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Frontiers in Immunology 2020Induction of cellular immune responses rely on Major histocompatibility complex (MHC) molecules presenting pathogenic peptides to T cells. Peptide processing, transport,...
Induction of cellular immune responses rely on Major histocompatibility complex (MHC) molecules presenting pathogenic peptides to T cells. Peptide processing, transport, loading and editing is a constitutive process in most cell types, but is accelerated upon infection. Recently, an unexpected complexity in the number of functional genes involved in MHC class I peptide cleavage, peptide transport, peptide loading and editing was found in teleosts, originating from the second and third whole genome duplication events. Salmonids have expanded upon this with functional duplicates also from a fourth unique salmonid whole genome duplication. However, little is known about how individual gene duplicates respond in the context of stimulation. Here we set out to investigate how interferon gamma (IFNg) regulates the transcription of immune genes in Atlantic salmon with particular focus on gene duplicates and MHC pathways. We identified a range of response patterns in Atlantic salmon gene duplicates, with upregulation of all duplicates for some genes, like interferon regulatory factor 1 (IRF1) and interferon induced protein 44-like (IFI44.L), but only induction of one or a few duplicates of other genes, such as TAPBP and ERAP2. A master regulator turned out to be the IRF1 and not the enhanceosome as seen in mammals. If IRF1 also collaborates with CIITA and possibly NLRC5 in regulating IFNg induction of MHCI and MHCII expression in Atlantic salmon, as in zebrafish, remains to be established. Altogether, our results show the importance of deciphering between gene duplicates, as they often respond very differently to stimulation and may have different biological functions.
Topics: Animals; Cell Line; Evolution, Molecular; Fish Proteins; Gene Duplication; Gene Expression Regulation; Head Kidney; Histocompatibility Antigens Class I; Interferon Regulatory Factor-1; Interferon-gamma; Intracellular Signaling Peptides and Proteins; Major Histocompatibility Complex; Nuclear Proteins; Phylogeny; Promoter Regions, Genetic; Salmo salar; Trans-Activators; Zebrafish
PubMed: 33123146
DOI: 10.3389/fimmu.2020.571650 -
Gene Mar 2021The transcriptomic response of Senegalese sole (Solea senegalensis) triggered by two betanodaviruses with different virulence to that fish species has been assessed...
The transcriptomic response of Senegalese sole (Solea senegalensis) triggered by two betanodaviruses with different virulence to that fish species has been assessed using an OpenArray® platform based on TaqMan™ quantitative PCR. The transcription of 112 genes per sample has been evaluated at two sampling times in two organs (head kidney and eye/brain-pooled samples). Those genes were involved in several roles or pathways, such as viral recognition, regulation of type I (IFN-1)-dependent immune responses, JAK-STAT cascade, interferon stimulated genes, protein ubiquitination, virus responsive genes, complement system, inflammatory response, other immune system effectors, regulation of T-cell proliferation, and proteolysis and apoptosis. The highly virulent isolate, wSs160.3, a wild type reassortant containing a RGNNV-type RNA1 and a SJNNV-type RNA2 segments, induced the expression of a higher number of genes in both tested organs than the moderately virulent strain, a recombinant harbouring mutations in the protruding domain of the capsid protein. The number of differentially expressed genes was higher 2 days after the infection with the wild type isolate than at 3 days post-inoculation. The wild type isolate also elicited an exacerbated interferon 1 response, which, instead of protecting sole against the infection, increases the disease severity by the induction of apoptosis and inflammation-derived immunopathology, although inflammation seems to be modulated by the complement system. Furthermore, results derived from this study suggest a potential important role for some genes with high expression after infection with the highly virulent virus, such as rtp3, sacs and isg15. On the other hand, the infection with the mutant does not induce immune response, probably due to an altered recognition by the host, which is supported by a different viral recognition pathway, involving myd88 and tbkbp1.
Topics: Animals; Brain; Eye; Fish Diseases; Flatfishes; Gene Expression Profiling; Head Kidney; Immunogenetic Phenomena; Interferon Type I; Nodaviridae; Polymerase Chain Reaction; RNA-Seq; Virulence; Virus Replication
PubMed: 33444680
DOI: 10.1016/j.gene.2021.145430 -
Frontiers in Immunology 2022Immunoglobulin (Ig) M is an important immune effector that protects organisms from a wide variety of pathogens. However, little is known about the immune response of gut...
