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Yan L, Nur Faidah A, Sun L, Cao C. Hemolin increases the immune response of a caterpillar to NPV infection. JOURNAL OF INSECT PHYSIOLOGY 2024; 155:104651. [PMID: 38763360 DOI: 10.1016/j.jinsphys.2024.104651] [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: 01/28/2024] [Revised: 04/26/2024] [Accepted: 05/15/2024] [Indexed: 05/21/2024]
Abstract
Hemolin, a member of the immunoglobulin superfamily, plays a crucial role in the immune responses of insects against pathogens. However, the innate immune response of Hemolin to baculovirus infection varies among different insects, and the antiviral effects of Hemolin in Hyphantria cunea (HcHemolin) remain poorly understood. Our results showed that HcHemolin was expressed throughout all developmental stages, with higher expressions observed during pupal and adult stages of H. cunea. Additionally, HcHemolin was expressed in reproductive and digestive organs. The expression levels of the HcHemolin were induced significantly following H. cunea nucleopolyhedrovirus (HcNPV) infection. The susceptibility of H. cunea larvae to HcNPV decreased upon silencing of HcHemolin, resulting in a 40% reduction in median lifespan compared to the control group. The relative growth rate (RGR), the relative efficiency of consumption rate (RCR), the efficiency of the conversion of ingested food (ECI), and efficiency of the conversion of digested food (ECD) of silenced H. cunea larvae were significantly lower than those of the control group. Immune challenge assays showed that the median lifespan of treated H. cunea larvae was two-fold longer than the control group after HcNPV and HcHemolin protein co-injection. Therefore, we propose that HcHemolin plays a crucial role in regulating the growth, development, and food utilization of H. cunea, as well as in the antiviral immune response against HcNPV. These findings provide implications for the development of targeted nucleic acid pesticides and novel strategies for pollution-free biological control synergists for HcNPV.
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Affiliation(s)
- Liqiong Yan
- Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education, Northeast Forestry University, Harbin, Heilongjiang 150040, China.
| | - Arina Nur Faidah
- Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education, Northeast Forestry University, Harbin, Heilongjiang 150040, China.
| | - Lili Sun
- Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education, Northeast Forestry University, Harbin, Heilongjiang 150040, China.
| | - Chuanwang Cao
- Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education, Northeast Forestry University, Harbin, Heilongjiang 150040, China.
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Han G, Li C, Zhang N, Liu Q, Huang L, Xia Y, Xu J. CmHem, a hemolin-like gene identified from Cnaphalocrocis medinalis, involved in metamorphosis and baculovirus infection. PeerJ 2023; 11:e16225. [PMID: 37810787 PMCID: PMC10559889 DOI: 10.7717/peerj.16225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Accepted: 09/12/2023] [Indexed: 10/10/2023] Open
Abstract
Background As a member of the immunoglobulin superfamily, hemolins play a vital role in insect development and defense against pathogens. However, the innate immune response of hemolin to baculovirus infection varies among different insects. Methods and results In this study, the hemolin-like gene from a Crambidae insect, Cnaphalocrocis medinalis, CmHem was cloned, and its role in insect development and baculovirus infection was analyzed. A 1,528 bp contig as potential hemolin-like gene of C. medinalis was reassembled from the transcriptome. Further, the complete hemolin sequence of C. medinalis (CmHem) was cloned and sequenced. The cDNA of CmHem was 1,515 bp in length and encoded 408 amino acids. The deduced amino acid of CmHem has relatively low identities (41.9-62.3%) to various insect hemolins. However, it contains four Ig domains similarity to other insect hemolins. The expression level of CmHem was the highest in eggs, followed by pupae and adults, and maintained a low expression level at larval stage. The synthesized siRNAs were injected into mature larvae, and the CmHem transcription decreased by 51.7%. Moreover, the abdominal somites of larvae became straightened, could not pupate normally, and then died. Infection with a baculovirus, C. medinalis granulovirus (CnmeGV), the expression levels of CmHem in the midgut and fat body of C. medinalis significantly increased at 12 and 24 h, respectively, and then soon returned to normal levels. Conclusions Our results suggested that hemolin may be related to the metamorphosis of C. medinalis. Exposure to baculovirus induced the phased expression of hemolin gene in the midgut and fat body of C. medinalis, indicated that hemolin involved in the immune recognition of Crambidae insects to baculovirus.
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Affiliation(s)
- Guangjie Han
- Lixiahe District Institute of Agricultural Sciences in Jiangsu, Yangzhou, China
| | - Chuanming Li
- Lixiahe District Institute of Agricultural Sciences in Jiangsu, Yangzhou, China
| | - Nan Zhang
- Lixiahe District Institute of Agricultural Sciences in Jiangsu, Yangzhou, China
| | - Qin Liu
- Lixiahe District Institute of Agricultural Sciences in Jiangsu, Yangzhou, China
| | - Lixin Huang
- Lixiahe District Institute of Agricultural Sciences in Jiangsu, Yangzhou, China
| | - Yang Xia
- Lixiahe District Institute of Agricultural Sciences in Jiangsu, Yangzhou, China
| | - Jian Xu
- Lixiahe District Institute of Agricultural Sciences in Jiangsu, Yangzhou, China
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Qiao X, Liu C, Wang W, Yang C, Li M, Yi Q, Kong N, Qiu L, Liu X, Wang L, Song L. A neural cell adhesion molecule from oyster Crassostrea gigas: Molecular identification and immune functional characterization. Int J Biol Macromol 2023; 247:125756. [PMID: 37429340 DOI: 10.1016/j.ijbiomac.2023.125756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 07/02/2023] [Accepted: 07/07/2023] [Indexed: 07/12/2023]
Abstract
Neural cell adhesion molecules (NCAMs) are large cell-surface glycoproteins playing important roles in cell-cell and cell-extracellular matrix interactions in nervous system. Recent study identified a homologue of NCAM (CgNCAM) from the Pacific oyster Crassostrea gigas. Its ORF was of 2634 bp which encodes a protein (877 amino acids) consisting of five immunoglobulin domains and two fibronectin type III domains. CgNCAM transcripts were broadly distributed in oyster tissues especially in mantle, labial palp and haemolymph. CgNCAM showed up-regulated expression in haemocytes of oysters after Vibrio splendidus and Staphylococcus aureus stimulation. The recombinant CgNCAM protein (rCgNCAM) was able to bind manose, lipopolysaccharide and glucan, as well as different microbes including Gram-negative bacteria and fungi. rCgNCAM displayed bacterial agglutination and hemagglutination activity. CgNCAM improved the phagocytosis of haemocytes towards V. splendidus by regulating the expression of CgIntegrin, CgRho J and CgMAPKK. Moreover, CgNCAM was involved in the extracellular trap establishment of haemocytes after V. splendidus stimulation. The results collectively indicated that CgNCAM acted as a recognition receptor executing multiple immune functions to recognize and eliminate invading microorganisms in innate immunity of oysters.
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Affiliation(s)
- Xue Qiao
- Liaoning Key Laboratory of Marine Animal Immunology, Dalian Ocean University, Dalian 116023, China; Liaoning Key Laboratory of Marine Animal Immunology and Disease Control, Dalian Ocean University, Dalian 116023, China
| | - Conghui Liu
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
| | - Weilin Wang
- Liaoning Key Laboratory of Marine Animal Immunology, Dalian Ocean University, Dalian 116023, China; Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Laboratory of Marine Fisheries Science and Food Production Process, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266235, China; Liaoning Key Laboratory of Marine Animal Immunology and Disease Control, Dalian Ocean University, Dalian 116023, China
| | - Chuanyan Yang
- Liaoning Key Laboratory of Marine Animal Immunology, Dalian Ocean University, Dalian 116023, China; Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Liaoning Key Laboratory of Marine Animal Immunology and Disease Control, Dalian Ocean University, Dalian 116023, China
| | - Meijia Li
- Liaoning Key Laboratory of Marine Animal Immunology, Dalian Ocean University, Dalian 116023, China; Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
| | - Qilin Yi
- Liaoning Key Laboratory of Marine Animal Immunology, Dalian Ocean University, Dalian 116023, China; Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Laboratory of Marine Fisheries Science and Food Production Process, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266235, China; Liaoning Key Laboratory of Marine Animal Immunology and Disease Control, Dalian Ocean University, Dalian 116023, China
| | - Ning Kong
- Liaoning Key Laboratory of Marine Animal Immunology, Dalian Ocean University, Dalian 116023, China; Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Laboratory of Marine Fisheries Science and Food Production Process, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266235, China; Liaoning Key Laboratory of Marine Animal Immunology and Disease Control, Dalian Ocean University, Dalian 116023, China
| | - Limei Qiu
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
| | - Xiyang Liu
- Liaoning Key Laboratory of Marine Animal Immunology, Dalian Ocean University, Dalian 116023, China; Liaoning Key Laboratory of Marine Animal Immunology and Disease Control, Dalian Ocean University, Dalian 116023, China
| | - Lingling Wang
- Liaoning Key Laboratory of Marine Animal Immunology, Dalian Ocean University, Dalian 116023, China; Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Laboratory of Marine Fisheries Science and Food Production Process, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266235, China; Liaoning Key Laboratory of Marine Animal Immunology and Disease Control, Dalian Ocean University, Dalian 116023, China.
| | - Linsheng Song
- Liaoning Key Laboratory of Marine Animal Immunology, Dalian Ocean University, Dalian 116023, China; Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Laboratory of Marine Fisheries Science and Food Production Process, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266235, China; Liaoning Key Laboratory of Marine Animal Immunology and Disease Control, Dalian Ocean University, Dalian 116023, China.
