Expression of a phenoloxidase cascade inhibitor enhances the virulence of the fungus Beauveria bassiana against the insect Helicoverpa armigera
作者：
Liu, Zhan-Chi;Zhou, Liu;Wang, Jia-Lin;Liu, Xu-Sheng
* （ 期刊：
DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY ,2021年117(1):103986 ISSN：0145-305X
作者机构：
[Liu, Xu-Sheng; Wang, Jia-Lin; Liu, Zhan-Chi; Zhou, Liu] Cent China Normal Univ, Sch Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, 152 Luoyu Rd, Wuhan 430079, Peoples R China.
通讯机构：
[Liu, Xu-Sheng] C;Cent China Normal Univ, Sch Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, 152 Luoyu Rd, Wuhan 430079, Peoples R China.
关键词：
Prophenoloxidase;Biological control;Genetic engineering;Virulence;Beauveria bassiana
摘要：
Entomopathogenic fungi have high potential for controlling insect pests, although the slow killing speed has blocked their widespread application. To increase the virulence of entomopathogenic fungi, genetic modification can be employed. Egf1.0 is an immunosuppressive protein encoded by polydnavirus, carried by parasitoid wasp Microplitis demolitor, which blocks the prophenoloxidase (PPO) activation response of host insects. In this study, we explored the feasibility of genetically modifying entomopathogenic fungi with increased virulence by expressing Egf1.0. In comparison with the wild-type parents, the median lethal concentration (LC50) of Beauveria bassiana expressing Egf1.0 against Helicoverpa armigera was reduced by 2.7-fold, and the median lethal time (LT50) was reduced by 22.8%. In vitro assay showed that recombinant Egf1.0 was able to inhibit the PPO activation response of H. armigera. In vivo assay revealed that the expression of Egf1.0 in B. bassiana caused a higher degree of suppression to PPO activation response of H. armigera. These assays suggested that the increased virulence of the transgenic fungi is due to the increased ability to suppress the host insect's immune response. Moreover, colony growth, conidia yield, and germination assays revealed that the expression of Egf1.0 in B. bassiana had no effect on its growth and development. In conclusion, the expression of Egf1.0 can significantly enhance the pathogenicity of B. bassiana against host insects.
语种：
英文
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Steroid hormone 20-hydroxyecdysone promotes CTL1-mediated cellular immunity in Helicoverpa armigera
作者：
Wang, Gui-Jie;Wang, Wen-Wen;Liu, Yu;Chai, Lian-Qin;Wang, Guo-Xiu;...
期刊：
昆虫科学(英文) ,2021年28(5):1399-1413 ISSN：1672-9609
通讯作者：
Wang, Jia-Lin
作者机构：
[Liu, Xu-Sheng; Wang, Wen-Wen; Wang, Gui-Jie; Liu, Yu; Wang, Guo-Xiu; Wang, Jia-Lin; Wang, Yu-Feng] Cent China Normal Univ, Sch Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan 430079, Peoples R China.;[Chai, Lian-Qin] Henan Univ, Sch Life Sci, Kaifeng 475004, Henan, Peoples R China.
通讯机构：
[Wang, Jia-Lin] C;Cent China Normal Univ, Sch Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan 430079, Peoples R China.
关键词：
C-type lectin;encapsulation;phagocytosis;20-hydroxyecdysone
摘要：
Mermithid nematodes, such as Ovomermis sinensis, are used as biological control agents against many insect pests, including cotton bollworm (Helicoverpa armigera). However, given the host's robust immune system, the infection rate of O. sinensis is low, thus restricting its widespread use. To understand the host defense mechanisms against mermithid nematodes, we identified and characterized a protein involved in the recognition of O. sinensis, the potential O. sinensis-binding protein C-type lectin 1 (HaCTL1a and/or HaCTL1b), which was eluted from the surface of O. sinensis after incubation with H. armigera plasma. HaCTL1b is homologous to the previously reported HaCTL1a protein. HaCTL1 was predominantly expressed in hemocytes and was induced by the steroid hormone 20-hydroxyecdysone through ecdysone receptor (HaEcR) or ultraspiracle (HaUSP), or both. Binding assays confirmed the interactions of the HaCTL1 proteins with O. sinensis but not with Romanomermis wuchangensis, a parasitic nematode of mosquito. Moreover, the HaCTL1 proteins were secreted into the hemocoel and promoted hemocyte-mediated encapsulation and phagocytosis. A knockdown of HaEcR and/or HaUSP resulted in compromised encapsulation and phagocytosis. Thus, HaCTL1 appears to modulate cellular immunity in the defense against parasitic nematodes, and the 20-hydroxyecdysone–HaEcR–HaUSP complex is involved in regulating the process. © 2020 Institute of Zoology, Chinese Academy of Sciences
语种：
英文
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Mechanism of Metarhizium rileyi evading cellular immune responses in Helicoverpa armigera
作者：
Li, Li;Zhong, Ke;Wang, Jia-Lin;Liu, Xu-Sheng
* （ 期刊：
Archives of Insect Biochemistry and Physiology ,2021年106(3):e21769- ISSN：0739-4462
作者机构：
[Liu, Xu-Sheng; Li, Li; Wang, Jia-Lin; Zhong, Ke] Cent China Normal Univ, Sch Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan 430079, Peoples R China.
通讯机构：
[Liu, Xu-Sheng] C;Cent China Normal Univ, Sch Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan 430079, Peoples R China.
关键词：
cellular immune response;entomopathogenic fungi;Helicoverpa armigera;hyphal bodies;Metarhizium rileyi
摘要：
Upon entry into the hemocoel of host insects, entomopathogenic fungi switch to yeast-like hyphal bodies that are not recognized by host hemocytes and replicate extensively in the hemolymph. The mechanism by which hyphal bodies evade host cellular immunity is not well understood. This study compares Metarhizium rileyi conidia and hyphal bodies with respect to elicitation of the immune response of Helicoverpa armigera and recognition by host pattern recognition receptors (PRRs). We found that the ability of host hemocytes to phagocytize and nodulate hyphal bodies was weaker than those responses against conidia, suggesting that hyphal bodies are more able to evade host cellular immunity. Additionally, we found that the binding affinity of H. armigera β-1,3-glucan recognition proteins was much lower for hyphal bodies than for conidia. We observed no agglutination response of H. armigera C-type lectin 3 (HaCTL3) against hyphal bodies, and HaCTL3 bound significantly less to hyphal bodies than to conidia, indicating that host PRRs have a lower affinity for hyphal bodies than for conidia. This study provides direct evidence that the mechanism whereby entomopathogenic fungi escape host cellular immunity involves the inability of host PRRs to sufficiently recognize hyphal bodies to elicit the cellular immune response.
