Pub Date : 2026-01-06DOI: 10.1016/j.dci.2026.105550
Bangyao Liang , Wei Meng , Meihan Chen , Hongfei Miao , Yuhan Ren , Hongyu Liu , Zhenhui Liu , Chen Sun
Peroxiredoxin 4 (Prdx4), a typical 2-Cys peroxiredoxin, functions as both an antioxidant enzyme and a regulator of immune processes, yet its roles in early chordates remain unclear. Here, we identified and characterized a Prdx4 homolog from amphioxus (Branchiostoma japonicum), termed BjPrdx4. Sequence analyses revealed conserved catalytic motifs and an N-terminal signal peptide, supporting its classification as Prdx4. BjPrdx4 was constitutively expressed across multiple tissues, with prominent localization in immune-associated tissues, and its expression was markedly induced following Vibrio anguillarum challenge. Infection also triggered BjPrdx4 secretion into the extracellular milieu and altered its oligomeric states. Recombinant BjPrdx4 exhibited robust thiol-dependent peroxidase activity, efficiently eliminating hydrogen peroxide and protecting plasmid DNA from oxidative damage, confirming its antioxidant function. Functionally, extracellular BjPrdx4 preserved gill integrity and reduced bacterial burden during infection. Transcriptomic and qRT-PCR analyses further demonstrated that BjPrdx4 influenced immune-related pathways, including phagocytosis and lysosomal activity, and positively regulated ras expression, suggesting involvement in Ras–MAPK signaling. Together, these findings reveal that BjPrdx4 integrates antioxidant defense with immunomodulatory functions, highlighting its dual role in amphioxus antibacterial immunity and underscoring the evolutionary significance of Prdx4 multifunctionality in basal chordates.
{"title":"Peroxiredoxin 4 from amphioxus: An antioxidant enzyme with immunomodulatory roles in defense against Vibrio anguillarum","authors":"Bangyao Liang , Wei Meng , Meihan Chen , Hongfei Miao , Yuhan Ren , Hongyu Liu , Zhenhui Liu , Chen Sun","doi":"10.1016/j.dci.2026.105550","DOIUrl":"10.1016/j.dci.2026.105550","url":null,"abstract":"<div><div>Peroxiredoxin 4 (Prdx4), a typical 2-Cys peroxiredoxin, functions as both an antioxidant enzyme and a regulator of immune processes, yet its roles in early chordates remain unclear. Here, we identified and characterized a Prdx4 homolog from amphioxus (<em>Branchiostoma japonicum</em>), termed BjPrdx4. Sequence analyses revealed conserved catalytic motifs and an N-terminal signal peptide, supporting its classification as Prdx4. BjPrdx4 was constitutively expressed across multiple tissues, with prominent localization in immune-associated tissues, and its expression was markedly induced following <em>Vibrio anguillarum</em> challenge. Infection also triggered BjPrdx4 secretion into the extracellular milieu and altered its oligomeric states. Recombinant BjPrdx4 exhibited robust thiol-dependent peroxidase activity, efficiently eliminating hydrogen peroxide and protecting plasmid DNA from oxidative damage, confirming its antioxidant function. Functionally, extracellular BjPrdx4 preserved gill integrity and reduced bacterial burden during infection. Transcriptomic and qRT-PCR analyses further demonstrated that BjPrdx4 influenced immune-related pathways, including phagocytosis and lysosomal activity, and positively regulated <em>ras</em> expression, suggesting involvement in Ras–MAPK signaling. Together, these findings reveal that BjPrdx4 integrates antioxidant defense with immunomodulatory functions, highlighting its dual role in amphioxus antibacterial immunity and underscoring the evolutionary significance of Prdx4 multifunctionality in basal chordates.</div></div>","PeriodicalId":11228,"journal":{"name":"Developmental and comparative immunology","volume":"175 ","pages":"Article 105550"},"PeriodicalIF":2.4,"publicationDate":"2026-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145932748","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2026-01-06DOI: 10.1016/j.dci.2026.105548
Hong Qi , Jia-Yang He , Jia-Ru Zhou , Yun-Xiang Lin , Yu-Rong Lei, Hai Zhu He, Wei-Yang Huang, Qi-Wei Qin, Hong-Yan Sun
Recent studies found that non-coding RNA could be involved in the development of pathogen infection. In this study, the role of non-coding RNA miRNA-181c (miR-181c) response to Iridovirus SGIV (an important viral pathogen and can cause huge economic losses in marine fish industry) infection was explored in Epinephelus coioides, an important economic fish in South China. The results showed that SGIV infection inhibited the expression of E. coioides miR-181c. Upregulated miR-181c significantly inhibited the invasion of SGIV, the expressions of key SGIV genes (MCP, ICP18, LITAF and VP19), SGIV-induced CPE, and the titers of SGIV. Programmed cell death 4 (PDCD4) of E. coioides was a direct target of miR-181c. miR-181c could regulate the expressions of the immune- and apoptosis-related factors, and SGIV-induced apoptosis via targeting PDCD4. Downregulated miR-181c could produce the opposite results. These findings would be useful for exploring miRNAs for potentially controlling viral infection.
