Ronald Collman, M.D., is Professor of Medicine and Microbiology at the University of Pennsylvania's Perelman School of Medicine, and Co-Director of the Penn Center for AIDS Research. Dr. Collman received his undergraduate and MD degrees at Boston University School of Medicine, clinical residency and Pulmonary fellowship at Temple University and the University of Pennsylvania School of Medicine, respectively, and postdoctoral training in Microbiology at Penn. Dr. Collman has a longstanding research program focused on HIV entry mechanisms and target cell tropism including macrophage tropism, role of cell tropism in viral pathogenesis including neuropathogenesis, as well as coreceptor use and cell targeting in natural and non-natural host SIV infection. He has a major research interest in the human microbiome focused on the respiratory tract, an emerging area of microbiome studies, including bacteria, fungi and viruses in the upper and lower respiratory tract. His group uses novel sampling and analytical approaches to understand the microbiome in this niche, has defined the normal lung microbial population, and is focused on understanding aberrant microbiota in the lungs in HIV/AIDS along with other immunodeficiency states such as organ transplantation.