Fish & shellfish immunology最新文献

{"title":"Hepcidin defense patterns in intestine of mandarin fish (Siniperca chuatsi) against Aeromonas hydrophila infection","authors":"Jin-hua Gao ,&nbsp;Jin-liang Zhao ,&nbsp;Ning-xin Guo ,&nbsp;Temesgen Tola ,&nbsp;Wen-bo Xue ,&nbsp;Kang-ning Cai ,&nbsp;Xiao-li Yao ,&nbsp;Miao Hu","doi":"10.1016/j.fsi.2024.110003","DOIUrl":"10.1016/j.fsi.2024.110003","url":null,"abstract":"<div><div>Bacterial septicemia caused by <em>Aeromonas hydrophila</em> is one of the common bacterial diseases in aquaculture. Antimicrobial peptides, including hepcidin, are key components of the innate immune system in fish, playing a role in defense against pathogens. This study investigated the defense patterns of hepcidin in mandarin fish (<em>Siniperca chuatsi</em>) following <em>A. hydrophila</em> infection using gene expression analysis and <em>in vitro</em> antibacterial assays. We measured changes in the expression of iron metabolism-related genes (<em>hepcidin</em>, <em>fpn, ftn, tf, tfr1</em>) and immune-related genes <em>(il-1β, il-6, il-8, il-10, tnf-α, socs3, nkap</em>, <em>tlr1, tlr2</em>) in the intestine post-infection. MBC experiment demonstrated that the hepcidin synthetic peptide has an inhibitory effect on the growth of <em>V. parahaemolyticus</em> (32 μg/ml), <em>A. hydrophilus</em> (64 μg/ml), and <em>F. columnaris</em> (128 μg/ml), but not <em>E. tarda</em> (&gt;256 μg/ml). After <em>A. hydrophilus</em> challenge, <em>fpn</em>, <em>tf</em> and <em>tfr1</em> with peak expression at 24 hpi (2.75), 12 hpi (4.43) and 6 hpi (7.41), respectively. <em>Hepcidin</em> and <em>ftn</em> expression was highest at 48 hpi (115.01) and 72 hpi (4.16). The Fe²⁺ content peaked at 6 hpi (2.64 μmol/l) and reached its lowest at 12 hpi (1.12 μmol/l) in the intestine. After pathogen challenge, <em>il-1β</em>, <em>il-8</em>, <em>socs3</em>, <em>tlr2</em>, and <em>hepcidin</em> showed trends of increased and then decreased, with peak expression at 72 hpi (5.13, 37.05, 3.08) and 48 hpi (5.35, 115.01), respectively. These findings suggested that hepcidin plays a key role in the defense against <em>A. hydrophila</em>: initially restricting bacterial growth through iron metabolism (0–48 hpi), and later modulating immune responses via the TNF (by inducing <em>il-1β</em> and <em>socs3</em>) and Toll-like receptor pathways (by inducing <em>il-8</em> and <em>tlr2</em>) (48–96 hpi). This study provides novel insights into the immune function of hepcidin in fish and its potential application in managing bacterial infections in aquaculture.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"155 ","pages":"Article 110003"},"PeriodicalIF":4.1,"publicationDate":"2024-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142568256","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Kinetics of viral hemorrhagic septicemia virus (VHSV) and immune response in olive flounder (Paralichthys olivaceus) at altered temperature","authors":"Yo-Seb Jang ,&nbsp;Su-Young Yoon ,&nbsp;Rahul Krishnan ,&nbsp;Myung-Joo Oh","doi":"10.1016/j.fsi.2024.110004","DOIUrl":"10.1016/j.fsi.2024.110004","url":null,"abstract":"<div><div>Viral hemorrhagic septicemia virus (VHSV) is a pathogen that causes hemorrhagic septicemia in olive flounder at water temperatures below 15 °C, leading to symptoms such as abdominal swelling due to ascites and muscle hemorrhaging, and in severe cases, mortality. In this study, we investigated the proliferation of NCCs, the transcriptional analysis of CD4 and CD8, and the expression of pro-inflammatory cytokines (IL-1β, IL6, TNFα) and the cytokines (IL12, IL15, IFN-1β, IFNγ) involved in cytotoxic cell activation in the kidney of olive flounder during VHSV infection at suboptimal temperature (17 °C) and following a shift to optimal temperature (10 °C). Following viral infection, the population of NCCs and CD8 gene expression steadily increased. Meanwhile, IL12, IL15, and IFN-1β levels exhibited an early surge, reaching their peak within 1–2 days post-challenge at 17 °C. Notably, in olive flounder that were re-challenged with VHSV at 10 °C after an initial challenge at 17 °C, there was a rapid and robust expansion of NCCs and increased CD4 and CD8 gene expression, demonstrating the mounting of immune memory by NCCs and an efficient adaptive immune response from CD4⁺ and CD8⁺ T cells against VHSV infection.