{"title":"miR-181c Regulates the process of the Infection of Singapore Grouper Iridovirus via targeting PDCD4 in Epinephelus coioides","authors":"Hong Qi , Jia-Yang He , Jia-Ru Zhou , Yun-Xiang Lin , Yu-Rong Lei, Hai Zhu He, Wei-Yang Huang, Qi-Wei Qin, Hong-Yan Sun","doi":"10.1016/j.dci.2026.105548","DOIUrl":"10.1016/j.dci.2026.105548","url":null,"abstract":"<div><div>Recent studies found that non-coding RNA could be involved in the development of pathogen infection. In this study, the role of non-coding RNA miRNA-181c (miR-181c) response to Iridovirus SGIV (an important viral pathogen and can cause huge economic losses in marine fish industry) infection was explored in <em>Epinephelus coioides</em>, an important economic fish in South China. The results showed that SGIV infection inhibited the expression of <em>E</em>. <em>coioides</em> miR-181c. Upregulated miR-181c significantly inhibited the invasion of SGIV, the expressions of key SGIV genes (<em>MCP</em>, <em>ICP18</em>, LITAF and VP19), SGIV-induced CPE, and the titers of SGIV. Programmed cell death 4 (PDCD4) of <em>E</em>. <em>coioides</em> was a direct target of miR-181c. miR-181c could regulate the expressions of the immune- and apoptosis-related factors, and SGIV-induced apoptosis via targeting PDCD4. Downregulated miR-181c could produce the opposite results. These findings would be useful for exploring miRNAs for potentially controlling viral infection.</div></div>","PeriodicalId":11228,"journal":{"name":"Developmental and comparative immunology","volume":"175 ","pages":"Article 105548"},"PeriodicalIF":2.4,"publicationDate":"2026-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145917372","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2026-01-01DOI: 10.1016/j.dci.2025.105541
Lifang Wen , Sisi Wei , Li Wu , Zhenqi Xin , Mingshan Song , Weifeng Wang , Baoying Guo
{"title":"Transcriptomic analysis reveals the immune-related function of miR-122 in Larimichthys crocea","authors":"Lifang Wen , Sisi Wei , Li Wu , Zhenqi Xin , Mingshan Song , Weifeng Wang , Baoying Guo","doi":"10.1016/j.dci.2025.105541","DOIUrl":"10.1016/j.dci.2025.105541","url":null,"abstract":"","PeriodicalId":11228,"journal":{"name":"Developmental and comparative immunology","volume":"174 ","pages":"Article 105541"},"PeriodicalIF":2.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145833396","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2026-01-01DOI: 10.1016/j.dci.2025.105542
Li Lu, Tao Wang, Xiaopeng Wang, Liangjie Liu, An Liu, Haihui Ye
Environmental factors such as temperature, salinity, illumination intensity, and photoperiod exert profound influences on the physiology and reproduction of aquatic crustaceans. In this study, female mud crabs (Scylla paramamosain) were exposed to combined high-temperature and strong illumination stress (30 °C, 6000 lx) or maintained under control conditions (25 °C, 600 lx) for 30 days. To elucidate the impact of combined high-temperature and strong illumination stress on ovarian development, we conducted integrated analyses of transcriptomic data (RNA-Seq) from the hepatopancreas and ovary, alongside lipidomic profiles of the hepatopancreas and hemolymph. The hepatopancreas exhibited downregulation of lipid synthesis genes (e.g., Fasn, SCD5) and upregulation of lipid catabolism genes (e.g., BBOX1, Pnlip), which was associated with reduced lipid storage. Enrichment of sphingolipid signaling and autophagy pathways in hemolymph, along with elevated phosphatidylethanolamine species, indicated activation of protective mechanisms to maintain systemic balance. The ovary contained 1,457 differentially expressed genes, including upregulated stress-related genes (e.g., Lrp1b, Tcab1) and downregulated reproduction-related genes (e.g., Igf1r, LENG9), reflecting a trade-off between reproductive suppression and stress adaptation. In conclusion, these findings provide new insights into the adaptation of the mud crab to dual environmental stressors through coordinated molecular adjustments, offering valuable information for aquaculture management in response to sudden weather changes.
