced by G alone, and that this was highly dependent on the integrity of the CX3C motif. There was no evidence that sG or the CX3C motif impaired immune responses against RSV G or the rB/HPIV3 vector. rB/HPIV3 expressing wt RSV G provides a bivalent vaccine against RSV and HPIV3.

scholarly journals Replication-Competent or Attenuated, Nonpropagating Vesicular Stomatitis Viruses Expressing Respiratory Syncytial Virus (RSV) Antigens Protect Mice against RSV Challenge

2001 ◽  
Vol 75 (22) ◽  
pp. 11079-11087 ◽  
Author(s):  
Jeffrey S. Kahn ◽  
Anjeanette Roberts ◽  
Carla Weibel ◽  
Linda Buonocore ◽  
John K. Rose
Keyword(s):  
Respiratory Syncytial Virus ◽  
Neutralizing Antibodies ◽  
Protective Immunity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Complete Protection ◽  
Attractive Candidate ◽  
Fusion Glycoprotein ◽  
Vesicular Stomatitis ◽  
Syncytial Virus ◽  
Detectable Serum

ABSTRACT Foreign glycoproteins expressed in recombinant vesicular stomatitis virus (VSV) can elicit specific and protective immunity in the mouse model. We have previously demonstrated the expression of respiratory syncytial virus (RSV) G (attachment) and F (fusion) glycoprotein genes in recombinant VSV. In this study, we demonstrate the expression of RSV F and G glycoproteins in attenuated, nonpropagating VSVs which lack the VSV G gene (VSVΔG) and the incorporation of these RSV proteins into recombinant virions. We also show that intranasal vaccination of mice with nondefective VSV recombinants expressing RSV G (VSV-RSV G) or RSV F (VSV-RSV F) elicited RSV-specific antibodies in serum (by enzyme-linked immunosorbent assay [ELISA]) as well as neutralizing antibodies to RSV and afford complete protection against RSV challenge. In contrast, VSVΔG-RSV F induced detectable serum antibodies to RSV by ELISA, but no detectable neutralizing antibodies, yet it still protected from RSV challenge. VSVΔG-RSV G failed to induce any detectable serum (by ELISA) or neutralizing antibodies and failed to protect from RSV challenge. The attenuated, nonpropagating VSVΔG-RSV F is a particularly attractive candidate for a live attenuated recombinant RSV vaccine.

scholarly journals Newcastle Disease Virus-Like Particles Containing Respiratory Syncytial Virus G Protein Induced Protection in BALB/c Mice, with No Evidence of Immunopathology

2009 ◽  
Vol 84 (2) ◽  
pp. 1110-1123 ◽  
Author(s):  
Matthew R. Murawski ◽  
Lori W. McGinnes ◽  
Robert W. Finberg ◽  
Evelyn A. Kurt-Jones ◽  
Michael J. Massare ◽  
...  
Keyword(s):  
Respiratory Syncytial Virus ◽  
Newcastle Disease Virus ◽  
G Protein ◽  
Disease Virus ◽  
Newcastle Disease ◽  
Neutralizing Antibodies ◽  
Respiratory Infections ◽  
Chimeric Protein ◽  
Virus Like Particle ◽  
Syncytial Virus

ABSTRACT Respiratory syncytial virus (RSV) is the leading cause of serious respiratory infections in children as well as a serious cause of disease in elderly and immunosuppressed populations. There are no licensed vaccines available to prevent RSV disease. We have developed a virus-like particle (VLP) vaccine candidate for protection from RSV. The VLP is composed of the NP and M proteins of Newcastle disease virus (NDV) and a chimeric protein containing the cytoplasmic and transmembrane domains of the NDV HN protein and the ectodomain of the human RSV G protein (H/G). Immunization of mice with 10 or 40 μg total VLP-H/G protein by intraperitoneal or intramuscular inoculation stimulated antibody responses to G protein which were as good as or better than those stimulated by comparable amounts of UV-inactivated RSV. Immunization of mice with two doses or even a single dose of these particles resulted in the complete protection of mice from RSV replication in the lungs. Immunization with these particles induced neutralizing antibodies with modest titers. Upon RSV challenge of VLP-H/G-immunized mice, no enhanced pathology in the lungs was observed, although lungs of mice immunized in parallel with formalin-inactivated RSV (FI-RSV) showed the significant pathology that has previously been documented after immunization with FI-RSV. Thus, the VLP-H/G candidate vaccine was immunogenic in BALB/c mice and prevented replication of RSV in murine lungs, with no evidence of immunopathology. These data support further development of virus-like particle vaccine candidates for protection against RSV.