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He X, Zhou T, Cai Y, Liu Y, Zhao S, Zhang J, Wang X, Zhang R. A Versatile Hemolin With Pattern Recognitional Contributions to the Humoral Immune Responses of the Chinese Oak Silkworm Antheraea pernyi. Front Immunol 2022; 13:904862. [PMID: 35669768 PMCID: PMC9163686 DOI: 10.3389/fimmu.2022.904862] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2022] [Accepted: 04/25/2022] [Indexed: 11/13/2022] Open
Abstract
Hemolin is a distinctive immunoglobulin superfamily member involved in invertebrate immune events. Although it is believed that hemolin regulates hemocyte phagocytosis and microbial agglutination in insects, little is known about its contribution to the humoral immune system. In the present study, we focused on hemolin in Antheraea pernyi (Ap-hemolin) by studying its pattern recognition property and humoral immune functions. Tissue distribution analysis demonstrated the mRNA level of Ap-hemolin was extremely immune-inducible in different tissues. The results of western blotting and biolayer interferometry showed recombinant Ap-hemolin bound to various microbes and pathogen-associated molecular patterns. In further immune functional studies, it was detected that knockdown of hemolin regulated the expression level of antimicrobial peptide genes and decreased prophenoloxidase activation in the A. pernyi hemolymph stimulated by microbial invaders. Together, these data suggest that hemolin is a multifunctional pattern recognition receptor that plays critical roles in the humoral immune responses of A. pernyi.
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Affiliation(s)
- Xueshan He
- School of Medical Devices, Shenyang Pharmaceutical University, Shenyang, China
| | - Tianyang Zhou
- School of Life Science and Bio-Pharmaceutics, Shenyang Pharmaceutical University, Shenyang, China
| | - Yuchen Cai
- School of Medical Devices, Shenyang Pharmaceutical University, Shenyang, China
| | - Yang Liu
- Research and Development Department, Liaoning Applos Biotechnology Co., Ltd, Shenyang, China
| | - Siqi Zhao
- School of Life Science and Bio-Pharmaceutics, Shenyang Pharmaceutical University, Shenyang, China
| | - Jinghai Zhang
- School of Medical Devices, Shenyang Pharmaceutical University, Shenyang, China
| | - Xialu Wang
- School of Medical Devices, Shenyang Pharmaceutical University, Shenyang, China
- *Correspondence: Rong Zhang, ; Xialu Wang,
| | - Rong Zhang
- School of Life Science and Bio-Pharmaceutics, Shenyang Pharmaceutical University, Shenyang, China
- *Correspondence: Rong Zhang, ; Xialu Wang,
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Regulators and signalling in insect antimicrobial innate immunity: Functional molecules and cellular pathways. Cell Signal 2021; 83:110003. [PMID: 33836260 DOI: 10.1016/j.cellsig.2021.110003] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 04/02/2021] [Accepted: 04/02/2021] [Indexed: 12/29/2022]
Abstract
Insects possess an immune system that protects them from attacks by various pathogenic microorganisms that would otherwise threaten their survival. Immune mechanisms may deal directly with the pathogens by eliminating them from the host organism or disarm them by suppressing the synthesis of toxins and virulence factors that promote the invasion and destructive action of the intruder within the host. Insects have been established as outstanding models for studying immune system regulation because innate immunity can be explored as an integrated system at the level of the whole organism. Innate immunity in insects consists of basal immunity that controls the constitutive synthesis of effector molecules such as antimicrobial peptides, and inducible immunity that is activated after detection of a microbe or its product(s). Activation and coordination of innate immune defenses in insects involve evolutionary conserved immune factors. Previous research in insects has led to the identification and characterization of distinct immune signalling pathways that modulate the response to microbial infections. This work has not only advanced the field of insect immunology, but it has also rekindled interest in the innate immune system of mammals. Here we review the current knowledge on key molecular components of insect immunity and discuss the opportunities they present for confronting infectious diseases in humans.
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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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7
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Abstract
The composition of insect hemolymph can change depending on many factors, e.g. access to nutrients, stress conditions, and current needs of the insect. In this chapter, insect immune-related polypeptides, which can be permanently or occasionally present in the hemolymph, are described. Their division into peptides or low-molecular weight proteins is not always determined by the length or secondary structure of a given molecule but also depends on the mode of action in insect immunity and, therefore, it is rather arbitrary. Antimicrobial peptides (AMPs) with their role in immunity, modes of action, and classification are presented in the chapter, followed by a short description of some examples: cecropins, moricins, defensins, proline- and glycine-rich peptides. Further, we will describe selected immune-related proteins that may participate in immune recognition, may possess direct antimicrobial properties, or can be involved in the modulation of insect immunity by both abiotic and biotic factors. We briefly cover Fibrinogen-Related Proteins (FREPs), Down Syndrome Cell Adhesion Molecules (Dscam), Hemolin, Lipophorins, Lysozyme, Insect Metalloproteinase Inhibitor (IMPI), and Heat Shock Proteins. The reader will obtain a partial picture presenting molecules participating in one of the most efficient immune strategies found in the animal world, which allow insects to inhabit all ecological land niches in the world.
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Affiliation(s)
- Iwona Wojda
- Department of Immunobiology, Institute of Biological Sciences, Maria Curie-Skłodowska University, Lublin, Poland.
| | - Małgorzata Cytryńska
- Department of Immunobiology, Institute of Biological Sciences, Maria Curie-Skłodowska University, Lublin, Poland
| | - Agnieszka Zdybicka-Barabas
- Department of Immunobiology, Institute of Biological Sciences, Maria Curie-Skłodowska University, Lublin, Poland
| | - Jakub Kordaczuk
- Department of Immunobiology, Institute of Biological Sciences, Maria Curie-Skłodowska University, Lublin, Poland
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Wang X, Luo H, Zhang R. Innate immune responses in the Chinese oak silkworm, Antheraea pernyi. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2018; 83:22-33. [PMID: 29241953 DOI: 10.1016/j.dci.2017.12.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Revised: 12/10/2017] [Accepted: 12/11/2017] [Indexed: 06/07/2023]
Abstract
Innate immunity, the evolutionarily conserved defense system, has been extensively analyzed in insect models over recent decades. The significant progress in this area has formed our dominant conceptual framework of the innate immune system, but critical advances in other insects have had a profound impact on our insights into the mystery of innate immunity. In recent years, we focused on the immune responses in Antheraea pernyi, an important commercial silkworm species reared in China. Here, we review the immune responses of A. pernyi based on immune-related gene-encoded proteins that are divided into five categories, namely pattern recognition receptors, hemolymph proteinases and their inhibitors, prophenoloxidase, Toll pathway factors and antimicrobial peptides, and others. Although the summarized information is limited since the research on A. pernyi immunity is in its infancy, we hope to provide evidence for further exploration of innate immune mechanisms.
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Affiliation(s)
- Xialu Wang
- School of Medical Devices, Shenyang Pharmaceutical University, Shenyang, 110016, Liaoning, China
| | - Hao Luo
- School of Life Science and Bio-pharmaceutics, Shenyang Pharmaceutical University, Shenyang, 110016, Liaoning, China
| | - Rong Zhang
- School of Life Science and Bio-pharmaceutics, Shenyang Pharmaceutical University, Shenyang, 110016, Liaoning, China.
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Investigation of immunogenic properties of Hemolin from silkworm, Bombyx mori as carrier protein: an immunoinformatic approach. Sci Rep 2018; 8:6957. [PMID: 29725106 PMCID: PMC5934409 DOI: 10.1038/s41598-018-25374-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Accepted: 04/20/2018] [Indexed: 11/08/2022] Open
Abstract
Infectious diseases are the major cause of high mortality among infants and geriatric patients. Vaccines are the only weapon in our arsenal to defend us ourselves against innumerable infectious diseases. Though myriad of vaccines are available, still countless people die due to microbial infections. Subunit vaccine is an effective strategy of vaccine development, combining a highly immunogenic carrier protein with highly antigenic but non-immunogenic antigen (haptens). In this study we have made an attempt to utilize the immunoinformatic tool for carrier protein development. Immunogenic mediators (T-cell, B-cell, IFN-γ epitopes) and physiochemical properties of hemolin protein of silkworm, Bombyx mori were studied. Hemolin was found to be non-allergic and highly antigenic in nature. The refined tertiary structure of modelled hemolin was docked against TLR3 and TLR4-MD2 complex. Molecular dynamics study emphasized the stable microscopic interaction between hemolin and TLRs. In-silico cloning and codon optimization was carried out for effective expression of hemolin in E. coli expression system. The overall presence of Cytotoxic T Lymphocytes (CTL), Humoral T Lymphocytes (HTL), and IFN-γ epitopes with high antigenicity depicts the potential of hemolin as a good candidate for carrier protein.
