Fish & shellfish immunology最新文献_第6页

Butyrate-induced trained immunity enhances bacterial killing ability of head kidney macrophages in turbot (Scophthalmus maximus L.) 丁酸盐诱导的训练免疫增强了大菱鲆（Scophthalmus maximus L.）头肾巨噬细胞杀灭细菌的能力。

IF 3.9 2区农林科学 Q1 FISHERIES

Fish & shellfish immunology

Pub Date : 2026-01-27 DOI: 10.1016/j.fsi.2026.111165

Shu Zhao , Jinjin Zhang , Wentao Wang , Shufei Liang , Mengqi Chen , Rui Shao , Xinmeng Liao , Qinghui Ai , Kangsen Mai , Min Wan

Trained immunity represents an evolutionarily conserved form of innate immune memory established through epigenetic and metabolic reprogramming. This study has demonstrated for the first time that butyrate, a key gut microbiota-derived metabolite, induces trained immunity in teleost macrophages. Our results revealed that priming head kidney macrophages (HKMs) from turbot (Scophthalmus maximus L.) with 1 μM of sodium butyrate (NaB) for 24 h followed by a 5-day training period, established a durable memory phenotype of HKMs. Importantly, the bactericidal capacity against Edwardsiella tarda (E. tarda) infection was significantly enhanced in butyrate-trained HKMs, accompanied by the elevated pro-inflammatory response with significantly elevated expression of il-1β and tnf-α. Mechanistically, butyrate training activated the HIF-1α signaling pathway, modulated a late-phase metabolic shift towards anaerobic glycolysis and TCA cycle, evidenced by altered citrate metabolism and glutamine pathway activation. Furthermore, the gene expression of acly, acss1 and acss2 was increased, while the expression of acc1 was suppressed, leading to the increased acetyl-CoA pools. On the other hand, butyrate induced persistent epigenetic remodeling, evidenced by increased expression of histone acetyltransferase CBP/P300, HDAC3 suppression, and a robust accumulation of H3K27 acetylation. Remarkably, in vivo pretreatment with butyrate at a low dose conferred a 20 % survival advantage against a lethal E. tarda challenge in juvenile turbot after 14 days post-exposure to butyrate compared to that in control group. These findings have established that butyrate drives innate immune memory in fish, offering novel insights and a promising candidate for prophylactic strategies against pathogenic infection in aquaculture.

训练免疫代表了一种通过表观遗传和代谢重编程建立的先天免疫记忆的进化保守形式。这项研究首次证明，丁酸盐是一种关键的肠道微生物衍生代谢物，可诱导硬骨巨噬细胞的训练免疫。结果表明，1 μM丁酸钠（NaB）刺激大菱鲆（schophthalmus maximus L.）头肾巨噬细胞（HKMs） 24小时，然后进行5天的训练，建立了HKMs的持久记忆表型。重要的是，在丁酸盐训练的HKMs中，对迟缓爱德华氏菌（e.t tarda）感染的杀菌能力显著增强，同时伴随着il - 1β和tnfα表达显著升高的促炎反应。从机制上讲，丁酸盐训练激活了HIF-1α信号通路，调节了向厌氧糖酵解和TCA循环的晚期代谢转变，这可以通过改变柠檬酸盐代谢和谷氨酰胺途径激活来证明。acly、acss1和acss2基因表达增加，而acc1基因表达被抑制，导致乙酰辅酶a库增加。另一方面，丁酸盐诱导了持续的表观遗传重塑，表现为组蛋白乙酰转移酶CBP/P300的表达增加、HDAC3的抑制和H3K27乙酰化的大量积累。值得注意的是，与对照组相比，暴露于丁酸盐14天后，低剂量丁酸盐在体内预处理可使大比目鱼幼鱼在对抗致命的迟来大肠杆菌攻击后的生存优势提高20%。这些发现证实了丁酸盐驱动鱼类的先天免疫记忆，为水产养殖中预防致病性感染的策略提供了新的见解和有希望的候选策略。

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引用次数: 0

Robigenin in combating largemouth bass ranavirus: Investigating the antiviral potency and underlying mechanisms 罗比吉宁对抗大口黑鲈病毒：抗病毒效力和潜在机制的研究。

