Significant economic losses in global tilapia farming have been attributed to tilapia parvovirus (TiPV). There is an urgent need for therapeutic drug discovery, as no effective drugs currently exist to control TiPV infection. Quercetin, a polyphenolic flavonoid found in natural products, effectively inhibits the growth of several viral pathogens. This study evaluated the ability of quercetin to inhibit TiPV replication in a tilapia heart (TH) cell line. MTT assay was used to assess the cytotoxic effects of quercetin on TH cells. H2DCF-DA was used to measure quercetin-induced ROS production in TH cells. Fluorescence microscopy revealed no mitochondrial membrane and nucleus alterations at high quercetin concentrations, as assessed by rhodamine 123 and Hoechst 33,258 staining. Immune-responsive genes (TNF-α, TLR-7, IL-8, MHC-II, IFNγ, and NF-κβ) were studied in TH cells exposed to quercetin test groups (TG1-TG6) at different intervals by RT-qPCR. At 96 h post-exposure, immune-related genes were significantly upregulated in TH cells exposed to 40 and 50 μg/mL quercetin. Quercetin's inhibitory activity against TiPV infection was assessed by morphological changes, cytopathic effects, viral titre quantification by TCID50, TiPV detection by PCR, and viral load quantification by qPCR. The results showed a significant reduction in CPE, TCID50, PCR bands, and viral copies in TH cells treated with higher quercetin concentrations than in non-quercetin-exposed cells. The increase in immune gene expression and decrease in CPE, TCID50, PCR band intensity, and viral load were concentration- and time-dependent manner. This study confirmed the potent antiviral effects of quercetin against TiPV infection, suggesting its potential use as a control drug.
{"title":"Immune response and inhibitory effects of quercetin on tilapia parvovirus: an in vitro approach","authors":"Gani Taju, Allahbagash Badhusha, Seepoo Abdul Majeed, Venkatesan Rajkumar, Mohamed Jaffer Abdul Wazith, Sivaraj Mithra, Kumarasamy Kanimozhi, Azeez Sait Sahul Hameed","doi":"10.1016/j.dci.2025.105505","DOIUrl":"10.1016/j.dci.2025.105505","url":null,"abstract":"<div><div>Significant economic losses in global tilapia farming have been attributed to tilapia parvovirus (TiPV). There is an urgent need for therapeutic drug discovery, as no effective drugs currently exist to control TiPV infection. Quercetin, a polyphenolic flavonoid found in natural products, effectively inhibits the growth of several viral pathogens. This study evaluated the ability of quercetin to inhibit TiPV replication in a tilapia heart (TH) cell line. MTT assay was used to assess the cytotoxic effects of quercetin on TH cells. H<sub>2</sub>DCF-DA was used to measure quercetin-induced ROS production in TH cells. Fluorescence microscopy revealed no mitochondrial membrane and nucleus alterations at high quercetin concentrations, as assessed by rhodamine 123 and Hoechst 33,258 staining. Immune-responsive genes (<em>TNF-α, TLR-7, IL-8, MHC-II, IFNγ</em>, and <em>NF-κβ</em>) were studied in TH cells exposed to quercetin test groups (TG1-TG6) at different intervals by RT-qPCR. At 96 h post-exposure, immune-related genes were significantly upregulated in TH cells exposed to 40 and 50 μg/mL quercetin. Quercetin's inhibitory activity against TiPV infection was assessed by morphological changes, cytopathic effects, viral titre quantification by TCID<sub>50</sub>, TiPV detection by PCR, and viral load quantification by qPCR. The results showed a significant reduction in CPE, TCID<sub>50</sub>, PCR bands, and viral copies in TH cells treated with higher quercetin concentrations than in non-quercetin-exposed cells. The increase in immune gene expression and decrease in CPE, TCID<sub>50</sub>, PCR band intensity, and viral load were concentration- and time-dependent manner. This study confirmed the potent antiviral effects of quercetin against TiPV infection, suggesting its potential use as a control drug.</div></div>","PeriodicalId":11228,"journal":{"name":"Developmental and comparative immunology","volume":"172 ","pages":"Article 105505"},"PeriodicalIF":2.4,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145387934","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 : 2025-11-01DOI: 10.1016/j.dci.2025.105489
Guangcai Wei , Jianhui Zhao , Qingyun Zuo , Manting Sun , Hua Wei , Haofeng Wang , Guiwen Yang , Eakapol Wangkahart , Lei Wang , Fumiao Zhang
Activation-induced deaminase (AID) is a key enzyme that catalyzes the deamination of cytosine to uracil in DNA, driving somatic hypermutation (SHM) and class switch recombination (CSR) of antibody genes to promote antibody diversification in the adaptive immunity. The AID gene from Cyprinus carpio (CcAID) has a full-length open reading frame of 633 bp and encodes a protein of 210 amino acids. CcAID shares structural and functional similarities with apolipoprotein B mRNA-editing enzyme, catalytic polypeptide-like (APOBEC) family members and contains a conserved catalytic domain characteristic of cytidine deaminases. Notably, the absence of two key phosphorylation sites in CcAID (Ser38 and Tyr184) may be a significant factor contributing to the markedly lower levels of somatic hypermutation (SHM) in teleost fish. A high level of CcAID transcript expression was detected in carp larvae on the sixth day after fertilization. Intraperitoneal injection of T-independent and T-dependent antigens preferentially upregulated CcAID expression in head kidney and splenic lymphocytes. Immunofluorescence analysis confirmed its expression in IgM+ spleen lymphocytes. Recombinant CcAID exhibited cytidine deaminase activity. These findings indicate that CcAID is specifically expressed in IgM+ spleen lymphocytes, suggesting its potential role in antibody production.
