scholarly journals Structures of respiratory syncytial virus G antigen bound to broadly neutralizing antibodies

2018 ◽  
Vol 3 (21) ◽  
pp. eaar3534 ◽  
Author(s):  
Stanislav O. Fedechkin ◽  
Natasha L. George ◽  
Jacob T. Wolff ◽  
Lawrence M. Kauvar ◽  
Rebecca M. DuBois
Keyword(s):  
Respiratory Syncytial Virus ◽  
Neutralizing Antibodies ◽  
Broadly Neutralizing Antibodies ◽  
Syncytial Virus

scholarly journals Characterization of Pre-F-GCN4t, a Modified Human Respiratory Syncytial Virus Fusion Protein Stabilized in a Noncleaved Prefusion Conformation

2017 ◽  
Vol 91 (13) ◽  
Author(s):  
Normand Blais ◽  
Martin Gagné ◽  
Yoshitomo Hamuro ◽  
Patrick Rheault ◽  
Martine Boyer ◽  
...  
Keyword(s):  
Respiratory Syncytial Virus ◽  
Antibody Response ◽  
Neutralizing Antibodies ◽  
Neutralizing Antibody ◽  
Human Respiratory Syncytial Virus ◽  
Vaccine Antigen ◽  
Significant Advance ◽  
F Protein ◽  
Syncytial Virus

ABSTRACT The human respiratory syncytial virus (hRSV) fusion (F) protein is considered a major target of the neutralizing antibody response to hRSV. This glycoprotein undergoes a major structural shift from the prefusion (pre-F) to the postfusion (post-F) state at the time of virus-host cell membrane fusion. Recent evidences suggest that the pre-F state is a superior target for neutralizing antibodies compared to the post-F state. Therefore, for vaccine purposes, we have designed and characterized a recombinant hRSV F protein, called Pre-F-GCN4t, stabilized in a pre-F conformation. To show that Pre-F-GCN4t does not switch to a post-F conformation, it was compared with a recombinant post-F molecule, called Post-F-XC. Pre-F-GCN4t was glycosylated and trimeric and displayed a conformational stability different from that of Post-F-XC, as shown by chemical denaturation. Electron microscopy analysis suggested that Pre-F-GCN4t adopts a lollipop-like structure. In contrast, Post-F-XC had a typical elongated conical shape. Hydrogen/deuterium exchange mass spectrometry demonstrated that the two molecules had common rigid folding core and dynamic regions and provided structural insight for their biophysical and biochemical properties and reactivity. Pre-F-GCN4t was shown to deplete hRSV-neutralizing antibodies from human serum more efficiently than Post-F-XC. Importantly, Pre-F-GCN4t was also shown to bind D25, a highly potent monoclonal antibody specific for the pre-F conformation. In conclusion, this construct presents several pre-F characteristics, does not switch to the post-F conformation, and presents antigenic features required for a protective neutralizing antibody response. Therefore, Pre-F-GCN4t can be considered a promising candidate vaccine antigen. IMPORTANCE Human respiratory syncytial virus (RSV) is a global leading cause of infant mortality and adult morbidity. The development of a safe and efficacious RSV vaccine remains an important goal. The RSV class I fusion (F) glycoprotein is considered one of the most promising vaccine candidates, and recent evidences suggest that the prefusion (pre-F) state is a superior target for neutralizing antibodies. Our study presents the physicochemical characterization of Pre-F-GCN4t, a molecule designed to be stabilized in the pre-F conformation. To confirm its pre-F conformation, Pre-F-GCN4t was analyzed in parallel with Post-F-XC, a molecule in the post-F conformation. Our results show that Pre-F-GCN4t presents characteristics of a stabilized pre-F conformation and support its use as an RSV vaccine antigen. Such an antigen may represent a significant advance in the development of an RSV vaccine.

scholarly journals Induction of mucosal immunity and protection by intranasal immunization with a respiratory syncytial virus subunit vaccine formulation

2014 ◽  
Vol 95 (2) ◽  
pp. 301-306 ◽  
Author(s):  
R. Garg ◽  
L. Latimer ◽  
E. Simko ◽  
V. Gerdts ◽  
A. Potter ◽  
...  
Keyword(s):  
T Cells ◽  
Respiratory Syncytial Virus ◽  
Lymph Nodes ◽  
Neutralizing Antibodies ◽  
Subunit Vaccine ◽  
Affinity Maturation ◽  
Protein Formulation ◽  
Cross Presentation ◽  
Mucosal Surfaces ◽  
Syncytial Virus