Immunoglobulin (Ig) M is an important immune effector that protects organisms from a wide variety of pathogens. However, little is known about the immune response of gut mucosal IgM during bacterial invasion. Here, we generated polyclonal antibodies against common carp IgM and developed a model of carp infection with intraperitoneal injection. Our findings indicated that both innate and adaptive immune responses were effectively elicited after infection. Upon bacterial infection, IgM B cells were strongly induced in the gut and head kidney, and bacteria-specific IgM responses were detected in high levels both in the gut mucus and serum. Moreover, our results suggested that IgM responses may vary in different infection strategies. Overall, our findings revealed that the infected common carp exhibited high resistance to this representative enteropathogenic bacterium upon reinfection, suggesting that IgM plays a key role in the defense mechanisms of the gut against bacterial invasion. Significantly, the second injection of induces strong local mucosal immunity in the gut, which is essential for protection against intestinal pathogens, providing reasonable insights for vaccine preparation.
Topics: Animals; Aeromonas hydrophila; Carps; Immunity, Mucosal; Immunoglobulin M; Head Kidney
PubMed: 36466906
DOI: 10.3389/fimmu.2022.1037517 -
Toxins Feb 2022subsp. () is a Gram-negative bacterium that infects a large number of marine fish species in Europe, Asia, and America, both in aquacultures and in the natural...
subsp. () is a Gram-negative bacterium that infects a large number of marine fish species in Europe, Asia, and America, both in aquacultures and in the natural environment. Among the affected hosts are economically important cultured fish, such as sea bream (), sea bass (), yellowtail (), and cobia (). The best characterized virulence factor of is the Apoptosis-Inducing Protein of 56 kDa (AIP56), a secreted AB-type toxin that has been shown to induce apoptosis of sea bass phagocytes during infection. AIP56 has an A subunit that displays metalloprotease activity against NF-kB p65 and a B subunit that mediates binding and internalization of the A subunit in susceptible cells. Despite the fact that the gene is highly prevalent in isolates from different fish species, the toxicity of AIP56 has only been studied in sea bass. In the present study, the toxicity of AIP56 for sea bream was evaluated. Ex vivo assays showed that sea bream phagocytes are resistant to AIP56 cytotoxicity and that resistance was associated with an inefficient internalization of the toxin by those cells. Accordingly, in vivo intoxication assays revealed that sea bream is much more resistant to AIP56-induced lethality than sea bass. These findings, showing that the effect of AIP56 is different in sea bass and sea bream, set the basis for future studies to characterize the effects of AIP56 and to fully elucidate its virulence role in different susceptible hosts.
Topics: Animals; Apoptosis Regulatory Proteins; Bacterial Proteins; Bacterial Toxins; Bass; Head Kidney; Leukocytes; Liver; Photobacterium; Sea Bream; Spleen; Transcription Factor RelA
PubMed: 35202146
DOI: 10.3390/toxins14020119 -
European Journal of Human Genetics :... Dec 2020Although over 50 genes are known to cause renal malformation if mutated, the underlying genetic basis, most easily identified in syndromic cases, remains unsolved in...
Although over 50 genes are known to cause renal malformation if mutated, the underlying genetic basis, most easily identified in syndromic cases, remains unsolved in most patients. In search of novel causative genes, whole-exome sequencing in a patient with renal, i.e., crossed fused renal ectopia, and extrarenal, i.e., skeletal, eye, and ear, malformations yielded a rare heterozygous variant in the GDF6 gene encoding growth differentiation factor 6, a member of the BMP family of ligands. Previously, GDF6 variants were reported to cause pleiotropic defects including skeletal, e.g., vertebral, carpal, tarsal fusions, and ocular, e.g., microphthalmia and coloboma, phenotypes. To assess the role of GDF6 in the pathogenesis of renal malformation, we performed targeted sequencing in 193 further patients identifying rare GDF6 variants in two cases with kidney hypodysplasia and extrarenal manifestations. During development, gdf6 was expressed in the pronephric tubule of Xenopus laevis, and Gdf6 expression was observed in the ureteric tree of the murine kidney by RNA in situ hybridization. CRISPR/Cas9-derived knockout of Gdf6 attenuated migration of murine IMCD3 cells, an effect rescued by expression of wild-type but not mutant GDF6, indicating affected variant function regarding a fundamental developmental process. Knockdown of gdf6 in Xenopus laevis resulted in impaired pronephros development. Altogether, we identified rare heterozygous GDF6 variants in 1.6% of all renal anomaly patients and 5.4% of renal anomaly patients additionally manifesting skeletal, ocular, or auricular abnormalities, adding renal hypodysplasia and fusion to the phenotype spectrum of GDF6 variant carriers and suggesting an involvement of GDF6 in nephrogenesis.