{"title":"Expression and characterization of activation-induced deaminase (AID) with dehydroaminase activity and its localization in IgM+ lymphocytes of spleen of common carp (Cyprinus carpio)","authors":"Guangcai Wei , Jianhui Zhao , Qingyun Zuo , Manting Sun , Hua Wei , Haofeng Wang , Guiwen Yang , Eakapol Wangkahart , Lei Wang , Fumiao Zhang","doi":"10.1016/j.dci.2025.105489","DOIUrl":"10.1016/j.dci.2025.105489","url":null,"abstract":"<div><div>Activation-induced deaminase (AID) is a key enzyme that catalyzes the deamination of cytosine to uracil in DNA, driving somatic hypermutation (SHM) and class switch recombination (CSR) of antibody genes to promote antibody diversification in the adaptive immunity. The AID gene from <em>Cyprinus carpio</em> (CcAID) has a full-length open reading frame of 633 bp and encodes a protein of 210 amino acids. CcAID shares structural and functional similarities with apolipoprotein B mRNA-editing enzyme, catalytic polypeptide-like (APOBEC) family members and contains a conserved catalytic domain characteristic of cytidine deaminases. Notably, the absence of two key phosphorylation sites in CcAID (Ser38 and Tyr184) may be a significant factor contributing to the markedly lower levels of somatic hypermutation (SHM) in teleost fish. A high level of CcAID transcript expression was detected in carp larvae on the sixth day after fertilization. Intraperitoneal injection of T-independent and T-dependent antigens preferentially upregulated CcAID expression in head kidney and splenic lymphocytes. Immunofluorescence analysis confirmed its expression in IgM<sup>+</sup> spleen lymphocytes. Recombinant CcAID exhibited cytidine deaminase activity. These findings indicate that CcAID is specifically expressed in IgM<sup>+</sup> spleen lymphocytes, suggesting its potential role in antibody production.</div></div>","PeriodicalId":11228,"journal":{"name":"Developmental and comparative immunology","volume":"172 ","pages":"Article 105489"},"PeriodicalIF":2.4,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145279227","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 : 2025-11-01DOI: 10.1016/j.dci.2025.105508
Faith J. Boyer-Millander , Aaron T. Martin , Chadwick A. Hamm , Arthur G. Appel , Elizabeth Hiltbold Schwartz
There is growing interest in insects as subjects for comparative immunological studies; however, very little has been done to quantitatively characterize insect immune cells using modern techniques such as flow cytometry, and virtually no work of this kind has been done in Periplaneta americana. Here, we use an array of general molecular probes including fluorescent lectins, lysosomal indicators, and functional assays to distinguish and characterize insect immune cells (hemocytes) based on cell markers and functions. We have utilized fluorescent tracers of lysosomal content, ROS production, and phagocytosis, as well as microscopic examination of morphology and melanization to distinguish hemocyte types based on these functions. Our findings support the use of lectins as an additional means of separating at least three populations of cockroach immune cells coupled with morphological measurements such as size and complexity. Our results indicate that many functions are enriched in the more granular hemocyte population as these are the cells that exhibit phagocytosis and melanization.
