Dataset Information

Differential immune gene response in gills, skin, and spleen of rainbow trout Oncorhynchus mykiss infected by Ichthyophthirius multifiliis.

ABSTRACT: Infection of rainbow trout with the parasitic ciliate Ichthyopthirius multifiliis induces differential responses in gills, skin and spleen. A controlled experimental infection was performed and expression of immune-relevant genes in skin, gills, and spleen were recorded by qPCR at day 1 and 8 after parasite exposure. Infection induced a marked reaction involving regulation of innate and adaptive immune genes in rainbow trout at day 8 post-infection. The expression level of a total of 22 out of 24 investigated genes was significantly higher in gills compared to skin reflecting the more sensitive and delicate structure of gills. Especially pro-inflammatory cytokines IL-6, IL-17 C1, regulatory cytokines IL-4/13A, IL-10, TGF?, complement factor C5, chemokines CK10, CK12, acute phase proteins (precerebellin, hepcidin) and immunoglobulins (IgM, IgT) displayed differential expression levels. The spleen, a central immune organ with no trace of the parasite, showed elevated expression of IgM, IgT, complement factor C5 and chemokine CK10 (compared to skin and gills directly exposed to the parasite), indicating an interaction between the infected surface sites and central immune organs. This communication could be mediated by chemokines CK10 and CK12 and cytokine IL-4/13A and may at least partly explain the establishment of a systemic response in rainbow trout against the parasite.

SUBMITTER: Syahputra K

PROVIDER: S-EPMC6586319 | biostudies-literature | 2019

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Differential immune gene response in gills, skin, and spleen of rainbow trout Oncorhynchus mykiss infected by Ichthyophthirius multifiliis.

Syahputra Khairul K Kania Per W PW Al-Jubury Azmi A Marnis Huria H Setyawan Agung Cahyo AC Buchmann Kurt K

PloS one 20190620 6

Infection of rainbow trout with the parasitic ciliate Ichthyopthirius multifiliis induces differential responses in gills, skin and spleen. A controlled experimental infection was performed and expression of immune-relevant genes in skin, gills, and spleen were recorded by qPCR at day 1 and 8 after parasite exposure. Infection induced a marked reaction involving regulation of innate and adaptive immune genes in rainbow trout at day 8 post-infection. The expression level of a total of 22 out of 2 ...[more]

