Pub Date : 2026-01-16DOI: 10.1016/j.fsi.2026.111131
Ziyue Zhao , Li Nie , Jiong Chen , Chenjie Fei
Macrophage colony-stimulating factor (M-CSF) is a key hematopoietic cytokine that governs the proliferation, survival, and functional specialization of monocytes and macrophages in vertebrates. Although its roles are well characterized in mammals, knowledge of M-CSF-mediated immune regulation in teleost fish remains limited. In this study, we characterized the M-CSF homolog from largemouth bass (Micropterus salmoides) and investigated its structural features, tissue distribution and immunomodulatory functions. Sequence alignment revealed that largemouth bass M-CSF possesses a signature CSF domain and shares conserved cysteine and histidine residues essential for dimerization and receptor binding in mammals, indicating evolutionary conservation of its functional motifs. Quantitative expression analysis showed broad tissue distribution, with predominant expression in the head kidney and spleen. Recombinant M-CSF (rM-CSF) significantly enhanced monocyte/macrophages (MO/MФ) proliferation and upregulated the anti-apoptotic gene Bcl2, suggesting its role in promoting MO/MФ survival. Moreover, rM-CSF increased arginase activity and induced the expression of anti-inflammatory genes (i.e., IL-10 and TGF-β), indicative of M2-like polarization. Together, these findings demonstrate that largemouth bass M-CSF promotes macrophage proliferation, survival, and modulates functional phenotypes, thereby providing new insight into the evolutionarily conserved mechanisms of innate immune regulation in teleost fish.
{"title":"M-CSF regulates macrophage proliferation, survival, and anti-inflammatory responses in largemouth bass (Micropterus salmoides)","authors":"Ziyue Zhao , Li Nie , Jiong Chen , Chenjie Fei","doi":"10.1016/j.fsi.2026.111131","DOIUrl":"10.1016/j.fsi.2026.111131","url":null,"abstract":"<div><div>Macrophage colony-stimulating factor (M-CSF) is a key hematopoietic cytokine that governs the proliferation, survival, and functional specialization of monocytes and macrophages in vertebrates. Although its roles are well characterized in mammals, knowledge of M-CSF-mediated immune regulation in teleost fish remains limited. In this study, we characterized the M-CSF homolog from largemouth bass (<em>Micropterus salmoides</em>) and investigated its structural features, tissue distribution and immunomodulatory functions. Sequence alignment revealed that largemouth bass M-CSF possesses a signature CSF domain and shares conserved cysteine and histidine residues essential for dimerization and receptor binding in mammals, indicating evolutionary conservation of its functional motifs. Quantitative expression analysis showed broad tissue distribution, with predominant expression in the head kidney and spleen. Recombinant M-CSF (rM-CSF) significantly enhanced monocyte/macrophages (MO/MФ) proliferation and upregulated the anti-apoptotic gene <em>Bcl2</em>, suggesting its role in promoting MO/MФ survival. Moreover, rM-CSF increased arginase activity and induced the expression of anti-inflammatory genes (i.e., <em>IL-10</em> and <em>TGF-β</em>), indicative of M2-like polarization. Together, these findings demonstrate that largemouth bass M-CSF promotes macrophage proliferation, survival, and modulates functional phenotypes, thereby providing new insight into the evolutionarily conserved mechanisms of innate immune regulation in teleost fish.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"170 ","pages":"Article 111131"},"PeriodicalIF":3.9,"publicationDate":"2026-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145997687","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}
Pub Date : 2026-01-16DOI: 10.1016/j.fsi.2026.111130
Xinyu He , Yuxi Li , Xinyue Wan , Qingding Hao , Yang Li , Guoqing Shen , Kaimin Zhou , Weiwei Li , Qun Wang , Youting Zhu
Phagocytosis by circulating hemocytes is crucial for antibacterial defense in crustaceans, but how intracellular trafficking GTPases coordinate this process remains poorly understood. Here, we identified and characterized a Rab6 ortholog (EsRab6) from the Chinese mitten crab, Eriocheir sinensis, and defined its role in hemocyte phagocytosis and resistance to Vibrio parahaemolyticus. EsRab6 encodes a typical Rab6 GTPase with conserved nucleotide-binding and Rab family motifs and clusters within the invertebrate Rab6 clade. Transcripts were widely expressed, with higher levels in the hepatopancreas and eyestalk, yet EsRab6 was rapidly and transiently upregulated in hemocytes following V. parahaemolyticus challenge. RNA interference-mediated knockdown of EsRab6 resulted in a significant reduction in FITC-labeled bacterial uptake by hemocytes, as shown by microscopy and flow cytometry. Immunofluorescence and LysoTracker staining showed that EsRab6 relocates from a diffuse cytosolic pattern to punctate vesicles that colocalize with lysosomes during infection. Simultaneously, EsRab6 knockdown significantly decreased lysosome-associated signals, indicating a role for EsRab6 in lysosome formation or stability. In vivo, dsRNA-mediated silencing of EsRab6 results in higher hemolymph bacterial loads and significantly lower survival rates following V. parahaemolyticus infection. Overall, these findings identify EsRab6 as a conserved trafficking regulator that links phagosome–lysosome biogenesis to adequate bacterial clearance in crab hemocytes and suggest that Rab6-dependent pathways could be targeted to enhance disease resistance in crustacean aquaculture.
