Abstract
Infection with Respiratory Syncytial Virus (RSV) causes both upper and lower respiratory tract disease in humans, leading to significant morbidity and mortality in both young children and older adults. Currently, there is no licensed vaccine available, and therapeutic options are limited. During the infection process, the type I viral fusion (F) glycoprotein on the surface of the RSV particle rearranges from a metastable prefusion conformation to a highly stable postfusion form. In people naturally infected with RSV, most potent neutralizing antibodies are directed to the prefusion form of the F protein. Therefore, an engineered RSV F protein stabilized in the prefusion conformation (DS-Cav1) is an attractive vaccine candidate. Long-term stability at 4°C or higher is a desirable attribute for a commercial subunit vaccine antigen. To assess the stability of DS-Cav1, we developed assays using D25, an antibody which recognizes the prefusion F-specific antigenic site Ø, and a novel antibody 4D7, which was found to bind antigenic site I on the postfusion form of RSV F. Biophysical analysis indicated that, upon long-term storage at 4°C, DS-Cav1 undergoes a conformational change, adopting alternate structures that concomitantly lose the site Ø epitope and gain the ability to bind 4D7.
MeSH terms
-
Antibodies, Monoclonal / immunology
-
Antibodies, Monoclonal / metabolism
-
Antibodies, Neutralizing / immunology
-
Antibodies, Viral / immunology
-
Antigen-Antibody Reactions / immunology
-
Antigens / immunology*
-
Antigens / metabolism
-
Epitopes / immunology
-
HEK293 Cells
-
Humans
-
Microscopy, Electron, Transmission
-
Protein Stability
-
Recombinant Proteins / biosynthesis
-
Recombinant Proteins / immunology
-
Recombinant Proteins / isolation & purification
-
Respiratory Syncytial Virus Infections / prevention & control
-
Respiratory Syncytial Virus Vaccines / immunology
-
Respiratory Syncytial Virus, Human / metabolism*
-
Surface Plasmon Resonance
-
Vaccines, Subunit / immunology*
-
Vaccines, Subunit / metabolism
-
Viral Fusion Proteins / genetics
-
Viral Fusion Proteins / immunology*
-
Viral Fusion Proteins / metabolism
Substances
-
Antibodies, Monoclonal
-
Antibodies, Neutralizing
-
Antibodies, Viral
-
Antigens
-
Epitopes
-
Recombinant Proteins
-
Respiratory Syncytial Virus Vaccines
-
Vaccines, Subunit
-
Viral Fusion Proteins
Grants and funding
The research was fully funded by Merck and Co., Inc. The funder provided support in the form of salaries for all authors, but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of these authors are articulated in the 'author contributions' section.