title: Role of Antimicrobial Peptides in Amphibian Defense Against Trematode Infection.
abstract: Antimicrobial peptides (AMPs) contribute to the immune defenses of many vertebrates, including amphibians. As larvae, amphibians are often exposed to the infectious stages of trematode parasites, many of which must penetrate the host's skin, potentially interacting with host AMPs. We tested the effects of the natural AMPs repertoires on both the survival of trematode infectious stages as well as their ability to infect larval amphibians. All five trematode species exhibited decreased survival of cercariae in response to higher concentrations of adult bullfrog AMPs, but no effect when exposed to AMPs from larval bullfrogs. Similarly, the use of norepinephrine to remove AMPs from larval bullfrogs, Pacific chorus frogs, and gray treefrogs had only weak (gray treefrogs) or non-significant (other tested species) effects on infection success by Ribeiroia ondatrae. We nonetheless observed strong differences in parasite infection as a function of both host stage (first- versus second-year bullfrogs) and host species (Pacific chorus frogs versus gray treefrogs) that were apparently unrelated to AMPs. Taken together, our results suggest that AMPs do not play a significant role in defending larval amphibians against trematode cercariae, but that they could be one mechanism helping to prevent infection of post-metamorphic amphibians, particularly for highly aquatic species.
authors.affiliation: Department of Ecology and Evolutionary Biology, University of Colorado Boulder, Ramaley N122 CB334, Boulder, CO, 80309, USA. dana.calhoun@colorado.edu.
authors.forename: Dana M
authors.initials: DM
authors.lastname: Calhoun
authors.affiliation: Department of Biology, University of Massachusetts Boston, 100 Morrissey Blvd., Boston, MA, 02125, USA.
authors.forename: Doug
authors.initials: D
authors.lastname: Woodhams
authors.affiliation: Department of Ecology and Evolutionary Biology, University of Colorado Boulder, Ramaley N122 CB334, Boulder, CO, 80309, USA.
authors.forename: Cierra
authors.initials: C
authors.lastname: Howard
authors.affiliation: George Washington University Law School, George Washington University, 2000 H St NW, Washington, DC, 20052, USA.
authors.forename: Bryan E
authors.initials: BE
authors.lastname: LaFonte
authors.affiliation: Department of Ecology and Evolutionary Biology, University of Colorado Boulder, Ramaley N122 CB334, Boulder, CO, 80309, USA.
authors.forename: Jacklyn R
authors.initials: JR
authors.lastname: Gregory
authors.affiliation: Department of Ecology and Evolutionary Biology, University of Colorado Boulder, Ramaley N122 CB334, Boulder, CO, 80309, USA.
authors.forename: Pieter T J
authors.initials: PT
authors.lastname: Johnson
mesh_terms: D000818:Animals; D000890:Anti-Infective Agents; D001001:Anura / Q000469:parasitology*; D010455:Peptides / Q000502:physiology*; D014200:Trematoda; D014201:Trematode Infections
chemical_list: D000890:Anti-Infective Agents; D010455:Peptides
keywords: antimicrobial peptides; disease ecology; trematodes; wildlife immunology