Fish & shellfish immunology最新文献

{"title":"The effect of acute heat stress on the Chinook salmon immune system and their ability to combat Vibrio anguillarum infection and mortality","authors":"Emily J. McKenzie ,&nbsp;Noah P. Rogozynski ,&nbsp;Tania Rodríguez-Ramos ,&nbsp;John W. Heath ,&nbsp;Brian Dixon","doi":"10.1016/j.fsi.2025.110905","DOIUrl":"10.1016/j.fsi.2025.110905","url":null,"abstract":"<div><div>The frequency, duration, and intensity of heatwaves in western Canada is expected to rise in the coming years, and as a result, shallow streams will also experience drastic temperature fluctuations. This poses a problem for salmonids as encountering high water temperatures may increase their susceptibility to infectious disease. An environmentally applicable mock heat shock was performed on juvenile Chinook salmon and their immunological responses were measured for 14 days afterwards. Chinook salmon also received an injection of live <em>Vibrio anguillarum</em> after heat shock to determine if heat rendered them immunocompromised to systemic bacterial infection. <em>il1b, il8, tnfa, il10, tgfb, hsp47, hsp70,</em> and <em>hsp90</em> transcripts were quantified by qPCR in the spleen, gills, and hindgut. Heat shock did not affect mortality rates due to vibriosis compared to controls. Additionally, heat shock mitigated the pro-inflammatory and anti-inflammatory responses needed to combat infection by initially upregulating <em>il1b, tnfa, il8,</em> and <em>il10,</em> then returning to control levels by three days post-infection. Transcripts of <em>hsp47</em> and <em>hsp90</em> were upregulated in response to both heat shock and <em>V. anguillarum</em>. This research reports the first HSP47 protein measurements in Chinook salmon in plasma, which did not differ between any treatment groups. Plasma cortisol and lactate concentrations significantly increased, then returned to basal levels 6-h post-heat shock. Altogether, these data indicate that the experimental heat shock had a positive preconditioning effect on Chinook salmon and provides new insights on the interactions between the host, environment, and pathogen over a 14-day period.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"167 ","pages":"Article 110905"},"PeriodicalIF":3.9,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145211861","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":"Assessment of immune and pro-apoptotic functions of mitogen-activated protein kinase-interacting kinase 2 (MKNK2) in yellowtail clownfish (Amphiprion clarkii)","authors":"H.A.C.R. Hanchapola ,&nbsp;D.S. Liyanage ,&nbsp;W.K.M. Omeka ,&nbsp;Yasara Kavindi Kodagoda ,&nbsp;M.A.H. Dilshan ,&nbsp;D.C.G. Rodrigo ,&nbsp;G.A.N.P. Ganepola ,&nbsp;B.P.M. Vileka Jayamali ,&nbsp;Gaeun Kim ,&nbsp;Jeongeun Kim ,&nbsp;Qiang Wan ,&nbsp;Jihun Lee ,&nbsp;Jehee Lee","doi":"10.1016/j.fsi.2025.110904","DOIUrl":"10.1016/j.fsi.2025.110904","url":null,"abstract":"<div><div>Mitogen-activated protein kinase-interacting serine/threonine-protein kinase 2 (MKNK2) regulates protein synthesis by phosphorylating eukaryotic initiation factor 4E (<em>eIF4E</em>). In this study, we characterized the yellowtail clownfish (<em>Amphiprion clarkii) MKNK2</em> gene, <em>AcMKNK2</em>, by investigating its transcriptional responses and functional properties using different functional assays. The <em>AcMKNK2</em> gene contains a 1425 bp open reading frame encoding 467 amino acids. The protein has a predicted molecular weight of 53.25 kDa and an isoelectric point value of 6.10. Two conserved active motifs (²¹⁰ENIL²¹³ and ²²⁹DLG²³¹) and a protein kinase ATP binding site were identified in the AcMKNK2 amino acid sequence. The highest constitutive expression of <em>AcMKNK2</em> was found in muscle tissue under normal physiological conditions, while significant upregulation was observed under stimulations with polyinosinic:polycytidylic acid (poly(I:C)), lipopolysaccharide (LPS), and <em>Vibrio