{"title":"Rab6 mediates lysosome biogenesis to regulate phagocytosis and bacterial clearance in the Chinese mitten crab Eriocheir sinensis","authors":"Xinyu He , Yuxi Li , Xinyue Wan , Qingding Hao , Yang Li , Guoqing Shen , Kaimin Zhou , Weiwei Li , Qun Wang , Youting Zhu","doi":"10.1016/j.fsi.2026.111130","DOIUrl":"10.1016/j.fsi.2026.111130","url":null,"abstract":"<div><div>Phagocytosis by circulating hemocytes is crucial for antibacterial defense in crustaceans, but how intracellular trafficking GTPases coordinate this process remains poorly understood. Here, we identified and characterized a Rab6 ortholog (<em>Es</em>Rab6) from the Chinese mitten crab, <em>Eriocheir sinensis</em>, and defined its role in hemocyte phagocytosis and resistance to <em>Vibrio parahaemolyticus</em>. <em>EsRab6</em> encodes a typical Rab6 GTPase with conserved nucleotide-binding and Rab family motifs and clusters within the invertebrate Rab6 clade. Transcripts were widely expressed, with higher levels in the hepatopancreas and eyestalk, yet <em>Es</em>Rab6 was rapidly and transiently upregulated in hemocytes following <em>V. parahaemolyticus</em> challenge. RNA interference-mediated knockdown of <em>EsRab6</em> resulted in a significant reduction in FITC-labeled bacterial uptake by hemocytes, as shown by microscopy and flow cytometry. Immunofluorescence and LysoTracker staining showed that <em>Es</em>Rab6 relocates from a diffuse cytosolic pattern to punctate vesicles that colocalize with lysosomes during infection. Simultaneously, <em>EsRab6</em> knockdown significantly decreased lysosome-associated signals, indicating a role for <em>Es</em>Rab6 in lysosome formation or stability. In vivo, dsRNA-mediated silencing of <em>EsRab6</em> results in higher hemolymph bacterial loads and significantly lower survival rates following <em>V. parahaemolyticus</em> infection. Overall, these findings identify <em>Es</em>Rab6 as a conserved trafficking regulator that links phagosome–lysosome biogenesis to adequate bacterial clearance in crab hemocytes and suggest that Rab6-dependent pathways could be targeted to enhance disease resistance in crustacean aquaculture.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"170 ","pages":"Article 111130"},"PeriodicalIF":3.9,"publicationDate":"2026-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145997735","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}
Pub Date : 2026-01-14DOI: 10.1016/j.fsi.2026.111129
Jiqing Liu , Mei Ying , Xuemei Duan , Chenghua Li
Insulin-like growth factor 2 mRNA-binding proteins (IGF2BPs) are conserved N6-methyladenosine (m6A) readers known to orchestrate diverse host immune responses. However, its function in Apostichopus japonicus remains unclear during Vibrio splendidus infection. In this study, we identified a single IGF2BP homolog (AjIGF2BP) in Apostichopus japonicus, which was markedly upregulated following Vibrio splendidus infection. Functional analysis revealed that AjIGF2BP knockdown significantly reduced bacterial load in coelomocytes and mitigated skin ulcer syndrome. Transcriptomic profiling revealed that AjIGF2BP knockdown significantly perturbed apoptotic pathways, among which the E3 ubiquitin ligase ring finger protein 34 (AjRNF34) emerged as a strongly downregulated downstream effector. Mechanistically, AjIGF2BP directly bound to and stabilized AjRNF34 mRNA in an m6A-dependent manner. Rescue experiments confirmed that AjRNF34 was essential for the anti-apoptotic function of AjIGF2BP. Furthermore, AjRNF34 physically interacted with the executioner caspase Ajcaspase-3 via its RING domain and promoted both K48-linked ubiquitination, facilitating its proteasomal degradation and thereby suppressing apoptosis. Collectively, our findings unveil a novel AjIGF2BP/AjRNF34/Ajcaspase-3 regulatory axis through which m6A reader inhibits apoptosis to facilitate bacterial infection, offering new insights into the epigenetic regulatory mechanisms of immunity in echinoderms.
