| 1. |
- Altmann, Simone, et al.
(författare)
-
Toll-like receptors in maraena whitefish : Evolutionary relationship among salmonid fishes and patterns of response to Aeromonas salmonicida
- 2016
-
Ingår i: Fish and Shellfish Immunology. - : Elsevier BV. - 1050-4648 .- 1095-9947. ; 54, s. 391-401
-
Tidskriftsartikel (refereegranskat)abstract
- Toll-like receptors (TLRs) interact directly with particular pathogenic structures and are thus highly important to innate immunity. The present manuscript characterises a suite of 14 TLR5 in maraena whitefish (Coregonus maraena), a salmonid species with increasing importance for aquaculture. Whitefish TLRs were structurally and evolutionary analysed. The results revealed a close relationship with TLR5 from salmonid fish species rainbow trout and Atlantic salmon. Profiling the baseline expression of TLR genes in whitefish indicated that mainly members of the TLR11 family were highly expressed across all investigated tissues. A stimulation model with inactivated Aeromonas salmonicida was used to induce inflammation in the peritoneal cavity of whitefish. This bacterial challenge induced the expression of pro-inflammatory cytokine genes and evoked a strong influx of granulated cells of myeloid origin into the peritoneal cavity. As a likely consequence, the abundance of TLR-encoding transcripts increased moderately in peritoneal cells, with the highest levels of transcripts encoding non-mammalian TLR22a and a soluble TLR5 variant. In the course of inflammation, the proportion of granulated cells increased in peripheral blood accompanied by elevated TLR copy numbers in spleen and simultaneously reduced TLR copy numbers in head kidney at day 3 post-stimulation. Altogether, the present study provides in-vivo evidence for relatively modest TLR response patterns, but marked trafficking of myeloid cells as an immunophysiological consequence of A. salmonicida inflammation in whitefish. The present results contribute to improved understanding of the host-pathogen interaction in salmonid fish.
|
|
| 2. |
- Angthong, Pacharaporn, et al.
(författare)
-
Cloning and characterization of a melanization inhibition protein (PmMIP) of the black tiger shrimp, Penaeus monodon
- 2010
-
Ingår i: Fish and Shellfish Immunology. - : Elsevier BV. - 1050-4648 .- 1095-9947. ; 29:3, s. 464-468
-
Tidskriftsartikel (refereegranskat)abstract
- Melanization is an important component of the innate immune responses in invertebrates and it is essential for defense against invading microorganism. Melanin formation, which is a result of activation of the so called prophenoloxidase activating system, needs to be controlled due to the dangerous effects of quinones and melanin which are produced during the process of melanization. Here, a cDNA for a melanization inhibition protein (MIP), named PmMIP, was identified from the black tiger shrimp, Penaeus monodon by RT-PCR using degenerated oligonucleotide primers and RACE-PCR. The complete sequence significantly matched MIP of the freshwater crayfish Pacifastacus leniusculus (PlMIP). PmMIP contains an N-terminal signal peptide and a fibrinogen related domain (FReD). RT-PCR was applied to examine the expression profiles of PmMIP in various tissues of juvenile P. monodon. PmMIP was expressed in all examined tissues except hemocytes and at very low levels in hepatopancreas and ovaries. The expression of this gene was very low during the larval stages and hardly present in egg and at the nauplius stage. A time-course expression analysis of PmMIP upon Vibrio harveyi challenge at protein levels in plasma was determined. The result shows that MIP protein in plasma was induced at 6 h and disappeared at 12 and 24 h and then the protein reappeared at 48 and 72 h post injection. These results suggest that upon bacterial infection the PmMIP protein is first released from tissues into hemolymph and then degraded to allow melanization to occur for fighting against bacteria.
|
|
| 3. |
- Apitanyasai, Kantamas, et al.
(författare)
-
Characterization of a hemocyte homeostasis-associated-like protein (HHAP) in the freshwater crayfish Pacifastacus leniusculus
- 2016
-
Ingår i: Fish and Shellfish Immunology. - : Elsevier BV. - 1050-4648 .- 1095-9947. ; 58, s. 429-435
-
Tidskriftsartikel (refereegranskat)abstract
- Hemocyte homeostasis-associated-like protein (HHAP) in the freshwater crayfish Pacifastacus leniusculus has a distinct role from that of its homolog PmHHAP in the shrimp Penaeus monodon. Knockdown of PIHHAP in vitro using double-stranded RNA (dsRNA) had no effect on the cell morphology of hematopoietic tissue (HPT) cells. The total hemocyte number and caspase activity were unchanged after PIHHAP knockdown in vivo, in contrast to the results found in shrimp. Moreover, suppression of PIHHAP both in vitro and in vivo did not change the mRNA levels of some genes involved in hematopoiesis and hemocyte homeostasis. Interestingly, bacterial count and scanning electron microscope revealed that depletion of PIHHAP in intestine by RNAi resulted in higher number of bacteria in the crayfish intestine. Together, these results suggest that PIHHAP is not involved in hemocyte homeostasis in the crayfish P. leniusculus but appears to affect the bacterial number in the intestine through an unknown mechanism. Since PIHHAP has different functions from PmHHAP, we therefore named it HHAP-like protein.
|
|
| 4. |
- Baruah, Kartik
(författare)
-
Beta-glucan's varying structure characteristics modulate survival and immune-related genes expression from Vibrio harveyi-infected Artemia franciscana in gnotobiotic conditions
- 2020
-
Ingår i: Fish and Shellfish Immunology. - : Elsevier BV. - 1050-4648 .- 1095-9947. ; 102, s. 307-315
-
Tidskriftsartikel (refereegranskat)abstract
- beta-Glucans have long been used as an immunostimulant in aquaculture. However, the relationship of its structure to its immunomodulatory properties are poorly understood. In this study, the particle size and chemical structure of beta-glucans extracted from wild-type strain of baker's yeast (Saccharomyces cerevisiae) and its null-mutant yeasts Gas1 were characterised. Using Sigma beta-glucan as a reference, the immunomodulatory properties of these polysaccharides in the germ-free Anemia franciscana model system in the presence of Vibrio harveyi bacterial challenge were investigated. The survival of the A. franciscana nauplii, upon challenge with V. harveyi, was significantly higher in all three glucan-treated groups compared to the control. The glucan Gas1 with a lower degree of branching and shorter side chain length had the most prominent V. harveyi-protective effects. The particle size did not affect the nauplii survival when challenged with V. harveyi. Results also showed that the salutary effect of the tested glucans was associated with the upregulation of innate immune genes such as lipopolysaccharide and beta-1,3-glucan-binding protein (lgbp), high mobility group box protein (hmgb), and prophenoloxidase (proPO). Interestingly, the up-regulation of superoxidase dismutase (sod) and glutathione-stransferase (gst) was only observed in Gas1 treated group, indicating that Gas1 could function to induce higher reactive oxygen species and stronger immunomodulatory function in A. franciscana, and therefore higher survival rate. The expression of heat shock protein 70 (hsp70), peroxinectin (pm), and down syndrome cell adhesion molecule (dscam) remain unaltered in response to glucan treatment. Taken together, this study provides insights into the structure-function relationship of beta-glucan and the results confirmed that beta-glucan can be an effective immunostimulant in aquaculture, especially the Gas1 glucan.