{"title":"A flow cytometric approach to identifying the relative abundance and functional capacities of hemocyte subsets in the American cockroach, Periplaneta americana (L.)","authors":"Faith J. Boyer-Millander , Aaron T. Martin , Chadwick A. Hamm , Arthur G. Appel , Elizabeth Hiltbold Schwartz","doi":"10.1016/j.dci.2025.105508","DOIUrl":"10.1016/j.dci.2025.105508","url":null,"abstract":"<div><div>There is growing interest in insects as subjects for comparative immunological studies; however, very little has been done to quantitatively characterize insect immune cells using modern techniques such as flow cytometry, and virtually no work of this kind has been done in <em>Periplaneta americana</em>. Here, we use an array of general molecular probes including fluorescent lectins, lysosomal indicators, and functional assays to distinguish and characterize insect immune cells (hemocytes) based on cell markers and functions. We have utilized fluorescent tracers of lysosomal content, ROS production, and phagocytosis, as well as microscopic examination of morphology and melanization to distinguish hemocyte types based on these functions. Our findings support the use of lectins as an additional means of separating at least three populations of cockroach immune cells coupled with morphological measurements such as size and complexity. Our results indicate that many functions are enriched in the more granular hemocyte population as these are the cells that exhibit phagocytosis and melanization.</div></div>","PeriodicalId":11228,"journal":{"name":"Developmental and comparative immunology","volume":"172 ","pages":"Article 105508"},"PeriodicalIF":2.4,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145451150","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 : 2025-10-19DOI: 10.1016/j.dci.2025.105499
Ting Yu , Haoxiang Chen , Peipei Yu , Simei Hu , Kai Luo , Weihua Gao , Hanwen Yuan , Zhang Jingchen , Yang Xuefen , Shuhuan Zhang , Qiaoqing Xu , Qingping Lian
SIGIRR is a cell membrane protein in the TIR superfamily, widely expressed in tissues and organs. It has a unique structure and acts as a negative regulator of downstream inflammatory signaling pathways. Danio rerio (zebrafish) were experimentally infected with Mycobacterium marinum to investigate the role of SIGIRR in modulating host immune responses to bacterial infection. Following intraperitoneal injection of M. marinum, SIGIRR gene-deficient zebrafish exhibited an earlier onset of mortality compared to wild type, with the first death occurring sooner and all individuals dying by the fifth week. Wild-type zebrafish began dying in week two and all died by week seven, while SIGIRR−/− mutants died significantly faster. A zebrafish liver cell model was established, and apoptosis was measured by flow cytometry 24 h post-infection. Apoptosis was 16 % in wild-type cells and 25 % in SIGIRR−/− mutant cells. The addition of SIGIRR polyclonal antibody to wild-type liver cells increased apoptosis to 18 % after M. marinum challenge. Significant differences were observed among the three groups. These results show that SIGIRR critically suppresses the inflammatory response during bacterial infection.
{"title":"SIGIRR deficiency aggravates Mycobacterium marinum induced mortality and hepatic apoptosis in zebrafish","authors":"Ting Yu , Haoxiang Chen , Peipei Yu , Simei Hu , Kai Luo , Weihua Gao , Hanwen Yuan , Zhang Jingchen , Yang Xuefen , Shuhuan Zhang , Qiaoqing Xu , Qingping Lian","doi":"10.1016/j.dci.2025.105499","DOIUrl":"10.1016/j.dci.2025.105499","url":null,"abstract":"<div><div>SIGIRR is a cell membrane protein in the TIR superfamily, widely expressed in tissues and organs. It has a unique structure and acts as a negative regulator of downstream inflammatory signaling pathways. <em>Danio rerio</em> (zebrafish) were experimentally infected with <em>Mycobacterium marinum</em> to investigate the role of SIGIRR in modulating host immune responses to bacterial infection. Following intraperitoneal injection of <em>M. marinum</em>, SIGIRR gene-deficient zebrafish exhibited an earlier onset of mortality compared to wild type, with the first death occurring sooner and all individuals dying by the fifth week. Wild-type zebrafish began dying in week two and all died by week seven, while SIGIRR<sup>−/−</sup> mutants died significantly faster. A zebrafish liver cell model was established, and apoptosis was measured by flow cytometry 24 h post-infection. Apoptosis was 16 % in wild-type cells and 25 % in SIGIRR<sup>−/−</sup> mutant cells. The addition of SIGIRR polyclonal antibody to wild-type liver cells increased apoptosis to 18 % after M. marinum challenge. Significant differences were observed among the three groups. These results show that SIGIRR critically suppresses the inflammatory response during bacterial infection.</div></div>","PeriodicalId":11228,"journal":{"name":"Developmental and comparative immunology","volume":"172 ","pages":"Article 105499"},"PeriodicalIF":2.4,"publicationDate":"2025-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145344056","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}
Morganella morganii has emerged as a significant pathogen in aquaculture, yet its effects on largemouth bass (Micropterus salmoides) remain poorly understood. We isolated a pathogenic M. morganii strain (SH6) from diseased bass, caused over 76 % mortality in challenge tests with characteristic hemorrhaging, ascites, and hepatic lesions. Histopathological analysis revealed severe granulomatous inflammation and melanomacrophage centers in infected livers. Transcriptomic profiling identified 5799 differentially expressed genes, with significant enrichment in lipid metabolism pathways (fatty acid degradation) and immune responses (TLR signaling, cytokine-cytokine interactions). Notably, immune regulators (il10, irak4, myd88) were upregulated while drug metabolism enzymes (cytochrome P450) were suppressed. Antibiotic susceptibility testing indicated clinical potential for enrofloxacin and ciprofloxacin treatment, though resistance to azithromycin was observed. These findings demonstrate M. morganii's significant threat to bass aquaculture through metabolic disruption and immune function, meanwhile identifying potential treatment options.
