Dr. Duncan received his MD and PhD degrees from the University of Texas Southwestern Medical Center before training in Internal Medicine and Infectious Diseases at the University of North Carolina at Chapel Hill. Dr. Duncan is an actively practicing physician scientist with clinical interest in Sexually Transmitted Infections, particularly those caused by Neisseria gonorrhoeae. The Duncan lab focuses on the role of host signaling pathways in both immune protection and pathogenesis of infection with N. gonorrhoeae. Dr. Duncan’s early studies focused on the molecular events related to activation of the family of innate immune signaling proteins known as NOD-like receptors (NLRs) by N. gonorrhoeae and other pathogens. N gonorrhoeae potently activates NLRP3 which forms a complex known as the inflammasome resulting in production of inflammatory cytokines that responsible for the robust inflammatory exudate associated with gonococcal urethritis. At the same time, N. gonorrhoeae expresses enzymes that alter the recognition of peptidoglycan by host NLR proteins that sense bacterial cell wall components, promoting immune evasion by the bacteria. Dr. Duncan’s lab has also pursued studies into the other mechanisms by which N. gonorrhoeae evades the human adaptive immune response. Dr. Duncan’s team has found that N. gonorrhoeae suppresses host antigen presenting cells’ ability to stimulate T lymphocytes through the release of outer-membrane vesicles and PorB, the major protein constituent of those vesicles, into the extracellular environment. Dr. Duncan’s current research efforts focus on utilizing a combination of basic bench research, murine infection models, and a unique human challenge model to identify immunologic correlates of protection from N. gonorrhoeae.
Joseph Alexander Duncan, MD, PhD