|
|
| 5. |
- Baruah, Kartik
(författare)
-
Differential expression of immune-related biomarkers in primary cultures from Atlantic salmon ( Salmo salar ) exposed to processed Paecilomyces variotii with or without inactivated Moritella viscosa
- 2024
-
Ingår i: Fish and Shellfish Immunology. - 1050-4648 .- 1095-9947. ; 148
-
Tidskriftsartikel (refereegranskat)abstract
- Paecilomyces variotii (a filamentous fungus), is a promising novel protein source in fish feeds due to its high nutritional value. Also, P. variotii has Microbial-Associated Molecular Patterns (MAMPs) such as glucans and nucleic acids that could modulate the host's immune response. To understand the potential bioactive properties of this fungus in Atlantic salmon (Salmo salar), our study was conducted to evaluate the gene expression of immune-related biomarkers (e.g., cytokines, effector molecules and receptors) on primary cultures from salmon head kidney (HKLs) and spleen leukocytes (SLs) exposed to either UV inactivated or fractions from P. variotii with or without inactivated Moritella viscosa (a skin pathogen in salmonids). Moreover, the effect of the fermentation conditions and down-stream processing on the physical ultrastructure and cell wall glucan content of P. variotii was characterized. The results showed that drying had a significant effect on the cell wall ultrastructure of the fungi and the choice of fermentation has a significant effect on the quantity of beta-glucans in P. variotii. Furthermore, stimulating Atlantic salmon HKLs and SLs with P. variotii and its fractions induced gene expression related to pro-inflammatory (tnf alpha, il1 beta) and antimicrobial response (cath2) in HKLs, while response in SLs was related to both pro-inflammatory and regulatory response (tnf alpha, il6 and il10). Similarly, the stimulation with inactivated M. viscosa alone led to an up-regulation of genes related to pro-inflammatory (tnf alpha, il1 beta, il6) antimicrobial response (cath2), intra-cellular signalling and recognition of M. viscosa (sclra, sclrb) and a suppression of regulatory response (il10) in both HKLs and SLs. Interestingly, the co-stimulation of cells with P. variotii and M. viscosa induced immune homeostasis (il6, tgf beta) and antimicrobial response (cath2) in SLs at 48h. Thus, P. variotii induces immune activation and cellular communication in Atlantic salmon HKLs and SLs and modulates M. viscosa induced pro-inflammatory responses in SLs. Taken together, the results from physical and chemical characterization of the fungi, along with the differential gene expression of key immune biomarkers, provides a theoretical basis for designing feeding trials and optimize diets with P. variotii as a functional novel feed ingredient for Atlantic salmon.
|
|
| 6. |
- Donpudsa, Suchao, et al.
(författare)
-
Proteinase inhibitory activities of two two-domain Kazal proteinase inhibitors from the freshwater crayfish Pacifastacus leniusculus and the importance of the P2 position in proteinase inhibitory activity
- 2010
-
Ingår i: Fish and Shellfish Immunology. - : Elsevier BV. - 1050-4648 .- 1095-9947. ; 29:5, s. 716-723
-
Tidskriftsartikel (refereegranskat)abstract
- Serine proteinase inhibitors are found ubiquitously in living organisms and involved in homeostasis of processes using proteinases as well as innate immune defense. Two two-domain Kazal-type serine proteinase inhibitors (KPIs), KPI2 and KPI8, have been identified from the hemocyte cDNA library of the crayfish Pacifastacus leniusculus. Unlike other KPIs from P. leniusculus, they are found specific to the hernocytes and contain an uncommon P-2 amino acid residue, Gly. To unveil their inhibitory activities, the two KPIs and their domains were over-expressed. By testing against subtilisin, trypsin, chymotrypsin and elastase, the KPI2 was found to inhibit strongly against subtilisin and weakly against trypsin, while the KPI8 was strongly active against only trypsin. With their P-1 Set and Lys residues, the KPI2_domain2 and KPI8_domain2 were responsible for strong inhibition against subtilisin and trypsin, respectively. Mutagenesis of KPI8_domain1 at P-2 amino acid residue from Gly to Pro, mimicking the P-2 residue of KPI8_domain2, rendered the KPI8_domain1 strongly active against trypsin, indicating the important role of P-2 residue in inhibitory activities of the Kazal-type serine proteinase inhibitors. Only the KPI2 was found to inhibit against the extracellular serine proteinases from the pathogenic oomycete of the freshwater crayfish, Aphanomyces astaci.
|
|
| 7. |
|
|
| 8. |
- Espinosa-Ruiz, Cristóbal, et al.
(författare)
-
Immunotoxicological effects of perfluorooctanesulfonic acid on European seabass are reduced by polyethylene microplastics
- 2023
-
Ingår i: Fish and Shellfish Immunology. - : Elsevier. - 1050-4648 .- 1095-9947. ; 137
-
Tidskriftsartikel (refereegranskat)abstract
- Marine environments receive plastic waste, where it suffers a transformation process into smaller particles. Among them, microplastics (MPs; <5 mm) are ingested by aquatic organisms leading to negative effects on animal welfare. The interactions between MPs, contaminants and organisms are poorly understood. To clarify this issue, European seabass (Dicentrarchus labrax L.) were fed with diets supplemented with 0 (control), polyethylene (PE) MPs (100 mg/kg diet), perfluorooctanesulfonic acid (PFOS, 4.83 μg/kg diet) or PFOS adsorbed to MPs (MPs-PFOS; final concentrations of 4.83 μg and 100 mg of PFOS and MP per kg of feed, respectively). Samples of skin mucus, serum, head-kidney (HK), liver, muscle, brain and intestine were obtained. PFOS levels were high in the liver of fish fed with the PFOS-diet, and markedly reduced when adsorbed to MPs. Compared to the control groups, liver EROD activity did not show any significant changes, whereas brain and muscle cholinesterase activities were decreased in all the groups. The histological and morphometrical study on liver and intestine showed significant alterations in fish fed with the experimental diets. At functional level, all the experimental diets affected the humoral (peroxidase, IgM, protease and bactericidal activities) as well as cellular (phagocytosis, respiratory burst and peroxidase) activities of HK leukocytes, being more marked those effects caused by the PFOS diet. Besides, treatments produced inflammation and oxidative stress as evidenced at gene level. Principal component analysis demonstrated that seabass fed with MPs-PFOS showed more similar effects to MPs alone than to PFOS. Overall, seabass fed with MPs-PFOS diet showed similar or lower toxicological alterations than those fed with MPs or PFOS alone demonstrating the lack of additive effects or even protection against PFOS toxicity.
|
|
| 9. |
- Gadan, K, et al.
(författare)
-
Slow release cortisol implants result in impaired innate immune responses and higher infection prevalence following experimental challenge with infectious pancreatic necrosis virus in Atlantic salmon (Salmo salar) parr.
