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Thongsoi R, Maskaew S, Puechpon P, Noppradit B, Inaek N, Utarabhand P, Runsaeng P. Identification of an essential role against shrimp pathogens of prophenoloxidase activating enzyme 1 (PPAE1) from Fenneropenaeus merguiensis hemocytes. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2024; 151:105088. [PMID: 37923098 DOI: 10.1016/j.dci.2023.105088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2023] [Revised: 10/21/2023] [Accepted: 10/24/2023] [Indexed: 11/07/2023]
Abstract
Prophenoloxidase (proPO) activating enzymes, known as PPAEs, are pivotal in activating the proPO system within invertebrate immunity. A cDNA encoding a PPAE derived from the hemocytes of banana shrimp, Fenneropenaeus merguiensis have cloned and analyzed, referred to as FmPPAE1. The open reading frame of FmPPAE1 encompasses 1392 base pairs, encoding a 464-amino acid peptide featuring a presumed 19-amino acid signal peptide. The projected molecular mass and isoelectric point of this protein stand at 50.5 kDa and 7.82, respectively. Structure of FmPPAE1 consists of an N-terminal clip domain and a C-terminal serine proteinase domain, housing a catalytic triad (His272, Asp321, Ser414) and a substrate binding site (Asp408, Ser435, Gly437). Expression of the FmPPAE1 transcript is specific to hemocytes and is heightened upon encountering pathogens like Vibrio parahaemolyticus, Vibrio harveyi, and white spot syndrome virus (WSSV). Using RNA interference to silence the FmPPAE1 gene resulted in reduced hemolymph phenoloxidase (PO) activity and decreased survival rates in shrimp co-injected with pathogenic agents. These findings strongly indicate that FmPPAE1 plays a vital role in regulating the proPO system in shrimp. Furthermore, upon successful production of recombinant FmPPAE1 protein (rFmPPAE1), it became evident that this protein exhibited remarkable abilities in both agglutinating and binding to a wide range of bacterial strains. These interactions were primarily facilitated through the recognition of bacterial lipopolysaccharides (LPS) or peptidoglycans (PGN) found in the cell wall. This agglutination process subsequently triggered melanization, a critical immune response. Furthermore, rFmPPAE1 exhibited the ability to actively impede the growth of pathogenic bacteria harmful to shrimp, including V. harveyi and V. parahaemolyticus. These findings strongly suggest that FmPPAE1 not only plays a pivotal role in activating the proPO system but also possesses inherent antibacterial properties, actively contributing to the suppression of bacterial proliferation. In summary, these results underscore the substantial involvement of FmPPAE1 in activating the proPO system in F. merguiensis and emphasize its crucial role in the shrimp's immune defense against invading pathogens.
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Affiliation(s)
- Ratiporn Thongsoi
- Division of Health and Applied Sciences, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla, Thailand
| | - Siriluk Maskaew
- Division of Health and Applied Sciences, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla, Thailand
| | - Panumas Puechpon
- Division of Health and Applied Sciences, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla, Thailand
| | - Benjaporn Noppradit
- Division of Health and Applied Sciences, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla, Thailand
| | - Napassawan Inaek
- Division of Health and Applied Sciences, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla, Thailand
| | - Prapaporn Utarabhand
- Division of Health and Applied Sciences, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla, Thailand
| | - Phanthipha Runsaeng
- Division of Health and Applied Sciences, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla, Thailand.
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Qin W, Lu Y, Wang H, Liu B, Jiang Z, Zhou C, Huang X, Dai X, Ren Q. Characterization and functional analysis of a clip domain serine protease (MncSP) and its alternative transcript (MncSP-isoform) from Macrobrachium nipponense. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2022; 126:104237. [PMID: 34450128 DOI: 10.1016/j.dci.2021.104237] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 08/16/2021] [Accepted: 08/19/2021] [Indexed: 06/13/2023]
Abstract
Clip domain serine protease (cSPs) play an important role in the innate immune defense of crustaceans. In this study, a clip domain serine protease (MncSP) and its alternative transcript (MncSP-isoform) were identified from Macrobrachium nipponense. The full-length cDNA sequences of MncSP and MncSP-isoform were 2447 and 2351 bp with open reading frames comprising 1497 and 1401 bp nucleotides and encoding 498 and 466 amino acids, respectively. The genome of MncSP had 10 exons and 9 introns. MncSP contained all 10 exons, whereas MncSP-isoform lacked the second exon. MncSP and MncSP-isoform contained a signal peptide, a clip domain, and a Tryp_SPc domain. Phylogenetic tree analysis showed that MncSP and MncSP-isoform clustered with cSPs from Palaemonidae. MncSP and MncSP-isoform were widely distributed in hemocytes, heart, hepatopancreas, gills, stomach, and intestine. The expression profiles of MncSP and MncSP-isoform in the hemocytes of M. nipponense changed after simulation by Vibrio parahaemolyticus or Staphylococcus aureus. The RNAi of MncSP could inhibit the expression of antimicrobial peptides (AMPs), including crustins and anti-lipopolysaccharide factors. Phenoloxidase activity was also down-regulated in MncSP-silenced prawns. This study indicated that MncSP participated in the synthesis of AMPs and the activation of prophenoloxidase.
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Affiliation(s)
- Wei Qin
- Jiangsu Province Engineering Research Center for Aquatic Animals Breeding and Green Efficient Aquacultural Technology, College of Marine Science and Engineering, Nanjing Normal University, Nanjing, Jiangsu Province, 210023,China
| | - Yang Lu
- Nanjing Hydraulic Research Institute, Nanjing, Jiangsu Province, 210024, China
| | - Hongyu Wang
- Jiangsu Province Engineering Research Center for Aquatic Animals Breeding and Green Efficient Aquacultural Technology, College of Marine Science and Engineering, Nanjing Normal University, Nanjing, Jiangsu Province, 210023,China
| | - Beixiang Liu
- Jiangsu Province Engineering Research Center for Aquatic Animals Breeding and Green Efficient Aquacultural Technology, College of Marine Science and Engineering, Nanjing Normal University, Nanjing, Jiangsu Province, 210023,China
| | - Zuosheng Jiang
- Jiangsu Province Engineering Research Center for Aquatic Animals Breeding and Green Efficient Aquacultural Technology, College of Marine Science and Engineering, Nanjing Normal University, Nanjing, Jiangsu Province, 210023,China
| | - Chengxiang Zhou
- Jiangsu Province Engineering Research Center for Aquatic Animals Breeding and Green Efficient Aquacultural Technology, College of Marine Science and Engineering, Nanjing Normal University, Nanjing, Jiangsu Province, 210023,China
| | - Xin Huang
- Jiangsu Province Engineering Research Center for Aquatic Animals Breeding and Green Efficient Aquacultural Technology, College of Marine Science and Engineering, Nanjing Normal University, Nanjing, Jiangsu Province, 210023,China.
| | - Xiaoling Dai
- Jiangsu Province Engineering Research Center for Aquatic Animals Breeding and Green Efficient Aquacultural Technology, College of Marine Science and Engineering, Nanjing Normal University, Nanjing, Jiangsu Province, 210023,China.
| | - Qian Ren
- Jiangsu Province Engineering Research Center for Aquatic Animals Breeding and Green Efficient Aquacultural Technology, College of Marine Science and Engineering, Nanjing Normal University, Nanjing, Jiangsu Province, 210023,China.
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Boonchuen P, Sakhor H, Jaree P, Somboonwiwat K. Shrimp Vago5 activates an innate immune defense upon bacterial infection. FISH & SHELLFISH IMMUNOLOGY 2022; 120:122-132. [PMID: 34742902 DOI: 10.1016/j.fsi.2021.10.044] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2021] [Revised: 10/25/2021] [Accepted: 10/27/2021] [Indexed: 06/13/2023]
Abstract
Acute hepatopancreatic necrosis disease, AHPND, caused by a specific Vibrio parahaemolyticus (VPAHPND) strain, results in a great loss of global shrimp production. This study performed suppression subtractive hybridization (SSH) to identify differentially expressed genes from white shrimp Penaeus vannamei hemocyte upon VPAHPND infection. Among the immune-related genes identified, Vago5, kunitz, secretory leukocyte proteinase inhibitor, and profilin are the most abundant genes classified as the up-regulated genes in the SSH library. The qRT-PCR results show that only Vago5 was highly up-regulated at 3 and 6 h post-VPAHPND challenge, whereas kunitz, secretory leukocyte proteinase inhibitor, and profilin were highly up-regulated at 48 h post-VPAHPND challenge. As an early VPAHPND infection-responsive gene, Vago5 was further functional characterized by RNA interference. Knockdown of Vago5 gene resulted in the significantly rapid increase of shrimp mortality and the number of bacteria in the stomach and hepatopancreas upon VPAHPND infection. Moreover, downstream genes of Toll, IMD, and JAK/STAT pathways and phenoloxidase system were analyzed for the expression in the VPAHPND-infected shrimp hemocyte after dsVago5 treatment. Vago5 gene knockdown resulted in a significant decrease in transcript levels of PEN4, TNF, and PO2 genes as well as PO activity in the hemolymph, suggesting that Vago5 might modulate antibacterial infection through activation of the genes in the NF-κB mediated pathways, JAK/STAT pathway, and phenoloxidase system.