harveyi</em> in the blood, gill, and head kidney tissues. Subcellular localization analysis revealed that the AcMKNK2 protein is localized to the nucleus. Furthermore, AcMKNK2 overexpression increased the production of reactive oxygen species and the <em>Bax</em>/<em>Bcl-</em>2 mRNA expression ratio in fathead minnow cells exposed to H₂O₂, emphasizing the pro-apoptotic activities under oxidative stress conditions. Furthermore, RAW267.4 cells overexpressing <em>AcMKNK2</em> demonstrated a significant increase in the expression of M1 marker genes and NO production after LPS stimulation. Overall, these findings suggest that AcMKNK2 mediates cellular stress responses and regulates host immunity in yellowtail clownfish by driving pro-apoptotic pathways and enhancing pro-inflammatory mechanisms.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"167 ","pages":"Article 110904"},"PeriodicalIF":3.9,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145211816","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":"Molecular characterization and expression analysis of the TRAF gene family in the fourfinger threadfin (Eleutheronema tetradactylum)","authors":"Linjuan Wang ,&nbsp;Yifei Pan ,&nbsp;Huijuan Zhang ,&nbsp;Minxuan Jin ,&nbsp;Anna Zheng ,&nbsp;Jingheng Lu ,&nbsp;Weibin Liu ,&nbsp;Jiandong Zhang ,&nbsp;Baogui Tang ,&nbsp;Jiansheng Huang ,&nbsp;Bei Wang ,&nbsp;Jing Li ,&nbsp;Zhongliang Wang","doi":"10.1016/j.fsi.2025.110906","DOIUrl":"10.1016/j.fsi.2025.110906","url":null,"abstract":"<div><div>Originally characterized as adapter proteins linking TNF receptors to downstream signaling cascades, tumor necrosis factor receptor-associated factors (TRAFs) have since been recognized as pivotal signal transducers for multiple receptor families, regulating diverse biological processes. To date, seven mammalian <em>TRAF</em> members (<em>TRAF1</em>-<em>7</em>) have been identified, with well-documented roles in mediating innate immune responses. However, the functional significance of <em>TRAFs</em> in the innate immunity of the fourfinger threadfin (<em>Eleutheronema tetradactylum</em>) remains poorly understood. In this study, we identified and characterized eight <em>TRAF</em> genes in <em>E. tetradactylum</em>, designated <em>EtTRAF2a</em>, <em>EtTRAF2b</em>, <em>EtTRAF2-like</em>, <em>EtTRAF3</em>, <em>EtTRAF4a</em>, <em>EtTRAF5</em>, <em>EtTRAF6</em>, and <em>EtTRAF7</em>. Comprehensive sequence analysis revealed structural features conserved, including a C-terminal MATH domain and an N-terminal RING domain in all EtTRAFs, whereas EtTRAF7 uniquely contained seven WD40 repeat domains in its C-terminal region. Tissue distribution profiling via quantitative real-time PCR (qPCR) demonstrated constitutive expression of all eight <em>EtTRAF</em> genes across eight healthy tissues (skin, liver, brain, gill, spleen, kidney, heart, and intestine), with notably higher transcript levels in the liver and gill. Furthermore, the lipopolysaccharide (LPS) challenge induced significant temporal modulation of <em>EtTRAF</em> expression patterns. Collectively, our systematic investigation of <em>TRAFs</em> in <em>E. tetradactylum</em> provides critical insights into their putative roles in innate immune defense against pathogens and establishes a framework for future functional studies on TRAF-mediated signaling in teleost fishes.