Food safetyResearchers discover a molecule's previously unknown role in fighting off E. coli

Despite ongoing public health efforts, E. coli outbreaks continue to infiltrate the food supply, annually causing significant sickness and death throughout the world.

The research community, however, is gaining ground. A La Jolla Institute for Allergy and Immunology release reports that in a major finding, published in the scientific journal Nature, researchers from the La Jolla Institute for Allergy & Immunology have discovered a molecule’s previously unknown role in fighting off E. coli and other bacterial infections, a discovery that could lead to new ways to protect people from these dangerous microorganisms.

“We’ve found that a certain molecule, known as HVEM, expressed by the cells lining the surface of the lung and intestine, is critical to protecting the body from E. coli, pneumococcus and other bacterial infections that enter our bodies through the lining of our respiratory or intestinal tracts,” said Mitchell Kronenberg, Ph.D., La Jolla Institute’s president and chief scientific officer, who led the research team. “We discovered that HVEM acts in these cells like a border guard that responds to the presence of invasive bacteria and signals the immune system to send in more troops. Without its involvement as part of the epithelial protective barrier, the body could be overrun by certain disease causing bacteria,” said Dr. Kronenberg, adding that he is hopeful the discovery will advance efforts toward developing new treatments or vaccines against bacterial infections.

“People knew that epithelial cells protect the body’s mucosal borders from infection,” said Dr. Kronenberg. “But what wasn’t known was that HVEM is critically important in turning on the epithelial cell anti-bacterial response.” Epithelial cells line the body’s mucosal borders, which include the mouth, nose, intestines and lungs and are the most common entry points for infectious pathogens. “We found that HVEM and another receptor (the receptor for IL-22) have to act together in the epithelial cells to trigger immune protection. Without these two receptors acting in concert, the body couldn’t withstand the infection,” said Dr. Kronenberg.

Richard S. Blumberg, M.D., a professor of medicine at Harvard Medical School and chief of the division of Gastroenteroogy, Hepatology and Endoscopy at Brigham and Women’s Hospital, called the finding important on many levels. “It is of great biological interest because it shows how this very novel pathway has an important role to play in the management of infections at the epithelial boundaries, which is the entry point for the vast majority of infectious diseases,” he said.