{"title":"Transcriptomic and lipidomic analysis provide insights into ovarian development of the mud crab Scylla paramamosain under high-temperature and strong illumination conditions","authors":"Li Lu, Tao Wang, Xiaopeng Wang, Liangjie Liu, An Liu, Haihui Ye","doi":"10.1016/j.dci.2025.105542","DOIUrl":"10.1016/j.dci.2025.105542","url":null,"abstract":"<div><div>Environmental factors such as temperature, salinity, illumination intensity, and photoperiod exert profound influences on the physiology and reproduction of aquatic crustaceans. In this study, female mud crabs (<em>Scylla paramamosain</em>) were exposed to combined high-temperature and strong illumination stress (30 °C, 6000 lx) or maintained under control conditions (25 °C, 600 lx) for 30 days. To elucidate the impact of combined high-temperature and strong illumination stress on ovarian development, we conducted integrated analyses of transcriptomic data (RNA-Seq) from the hepatopancreas and ovary, alongside lipidomic profiles of the hepatopancreas and hemolymph. The hepatopancreas exhibited downregulation of lipid synthesis genes (e.g., <em>Fasn</em>, <em>SCD5</em>) and upregulation of lipid catabolism genes (e.g., <em>BBOX1</em>, <em>Pnlip</em>), which was associated with reduced lipid storage. Enrichment of sphingolipid signaling and autophagy pathways in hemolymph, along with elevated phosphatidylethanolamine species, indicated activation of protective mechanisms to maintain systemic balance. The ovary contained 1,457 differentially expressed genes, including upregulated stress-related genes (e.g., <em>Lrp1b</em>, <em>Tcab1</em>) and downregulated reproduction-related genes (e.g., <em>Igf1r</em>, <em>LENG9</em>), reflecting a trade-off between reproductive suppression and stress adaptation. In conclusion, these findings provide new insights into the adaptation of the mud crab to dual environmental stressors through coordinated molecular adjustments, offering valuable information for aquaculture management in response to sudden weather changes.</div></div>","PeriodicalId":11228,"journal":{"name":"Developmental and comparative immunology","volume":"174 ","pages":"Article 105542"},"PeriodicalIF":2.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145833314","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2026-01-01DOI: 10.1016/j.dci.2025.105540
Zhou Jiang , Yue Jiang , Bo Liu , Han Zhang , Rui Li , Sijing Chen , Fei Pu , Shuimu Hu , Hongshu Chi , Ning Li , Peng Xu , Tao Zhou
L-amino acid oxidase (laao) is a key immune factor capable of producing reactive oxygen species (ROS) and has been demonstrated to possess significant antibacterial and immunomodulatory functions in a variety of organisms. In recent years, increasing attention has been paid to the role of laao in the immune defense of fish against Cryptocaryon irritans infection. In this study, the laao of large yellow croaker (Larimichthys crocea) was successfully cloned, and its structural and functional characteristics were systematically analyzed. The full-length ORF of large yellow croaker was 1578 bp, encoding 526 amino acids. Structural prediction indicated that the protein possesses typical features of a secretory protein, including a distinct signal peptide region and three potential N-glycosylation sites. The Laao of large yellow croaker shows high conservation at key catalytic residues compared with those of Danio rerio and Bothrops pauloensis. Molecular docking further revealed a clear substrate preference, with hydrophobic amino acids exhibiting the strongest binding affinity, whereas polar substrates showed weaker interactions. Phylogenetic analysis revealed that laao is highly conserved among teleosts, showing the highest sequence similarity to Collichthys lucidus (96.57 %) and Nibea albiflora (81.57 %). The tissue expression analysis demonstrated that laao exhibits a tissue-specific expression pattern in large yellow croaker, being mainly expressed in the gills, fins, kidneys, and spleen, with the lowest expression in the brain. Following C. irritans infection, laao expression in the gills and spleen responded rapidly, reaching a peak at 24 h post-infection. However, although laao expression peaked in the skin as early as 12 h post-infection, its expression level was relatively low. The transcriptomic data before and after infection also confirmed that laao was activated upon C. irritans challenge, showing differential expression with an overall upregulation trend. The qRT-PCR results further demonstrated that overexpression of laao significantly altered the expression patterns of immune-related genes (hif1, tnf-α, il-8, il-1β and stat3) were downregulated, while jak1 was upregulated-suggesting that laao may participate in host immune regulation by suppressing inflammatory signaling and activating cytokine-mediated pathways. In summary, this study reveals the structural features of laao and its response characteristics during C. irritans infection, providing a theoretical basis for further understanding the role of large yellow croaker laao in fish immune defense and for developing novel immune prevention and control strategies.