- 2012
-
Ingår i: Fish & shellfish immunology. - : Elsevier BV. - 1095-9947 .- 1050-4648. ; 32:5, s. 637-44
-
Tidskriftsartikel (refereegranskat)abstract
- Stress can affect the immune system and increase susceptibility to various diseases but knowledge of the underlying mechanisms is scarce. There is a complex interaction between the immune system and the endocrine system of vertebrates. In fish, cortisol is a key hormone regulating stress response and recent studies have also suggested that this hormone can affect the immune system, where cortisol is mainly regarded as an immunosuppressive factor. The aim of the present study was to examine the impact of chronically elevated levels of cortisol on the immune response and susceptibility to experimental infection with infectious pancreatic necrosis virus (IPNV). Further, the effect of IPNV challenge on circulating levels of cortisol was investigated. Atlantic salmon parr were implanted intraperitoneally with sustained-release implants of bovine of cortisol (50 μg cortisol g(-1) body weight in an implant based on vegetable lipids). Vehicle implants were used as control (sham-injected). At 45 days after implantation (DAI), fish were challenged with a low virulent isolate of IPNV (by immersion). Samples of plasma, liver and head kidney was taken from fish before and 24 h, 48 h, 7 days week and 21 days post infection (DPI). Cortisol level in plasma was measured using radioimmunoassay and gene expression in liver and head kidney was analyzed with real-time PCR (RT-PCR). Infection prevalence in infected fish was assessed by virus culture and RT-PCR of head kidney samples. Cortisol implantation compared with sham-implanted fish had increased levels of plasma cortisol at 45 DAI. The relative expression of Interferon alpha-1 (IFNα-1), Myxo virus-1 Mx, Heat-shock protein 70 (HSP70), Serum amyloid A (SAA), Glucocorticoid receptor (GR) and Heat-shock protein 90 (HSP90) tends to be down-regulated by cortisol implantation. There was a higher prevalence of fish with detectable levels of IPNV, as measured by cell culture and RT-PCR, in the cortisol-implanted group challenged with IPNV (0 = 0.0305) relative to the group that received a sham implantation. Further, cortisol seems to delay the induction of the antiviral IFNα-1 pathway and Mx mRNA expression. This study shows that elevated plasma cortisol level leads to an impaired innate immune response, and higher virus (IPNV) prevalence in Atlantic salmon parr.
|
|
| 10. |
- Guo, Enen, et al.
(författare)
-
A Pacifastacus leniusculus serine protease interacts with WSSV
- 2017
-
Ingår i: Fish and Shellfish Immunology. - : Elsevier BV. - 1050-4648 .- 1095-9947. ; 68, s. 211-219
-
Tidskriftsartikel (refereegranskat)abstract
- Serine proteases are involved in many critical physiological processes including virus spread and replication. In the present study, we identified a new clip-domain serine protease (PIcSP) in the crayfish Pacifastacus leniusculus hemocytes, which can interact with the White Spot Syndrome Virus (WSSV) envelope protein VP28. It was characterized by a classic clip domain with six strictly conserved Cys residues, and contained the conserved His-Asp-Ser (H-D-S)motif in the catalytic domain. Furthermore, signal peptide prediction revealed that it has a 16-residue secretion signal peptide. Tissue distribution showed that it was mainly located in P. leniusculus hemocytes, and its expression was increased in hemocytes upon WSSV challenge. In vitro knock down of PIcSP decreased both the expression of VP28 and the WSSV copy number in hematopoietic stem (HPT) cells. Accordingly, these data suggest that the new serine protease may be of importance for WSSV infection into hematopoietic cells.
|
|
| 11. |
- Hernandez-Perez, Ariadne, et al.
(författare)
-
Environmental concentrations of sulfamethoxazole increase crayfish Pacifastacus leniusculus susceptibility to White Spot Syndrome Virus
- 2020
-
Ingår i: Fish and Shellfish Immunology. - : ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD. - 1050-4648 .- 1095-9947. ; 102, s. 177-184
-
Tidskriftsartikel (refereegranskat)abstract
- Antibiotics used for humans and livestock are emerging as pollutants in aquatic environments. However, little is known about their effect on aquatic organisms, especially in crustaceans. In the present study, the freshwater crayfish Pacifastacus leniusculus was exposed during 21 days to environmental concentrations of sulfamethoxazole (SMX) (100 ng/L and 1 mu g/L). Subsequently, the crayfish susceptibility to infection was evaluated by using White Spot Syndrome Virus (WSSV) challenge, a well-known crustacean pathogen. The median survival time of the infected crayfish exposed to 100 ng/L SMX was one day, whereas the control and the group exposed to 1 mu g/L SMX survived for two and three days, respectively. In order to elucidate the effect of SMX upon the crayfish immune response, new sets of crayfish were exposed to the same SMX treatments to evaluate mRNA levels of immune-related genes which are expressed and present in hemocytes and intestine, and to perform total and differential hemocyte counts. These results show a significant down-regulation of the antimicrobial peptide (AMP) Crustin 3 in hemocytes from the 100 ng/L SMX group, as well as a significant up-regulation of the AMP Crustin 1 in intestines from the 1 mu g/L SMX group. Semigranular and total hemocyte cell number were observed to be significantly lower after exposure to 100 ng/L SMX in comparison with the control group. The present study demonstrates that environmentally relevant SMX concentrations in the water at 100 ng/L led to an increased WSSV susceptibility, that may have been caused by a reduction of circulating hemocytes. Nevertheless, SMX concentrations of 1 mu g/L could marginally and for a few days have an immunostimulatory effect.
|
|
| 12. |
- Hernroth, Bodil, 1951-
(författare)
-
Factors influencing bactericidal activity of blue mussel (Mytilus edulis) haemocytes against Salmonella typhimurium
- 2003
-
Ingår i: Fish and Shellfish Immunology. - 1050-4648 .- 1095-9947. ; 14:2, s. 93-104
-
Tidskriftsartikel (refereegranskat)abstract
- This study showed that in vitro survival of Salmonella typhimurium, after exposure to haemocytes of Mytilus edulis, was significantly affected by the lipopolysaccharides (LPS) structures expressed on the cell surface of the bacteria. Survival seemed to be affected by the surrounding temperature as well. Mussel haemocytes were in vitro exposed to mutants of S. typhimurium, expressing differences in O -antigen polysaccharide chains and core sugars of LPS on their cell surface. Surviving cells of the mutants were determined after incubation with the haemocytes at different temperatures, using a colorimetric assay. In addition, a complementary study on clearance of these mutants, inoculated into the adductor muscle of mussels, was performed at 6 and 20 degrees C. It was concluded that the survival index (SI%) measured in vitro for the mutant with complete LPS was significantly lower at 6 degrees C (c.15%) compared to that at 14 and 20 degrees C (c.70%). SI% for the other mutants was c.35-45% and was not affected by temperature. The in vivo study at 20 degrees C showed that during the first 24h, the clearance rate for the mutants with complete LPS was significantly higher than for the others. Thereafter all mutants, with exception for the most deficient, started to increase in numbers and caused death to the mussels. At 6 degrees C the mutants were slowly reduced and after 17 days, viable cells of the mutant with complete LPS were still detectable in the haemolymph. The study indicated that the mussel haemocytes responded in relation to the LPS of the mutants. However, more intact LPS also seemed to protect the bacteria from being killed. The higher temperatures favoured the growth of the mutants that managed to resist the haemocyte defence. Cell surface properties and temperature seem to affect the survival of bacteria in mussels, which consequently can affect risk assessments in regard to public health.
|
|
| 13. |
- Hernroth, Bodil, 1951-, et al.
