Fish & shellfish immunology最新文献

{"title":"Grass carp Hnf4β orchestrates antibacterial defense via the AIF/Hnf4α/caspase 3 signaling axis","authors":"Dong Yan ,&nbsp;Ming Xian Chang","doi":"10.1016/j.fsi.2025.110534","DOIUrl":"10.1016/j.fsi.2025.110534","url":null,"abstract":"<div><div>Hepatocyte nuclear factor 4 (HNF4), a transcription factor family critical for hepatic development and metabolic homeostasis, consists of three isoforms (HNF4α, HNF4β, HNF4γ). While HNF4α and HNF4γ are evolutionarily conserved across vertebrates, HNF4β is restricted to teleosts, amphibians and birds, with its antimicrobial function poorly characterized. Here, we investigate the role of grass carp Hnf4β (gcHnf4β) in response to <em>Aeromonas salmonicida</em> infection, uncovering a novel antibacterial signaling axis. Overexpression of gcHnf4β significantly attenuates bacterial proliferation and augments <em>Ctenopharyngodon idella kidney</em> (CIK) cell viability through transcriptional upregulation of caspase 3, caspase 9 and apoptosis-inducing factor (AIF). Mechanistically, gcHnf4β acts as a transcriptional hub, directly interacting with AIF and forming a ternary complex with gcHnf4α to indirectly engage caspase 3. Subcellular dynamics show nuclear retention of gcHnf4β during infection, concurrent with cytoplasmic-to-nuclear translocation of AIF/caspase 3 and their co-localization in the nucleus. Functional validation reveals that AIF knockdown or caspase 3 inhibition abolishes antibacterial activity mediated by gcHnf4β, whereas caspase 9 inhibition does not. Our findings establish gcHnf4β as a critical regulator of antimicrobial immunity, providing novel insights into host-pathogen interactions and potential targets for aquaculture disease control.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"165 ","pages":"Article 110534"},"PeriodicalIF":4.1,"publicationDate":"2025-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144518086","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":"Krϋppel-like factor 12a and 12b inhibit Cyvirus cyprinidallo3 replication by repressing viral ORF8 promoter activity","authors":"Xinyue Hu ,&nbsp;Yingying Li ,&nbsp;Yingying Wang ,&nbsp;Defeng Zhang ,&nbsp;Donghai Liu ,&nbsp;Qing Wang ,&nbsp;Shucheng Zheng","doi":"10.1016/j.fsi.2025.110522","DOIUrl":"10.1016/j.fsi.2025.110522","url":null,"abstract":"<div><div><em>Cyvirus cyprinidallo3</em>, also known as <em>Cyprinid herpesvirus 3</em> (CyHV-3), is a highly infectious and lethal DNA virus causing considerable economic losses in the common carp and koi farming sectors. The pathogenesis caused by CyHV-3 is still poorly understood and effective control measures remain unavailable. Previously, we found that the immediate early (IE) gene <em>ORF8</em> promoter of CyHV-3 exhibits the highest activity in the host cells. However, the transcriptional regulatory mechanism of the viral <em>ORF8</em> promoter remains unknown. Herein, the potential transcription factors Krϋppel-like factors (KLFs) 12a and 12b from common carp (<em>Cyprinus carpio</em>) targeting the <em>ORF8</em> promoter were characterized. <em>KLF12a</em> and <em>KLF12b</em> were widely expressed in various tissues of common carp and the corresponding proteins are primarily localized to the nucleus of common carp brain cell line (CCB). Particularly, <em>KLF12a</em> and <em>KLF12b</em> overexpression significantly suppressed the <em>ORF8</em> promoter activity and deletion of the <em>ORF8</em> promoter region containing <em>KLF12</em> binding sites resulted in a marked decrease in activity. Continuous deletion of the viral <em>ORF8</em> promoter at 75 bp intervals further revealed that −203∼-53 region is strongly required for the viral <em>ORF8</em> promoter activity. More importantly, both <em>KLF12a</em> and <em>KLF12b</em> overexpression markedly reduced viral genome copies number, and virions in CCB cells. Taken together, <em>Cyprinus carpio</em> KLF12a and KLF12b inhibit CyHV-3 replication by repressing viral <em>ORF8</em> promoter activity, which provides a foundation for further investigation into the transcriptional regulatory mechanisms of IE genes in CyHV-3.