{"title":"IGF2BP stabilizes RNF34 mRNA to orchestrate apoptosis and host susceptibility to Vibrio splendidus in Apostichopus japonicus","authors":"Jiqing Liu , Mei Ying , Xuemei Duan , Chenghua Li","doi":"10.1016/j.fsi.2026.111129","DOIUrl":"10.1016/j.fsi.2026.111129","url":null,"abstract":"<div><div>Insulin-like growth factor 2 mRNA-binding proteins (IGF2BPs) are conserved N6-methyladenosine (m6A) readers known to orchestrate diverse host immune responses. However, its function in <em>Apostichopus japonicus</em> remains unclear during <em>Vibrio splendidus</em> infection. In this study, we identified a single IGF2BP homolog (AjIGF2BP) in <em>Apostichopus japonicus</em>, which was markedly upregulated following <em>Vibrio splendidus</em> infection. Functional analysis revealed that AjIGF2BP knockdown significantly reduced bacterial load in coelomocytes and mitigated skin ulcer syndrome. Transcriptomic profiling revealed that AjIGF2BP knockdown significantly perturbed apoptotic pathways, among which the E3 ubiquitin ligase ring finger protein 34 (AjRNF34) emerged as a strongly downregulated downstream effector. Mechanistically, AjIGF2BP directly bound to and stabilized <em>AjRNF3</em>4 mRNA in an m6A-dependent manner. Rescue experiments confirmed that AjRNF34 was essential for the anti-apoptotic function of AjIGF2BP. Furthermore, AjRNF34 physically interacted with the executioner caspase Ajcaspase-3 via its RING domain and promoted both K48-linked ubiquitination, facilitating its proteasomal degradation and thereby suppressing apoptosis. Collectively, our findings unveil a novel AjIGF2BP/AjRNF34/Ajcaspase-3 regulatory axis through which m6A reader inhibits apoptosis to facilitate bacterial infection, offering new insights into the epigenetic regulatory mechanisms of immunity in echinoderms.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"170 ","pages":"Article 111129"},"PeriodicalIF":3.9,"publicationDate":"2026-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145974560","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}
Pub Date : 2026-01-14DOI: 10.1016/j.fsi.2026.111132
Ting Li , Na Yang , Da Teng , Ruoyu Mao , Ya Hao , Huihui Han , Yankang Wu , Xiumin Wang , Jianhua Wang
Tilapia (GIFT, Oreochromis niloticus) has been an economically important freshwater species in China because of its high-quality meat, high yield and high fertility, etc. At present, the high-density breeding industry has suffered great damage from Aeromonas veronii (A. veronii) infections, and the extensive use of antibiotics in aquaculture has resulted in the prevalence of antibiotic-resistant bacteria, resulting in huge economic losses. In this study, we investigated the antibacterial effect of a marine peptide-N6NH2 and its D-enantiomer (DN6NH2) on acute A. veronii infections of O. niloticus models, with traditional veterinary antibiotics as controls and found that the DN6NH2 had stronger antibacterial activity in vivo than the parent peptide N6NH2 and florfenicol. The mortality results showed that DN6NH2 had more potent efficacy at a dose of 10 mg/kg (81.82 % survival) in O. niloticus peritoneal infection model than 10 mg/kg N6NH2 (51.52 %) and 10 mg/kg florfenicol (30.30 %). Histopathologic changes observed by HE staining showed significant alleviation in the DN6NH2 group, inflammation, bleeding and necrosis of the liver, intestine, spleen and gills have been reduced. In addition, in the spleen and head kidney, DN6NH2 was effective in alleviating the strong immune response to A. veronii infection in O. niloticus by real-time quantitative RT-PCR. In addition, DN6NH2 significantly reduced nuclear factor-kappaB p65 (NF-κB p65) levels in the spleen after A. veronii infection, indicating its good immunomodulatory capacity. These results suggest the protective action of DN6NH2 against A. veronii and the potential of this peptide as a promising candidate for aquaculture applications.
