title: Description of an Atlantic salmon (Salmo salar L.) type II interleukin-1 receptor cDNA and analysis of interleukin-1 receptor expression in amoebic gill disease-affected fish.
abstract: Previously, we showed that IL-1β transcription is induced in the gills of amoebic gill disease (AGD)-affected fish in an AGD lesion-restricted fashion. However, in this environment, there is very little evidence of inflammation on histopathological or transcriptional levels and we hypothesised that aberrant signalling may occur. As a first step in investigating this issue, we cloned and sequenced the Atlantic salmon IL-1 receptor type II (IL-1RII) mRNA, and then examined the expression of both the IL-1RI (IL-1 receptor-like protein) and II during Neoparamoeba perurans infection. In gill lesions from AGD-affected fish, a step-wise temporal increase in the relative expression of IL-1β coincided with a significant reduction in IL-1RI, whereas the IL-1RII mRNA remained unchanged. Down-regulation of IL-1RI could explain the paucity of inflammation in affected tissue, although simultaneous up-regulation of IL-1β-inducible transcripts indicated that this is not due to a complete blockage of the IL-1RI pathway. Rather, it appears that IL-1RI transcription is reduced and this rate limits the effects of chronic IL-1β over-expression.
authors.affiliation: National Centre for Marine Conservation and Resource Sustainability, University of Tasmania, Launceston 7250, Australia. Richard.Morrison@dpipwe.tas.gov.au
authors.forename: R N
authors.initials: RN
authors.lastname: Morrison
authors.forename: N D
authors.initials: ND
authors.lastname: Young
authors.forename: B F
authors.initials: BF
authors.lastname: Nowak
mesh_terms: D000562:Amebiasis / Q000276:immunology* / Q000662:veterinary*; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D005393:Fish Diseases / Q000276:immunology*; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D053583:Interleukin-1beta / Q000276:immunology; D008969:Molecular Sequence Data; D017472:Receptors, Interleukin-1 / Q000737:chemistry / Q000235:genetics* / Q000276:immunology*; D020317:Salmo salar / Q000235:genetics / Q000276:immunology; D016415:Sequence Alignment; D013997:Time Factors
chemical_list: D018076:DNA, Complementary; D053583:Interleukin-1beta; D017472:Receptors, Interleukin-1