{"title":"Molecular characterization of laao in large yellow croaker and its functional response to Cryptocaryon irritans infection","authors":"Zhou Jiang , Yue Jiang , Bo Liu , Han Zhang , Rui Li , Sijing Chen , Fei Pu , Shuimu Hu , Hongshu Chi , Ning Li , Peng Xu , Tao Zhou","doi":"10.1016/j.dci.2025.105540","DOIUrl":"10.1016/j.dci.2025.105540","url":null,"abstract":"<div><div>L-amino acid oxidase (<em>laao</em>) is a key immune factor capable of producing reactive oxygen species (ROS) and has been demonstrated to possess significant antibacterial and immunomodulatory functions in a variety of organisms. In recent years, increasing attention has been paid to the role of <em>laao</em> in the immune defense of fish against <em>Cryptocaryon irritans</em> infection. In this study, the <em>laao</em> of large yellow croaker (<em>Larimichthys crocea</em>) was successfully cloned, and its structural and functional characteristics were systematically analyzed. The full-length ORF of large yellow croaker was 1578 bp, encoding 526 amino acids. Structural prediction indicated that the protein possesses typical features of a secretory protein, including a distinct signal peptide region and three potential N-glycosylation sites. The Laao of large yellow croaker shows high conservation at key catalytic residues compared with those of <em>Danio rerio</em> and <em>Bothrops pauloensis</em>. Molecular docking further revealed a clear substrate preference, with hydrophobic amino acids exhibiting the strongest binding affinity, whereas polar substrates showed weaker interactions. Phylogenetic analysis revealed that <em>laao</em> is highly conserved among teleosts, showing the highest sequence similarity to <em>Collichthys lucidus</em> (96.57 %) and <em>Nibea albiflora</em> (81.57 %). The tissue expression analysis demonstrated that <em>laao</em> exhibits a tissue-specific expression pattern in large yellow croaker, being mainly expressed in the gills, fins, kidneys, and spleen, with the lowest expression in the brain. Following <em>C. irritans</em> infection, <em>laao</em> expression in the gills and spleen responded rapidly, reaching a peak at 24 h post-infection. However, although <em>laao</em> expression peaked in the skin as early as 12 h post-infection, its expression level was relatively low. The transcriptomic data before and after infection also confirmed that laao was activated upon <em>C. irritans</em> challenge, showing differential expression with an overall upregulation trend. The qRT-PCR results further demonstrated that overexpression of laao significantly altered the expression patterns of immune-related genes (<em>hif1, tnf-α, il-8, il-1β</em> and <em>stat3</em>) were downregulated, while jak1 was upregulated-suggesting that <em>laao</em> may participate in host immune regulation by suppressing inflammatory signaling and activating cytokine-mediated pathways. In summary, this study reveals the structural features of <em>laao</em> and its response characteristics during <em>C. irritans</em> infection, providing a theoretical basis for further understanding the role of large yellow croaker <em>laao</em> in fish immune defense and for developing novel immune prevention and control strategies.</div></div>","PeriodicalId":11228,"journal":{"name":"Developmental and comparative immunology","volume":"174 ","pages":"Article 105540"},"PeriodicalIF":2.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145803387","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2026-01-01DOI: 10.1016/j.dci.2025.105543
Jiangwei Zhou , Wenwei Huang , Weicheng Yang , Sixun Li , Mengmeng Wu , Min Zhang , Zihang Xie , Lilin Zhan , Qiang Li , Jianrong Huang
Toll-like receptors (TLRs) are a family of pattern recognition receptors (PRRs) central to innate immunity. In teleost fish, TLRs play a pivotal role in defending against diverse microbial invaders, yet their evolutionary adaptation and functional specialization in Spinibarbus hollandi (army fish) remain uncharacterized. This study reports the first molecular cloning and functional analysis of TLR3, TLR4, TLR5M, and TLR18 in S. hollandi. All four TLRs possess conserved intracellular Toll/IL-1 receptor (TIR) domains and extracellular leucine-rich repeat (LRR) domains. Basal expression profiling reveals distinct tissue specificity: TLR3 and TLR5M are highly expressed in the liver, TLR4 dominates in the brain and eye, and TLR18 shows minimal constitutive expression. After Aeromonas veronii challenge, liver TLR5M is most dramatically upregulated and acts as an early-response core gene. Phylogenetic analysis confirms high homology between S. hollandi TLRs and cyprinid orthologs. Molecular evolutionary analysis identifies positive selection sites in the LRR domains of TLR3 and TLR5M, indicative of adaptive optimization for pathogen recognition. These findings clarify TLR-mediated bacterial immunity in S. hollandi and provide candidate targets for aquaculture disease resistance breeding.