{"title":"Potent dual-function of marine peptide N6NH2 and its D-enantiomer to combat MDR A. veronii infection in tilapia (GIFT, Oreochromis niloticus)","authors":"Ting Li , Na Yang , Da Teng , Ruoyu Mao , Ya Hao , Huihui Han , Yankang Wu , Xiumin Wang , Jianhua Wang","doi":"10.1016/j.fsi.2026.111132","DOIUrl":"10.1016/j.fsi.2026.111132","url":null,"abstract":"<div><div>Tilapia (GIFT, <em>Oreochromis niloticus</em>) has been an economically important freshwater species in China because of its high-quality meat, high yield and high fertility, etc. At present, the high-density breeding industry has suffered great damage from <em>Aeromonas veronii</em> (<em>A. veronii</em>) infections, and the extensive use of antibiotics in aquaculture has resulted in the prevalence of antibiotic-resistant bacteria, resulting in huge economic losses. In this study, we investigated the antibacterial effect of a marine peptide-N6NH<sub>2</sub> and its D-enantiomer (DN6NH<sub>2</sub>) on acute <em>A. veronii</em> infections of <em>O. niloticus</em> models, with traditional veterinary antibiotics as controls and found that the DN6NH2 had stronger antibacterial activity in vivo than the parent peptide N6NH<sub>2</sub> and florfenicol. The mortality results showed that DN6NH<sub>2</sub> had more potent efficacy at a dose of 10 mg/kg (81.82 % survival) in <em>O. niloticus</em> peritoneal infection model than 10 mg/kg N6NH<sub>2</sub> (51.52 %) and 10 mg/kg florfenicol (30.30 %). Histopathologic changes observed by HE staining showed significant alleviation in the DN6NH<sub>2</sub> group, inflammation, bleeding and necrosis of the liver, intestine, spleen and gills have been reduced. In addition, in the spleen and head kidney, DN6NH<sub>2</sub> was effective in alleviating the strong immune response to <em>A. veronii</em> infection in <em>O. niloticus</em> by real-time quantitative RT-PCR. In addition, DN6NH<sub>2</sub> significantly reduced nuclear factor-kappaB p65 (NF-κB p65) levels in the spleen after <em>A. veronii</em> infection, indicating its good immunomodulatory capacity. These results suggest the protective action of DN6NH<sub>2</sub> against <em>A. veronii</em> and the potential of this peptide as a promising candidate for aquaculture applications.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"170 ","pages":"Article 111132"},"PeriodicalIF":3.9,"publicationDate":"2026-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145988963","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}
Pub Date : 2026-01-13DOI: 10.1016/j.fsi.2026.111128
Yi Chen , Wen-Xiong Wang
Barrier mucosal tissues in marine invertebrates coordinate filtration, gas exchange, and frontline innate immunity, yet their cellular organization and division of functions remain poorly resolved. This study generated a tissue-resolved single-cell atlas in a marine invertebrate Crassostrea hongkongensis, defining twenty cell types. The framework revealed a diversified phagocyte lineage composed by five phagocytic cells with three terminal strategies: rapid extracellular containment, deep intracellular clearance, and a resolution program that couples degradation with matrix restoration. We also identified three humoral immune populations with complementary recognition and effector roles that collaborated with phagocytes and epithelial cells. Barrier epithelium supports acted as organizers rather than redundant producers of soluble effectors, and shaped immune activity through defined communication and adhesion programs that coordinated proliferation, survival, and migration. A neural-related compartment comprised of neural progenitor-like, neuron-like, and neuroendocrine cells, and exhibited predominantly sender roles toward epithelial and immune targets consistent with transmitter and peptide-mediated control of ciliary flow, secretory activity, as well as the priming of phagocytic and humoral effectors. Ligand receptor inference highlighted adhesion modules centering on neural cell adhesion molecule (NCAM) and the receptor type protein tyrosine phosphatase (PTPRM) as the key pathways of communication between neural, epithelial, and immune populations. Our finding present a compact taxonomy to map immune programs with precise cellular contexts, and further our understanding of resilience and health in variable coastal environments.
{"title":"Oyster cellular architecture and innate immune programs resolved by single-cell RNA sequencing","authors":"Yi Chen , Wen-Xiong Wang","doi":"10.1016/j.fsi.2026.111128","DOIUrl":"10.1016/j.fsi.2026.111128","url":null,"abstract":"<div><div>Barrier mucosal tissues in marine invertebrates coordinate filtration, gas exchange, and frontline innate immunity, yet their cellular organization and division of functions remain poorly resolved. This study generated a tissue-resolved single-cell atlas in a marine invertebrate <em>Crassostrea hongkongensis</em>, defining twenty cell types. The framework revealed a diversified phagocyte lineage composed by five phagocytic cells with three terminal strategies: rapid extracellular containment, deep intracellular clearance, and a resolution program that couples degradation with matrix restoration. We also identified three humoral immune populations with complementary recognition and effector roles that collaborated with phagocytes and epithelial cells. Barrier epithelium supports acted as organizers rather than redundant producers of soluble effectors, and shaped immune activity through defined communication and adhesion programs that coordinated proliferation, survival, and migration. A neural-related compartment comprised of neural progenitor-like, neuron-like, and neuroendocrine cells, and exhibited predominantly sender roles toward epithelial and immune targets consistent with transmitter and peptide-mediated control of ciliary flow, secretory activity, as well as the priming of phagocytic and humoral effectors. Ligand receptor inference highlighted adhesion modules centering on neural cell adhesion molecule (NCAM) and the receptor type protein tyrosine phosphatase (PTPRM) as the key pathways of communication between neural, epithelial, and immune populations. Our finding present a compact taxonomy to map immune programs with precise cellular contexts, and further our understanding of resilience and health in variable coastal environments.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"170 ","pages":"Article 111128"},"PeriodicalIF":3.9,"publicationDate":"2026-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145974595","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}
Pub Date : 2026-01-12DOI: 10.1016/j.fsi.2026.111122
Jingting Qi , Wenting Wang , Yimeng Liu , Qiao Huang , Mingli Liu , Chaoguang Wei , Yuang Jiang , Zhichao Wu , Zhitao Qi , Jiulin Chan , Peng Hu
The largemouth bass (Micropterus salmoides), commonly known as the California bass, is a species of significant economic importance in global freshwater aquaculture. Largemouth bass virus (LMBV) has emerged as a major pathogen that poses a substantial threat to the sustainability of largemouth bass aquaculture. In this study, we established a novel Micropterus salmoides caudal fin (MSCF) cell line that supports LMBV propagation and enables investigation of virus-induced fundamental patterns of molecular responses. Characterization of the MSCF line revealed an initial mixture of epithelial-like and fibroblast-like cells that became uniformly epithelial by passage 20. Transcriptomic analysis revealed that LMBV infection significantly altered the transcription levels of 262 genes (201 up-regulated genes and 61 down-regulated), which were functionally enriched in key antiviral pathways such as apoptosis, FoxO signaling, and RIG-I-like receptor signaling. The observed expression patterns suggest that LMBV employs a potential strategy to manipulate host cell survival and disrupt innate immune responses. Collectively, we have developed an LMBV-susceptible cell line (MSCF), which provides an ideal platform for studying LMBV virology and elucidating the host defense mechanisms against LMBV.