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"155 ","pages":"Article 110004"},"PeriodicalIF":4.1,"publicationDate":"2024-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142568260","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Paralichthys olivaceus GSDME-mediated pyroptosis is regulated by multiple caspases in different manners","authors":"Kangwei Hao ,&nbsp;Liming Yuan ,&nbsp;Chao Yu ,&nbsp;Hang Xu ,&nbsp;Li Sun","doi":"10.1016/j.fsi.2024.110002","DOIUrl":"10.1016/j.fsi.2024.110002","url":null,"abstract":"<div><div>Pyroptosis is a type of programmed cell death mediated by gasdermin (GSDM). GSDM is activated by caspase (CASP), which cleaves GSDM to release the N-terminal (NT) fragment that forms channels in the plasma membrane and leads to cell death. To date, research on pyroptosis in teleost is limited. In this study, we examined the activation and regulation mechanism of pyroptosis in flounder <em>Paralichthys olivaceus</em>. <em>P. olivaceus</em> gasdermin E (PoGSDME) was found to be cleaved by six <em>P. olivaceus</em> caspases (PoCASP1/3a/3b/7/8a/8b). PoCASP1/3a/3b/7 cleaved primarily at ₂₄₅FEAD₂₄₈, which generated an NT fragment (NT₂₄₈) that induced robust pyroptosis. PoCASP8a/8b cleaved both the full length PoGSDME and NT₂₄₈ at ₂₀₂IEKD₂₀₅, thus destroying the biological activity of PoGSDME and NT₂₄₈. Nine residues crucial for PoGSDME function were identified, of which, F2, L19, and G85 were essential to plasma membrane translocation. During bacterial infection, PoGSDME and PoCASP1 expressions were significantly upregulated in flounder tissues, and PoGSDME, as well as PoCASP1, activation occurred in flounder cells accompanied with the processing cleavage of IL-1β and IL-18. Together these results revealed both the activation and the inhibition mechanisms of GSDME-mediated pyroptosis in flounder, and added new insights into the regulation of pyroptosis in fish.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"155 ","pages":"Article 110002"},"PeriodicalIF":4.1,"publicationDate":"2024-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142568263","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Corrigendum to \"Sargassum horneri extracts stimulate innate immunity, enhance growth performance, and upregulate immune genes in the white shrimp Litopenaeus vannamei\" [Fish Shellfish Immunol. 102 (2020) 276-285].","authors":"Po-Tsang Lee, Hoang Trieu Quan Tran, Huai-Ting Huang, Fan-Hua Nan, Meng-Chou Lee","doi":"10.1016/j.fsi.2024.109970","DOIUrl":"10.1016/j.fsi.2024.109970","url":null,"abstract":"","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":" ","pages":"109970"},"PeriodicalIF":4.1,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142461262","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A novel LPS binding /bactericidal permeability-increasing protein (LBP/BPI) from the scallop Argopecten purpuratus plays an essential role in host resistance to Vibrio infection","authors":"Antonia Jorquera ,&nbsp;Camila Montecinos ,&nbsp;Yurubí Borregales ,&nbsp;Katherine Muñoz-Cerro ,&nbsp;Roxana González ,&nbsp;Max Santelices ,&nbsp;Rodrigo Rojas ,&nbsp;Luis Mercado ,&nbsp;Felipe Ramírez ,&nbsp;Fanny Guzmán ,&nbsp;Rodolfo Farlora ,&nbsp;Cristian