IF 3.9 2区农林科学 Q1 FISHERIES

Fish & shellfish immunology

Pub Date : 2026-01-27 DOI: 10.1016/j.fsi.2026.111163

Wenyu Liao , Lin Huang , Jieying Yu , Mingzhu Liu , Nijia Xue , Junxiang Lai , Ermeng Yu , Fei Ling , Shuyu Han , Ying Pan , Pengfei Li , Qing Yu

The largemouth bass ranavirus (LMBV) represents a significant pathogen causing severe damage to the aquaculture industry, for which specific prevention and control measures are currently lacking. This study systematically evaluated the anti-LMBV activity of the natural flavonol compound robigenin and elucidated its underlying molecular mechanisms through both in vitro cell experiments and in vivo infection models. The results demonstrated that robigenin at concentrations ≤6.25 μg/mL exhibited no significant cytotoxicity to the fathead minnow cells (FHM). Within this concentration range, its anti-LMBV efficacy increased in a dose-dependent manner. Robigenin was found to inhibit LMBV infection by blocking viral entry and replication phases without interfering with virus-receptor binding. Additionally, the results revealed that robigenin upregulated the expression of interferon-related genes, including IRF3, IRF7, IFN, ISG15, and MAVS, thereby enhancing cellular immune responses. In vivo experiments further confirmed that robigenin significantly alleviated LMBV-induced symptoms in juvenile Micropterus salmoides and markedly improved survival rates. In conclusion, this study provides the first evidence that robigenin effectively suppresses LMBV infection, offering both a promising candidate compound and theoretical foundation for the eco-friendly control of aquatic viral diseases.

大口黑鲈ranv （LMBV）是一种对水产养殖业造成严重危害的重要病原体，目前缺乏具体的防治措施。本研究通过体外细胞实验和体内感染模型，系统评价了天然黄酮醇类化合物罗比黄酮素的抗lmbv活性，并阐明了其潜在的分子机制。结果表明，罗比吉宁在浓度≤6.25 μg/mL时对鱼头鱼细胞无明显的细胞毒性。在此浓度范围内，其抗lmbv效果呈剂量依赖性增加。发现罗比吉宁通过阻断病毒进入和复制阶段而不干扰病毒受体结合来抑制LMBV感染。此外，研究结果显示，robigenin上调干扰素相关基因的表达，包括IRF3、IRF7、IFN、ISG15和MAVS，从而增强细胞免疫应答。体内实验进一步证实，罗比吉宁可显著缓解lmbv诱导的小鱼幼鱼症状，显著提高存活率。综上所述，本研究首次证实罗比吉宁能有效抑制LMBV感染，为水生病毒性疾病的生态控制提供了有前景的候选化合物和理论基础。

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引用次数: 0

Vertical transmission of Edwardsiella ictaluri in laboratory zebrafish revealed by highly-sensitive single molecule RNA in situ hybridization 高敏感单分子RNA原位杂交技术揭示了爱德华氏菌在实验室斑马鱼中的垂直传播

IF 3.9 2区农林科学 Q1 FISHERIES

Fish & shellfish immunology

Pub Date : 2026-01-26 DOI: 10.1016/j.fsi.2026.111159

Chaofan Wang , Liyue Liu , Houpeng Wang , Jiangyue Lei , Jiang Zeng , Yonghua Sun , Ding Ye

Edwardsiella ictaluri (E. ictaluri) is a significant bacterial pathogen responsible for severe losses in freshwater aquaculture and poses emerging concerns for laboratory zebrafish (Danio rerio) colonies. Although previous studies have suggested the potential for intergenerational or vertical transmission of E. ictaluri, direct experimental evidence supporting this hypothesis has remained lacking. In this study, we developed a hybridization chain reaction–enhanced single-molecule fluorescence in situ hybridization (HCR-smFISH) assay that enables highly sensitive, single-cell– and single-molecule–level detection of E. ictaluri within host tissues. Using an established zebrafish infection model, we characterized the tissue tropism and spatial distribution of the pathogen in key immune and metabolic organs, including the spleen, gills, and liver. Notably, whole-embryo imaging provided direct evidence of maternally mediated transmission, demonstrating that bacterial signal adhere to the chorion surface of eggs. Subsequent disinfection trials demonstrated that NaClO surface sterilization effectively eliminated egg-associated bacteria and alleviated infection-induced inflammatory responses in the progeny. Collectively, these findings fill a critical knowledge gap regarding the vertical transmission of E. ictaluri and offer practical guidance for disease prevention, broodstock management, and the establishment of specific pathogen-free zebrafish lines in research and aquaculture settings.