{"title":"Pathological insights and molecular responses to Morganella morganii infection in largemouth bass (Micropterus salmoides)","authors":"Wenji Huang , Xiaoming Zhang , Sijia Wan, Yanan Liu, Lan He, Ling Shao","doi":"10.1016/j.dci.2025.105497","DOIUrl":"10.1016/j.dci.2025.105497","url":null,"abstract":"<div><div><em>Morganella morganii</em> has emerged as a significant pathogen in aquaculture, yet its effects on largemouth bass (<em>Micropterus salmoides</em>) remain poorly understood. We isolated a pathogenic <em>M. morganii</em> strain (SH6) from diseased bass, caused over 76 % mortality in challenge tests with characteristic hemorrhaging, ascites, and hepatic lesions. Histopathological analysis revealed severe granulomatous inflammation and melanomacrophage centers in infected livers. Transcriptomic profiling identified 5799 differentially expressed genes, with significant enrichment in lipid metabolism pathways (fatty acid degradation) and immune responses (TLR signaling, cytokine-cytokine interactions). Notably, immune regulators (<em>il10</em>, <em>irak4</em>, <em>myd88</em>) were upregulated while drug metabolism enzymes (cytochrome P450) were suppressed. Antibiotic susceptibility testing indicated clinical potential for enrofloxacin and ciprofloxacin treatment, though resistance to azithromycin was observed. These findings demonstrate <em>M. morganii</em>'s significant threat to bass aquaculture through metabolic disruption and immune function, meanwhile identifying potential treatment options.</div></div>","PeriodicalId":11228,"journal":{"name":"Developmental and comparative immunology","volume":"172 ","pages":"Article 105497"},"PeriodicalIF":2.4,"publicationDate":"2025-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145328390","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}
Vibrio alginolyticus presents a significant threat to the aquaculture sector of crustaceans, specifically Scylla paramamosain. Hemocyte proliferation is critical for the host's ongoing defense against bacterial pathogens and the maintenance of immune homeostasis. However, the molecular pathways governing hemocyte proliferation and immune responses in crustaceans are not fully elucidated. Building on our prior study, this study examines the effects of V. alginolyticus infection on immune tissue integrity and intestinal microbiota composition in S. paramamosain, with a focus on the role of the hemocyte proliferation regulator Astakine in host immune defense. Our results indicate that V. alginolyticus infection induces substantial histopathological injury to the hepatopancreas, gills, and intestinal tissues. Additionally, V. alginolyticus infection significantly modulates the composition and diversity of the intestinal microbiota. Astakine inhibits V. alginolyticus replication both in vivo and in vitro, while enhancing hemocyte proliferation, which promotes cell proliferation by accelerating G1/S cell cycle progression, and stimulating the secretion of antimicrobial peptides such as crustin and ALFs. Transcriptomic profiling reveals that Astakine activates cell proliferation signaling pathways, suppresses apoptosis pathways, and up-regulates immune-related genes including jak, stat, ALF, Hsp90, and PI3K, while down-regulating apoptosis-associated gene caspase-2. This study offers new insights into the molecular mechanisms by which crustacean hemocyte proliferation contributes to antibacterial immunity.