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Affiliation(s)
- Pakpoom Boonchuen
- Center of Excellence for Molecular Biology and Genomics of Shrimp, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Thailand
| | - Hafeeza Sakhor
- Center of Excellence for Molecular Biology and Genomics of Shrimp, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Thailand
| | - Phattarunda Jaree
- Center of Applied Shrimp Research and Innovation, Institute of Molecular Biosciences, Mahidol University, Salaya, Nakhon Pathom, Thailand
| | - Kunlaya Somboonwiwat
- Center of Excellence for Molecular Biology and Genomics of Shrimp, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Thailand.
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Zhuang XN, Luan YY, Lv TR, Ren CM, Wang L, Li Q, Li DX. PAP1 activates the prophenoloxidase system against bacterial infection in Musca domestica. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2021; 124:104184. [PMID: 34171367 DOI: 10.1016/j.dci.2021.104184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Revised: 06/20/2021] [Accepted: 06/21/2021] [Indexed: 06/13/2023]
Abstract
We previously identified three putative prophenoloxidase-activating proteinase (mdPAP1, mdPAP2, and mdPAP3) genes from housefly Musca domestica by transcriptomic analysis. In this study, mdPAP1 cDNA was cloned, and the function of its encoded protein was analyzed. The cDNA of mdPAP1 was 1358 bp, and it contained a single open reading frame of 1122 bp encoding a predicted MdPAP1 protein of 373 amino acids. The estimated molecular weight of MdPAP1 was 41267.08 Da with an isoelectric point of 6.25. The deduced amino acid sequence of MdPAP1 exhibited high similarity to known PAPs of insects. mdPAP1 was detected in larvae, pupae, and adult housefly, and the expression level of mdPAP1 was upregulated in bacterial challenged larvae. The recombinant protein of MdPAP1 expressed in Escherichia coli could cleave the prophenoloxidase into phenoloxidase in M. domestica hemolymph infected by bacteria and result in a significant increase of the total phenoloxidase activity. In addition, RNA interference-mediated gene silencing of mdPAP1 significantly increased the mortality of M. domestica larvae. Results indicated that mdPAP1 was involved in the activation of the prophenoloxidase against bacterial infection in M. domestica.
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Affiliation(s)
- Xu-Na Zhuang
- Biotechnology Department, School of Biological Sciences and Biotechnology, University of Jinan, Jinan, 250022, China
| | - Yuan-Yuan Luan
- Biotechnology Department, School of Biological Sciences and Biotechnology, University of Jinan, Jinan, 250022, China
| | - Tong-Rui Lv
- Biotechnology Department, School of Biological Sciences and Biotechnology, University of Jinan, Jinan, 250022, China
| | - Cheng-Ming Ren
- Biotechnology Department, School of Biological Sciences and Biotechnology, University of Jinan, Jinan, 250022, China
| | - Lei Wang
- Biotechnology Department, School of Biological Sciences and Biotechnology, University of Jinan, Jinan, 250022, China
| | - Qiang Li
- Biotechnology Department, School of Biological Sciences and Biotechnology, University of Jinan, Jinan, 250022, China
| | - Dian-Xiang Li
- Biotechnology Department, School of Biological Sciences and Biotechnology, University of Jinan, Jinan, 250022, China.
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Chen RY, Keddie BA. The Galleria mellonella-Enteropathogenic Escherichia coli Model System: Characterization of Pathogen Virulence and Insect Immune Responses. JOURNAL OF INSECT SCIENCE (ONLINE) 2021; 21:6329131. [PMID: 34314494 PMCID: PMC8315237 DOI: 10.1093/jisesa/ieab046] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Indexed: 05/22/2023]
Abstract
The use of Galleria mellonella (Linnaeus) (Lepidoptera: Pyralidae), an economical insect model, for the study of enteropathogenic Escherichia coli (Migula) (EPEC), a diarrheagenic human pathogen, has been demonstrated previously but remains poorly understood. The present study characterizes the Galleria-EPEC system extensively for future studies using this system. We found that EPEC causes disease in G. mellonella larvae when injected intrahemocoelically but not orally. Disease manifests as increased mortality, decreased survival time, delayed pupation, decreased pupal mass, increased pupal duration, and hemocytopenia. Disease symptoms are dose-dependent and can be used as metrics for measuring EPEC virulence in future studies. The type III secretion system was only partially responsible for EPEC virulence in G. mellonella while the majority of the virulence remains unknown in origin. EPEC elicits insect anti-bacterial immune responses including melanization, hemolymph coagulation, nodulation, and phagocytosis. The immune responses were unable to control EPEC replication in the early stage of infection (≤3 h post-injection). EPEC clearance from the hemocoel does not guarantee insect survival. Overall, this study provided insights into EPEC virulence and pathogenesis in G. mellonella and identified areas of future research using this system.
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Affiliation(s)
- Robin Y Chen
- Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E9, Canada
- Corresponding author, e-mail:
| | - B Andrew Keddie
- Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E9, Canada
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F. Q. Smith D, Casadevall A. Fungal immunity and pathogenesis in mammals versus the invertebrate model organism Galleria mellonella. Pathog Dis 2021; 79:ftab013. [PMID: 33544836 PMCID: PMC7981337 DOI: 10.1093/femspd/ftab013] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Accepted: 02/03/2021] [Indexed: 02/07/2023] Open
Abstract
In recent decades, Galleria mellonella (Lepidoptera: Pyralidae) have emerged as a model system to explore experimental aspects of fungal pathogenesis. The benefits of the G. mellonella model include being faster, cheaper, higher throughput and easier compared with vertebrate models. Additionally, as invertebrates, their use is subject to fewer ethical and regulatory issues. However, for G. mellonella models to provide meaningful insight into fungal pathogenesis, the G. mellonella-fungal interactions must be comparable to mammalian-fungal interactions. Indeed, as discussed in the review, studies suggest that G. mellonella and mammalian immune systems share many similarities, and fungal virulence factors show conserved functions in both hosts. While the moth model has opened novel research areas, many comparisons are superficial and leave large gaps of knowledge that need to be addressed concerning specific mechanisms underlying G. mellonella-fungal interactions. Closing these gaps in understanding will strengthen G. mellonella as a model for fungal virulence in the upcoming years. In this review, we provide comprehensive comparisons between fungal pathogenesis in mammals and G. mellonella from immunological and virulence perspectives. When information on an antifungal immune component is unknown in G. mellonella, we include findings from other well-studied Lepidoptera. We hope that by outlining this information available in related species, we highlight areas of needed research and provide a framework for understanding G. mellonella immunity and fungal interactions.
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Affiliation(s)
- Daniel F. Q. Smith
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, The Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | - Arturo Casadevall
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, The Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
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Nunes C, Sucena É, Koyama T. Endocrine regulation of immunity in insects. FEBS J 2020; 288:3928-3947. [PMID: 33021015 DOI: 10.1111/febs.15581] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2020] [Revised: 09/03/2020] [Accepted: 09/29/2020] [Indexed: 12/11/2022]
Abstract
Organisms have constant contact with potentially harmful agents that can compromise their fitness. However, most of the times these agents fail to cause serious disease by virtue of the rapid and efficient immune responses elicited in the host that can range from behavioural adaptations to immune system triggering. The immune system of insects does not comprise the adaptive arm, making it less complex than that of vertebrates, but key aspects of the activation and regulation of innate immunity are conserved across different phyla. This is the case for the hormonal regulation of immunity as a part of the broad organismal responses to external conditions under different internal states. In insects, depending on the physiological circumstances, distinct hormones either enhance or suppress the immune response integrating individual (and often collective) responses physiologically and behaviourally. In this review, we provide an overview of our current knowledge on the endocrine regulation of immunity in insects, its mechanisms and implications on metabolic adaptation and behaviour. We highlight the importance of this multilayered regulation of immunity in survival and reproduction (fitness) and its dependence on the hormonal integration with other mechanisms and life-history traits.
