Strike while the iron is hot: a grad student investigates a promising TB drug target
Imagine yourself as a tiny bacterium that has been coughed into the air from the lungs of a person infected with tuberculosis (TB). Floating through the air inside microscopic water droplets, you are quickly inhaled by an unsuspecting person sitting on the other side of the train. Once inside this new host, your first inclination is to attack—but how?
Reeder Robinson, a biochemistry Ph.D. student working in the Fralin Life Science Institute, studies the biochemical pathways that TB bacteria use to attack their hosts. One attack of particular interest to Robinson is the biosynthesis of siderophores—tiny, iron-gobbling molecules that the bacteria secrete to steal iron from the human body and use it for their own needs.
Robinson investigates how enzymes involved in siderophore biosynthesis work in order to develop drugs against them in the future. If not treated effectively, TB can be fatal. One third of the world’s population is infected, and in 2012 there were 1.3 million TB-related deaths, according to the Centers for Disease Control and Prevention. TB is most prevalent in people who have HIV or otherwise weak immune systems. The disease often attacks the lungs, but can attack other organs such as the brain, kidney, and spine. TB is spread through bacterial pathogens, and some strains are drug-resistant.
“Bacterial pathogens are becoming more and more drug resistant. As scientists, we must develop new drugs to act on different targets that bacteria have not adapted to yet,” Robinson said. “Enzymes involved in siderophore biosynthesis are attractive drug targets because there are no similar enzymes present in the human body and, therefore, inhibiting those pathways should not cause major side effects to humans.”
This summer, Robinson received the Vincent Massey award for his research as part of the 18th International Symposium on Flavins and Flavoproteins, held July 25-August 5 in Thailand. He is advised by Pablo Sobrado, associate professor of biochemistry in the College of Agriculture and Life Sciences, Fralin Life Science Institute affiliate, and key member of the Virginia Tech Center for Drug Discovery.
The Sobrado research team studies enzymes in a variety of bacterial pathogens to develop better treatment for the diseases they cause, including TB, Chagas disease, and fungal infections. These diseases are of greatest threat to developing countries where treatment may not be as readily available.
“Our group is targeting key biological functions in several human pathogens like parasites, bacteria, and fungi,” Sobrado said. “As we understand the differences and common features among these pathogens, we hope to discover new broad-spectrum antimicrobials for the treatment of several human diseases.”
Robinson began working with Sobrado in 2009 as an undergraduate and received his bachelor’s degree in biochemistry from Virginia Tech in 2010. He plans to graduate with his Ph.D. in May 2015.
During his trip to Thailand, Robinson was able to meet researchers from across the world that have long partnered with the Sobrado team. He received a monetary award of $700, and more than 150 people attended his research presentation.
“Going to Thailand for this conference was an amazing opportunity that I will remember for the rest of my life,” Robinson said. “I was exposed to a different culture, met a lot of amazing people who I will keep in contact with throughout my career, and was able to obtain valuable insights from other world class scientists on my research.”
By Lindsay Key