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Li J, Mao Y, Yi J, Lin M, Xu H, Cheng Y, Wu H, Liu J. Induced expression modes of genes related to Toll, Imd, and JAK/STAT signaling pathway-mediated immune response in Spodoptera frugiperda infected with Beauveria bassiana. Front Physiol 2023; 14:1249662. [PMID: 37693000 PMCID: PMC10484109 DOI: 10.3389/fphys.2023.1249662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 08/11/2023] [Indexed: 09/12/2023] Open
Abstract
Spodoptera frugiperda is one of the most harmful pests that attack maize and other major food crops and causes huge economic loss every year in China and other countries and regions. Beauveria bassiana, a kind of entomological fungus that is highly pathogenic to pests, is harmless to the environment and human beings. However, at present, S. frugiperda has gradually developed resistance to many pesticides and microbial insecticides. In this study, transcriptome sequencing was conducted to analyze the differences in gene expression between B. bassiana-infected and -uninfected S. frugiperda. More than 160 Gb of clean data were obtained as 150-bp paired-end reads using the Illumina HiSeq™ 4000 platform, and 2,767 and 2,892 DEGs were identified in LH36vsCK36 and LH144vsCK144, respectively. In order to explore the roles of JAK/STAT, Toll, and Imd signaling pathways in antifungal immune response in S. frugiperda against B. bassiana infection, the expression patterns of those signaling pathway-related genes in B. bassiana-infected S. frugiperda were analyzed by quantitative real-time PCR. In addition, antifungal activity experiments revealed that the suppression of JAK/STAT, Toll, and Imd signaling pathways by inhibitors could inhibit the antifungal activity to a large extent and lead to increased sensitivity of S. frugiperda to B. bassiana infection, indicating that JAK/STAT, Toll, and Imd signaling pathways and their associated genes might be involved in the synthesis and secretion of antifungal substances. This study implied that JAK/STAT, Toll, and Imd signaling pathways played crucial roles in the antifungal immune response of the S. frugiperda larvae, in which the related genes of these signaling pathways could play special regulatory roles in signal transduction. This study would improve our understanding of the molecular mechanisms underlying innate immunity and provide the basis for a wide spectrum of strategies against antifungal resistance of S. frugiperda.
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Affiliation(s)
| | | | | | | | | | | | - Han Wu
- Institute of Nanfan and Seed Industry, Guangdong Academy of Sciences, Guangzhou, China
| | - Jianbai Liu
- Institute of Nanfan and Seed Industry, Guangdong Academy of Sciences, Guangzhou, China
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Shi G, Kang Z, Liu H, Ren F, Zhou Y. The effects of quercetin combined with nucleopolyhedrovirus on the growth and immune response in the silkworm (Bombyx mori). ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2021; 108:e21839. [PMID: 34427962 DOI: 10.1002/arch.21839] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 08/07/2021] [Accepted: 08/12/2021] [Indexed: 06/13/2023]
Abstract
Flavonoids are secondary metabolites that help plants resist insect attack. It can resist insect attack by inhibiting insect immune defense, and pathogens can also inhibit insect immune defense. It is speculated that the combination of flavonoids and pathogens may inhibit the immune defense and have stronger toxicity to silkworm. In this study, the combined treatment of quercetin with Bombyx mori nuclear polyhedrosis virus (BmNPV) had significant negative effects on the growth and survival of silkworm compared with BmNPV group. The detoxifying enzyme activity of BmNPV group was significantly increased at 96 h, while the activity of the combined treatment group was significantly decreased with the increase of quercetin exposure time (72 or 96 h). The activity of antioxidant enzymes also showed a similar trend, that was, the activity of antioxidant enzymes in the combined treatment group also decreased significantly with the increase of quercetin exposure time, which led to the increase of reactive oxygen species content. The silkworm cells would produce lipid peroxidation, malondialdehyde content was significantly increased, so that the expression of immune-related genes (the antimicrobial peptide, Toll pathway, IMD pathway, JAK-STAT pathway, and melanin genes) were decreased, leading to the damage of the immune system of silkworm. These results indicated that quercetin combined with BmNPV could inhibit the activities of protective enzymes and lead to oxidative damage to silkworm. It can also affect the immune response of the silkworm, and thus resulting in abnormal growth. This study provides the novel conclusion that quercetin accumulation will increase the susceptibility of silkworm to pathogens.