{"title":"Transcriptome analysis the Astakine induced proliferation of hemocytes to regulate anti-bacterial immunity in Scylla paramamosain","authors":"Zhijuan Liu, Xinqi Liao, Xiaojun Zhong, Menghua Yang, Xiujuan Zhou","doi":"10.1016/j.dci.2025.105495","DOIUrl":"10.1016/j.dci.2025.105495","url":null,"abstract":"<div><div><em>Vibrio alginolyticus</em> presents a significant threat to the aquaculture sector of crustaceans, specifically <em>Scylla paramamosain</em>. Hemocyte proliferation is critical for the host's ongoing defense against bacterial pathogens and the maintenance of immune homeostasis. However, the molecular pathways governing hemocyte proliferation and immune responses in crustaceans are not fully elucidated. Building on our prior study, this study examines the effects of <em>V. alginolyticus</em> infection on immune tissue integrity and intestinal microbiota composition in <em>S. paramamosain</em>, with a focus on the role of the hemocyte proliferation regulator Astakine in host immune defense. Our results indicate that <em>V. alginolyticus</em> infection induces substantial histopathological injury to the hepatopancreas, gills, and intestinal tissues. Additionally, <em>V. alginolyticus</em> infection significantly modulates the composition and diversity of the intestinal microbiota. Astakine inhibits <em>V. alginolyticus</em> replication both in <em>vivo</em> and <em>in vitro</em>, while enhancing hemocyte proliferation, which promotes cell proliferation by accelerating G1/S cell cycle progression, and stimulating the secretion of antimicrobial peptides such as crustin and ALFs. Transcriptomic profiling reveals that Astakine activates cell proliferation signaling pathways, suppresses apoptosis pathways, and up-regulates immune-related genes including <em>jak</em>, <em>stat</em>, <em>ALF</em>, <em>Hsp90</em>, and <em>PI3K</em>, while down-regulating apoptosis-associated gene <em>caspase-2.</em> This study offers new insights into the molecular mechanisms by which crustacean hemocyte proliferation contributes to antibacterial immunity.</div></div>","PeriodicalId":11228,"journal":{"name":"Developmental and comparative immunology","volume":"172 ","pages":"Article 105495"},"PeriodicalIF":2.4,"publicationDate":"2025-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145312583","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 : 2025-10-15DOI: 10.1016/j.dci.2025.105492
Xiaona Zhang , Huan Wang , Lei Liu , Ronghua Li , Yangfang Ye , Weiwei Song , Ce Shi , Chunlin Wang , Changkao Mu
Wnt/β-catenin signalling regulates many physiological processes in organisms, including development and tissue homeostasis maintenance. Signal transduction in this pathway involves the regulation of its multiprotein complex, which targets β-catenin for proteasomal degradation. The genes encoding the cytoplasmic regulatory proteins β-catenin and GSK-3β in Portunus trituberculatus were successfully cloned and characterized here. Ptβ-catenin was most highly expressed in hemocytes, PtGSK-3β in ovarian tissue, and both genes were significantly upregulated at ovarian stage III, as revealed by quantitative real-time RT-PCR analysis. Continuous injection of the Wnt/β-catenin signalling activator CHIR-98014 resulted in decreased expression of PtGSK-3β, increased expression of Ptβ-catenin, decreased expression of PtVg (vitellogenin) and the content of rPtVn (vitellin). Additionally, it resulted in a significant reduction in both gonadosomatic index (GSI) and oocyte diameter. HE staining revealed diminished vitellogenic granules and the formation of cytoplasmic vacuoles in the oocytes. By contrast, continuous injection ETC-159, a potent inhibitor of Wnt/β-catenin signalling caused increased expression of PtGSK-3β, decreased expression of Ptβ-catenin, increased expression of PtVg and the content of rPtVn. Furthermore, it resulted in an increased GSI, larger oocyte diameter, and HE staining revealed a greater number of yolk granules and a tight arrangement of oocytes. This study elucidates the critical regulatory function of Wnt/β-catenin signaling in P. trituberculatus ovarian development, establishing a foundation for future investigations into the molecular mechanisms governing crustacean reproductive physiology.