(författare)
-
Impact of ocean acidification on antimicrobial activity in gills of the blue mussel (Mytilus edulis)
- 2016
-
Ingår i: Fish and Shellfish Immunology. - : Elsevier. - 1050-4648 .- 1095-9947. ; 55, s. 452-459
-
Tidskriftsartikel (refereegranskat)abstract
- Here, we aimed to investigate potential effects of ocean acidification on antimicrobial peptide (AMP) activity in the gills of Mytilus edulis, as gills are directly facing seawater and the changing pH (predicted to be reduced from ∼8.1 to ∼7.7 by 2100). The AMP activity of gill and haemocyte extracts was compared at pH 6.0, 7.7 and 8.1, with a radial diffusion assay against Escherichia coli. The activity of the gill extracts was not affected by pH, while it was significantly reduced with increasing pH in the haemocyte extracts. Gill extracts were also tested against different species of Vibrio (V. parahaemolyticus, V. tubiashii, V. splendidus, V. alginolyticus) at pH 7.7 and 8.1. The metabolic activity of the bacteria decreased by ∼65–90%, depending on species of bacteria, but was, as in the radial diffusion assay, not affected by pH. The results indicated that AMPs from gills are efficient in a broad pH-range. However, when mussels were pre-exposed for pH 7.7 for four month the gill extracts presented significantly lower inhibit of bacterial growth. A full in-depth proteome investigation of gill extracts, using LC-Orbitrap MS/MS technique, showed that among previously described AMPs from haemocytes of Mytilus, myticin A was found up-regulated in response to lipopolysaccharide, 3 h post injection. Sporadic occurrence of other immune related peptides/proteins also pointed to a rapid response (0.5–3 h p.i.). Altogether, our results indicate that the gills of blue mussels constitute an important first line defence adapted to act at the pH of seawater. The antimicrobial activity of the gills is however modulated when mussels are under the pressure of ocean acidification, which may give future advantages for invading pathogens.
|
|
| 14. |
- Hernroth, Bodil, 1951, et al.
(författare)
-
Impact of ocean acidification on antimicrobial activity in gills of the blue mussel (Mytilus edulis)
- 2016
-
Ingår i: Fish and Shellfish Immunology. - : Elsevier BV. - 1050-4648 .- 1095-9947. ; 55, s. 452-459
-
Tidskriftsartikel (refereegranskat)abstract
- Here, we aimed to investigate potential effects of ocean acidification on antimicrobial peptide (AMP) activity in the gills of Mytilus edulis, as gills are directly facing seawater and the changing pH (predicted to be reduced from ∼8.1 to ∼7.7 by 2100). The AMP activity of gill and haemocyte extracts was compared at pH 6.0, 7.7 and 8.1, with a radial diffusion assay against Escherichia coli. The activity of the gill extracts was not affected by pH, while it was significantly reduced with increasing pH in the haemocyte extracts. Gill extracts were also tested against different species of Vibrio (V. parahaemolyticus, V. tubiashii, V. splendidus, V. alginolyticus) at pH 7.7 and 8.1. The metabolic activity of the bacteria decreased by ∼65–90%, depending on species of bacteria, but was, as in the radial diffusion assay, not affected by pH. The results indicated that AMPs from gills are efficient in a broad pH-range. However, when mussels were pre-exposed for pH 7.7 for four month the gill extracts presented significantly lower inhibit of bacterial growth. A full in-depth proteome investigation of gill extracts, using LC-Orbitrap MS/MS technique, showed that among previously described AMPs from haemocytes of Mytilus, myticin A was found up-regulated in response to lipopolysaccharide, 3 h post injection. Sporadic occurrence of other immune related peptides/proteins also pointed to a rapid response (0.5–3 h p.i.). Altogether, our results indicate that the gills of blue mussels constitute an important first line defence adapted to act at the pH of seawater. The antimicrobial activity of the gills is however modulated when mussels are under the pressure of ocean acidification, which may give future advantages for invading pathogens.
|
|
| 15. |
|
|
| 16. |
- Hernroth, Bodil, 1951, et al.
(författare)
-
Simulated climate change causes immune suppression and protein damage in the crustacean Nephrops norvegicus
- 2012
-
Ingår i: Fish & Shellfish Immunology. - : Elsevier BV. - 1050-4648 .- 1095-9947. ; 33:5, s. 1095-1101
-
Tidskriftsartikel (refereegranskat)abstract
- Rising atmospheric carbon dioxide concentration is causing global warming, which affects oceans by elevating water temperature and reducing pH. Crustaceans have been considered tolerant to ocean acidification because of their retained capacity to calcify during subnormal pH. However, we report here that significant immune suppression of the Norway lobster, Nephrops norvegicus, occurs after a 4-month exposure to ocean acidification (OA) at a level predicted for the year 2100 (hypercapnic seawater with a pH lowered by 0.4 units). Experiments carried out at different temperatures (5, 10, 12, 14, 16, and 18 °C) demonstrated that the temperature within this range alone did not affect lobster immune responses. In the OA-treatment, hemocyte numbers were reduced by almost 50% and the phagocytic capacity of the remaining hemocytes was inhibited by 60%. The reduction in hemocyte numbers was not due to increased apoptosis in hematopoetic tissue. Cellular responses to stress were investigated through evaluating advanced glycation end products (AGE) and lipid oxidation in lobster hepatopancreata, and OA-treatment was shown to significantly increase AGEs', indicating stress-induced protein alterations. Furthermore, the extracellular pH of lobster hemolymph was reduced by approximately 0.2 units in the OA-treatment group, indicating either limited pH compensation or buffering capacity. The negative effects of OA-treatment on the nephropidae immune response and tissue homeostasis were more pronounced at higher temperatures (12–18 °C versus 5 °C), which may potentially affect disease severity and spread. Our results signify that ocean acidification may have adverse effects on the physiology of lobsters, which previously had been overlooked in studies of basic parameters such as lobster growth or calcification.
|
|
| 17. |
- Hernroth, Bodil, 1951-
(författare)
-
The influence of temperature and dose on antibacterial peptide response against lipopolysaccharide in the blue mussel, Mytilus edulis.