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Affiliation(s)
- Guiqin Shi
- Zhengzhou University of Light Industry, Zhengzhou, China
| | - Zhaoyang Kang
- Zhengzhou University of Light Industry, Zhengzhou, China
| | - Huijuan Liu
- Zhengzhou University of Light Industry, Zhengzhou, China
| | - Fei Ren
- Zhengzhou University of Light Industry, Zhengzhou, China
| | - Yuan Zhou
- Zhengzhou University of Light Industry, Zhengzhou, China
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Shi G, Kang Z, Ren F, Zhou Y, Guo P. Effects of Quercetin on the Growth and Expression of Immune-Pathway-Related Genes in Silkworm (Lepidoptera: Bombycidae). JOURNAL OF INSECT SCIENCE (ONLINE) 2020; 20:5960128. [PMID: 33159528 PMCID: PMC7648594 DOI: 10.1093/jisesa/ieaa124] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Indexed: 05/05/2023]
Abstract
Quercetin is a flavonoid produced as a defense by plants. The effects of 1% quercetin on the growth and development of Bombyx mori were studied. The activities of the enzymes superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), carboxy-lesterase (CarEs), and glutathione S-transferase (GST) were all measured at 24, 48, 72, and 96 h after quercetin exposure. The results show that quercetin induces the activities of antioxidant and detoxification enzymes. With longer exposure times, enzyme activity first increased and then decreased. The relative expressions of AMP (defensin, CecA), the Toll pathway (cactus, Spatzle, and Rel), the IMD pathway (Imd, Fadd, and Dorsal), the JAK-STAT pathway (STAT, HOP, and Pi3k60), and the Melanization gene (DDC and PAH) were analyzed using quantitative polymerase chain reaction (qPCR). The results indicated that long-term exposure to quercetin could inhibit the expression of immune-related pathway genes in silkworms. This suggests that it can inhibit the activities of antioxidant and detoxifying enzymes, thus inhibiting the immune system and affecting the growth and development, resulting in an increase in the death rate in silkworm. This study provides the novel conclusion that quercetin accumulation inhibits the immune system of silkworm and increases its death rate, a result that may promote the development and utilization of better biopesticides that avoid environmental pollution.
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Affiliation(s)
- Guiqin Shi
- The College of Food and Biological Engineering, Zhengzhou University of Light Industry, Zhengzhou, China
- Corresponding author, e-mail:
| | - Zhaoyang Kang
- The College of Food and Biological Engineering, Zhengzhou University of Light Industry, Zhengzhou, China
| | - Fei Ren
- The College of Food and Biological Engineering, Zhengzhou University of Light Industry, Zhengzhou, China
| | - Yuan Zhou
- The College of Food and Biological Engineering, Zhengzhou University of Light Industry, Zhengzhou, China
| | - Penglei Guo
- The College of Food and Biological Engineering, Zhengzhou University of Light Industry, Zhengzhou, China
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Li F, Li M, Wang H, Mao T, Chen J, Lu Z, Qu J, Fang Y, Li B. Effects of phoxim pesticide on the immune system of silkworm midgut. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2020; 164:58-64. [PMID: 32284137 DOI: 10.1016/j.pestbp.2019.12.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 12/11/2019] [Accepted: 12/26/2019] [Indexed: 06/11/2023]
Abstract
Silkworm (Bombyx mori) is an important economic insect. Bombyx mori, which is exposed to sublethal doses of pesticides, has a low or no mortality rate, while it is susceptible to infections triggered by foreign pathogens. The immune regulatory mechanism of silkworms caused by trace pesticides still remains unclear. The midgut is the major organ of silkworm for digestion and nutrient absorption, and it plays a critical defensive role against pathogens. In the present study, the silkworm was susceptible to Enterobacter cloacae sp. (E. cloacae) after exposure to sublethal dose of phoxim. The body weight and survival rate of the phoxim-E. cloacae co-treatment group were significantly decreased after 120 h of treatment compared with the phoxim treatment group. The immune responses and expressions of immune-related genes were dysregulated in the midgut of silkworm following exposure to phoxim. Digital gene expression (DGE) analysis revealed that 44 immune response-related and immune defense-related genes were differentially expressed. qRT-PCR results indicated that the transcriptional levels of antimicrobial peptide genes Bmdefensin1, BmcecA, Bmglv1, Bmglv2, Bmmoricin and BmmoricinB3 were down-regulated by 0.77-, 0.37-, 0.05-, 0.19-, 0.34- and 0.54-fold, respectively. The transcriptional levels of Toll signaling pathway genes Bmcactus, Bmspatzle and Bmrel were down-regulated by 0.4-, 0.37- and 0.96-fold, respectively. Peritrophic membrane (PM) protein-related genes BmCBP-02, BmPM-41, BmPM-43 and BmCDA7 were down-regulated by 0.18-, 0.02-, 0.66- and 0.16-fold, respectively. The expressions of Toll signaling pathway genes were down-regulated at 48 h and 72 h. Immune deficiency (IMD) and Janus kinase and signal transducer and activator of transcription (JAK/STAT) signaling pathway genes were dysregulated after phoxim exposure. These results indicated that phoxim might cause damage to the PM and reduce the immune response of the silkworm, leading to susceptibility of silkworm to disease and damage from foreign pathogens.
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Affiliation(s)
- Fanchi Li
- School of Basic Medicine and Biological Sciences, Soochow University, Suzhou, Jiangsu 215123, PR China; Sericulture Institute of Soochow University, Suzhou, Jiangsu 215123, PR China
| | - Mengxue Li
- School of Basic Medicine and Biological Sciences, Soochow University, Suzhou, Jiangsu 215123, PR China
| | - Hui Wang
- School of Basic Medicine and Biological Sciences, Soochow University, Suzhou, Jiangsu 215123, PR China
| | - Tingting Mao
- School of Basic Medicine and Biological Sciences, Soochow University, Suzhou, Jiangsu 215123, PR China
| | - Jian Chen
- School of Basic Medicine and Biological Sciences, Soochow University, Suzhou, Jiangsu 215123, PR China
| | - Zhengting Lu
- School of Basic Medicine and Biological Sciences, Soochow University, Suzhou, Jiangsu 215123, PR China
| | - Jianwei Qu
- School of Basic Medicine and Biological Sciences, Soochow University, Suzhou, Jiangsu 215123, PR China
| | - Yilong Fang
- School of Basic Medicine and Biological Sciences, Soochow University, Suzhou, Jiangsu 215123, PR China
| | - Bing Li
- School of Basic Medicine and Biological Sciences, Soochow University, Suzhou, Jiangsu 215123, PR China; Sericulture Institute of Soochow University, Suzhou, Jiangsu 215123, PR China.
