New Research Reveals How Giardia Parasite Changes Its Appearance
Summary
A 20 year search has helped international research scholar Hugo D. Luján explain how the Giardia parasite hides from the immune system.
Giardia parasites can change the proteins on their surface, which helps them to evade the immune system, but only one protein is on the surface at any one time. This Giardia parasite has been engineered to exhibit two proteins on its surface, shown in green and red.
Like a gang of bandits that changes clothes after a heist to avoid capture, the intestinal parasite Giardia lamblia alters its appearance to outwit the human immune system. Now, after a 20-year search, experiments by Howard Hughes Medical Institute international research scholar Hugo D. Luján reveal how the parasite shifts disguises.
The findings, published in the December 11, 2008, issue of the journal Nature, are a first step toward developing vaccines against Giardia and other pathogens that change their outer coats as a defense strategy, said Luján, a scientist at the Catholic University of Córdoba in Argentina. Currently, there is no vaccine to protect against Giardia infection, which is a major cause of diarrhea in much of the world. The World Health Organization estimates that more than 200 million people contract Giardia each year. The parasite, which is spread through feces in contaminated soil or water, can persist as a microscopic cyst for months or years. Giardia infections can also last for months, as the parasite has evolved a cunning defense to evade the human immune system.