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Updated: Mar 8, 2026
An Improved and High Throughput Respiratory Syncytial Virus RSV Micro-neutralization Assay
Published on: January 26, 2019
A novel pre-fusion conformation-specific neutralizing epitope on the respiratory syncytial virus fusion protein
Jarrod J Mousa1, Nurgun Kose1, Pranathi Matta1
1Vanderbilt Vaccine Center, Vanderbilt University Medical Center, Nashville, Tennessee 37232, USA.
Insights
Researchers discovered new neutralizing antibodies targeting a novel site on the Respiratory Syncytial Virus (RSV) fusion protein. These antibodies show broad reactivity against RSV subgroups, offering potential for improved RSV vaccine development.
Area of Science:
- Virology
- Immunology
- Structural Biology
Background:
- Respiratory Syncytial Virus (RSV) is a significant human pathogen causing widespread infant infections and lifelong re-infections.
- Despite extensive research, a licensed RSV vaccine remains unavailable.
- Current vaccine candidates often target the conserved RSV fusion (F) surface glycoprotein.
Purpose of the Study:
- To characterize the human B cell response to the RSV F protein.
- To identify novel neutralizing monoclonal antibodies (mAbs) against the pre-fusion conformation of RSV F.
Main Methods:
- Isolation and characterization of 13 neutralizing human mAbs from a single donor.
- Epitope binning to identify antibody binding sites.
- X-ray crystallography to determine the structure of an mAb-F protein complex.
Main Results:
- Identification of a new antigenic site, site VIII, on the RSV F globular head domain.
- These mAbs exhibit broad cross-reactivity against RSV subgroups A and B.
- Structural analysis revealed extensive interactions of a site VIII mAb (hRSV90) with the F protein, overlapping with known sites II and Ø.
Conclusions:
- The newly identified antigenic site VIII is a promising target for RSV vaccine design.
- Broadly neutralizing antibodies targeting site VIII could lead to more effective RSV vaccines.
- Structural insights provide a basis for rational vaccine antigen design.
Abstract:
Respiratory syncytial virus (RSV) remains a major human pathogen, infecting the majority of infants before age two and causing re-infection throughout life. Despite decades of RSV research, there is no licensed RSV vaccine. Most candidate vaccines studied to date have incorporated the RSV fusion (F) surface glycoprotein, because the sequence of F is highly conserved among strains of RSV. To better define the human B cell response to RSV F, we isolated from a single donor 13 new neutralizing human monoclonal antibodies (mAbs) that recognize the RSV F protein in the pre-fusion conformation. Epitope binning studies showed that the majority of neutralizing mAbs targeted a new antigenic site on the globular head domain of F, designated here antigenic site VIII, which occupies an intermediate position between the previously defined major antigenic sites II and site Ø. Antibodies to site VIII competed for binding with antibodies to both of those adjacent neutralizing sites. The new mAbs exhibited unusual breadth for pre-fusion F-specific antibodies, cross-reacting with F proteins from both RSV subgroups A and B viruses. We solved the X-ray crystal structure of one site VIII mAb, hRSV90, in complex with pre-fusion RSV F protein. The structure revealed a large footprint of interaction for hRSV90 on RSV F, in which the heavy chain and light chain both have specific interactions mediating binding to site VIII, the heavy chain overlaps with site Ø, and the light chain interacts partially with site II.