{"title":"The Wnt/β-catenin signalling pathway regulates ovarian development in the swimming crab Portunus trituberculatus","authors":"Xiaona Zhang , Huan Wang , Lei Liu , Ronghua Li , Yangfang Ye , Weiwei Song , Ce Shi , Chunlin Wang , Changkao Mu","doi":"10.1016/j.dci.2025.105492","DOIUrl":"10.1016/j.dci.2025.105492","url":null,"abstract":"<div><div>Wnt/β-catenin signalling regulates many physiological processes in organisms, including development and tissue homeostasis maintenance. Signal transduction in this pathway involves the regulation of its multiprotein complex, which targets β-catenin for proteasomal degradation. The genes encoding the cytoplasmic regulatory proteins β-catenin and GSK-3β in <em>Portunus trituberculatus</em> were successfully cloned and characterized here. <em>Ptβ-catenin</em> was most highly expressed in hemocytes, <em>PtGSK-3β</em> in ovarian tissue, and both genes were significantly upregulated at ovarian stage III, as revealed by quantitative real-time RT-PCR analysis. Continuous injection of the Wnt/β-catenin signalling activator CHIR-98014 resulted in decreased expression of <em>PtGSK-3β</em>, increased expression of <em>Ptβ-catenin</em>, decreased expression of <em>PtVg</em> (vitellogenin) and the content of r<em>PtVn</em> (vitellin). Additionally, it resulted in a significant reduction in both gonadosomatic index (GSI) and oocyte diameter. HE staining revealed diminished vitellogenic granules and the formation of cytoplasmic vacuoles in the oocytes. By contrast, continuous injection ETC-159, a potent inhibitor of Wnt/β-catenin signalling caused increased expression of <em>PtGSK-3β</em>, decreased expression of <em>Ptβ-catenin</em>, increased expression of <em>PtVg</em> and the content of r<em>PtVn</em>. Furthermore, it resulted in an increased GSI, larger oocyte diameter, and HE staining revealed a greater number of yolk granules and a tight arrangement of oocytes. This study elucidates the critical regulatory function of Wnt/β-catenin signaling in <em>P. trituberculatus</em> ovarian development, establishing a foundation for future investigations into the molecular mechanisms governing crustacean reproductive physiology.</div></div>","PeriodicalId":11228,"journal":{"name":"Developmental and comparative immunology","volume":"172 ","pages":"Article 105492"},"PeriodicalIF":2.4,"publicationDate":"2025-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145307041","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 : 2025-10-13DOI: 10.1016/j.dci.2025.105493
Solange C. Antão , Daniel B. Pavanelo , Eliane Esteves , Marcelly B. Nassar , Beatriz I. Alonso , Pablo Vera , Marcelo B. Labruna , Petr Kopáček , Sirlei Daffre , Ludek Zurek , Fernanda Dias da Silva , Marisa Farber , Andréa C. Fogaça
Besides carrying pathogens, ticks also harbor commensal and mutualistic microorganisms that constitute their microbiota. This microbial community can modulate the tick immune system and influence pathogen acquisition, either facilitating or hindering colonization. Additionally, the microbiota may impact tick fitness. Although the ticks Amblyomma sculptum and Amblyomma aureolatum are important vectors of Rickettsia rickettsii, the causative agent of Brazilian spotted fever, A. sculptum is much less susceptible to infection than A. aureolatum. Intriguingly, while A. aureolatum midgut harbors an abundant microbiota, mostly composed of bacteria of the Francisella genus, A. sculptum presents a markedly reduced bacterial community. In the current study, we quantified the total bacterial load also in the salivary glands and ovaries of adult A. sculptum and A. aureolatum, besides midgut. Across all analyzed organs, bacterial loads were consistently lower in A. sculptum than in A. aureolatum, regardless of whether the ticks had fed on naïve or R. rickettsii-inoculated hosts. High-throughput sequencing of the V3-V4 hypervariable region of the bacterial 16S rRNA gene revealed that Francisella endosymbiont is the dominant taxon in all organs of control A. aureolatum, with the highest relative frequency in the ovaries and the lowest in the midgut. The highest relative frequency of Francisella in the ovaries correlates with the lower susceptibility of this organ to R. rickettsii, suggesting that the endosymbiosis may limit infection. No 16S rRNA gene sequences could be obtained for A. sculptum samples, likely due to their low bacterial content. To investigate the role played by the microbiota on rickettsial acquisition and tick fitness, A. aureolatum engorged females were treated with either tetracycline or ciprofloxacin. Tetracycline treatment significantly reduced bacterial loads and antimicrobial peptide transcript levels in the eggs, and this was followed by a higher acquisition of R. rickettsii by hatched larvae. Additionally, tetracycline negatively impacted tick development, reducing the molt success from the larval to the nymphal stage. These results suggest that maternal microbiota plays a role in shaping offspring immunity, pathogen susceptibility, and tick development. The multifaceted role of tick microbiota in both development and vector competence underscores its potential as a biotechnological resource for developing new strategies to control tick-borne diseases.