伊塔卢氏爱德华氏菌（Edwardsiella ictaluri）是一种重要的细菌性病原体，可导致淡水水产养殖业的严重损失，并引起实验室斑马鱼（Danio rerio）菌落的新关注。虽然以前的研究表明伊氏伊氏杆菌可能存在代际或垂直传播，但仍然缺乏支持这一假设的直接实验证据。在这项研究中，我们开发了一种杂交链反应增强的单分子荧光原位杂交（HCR-smFISH）检测方法，该方法可以在宿主组织中高度敏感地检测到E. ictaluri。利用建立的斑马鱼感染模型，我们表征了病原体在脾脏、鳃和肝脏等关键免疫和代谢器官中的组织趋向性和空间分布。值得注意的是，全胚胎成像提供了母体介导传播的直接证据，表明细菌信号粘附在卵子的绒毛膜表面。随后的消毒试验表明，NaClO表面灭菌有效地消除了鸡蛋相关细菌，减轻了后代感染引起的炎症反应。总的来说,这些发现填补关键知识缺口的垂直传播大肠ictaluri和疾病预防提供实践指导,斑马鱼养殖管理和建立特定的无菌线的研究和水产养殖的设置。

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引用次数: 0

The RNA sensor MDA5 contributes to the antiviral immune response in Crassostrea gigas by modulating the MAVS-mediated signaling pathway RNA传感器MDA5通过调节mavs介导的信号通路参与长牡蛎的抗病毒免疫应答。

IF 3.9 2区农林科学 Q1 FISHERIES

Fish & shellfish immunology

Pub Date : 2026-01-26 DOI: 10.1016/j.fsi.2026.111160

Yingmei Xu , Yuhao Jin , Mengjia Chen , Yuqing Zeng , Yiqing Wang , Xiaoyu Gu , Xue Qiao , Lingling Wang , Linsheng Song

Melanoma differentiation–associated gene 5 (MDA5) is a key member of the RIG-I-like receptor (RLR) family that detects viral RNA in the cytoplasm and triggers antiviral innate immunity mainly via the MAVS-dependent signaling cascade. In the present study, a MDA5-like homologue (CgMDA5) containing two N-terminal CARD domains, a central DExD/H-box helicase domain and a C-terminal domain (CTD) was identified from Pacific oyster (Crassostrea gigas). CgMDA5 mRNA transcripts were detected in all examined oyster tissues, with the highest level in haemocytes. The mRNA expression of CgMDA5 in haemocytes was significantly upregulated by poly (I:C) and 5′-ppp dsRNA stimulation. CgMDA5 protein exhibited strong in vitro binding activity toward poly (I:C) and dsRNA of 100 bp and 1000 bp in length, with a marked preference for longer dsRNA. The interaction of CgMDA5 and CgMAVS was detected and affirmed by Co-IP after transfection into HEK293T cells. In CgMDA5-RNAi oyster, the mRNA expression level of CgMAVS was down-regulated post poly (I:C) stimulation. Moreover, both RNAi of CgMDA5 and CgMAVS down-regulated the mRNA expression of CgIRF1, CgIRF8 and CgIFNLP. These findings collectively suggest that CgMDA5 is capable of interacting with CgMAVS, thereby activating the CgIRF-CgIFNLP signaling pathway to mediate antiviral immune responses in oyster.

黑色素瘤分化相关基因5 （MDA5）是rig - i样受体（RLR）家族的关键成员，主要通过mavs依赖性信号级联检测细胞质中的病毒RNA并触发抗病毒先天免疫。本研究从太平洋牡蛎（Crassostrea gigas）中鉴定出一个mda5样同源物（CgMDA5），该同源物包含两个n端CARD结构域、一个中央DExD/H-box解旋酶结构域和一个c端结构域（CTD）。在所有牡蛎组织中均检测到CgMDA5 mRNA转录本，其中血细胞中表达量最高。poly （I:C）和5'-ppp dsRNA刺激后，血细胞中CgMDA5 mRNA表达显著上调。CgMDA5蛋白对长度为100 bp和1000 bp的poly （I:C）和dsRNA具有较强的体外结合活性，对长度较长的dsRNA具有明显的亲和性。转染HEK293T细胞后，通过Co-IP检测CgMDA5与CgMAVS的相互作用，并进行了确认。在CgMDA5-RNAi牡蛎中，poly （I:C）刺激后CgMAVS mRNA表达水平下调。此外，CgMDA5和CgMAVS的RNAi均下调CgIRF1、CgIRF8和CgIFNLP的mRNA表达。这些结果共同表明，CgMDA5能够与CgMAVS相互作用，从而激活CgIRF-CgIFNLP信号通路，介导牡蛎的抗病毒免疫反应。