- 2003
-
Ingår i: Fish and Shellfish Immunology. - 1050-4648 .- 1095-9947. ; 14:1, s. 25-37
-
Tidskriftsartikel (refereegranskat)abstract
- Blue mussels (Mytilus edulis) were inoculated with two different doses of lipopolysaccharides (LPS) or phosphate-saline (PS) buffer under different temperature conditions (6 and 20 degrees C). The activity of the antibacterial peptide fraction, purified through reverse phase chromatography from mussel haemolyph, was compared at different time intervals after the inoculation. The activity was determined as the minimal peptide concentration that inhibited growth of the Gram-negative bacteria Escherichia coli D21, by using radial diffusion assay. The antibacterial activity for mussels inoculated with LPS changed over time, both at 6 and 20 degrees C, but those inoculated with PS-buffer did not. The response was enhanced within a time course of 3h. The higher temperature did increase the inhibitory activity and made the mussel respond at an earlier stage, in comparison to that at 6 degrees C. At 20 degrees C, mussels inoculated with 10 microg of LPS responded faster than those inoculated with 0.1 microg of LPS. In addition, cytotoxic effects of LPS on mussel haemocytes were investigated in vitro, using a colorimetric assay. The survival index (SI%) for haemocytes decreased with 76% at 6 degrees C but increased with 100% at 20 degrees C, irrespective of the dose of LPS. This indicated that LPS did not influence the viability of the haemocytes but the high temperature increased their metabolic state. Likely, antibacterial response was provoked by LPS in a dose-dependent manner and favoured by higher metabolic state of the haemocytes, elicited at higher temperature. These results provide important considerations for variability in the internal defence of mussels and consequently, also the retention of viable human pathogens in mussels.
|
|
| 18. |
|
|
| 19. |
- Hu, M., et al.
(författare)
-
Effect of pH and temperature on antioxidant responses of the thick shell mussel Mytilus coruscus
- 2015
-
Ingår i: Fish and Shellfish Immunology. - : Elsevier BV. - 1050-4648 .- 1095-9947. ; 46:2, s. 573-583
-
Tidskriftsartikel (refereegranskat)abstract
- This study evaluated the combined effects of seawater pH decrease and temperature increase on the activity of antioxidant enzymes in the thick shell mussel Mytilus coruscus, an ecological and economic bivalve species widely distributed along the East China Sea. Mussels were exposed to three pH levels (8.1, 7.7 and 7.3) and two temperatures (25 °C and 30 °C) for 14 days. Activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), glutathione (GSH), acid phosphatase (ACP), alkaline phosphatase (AKP) and glutamic-pyruvic transaminase (GPT) were measured in gills and digestive glands after 1, 3, 7 and 14 days of exposure. All enzymatic activities were significantly impacted by pH, temperature. Enzymatic activities at the high temperature were significantly higher than those at the low temperature, and the mussels exposed to pH 7.3 showed significantly higher activities than those under higher pH condition for all enzymes except ACP. There was no interaction between temperature and pH in two third of the measured activities suggesting similar mode of action for both drivers. Interaction was only consistently significant for GPX. PCA revealed positive relationships between the measured biochemical indicators in both gills and digestive glands. Overall, our results suggest that decreased pH and increased temperature induce a similar anti-oxidative response in the thick shell mussel. © 2015 Elsevier Ltd.
|
|
| 20. |
- Huyben, David, et al.
(författare)
-
Haematological and intestinal health parameters of rainbow trout are influenced by dietary live yeast and increased water temperature
- 2019
-
Ingår i: Fish and Shellfish Immunology. - : Elsevier BV. - 1050-4648 .- 1095-9947. ; 89, s. 525-536
-
Tidskriftsartikel (refereegranskat)abstract
- Live yeast may be a sustainable protein source in salmonid diets while exhibiting a probiotic effect to counteract environmental stressors, such as increased water temperature that is being exacerbated by climate change. The objective of this study was to evaluate the effects of feeding a high dietary inclusion of live yeast and increased water temperature on growth, haematological and intestinal physiology of rainbow trout. For six weeks, 129 g fish in 16 tanks (n = 4) were fed either a diet based on fishmeal or based on live yeast (214 g kg −1 of diet or 7.6 log CFU g −1 of Saccharomyces cerevisiae) that replaced 40% of fishmeal protein while fish were reared in water temperatures of either 11 °C (cold) or 18 °C (warm). Fish weights, caudal blood and proximal and distal intestines were collected and analysed. Fish fed live yeast resulted in reduced growth (SGR and WG) and higher FCR, while growth in cold and warm water was similar despite differences in TGC. However, increased mortality, plasma cortisol, and intestinal oedema and villous damage indicated fish reared in warm water were subjected to chronic stress. Temperature had a significant effect on haematocrit and red blood cell counts that resulted in significantly higher haemoglobin levels in fish kept in warm water attributed to an elevated oxygen demand. In the proximal intestine, increased temperature resulted in reduced expression of pro-inflammatory cytokines, e.g. TNFα and IL8, that were further reduced in fish fed live yeast. In addition, feeding live yeast reduced gene expression of CLD6 involved in gut barrier function, which suggests that the level of yeast was too high and masked any beneficial effects on fish health. In conclusion, feeding a high inclusion of live yeast reduced fish growth and expression of intestinal genes, while increasing the temperature from 11 to 18 °C subjected fish to chronic stress that restricted growth, suppressed innate immunity and induced intestinal damage. Replacing 40% of fishmeal protein with live yeast did not counteract negative effects caused by increased temperature, thus alternative strategies need to be explored and implemented to protect the growth and health of rainbow trout from seasonal and long-term rises in water temperature. © 2019
|
|
| 21. |
|
|
| 22. |
|
|
| 23. |
- Jiravanichpaisal, Pikul, et al.
(författare)
-
Expression of immune-related genes in larval stages of the giant tiger shrimp, Penaeus monodon
- 2007
-
Ingår i: Fish and Shellfish Immunology. - : Elsevier BV. - 1050-4648 .- 1095-9947. ; 23:4, s. 815-824
-
Tidskriftsartikel (refereegranskat)abstract
- Shrimp undergo several morphologically different stages during development and therefore the expression of some immune-related genes such as prophenoloxidase (proPO), peroxinectin (Prx), crustin (Crus), penaeidin (Pen), transglutaminase (TGase), haemocyanin (Hc) and astakine (Ak) were determined during larval development of the shrimp (Penaeus monodon), i.e. nauplius 4 (N4), protozoea 1 and 3 (Z1 and 3), mysis 3 (My 3), post-larvae 3 (PL3) and also in haemocytes of juveniles. Semi-quantitative RT-PCR analysis showed that all transcripts were already present in the early larval stage of N4 but at different levels. The transcript of proPO was found to be extremely low or even absent at N4, whereas Prx, Crus, Pen, TGase, Hc and Ak were significantly expressed at all larval stages. Up to now expression of proPO and Prx has only been reported from haemocytes in crustaceans and in this study Prx also appeared to be expressed in stages which appear to lack haemocytes. Thus, this may suggest that Prx is expressed in other cells than haemocytes. It is well known among invertebrates that the proPO system plays a crucial role as an immune effector molecule against microbes. However, in this study, the transcript of proPO was low during the larval stages and hardly present at all at N4. This might indicate that the development of immune-competent haemocytes during the larval stages is not completed and as a consequence they are likely to be more susceptible to infectious diseases during these stages.
|
|
| 24. |
|
|
| 25. |
- Junkunlo, Kingkamon, et al.