Hyphal bodies had a greater ability to evade the host cellular immunity.
Hyphal bodies evade PRR recognition.
语种：
英文
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C-type lectin-mediated microbial homeostasis is critical for helicoverpa armigera larval growth and development
作者：
Wang, Wenwen;Wang, Guijie;Zhuo, Xiaorong;Liu, Yu;Tang, Lin;...
期刊：
PLOS Pathogens ,2020年16(9):e1008901 ISSN：1553-7366
通讯作者：
Wang, Jialin
作者机构：
[Liu, Xusheng; Wang, Guijie; Liu, Yu; Wang, Jialin; Wang, Wenwen; Tang, Lin; Zhuo, Xiaorong] Cent China Normal Univ, Hubei Key Lab Genet Regulat & Integrat Biol, Sch Life Sci, Wuhan, Peoples R China.
通讯机构：
[Wang, Jialin] C;Cent China Normal Univ, Hubei Key Lab Genet Regulat & Integrat Biol, Sch Life Sci, Wuhan, Peoples R China.
关键词：
Larvae;Gut bacteria;Fats;Bacteria;Physiological parameters;Staphylococcus aureus;Phagocytosis;Body weight
摘要：
The immune system of a host functions critically in shaping the composition of the microbiota, and some microbes are involved in regulating host endocrine system and development. However, whether the immune system acts on endocrine and development by shaping the composition of the microbiota remains unclear, and few molecular players or microbes involved in this process have been identified. In the current study, we found that RNA interference of a C-type lectin (HaCTL3) in the cotton bollworm Helicoverpa armigera suppresses ecdysone and juvenile hormone signaling, thus reducing larval body size and delaying pupation. Depletion of HaCTL3 also results in an increased abundance of Enterocuccus mundtii in the hemolymph, which may escape from the gut. Furthermore, HaCTL3 and its controlled antimicrobial peptides (attacin, lebocin, and gloverin) are involved in the clearance of E. mundtii from the hemolymph via phagocytosis or direct bactericidal activity. Injection of E. mundtii into larval hemocoel mimics HaCTL3-depleted phenotypes and suppresses ecdysone and juvenile hormone signaling. Taken together, we conclude that HaCTL3 maintains normal larval growth and development of H. armigera via suppressing the abundance of E. mundtii in the hemolymph. Our results provide the first evidence of an immune system acting on an endocrine system to modulate development via shaping the composition of microbiota in insect hemolymph. Thus, this study will deepen our understanding of the interaction between immunity and development. © 2020 Wang et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
语种：
英文
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Molecular characterization of immune responses of Helicoverpa armigera to infection with the mermithid nematode Ovomermis sinensis
作者：
Wang, Gui-Jie;Zhuo, Xiao-Rong;Wang, Wen-Wen;Liu, Xu-Sheng
（ ;Wang, Guo-Xiu;...
期刊：
BMC Genomics ,2019年20(1):1-11 ISSN：1471-2164
通讯作者：
Wang, Jia-Lin
作者机构：
[Liu, Xu-Sheng; Wang, Wen-Wen; Wang, Gui-Jie; Zhuo, Xiao-Rong; Wang, Guo-Xiu; Wang, Jia-Lin] Cent China Normal Univ, Sch Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan 430079, Hubei, Peoples R China.
通讯机构：
[Wang, Jia-Lin] C;Cent China Normal Univ, Sch Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan 430079, Hubei, Peoples R China.
关键词：
Ovomermis sinensis;Helicoverpa armigera;Immunity;Parasitism;Fat body
摘要：
Background: Mermithid nematodes, such as Ovomermis sinensis, display a broad host range including some lepidopteran pests. Infective juveniles penetrate their host through the cuticle, complete their growth within the hemocoel and eventually kill the host upon their emergence. Hence, mermithid nematodes are considered potential biological control agents of insect pests. Our previous data indicate that the infection rate of O. sinensis on cotton bollworm (Helicoverpa armigera) is low, which may be largely due to the strong immune system of the host. However, current knowledge on the interactions of mermithid nematodes with their hosts and the mechanisms employed by hosts to defend themselves against mermithid nematodes is limited. Results: Here, we investigated the response of H. armigera to O. sinensis infection. Parasitism by O. sinensis caused a sharp decline in the survival rate of H. armigera. The hemocytic phagocytosis ability, antibacterial activity, and phenoloxidase (PO) activity in plasma of H. armigera increased at 1 d post parasitism (dpp) but decreased at 3 dpp. Further, we investigated gene expression in the fat body of parasitized and non-parasitized H. armigera larvae at 1, 3, and 5 dpp using a digital gene expression system. In total, 41, 60 and 68 immune-related differentially expressed genes were identified at 1, 3, and 5 dpp, respectively. These genes encoded pattern recognition receptors (PRRs), antimicrobial peptides (AMPs), serine proteases (SPs), SP inhibitors, mucins and other immune-related proteins. The expression of most PRRs, AMPs, SPs, and mucins was upregulated in the fat body of larvae at 1 dpp, downregulated at 3 dpp, and then again upregulated at 5 dpp by O. sinensis. The increased expression of SP inhibitors may contribute to the inhibited PO activity at 5 dpp. Conclusions: This study demonstrates that parasitism by O. sinensis modulates the immune reaction of the host H. armigera by altering the expression of immune-related genes. Our data provide a basis for future investigation of the molecular mechanisms employed by the mermithid nematode O. sinensis to modulate the immunity of the host H. armigera. These data will also likely facilitate the improvement of success in parasitism of H. armigera by O. sinensis. © 2019 The Author(s).
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英文
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Ingestion of killed bacteria activates antimicrobial peptide genes in Drosophila melanogaster and protects flies from septic infection
作者：
Wen, Yunyun;He, Zhen;Xu, Tao;Jiao, Yan;Liu, Xusheng
（ ;...