Topics: Adolescent; Adult; Animals; Cell Line; Child; Child, Preschool; Female; Growth Differentiation Factor 6; Heterozygote; Humans; Infant; Kidney Tubules; Male; Mice; Mutation; Urogenital Abnormalities; Vesico-Ureteral Reflux; Xenopus
PubMed: 32737436
DOI: 10.1038/s41431-020-0678-9 -
Fish & Shellfish Immunology Aug 2022The λ-carrageenin is a sulphated mucopolysaccharide that has been used for decades to induce experimental inflammation in mammals. However, it has been little...
The λ-carrageenin is a sulphated mucopolysaccharide that has been used for decades to induce experimental inflammation in mammals. However, it has been little considered in fish. We studied the in vitro effects of λ-carrageenin on gilthead seabream (Sparus aurata L.) head-kidney leucocytes (HKLs). For this purpose, HKLs were incubated with serial concentrations (from 0 to 1,000 μg mL-1) of λ-carrageenin for 3, 6, 12 and 24 h to assess its influence on cell viability and morphology, cell activity and modulation of several selected inflammation-related genes. The viability results demonstrated that λ-carrageenin has no negative effects on HKLs. The respiratory burst activity and phagocytic ability of HKLs after being incubated with λ-carrageenin (100 and 1,000 μg mL) for 24 h were increased, whereas the phagocytic capacity was inhibited by the higher dose at the same experimental time compared with control samples. However, the peroxidase activity of HKLs was not changed by incubation with λ-carrageenin. According to transmission electron microscopy results, incubation of HKLs with the higher dose of λ-carrageenin appeared to activate the cells being evident different morphological changes without sign of cell death. Furthermore, up-regulation of three proinflammatory cytokines (il1b, tnfa, and il6) and down-regulation of anti-inflammatory genes (tgfb) were denoted in HKLs incubated with carrageenin. The present results provide a detailed approach to the effects of λ-carrageenin on fish leucocytes, which could have some impact on how we understand the response of these cells when inducing an inflammatory process in fish.
Topics: Animals; Carrageenan; Head Kidney; Inflammation; Kidney; Leukocytes; Mammals; Sea Bream
PubMed: 35842113
DOI: 10.1016/j.fsi.2022.07.030 -
Ecotoxicology and Environmental Safety Dec 2021Acidized water environment can impact many physiological processes of aquatic animals. The response of the head kidney to acidification, especially the immune response,...
Acidized water environment can impact many physiological processes of aquatic animals. The response of the head kidney to acidification, especially the immune response, is of great significance to health. This study analyzed the histological and transcriptional changes under different acidification levels (C group, pH 8.1; P group, pH 7.4; E group, pH 3.5) in the short term (12 h, 36 h and 60 h) in the head kidney of juvenile L. calcarifer. The results showed that the acidification of the water environment caused tissue damage to the head kidney of L. calcarifer, and the damage appeared earlier and was stronger in the extreme pH group. The transcriptional response of L. calcarifer head kidney increased with the increase of acidification level. The two treatments transcriptional responses showed different trends in terms of time. After KEGG function enrichment, with the increase of stimulation time, the proportion of down-regulated pathways was increasing, and the types of pathway enrichment at different acidification levels were quite different at the initial stage. At 12 h, the first category in the P group with the most significant number of pathways was 'Metabolism', and the first category in the E group with the largest number of pathways was 'Human Diseases'. At 60 h, the enrichment pathways of the two groups were highly overlapping in immune-related pathways, which contained 26 common DEGs. They had a dominant expression pattern. In the P group, the expression level decreased with time. In the E group, the down-regulation degree of expression level at 12 h reached the level of the P group at 60 h, and the expression level remained low until 60 h. Through the correlation network, interferon regulatory factor 7 (IRF7), Tripartite motif containing-21 (TRIM21), Signal transducer and activator of transcription 1 (STAT1) and Signal transducer and activator of transcription 3 (STAT3) were found to have the most correlation with other genes. In this study, juvenile L. calcarifer showed different coping strategies to different levels of acute acidification stress, but all of them resulted in the extensive weakening of head kidney immune function.