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Patrnogic J, Heryanto C, Ozakman Y, Eleftherianos I. Transcript analysis reveals the involvement of NF-κB transcription factors for the activation of TGF-β signaling in nematode-infected Drosophila. Immunogenetics 2019; 71:501-510. [PMID: 31147740 DOI: 10.1007/s00251-019-01119-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2018] [Accepted: 05/11/2019] [Indexed: 11/27/2022]
Abstract
The common fruit fly Drosophila melanogaster is a powerful model for studying signaling pathway regulation. Conserved signaling pathways underlying physiological processes signify evolutionary relationship between organisms and the nature of the mechanisms they control. This study explores the cross-talk between the well-characterized nuclear factor kappa B (NF-κB) innate immune signaling pathways and transforming growth factor beta (TGF-β) signaling pathway in response to parasitic nematode infection in Drosophila. To understand the link between signaling pathways, we followed on our previous studies by performing a transcript-level analysis of different TGF-β signaling components following infection of immune-compromised Drosophila adult flies with the nematode parasites Heterorhabditis gerrardi and H. bacteriophora. Our findings demonstrate the requirement of NF-κB transcription factors for activation of TGF-β signaling pathway in Drosophila in the context of parasitic nematode infection. We observe significant decrease in transcript level of glass bottom boat (gbb) and screw (scw), components of the bone morphogenic protein (BMP) branch, as well as Activinβ (actβ) which is a component of the Activin branch of the TGF-β signaling pathway. These results are observed only in H. gerrardi nematode-infected flies compared to uninfected control. Also, this significant decrease in transcript level is found only for extracellular ligands. Future research examining the mechanisms regulating the interaction of these signaling pathways could provide further insight into Drosophila anti-nematode immune function against infection with potent parasitic nematodes.
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Affiliation(s)
- Jelena Patrnogic
- Infection and Innate Immunity Laboratory, Department of Biological Sciences, Institute for Biomedical Sciences, The George Washington University, Washington, DC, USA
| | - Christa Heryanto
- Infection and Innate Immunity Laboratory, Department of Biological Sciences, Institute for Biomedical Sciences, The George Washington University, Washington, DC, USA
| | - Yaprak Ozakman
- Infection and Innate Immunity Laboratory, Department of Biological Sciences, Institute for Biomedical Sciences, The George Washington University, Washington, DC, USA
| | - Ioannis Eleftherianos
- Infection and Innate Immunity Laboratory, Department of Biological Sciences, Institute for Biomedical Sciences, The George Washington University, Washington, DC, USA.
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6
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Patrnogic J, Heryanto C, Eleftherianos I. Transcriptional up-regulation of the TGF-β intracellular signaling transducer Mad of Drosophila larvae in response to parasitic nematode infection. Innate Immun 2018; 24:349-356. [PMID: 30049242 PMCID: PMC6830907 DOI: 10.1177/1753425918790663] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The common fruit fly Drosophila melanogaster is an exceptional
model for dissecting innate immunity. However, our knowledge on responses to
parasitic nematode infections still lags behind. Recent studies have
demonstrated that the well-conserved TGF-β signaling pathway participates in
immune processes of the fly, including the anti-nematode response. To elucidate
the molecular basis of TGF-β anti-nematode activity, we performed a transcript
level analysis of different TGF-β signaling components following infection of
D. melanogaster larvae with the nematode parasite
Heterorhabditis gerrardi. We found no significant changes
in the transcript level of most extracellular ligands in both bone morphogenic
protein (BMP) and activin branches of the TGF-β signaling pathway between
nematode-infected larvae and uninfected controls. However, extracellular ligand,
Scw, and Type I receptor, Sax, in the BMP pathway as well as the Type I
receptor, Babo, in the activin pathway were substantially up-regulated following
H. gerrardi infection. Our results suggest that receptor
up-regulation leads to transcriptional up-regulation of the intracellular
component Mad in response to H. gerrardi following changes in
gene expression of intracellular receptors of both TGF-β signaling branches.
These findings identify the involvement of certain TGF-β signaling pathway
components in the immune signal transduction of D. melanogaster
larvae against parasitic nematodes.