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引用次数: 0

Two interleukin-1β types reinforce innate immune response modulation in Japanese medaka, Oryzias latipes 两种类型的白细胞介素1β增强了日本稻科植物的先天免疫反应调节

IF 3.9 2区农林科学 Q1 FISHERIES

Fish & shellfish immunology

Pub Date : 2026-01-26 DOI: 10.1016/j.fsi.2026.111157

Mizanur Rahman Washim , Natsuki Morimoto , Takechiyo Sumiyoshi , Aki Nishihara , Siva Nallaperumal , Tomoya Kono , Jun-ichi Hikima

Interleukin-1β is a pro-inflammatory cytokine with pluripotent roles in mediating immune response. In fish, IL-1β plays a major role in inflammatory responses to pathogenic infections, though its immunological functions through direct stimulation have not been studied in detail. In this study, two IL-1β genes (il1b1 and il1b2) from the Japanese medaka (Oryzias latipes) were identified and characterized. The broad immunostimulatory effects of recombinant IL-1β (OlrIL-1β) from Japanese medaka were explored using embryonic fibroblast-like cell line (OLHdrR-e3) and primary cultured kidney cells. Recombinant proteins were produced via prokaryotic expression based on predicted mature isoforms IL-1β1_Asp⁹⁵ (type II) and IL-1β2_Asp¹²¹ (type I) to investigate their distinct functional characteristics. Then, their immune-related gene expression, phagocytosis, and reactive oxygen species (ROS) production ability were evaluated in vitro and ex vivo. rIL-1β triggers the expression of not only pro-inflammatory cytokines such as il1b, tnfa, il6, il8, mcp1b, and csf1b, but also the antimicrobial peptide, def1b. Additionally, they upregulate the expression of cell specific markers, including macrophage- and granulocyte-specific genes mpeg1.1, mpx2, and epx, and nitric oxide synthase (NO) gene nos1. Moreover, medaka OlrIL-1β proteins exhibited robust phagocytosis and superoxide anion production ability than those in unstimulated control. In all evaluations, the OlrIL-1β proteins corresponding to the predicted cleavage sites exhibited strong immune activation, with type I OlIL-1β2_Asp¹²¹ demonstrating more potent response than type II. To our knowledge, this is the study to reveal the immunomodulatory functions of Japanese medaka IL-1β, highlighting its potential in immunotherapy for disease prevention and control in aquaculture.

白细胞介素-1β是一种促炎细胞因子，在介导免疫反应中具有多能性作用。在鱼类中，IL-1β在致病性感染的炎症反应中起主要作用，尽管其通过直接刺激的免疫功能尚未得到详细研究。本研究从日本稻（Oryzias latipes）中鉴定了两个IL-1β基因il1b1和il1b2。利用胚胎成纤维细胞样细胞系（OLHdrR-e3）和原代培养的肾细胞，研究了重组日本medaka IL-1β (OlrIL-1β)的广泛免疫刺激作用。以预测成熟亚型IL-1β1_Asp95 （II型）和IL-1β2_Asp121 （I型）为基础，通过原核表达制备重组蛋白，研究其不同的功能特征。然后，在体外和离体实验中评估它们的免疫相关基因表达、吞噬能力和活性氧（ROS）产生能力。il -1β不仅能触发il - 1b、tnfa、il - 6、il - 8、mcp1b和csf1b等促炎细胞因子的表达，还能触发抗菌肽def1b的表达。此外，它们上调细胞特异性标记物的表达，包括巨噬细胞和粒细胞特异性基因mpeg1.1、mpx2和epx，以及一氧化氮合酶（NO）基因nos1。此外，与未受刺激的对照组相比，medaka OlrIL-1β蛋白具有较强的吞噬能力和超氧阴离子产生能力。在所有的评估中，预测切割位点对应的OlrIL-1β蛋白表现出很强的免疫激活，I型oil -1β 2_asp121比II型表现出更强的应答。据我们所知，本研究揭示了日本medaka IL-1β的免疫调节功能，突出了其在水产养殖疾病预防和控制中的免疫治疗潜力。