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"167 ","pages":"Article 110906"},"PeriodicalIF":3.9,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145206033","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":"Evolutionary analysis and immune-induced expression and m6A modification of RIPK1 and RIPK2 in the miiuy croaker","authors":"Qianru Xing ,&nbsp;Shang Geng ,&nbsp;Xing Lv ,&nbsp;Yuena Sun ,&nbsp;Tianjun Xu","doi":"10.1016/j.fsi.2025.110903","DOIUrl":"10.1016/j.fsi.2025.110903","url":null,"abstract":"<div><div>Receptor Interacting Protein Kinases (RIPKs), including RIPK1 and RIPK2, are key mediators of inflammatory signaling and inflammatory cell death. In this study, we identified the RIPK1 and RIPK2 genes in the miiuy croaker (<em>Miichthys miiuy</em>) and analyzed their evolutionary conservation and structural characteristics using bioinformatics approaches, highlighting their potential immune functions. Notably, research on the role of N6-methyladenosine (m⁶A) modification in regulating RIPKs remains limited. Here, methylated RNA immunoprecipitation sequencing (MeRIP-seq) revealed significant m⁶A enrichment near the stop codons of RIPK1 and RIPK2 of <em>Miichthys miiuy</em>, which was further confirmed by MeRIP-PCR. Expression analyses showed that RIPK1 and RIPK2 were markedly upregulated after poly(I:C) and LPS stimulation. Interestingly, poly(I:C) increased the m⁶A modification level of RIPK1, whereas LPS reduced the m⁶A level of RIPK2. Moreover, treatment with the methylation inhibitor cycloleucine further elevated their expression. These findings suggest that m⁶A modification may participate in fine-tuning the immune regulatory networks involving RIPK1 and RIPK2, potentially modulating their expression dynamics in response to diverse immune stimuli. This work provides valuable insights into the epigenetic regulation of RIPK family members and offers a foundation for exploring m⁶A-mediated control of fish innate immunity.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"167 ","pages":"Article 110903"},"PeriodicalIF":3.9,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145181942","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":"Teleost HMGB1 paralogues mediate protective autophagy by interacting with NOD2 and ATG16L1 and activating ROS/Akt/mTOR pathway against Aeromonas hydrophila infection","authors":"Dan Wang,&nbsp;Linan Chen,&nbsp;Xiaoyu Ma,&nbsp;Zhe Wang,&nbsp;Hong Zhou","doi":"10.1016/j.fsi.2025.110902","DOIUrl":"10.1016/j.fsi.2025.110902","url":null,"abstract":"<div><div>As a multifunctional regulator, high mobility group box 1 (HMGB1) plays an important role in DNA transcription, autophagy, infection and inflammation in mammals based on its cellular localization. Unlike in mammals, some teleost has two HMGB1 paralogues, and the DNA-binding and pro-inflammatory functions of extracellular HMGB1 have been characterized in various fish species, but the functional role of intracellular HMGB1 in bacterial infection remains elusive. In this study, the inducible effect of <em>Aeromonas hydrophila</em> (<em>A. hydrophila</em>) on autophagy was identified by using the autophagy related gene 7 (<em>Atg7</em>)-knockdown Epithelioma papulosum cyprini (EPC) cells, where fish HMGB1 paralogues have been defined as the autophagy regulator in our previous study. Consistently, the HMGB1 paralogues were proved to mediate <em>A. hydrophila-</em>induced autophagy by knockout HMGB1 paralogues and using HMGB1 inhibitors in the same cells, and suggested the defensive role of HMGB1 paralogues against <em>A. hydrophila</em> infection. Mechanistically, in accordance with the findings that nucleotide-binding oligomerization domain 2 (NOD2) but not NOD1 was involved in <em>A. hydrophila</em>-induced autophagy, HMGB1 mediated autophagy by interaction with NOD2 and ATG16L1. In addition, transcriptomic and western blotting assays further uncovered that HMGB1 regulated <em>A. hydrophila</em>-induced autophagy potentially by the ROS/AKT/mTOR signaling pathway. Furthermore, the physiological importance of HMGB1-mediated autophagic mechanism was strengthened in the primary neutrophils of grass carp, in which a complete autophagy flux mediated by HMGB1 facilitated <em>A. hydrophila</em> clearance. Notably, two HMGB1 paralogues played the same role in aforementioned events. Taken together, the intracellular role of fish HMGB1 paralogues in the autophagic response to <em>A. hydrophila</em> infection provided new insights into the immunological function of fish HMGB1, and offered clues as to how fish can defend themselves against bacterial infection.