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Affiliation(s)
| | - Élio Sucena
- Instituto Gulbenkian de Ciência, Oeiras, Portugal.,Departamento de Biologia Animal, Faculdade de Ciências, Universidade de Lisboa, Lisbon, Portugal
| | - Takashi Koyama
- Department of Biology, University of Copenhagen, Copenhagen, Denmark
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Liu HW, Wang LL, Meng Z, Tang X, Li YS, Xia QY, Zhao P. A clip domain serine protease involved in moulting in the silkworm, Bombyx mori: cloning, characterization, expression patterns and functional analysis. INSECT MOLECULAR BIOLOGY 2017; 26:507-521. [PMID: 28597953 DOI: 10.1111/imb.12312] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Clip domain serine proteases (CLIPs), characterized by one or more conserved clip domains, are essential components of extracellular signalling cascades in various biological processes, especially in innate immunity and the embryonic development of insects. Additionally, CLIPs may have additional non-immune functions in insect development. In the present study, the clip domain serine protease gene Bombyx mori serine protease 95 (BmSP95), which encodes a 527-residue protein, was cloned from the integument of B. mori. Bioinformatics analysis indicated that BmSP95 is a typical CLIP of the subfamily D and possesses a clip domain at the N terminus, a trypsin-like serine protease (tryp_spc) domain at the C terminus and a conserved proline-rich motif between these two domains. At the transcriptional level, BmSP95 is expressed in the integument during moulting and metamorphosis, and the expression pattern is consistent with the fluctuating 20-hydroxyecdysone (20E) titre in B. mori. At the translational level, BmSP95 protein is synthesized in the epidermal cells, secreted as a zymogen and activated in the moulting fluid. Immunofluorescence revealed that BmSP95 is distributed into the old endocuticle in the moulting stage. The expression of BmSP95 was upregulated by 20E. Moreover, expression of BmSP95 was downregulated by pathogen infection. RNA interference-mediated silencing of BmSP95 led to delayed moulting from pupa to moth. These results suggest that BmSP95 is involved in integument remodelling during moulting and metamorphosis.
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Affiliation(s)
- H-W Liu
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - L-L Wang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Z Meng
- College of Biotechnology, Southwest University, Chongqing, China
| | - X Tang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Y-S Li
- Vitamin D Research Institute, Shaanxi University of Technology, Hanzhong, Shaanxi, China
| | - Q-Y Xia
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - P Zhao
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
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Sheehan G, Kavanagh K. Analysis of the early cellular and humoral responses of Galleria mellonella larvae to infection by Candida albicans. Virulence 2017; 9:163-172. [PMID: 28872999 PMCID: PMC5955201 DOI: 10.1080/21505594.2017.1370174] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Galleria mellonella larvae were administered an inoculum of Candida albicans and the response to infection over 24 hours was monitored. The yeast cell density in infected larvae declined initially but replication commenced six hours post-infection. The hemocyte density decreased from 5.2 × 106/ml to 2.5 × 106/ml at 2 hours but increased to 4.2 × 106 at 6 hours and decreased subsequently. Administration of β – glucan to larvae also caused a fluctuation in hemocyte density (5.1 ± 0.22 × 106/ml (0 hour) to 6.25 ± 0.25 × 106/ml (6 hour) (p < 0.05) to 5 ± 2.7 × 106 (24 hour)) and the population showed an increase in the density of small, granular cells at 24 hours (p < 0.05). Hemocytes from larvae inoculated with β – glucan for 6 or 24 hours showed faster killing of C. albicans cells (53 ± 4.1% (p < 0.01), 64 ± 3.7%, (p < 0.01), respectively) than hemocytes from control larvae (24 ± 11%) at 60 min. Proteomic analysis indicated increased abundance of immune related proteins cecropin-A (5 fold) and prophenoloxidase-activating proteinase-1 (5 fold) 6 hours post infection but by 24 hours there was elevated abundance of muscle (tropomyosin 2 (141 fold), calponin (66 fold), troponin I (62 fold)) and proteins indicative of cellular stress (glutathione-S-transferase-like protein (114 fold)), fungal dissemination (muscle protein 20-like protein (174 fold)) and tissue breakdown (mitochondrial cytochrome c (10 fold)). Proteins decreased in abundance at 24 hour included β – 1,3 – glucan recognition protein precursor (29 fold) and prophenoloxidase subunit 2 (25 fold).
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Affiliation(s)
- Gerard Sheehan
- a Department of Biology , Maynooth University , Maynooth, Co. Kildare , Ireland
| | - Kevin Kavanagh
- a Department of Biology , Maynooth University , Maynooth, Co. Kildare , Ireland
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Monwan W, Amparyup P, Tassanakajon A. A snake-like serine proteinase (PmSnake) activates prophenoloxidase-activating system in black tiger shrimp Penaeus monodon. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2017; 67:229-238. [PMID: 27693192 DOI: 10.1016/j.dci.2016.09.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Revised: 09/26/2016] [Accepted: 09/26/2016] [Indexed: 06/06/2023]
Abstract
Clip domain serine proteinases (ClipSPs) play critical roles in the activation of proteolytic cascade in invertebrate immune systems including the prophenoloxidase (proPO) activating system. In this study, we characterized a snake-like serine protease, namely PmSnake, from the shrimp Penaeus monodon which has previously been identified based on the subtractive cDNA library of proPO double-stranded RNA (dsRNA)-treated hemocytes. An open reading frame of PmSnake contains 1068 bp encoding a predicted protein of 355 amino acid residues with a putative signal peptide of 22 amino acids and two conserved domains (N-terminal clip domain and C-terminal trypsin-like serine proteinase domain). Sequence analysis revealed that PmSnake was closest to the AeSnake from ant Acromyrmex echinatior (53% similarity), but was quite relatively distant from other shrimp PmclipSPs. PmSnake transcript was mainly expressed in shrimp hemocytes and up-regulated after systemic Vibrio harveyi infection indicating that it is an immune-responsive gene. Suppression of PmSnake expression by dsRNA interference reduced both transcript and protein levels leading to a reduction of the hemolymph phenoloxidase (PO) activity (36%), compared to the control, suggesting that the PmSnake functions as a clip-SP in shrimp proPO system. Western blot analysis using anti-PmSnake showed that the PmSnake was detected in hemocytes but not in cell-free plasma. In vitro PO activity and serine proteinase activity assays showed that adding rPmSnake into the shrimp hemolymph could increase PO activity as well as serine proteinase activity suggesting that the rPmSnake activates the proPO system via serine proteinase cascade.
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Affiliation(s)
- Warunthorn Monwan
- Center of Excellence for Molecular Biology and Genomics of Shrimp, Department of Biochemistry, Faculty of Science, Chulalongkorn University, 254 Phayathai Road, Bangkok 10330, Thailand
| | - Piti Amparyup
- Center of Excellence for Molecular Biology and Genomics of Shrimp, Department of Biochemistry, Faculty of Science, Chulalongkorn University, 254 Phayathai Road, Bangkok 10330, Thailand; National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), 113 Paholyothin Road, Klong1, Klong Luang, Pathumthani 12120, Thailand
| | - Anchalee Tassanakajon
- Center of Excellence for Molecular Biology and Genomics of Shrimp, Department of Biochemistry, Faculty of Science, Chulalongkorn University, 254 Phayathai Road, Bangkok 10330, Thailand.