{"title":"Molecular characterization and expression analysis of four toll-like receptors genes: TLR3, TLR4, TLR5M and TLR18 in Spinibarbu hollandi under Aeromonas veronii infection","authors":"Jiangwei Zhou , Wenwei Huang , Weicheng Yang , Sixun Li , Mengmeng Wu , Min Zhang , Zihang Xie , Lilin Zhan , Qiang Li , Jianrong Huang","doi":"10.1016/j.dci.2025.105543","DOIUrl":"10.1016/j.dci.2025.105543","url":null,"abstract":"<div><div>Toll-like receptors (TLRs) are a family of pattern recognition receptors (PRRs) central to innate immunity. In teleost fish, TLRs play a pivotal role in defending against diverse microbial invaders, yet their evolutionary adaptation and functional specialization in <em>Spinibarbus hollandi</em> (army fish) remain uncharacterized. This study reports the first molecular cloning and functional analysis of TLR3, TLR4, TLR5M, and TLR18 in <em>S. hollandi</em>. All four TLRs possess conserved intracellular Toll/IL-1 receptor (TIR) domains and extracellular leucine-rich repeat (LRR) domains. Basal expression profiling reveals distinct tissue specificity: TLR3 and TLR5M are highly expressed in the liver, TLR4 dominates in the brain and eye, and TLR18 shows minimal constitutive expression. After <em>Aeromonas veronii</em> challenge, liver TLR5M is most dramatically upregulated and acts as an early-response core gene. Phylogenetic analysis confirms high homology between <em>S. hollandi</em> TLRs and cyprinid orthologs. Molecular evolutionary analysis identifies positive selection sites in the LRR domains of TLR3 and TLR5M, indicative of adaptive optimization for pathogen recognition. These findings clarify TLR-mediated bacterial immunity in <em>S. hollandi</em> and provide candidate targets for aquaculture disease resistance breeding.</div></div>","PeriodicalId":11228,"journal":{"name":"Developmental and comparative immunology","volume":"174 ","pages":"Article 105543"},"PeriodicalIF":2.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145849320","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2025-12-27DOI: 10.1016/j.dci.2025.105544
Yuwen Luo , Mengyi Dong , Yuxi Shen , Xuelian Xiang , Jiadai Lv , Yi Sun , Yongxin Li , Yamei Huang , Min Cui , Xinfeng Han , Jing Xia , Yong Huang
China has a great demand for poultry, while avian influenza (AI) remains widespread and exhibits high instability, posing a persistent challenge to the poultry industry. Elucidating the genetic stability of avian influenza variants and their implications for pathogenicity is key for pandemic risk mitigation. H9 and H6 AIVs have co-circulated in China due to a specific evolutionary dynamic: H9 AIVs serve as stable genetic reservoirs, whereas H6 AIVs act as platforms for multi-subtype reassortment. This reassortment process continually generates novel variants with unpredictable virulence, posing a persistent biosecurity threat to poultry production. Genetic stability analysis of H9/H6 AI viral Ribonucleoprotein (vRNP) complexes (PB2, PB1, PA, NP) revealed clear subtype-specific divergence. H9 AIVs retained highly conserved gene constellations, whereas H6 AIVs exhibited pronounced plasticity, acquiring 42.5 % of PB2, 20.1 % of PA, and 23.7 % of NP genes from other AIV subtypes. The H9vRNP-H6 reassortant (H6N2 backbone carrying H9N2 vRNP) showed enhanced replicability in both MDCK cells (4.7 → 5.7 log10TCID50/mL) and embryonated eggs (6.7 → 7.7 log10EID50/mL), with significantly promoted pathogenicity in chicks. These findings highlight the urgent need to integrate genetic surveillance of H9 and H6 AIVs into targeted prevention frameworks, thereby forestalling the emergence of pandemic-prone reassortants and mitigating potential losses to the poultry industry and public health. Hence, such research would provide a theoretical basis for the development of novel vaccines and enhance strategies for the control and prevention of avian influenza.