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"167 ","pages":"Article 110902"},"PeriodicalIF":3.9,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145181897","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":"Oral immunization with recombinant L. lactis expressing RGNNV capsid protein protects grouper against RGNNV infection","authors":"Xiaojing Hua ,&nbsp;Haoqi Du ,&nbsp;Yan Zhang ,&nbsp;Yanzhi Yu ,&nbsp;Yuanan Lu ,&nbsp;Xueqin Liu","doi":"10.1016/j.fsi.2025.110900","DOIUrl":"10.1016/j.fsi.2025.110900","url":null,"abstract":"<div><div>Nervous necrosis virus (NNV) is a highly pathogenic positive-sense RNA virus that causes substantial economic losses in global grouper aquaculture industry. Its capsid protein (CP) exhibits strong antigenicity properties and represents a promising immunogen for vaccine development. Among the four major NNV genotypes, Redspotted grouper nervous necrosis virus (RGNNV) is the most prevalent. Lactic Acid Bacteria (LAB) are attractive oral vaccine delivery platforms, capable of inducing both mucosal and systemic immune responses. In this study, <em>Lactococcus lactis</em> (<em>L. lactis</em>) expression system was used with lactose as a screening marker to produce the RGNNV-CP. We successfully constructed the recombinant strain pNZ8149-Usp45-CP/<em>L. lactis</em> NZ3900, and confirmed protein expression by the immunofluorescence assay (IFA) and western blotting. Grouper were orally immunized with this strain and then challenged with RGNNV to assess immune protection. The recombinant L. <em>lactis</em> demonstrated persistent colonization capacity in fish intestinal and enhanced mucosal barrier function, indicating safety for the host. Also, oral vaccination elicited strong neutralizing responses, with serum antibody titers peaking on day 28 post-immunization. Upregulation of immune-related genes in the brain, intestine, and visceral tissues further supported robust immune activation. Vaccinated fish showed reduced viral loads and lower mortality, confirming vaccine's efficacy. These findings highlight pNZ8149-Usp45-CP/<em>L. lactis</em> NZ3900 as a promising antibiotic-free oral vaccine candidate for protecting grouper against RGNNV.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"167 ","pages":"Article 110900"},"PeriodicalIF":3.9,"publicationDate":"2025-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145174308","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":"Effects of feed supplementation with fermented Broussonetia papyrifera leaves on non-specific immune responses, resistance to Vibrio parahaemolyticus, growth, intestinal histology, and microbiota of white shrimp (Penaeus vannamei)","authors":"Guan-Lin Lai,&nbsp;Yu-Ru Lin,&nbsp;Ta-Jeng Yang,&nbsp;Yu-Ting Chu,&nbsp;Fan-Hua Nan,&nbsp;Yeh-Fang Hu","doi":"10.1016/j.fsi.2025.110901","DOIUrl":"10.1016/j.fsi.2025.110901","url":null,"abstract":"<div><div>White shrimp (<em>Penaeus vannamei</em>) is a globally significant aquaculture species, yet the industry often suffers economic losses due to pathogens, water quality fluctuations, and climate change. Aquaculture technology frequently incorporates probiotics or herbal supplements to enhance shrimp immunity and growth performance. <em>Broussonetia papyrifera</em> leaf has long been used as a medicinal herb. However, due to the large molecular size of their active compounds, absorption by organisms is limited, making microbial fermentation necessary before use in feed. This study investigated the effects of fermented <em>B. papyrifera</em> leaf (FBL) on white shrimp immunity, resistance to <em>Vibrio parahaemolyticus</em>, and growth performance. <em>In vivo</em> trial confirmed that FBL is non-toxic to shrimp hemocytes and demonstrated that FBL concentrations between 50 and 1000 μg/mL significantly enhanced respiratory burst, phenoloxidase, and phagocytic