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Affiliation(s)
- Jelena Patrnogic
- Infection and Innate Immunity Laboratory, Department of Biological Sciences, The George Washington University, Washington DC, USA
| | - Christa Heryanto
- Infection and Innate Immunity Laboratory, Department of Biological Sciences, The George Washington University, Washington DC, USA
| | - Ioannis Eleftherianos
- Infection and Innate Immunity Laboratory, Department of Biological Sciences, The George Washington University, Washington DC, USA
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Gu Z, Li F, Hu J, Ding C, Wang C, Tian J, Xue B, Xu K, Shen W, Li B. Sublethal dose of phoxim and Bombyx mori nucleopolyhedrovirus interact to elevate silkworm mortality. PEST MANAGEMENT SCIENCE 2017; 73:554-561. [PMID: 27220913 DOI: 10.1002/ps.4326] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2016] [Revised: 04/29/2016] [Accepted: 05/22/2016] [Indexed: 06/05/2023]
Abstract
BACKGROUND Silkworm (Bombyx mori) is an economically important insect. It is relatively less resistant to certain chemicals and environment exposures such as pesticides and pathogens. After pesticide exposures, the silkworms are more susceptible to microbial infections. The mechanism underlying the susceptibility might be related to immune response and oxidative stress. RESULTS A sublethal dose of phoxim combined with Bombyx mori nucleopolyhedrovirus (BmNPV) elevated the silkworm mortality at 96 h. We found a higher content of H2 O2 and increased levels of genes related to oxidative stress and immune response after treatment with a sublethal dose of phoxim for 24 h or 48 h. However, such response decreased with longer pesticide treatment. Mortality increased by 44% when B. mori was exposed to combined treatment with BmNPV and phoxim rather than BmNPV alone. The level of examined immune-related and oxidative-stress-related genes significantly decreased in the combined treatment group compared with the BmNPV group. Our results indicated that, with long-term exposure to pesticides such as OPs, even at sublethal dose, the oxidative stress response and immune responses in silkworm were inhibited, which may lead to further immune impairment and accumulation of oxidative stress, resulting in susceptibility to the virus and harm to the silkworm. CONCLUSION Our study provided insights for understanding the susceptibility to pathogen after pesticide exposures, which may promote the development of better pesticide controls to avoid significant economic losses. © 2016 Society of Chemical Industry.
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Affiliation(s)
- ZhiYa Gu
- School of Basic Medicine and Biological Sciences, Soochow University, Suzhou, Jiangsu, China
| | - FanChi Li
- School of Basic Medicine and Biological Sciences, Soochow University, Suzhou, Jiangsu, China
| | - JingSheng Hu
- School of Basic Medicine and Biological Sciences, Soochow University, Suzhou, Jiangsu, China
| | - Chao Ding
- School of Basic Medicine and Biological Sciences, Soochow University, Suzhou, Jiangsu, China
| | - Chaoqian Wang
- School of Basic Medicine and Biological Sciences, Soochow University, Suzhou, Jiangsu, China
| | - JiangHai Tian
- School of Basic Medicine and Biological Sciences, Soochow University, Suzhou, Jiangsu, China
| | - Bin Xue
- School of Basic Medicine and Biological Sciences, Soochow University, Suzhou, Jiangsu, China
| | - KaiZun Xu
- School of Basic Medicine and Biological Sciences, Soochow University, Suzhou, Jiangsu, China
| | - WeiDe Shen
- School of Basic Medicine and Biological Sciences, Soochow University, Suzhou, Jiangsu, China
- National Engineering Laboratory for Modern Silk, Soochow University, Suzhou, Jiangsu, China
| | - Bing Li
- School of Basic Medicine and Biological Sciences, Soochow University, Suzhou, Jiangsu, China
- National Engineering Laboratory for Modern Silk, Soochow University, Suzhou, Jiangsu, China
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Gu Z, Zhou Y, Xie Y, Li F, Ma L, Sun S, Wu Y, Wang B, Wang J, Hong F, Shen W, Li B. The adverse effects of phoxim exposure in the midgut of silkworm, Bombyx mori. CHEMOSPHERE 2014; 96:33-38. [PMID: 23899924 DOI: 10.1016/j.chemosphere.2013.06.089] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Accepted: 06/29/2013] [Indexed: 06/02/2023]
Abstract
The silkworm is an important economic insect. Poisoning of silkworms by organophosphate pesticides causes tremendous loss to the sericulture. In this study, Solexa sequencing technology was performed to profile the gene expression changes in the midgut of silkworms in response to 24h of phoxim exposure and the impact on detoxification, apoptosis and immune defense were addressed. The results showed that 254 genes displayed at least 2.0-fold changes in expression levels, with 148 genes up-regulated and 106 genes down-regulated. Cytochrome P450 played an important role in detoxification. Histopathology examination and transmission electron microscope revealed swollen mitochondria and disappearance of the cristae of mitochondria, which are the important features in insect apoptotic cells. Cytochrome C release from mitochondria into the cytoplasm was confirmed. In addition, the Toll and immune deficiency (IMD) signal pathways were all inhibited using qRT-PCR. Our results could help better understand the impact of phoxim exposure on silkworm.