{"title":"Interactions between microbiota and immunity shape pathogen acquisition and fitness in Amblyomma spp. ticks","authors":"Solange C. Antão , Daniel B. Pavanelo , Eliane Esteves , Marcelly B. Nassar , Beatriz I. Alonso , Pablo Vera , Marcelo B. Labruna , Petr Kopáček , Sirlei Daffre , Ludek Zurek , Fernanda Dias da Silva , Marisa Farber , Andréa C. Fogaça","doi":"10.1016/j.dci.2025.105493","DOIUrl":"10.1016/j.dci.2025.105493","url":null,"abstract":"<div><div>Besides carrying pathogens, ticks also harbor commensal and mutualistic microorganisms that constitute their microbiota. This microbial community can modulate the tick immune system and influence pathogen acquisition, either facilitating or hindering colonization. Additionally, the microbiota may impact tick fitness. Although the ticks <em>Amblyomma sculptum</em> and <em>Amblyomma aureolatum</em> are important vectors of <em>Rickettsia rickettsii</em>, the causative agent of Brazilian spotted fever, <em>A. sculptum</em> is much less susceptible to infection than <em>A. aureolatum</em>. Intriguingly, while <em>A. aureolatum</em> midgut harbors an abundant microbiota, mostly composed of bacteria of the <em>Francisella</em> genus, <em>A. sculptum</em> presents a markedly reduced bacterial community. In the current study, we quantified the total bacterial load also in the salivary glands and ovaries of adult <em>A. sculptum</em> and <em>A. aureolatum</em>, besides midgut. Across all analyzed organs, bacterial loads were consistently lower in <em>A. sculptum</em> than in <em>A. aureolatum</em>, regardless of whether the ticks had fed on naïve or <em>R. rickettsii</em>-inoculated hosts. High-throughput sequencing of the V3-V4 hypervariable region of the bacterial 16S rRNA gene revealed that <em>Francisella</em> endosymbiont is the dominant taxon in all organs of control <em>A. aureolatum</em>, with the highest relative frequency in the ovaries and the lowest in the midgut. The highest relative frequency of <em>Francisella</em> in the ovaries correlates with the lower susceptibility of this organ to <em>R. rickettsii</em>, suggesting that the endosymbiosis may limit infection. No 16S rRNA gene sequences could be obtained for <em>A. sculptum</em> samples, likely due to their low bacterial content. To investigate the role played by the microbiota on rickettsial acquisition and tick fitness, <em>A. aureolatum</em> engorged females were treated with either tetracycline or ciprofloxacin. Tetracycline treatment significantly reduced bacterial loads and antimicrobial peptide transcript levels in the eggs, and this was followed by a higher acquisition of <em>R. rickettsii</em> by hatched larvae. Additionally, tetracycline negatively impacted tick development, reducing the molt success from the larval to the nymphal stage. These results suggest that maternal microbiota plays a role in shaping offspring immunity, pathogen susceptibility, and tick development. The multifaceted role of tick microbiota in both development and vector competence underscores its potential as a biotechnological resource for developing new strategies to control tick-borne diseases.</div></div>","PeriodicalId":11228,"journal":{"name":"Developmental and comparative immunology","volume":"172 ","pages":"Article 105493"},"PeriodicalIF":2.4,"publicationDate":"2025-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145299173","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 : 2025-10-11DOI: 10.1016/j.dci.2025.105490
Shixiong Zhan , Defu Yao , Yueling Zhang
Shrimp hemocyanin plays multifunctional roles in immunity, both in its native form and as proteolytic fragments generated during infection. Here, we characterize LvHcS52, a hemocyanin-derived peptide identified in the serum of white spot syndrome virus (WSSV)-infected Litopenaeus vannamei. Through molecular weight analysis, N-terminal and de novo sequencing, and bioinformatic prediction, we define LvHcS52 as a 55-amino acid fragment (residues 526–580 of hemocyanin; accession CAA57880) with a molecular mass of 5824.09 Da, structurally featuring one α-helix and two β-strands. Both recombinant and synthetic LvHcS52 significantly inhibited WSSV gene expression (ie1 and vp28), reduced viral loads, and improved shrimp survival. Mechanistically, LvHcS52 binds the WSSV envelope protein VP28 and host β-integrin on hemocytes, promoting viral phagocytosis. Moreover, it also activates the STAT signaling pathway and upregulates anti-lipopolysaccharide factors (ALFs) to restrict viral replication. Our findings underscore the immunological versatility of hemocyanin and illustrate how invertebrates maximize limited immune components to mount effective antiviral responses. This study provides new insights into crustacean innate immunity and opens avenues for developing peptide-based antiviral strategies in aquaculture.