The majority of infections, including those caused by respiratory syncytial virus (RSV), occur at mucosal surfaces. As no RSV vaccine is available our goal is to produce an effective subunit vaccine with an adjuvant suitable for mucosal delivery and cross-presentation. A truncated secreted version of the RSV fusion (ΔF) protein formulated with polyI : C, an innate defence regulator peptide and polyphosphazene, induced local and systemic immunity, including affinity maturation of RSV F-specific IgG, IgA and virus-neutralizing antibodies, and F-specific CD8+ T-cells in the lung, when delivered intranasally. Furthermore, this ΔF protein formulation promoted the production of CD8+ central memory T-cells in the mediastinal lymph nodes and provided protection from RSV challenge. Formulation of ΔF protein with this adjuvant combination enhanced uptake by lung dendritic cells and trafficking to the draining lymph nodes. The ΔF protein formulation was confirmed to be highly efficacious and safe in cotton rats.

scholarly journals Autocrine Regulation and Experimental Modulation of Interleukin-6 Expression by Human Pulmonary Epithelial Cells Infected with Respiratory Syncytial Virus

1998 ◽  
Vol 72 (3) ◽  
pp. 2496-2499 ◽  
Author(s):  
Zili Jiang ◽  
Masaru Kunimoto ◽  
Janak A. Patel
Keyword(s):  
Respiratory Syncytial Virus ◽  
Epithelial Cells ◽  
Cell Cultures ◽  
Interleukin 6 ◽  
Neutralizing Antibodies ◽  
Antiviral Agent ◽  
Significant Inhibition ◽  
Necrosis Factor Alpha ◽  
Tnf Α ◽  
Syncytial Virus

ABSTRACT The mechanisms of regulation of interleukin-6 (IL-6) production in respiratory syncytial virus (RSV)-infected respiratory epithelial cells were evaluated in A549 cell cultures. Incubation with purified RSV resulted in significant production of IL-1α, IL-1β, IL-6, and tumor necrosis factor alpha (TNF-α). Addition of saturating concentrations of neutralizing antibodies against IL-1α, IL-1β, or TNF-α into purified RSV-infected cell cultures resulted in a significant inhibition of IL-6 production, although anti-IL-1α antibody had the most predominant effect (80% inhibition). Anti-IL-1α antibody also almost completely blocked the expression of mRNA for IL-6. Addition of therapeutic concentrations of dexamethasone (1 μM) or ribavirin (90 μg/ml), an antiviral agent, also significantly inhibited the synthesis of IL-6. Hence, in clinical settings, pharmacological agents such as the specific antagonists of IL-6-inducing cytokines, as well as dexamethasone and ribavirin, could be used to modulate IL-6 production.

scholarly journals Simultaneous Administration of Recombinant Measles Viruses Expressing Respiratory Syncytial Virus Fusion (F) and Nucleo (N) Proteins Induced Humoral and Cellular Immune Responses in Cotton Rats

Vaccines ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 27 ◽  
Author(s):  
Yoshiaki Yamaji ◽  
Akihito Sawada ◽  
Yosuke Yasui ◽  
Takashi Ito ◽  
Tetsuo Nakayama
Keyword(s):  
Respiratory Syncytial Virus ◽  
Immune Responses ◽  
Neutralizing Antibodies ◽  
Simultaneous Administration ◽  
Cellular Immune Responses ◽  
Immunization Group ◽  
Cotton Rats ◽  
Ifn Γ ◽  
Syncytial Virus ◽  
Cellular Immune

We previously reported that recombinant measles virus expressing the respiratory syncytial virus (RSV) fusion protein (F), MVAIK/RSV/F, induced neutralizing antibodies against RSV, and those expressing RSV-NP (MVAIK/RSV/NP) and M2-1 (MVAIK/RSV/M2-1) induced RSV-specific CD8+/IFN-γ+ cells, but not neutralizing antibodies. In the present study, MVAIK/RSV/F and MVAIK/RSV/NP were simultaneously administered to cotton rats and immune responses and protective effects were compared with MVAIK/RSV/F alone. Sufficient neutralizing antibodies against RSV and RSV-specific CD8+/IFN-γ+ cells were observed after re-immunization with simultaneous administration. After the RSV challenge, CD8+/IFN-γ+ increased in spleen cells obtained from the simultaneous immunization group in response to F and NP peptides. Higher numbers of CD8+/IFN-γ+ and CD4+/IFN-γ+ cells were detected in lung tissues from the simultaneous immunization group after the RSV challenge. No detectable RSV was recovered from lung homogenates in the immunized groups. Mild inflammatory reactions with the thickening of broncho-epithelial cells and the infiltration of inflammatory cells were observed in lung tissues obtained from cotton rats immunized with MVAIK/RSV/F alone after the RSV challenge. No inflammatory responses were observed after the RSV challenge in the simultaneous immunization groups. The present results indicate that combined administration with MVAIK/RSV/F and MVAIK/RSV/NP induces humoral and cellular immune responses and shows effective protection against RSV, suggesting the importance of cellular immunity.

