PRKX down-regulates TAK1/IRF7 signaling in the antiviral innate immunity of black carp .

TGF-β-activated kinase-1 (TAK1), tightly related to innate immunity, is phosphorylated and activated by X-linked protein kinase (PRKX) in humans and mammals, which belongs to the c-AMP-dependent protein kinase family. However, the relationship between PRKX and TAK1 remains unknown in teleost. It has been reported in vertebrates for the first time that TAK1 of black carp (bcTAK1) interacts with bcIRF7 and is capable to up-regulate bcIRF7-mediated IFN signaling in our previous study.

Characterization of CD166 from Nile tilapia (Oreochromis niloticus) displays a broad pathogen recognition spectrum and involved the immune response to microbial aggression.

CD166 is a member of the immunoglobulin superfamily of cell adhesion molecules, and its mediated adhesion plays a crucial role in different physiological and pathological phenomena, especially related to leukocyte extravasation, immune synapse stability, T cell activation and proliferation. In this study, CD166 was identified from Nile tilapia (Oreochromis niloticus, OnCD166). OnCD166 contains an open reading frame of 1671 bp that encodes a peptide of 556 amino acids, and contains five consecutive extracellular immunoglobulin domains.

Zebrafish BID Exerts an Antibacterial Role by Negatively Regulating p53, but in a Caspase-8-Independent Manner.

Bid (BH3-interacting domain death agonist), a member of the Bcl-2 family, plays a crucial role in the initiation of apoptosis. Independent of its apoptotic function, Bid is also involved in the regulation of inflammation and innate immunity. However, the role of Bid during bacterial pathogen infection remains unclear.

Crosstalks between NOD1 and Histone H2A Contribute to Host Defense against Infection in Zebrafish.

Correlation studies about NOD1 and histones have not been reported. In the present study, we report the functional correlation between NOD1 and the histone H2A variant in response to infection. In zebrafish, NOD1 deficiency significantly promoted proliferation and decreased larval survival.

Roles of PRR-Mediated Signaling Pathways in the Regulation of Oxidative Stress and Inflammatory Diseases.

Oxidative stress is a major contributor to the pathogenesis of various inflammatory diseases. Accumulating evidence has shown that oxidative stress is characterized by the overproduction of reactive oxygen species (ROS). Previous reviews have highlighted inflammatory signaling pathways, biomarkers, molecular targets, and pathogenetic functions mediated by oxidative stress in various diseases.

Copper Regulates the Susceptibility of Zebrafish Larvae to Inflammatory Stimuli by Controlling Neutrophil/Macrophage Survival.

Copper has been revealed to negatively affect the hematopoietic system, which has an important function in immune pathogen defense, but little is known about the potential mechanism. In this study, copper-stressed larvae exhibited significantly increased mortality as well as reduced percentages of GFP-labeled macrophages and neutrophils after () infection. However, those copper-stressed GFP-labeled macrophages and neutrophils showed more rapid responses to infection.

Transcriptomic responses of S100 family to bacterial and viral infection in zebrafish.

The S100 family proteins are a group of small acidic polypeptides and have diverse functions in regulating many aspects of physiological processes. They are structurally conserved and possess two EF-hands which are central for calcium-mediated functions. In this study, 14 S100 cDNA sequences were determined in zebrafish and their genomic organizations confirmed.

NS38 is required for aquareovirus replication via interaction with viral core proteins and host eIF3A.

Aquareoviruses contain an 11-segmented double-stranded RNA genome. Previous studies indicated that NS38, a virus-encoded putative single-stranded RNA binding protein, interacts with NS80 in viral inclusion bodies (VIBs). However, the role of NS38 in aquareovirus infection remained unclear.

Identification and expression analysis of IL-4/13 receptors in grass carp Ctenopharyngodon idella.

Interleukin (IL)-4 and IL-13 are T helper 2 (Th2) cytokines with pleiotropic functions. IL-4 interacts with two receptors consisting of IL-4Rα/γ chain receptor (γC) and IL-4Rα/IL-13Rα1. In contrast, IL-13 binds to IL-13Rα2 but also shares the receptor complex containing IL-4Rα/IL-13Rα1.

