Человеческие антитела заблокируют белок слияния кори до незаметных уровней

One specific antibody, designated 4F09, reduced measles virus levels in the lungs of infected rats to completely undetectable levels by physically locking the virus's fusion protein in place. This mechanism prevents the structural change the virus requires to breach human cell membranes.

Mapping the Human Immune Response

Previous research into measles immunity relied heavily on mouse antibodies and indirect methods, leaving the human structural response largely uncharacterized. A research team led by Dr. Erica Ollmann Saphire of the La Jolla Institute for Immunology changed this by isolating memory B cells from a donor who had received three measles vaccinations. From these cells, the team engineered and purified over 100 individual human monoclonal antibodies, each targeting a specific site on the virus.

Using cryo-electron microscopy, the scientists produced the first atomic-resolution structural maps of human antibodies bound to measles virus proteins. The mapping identified nine distinct sites across the virus's two surface proteins: Hemagglutinin (H) and Fusion (F).

Challenging the H-Protein Dominance Assumption

For years, the prevailing assumption in the field was that protection against measles was driven almost exclusively by antibodies targeting the H protein, with the F protein playing only a minor role. This study proves that antibodies against both proteins confer powerful, independent protection.

Most importantly, the antibodies identified target regions of the virus that appear nearly identical across all known circulating measles strains. This structural conservation suggests the virus may lack the mutational flexibility to escape these antibodies without compromising its own survival.

Researchers are now seeking partners to translate these findings into clinical medicines, aiming to develop both rapid post-exposure preventives and therapeutics for the immunocompromised, pregnant women, and infants who cannot safely receive the measles vaccine.

Source: Researchers identify first suite of human antibodies against measles virus
Domain: nih.gov