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Cloning, expression and characterization of Ostrinia furnacalis serpin1, a regulator of the prophenoloxidase activation system. Comp Biochem Physiol B Biochem Mol Biol 2016; 192:9-20. [DOI: 10.1016/j.cbpb.2015.11.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Revised: 11/10/2015] [Accepted: 11/11/2015] [Indexed: 01/29/2023]
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12
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Adamo SA, Davies G, Easy R, Kovalko I, Turnbull KF. Reconfiguration of the immune system network during food limitation in the caterpillar Manduca sexta. ACTA ACUST UNITED AC 2016; 219:706-18. [PMID: 26747906 DOI: 10.1242/jeb.132936] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Accepted: 12/17/2015] [Indexed: 11/20/2022]
Abstract
Dwindling resources might be expected to induce a gradual decline in immune function. However, food limitation has complex and seemingly paradoxical effects on the immune system. Examining these changes from an immune system network perspective may help illuminate the purpose of these fluctuations. We found that food limitation lowered long-term (i.e. lipid) and short-term (i.e. sugars) energy stores in the caterpillar Manduca sexta. Food limitation also: altered immune gene expression, changed the activity of key immune enzymes, depressed the concentration of a major antioxidant (glutathione), reduced resistance to oxidative stress, reduced resistance to bacteria (Gram-positive and -negative bacteria) but appeared to have less effect on resistance to a fungus. These results provide evidence that food limitation led to a restructuring of the immune system network. In severely food-limited caterpillars, some immune functions were enhanced. As resources dwindled within the caterpillar, the immune response shifted its emphasis away from inducible immune defenses (i.e. those responses that are activated during an immune challenge) and increased emphasis on constitutive defenses (i.e. immune components that are produced consistently). We also found changes suggesting that the activation threshold for some immune responses (e.g. phenoloxidase) was lowered. Changes in the configuration of the immune system network will lead to different immunological strengths and vulnerabilities for the organism.
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Affiliation(s)
- Shelley A Adamo
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, Nova Scotia, Canada B3H 4R2
| | - Gillian Davies
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, Nova Scotia, Canada B3H 4R2
| | - Russell Easy
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, Nova Scotia, Canada B3H 4R2
| | - Ilya Kovalko
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, Nova Scotia, Canada B3H 4R2
| | - Kurtis F Turnbull
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, Nova Scotia, Canada B3H 4R2
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Genome-wide identification and expression profiling of serine proteases and homologs in the diamondback moth, Plutella xylostella (L.). BMC Genomics 2015; 16:1054. [PMID: 26653876 PMCID: PMC4676143 DOI: 10.1186/s12864-015-2243-4] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Accepted: 11/25/2015] [Indexed: 12/02/2022] Open
Abstract
Background Serine proteases (SPs) are crucial proteolytic enzymes responsible for digestion and other processes including signal transduction and immune responses in insects. Serine protease homologs (SPHs) lack catalytic activity but are involved in innate immunity. This study presents a genome-wide investigation of SPs and SPHs in the diamondback moth, Plutella xylostella (L.), a globally-distributed destructive pest of cruciferous crops. Results A total of 120 putative SPs and 101 putative SPHs were identified in the P. xylostella genome by bioinformatics analysis. Based on the features of trypsin, 38 SPs were putatively designated as trypsin genes. The distribution, transcription orientation, exon-intron structure and sequence alignments suggested that the majority of trypsin genes evolved from tandem duplications. Among the 221 SP/SPH genes, ten SP and three SPH genes with one or more clip domains were predicted and designated as PxCLIPs. Phylogenetic analysis of CLIPs in P. xylostella, two other Lepidoptera species (Bombyx mori and Manduca sexta), and two more distantly related insects (Drosophila melanogaster and Apis mellifera) showed that seven of the 13 PxCLIPs were clustered with homologs of the Lepidoptera rather than other species. Expression profiling of the P. xylostella SP and SPH genes in different developmental stages and tissues showed diverse expression patterns, suggesting high functional diversity with roles in digestion and development. Conclusions This is the first genome-wide investigation on the SP and SPH genes in P. xylostella. The characterized features and profiled expression patterns of the P. xylostella SPs and SPHs suggest their involvement in digestion, development and immunity of this species. Our findings provide a foundation for further research on the functions of this gene family in P. xylostella, and a better understanding of its capacity to rapidly adapt to a wide range of environmental variables including host plants and insecticides. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-2243-4) contains supplementary material, which is available to authorized users.
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Lu A, Zhang Q, Zhang J, Yang B, Wu K, Xie W, Luan YX, Ling E. Insect prophenoloxidase: the view beyond immunity. Front Physiol 2014; 5:252. [PMID: 25071597 PMCID: PMC4092376 DOI: 10.3389/fphys.2014.00252] [Citation(s) in RCA: 180] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Accepted: 06/17/2014] [Indexed: 11/13/2022] Open
Abstract
Insect prophenoloxidase (PPO) is an important innate immunity protein due to its involvement in cellular and humoral defense. It belongs to a group of type-3 copper-containing proteins that occurs in almost all organisms. Insect PPO has been studied for over a century, and the PPO activation cascade is becoming clearer. The insect PPO activation pathway incorporates several important proteins, including pattern-recognition receptors (PGRP, β GRP, and C-type lectins), serine proteases, and serine protease inhibitors (serpins). Due to their complexity, PPO activation mechanisms vary among insect species. Activated phenoloxidase (PO) oxidizes phenolic molecules to produce melanin around invading pathogens and wounds. The crystal structure of Manduca sexta PPO shows that a conserved amino acid, phenylalanine (F), can block the active site pocket. During activation, this blocker must be dislodged or even cleaved at the N-terminal sequence to expose the active site pockets and allow substrates to enter. Thanks to the crystal structure of M. sexta PPO, some domains and specific amino acids that affect PPO activities have been identified. Further studies of the relationship between PPO structure and enzyme activities will provide an opportunity to examine other type-3 copper proteins, and trace when and why their various physiological functions evolved. Recent researches show that insect PPO has a relationship with neuron activity, longevity, feces melanization (phytophagous insects) and development, which suggests that it is time for us to look back on insect PPO beyond the view of immunity in this review.
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Affiliation(s)
- Anrui Lu
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences Shanghai, China
| | - Qiaoli Zhang
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences Shanghai, China
| | - Jie Zhang
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences Shanghai, China
| | - Bing Yang
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences Shanghai, China
| | - Kai Wu
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences Shanghai, China
| | - Wei Xie
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences Shanghai, China
| | - Yun-Xia Luan
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences Shanghai, China
| | - Erjun Ling
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences Shanghai, China
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Shi M, Chen XY, Zhu N, Chen XX. Molecular identification of two prophenoloxidase-activating proteases from the hemocytes of Plutella xylostella (Lepidoptera: Plutellidae) and their transcript abundance changes in response to microbial challenges. JOURNAL OF INSECT SCIENCE (ONLINE) 2014; 14:179. [PMID: 25399433 PMCID: PMC5633980 DOI: 10.1093/jisesa/ieu041] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Accepted: 05/08/2013] [Indexed: 06/01/2023]
Abstract
The phenoloxidase (PO) activation system plays an important role in insect innate immunity, particularly in wound healing and pathogen defense. A key member of this system is prophenoloxidase-activating protease (PAP), which is the direct activator of prophenoloxidase (proPO). Despite their importance in the insect PO activation system, content of studies is limited. In this article, we identify two complementary DNAs (cDNAs), PxPAPa and PxPAPb, encoding possible PAPs, from immunized larval hemocytes of the diamondback moth, Plutella xylostella (L.), by RACE method. PxPAPa is 1,149-bp long and encodes a 382-residue open reading frame (ORF) with a predicted 17-residue signal peptide, a clip domain, and a Tryp_Spc domain. PxPAPb is 1,650-bp long and encodes a 440-residue ORF with a predicted 20-residue signal peptide, two clip domains, and a Tryp_Spc domain. PxPAPa and PxPAPb have a high sequence similarity to Manduca sexta (L.) PAP1 and PAP3, respectively. We also examined the transcript patterns of PxPAPa, PxPAPb, and pxPAP3, another clip-domain serine protease gene, response to different microbial challenges by using real-time quantitative polymerase chain reaction. The results show that the transcript abundance of PxPAPa is significantly increased by Micrococcus luteus and Escherichia coli but not Candida albicans. PxPAPb is induced only by Mi. luteus, whereas pxPAP3 could be induced by all the microbes in the test, but the transcript patterns of Mi. luteus, E. coli, and C. albicans are completely different. This study provides new insights into the molecular events that occur during the immune response, particularly melanization cascade that is involved in encapsulation and nodulation of pathogen or parasite invaders via hemocytes in host insects.