期刊：
DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY ,2019年95(1):10-18 ISSN：0145-305X
通讯作者：
Yu, Xiao-Qiang
作者机构：
[Liu, Xusheng; Jiao, Yan; He, Zhen; Xu, Tao; Yu, Xiao-Qiang; Wen, Yunyun; Wang, Yu-Feng] Cent China Normal Univ, Sch Life Sci, Wuhan 430079, Hubei, Peoples R China.;[Yu, Xiao-Qiang] Univ Missouri, Sch Biol Sci, Div Cell Biol & Biophys, Kansas City, MO 64110 USA.
通讯机构：
[Yu, Xiao-Qiang] C;Cent China Normal Univ, Sch Life Sci, Wuhan 430079, Hubei, Peoples R China.
关键词：
Antimicrobial peptide;IMD;Ingestion;Local immune response;MyD88;Systemic immune response
摘要：
Drosophila melanogaster possesses a sophisticated and effective immune system composed of humoral and cellular immune responses, and production of antimicrobial peptides (AMPs) is an important defense mechanism. Expression of AMPs is regulated by the Toll and IMD (immune deficiency) pathways. Production of AMPs can be systemic in the fat body or a local event in the midgut and epithelium. So far, most studies focus on systemic septic infection in adult flies and little is known about AMP gene activation after ingestion of killed bacteria. In this study, we investigated activation of AMP genes in the wild-type w 1118 , MyD88 and Imd mutant flies after ingestion of heat-killed Escherichia coli and Staphylococcus aureus. We showed that ingestion of E. coli activated most AMP genes, including drosomycin and diptericin, in the first to third instar larvae and pupae, while ingestion of S. aureus induced only some AMP genes in some larval stages or in pupae. In adult flies, ingestion of killed bacteria activated AMP genes differently in males and females. Interestingly, ingestion of killed E. coli and S. aureus in females conferred resistance to septic infection by both live pathogenic Enterococcus faecalis and Pseudomonas aeruginosa, and ingestion of E. coli in males conferred resistance to P. aeruginosa infection. Our results indicated that E. coli and S. aureus can activate both the Toll and IMD pathways, and systemic and local immune responses work together to provide Drosophila more effective protection against infection. © 2019 Elsevier Ltd
语种：
英文
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An in vitro study of NF-κB factors cooperatively in regulation of Drosophila melanogaster antimicrobial peptide genes
作者：
Chowdhury, Munmun;Zhang, Jie;Xu, Xiao-Xia;He, Zhen;Lu, Yuzhen;...
期刊：
DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY ,2019年95(1):50-58 ISSN：0145-305X
通讯作者：
Yu, Xiao-Qiang
作者机构：
[Xu, Xiao-Xia; He, Zhen; Yu, Xiao-Qiang; Zhang, Jie; Chowdhury, Munmun] Univ Missouri, Sch Biol Sci, Div Cell Biol & Biophys, Kansas City, MO 64110 USA.;[Liu, Xu-Sheng; He, Zhen; Yu, Xiao-Qiang; Wang, Yu-Feng] Cent China Normal Univ, Sch Life Sci, Wuhan 430079, Hubei, Peoples R China.;[Yu, Xiao-Qiang; Lu, Yuzhen] South China Normal Univ, Sch Life Sci, Inst Insect Sci & Technol, Guangdong Prov Key Lab Insect Dev Biol & Appl Tec, Guangzhou 510631, Guangdong, Peoples R China.;[Yu, Xiao-Qiang; Lu, Yuzhen] South China Normal Univ, Sch Life Sci, Inst Insect Sci & Technol, Guangzhou Key Lab Insect Dev Regulat & Applicat R, Guangzhou 510631, Guangdong, Peoples R China.;[Xu, Xiao-Xia] South China Agr Univ, Coll Agr, Guangzhou 510642, Guangdong, Peoples R China.
通讯机构：
[Yu, Xiao-Qiang] U;Univ Missouri, Sch Biol Sci, Div Cell Biol & Biophys, Kansas City, MO 64110 USA.
关键词：
*Antimicrobial peptide;*DIF;*Dorsal;*NF-kappaB factors;*Relish
摘要：
An important innate immune response in Drosophila melanogaster is the production of antimicrobial peptides (AMPs). Expression of AMP genes is mediated by the Toll and immune deficiency (IMD) pathways via NF-kappaB transcription factors Dorsal, DIF and Relish. Dorsal and DIF act downstream of the Toll pathway, whereas Relish acts in the IMD pathway. Dorsal and DIF are held inactive in the cytoplasm by the IkappaB protein Cactus, while Relish contains an IkappaB-like inhibitory domain at the C-terminus. NF-kappaB factors normally form homodimers and heterodimers to regulate gene expression, but formation of heterodimers between Relish and DIF or Dorsal and the specificity and activity of the three NF-kappaB homodimers and heterodimers are not well understood. In this study, we compared the activity of Rel homology domains (RHDs) of Dorsal, DIF and Relish in activation of Drosophila AMP gene promoters, demonstrated that Relish-RHD (Rel-RHD) interacted with both Dorsal-RHD and DIF-RHD, Relish-N interacted with DIF and Dorsal, and overexpression of individual RHD and co-expression of any two RHDs activated the activity of AMP gene promoters to various levels, suggesting formation of homodimers and heterodimers among Dorsal, DIF and Relish. Rel-RHD homodimers were stronger activators than heterodimers of Rel-RHD with either DIF-RHD or Dorsal-RHD, while DIF-RHD-Dorsal-RHD heterodimers were stronger activators than either DIF-RHD or Dorsal-RHD homodimers in activation of AMP gene promoters. We also identified the nucleotides at the 6th and 8th positions of the 3' half-sites of the kappaB motifs that are important for the specificity and activity of NF-kappaB transcription factors.
语种：
英文
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Toll family members bind multiple Spätzle proteins and activate antimicrobial peptide gene expression in Drosophila
作者：
Chowdhury, Munmun;Li, Chun-Feng;He, Zhen;Lu, Yuzhen;Liu, Xu-Sheng
（ ;...
期刊：
Journal of Biological Chemistry ,2019年294(26):10172-10181 ISSN：0021-9258
通讯作者：
Yu, Xiao-Qiang;Strand, Michael R.