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Affiliation(s)
- ZhiYa Gu
- School of Basic Medicine and Biological Sciences, Soochow University, Suzhou, Jiangsu 215123, PR China
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Wang L, Kounatidis I, Ligoxygakis P. Drosophila as a model to study the role of blood cells in inflammation, innate immunity and cancer. Front Cell Infect Microbiol 2014; 3:113. [PMID: 24409421 PMCID: PMC3885817 DOI: 10.3389/fcimb.2013.00113] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Accepted: 12/21/2013] [Indexed: 01/07/2023] Open
Abstract
Drosophila has a primitive yet effective blood system with three types of haemocytes which function throughout different developmental stages and environmental stimuli. Haemocytes play essential roles in tissue modeling during embryogenesis and morphogenesis, and also in innate immunity. The open circulatory system of Drosophila makes haemocytes ideal signal mediators to cells and tissues in response to events such as infection and wounding. The application of recently developed and sophisticated genetic tools to the relatively simple genome of Drosophila has made the fly a popular system for modeling human tumorigensis and metastasis. Drosophila is now used for screening and investigation of genes implicated in human leukemia and also in modeling development of solid tumors. This second line of research offers promising opportunities to determine the seemingly conflicting roles of blood cells in tumor progression and invasion. This review provides an overview of the signaling pathways conserved in Drosophila during haematopoiesis, haemostasis, innate immunity, wound healing and inflammation. We also review the most recent progress in the use of Drosophila as a cancer research model with an emphasis on the roles haemocytes can play in various cancer models and in the links between inflammation and cancer.
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Affiliation(s)
- Lihui Wang
- Laboratory of Genes and Development, Department of Biochemistry, University of Oxford Oxford, UK
| | - Ilias Kounatidis
- Laboratory of Genes and Development, Department of Biochemistry, University of Oxford Oxford, UK
| | - Petros Ligoxygakis
- Laboratory of Genes and Development, Department of Biochemistry, University of Oxford Oxford, UK
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10
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Imler JL. Overview of Drosophila immunity: a historical perspective. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2014; 42:3-15. [PMID: 24012863 DOI: 10.1016/j.dci.2013.08.018] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Revised: 05/01/2013] [Accepted: 05/01/2013] [Indexed: 05/24/2023]
Abstract
The functional analysis of genes from the model organism Drosophila melanogaster has provided invaluable information for many cellular and developmental or physiological processes, including immunity. The best-understood aspect of Drosophila immunity is the inducible humoral response, first recognized in 1972. This pioneering work led to a remarkable series of findings over the next 30 years, ranging from the identification and characterization of the antimicrobial peptides produced, to the deciphering of the signalling pathways activating the genes that encode them and, ultimately, to the discovery of the receptors sensing infection. These studies on an insect model coincided with a revival of the field of innate immunity, and had an unanticipated impact on the biomedical field.
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Affiliation(s)
- Jean-Luc Imler
- Faculté des Sciences de la Vie, Université de Strasbourg, Strasbourg, France; UPR9022 du CNRS, Institut de Biologie Moléculaire et Cellulaire, Strasbourg, France.
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The role of innate immunity in conditioning mosquito susceptibility to West Nile virus. Viruses 2013; 5:3142-70. [PMID: 24351797 PMCID: PMC3967165 DOI: 10.3390/v5123142] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2013] [Revised: 11/13/2013] [Accepted: 12/09/2013] [Indexed: 01/02/2023] Open
Abstract
Arthropod-borne viruses (arboviruses) represent an emerging threat to human and livestock health globally. In particular, those transmitted by mosquitoes present the greatest challenges to disease control efforts. An understanding of the molecular basis for mosquito innate immunity to arbovirus infection is therefore critical to investigations regarding arbovirus evolution, virus-vector ecology, and mosquito vector competence. In this review, we discuss the current state of understanding regarding mosquito innate immunity to West Nile virus. We draw from the literature with respect to other virus-vector pairings to attempt to draw inferences to gaps in our knowledge about West Nile virus and relevant vectors.
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Imler JL. WITHDRAWN: Overview of Drosophila immunity: A historical perspective. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2013:S0145-305X(13)00128-6. [PMID: 23665509 DOI: 10.1016/j.dci.2013.05.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Revised: 05/01/2013] [Accepted: 05/01/2013] [Indexed: 06/02/2023]
Abstract
This article has been withdrawn at the request of the author. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.
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Affiliation(s)
- Jean-Luc Imler
- Faculté des Sciences de la Vie, Université de Strasbourg, Strasbourg, France; UPR9022 du CNRS, Institut de Biologie Moléculaire et Cellulaire, Strasbourg, France.
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13
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Tanji T, Shiraishi H, Natori S, Ohashi-Kobayashi A. Differential activation of the lectin and antimicrobial peptide genes in Sarcophaga peregrina (the flesh fly). ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2008; 69:189-198. [PMID: 18949806 DOI: 10.1002/arch.20280] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Sarcophaga lectin is an immune defense protein which is transcriptionally induced upon immune challenge in the flesh fly, Sarcophaga peregrina. So far, we have revealed that the Sarcophaga lectin gene has multiple NF-kappaB -binding motifs in its promoter. Here we showed that the nuclear extracts from Sarcophaga-derived culture cells, NIH-Sape-4, and larval fat bodies have binding activity to the multiple kappaB motifs in the lectin gene promoter, some of which were responsive to immune stimuli. We also compared the expression profiles of the lectin gene with those of the antibacterial peptide genes from the point of view of inducers, expression tissues and local induction in digestive tracts. In each case, the lectin gene was activated in different manners from other inducible defense genes. These results indicate the complex regulation of the lectin gene, possibly by NF-kappaB -related transcription factors.