activity (<em>p</em> &lt; 0.05). There are three experiments in the <em>in vivo</em> trials. Firstly, a 56-day feeding trial was conducted using five dietary treatments: control, FBL0.5 (0.5 g/kg), FBL1 (1 g/kg), FBL5 (5 g/kg), and FBL10 (10 g/kg). The results indicated that the FBL5 group exhibited notably improved growth performance, as well as enhanced intestinal structure and microbial composition. Following, a 28-day <em>in vivo</em> immune trial, shrimp were fed the same FBL diets to evaluate their effects on non-specific immune responses. The results showed that dietary supplementation with FBL significantly modulated immune responses and upregulated immune-related gene expressions, particularly on Days 7 and 14 (<em>p</em> &lt; 0.05). Finally, a challenge test revealed that the FBL5 group significantly reduced mortality after <em>V. parahaemolyticus</em> infection compared to the control group (<em>p</em> &lt; 0.05). In summary, this study demonstrates that supplementing 5 g FBL per kilogram of feed can bolster immune responses, improve growth performance, and enhance resistance to Vibrio infections in <em>P. vannamei</em>.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"167 ","pages":"Article 110901"},"PeriodicalIF":3.9,"publicationDate":"2025-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145174329","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":"Oral feeding of egg yolk antibody provide passive immune protection against largemouth bass iridovirus","authors":"Jinqiao Cao ,&nbsp;Shijia Liu ,&nbsp;Jiayi Luo ,&nbsp;Xia Liang ,&nbsp;Quan Wang ,&nbsp;Zengjian Liang ,&nbsp;Yunshang Ning ,&nbsp;Tao Xu ,&nbsp;Qiwei Qin ,&nbsp;Sumei Xiao ,&nbsp;Sheng Zhou","doi":"10.1016/j.fsi.2025.110898","DOIUrl":"10.1016/j.fsi.2025.110898","url":null,"abstract":"<div><div>This study aimed to isolate water-soluble fraction (WSF) containing egg yolk immunoglobulin (IgY) from inactivated Largemouth bass (<em>Micropterus salmoides</em>) iridovirus (LMBV)-immunized egg yolks and assess their oral efficacy in preventing LMBV infection in largemouth bass. Through western blotting and indirect ELISA methods, it was observed that IgY specifically recognized major capsid protein (MCP), with its titer peaking at 8 weeks post-initial immunization and subsequently stabilizing. In vitro, antibody neutralization experiments demonstrated the ability of IgY to neutralize the virus and inhibit its replication. Animal experiments revealed a relative protection rate of approximately 54 % in the specific IgY group, accompanied by significantly reduced viral copy numbers, expression levels of inflammatory factors, and alleviated tissue pathological changes. Serum peptide detection indicated the presence of LMBV and IgY-related peptides circulating in the blood, which may contribute to virus neutralization. These findings suggest that polyclonal antibody IgY exhibits effective preventive properties against LMBV.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"167 ","pages":"Article 110898"},"PeriodicalIF":3.9,"publicationDate":"2025-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145155052","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":"Two isoforms of Rel gene involved in the immune regulation of pearl oyster Pinctada fucata martensii","authors":"Hongxi Chen ,&nbsp;Guixuan Chen ,&nbsp;Zhihao Chen ,&nbsp;Xiaowen Lu ,&nbsp;Shirong Fu ,&nbsp;Weijiang Liao ,&nbsp;Yu Jiao ,&nbsp;Qingheng Wang ,&nbsp;Chuangye Yang ,&nbsp;Yuewen Deng","doi":"10.1016/j.fsi.2025.110895","DOIUrl":"10.1016/j.fsi.2025.110895","url":null,"abstract":"<div><div>Rel gene from pearl oyster <em>Pinctada fucata martensii</em> (Pm-Rel) belongs to the nuclear factor kappa B (NF-κB) gene family and involved in the immune regulation in pearl oyster. In this study, two isoforms of Pm-Rel (Pm-Rel349 and Pm-Rel418) were verified and functionally analyzed. Sequence analysis revealed that Pm-Rel349 and Pm-Rel418 were produced