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Sampath V. Bacterial endotoxin-lipopolysaccharide; structure, function and its role in immunity in vertebrates and invertebrates. ACTA ACUST UNITED AC 2018. [DOI: 10.1016/j.anres.2018.08.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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Bosch RV, Alvarez-Flores MP, Maria DA, Chudzinski-Tavassi AM. Hemolin triggers cell survival on fibroblasts in response to serum deprivation by inhibition of apoptosis. Biomed Pharmacother 2016; 82:537-46. [PMID: 27470394 DOI: 10.1016/j.biopha.2016.05.043] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Revised: 05/24/2016] [Accepted: 05/26/2016] [Indexed: 02/06/2023] Open
Abstract
Fibroblasts are the main cellular component of connective tissues and play important roles in health and disease through the production of collagen, fibronectin and growth factors. Under certain conditions, such as wound healing, fibroblasts intensify their metabolic demand, while the restriction of nutrients affect matrix composition, cell metabolism and behavior. In lepidopterans, wound healing is regulated by ecdysteroid hormones, which upregulate multifunctional proteins such as hemolin. However, the role of hemolin in cell proliferation and wound healing is not clear. rLosac is a recombinant hemolin from the caterpillar Lonomia obliqua whose proliferative and cytoprotective effects on endothelial cells have been described. Here, we show that rLosac induces a marked cell survival effect on fibroblast submitted to serum deprivation, which is observable as early as 24h, as demonstrated through the MTT assay, as well as an increase in migration of human dermal fibroblasts (HDF). No effects on cell proliferation or cell cycle distribution of fibroblasts in normal conditions were observed, suggesting that rLosac induces an effect in stressful conditions such serum deprivation but not when nutrient are sufficient. By flow cytometry, rLosac caused an apparent dose-dependent increase in cells in the S phase of the cell cycle and a significant reduction of cells with fragmented DNA. Furthermore, treatment with rLosac results in a significant decrease in the production of reactive oxygen species and in the loss of mitochondrial membrane potential, indicating that a reduction in oxidative stress is involved in rLosac-mediated cytoprotection. Our results also show an up-regulation of Bcl-2 and a down-regulation of Bax protein levels, inhibition of cytochrome c release and a reduction in caspase-3 levels, all considered critical factors for apoptosis. Moreover, rLosac treatment reduces the morphological changes induced by prolonged serum deprivation including the emergence of apoptotic bodies, nucleus fragmentation, cytoplasmic vacuolization and loss of extracellular matrix organization. The wound scratch test assay revealed that rLosac could enhance wound healing in vitro. Altogether, these findings suggest that rLosac strongly induces cellular protection in conditions of stress by serum deprivation preventing damage and loss of mitochondrial function by inhibiting apoptosis. This finding opens a new perspective to further understand the role of hemolin proteins during cellular processes such as wound healing and development.
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Affiliation(s)
- Rosemary Viola Bosch
- Biochemistry and Biophysics Laboratory, Butantan Institute, São Paulo, SP, Brazil
| | - Miryam Paola Alvarez-Flores
- Biochemistry and Biophysics Laboratory, Butantan Institute, São Paulo, SP, Brazil; Center of Research in Toxins, Immune Response and Cell Signaling (CETICS), Butantan Institute, São Paulo, SP, Brazil; Center of Excellence in the New Target Discovery, Butantan Institute, São Paulo, SP, Brazil.
| | | | - Ana Marisa Chudzinski-Tavassi
- Biochemistry and Biophysics Laboratory, Butantan Institute, São Paulo, SP, Brazil; Center of Research in Toxins, Immune Response and Cell Signaling (CETICS), Butantan Institute, São Paulo, SP, Brazil; Center of Excellence in the New Target Discovery, Butantan Institute, São Paulo, SP, Brazil.
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12
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Faye I, Lindberg BG. Towards a paradigm shift in innate immunity-seminal work by Hans G. Boman and co-workers. Philos Trans R Soc Lond B Biol Sci 2016; 371:20150303. [PMID: 27160604 PMCID: PMC4874399 DOI: 10.1098/rstb.2015.0303] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/16/2016] [Indexed: 11/12/2022] Open
Abstract
Four decades ago, immunological research was dominated by the field of lymphoid biology. It was commonly accepted that multicellular eukaryotes defend themselves through phagocytosis. The lack of lymphoid cells in insects and other simpler animals, however, led to the common notion that they might simply lack the capacity defend themselves with humoral factors. This view was challenged by microbiologist Hans G. Boman and co-workers in a series of publications that led to the advent of antimicrobial peptides as a universal arm of the immune system. Besides ingenious research, Boman ignited his work by posing the right questions. He started off by asking himself a simple question: 'Antibodies take weeks to produce while many microbes divide hourly; so how come we stay healthy?'. This led to two key findings in the field: the discovery of an inducible and highly potent antimicrobial immune response in Drosophila in 1972, followed by the characterization of cecropin in 1981. Despite broadly being considered an insect-specific response at first, the work of Boman and co-workers eventually created a bandwagon effect that unravelled various aspects of innate immunity.This article is part of the themed issue 'Evolutionary ecology of arthropod antimicrobial peptides'.
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Affiliation(s)
- Ingrid Faye
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm 106 91, Sweden
| | - Bo G Lindberg
- MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Faculty of Natural Sciences, Imperial College, London SW7 2AZ, UK
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Molecular cloning and expression analysis of a hemolin-like molecule from Antheraea pernyi. Int Immunopharmacol 2015; 26:65-71. [DOI: 10.1016/j.intimp.2015.03.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Revised: 03/10/2015] [Accepted: 03/10/2015] [Indexed: 11/19/2022]
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Browne N, Surlis C, Maher A, Gallagher C, Carolan JC, Clynes M, Kavanagh K. Prolonged pre-incubation increases the susceptibility of Galleria mellonella larvae to bacterial and fungal infection. Virulence 2015; 6:458-65. [PMID: 25785635 DOI: 10.1080/21505594.2015.1021540] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Galleria mellonella larvae are widely used for assessing the virulence of microbial pathogens and for measuring the in vivo activity of antimicrobial agents and produce results comparable to those that can be obtained using mammals. The aim of the work described here was to ascertain the effect of pre-incubation at 15°C for 1, 3, 6 or 10 weeks on the susceptibility of larvae to infection with Candida albicans and Staphylococcus aureus. Larvae infected with C. albicans after 1 week pre-incubation at 15°C showed 73.3 ± 3.3% survival at 24 hours post-infection while those infected after 10 weeks pre-incubation showed 30 ± 3.3% survival (P < 0.01). Larvae infected with S. aureus after 1 week pre-incubation showed 65.5 ± 3.3% survival after 24 hours while those infected after 10 weeks pre-incubation showed 13.3 ± 3.3% (P < 0.001). Analysis of the haemocyte density in larvae pre-incubated for 3-10 weeks showed a reduction in haemocytes over time but a proportionate increase in the density of granular haemocytes in the population as determined by FACS analysis. Proteomic analysis revealed decreased abundance of proteins associated with metabolic pathways (e.g. malate dehydrogenase, fructose-1,6-bisphosphatase, glyceraldehyde-3-phosphate dehydrogenase) and prophenoloxidase. G. mellonella larvae are a useful in vivo model system but the duration of the pre-incubation stage significantly affects their susceptibility to microbial pathogens possibly as a result of altered metabolism.
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Affiliation(s)
- Niall Browne
- a Department of Biology; Maynooth University ; Maynooth , Kildare , Ireland
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15
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Abstract
Lepidopteran insects provide important model systems for innate immunity of insects, particularly for cell biology of hemocytes and biochemical analyses of plasma proteins. Caterpillars are also among the most serious agricultural pests, and understanding of their immune systems has potential practical significance. An early response to infection in lepidopteran larvae is the activation of hemocyte adhesion, leading to phagocytosis, nodule formation, or encapsulation. Plasmatocytes and granular cells are the hemocyte types involved in these responses. Infectious microorganisms are recognized by binding of hemolymph plasma proteins to microbial surface components. This "pattern recognition" triggers phagocytosis and nodule formation, activation of prophenoloxidase and melanization and the synthesis of antimicrobial proteins that are secreted into the hemolymph. Many hemolymph proteins that function in such innate immune responses of insects were first discovered in lepidopterans. Microbial proteinases and nucleic acids released from lysed host cells may also activate lepidopteran immune responses. Hemolymph antimicrobial peptides and proteins can reach high concentrations and may have activity against a broad spectrum of microorganisms, contributing significantly to clearing of infections. Serine proteinase cascade pathways triggered by microbial components interacting with pattern recognition proteins stimulate activation of the cytokine Spätzle, which initiates the Toll pathway for expression of antimicrobial peptides. A proteinase cascade also results inproteolytic activation of phenoloxidase and production of melanin coatings that trap and kill parasites and pathogens. The proteinases in hemolymph are regulated by specific inhibitors, including members of the serpin superfamily. New developments in lepidopteran functional genomics should lead to much more complete understanding of the immune systems of this insect group.
