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Qu S, Wang S. Interaction of entomopathogenic fungi with the host immune system. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2018; 83:96-103. [PMID: 29355579 DOI: 10.1016/j.dci.2018.01.010] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Revised: 01/14/2018] [Accepted: 01/15/2018] [Indexed: 06/07/2023]
Abstract
Entomopathogenic fungi can invade wide range of insect hosts in the natural world and have been used as environmentally friendly alternatives to chemical insecticides for pest control. Studies of host-pathogen interactions provide valuable insights into the coevolutionay arms race between fungal pathogens and their hosts. Entomopathogenic fungi have evolved a series of sophisticated strategies to counter insect immune defenses. In response to fungal infection, insect hosts rely on behavior avoidance, physical barrier and innate immune defenses in the fight against invading pathogens. The insect cuticle acts as the first physical barrier against pathogens. It is an inhospitable physiological environment that contains chemicals (e.g., antimicrobial peptides and reactive oxygen species), which inhibit fungal growth. In addition, innate immune responses, including cellular immunity and humoral immunity, play critical roles in preventing fungal infection. In this review, we outline the current state of our knowledge of insect defenses to fungal infection and discuss the strategies by which entomopathogenic fungi counter the host immune system. Increased knowledge regarding the molecular interactions between entomopathogenic fungi and the insect host could provide new strategies for pest management.
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Affiliation(s)
- Shuang Qu
- Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Sibao Wang
- Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China.
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102
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Wang Y, Zhang XW, Wang H, Fang WH, Ma H, Zhang F, Wang Y, Li XC. SpCrus3 and SpCrus4 share high similarity in mud crab (Scylla paramamosain) exhibiting different antibacterial activities. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2018; 82:139-151. [PMID: 29352984 DOI: 10.1016/j.dci.2018.01.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 01/09/2018] [Accepted: 01/10/2018] [Indexed: 06/07/2023]
Abstract
Type I crustins are crucial effectors of crustacean immune system. Various type I crustins with high sequence diversity possess different antimicrobial activities. To date, the mechanism on how the sequence diversity of type I crustins affects their antimicrobial activities is largely unclear, and how different crustins function together against bacterial invasion still remains unknown. In this study, we identified two novel type I crustins, namely, SpCrus3 and SpCrus4, from an economically important crab, Scylla paramamosain. Either SpCrus3 or SpCrus4 was highly expressed in gill. After challenges with Vibrio parahemolyticus or Staphylococcus aureus, SpCrus4 was up-regulated, whereas SpCrus3 was down-regulated. No significant expression change of SpCrus3 and SpCrus4 was observed after white spot syndrome virus injection, suggesting that these two genes may not participate in the antiviral immune responses. SpCrus3 and SpCrus4 had the common 5' terminus and high similarity of 66.06%, but SpCrus4 exhibited stronger antimicrobial activity than that of SpCrus3. Microorganism-binding assay results revealed that both SpCrus3 and SpCrus4 exhibited binding ability to all tested microorganisms. Furthermore, the polysaccharide-binding assay showed that these two proteins exhibited strong binding activity to bacterial polysaccharides, such as lipopolysaccharide (LPS), lipoteichoic acid (LTA), and peptidoglycan (PGN). SpCrus3 and SpCrus4 exhibited stronger binding activity to LPS or LTA than to PGN. Moreover, SpCrus4 showed stronger binding activity to LTA than that of SpCrus3, which may be responsible for the significantly distinct antimicrobial activity between these two proteins. In addition, SpCrus4 displayed stronger agglutination activity against several kinds of microorganisms than that of SpCrus3. This increased agglutination activity may also contribute to the strong antibacterial activity of SpCrus4. On the basis of all these results, a possible antibacterial mode exerted by SpCrus3 and SpCrus4 was proposed as follows. SpCrus3 was highly expressed in normal crabs to maintain low-level antibacterial activity without bacterial challenges. When crabs were challenged with bacteria, large amount of SpCrus4 was generated to exhibit strong antibacterial activity against bacterial invasion. This study provides new insights to understand the antibacterial functions and mechanisms of type I crustins.
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Affiliation(s)
- Yue Wang
- East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Key Laboratory of East China Sea Fishery Resources Exploitation, Ministry of Agriculture, Shanghai, 200090, China; College of Life Science, Henan Normal University, Xinxiang, Henan, 453007, China
| | - Xiao-Wen Zhang
- College of Life Science, Henan Normal University, Xinxiang, Henan, 453007, China
| | - Hui Wang
- East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Key Laboratory of East China Sea Fishery Resources Exploitation, Ministry of Agriculture, Shanghai, 200090, China
| | - Wen-Hong Fang
- East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Key Laboratory of East China Sea Fishery Resources Exploitation, Ministry of Agriculture, Shanghai, 200090, China
| | - Hongyu Ma
- Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou, 515063, China
| | - Fengxia Zhang
- Department of Arts and Sciences, New York University, Shanghai, 200122, China
| | - Yuan Wang
- East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Key Laboratory of East China Sea Fishery Resources Exploitation, Ministry of Agriculture, Shanghai, 200090, China
| | - Xin-Cang Li
- East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Key Laboratory of East China Sea Fishery Resources Exploitation, Ministry of Agriculture, Shanghai, 200090, China.
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103
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Huang Y, Han K, Ren Q. Cloning and Analysis of Gene Expression of Two Toll Receptors in Freshwater Pearl Mussel Hyriopsis cumingii. Front Physiol 2018; 9:133. [PMID: 29556200 PMCID: PMC5845394 DOI: 10.3389/fphys.2018.00133] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Accepted: 02/09/2018] [Indexed: 11/13/2022] Open
Abstract
Toll receptors are involved in innate immunity of invertebrates. In this study, we identify and characterize two Toll genes (named HcToll4 and HcToll5) from triangle sail mussel Hyriopsis cumingii. HcToll4 has complete cDNA sequence of 3,162 bp and encodes a protein of 909 amino acids. HcToll5 cDNA is 4,501 bp in length and encodes a protein of 924 amino acids. Both deduced HcToll4 and HcToll5 protein contain signal peptide, extracellular leucine rich repeats (LRRs), and intracellular Toll/interleukin-1 (IL-1) receptor domains. Quantitative real-time PCR analysis revealed that HcToll4 and HcToll5 were largely distributed in the hepatopancreas and could be detected in the gills and mantle. HcToll4 and HcToll5 expression could respond to Staphylococcus aureus, Vibrio parahaemolyticus, White spot syndrome virus (WSSV) or Poly I:C challenge. RNA interference by siRNA results showed that HcToll4 and HcToll5 were involved in the regulation of theromacin (HcThe) and whey acidic protein (HcWAP) expression. Based on these results, HcToll4 and HcToll5 might play pivotal function in H. cumingii innate immune response.
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Affiliation(s)
- Ying Huang
- Jiangsu Key Laboratory for Biodiversity and Biotechnology and Jiangsu Key Laboratory for Aquatic Crustacean Diseases, College of Life Sciences, Nanjing Normal University, Nanjing, China.,College of Oceanography, Hohai University, Nanjing, China
| | - Keke Han
- Jiangsu Key Laboratory for Biodiversity and Biotechnology and Jiangsu Key Laboratory for Aquatic Crustacean Diseases, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Qian Ren
- Jiangsu Key Laboratory for Biodiversity and Biotechnology and Jiangsu Key Laboratory for Aquatic Crustacean Diseases, College of Life Sciences, Nanjing Normal University, Nanjing, China.,Co-Innovation Center for Marine Bio-Industry Technology of Jiangsu Province, Lianyungang, China
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104
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Tassanakajon A, Rimphanitchayakit V, Visetnan S, Amparyup P, Somboonwiwat K, Charoensapsri W, Tang S. Shrimp humoral responses against pathogens: antimicrobial peptides and melanization. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2018; 80:81-93. [PMID: 28501515 DOI: 10.1016/j.dci.2017.05.009] [Citation(s) in RCA: 165] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Revised: 05/10/2017] [Accepted: 05/10/2017] [Indexed: 06/07/2023]
Abstract
Diseases have caused tremendous economic losses and become the major problem threatening the sustainable development of shrimp aquaculture. The knowledge of host defense mechanisms against invading pathogens is essential for the implementation of efficient strategies to prevent disease outbreaks. Like other invertebrates, shrimp rely on the innate immune system to defend themselves against a range of microbes by recognizing and destroying them through cellular and humoral immune responses. Detection of microbial pathogens triggers the signal transduction pathways including the NF-κB signaling, Toll and Imd pathways, resulting in the activation of genes involved in host defense responses. In this review, we update the discovery of components of the Toll and Imd pathways in shrimp and their participation in the regulation of shrimp antimicrobial peptide (AMP) synthesis. We also focus on a recent progress on the two most powerful and the best-studied shrimp humoral responses: AMPs and melanization. Shrimp AMPs are mainly cationic peptides with sequence diversity which endues them the broad range of activities against microorganisms. Melanization, regulated by the prophenoloxidase activating cascade, also plays a crucial role in killing and sequestration of invading pathogens. The progress and emerging research on mechanisms and functional characterization of components of these two indispensable humoral responses in shrimp immunity are summarized and discussed. Interestingly, the pattern recognition protein (PRP) crosstalk is evidenced between the proPO activating cascade and the AMP synthesis pathways in shrimp, which enables the innate immune system to build up efficient immune responses.
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Affiliation(s)
- Anchalee Tassanakajon
- Center of Excellence for Molecular Biology and Genomics of Shrimp, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Phyathai Road, Bangkok 10330, Thailand.
| | - Vichien Rimphanitchayakit
- Center of Excellence for Molecular Biology and Genomics of Shrimp, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Phyathai Road, Bangkok 10330, Thailand
| | - Suwattana Visetnan
- Center of Excellence for Molecular Biology and Genomics of Shrimp, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Phyathai Road, Bangkok 10330, Thailand
| | - Piti Amparyup
- National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), 113 Paholyothin Road, Klong1, Klong Luang, Pathumthani 12120, Thailand
| | - Kunlaya Somboonwiwat
- Center of Excellence for Molecular Biology and Genomics of Shrimp, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Phyathai Road, Bangkok 10330, Thailand
| | - Walaiporn Charoensapsri
- National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), 113 Paholyothin Road, Klong1, Klong Luang, Pathumthani 12120, Thailand
| | - Sureerat Tang
- National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), 113 Paholyothin Road, Klong1, Klong Luang, Pathumthani 12120, Thailand
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105
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Vieira CS, Moreira OC, Batista KKS, Ratcliffe NA, Castro DP, Azambuja P. The NF-κB Inhibitor, IMD-0354, Affects Immune Gene Expression, Bacterial Microbiota and Trypanosoma cruzi Infection in Rhodnius prolixus Midgut. Front Physiol 2018. [PMID: 30233391 DOI: 10.3389/fphys.2018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2023] Open
Abstract
Rhodnius prolixus is an insect vector of Trypanosoma cruzi, the causative agent of Chagas disease in Latin America. Nuclear factor-κB (NF-κB) transcription factors (TF) are conserved components of the innate immune system in several multicellular organisms including insects. The drug IMD-0354 [N-(3,5-bis-trifluoromethyl-phenyl)-5-chloro-2-hydroxy-benzamide] is a selective inhibitor of IκB kinases. It blocks IκBα phosphorylation thus preventing nuclear translocation of the NF-κb TF. In humans, NF-κB is involved in several biological processes such as inflammation, cell proliferation and immunity. In insects, the activation of the immune system upon microbial challenge can be controlled by signaling pathways such as the immune deficiency (IMD) and Toll, to combat infection. These activated pathways signal to downstream NF-κB TF to stimulate specific immune genes, triggering the synthesis of several molecules such as the antimicrobial peptides. In Drosophila melanogaster, the activation and regulation of NF-κB TF have been elucidated, while in triatomines these mechanisms are not fully understood Therefore, the present study investigated the effects of oral administration of the drug IMD-0354 on the R. prolixus immune response to challenge with bacteria and T. cruzi, as well as the impact on the gut bacterial microbiota. R. prolixus were fed with rabbit blood containing IMD-0354 and Escherichia coli, Staphylococcus aureus, or T. cruzi. The effects of IMD-0354 on insect mortality and antimicrobial activity in insect midgut samples, as well as the relative expression of R. prolixus immune genes were recorded. The bacterial microbiota was analyzed, and viable parasites were counted in insect midgut samples. The IMD-0354 treatment modulated antibacterial activity and the gene expression patterns of defensin A, defensin B, defensin C, and prolixicin, and the genes involved in the IMD and Toll pathways. Additionally, there was an increase of bacterial microbiota in treated insects. Insects treated with IMD-0354 and concomitantly infected with bacteria or T. cruzi through the blood meal had increased mortality, while the T. cruzi population in R. prolixus midgut was reduced. The inhibitory effect of IMD-0354 indicates the importance of NF-κB TF in the innate immune responses involved in the control of bacteria and parasite infections in the R. prolixus midgut.
