Fish & shellfish immunology最新文献

{"title":"In-vivo evaluation of silver nanoparticles-enhanced Chlorella protein nanovaccine for immunological defense in grouper (Epinephelus sp) against RNA viral infections","authors":"Defa Rizqi Machfuda ,&nbsp;Uun Yanuhar ,&nbsp;Asus Maizar Suryanto Hertika ,&nbsp;Ranjith Kumar Rajamani ,&nbsp;Heru Suryanto ,&nbsp;Nezya Pramudya Wardani ,&nbsp;Andik Isdianto ,&nbsp;Aisha Surya Ananda","doi":"10.1016/j.fsi.2026.111191","DOIUrl":"10.1016/j.fsi.2026.111191","url":null,"abstract":"<div><div>Viral RNA diseases, notably Viral Nervous Necrosis (VNN), routinely produce very high losses (≈80–100% mortality) in cultured groupers (<em>Epinephelus sp.),</em> driving major economic impacts across Asia. Conventional vaccination has been unreliable, largely because of antigen instability and suboptimal, short-lived immunity. Nanovaccine platforms-here, <em>Chlorella</em>-derived proteins augmented with silver nanoparticles (AgNPs)-offer a route to better antigen delivery and immune modulation in aquatic hosts. This study evaluated the efficacy of an AgNPs- <em>Chlorella vulgaris</em> protein nanovaccine in VNN-challenged groupers to enhance growth, hematology, survival, and tissue integrity. Eight cohorts were examined: two controls (K−, K+) and six dosing regimens (T1–T6). Fish received the nanovaccine by injection, followed by viral challenge. Key endpoints included hematological indices (RBC, WBC, hemoglobin, hematocrit, mean corpuscular hemoglobin (MCH), mean corpuscular volume (MCV), mean corpuscular hemoglobin concentration (MCHC)), histopathology of intestine and kidney, and flow-cytometric profiling of CD4, CD8, IgM, growth (length, weight), survival rate (SR), and relative percent survival (RPS). Nanovaccination significantly enhanced performance and immunity. The T3 dose yielded the best outcomes, with body length 12.73 ± 0.87 cm and weight 18.00 ± 1.50 g, SR = 90% and RPS = 82%. Hematology improved (RBC 2.52 × 10⁶ cells/μL, WBC 1.76 × 10³ cells/μL, hemoglobin 7.4 g/dL, MCV 102 μm³, MCHC 26.4%). Immune readouts showed CD4⁺ 13.44%, CD8⁺ 8.48%, and IgM 4.25%. Fish tissue showed milder lesions (≤25% damage) compared to those infected with severe injury virus (&gt;45%). The Nanovaccine supports its potential as environmentally friendly and long-lasting means of protecting marine aquaculture from disease. This work supports the objectives of SDG 14, emphasizing the conservation of life below water.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"171 ","pages":"Article 111191"},"PeriodicalIF":3.9,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146131569","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":"Antimicrobial peptide mSshep 1 from Sebastes schlegelii combines broad-spectrum antibacterial activity, membrane-disruptive mechanism and in vivo protective efficacy","authors":"Hao Jing ,&nbsp;Guang-hua Wang ,&nbsp;Kai Yang ,&nbsp;Zi-yue Chen ,&nbsp;Zhi-shu Zhu ,&nbsp;Nuo Sun ,&nbsp;Yi-lin Du ,&nbsp;Zi-qi Wang ,&nbsp;Min Zhang","doi":"10.1016/j.fsi.2026.111192","DOIUrl":"10.1016/j.fsi.2026.111192","url":null,"abstract":"<div><div>Hepcidins, a family of cysteine-rich antimicrobial peptides, play a pivotal role in the innate immune defense of teleosts. This study aimed to characterize the antibacterial activity, mechanism of action, and <em>in vitro</em>/<em>in vivo</em> protective efficacy of the mature peptide mSshep 1 derived from hepcidin 1 of <em>Sebastes schlegelii</em> (<em>Sshepcidin 1</em>), and to verify the functional role of <em>Sshepcidin 1</em> via RNA interference (RNAi). Time-kill kinetic assay showed that mSshep 1 exhibited rapid and broad-spectrum bactericidal activity against <em>Staphylococcus aureus</em>, <em>Edwardsiella piscicida</em>, <em>Listonella anguillarum</em>, and <em>Aeromonas hydrophila</em>, with complete eradication of all tested strains within 120 min. Thermal stability analysis revealed that mSshep 1 retained significant antibacterial activity against most pathogens even after treatment at 100 °C for 30 min, and circular dichroism spectroscopy confirmed only minor conformational changes without substantial secondary structure alterations. Mechanistically, mSshep 1 exerted bactericidal effects by disrupting bacterial membrane integrity, as evidenced