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16
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Baculovirus resistance in codling moth (Cydia pomonella L.) caused by early block of virus replication. Virology 2010; 410:360-7. [PMID: 21190707 DOI: 10.1016/j.virol.2010.11.021] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2010] [Revised: 10/29/2010] [Accepted: 11/22/2010] [Indexed: 11/21/2022]
Abstract
An up to 10,000-fold resistance against the biocontrol agent Cydia pomonella granulovirus (CpGV) was observed in field populations of codling moth, C. pomonella, in Europe. Following different experimental approaches, a modified peritrophic membrane, a modified midgut receptor, or a change of the innate immune response could be excluded as possible resistance mechanisms. When CpGV replication was traced by quantitative PCR in different tissues of susceptible and resistant insects after oral and intra-hemocoelic infection, no virus replication could be detected in any of the tissues of resistant insects, suggesting a systemic block prior to viral DNA replication. This conclusion was corroborated by fluorescence microscopy using a modified CpGV (bacCpGV(hsp-eGFP)) carrying enhanced green fluorescent gene (eGFP), which showed that infection in resistant insects did not spread. In conclusion, the different lines of evidence indicate that CpGV can enter but not replicate in the cells of resistant codling moth larvae.
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17
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Alvarez-Flores MP, Furlin D, Ramos OHP, Balan A, Konno K, Chudzinski-Tavassi AM. Losac, the first hemolin that exhibits procogulant activity through selective factor X proteolytic activation. J Biol Chem 2010; 286:6918-28. [PMID: 21177860 DOI: 10.1074/jbc.m110.167718] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Envenoming by the contact of human skin with Lonomia obliqua caterpillars promotes a hemorrhagic syndrome characterized by a consumptive coagulopathy. Losac (Lonomia obliqua Stuart factor activator) is a component of the bristle of L. obliqua that is probably partially responsible for the observed syndrome because it activates factor X and is recognized by an effective antilonomic serum. Here we unveil the proteolytic activity of Losac and demonstrate the feasibility of its recombinant production. On the other hand, Losac has no homology to known proteases, but it can be inhibited by PMSF, a serine protease inhibitor. Instead, it shows closer homology to members of the hemolin family of proteins, a group of cell adhesion molecules. The recombinant protein (rLosac) shortened the coagulation time of normal and deficient plasmas, whereas it was ineffective in factor X-deficient plasma unless reconstituted with this protein. rLosac was able to activate factor X in a dose- and time-dependent manner but not γ-carboxyglutamic acid domainless factor X. Moreover, phospholipids and calcium ions increased rLosac activity. Also, rLosac had no effect on fibrin or fibrinogen, indicating its specificity for blood coagulation activation. Linear double reciprocal plots indicate that rLosac follows a Michaelis-Menten kinetics. Cleavage of factor X by rLosac resulted in fragments that are compatible with those generated by RVV-X (a well known factor X activator). Together, our results validate Losac as the first protein from the hemolin family exhibiting procoagulant activity through selective proteolysis on coagulation factor X.
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18
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Kim RJ, Jo YH, Oh SH, Park CH, Noh MY, Lee HJ, Kim S, Lee YS, Kim I, Han YS. Cloning and expression pattern of a hemolin homologue from the diamondback moth, Plutella xylostella. Genes Genomics 2010. [DOI: 10.1007/s13258-010-0834-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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19
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Schmidt O, Söderhäll K, Theopold U, Faye I. Role of adhesion in arthropod immune recognition. ANNUAL REVIEW OF ENTOMOLOGY 2010; 55:485-504. [PMID: 19743913 DOI: 10.1146/annurev.ento.54.110807.090618] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The recognition and inactivation of toxins and pathogens are mediated by a combination of cell-free and cellular mechanisms. A number of soluble and membrane-bound pattern recognition molecules interact with elicitors to become involved in both cell-free inactivation as well as cellular uptake reactions. Here we describe the possible recognition and effector function of key arthropod immune proteins, such as peroxinectin, hemolin, and hemomucin, as an outcome of changes in adhesiveness, which drive self-assembly reactions leading to cell-free coagulation and cellular uptake reactions. The fact that some of these proteins are essential for immune and developmental functions in some species, but are not found in closely related species, may point to the existence of multiprotein assemblies, which are conserved at the mechanistic level and can function with more than one combination of protein constituents.
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Affiliation(s)
- Otto Schmidt
- Insect Molecular Biology, University of Adelaide, Glen Osmond, SA 5064, Australia.
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20
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Shaik HA, Sehnal F. Hemolin expression in the silk glands of Galleria mellonella in response to bacterial challenge and prior to cell disintegration. JOURNAL OF INSECT PHYSIOLOGY 2009; 55:781-787. [PMID: 19414015 DOI: 10.1016/j.jinsphys.2009.04.010] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2009] [Revised: 04/06/2009] [Accepted: 04/22/2009] [Indexed: 05/27/2023]
Abstract
Hemolin, a member of the immunoglobulin protein superfamily, functions in Lepidoptera as an opsonin in defence against potential pathogens and seems to play a role in tissue morphogenesis. We show that hemolin gene is expressed in several organs of Galleria mellonella larvae, including the nervous system and the silk glands. The expression in the silk glands of the wandering larvae and their isolated abdomens is enhanced within 6h after an injection of bacteria, lipopolysaccharides, or peptidoglycans. The magnitude of silk gland response to bacterial challenge is similar to that seen in the fat body. A profound rise of hemolin expression without bacterial inoculation occurs in the silk glands of isolated abdomens when they are induced to pupate by a topical application of 20-hydroxyecdysone (20E). The induction of pupation is associated with silk gland programming for disintegration by apoptosis and phagocytosis. Administration of a juvenile hormone agonist prevents pupation and abolishes the stimulatory 20E effect on the hemolin expression. Hemolin protein can be immunodetected in the silk glands as well as in the spun-out cocoon silk. The results suggest that silk glands are a component of the insect immune system and that hemolin may mark the apoptic cells for the elimination by hemocytes.
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Affiliation(s)
- Haq Abdul Shaik
- Biology Centre of the Academy of Sciences, Branisovska 31, 370 05 Ceské Budejovice, Czech Republic.
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21
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Huang L, Cheng T, Xu P, Duan J, Fang T, Xia Q. Immunoglobulin superfamily is conserved but evolved rapidly and is active in the silkworm, Bombyx mori. INSECT MOLECULAR BIOLOGY 2009; 18:517-530. [PMID: 19604311 DOI: 10.1111/j.1365-2583.2009.00896.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Immunoglobulin superfamily (IgSF) proteins are known for their abilities to specifically recognize and adhere to cells. In this paper, we predicted the presence of 133 IgSF proteins in the silkworm (Bombyx mori) genome. Comparison with similar proteins in other model organisms (Caenorhabditis elegans, Drosophila melanogaster, Anopheles gambiae, Apis mellifera and Homo sapiens) indicated that IgSF proteins are conserved but have rapidly evolved from worms to human beings. However, these proteins are well conserved amongst insects. Silkworm microarray-based expression data showed tissue expression of 57 IgSF genes and microbe-induced differential expression of 37 genes. Based on the expression data, we can conclude that the silkworm IgSF is active.
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Affiliation(s)
- L Huang
- Institute of Sericulture and Systems Biology, Southwest University, Chongqing, China.
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22
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Labropoulou V, Douris V, Stefanou D, Magrioti C, Swevers L, Iatrou K. Endoparasitoid wasp bracovirus-mediated inhibition of hemolin function and lepidopteran host immunosuppression. Cell Microbiol 2008; 10:2118-28. [DOI: 10.1111/j.1462-5822.2008.01195.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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23
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Aye TT, Shim JK, Rhee IK, Lee KY. Upregulation of the immune protein gene hemolin in the epidermis during the wandering larval stage of the Indian meal moth, Plodia interpunctella. JOURNAL OF INSECT PHYSIOLOGY 2008; 54:1301-1305. [PMID: 18675821 DOI: 10.1016/j.jinsphys.2008.07.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2008] [Revised: 06/11/2008] [Accepted: 07/07/2008] [Indexed: 05/26/2023]
Abstract
Expression of hemolin, which generates an immune protein, was up-regulated in wandering fifth instar larval stage of Plodia interpunctella. The mRNA level peaked in the middle of the wandering stage. Major expression was in the epidermis, rather than in the fat body or gut. To test a possible ecdysteroid effect on hemolin induction we treated with RH-5992, an ecdysteroid agonist, and KK-42, which inhibits ecdysteroid biosynthesis in both feeding and wandering fifth instar larvae. When feeding larvae were treated with RH-5992 the hemolin mRNA level was increased. When wandering larvae were treated with KK-42 its level was reduced. In addition, when KK-42-treated larvae were subsequently treated with RH-5992 the hemolin mRNA level was recovered. These results strongly suggest that ecdysteroid up-regulates the expression of hemolin mRNA. Hormonal and bacterial effects on hemolin induction were further analyzed at the tissue level. Major induction of hemolin mRNA was detected following both RH-5992 treatment and bacterial injection in the epidermis of both feeding and wandering larvae. Minor induction of hemolin was detected in the fat body following a bacterial injection, but not RH-5992 treatment. We infer that in P. interpunctella larvae, the epidermis is the major tissue for hemolin induction in naïve insects and in insects manipulated with bacterial and hormonal treatments.