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Affiliation(s)
- Cecilia S Vieira
- Laboratório de Bioquímica e Fisiologia de Insetos, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz (IOC/FIOCRUZ), Rio de Janeiro, Brazil
| | - Otacílio C Moreira
- Laboratório de Biologia Molecular e Doenças Endêmicas, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz (IOC/FIOCRUZ), Rio de Janeiro, Brazil
| | - Kate K S Batista
- Laboratório de Bioquímica e Fisiologia de Insetos, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz (IOC/FIOCRUZ), Rio de Janeiro, Brazil
| | - Norman A Ratcliffe
- Laboratório de Biologia de Insetos, Universidade Federal Fluminense, Niterói, Brazil
- College of Science, Swansea University, Wales, United Kingdom
| | - Daniele P Castro
- Laboratório de Bioquímica e Fisiologia de Insetos, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz (IOC/FIOCRUZ), Rio de Janeiro, Brazil
- Departamento de Entomologia Molecular, Instituto Nacional de Entomologia Molecular (INCT-EM), Rio de Janeiro, Brazil
| | - Patrícia Azambuja
- Laboratório de Bioquímica e Fisiologia de Insetos, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz (IOC/FIOCRUZ), Rio de Janeiro, Brazil
- Departamento de Entomologia Molecular, Instituto Nacional de Entomologia Molecular (INCT-EM), Rio de Janeiro, Brazil
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106
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Brennan JJ, Messerschmidt JL, Williams LM, Matthews BJ, Reynoso M, Gilmore TD. Sea anemone model has a single Toll-like receptor that can function in pathogen detection, NF-κB signal transduction, and development. Proc Natl Acad Sci U S A 2017; 114:E10122-E10131. [PMID: 29109290 PMCID: PMC5703304 DOI: 10.1073/pnas.1711530114] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
In organisms from insects to vertebrates, Toll-like receptors (TLRs) are primary pathogen detectors that activate downstream pathways, specifically those that direct expression of innate immune effector genes. TLRs also have roles in development in many species. The sea anemone Nematostella vectensis is a useful cnidarian model to study the origins of TLR signaling because its genome encodes a single TLR and homologs of many downstream signaling components, including the NF-κB pathway. We have characterized the single N. vectensis TLR (Nv-TLR) and demonstrated that it can activate canonical NF-κB signaling in human cells. Furthermore, we show that the intracellular Toll/IL-1 receptor (TIR) domain of Nv-TLR can interact with the human TLR adapter proteins MAL and MYD88. We demonstrate that the coral pathogen Vibrio coralliilyticus causes a rapidly lethal disease in N. vectensis and that heat-inactivated V. coralliilyticus and bacterial flagellin can activate a reconstituted Nv-TLR-to-NF-κB pathway in human cells. By immunostaining of anemones, we show that Nv-TLR is expressed in a subset of cnidocytes and that many of these Nv-TLR-expressing cells also express Nv-NF-κB. Additionally, the nematosome, which is a Nematostella-specific multicellular structure, expresses Nv-TLR and many innate immune pathway homologs and can engulf V. coralliilyticus Morpholino knockdown indicates that Nv-TLR also has an essential role during early embryonic development. Our characterization of this primitive TLR and identification of a bacterial pathogen for N. vectensis reveal ancient TLR functions and provide a model for studying the molecular basis of cnidarian disease and immunity.
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107
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Qiu W, He JH, Zuo H, Niu S, Li C, Zhang S, Weng S, He J, Xu X. Identification, characterization, and function analysis of the NF-κB repressing factor (NKRF) gene from Litopenaeus vannamei. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2017; 76:83-92. [PMID: 28564581 DOI: 10.1016/j.dci.2017.05.020] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Revised: 05/26/2017] [Accepted: 05/26/2017] [Indexed: 06/07/2023]
Abstract
The NF-κB family transcription factors regulate a wide spectrum of biological processes, in particular immune responses. The studies in human suggest that the NF-κB repressing factor (NKRF) negatively regulates the activity of NF-κB through a direct protein-protein interaction. However, the function of NKRF has not been studied outside mammals up to now. The current study identified a NKRF gene (LvNKRF) from the Pacific white shrimp, Litopenaeus vannamei, which showed homology with NKRFs from insects, fishes and mammals. LvNKRF was high expressed in intestine, stomach and muscle tissues and was localized in the nucleus. LvNKRF could interact with both Dorsal and Relish, the two members of the shrimp NF-κB family. Interestingly, although sharing a similar protein structure with that of human NKRF, LvNKRF showed no inhibitory but instead enhancing effects on activities of Dorsal and Relish, which was contrary to those of mammalian NKRFs. The expression of LvNKRF could not be induced by Gram-positive and -negative bacteria and immunostimulants lipopolysaccharide (LPS) and poly (I:C) but was significantly up-regulated after white spot syndrome virus (WSSV) infection. Silencing of LvNKRF significantly decreased the mortalities of shrimp caused by WSSV infection and down-regulated the WSSV copies and the expression of WSSV structural gene in tissues. These suggested that LvNKRF could facilitate the infection of shrimp by WSSV, which may be an additional strategy for WSSV to hijack the host NF-κB pathway to favor its own replication. The current study could provide a valuable context for further investigating the evolutionary derivation of NKRFs and facilitate the study of regulatory mechanisms of invertebrate NF-κB pathways.
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Affiliation(s)
- Wei Qiu
- MOE Key Laboratory of Aquatic Product Safety/State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, PR China; School of Marine Sciences, Sun Yat-sen University, Guangzhou, PR China; School of Biology and Engineering, Guizhou Medical University, Guiyang 550025, China
| | - Jian-Hui He
- MOE Key Laboratory of Aquatic Product Safety/State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, PR China; Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, Guangzhou, PR China
| | - Hongliang Zuo
- MOE Key Laboratory of Aquatic Product Safety/State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, PR China; Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, Guangzhou, PR China; School of Marine Sciences, Sun Yat-sen University, Guangzhou, PR China; South China Sea Resource Exploitation and Protection Collaborative Innovation Center (SCS-REPIC), Guangzhou, PR China
| | - Shengwen Niu
- MOE Key Laboratory of Aquatic Product Safety/State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, PR China; Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, Guangzhou, PR China
| | - Chaozheng Li
- MOE Key Laboratory of Aquatic Product Safety/State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, PR China; Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, Guangzhou, PR China; School of Marine Sciences, Sun Yat-sen University, Guangzhou, PR China
| | - Shuang Zhang
- MOE Key Laboratory of Aquatic Product Safety/State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, PR China; Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, Guangzhou, PR China
| | - Shaoping Weng
- MOE Key Laboratory of Aquatic Product Safety/State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, PR China; Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, Guangzhou, PR China
| | - Jianguo He
- MOE Key Laboratory of Aquatic Product Safety/State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, PR China; Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, Guangzhou, PR China; School of Marine Sciences, Sun Yat-sen University, Guangzhou, PR China; South China Sea Resource Exploitation and Protection Collaborative Innovation Center (SCS-REPIC), Guangzhou, PR China.
| | - Xiaopeng Xu
- MOE Key Laboratory of Aquatic Product Safety/State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, PR China; Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, Guangzhou, PR China; South China Sea Resource Exploitation and Protection Collaborative Innovation Center (SCS-REPIC), Guangzhou, PR China.
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108
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Su P, Liu X, Pang Y, Liu C, Li R, Zhang Q, Liang H, Wang H, Li Q. The archaic roles of the lamprey NF-κB (lj-NF-κB) in innate immune responses. Mol Immunol 2017; 92:21-27. [PMID: 29031044 DOI: 10.1016/j.molimm.2017.10.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Revised: 09/30/2017] [Accepted: 10/02/2017] [Indexed: 11/27/2022]
Abstract
The nuclear factor-kappa B (NF-κB) is a pleiotropic transcription factor regulating the expression of genes involved in various biological processes including the immune response and inflammation. Lamprey is regarded as a key species to provide meaningful clues for understanding the evolution of immune system; nevertheless, no information about lamprey NF-κB is reported. Thus, we have characterized a NF-κB homolog in lamprey (lj-NF-κB) for the deeper understanding of the role it played in lamprey immune system. The sequence and 3D structure analyses demonstrate that lj-NF-κB contained a Rel homology domain (RHD) and seven ankyrin repeats domains (ANKs), which would exhibit functional similarities to NF-κB superfamily proteins. This hypothesis was further proved by experiments. We found that the RHD of lj-NF-κB could interact with a mammalian κB response element, translocate to the nucleus to modulate gene (IL-6, IL-1β and TNF-α) expression, and the nuclear localization signals (NLS) was essential for the nuclear translocation. Furthermore, the ANKs of lj-NF-κB are the inhibition signal for the RHD of lj-NF-κB. The present results allow us to surmise that the lj-NF-κB should play a key role in immune response of lamprey, and the function of NF-κB has been maintained during evolution.
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Affiliation(s)
- Peng Su
- College of Life Science, Liaoning Normal University, Dalian 116082, China; Lamprey Research Center, Liaoning Normal University, Dalian 116082, China
| | - Xin Liu
- College of Life Science, Liaoning Normal University, Dalian 116082, China; Lamprey Research Center, Liaoning Normal University, Dalian 116082, China
| | - Yue Pang
- College of Life Science, Liaoning Normal University, Dalian 116082, China; Lamprey Research Center, Liaoning Normal University, Dalian 116082, China
| | - Chang Liu
- College of Life Science, Liaoning Normal University, Dalian 116082, China; Lamprey Research Center, Liaoning Normal University, Dalian 116082, China
| | - Ranran Li
- College of Life Science, Liaoning Normal University, Dalian 116082, China; Lamprey Research Center, Liaoning Normal University, Dalian 116082, China
| | - Qiong Zhang
- College of Life Science, Liaoning Normal University, Dalian 116082, China; Lamprey Research Center, Liaoning Normal University, Dalian 116082, China
| | - Hongfang Liang
- College of Life Science, Liaoning Normal University, Dalian 116082, China; Lamprey Research Center, Liaoning Normal University, Dalian 116082, China
| | - Hao Wang
- College of Life Science, Liaoning Normal University, Dalian 116082, China; Lamprey Research Center, Liaoning Normal University, Dalian 116082, China
| | - Qingwei Li
- College of Life Science, Liaoning Normal University, Dalian 116082, China; Lamprey Research Center, Liaoning Normal University, Dalian 116082, China.
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109
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Shakeel M, Xu X, Xu J, Zhu X, Li S, Zhou X, Yu J, Xu X, Hu Q, Yu X, Jin F. Identification of immunity-related genes in Plutella xylostella in response to fungal peptide destruxin A: RNA-Seq and DGE analysis. Sci Rep 2017; 7:10966. [PMID: 28887550 PMCID: PMC5591186 DOI: 10.1038/s41598-017-11298-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Accepted: 08/17/2017] [Indexed: 11/09/2022] Open
Abstract
Plutella xylostella has become the major lepidopteran pest of Brassica owing to its strong ability of resistance development to a wide range of insecticides. Destruxin A, a mycotoxin of entomopathogenic fungus, Metarhizium anisopliae, has broad-spectrum insecticidal effects. However, the interaction mechanism of destruxin A with the immune system of P. xylostella at genomic level is still not well understood. Here, we identified 129 immunity-related genes, including pattern recognition receptors, signal modulators, few members of main immune pathways (Toll, Imd, and JAK/STAT), and immune effectors in P. xylostella in response to destruxin A at three different time courses (2 h, 4 h, and 6 h). It is worthy to mention that the immunity-related differentially expressed genes (DEGs) analysis exhibited 30, 78, and 72 up-regulated and 17, 13, and 6 down-regulated genes in P. xylostella after destruxin A injection at 2 h, 4 h, and 6 h, respectively, compared to control. Interestingly, our results revealed that the expression of antimicrobial peptides that play a vital role in insect immune system was up-regulated after the injection of destruxin A. Our findings provide a detailed information on immunity-related DEGs and reveal the potential of P. xylostella to limit the infection of fungal peptide destruxin A by increasing the activity of antimicrobial peptides.
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Affiliation(s)
- Muhammad Shakeel
- College of Agriculture, South China Agricultural University, Laboratory of Bio-Pesticide Creation and Application of Guangdong Province, Guangzhou, P.R. China
| | - Xiaoxia Xu
- College of Agriculture, South China Agricultural University, Laboratory of Bio-Pesticide Creation and Application of Guangdong Province, Guangzhou, P.R. China
| | - Jin Xu
- College of Agriculture, South China Agricultural University, Laboratory of Bio-Pesticide Creation and Application of Guangdong Province, Guangzhou, P.R. China
| | - Xun Zhu
- State Key Laboratory for Biology of Plant Disease and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Shuzhong Li
- College of Agriculture, South China Agricultural University, Laboratory of Bio-Pesticide Creation and Application of Guangdong Province, Guangzhou, P.R. China
| | | | | | | | - Qiongbo Hu
- College of Agriculture, South China Agricultural University, Laboratory of Bio-Pesticide Creation and Application of Guangdong Province, Guangzhou, P.R. China
| | - Xiaoqiang Yu
- School of Biological Sciences, University of Missouri-Kansas, Kansas City, MO, 64110, USA
| | - Fengliang Jin
- College of Agriculture, South China Agricultural University, Laboratory of Bio-Pesticide Creation and Application of Guangdong Province, Guangzhou, P.R. China.