{"title":"Impact of viral ribonucleoprotein complex genetic stability on pathogenicity in H9N2 and H6N2 avian influenza viruses","authors":"Yuwen Luo , Mengyi Dong , Yuxi Shen , Xuelian Xiang , Jiadai Lv , Yi Sun , Yongxin Li , Yamei Huang , Min Cui , Xinfeng Han , Jing Xia , Yong Huang","doi":"10.1016/j.dci.2025.105544","DOIUrl":"10.1016/j.dci.2025.105544","url":null,"abstract":"<div><div>China has a great demand for poultry, while avian influenza (AI) remains widespread and exhibits high instability, posing a persistent challenge to the poultry industry. Elucidating the genetic stability of avian influenza variants and their implications for pathogenicity is key for pandemic risk mitigation. H9 and H6 AIVs have co-circulated in China due to a specific evolutionary dynamic: H9 AIVs serve as stable genetic reservoirs, whereas H6 AIVs act as platforms for multi-subtype reassortment. <strong>This reassortment process continually generates novel variants with unpredictable virulence, posing a persistent biosecurity threat to poultry production.</strong> Genetic stability analysis of H9/H6 AI viral Ribonucleoprotein (vRNP) complexes (<em>PB2, PB1, PA, NP</em>) revealed clear subtype-specific divergence. H9 AIVs retained highly conserved gene constellations, whereas H6 AIVs exhibited pronounced plasticity, acquiring 42.5 % of <em>PB2</em>, 20.1 % of <em>PA</em>, and 23.7 % of <em>NP</em> genes from other AIV subtypes. The H9vRNP-H6 reassortant (H6N2 backbone carrying H9N2 vRNP) showed enhanced replicability in both MDCK cells (4.7 → 5.7 log<sub>10</sub>TCID<sub>50</sub>/mL) and embryonated eggs (6.7 → 7.7 log<sub>10</sub>EID<sub>50</sub>/mL), with significantly promoted pathogenicity in chicks. These findings <strong>highlight the urgent need to integrate genetic surveillance of H9 and H6 AIVs into targeted prevention frameworks</strong>, thereby forestalling the emergence of pandemic-prone reassortants and mitigating potential losses to the poultry industry and public health. Hence, such research would provide a theoretical basis for the development of novel vaccines and enhance strategies for the control and prevention of avian influenza.</div></div>","PeriodicalId":11228,"journal":{"name":"Developmental and comparative immunology","volume":"175 ","pages":"Article 105544"},"PeriodicalIF":2.4,"publicationDate":"2025-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145855021","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2025-12-16DOI: 10.1016/j.dci.2025.105539
Xiaofeng Liu , Qian Hou , Zejun Zhou
Bacterial pathogens like Aeromonas hydrophila threaten aquaculture by compromising fish immune defenses. The intestinal barrier is a critical frontline defense against pathogenic bacteria in fish, yet its regulation by neuroimmune mechanisms remains poorly understood. In this study, we investigated the role of vasoactive intestinal peptide (VIP) in the immune response of grass carp (Ctenopharyngodon idella) following bacterial challenge. The full-length grass carp VIP gene was 462 bp, encoding a 153-amino acid precursor protein with high sequence conservation across vertebrates. VIP expression was highest in the intestinal tract and significantly upregulated upon A. hydrophila infection. Administration of recombinant grass carp VIP protein enhanced intestinal barrier function by increasing the expression of tight junction molecules (ZO-1, Occludin, Claudin-1) and the immunoregulatory cytokine IL-22, while reducing plasma LPS and D-lactate levels. Furthermore, grass carp VIP treatment promoted the expression of the mucosal barrier component MUC2 and antimicrobial peptides (LEAP-2, Lyz1, Hepcidin-1), reduced bacterial load, and significantly improved survival rates. Mechanistic studies confirmed that VIP interacted specifically with the VIP receptor 2 (VIPR2), and knockdown of VIPR2 abolished the protective effects of VIP on barrier integrity and antimicrobial immunity. These findings demonstrate that the VIP-VIPR2 axis plays a crucial role in modulating intestinal immunity in grass carp, offering new insights into neuroimmune regulation in aquatic animals during pathogenic challenge.