作者机构：
[He, Zhen; Yu, Xiao-Qiang; Li, Chun-Feng; Chowdhury, Munmun] Univ Missouri, Sch Biol Sci, Div Cell Biol & Biophys, Kansas City, MO 64110 USA.;[Liu, Xu-Sheng; He, Zhen; Yu, Xiao-Qiang; Wang, Yu-Feng] Cent China Normal Univ, Sch Life Sci, Wuhan 430079, Hubei, Peoples R China.;[Yu, Xiao-Qiang; Lu, Yuzhen] South China Normal Univ, Guangzhou Key Lab Insect Dev Regulat & Applicat R, Inst Insect Sci & Technol, Guangzhou 510631, Guangdong, Peoples R China.;[Yu, Xiao-Qiang; Lu, Yuzhen] South China Normal Univ, Sch Life Sci, Guangzhou 510631, Guangdong, Peoples R China.;[Li, Chun-Feng] Southwest Univ, State Key Lab Silkworm Genome Biol, Chongqing 400716, Peoples R China.
通讯机构：
[Yu, Xiao-Qiang; Strand, Michael R.] U;Univ Missouri, Sch Biol Sci, Div Cell Biol & Biophys, Kansas City, MO 64110 USA.;Univ Georgia, Dept Entomol, Athens, GA 30602 USA.
关键词：
Spatzle;antimicrobial peptide (AMP);cytokine response;gene regulation;insect immunity;sex-specific difference;signal transduction;toll receptor
摘要：
The Toll signaling pathway in Drosophila melanogaster regulates several immune-related functions, including the expression of antimicrobial peptide (AMP) genes. The canonical Toll receptor (Toll-1) is activated by the cytokine Spätzle (Spz-1), but Drosophila encodes eight other Toll genes and five other Spz genes whose interactions with one another and associated functions are less well-understood. Here, we conducted in vitro assays in the Drosophila S2 cell line with the Toll/interleukin-1 receptor (TIR) homology domains of each Toll family member to determine whether they can activate a known target of Toll-1, the promoter of the antifungal peptide gene drosomycin. All TIR family members activated the drosomycin promoter, with Toll-1 and Toll-7 TIRs producing the highest activation. We found that the Toll-1 and Toll-7 ectodomains bind Spz-1, -2, and -5, and also vesicular stomatitis virus (VSV) virions, and that Spz-1, -2, -5, and VSV all activated the promoters of drosomycin and several other AMP genes in S2 cells expressing full-length Toll-1 or Toll-7. In vivo experiments indicated that Toll-1 and Toll-7 mutants could be systemically infected with two bacterial species (Enterococcus faecalis and Pseudomonas aeruginosa), the opportunistic fungal pathogen Candida albicans, and VSV with different survival times in adult females and males compared with WT fly survival. Our results suggest that all Toll family members can activate several AMP genes. Our results further indicate that Toll-1 and Toll-7 bind multiple Spz proteins and also VSV, but they differentially affect adult survival after systemic infection, potentially because of sex-specific differences in Toll-1 and Toll-7 expression. © 2019 Chowdhury et al.
语种：
英文
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20-Hydroxyecdysone promotes release of GBP-binding protein from oenocytoids to suppress hemocytic encapsulation
作者：
Zhuo, Xiao-Rong;Chen, Lei;Wang, Gui-Jie;Liu, Xu-Sheng
（ ;Wang, Yu-Feng;...
期刊：
Insect Biochemistry and Molecular Biology ,2018年92:53-64 ISSN：0965-1748
通讯作者：
Wang, Jia-Lin
作者机构：
[Liu, Xu-Sheng; Wang, Gui-Jie; Zhuo, Xiao-Rong; Yu, Xiao-Qiang; Chen, Lei; Wang, Jia-Lin; Liu, Ke; Wang, Yu-Feng] Cent China Normal Univ, Sch Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan 430079, Hubei, Peoples R China.;[Yu, Xiao-Qiang] Univ Missouri, Sch Biol Sci, Kansas City, MO 64110 USA.
通讯机构：
[Wang, Jia-Lin] C;Cent China Normal Univ, Sch Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan 430079, Hubei, Peoples R China.
关键词：
*20-Hydroxyecdysone;*Encapsulation;*GBP-binding protein;*Growth-blocking peptide;*Hemocytes
摘要：
Growth-blocking peptide (GBP) is an insect cytokine that stimulates plasmatocyte adhesion, thereby playing a critical role in encapsulation reaction. It has been previously demonstrated that GBP-binding protein (GBPB) is released upon oenocytoid lysis in response to GBP and is responsible for subsequent clearance of GBP from hemolymph. However, current knowledge about GBPB is limited and the mechanism by which insects increase GBPB levels to inactivate GBP remains largely unexplored. Here, we have identified one GBP precursor (HaGBP precursor) gene and two GBPB (namely HaGBPB1 and HaGBPB2) genes from the cotton bollworm, Helicoverpa armigera. The HaGBP precursor was found to be predominantly expressed in fat body, whereas HaGBPB1 and HaGBPB2 were mainly expressed in hemocytes. Immunological analyses indicated that both HaGBPB1 and HaGBPB2 are released from hemocytes into the plasma during the wandering stage. Additionally, 20-hydroxyecdysone (20E) treatment or bead challenge could promote the release of HaGBPB1 and HaGBPB2 at least partly from oenocytoids into the plasma. Furthermore, we demonstrate that the N-terminus of HaGBPB1 is responsible for binding to HaGBP and suppresses HaGBP-induced plasmatocyte spreading and encapsulation. Overall, this study helps to enrich our understanding of the molecular mechanism underlying 20E mediated regulation of plasmatocyte adhesion and encapsulation via GBP-GBPB interaction. © 2017 Elsevier Ltd
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英文
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The entomopathogenic fungus Nomuraea rileyi impairs cellular immunity of its host Helicoverpa armigera
作者：
Zhong, Ke;Liu, Zhan-Chi;Wang, Jia-Lin;Liu, Xu-Sheng
* （ 期刊：
Archives of Insect Biochemistry and Physiology ,2017年96(1):e21402- ISSN：0739-4462
通讯作者：
Liu, Xu-Sheng
作者机构：
[Liu, Xu-Sheng; Wang, Jia-Lin; Zhong, Ke; Liu, Zhan-Chi] Cent China Normal Univ, Sch Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan 430079, Hubei, Peoples R China.