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Affiliation(s)
- Min Shi
- Ministry of Agriculture Key Lab of Agricultural Entomology, Institute of Insect Sciences, Zhejiang University, 866 Yuhangtang Rd., Hangzhou 310058, China
| | - Xiao-Yu Chen
- Ministry of Agriculture Key Lab of Agricultural Entomology, Institute of Insect Sciences, Zhejiang University, 866 Yuhangtang Rd., Hangzhou 310058, China
| | - Ni Zhu
- Ministry of Agriculture Key Lab of Agricultural Entomology, Institute of Insect Sciences, Zhejiang University, 866 Yuhangtang Rd., Hangzhou 310058, China
| | - Xue-Xin Chen
- Ministry of Agriculture Key Lab of Agricultural Entomology, Institute of Insect Sciences, Zhejiang University, 866 Yuhangtang Rd., Hangzhou 310058, China
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Jang IK, Pang Z, Yu J, Kim SK, Seo HC, Cho YR. Selectively enhanced expression of prophenoloxidase activating enzyme 1 (PPAE1) at a bacteria clearance site in the white shrimp, Litopenaeus vannamei. BMC Immunol 2011; 12:70. [PMID: 22208405 PMCID: PMC3268739 DOI: 10.1186/1471-2172-12-70] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2011] [Accepted: 12/30/2011] [Indexed: 01/03/2023] Open
Abstract
BACKGROUND The prophenoloxidase-activating (PO activating) system plays an important role in the crustacean innate immunity, particularly in wound healing and pathogen defense. A key member of this system is prophenoloxidase-activating enzyme (PPAE), which is the direct activator of prophenoloxidase (proPO). Despite their importance in crustacean PO activating system, the studies on them remain limited. RESULTS Here we report on a PPAE of white shrimp, Litopenaeus vannamei (lvPPAE1), which showed 94% similarity to PPAE1 of Penaeus monodon. We found that lvPPAE1 in fluid hemocytes was down regulated after challenge by Vibrio harveyi but was enhanced when shrimps were exposed to a bacteria-rich environment for long-term. In vivo gene silence of lvPPAE1 by RNAi can significantly reduce the phenoloxidase activity (PO) and increase the susceptibility of shrimps to V. harveyi. Although lvPPAE1 was down-regulated in fluid hemocytes by Vibrio challenge, its expression increased significantly in gill after bacteria injection, which is the primary bacteria-clearance tissue. CONCLUSION Suppressed expression in fluid hemocytes and enhanced expression in gill indicates selectively enhanced expression at the bacterial clearance site. This is a novel feature for PPAE expression. The results will contribute to our understanding of the PO activating system in crustaceans.
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Affiliation(s)
- In-Kwon Jang
- National Fisheries Research & Development Institute, #707 Eulwang dong, Jung-gu, Incheon, Republic of Korea
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Charoensapsri W, Amparyup P, Hirono I, Aoki T, Tassanakajon A. PmPPAE2, a new class of crustacean prophenoloxidase (proPO)-activating enzyme and its role in PO activation. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2011; 35:115-124. [PMID: 20837056 DOI: 10.1016/j.dci.2010.09.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2010] [Revised: 09/02/2010] [Accepted: 09/02/2010] [Indexed: 05/29/2023]
Abstract
The prophenoloxidase (proPO) activating system plays an important role in the defense against microbial invasion in invertebrates. In the present study, we report a second proPO-activating enzyme (designated PmPPAE2) from the hemocytes of the black tiger shrimp, Penaeus monodon. PmPPAE2 contained the structural features of the clip domain serine proteinase family and exhibited 51% amino acid sequence similarity to the insect Manduca sexta PAP-1. Amino acid sequence alignment with the available arthropod PPAE sequences demonstrated that PmPPAE2 is a new class of crustacean PPAE. Transcript expression analysis revealed that PmPPAE2 transcripts were mainly expressed in hemocytes. Double-stranded RNA-mediated suppression of PmPPAE2 transcript levels resulted in a significant decrease in the total hemolymph PO activity (41%) and also increased the shrimp's susceptibility to Vibrio harveyi infection. Genomic organization analysis revealed that PmPPAE1 and PmPPAE2 are encoded by different genomic loci. The PmPPAE1 gene consists of ten exons and nine introns, whilst PmPPAE2 comprises of eight exons interrupted by seven introns. Analysis of the larval developmental stage expression of the four key genes in the shrimp proPO system (PmPPAE1, PmPPAE2, PmproPO1 and PmproPO2) revealed that PmPPAE1 and PmproPO2 transcripts were expressed in all larval stages (nauplius, protozoea, mysis and post-larvae), whilst PmPPAE2 and PmproPO1 transcripts were mainly presented in the late larval developmental stages (mysis and post-larvae). These results suggest that the PmPPAE2 functions as a shrimp PPAE and possibly mediates the activation of PmproPO1.
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Affiliation(s)
- Walaiporn Charoensapsri
- Center of Excellence for Molecular Biology and Genomics of Shrimp, Department of Biochemistry, Faculty of Science, Chulalongkorn University, 254 Phayathai Road, Bangkok 10330, Thailand
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18
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Fang Q, Wang L, Zhu J, Li Y, Song Q, Stanley DW, Akhtar ZR, Ye G. Expression of immune-response genes in lepidopteran host is suppressed by venom from an endoparasitoid, Pteromalus puparum. BMC Genomics 2010; 11:484. [PMID: 20813030 PMCID: PMC2996980 DOI: 10.1186/1471-2164-11-484] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2010] [Accepted: 09/02/2010] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND The relationships between parasitoids and their insect hosts have attracted attention at two levels. First, the basic biology of host-parasitoid interactions is of fundamental interest. Second, parasitoids are widely used as biological control agents in sustainable agricultural programs. Females of the gregarious endoparasitoid Pteromalus puparum (Hymenoptera: Pteromalidae) inject venom along with eggs into their hosts. P. puparum does not inject polydnaviruses during oviposition. For this reason, P. puparum and its pupal host, the small white butterfly Pieris rapae (Lepidoptera: Pieridae), comprise an excellent model system for studying the influence of an endoparasitoid venom on the biology of the pupal host. P. puparum venom suppresses the immunity of its host, although the suppressive mechanisms are not fully understood. In this study, we tested our hypothesis that P. puparum venom influences host gene expression in the two main immunity-conferring tissues, hemocytes and fat body. RESULTS At 1 h post-venom injection, we recorded significant decreases in transcript levels of 217 EST clones (revealing 113 genes identified in silico, including 62 unknown contigs) derived from forward subtractive libraries of host hemocytes and in transcript levels of 288 EST clones (221 genes identified in silico, including 123 unknown contigs) from libraries of host fat body. These genes are related to insect immune response, cytoskeleton, cell cycle and apoptosis, metabolism, transport, stress response and transcriptional and translational regulation. We verified the reliability of the suppression subtractive hybridization (SSH) data with semi-quantitative RT-PCR analysis of a set of randomly selected genes. This analysis showed that most of the selected genes were down-regulated after venom injection. CONCLUSIONS Our findings support our hypothesis that P. puparum venom influences gene expression in host hemocytes and fat body. Specifically, the venom treatments led to reductions in expression of a large number of genes. Many of the down-regulated genes act in immunity, although others act in non-immune areas of host biology. We conclude that the actions of venom on host gene expression influence immunity as well as other aspects of host biology in ways that benefit the development and emergence of the next generation of parasitoids.