PMID: 31220151

Similar Datasets

Project description:Purpose: a transcriptomic analysis was performed to extend our understanding on the immune response picture of rainbow trout exposed to I. multifiliis. Methods: Gill samples were collected from fish in each tank (control and infected group) at day 8 after infection. Total RNA was extracted using RTN350 (Sigma-Aldrich), according to the manufacturer’s instruction and subsequently, DNase treated with DNase I (Thermo Scientific, USA). Quality and integrity of the total RNA were checked on an Agilent Bioanalyzer 2100 total RNA Nano series II chip (Agilent, Amstelveen, Netherlands). Illumina RNAseq libraries were prepared from 500 ng total RNA using the Illumina TruSeqTM Stranded mRNA LT Sample Prep Kit according to the manufacturer’s instructions (Illumina Inc. San Diego, CA, USA). All RNAseq libraries (150-750 bp inserts) were sequenced on an Illumina HiSeq2500 sequencer as 1 x 50 nucleotides single-end reads according to the manufacturer’s protocol. Image analysis and base calling were done using the Illumina pipeline. Reads were aligned to the Rainbow trout reference genome (http://www.genoscope.cns.fr/trout/data/) using TopHat (version 2.0.5) and on average 53.4% of the RNAseq reads could be mapped. The resulting files were filtered using SAMtools (version 0.1.18) to exclude secondary alignment of reads. For statistical comparison of gene expression levels between groups, aligned fragments per predicted gene were counted from SAM alignment files using the Python package HTSeq (version 0.5.3p9). To make comparisons across samples possible, these fragment counts were corrected for the total amount of sequencing performed for each sample. As a correction scalling factor, we employed library size estimates determined using the R/Bioconductor (release 2.11) package DESeq. Read counts were normalized by dividing the raw counts obtained from HTSeq by its scale factor. Correction for false positives is included in the statistical analysis of gene expression through DESeq. The cut-off for significance was set to adjusted p<0.05 and at least 2-fold change. Results: a transcriptomic analysis was performed on infected rainbow trout gills and it showed that a total of 3,352 (7.2%) out of 46,585 identified genes were revealed significantly expressed after parasite infection. Of differentially expressed genes, 1.796 genes were up-regulated and 1.556 genes down-regulated. These were classified into 61 Gene Ontology (GO) terms and mapped to 282 reference canonical pathways in the Kyoto Encyclopedia of Genes and Genomes (KEGG) databases. Infection of I. multifiliis induced a clear differential expression of immune genes, related to both innate and adaptive immunity. A total of 268 (6.86%) regulated genes was known to take part in 16 immune-related pathways. These involved pathways related to the innate immune system such as Chemokine signaling pathway, Platelet activation, Toll-like receptor signaling pathway, NOD-like receptor signaling pathway, and Leukocyte transendothelial migration. Conclusion: a transcriptomic profile of rainbow trout gills exposed to the parasitic I. multifiliis was reported for the first time. A total of 3,355 differentially expressed unigenes were identified. Of these were 1,184 unigenes (mapped to 952 genes) annotated 282 KEGG pathways and 268 unigenes were associated with 16 immune pathways. Most unigenes were related to innate immune system pathways (Chemokine signaling pathway, Platelet activation, Toll-like receptor signaling pathway, NOD-like receptor signaling pathway, and Leukocyte transendothelial migration) although a number of unigenes was related to adaptive responses (antigen processing and presentation, T and B cell receptor signaling pathway). The present study gave a far better resolution of the immune response of rainbow trout exposed to a parasitic protozoan than has ever been presented previously. The identification of a series of immune genes involved in several but important was useful for understanding of immune mechanism of the rainbow trout responding to the parasite I. multifiliis. Our results provide tools to link innate and adaptive immune elements in the process and present basic information which will be useful in the future studies related to immunoprophylaxis.

Project description:The transmission of puffy skin disease (PSD) to rainbow trout Oncorhynchus mykiss Walbaum was tested in the laboratory by conducting co-habitation challenges with puffy skin (PS)-affected fish (Trojans) collected from the field. Two separate challenges were conducted using Trojans sourced from two different sites and diploid (first trial) or triploid (second trial) naïve fish. PSD-specific clinical signs were observed in both groups of naïve fish, with 66% of the fish sampled during the challenges showing signs of varying severity. The first clinical features of PSD were presented as white oval skin patches on one or both flanks 15-21 days post-challenge (dpc). The extent of the lesions ranged from 10 to 90% of the body surface, depending on the severity of the lesion. Both the severity and number of affected fish increased during the challenge. Macroscopically, oedema of the skin and multifocal petechial haemorrhaging were observed towards the end of the trials. Abnormal fish behaviour consisting of "flashing" and excessive mucous production was noted from 15 dpc onwards. Fish with severe PSD lesions also displayed inappetence and associated emaciation. Rodlet cells were observed in 41% of the fresh skin scrapes analysed from the second trial. Histologically epidermal oedema was observed in 31% of the naive fish showing gross pathology, with additional 12% displaying epidermal hyperplasia, mostly observed at the end of the challenge. Other concomitant features of the PSD lesions in challenged fish were epithelial erosion and sloughing, and occasionally mild or focal inflammation. No consistent pathology of internal organs was observed. The parasites Ichthyophthirius multifiliis and Ichthyobodo necator were observed in skin samples of a proportion of naïve challenged fish and in Trojans but not in control fish. The presence of these and other known fish pathogens in the skin of PSD-fish was confirmed by high-throughput sequencing analysis. In summary, we have demonstrated that PSD is a transmissible condition. However, even though a number of known fish pathogens were identified in the skin tissues of PSD-fish, the actual causative infectious agent(s) remain(s) unknown.

Dataset Information

Differential immune gene response in gills, skin, and spleen of rainbow trout Oncorhynchus mykiss infected by Ichthyophthirius multifiliis.

Publications

Differential immune gene response in gills, skin, and spleen of rainbow trout Oncorhynchus mykiss infected by Ichthyophthirius multifiliis.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets