Structure of Human Astrovirus Capsid May Lead to Vaccinations

New research published in theJournal of Virologyshows how neutralizing antibodies bind to human astrovirus, providing a map for the development of a vaccine.

Human astroviruses infect nearly everyone during childhood, and can cause diarrhea, fever, and vomiting. In most individuals, this is not a serious disease, but in young cancer patients, it poses much more of a threat.

“There were all these young cancer patients who were successfully fighting their cancer, but they were getting severe chronic astrovirus infections because the chemotherapy suppressed their immune systems, and there was no treatment for it,” said researcher Rebecca DuBois.

For the study, researchers used X-ray crystallography to demonstrate how a specific protein structure on the surface of the virus is blocked by a neutralizing antibody, preventing the virus from infecting human cells.

“We’ve identified a site of vulnerability on the surface of the virus that we can now target for development of a vaccine or antiviral therapy,” DuBois said. “These are the first results showing how a neutralizing antibody blocks this virus.”

The study demonstrated how the antibody binds to the astrovirus capsid spike domain, which projects from the surface of the virus. When the antibody binds to the spike domain, it blocks the virus from attaching to and infecting human cells.

The authors noted that the study provides a guide to design a vaccine based on the spike domain that can induce neutralizing antibodies and prevent infection in children. Furthermore, it highlights the potential of developing therapeutic antibodies that can treat severe astrovirus infections.

“Antibody therapeutics is a rapidly growing field,” DuBois said. “Many immunotherapies are being developed to target cancer cells, and we expect to see a growing number of antibody therapies for infectious diseases over the next 10 years.”