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Affiliation(s)
- Qi Fang
- State Key Laboratory of Rice Biology & Key Laboratory of Molecular Biology of Crop Pathogens and Insects of Ministry of Agriculture, Institute of Insect Sciences, Zhejiang University, Hangzhou 310029, China
| | - Lei Wang
- State Key Laboratory of Rice Biology & Key Laboratory of Molecular Biology of Crop Pathogens and Insects of Ministry of Agriculture, Institute of Insect Sciences, Zhejiang University, Hangzhou 310029, China
| | - Jiaying Zhu
- State Key Laboratory of Rice Biology & Key Laboratory of Molecular Biology of Crop Pathogens and Insects of Ministry of Agriculture, Institute of Insect Sciences, Zhejiang University, Hangzhou 310029, China
| | - Yanmin Li
- State Key Laboratory of Rice Biology & Key Laboratory of Molecular Biology of Crop Pathogens and Insects of Ministry of Agriculture, Institute of Insect Sciences, Zhejiang University, Hangzhou 310029, China
| | - Qisheng Song
- Division of Plant Sciences, University of Missouri, Columbia, MO 65211, USA
| | - David W Stanley
- USDA/Agricultural Research Service, Biological Control of Insects Research Laboratory, Columbia, MO 65203, USA
| | - Zunnu-raen Akhtar
- State Key Laboratory of Rice Biology & Key Laboratory of Molecular Biology of Crop Pathogens and Insects of Ministry of Agriculture, Institute of Insect Sciences, Zhejiang University, Hangzhou 310029, China
| | - Gongyin Ye
- State Key Laboratory of Rice Biology & Key Laboratory of Molecular Biology of Crop Pathogens and Insects of Ministry of Agriculture, Institute of Insect Sciences, Zhejiang University, Hangzhou 310029, China
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Zhang C, Zhou D, Zheng S, Liu L, Tao S, Yang L, Hu S, Feng Q. A chymotrypsin-like serine protease cDNA involved in food protein digestion in the common cutworm, Spodoptera litura: Cloning, characterization, developmental and induced expression patterns, and localization. JOURNAL OF INSECT PHYSIOLOGY 2010; 56:788-799. [PMID: 20149796 DOI: 10.1016/j.jinsphys.2010.02.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2009] [Revised: 02/01/2010] [Accepted: 02/02/2010] [Indexed: 05/26/2023]
Abstract
A full-length cDNA (Slctlp2) encoding a chymotrypsin-like serine protease was cloned from Spodoptera litura. This cDNA encoded a putative serine protease with a predicted molecular mass of 30.6kDa, which contained a serine protease catalytic motif GDSGGPL. Temporal and spatial expression of Slctlp2 mRNA and protein detected by Northern blotting, RT-PCR, qPCR and Western blotting analyses revealed that both Slctlp2 mRNA and protein were mainly present in the foregut and midgut of the 5th and 6th instar larvae during the feeding stages. In situ hybridization and immunohistochemistry confirmed that both Slctlp2 mRNA and protein were predominately present in the midgut. Expression of the gene was not induced by bacterial infection. Juvenile hormone III induced the gene expression, while 20-hydroxyecdysone had no impact on the expression. The expression of Slctlp2 mRNA and protein was down-regulated by starvation but up-regulated by re-feeding. The SlCTLP2 protein was detected in the lumen residues of the anterior, middle and posterior midgut and feces of the feeding 6th instar larvae, suggesting that it was secreted from the epithelium into the lumen of the gut. The results suggest that this Slctlp2 gene may be involved in digestive process of food proteins during the feeding stages of the larval development.
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Affiliation(s)
- Chun Zhang
- Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou 510631, China
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20
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van't Hof AE, Saccheri IJ. Industrial melanism in the peppered moth is not associated with genetic variation in canonical melanisation gene candidates. PLoS One 2010; 5:e10889. [PMID: 20526362 PMCID: PMC2878321 DOI: 10.1371/journal.pone.0010889] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2010] [Accepted: 05/05/2010] [Indexed: 02/01/2023] Open
Abstract
Industrial melanism in the peppered moth (Biston betularia) is an iconic case study of ecological genetics but the molecular identity of the gene determining the difference between the typical and melanic (carbonaria) morphs is entirely unknown. We applied the candidate gene approach to look for associations between genetic polymorphisms within sixteen a priori melanisation gene candidates and the carbonaria morph. The genes were isolated and sequence characterised in B. betularia using degenerate PCR and from whole-transcriptome sequence. The list of candidates contains all the genes previously implicated in melanisation pattern differences in other insects, including aaNAT, DOPA-decarboxylase, ebony, tan, tyrosine hydroxylase, yellow and yellow2 (yellow-fa). Co-segregation of candidate gene alleles and carbonaria morph was tested in 73 offspring of a carbonaria male-typical female backcross. Surprisingly, none of the sixteen candidate genes was in close linkage with the locus controlling the carbonaria-typical polymorphism. Our study demonstrates that the 'carbonaria gene' is not a structural variant of a canonical melanisation pathway gene, neither is it a cis-regulatory element of these enzyme-coding genes. The implication is either that we have failed to characterize an unknown enzyme-coding gene in the melanisation pathway, or more likely, that the 'carbonaria gene' is a higher level trans-acting factor which regulates the spatial expression of one or more of the melanisation candidates in this study to alter the pattern of melanin production.
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Affiliation(s)
- Arjen E. van't Hof
- School of Biological Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Ilik J. Saccheri
- School of Biological Sciences, University of Liverpool, Liverpool, United Kingdom
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21
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Huang J, Ohta H, Inoue N, Takao H, Kita T, Ozoe F, Ozoe Y. Molecular cloning and pharmacological characterization of a Bombyx mori tyramine receptor selectively coupled to intracellular calcium mobilization. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2009; 39:842-849. [PMID: 19833207 DOI: 10.1016/j.ibmb.2009.10.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2009] [Revised: 09/27/2009] [Accepted: 10/01/2009] [Indexed: 05/28/2023]
Abstract
Tyramine (TA) is a biogenic amine in invertebrates. cDNA encoding the TA receptor (TAR) BmTAR2 was cloned from the nerve tissue of the silkworm Bombyx mori. The receptor's functional and pharmacological properties were examined in BmTAR2-transfected HEK-293 cells. In [(3)H]TA binding assays, BmTAR2 showed considerably higher affinity for TA than for other biogenic amines, with an IC(50) value of 57.5 nM. Moreover, TA induced a dose-dependent increase in intracellular Ca(2+) concentration ([Ca(2+)](i)) in cells, with an EC(50) value of 11.6 nM, whereas octopamine and dopamine increased [Ca(2+)](i) only at concentrations above 100 microM. A few antagonists were found to inhibit the TA-induced increases in [Ca(2+)](i); the rank order of potency was yohimbine > chlorpromazine > mianserin. TA showed no effect on intracellular cAMP concentration. The data indicate that BmTAR2 belongs to the second class of TARs, which are selectively coupled to intracellular Ca(2+) mobilization. RT-PCR analysis revealed that BmTAR2 was expressed predominantly in the nervous tissue of B. mori larvae, suggesting that TA has neurotransmitter and neuromodulatory roles that are mediated by BmTAR2.
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Affiliation(s)
- Jia Huang
- Department of Life Science and Biotechnology, Faculty of Life and Environmental Science, Shimane University, Matsue, Shimane, Japan
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22
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Liu F, Ling E, Wu S. Gene expression profiling during early response to injury and microbial challenges in the silkworm, Bombyx mori. ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2009; 72:16-33. [PMID: 19557735 DOI: 10.1002/arch.20320] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
To identify Bombyx mori genes involved in the early response to injury and microbial challenge, we performed genome-wide gene expression-profiling experiments using oligonucleotide DNA microarrays. Of approximately 23,000 genes examined, 465 displayed changes in mRNA expression levels. Of these, 306 were induced and 159 were repressed in response to injury (injection with phosphate buffer saline) or challenges by Gram-negative (Serratia marcescens), Gram-positive bacteria (Staphylococcus aureus), or fungus (Beauveria bassiana). Many of these differentially expressed genes can be assigned to specific functional groups of the innate immune response, including recognition, signaling, melanization and coagulation, and antimicrobial peptides. Seventeen percent of differentially expressed genes encode proteins with no obvious similarity to known functional domains. Of particular interest is a member of the juvenile hormone-binding protein family, which was highly induced by both injury and microbial challenges. The possible role of juvenile hormone in innate immunity is discussed.
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Affiliation(s)
- Fei Liu
- Research Center for Insect Science, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, The Chinese Academy of Sciences Graduate School, Shanghai, People's Republic of China
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Winterhalter WE, Fedorka KM. Sex-specific variation in the emphasis, inducibility and timing of the post-mating immune response in Drosophila melanogaster. Proc Biol Sci 2009; 276:1109-17. [PMID: 19129115 DOI: 10.1098/rspb.2008.1559] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Ecological immunology attempts to explain variation in immune function. Much of this work makes predictions about how potential hosts should invest in overall immunity. However, this 'overall' perspective under-emphasizes other critical aspects, such as the specificity, inducibility and timing of an immune response. Here, we investigate these aspects by examining gene regulation across several immune system components in both male and female Drosophila melanogaster prior to and after mating. To elucidate potentially important temporal dynamics, we also assayed several genes over time. We found that males and females emphasized different components of their immune system, however overall investment was similar. Specifically, the sexes emphasized different gene paralogues within major gene families, and males tended to invest more in gram-negative defence. By contrast, the inducibility of the immune response was both transient (lasting approx. 24 hours) and equal between the sexes. Furthermore, mating tended to induce humoral gene upregulation, while cell-mediated genes were unaffected. Within the humoral system, gram-negative bacterial defence genes exhibited a greater inducibility than those associated with fungal or gram-positive bacterial defence. Our results suggest that variation in the effectiveness of the immune response between the sexes may be driven by differences in emphasis rather than overall investment.
