Research in the Lesser Lab is focused on understanding how bacterial pathogens co-opt eukaryotic host cell processes to promote infection and cause disease. Our studies are united by our interest in studying questions related to specialized nanomachines (Type III Secretion Systems) that numerous Gram-negative bacteria utilize to deliver tens of proteins (effectors) into host cells. We are particularly interested in studying aspects of pathogenesis of Shigella flexneri, a professional intracytosolic human pathogen.