[Measles Virus]

Area of Science:

• Virology
• Immunology
• Structural Biology

Background:

• Measles virus (MeV) is highly contagious and a leading cause of childhood mortality.
• Increased vaccination coverage has led to significant progress in measles elimination efforts.
• The MeV hemagglutinin (H) protein mediates viral entry by interacting with cellular receptors.

Purpose of the Study:

• To elucidate the role of the MeV H protein in viral infection and vaccine effectiveness.
• To understand the structural basis for MeV receptor interactions and neutralization.
• To explain the long-term efficacy of existing measles vaccines.

Main Methods:

• Analysis of MeV H protein structure and function.
• Investigation of H protein interactions with cellular receptors SLAM and nectin-4.
• Epitope mapping of the H protein's receptor binding site.

Main Results:

• The H protein binds to SLAM on immune cells and nectin-4 on epithelial cells, explaining MeV's properties.
• Receptor binding by H protein triggers conformational changes in the fusion (F) protein for viral entry.
• The receptor binding site on the H protein is a key neutralizing epitope.
• Functional constraints on this epitope limit amino acid changes, contributing to vaccine efficacy.

Conclusions:

• The MeV H protein's interaction with two distinct receptors is crucial for viral pathogenesis.
• The conserved nature of the H protein's receptor binding site explains the enduring effectiveness of current measles vaccines.
• Understanding these interactions provides insights into MeV control and vaccine development.