( ut they don't look anything like the ho...)UCSD team unmasks family of immune system invaders

When spoiled food is eaten, the pathogenic bacteria pass into the intestine and colon, where they meet up with a layer of cells lining these organs called the epithelial cells. The epithelial cells form a protective wall without any doors, a barrier that blocks bacterial entry from the intestine and colon into the rest of the body. However, bacterial pathogens can inject effector proteins into the intestinal epithelial cells, creating a door in the barrier.

"As a result, these bacteria proteins are the bad guys that make you sick," said Alto. "Instead of curing the illness by giving a patient antibiotics, it might be possible to target these effectors, turning their virulant actions into something benign."

The researchers used a molecular "fingerprinting" approach to identify the family of hijackers. Using this molecular fingerprint and computer-aided searches, they discovered a number of proteins having the same molecular pattern ?all were proteins used by pathogenic microorganisms. UCSD researchers were able to determine that additional bacterial proteins used a common strategy to hijack the cells' communication network.

"The novel findings of this research are particularly gratifying since this work not only included scientists from our laboratory, but also other UCSD colleagues as well as investigators from the University of Toronto," said Dixon. "This illustrates how advances in a field like bacterial pathogenesis requires the talents and diverse expertise of many scientists."

Their insights into the mechanisms of bacterial pathogens could lead to novel treatments for diseases such as dysentery. These findings may prove to be especially helpful in fighting bacterial disease in Third-World countries, in children and those with suppressed immune systems, such as HIV/AIDS patients.

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Source:University of California - San Diego