Dr. Mark S. McClain is interested in bacterial pathogenesis, with an emphasis in bacterial protein toxins, which play critical roles in infectious diseases. Working with the Cover lab, Mark studies two proteins secreted by H. pylori – VacA and CagA. VacA is a secreted pore-forming toxin with a variety of effects on epithelial cells. CagA is a protein that is translocated directly from the bacterial cytoplasm into the cytoplasm of host epithelial cells through a specialized secretion apparatus. Using molecular biological, biochemical, and cell biological techniques, his current studies focus on structure-function relationships of the VacA toxin and the type IV secretion apparatus required for CagA secretion.
Mark’s own lab studies the Clostridium perfringens epsilon toxin. C. perfringens is a gram positive, anaerobic bacterium that causes a wide variety of illnesses, ranging from diarrhea to lethal toxemias, in humans and other animals. The epsilon toxin is an extremely potent pore-forming toxin responsible for an often fatal enterotoxemia in animals (particularly livestock, but also possibly in humans). A recent study suggests the toxin contributes to Multiple Sclerosis. Using molecular biological, biochemical, and cell biological techniques, the lab seeks to develop safe and effective inhibitors of the toxin. The lab also is working to understand the interaction between the toxin and mammalian cells and the cellular responses to the toxin.
Through studying such toxins, Mark expects to better understand the molecular events that contribute to disease and to develop therapeutic inhibitors to treat disease.