{"title":"Establishment of a caudal fin cell line from largemouth bass (Micropterus salmoides) and its transcriptomic response to largemouth bass virus infection","authors":"Jingting Qi , Wenting Wang , Yimeng Liu , Qiao Huang , Mingli Liu , Chaoguang Wei , Yuang Jiang , Zhichao Wu , Zhitao Qi , Jiulin Chan , Peng Hu","doi":"10.1016/j.fsi.2026.111122","DOIUrl":"10.1016/j.fsi.2026.111122","url":null,"abstract":"<div><div>The largemouth bass (<em>Micropterus salmoides</em>), commonly known as the California bass, is a species of significant economic importance in global freshwater aquaculture. Largemouth bass virus (LMBV) has emerged as a major pathogen that poses a substantial threat to the sustainability of largemouth bass aquaculture. In this study, we established a novel Micropterus salmoides caudal fin (MSCF) cell line that supports LMBV propagation and enables investigation of virus-induced fundamental patterns of molecular responses. Characterization of the MSCF line revealed an initial mixture of epithelial-like and fibroblast-like cells that became uniformly epithelial by passage 20. Transcriptomic analysis revealed that LMBV infection significantly altered the transcription levels of 262 genes (201 up-regulated genes and 61 down-regulated), which were functionally enriched in key antiviral pathways such as apoptosis, FoxO signaling, and RIG-I-like receptor signaling. The observed expression patterns suggest that LMBV employs a potential strategy to manipulate host cell survival and disrupt innate immune responses. Collectively, we have developed an LMBV-susceptible cell line (MSCF), which provides an ideal platform for studying LMBV virology and elucidating the host defense mechanisms against LMBV.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"170 ","pages":"Article 111122"},"PeriodicalIF":3.9,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145974594","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}
Pub Date : 2026-01-12DOI: 10.1016/j.fsi.2026.111124
Dianyang Zhou , Ping Han , Yadong Xue , Zhennan Sun , Longdi Wang , Xiumei Liu , Jianming Chen , Yajun Wang , Suming Zhou , Xue Sun , Xinxin Du , Xubo Wang
The silver pomfret (Pampus argenteus), a vital aquaculture species, is highly susceptible to Vibrio parahaemolyticus infections, yet the molecular mechanisms underlying its immune response remain poorly understood. This study investigated gill responses to V. parahaemolyticus infection via intraperitoneal injection, analyzing histopathological, transcriptomic, and enzymatic changes at 3, 6, 12, 24 and 48 h post-infection (hpi). Histological analysis revealed progressive gill damage, with significant architectural disruption from 6 hpi and severe lesions by 48 hpi. Transcriptome profiling of 18 cDNA libraries generated 40–67 million clean reads, yielding 4492–5231 differentially expressed genes (DEGs) across time points, with 1094–2174 unique DEGs per time point. Inflammatory cytokines (tnf-α, il-1β, il-8, il-12) showed robust upregulation, peaking at 6–24 hpi, indicative of an active immune response. Gene Ontology (GO) and KEGG analyses identified enriched pathways, including “oxidative phosphorylation” (3–48 hpi) and “tight junction” (24 hpi), with “oxidoreductase activity” and “aerobic respiration” as the dominant functional categories. Oxidative stress markers (MDA, SOD, CAT, POD) exhibited time-dependent increases, reflecting enhanced antioxidant defenses. Weighted Gene Co-expression Network Analysis (WGCNA) revealed the turquoise module as being strongly correlated with infection, identifying hub genes (gapdh, gapdhs, pgam2, g6pd, taldo1, pgam1a) critical to immune regulation. This study is the first to systematically investigate the temporal crosstalk between inflammatory responses, oxidative stress, and metabolic reprogramming in silver pomfret gills during V. parahaemolyticus infection, providing novel molecular targets for the control of vibriosis.