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110
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Temperature stress and insect immunity. J Therm Biol 2017; 68:96-103. [DOI: 10.1016/j.jtherbio.2016.12.002] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Revised: 12/01/2016] [Accepted: 12/05/2016] [Indexed: 11/18/2022]
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111
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Xu J, Xu X, Shakeel M, Li S, Wang S, Zhou X, Yu J, Xu X, Yu X, Jin F. The Entomopathogenic Fungi Isaria fumosorosea Plays a Vital Role in Suppressing the Immune System of Plutella xylostella: RNA-Seq and DGE Analysis of Immunity-Related Genes. Front Microbiol 2017; 8:1421. [PMID: 28804478 PMCID: PMC5532397 DOI: 10.3389/fmicb.2017.01421] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 07/13/2017] [Indexed: 11/13/2022] Open
Abstract
Most, if not all, entomopathogenic fungi have been used as alternative control agents to decrease the insect resistance and harmful effects of the insecticides on the environment. Among them, Isaria fumosorosea has also shown great potential to control different insect pests. In the present study, we explored the immune response of P. xylostella to the infection of I. fumosorosea at different time points by using RNA-Sequencing and differential gene expression technology at the genomic level. To gain insight into the host-pathogen interaction at the genomic level, five libraries of P. xylostella larvae at 12, 18, 24, and 36 h post-infection and a control were constructed. In total, 161 immunity-related genes were identified and grouped into four categories; immune recognition families, toll and Imd pathway, melanization, and antimicrobial peptides (AMPs). The results of differentially expressed immunity-related genes depicted that 15, 13, 53, and 14 up-regulated and 38, 51, 56, and 49 were down-regulated in P. xylostella at 12, 18, 24, and 36 h post-treatment, respectively. RNA-Seq results of immunity-related genes revealed that the expression of AMPs was reduced after treatment with I. fumosorosea. To validate RNA-Seq results by RT-qPCR, 22 immunity-related genes were randomly selected. In conclusion, our results demonstrate that I. fumosorosea has the potential to suppress the immune response of P. xylostella and can become a potential biopesticide for controlling P. xylostella.
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Affiliation(s)
- Jin Xu
- Laboratory of Bio-Pesticide and Application of Guangdong Province, College of Agriculture, South China Agricultural UniversityGuangzhou, China
| | - Xiaoxia Xu
- Laboratory of Bio-Pesticide and Application of Guangdong Province, College of Agriculture, South China Agricultural UniversityGuangzhou, China
| | - Muhammad Shakeel
- Laboratory of Bio-Pesticide and Application of Guangdong Province, College of Agriculture, South China Agricultural UniversityGuangzhou, China
| | - Shuzhong Li
- Laboratory of Bio-Pesticide and Application of Guangdong Province, College of Agriculture, South China Agricultural UniversityGuangzhou, China
| | - Shuang Wang
- Laboratory of Bio-Pesticide and Application of Guangdong Province, College of Agriculture, South China Agricultural UniversityGuangzhou, China
| | | | - Jialin Yu
- Beijing Genomic InstituteShenzhen, China
| | | | - Xiaoqiang Yu
- School of Biological Sciences, University of Missouri-KansasKansas City, MO, United States
| | - Fengliang Jin
- Laboratory of Bio-Pesticide and Application of Guangdong Province, College of Agriculture, South China Agricultural UniversityGuangzhou, China
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112
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Toll ligand Spätzle3 controls melanization in the stripe pattern formation in caterpillars. Proc Natl Acad Sci U S A 2017; 114:8336-8341. [PMID: 28716921 DOI: 10.1073/pnas.1707896114] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
A stripe pattern is an aposematic or camouflage coloration often observed among various caterpillars. However, how this ecologically important pattern is formed is largely unknown. The silkworm dominant mutant Zebra (Ze) has a black stripe in the anterior margin of each dorsal segment. Here, fine linkage mapping of 3,135 larvae revealed a 63-kbp region responsible for the Ze locus, which contained three candidate genes, including the Toll ligand gene spätzle3 (spz-3). Both electroporation-mediated ectopic expression and RNAi analyses showed that, among candidate genes, only processed spz-3 induced melanin pigmentation and that Toll-8 was the candidate receptor gene of spz-3 This Toll ligand/receptor set is also involved in melanization of other mutant Striped (pS ), which has broader stripes. Additional knockdown of 5 other spz family and 10 Toll-related genes caused no drastic change in the pigmentation of either mutant, suggesting that only spz-3/Toll-8 is mainly involved in the melanization process rather than pattern formation. The downstream pigmentation gene yellow was specifically up-regulated in the striped region of the Ze mutant, but spz-3 showed no such region-specific expression. Toll signaling pathways are known to be involved in innate immunity, dorsoventral axis formation, and neurotrophic functions. This study provides direct evidence that a Toll signaling pathway is co-opted to control the melanization process and adaptive striped pattern formation in caterpillars.
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113
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Transcription Factor Forkhead Regulates Expression of Antimicrobial Peptides in the Tobacco Hornworm, Manduca sexta. Sci Rep 2017; 7:2688. [PMID: 28578399 PMCID: PMC5457402 DOI: 10.1038/s41598-017-02830-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Accepted: 04/19/2017] [Indexed: 12/13/2022] Open
Abstract
Antimicrobial peptides (AMPs) play an important role in defense against microbial infections in insects. Expression of AMPs is regulated mainly by NF-κB factors Dorsal, Dif and Relish. Our previous study showed that both NF-κB and GATA-1 factors are required for activation of moricin promoter in the tobacco hornworm, Manduca sexta, and a 140-bp region in the moricin promoter contains binding sites for additional transcription factors. In this study, we identified three forkhead (Fkh)-binding sites in the 140-bp region of the moricin promoter and several Fkh-binding sites in the lysozyme promoter, and demonstrated that Fkh-binding sites are required for activation of both moricin and lysozyme promoters by Fkh factors. In addition, we found that Fkh mRNA was undetectable in Drosophila S2 cells, and M. sexta Fkh (MsFkh) interacted with Relish-Rel-homology domain (RHD) but not with Dorsal-RHD. Dual luciferase assays with moricin mutant promoters showed that co-expression of MsFkh with Relish-RHD did not have an additive effect on the activity of moricin promoter, suggesting that MsFkh and Relish regulate moricin activation independently. Our results suggest that insect AMPs can be activated by Fkh factors under non-infectious conditions, which may be important for protection of insects from microbial infection during molting and metamorphosis.
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114
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Wojda I. Immunity of the greater wax moth Galleria mellonella. INSECT SCIENCE 2017; 24:342-357. [PMID: 26847724 DOI: 10.1111/1744-7917.12325] [Citation(s) in RCA: 169] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Revised: 12/29/2015] [Accepted: 01/19/2016] [Indexed: 06/05/2023]
Abstract
Investigation of insect immune mechanisms provides important information concerning innate immunity, which in many aspects is conserved in animals. This is one of the reasons why insects serve as model organisms to study virulence mechanisms of human pathogens. From the evolutionary point of view, we also learn a lot about host-pathogen interaction and adaptation of organisms to conditions of life. Additionally, insect-derived antibacterial and antifungal peptides and proteins are considered for their potential to be applied as alternatives to antibiotics. While Drosophila melanogaster is used to study the genetic aspect of insect immunity, Galleria mellonella serves as a good model for biochemical research. Given the size of the insect, it is possible to obtain easily hemolymph and other tissues as a source of many immune-relevant polypeptides. This review article summarizes our knowledge concerning G. mellonella immunity. The best-characterized immune-related proteins and peptides are recalled and their short characteristic is given. Some other proteins identified at the mRNA level are also mentioned. The infectious routes used by Galleria natural pathogens such as Bacillus thuringiensis and Beauveria bassiana are also described in the context of host-pathogen interaction. Finally, the plasticity of G. mellonella immune response influenced by abiotic and biotic factors is described.
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Affiliation(s)
- Iwona Wojda
- Maria Curie-Sklodowska University, Faculty of Biology and Biotechnology, Institute of Biology and Biochemistry, Department of Immunobiology, Akademicka 19, 20-033, Lublin, Poland
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115
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TmCactin plays an important role in Gram-negative and -positive bacterial infection by regulating expression of 7 AMP genes in Tenebrio molitor. Sci Rep 2017; 7:46459. [PMID: 28418029 PMCID: PMC5394457 DOI: 10.1038/srep46459] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Accepted: 03/17/2017] [Indexed: 01/06/2023] Open
Abstract
Cactin was originally identified as an interactor of the Drosophila IκB factor Cactus and shown to play a role in controlling embryonic polarity and regulating the NF-κB signaling pathway. While subsequent studies have identified the roles for Cactin in the mammalian immune response, the immune function of Cactin in insects has not been described yet. Here, we identified a Cactin gene from the mealworm beetle, Tenebrio molitor (TmCactin) and characterized its functional role in innate immunity. TmCactin was highly expressed in prepupa to last instar stages, and its expression was high in the integument and Malpighian tubules of last instar larvae and adults. TmCactin was induced in larvae after infection with different pathogens and detectable within 3 hours of infection. The highest levels of TmCactin expression were detected at 9 hours post infection. TmCactin RNAi significantly decreased the survival rates of larvae after challenge with Escherichia coli and Staphylococcus aureus, but had no significant effect after challenge with Candida albicans. Furthermore, TmCactin RNAi significantly reduced the expression of seven antimicrobial peptide genes (AMPs) after bacterial challenge. Our results suggest that TmCactin may serve as an important regulator of innate immunity, mediating AMP responses against both Gram-positive and Gram-negative bacteria in T. molitor.
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116
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Maki K, Shibata T, Kawabata SI. Transglutaminase-catalyzed incorporation of polyamines masks the DNA-binding region of the transcription factor Relish. J Biol Chem 2017; 292:6369-6380. [PMID: 28258224 DOI: 10.1074/jbc.m117.779579] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 02/27/2017] [Indexed: 02/01/2023] Open
Abstract
In Drosophila, the final immune deficiency (IMD) pathway-dependent signal is transmitted through proteolytic conversion of the nuclear factor-κB (NF-κB)-like transcription factor Relish to the active N-terminal fragment Relish-N. Relish-N is then translocated from the cytosol into the nucleus for the expression of IMD-controlled genes. We previously demonstrated that transglutaminase (TG) suppresses the IMD pathway by polymerizing Relish-N to inhibit its nuclear translocation. Conversely, we also demonstrated that orally ingested synthetic amines, such as monodansylcadaverine (DCA) and biotin-labeled pentylamine, are TG-dependently incorporated into Relish-N, causing the nuclear translocation of modified Relish-N in gut epithelial cells. It remains unclear, however, whether polyamine-containing Relish-N retains transcriptional activity. Here, we used mass spectrometry analysis of a recombinant Relish-N modified with DCA by TG activity after proteolytic digestion and show that the DCA-modified Gln residues are located in the DNA-binding region of Relish-N. TG-catalyzed DCA incorporation inhibited binding of Relish-N to the Rel-responsive element in the NF-κB-binding DNA sequence. Subcellular fractionation of TG-expressing Drosophila S2 cells indicated that TG was localized in both the cytosol and nucleus. Of note, natural polyamines, including spermidine and spermine, competitively inhibited TG-dependent DCA incorporation into Relish-N. Moreover, in vivo experiments demonstrated that Relish-N was modified by spermine and that this modification reduced transcription of IMD pathway-controlled cecropin A1 and diptericin genes. These findings suggest that intracellular TG regulates Relish-N-mediated transcriptional activity by incorporating polyamines into Relish-N and via protein-protein cross-linking.
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Affiliation(s)
- Kouki Maki
- From the Graduate School of Systems Life Sciences
| | - Toshio Shibata
- Institute for Advanced Study, and.,Department of Biology, Faculty of Science, Kyushu University, Fukuoka 819-0395, Japan
| | - Shun-Ichiro Kawabata
- From the Graduate School of Systems Life Sciences, .,Department of Biology, Faculty of Science, Kyushu University, Fukuoka 819-0395, Japan
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117
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Shi Z, Liang H, Hou Y. Functional analysis of a NF-κB transcription factor in the immune defense of Oriental fruit fly, Bactrocera dorsalis Hendel (Diptera: Tephritidae). BULLETIN OF ENTOMOLOGICAL RESEARCH 2017; 107:251-260. [PMID: 27871341 DOI: 10.1017/s0007485316000845] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Although some novel antimicrobial peptides (AMP) have been successfully isolated from Bactrocera dorsalis Hendel, the mechanisms underlying the induction of these peptides are still elusive. The homolog of NF-κB transcription factor Relish, designated as BdRelish, was cloned from B. dorsalis. The full length cDNA of BdRelish is 3954 bp with an open reading frame that encodes 1013 amino acids. Similar to Drosophila Relish and the mammalian p100, it is a compound protein containing a conserved Rel homology domain, an IPT (Ig-like, plexins, transcription factors) domain and an IκB-like domain (four ankyrin repeats), the nuclear localization signal RKRRR is also detected at the residues 449-453, suggesting that it has homology to Relish and it is a member of the Rel family of transcription activator proteins. Reverse transcription quantitative polymerase chain reaction analysis reveals that BdRelish mRNAs are detected in different quantities from various tissues and the highest transcription level of BdRelish is determined in fat body. The injection challenge of Escherichia coli and Staphylococcus aureas significantly upregulated the expression of BdRelish. The injection of BdRelish dsRNA markedly reduced the expression of BdRelish and decreased the transcription magnitude of antimicrobial peptides. Individuals injected BdRelish dsRNA died at a significantly faster rate compared with the control groups. Therefore, BdRelish is vital for the transcription of AMPs to attack the invading bacteria.