Functional characterization of a short peptidoglycan recognition protein from Chinese giant salamander (.

Peptidoglycan (PGN) recognition proteins (PGRPs) are important pattern recognition receptors (PRRs) involved in immune defense against bacterial infections. In this study, a short PGRP (termed AdPGRP-S1) was cloned and functionally characterized from Chinese giant salamander (), the largest extant urodela amphibian species. AdPGRP-S1 was 184 aa in length and shared 38.

Sequence and Expression Analysis of Interferon Regulatory Factor 10 (IRF10) in Three Diverse Teleost Fish Reveals Its Role in Antiviral Defense.

Background: Interferon regulatory factor (IRF) 10 was first found in birds and is present in the genome of other tetrapods (but not humans and mice), as well as in teleost fish. The functional role of IRF10 in vertebrate immunity is relatively unknown compared to IRF1-9. The target of this research was to clone and characterize the IRF10 genes in three economically important fish species that will facilitate future evaluation of this molecule in fish innate and adaptive immunity.

The combined effects of UV-C radiation and H2O2 on Microcystis aeruginosa, a bloom-forming cyanobacterium.

In order to get insight into the impacts of UVC/H2O2 on Microcystis aeruginosa, physiological and morphological changes as well as toxicity were detected under different UVC/H2O2 treatments. In the presence of sole UVC or H2O2, the net oxygen evolution rate decreased significantly (p<0.05) since activity of photosystem II (PSII) was inhibited.

Gene cloning and induced expression pattern of IRF4 and IRF10 in the Asian swamp eel (Monopterus albus).

The Asian swamp eel (Monopterus albus) is one of the most economically important freshwater fish in East Asia, but data on the immune genes of M. albus are scarce compared to other commercially important fish. A better understanding of the eel's immune responses may help in developing strategies for disease management, potentially improving yields and mitigating losses.

Intracellular interferons in fish: a unique means to combat viral infection.

We demonstrate for the first time in vertebrates, that alternative splicing of interferon (IFN) genes can lead to a functional intracellular IFN (iIFN). Fish IFN genes possess introns and in rainbow trout three alternatively spliced transcripts of the IFN1 gene exist. Two of the encoded IFNs are predicted to lack a signal peptide.

Expression pattern, promoter activity and bactericidal property of β-defensin from the mandarin fish Siniperca chuatsi.

β-Defensin (BD) are cysteine-rich, cationic antimicrobial peptides which play an important role in innate immune system against invading microbes. In the present study, the cDNA cloning, expression analysis, transcriptional regulation and antimicrobial activity of β-defensin (ScBD) from mandarin fish (Siniperca chuatsi) were characterized. The cDNA sequence of ScBD is 596 bp which encodes a protein of 63 amino acids (aa).

Cloning and expression analysis of a long type peptidoglycan recognition protein (PGRP-L) from Xenopus tropicalis.

Peptidoglycan recognition proteins (PGRPs) are a family of pattern recognition receptors (PRRs) of the immune system, which bind and hydrolyze bacterial peptidoglycan. Here, a long type PGRP (PGRP-L) was first cloned in the lower vertebrate species Xenopus tropicalis (Xt). The XtPGRP-L possessed a conserved genomic structure with five exons and four introns.

Expression and functional characterization of the RIG-I-like receptors MDA5 and LGP2 in Rainbow trout (Oncorhynchus mykiss).

The retinoic acid-inducible gene I (RIG-I)-like receptors (RLR) comprise three homologues: RIG-I, melanoma differentiation-associated gene 5 (MDA5), and laboratory of genetics and physiology 2 (LGP2). They activate the host interferon (IFN) system upon recognition of viral RNA pathogen-associated molecular patterns (PAMPs) in the cytoplasm. Bioinformatic analysis of the sequenced vertebrate genomes suggests that the cytosolic surveillance system is conserved in lower vertebrates, and recent functional studies have confirmed that RIG-I is important to fish antiviral immunity.