通讯机构：
[Liu, Xu-Sheng] C;Cent China Normal Univ, Sch Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan 430079, Hubei, Peoples R China.
关键词：
cellular immune response;entomopathogenic fungus;hemocyte;insect immunity;Nomuraea rileyi
摘要：
In this study, we investigated the effect of the entomopathogenic fungus Nomuraea rileyi on Helicoverpa armigera cellular immune responses. Nomuraea rileyi infection had no effect on total hemocyte count (THC), but impaired hemocyte-mediated phagocytosis, nodulation, and encapsulation responses. Nomuraea rileyi infection led to a significant reduction in hemocyte spreading. An in vitro assay revealed that plasma from N. rileyi infected H. armigera larvae suppressed the spreading ability of hemocytes from naïve larvae. We infer that N. rileyi suppresses the cellular immune response of its host, possibly by secreting exogenous, cytotoxic compounds into the host's hemolymph. © 2017 Wiley Periodicals, Inc.
语种：
英文
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C-type lectin interacting with β-integrin enhances hemocytic encapsulation in the cotton bollworm, Helicoverpa armigera
作者：
Wang, Pan;Zhuo, Xiao-Rong;Tang, Lin;Liu, Xu-Sheng
（ ;Wang, Yu-Feng;...
期刊：
Insect Biochemistry and Molecular Biology ,2017年86:29-40 ISSN：0965-1748
通讯作者：
Wang, Jia-Lin
作者机构：
[Liu, Xu-Sheng; Zhuo, Xiao-Rong; Tang, Lin; Wang, Guo-Xiu; Wang, Pan; Yu, Xiao-Qiang; Wang, Jia-Lin; Wang, Yu-Feng] Cent China Normal Univ, Sch Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan 430079, Peoples R China.;[Yu, Xiao-Qiang] Univ Missouri, Sch Biol Sci, Kansas City, MO 64110 USA.
通讯机构：
[Wang, Jia-Lin] C;Cent China Normal Univ, Sch Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan 430079, Peoples R China.
关键词：
*20-HydroxyEcdysone;*C-type lectin;*Encapsulation;*Melanization;*beta-Integrin
摘要：
The encapsulation reaction in invertebrates is analogous to granuloma formation in vertebrates, and this reaction is severely compromised when ecdysone signaling is blocked. However, the molecular mechanism underlying the encapsulation reaction and its regulation by ecdysone remains obscure. In our previous study, we found that the C-type lectin HaCTL3, from the cotton bollworm Helicoverpa armigera, is involved in anti-bacterial immune response, acting as a pattern recognition receptor (PRR). In the current study, we demonstrate that HaCTL3 is involved in defense against parasites and directly binds to the surface of nematodes. Our in vitro and in vivo studies indicate that HaCTL3 enhances hemocytic encapsulation and melanization, whereas H. armigera β-integrin (Haβ-integrin), located on the surface of hemocytes, participates in encapsulation. Additionally, co-immunoprecipitation experiments reveal HaCTL3 interacts with Haβ-integrin, and knockdown of Haβ-integrin leads to reduced encapsulation of HaCTL3-coated beads. These results indicate that Haβ-integrin serves as a hemocytic receptor of HaCTL3 during the encapsulation reaction. Furthermore, we demonstrate that 20-hydroxyecdysone (20E) treatment dramatically induces the expression of HaCTL3, and knockdown of the 20E receptor (EcR)/ultraspiracle (USP), abrogates this response. Overall, this study provides the first evidence of the presence of a hemocytic receptor (Haβ-integrin), that interacts with the PRR HaCTL3 to facilitate encapsulation reaction in insects and demonstrates the regulation of this process by the steroid hormone ecdysone. © 2017 Elsevier Ltd
语种：
英文
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Identification and characterization of a gene involved in the encapsulation response of Helicoverpa armigera haemocytes
作者：
Hu, Q. -Q.;Wei, X. -H.;Li, Y. -P.;Wang, J. -L.;Liu, X. -S.
* （ 期刊：
Insect Molecular Biology ,2017年26(6):752-762 ISSN：0962-1075
作者机构：
[Liu, X. -S.; Li, Y. -P.; Hu, Q. -Q.; Wei, X. -H.; Wang, J. -L.] Cent China Normal Univ, Sch Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, 152 Luoyu Rd, Wuhan 430079, Hubei, Peoples R China.
通讯机构：
[Liu, X. -S.] C;Cent China Normal Univ, Sch Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, 152 Luoyu Rd, Wuhan 430079, Hubei, Peoples R China.
关键词：
encapsulation;insect immunity;cellular immune response;haemocyte;Helicoverpa armigera
摘要：
Encapsulation is a kind of cellular immune response of insect haemocytes, which results in the formation of capsules around invading parasites. However, the molecular mechanism of this response is largely unknown. In this study, we identified a potential immune-related gene in the cotton bollworm, Helicoverpa armigera, called defence protein 1 (Ha-DFP1). A tissue distribution analysis revealed that Ha-DFP1 protein was expressed in haemocytes and secreted into the haemolymph of Helic. armigera larvae. The Ha-DFP1 mRNA transcript level in haemocytes and the concentration of the Ha-DFP1 protein in haemolymph both increased after injecting chromatography beads. Purified recombinant Ha-DFP1 bound to the surface of haemocytes and promoted haemocyte encapsulation on chromatography beads in vitro. The spreading ability of haemocytes was inhibited when Ha-DFP1 expression in Helic. armigera larval haemocytes decreased in response to the injection of double-stranded RNA specific to Ha-DFP1, and the encapsulation ability of haemocytes was impaired. Based on these results, we speculate that Ha-DFP1 plays an important role in the Helic. armigera encapsulation response, possibly by binding to the haemocyte surface and mediating spreading behaviour. © 2017 The Royal Entomological Society
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英文
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MOLECULAR CHARACTERIZATION OF AUTOPHAGY-RELATED GENE 5 FROM Spodoptera exigua AND EXPRESSION ANALYSIS UNDER VARIOUS STRESS CONDITIONS
作者：
Liu, Kai-Yu;Xia, Yu-Qian;Zhou, Jing;Chen, Zu-Wen;Lu, Dandan;...
