January 30, 2006

Protein Helps Body Fight Off Legionnaire’s Disease

NEW YORK (Reuters Health) - A protein called Birc1e, found within the cells of the body, plays a key role in detecting and controlling infection with Legionella pneumophila, the bacterium that causes Legionnaire's disease, according to a new report.

Legionnaires' disease, a severe type of pneumonia, gets its name from a 1976 outbreak that occurred among people staying at a Philadelphia hotel that was hosting an American Legion convention. Later, the organism that caused the illness was named Legionella.

Previous reports have shown that Birc1 proteins resemble cell receptors found in the immune system. Their actual role, if any, in this system, however, was unclear, Dr. Craig R. Roy, from Yale University in New Haven, Connecticut, and colleagues note.

In the present study, reported in Nature Immunology, the researchers examined the function of Birc1e in mouse cells harboring L. pneumophila. They found that a Birc1e-related chemical reaction limited the bacterium's ability to make copies of itself.

The findings establish "Birc1e as an important component of the body's natural immune system and illustrate the importance of Birc1e in regulation of the body's response to Legionella pneumophila infection, the authors conclude.

SOURCE: Nature Immunology, January 29th online, 2006.