by increased propidium iodide penetration, elevated intracellular reactive oxygen species levels, and obvious morphological damage observed via scanning and transmission electron microscopy. <em>In vitro</em>, mSshep 1 showed no cytotoxicity to HEK293T, EPC, and SSI cells at concentrations up to 128 μM, and effectively eliminated intracellular <em>E. piscicida</em> in SSI cells while upregulating the expression of immune-related genes. <em>In vivo</em> experiments demonstrated that pre-injection of mSshep 1 (1, 2, 5 μg/g body weight) significantly improved the survival rate of <em>S. schlegelii</em> challenged with <em>E. piscicida</em> and reduced bacterial loads in the liver, spleen, and head kidney. RNAi analysis showed that si-Sshep1-1 (2 μg/g body weight) stably silenced <em>Sshepcidin 1</em> expression in multiple tissues, and <em>Sshepcidin 1</em> knockdown significantly increased bacterial loads in <em>E. piscicida</em>-challenged fish and disrupted the expression balance of immune-related genes. Collectively, these findings confirm that mSshep 1 is a promising candidate for the development of novel antibacterial agents in aquaculture, and <em>Sshepcidin 1</em> plays a crucial role in the innate immune defense of <em>S. schlegelii</em> against bacterial infections.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"171 ","pages":"Article 111192"},"PeriodicalIF":3.9,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146131462","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":"Novel stomach-predominant C-type lectin (LvnCTL) triggers immune response against Vibrio parahaemolyticus and WSSV in shrimp Litopenaeus vannamei","authors":"Shengwen Niu ,&nbsp;Ning Fu ,&nbsp;Yuyu Wang ,&nbsp;Mengxin Xing ,&nbsp;Meiling An ,&nbsp;Hongli Xu ,&nbsp;Bang Xiao ,&nbsp;Weiyan Song ,&nbsp;Yongqing Zeng ,&nbsp;Orlando Borras-Hidalgo ,&nbsp;Hui Wang","doi":"10.1016/j.fsi.2026.111158","DOIUrl":"10.1016/j.fsi.2026.111158","url":null,"abstract":"<div><div>C-type lectins (CTLs) are members of pattern recognition receptors (PRRs), which can bind to carbohydrates on the surface of pathogens and take part in the immune response of shrimp. In this study, we identified and characterized a novel stomach-predominant C-type lectin (named LvnCTL) in <em>Litopenaeus vannamei</em> (<em>L. vannamei</em>). LvnCTL consists of a signal peptide at the N-terminal and a typical C-type lectin-like domain (CTLD) at the C-terminal. Phylogenetic analysis revealed that LvnCTL clusters into a distinct clade more closely related to vertebrate CTLs than to invertebrate CTLs. LvnCTL was highly expressed in the stomach, and its expression was significantly induced by immune stimuli and pathogen infections. Functional assays showed that silencing of LvnCTL enhanced the replication of <em>Vibrio parahaemolyticus</em> and white spot syndrome virus (WSSV), thereby increasing shrimp susceptibility. In contrast, recombinant LvnCTL effectively agglutinated both the Gram-negative bacterium <em>V. parahaemolyticus</em> and the Gram-positive bacterium <em>Staphylococcus aureus</em> in a Ca²⁺-dependent manner. Furthermore, LvnCTL silencing markedly altered the expression of immune-related genes, including antimicrobial peptides, cytokines, and prophenoloxidase (proPO) genes. Taken together, these findings suggest that LvnCTL plays a crucial role in the shrimp immune response to inhibit pathogen invasion.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"171 ","pages":"Article 111158"},"PeriodicalIF":3.9,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146096966","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":"Medium-chain fatty acids as feed supplements on immune enhancement in sustainable aquaculture","authors":"Seyed Hossein Hoseinifar ,&nbsp;Majid Khanzadeh ,&nbsp;Zahra Nemati ,&nbsp;Marina Paolucci ,&nbsp;Hien Van Doan","doi":"10.1016/j.fsi.2026.111161","DOIUrl":"10.1016/j.fsi.2026.111161","url":null,"abstract":"<div><div>In terms of chemical structure, medium-chain fatty acids (MCFAs) have carbon chain lengths of 6–12 atoms. These fatty acids can be found in high amounts in natural sources such as coconut oil, palm kernel oil, and dairy products. Regarding the types of medium-chain fatty acids that received more attention, caproic acid (C6), caprylic acid (C8), capric acid (C10), and lauric acid (C12) can be mentioned. The metabolism of these acids in the bodies of aquatic animals is fast, and they have rapid absorption in the intestine. They reach the liver directly via the mesenteric vessels and the portal vein. In the liver, digestion processes like energy production occur. Studies conducted on aquatic animals showed beneficial effects of these fatty acids on growth performance, feed efficiency, and modulation of gut microbiota composition. Also, results confirm the beneficial effects of these functional feed additives on the antioxidant defence system and immune response in different aquatic species. The present review paper deals with the application and effects of MCFAs and their salts in aquaculture. The focus of this review was on their effects on growth performance, immunobiochemical responses, immune gene expression, and activities of antioxidant and digestive enzymes. Possible mechanisms of action of these fatty acids on the mentioned parameters and their effects on the improvement of resistance against pathogens were reviewed in detail. The aim of this paper is to show the potential of MCFAs for the health and production of aquatic species. In addition to the above cases, research gaps and the areas that need further studies are described in this review.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"171 ","pages":"Article 111161"},"PeriodicalIF":3.9,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146085038","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":"Single-cell RNA-seq reveals cellular dynamics and emergency hematopoiesis in banana shrimp Penaeus merguiensis hemocytes upon Yellow Head Virus infection","authors":"Keiichiro Koiwai ,&nbsp;Phattarunda Jaree ,&nbsp;Kanjanaporn Nanthajak ,&nbsp;Masachika Harada ,&nbsp;Hiroki Kusaka ,&nbsp;Ammara Sinprasertporn ,&nbsp;Hajime Yuasa ,&nbsp;Kayo Konishi ,&nbsp;Reiko Nozaki ,&nbsp;Hidehiro Kondo ,&nbsp;Jumroensri Thawonsuwan ,&nbsp;Kunlaya Somboonwiwat ,&nbsp;Ikuo Hirono","doi":"10.1016/j.fsi.2026.111178","DOIUrl":"10.1016/j.fsi.2026.111178","url":null,"abstract":"<div><div>As global aquaculture of penaeid shrimp expands, the banana shrimp (<em>Penaeus merguiensis</em>) has gained attention as a promising sustainable alternative to the non-native <em>P. vannamei</em>. However, its cellular immune response to major pathogens like yellow head virus (YHV) remains poorly understood, limiting effective disease management. In this study, we established a comprehensive reference transcriptome for <em>P. merguiensis</em> by integrating data from 13 major tissues and conducted single-cell RNA sequencing (scRNA-seq) on hemocytes under normal and YHV-infected conditions. We identified eight distinct hemocyte clusters (cluster 0–7) and demonstrated that YHV infection triggers a massive turnover of the hemocyte landscape. Specifically, mature immune-active clusters expressing <em>anti-lipopolysaccharide factor</em>s (<em>ALF</em>s) and <em>lysozyme</em>s were significantly depleted, likely due to virus-induced apoptosis. Conversely, a marked expansion of an immature hemocyte progenitor cluster (cluster 4) was observed, indicating a host-driven emergency hematopoiesis response. Our analysis further revealed that global transcriptional changes are heavily biased by these composition shifts: 30.7% of the total 114 globally regulated genes were identified as cluster-specific markers. These findings provide a high-resolution model of crustacean immune dynamics and highlight the necessity of single-cell analysis for accurately deciphering host-pathogen interactions.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"171 ","pages":"Article 111178"},"PeriodicalIF":3.9,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146118298","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":"IL-7 enhances the protective efficacy of inactivated grass carp reovirus vaccine as adjuvant in grass carp (Ctenopharyngodon idella)","authors":"Shijie Wang ,&nbsp;Yizhong Lu ,&nbsp;Yuezong Xu ,&nbsp;Guanyu Chen ,&nbsp;Jingjing Zhang ,&nbsp;Jianguo Su ,&nbsp;Chunrong Yang","doi":"10.1016/j.fsi.2026.111183","DOIUrl":"10.1016/j.fsi.2026.111183","url":null,"abstract":"<div><div>Grass carp reovirus (GCRV) causes severe