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Affiliation(s)
- Z Shi
- State Key Laboratory of Ecological Pest Control of Fujian-Taiwan Crops,Fujian Agriculture and Forestry University,Fuzhou, 350002,China
| | - H Liang
- State Key Laboratory of Ecological Pest Control of Fujian-Taiwan Crops,Fujian Agriculture and Forestry University,Fuzhou, 350002,China
| | - Y Hou
- State Key Laboratory of Ecological Pest Control of Fujian-Taiwan Crops,Fujian Agriculture and Forestry University,Fuzhou, 350002,China
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118
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Molecular Cloning, Bioinformatic Analysis, and Expression of Bombyx mori Lebocin 5 Gene Related to Beauveria bassiana Infection. BIOMED RESEARCH INTERNATIONAL 2017; 2017:9390803. [PMID: 28194425 PMCID: PMC5282435 DOI: 10.1155/2017/9390803] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Revised: 11/21/2016] [Accepted: 12/19/2016] [Indexed: 11/22/2022]
Abstract
A full-length cDNA of lebocin 5 (BmLeb5) was first cloned from silkworm, Bombyx mori, by rapid amplification of cDNA ends. The BmLeb5 gene is 808 bp in length and the open reading frame encodes a 179-amino acid hydroxyproline-rich peptide. Bioinformatic analysis results showed that BmLeb5 owns an O-glycosylation site and four RXXR motifs as other lebocins. Sequence similarity and phylogenic analysis results indicated that lebocins form a multiple gene family in silkworm as cecropins. Quantitative real-time PCR analysis revealed that BmLeb5 was highest expressed in the fat body. In the silkworm larvae infected by Beauveria bassiana, the expression level of BmLeb5 was upregulated in the fat body and hemolymph which are the most important immune tissues in silkworm. The recombinant protein of BmLeb5 was for the first time successfully expressed with prokaryotic expression system and purified. There are no reports so far that the expression of lebocins could be induced by entomopathogenic fungus. Our study suggested that BmLeb5 might play an important role in the immune response of silkworm to defend B. bassiana infection. The results also provided helpful information for further studying the lebocin family functioned in antifungal immune response in the silkworm.
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119
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Wang RJ, Lin Z, Jiang H, Li J, Saha TT, Lu Z, Lu Z, Zou Z. Comparative analysis of peptidoglycan recognition proteins in endoparasitoid wasp Microplitis mediator. INSECT SCIENCE 2017; 24:2-16. [PMID: 26549814 DOI: 10.1111/1744-7917.12290] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 10/29/2015] [Indexed: 06/05/2023]
Abstract
Peptidoglycan recognition proteins (PGRPs) are a family of innate immune receptors that specifically recognize peptidoglycans (PGNs) on the surface of a number of pathogens. Here, we have identified and characterized six PGRPs from endoparasitoid wasp, Microplitis mediator (MmePGRPs). To understand the roles of PGRPs in parasitoid wasps, we analyzed their evolutionary relationship and orthology, expression profiles during different developmental stages, and transcriptional expression following infection with Gram-positive and -negative bacteria and a fungus. MmePGRP-S1 was significantly induced in response to pathogenic infection. This prompted us to evaluate the effects of RNA interference mediated gene specific knockdown of MmePGRP-S1. The knockdown of MmePGRP-S1 (iMmePGRP-S1) dramatically affected wasps' survival following challenge by Micrococcus luteus, indicating the involvement of this particular PGRP in immune responses against Gram-positive bacteria. This action is likely to be mediated by the Toll pathway, but the mechanism remains to be determined. MmePGRP-S1 does not play a significant role in anti-fungal immunity as indicated by the survival rate of iMmePGRP-S1 wasps. This study provides a comprehensive characterization of PGRPs in the economically important hymenopteran species M. mediator.
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Affiliation(s)
- Rui-Juan Wang
- Department of Entomology, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing
| | - Zhe Lin
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing
| | - Hong Jiang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing
| | - Jiancheng Li
- Key Laboratory of Integrated Pest Management on Crops in Northern Region of North China, Ministry of Agriculture, IPM Center of Hebei Province, Institute of Plant Protection, Hebei Academy of Agriculture and Forestry Sciences, Baoding, China
| | - Tusar T Saha
- Department of Entomology, University of California, Riverside, CA, USA
| | - Ziyun Lu
- Key Laboratory of Integrated Pest Management on Crops in Northern Region of North China, Ministry of Agriculture, IPM Center of Hebei Province, Institute of Plant Protection, Hebei Academy of Agriculture and Forestry Sciences, Baoding, China
| | - Zhiqiang Lu
- Department of Entomology, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi
| | - Zhen Zou
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing
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120
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Arp AP, Hunter WB, Pelz-Stelinski KS. Annotation of the Asian Citrus Psyllid Genome Reveals a Reduced Innate Immune System. Front Physiol 2016; 7:570. [PMID: 27965582 PMCID: PMC5126049 DOI: 10.3389/fphys.2016.00570] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Accepted: 11/09/2016] [Indexed: 01/06/2023] Open
Abstract
Citrus production worldwide is currently facing significant losses due to citrus greening disease, also known as Huanglongbing. The citrus greening bacteria, Candidatus Liberibacter asiaticus (CLas), is a persistent propagative pathogen transmitted by the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae). Hemipterans characterized to date lack a number of insect immune genes, including those associated with the Imd pathway targeting Gram-negative bacteria. The D. citri draft genome was used to characterize the immune defense genes present in D. citri. Predicted mRNAs identified by screening the published D. citri annotated draft genome were manually searched using a custom database of immune genes from previously annotated insect genomes. Toll and JAK/STAT pathways, general defense genes Dual oxidase, Nitric oxide synthase, prophenoloxidase, and cellular immune defense genes were present in D. citri. In contrast, D. citri lacked genes for the Imd pathway, most antimicrobial peptides, 1,3-β-glucan recognition proteins (GNBPs), and complete peptidoglycan recognition proteins. These data suggest that D. citri has a reduced immune capability similar to that observed in A. pisum, P. humanus, and R. prolixus. The absence of immune system genes from the D. citri genome may facilitate CLas infections, and is possibly compensated for by their relationship with their microbial endosymbionts.
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Affiliation(s)
- Alex P Arp
- Citrus Research and Education Center, Department of Entomology and Nematology, University of Florida Fort Pierce, FL, USA
| | - Wayne B Hunter
- U.S. Horticultural Research Lab, Agricultural Research Service, United State Department of Agriculture Fort Pierce, FL, USA
| | - Kirsten S Pelz-Stelinski
- Citrus Research and Education Center, Department of Entomology and Nematology, University of Florida Fort Pierce, FL, USA
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121
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Xiong XP, Kurthkoti K, Chang KY, Li JL, Ren X, Ni JQ, Rana TM, Zhou R. miR-34 Modulates Innate Immunity and Ecdysone Signaling in Drosophila. PLoS Pathog 2016; 12:e1006034. [PMID: 27893816 PMCID: PMC5125713 DOI: 10.1371/journal.ppat.1006034] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Accepted: 10/31/2016] [Indexed: 12/31/2022] Open
Abstract
microRNAs are endogenous small regulatory RNAs that modulate myriad biological processes by repressing target gene expression in a sequence-specific manner. Here we show that the conserved miRNA miR-34 regulates innate immunity and ecdysone signaling in Drosophila. miR-34 over-expression activates antibacterial innate immunity signaling both in cultured cells and in vivo, and flies over-expressing miR-34 display improved survival and pathogen clearance upon Gram-negative bacterial infection; whereas miR-34 knockout animals are defective in antibacterial defense. In particular, miR-34 achieves its immune-stimulatory function, at least in part, by repressing the two novel target genes Dlg1 and Eip75B. In addition, our study reveals a mutual repression between miR-34 expression and ecdysone signaling, and identifies miR-34 as a node in the intricate interplay between ecdysone signaling and innate immunity. Lastly, we identify cis-regulatory genomic elements and trans-acting transcription factors required for optimal ecdysone-mediated repression of miR-34. Taken together, our study enriches the repertoire of immune-modulating miRNAs in animals, and provides new insights into the interplay between steroid hormone signaling and innate immunity.
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Affiliation(s)
- Xiao-Peng Xiong
- Tumor Initiation and Maintenance Program; Sanford Burnham Prebys Medical Discovery Institute, California, United States of America
- Development, Aging and Regeneration Program, Sanford Burnham Prebys Medical Discovery Institute, California, United States of America
| | - Krishna Kurthkoti
- Tumor Initiation and Maintenance Program; Sanford Burnham Prebys Medical Discovery Institute, California, United States of America
- Development, Aging and Regeneration Program, Sanford Burnham Prebys Medical Discovery Institute, California, United States of America
| | - Kung-Yen Chang
- Tumor Initiation and Maintenance Program; Sanford Burnham Prebys Medical Discovery Institute, California, United States of America
- Department of Pediatrics, University of California San Diego School of Medicine, California, United States of America
| | - Jian-Liang Li
- Sanford Burnham Prebys Medical Discovery Institute, Orlando, Florida, United States of America
| | - Xingjie Ren
- Gene Regulatory Laboratory, School of Medicine, Tsinghua University, Beijing, China
| | - Jian-Quan Ni
- Gene Regulatory Laboratory, School of Medicine, Tsinghua University, Beijing, China
| | - Tariq M. Rana
- Tumor Initiation and Maintenance Program; Sanford Burnham Prebys Medical Discovery Institute, California, United States of America
- Department of Pediatrics, University of California San Diego School of Medicine, California, United States of America
| | - Rui Zhou
- Tumor Initiation and Maintenance Program; Sanford Burnham Prebys Medical Discovery Institute, California, United States of America
- Development, Aging and Regeneration Program, Sanford Burnham Prebys Medical Discovery Institute, California, United States of America
- * E-mail:
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122
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Lorenz A, Pawar V, Häussler S, Weiss S. Insights into host-pathogen interactions from state-of-the-art animal models of respiratory Pseudomonas aeruginosa infections. FEBS Lett 2016; 590:3941-3959. [PMID: 27730639 DOI: 10.1002/1873-3468.12454] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2016] [Revised: 10/04/2016] [Accepted: 10/07/2016] [Indexed: 12/29/2022]
Abstract
Pseudomonas aeruginosa is an important opportunistic pathogen that can cause acute respiratory infections in immunocompetent patients or chronic infections in immunocompromised individuals and in patients with cystic fibrosis. When acquiring the chronic infection state, bacteria are encapsulated within biofilm structures enabling them to withstand diverse environmental assaults, including immune reactions and antimicrobial therapy. Understanding the molecular interactions within the bacteria, as well as with the host or other bacteria, is essential for developing innovative treatment strategies. Such knowledge might be accumulated in vitro. However, it is ultimately necessary to confirm these findings in vivo. In the present Review, we describe state-of-the-art in vivo models that allow studying P. aeruginosa infections in molecular detail. The portrayed mammalian models exclusively focus on respiratory infections. The data obtained by alternative animal models which lack lung tissue, often provide molecular insights that are easily transferable to mammals. Importantly, these surrogate in vivo systems reveal complex molecular interactions of P. aeruginosa with the host. Herein, we also provide a critical assessment of the advantages and disadvantages of such models.