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Affiliation(s)
- Tin Tin Aye
- School of Applied Biosciences, College of Agriculture and Life Sciences, Kyungpook National University, 1370 Sankyukdong, Daegu 702-701, Republic of Korea
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24
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Garver LS, Xi Z, Dimopoulos G. Immunoglobulin superfamily members play an important role in the mosquito immune system. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2008; 32:519-31. [PMID: 18036658 PMCID: PMC2483948 DOI: 10.1016/j.dci.2007.09.007] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2007] [Revised: 08/29/2007] [Accepted: 09/03/2007] [Indexed: 05/15/2023]
Abstract
Immunoglobulin superfamily (IgSF) proteins are known for their ability to specifically recognize and adhere to other molecules, mediating cell-surface reception and pathogen recognition. Mammalian IgSF proteins such as antibodies are among the best characterized molecules of the immune system; in contrast, the involvement of invertebrate IgSF members in immunity has not been broadly studied. Analysis of the predicted Anopheles gambiae transcriptome identified 138 proteins that have at least one immunoglobulin domain. Challenge with Plasmodium, Gram-negative or Gram-positive bacteria resulted in significant regulation of 85 IgSF genes, indicating potential roles for these molecules in infection responses and immunity. Based on sequence and expression data, six infection-responsive with immunoglobulin domain (IRID 1-6) genes were chosen and functionally characterized with regard to their role in innate immunity. Reverse-genetic gene-silencing assays showed IRID3, IRID5 and IRID6 contribute to viability upon bacterial infection while IRID4 and IRID6 are involved in limiting Plasmodium falciparum infection.
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Affiliation(s)
- Lindsey S Garver
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
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25
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Bao Y, Yamano Y, Morishima I. Induction of hemolin gene expression by bacterial cell wall components in eri-silkworm, Samia cynthia ricini. Comp Biochem Physiol B Biochem Mol Biol 2007; 146:147-51. [PMID: 17126583 DOI: 10.1016/j.cbpb.2006.10.092] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2006] [Revised: 10/03/2006] [Accepted: 10/10/2006] [Indexed: 10/24/2022]
Abstract
A cDNA clone encoding hemolin was isolated from fat body of immunized Samia cynthia ricini larvae based on subtractive suppression hybridization method. The cDNA encodes 413 amino acid residue open reading frame with an 18 residue predicted signal peptide. The expression of the gene was strongly induced in fat body and midgut by an injection of bacterial cells or peptidoglycans, but very weakly by lipopolysaccharide. The mRNA expression in the fat body was detected as early as 3 h post-injection, and reached the peak level at 12 h.
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Affiliation(s)
- Yanyuan Bao
- Department of Biochemistry and Biotechnology, Tottori University, Tottori 680-8553, Japan
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26
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Terenius O, Bettencourt R, Lee SY, Li W, Söderhäll K, Faye I. RNA interference of Hemolin causes depletion of phenoloxidase activity in Hyalophora cecropia. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2007; 31:571-5. [PMID: 17129606 DOI: 10.1016/j.dci.2006.09.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2006] [Revised: 09/20/2006] [Accepted: 09/30/2006] [Indexed: 05/12/2023]
Abstract
Melanization is regulated by the prophenoloxidase cascade and functions as a response to intruding microorganisms in invertebrates. When injecting dsRNA of the lepidopteran immune protein hemolin in pupae of Hyalophora cecropia (Lepidoptera: Saturniidae), we observed a significant reduction in phenoloxidase activity after 24 h, but not after 72 h. The link between hemolin and the prophenoloxidase system suggests that hemolin is a pattern recognition protein important for the triggering of the prophenoloxidase cascade in the defence against bacterial infections.
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Affiliation(s)
- Olle Terenius
- Department of Genetics, Microbiology and Toxicology, Stockholm University, 106 91 Stockholm, Sweden
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27
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Eleftherianos I, Gökçen F, Felföldi G, Millichap PJ, Trenczek TE, ffrench-Constant RH, Reynolds SE. The immunoglobulin family protein Hemolin mediates cellular immune responses to bacteria in the insect Manduca sexta. Cell Microbiol 2006; 9:1137-47. [PMID: 17166232 DOI: 10.1111/j.1462-5822.2006.00855.x] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Bacterial recognition in the lepidopteran insect, Manduca sexta, is mediated by pattern recognition proteins including Hemolin, Peptidoglycan recognition protein (PGRP) and Immulectin-2. These proteins bind to molecular patterns present on the surface of bacteria and trigger a protective response involving humoral and cellular reactions. Cellular mechanisms mediated by haemocytes include phagocytosis, encapsulation, and the formation of melanotic nodules. Here, we show that a non-pathogenic strain of Escherichia coli induces mRNA transcription and protein expression of Hemolin and PGRP but not Immulectin-2 in Manduca haemocytes. This upregulation can be effectively prevented (knocked-down) using RNA interference (RNAi) following injection of double-stranded (ds) RNA. Knock-down of Hemolin significantly decreased the ability of insects to clear E. coli from the haemolymph and caused a reduction in the number of free haemocytes. RNAi of Hemolin reduced the ability of haemocytes to engulf bacteria through phagocytosis and to form melanotic nodules in vivo. Importantly, washed haemocytes taken from RNAi-treated insects showed reduced ability to form microaggregates around bacteria in vitro. This shows that the immune function affected by RNAi knock-down of Hemolin is intrinsic to the haemocytes. In contrast, RNAi of PGRP had no effect on any of these cellular immune functions. These results demonstrate the vital role of Hemolin in Manduca cellular immune responses.
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28
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Rahman MM, Ma G, Roberts HLS, Schmidt O. Cell-free immune reactions in insects. JOURNAL OF INSECT PHYSIOLOGY 2006; 52:754-62. [PMID: 16753175 DOI: 10.1016/j.jinsphys.2006.04.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2006] [Revised: 04/04/2006] [Accepted: 04/04/2006] [Indexed: 05/10/2023]
Abstract
Insects, like many other multicellular organisms, are able to recognise and inactivate potential pathogens and toxins in the absence of cells. Here we show that the recognition and inactivation of lipopolysaccharides (LPS) and bacteria is mediated by lipophorin particles, which are the lipid carrier in insects. In immune-induced insects sub-populations of lipophorin particles are associated with pattern recognition proteins and regulatory proteins that activate prophenoloxidase. Moreover, interactions with lectins result in the assembly of lipophorin particles into cage-like coagulation products, effectively protecting the surrounding tissues and cells from the potentially damaging effects of pathogens and phenoloxidase products. The existence of cell-free defence reactions implies that immune signals exist upstream of cell-bound receptors.
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Affiliation(s)
- M Mahbubur Rahman
- Insect Molecular Biology, University of Adelaide, Glen Osmond, SA 5064, Australia
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29
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Bergin D, Murphy L, Keenan J, Clynes M, Kavanagh K. Pre-exposure to yeast protects larvae of Galleria mellonella from a subsequent lethal infection by Candida albicans and is mediated by the increased expression of antimicrobial peptides. Microbes Infect 2006; 8:2105-12. [PMID: 16782387 DOI: 10.1016/j.micinf.2006.03.005] [Citation(s) in RCA: 107] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2005] [Accepted: 03/26/2006] [Indexed: 11/28/2022]
Abstract
Pre-exposure of the larvae of Galleria mellonella to Candida albicans or Saccharomyces cerevisiae protects against a subsequent infection with 10(6) C. albicans cells. This protection can also be induced by exposing larvae to glucan or laminarin prior to the administration of the potentially lethal inoculum. Analysis of the genes coding for galiomicin, a defensin in G. mellonella, a cysteine-rich antifungal peptide gallerimycin, an iron-binding protein transferrin and an inducible metalloproteinase inhibitor (IMPI) from G. mellonella demonstrated increased expression, which is at its highest after 24 h of the initial inoculum. Examination of the expression of proteins in the insect haemolymph using 2D electrophoresis and MALDI TOF analysis revealed an increased expression of a number of proteins associated with the insect immune response to infection 24 h after the initial exposure. This study demonstrates that the larvae of G. mellonella can withstand a lethal inoculum of C. albicans if pre-exposed to a non-lethal dose of yeast or polysaccharide 24 h previously which is mediated by increased expression of a number of antimicrobial peptides and the appearance of a number of peptides in the challenged larvae.