Valenzuela ,&nbsp;Katherina Brokordt ,&nbsp;Paulina Schmitt","doi":"10.1016/j.fsi.2024.109989","DOIUrl":"10.1016/j.fsi.2024.109989","url":null,"abstract":"<div><div>Lipopolysaccharide binding proteins (LBPs) and bactericidal permeability increasing proteins (BPIs) play significant roles in the immune response of vertebrates against bacterial pathogens. These soluble proteins produced by immune cells, specifically interact with and bind to bacterial lipopolysaccharides (LPS), with BPIs also displaying antibacterial activity. In <em>Argopecten purpuratus</em> scallop larvae resistant to <em>Vibrio bivalvicida</em> VPAP30<em>,</em> we identified a significant overexpression of a transcript displaying molecular features of an LBP/BPI protein, both before and after infection. Therefore, in the present work we aimed to understand the role of this novel LBP/BPI, named ApLBP/BPI3, in the scallop resistance to this <em>Vibrio</em>. The ApLBP/BPI3 open reading frame encodes a putative protein of 506 amino acids, with a molecular weight 56.78 kDa. The protein contains a C-terminal domain of 403-amino acid that, after theorical cleavage, displays a soluble form of 44.99 kDa, featuring two BPI/LBP/CETP domains, an apolar binding pocket, a single disulfide bond and a BPI dimerization interface. Phylogenetic analysis reveals high similarity between ApLBP/BPI3 and other mollusk LBP/BPI proteins. <em>Aplbp/bpi3</em> transcripts were constitutively and highly expressed in hemocytes, gills, mantle, and digestive gland tissues, and were induced following VPAP30 infection in scallop larvae and adult hemocytes. We characterized ApLBP/BPI3 protein using a polyclonal antibody against a synthetic peptide. ApLBP/BPI3 was secreted to the media by infected cultured hemocytes, detected by ELISA. ApLBP/BPI3 was spotted inside non-infected hemocytes, bound to the cell wall of <em>V. bivalvicida</em> after <em>in vitro</em> hemocyte infection, and coating the gills and mantle epithelial barriers before and after an <em>in vivo</em> immune challenge, with stronger detection after VPAP30 injection, detected by immunofluorescence. Infected scallop larvae showed increased ApLBP/BPI3 levels, with slightly higher production in resistant larvae, determined by Western blot. Finally, silencing the <em>Aplbp/bpi3</em> transcript through RNA interference and and subsequently infecting scallop juveniles with an LD50 of <em>V. bivalvicida</em> resulted in 100 % mortality. Altogether, results demonstrate the essential role of this immune effector in the resistance of <em>A. purpuratus</em>.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"154 ","pages":"Article 109989"},"PeriodicalIF":4.1,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142544626","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of inhibitory, immunomodulatory, survival, and growth effects of host-derived Weissella confusa on Macrobrachium rosenbergii challenged with Vibrio parahaemolyticus","authors":"Kristelle Mae C. Tardecilla ,&nbsp;Mary Beth B. Maningas","doi":"10.1016/j.fsi.2024.109964","DOIUrl":"10.1016/j.fsi.2024.109964","url":null,"abstract":"<div><div><em>Macrobrachium rosenbergii</em> is a highly valuable prawn species in aquaculture due to its current growing demand in the market. However, various bacterial diseases caused by <em>Vibrio parahaemolyticus</em> have been observed to induce mortality in larval, juvenile, and adult stages of <em>M. rosenbergii.