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Affiliation(s)
- Anne Lorenz
- Institute for Molecular Bacteriology, Center of Clinical and Experimental Infection Research, TWINCORE GmbH, A Joint Venture of the Hannover Medical School and the Helmholtz Center for Infection Research, Germany
| | - Vinay Pawar
- Department of Molecular Bacteriology, Helmholtz Center for Infection Research, Braunschweig, Germany.,Department of Molecular Immunology, Helmholtz Center for Infection Research, Braunschweig, Germany.,Institute of Immunology, Medical School Hannover, Germany
| | - Susanne Häussler
- Institute for Molecular Bacteriology, Center of Clinical and Experimental Infection Research, TWINCORE GmbH, A Joint Venture of the Hannover Medical School and the Helmholtz Center for Infection Research, Germany.,Department of Molecular Bacteriology, Helmholtz Center for Infection Research, Braunschweig, Germany
| | - Siegfried Weiss
- Department of Molecular Immunology, Helmholtz Center for Infection Research, Braunschweig, Germany.,Institute of Immunology, Medical School Hannover, Germany
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123
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A deep insight into the whole transcriptome of midguts, ovaries and salivary glands of the Amblyomma sculptum tick. Parasitol Int 2016; 66:64-73. [PMID: 27789388 DOI: 10.1016/j.parint.2016.10.011] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Revised: 10/17/2016] [Accepted: 10/18/2016] [Indexed: 01/31/2023]
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124
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Eleftherianos I, Castillo JC, Patrnogic J. TGF-β signaling regulates resistance to parasitic nematode infection in Drosophila melanogaster. Immunobiology 2016; 221:1362-1368. [PMID: 27473342 DOI: 10.1016/j.imbio.2016.07.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2016] [Revised: 07/19/2016] [Accepted: 07/22/2016] [Indexed: 12/13/2022]
Abstract
Over the past decade important advances have been made in the field of innate immunity; however, our appreciation of the signaling pathways and molecules that participate in host immune responses to parasitic nematode infections lags behind that of responses to microbial challenges. Here we have examined the regulation and immune activity of Transforming Growth Factor-beta (TGF-β) signaling in the model host Drosophila melanogaster upon infection with the nematode parasites Heterorhabditis gerrardi and H. bacteriophora containing their mutualistic bacteria Photorhabdus. We have found that the genes encoding the Activin and Bone Morphogenic Protein (BMP) ligands Dawdle (Daw) and Decapentaplegic (Dpp) are transcriptionally induced in flies responding to infection with the nematode parasites, containing or lacking their associated bacteria. We also show that deficient Daw or Dpp regulates the survival of D. melanogaster adults to the pathogens, whereas inactivation of Daw reduces the persistence of the nematodes in the mutant flies. These findings demonstrate a novel role for the TGF-β signaling pathways in the host anti-nematode immune response. Understanding the molecular mechanisms of host anti-nematode processes will potentially lead to the development of novel means for the efficient control of parasitic nematodes.
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Affiliation(s)
- Ioannis Eleftherianos
- Department of Biological Sciences, The George Washington University, Washington, DC, USA.
| | - Julio Cesar Castillo
- Department of Biological Sciences, The George Washington University, Washington, DC, USA; Laboratory of Malaria and Vector Research, National Institutes of Health, MD, USA
| | - Jelena Patrnogic
- Department of Biological Sciences, The George Washington University, Washington, DC, USA
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125
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Rosa RD, Capelli-Peixoto J, Mesquita RD, Kalil SP, Pohl PC, Braz GR, Fogaça AC, Daffre S. Exploring the immune signalling pathway-related genes of the cattle tick Rhipicephalus microplus: From molecular characterization to transcriptional profile upon microbial challenge. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2016; 59:1-14. [PMID: 26724380 DOI: 10.1016/j.dci.2015.12.018] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Revised: 12/21/2015] [Accepted: 12/22/2015] [Indexed: 05/24/2023]
Abstract
In dipteran insects, invading pathogens are selectively recognized by four major pathways, namely Toll, IMD, JNK, and JAK/STAT, and trigger the activation of several immune effectors. Although substantial advances have been made in understanding the immunity of model insects such as Drosophila melanogaster, knowledge on the activation of immune responses in other arthropods such as ticks remains limited. Herein, we have deepened our understanding of the intracellular signalling pathways likely to be involved in tick immunity by combining a large-scale in silico approach with high-throughput gene expression analysis. Data from in silico analysis revealed that although both the Toll and JAK/STAT signalling pathways are evolutionarily conserved across arthropods, ticks lack central components of the D. melanogaster IMD pathway. Moreover, we show that tick immune signalling-associated genes are constitutively transcribed in BME26 cells (a cell lineage derived from embryos of the cattle tick Rhipicephalus microplus) and exhibit different transcriptional patterns in response to microbial challenge. Interestingly, Anaplasma marginale, a pathogen that is naturally transmitted by R. microplus, causes downregulation of immune-related genes, suggesting that this pathogen may manipulate the tick immune system, favouring its survival and vector colonization.
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Affiliation(s)
- Rafael D Rosa
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, 05508-900 São Paulo, SP, Brazil
| | - Janaína Capelli-Peixoto
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, 05508-900 São Paulo, SP, Brazil
| | - Rafael D Mesquita
- Department of Biochemistry, Institute of Chemistry, Federal University of Rio de Janeiro, 21941-909 Rio de Janeiro, RJ, Brazil
| | - Sandra P Kalil
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, 05508-900 São Paulo, SP, Brazil
| | - Paula C Pohl
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, 05508-900 São Paulo, SP, Brazil
| | - Glória R Braz
- Department of Biochemistry, Institute of Chemistry, Federal University of Rio de Janeiro, 21941-909 Rio de Janeiro, RJ, Brazil
| | - Andrea C Fogaça
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, 05508-900 São Paulo, SP, Brazil
| | - Sirlei Daffre
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, 05508-900 São Paulo, SP, Brazil.
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126
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Wu C, Chen C, Dai J, Zhang F, Chen Y, Li W, Pastor-Pareja JC, Xue L. Toll pathway modulates TNF-induced JNK-dependent cell death in Drosophila. Open Biol 2016. [PMID: 26202785 PMCID: PMC4632500 DOI: 10.1098/rsob.140171] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Signalling networks that control the life or death of a cell are of central interest in modern biology. While the defined roles of the c-Jun N-terminal kinase (JNK) pathway in regulating cell death have been well-established, additional factors that modulate JNK-mediated cell death have yet to be fully elucidated. To identify novel regulators of JNK-dependent cell death, we performed a dominant-modifier screen in Drosophila and found that the Toll pathway participates in JNK-mediated cell death. Loss of Toll signalling suppresses ectopically and physiologically activated JNK signalling-induced cell death. Our epistasis analysis suggests that the Toll pathway acts as a downstream modulator for JNK-dependent cell death. In addition, gain of JNK signalling results in Toll pathway activation, revealed by stimulated transcription of Drosomycin (Drs) and increased cytoplasm-to-nucleus translocation of Dorsal. Furthermore, the Spätzle (Spz) family ligands for the Toll receptor are transcriptionally upregulated by activated JNK signalling in a non-cell-autonomous manner, providing a molecular mechanism for JNK-induced Toll pathway activation. Finally, gain of Toll signalling exacerbates JNK-mediated cell death and promotes cell death independent of caspases. Thus, we have identified another important function for the evolutionarily conserved Toll pathway, in addition to its well-studied roles in embryonic dorso-ventral patterning and innate immunity.
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Affiliation(s)
- Chenxi Wu
- Institute of Intervention Vessel, Shanghai 10th People's Hospital, Shanghai Key Laboratory of Signaling and Disease Research, School of Life Science and Technology, Tongji University, 1239 Siping Road, Shanghai 200092, People's Republic of China
| | - Changyan Chen
- Institute of Intervention Vessel, Shanghai 10th People's Hospital, Shanghai Key Laboratory of Signaling and Disease Research, School of Life Science and Technology, Tongji University, 1239 Siping Road, Shanghai 200092, People's Republic of China
| | - Jianli Dai
- School of Life Sciences, Tsinghua University, Medical Science Building, D224, Beijing 100084, People's Republic of China
| | - Fan Zhang
- School of Life Science and Technology, Tongji University, 1239 Siping Road, Shanghai 200092, People's Republic of China
| | - Yujun Chen
- Institute of Intervention Vessel, Shanghai 10th People's Hospital, Shanghai Key Laboratory of Signaling and Disease Research, School of Life Science and Technology, Tongji University, 1239 Siping Road, Shanghai 200092, People's Republic of China
| | - Wenzhe Li
- Institute of Intervention Vessel, Shanghai 10th People's Hospital, Shanghai Key Laboratory of Signaling and Disease Research, School of Life Science and Technology, Tongji University, 1239 Siping Road, Shanghai 200092, People's Republic of China
| | - José Carlos Pastor-Pareja
- School of Life Sciences, Tsinghua University, Medical Science Building, D224, Beijing 100084, People's Republic of China
| | - Lei Xue
- Institute of Intervention Vessel, Shanghai 10th People's Hospital, Shanghai Key Laboratory of Signaling and Disease Research, School of Life Science and Technology, Tongji University, 1239 Siping Road, Shanghai 200092, People's Republic of China
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127
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Zuo H, Yuan J, Chen Y, Li S, Su Z, Wei E, Li C, Weng S, Xu X, He J. A MicroRNA-Mediated Positive Feedback Regulatory Loop of the NF-κB Pathway in Litopenaeus vannamei. THE JOURNAL OF IMMUNOLOGY 2016; 196:3842-53. [DOI: 10.4049/jimmunol.1502358] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Accepted: 02/23/2016] [Indexed: 01/17/2023]
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Co-expression of Dorsal and Rel2 Negatively Regulates Antimicrobial Peptide Expression in the Tobacco Hornworm Manduca sexta. Sci Rep 2016; 6:20654. [PMID: 26847920 PMCID: PMC4742911 DOI: 10.1038/srep20654] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Accepted: 12/30/2015] [Indexed: 12/14/2022] Open
Abstract
Nuclear factor κB (NF-κB) plays an essential role in regulation of innate immunity. In mammals, NF-κB factors can form homodimers and heterodimers to activate gene expression. In insects, three NF-κB factors, Dorsal, Dif and Relish, have been identified to activate antimicrobial peptide (AMP) gene expression. However, it is not clear whether Dorsal (or Dif) and Relish can form heterodimers. Here we report the identification and functional analysis of a Dorsal homologue (MsDorsal) and two Relish short isoforms (MsRel2A and MsRel2B) from the tobacco hornworm, Manduca sexta. Both MsRel2A and MsRel2B contain only a Rel homology domain (RHD) and lack the ankyrin-repeat inhibitory domain. Overexpression of the RHD domains of MsDorsal and MsRel2 in Drosophila melanogaster S2 and Spodoptera frugiperda Sf9 cells can activate AMP gene promoters from M. sexta and D. melanogaster. We for the first time confirmed the interaction between MsDorsal-RHD and MsRel2-RHD, and suggesting that Dorsal and Rel2 may form heterodimers. More importantly, co-expression of MsDorsal-RHD with MsRel2-RHD suppressed activation of several M. sexta AMP gene promoters. Our results suggest that the short MsRel2 isoforms may form heterodimers with MsDorsal as a novel mechanism to prevent over-activation of antimicrobial peptides.
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129
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Sun JJ, Lan JF, Shi XZ, Yang MC, Niu GJ, Ding D, Zhao XF, Yu XQ, Wang JX. β-Arrestins Negatively Regulate the Toll Pathway in Shrimp by Preventing Dorsal Translocation and Inhibiting Dorsal Transcriptional Activity. J Biol Chem 2016; 291:7488-504. [PMID: 26846853 DOI: 10.1074/jbc.m115.698134] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Indexed: 12/30/2022] Open
Abstract
The Toll signaling pathway plays an important role in the innate immunity ofDrosophila melanogasterand mammals. The activation and termination of Toll signaling are finely regulated in these animals. Although the primary components of the Toll pathway were identified in shrimp, the functions and regulation of the pathway are seldom studied. We first demonstrated that the Toll signaling pathway plays a central role in host defense againstStaphylococcus aureusby regulating expression of antimicrobial peptides in shrimp. We then found that β-arrestins negatively regulate Toll signaling in two different ways. β-Arrestins interact with the C-terminal PEST domain of Cactus through the arrestin-N domain, and Cactus interacts with the RHD domain of Dorsal via the ankyrin repeats domain, forming a heterotrimeric complex of β-arrestin·Cactus·Dorsal, with Cactus as the bridge. This complex prevents Cactus phosphorylation and degradation, as well as Dorsal translocation into the nucleus, thus inhibiting activation of the Toll signaling pathway. β-Arrestins also interact with non-phosphorylated ERK (extracellular signal-regulated protein kinase) through the arrestin-C domain to inhibit ERK phosphorylation, which affects Dorsal translocation into the nucleus and phosphorylation of Dorsal at Ser(276)that impairs Dorsal transcriptional activity. Our study suggests that β-arrestins negatively regulate the Toll signaling pathway by preventing Dorsal translocation and inhibiting Dorsal phosphorylation and transcriptional activity.
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Affiliation(s)
- Jie-Jie Sun
- From the Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan, Shandong 250100, China and
| | - Jiang-Feng Lan
- From the Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan, Shandong 250100, China and
| | - Xiu-Zhen Shi
- From the Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan, Shandong 250100, China and
| | - Ming-Chong Yang
- From the Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan, Shandong 250100, China and
| | - Guo-Juan Niu
- From the Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan, Shandong 250100, China and
| | - Ding Ding
- From the Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan, Shandong 250100, China and
| | - Xiao-Fan Zhao
- From the Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan, Shandong 250100, China and
| | - Xiao-Qiang Yu
- the Division of Molecular Biology and Biochemistry, School of Biological Sciences, University of Missouri, Kansas City, Missouri 64110
| | - Jin-Xing Wang
- From the Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan, Shandong 250100, China and
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130
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Insect Immunity to Entomopathogenic Nematodes and Their Mutualistic Bacteria. Curr Top Microbiol Immunol 2016; 402:123-156. [PMID: 27995342 DOI: 10.1007/82_2016_52] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Entomopathogenic nematodes are important organisms for the biological control of insect pests and excellent models for dissecting the molecular basis of the insect immune response against both the nematode parasites and their mutualistic bacteria. Previous research involving the use of various insects has found distinct differences in the number and nature of immune mechanisms that are activated in response to entomopathogenic nematode parasites containing or lacking their associated bacteria. Recent studies using model insects have started to reveal the identity of certain molecules with potential anti-nematode or antibacterial activity as well as the molecular components that nematodes and their bacteria employ to evade or defeat the insect immune system. Identification and characterization of the genes that regulate the insect immune response to nematode-bacteria complexes will contribute significantly to the development of improved practices to control insects of agricultural and medical importance, and potentially nematode parasites that infect mammals, perhaps even humans.
