Understanding norovirus structures to develop treatments for food poisoning

The Cold Spring Harbor laboratory conducted research on norovirus structures, which could help develop treatments for food poisoning.

The study of the complex structure of the norovirus, the capsid, which allows the virus to attach to the human host could help develop treatments against food poisoning such as vaccines.

The need for food poisoning treatments

Noroviruses are a major cause of outbreaks of foodborne illness. According to the Cold Spring Harbor laboratory, they account for 58% of all homes and are responsible for 685 million cases per year worldwide. Despite this, there is no effective treatment currently.

Understanding norovirus structures

In vaccines, specific antibodies will need to recognize and bind capsids. James Jung, a postdoctoral fellow at Dr. Leemor Joshua-Tor's lab, explained, "We need to understand what the forms of the norovirus capsid look like and the differences in shape between different strains."

What do capsids look like?

The team used a cryo-electron microscope to badyze four different strains of norovirus structures in high resolution.

Jung said, "Previously, it was thought that norovirus shells existed in single bademblies consisting of 180 building blocks and 90 surface peaks."

"We discovered an unexpected mix of different sizes and shapes of shells. We found a smaller shape, consisting of only 60 building blocks with 30 surface points placed farther apart. We also found larger hulls consisting of 240 building blocks with 120 surface spikes raised significantly above the base of the hull and forming a two-layered architecture that could interact differently with human cells. "

Vaccine development

Jung concluded, "Each strain will interact differently with human cells. The way the antibodies bind will also be different. Vaccines must be formulated to take into account variations between strains and structural forms. "

The results of the norovirus shell architecture are published in the journal PNAS, entitled "High-resolution cryo-EM structures of human norovirus shells of epidemic strains reveal variations in size".