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引用次数: 0

Mechanism of Pseudomonas plecoglossicida T6SS effector vgrG1a in disrupting hepatic immunometabolic homeostasis in large yellow croaker 绿舌假单胞菌T6SS效应物vgrG1a破坏大黄鱼肝脏免疫代谢稳态的机制

IF 3.9 2区农林科学 Q1 FISHERIES

Fish & shellfish immunology

Pub Date : 2026-01-24 DOI: 10.1016/j.fsi.2026.111147

Peng Xizhi , Sun Yujia , Li Haoyang , Yan Qingpi

Pseudomonas plecoglossicida, a significant pathogen of large yellow croaker (Larimichthys crocea), employs its Type VI secretion system (T6SS1) as a key virulence determinant. However, the role of the T6SS1 spike protein, VgrG1a, in pathogenesis remains poorly understood. This study elucidates the critical function of vgrG1a in disrupting hepatic immunometabolic homeostasis by constructing a vgrG1a deletion mutant (ΔvgrG1a). We found that the ΔvgrG1a strain exhibited markedly attenuated virulence, increasing host survival by 40 % compared to wild-type challenge. Histopathological and ultrastructural analyses revealed that vgrG1a deletion significantly alleviated hepatic vacuolar degeneration, inflammatory infiltration, glycogen depletion, and mitochondrial damage. Physio-biochemical assays demonstrated that the metabolic disturbances in ATP synthase activity, NAD⁺/NADH ratio, and glutathione content were considerably milder in the ΔvgrG1a-infected group. Proteomic and qRT-PCR analyses indicated that vgrG1a activates a robust pro-inflammatory cytokine storm via the Toll-like receptor 2 (TLR2) and nucleotide-binding oligomerization domain-containing protein 2 (NOD2) signaling pathways. Concurrently, it potently suppressed the AMPK signaling pathway and the expression of key metabolic genes involved in gluconeogenesis (Pck1) and fatty acid β-oxidation (Acaa2). Our findings demonstrate that vgrG1a, as a key T6SS1 component, drives hepatic immunometabolic dysregulation by coordinately activating innate immune responses and inhibiting AMPK-mediated energy metabolism, providing novel insights into the pathogenesis of microbes.

巨舌假单胞菌是大黄鱼（Larimichthys crocea）的重要病原菌，其VI型分泌系统（T6SS1）是关键的毒力决定因素。然而，T6SS1刺突蛋白VgrG1a在发病机制中的作用仍然知之甚少。本研究通过构建vgrG1a缺失突变体阐明了vgrG1a在破坏肝脏免疫代谢稳态中的关键功能（ΔvgrG1a）。我们发现ΔvgrG1a菌株的毒力明显减弱，与野生型相比，宿主存活率提高了40%。组织病理学和超微结构分析显示，vgrG1a缺失显著减轻了肝空泡变性、炎症浸润、糖原消耗和线粒体损伤。生理生化实验表明，ΔvgrG1a-infected组在ATP合成酶活性、NAD+/NADH比值和谷胱甘肽含量方面的代谢紊乱程度较轻。蛋白质组学和qRT-PCR分析表明，vgrG1a通过toll样受体2 （TLR2）和核苷酸结合寡聚结构域蛋白2 （NOD2）信号通路激活了强大的促炎细胞因子风暴。同时，它还能有效抑制AMPK信号通路和糖异生（Pck1）、脂肪酸β氧化（Acaa2）等关键代谢基因的表达。我们的研究结果表明，vgrG1a作为T6SS1的关键成分，通过协调激活先天免疫反应和抑制ampk介导的能量代谢来驱动肝脏免疫代谢失调，为微生物的发病机制提供了新的见解。

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引用次数: 0

Population-specific transcriptomics of Pacific oyster after exposure to a highly pathogenic, globally distributed virus 暴露于一种全球分布的高致病性病毒后的太平洋牡蛎种群特异性转录组学。