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Affiliation(s)
- Takahiro Tanji
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
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Davis MM, Primrose DA, Hodgetts RB. A member of the p38 mitogen-activated protein kinase family is responsible for transcriptional induction of Dopa decarboxylase in the epidermis of Drosophila melanogaster during the innate immune response. Mol Cell Biol 2008; 28:4883-95. [PMID: 18519585 PMCID: PMC2493365 DOI: 10.1128/mcb.02074-07] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2007] [Revised: 01/02/2008] [Accepted: 05/22/2008] [Indexed: 11/20/2022] Open
Abstract
Drosophila innate immunity is controlled primarily by the activation of IMD (immune deficiency) or Toll signaling leading to the production of antimicrobial peptides (AMPs). IMD signaling also activates the JUN N-terminal kinase (JNK) cascade, which is responsible for immune induction of non-antimicrobial peptide immune gene transcription though the transcription factor AP-1. Transcription of the Dopa decarboxylase (Ddc) gene is induced in response to gram-negative and gram-positive septic injury, but not aseptic wounding. Transcription is induced throughout the epidermis and not specifically at the site of infection. Ddc transcripts are detectible within 2 h and remain high for several hours following infection with either gram-negative or gram-positive bacteria. Using Ddc-green fluorescent protein (GFP) reporter gene constructs, we show that a conserved consensus AP-1 binding site upstream of the Ddc transcription start site is required for induction. However, neither the Toll, IMD, nor JNK pathway is involved. Rather, Ddc transcription depends on a previously uncharacterized member of the p38 mitogen-activated protein kinase family, p38c. We propose that the involvement of DDC in a new pathway involved in Drosophila immunity increases the levels of dopamine, which is metabolized to produce reactive quinones that exert an antimicrobial effect on invading bacteria.
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Affiliation(s)
- Monica M Davis
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2E9, Canada
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15
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Abstract
To combat infection, the fruit fly Drosophila melanogaster relies on multiple innate defense reactions, many of which are shared with higher organisms. These reactions include the use of physical barriers together with local and systemic immune responses. First, epithelia, such as those beneath the cuticle, in the alimentary tract, and in tracheae, act both as a physical barrier and local defense against pathogens by producing antimicrobial peptides and reactive oxygen species. Second, specialized hemocytes participate in phagocytosis and encapsulation of foreign intruders in the hemolymph. Finally, the fat body, a functional equivalent of the mammalian liver, produces humoral response molecules including antimicrobial peptides. Here we review our current knowledge of the molecular mechanisms underlying Drosophila defense reactions together with strategies evolved by pathogens to evade them.
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Affiliation(s)
- Bruno Lemaitre
- Centre de Génétique Moléculaire, CNRS, 91198 Gif-sur-Yvette, France.
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16
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Mylonakis E, Aballay A. Worms and flies as genetically tractable animal models to study host-pathogen interactions. Infect Immun 2005; 73:3833-41. [PMID: 15972468 PMCID: PMC1168613 DOI: 10.1128/iai.73.7.3833-3841.2005] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
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17
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Affiliation(s)
- Bruno Lemaitre
- Centre de Génétique Moléculaire, Centre National de la Recherche Scientifique, F-91198 Gif-sur-Yvette, France.
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18
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Senger K, Armstrong GW, Rowell WJ, Kwan JM, Markstein M, Levine M. Immunity regulatory DNAs share common organizational features in Drosophila. Mol Cell 2004; 13:19-32. [PMID: 14731391 DOI: 10.1016/s1097-2765(03)00500-8] [Citation(s) in RCA: 118] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Infection results in the rapid activation of immunity genes in the Drosophila fat body. Two classes of transcription factors have been implicated in this process: the REL-containing proteins, Dorsal, Dif, and Relish, and the GATA factor Serpent. Here we present evidence that REL-GATA synergy plays a pervasive role in the immune response. SELEX assays identified consensus binding sites that permitted the characterization of several immunity regulatory DNAs. The distribution of REL and GATA sites within these DNAs suggests that most or all fat-specific immunity genes contain a common organization of regulatory elements: closely linked REL and GATA binding sites positioned in the same orientation and located near the transcription start site. Aspects of this "regulatory code" are essential for the immune response. These results suggest that immunity regulatory DNAs contain constrained organizational features, which may be a general property of eukaryotic enhancers.
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Affiliation(s)
- Kate Senger
- Department of Molecular and Cellular Biology, Division of Genetics and Development, University of California, Berkeley, Berkeley, CA 94720, USA
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19
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Tanji T, Kobayashi A, Natori S. Activation of the Sarcophaga lectin gene promoter in transgenic Drosophila. ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2002; 50:131-138. [PMID: 12111973 DOI: 10.1002/arch.10039] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
We established transgenic Drosophila strains in which the lacZ gene was expressed under the control of the 5'-upstream regulatory region of the Sarcophaga lectin gene promoter (3.1 kbp). The reporter gene was expressed in the fat bodies of the transgenic larvae when they were immunized by body pricking or treatment with Escherichia coli, which was the same as the Sarcophaga lectin gene expression in Sarcophaga larvae. However, the same reporter gene was found to be expressed constitutively in the digestive tracts of the transgenic larvae even without immunization.