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Affiliation(s)
- David Bergin
- Department of Biology, Medical Mycology Unit, NICB, National University of Ireland Maynooth, Co. Kildare, Ireland
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30
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Ma G, Hay D, Li D, Asgari S, Schmidt O. Recognition and inactivation of LPS by lipophorin particles. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2006; 30:619-26. [PMID: 16386790 DOI: 10.1016/j.dci.2005.09.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2005] [Revised: 09/02/2005] [Accepted: 09/06/2005] [Indexed: 05/06/2023]
Abstract
Lipophorin is the major lipid carrier in insects, but various observations indicate that lipophorin is also involved in immune reactions. To examine a possible role of lipophorin in defence reactions, we mixed hemolymph plasma from Galleria mellonella with LPS and noticed that lipophorin forms detergent-insoluble aggregates, while most other plasma proteins are not affected. Lipophorin particles isolated by low-density gradient centrifugation retained LPS-induced aggregation properties, which suggested to us that these immune-reactive particles are able to recognise LPS and respond by forming insoluble aggregates. Antibodies against LPS-binding proteins, such as immulectin-2 and beta-1,3-glucan binding protein, cross-reacted with proteins associated with purified lipophorin particles. To examine whether LPS-mediated aggregates inactivate LPS, we added LPS-lipophorin mixtures to purified lipophorin particles and monitored aggregate formation. Under these conditions lipophorin did not form insoluble aggregates, which indicates that lipophorin particles sequester LPS into non-toxic aggregates.
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Affiliation(s)
- Gang Ma
- Insect Molecular Biology, Department of Applied & Molecular Ecology, School of Agriculture and Wine, University of Adelaide, Waite Campus, Glen Osmond, SA 5064, Australia
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31
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Roxström-Lindquist K, Assefaw-Redda Y, Rosinska K, Faye I. 20-Hydroxyecdysone indirectly regulates Hemolin gene expression in Hyalophora cecropia. INSECT MOLECULAR BIOLOGY 2005; 14:645-52. [PMID: 16313564 DOI: 10.1111/j.1365-2583.2005.00593.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Development and innate immune defence are two vital processes that have been demonstrated to use the same or similar molecules and signalling pathways in insects. Hemolin is a moth haemolymph protein belonging to the immunoglobulin superfamily. It is strongly induced upon bacterial infection. However, recent studies indicate a developmental regulation of hemolin. We show that the steroid hormone 20-hydroxyecdysone (20E) can activate the expression of Hyalophora cecropia Hemolin (HcHemolin) in the fat body of diapausing pupae. Using the protein synthesis inhibitor cycloheximide we demonstrate that Hemolin up-regulation by 20E requires ongoing protein synthesis. Moreover, 20E enhances transcription of the Hemolin gene in response to bacteria. Comparing the upstream regions of Manduca sexta Hemolin (MsHemolin) and HcHemolin, we identified four putative regulatory sites. Two are putative hormone response elements (HREs), one with an imperfect inverted repeat (HRE-IR) and one with a monomeric site (HRE-M). An additional monomeric hormone receptor site (MRE) is present only in HcHemolin. The third conserved motif is similar to the interferon (IFN) regulatory factor binding element (IRF-E) and IFN-stimulated response element (ISRE). The fourth conserved element is a kappaB motif situated between the Cap-site and the TATA-box. Finally, by electrophoresis mobility shift assay we demonstrate that the HRE-IR forms specific complexes with nuclear extract proteins of normal pupae that increase after 20E stimulation.
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Affiliation(s)
- K Roxström-Lindquist
- Department of Genetics, Microbiology and Toxicology, Stockholm University, Stockholm, Sweden
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32
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Hirai M, Terenius O, Li W, Faye I. Baculovirus and dsRNA induce Hemolin, but no antibacterial activity, in Antheraea pernyi. INSECT MOLECULAR BIOLOGY 2004; 13:399-405. [PMID: 15271212 DOI: 10.1111/j.0962-1075.2004.00497.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Hemolin is one of the haemolymph proteins most strongly induced upon bacterial infection in Lepidoptera. When we applied RNA interference (RNAi) to suppress Hemolin expression in the Chinese oak silk moth Antheraea pernyi, we discovered that Hemolin is induced by double-stranded RNA (dsRNA) per se. As dsRNA is recognized as a virus pattern molecule, we then investigated the effect of a baculovirus (ApNPV) infection. We found that Hemolin is induced and expressed with similar kinetics as upon dsRNA injection. Notably, no Attacin gene expression or antibacterial activity was recorded. When baculovirus and high amounts of dsRNA were coinjected, the viral symptoms appeared earlier with Hemolin dsRNA than with GFP dsRNA. This indicates that silencing of hemolin affected the progress of the viral infection.
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Affiliation(s)
- M Hirai
- Department of Genetics, Stockholm University, Stockholm, Sweden
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33
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Metheniti A, Giannakas N, Katsoulas HL, Soldatos AN, Tsakas S, Lambropoulou M. Evidence for a LPS-binding protein in medfly hemocyte surface: mediation in LPS internalization but not in LPS signaling. ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2003; 54:25-36. [PMID: 12942513 DOI: 10.1002/arch.10096] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
A doublet of medfly hemocyte proteins with a molecular mass of about 55 and 50 kDa were precipitated with LPS. Antibodies raised against human CD14 recognize the same doublet of proteins. These results support that mammalian CD14 and the doublet of protein bands in medfly hemocytes share common epitopes. This doublet of protein bands is released from hemocytes upon LPS triggering. A portion of the released protein is clustered on the surface of a distinct hemocyte type and the other remains soluble. The membrane-bound LPS-binding protein is involved in LPS internalization and Escherichia coli phagocytosis but not in LPS signaling.
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Goldsworthy G, Chandrakant S, Opoku-Ware K. Adipokinetic hormone enhances nodule formation and phenoloxidase activation in adult locusts injected with bacterial lipopolysaccharide. JOURNAL OF INSECT PHYSIOLOGY 2003; 49:795-803. [PMID: 12880660 DOI: 10.1016/s0022-1910(03)00118-5] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Interactions between the locust endocrine and immune systems have been studied in vivo in relation to nodule formation and activation of the prophenoloxidase cascade in the haemolymph. Injection of bacterial lipopolysaccharide (LPS) extracted from Escherichia coli induces nodule formation in larval and adult locusts but does not increase phenoloxidase activity in the haemolymph. Nodule formation starts rapidly after injection of LPS and is virtually complete within 8 h, nodules occurring mainly associated with the dorsal diaphragm on either side of the heart, but sometimes with smaller numbers associated with the ventral diaphragm on either side of the nerve cord. Co-injection of adipokinetic hormone-I (Lom-AKH-I) with LPS stimulates greater numbers of nodules to be formed in larval and adult locusts, and activates phenoloxidase in the haemolymph of mature adults but not of nymphs. The effect of co-injection of Lom-AKH-I with LPS on nodule formation is seen at low doses of hormone; only 0.4 pmol of Lom-AKH-I per adult locust is needed to produce a 50% increase in the number of nodules formed. When different components of LPS from the E. coli Rd mutant are tested, the mono- and the diphosphoryl Lipid A components have similar effects to the intact LPS. Remarkably, detoxified LPS activates phenoloxidase in the absence of Lom-AKH-I, although co-injection with hormone does enhance this response. Both diphosphoryl Lipid A and detoxified LPS induce a level of nodule formation that is enhanced by co-injection of Lom-AKH-I, but monophosphoryl Lipid A does not initiate nodule formation even when injected with hormone. Co-injection of a water-soluble inhibitor of eicosanoid synthesis, diclofenac (2-[(2, 6-dichlorophenyl)amino] benzeneacetic acid), reduces nodule formation in response to injections of LPS (both in the absence and presence of hormone) in a dose-dependent manner, but does not prevent activation of phenoloxidase in adult locusts. It is shown that nodule formation and activation of the prophenoloxidase in locust haemolymph can both be enhanced by Lom-AKH-I, but it is argued that these processes involve distinct mechanisms in which eicosanoid synthesis is important for nodule formation, but not for the increased phenoloxidase activity.
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Affiliation(s)
- Graham Goldsworthy
- Department of Biology, Birkbeck College, University of London, Malet Street, London WC1E 7HX, UK.