scholarly journals The antigenic and genetic variability of bovine respiratory syncytial virus with emphasis on the G protein

2012 ◽  
Vol 48 (No. 9) ◽  
pp. 254-266 ◽  
Author(s):  
V. Valentova
Keyword(s):  
Respiratory Syncytial Virus ◽  
Genetic Variability ◽  
G Protein ◽  
Viral Protein ◽  
Neutralizing Antibodies ◽  
Vaccine Development ◽  
Clinical Symptoms ◽  
Bovine Respiratory Syncytial Virus ◽  
Th2 Response ◽  
Syncytial Virus

Bovine respiratory syncytial virus (BRSV) and related human respiratory syncytial virus (HRSV) are major respiratory tract pathogens in calves and infants, respectively. Great attention is now paid to prevention of the disease caused by these agents. Glycoprotein G is the most variable viral protein and antigenic grouping of RSV isolates is based on distinct antigenic reactivity patterns determined with a set of G protein specific mAbs. Genetic variability of the G protein is used during epidemiology and epizootiology studies of HRSV and BRSV diseases, respectively. The constant genetic drift can be observed within G protein sequences. Both cell-mediated and antibody-mediated immune responses contribute to efficient protection against RSV infection. The neutralizing antibodies are induced by F and G proteins. The G protein fails to induce cytotoxic lymphocytes response and may causes aberrant Th2 response leading to enhancement of clinical symptoms in subsequently infected vaccines. The G as the most variable viral protein associated with immunopathologic effect is a critical factor in vaccine development.

scholarly journals Eliminating a Region of Respiratory Syncytial Virus Attachment Protein Allows Induction of Protective Immunity without Vaccine-enhanced Lung Eosinophilia

1998 ◽  
Vol 187 (11) ◽  
pp. 1921-1926 ◽  
Author(s):  
Tim E. Sparer ◽  
Stephen Matthews ◽  
Tracy Hussell ◽  
Aaron J. Rae ◽  
Blanca Garcia-Barreno ◽  
...  
Keyword(s):  
Amino Acids ◽  
Weight Loss ◽  
Respiratory Syncytial Virus ◽  
G Protein ◽  
Protective Immunity ◽  
Virus Disease ◽  
Recombinant Vaccinia Virus ◽  
Wild Type ◽  
Lung Eosinophilia ◽  
Syncytial Virus

In a murine model of respiratory syncytial virus disease, prior sensitization to the attachment glycoprotein (G) leads to pulmonary eosinophilia and enhanced illness. Three different approaches were taken to dissect the region of G responsible for enhanced disease and protection against challenge. First, mutant viruses, containing frameshifts that altered the COOH terminus of the G protein, were used to challenge mice sensitized by scarification with recombinant vaccinia virus (rVV) expressing wild-type G. Second, cDNA expressing these mutated G proteins were expressed by rVV and used to vaccinate mice before challenge with wild-type respiratory syncytial virus (RSV). These studies identified residues 193–205 to be responsible for G-induced weight loss and lung eosinophilia and showed that this region was not was not necessary for induction of protective immunity. Third, mice were sensitized using an rVV that expressed only amino acids 124–203 of the G protein. Upon RSV challenge, mice sensitized with this rVV developed enhanced weight loss and eosinophilia. This is the first time that a region within RSV (amino acids 193–203) has been shown to be responsible for induction of lung eosinophilia and disease enhancement. Moreover, we now show that it is possible to induce protective immunity with an altered G protein without inducing a pathological response.

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