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Affiliation(s)
- Takahiro Tanji
- Department of Cell Biochemistry, Graduate School of Pharmaceutical Sciences, University of Tokyo, Bunkyo-ku, Tokyo, Japan
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20
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Abstract
Insects have been very successful in adapting to their environment, and the ability of the insect immune system to detect and elicit the appropriate response against various invading pathogens has helped in this success. Unlike the vertebrate immune system, which consists of both innate and adaptive components, insect immunity probably consists entirely of an innate immune response, as no evidence of an adaptive response has been found. The innate immune response is described as either a reaction against "lack of self," or the interaction between host germline-encoded receptors and molecules unique to a particular class of invading organisms. Once the invading organism is recognized, the host immune response can be activated via signaling pathways that lead to the appropriate reaction. This review endeavors to put forth how through genetic, molecular, and biochemical studies of the fruit fly Drosophila melanogaster, as well as other insects, it is now understood that aspects of the insect and vertebrate innate immune system are very similar.
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Affiliation(s)
- M J Williams
- Umeå Centre for Molecular Pathogenesis, Umeå University, S-901 87 Umeå, Sweden
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21
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Rutschmann S, Kilinc A, Ferrandon D. Cutting edge: the toll pathway is required for resistance to gram-positive bacterial infections in Drosophila. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2002; 168:1542-6. [PMID: 11823479 DOI: 10.4049/jimmunol.168.4.1542] [Citation(s) in RCA: 155] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
In Drosophila, the response against various microorganisms involves different recognition and signaling pathways, as well as distinct antimicrobial effectors. On the one hand, the immune deficiency pathway regulates the expression of antimicrobial peptides that are active against Gram-negative bacteria. On the other hand, the Toll pathway is involved in the defense against filamentous fungi and controls the expression of antifungal peptide genes. The gene coding for the only known peptide with high activity against Gram-positive bacteria, Defensin, is regulated by both pathways. So far, survival experiments to Gram-positive bacteria have been performed with Micrococcus luteus and have failed to reveal the involvement of one or the other pathway in host defense against such infections. In this study, we report that the Toll pathway, but not that of immune deficiency, is required for resistance to other Gram-positive bacteria and that this response does not involve Defensin.
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Affiliation(s)
- Sophie Rutschmann
- Institut de Biologie Moléculaire et Cellulaire, Unité Propre de Recherche 9022 du Centre National de la Recherche Scientifique, Strasbourg, France
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22
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Georgel P, Naitza S, Kappler C, Ferrandon D, Zachary D, Swimmer C, Kopczynski C, Duyk G, Reichhart JM, Hoffmann JA. Drosophila immune deficiency (IMD) is a death domain protein that activates antibacterial defense and can promote apoptosis. Dev Cell 2001; 1:503-14. [PMID: 11703941 DOI: 10.1016/s1534-5807(01)00059-4] [Citation(s) in RCA: 327] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
We report the molecular characterization of the immune deficiency (imd) gene, which controls antibacterial defense in Drosophila. imd encodes a protein with a death domain similar to that of mammalian RIP (receptor interacting protein), a protein that plays a role in both NF-kappaB activation and apoptosis. We show that imd functions upstream of the DmIKK signalosome and the caspase DREDD in the control of antibacterial peptide genes. Strikingly, overexpression of imd leads to constitutive transcription of these genes and to apoptosis, and both effects are blocked by coexpression of the caspase inhibitor P35. We also show that imd is involved in the apoptotic response to UV irradiation. These data raise the possibility that antibacterial response and apoptosis share common control elements in Drosophila.
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Affiliation(s)
- P Georgel
- Institut de Biologie Moleculaire et Cellulaire, UPR 9022 du CNRS, Strasbourg, France
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23
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Wu LP, Choe KM, Lu Y, Anderson KV. Drosophila immunity: genes on the third chromosome required for the response to bacterial infection. Genetics 2001; 159:189-99. [PMID: 11560896 PMCID: PMC1461779 DOI: 10.1093/genetics/159.1.189] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
We have screened the third chromosome of Drosophila melanogaster for mutations that prevent the normal immune response. We identified mutant lines on the basis of their failure to induce transcription of an antibacterial peptide gene in response to infection or their failure to form melanized clots at the site of wounding. These mutations define 14 genes [immune response deficient (ird) genes] that have distinct roles in the immune response. We have identified the molecular basis of several ird phenotypes. Two genes, scribble and kurtz/modulo, affect the cellular organization of the fat body, the tissue responsible for antimicrobial peptide production. Two ird genes encode components of the signaling pathways that mediate responses to bacterial infection, a Drosophila gene encoding a homolog of I kappa B kinase (DmIkk beta) and Relish, a Rel-family transcription factor. These genetic studies should provide a basis for a comprehensive understanding of the genetic control of immune responses in Drosophila.