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131
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Zug R, Hammerstein P. Wolbachia and the insect immune system: what reactive oxygen species can tell us about the mechanisms of Wolbachia-host interactions. Front Microbiol 2015; 6:1201. [PMID: 26579107 PMCID: PMC4621438 DOI: 10.3389/fmicb.2015.01201] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 10/15/2015] [Indexed: 01/06/2023] Open
Abstract
Wolbachia are intracellular bacteria that infect a vast range of arthropod species, making them one of the most prevalent endosymbionts in the world. Wolbachia's stunning evolutionary success is mostly due to their reproductive parasitism but also to mutualistic effects such as increased host fecundity or protection against pathogens. However, the mechanisms underlying Wolbachia phenotypes, both parasitic and mutualistic, are only poorly understood. Moreover, it is unclear how the insect immune system is involved in these phenotypes and why it is not more successful in eliminating the bacteria. Here we argue that reactive oxygen species (ROS) are likely to be key in elucidating these issues. ROS are essential players in the insect immune system, and Wolbachia infection can affect ROS levels in the host. Based on recent findings, we elaborate a hypothesis that considers the different effects of Wolbachia on the oxidative environment in novel vs. native hosts. We propose that newly introduced Wolbachia trigger an immune response and cause oxidative stress, whereas in coevolved symbioses, infection is not associated with oxidative stress, but rather with restored redox homeostasis. Redox homeostasis can be restored in different ways, depending on whether Wolbachia or the host is in charge. This hypothesis offers a mechanistic explanation for several of the observed Wolbachia phenotypes.
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Affiliation(s)
- Roman Zug
- Institute for Theoretical Biology, Humboldt-Universität zu Berlin, Berlin, Germany
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132
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Wang Z, Wu D, Liu Y, Xia X, Gong W, Qiu Y, Yang J, Zheng Y, Li J, Wang YF, Xiang Y, Hu Y, Zhou X. Drosophila Dicer-2 has an RNA interference-independent function that modulates Toll immune signaling. SCIENCE ADVANCES 2015; 1:e1500228. [PMID: 26601278 PMCID: PMC4646792 DOI: 10.1126/sciadv.1500228] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Accepted: 09/13/2015] [Indexed: 06/05/2023]
Abstract
Dicer-2 is the central player for small interfering RNA biogenesis in the Drosophila RNA interference (RNAi) pathway. Intriguingly, we found that Dicer-2 has an unconventional RNAi-independent function that positively modulates Toll immune signaling, which defends against Gram-positive bacteria, fungi, and some viruses, in both cells and adult flies. The loss of Dicer-2 expression makes fruit flies more susceptible to fungal infection. We further revealed that Dicer-2 posttranscriptionally modulates Toll signaling because Dicer-2 is required for the proper expression of Toll protein but not for Toll protein stability or Toll mRNA transcription. Moreover, Dicer-2 directly binds to the 3' untranslated region (3'UTR) of Toll mRNA via its PAZ (Piwi/Argonaute/Zwille) domain and is required for protein translation mediated by Toll 3'UTR. The loss of Toll 3'UTR binding activity makes Dicer-2 incapable of promoting Toll signaling. These data indicate that the interaction between Dicer-2 and Toll mRNA plays a pivotal role in Toll immune signaling. In addition, we found that Dicer-2 is also required for the Toll signaling induced by two different RNA viruses in Drosophila cells. Consequently, our findings uncover a novel RNAi-independent function of Dicer-2 in the posttranscriptional regulation of Toll protein expression and signaling, indicate an unexpected intersection of the RNAi pathway and the Toll pathway, and provide new insights into Toll immune signaling, Drosophila Dicer-2, and probably Dicer and Dicer-related proteins in other organisms.
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Affiliation(s)
- Zhaowei Wang
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, Hubei 430072, China
| | - Di Wu
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, Hubei 430072, China
| | - Yongxiang Liu
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, Hubei 430072, China
| | - Xiaoling Xia
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, Hubei 430072, China
| | - Wanyun Gong
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, Hubei 430072, China
| | - Yang Qiu
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, Hubei 430072, China
| | - Jie Yang
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, Hubei 430072, China
| | - Ya Zheng
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, College of Life Science, Central China Normal University, Wuhan, Hubei 430079, China
| | - Jingjing Li
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, College of Life Science, Central China Normal University, Wuhan, Hubei 430079, China
| | - Yu-Feng Wang
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, College of Life Science, Central China Normal University, Wuhan, Hubei 430079, China
| | - Ye Xiang
- School of Medicine, Tsinghua University, Beijing 100084, China
| | - Yuanyang Hu
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, Hubei 430072, China
| | - Xi Zhou
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, Hubei 430072, China
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133
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Redefining metamorphosis in spiny lobsters: molecular analysis of the phyllosoma to puerulus transition in Sagmariasus verreauxi. Sci Rep 2015; 5:13537. [PMID: 26311524 PMCID: PMC4550925 DOI: 10.1038/srep13537] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Accepted: 07/29/2015] [Indexed: 12/20/2022] Open
Abstract
The molecular understanding of crustacean metamorphosis is hindered by small sized individuals and inability to accurately define molt stages. We used the spiny lobster Sagmariasus verreauxi where the large, transparent larvae enable accurate tracing of the transition from a leaf-shaped phyllosoma to an intermediate larval-juvenile phase (puerulus). Transcriptomic analysis of larvae at well-defined stages prior to, during, and following this transition show that the phyllosoma-puerulus metamorphic transition is accompanied by vast transcriptomic changes exceeding 25% of the transcriptome. Notably, genes previously identified as regulating metamorphosis in other crustaceans do not fluctuate during this transition but in the later, morphologically-subtle puerulus-juvenile transition, indicating that the dramatic phyllosoma-puerulus morphological shift relies on a different, yet to be identified metamorphic mechanism. We examined the change in expression of domains and gene families, with focus on several key genes. Our research implies that the separation in molecular triggering systems between the phyllosoma-puerulus and puerulus-juvenile transitions might have enabled the extension of the oceanic phase in spiny lobsters. Study of similar transitions, where metamorphosis is uncoupled from the transition into the benthic juvenile form, in other commercially important crustacean groups might show common features to point on the evolutionary advantage of this two staged regulation.
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134
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Identification and molecular characterization of dorsal and dorsal-like genes in the cyclopoid copepod Paracyclopina nana. Mar Genomics 2015; 24 Pt 3:319-27. [PMID: 26297599 DOI: 10.1016/j.margen.2015.08.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Revised: 07/08/2015] [Accepted: 08/07/2015] [Indexed: 01/18/2023]
Abstract
To date, knowledge of the immune system in aquatic invertebrates has been reported in only a few model organisms, even though all metazoans have an innate immune system. In particular, information on the copepod's immunity and the potential role of key genes in the innate immune systems is still unclear. In this study, we identified dorsal and dorsal-like genes in the cyclopoid copepod Paracyclopina nana. In silico analyses for identifying conserved domains and phylogenetic relationships supported their gene annotations. The transcriptional levels of both genes were slightly increased from the nauplius to copepodid stages, suggesting that these genes are putatively involved in copepodid development of P. nana. To examine the involvement of both genes in the innate immune response and under stressful conditions, the copepods were exposed to lipopolysaccharide (LPS), different culture densities, salinities, and temperatures. LPS significantly upregulated mRNA expressions of dorsal and dorsal-like genes, suggesting that both genes are transcriptionally sensitive in response to immune modulators. Exposure to unfavorable culture conditions also increased mRNA levels of dorsal and dorsal-like genes. These findings suggest that transcriptional regulation of the dorsal and dorsal-like genes would be associated with environmental changes in P. nana.
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135
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Abstract
Small ubiquitin-like modifier (SUMO) modification modulates the expression of defense genes in Drosophila, activated by the Toll/nuclear factor-κB and immune-deficient/nuclear factor-κB signaling networks. We have, however, limited understanding of the SUMO-modulated regulation of the immune response and lack information on SUMO targets in the immune system. In this study, we measured the changes to the SUMO proteome in S2 cells in response to a lipopolysaccharide challenge and identified 1619 unique proteins in SUMO-enriched lysates. A confident set of 710 proteins represents the immune-induced SUMO proteome and analysis suggests that specific protein domains, cellular pathways, and protein complexes respond to immune stress. A small subset of the confident set was validated by in-bacto SUMOylation and shown to be bona-fide SUMO targets. These include components of immune signaling pathways such as Caspar, Jra, Kay, cdc42, p38b, 14-3-3ε, as well as cellular proteins with diverse functions, many being components of protein complexes, such as prosß4, Rps10b, SmD3, Tango7, and Aats-arg. Caspar, a human FAF1 ortholog that negatively regulates immune-deficient signaling, is SUMOylated at K551 and responds to treatment with lipopolysaccharide in cultured cells. Our study is one of the first to describe SUMO proteome for the Drosophila immune response. Our data and analysis provide a global framework for the understanding of SUMO modification in the host response to pathogens.
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136
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Ma X, Li X, Dong S, Xia Q, Wang F. A Fas associated factor negatively regulates anti-bacterial immunity by promoting Relish degradation in Bombyx mori. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2015; 63:144-151. [PMID: 26101847 DOI: 10.1016/j.ibmb.2015.06.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Revised: 06/15/2015] [Accepted: 06/18/2015] [Indexed: 06/04/2023]
Abstract
Negative regulation is required to keep NF-κB-dependent immune response under tight control. In previous study, we have identified a Fas associated factor (FAF) family member in Bombyx mori, BmFAF, and proposed it may act as a negative regulator in immune response. In this study, we found knock-down of BmFAF by RNAi led to a remarkable increase in transcriptional level of several antimicrobial peptide genes, including BmCecropinA1 and BmMoricin, and higher survival rate to Gram-negative bacterial infection. We also confirmed the regulatory role of BmFAF in suppressing NF-κB-dependent transcription by employing an inducible promoter in BmE cells. Consistent with these physiological phenotypes, BmFAF suppressed the activity of the essential transcription factor, Relish, in IMD signaling pathway by promoting its proteasomal degradation through direct interaction. In addition, by constructing various truncation mutants, we further demonstrated that UBA domain in BmFAF is required for the inhibitory role, and potential ubiquitination also occurs in this domain. Taken together, our results suggest that BmFAF is a negative regulator of IMD pathway by mediating degradation of Relish.
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Affiliation(s)
- Xiaojuan Ma
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400716, China
| | - Xianyang Li
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400716, China
| | - Shifeng Dong
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400716, China
| | - Qingyou Xia
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400716, China
| | - Fei Wang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400716, China.
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137
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Sun J, Xu G, Wang Z, Li Q, Cui Y, Xie L, Zhang R. The Effect of NF-κB Signalling Pathway on Expression and Regulation of Nacrein in Pearl Oyster, Pinctada fucata. PLoS One 2015; 10:e0131711. [PMID: 26158525 PMCID: PMC4497715 DOI: 10.1371/journal.pone.0131711] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Accepted: 06/04/2015] [Indexed: 12/15/2022] Open
Abstract
Nacrein is the first identified and widely investigated molluscan matrix protein and is considered to play an important role in the shell formation of the pearl oyster, Pinctada fucata. Here, we investigate the effect of the NF-κB signalling pathway on Nacrein gene expression in P. fucata to elucidate the mechanisms involved in shell formation. Inhibition of NF-κB signalling decreased Nacrein promoter-dependent luciferase activity. However, co-transfection of the Nacrein promoter vector with Pf-IKK or Pf-Rel expression plasmids could enhance luciferase activity, thus proving NF-κB signalling could regulate the transcriptional activity of the Nacrein promoter. Gene silencing by RNA interference and subsequent observation of the inner surface of the nacreous layer of oyster shells by SEM, showed that suppression of the gene Pf-Rel lead to a partial inhibition of Nacrein expression, not only at the mRNA level but also at the protein level. The inner surface of the shells became abnormal. Electrophoretic mobility shift assays (EMSAs) revealed that Pf-Rel could directly bind to the relative sites of the Nacrein promoter. These results confirm that an important component of the NF-κB signalling pathway, Pf-Rel, can directly bind the Nacrein promoter in P. fucata, and regulate its transcription and shell formation.