</em> While antibiotics are commonly used to manage these diseases, they contribute to antimicrobial resistance, a global concern with serious environmental and health implications. Consequently, the scientific community is exploring host-derived beneficial microorganisms as functional feed additives, offering eco-friendly alternatives that boost shrimp and prawn immunity. The purpose of this study was to examine the effects of host-derived beneficial microorganisms from the gut of <em>M. rosenbergii</em>, on the inhibition, immunomodulation, survival, and growth of <em>M. rosenbergii</em> when exposed to <em>V. parahaemolyticus</em>. The result of this study showed that <em>Weissella confusa</em> C6, a lactic acid bacterium isolated from the gut of <em>M. rosenbergii</em>, significantly inhibits the growth of <em>V. parahaemolyticus</em> R1 as demonstrated in agar well diffusion assay and co-culture assay. Additionally, it showed immunomodulatory effects, indicated by elevated total hemocyte count (THC) and phenoloxidase (PO) activity during the bacterial challenge test. Furthermore, supplementing the diet with <em>W. confusa</em> led to significant improvements in <em>M. rosenbergii</em>, including increased survival rates, weight gain, specific growth rate, better feed conversion ratio, and reduced density of <em>V. parahaemolyticus</em> in the prawn's gut. Therefore, it can be considered a viable option for use as a feed supplement in prawn farming, enhancing <em>M. rosenbergii'</em>s immune system, disease resistance, and overall health.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"154 ","pages":"Article 109964"},"PeriodicalIF":4.1,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142461334","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterization, expressional and evolutionary analysis of five fish-specific CCRs (CCR4La, CCR4Lc, CCR12a1, CCR12a2, and CCR12b) in largemouth bass (Micropterus salmoides)","authors":"Xiangyu Pi ,&nbsp;Xuan Wei ,&nbsp;Mingzhu Pan ,&nbsp;Eakapol Wangkahart ,&nbsp;Qihuan Zhang ,&nbsp;Zisheng Wang ,&nbsp;Zhitao Qi","doi":"10.1016/j.fsi.2024.109984","DOIUrl":"10.1016/j.fsi.2024.109984","url":null,"abstract":"<div><div>CC chemokine receptors (CCRs), the numbers of the G protein-coupled receptor (GPCR) superfamily, had crucial roles in treating infection, inflammation, and tissue damage by binding to their ligands. In this study, five fish-specific CCRs, namely CCR4La, CCR4Lc, CCR12a1, CCR12a2, and CCR12b, were identified in largemouth bass (<em>Micropterus salmoides</em>). The correction of nomenclatures of these CCRs were confirmed by phylogenetic analysis, structural analysis and genomic synteny analysis. Following 1 × 10⁶ CFU/mL and 1 × 10⁷ CFU/mL <em>Edwardsiella piscicida</em> infection, these five CCRs were significantly induced in spleen of largemouth bass, indicating their important roles in the immune response against bacterial infection. Selection pressure analysis revealed that CCR4La, CCR4Lc, CCR12a1, and CCR12a2 underwent negative selection pressure, whereas CCR12b experienced positive selection pressure. Robust selection site detection methods identified that positive selected sites of CCR4La, CCR4Lc, CCR12a1, and CCR12a2 mainly distributed in their extracellular regions, which involved in ligand binding and pathogen interaction. Similarly, the positive selected sites of CCR12b were also located in its extracellular regions. The accuracy of the pressure selected sites were also validated by molecular docking analysis. The potential ligands for these five CCRs were identified by molecular docking analysis, with finding that CCL3 and CCL5 might be the ligands of largemouth bass CCR4La/Lc, and CCL5, CCL8, CCL7, CCL13 and CCL26 might be that of largemouth bass CCR12a1/a2/b. Our results provided basis for elucidating the functions of chemokine-receptor complex in largemouth bass.