IF 3.9 2区农林科学 Q1 FISHERIES

Fish & shellfish immunology

Pub Date : 2026-01-23 DOI: 10.1016/j.fsi.2026.111154

Bernarda Calla , Neil F. Thompson , Colleen A. Burge

Disease outbreaks in marine invertebrates, particularly in cultivated species, have increased as stressful environmental conditions become more frequent. The Ostreid herpesvirus and its microvariants have caused substantial mortalities in Pacific oysters globally, heavily impacting aquaculture production in localities where the virus becomes established. This study investigates the molecular response of Pacific oysters to OsHV-1 μVar infection in two oyster populations: a population of Miyagi oysters, and a population of Midori oysters. Although viral infection elicited a general and significant up-regulation of antiviral defense transcripts that was very similar in both populations and that included RIG-I like receptors and the interferon-like pathway, gene-wise clustering analyses clearly differentiated both populations. Among differences between Midori and Miyagi were several immunity-related genes and histone-coding genes that indicated possible pre-transcriptional mechanisms of gene regulation influencing disease outcomes. Among other differences, genes encoding for viral sensing proteins (SAMD9 and NFX-1 zinc finger) showed higher basal and infection-induced expression in Midori, whereas Miyagi oysters exhibited greater up-regulation of ubiquitination pathways. We also compared the general response of Pacific oysters to different OsHV-1 μVars strains, concluding that there is no marked difference between the oyster response to a U.S. OsHV-1 μVar compared to an Australian μVar. These results are important for future work that focuses on developing Pacific oysters that are tolerant to OsHV-1 μVars and to develop additional management strategies to prevent the spread of this viral disease.

海洋无脊椎动物，特别是养殖物种的疾病爆发，随着紧张的环境条件变得更加频繁而增加。牡蛎疱疹病毒及其微变异已在全球范围内造成太平洋牡蛎大量死亡，严重影响该病毒形成地区的水产养殖生产。本研究在宫城牡蛎和Midori牡蛎两个牡蛎种群中研究了太平洋牡蛎对OsHV-1 μVar感染的分子反应。尽管病毒感染引起抗病毒防御转录物的普遍和显著上调，这在两个群体中非常相似，包括rig - 1样受体和干扰素样途径，但基因聚类分析清楚地区分了两个群体。Midori和Miyagi之间的差异在于一些免疫相关基因和组蛋白编码基因，这些基因调控可能影响疾病结局的转录前机制。在其他差异中，编码病毒传感蛋白的基因（SAMD9和NFX-1锌指）在Midori牡蛎中表现出更高的基础和感染诱导表达，而宫城牡蛎则表现出更大的泛素化途径上调。我们还比较了太平洋牡蛎对不同OsHV-1 μVar菌株的总体反应，结论是牡蛎对美国OsHV-1 μVar的反应与对澳大利亚OsHV-1 μVar的反应没有显著差异。这些结果对于未来开发耐受OsHV-1 μVars的太平洋牡蛎和制定其他管理策略以防止这种病毒性疾病的传播具有重要意义。

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引用次数: 0

Pathogen coinfections in wild and farmed salmonids: A systematic review 野生和养殖鲑鱼的病原体共感染：系统综述。

IF 3.9 2区农林科学 Q1 FISHERIES

Fish & shellfish immunology

Pub Date : 2026-01-23 DOI: 10.1016/j.fsi.2026.111155

Yessica Ortega , Débora Torrealba , José Gallardo-Matus , Fernanda Fernández , Carolina Figueroa , Paulina Bustos , Pablo Conejeros , Brian Dixon , Marcos Mancilla

Coinfections have been reported in a wide range of organisms, including wild and farmed salmon and trout. However, the effects of coinfections on host resistance to pathogens remain poorly understood. A primary pathogen can modulate the host's immune response to subsequent infections, either by suppressing or priming the immune system. However, in some cases, pathogens may compete within the same host, potentially reducing or neutralizing the severity and impact of the disease. This systematic review examines the impacts of coinfections on farmed and wild salmonids, synthesizing evidence from 146 studies that met the eligibility criteria. Field evidence from 90 studies demonstrates that pathogen coinfections are widespread in salmonids across diverse geographic regions and aquatic environments. Coinfections were most frequently reported in Atlantic salmon and rainbow trout but were also documented in multiple wild salmonid species, indicating that coinfection is a pervasive phenomenon across the Salmonidae family. Complex coinfections involving three or more pathogens were common, and among pairwise interactions, parasite–parasite, virus-virus and bacteria–bacteria coinfections predominated. Experimental evidence shows that both intra- and interspecific coinfections strongly influence disease outcomes in salmonids. Notably, strategies to mitigate coinfection remain poorly explored, and there is still limited understanding of how host immune responses shape pathogen–pathogen interactions. Overall, coinfection emerges as a context-dependent and underappreciated driver of disease risk across wild and farmed salmonids, highlighting the need to strengthen disease surveillance frameworks through explicit coinfection reporting, as current monitoring approaches likely underestimate its frequency and epidemiological relevance.