{"title":"LvHcS52, a Litopenaeus vannamei hemocyanin-derived peptide, restricts WSSV infection by promoting phagocytosis and activating the STAT signaling pathway","authors":"Shixiong Zhan , Defu Yao , Yueling Zhang","doi":"10.1016/j.dci.2025.105490","DOIUrl":"10.1016/j.dci.2025.105490","url":null,"abstract":"<div><div>Shrimp hemocyanin plays multifunctional roles in immunity, both in its native form and as proteolytic fragments generated during infection. Here, we characterize LvHcS52, a hemocyanin-derived peptide identified in the serum of white spot syndrome virus (WSSV)-infected <em>Litopenaeus vannamei</em>. Through molecular weight analysis, N-terminal and <em>de novo</em> sequencing, and bioinformatic prediction, we define LvHcS52 as a 55-amino acid fragment (residues 526–580 of hemocyanin; accession CAA57880) with a molecular mass of 5824.09 Da, structurally featuring one α-helix and two β-strands. Both recombinant and synthetic LvHcS52 significantly inhibited WSSV gene expression (<em>ie1</em> and <em>vp28</em>), reduced viral loads, and improved shrimp survival. Mechanistically, LvHcS52 binds the WSSV envelope protein VP28 and host β-integrin on hemocytes, promoting viral phagocytosis. Moreover, it also activates the STAT signaling pathway and upregulates anti-lipopolysaccharide factors (<em>ALFs</em>) to restrict viral replication. Our findings underscore the immunological versatility of hemocyanin and illustrate how invertebrates maximize limited immune components to mount effective antiviral responses. This study provides new insights into crustacean innate immunity and opens avenues for developing peptide-based antiviral strategies in aquaculture.</div></div>","PeriodicalId":11228,"journal":{"name":"Developmental and comparative immunology","volume":"172 ","pages":"Article 105490"},"PeriodicalIF":2.4,"publicationDate":"2025-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145279299","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}
We established a cohabitation model to study shrimp survival after a white spot syndrome virus (WSSV) outbreak. Naïve shrimp were reared individually in plastic boxes immersed in a tank with ten free-roaming shrimp injected each with 1000 copies of purified WSSV. A WSSV outbreak commenced from day four (elevated mortality levels), which lasted for about 10 days. When no further mortalities occurred, surviving shrimp were collected for observation. Survival levels of the cohabitating shrimp were between 5.3 % and 15.9 % from independent infection trials. Determination of viral loads by qPCR and RT-PCR demonstrated 10,000-fold higher viral copy numbers in the moribund shrimp than in the survivors. Western blot analysis using an anti-VP28 antibody confirmed PCR results that high VP28 expression occurs in moribund shrimp, but no signals were detected in the survivors. Histological examination depicted eosinophilic inclusion bodies with hypertrophied (swollen) nuclei and marginated, slightly basophilic, chromatin in the moribund shrimp, but not in the survivors. These data suggest that the surviving shrimp are resilient and posses a mechanism to curtail viremia. Expression levels of selected antimicrobial factors – ALF3, ALF6, PmCrustin1, PmPenaeidin3 and PmPenaeidin5 were compared between moribund and survivor shrimp. PmCrustin1 and ALF3 expression were substantially higher in the moribund shrimp than those of survivors. Interestingly, expression levels of PmCrustin1 were correlated positively with viral loads. Our data provides new insight into WSSV resilience in Penaeus monondon.
{"title":"Persistence of viral load in shrimp that survived WSSV infection","authors":"Phasini Buathongkam , Jiraporn Srisala , Chanisara Srivihok , Sithichoke Tangphatsornruang , Christopher J. Coates , Suparat Taengchaiyaphum , Siripong Thitamadee , Kallaya Sritunyalucksana","doi":"10.1016/j.dci.2025.105488","DOIUrl":"10.1016/j.dci.2025.105488","url":null,"abstract":"<div><div>We established a cohabitation model to study shrimp survival after a white spot syndrome virus (WSSV) outbreak. Naïve shrimp were reared individually in plastic boxes immersed in a tank with ten free-roaming shrimp injected each with 1000 copies of purified WSSV. A WSSV outbreak commenced from day four (elevated mortality levels), which lasted for about 10 days. When no further mortalities occurred, surviving shrimp were collected for observation. Survival levels of the cohabitating shrimp were between 5.3 % and 15.9 % from independent infection trials. Determination of viral loads by qPCR and RT-PCR demonstrated 10,000-fold higher viral copy numbers in the moribund shrimp than in the survivors. Western blot analysis using an <em>anti</em>-VP28 antibody confirmed PCR results that high VP28 expression occurs in moribund shrimp, but no signals were detected in the survivors. Histological examination depicted eosinophilic inclusion bodies with hypertrophied (swollen) nuclei and marginated, slightly basophilic, chromatin in the moribund shrimp, but not in the survivors. These data suggest that the surviving shrimp are resilient and posses a mechanism to curtail viremia. Expression levels of selected antimicrobial factors – <em>ALF3</em>, <em>ALF6</em>, <em>PmCrustin1</em>, <em>PmPenaeidin3</em> and <em>PmPenaeidin5</em> were compared between moribund and survivor shrimp. <em>PmCrustin1</em> and <em>ALF3</em> expression were substantially higher in the moribund shrimp than those of survivors. Interestingly, expression levels of <em>PmCrustin1</em> were correlated positively with viral loads<em>.</em> Our data provides new insight into WSSV resilience in <em>Penaeus monondon.</em></div></div>","PeriodicalId":11228,"journal":{"name":"Developmental and comparative immunology","volume":"172 ","pages":"Article 105488"},"PeriodicalIF":2.4,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145279235","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}
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