02.20.08
Pathogens & Parasites
In today’s show, adapted from an article published this month on the Oscar Web site written by Mary Jane Gore, we look at the research of Dr. William Petri, chief of the UVa Division of Infectious Diseases and International Health, and his study of a voracious parasite that is said to kill nearly 100, 000 people each year.
If you have ever contemplated working as a biological researcher then you would probably have considered these questions: what happens when a cell’s life ends? And, what are the mechanisms that control decay?
Contemplating just these types questions during a recent study, a UVa-led research team, directed by Dr. William Petri, chief of the UVa Division of Infectious Diseases and International Health, made discoveries which are helping to stop one of the world’s most voracious parasites.
The team included Douglas Boettner (now completing postdoctoral work in Miami), U.Va. graduate students Alicia S. Linford and Sarah Buss and faculty colleagues Dr. Eric Houpt and Dr. Nicholas Sherman of UVa and Dr. Christopher D. Huston of the University of Vermont.
Their work revolved around the hypothesis that identifying molecules involved in the corpse ingestion would provide insight into how the amoebae cause colitis in children. These amoebae, properly known as entamoeba histolytica, cause colitis, or inflammation of the colon. They do this by attacking and killing human immune cells in mere seconds. It then it hides the evidence by eating the cells’ corpses.
In doing so, per data from Dr. Gerald Mandell of U.Va. Infectious Diseases and editor of Mandell, Douglas and Bennett’s Principles and Practice of Infectious Diseases, 6th edition, this murderous marauder “on a global basis, affects approximately 50 million people each year, causing diarrhea, malnutrition and nearly 100,000 deaths.
Dr. Petri’s team identified a particular protein on the surface of the ameba called a kinase, PATMK. Their work, published in the Jan. 18 issue of PLoS Pathogens, a peer-reviewed, open-access journal from the Public Library of Science, outlined a special technique called RNA interference, which inhibits the actions of this kinase, thus preventing the amoebae from eating the dead cells.
Dr. Petri, said, “by blocking this kinase, we have for the first time prevented the ameba from colonizing and invading the gut. This means that we are a step closer to preventing this disease, which wreaks havoc among children worldwide.”
The first author of the paper, Douglas Boettner said, “infection and further invasion into the gut require the clearance of dead cells in order to prevent immune recognition of the damaged tissue. PATMK is the first individual member of a large family of proteins to be assigned a function related to the clearance of dying tissue during pathogenesis.”
Boettner added, “this protein may be a pivotal vaccination target because these preliminary studies show that alterations in PATMK function reduced progression of amoebiasis in mice, a vaccine that ultimately would prevent this ameba from clearing the damaged host may draw in helpful immune cells, and thus help to clear this infection.”
Their work has shown how infection depends upon the ameba’s consumption of dead cells. By identifying the molecule that controls this consumption, scientists are one step closer to the ultimate goal of preventing the diseases caused by this parasite.
You’ve been listening to the Oscar Show, I’m Jacob Canon. Join us next week when our topic will be the research of Adrienne Felt, a fourth-year computer science major in the School of Engineering and Applied Science, concerning privacy issues surrounding social networking platforms such as Facebook.