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"165 ","pages":"Article 110522"},"PeriodicalIF":4.1,"publicationDate":"2025-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144501447","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":"Penaeus chinensis nearing a critical threshold of susceptibility to Decapod iridescent virus 1 (DIV1)","authors":"Xiao-Meng Guo ,&nbsp;Guo-Hao Wang ,&nbsp;Xiao-Ling Chen ,&nbsp;Jing-Yi Xing ,&nbsp;Liang Qiu ,&nbsp;Jia-Yun Yao ,&nbsp;Jie Huang","doi":"10.1016/j.fsi.2025.110523","DOIUrl":"10.1016/j.fsi.2025.110523","url":null,"abstract":"<div><div>This study delves into the susceptibility of Chinese shrimp, <em>Penaeus chinensis</em>, to Decapod iridescent virus 1 (DIV1), a pathogen of significant concern in crustacean aquaculture. Our research meticulously evaluated the infection potential of DIV1 through both invasive (intramuscular injection) and non-invasive (<em>per os</em>) experimental methodologies. The outcomes revealed that intramuscular injection effectively induced infection in <em>P. chinensis</em>, manifesting clinical signs and resulting in 100 % mortality within five days post-infection (dpi). In contrast, <em>per os</em> challenge resulted in a low viral load infection at 3 day post-infection (dpi), which did not persist beyond the 9 dpi, showing a late-stage clearance of iDIV1. These results were corroborated through molecular detection, histopathological examination, <em>in situ</em> DIG-labeling loop-mediated isothermal amplification (ISDL), and transmission electron microscopy (TEM). The study concludes that, while <em>P. chinensis</em> is not considered a susceptible host for DIV1, its susceptibility is nearing a critical threshold. These findings underscore the imperative for continuous virus surveillance and research into host susceptibility to preempt potential economic repercussions for the aquaculture industry.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"165 ","pages":"Article 110523"},"PeriodicalIF":4.1,"publicationDate":"2025-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144514414","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":"Heat-inactivated Mycobacterium marinum as a vaccine adjuvant and a trained immunity inducer in rainbow trout (Oncorhynchus mykiss)","authors":"Kyung Min Lee,&nbsp;Ki Hong Kim","doi":"10.1016/j.fsi.2025.110521","DOIUrl":"10.1016/j.fsi.2025.110521","url":null,"abstract":"<div><div>The increasing need for effective disease prevention strategies in aquaculture highlights the importance of developing novel vaccine adjuvants and immunostimulants. This study aimed to investigate the immunomodulatory potential of heat-killed <em>Mycobacterium marinum</em> in rainbow trout (<em>Oncorhynchus mykiss</em>), with a focus on its dual role as a vaccine adjuvant and an inducer of trained immunity. To this end, we evaluated the effects of co-immunizing fish with heat-killed <em>M. marinum</em> and a live attenuated <em>Vibrio anguillarum</em> vaccine. This combination significantly enhanced protective efficacy, as demonstrated by increased survival rates, elevated serum antibody titers, and early upregulation of pro-inflammatory cytokines and immune-related genes. In addition, heat-killed <em>M. marinum</em> alone conferred non-specific protection against <em>V. anguillarum</em> infection, characterized by earlier bacterial clearance, heightened inflammatory gene expression, and epigenetic modifications, including increased H3K4me3 and H3K27ac at cytokine gene promoters. These findings support the use of heat-killed <em>M. marinum</em> as both an effective vaccine adjuvant and a promising inducer of trained immunity in aquaculture species.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"165 ","pages":"Article 110521"},"PeriodicalIF":4.1,"publicationDate":"2025-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144501446","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":"The barramundi (Lates calcarifer) mucus glycome is conserved across oral, skin and gill tissues but varies between individuals","authors":"Kristina A. Thomsson ,&nbsp;John Benktander ,&nbsp;Mattias Erhardsson ,&nbsp;James W. Wynne ,&nbsp;Richard S. Taylor ,&nbsp;Sara K. Lindén","doi":"10.1016/j.fsi.2025.110515","DOIUrl":"10.1016/j.fsi.2025.110515","url":null,"abstract":"<div><div>Infections cause recurring setbacks in aquaculture and the mucus covering the fish surfaces is the first barrier pathogens encounter. The mucus is made up by highly glycosylated mucin glycoproteins. The glycan part of the mucins confers many