[Frontiers in Bioscience S1, 68-91, June 1, 2009]
Immune defenses of Xenopus laevis against Batrachochytrium dendrobatidis
Louise A. Rollins-Smith1,2, Jeremy P. Ramsey1, Laura K. Reinert1, Douglas C. Woodhams1,3, Lauren J. Livo4, Cynthia Carey4
1Department of Microbiology and Immunology, 2Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN 37232 USA, 3Department of Biology, James Madison University, Harrisonburg VA 22807 USA, 4Department of Integrative Physiology, University of Colorado, Boulder, CO 80309
TABLE OF CONTENTS
Amphibian populations are declining at an unprecedented rate worldwide. A number of declines have been linked to a pathogenic skin fungus, Batrachochytrium dendrobatidis. Although amphibians have robust immune defenses, many species seem to be very susceptible to infection by this fungus and to development of the lethal disease called chytridiomycosis. One species that is relatively resistant to B. dendrobatidis is Xenopus laevis. Because X. laevis has been used as a model for studies of immunity in amphibians and because it is relatively resistant to chytridiomycosis, it is a good model to examine immune defenses against B. dendrobatidis. Although much less is known about immune defenses in Bufo boreas, it serves as a second model species because it is very susceptible to B. dendrobatidis. Here we review what is known about innate antimicrobial peptide defenses in the skin and the development of immune responses following experimental immunization with heat-killed fungal cells. Development of an immunization protocol in X. laevis that induces effective defenses may suggest better strategies for protecting vulnerable species such as B. boreas.