Professor, Department of Pathology, Microbiology, and Immunology
Professor, Department of Pediatrics
Professor, Department of Biological Sciences
Research Interests: The main focus of my research is host and pathogen interactions using amphibian model systems. Our work also falls into the category of Eco-Immunology. Currently, my laboratory is pursuing a number of questions concerning the nature of innate and adaptive immune defenses in frog skin against two novel chytrid pathogens linked to global amphibian declines. Understanding the immune defense mechanisms of amphibians has taken on increased importance in recent years because of the urgent problem of global amphibian declines. Little is known about the conventional adaptive immune response against Batrachochytrium dendrobatidis (Bd) and a recently discovered closely related chytrid Batrachochytrium salamandrivorans (Bsal). Our ongoing studies have shown that Bd releases factors which inhibit lymphocyte responses. Preliminary studies suggest that Bsal also releases factors that inhibit immunity. Current research investigates the specific mechanisms by which these fungi may escape immunity. Another focus of my research is the study of antimicrobial peptides in frog skin in defense against bacterial, viral, and fungal pathogens. Currently, we are using growth inhibition assays to test the ability of purified antimicrobial peptides to interfere with growth of specific pathogens that have been associated with global amphibian declines. Another newer area of research is the effects of temperature on immune defenses of local Tennessee amphibians. This relates to the question of how climate change may impact southern amphibians. With collaborators, we are also studying the role of skin microbiota as protectors of amphibians from Bd and Bsal.
Keywords: Innate immune defenses, host and pathogen interactions, immune defenses against Batrachochytrium dendrobatidis, immune defenses against Batrachochytrium salamandrivorans, global amphibian declines, skin microbiota, antimicrobial peptides, climate change research