title: Piscidins in the intestine of European perch, Perca fluviatilis, naturally infected with an enteric worm.
abstract: This study set out to determine how an enteric parasite, the thorny-headed worm Acanthocephalus lucii, affected the expression of antimicrobial peptides (piscidins) in its host population, the European perch (Perca fluviatilis) collected from Lake Piediluco in Central Italy. A total of 87 perch were examined; 44 (50.5%) were infected with A. lucii (1-18 worms fish(-1)). Pathological changes and immune response were assessed using histological, ultrastructural and immunohistochemical techniques. The acanthocephalans only penetrated the surficial zone of the intestinal wall and induced only slight inflammation. The main damage was destruction of the mucosal epithelium covering the villi adjacent to the parasite's attachment site, and included necrosis and degeneration. Infected intestine had numerous mast cells (MCs), often in close proximity to, and within, the capillaries, and were associated with fibroblasts of the submucosal layer. Mast cells were irregular in shape with a cytoplasm filled by numerous electron-dense, membrane-bounded granules. Immunostaining of intestine with antibodies against the antimicrobial peptides piscidin 3 and piscidin 4 showed subpopulations of MCs that were positive. Piscidin-positive MCs were mainly observed among the epithelial cells of the intestine, but also within the submucosa. In both uninfected and parasite-infected perch, the number of MCs positive for piscidin 4 was higher than those immunoreactive with piscidin 3 (p < 0.05). For both piscidins, there was no significant difference in the number of positive MCs between parasite-infected and uninfected intestine (p > 0.05). However, uninfected fish showed higher immunostaining intensity for piscidin 3 than infected conspecifics (p < 0.05).
authors.affiliation: Department of Life Sciences and Biotechnology, University of Ferrara, St. Borsari 46, 44121 Ferrara, Italy. Electronic address: dzb@unife.it.
authors.forename: Bahram S
authors.initials: BS
authors.lastname: Dezfuli
authors.forename: Alice
authors.initials: A
authors.lastname: Lui
authors.forename: Luisa
authors.initials: L
authors.lastname: Giari
authors.forename: Flavio
authors.initials: F
authors.lastname: Pironi
authors.forename: Maurizio
authors.initials: M
authors.lastname: Manera
authors.forename: Massimo
authors.initials: M
authors.lastname: Lorenzoni
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Noga
mesh_terms: D000049:Acanthocephala / Q000276:immunology*; D000704:Analysis of Variance; D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000276:immunology*; D005393:Fish Diseases / Q000276:immunology / Q000469:parasitology*; D029941:Fish Proteins / Q000276:immunology; D005786:Gene Expression Regulation / Q000276:immunology*; D006374:Helminthiasis, Animal / Q000276:immunology*; D007150:Immunohistochemistry / Q000662:veterinary; D007411:Intestinal Diseases, Parasitic / Q000276:immunology / Q000662:veterinary*; D007413:Intestinal Mucosa / Q000648:ultrastructure; D007558:Italy; D008407:Mast Cells / Q000276:immunology / Q000378:metabolism; D008854:Microscopy, Electron / Q000662:veterinary; D010471:Perches
chemical_list: D023181:Antimicrobial Cationic Peptides; D029941:Fish Proteins
keywords: Endoparasite; Immunohistochemistry; Mast cells; Piscidins