hemorrhagic disease and significant threat to grass carp (<em>Ctenopharyngodon idella</em>) aquaculture. Although inactivated vaccines are commonly used, their limited protective efficacy necessitates effective adjuvants. In this study, recombinant grass carp interleukin-7 (rIL-7) and its enterokinase-cleaved form (EK rIL-7), obtained by removing the fusion tag using enterokinase, were successfully expressed, purified, and evaluated as adjuvants for an inactivated GCRV vaccine. Following GCRV challenge, both rIL-7 adjuvanted and EK rIL-7 adjuvanted vaccines significantly increased the survival of grass carp and effectively suppressed viral replication in the head kidney and spleen. Histopathological examination further confirmed that fish in the IL-7 adjuvant exhibited significantly reduced tissue damage compared to other treatments. Additionally, IL-7 enhanced both innate and adaptive immune responses in grass carp. The activities of serum enzymes (SOD, LDH and LZM) in the groups receiving IL-7 in combination with the vaccine increased significantly, reflecting the enhancement of antioxidant capacity and non-specific immune defense ability. In parallel, IL-7 treatment promoted IgM synthesis at both the transcriptional and serum antibody levels and increased the expression of immune-related genes such as CD4(-1, −2), MHCII (α, β), IFN-γ2, and IL-1β, indicating the activation of both humoral and cellular immune pathways. However, the difference between EK rIl-7 and rIl-7 is not significant. Collectively, these findings demonstrate that IL-7 acts as a potent adjuvant to enhance the protective efficacy of inactivated GCRV vaccines, and provide valuable insights for exploring other cytokines as immune adjuvants in the prevention of viral diseases in aquaculture.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"171 ","pages":"Article 111183"},"PeriodicalIF":3.9,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146124174","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 comparative study on hemolymph sampling methods: Monthly variations in hemocyte characteristics of farmed oyster Crassostrea corteziensis (Bivalvia: ostreidae)","authors":"Miguel Ángel Hurtado–Oliva ,&nbsp;Elena Palacios–Mechetnov","doi":"10.1016/j.fsi.2026.111153","DOIUrl":"10.1016/j.fsi.2026.111153","url":null,"abstract":"<div><div>Immune bivalve mollusk response is closely related to environmental conditions (i.e. seawater temperature and salinity, availability and food quality); including routine handling that occurs during sea farming, such as manipulation for size sorting and cleaning epibionts from shells. Storage (hypoxia, dry conditions, etc.), transportation, and acclimatization to laboratory conditions of wild or reared organisms are also known to exert significant changes in bivalve mollusk immune cell responses. Therefore, the aim of the present study is to assess the effect of hemolymph withdrawal handled in two different conditions (field vs. laboratory) in monthly variations of both morphological and functional hemocyte characteristics in oyster <em>C. corteziensis</em>. Hemolymph samples were extracted from oysters immediately sampled at the farming site (field), and from oysters stored in dry-cold conditions and terrestrially transported during 2 h to the laboratory facilities. Total (THC) and differential (DHC) hemocyte counts, hemocyte mortality (HM), and anion superoxide production (ASO/hemocyte) were assessed in hemolymph samples obtained from oysters in both handled conditions (field vs. laboratory). Sea surface temperature (SST), salinity, pH, seston (total, inorganic, and organic particulate matter), and chlorophyll-a (Chl-a) were monthly assessed in seawater samples. THC, DHC, HM, and ASO/hemocyte production were not different between hemolymph samples withdrawal from oysters handled in both conditions. All immune parameters assessed were significantly different between sampling dates, but most were not significantly correlated with physicochemical seawater parameters assessed, except THC and hyalinocyte count (HC), which were positively correlated with phytoplankton availability (i.e. Chl-a) that increased during winter, and granulocytes that increased with SST rise but negatively correlated with OCI, along with seston