Cloning of two rainbow trout nucleotide-binding oligomerization domain containing 2 (NOD2) splice variants and functional characterization of the NOD2 effector domains.

Nucleotide-binding oligomerization domain 2 (NOD2) is a cytoplasmic pattern recognition receptor (PRR), which is involved in innate antibacterial and antiviral responses. Here, two NOD2 splice variants, trNOD2a and trNOD2b, are reported in rainbow trout Oncorhynchus mykiss, that share 63% and 61% similarity with human NOD2, respectively. These two trout NOD2 splice variants were shown to be constitutively expressed in thymus, gills, skin, muscle, liver, spleen, head kidney, intestine, heart, and brain, with the expression of trout NOD2 (trNOD2) mainly contributed by trNOD2a in all the examined tissues.

Origin and evolution of the RIG-I like RNA helicase gene family.

Background: The DExD/H domain containing RNA helicases such as retinoic acid-inducible gene I (RIG-I) and melanoma differentiation-associated gene 5 (MDA5) are key cytosolic pattern recognition receptors (PRRs) for detecting nucleotide pathogen associated molecular patterns (PAMPs) of invading viruses. The RIG-I and MDA5 proteins differentially recognise conserved PAMPs in double stranded or single stranded viral RNA molecules, leading to activation of the interferon system in vertebrates. They share three core protein domains including a RNA helicase domain near the C terminus (HELICc), one or more caspase activation and recruitment domains (CARDs) and an ATP dependent DExD/H domain.

Identification of an additional two-cysteine containing type I interferon in rainbow trout Oncorhynchus mykiss provides evidence of a major gene duplication event within this gene family in teleosts.

Multiple type I interferons (IFNs) have recently been identified in salmonids, containing two or four conserved cysteines. In this work, a novel two-cysteine containing (2C) IFN gene was identified in rainbow trout. This novel trout IFN gene (termed IFN5) formed a phylogenetic group that is distinct from the other three salmonid IFN groups sequenced to date and had a close evolutionary relationship with IFNs from advanced fish species.

Molecular identification and expression analysis of tumor necrosis factor receptor-associated factor 2 in grass carp Ctenopharyngodon idella.

Tumor necrosis factor receptor-associated factor 2 (TRAF2) is a crucial component of almost the entire tumor necrosis factor receptor superfamily signaling pathway. In the present study, a TRAF2 gene has been cloned from grass carp (Ctenopharyngodon idella) by reverse transcription-polymerase chain reaction and rapid amplification of cDNA ends. The full-length cDNA is 3162 bp, including a 60 bp 5' untranslated region (UTR), a 1611 bp open reading frame, and a 1491 bp 3' UTR.

A new fluorescent quantitative PCR-based in vitro neutralization assay for white spot syndrome virus.

A fluorescent quantitative PCR (FQ-PCR) assay utilizing SYBR green I dye is described for quantitation of white spot syndrome virus (WSSV) particles isolated from infected crayfish, Cambarus clarkii. For this assay, a primer set was designed which amplifies, with high efficiency and specificity, a 129bp target sequence within ORF167 of the WSSV genome. Conveniently, WSSV particles can be added into the FQ-PCR assay with a simple and convenient method to release its DNA.

Gene structure and transcription of IRF-2 in the mandarin fish Siniperca chuatsi with the finding of alternative transcripts and microsatellite in the coding region.

The gene of interferon regulatory factor-2 (IRF-2) has been cloned from the mandarin fish (Siniperca chuatsi). The IRF-2 gene has 6,418 nucleotides (nt) and contains eight exons and seven introns, encoding two mRNAs. The two IRF-2 mRNAs each contained an open reading frame of 873 nt, which both translate into the same 291 amino acids but differed in their 5' untranslated region: one mRNA was transcribed initially from the exon 1 bypassing exon 2, while the other was transcribed from the exon 2.