{"title":"Combined histopathological, immunoenzymatic and transcriptomic analyses reveal the immune response mechanisms of silver pomfret infected by Vibrio parahaemolyticus","authors":"Dianyang Zhou , Ping Han , Yadong Xue , Zhennan Sun , Longdi Wang , Xiumei Liu , Jianming Chen , Yajun Wang , Suming Zhou , Xue Sun , Xinxin Du , Xubo Wang","doi":"10.1016/j.fsi.2026.111124","DOIUrl":"10.1016/j.fsi.2026.111124","url":null,"abstract":"<div><div>The silver pomfret (<em>Pampus argenteus</em>), a vital aquaculture species, is highly susceptible to <em>Vibrio parahaemolyticus</em> infections, yet the molecular mechanisms underlying its immune response remain poorly understood. This study investigated gill responses to <em>V. parahaemolyticus</em> infection via intraperitoneal injection, analyzing histopathological, transcriptomic, and enzymatic changes at 3, 6, 12, 24 and 48 h post-infection (hpi). Histological analysis revealed progressive gill damage, with significant architectural disruption from 6 hpi and severe lesions by 48 hpi. Transcriptome profiling of 18 cDNA libraries generated 40–67 million clean reads, yielding 4492–5231 differentially expressed genes (DEGs) across time points, with 1094–2174 unique DEGs per time point. Inflammatory cytokines (<em>tnf-α</em>, <em>il-1β</em>, <em>il-8</em>, <em>il-12</em>) showed robust upregulation, peaking at 6–24 hpi, indicative of an active immune response. Gene Ontology (GO) and KEGG analyses identified enriched pathways, including “oxidative phosphorylation” (3–48 hpi) and “tight junction” (24 hpi), with “oxidoreductase activity” and “aerobic respiration” as the dominant functional categories. Oxidative stress markers (MDA, SOD, CAT, POD) exhibited time-dependent increases, reflecting enhanced antioxidant defenses. Weighted Gene Co-expression Network Analysis (WGCNA) revealed the turquoise module as being strongly correlated with infection, identifying hub genes (<em>gapdh</em>, <em>gapdhs</em>, <em>pgam2</em>, <em>g6pd</em>, <em>taldo1</em>, <em>pgam1a</em>) critical to immune regulation. This study is the first to systematically investigate the temporal crosstalk between inflammatory responses, oxidative stress, and metabolic reprogramming in silver pomfret gills during <em>V. parahaemolyticus</em> infection, providing novel molecular targets for the control of vibriosis.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"170 ","pages":"Article 111124"},"PeriodicalIF":3.9,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145974591","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}
Pub Date : 2026-01-12DOI: 10.1016/j.fsi.2026.111123
Yanqi Zhao , Xiaohui Zheng , Siting Wu , Minyao Bi , Jiaming Hu , Shaojie Liu , Jingguang Wei , Qiwei Qin
Singapore grouper iridovirus (SGIV) and red-spotted grouper nervous necrosis virus (RGNNV) are major pathogens that cause high mortality and substantial economic losses in grouper aquaculture. The role of ring finger protein 5 (RNF5), an E3 ubiquitin ligase, in the antiviral innate immunity of teleosts remains poorly understood. In this study, a homolog of the RNF5 gene was identified and functionally characterized from Epinephelus coioides, which was designated EcRNF5. The open reading frame (ORF) of EcRNF5 is 645 nucleotides in length, encoding a 214-amino acid protein that contains a characteristic RING domain. Phylogenetic analysis revealed that EcRNF5 shares the closest evolutionary relationship with its ortholog in Epinephelus fuscoguttatus. EcRNF5 was ubiquitously expressed in all examined tissues. Furthermore, its transcription level was significantly upregulated in grouper spleen (GS) cells following challenge with SGIV or RGNNV. Overexpression of EcRNF5 enhanced SGIV and RGNNV replication in vitro. Concurrently, it suppressed the expression of interferon-related genes and pro-inflammatory cytokines. The promoter activities of interferon 3 (IFN3), interferon-stimulated response element (ISRE), and nuclear factor kappa B (NF-κB) were also inhibited. In addition, EcRNF5 attenuated IFN3 promoter activation induced by the key signaling molecules: EcSTING, EcTBK1, EcIRF3, and EcIRF7. Co-immunoprecipitation (Co-IP) assays confirmed physical interactions between EcRNF5 and these four innate immune signaling molecules. Collectively, these findings provide novel insights into the functional role of RNF5 in fish-virus interactions and shed light on the molecular mechanisms underlying SGIV and RGNNV pathogenicity in grouper.