availability. HM decreased with THC and HC increase, suggesting a link with hemocyte proliferation but without compromising immune response. Hemocyte oxidative capacity (i.e. ASO/hemocyte) increased significantly with oyster condition, which coincided with the increase of phytoplankton availability (i.e. Chl-a). Although increasing energy allocation improves oyster physiological condition –including immune response– circulating hemocyte increased and their respective oxidative capacity were more likely to be due to a response to availability and consumption on certain toxin-producing phytoplankton species (dinoflagellates). Hemolymph withdrawal from oysters directly in field could be advantageous, mainly when no other tissues than immune cells and plasma are required to be analyzed, avoiding whole oyster transportation.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"171 ","pages":"Article 111153"},"PeriodicalIF":3.9,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146092607","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":"Impacts of encapsulated azadirachtin (Azadirachta indica) in the diet of Nile tilapia (Oreochromis niloticus)","authors":"Matheus Berlofa Ferreira ,&nbsp;Gabriel Antonio Cuzma Costa ,&nbsp;Paola Capistrano dos Santos ,&nbsp;Domickson Silva Costa ,&nbsp;Vanessa Perenguez Riofrio ,&nbsp;Camila Lisarb Velasquez Bastolla ,&nbsp;Miguel Saldaña-Serrano ,&nbsp;Marília Tedesco ,&nbsp;Gracienhe Gomes dos Santos ,&nbsp;Maria Clara Miguel Libanori ,&nbsp;Caio Francisco Santana Farias ,&nbsp;Bruno Corrêa da Silva ,&nbsp;Alexsandra Valério ,&nbsp;Afonso Celso Dias Bainy ,&nbsp;Mauricio Laterça Martins ,&nbsp;Marco Shizuo Owatari ,&nbsp;José Luiz Pedreira Mouriño","doi":"10.1016/j.fsi.2026.111156","DOIUrl":"10.1016/j.fsi.2026.111156","url":null,"abstract":"<div><div>Various plant-based products are currently undergoing testing in aquaculture as growth and/or health enhancers for fish, serving as substitutes for chemicals and antibiotics that may be detrimental to animal and consumer well-being. Azadirachtin is a bioactive compound extracted from the <em>Azadirachta indica</em> plant, with great microbicidal and immunostimulant potential. The aim of this study was to evaluate the effects of dietary azadirachtin supplementation on the zootechnical performance and health of juvenile Nile tilapia (<em>Oreochromis niloticus</em>) reared in a recirculating aquaculture system. Juvenile tilapia (<em>n</em> = 400; mean weight 13.03 ± 0.77 g) were randomly distributed into 20 experimental units (EUs) divided into five groups with four replicates each. Over a 45-day period, four groups were given diets containing azadirachtin at concentrations of 20, 70, 120, and 170 mg kg⁻¹, while a control (0 mg kg⁻¹) group was fed a diet without the compound. At the end of this period, assessments were conducted on growth performance, haematoimmunological parameters, histological conditions of the liver, spleen, kidney, and intestine, as well as analyses of intestinal microbiota, hepatic antioxidant enzymatic activity, and malondialdehyde content. No significant differences were found in growth performance, whereas the inclusion of 170 mg kg⁻¹ of azadirachtin resulted in higher antimicrobial activity of fish blood plasma against <em>Aeromonas hydrophila</em> and lower intestinal <em>Streptococcus</em> spp. counts compared to non-supplemented fish. The mean corpuscular haemoglobin concentration was significantly lower in fish from the 170 mg kg⁻¹ treatment group than in the control group. Conversely, dietary inclusion of azadirachtin adversely affected the structure and overall health of organs, especially the kidney and liver. Malondialdehyde content in the hepatic tissue of Nile tilapia was significantly higher in fish from the 120 mg kg⁻¹ treatment than in the 20 mg kg⁻¹ treatment and the control group. Fish from the 120 and 170 mg kg⁻¹ treatments showed a significant increase in superoxide dismutase activity compared to the control group. Although some beneficial effects on immunity have been observed, such as increased agglutination titre and enhanced antimicrobial activity of fish blood plasma against <em>A. hydrophila</em>, as well as reduced levels of <em>Streptococcus</em> spp. in the intestine, caution is advised when incorporating azadirachtin into the diet of juvenile <em>O. niloticus</em> as it may have the potential to compromise the integrity of tissues in vital organs.