Scientists discover E coli's Achilles heel

Washington, July 16 (IANS) Researchers have identified E. coli's Achilles heel - a molecule's previously unknown role in fighting it off and other bacterial infections.

The lethal bug continues to infiltrate and contaminate food supplies, causing sickness and death worldwide, defying determined global efforts to put it down.

"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, who led the study.

"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," said Kronenberg, president and chief scientific officer of the La Jolla Institute for Allergy & Immunology, US.

Without its involvement as part of the epithelial protective barrier, the body could be overrun by certain disease causing bacteria," said Kronenberg.

The discovery would open the way to develop more effective treatment or vaccines against bacterial infections, he added, according to a La Jolla statement.

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.

"People knew that epithelial cells protect the body's mucosal borders from infection," said Kronenberg. "But what wasn't known was that HVEM is critically important in turning on the epithelial cell anti-bacterial response."

Richard S. Blumberg, 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.