Topics: Animals; Head Kidney; Humans; Hydrogen-Ion Concentration; Immunity; Perciformes
PubMed: 34478980
DOI: 10.1016/j.ecoenv.2021.112712 -
MicroPublication Biology 2023Histone deacetylases (HDACs) are key posttranslational modulators of the proteome. We show that expression of ( ) is dynamic and appears in a tissue specific manner...
Histone deacetylases (HDACs) are key posttranslational modulators of the proteome. We show that expression of ( ) is dynamic and appears in a tissue specific manner throughout embryonic development of the frog Xenopus . Interestingly, transcripts often associate with ciliated tissues, like the left-right organizer at neurula stage or the pronephros. In the embryonic skin, Hdac6 protein localizes to the cilia base, suggesting a functional link.
PubMed: 37649557
DOI: 10.17912/micropub.biology.000919 -
Scientific Reports Aug 2019Autosomal dominant tubulointerstitial kidney disease (ADTKD) is a genetically heterogeneous renal disorder leading to progressive loss of renal function. ADTKD-REN is...
Autosomal dominant tubulointerstitial kidney disease (ADTKD) is a genetically heterogeneous renal disorder leading to progressive loss of renal function. ADTKD-REN is due to rare mutations in renin, all localized in the protein leader peptide and affecting its co-translational insertion in the endoplasmic reticulum (ER). Through exome sequencing in an adult-onset ADTKD family we identified a new renin variant, p.L381P, mapping in the mature protein. To assess its pathogenicity, we combined genetic data, computational and predictive analysis and functional studies. The L381P substitution affects an evolutionary conserved residue, co-segregates with renal disease, is not found in population databases and is predicted to be deleterious by in silico tools and by structural modelling. Expression of the L381P variant leads to its ER retention and induction of the Unfolded Protein Response in cell models and to defective pronephros development in zebrafish. Our work shows that REN mutations outside of renin leader peptide can cause ADTKD and delineates an adult form of ADTKD-REN, a condition which has usually its onset in childhood. This has implications for the molecular diagnosis and the estimated prevalence of the disease and points at ER homeostasis as a common pathway affected in ADTKD-REN, and possibly more generally in ADTKD.
Topics: Adult; Age of Onset; Amino Acid Sequence; Endoplasmic Reticulum; Genes, Dominant; Humans; Male; Mutation; Nephritis, Interstitial; Pedigree; Renin
PubMed: 31406136
DOI: 10.1038/s41598-019-48014-6 -
Development (Cambridge, England) Jul 2019Renal functional units known as nephrons undergo patterning events during development that create a segmental array of cellular compartments with discrete physiological...
Renal functional units known as nephrons undergo patterning events during development that create a segmental array of cellular compartments with discrete physiological identities. Here, from a forward genetic screen using zebrafish, we report the discovery that transcription factor AP-2 alpha () coordinates a gene regulatory network that activates the terminal differentiation program of distal segments in the pronephros. We found that acts downstream of Iroquois homeobox 3b (), a distal lineage transcription factor, to operate a circuit consisting of , and genes encoding solute transporters that dictate the specialized metabolic functions of distal nephron segments. Interestingly, this regulatory node is distinct from other checkpoints of differentiation, such as polarity establishment and ciliogenesis. Thus, our studies reveal insights into the genetic control of differentiation, where is essential for regulating a suite of segment transporter traits at the final tier of zebrafish pronephros ontogeny. These findings have relevance for understanding renal birth defects, as well as efforts to recapitulate nephrogenesis to facilitate drug discovery and regenerative therapies.
Topics: Animals; Animals, Genetically Modified; Body Patterning; Cell Differentiation; Embryo, Nonmammalian; Gene Expression Regulation, Developmental; Genes, Switch; Kidney; Nephrons; Organogenesis; Pronephros; Transcription Factor AP-2; Zebrafish; Zebrafish Proteins
PubMed: 31160420
DOI: 10.1242/dev.172387