scholarly journals Infants Infected with Respiratory Syncytial Virus Generate Potent Neutralizing Antibodies that Lack Somatic Hypermutation

Immunity ◽  
2018 ◽  
Vol 48 (2) ◽  
pp. 339-349.e5 ◽  
Author(s):  
Eileen Goodwin ◽  
Morgan S.A. Gilman ◽  
Daniel Wrapp ◽  
Man Chen ◽  
Joan O. Ngwuta ◽  
...  
Keyword(s):  
Respiratory Syncytial Virus ◽  
Neutralizing Antibodies ◽  
Somatic Hypermutation ◽  
Syncytial Virus

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 Immunogenicity and Safety of 3 Formulations of a Respiratory Syncytial Virus Candidate Vaccine in Nonpregnant Women: A Phase 2, Randomized Trial

2019 ◽  
Vol 220 (11) ◽  
pp. 1816-1825 ◽  
Author(s):  
Tino F Schwarz ◽  
Roderick A McPhee ◽  
Odile Launay ◽  
Geert Leroux-Roels ◽  
Jaak Talli ◽  
...  
Keyword(s):  
Respiratory Syncytial Virus ◽  
Neutralizing Antibodies ◽  
Geometric Mean ◽  
Neutralizing Antibody ◽  
Candidate Vaccine ◽  
Phase 2 ◽  
Serious Adverse Events ◽  
Intramuscular Dose ◽  
Syncytial Virus ◽  
Neonates And Infants

Abstract Background Respiratory syncytial virus (RSV) is a common cause of respiratory tract illness and hospitalization in neonates and infants. RSV vaccination during pregnancy may protect offspring in their first months of life. Methods This randomized, observer-blind, multicenter, phase 2 study evaluated the immunogenicity and safety of an RSV candidate vaccine in healthy nonpregnant women aged 18–45 years. Four hundred participants were randomized (1:1:1:1) to receive a single intramuscular dose of vaccine containing 30 µg, 60 µg, or 120 µg of RSV fusion protein engineered to preferentially maintain a prefusion conformation (RSV-PreF vaccine) or placebo. Results Thirty days postvaccination, RSV-A neutralizing antibody geometric mean titers (GMTs) increased 3.75-, 4.42- and 4.36-fold; RSV-B neutralizing antibody GMTs 2.36-, 2.54- and 2.76-fold; and palivizumab competing antibody (PCA) concentrations 11.69-, 14.38- and 14.24-fold compared with baseline levels in the 30 µg, 60 µg, and 120 µg RSV-PreF groups, respectively. Antibody titers and PCA concentrations at day 30 were significantly higher with the 120 µg compared to the 30 µg RSV-PreF vaccine. All RSV-PreF vaccine formulations and the placebo had similar reactogenicity profiles. No serious adverse events were considered to be related to the RSV-PreF vaccine. Conclusions The 3 formulations of the investigational RSV-PreF vaccine were well-tolerated and induced RSV-A and RSV-B neutralizing antibodies and PCAs in healthy, nonpregnant women. Clinical Trials Registration NCT02956837.

Humoral immunity to respiratory syncytial virus in young and elderly adults

2009 ◽  
Vol 137 (12) ◽  
pp. 1684-1686 ◽  
Author(s):  
C. TERROSI ◽  
G. Di GENOVA ◽  
B. MARTORELLI ◽  
M. VALENTINI ◽  
M. G. CUSI
Keyword(s):  
Respiratory Syncytial Virus ◽  
Neutralizing Antibodies ◽  
Serum Antibody ◽  
Age Groups ◽  
The Elderly ◽  
Elderly Subjects ◽  
Rsv Infection ◽  
Syncytial Virus ◽  
Relationship Of ◽  
The Relationship

SUMMARYRespiratory syncytial virus (RSV) has been demonstrated to cause substantial disease in elderly and immunocompromised subjects. The relationship of serum antibody to RSV infection and the risk of infection in elderly subjects is controversial, thus we evaluated the presence of neutralizing antibodies to RSV in healthy people of different age groups and the correlation with viral protection. Baseline blood samples from 197 subjects aged 20–80 years were analysed for the presence of anti-RSV antibodies either by indirect immunofluorescence and microneutralization test. The percentage of people who had neutralizing antibodies to RSV was significantly higher (P=0·001) in the youngest group (92·51%) compared to the frail group (36·21%). The RSV antibody level tends to wane in some older people; this factor could determine proneness to RSV re-infections in the elderly who are at a greater risk of developing severe respiratory disease.

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