期刊：
Archives of Insect Biochemistry and Physiology ,2016年92(4):225-241 ISSN：0739-4462
作者机构：
[Liu, Xu-Sheng; Zhou, Jing; Zhang, Ning-Zhao; Liu, Kai-Yu; Ai, Hui; Xia, Yu-Qian; Chen, Zu-Wen; Lu, Dandan] Cent China Normal Univ, Sch Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan 430079, Peoples R China.;[Zhou, Li-Lin] Wuhan Vegetable Res Inst, Dept Plant Protect, Wuhan, Peoples R China.
通讯机构：
[Ai, Hui] C;Cent China Normal Univ, Sch Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan 430079, Peoples R China.
关键词：
Spodoptera exigua;ATG5;autophagy;qPCR;Western blot
摘要：
Autophagy is not only involved in development, but also has been proved to attend immune response against invading pathogens. Autophagy protein 5 (ATG5) is an important autophagic protein, which plays a crucial role in autophagosome elongation. Although ATG5 has been well studied in mammal, yeast, and Drosophila, little is known about ATG5 in lepidopteran insects. We cloned putative SeAtg5 gene from Spodoptera exigua larvae by the rapid amplification of cDNA ends method, and its characteristics and the influences of multiple exogenous factors on its expression levels were then investigated. The results showed that the putative S. exigua SeATG5 protein is highly homologous to other insect ATG5 proteins, which has a conserved Pfm domain and multiple phosphorylation sites. Next, fluorescence microscope observation showed that mCherry-SeATG5 was distributed in both nucleus and cytoplasm of Spodoptera litura Sl-HP cells and partially co-localized with BmATG6-GFP, but it almost has no significant co-localization with GFP-HaATG8. Then, the Western blot analysis demonstrated that GFP-SeATG5 conjugated with ATG12. Moreover, real-time PCR revealed that its expression levels significantly increased at the initiation of pupation and the stage of adult. In addition, the expression levels of SeAtg5 can be enhanced by the starvation, UV radiation, and infection of baculovirus and bacterium. However, the expression levels of SeAtg5 decreased at 24 h post treatments in all these treatments except in starvation. These results suggested that SeATG5 might be involved in response of S. exigua under various stress conditions.
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英文
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Rab3 is involved in cellular immune responses of the cotton bollworm, Helicoverpa armigera
作者：
Li, Jie;Song, Cai-Xia;Li, Yu-Ping;Li, Li;Wei, Xiu-Hong;...
期刊：
DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY ,2015年50(2):78-86 ISSN：0145-305X
作者机构：
[Liu, Xu-Sheng; Li, Li; Song, Cai-Xia; Li, Jie; Wang, Jia-Lin; Wei, Xiu-Hong; Li, Yu-Ping] Cent China Normal Univ, Sch Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan 430079, Peoples R China.;[Wang, Jia-Lin] Cent China Normal Univ, Sch Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, 152 Luoyu Rd, Wuhan 430079, Peoples R China.
通讯机构：
[Wang, Jia-Lin] C;Cent China Normal Univ, Sch Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, 152 Luoyu Rd, Wuhan 430079, Peoples R China.
会议名称：
The 5th International Symposium on Insect Physiology, Biochemistry and Molecular Biology
会议时间：
2015-06-15
会议地点：
中国广东广州
关键词：
Rab GTPase;Phagocytosis;Nodulation;Encapsulation;Cellular immune response;Helicoverpa armigera
摘要：
Rab3, a member of the Rab GTPase family, has been found. to be involved in Innate immunity. However, the precise function of this GTPase in innate immunity remains unknown. In this study, we identified a Rab3 gene (Ha-Rab3) from the cotton bollworm, Helicoverpa armigera and studied its roles in innate immune responses. Expression of Ha-Rab3 was upregulated in the hemocytes of H. armigera larvae after the injection of Escherichia coil or chromatography beads. The dsRNA-mediated knockdown of Ha-Rab3 gene in H. armigera larval hemocytes led to significant reduction in the phagocytosis and nodulation activities of hemocytes against E. coil, significant increase in the bacterial load in larval hemolymph, and significant reduction in the encapsulation activities of hemocytes toward invading chromatography beads. Further-more, Ha-Rab3 knockdown significantly suppressed spreading of plasmatocytes. These results' suggest that Ha-Rab3 plays important roles in H. arrnigera cellular immune responses, possibly by mediating spreading of hemocytes. (C) 2015 Elsevier Ltd. All rights reserved.
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英文
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Molecular characterization of a peptidoglycan recognition protein from the cotton bollworm, Helicoverpa armigera and its role in the prophenoloxidase activation pathway
作者：
Li, Yu-Ping;Xiao, Min;Li, Li;Song, Cai-Xia;Wang, Jia-Lin;...
期刊：
Molecular Immunology ,2015年65(1):123-132 ISSN：0161-5890
通讯作者：
Liu, Xu-Sheng
作者机构：
[Liu, Xu-Sheng; Li, Li; Song, Cai-Xia; Wang, Jia-Lin; Li, Yu-Ping; Xiao, Min] Cent China Normal Univ, Sch Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan 430079, Peoples R China.;[Liu, Xu-Sheng] Cent China Normal Univ, Sch Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, 152 Luoyu Rd, Wuhan 430079, Peoples R China.
通讯机构：
[Liu, Xu-Sheng] C;Cent China Normal Univ, Sch Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, 152 Luoyu Rd, Wuhan 430079, Peoples R China.
