Katherine S. Ralston, Ph.D.

Research

My research will unravel the mechanism by which the tropical parasite Entamoeba histolytica kills human intestinal cells. This pathogen—which is responsible for the diarrheal disease amoebiasis—has the ability to dissolve tissues. It had previously been thought that the amoeba must secrete a cell-destroying toxin, but as a postdoctoral fellow I showed that E. histolytica actually takes small but lethal bites out of host cells, a process dubbed trogocytosis. I will work to identify the genes that E. histolytica employs to nibble on host tissues and determine whether nibbling on host cells helps amoebae to evade detection by the host immune system. In addition, I will explore how being bitten by E. histolytica destroys host cells, a reaction that may trigger a novel form of self-induced cell death. These findings could lead to new methods for treating or preventing infection with amoebae or other pathogens that use trogocytosis to invade host tissues.