{"title":"The VIP-VIPR2 axis strengthens intestinal barrier integrity and antimicrobial immunity in Ctenopharyngodon idella","authors":"Xiaofeng Liu , Qian Hou , Zejun Zhou","doi":"10.1016/j.dci.2025.105539","DOIUrl":"10.1016/j.dci.2025.105539","url":null,"abstract":"<div><div>Bacterial pathogens like <em>Aeromonas hydrophila</em> threaten aquaculture by compromising fish immune defenses. The intestinal barrier is a critical frontline defense against pathogenic bacteria in fish, yet its regulation by neuroimmune mechanisms remains poorly understood. In this study, we investigated the role of vasoactive intestinal peptide (VIP) in the immune response of grass carp (<em>Ctenopharyngodon idella</em>) following bacterial challenge. The full-length grass carp VIP gene was 462 bp, encoding a 153-amino acid precursor protein with high sequence conservation across vertebrates. VIP expression was highest in the intestinal tract and significantly upregulated upon <em>A. hydrophila</em> infection. Administration of recombinant grass carp VIP protein enhanced intestinal barrier function by increasing the expression of tight junction molecules (<em>ZO-1</em>, <em>Occludin</em>, <em>Claudin-1</em>) and the immunoregulatory cytokine IL-22, while reducing plasma LPS and D-lactate levels. Furthermore, grass carp VIP treatment promoted the expression of the mucosal barrier component <em>MUC2</em> and antimicrobial peptides (<em>LEAP-2</em>, <em>Lyz1</em>, <em>Hepcidin-1</em>), reduced bacterial load, and significantly improved survival rates. Mechanistic studies confirmed that VIP interacted specifically with the VIP receptor 2 (VIPR2), and knockdown of VIPR2 abolished the protective effects of VIP on barrier integrity and antimicrobial immunity. These findings demonstrate that the VIP-VIPR2 axis plays a crucial role in modulating intestinal immunity in grass carp, offering new insights into neuroimmune regulation in aquatic animals during pathogenic challenge.</div></div>","PeriodicalId":11228,"journal":{"name":"Developmental and comparative immunology","volume":"174 ","pages":"Article 105539"},"PeriodicalIF":2.4,"publicationDate":"2025-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145780393","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2025-12-15DOI: 10.1016/j.dci.2025.105538
Wei-Wei Fang , Yi-Xin Wu , Yi-Bin Cao , Xin-Jiang Lu , Jian-Rao Hu
Hypoxia compromises host defense in fish by impairing macrophage function, but the underlying mechanisms remain unclear. This study elucidates the molecular mechanisms by which hypoxia disrupts monocytes/macrophages (MO/MФ) function in Japanese sea bass (Lateolabrax japonicus), with a particular focus on the regulatory role of heme biosynthesis and its key gene, 5′-aminolevulinate synthase 2 (ALAS2). Phylogenetic analysis confirmed high evolutionary conservation of ALAS2 across vertebrates, supporting its fundamental role in heme metabolism. Transcriptomic analysis revealed that hypoxia induced the upregulation of genes involved in heme biosynthesis of MO/MФ, particularly ALAS2. Functional assays demonstrated that heme accumulation under hypoxic conditions impaired MO/MФ phagocytic and bactericidal activities, while also promoted the production of pro-inflammatory cytokines. These dysfunctions were mediated by the ALAS2-heme signaling axis, which orchestrated inflammatory responses and metabolic reprogramming throughout the study. Knockdown of ALAS2 enhanced phagocytic activity and suppressed pro-inflammatory cytokine expression, suggesting its critical role in modulating MO/MФ function under hypoxia. Furthermore, inhibition of heme synthesis improved fish survival rates and reduced bacterial burdens during Vibrio harveyi infection. These findings elucidate the pivotal role of heme in regulating MO/MФ function and host defense under hypoxic conditions, providing mechanistic insights into hypoxia-induced immune suppression in aquaculture.
{"title":"Hypoxia impairs monocyte/macrophage function and host defense via ALAS2-mediated heme biosynthesis in Japanese sea bass (Lateolabrax japonicus)","authors":"Wei-Wei Fang , Yi-Xin Wu , Yi-Bin Cao , Xin-Jiang Lu , Jian-Rao Hu","doi":"10.1016/j.dci.2025.105538","DOIUrl":"10.1016/j.dci.2025.105538","url":null,"abstract":"<div><div>Hypoxia compromises host defense in fish by impairing macrophage function, but the underlying mechanisms remain unclear. This study elucidates the molecular mechanisms by which hypoxia disrupts monocytes/macrophages (MO/MФ) function in Japanese sea bass (<em>Lateolabrax japonicus</em>), with a particular focus on the regulatory role of heme biosynthesis and its key gene, <em>5′-aminolevulinate synthase 2</em> (<em>ALAS2</em>). Phylogenetic analysis confirmed high evolutionary conservation of <em>ALAS2</em> across vertebrates, supporting its fundamental role in heme metabolism. Transcriptomic analysis revealed that hypoxia induced the upregulation of genes involved in heme biosynthesis of MO/MФ, particularly <em>ALAS2</em>. Functional assays demonstrated that heme accumulation under hypoxic conditions impaired MO/MФ phagocytic and bactericidal activities, while also promoted the production of pro-inflammatory cytokines. These dysfunctions were mediated by the <em>ALAS2</em>-heme signaling axis, which orchestrated inflammatory responses and metabolic reprogramming throughout the study. Knockdown of <em>ALAS2</em> enhanced phagocytic activity and suppressed pro-inflammatory cytokine expression, suggesting its critical role in modulating MO/MФ function under hypoxia. Furthermore, inhibition of heme synthesis improved fish survival rates and reduced bacterial burdens during <em>Vibrio harveyi</em> infection. These findings elucidate the pivotal role of heme in regulating MO/MФ function and host defense under hypoxic conditions, providing mechanistic insights into hypoxia-induced immune suppression in aquaculture.