据报道，在包括野生和养殖鲑鱼和鳟鱼在内的多种生物中都存在共感染。然而，共感染对宿主对病原体的抗性的影响仍然知之甚少。原发病原体可以通过抑制或启动免疫系统来调节宿主对后续感染的免疫反应。然而，在某些情况下，病原体可能在同一宿主内竞争，可能减轻或抵消疾病的严重程度和影响。本系统综述研究了共感染对养殖和野生鲑鱼的影响，综合了146项符合资格标准的研究的证据。来自90项研究的实地证据表明，病原体共感染在不同地理区域和水生环境中的鲑鱼中广泛存在。共同感染在大西洋鲑鱼和虹鳟鱼中最常见，但在多种野生鲑鱼物种中也有记录，表明共同感染是整个鲑鱼科普遍存在的现象。涉及三种或更多病原体的复杂共感染很常见，在成对相互作用中，寄生虫-寄生虫、病毒-病毒和细菌-细菌共感染占主导地位。实验证据表明，种内和种间共感染都强烈影响鲑鱼的疾病结果。值得注意的是，减轻共感染的策略仍未得到充分探索，并且对宿主免疫反应如何影响病原体-病原体相互作用的理解仍然有限。总体而言，在野生和养殖鲑科鱼类中，共同感染是一种依赖环境且未得到充分重视的疾病风险驱动因素，突出表明需要通过明确的共同感染报告来加强疾病监测框架，因为目前的监测方法可能低估了其频率和流行病学相关性。

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引用次数: 0

An OASL homologue involved in IFN-like antiviral signal by binding MDA5 in the Pacific oyster Crassostrea gigas OASL同源物通过结合MDA5在太平洋牡蛎长牡蛎中参与ifn样抗病毒信号。

IF 3.9 2区农林科学 Q1 FISHERIES

Fish & shellfish immunology

Pub Date : 2026-01-22 DOI: 10.1016/j.fsi.2026.111152

Yuqing Zeng , Yuhao Jin , Xiaoyu Gu , Yifan Gu , Yiqing Wang , Mengjia Chen , Xue Qiao , Lingling Wang , Linsheng Song

The 2′,5′-oligoadenylate synthetases like (OASL) is a representative member of interferon-stimulated genes (ISGs), which plays a critical role in the innate immune defense against viral infections by sensing dsRNA and assisting RIG-I-like receptors (RLR) mediated antiviral signal. In the present study, an OASL homologue (named CgOASL) with a conserved OAS1_C domain was identified in the Pacific oyster Crassostrea gigas. The mRNA transcripts of CgOASL were widely detected in all the tested tissues with the highest expression level in adductor muscle. The mRNA expression level of CgOASL in haemocytes was significantly upregulated after poly (I:C) and recombinant IFN-like protein (rCgIFNLP) stimulation. After RNAi of CgIFNLP and its receptor CgIFNR-3, the mRNA expression of CgOASL was significantly down-regulated compared to control group after poly (I:C) stimulation. And the recombinant CgOASL (rCgOASL) showed strong in vitro binding affinity for dsRNA. Upon co-transfection of CgOASL and RIG-I-like receptors (RLR) member (CgRIG-I and CgMDA5), the Co-IP assays revealed a specific interaction of CgOASL with CgMDA5, but not with CgRIG-I, which is consistent with the activities of vertebrate OASL proteins. This interaction was further confirmed by pull-down experiments. And transfection of CgOASL also significantly induced the ISG expression in HEK293T cells. Taken together, CgOASL was an ISG regulated by CgIFNLP, capable of recognizing dsRNA and interacting with CgMDA5 to exert antiviral activity. These findings highlight its potential role in oyster antiviral innate immunity and offer new insights into the functional evolution of OASL proteins in invertebrates.

