Dr. Gunn is a Professor in the Dept. of Microbial Infection & Immunity and the Center for Microbial Interface Biology in the Ohio State University COM. He serves as Vice Chair of his Dept., Vice Director of his Center, and Director of a prestigious undergraduate program. He studies acute,chronic infections caused by Salmonella and Francisella. In Salmonella, he explores the mechanisms used to survive harsh conditions within the human host including innate immune defenses, the macrophage phagosome and the gallbladder. He identified bacterial LPS modification as a means of resisting immune clearance and his studies of chronic infection of the gallbladder in typhoid carriers gave rise to a new animal model and the observation that biofilm formation on gallstones was a source of chronic carriage. In Francisella, he examines the regulation of virulence and survival within host macrophages. Finally, he is developing therapeutics that target the factors,mechanisms resulting from his studies.