of the mucus properties and pathogen regulating activities of the mucins, but these glycans remain largely uncharacterised in a range of aquacultured fish species. Barramundi (<em>Lates calcarifer</em>), also called Asian Sea Bass, is cultured in southeast Asia, Australia, USA, UK, Netherlands and Israel. Here we identified 74 O-glycans and three N-glycans in mucus from the oral cavity, skin, gills and intestine using liquid chromatography mass spectrometry. O-glycans from the oral cavity, skin and gill mucus were highly acidic and similar between these epithelia. The barramundi O-glycome displayed a relatively large inter-individual variation, which lead to that glycan features differing between oral cavity, skin and gills were not clearly distinguishable, although the intestinal glycan profiles clearly differed from the other epithelial sites. Barramundi intestinal glycans contained large glycans consisting of up to 14 monosaccharides, often including core 2 glycans with diHexNAc epitopes. This glycan library can serve as a platform for other studies, for example aiming for characterising host-microbe interactions, diagnostic purposes or disease intervention therapies. Furthermore, identification of novel glycans adds to the total glycan library available, leading to that artificial intelligence driven glycomics will become more accurate, allowing the glycomics field to move from a manual and time-consuming activity performed by specialists to automatic data analysis, more similar to other omics.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"165 ","pages":"Article 110515"},"PeriodicalIF":4.1,"publicationDate":"2025-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144511671","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":"Mudskipper β-def2 exhibits potent broad-spectrum bactericidal activity via membrane-disrupting and DNA-targeting mechanisms","authors":"Ya-Zhen Hu ,&nbsp;Ning-Xi Tan ,&nbsp;Jia-Feng Cao ,&nbsp;Jiong Chen","doi":"10.1016/j.fsi.2025.110520","DOIUrl":"10.1016/j.fsi.2025.110520","url":null,"abstract":"<div><div>Defensins, cysteine-rich host defense peptides critical for host's antibacterial immunity, remain understudied in intertidal living species. Here, we characterize muβ-def2, a 43-amino-acid β-defensin from mudskipper with three pairs of disulfide structures (C1-C5, C2-C4, C3-C6) and a cationic amphiphilic topology, featuring a hydrophobic face and a charge-rich surface (+4.5 net charge, pI 8.9). Phylogenetic analysis reveals its tight clustering within the β-def2 subclass, highlighting conserved evolutionary antimicrobial functions. muβ-def2 exhibits potent broad-spectrum bactericidal activity, with minimum bactericidal concentrations (MBCs) ranging from &lt;1 μM (e.g., <em>S. aureus</em>) to 32 μM (<em>L. monocytogenes</em>), and rapid killing kinetics (e.g., <em>A. veronii</em> eradication within 160 min). This activity persists across temperature (28°C-100 °C) and pH (5.5–9.0) extremes, underscoring environmental robustness. Mechanistically, muβ-def2 disrupts bacterial membranes through selective targeting of prokaryotic phospholipid surfaces, with subsequent detection of genomic DNA interactions that likely occur as a downstream consequence of membrane permeabilization. Notably, incubation with pathogen-associated molecular patterns (PAMPs) diminishes its bactericidal efficacy, suggesting competitive inhibition of peptide-PAMP interactions. These findings elucidate a dual membrane-DNA attack mechanism for muβ-def2, emphasizing its potential as an antimicrobial agent that may also be used for therapeutic applications against multidrug-resistant pathogens.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"165 ","pages":"Article 110520"},"PeriodicalIF":4.1,"publicationDate":"2025-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144501347","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":"The infection biology of piscine myocarditis virus in Atlantic salmon: Can a local immune response aid eliminating the virus from the heart","authors":"Antoni Malachowski,&nbsp;Shiferaw Jenberie,&nbsp;Roy Ambli Dalmo,&nbsp;Jaya Kumari Swain","doi":"10.1016/j.fsi.2025.110518","DOIUrl":"10.1016/j.fsi.2025.110518","url":null,"abstract":"<div><div>Cardiomyopathy syndrome, caused by piscine myocarditis virus (PMCV), continues to pose a significant threat to the Norwegian Atlantic salmon farming industry. In this study, we assessed expression of various innate and adaptive immune marker genes in atrium, ventricle, spleen, and head kidney (HK) over a period of 16 weeks post PMCV infection (WPI), with samples collected weekly or biweekly.