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"154 ","pages":"Article 109984"},"PeriodicalIF":4.1,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142497573","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Recombinant Bacillus subtilis expressing functional peptide and its effect on blunt snout bream (Megalobrama amblycephala) in two state of stress","authors":"Wei Xiong ,&nbsp;Guang-zhen Jiang ,&nbsp;Chao-fan He ,&nbsp;Hao-kun Hua ,&nbsp;Mian-ting Du ,&nbsp;Wan-ting Huang ,&nbsp;Hui-ting Xu ,&nbsp;Mei-ting Zhou ,&nbsp;Xi Wang ,&nbsp;Hui-xing Guo ,&nbsp;Ai-min Wang ,&nbsp;Shang-zhi Sun ,&nbsp;Wen-bin Liu","doi":"10.1016/j.fsi.2024.109980","DOIUrl":"10.1016/j.fsi.2024.109980","url":null,"abstract":"<div><div>This study was conducted to investigate the effects of recombinant <em>Bacillus subtilis</em> CM66-P4' (secreting P4, which related to previous research in this laboratory) on the antioxidant capacity and immune function of blunt snout bream (<em>Megalobrama amblycephala</em>) through in vitro and in vivo experiment. The culture experiment was divided into 3 groups, including control group (CG, with no additional bacteria), original bacteria group (OBG, with 2 × 10⁹ CFU/kg <em>Bacillus subtilis</em> CM66) and recombinant bacteria group (RBG, with 2 × 10⁹ CFU/kg <em>Bacillus subtilis</em> CM66-P4′). After 8 weeks of feeding, a part of the fish were subjected to fishing stress, and the rest were subjected to starvation stress test. Blood samples were collected for the determination of immune and stress-related indexes. The hepatocytes were divided into control group (CG) and experiment group with P4 peptide (LTG and HTG). The cells were collected after starvation treatment and the expression of related genes was detected. The results showed as follows: compared with the CG group, the gene expressions of hepatocytic <em>hsp60</em> and <em>hsp70</em> in the LTG and HTG groups were significantly suppressed after 24 h starvation stress (<em>P</em> &lt; 0.05). The content of MDA, the activities of AKP and ALT in OBG group were significantly changed after 30 days starvation (<em>P</em> &lt; 0.05), while the indexes in RBG group had no significant change. The changes of plasma cortisol, malondialdehyde (MDA) and Immunoglobulin M (IgM) in CG and OBG groups were significantly changed at 4 h after fishing stress (<em>P</em> &lt; 0.05), while the indexes in RBG group was not. In conclusion, this study confirmed that <em>Bacillus subtilis</em> CM66-P4′ has great potential in preventing adverse effects of stress on aquatic livestock.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"154 ","pages":"Article 109980"},"PeriodicalIF":4.1,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142497589","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Arginine alleviates LPS-induced leukocytes inflammation and apoptosis via adjusted NODs signaling","authors":"Yuan-Xin Qian,&nbsp;Feng-Feng Zhou,&nbsp;Qiang Chen,&nbsp;Fen Dong,&nbsp;Han-Ying Xu,&nbsp;Yu-Long Sun,&nbsp;Ji-Teng Wang,&nbsp;Tao Han","doi":"10.1016/j.fsi.2024.109985","DOIUrl":"10.1016/j.fsi.2024.109985","url":null,"abstract":"<div><div>Arginine plays a key role in regulating the immune function of fish. To evaluate the effect of arginine on the immune response of largemouth bass (<em>Micropterus salmoides</em>), the effects of arginine on cell viability, NADPH oxidase activity, respiratory burst activity, and NO production of leukocytes were analyzed both <em>in vitro</em> and <em>in vivo</em>. In this study, we found that arginine could promote the respiratory burst activity of leucocytes both <em>in vivo</em> and <em>in vitro</em>. By incubating leukocytes with the combination of LPS and arginine, we found that arginine supplementation inhibited the expression of inflammatory genes (<em>tumor necrosis factor-alpha</em>, <em>tnfα</em>; <em>interleukin</em>(<em>il</em>) <em>8</em> and <em>il10</em>) and apoptotic genes (<em>caspase 3</em>, <em>caspase 8</em>, and <em>caspase 9</em>) induced by LPS, as well as promoted the