title: Immune gene expression profiling of Proliferative Kidney Disease in rainbow trout Oncorhynchus mykiss reveals a dominance of anti-inflammatory, antibody and T helper cell-like activities.
abstract: The myxozoan Tetracapsuloides bryosalmonae is the causative agent of Proliferative Kidney Disease (PKD) targeting primarily the kidney of infected fish where it causes a chronic lymphoid immunopathology. Although known to be associated with suppression of some cellular aspects of innate immunity and a prominent lymphocytic hyperplasia, there remains a considerable knowledge gap in our understanding of the underlying immune mechanisms driving PKD pathogenesis. To provide further insights, the expression profiles of a panel of innate/inflammatory and adaptive immune molecules were examined in rainbow trout Oncorhynchus mykiss following a natural exposure to the parasite. Relative to controls, fish with early to advanced stages of kidney pathology exhibited up-regulation of the inflammatory cytokines interleukin (IL)-6 and IL-11, although remaining refractory towards genes indicative of macrophage activity. Antimicrobial peptides (AMPs) and anti-inflammatory markers, including cathelicidin (CATH) and IL-10 were markedly up-regulated during clinical disease. Up-regulation of adaptive immune molecules, including cell markers and antibody genes reflect the lymphocytic dominance of this disease and the likely importance of lymphocyte subsets in PKD pathogenesis. Up-regulation of T helper (TH) cell-like response genes and transcription factors implies that T. bryosalmonae may elicit a complex interplay between TH cell subsets. This work, for the first time in the study of fish-myxozoan interactions, suggests that PKD pathogenesis is shaped by an anti-inflammatory phenotype, a profound B cell/antibody response and dysregulated TH cell-like activities. A better understanding of the functional roles of fish immune cells and molecules in PKD pathogenesis may facilitate future development of control measures against this disease.
authors.affiliation: Scottish Fish Immunology Research Centre, School of Biological Sciences, University of Aberdeen, Tillydrone Avenue, Aberdeen AB24 2TZ, UK. j.holland@abdn.ac.uk.
authors.forename: Bartolomeo
authors.initials: B
authors.lastname: Gorgoglione
authors.forename: Tiehui
authors.initials: T
authors.lastname: Wang
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Secombes
authors.forename: Jason W
authors.initials: JW
authors.lastname: Holland
mesh_terms: D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000235:genetics* / Q000378:metabolism; D005393:Fish Diseases / Q000235:genetics / Q000276:immunology* / Q000469:parasitology; D029941:Fish Proteins / Q000235:genetics* / Q000378:metabolism; D020869:Gene Expression Profiling / Q000662:veterinary; D005786:Gene Expression Regulation; D007668:Kidney / Q000276:immunology* / Q000469:parasitology / Q000473:pathology; D007674:Kidney Diseases / Q000276:immunology / Q000469:parasitology / Q000662:veterinary*; D055764:Myxozoa / Q000302:isolation & purification / Q000502:physiology; D017686:Oncorhynchus mykiss; D016133:Polymerase Chain Reaction / Q000662:veterinary
chemical_list: D023181:Antimicrobial Cationic Peptides; D029941:Fish Proteins