</div><div>The results showed early detection of virus in HK at 1 WPI, while other tissues tested positive from 2 WPI. A trend of virus clearance was noted in ventricle, with 3 out of 6 fish testing negative for virus at 16 WPI, while a low but persistent virus load was observed in other tissues. An overall positive correlation between virus load and cell-mediated immune markers was identified.</div><div>When comparing the two heart compartments, atrium exhibited higher expression of proinflammatory, anti-inflammatory, and cytotoxic T cell marker genes than ventricle. However, similar difference was not evident between the HK and spleen. Furthermore, these marker genes exhibited higher expression in heart compartments compared to lymphoid tissues.</div><div>An antiviral response mediated by Mx was evident across all four tissues, while the type I IFN response did not display a clear pattern of expression during the infection process. Overall, the results indicate that more severe CMS disease progression in atrium compared to ventricle could be attributed to higher inflammatory and cytotoxic T cell responses related to higher viral load/replication. Additionally, our findings highlight early primary virus replication and long-term persistence in lymphoid tissues, with no signs of clearance.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"165 ","pages":"Article 110518"},"PeriodicalIF":4.1,"publicationDate":"2025-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144505202","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":"Screening and characterization of host proteins interacting with rhabdovirus glycoprotein","authors":"Weichao Chen,&nbsp;Jialong Yu,&nbsp;Meijia He,&nbsp;Xinbo Hou,&nbsp;Chao Zhao","doi":"10.1016/j.fsi.2025.110517","DOIUrl":"10.1016/j.fsi.2025.110517","url":null,"abstract":"<div><div>Spring viraemia of carp virus (SVCV), a member of the <em>Rhabdoviridae</em> family, is responsible for triggering epidemic diseases in cyprinid fish. Viral envelope glycoprotein plays a crucial role in mediating viral invasion, assembly, and release by interacting with host proteins. Using the yeast membrane two-hybrid screening in zebrafish embryo libraries, several proteins that interact with SVCV glycoprotein were identified. Annotation analysis showed that host proteins were mainly implicated in binding, molecular function regulator, and transcription regulator activity, as well as involvement in translation, folding, and transport. Through one-on-one Y2H verification experiment, 9 positive clones associated with viral infection process were obtained, including CCTα, GFAP, ACTB2, RPL24, and RPS3. Molecular docking analysis indicated that the interaction between G and CCTα occurs primarily through hydrogen bonding and hydrophobic interactions, with binding site located at ARG89∼HIS98 of glycoprotein. Site-directed mutagenesis showed that TYR91, GLN94, and TYR95 were critical binding sites for the interaction between viral G protein and host CCTα protein. Moreover, overexpression of CCTα protein in SVCV-infected ZF4 cells promoted viral G protein gene expression. These results demonstrated that G-CCTα could act as a promising new target for anti-SVCV drug development.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"165 ","pages":"Article 110517"},"PeriodicalIF":4.1,"publicationDate":"2025-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144365782","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 characteristics and functional differentiation of two IL-10 genes in barbel chub Squaliobarbus curriculus","authors":"Hong Yang ,&nbsp;Beibei Qin ,&nbsp;Jiaojiao Fu ,&nbsp;Mengyuan Zhang ,&nbsp;Hongquan Wang ,&nbsp;Tiaoyi Xiao ,&nbsp;Zhao Lv","doi":"10.1016/j.fsi.2025.110514","DOIUrl":"10.1016/j.fsi.2025.110514","url":null,"abstract":"<div><div>Interleukin-10 (IL-10), an anti-inflammatory cytokine, plays crucial roles in balancing excessive inflammation in fish during infectious diseases. In this study, we identified two IL-10 gene copies in barbel chub (<em>Squaliobarbus curriculus</em>), designated as <em>Sc</em>IL-10A and <em>Sc</em>IL-10B. Gene collinearity analysis revealed that <em>Sc</em>IL-10A and <em>Sc</em>IL-10B were located on different chromosomes, and only <em>Sc</em>IL-10A shared a conserved gene block with IL-10s from other vertebrates. Both <em>Sc</em>IL-10A and <em>Sc</em>IL-10B possessed a typical IL-10 protein domain and showed substantial sequence homology with their counterparts in other cyprinid species. Subcellular localization analysis and CHO-S cell expression experiments indicated that <em>Sc</em>IL-10A was secreted, whereas <em>Sc</em>IL-10B was membrane-localized. Tissue-specific expression profiling manifested that <em>Sc</em>IL-10A was predominantly expressed in immune-related tissues, including the spleen, kidney, and head kidney, while <em>Sc</em>IL-10B exhibited ubiquitous expression across all examined tissues. Following LPS challenge, both <em>Sc</em>IL-10A and <em>Sc</em>IL-10B showed the significantly upregulated mRNA expression levels and the similar expression patterns in <em>S</em>. <em>curriculus</em> kidney (<em>Sc</em>K) cells. Transcriptomic data revealed that overexpression of <em>Sc</em>IL-10A and <em>Sc</em>IL-10B induced two distinct lists of differentially expressed genes in <em>Sc</em>K cells. Specifically, <em>Sc</em>IL-10B overexpression significantly downregulated the expression of multiple pro-inflammatory factors, including CXCL8, CXCL11, IL-8, and IL-34, while <em>Sc</em>IL-10A overexpression showed minimal impact on these pro-inflammatory factors expression. In LPS-stimulated <em>Sc</em>K cells, however, Western blot analysis demonstrated that both <em>Sc</em>IL-10A and <em>Sc</em>IL-10B overexpression significantly reduced the protein levels of key pro-inflammatory cytokines TNF-α and IL-1β, suggesting their potential synergistic role in inflammation regulation. This study first discovers the molecular characteristics and functional differentiation of two copied IL-10s in barbel chub, providing a novel insight into the evolutionary biology of IL-10 and the diversity of anti-inflammatory mechanisms in fish.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"165 ","pages":"Article 110514"},"PeriodicalIF":4.1,"publicationDate":"2025-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144481131","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 the efficacy of microencapsulatedscaffold against Edwardsiellatardain oral vaccinated Nile tilapia (Oreochromis niloticus)","authors":"Preetham Elumalai ,&nbsp;K. Nandhakumar ,&nbsp;Sreeja Lakshmi ,&nbsp;Eakapol Wangkahart","doi":"10.1016/j.fsi.2025.110513","DOIUrl":"10.1016/j.fsi.2025.110513","url":null,"abstract":"<div><div>Edwardsiellatarda, a re-emerging pathogen, significantly impacts the productivity of marine and freshwater aquaculture by causing edwardsiellosis. Vaccination is a promising strategy to address this challenge. This study explores an innovative oral vaccination approach using a biomaterial-based scaffold encapsulated with an α-Ketoglutarate (AKG) adjuvant to combat <em>E. tarda</em> in Nile tilapia (<em>Oreochromis niloticus</em>). The scaffold was prepared through ion-gelation using chitosan and alginate, and its structural properties were characterized using Fourier Transform Infrared Spectroscopy (FTIR) and scanning electron microscopy (SEM). The vaccinated group exhibited significantly higher levels of lysozyme, myeloperoxidase, antiprotease, and superoxide dismutase compared to the control group (<em>P</em> &lt; 0.05). Furthermore, increased levels of specific antibody Immunoglobulin M (IgM) were observed, with notable differences between the prime and booster vaccinations. The treatment group fed with the AKG-encapsulated vaccine demonstrated high survival rates. Histological analyses of the spleen, kidney, brain, and gut at 45 days post-vaccination (dpv) confirmed the vaccine's efficacy. These findings highlight the potential of this scaffold-based oral vaccine delivery system as a novel and effective approach for aquaculture. This strategy could also be adapted for the delivery of other vaccines and therapeutics in aquatic species.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"165 ","pages":"Article 110513"},"PeriodicalIF":4.1,"publicationDate":"2025-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144470915","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}