(författare)
-
Transglutaminase 1 and 2 are localized in different blood cells in the freshwater crayfish Pacifastacus leniusculus
- 2020
-
Ingår i: Fish and Shellfish Immunology. - : ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD. - 1050-4648 .- 1095-9947. ; 104, s. 83-91
-
Tidskriftsartikel (refereegranskat)abstract
- In the present study we show that hemocytes in the freshwater crayfish Pacifastacus leniusculus express two different transglutaminases. We describe the sequence of a previously unknown TGase (Pl_TGase1) and named this as Pl_TGase2 and compared this sequence with similar sequences from other crustaceans. The catalytic core domain is similar to the previously described TGase in P. leniusculus, but Pl_TGase2 has significant differences in the N-terminal and C-terminal domains. Further, we show conclusive evidences that these different transglutaminases are specific for different hemocyte types so that Pl_TGase1 is expressed in the hematopoietic tissue and in the cytoplasm of semigranular hemocytes, while Pl_TGase2 is expressed in vesicles in the granular hemocytes. By in situ hybridization we show that both Pl_TGase1 and Pl_TGase2 mRNA are present only in a subset of the respective hemocyte population. This observation indicates that there may be different subtypes of semigranular as well as granular hemocytes which may have different specific functions.
|
|
| 26. |
- Kvamme, Bjørn Olav, et al.
(författare)
-
Modulation of innate immune responses in Atlantic salmon by chronic hypoxia-induced stress.
- 2013
-
Ingår i: Fish & shellfish immunology. - : Elsevier BV. - 1095-9947 .- 1050-4648. ; 34:1, s. 55-65
-
Tidskriftsartikel (refereegranskat)abstract
- Atlantic salmon post-smolts were exposed to either chronic hypoxic (Hy) or normal oxygen (No) conditions in seawater tanks for 58 days, mimicking conditions typical of sea cages for farmed salmon at some periods of the year. By day 29 head kidney macrophages were isolated and subjected to invitro poly I:C stimulation to simulate viral infection, and samples were collected over 48h. By day 58 fish were subjected to invivo stimulation using poly I:C or a Vibrio water-based vaccine to simulate viral or bacterial infection, respectively. The fish were monitored for stress responses and expression of several pro-inflammatory genes in head kidney and intestinal tissue up to five days post-injection. Stress load was monitored by plasma cortisol estimation at days 29 and 58, and on days 1, 2, 3 and 5 post-injection in the invivo trial. Hy exposure resulted in elevated plasma cortisol levels on day 29 compared to No, while on day 58 cortisol levels were higher in the control group. Additionally, both poly I:C and the Vibrio vaccine gave significantly increased cortisol levels one day post-injection compared to PBS treated controls, irrespective of previous oxygen exposure. Invitro stimulation of macrophages with poly I:C revealed higher IFNα mRNA levels at 6, 12 and 24h and for Mx at 12 and 24h post-stimulation, for both No and Hy individuals. Moreover, IFNα levels were higher in No than in Hy individuals at all time points, and a similar difference was seen in Mx at 48h. Invivo stimulation with poly I:C elicited strong elevation of the IL-1β, IFNγ, Mx and IP10 mRNA transcripts in head kidney, while TNFα1 and IFNα were found unaffected. The Vibrio vaccine elicited a strong up regulation of IL-1β, IFNγ and IP10 mRNA, whereas Mx, TNFα1 and IFNα appeared unchanged. Significant differences in expression between different oxygen exposure groups were found for all genes and both stimuli. The overall trend suggests that long-term hypoxia either reduces or delays the expression of these genes in head kidney. Expression of IFNγ and Mx in intestinal tissues also showed a strong up regulation of the genes following poly I:C stimulation, and also here the overall trend suggests that chronic hypoxia results in a lower or delayed expression of the measured genes. In summary, our results indicate that chronic hypoxia modulates the expression of important immune related genes putatively altering the immune response. As the effect is present in isolated macrophages as well as head kidney and intestinal tissue the modulation appears to be affecting local as well as systemic responses.
|
|
| 27. |
- Lampe, E. O., et al.
(författare)
-
A study of virulence factors in the fish pathogen F. noatunensis ssp noatunensis
- 2013
-
Ingår i: Fish and Shellfish Immunology. - : Elsevier. - 1050-4648 .- 1095-9947. ; 34:6, s. 1716-1716
-
Tidskriftsartikel (refereegranskat)abstract
- The bacterium Francisella noatunensis ssp. noatunensis (in text: F. noatunensis) is the ethiological agent of the disease francisellosis in Atlantic cod. Francisellosis has been one of the major limiting factors in the development of Norwegian aquaculture industry based on Atlantic cod. Lacking an effective treatment or vaccine there is urgent need for studies related to the pathogenesis of the disease.The closely related human pathogen F. tularensis is more extensively studied and due to relatively high sequence similarity with F. noatunensis, indirect evidence on important virulence factors can be obtained by reverse genetics. The Francisella Pathogenicity Island (FPI) has been identified in all sequenced genomes of Francisella sp. and contains genes associated with the ability of the bacterium to survive and replicate within macrophages.To elucidate the pathogenesis of F. noatunensis, infection assays have been performed on primary cells extracted from the head kidney of Atlantic cod. Disruptive mutations of the potential virulence factors IglC, IglD (important for intracellular growth in F. tularensis subsp.) and ClpB (a heat shock protein identified in F. tularensis), have been constructed in F. noatunensis and the infection pattern is in the process of characterization. Model systems that are utilized in the characterization are the amoebae and professional phagocyte Dictyostelium discoideum, zebrafish and macrophages extracted from head kidney of Atlantic cod.
|
|
| 28. |
|
|
| 29. |
- Liu, Haipeng, et al.
(författare)
-
Antiviral immunity in crustaceans
- 2009
-
Ingår i: Fish and Shellfish Immunology. - : Elsevier BV. - 1050-4648 .- 1095-9947. ; 27:2, s. 79-88
-
Forskningsöversikt (refereegranskat)abstract
- Viral diseases of shrimp have caused negative effects on the economy in several countries in Asia, south Americas and Americas, where they have numerous shrimp culture industries. The studies on the immunity of shrimp and other crustaceans have mainly focused on general aspects of immunity and as a consequence little is known about the antiviral responses in crustaceans. The aim of this review is to update recent knowledge of innate immunity against viral infections in crustaceans. Several antiviral molecules have been isolated and characterized recently from decapods. Characterization and identification of these molecules might provide a promising strategy for protection and treatment of these viral diseases. In addition dsRNA-induced antiviral immunity is also included.
|
|
| 30. |
- Mougin, Julia, 1994, et al.