by the exon-deleted and intron-inserted, respectively. Pm-Rel349 lost the C-terminal region, and retained the N-terminal RHD-DNA bind and RHD-dimer region, while Pm-Rel418 lost the N-terminal region, and contained partial RHD-DNA bind, IPT domain and C-terminal TAD region. Both of them were significantly up-regulated at 24 h after transplantation and localized in the cytoplasm and nucleus, with mainly localization in the cytoplasm. Over-expression of Pm-Rel349 and Pm-Rel418 could activate the NF-κB signal pathway, and co-high-expression of both genes yields a stronger activation effect than individual high expression, indicating Pm-Rel349 and Pm-Rel418 have a synergistic effect, and bimolecular fluorescence complementation assay confirmed the interaction between Pm-Rel349 and Pm-Rel418. These findings suggest that Pm-Rel349 and Pm-Rel418 are crucial regulators of immune responses in <em>P</em>. <em>f</em>. <em>martensii</em>.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"167 ","pages":"Article 110895"},"PeriodicalIF":3.9,"publicationDate":"2025-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145174333","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 a tilapia epitopes vaccine against Streptococcus agalactiae based on phage display technology","authors":"Jun-Jie Sheng ,&nbsp;Xue-Feng Wei ,&nbsp;Mao-Lin Liu ,&nbsp;Xiao-Hang Ren ,&nbsp;Ming-Zhu Liu ,&nbsp;Bin Zhu","doi":"10.1016/j.fsi.2025.110896","DOIUrl":"10.1016/j.fsi.2025.110896","url":null,"abstract":"<div><div>Tilapia ranks among the world's leading aquaculture species, but <em>Streptococcus agalactiae</em> (<em>S. agalactiae</em>) severely limits the growth of the global tilapia industry. Vaccination has been proven to be a promising strategy for controlling this disease. In this study, a Ph.D.-12 phage display library was screened using serum from <em>S. agalactiae</em> survivors, leading to the identification and synthesis of two peptides (P1 and P2). Subsequently, an epitope vaccine was prepared by combining the peptide with adjuvant, and tilapia were immunized with a prime-boost strategy to evaluate its protective effect. Serum and tissue samples of immunized fish were collected periodically after the primary immunization, and the immunization effect was evaluated by combining enzyme-linked immunosorbent assay (ELISA), enzyme activity assays and quantitative real-time PCR (qRT-PCR). The results showed that the vaccine significantly enhanced host immune responses, including elevated specific antibody titers and upregulation of <em>CD8</em>, a marker of T cell activation. Notably, the epitope vaccine conferred protection against <em>S. agalactiae</em> challenge within 14 days post-challenge with a survival rate of up to 54.29 % in the group treated with Adjuvant-P1 (20 μg/g). Unlike traditional reverse vaccinology approaches, this method employed phage display to directly identify conformational epitopes, leading to the discovery of new conserved epitopes and suggesting that P1 and P2 peptide mimotopes hold potential as <em>S. agalactiae</em> candidate antigens. However, while this study provided preliminary evidence of the vaccine's efficacy against <em>S. agalactiae</em> over a 35-day period, further validation of the vaccine's durability and generalizability by extending the observation window and using different <em>S. agalactiae</em> strains is necessary. In conclusion, two mimotopes against <em>S. agalactiae</em> were directly identified by phage display in this study, which lays the foundation for the development of highly efficient and chemically synthesizable <em>S. agalactiae</em> vaccines for tilapia, and contributes to the promotion of the sustainable development of the tilapia industry.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"167 ","pages":"Article 110896"},"PeriodicalIF":3.9,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145148409","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}