arginine metabolism. Arginine supplementation significantly induced (<em>cd4-like</em>) <em>cd4</em> gene expression after LPS challenge. Further studies showed that LPS could significantly increase <em>nucleotide-binding oligomerization domain containing 1</em> (<em>nod1</em>) gene expression, but decreased the <em>nod2</em> gene. The arginine supplementation increased nuclear factor kappa-B (NF-κB) protein level. In conclusion, arginine can alleviate LPS-induced inflammatory response and apoptosis as well as induce <em>cd4</em> gene expression against LPS challenge <em>via</em> adjusting the expression of NODs signaling.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"154 ","pages":"Article 109985"},"PeriodicalIF":4.1,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142497572","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cell death induced by Lepeophtheirus salmonis labial gland protein 3 in salmonid fish leukocytes: A mechanism for disabling host immune responses","authors":"Helena Marie Doherty Midtbø ,&nbsp;Andreas Borchel ,&nbsp;H. Craig Morton ,&nbsp;Richard Paley ,&nbsp;Sean Monaghan ,&nbsp;Gyri Teien Haugland ,&nbsp;Aina-Cathrine Øvergård","doi":"10.1016/j.fsi.2024.109992","DOIUrl":"10.1016/j.fsi.2024.109992","url":null,"abstract":"<div><div>The salmon louse (<em>Lepeophtheirus salmonis</em>) is an ectoparasite feeding on mucus, skin, and blood of salmonids. On parasitised fish erosions and, at later lice stages, ulcerations appear at the louse feeding site. In susceptible species like Atlantic salmon (<em>Salmo salar</em>) with a limited rejection of lice, only a mild inflammatory response with minor influx of immune cells is seen at these lesions, as the salmon louse secrete proteins that can dampen immune responses. In a previous study, <em>Lepeophtheirus salmonis</em> labial gland protein 3 (LsLGP3) was suggested to dampen cellular responses, and the present study aimed at increasing our understanding of its mode of action. LsLGP3 was found to be secreted on to the host skin, and both <em>in vivo</em> and <em>in vitro</em> experiments were performed to elucidate its function. Histological analysis of the louse attachment site revealed an epidermal and dermal influx of mainly macrophages and granulocytes after 5 days post infestation. The immune cell influx was deeper in the dermis throughout the louse infestation, and LsLGP3 may be involved in dampening this response. Enriched populations of Atlantic salmon B-cells, T-cells, granulocytes, and monocytes were exposed to recombinant LsLGP3 (recLGP3) <em>in vitro</em>, resulting in a significant decrease in cell viability compared to non-exposed controls. An apoptotic cell morphology with “beads-on-a-string” like protrusions was seen in all leukocyte cell fractions after recLGP3 exposure, but not in erythrocytes or keratocytes. A decreased viability was also detected in pink salmon leucocytes, which was not in leucocytes from non-salmonid species. These functional insights suggest that LsLGP3 specifically induces apoptosis of salmonid leukocytes and is likely a key protein secreted by the lice that disables the Atlantic salmon ability to mount an adequate immune response towards the salmon louse. <em>In vivo</em> LsLGP3 knock down studies indicated that the effect is localised primarily at the lice feeding site, without affecting immune cells that are not situated adjacent to the lice-inflicted lesion. The findings from this study could significantly aid in the development of new immune based anti-salmon louse prophylactic measures and treatments.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"154 ","pages":"Article 109992"},"PeriodicalIF":4.1,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142557436","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}