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Yu XQ, Zhu YF, Ma C, Fabrick JA, Kanost MR. Pattern recognition proteins in Manduca sexta plasma. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2002; 32:1287-1293. [PMID: 12225919 DOI: 10.1016/s0965-1748(02)00091-7] [Citation(s) in RCA: 149] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Recognition of nonself is the first step in mounting immune responses. In the innate immune systems of both vertebrates and arthropods, such recognition, termed pattern recognition, is mediated by a group of proteins, known as pattern recognition proteins or receptors. Different pattern recognition proteins recognize and bind to molecules (molecular patterns) present on the surface of microorganisms but absent from animals. These molecular patterns include microbial cell wall components such as bacterial lipopolysaccharide, lipoteichoic acid and peptidoglycan, and fungal beta-1,3-glucans. Binding of pattern recognition proteins to these molecular patterns triggers responses such as phagocytosis, nodule formation, encapsulation, activation of proteinase cascades, and synthesis of antimicrobial peptides. In this article, we describe four classes of pattern recognition proteins, hemolin, peptidoglycan recognition protein, beta-1,3-glucan recognition proteins, and immulectins (C-type lectins) involved in immune responses of the tobacco hornworm, Manduca sexta.
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Affiliation(s)
- X-Q Yu
- Department of Biochemistry, Kansas State University, Manhattan, KS 66506, USA
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36
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Roxström-Lindquist K, Lindström-Dinnetz I, Olesen J, Engström Y, Faye I. An intron enhancer activates the immunoglobulin-related Hemolin gene in Hyalophora cecropia. INSECT MOLECULAR BIOLOGY 2002; 11:505-515. [PMID: 12230549 DOI: 10.1046/j.1365-2583.2002.00359.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Hemolin is the only insect member of the immunoglobulin (Ig) superfamily reported to be up-regulated during an immune response. In diapausing pupae of Hyalophora cecropia the gene is expressed in fat body cells and in haemocytes. Like the mammalian Ig kappa light chain gene, the Hemolin gene harbours an enhancer including a kappaB motif in one of its introns. This motif binds the H. cecropia Rel factor Cif (Cecropia immunoresponsive factor). The Hemolin third intron also mediates transient reporter gene expression in immunoresponsive Drosophila mbn-2 cells. Co-transfections of Drosophila SL2 cells showed that the Drosophila Rel factor Dif (Dorsal-related immunity factor), transactivates reporter gene constructs through the intron. Moreover, a 4.8-fold synergistic activation was obtained when Dif is combined with the rat C/EBP (CCAAT/enhancer element-binding protein) and human HMGI (high mobility group protein I). This is the first report of an insect immune-related gene that is up-regulated by an enhancer activity conferred through an intron.
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37
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Zakarian RJ, Dunphy GB, Albert PJ, Rau ME. Apolipophorin-III affects the activity of the haemocytes of Galleria mellonella larvae. JOURNAL OF INSECT PHYSIOLOGY 2002; 48:715-723. [PMID: 12770066 DOI: 10.1016/s0022-1910(02)00096-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Apolipophorin-III (apoLp-III) impaired the adhesion of plasmatocytes and a granular cell-subpopulation of larval Galleria mellonella to glass slides. The protein bound to haemocytes, limited the responses of the plasmatocytes to Bacillus subtilis and increased the percentage of a subgroup of granular cells with adhering bacteria. The total number of bacteria adhering to all the haemocytes on the slides declined. Injections of apoLp-III slowed bacterial removal from the haemolymph without affecting total haemocyte counts and impaired haemocyte attachment to glass slides. Purified apoLp-III bound to B. subtilis. ApoLp-III in serum bound to bacteria within 5 min, peaked at 15 min and was either shed or dissociated by 60 min. ApoLp-III bound to B. subtilis lowered the adhesion of the bacteria to the haemocytes and slowed the removal of the bacteria from the haemolymph.
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Affiliation(s)
- Robert J. Zakarian
- Department of Natural Resource Sciences, McGill University, 21, 111 Lakeshore Road, Ste. Anne de Bellevue, H9X 3V9, Québec, Canada
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38
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Bettencourt R, Terenius O, Faye I. Hemolin gene silencing by ds-RNA injected into Cecropia pupae is lethal to next generation embryos. INSECT MOLECULAR BIOLOGY 2002; 11:267-271. [PMID: 12000646 DOI: 10.1046/j.1365-2583.2002.00334.x] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
There is increasing evidence of an intimate connection between participants in the innate immune system and in development. Molecules involved in the determination of dorso-ventral polarity in Drosophila have related counterparts in the signalling pathways for immune gene activation in both insects and mammals. Hemolin from the Giant silkmoth, Hyalophora cecropia, identified as a bacteria-inducible molecule and a member of the immunoglobulin superfamily, is present as protein and transcripts in oocytes and embryos. We used RNA interference (RNAi) to investigate H. cecropia gene function in vivo and demonstrated that Hemolin is crucial for the normal development of embryos. When RNAi-females were mated, no larvae emerged from their eggs and when dissected, the eggs revealed malformed embryos. Western blot analysis confirmed the lack of Hemolin gene products. We conclude that Hemolin is necessary for development, since the silencing of Hemolin gene expression leads to embryonic lethality.
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Affiliation(s)
- R Bettencourt
- Department of Genetics, Stockholm University, Stockholm, Sweden
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Yu XQ, Kanost MR. Binding of hemolin to bacterial lipopolysaccharide and lipoteichoic acid. An immunoglobulin superfamily member from insects as a pattern-recognition receptor. EUROPEAN JOURNAL OF BIOCHEMISTRY 2002; 269:1827-34. [PMID: 11952784 DOI: 10.1046/j.1432-1033.2002.02830.x] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Hemolin, a plasma protein from lepidopteran insects, is composed of four immunoglobulin domains. Its synthesis is induced by microbial challenge. We investigated the biological functions of hemolin in Manduca sexta. It was found to bind to the surface of bacteria and yeast, and caused these micro-organisms to aggregate. Hemolin was demonstrated to bind to lipopolysaccharide (LPS) from Gram-negative bacteria and to lipoteichoic acid from Gram-positive bacteria. Binding of hemolin to smooth-type forms of LPS was competed for efficiently by lipoteichoic acid and by rough mutant (Ra and Rc) forms of LPS, which differ in polysaccharide length. Binding of hemolin to LPS was partially inhibited by calcium and phosphate. Hemolin bound to the lipid A component of LPS, and this binding was completely blocked by free phosphate. Our results suggest that hemolin has two binding sites for LPS, one that interacts with the phosphate groups of lipid A and one that interacts with the O-specific antigen and the outer-core carbohydrates of LPS. The binding properties of M. sexta hemolin suggest that it functions as a pattern-recognition protein with broad specificity in the defense against micro-organisms.
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Affiliation(s)
- Xiao-Qiang Yu
- Department of Biochemistry, Kansas State University, Manhattan 66506, USA
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40
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Nappi AJ, Vass E. Cytotoxic reactions associated with insect immunity. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2002; 484:329-48. [PMID: 11419001 DOI: 10.1007/978-1-4615-1291-2_33] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- A J Nappi
- Department of Biology, Loyola University Chicago, Chicago, IL 60626, USA
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41
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Bettencourt R, Gunne H, Gastinel L, Steiner H, Faye I. Implications of hemolin glycosylation and Ca2+-binding on homophilic and cellular interactions. EUROPEAN JOURNAL OF BIOCHEMISTRY 1999; 266:964-76. [PMID: 10583391 DOI: 10.1046/j.1432-1327.1999.00934.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Insects are useful models for the study of innate immune mechanisms because of their lack of antibodies and receptors involved in adaptive immune response. Nevertheless, hemolin cloned from moths is a soluble and membrane associated Ig-related molecule that is up-regulated during immune response [Lanz-Mendoza, H. & Faye, I. (1999) Dev. Comp. Immunol. 23, 359-374]. The hemolin monomeric form has four, pair-wise, interacting Ig-domains, forming a strongly bent horseshoe structure [Su, X.-D., Gastinel, L.N., Vaughn, D.E., Faye, I., Poon, P. & Bjorkman, P. (1998) Science 281, 991-995]. To elucidate the nature of its homophilic and cellular interactions, the glycosylation and Ca2+-binding properties of hemolin were investigated. We used Hyalophora cecropia hemolin isolated from hemolymph of bacteria-injected pupae, or produced as a recombinant protein in a baculovirus/insect cell system. Both types of hemolin contain N-acetylglucosamine and probably sialic acid, as indicated by peptide:N-glycosidase F and neuraminidase digestion and glycosylation detection by Western-blotting analysis. The N-acetylglucosamine residues on hemolin were confirmed with the use of specific lectins. In addition, hemolin was shown to specifically bind calcium when spotted onto nitrocellulose and treated as for 45Ca2+ autoradiography. Earlier studies demonstrated that hemolin can bind to hemocytes and this was tested for its dependence on calcium and carbohydrates, using hemolin-coated fluorescent microspheres. A greater level of attachment of microspheres occurred in the presence of calcium than if calcium was absent. Furthermore, this binding was inhibited by EGTA and N-acetylglucosamine or N-acetylneuraminic acid, implying that carbohydrates and calcium are crucial factors in homophilic binding and cell-adhesion events mediated by this Ig-superfamily molecule.