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Affiliation(s)
- Juan Sun
- Institute of Marine Biotechnology, School of Life Science, Tsinghua University, Beijing, China
| | - Guangrui Xu
- Institute of Marine Biotechnology, School of Life Science, Tsinghua University, Beijing, China
| | - Zeshi Wang
- Institute of Marine Biotechnology, School of Life Science, Tsinghua University, Beijing, China
| | - Qing Li
- Institute of Marine Biotechnology, School of Life Science, Tsinghua University, Beijing, China
| | - Yu Cui
- Institute of Marine Biotechnology, School of Life Science, Tsinghua University, Beijing, China
| | - Liping Xie
- Institute of Marine Biotechnology, School of Life Science, Tsinghua University, Beijing, China
- Protein Science Laboratory of the Ministry of Education, Tsinghua University, Beijing, China
- * E-mail: (LX); (RZ)
| | - Rongqing Zhang
- Institute of Marine Biotechnology, School of Life Science, Tsinghua University, Beijing, China
- Protein Science Laboratory of the Ministry of Education, Tsinghua University, Beijing, China
- * E-mail: (LX); (RZ)
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138
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Dynamic regulation of innate immune responses in Drosophila by Senju-mediated glycosylation. Proc Natl Acad Sci U S A 2015; 112:5809-14. [PMID: 25901322 DOI: 10.1073/pnas.1424514112] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The innate immune system is the first line of defense encountered by invading pathogens. Delayed and/or inadequate innate immune responses can result in failure to combat pathogens, whereas excessive and/or inappropriate responses cause runaway inflammation. Therefore, immune responses are tightly regulated from initiation to resolution and are repressed during the steady state. It is well known that glycans presented on pathogens play important roles in pathogen recognition and the interactions between host molecules and microbes; however, the function of glycans of host organisms in innate immune responses is less well known. Here, we show that innate immune quiescence and strength of the immune response are controlled by host glycosylation involving a novel UDP-galactose transporter called Senju. In senju mutants, reduced expression of galactose-containing glycans resulted in hyperactivation of the Toll signaling pathway in the absence of immune challenges. Genetic epistasis and biochemical analyses revealed that Senju regulates the Toll signaling pathway at a step that converts Toll ligand Spatzle to its active form. Interestingly, Toll activation in immune-challenged wild type (WT) flies reduced the expression of galactose-containing glycans. Suppression of the degalactosylation by senju overexpression resulted in reduced induction of Toll-dependent expression of an antimicrobial peptide, Drosomycin, and increased susceptibility to infection with Gram-positive bacteria. These data suggest that Senju-mediated galactosylation suppresses undesirable Toll signaling activation during the steady state; however, Toll activation in response to infection leads to degalactosylation, which raises the immune response to an adequate level and contributes to the prompt elimination of pathogens.
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139
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Xiong GH, Xing LS, Lin Z, Saha TT, Wang C, Jiang H, Zou Z. High throughput profiling of the cotton bollworm Helicoverpa armigera immunotranscriptome during the fungal and bacterial infections. BMC Genomics 2015; 16:321. [PMID: 26001831 PMCID: PMC4490664 DOI: 10.1186/s12864-015-1509-1] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Accepted: 03/31/2015] [Indexed: 12/03/2022] Open
Abstract
Background Innate immunity is essential in defending against invading pathogens in invertebrates. The cotton bollworm, Helicoverpa armigera (Hübner) is one of the most destructive lepidopteran pests, which causes enormous economic losses in agricultural production worldwide. The components of the immune system are largely unknown in this insect. The application of entomopathogens is considered as an alternative to the chemical insecticides for its control. However, few studies have focused on the molecular mechanisms of host-pathogen interactions between pest insects and their pathogens. Here, we investigated the immunotranscriptome of H. armigera larvae and examined gene expression changes after pathogen infections. This study provided insights into the potential immunity-related genes and pathways in H. armigera larvae. Results Here, we adopted a high throughput RNA-seq approach to determine the immunotranscriptome of H. armigera larvae injected with buffer, fungal pathogen Beauveria bassiana, or Gram-negative bacterium Enterobacter cloacae. Based on sequence similarity to those homologs known to participate in immune responses in other insects, we identified immunity-related genes encoding pattern recognition receptors, signal modulators, immune effectors, and nearly all members of the Toll, IMD and JAK/STAT pathways. The RNA-seq data indicated that some immunity-related genes were activated in fungus- and bacterium-challenged fat body while others were suppressed in B. bassiana challenged hemocytes, including the putative IMD and JAK-STAT pathway members. Bacterial infection elevated the expression of recognition and modulator genes in the fat body and signal pathway genes in hemocytes. Although fat body and hemocytes both are important organs involved in the immune response, our transcriptome analysis revealed that more immunity-related genes were induced in the fat body than that hemocytes. Furthermore, quantitative real-time PCR analysis confirmed that, consistent with the RNA-seq data, the transcript abundances of putative PGRP-SA1, Serpin1, Toll-14, and Spz2 genes were elevated in fat body upon B. bassiana infection, while the mRNA levels of defensin, moricin1, and gloverin1 were up-regulated in hemocytes. Conclusions In this study, a global survey of the host defense against fungal and bacterial infection was performed on the non-model lepidopteran pest species. The comprehensive sequence resource and expression profiles of the immunity-related genes in H. armigera are acquired. This study provided valuable information for future functional investigations as well as development of specific and effective agents to control this pest. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-1509-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Guang-Hua Xiong
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China. .,University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Long-Sheng Xing
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China. .,University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Zhe Lin
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.
| | - Tusar T Saha
- Department of Entomology, University of California Riverside, Riverside, CA, 92521, USA.
| | - Chengshu Wang
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200032, China.
| | - Haobo Jiang
- Department of Entomology and Plant Pathology, Oklahoma State University, 127 NRC, Stillwater, OK, 74078, USA.
| | - Zhen Zou
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.
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140
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Goto A, Fukuyama H, Imler JL, Hoffmann JA. The chromatin regulator DMAP1 modulates activity of the nuclear factor B (NF-B) transcription factor Relish in the Drosophila innate immune response. J Biol Chem 2015; 289:20470-6. [PMID: 24947515 DOI: 10.1074/jbc.c114.553719] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The host defense of the model organism Drosophila is under the control of two major signaling cascades controlling transcription factors of the NF-B family, the Toll and the immune deficiency (IMD) pathways. The latter shares extensive similarities with the mammalian TNF-R pathway and was initially discovered for its role in anti-Gram-negative bacterial reactions. A previous interactome study from this laboratory reported that an unexpectedly large number of proteins are binding to the canonical components of the IMD pathway. Here, we focus on DNA methyltransferase-associated protein 1 (DMAP1), which this study identified as an interactant of Relish, a Drosophila transcription factor reminiscent of the mammalian p105 NF-B protein. We show that silencing of DMAP1 expression both in S2 cells and in flies results in a significant reduction of Escherichia coli-induced expression of antimicrobial peptides. Epistatic analysis indicates that DMAP1 acts in parallel or downstream of Relish. Co-immunoprecipitation experiments further reveal that, in addition to Relish, DMAP1 also interacts with Akirin and the Brahma-associated protein 55 kDa (BAP55). Taken together, these results reveal that DMAP1 is a novel nuclear modulator of the IMD pathway, possibly acting at the level of chromatin remodeling.
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141
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A genetic screen and transcript profiling reveal a shared regulatory program for Drosophila linker histone H1 and chromatin remodeler CHD1. G3-GENES GENOMES GENETICS 2015; 5:677-87. [PMID: 25628309 PMCID: PMC4390582 DOI: 10.1534/g3.115.016709] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Chromatin structure and activity can be modified through ATP-dependent repositioning of nucleosomes and posttranslational modifications of core histone tails within nucleosome core particles and by deposition of linker histones into the oligonucleosome fiber. The linker histone H1 is essential in metazoans. It has a profound effect on organization of chromatin into higher-order structures and on recruitment of histone-modifying enzymes to chromatin. Here, we describe a genetic screen for modifiers of the lethal phenotype caused by depletion of H1 in Drosophila melanogaster. We identify 41 mis-expression alleles that enhance and 20 that suppress the effect of His1 depletion in vivo. Most of them are important for chromosome organization, transcriptional regulation, and cell signaling. Specifically, the reduced viability of H1-depleted animals is strongly suppressed by ubiquitous mis-expression of the ATP-dependent chromatin remodeling enzyme CHD1. Comparison of transcript profiles in H1-depleted and Chd1 null mutant larvae revealed that H1 and CHD1 have common transcriptional regulatory programs in vivo. H1 and CHD1 share roles in repression of numerous developmentally regulated and extracellular stimulus-responsive transcripts, including immunity-related and stress response-related genes. Thus, linker histone H1 participates in various regulatory programs in chromatin to alter gene expression.
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142
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Abstract
Anti-parasite responses of the snail Biomphalaria glabrata involve antigen-reactive plasma lectins termed fibrinogen-related proteins (FREPs) comprising a C-terminal fibrinogen (FBG) domain and one or two upstream immunoglobulin domains. FREPs are highly polymorphic; they derive from several gene families with multiple loci and alleles that are diversified by exon loss, alternative splicing, and random somatic mutation (gene conversion and point mutations). Individual B. glabrata snails have dynamically distinct FREP sequence repertoires. The immune relevance of B. glabrata FREPs is indicated by FREP binding to polymorphic antigens of (snail-specific) digenean parasites and altered resistance of B. glabrata to digeneans following RNAi knockdown of FREPs. The compatibility polymorphism hypothesis proposes that FREP mutation increases the range of germline-encoded immune recognition in B. glabrata to counter antigenically-varied parasites. Somatic mutation may result from sequence exchange among tandemly arranged FREP genes in the genome, and analysis of sequence variants also suggests involvement of cytidine deaminase-like activity or epigenetic regulation. Without current indications of selection or retention of effective sequence variants toward immunological memory, FREP diversification is thought to afford B. glabrata immunity that is anticipatory but not adaptive. More remains to be learned about this system; other mollusks elaborate diversified lectins consisting of single FBG domains, and bona fide FREPs were reported from additional gastropod species, but these may not be diversified. Future comparative immunological studies and gene discovery driven by next-generation sequencing will further clarify taxonomic distribution of FREP diversification and the underlying mutator mechanisms as a component of immune function in mollusks.
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Affiliation(s)
- Coen M Adema
- Biology Department, Center for Evolutionary and Theoretical Immunology, University of New Mexico, Albuquerque, NM, 87131, USA.
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143
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Stratoulias V, Heino TI. MANF silencing, immunity induction or autophagy trigger an unusual cell type in metamorphosing Drosophila brain. Cell Mol Life Sci 2014; 72:1989-2004. [PMID: 25511196 PMCID: PMC4412683 DOI: 10.1007/s00018-014-1789-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2014] [Revised: 11/17/2014] [Accepted: 11/20/2014] [Indexed: 12/31/2022]
Abstract
Glia are abundant cells in the brain of animals ranging from flies to humans. They perform conserved functions not only in neural development and wiring, but also in brain homeostasis. Here we show that by manipulating gene expression in glia, a previously unidentified cell type appears in the Drosophila brain during metamorphosis. More specifically, this cell type appears in three contexts: (1) after the induction of either immunity, or (2) autophagy, or (3) by silencing of neurotrophic factor DmMANF in glial cells. We call these cells MANF immunoreactive Cells (MiCs). MiCs are migratory based on their shape, appearance in brain areas where no cell bodies exist and the nuclear localization of dSTAT. They are labeled with a unique set of molecular markers including the conserved neurotrophic factor DmMANF and the transcription factor Zfh1. They possess the nuclearly localized protein Relish, which is the hallmark of immune response activation. They also express the conserved engulfment receptor Draper, therefore indicating that they are potentially phagocytic. Surprisingly, they do not express any of the common glial and neuronal markers. In addition, ultrastructural studies show that MiCs are extremely rich in lysosomes. Our findings reveal critical molecular and functional components of an unusual cell type in the Drosophila brain. We suggest that MiCs resemble macrophages/hemocytes and vertebrate microglia based on their appearance in the brain upon genetically challenged conditions and the expression of molecular markers. Interestingly, macrophages/hemocytes or microglia-like cells have not been reported in the fly nervous system before.
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Affiliation(s)
- Vassilis Stratoulias
- Department of Biosciences, University of Helsinki, P.O. Box 56, Viikinkaari 5, 00014, Helsinki, Finland,
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144
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Bandarra D, Biddlestone J, Mudie S, Müller HAJ, Rocha S. HIF-1α restricts NF-κB-dependent gene expression to control innate immunity signals. Dis Model Mech 2014; 8:169-81. [PMID: 25510503 PMCID: PMC4314782 DOI: 10.1242/dmm.017285] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Hypoxia and inflammation are intimately linked. It is known that nuclear factor κB (NF-κB) regulates the hypoxia-inducible factor (HIF) system, but little is known about how HIF regulates NF-κB. Here, we show that HIF-1α represses NF-κB-dependent gene expression. HIF-1α depletion results in increased NF-κB transcriptional activity both in mammalian cells and in the model organism Drosophila melanogaster. HIF-1α depletion enhances the NF-κB response, and this required not only the TAK-IKK complex, but also CDK6. Loss of HIF-1α results in an increased angiogenic response in mammalian cancer cells and increased mortality in Drosophila following infection. These results indicate that HIF-1α is required to restrain the NF-κB response, and thus prevents excessive and damaging pro-inflammatory responses.