关键词：
Helicoverpa armigera;Melanization;Pattern recognition receptor;Peptidoglycan recognition protein;Prophenoloxidase activation
摘要：
Peptidoglycan recognition proteins (PGRPs), which are evolutionarily conserved from invertebrates to vertebrates, function as pattern-recognition and effector molecules in innate immunity. In this study, a PGRP (HaPGRP-A) from the cotton bollworm, Helicoverpa armigera was identified and characterized. Sequence analysis indicated that HaPGRP-A is not an amidase-type PGRP. Increased levels of HaPGRP-A mRNA were observed in the fat body and hemocytes of H. armigera larvae following the injection of microbes or Sephadex beads. Analysis using purified recombinant HaPGRP-A showed that it (i) could bind and agglutinate Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus, (ii) enhanced prophenoloxidase activation in the presence of microbes, (iii) promoted the formation of melanotic nodules in vivo, and (iv) enhanced the melanization of Sephadex beads in vivo. RNA interference assays were performed to further confirm the function of HaPGRP-A. When the expression of HaPGRP-A in H. armigera larvae was inhibited by dsHaPGRP-A injection, the phenoloxidase activity in larval hemolymph was significantly decreased and RNAi-treated insects infected with bacteria showed higher bacterial growth in hemolymph compared with infected control larvae. These results indicated that HaPGRP-A acts as a pattern recognition receptor and binds to the invading organism to trigger the prophenoloxidase activation pathway of H. armigera, and the activated phenoloxidase may participate in the melanization process of nodulation and encapsulation responses. Copyright © 2015 Elsevier Ltd. All rights reserved.
语种：
英文
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SRP gene is required for Helicoverpa armigera prophenoloxidase activation and nodulation response
作者：
Qiao, Chuan;Li, Jie;Wei, Xiu-Hong;Wang, Jia-Lin;Wang, Yu-Feng;...
期刊：
DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY ,2014年44(1):94-99 ISSN：0145-305X
作者机构：
[Liu, Xu-Sheng; Li, Jie; Wang, Jia-Lin; Qiao, Chuan; Wei, Xiu-Hong; Wang, Yu-Feng] Cent China Normal Univ, Coll Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan 430079, Peoples R China.
通讯机构：
[Liu, Xu-Sheng] C;Cent China Normal Univ, Coll Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan 430079, Peoples R China.
关键词：
Helicoverpa armigera;SRP;Prophenoloxidase activation;Nodulation;Innate immunity
摘要：
SRP gene was first identified from the fall webworm, Hyphantria cunea as one of genes up-regulated after bacteria injection. A rent study in Spodoptera litura showed that stress-induced elevation of SRP expression highly correlates with reduced feeding activities and growth retardation of larvae. In this study, we identified a SRP gene from the cotton bollworm, Helicoverpa armigera, namely Ha-SRP, and studied its precise roles in insect immunity. Expressions of Ha-SRP were upregulated in H. armigera larval hemocytes after injection of Escherichia coli. When the expression of Ha-SRP in H. armigera larval hemocytes was inhibited by dsHa-SRP injection, the transcription of prophenoloxidase genes in hemocytes was repressed, phenoloxidase activity in bacteria-challenged larval hemolymph was significantly decreased, and nodule formation in bacteria-injected larvae was reduced. More importantly, RNAi-treated insects infected with E. coli showed higher bacterial growth in hemolymph compared with infected controls. These results suggest that Ha-SRP gene plays importance roles in H. armigera innate immunity, possibly by mediating prophenoloxidase activation and nodulation response.
语种：
英文
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Involvement of a pattern recognition receptor C-type lectin 7 in enhancing cellular encapsulation and melanization due to its carboxyl-terminal CRD domain in the cotton bollworm, Helicoverpa armigera
作者：
Wang, Jia-Lin
* （ ;Zhang, Qi;Tang, Lin;Chen, Lei;Liu, Xu-Sheng;...
期刊：
DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY ,2014年44(1):21-29 ISSN：0145-305X
作者机构：
[Wang, Jia-Lin; Zhang, Qi; Tang, Lin; Chen, Lei; Liu, Xu-Sheng; Wang, Yu-Feng] Cent China Normal Univ, Coll Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan 430079, Peoples R China.
通讯机构：
[Wang, Jia-Lin] C;Cent China Normal Univ, Coll Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan 430079, Peoples R China.
关键词：
C-type lectin;CRD;Encapsulation;Melanization;Helicoverpa armigera
摘要：
C-type lectins play important roles in innate immunity as pattern recognition receptors (PRRs). We have previously reported a novel C-type lectin HaCTL7 from the cotton bollworm (Helicoverpa armigera) which contains two carbohydrate-recognition domains (CRDs), namely N-terminal CRD1 and C-terminal CRD2. Interestingly, there are four but not six of conserved cysteine residues in CRD2 of HaCTL7, which is different from that of other dual CRD C-type lectins. In the current study, we expressed and purified recombinant HaCTL7 (rHaCTL7) as well as rCRD1 and rCRD2, and demonstrated that both rHaCTL7 and rCRD2, but not rCRD1, owned the agglutinate ability against both Gram-negative and Gram-positive bacteria in a calcium dependent manner. In addition, both rHaCTL7 and rCRD2, but not rCRD1, could bind to various bacteria, and enhanced haemocytes mediated encapsulation and melanization processes. HaCTL7 secreted from fat bodies is able to bind to granulocytes, plasmatocytes and oenocytoids, but not to spherulocytes. Recombinant HaCTL7 and rCRD2 are capable of binding to both granulocytes and oenocytoids, while rCRD1 can only bind to granulocytes. Our data suggest that as a PRR HaCTL7 enhances encapsulation and melanization likely through its C-terminal CRD2, but not N-terminal CRD1, which imply that the characteristic four cysteine structure of CRD2 plays key roles in innate immunity. © 2013 Elsevier Ltd.
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英文
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Identification and functional characterization of a peptidoglycan recognition protein from the cotton bollworm, helicoverpa armigera
作者：
Li, Li;Li, Yu-Ping;Song, Cai-Xia;Xiao, Min;Wang, Jia-Lin;...
期刊：
Archives of Insect Biochemistry and Physiology ,2014年86(4):240-258 ISSN：0739-4462
作者机构：
[Liu, Xu-Sheng; Li, Li; Song, Cai-Xia; Wang, Jia-Lin; Li, Yu-Ping; Xiao, Min] Cent China Normal Univ, Sch Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan 430079, Peoples R China.
通讯机构：
[Liu, Xu-Sheng] C;Cent China Normal Univ, Sch Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan 430079, Peoples R China.
