title: Immunohistochemical localization of inflammatory cells and cell cycle proteins in the gills of Loma salmonae infected rainbow trout (Oncorhynchus mykiss).
abstract: Microsporidial gill diseases particularly those caused by Loma salmonae incur significant economic losses to the salmonid aquaculture industry. The gill responses to infection include the formation of xenomas and the acute hyperplastic inflammatory responses once the xenomas rupture releasing infective spores. The aim of this work was to characterize the inflammatory responses of the gill to both the presence of the xenomas as well as the hyperplasia associated with L. salmonae infection in the rainbow trout gill following an experimental infection using immunohistochemistry. Hyperplastic lesions demonstrated numerous cells expressing PCNA as well as an apparent increased expression of caspase-3 and number of apoptotic cells (TUNEL positive cells). There was an expression of TNFα in individual cells within the gill and increased expression of a myeloid cell line antigen indicating the presence of granulocyte infiltration of both the hyperplastic lesions as well as the xenomas. Similar immune-reactivity was seen in gill EGCs. Hyperplastic gill lesions showed a marked infiltration of CD8+ cells and expression of MHC class I antigens. These findings suggest that L. salmonae xenomas may be subject to infiltration by the host immune cells as well as the mounting or a marked cellular cytotoxic immunoreaction in the resultant hyperplasia following xenoma rupture and spore release.
authors: Norwegian Institute for Water Research (NIVA), Thormøhlensgate 53 D, 5006 Bergen, Norway; Faculty of Biosciences and Aquaculture, University of Nordland, Bodø 8049, Norway. Electronic address: Mark.Powell@niva.no.
authors: Mark D
authors: MD
authors: Powell
authors: Faculty of Biosciences and Aquaculture, University of Nordland, Bodø 8049, Norway; Norwegian Veterinary Institute, 9480 Harstad, Norway.
authors: M Naveed
authors: MN
authors: Yousaf
authors: Department of Immunology and Microbiology, University of Southern Denmark, Odense C, Denmark.
authors: Karina Juhl
authors: KJ
authors: Rasmussen
authors: Freidrich Loeffler-Institut, Federal Research Institute for Animal Health, Institute of Immunology, Germany.
authors: Berndt
authors: B
authors: Köllner
authors: Scottish Fish Immunology Research Centre, School of Biological Sciences, University of Aberdeen, Tillydrone Avenue, Aberdeen AB24 2TZ, UK.
authors: Jun
authors: J
authors: Zou
authors: Scottish Fish Immunology Research Centre, School of Biological Sciences, University of Aberdeen, Tillydrone Avenue, Aberdeen AB24 2TZ, UK.
authors: Chris
authors: C
authors: Secombes
authors: Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown PE C1A 4P3, Canada.
authors: David J
authors: DJ
authors: Speare
mesh_terms: D000818:Animals; D017209:Apoptosis; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D005393:Fish Diseases / Q000276:immunology* / Q000469:parasitology; D005880:Gills / Q000276:immunology / Q000469:parasitology; D006965:Hyperplasia / Q000276:immunology / Q000469:parasitology / Q000662:veterinary; D007150:Immunohistochemistry / Q000662:veterinary; D020287:In Situ Nick-End Labeling / Q000662:veterinary; D007249:Inflammation; D050262:Loma / Q000502:physiology*; D016881:Microsporidiosis / Q000276:immunology / Q000469:parasitology / Q000662:veterinary*; D017686:Oncorhynchus mykiss
chemical_list: D018797:Cell Cycle Proteins
keywords: Apoptosis; CD8; Granulocyte; MHC I; Microsporidial gill disease; PCNA; Xenoma