Amino acid targeted as important mechanism in fighting infection

Mieulet V. Sci Signal. 2010;3(135):ra61.

Investigators from the University of Alberta have discovered that an amino acid, arginine, is required to let the body know that it’s being attacked by an infection.

Authors, Richard Lamb and post-doctoral fellow Virginie Mieulet, in the Faculty of Medicine & Dentistry, believe this may be an explanation as to why proper nutrition is so vital in fighting infection, according to a university press release.

The amino acid may also be the mechanism involved in chronic inflammation, like arthritis because if you have too much arginine it may cause the body to be in a constant state of thinking it is being attacked, the authors noted.

In a healthy person, macrophages arrive first at an infection site, engulfing infected cells and presenting a molecule that is recognized by the immune system on the surface of the infected cell which attracts more immune fighting cells to the area. According to Lamb it is known that arginine is essential for the function of macrophages but until now no one realized that arginine has a much bigger role.

In their 3-year study, Lamb and Mieulet presented arginine to a laboratory model and found the models were better able to fight infection even if they were malnourished.

“This is a major work,” Lamb stated in the release. “If this holds true in humans it shows that one aspect of nutrition that is critical is the level of amino acids.”

Although early in the research, this discovery could have implications for the millions of people in third world countries that do not get enough food and consequently become ill with infection.