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"171 ","pages":"Article 111156"},"PeriodicalIF":3.9,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146057336","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 CC motif chemokine 20-like genes differentially regulate leukocyte migration and survival via CC chemokine receptor 6 in ayu (Plecoglossus altivelis)","authors":"Jia-Feng Cao ,&nbsp;Yan Zhou ,&nbsp;Li-Jun Duan ,&nbsp;Shi-Li Shang ,&nbsp;Qian-Jin Zhou ,&nbsp;Jiong Chen","doi":"10.1016/j.fsi.2026.111176","DOIUrl":"10.1016/j.fsi.2026.111176","url":null,"abstract":"<div><div>Chemokine ligand 20 (CCL20) is a key mediator of inflammatory and homeostatic responses in mammal, acting through its receptor CC chemokine receptor 6 (CCR6). However, its functional roles in teleost fish remain poorly defined. In this study, we identified two <em>CCL20</em>-like genes (<em>PaCCL20l1</em> and <em>PaCCL20l2</em>) from ayu (<em>Plecoglossus altivelis</em>). Phylogenetic analysis confirmed their classification within the CCL20 subgroup. Tissue distribution analysis revealed ubiquitous expression of both genes, which were significantly upregulated in multiple tissues (liver, spleen, head kidney, gill, skin, and intestine) following infection with <em>Vibrio anguillarum</em>, albeit with distinct expression profiles. We produced the recombinant mature peptide of PaCCL20ls (rPaCCL20l1 and rPaCCL20l2) and generated specific antibodies. Functional assays demonstrated that both rPaCCL20l1 and rPaCCL20l2 exhibit chemotactic, and anti-apoptosis activities, but with differing cell specificities. rPaCCL20l1 attracted lymphocytes and neutrophils and inhibited lymphocyte apoptosis. In contrast, rPaCCL20l2 attracted monocytes/macrophages (MO/MΦ), lymphocytes, and neutrophils, and suppressed apoptosis in both MO/MΦ and lymphocytes. Crucially, neutralizing PaCCR6 completely abolished all effects of both rPaCCL20l1 and rPaCCL20l2. In conclusion, our findings demonstrate that <em>PaCCL20l1</em> and <em>PaCCL20l2</em> play pivotal but distinct roles in ayu immunity by modulating leukocyte recruitment and survival via PaCCR6 pathway.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"171 ","pages":"Article 111176"},"PeriodicalIF":3.9,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146104451","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":"CiLSM14Aa acts as a cytosolic dsRNA sensor to activate antiviral immunity against GCRV-II","authors":"Hui Jiang ,&nbsp;Chu Zhang ,&nbsp;Pengfei Li ,&nbsp;Yong-An Zhang ,&nbsp;Xiangmou Qin","doi":"10.1016/j.fsi.2026.111162","DOIUrl":"10.1016/j.fsi.2026.111162","url":null,"abstract":"<div><div>The innate immune system relies on pattern recognition receptors (PRRs) to detect viral pathogens and initiate antiviral responses. LSM14A, a conserved RNA-binding protein involved in mRNA metabolism, has recently emerged as a cytosolic nucleic acid sensor in vertebrates. However, its role in teleost immunity remains unclear. In this study, two LSM14A paralogs were identified in grass carp (<em>Ctenopharyngodon idella</em>), designated CiLSM14Aa and CiLSM14Ab, and their functions during infection with grass carp reovirus genotype II (GCRV-II) were investigated. Both CiLSM14Aa and CiLSM14Ab were significantly upregulated following GCRV-II infection or poly(I:C) stimulation. Overexpression of CiLSM14Aa or CiLSM14Ab inhibited GCRV-II replication and enhanced the expression of type I interferon and interferon-stimulated genes (ISGs). Further analysis revealed that CiLSM14Aa and CiLSM14Ab can form homodimers and heterodimers. Notably, only CiLSM14Aa demonstrated direct binding to double-stranded RNA (dsRNA), suggesting a specific role as a cytosolic dsRNA sensor. These results demonstrate the essential antiviral roles of CiLSM14A paralogs and reveal their contributions to the initiation of innate immune defenses against GCRV-II infection.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"171 ","pages":"Article 111162"},"PeriodicalIF":3.9,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146085048","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}