(författare)
-
Effects of dietary co-exposure to fungal and herbal functional feed additives on immune parameters and microbial intestinal diversity in rainbow trout (Oncorhynchus mykiss)
- 2023
-
Ingår i: Fish & Shellfish Immunology. - 1050-4648. ; 137
-
Tidskriftsartikel (refereegranskat)abstract
- Misuse and overuse of antibiotics in aquaculture has proven to be an unsustainable practice leading to increased bacterial resistance. An alternative strategy involves the inclusion of immunostimulants in fish diets, especially fungal and herbal compounds already authorized for human consumption, hence without environmental or public health concerns. In this study, we used a holistic and cross-disciplinary pipeline to assess the immunos-timulatory properties of two fungi: Trametes versicolor and Ganoderma lucidum; one herbal supplement, capsaicin in the form of Espelette pepper (Capsicum annuum), and a combination of these fungal and herbal additives on rainbow trout (Oncorhynchus mykiss). We investigated the impact of diet supplementation for 7 weeks on sur-vival, growth performance, cellular, humoral, and molecular immune parameters, as well as the intestinal mi-crobial composition of the fish. Uptake of herbal and fungal compounds influenced the expression of immune related genes, without generating an inflammatory response. Significant differences were detected in the spleen-tlr2 gene expression. Supplementation with herbal additives correlated with structural changes in the fish in-testinal microbiota and enhanced overall intestinal microbial diversity. Results demonstrated that the different treatments had no adverse effect on growth performance and survival, suggesting the safety of the different feed additives at the tested concentrations. While the mechanisms and multifactorial interactions remain unclear, this study provides insights not only in regard to nutrition and safety of these compounds, but also how a combined immune and gut microbiota approach can shed light on efficacy of immunostimulant compounds for potential commercial inclusion as feed supplements.
|
|
| 31. |
|
|
| 32. |
- Oweson, Carolina, et al.
(författare)
-
A comparative study on the influence of manganese on the bactericidal response of marine invertebrates
- 2009
-
Ingår i: Fish and Shellfish Immunology. - 1050-4648 .- 1095-9947. ; 27:3, s. 500-507
-
Tidskriftsartikel (refereegranskat)abstract
- Manganese, Mn, is a naturally abundant metal in marine sediments. During hypoxic conditions the metal converts into a bioavailable state and can reach levels that have been shown immunotoxic to the crustacean Nephrops norvegicus. For this species it has previously been shown that exposure to 15 mg L(-1) of Mn decreased the number of circulating haemocytes while it for the echinoderm Asterias rubens increased the number of coelomocytes. Here, we compared if five days of exposure to the same concentration of Mn affects the bactericidal capacity of these two species and the mollusc Mytilus edulis when inoculated with the bacterium Vibrio parahaemolyticus. Viable counts of the bacteria were investigated at a time-course post-injection in the blood and the digestive glands of Mn-exposed and un-exposed (controls) animals. Accumulation of Mn was also analyzed in these tissues. When exposed to Mn the haemocyte numbers were significantly reduced in M. edulis and it was shown that the bactericidal capacity was impaired in the mussels as well as in N. norvegicus. This was most obvious in the digestive glands. These two species also showed the highest accumulation of the metal. In A. rubens the bactericidal capacity was not affected and the metal concentration was similar to the exposure concentration. After a recovery period of three days the concentration of Mn was significantly reduced in all three species. However, in M. edulis and N. norvegicus it was still double that of A. rubens which could explain the remaining bactericidal suppression observed in N. norvegicus. This study pointed out that exposure to such Mn-levels that are realistic to find in nature could have effects on the whole organism level, in terms of susceptibility to infections. The effect seemed associated to the accumulated concentration of Mn which differed on species level.
|
|
| 33. |
- Oweson, Carolina, et al.
(författare)
-
A comparative study on the influence of manganese on the bactericidal response of marine invertebrates
- 2009
-
Ingår i: Fish and Shellfish Immunology. - : Academic Press Inc.. - 1050-4648 .- 1095-9947. ; 27:3, s. 500-507
-
Tidskriftsartikel (refereegranskat)abstract
- Manganese, Mn, is a naturally abundant metal in marine sediments. During hypoxic conditions the metal converts into a bioavailable state and can reach levels that have been shown immunotoxic to the crustacean Nephrops norvegicus. For this species it has previously been shown that exposure to 15 mg L(-1) of Mn decreased the number of circulating haemocytes while it for the echinoderm Asterias rubens increased the number of coelomocytes. Here, we compared if five days of exposure to the same concentration of Mn affects the bactericidal capacity of these two species and the mollusc Mytilus edulis when inoculated with the bacterium Vibrio parahaemolyticus. Viable counts of the bacteria were investigated at a time-course post-injection in the blood and the digestive glands of Mn-exposed and un-exposed (controls) animals. Accumulation of Mn was also analyzed in these tissues. When exposed to Mn the haemocyte numbers were significantly reduced in M. edulis and it was shown that the bactericidal capacity was impairedin the mussels as well as in N. norvegicus. This was most obvious in the digestive glands. These two species also showed the highest accumulation of the metal. In A. rubens the bactericidal capacity was not affected and the metal concentration was similar to the exposure concentration. After a recovery period of three days the concentration of Mn was significantly reduced in all three species. However, in M. edulis and N. norvegicus it was still double that of A. rubens which could explain the remaining bactericidal suppression observed in N. norvegicus. This study pointed out that exposure to such Mn-levels that are realistic to find in nature could have effects on the whole organism level, in terms of susceptibility to infections. The effect seemed associated to the accumulated concentration of Mn which differed on species level.
|
|
| 34. |
|
|
| 35. |
- Sharba, Sinan, et al.
(författare)
-
Rainbow trout gastrointestinal mucus, mucin production, mucin glycosylation and response to lipopolysaccharide
- 2022
-
Ingår i: Fish and Shellfish Immunology. - : Elsevier BV. - 1050-4648. ; 122, s. 181-190
-
Tidskriftsartikel (refereegranskat)abstract
- Mucus, whereof the highly glycosylated mucins are a major component, protects the epithelial mucosal surfaces. The aim of this study was to characterize the rainbow trout (Oncorhynchus mykiss) gastrointestinal mucus barrier function, mucin production, glycosylation and response to lipopolysaccharide. Both gastric and intestinal mucus was thick and impenetrable to bacteria-sized beads ex vivo. The secreted mucus covering the gastric epithelium predominantly contained sialylated mucins. Plume-like structures emerging from the gastric pits were both sialylated and fucosylated, indicating heterogeneity in gastric mucus secreted by the surface mucus cells and gland secretory cells, whereas intestinal mucus appeared more homogenous. In vivo metabolic mucin labelling revealed regional differences in mucin production and basal to apical transport, while lipopolysaccharide stimulation increased the rate of mucin production and basal to apical transport in both stomach and intestine. Using mass spectrometry, 34 mucin O-glycans were identified, with ∼70% of the relative abundance being sialylated, ∼40% di-sialylated and 20–25% fucosylated. No effects of lipopolysaccharide treatment were apparent regarding O-glycan repertoires, relative abundance of components, size distribution or core structures. Thus, the mucus production and organization differ between epithelial sites but provide a barrier to bacteria in both stomach and intestine. Furthermore, mucin production and basal to apical transport was stimulated by lipopolysaccharide in all regions, suggesting a mechanism to combat infections. © 2022
|
|
| 36. |
- Sirikharin, Ratchanok, et al.