{"title":"The E3 ligase RNF5 facilitates viral replication by suppressing innate immune responses in grouper","authors":"Yanqi Zhao , Xiaohui Zheng , Siting Wu , Minyao Bi , Jiaming Hu , Shaojie Liu , Jingguang Wei , Qiwei Qin","doi":"10.1016/j.fsi.2026.111123","DOIUrl":"10.1016/j.fsi.2026.111123","url":null,"abstract":"<div><div>Singapore grouper iridovirus (SGIV) and red-spotted grouper nervous necrosis virus (RGNNV) are major pathogens that cause high mortality and substantial economic losses in grouper aquaculture. The role of ring finger protein 5 (RNF5), an E3 ubiquitin ligase, in the antiviral innate immunity of teleosts remains poorly understood. In this study, a homolog of the RNF5 gene was identified and functionally characterized from <em>Epinephelus coioides</em>, which was designated EcRNF5. The open reading frame (ORF) of EcRNF5 is 645 nucleotides in length, encoding a 214-amino acid protein that contains a characteristic RING domain. Phylogenetic analysis revealed that EcRNF5 shares the closest evolutionary relationship with its ortholog in <em>Epinephelus fuscoguttatus</em>. EcRNF5 was ubiquitously expressed in all examined tissues. Furthermore, its transcription level was significantly upregulated in grouper spleen (GS) cells following challenge with SGIV or RGNNV. Overexpression of EcRNF5 enhanced SGIV and RGNNV replication in vitro. Concurrently, it suppressed the expression of interferon-related genes and pro-inflammatory cytokines. The promoter activities of interferon 3 (IFN3), interferon-stimulated response element (ISRE), and nuclear factor kappa B (NF-κB) were also inhibited. In addition, EcRNF5 attenuated IFN3 promoter activation induced by the key signaling molecules: EcSTING, EcTBK1, EcIRF3, and EcIRF7. Co-immunoprecipitation (Co-IP) assays confirmed physical interactions between EcRNF5 and these four innate immune signaling molecules. Collectively, these findings provide novel insights into the functional role of RNF5 in fish-virus interactions and shed light on the molecular mechanisms underlying SGIV and RGNNV pathogenicity in grouper.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"170 ","pages":"Article 111123"},"PeriodicalIF":3.9,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145974592","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}
Pub Date : 2026-01-12DOI: 10.1016/j.fsi.2026.111126
Ruiqi Lin , Zhihao Jiang , Qianqian Zhang , Shun Li , Xueying Qin , Xinyou Wang , Gaofeng Cheng , Zhen Xu , Weiguang Kong
Largemouth bass virus (LMBV) is a major pathogen threatening the aquaculture of largemouth bass, causing significant economic losses. Oral vaccination offers a practical and efficient strategy for disease prevention in farmed fish. In this study, a fusion CotC-MCP-3 gene was introduced into Bacillus subtilis 168 (Bs168) to enable surface display of the MCP-3 protein on bacterial spores through the anchoring protein CotC, thereby generating a candidate oral vaccine. At 28 days post-vaccination (dpv), qPCR analysis revealed pronounced upregulation of associated innate and adaptive immunity genes in the gut and head kidney of largemouth bass immunized with the MCP-3 vaccine. Vaccination markedly increased the abundance of IgM+ B cells in both the gut and head kidney, as well as total IgM levels in serum and gut mucus. Concomitantly, LMBV-specific IgM titers and neutralizing activities in both serum and gut mucus were significantly enhanced. Following the experimental LMBV challenge, fish in the MCP-3 vaccine group achieved a relative percent survival (RPS) of 68.7 %, accompanied by substantially lower viral loads in the head kidney, gut, and spleen, as well as notably attenuated histopathological lesions compared with the other groups. The Bs168-based MCP-3 oral vaccine provides strong protection against LMBV infection in largemouth bass, as demonstrated by these results, highlighting its potential as a promising strategy for managing viral diseases in aquaculture.