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Affiliation(s)
- R Bettencourt
- Department of Genetics, Stockholm University, Sweden
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42
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Abstract
Hemolin is hemolymph protein that is a member of the immunoglobulin superfamily. Its induced expression after bacterial infection suggests that it functions in the immune response. In this paper, we describe the expression of the Manduca sexta hemolin gene at certain developmental stages in the absence of microbial challenge. Hemolin was present at a very low level in hemolymph of naive larvae until the beginning of the wandering stage prior to pupation, when its concentration in hemolymph increased dramatically. At the same time, hemolin could be found in the fluid contained in the midgut lumen. The appearance of hemolin mRNA in fat body and midgut at the beginning of the wandering stage correlated with the presence of hemolin in the hemolymph and midgut lumen. Hemolin was present in hemolymph through the pupal and adult stages. Hemolin was also present in newly deposited eggs, and persisted in eggs throughout embryonic development. A hemolin cDNA isolated from an adult fat body library had the same sequence as those previously obtained from larval libraries. Hemolin purified from hemolymph of bacteria-injected larvae, from hemolymph of naive wandering stage larvae and adult moths, and from midgut fluid of wandering stage larvae had the same apparent mass, which was consistent with the mass predicted from the hemolin cDNA sequence. Hemolin from hemolymph of wandering stage larvae did not contain any detectable carbohydrate, but hemolin from the hemolymph of bacteria-injected larvae and from naive adult moths was associated with carbohydrate, although of different amounts and composition. These results suggest that a single hemolin gene is developmentally regulated and is also induced when insects are exposed to microbial infection. M. sexta hemolin apparently lacks post-translational covalent glycosylation, but instead is associated under some conditions with non-covalently bound carbohydrates. Arch.
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Affiliation(s)
- X Q Yu
- Department of Biochemistry, Kansas State University, Manhattan, Kansas 66506, USA
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43
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Koizumi N, Imai Y, Morozumi A, Imamura M, Kadotani T, Yaoi K, Iwahana H, Sato R. Lipopolysaccharide-binding protein of Bombyx mori participates in a hemocyte-mediated defense reaction against gram-negative bacteria. JOURNAL OF INSECT PHYSIOLOGY 1999; 45:853-859. [PMID: 12770298 DOI: 10.1016/s0022-1910(99)00069-4] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
BmLBP is a lipopolysaccharide-binding protein in B. mori and participates in bacterial clearance in vivo. Here, we investigated the function of BmLBP more specifically. More than 90% of injected gram-negative rough strains to which BmLBP binds were removed from the plasma within 30 min post-injection, whereas it required 8h for the clearance of smooth strains to which BmLBP does not bind. Observation of the hemocoel after the injection of Escherichia coli rough strain showed that melanized nodules were formed at 30 min post-injection when the clearance of injected E. coli cells had occurred. Fluorescence microscope observation revealed that E. coli cells were actually trapped in the nodules formed in vivo. Furthermore, plasma pre-treated E. coli rough cells (BmLBP bound) added to hemocytes isolated in vitro caused vigorous hemocyte aggregations with the bacteria, while plasma pre-treated smooth cells did not. The formation of aggregates was inhibited by anti-BmLBP serum pre-treatment, suggesting that BmLBP causes the clearance of bacteria by promoting hemocyte nodule formation.
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Affiliation(s)
- N Koizumi
- Department of Applied Biological Science, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Tokyo, Japan
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Yuan A, Pardy RL, Chia CP. Nonspecific interactions alter lipopolysaccharide patterns and protein mobility on sodium dodecyl sulfate polyacrylamide gels. Electrophoresis 1999; 20:1946-9. [PMID: 10451101 DOI: 10.1002/(sici)1522-2683(19990701)20:10<1946::aid-elps1946>3.0.co;2-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
In testing whether bacterial lipopolysaccharide (LPS) was a natural substrate for an esterase from the soil amebae Dictyostelium discoideum, we observed altered banding patterns of the LPS and changed protein mobility on sodium dodecyl sulfate (SDS) polyacrylamide gels after incubation of LPS with the enzyme. The initial interpretation of these results was that the enzyme had removed ester-linked acyl chains from the LPS, leading to a change in its migration on gels. However, esterase inactivated by treatment with either dithiothreitol (DTT), heat, or SDS generated the same mobility shifts. Bovine serum albumin (BSA) also induced the same change in the electrophoretic pattern. We conclude that the altered LPS patterns and protein mobility on SDS gels were caused by nonspecific interactions between LPS and protein.
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Affiliation(s)
- A Yuan
- School of Biological Sciences, University of Nebraska-Lincoln, 68588-0118, USA.
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45
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Mendoza HL, Faye I. Physiological aspects of the immunoglobulin superfamily in invertebrates. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 1999; 23:359-74. [PMID: 10426428 DOI: 10.1016/s0145-305x(99)00017-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Affiliation(s)
- H L Mendoza
- Instituto Nacional de Salud Publica, Centro De Investigacion sobre Enfermedades Infecciosas, Cuernavaca, Morelos, Mexico
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46
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Su XD, Gastinel LN, Vaughn DE, Faye I, Poon P, Bjorkman PJ. Crystal structure of hemolin: a horseshoe shape with implications for homophilic adhesion. Science 1998; 281:991-5. [PMID: 9703515 DOI: 10.1126/science.281.5379.991] [Citation(s) in RCA: 145] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Hemolin, an insect immunoglobulin superfamily member, is a lipopolysaccharide-binding immune protein induced during bacterial infection. The 3.1 angstrom crystal structure reveals a bound phosphate and patches of positive charge, which may represent the lipopolysaccharide binding site, and a new and unexpected arrangement of four immunoglobulin-like domains forming a horseshoe. Sequence analysis and analytical ultracentrifugation suggest that the domain arrangement is a feature of the L1 family of neural cell adhesion molecules related to hemolin. These results are relevant to interpretation of human L1 mutations in neurological diseases and suggest a domain swapping model for how L1 family proteins mediate homophilic adhesion.
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Affiliation(s)
- X D Su
- Division of Biology 156-29 and Howard Hughes Medical Institute, California Institute of Technology, Pasadena, CA 91125, USA
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47
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Abstract
The melanization reaction, which is a common response to parasite entry in invertebrate animals, especially arthropods, is due to the activity of an oxidoreductase, phenoloxidase. This enzyme is part of a complex system of proteinases, pattern recognition proteins and proteinase inhibitors constituting the so-called prophenoloxidase-activating system. It is proposed to be a non-self recognition system because conversion of prophenoloxidase to active enzyme can be brought about by minuscule amounts of molecules such as lipopolysaccharide, peptidoglycan and beta-1, 3-glucans from micro-organisms. Several components of this system recently have been isolated and their structure determined.
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Affiliation(s)
- K Söderhäll
- Division of Physiological Mycology, University of Uppsala, Sweden.
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48
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Bettencourt R, Lanz-Mendoza H, Lindquist KR, Faye I. Cell adhesion properties of hemolin, an insect immune protein in the Ig superfamily. EUROPEAN JOURNAL OF BIOCHEMISTRY 1997; 250:630-7. [PMID: 9461284 DOI: 10.1111/j.1432-1033.1997.00630.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The isolation of antibacterial peptides from the giant silkmoth Hyalophora cecropia has opened the area of animal antibiotics [Boman, H. G. (1991) Cell 65, 205-207] and the study of insect immune genes has revealed striking similarities to many immune response genes in mammals [Hultmark, D. (1994) Nature 267, 116-117]. However, the molecules and mechanisms behind primordial immune recognition are not understood. One candidate for one such recognition molecule is hemolin, a 48-kDa immunoglobulin-related protein first isolated from H. cecropia, where it is up-regulated upon infection and secreted into the hemolymph. Hemolin was shown to bind to bacteria and to hemocytes, giving rise to changes in hemocyte adhesiveness and intracellular phosphorylation patterns [Faye, I. & Kanost, M. (1997) in Molecular mechanisms of immune responses in insects (Brey, P. T. & Hultmark, D., eds) Chapman and Hall, London]. In the present publication, we give evidence for the presence of a 52-kDa membrane form of hemolin on hemocytes, based on flow-activated cell sorting and membrane protein extractions. In addition we reveal calcium-dependent homophilic binding properties of hemolin, using hemolin-coated microspheres. When biotinylated recombinant hemolin was allowed to bind to hemocyte membranes, higher molecular-mass complexes were formed. Furthermore, we used immunological methods and Northern-blot analysis to demonstrate the presence of hemolin in embryos and retinal discs, suggesting that hemolin is expressed in several tissues at different developmental stages. These results show novel cell adhesion features of hemolin, corroborating its multifunctional character with putative roles in cellular and humoral immunity and in development.
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Affiliation(s)
- R Bettencourt
- Department of Genetics, University of Stockholm, Sweden
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