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Affiliation(s)
- Wade E Winterhalter
- Department of Biology, University of Central Florida, 4000 Central Florida Boulevard, Orlando, FL 32816, USA
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Abdel-latief M, Hilker M. Innate immunity: eggs of Manduca sexta are able to respond to parasitism by Trichogramma evanescens. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2008; 38:136-45. [PMID: 18207075 DOI: 10.1016/j.ibmb.2007.10.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2007] [Revised: 10/01/2007] [Accepted: 10/04/2007] [Indexed: 05/12/2023]
Abstract
So far, it was unknown whether immune responses of insect eggs are inducible or suppressed by parasitism. We investigated whether transcription of immune related genes in eggs of Manduca sexta changed in response to parasitism by Trichogramma evanescens. First, using DDRT-PCR, several cDNA elements known to represent immune related M. sexta genes inducible by bacterial challenge were isolated from eggs. In addition, two novel cDNAs were found: (a) immulectin-V (IML-V) suggested to be involved in recognition of foreign bodies, and (b) a new like-moricin protein with possible antimicrobial effects (L-Mor). Quantitative real time RT-PCR analyses revealed enhanced transcription in parasitized eggs compared to unparasitized ones for IML-V, prophenoloxidase (ProPO), prophenoloxidase activating protease I (PAP I), and proparalytic peptide (ProPP). No significant differences between parasitized and unparasitized eggs were detected for sequences encoding the antimicrobial peptides L-Mor, leureptin Leu, and attacin II Att II. Transcript levels of other antibacterial peptides were suppressed after parasitization for 3d (cecropin 6, Cec 6) and 2d (gloverin, Glov). While nearly 100% of the Manduca eggs contained Trichogramma specimens 1d after exposure to parasitoids, only 64% of the host eggs harbored parasitoid larvae 4d after parasitization. Our data demonstrate that the immune system of Manduca eggs shows differentiated responses to parasitization and suggest that insect eggs can defend against parasitization.
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Affiliation(s)
- M Abdel-latief
- Department of Applied Zoology/Animal Ecology, Institute of Biology, Freie Universität Berlin, 12163 Berlin, Germany
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Aladaileh S, Nair SV, Raftos DA. Induction of phenoloxidase and other immunological activities in Sydney rock oysters challenged with microbial pathogen-associate molecular patterns. FISH & SHELLFISH IMMUNOLOGY 2007; 23:1196-1208. [PMID: 17977020 DOI: 10.1016/j.fsi.2007.05.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2006] [Revised: 05/06/2007] [Accepted: 05/21/2007] [Indexed: 05/25/2023]
Abstract
This study investigates the effects of two pathogen-associated molecular patterns (PAMPs), LPS and zymosan, on the Sydney rock oyster (Saccostrea glomerata) immune system. Phenoloxidase and phagocytic activities, total and differential haemocyte frequencies, as well as peroxide and superoxide concentrations were measured after the injection of lipopolysaccharide and zymosan. All of the immunological parameters were induced by both PAMPs. Phenoloxidase (monophenolase and diphenolase) and phagocytic activities, as well as the frequencies of phenoloxidase-positive haemocytes, hyalinocytes and granulocytes in the haemolymph, increased within 24 h of PAMP injection. Values for all of these parameters peaked within 48 h of challenge and began to decrease to levels that were indistinguishable from those of controls within 96h. The only exception to this pattern was diphenolase activity, which remained elevated for at least 96 h. Control saline injections that lacked PAMPs also induced responses in most of the parameters measured. However, reactions to saline injections were of far lower magnitude compared to those induced by PAMPs. All of the data suggest that the phenoloxidase and phagocytic systems of oysters are inducible components of the Sydney rock oyster immune system, and that induction is primarily due to increased frequencies of specialised haemocytes in the haemolymph.
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Affiliation(s)
- Saleem Aladaileh
- Department of Biological Sciences, Macquarie University, North Ryde, NSW 2109, Australia
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Vafopoulou X, Laufer H, Steel CGH. Spatial and temporal distribution of the ecdysteroid receptor (EcR) in haemocytes and epidermal cells during wound healing in the crayfish, Procambarus clarkii. Gen Comp Endocrinol 2007; 152:359-70. [PMID: 17399711 DOI: 10.1016/j.ygcen.2007.01.044] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2006] [Revised: 01/28/2007] [Accepted: 01/30/2007] [Indexed: 10/23/2022]
Abstract
Wound healing in crustaceans preserves the integrity of the integument and prevents entry of pathogens. We studied the interaction between the moulting hormones (ecdysteroids) and the cellular events under the wound during wound healing with or without bacteria infection. Wounding of the carapace by abrasion induced a rapid increase in circulating ecdysteroid levels to a low sustained plateau level for about 12 days, followed by a sharp premoult peak and moulting. Within 48h of wounding, the nuclear receptor for ecdysteroids (EcR) appeared in the nuclei of haemocytes (hyaline, semigranular and granulocytes), visualized by confocal laser scanning microscopy and anti-EcR. Hyaline haematocytes aggregated in layers below the wound site and granulocytes engaged in phagocytosis. Therefore, the immune system responds directly and rapidly to ecdysteroids. Epidermal cells developed EcR only several days after the haemocytes and only under intact carapace, not under the wound where they appeared apoptotic. At the wound margin, EcR-positive epidermal cells and fibroblasts proceeded to migrate across the wound between the layers of haemocytes. Epidermis was fully regenerated by day 15; at this time the ecdysteroid titre began rising towards a premoult peak and EcR disappeared from the nuclei of epidermal cells suggesting that high amounts of ecdysteroids exert negative control on EcR. When bacteria were injected at the time of wounding, both the plateau level of ecdysteroid titre and the cellular events of wound healing were prolonged by 5-7 days, showing that healing of the wound is slower and that the duration of the plateau phase of the titre depends on the degree of assault on the animal. We conclude that the low levels of ecdysteroids induced by wounding activate the immune system to begin healing below the wound and also stimulate adjacent epidermal cells to commence the process of wound repair.
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Affiliation(s)
- Xanthe Vafopoulou
- Department of Biology, York University, 4700 Keele St., Toronto, Ont., Canada M3J 1P3.
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Abstract
Interactions between immune systems, nervous systems, and behavior are well established in vertebrates. A comparative examination of these interactions in other animals will help us understand their evolution and present adaptive functions. Insects show immune-behavioral interactions similar to those seen in vertebrates, suggesting that many of them may have a highly conserved function. Activation of an immune response in insects results in illness-induced anorexia, behavioral fever, changes in reproductive behavior, and decreased learning ability in a broad range of species. Flight-or-fight behaviors result in a decline in disease resistance. In insects, illness-induced anorexia may enhance immunity. Stress-induced immunosuppression is probably due to physiological conflicts between the immune response and those of other physiological processes. Because insects occupy a wide range of ecological niches, they will be useful in examining how some immune-behavioral interactions are sculpted by an animal's behavioral ecology.
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Barat-Houari M, Hilliou F, Jousset FX, Sofer L, Deleury E, Rocher J, Ravallec M, Galibert L, Delobel P, Feyereisen R, Fournier P, Volkoff AN. Gene expression profiling of Spodoptera frugiperda hemocytes and fat body using cDNA microarray reveals polydnavirus-associated variations in lepidopteran host genes transcript levels. BMC Genomics 2006; 7:160. [PMID: 16790040 PMCID: PMC1559612 DOI: 10.1186/1471-2164-7-160] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2006] [Accepted: 06/21/2006] [Indexed: 01/12/2023] Open
Abstract
Background Genomic approaches provide unique opportunities to study interactions of insects with their pathogens. We developed a cDNA microarray to analyze the gene transcription profile of the lepidopteran pest Spodoptera frugiperda in response to injection of the polydnavirus HdIV associated with the ichneumonid wasp Hyposoter didymator. Polydnaviruses are associated with parasitic ichneumonoid wasps and are required for their development within the lepidopteran host, in which they act as potent immunosuppressive pathogens. In this study, we analyzed transcriptional variations in the two main effectors of the insect immune response, the hemocytes and the fat body, after injection of filter-purified HdIV. Results Results show that 24 hours post-injection, about 4% of the 1750 arrayed host genes display changes in their transcript levels with a large proportion (76%) showing a decrease. As a comparison, in S. frugiperda fat body, after injection of the pathogenic JcDNV densovirus, 8 genes display significant changes in their transcript level. They differ from the 7 affected by HdIV and, as opposed to HdIV injection, are all up-regulated. Interestingly, several of the genes that are modulated by HdIV injection have been shown to be involved in lepidopteran innate immunity. Levels of transcripts related to calreticulin, prophenoloxidase-activating enzyme, immulectin-2 and a novel lepidopteran scavenger receptor are decreased in hemocytes of HdIV-injected caterpillars. This was confirmed by quantitative RT-PCR analysis but not observed after injection of heat-inactivated HdIV. Conversely, an increased level of transcripts was found for a galactose-binding lectin and, surprisingly, for the prophenoloxidase subunits. The results obtained suggest that HdIV injection affects transcript levels of genes encoding different components of the host immune response (non-self recognition, humoral and cellular responses). Conclusion This analysis of the host-polydnavirus interactions by a microarray approach indicates that the presence of HdIV induces, directly or indirectly, variations in transcript levels of specific host genes, changes that could be responsible in part for the alterations observed in the parasitized host physiology. Development of such global approaches will allow a better understanding of the strategies employed by parasites to manipulate their host physiology, and will permit the identification of potential targets of the immunosuppressive polydnaviruses.
