Respiratory Syncytial Virus G Protein CX3C Motif Impairs Human Airway Epithelial and Immune Cell Responses

Chirkova, Tatiana; Boyoglu-Barnum, Seyhan; Gaston, Kelsey A.; Malik, Fahad Mumtaz; Trau, Steven P.; Oomens, Antonius G. P.; Anderson, Larry J.

doi:10.1128/jvi.01741-13

Cited by 84 publications

(93 citation statements)

References 85 publications

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“…The only difference between the REG and RMG proteins was the presence of glycosylation as N-and O-linked glycans in the RMG protein. Therefore, the observed shift toward a higher Th2/Th1 ratio after RMG vaccination could not be attributed simply to binding of the CX3C motif within the CCD to CX3CR1 (the fractalkine receptor) on several cell types, as suggested previously (54)(55)(56). Instead, the enhanced Th2 cytokine and chemokine levels could possibly be induced by the high level of O-linked sugars characteristic of mammalian-cell-expressed glycosylated RMG and also of the native-virus-associated G attachment protein.…”

Section: Discussionmentioning

confidence: 65%

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

Fuentes

Coyle

Golding

et al. 2015

J Virol

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New 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 in Escherichia 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 in E. 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.

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Section: Discussionmentioning

confidence: 65%

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

Fuentes

Coyle

Golding

et al. 2015

J Virol

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“…For example, in in vitro studies of human peripheral blood mononuclear cells and human AECs, we previously showed that the CX4C mutation affects immune responses to RSV. In this study, the CX4C mutation led to significant increases in levels of IFN-␣ and IFN-during infection of a human AEC line, an increase in IFN-␣ and TNF-␣ production by human plasmacytoid dendritic cells (pDCs) and monocytes, and an increase in IFN-␥ production in effector/ memory T cells (55). We also showed that the CX4C mutation affects many cytokines produced by RSV-infected primary human AECs (24).…”

Section: Discussionmentioning

confidence: 69%

Mutating the CX3C Motif in the G Protein Should Make a Live Respiratory Syncytial Virus Vaccine Safer and More Effective

Boyoglu-Barnum

Todd

Meng

et al. 2017

J Virol

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Respiratory syncytial virus (RSV) belongs to the family Paramyxoviridae and is the single most important cause of serious lower respiratory tract infections in young children, yet no highly effective treatment or vaccine is available. Through a CX3C chemokine motif ( 182 CWAIC 186 ) in the G protein, RSV binds to the corresponding chemokine receptor, CX3CR1. Since RSV binding to CX3CR1 contributes to disease pathogenesis, we investigated whether a mutation in the CX3C motif by insertion of an alanine, A 186 , within the CX3C motif, mutating it to CX4C ( 182 CWAIAC 187 ), which is known to block binding to CX3CR1, might decrease disease. We studied the effect of the CX4C mutation in two strains of RSV (A2 and r19F) in a mouse challenge model. We included RSV r19F because it induces mucus production and airway resistance, two manifestations of RSV infection in humans, in mice. Compared to wild-type (wt) virus, mice infected with CX4C had a 0.7 to 1.2 log 10 -fold lower virus titer in the lung at 5 days postinfection (p.i.) and had markedly reduced weight loss, pulmonary inflammatory cell infiltration, mucus production, and airway resistance after challenge. This decrease in disease was not dependent on decrease in virus replication but did correspond to a decrease in pulmonary Th2 and inflammatory cytokines. Mice infected with CX4C viruses also had higher antibody titers and a Th1-biased T cell memory response at 75 days p.i. These results suggest that the CX4C mutation in the G protein could improve the safety and efficacy of a live attenuated RSV vaccine.IMPORTANCE RSV binds to the corresponding chemokine receptor, CX3CR1, through a CX3C chemokine motif ( 182 CWAIC 186 ) in the G protein. RSV binding to CX3CR1 contributes to disease pathogenesis; therefore, we investigated whether a mutation in the CX3C motif by insertion of an alanine, A 186 , within the CX3C motif, mutating it to CX4C ( 182 CWAIAC 187 ), known to block binding to CX3CR1, might decrease disease. The effect of this mutation and treatment with the F(ab=) 2 form of the anti-RSV G 131-2G monoclonal antibody (MAb) show that mutating the CX3C motif to CX4C blocks much of the disease and immune modulation associated with the G protein and should improve the safety and efficacy of a live attenuated RSV vaccine.

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“…93 Consistent with the latter, stimulation of PBMC from healthy donors with hRSV infected A549 cells induced the production of IFN-g and IL-4. 94 In other studies, the concentration of IL-17 in nasopharyngeal aspirates of children during hRSV infection was higher at the moment of discharge of the hospital. 95 However, the data are controversial since the latter was only valid for infants that do not require ventilation.…”

Section: An Adequate Cd4mentioning

confidence: 99%

Aberrant T cell immunity triggered by human Respiratory Syncytial Virus and human Metapneumovirus infection

et al. 2016

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Human Respiratory syncytial virus (hRSV) and human metapneumovirus (hMPV) are the two major etiological viral agents of lower respiratory tract diseases, affecting mainly infants, young children and the elderly. Although the infection of both viruses trigger an antiviral immune response that mediate viral clearance and disease resolution in immunocompetent individuals, the promotion of long-term immunity appears to be deficient and reinfection are common throughout life. A possible explanation for this phenomenon is that hRSV and hMPV, can induce aberrant T cell responses, which leads to exacerbated lung inflammation and poor T and B cell memory immunity. The modulation of immune response exerted by both viruses include different strategies such as, impairment of immunological synapse mediated by viral proteins or soluble factors, and the induction of pro-inflammatory cytokines by epithelial cells, among others. All these viral strategies contribute to the alteration of the adaptive immunity in order to increase the susceptibility to reinfections.In this review, we discuss current research related to the mechanisms underlying the impairment of T and B cell immune responses induced by hRSV and hMPV infection. In addition, we described the role each virulence factor involved in immune modulation caused by these viruses.

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Respiratory Syncytial Virus G Protein CX3C Motif Impairs Human Airway Epithelial and Immune Cell Responses

Cited by 84 publications

References 85 publications

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

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

Mutating the CX3C Motif in the G Protein Should Make a Live Respiratory Syncytial Virus Vaccine Safer and More Effective

Aberrant T cell immunity triggered by human Respiratory Syncytial Virus and human Metapneumovirus infection

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