关键词：
peptidoglycan recognition protein;Helicoverpa armigera;encapsulation;phagocytosis
摘要：
Peptidoglycan recognition proteins (PGRPs) specifically bind to peptidoglycans, and play crucial roles as pattern recognition receptors (PRRs) in mediating innate immune responses. In this study, we identified and characterized a PGRP (HaPGRP-D) from the cotton bollworm, Helicoverpa armigera. Sequence analysis indicated that HaPGRP-D is an amidase-type PGRP. Expression of HaPGRP-D was upregulated in the hemocytes of H. armigera larvae after injecting Gram-negative Escherichia coli, Gram-positive Staphylococcus aureus, or chromatography beads. To test the biological activity of HaPGRP-D, purified recombinant protein was prepared. Subsequent analysis showed that rHaPGRP-D (i) could bind and agglutinate Gram-negative E. coli and Gram-positive S. aureus in a zinc-dependent manner, (ii) functioned as an amidase to degrade peptidoglycans in the presence of Zn 2+ , (iii) strongly inhibited the growth of E. coli and S. aureus in the presence of Zn 2+ , (iv) could bind to the surface of hemocytes, (v) increased the phagocytosis of E. coli cells by hemocytes in vitro, and (vi) promoted hemocyte encapsulation on chromatography beads in vitro. These results suggest that HaPGRP-D plays important roles as PRR, amidase, and opsonin in H. armigera humoral and cellular immune responses. © 2014 Wiley Periodicals, Inc.
语种：
英文
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20-hydroxyecdysone transcriptionally regulates humoral immunity in the fat body of Helicoverpa armigera
作者：
Wang, J-L.;Chen, L.;Tang, L.;Zhao, H-B.;Liu, X-S.
* （ ;...
期刊：
Insect Molecular Biology ,2014年23(6):842-856 ISSN：0962-1075
作者机构：
[Liu, X-S.; Wang, Y-F.; Chen, L.; Tang, L.; Wang, J-L.; Zhao, H-B.] Cent China Normal Univ, Sch Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan 430079, Peoples R China.
通讯机构：
[Liu, X-S.] C;Cent China Normal Univ, Sch Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan 430079, Peoples R China.
关键词：
Helicoverpa armigera;transcriptome;digital gene expression (DGE);fat body;immunity;20-hydroxyecdysone (20E)
摘要：
20-hydroxyecdysone (20E) increases its titre level during the wandering stage and influences innate immunity in many holometabolous insects. However, the function of 20E as an immune-activator or -suppressor needs to be determined. Here, the transcriptome of the peptidoglycan-challenged fat body of the cotton bollworm, Helicoverpa armigera, was analysed using Illumina sequencing technology. Overall, 32 073 unigenes were assembled with a mean length of 643 nucleotides. Gene expression dynamics in the fat body during the wandering stage and of peptidoglycan-challenged individuals were investigated by the digital gene expression system. Pattern recognition receptors [such as peptidoglycan recognition protein B (PGRP B), PGRP S2 precursor, C-type lectin 5, hemolin and β-1,3-glucan recognition protein 2a] and antimicrobial peptides (namely attacin, gloverin, gloverin precursor, gloverin-like, cecropin 2, cecropin D, cecropin D-like and i-type lysozyme) significantly increased their mRNA levels during the wandering stage. 20E treatment significantly induced the expression of these genes. Antibacterial activities were also enhanced during the wandering stage and after 20E injections. Bacillus subtilis peptidoglycan induced the expression of PGRP D, PGRP B, PGRP S2 precursor, gloverin, gloverin precursor, gloverin-like, cecropin 2, cecropin D and lebocin-like genes. These results demonstrate that 20E acts by enhancing humoral immunity in H. armigera. © 2014 The Royal Entomological Society.
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英文
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Cloning and functional analysis of glutathione peroxidase gene in red swamp crayfish Procambarus clarkii
作者：
Xia, Xiao-Fei;Zheng, Jin-Jing;Shao, Guang-Ming;Wang, Jia-Lin;Liu, Xu-Sheng
（ ;...
期刊：
Fish & Shellfish Immunology ,2013年34(6):1587-1595 ISSN：1050-4648
作者机构：
[Liu, Xu-Sheng; Shao, Guang-Ming; Zheng, Jin-Jing; Wang, Jia-Lin; Xia, Xiao-Fei; Wang, Yu-Feng] Cent China Normal Univ, Coll Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan 430079, Peoples R China.;[Wang, Yu-Feng] Cent China Normal Univ, Coll Life Sci, 152 Luoyu Ave, Wuhan 430079, Peoples R China.
通讯机构：
[Wang, Yu-Feng] C;Cent China Normal Univ, Coll Life Sci, 152 Luoyu Ave, Wuhan 430079, Peoples R China.
关键词：
Procambarus clarkii;GPx;Expression patterns;Microbe challenge;ROS
摘要：
Glutathione peroxidases (GPxs) are key enzymes in the antioxidant defense systems of living organisms, including crustaceans. The red swamp crayfish Procambarus clarkii is the most commonly farmed freshwater crayfish in Chinese inland nowadays due to its commercial value. However, high stocking density has resulted in adverse effects in growth performance and health. To investigate the function of GPxs in immune defense of the crayfish, we cloned and characterized a full length GPx (. PcGPx) from P. clarkii by a reverse-transcription polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE). The 931 bp PcGPx cDNA contains a 38 bp 5'-untranslated region (UTR), a 519 bp coding sequence (CDS) and a 375 bp 3'-UTR with a selenocysteine insertion sequence (SECIS). The PcGPx was predicted to encode 172 amino acids, and its putative molecular mass was 20.9kDa with a pI of 4.37. A selenocysteine (Sec) encoded by the unusual stop codon, TGA, was in the protein coding region. Phylogenetic analysis showed that PcGPx clustered with the GPxs from the penaeid shrimp Metapenaeus ensis and Caenorhabditis elegans, sharing much higher similarity with vertebrate GPx1 and GPx2 than with GPx3 and GPx5. Quantitative RT-PCR revealed that PcGPx was extremely highly expressed in ovary and early embryos. In addition, the levels of PcGPx mRNA and reactive oxygen species (ROS) significantly increased after challenge with gram-negative Vibrio harveyi, gram-positive Staphyloccocus aureus or white spot syndrome virus (WSSV). These results suggest that PcGPx may play important roles not only in immune defense, but also in oogenesis in the crayfish. © 2013 Elsevier Ltd.
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英文
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