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Affiliation(s)
- M Barat-Houari
- UMR 1231 Biologie Intégrative et Virologie des Insectes. INRA – Université de Montpellier II. Place Eugène Bataillon, Case Courrier 101, 34 095 Montpellier Cedex, France
| | - F Hilliou
- UMR 1112 R.O.S.E. INRA – Université de Nice-Sophia Antipolis, Laboratoire de Génomique Fonctionnelle des Insectes, 400 route des Chappes, BP 167, 06 903 Sophia Antipolis Cedex, France
| | - F-X Jousset
- UMR 1231 Biologie Intégrative et Virologie des Insectes. INRA – Université de Montpellier II. Place Eugène Bataillon, Case Courrier 101, 34 095 Montpellier Cedex, France
| | - L Sofer
- UMR 1112 R.O.S.E. INRA – Université de Nice-Sophia Antipolis, Laboratoire de Génomique Fonctionnelle des Insectes, 400 route des Chappes, BP 167, 06 903 Sophia Antipolis Cedex, France
| | - E Deleury
- UMR 1112 R.O.S.E. INRA – Université de Nice-Sophia Antipolis, Laboratoire de Génomique Fonctionnelle des Insectes, 400 route des Chappes, BP 167, 06 903 Sophia Antipolis Cedex, France
| | - J Rocher
- UMR 1231 Biologie Intégrative et Virologie des Insectes. INRA – Université de Montpellier II. Place Eugène Bataillon, Case Courrier 101, 34 095 Montpellier Cedex, France
| | - M Ravallec
- UMR 1231 Biologie Intégrative et Virologie des Insectes. INRA – Université de Montpellier II. Place Eugène Bataillon, Case Courrier 101, 34 095 Montpellier Cedex, France
| | - L Galibert
- UMR 1231 Biologie Intégrative et Virologie des Insectes. INRA – Université de Montpellier II. Place Eugène Bataillon, Case Courrier 101, 34 095 Montpellier Cedex, France
| | - P Delobel
- INRA U.M.R. Sciences pour l'Oenologie, Equipe Microbiologie – Bât 28, 2, place Viala, 34 060 Montpellier Cedex 01, France
| | - R Feyereisen
- UMR 1112 R.O.S.E. INRA – Université de Nice-Sophia Antipolis, Laboratoire de Génomique Fonctionnelle des Insectes, 400 route des Chappes, BP 167, 06 903 Sophia Antipolis Cedex, France
| | - P Fournier
- UMR 1231 Biologie Intégrative et Virologie des Insectes. INRA – Université de Montpellier II. Place Eugène Bataillon, Case Courrier 101, 34 095 Montpellier Cedex, France
| | - A-N Volkoff
- UMR 1231 Biologie Intégrative et Virologie des Insectes. INRA – Université de Montpellier II. Place Eugène Bataillon, Case Courrier 101, 34 095 Montpellier Cedex, France
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Wang Y, Zou Z, Jiang H. An expansion of the dual clip-domain serine proteinase family in Manduca sexta: gene organization, expression, and evolution of prophenoloxidase-activating proteinase-2, hemolymph proteinase 12, and other related proteinases. Genomics 2005; 87:399-409. [PMID: 16324822 PMCID: PMC2071929 DOI: 10.1016/j.ygeno.2005.10.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2005] [Revised: 10/11/2005] [Accepted: 10/14/2005] [Indexed: 11/26/2022]
Abstract
Prophenoloxidase-activating proteinases (PAPs) take part in insect defense responses including melanotic encapsulation and wound healing. To understand their gene structure and regulation, we screened a genomic library and isolated overlapping lambda clones for Manduca sexta PAP-2, hemolymph proteinase 12 (HP12), and HP24. Complete nucleotide sequence analysis indicated that all three genes encode polypeptides with two regulatory clip domains at the amino terminus, a linker region, and a catalytic serine proteinase domain at the carboxyl terminus. Each gene contains eight exons, with introns located at equivalent positions. Similar sequences are present in introns as well as exons, indicating that these genes arose from recent gene duplication and sequence divergence. We analyzed their 5' flanking sequences and identified putative immune and hormone responsive elements. Reverse transcription-polymerase chain reactions confirmed that PAP-2 and HP12 mRNA levels in the larval fat body and hemocytes increased after a bacterial challenge. However, HP24 expression was barely detected. PAP-2 transcripts in cultured fat body became less abundant after 20-hydroxyecdysone treatment. Thus, PAP-2, HP12, and HP24 mRNA levels are differentially regulated by immune and developmental signals. Comparison with HP15, HP23, and PAP-3 sequences suggested an evolutionary pathway of the dual clip-domain serine proteinases in M. sexta.
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MESH Headings
- 5' Flanking Region/genetics
- Amino Acid Sequence
- Animals
- Base Sequence
- DNA/chemistry
- DNA/genetics
- DNA/isolation & purification
- DNA, Complementary/chemistry
- DNA, Complementary/genetics
- DNA, Complementary/isolation & purification
- Evolution, Molecular
- Exons
- Gene Expression Regulation, Enzymologic
- Gene Order
- Insect Proteins/genetics
- Introns
- Manduca/enzymology
- Manduca/genetics
- Molecular Sequence Data
- Multigene Family/genetics
- Phylogeny
- Regulatory Sequences, Nucleic Acid/genetics
- Repetitive Sequences, Nucleic Acid/genetics
- Sequence Alignment
- Sequence Analysis, DNA
- Sequence Homology, Amino Acid
- Sequence Homology, Nucleic Acid
- Serine Endopeptidases/genetics
- Transcription Initiation Site
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Affiliation(s)
| | | | - Haobo Jiang
- Corresponding author. Fax: +1 405 744 6039. E-mail address: (H. Jiang)
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30
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Castillejo-López C, Häcker U. The serine protease Sp7 is expressed in blood cells and regulates the melanization reaction in Drosophila. Biochem Biophys Res Commun 2005; 338:1075-82. [PMID: 16256951 DOI: 10.1016/j.bbrc.2005.10.042] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2005] [Accepted: 10/07/2005] [Indexed: 01/15/2023]
Abstract
Serine proteases play a central role in defense against pathogens by regulating processes such as blood clotting, melanization of injured surfaces, and proteolytic activation of signaling pathways involved in innate immunity. Here, we present the functional characterization of the Drosophila serine protease Sp7 (CG3006) by inducible RNA interference. We show that Sp7 is constitutively expressed in blood cells during embryonic and larval stages. Silencing of the gene impairs the melanization reaction upon injury. Our data demonstrate that Sp7 is required for phenoloxidase activation and its activity is restricted to a subclass of blood cells, the crystal cells. Transcriptional up-regulation of Sp7 was observed after clean, septic injury and in flies expressing an activated form of Toll; however, mutations in the Toll or the IMD pathway did not abolish expression of Sp7, indicating the existence of other regulatory pathways and/or independent basal transcription.
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Affiliation(s)
- Casimiro Castillejo-López
- Department of Experimental Medical Science and Lund Strategic Research Center for Stem Cell Biology and Cell Therapy, Lund University, BMC B13, Klinikgatan 26, 22184 Lund, Sweden.
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