2',5'-oligoadenylate synthetases like （OASL）是干扰素刺激基因（ISGs）的代表成员，它通过感知dsRNA和辅助RIG-I-like受体（RLR）介导的抗病毒信号，在先天免疫防御病毒感染中起着至关重要的作用。在本研究中，在太平洋牡蛎长牡蛎中发现了一个OAS1_C结构域保守的OASL同源物（命名为CgOASL）。CgOASL mRNA转录本广泛存在于所有组织中，其中内收肌表达量最高。经poly（I:C）和重组ifn样蛋白（rCgIFNLP）刺激后，CgOASL在血细胞中的mRNA表达水平显著上调。对CgIFNLP及其受体CgIFNR-3进行RNAi后，poly（I:C）刺激后，CgOASL mRNA表达量较对照组显著下调。重组CgOASL （rCgOASL）对dsRNA具有较强的体外结合亲和力。在CgOASL和rig - i样受体（RLR）成员（cgrig - 1和CgMDA5）共转染后，Co-IP分析显示CgOASL与CgMDA5特异性相互作用，而不与cgrig - 1特异性相互作用，这与脊椎动物OASL蛋白的活性一致。下拉实验进一步证实了这种相互作用。转染CgOASL也能显著诱导HEK293T细胞中ISG的表达。综上所述，CgOASL是一个受CgIFNLP调控的ISG，能够识别dsRNA并与CgMDA5相互作用发挥抗病毒活性。这些发现突出了其在牡蛎抗病毒先天免疫中的潜在作用，并为无脊椎动物OASL蛋白的功能进化提供了新的见解。

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引用次数: 0

The roles of the BarA-UvrY two-component system in the virulence of Vibrio harveyi and the efficacy evaluation of mutant strains ΔbarA and ΔuvrY as live-attenuated vaccines BarA-UvrY双组分系统在哈维弧菌毒力中的作用以及突变株ΔbarA和ΔuvrY作为减毒活疫苗的效力评价

IF 3.9 2区农林科学 Q1 FISHERIES

Fish & shellfish immunology

Pub Date : 2026-01-22 DOI: 10.1016/j.fsi.2026.111151

Yilin Zhang , Fan Wu , Kevin WH. Kwok , Yiming Wen , Zhen Gan , Yishan Lu

As key bacterial signaling mechanisms, two-component systems (TCSs) regulate numerous cellular processes, with the BarA/UvrY system particularly important for controlling stress adaptation and virulence. However, the functions of BarA/UvrY in Vibrio harveyi, a major vibriosis-causing pathogen in marine fish, are still unclear. In this study, we analyzed the V. harveyi typical phenotypic alterations following barA and uvrY deletion, and the result indicated that deletion of barA and uvrY decreased maximum growth density and motility, and increased the susceptibility to pH stress, iron limitation, and antibiotics in V. harveyi. Besides, the biofilm formation pattern is a time-dependent process in V. harveyi. In addition, deletion of barA and uvrY reduced bacterial adhesion, intracellular ferrous ion concentration, while also increasing apoptosis and viability in host cell. Furthermore, the mutation impaired the ability of the bacteria to invade and replicate within primary grouper macrophages. Lastly, immunization with ΔbarA and ΔuvrY stimulated host immune responses through upregulation of immune-related genes and increased serum enzyme activity, providing substantial protection against V. harveyi infection in grouper. These results provide crucial insights into BarA/UvrY regulatory system of γ-proteobacteria and reveal novel aspects of pathogenic strategies employed in marine fish hosts.

作为关键的细菌信号机制，双组分系统（TCSs）调节了许多细胞过程，其中BarA/UvrY系统在控制应激适应和毒力方面尤为重要。然而，BarA/ uvery在引起海鱼弧菌病的主要病原体哈维弧菌中的作用尚不清楚。本研究分析了barA和uvrY缺失后harveyi弧菌的典型表型变化，结果表明barA和uvrY缺失降低了harveyi弧菌的最大生长密度和活力，增加了对pH胁迫、铁限制和抗生素的敏感性。此外，生物膜的形成模式是一个时间依赖性的过程。此外，barA和uvery的缺失降低了细菌粘附，胞内亚铁离子浓度，同时也增加了宿主细胞的凋亡和活力。此外，该突变损害了细菌入侵和复制原代石斑鱼巨噬细胞的能力。最后，ΔbarA和ΔuvrY免疫通过上调免疫相关基因和增加血清酶活性刺激宿主免疫反应，为石斑鱼提供了抵御哈维氏弧菌感染的实质性保护。这些结果为了解γ-蛋白杆菌的BarA/UvrY调控系统提供了重要的见解，并揭示了海洋鱼类宿主致病策略的新方面。

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引用次数: 0