{"title":"Surface-displayed MCP-3 vaccine in Bacillus subtilis elicits protective immune responses against LMBV infection in largemouth bass","authors":"Ruiqi Lin , Zhihao Jiang , Qianqian Zhang , Shun Li , Xueying Qin , Xinyou Wang , Gaofeng Cheng , Zhen Xu , Weiguang Kong","doi":"10.1016/j.fsi.2026.111126","DOIUrl":"10.1016/j.fsi.2026.111126","url":null,"abstract":"<div><div>Largemouth bass virus (LMBV) is a major pathogen threatening the aquaculture of largemouth bass, causing significant economic losses. Oral vaccination offers a practical and efficient strategy for disease prevention in farmed fish. In this study, a fusion CotC-MCP-3 gene was introduced into <em>Bacillus subtilis</em> 168 (<em>Bs</em>168) to enable surface display of the MCP-3 protein on bacterial spores through the anchoring protein CotC, thereby generating a candidate oral vaccine. At 28 days post-vaccination (dpv), qPCR analysis revealed pronounced upregulation of associated innate and adaptive immunity genes in the gut and head kidney of largemouth bass immunized with the MCP-3 vaccine. Vaccination markedly increased the abundance of IgM<sup>+</sup> B cells in both the gut and head kidney, as well as total IgM levels in serum and gut mucus. Concomitantly, LMBV-specific IgM titers and neutralizing activities in both serum and gut mucus were significantly enhanced. Following the experimental LMBV challenge, fish in the MCP-3 vaccine group achieved a relative percent survival (RPS) of 68.7 %, accompanied by substantially lower viral loads in the head kidney, gut, and spleen, as well as notably attenuated histopathological lesions compared with the other groups. The <em>Bs</em>168-based MCP-3 oral vaccine provides strong protection against LMBV infection in largemouth bass, as demonstrated by these results, highlighting its potential as a promising strategy for managing viral diseases in aquaculture.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"170 ","pages":"Article 111126"},"PeriodicalIF":3.9,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145984971","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}
Pub Date : 2026-01-12DOI: 10.1016/j.fsi.2026.111121
Guoqing Dai , Wei Xiao , Huiling Xing , Lili Shi
Yorkie
(Yki), a key effector of the Hippo signaling pathway, plays important roles in the regulation of cell proliferation and immune responses. In this study, two splice variants of the Yorkie gene (designated as LvYki-long and LvYki-short, respectively) were identified from Litopenaeus vannamei. The open reading frame (ORF) of LvYki-long is 1650 bp that encodes a putative protein of 549 amino acids. Compared with the amino acid sequence of LvYki-long, the amino acid sequence of LvYki-short is reduced by 78 amino acids (positions 416–493). Both LvYki-long and LvYki-short were universally expressed in all tested tissues. Following WSSV and DIV1 infection, their expression was significantly up-regulated in hemocytes and hepatopancreas but down-regulated in gills. The dsRNA-mediated knockdown of LvYki substantially enhanced the shrimp survival rate and reduced viral loads after WSSV and DIV1 infection. Besides, silencing of LvYki led to the down-regulation of Cactus, the up-regulation of Dorsal, as well as several AMPs (ALF1, ALF2, ALF4, and SWD3). Furthermore, silencing of LvYki also resulted in increased expression levels of Vago-JAK/STAT pathway components (Vago4, Vago5, and STAT), and the Co-IP results showed that LvYki could interact with LvIRF. The dual luciferase assay verified that LvYki significantly inhibited the activation of the Vago4 promoter by LvIRF. These results indicated that LvYki might antagonize the innate antiviral immunity through regulating the IRF and Dorsal-mediated antiviral pathways.
{"title":"Yorkie antagonizes innate antiviral immunity through regulating the IRF and Dorsal mediated antiviral pathways in Litopenaeus vannamei","authors":"Guoqing Dai , Wei Xiao , Huiling Xing , Lili Shi","doi":"10.1016/j.fsi.2026.111121","DOIUrl":"10.1016/j.fsi.2026.111121","url":null,"abstract":"<div><h3>Yorkie</h3><div>(<em>Yki</em>), a key effector of the Hippo signaling pathway, plays important roles in the regulation of cell proliferation and immune responses. In this study, two splice variants of the Yorkie gene (designated as <em>LvYki-long</em> and <em>LvYki-short</em>, respectively) were identified from <em>Litopenaeus vannamei.</em> The open reading frame (ORF) of <em>LvYki-long is</em> 1650 bp that encodes a putative protein of 549 amino acids. Compared with the amino acid sequence of LvYki-long, the amino acid sequence of LvYki-short is reduced by 78 amino acids (positions 416–493). Both <em>LvYki-long</em> and <em>LvYki-short</em> were universally expressed in all tested tissues. Following WSSV and DIV1 infection, their expression was significantly up-regulated in hemocytes and hepatopancreas but down-regulated in gills. The dsRNA-mediated knockdown of <em>LvYki</em> substantially enhanced the shrimp survival rate and reduced viral loads after WSSV and DIV1 infection. Besides, silencing of <em>LvYki</em> led to the down-regulation of <em>Cactus</em>, the up-regulation of <em>Dorsal,</em> as well as several AMPs (<em>ALF1</em>, <em>ALF2, ALF4,</em> and <em>SWD3</em>). Furthermore, silencing of <em>LvYki</em> also resulted in increased expression levels of Vago-JAK/STAT pathway components (<em>Vago4, Vago5,</em> and <em>STAT</em>)<em>,</em> and the Co-IP results showed that LvYki could interact with LvIRF. The dual luciferase assay verified that LvYki significantly inhibited the activation of the Vago4 promoter by LvIRF. These results indicated that <em>LvYki</em> might antagonize the innate antiviral immunity through regulating the IRF and Dorsal-mediated antiviral pathways.</div></div>","PeriodicalId":12127,"journal":{"name":"Fish & shellfish immunology","volume":"170 ","pages":"Article 111121"},"PeriodicalIF":3.9,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145974593","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}