</div></div>","PeriodicalId":11228,"journal":{"name":"Developmental and comparative immunology","volume":"174 ","pages":"Article 105538"},"PeriodicalIF":2.4,"publicationDate":"2025-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145773879","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2025-12-05DOI: 10.1016/j.dci.2025.105534
Xiantong Liu , Ruixue Wu , Ning Ning Wang , Hua Xu , Xiaojun Rong , Chao Li , Min Cao
The intestinal microbiota is a critical mediator of host immune responses and metabolic homeostasis, especially during the pathogenic challenge. This study investigated the dynamic remodeling of the gut microbiota and metabolome in Sebastes schlegelii following infection with the major aquaculture pathogen Edwardsiella piscicida. Using 16S rRNA gene sequencing and untargeted metabolomics, we analyzed the microbial community composition and metabolic profiles of intestinal samples at multiple time points post-infection. Our results revealed significant temporal shifts in bacterial diversity and structure. Notably, the abundances of genera such as Bacteroides, Bacillus, and Lactobacillus increased, while Comamonas and Cutibacterium decreased. Metabolomic analysis identified 1063 metabolites, with lipids and lipid-like molecules being the most abundant. Differential analysis revealed stage-specific metabolic alterations: early infection was marked by the upregulation of pro-inflammatory mediators such as lithocholic acid and palmitoylethanolamide, whereas late infection featured elevated levels of anti-inflammatory metabolites, including cholic acid and agmatine. KEGG pathway analysis indicated an initial enrichment in general metabolic processes, followed by a shift to steroid biosynthesis later in the infection. These findings suggest a coordinated “metabolic switch" mechanism that modulates inflammation and promotes recovery. This study provides novel insights into the microbiota–metabolite–immune network in S. schlegelii and highlights potential biomarkers for monitoring fish health status in aquaculture.
{"title":"Dynamic remodeling of gut microbiota and untargeted etabolomics in Sebastes schlegelii during Edwardsiella piscicida infection","authors":"Xiantong Liu , Ruixue Wu , Ning Ning Wang , Hua Xu , Xiaojun Rong , Chao Li , Min Cao","doi":"10.1016/j.dci.2025.105534","DOIUrl":"10.1016/j.dci.2025.105534","url":null,"abstract":"<div><div>The intestinal microbiota is a critical mediator of host immune responses and metabolic homeostasis, especially during the pathogenic challenge. This study investigated the dynamic remodeling of the gut microbiota and metabolome in <em>Sebastes schlegelii</em> following infection with the major aquaculture pathogen <em>Edwardsiella piscicida</em>. Using 16S rRNA gene sequencing and untargeted metabolomics, we analyzed the microbial community composition and metabolic profiles of intestinal samples at multiple time points post-infection. Our results revealed significant temporal shifts in bacterial diversity and structure. Notably, the abundances of genera such as <em>Bacteroides</em>, <em>Bacillus</em>, and <em>Lactobacillus</em> increased, while <em>Comamonas</em> and <em>Cutibacterium</em> decreased. Metabolomic analysis identified 1063 metabolites, with lipids and lipid-like molecules being the most abundant. Differential analysis revealed stage-specific metabolic alterations: early infection was marked by the upregulation of pro-inflammatory mediators such as lithocholic acid and palmitoylethanolamide, whereas late infection featured elevated levels of anti-inflammatory metabolites, including cholic acid and agmatine. KEGG pathway analysis indicated an initial enrichment in general metabolic processes, followed by a shift to steroid biosynthesis later in the infection. These findings suggest a coordinated “metabolic switch\" mechanism that modulates inflammation and promotes recovery. This study provides novel insights into the microbiota–metabolite–immune network in <em>S. schlegelii</em> and highlights potential biomarkers for monitoring fish health status in aquaculture.</div></div>","PeriodicalId":11228,"journal":{"name":"Developmental and comparative immunology","volume":"174 ","pages":"Article 105534"},"PeriodicalIF":2.4,"publicationDate":"2025-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145696210","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
扫码关注我们
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号