(författare)
-
Astakine1 forms protein complex in plasma
- 2019
-
Ingår i: Fish and Shellfish Immunology. - : Elsevier BV. - 1050-4648 .- 1095-9947. ; 94, s. 66-71
-
Tidskriftsartikel (refereegranskat)abstract
- Astakine 1 is a small cytokine-like peptide which is directly involved in hematopoiesis in crustaceans. Astakines are present in many different invertebrate groups primarily in arthropods. In this study we found that astakine1 was present as a high molecular weight (HMW) complex in plasma. It is known that calcium concentration are fluctuating in several crustaceans especially during the molting process. This HMW-complex was formed under low calcium concentrations in plasma and could be partially reversed provided calcium was added. The biological function of the naïve astakine1 and that in the HMW complex was about the same, but if the protein is to be isolated or studied for its function it is important to know about this property of astakine1 which may previously have hampered isolation and functional studies in other animals than freshwater crayfish.
|
|
| 37. |
- Sirikharin, Ratchanok, et al.
(författare)
-
Characterization of a cold-active transglutaminase from a crayfish, Pacifastacus leniusculus
- 2018
-
Ingår i: Fish and Shellfish Immunology. - : Elsevier BV. - 1050-4648 .- 1095-9947. ; 80, s. 546-549
-
Tidskriftsartikel (refereegranskat)abstract
- Transglutaminase (TGase) from signal crayfish (Pacifastacus leniusculus) and its activity at low temperatures was studied. TGase is an abundant protein in the hematopoietic (HPT) cells and this tissue was used for TGase enzyme preparation. The optimal temperature and pH for the activity of crayfish TGase were determined. We found that TGase activity at 4 degrees C showed nearly the same activity as at a temperature of 22 degrees C. TGase activity from crayfish was compared with guinea pig liver TGase activity at 4 degrees C and the crayfish TGase displayed a higher activity while guinea pig liver TGase had a very low activity at this low temperature. By comparing kinetic parameters to guinea pig liver TGase, the results showed that a high activity of crayfish TGase was due to a decreasing K-m value for pentylamine as a substrate, while it did not affect the k(cat) value (at 22 degrees C). The amino acid sequences of a krill and a crayfish TGase, which both are cold adapted, do not give any clue to why these two enzymes are cold-adapted. These results demonstrate that crayfish TGase is adapted to have significant activity at low temperatures and since crayfish are living in quite cold waters this is an interesting adaptation of this enzyme.
|
|
| 38. |
- Söderhäll, Irene, et al.
(författare)
-
Blood cell formation in crustaceans.
- 2022
-
Ingår i: Fish and Shellfish Immunology. - : Elsevier. - 1050-4648 .- 1095-9947. ; 131, s. 1335-1342
-
Tidskriftsartikel (refereegranskat)abstract
- In crustacean animals the hemocytes are key players in immunity and of crucial importance for the health of the animals. Hemocytes are mainly produced in the hematopoietic tissue and from there released into the circulation where they finally mature. In this review we summarize the latest findings about crustacean hemocyte formation. The role of the extracellular matrix and crosslinking enzyme transglutaminase is discussed. Moreover, important growth factors, transcriptional regulation and recent findings about inducers of hematopoiesis are covered. Finally, we discuss the use of different markers for classification of crustacean hemocytes.
|
|
| 39. |
- Thomsson, Kristina A, 1969, et al.
(författare)
-
Mucin O-glycosylation and pathogen binding ability differ between rainbow trout epithelial sites
- 2022
-
Ingår i: Fish & Shellfish Immunology. - : Elsevier BV. - 1050-4648. ; 131, s. 349-357
-
Tidskriftsartikel (refereegranskat)abstract
- Mucins are highly glycosylated proteins that make up the mucus covering internal and external surfaces of fish. Mucin O-glycans regulate pathogen quorum sensing, growth, virulence and attachment to the host. Knowledge on this mucosal defense system can enable alternative treatments to diseases posing a threat to productivity and welfare in aquaculture. Here, we characterize the rainbow trout (Oncorhynchus mykiss) gill, skin, pyloric ceca and distal intestinal mucin O-glycosylation and compare it to known teleost O-glycomes. We identified 54 O-glycans, consisting of up to nine monosaccharide residues. Skin glycans were most acidic, shortest on average and con-sisted mainly of NeuAc alpha 2-6GalNAc. Glycans from the gills were less acidic with predominantly core 1 and 2 glycans, whereas glycans from pyloric ceca and distal intestine expressed an increased number of core 5 glycans, distinctly decorated with NeuAc alpha 2-8NeuAc-like epitopes. When compared to Atlantic salmon and Arctic charr, trends on the core distribution, average size and overall acidity remained similar, although the epitopes varied. Rainbow trout mucins from gill and intestine bound A. salmonicida and A. hydrophila more efficiently than skin mucins. This is in line with a model where skin mucins with small glycans limit bacterial adhesion to the fish surface whereas the complex intestinal mucin glycans aid in trapping and removing pathogens from the epithelial surface.
|
|
| 40. |
|
|
| 41. |
|
|
| 42. |
|
|
| 43. |
|
|
| 44. |
- Zhang, Yanjiao, et al.
(författare)
-
Expression of immune-related genes in one phase of embryonic development of freshwater crayfish, Pacifastacus leniusculus
- 2010
-
Ingår i: Fish and Shellfish Immunology. - : Elsevier BV. - 1050-4648 .- 1095-9947. ; 28:4, s. 649-653
-
Tidskriftsartikel (refereegranskat)abstract
- Crayfish do not have larval stage as other crustacean such as penaeid shrimp they spawn their eggs until hatching and what hatches out from the eggs are miniature crayfish known as juveniles. In order to address the question whether immune genes are initially expressed during the embryo development in the egg stage, the expression of some immune-related genes: prophenoloxidase (proPO), peroxinectin, hemocyanin, anti-lipopolysaccharide factor (ALF), plcrustin, astakine-1, 2 and transglutaminase (TGase) were determined in the middle phase of crayfish embryo development. Furthermore, immune challenge was used to determine the immune response of eggs by immersing them in a solution of the highly pathogenic bacterium Aeromonas hydrophila. Semi-quantitative RT-PCR analysis showed that all tested genes are present except proPO in this phase of crayfish embryo development and none of the genes tested changed their expression following immersion in A. hydrophila. The proPO transcript has been reported from hemocytes in crustaceans and it plays crucial roles in crustacean immune response. This may indicate that the development of immune-competent hemocytes in this stage of crayfish embryo is not completed and the egg shell as such plays an important role as a shield in protecting the embryo from bacteria and maybe also other pathogens.
|
|
| 45. |
- Bargi, Sara, et al.
(författare)
-
Persistent currents in Bose gases confined in annular traps
- 2010
-
Ingår i: Physical Review A (Atomic, Molecular and Optical Physics). - 1050-2947. ; 82:4
-
Tidskriftsartikel (refereegranskat)abstract
- We examine the problem of stability of persistent currents in a mixture of two Bose gases trapped in an annular potential. We evaluate the critical coupling for metastability in the transition from quasi-one- to two-dimensional motion. We also evaluate the critical coupling for metastability in a mixture of two species as a function of the population imbalance. The stability of the currents is shown to be sensitive to the deviation from one-dimensional motion.
|
|