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Affiliation(s)
- Daniel Bandarra
- Centre for Gene Regulation and Expression, College of Life Sciences, University of Dundee, Dow Street, DD1 5EH, UK
| | - John Biddlestone
- Centre for Gene Regulation and Expression, College of Life Sciences, University of Dundee, Dow Street, DD1 5EH, UK
| | - Sharon Mudie
- Centre for Gene Regulation and Expression, College of Life Sciences, University of Dundee, Dow Street, DD1 5EH, UK
| | - H-Arno J Müller
- Division of Cell and Developmental Biology, College of Life Sciences, University of Dundee, Dow Street, DD1 5EH, UK
| | - Sonia Rocha
- Centre for Gene Regulation and Expression, College of Life Sciences, University of Dundee, Dow Street, DD1 5EH, UK.
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145
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Wu RCC, Cho WL. Cloning and characterization of microbial activated Aedes aegypti MEK4 (AaMEK4): influences of noncatalytic domains on enzymatic activity. INSECT MOLECULAR BIOLOGY 2014; 23:644-655. [PMID: 25039995 DOI: 10.1111/imb.12116] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Protein kinases are known to be involved in a number of signal transduction cascades. Both the stress-activated Jun N-terminal kinase (JNK) and mitogen-activated protein kinase (MAPK) p38 pathways have been shown to correlate with the insect immune response to microbial infection. MAP kinase kinase 4 (MEK4) is an upstream kinase of JNK and p38 kinase. The cDNA of AaMEK4 was cloned and characterized. AaMEK4 was activated by microbial lysates of Gram-positive, Gram-negative bacteria and yeast. The conserved lysine (K112 ) and the putative phosphorylation sites (S238 and T242 ) were shown to be important for kinase activity by site-directed mutagenesis. A common MAPK docking site (MAPK_dsA) was found and in addition, a new nearby docking site, MAPK_dsB, was identified in the N-terminal noncatalytic domain of AaMEK4. MAPK_dsB was shown to be a unique element in the MEK4 family. In this study, both MAPK_dsA and _dsB were demonstrated to be important to AaMEK4 enzymatic activity for the downstream protein kinase, Aap38.
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Affiliation(s)
- R C-C Wu
- Institute of Clinical Medicine, School of Medicine, National Yang-Ming University, Taipei City, Taiwan
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146
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Bonnay F, Nguyen XH, Cohen-Berros E, Troxler L, Batsche E, Camonis J, Takeuchi O, Reichhart JM, Matt N. Akirin specifies NF-κB selectivity of Drosophila innate immune response via chromatin remodeling. EMBO J 2014; 33:2349-62. [PMID: 25180232 PMCID: PMC4253524 DOI: 10.15252/embj.201488456] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The network of NF-κB-dependent transcription that activates both pro- and anti-inflammatory genes in mammals is still unclear. As NF-κB factors are evolutionarily conserved, we used Drosophila to understand this network. The NF-κB transcription factor Relish activates effector gene expression following Gram-negative bacterial immune challenge. Here, we show, using a genome-wide approach, that the conserved nuclear protein Akirin is a NF-κB co-factor required for the activation of a subset of Relish-dependent genes correlating with the presence of H3K4ac epigenetic marks. A large-scale unbiased proteomic analysis revealed that Akirin orchestrates NF-κB transcriptional selectivity through the recruitment of the Osa-containing-SWI/SNF-like Brahma complex (BAP). Immune challenge in Drosophila shows that Akirin is required for the transcription of a subset of effector genes, but dispensable for the transcription of genes that are negative regulators of the innate immune response. Therefore, Akirins act as molecular selectors specifying the choice between subsets of NF-κB target genes. The discovery of this mechanism, conserved in mammals, paves the way for the establishment of more specific and less toxic anti-inflammatory drugs targeting pro-inflammatory genes.
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Affiliation(s)
- François Bonnay
- UPR9022 du CNRS, Institut de Biologie Moléculaire et Cellulaire Université de Strasbourg, Strasbourg Cedex, France
| | - Xuan-Hung Nguyen
- UPR9022 du CNRS, Institut de Biologie Moléculaire et Cellulaire Université de Strasbourg, Strasbourg Cedex, France
| | - Eva Cohen-Berros
- UPR9022 du CNRS, Institut de Biologie Moléculaire et Cellulaire Université de Strasbourg, Strasbourg Cedex, France
| | - Laurent Troxler
- UPR9022 du CNRS, Institut de Biologie Moléculaire et Cellulaire Université de Strasbourg, Strasbourg Cedex, France
| | - Eric Batsche
- Département de Biologie du Développement, Institut Pasteur, CNRS URA2578, Unité de Régulation Epigénétique, Paris, France
| | | | - Osamu Takeuchi
- Laboratory of Infection and Prevention, Institute for Virus Research Kyoto University CREST, JST, Sakyo-ku, Kyoto, Japan
| | - Jean-Marc Reichhart
- UPR9022 du CNRS, Institut de Biologie Moléculaire et Cellulaire Université de Strasbourg, Strasbourg Cedex, France
| | - Nicolas Matt
- UPR9022 du CNRS, Institut de Biologie Moléculaire et Cellulaire Université de Strasbourg, Strasbourg Cedex, France
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147
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Mastore M, Binda Rossetti S, Giovannardi S, Scarì G, Brivio MF. Inducible factors with antimicrobial activity after immune challenge in the haemolymph of Red Palm Weevil (Insecta). Innate Immun 2014; 21:392-405. [PMID: 25114180 DOI: 10.1177/1753425914542446] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Accepted: 06/11/2014] [Indexed: 01/18/2023] Open
Abstract
Insects are capable of innate immune responses elicited after microbial infection. In this process, the receptor-mediated recognition of foreign bodies and the subsequent activation of immunocompetent cells lead to the synthesis ex novo of a peptide pool with antimicrobial activity. We investigated the inducible immune response of a coleopteran, Rhynchophorus ferrugineus, challenged with both Gram-negative and Gram-positive bacteria. After immunization, we evaluated the presence of antimicrobial peptides using either biochemical analyses or microbiological techniques. The antimicrobial properties of the newly synthesized protein pool, detectable in haemolymph fractions of low molecular mass, showed strong antibacterial activity against various bacterial strains (Escherichia coli, Pseudomonas sp. OX1, Bacillus subtilis and Micrococcus luteus). In addition to the preliminary study of the mechanism of action of the pool of antimicrobial peptides, we also investigated its effects on bacterial cell walls by means of fluorescence microscopy and scanning electron microscopy. The data suggest that the main effects seem to be directed at destabilizing and damaging the bacterial wall. This study provides data that help us to understand some aspects of the inducible innate immunity in a system model that lacks anticipatory responses. However, the weevil has finely tuned its defensive strategies to counteract effectively microbial infection.
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Affiliation(s)
- Maristella Mastore
- Comparative Immunology Laboratory, Department of Theoretical and Applied Sciences, University of Insubria, Varese, Italy
| | - Simona Binda Rossetti
- Comparative Immunology Laboratory, Department of Theoretical and Applied Sciences, University of Insubria, Varese, Italy
| | - Stefano Giovannardi
- Cell Physiology Laboratory, Department of Theoretical and Applied Sciences, University of Insubria, Varese, Italy
| | - Giorgio Scarì
- Department of Biosciences, University degli Studi of Milan, Milan, Italy
| | - Maurizio F Brivio
- Comparative Immunology Laboratory, Department of Theoretical and Applied Sciences, University of Insubria, Varese, Italy
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148
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Abstract
Hypoxia, or low oxygen availability, is an important physiological and pathological stimulus for multicellular organisms. Molecularly, hypoxia activates a transcriptional programme directed at restoration of oxygen homoeostasis and cellular survival. In mammalian cells, hypoxia not only activates the HIF (hypoxia-inducible factor) family, but also additional transcription factors such as NF-κB (nuclear factor κB). Here we show that hypoxia activates the IKK-NF-κB [IκB (inhibitor of nuclear factor κB)-NF-κB] pathway and the immune response in Drosophila melanogaster. We show that NF-κB activation is required for organism survival in hypoxia. Finally, we identify a role for the tumour suppressor Cyld, as a negative regulator of NF-κB in response to hypoxia in Drosophila. The results indicate that hypoxia activation of the IKK-NF-κB pathway and the immune response is an important and evolutionary conserved response.
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149
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Liu J, Kolliopoulou A, Smagghe G, Swevers L. Modulation of the transcriptional response of innate immune and RNAi genes upon exposure to dsRNA and LPS in silkmoth-derived Bm5 cells overexpressing BmToll9-1 receptor. JOURNAL OF INSECT PHYSIOLOGY 2014; 66:10-19. [PMID: 24831177 DOI: 10.1016/j.jinsphys.2014.05.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Revised: 05/04/2014] [Accepted: 05/06/2014] [Indexed: 06/03/2023]
Abstract
Injection or feeding of dsRNA is commonly used to induce specific gene silencing by RNAi in insects but very little research has been carried out to investigate non-specific effects on gene expression of dsRNA as pathogen-associated molecular pattern (PAMP). This study focuses on the potential role of the BmToll9-1 receptor to modulate the transcriptional response of innate immune and RNAi genes to dsRNA and lipopolysaccharide (LPS), which was used for comparison. To study this role, we took advantage of the silkmoth-derived Bm5 cell line, which does not express BmToll9-1 endogenously, and engineered a transformed cell line that permanently expresses BmToll9-1. Quantitative mRNA expression studies showed that BmToll9-1 can significantly alter the transcriptional response to dsRNA and LPS: (1) BmToll9-1 promotes the transcriptional response of Dicer2, encoding a key component of the RNAi machinery, and, to a lesser extent, that of transcription factors in the Jak-STAT and Toll pathways; and (2) BmToll9-1 represses the transcriptional induction of the IMD and Jak-STAT pathway genes, as well as the antimicrobial peptide (AMP) effector genes, by LPS. Thus, BmToll9-1 was identified as a modulator of innate immune and RNAi machinery gene expression that could be related to its preferential expression in the larval gut, the major barrier of pathogen entry. While BmToll9-1 was found to modulate RNAi-related gene expression, a reporter-based RNAi assay established no evidence for a direct interaction of BmToll9-1 with the intracellular RNAi machinery.
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Affiliation(s)
- Jisheng Liu
- Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Anna Kolliopoulou
- Insect Molecular Genetics and Biotechnology, Institute of Biosciences & Applications, National Centre for Scientific Research "Demokritos", Athens, Greece
| | - Guy Smagghe
- Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium.
| | - Luc Swevers
- Insect Molecular Genetics and Biotechnology, Institute of Biosciences & Applications, National Centre for Scientific Research "Demokritos", Athens, Greece.
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150
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Chen K, Liu C, He Y, Jiang H, Lu Z. A short-type peptidoglycan recognition protein from the silkworm: expression, characterization and involvement in the prophenoloxidase activation pathway. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2014; 45:1-9. [PMID: 24508981 PMCID: PMC9301656 DOI: 10.1016/j.dci.2014.01.017] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2013] [Revised: 01/18/2014] [Accepted: 01/18/2014] [Indexed: 05/16/2023]
Abstract
Recognition of invading microbes as non-self is the first step of immune responses. In insects, peptidoglycan recognition proteins (PGRPs) detect peptidoglycans (PGs) of bacterial cell wall, leading to the activation of defense responses. Twelve PGRPs have been identified in the silkworm, Bombyx mori, through bioinformatics analysis. However, their biochemical functions are mostly uncharacterized. In this study, we found PGRP-S5 transcript levels were up-regulated in fat body and midgut after bacterial infection. Using recombinant protein isolated from Escherichia coli, we showed that PGRP-S5 binds to PGs from certain bacterial strains and induces bacteria agglutination. Enzyme activity assay confirmed PGRP-S5 is an amidase; we also showed it is an antibacterial protein effective against both Gram-positive and -negative bacteria. Additionally, we demonstrated that specific recognition of PGs by PGRP-S5 is involved in the prophenoloxidase activation pathway. Together, these data suggest the silkworm PGRP-S5 functions as a pattern recognition receptor for the prophenoloxidase pathway initiation and as an effecter to inhibit bacterial growth as well. We finally discussed possible roles of PGRP-S5 as a receptor for antimicrobial peptide gene induction and as an immune modulator in the midgut.
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Affiliation(s)
- Kangkang Chen
- Department of Entomology, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Chen Liu
- Department of Entomology, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Yan He
- Department of Entomology and Plant Pathology, Oklahoma State University, Stillwater, OK 74078, USA
| | - Haobo Jiang
- Department of Entomology and Plant Pathology, Oklahoma State University, Stillwater, OK 74078, USA
| | - Zhiqiang Lu
- Department of Entomology, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi 712100, China; Key Laboratory of Plant Protection Resources and Pest Management, Ministry of Education, Northwest A&F University, Yangling, Shaanxi 712100, China.
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