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Affiliation(s)
- L P Wu
- Center for Agricultural Biotechnology, University of Maryland Biotechnology Institute, College Park, Maryland 20742, USA
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24
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Onfelt Tingvall T, Roos E, Engström Y. The imd gene is required for local Cecropin expression in Drosophila barrier epithelia. EMBO Rep 2001; 2:239-43. [PMID: 11266367 PMCID: PMC1083844 DOI: 10.1093/embo-reports/kve048] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Surfaces of higher eukaryotes are normally covered with microorganisms but are usually not infected by them. Innate immunity and the expression of gene-encoded antimicrobial peptides play important roles in the first line of defence in higher animals. The immune response in Drosophila promotes systemic expression of antimicrobial peptides in response to microbial infection. We now demonstrate that the epidermal cells underlying the cuticle of larvae respond to infected wounds by local expression of the genes for the antimicrobial peptide cecropin A. Thus, the Drosophila epidermis plays an active role in the innate defence against microorganisms. The immune deficiency (imd) gene was found to be a crucial component of the signal-induced epidermal expression in both embryos and larvae. In contrast, melanization, which is part of the wound healing process, is not dependent on the imd gene, indicating that the signalling pathways promoting melanization and antimicrobial peptide gene expression can be uncoupled.
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Affiliation(s)
- T Onfelt Tingvall
- Department of Molecular Biology and Functional Genomics, Arrhenius Laboratories for Natural Sciences, Stockholm University, S-106 91 Stockholm, Sweden
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25
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Lu Y, Wu LP, Anderson KV. The antibacterial arm of the drosophila innate immune response requires an IkappaB kinase. Genes Dev 2001; 15:104-10. [PMID: 11156609 PMCID: PMC312606 DOI: 10.1101/gad.856901] [Citation(s) in RCA: 150] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The ird5 gene was identified in a genetic screen for Drosophila immune response mutants. Mutations in ird5 prevent induction of six antibacterial peptide genes in response to infection but do not affect the induction of an antifungal peptide gene. Consistent with this finding, Escherichia coli survive 100 times better in ird5 adults than in wild-type animals. The ird5 gene encodes a Drosophila homolog of mammalian IkappaB kinases (IKKs). The ird5 phenotype and sequence suggest that the gene is specifically required for the activation of Relish, a Drosophila NF-kappaB family member.
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Affiliation(s)
- Y Lu
- Molecular Biology Program, Sloan-Kettering Institute, New York, New York 10021, USA
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26
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Rutschmann S, Jung AC, Zhou R, Silverman N, Hoffmann JA, Ferrandon D. Role of Drosophila IKK gamma in a toll-independent antibacterial immune response. Nat Immunol 2000; 1:342-7. [PMID: 11017107 DOI: 10.1038/79801] [Citation(s) in RCA: 216] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We have generated, by ethylmethane sulfonate mutagenesis, loss-of-function mutants in the Drosophila homolog of the mammalian I-kappa B kinase (IKK) complex component IKK gamma (also called NEMO). Our data show that Drosophila IKK gamma is required for the Relish-dependent immune induction of the genes encoding antibacterial peptides and for resistance to infections by Escherichia coli. However, it is not required for the Toll-DIF-dependent antifungal host defense. The results indicate distinct control mechanisms of the Rel-like transactivators DIF and Relish in the Drosophila innate immune response and show that Drosophila Toll does not signal through a IKK gamma-dependent signaling complex. Thus, in contrast to the vertebrate inflammatory response, IKK gamma is required for the activation of only one immune signaling pathway in Drosophila.
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Affiliation(s)
- S Rutschmann
- Institut de Biologie Moléculaire et Cellulaire, UPR 9022 du CNRS, 15, rue R. Descartes, F67084 Strasbourg, France
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27
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Engström Y. Induction and regulation of antimicrobial peptides in Drosophila. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 1999; 23:345-358. [PMID: 10426427 DOI: 10.1016/s0145-305x(99)00016-6] [Citation(s) in RCA: 111] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Activation of the innate immune response involves recognition of the infectious agent and the subsequent activation of cellular and humoral reactions. In insects, a number of immunity genes are activated at the level of transcription leading to the synthesis of antimicrobial peptides. Genetic analyses in Drosophila have identified several signal transduction pathways that promote activation of these immunity genes. Recent data suggest that the insect immune system is able to discriminate between a bacterial and a fungal infection, and responds by higher levels of activation of the appropriate peptides to repel the infection. These and other recent data on transcription factors and regulation of antimicrobial genes are integrated into a model to suggest how differential activation of antifungal and antibacterial peptides can occur in response to fungal and bacterial infection.
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Affiliation(s)
- Y Engström
- Department of Molecular Biology, Stockholm University, Sweden.
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28
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Han ZS, Enslen H, Hu X, Meng X, Wu IH, Barrett T, Davis RJ, Ip YT. A conserved p38 mitogen-activated protein kinase pathway regulates Drosophila immunity gene expression. Mol Cell Biol 1998; 18:3527-39. [PMID: 9584193 PMCID: PMC108934 DOI: 10.1128/mcb.18.6.3527] [Citation(s) in RCA: 151] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/1997] [Accepted: 03/17/1998] [Indexed: 02/07/2023] Open
Abstract
Accumulating evidence suggests that the insect and mammalian innate immune response is mediated by homologous regulatory components. Proinflammatory cytokines and bacterial lipopolysaccharide stimulate mammalian immunity by activating transcription factors such as NF-kappaB and AP-1. One of the responses evoked by these stimuli is the initiation of a kinase cascade that leads to the phosphorylation of p38 mitogen-activated protein (MAP) kinase on Thr and Tyr within the motif Thr-Gly-Tyr, which is located within subdomain VIII. We have investigated the possible involvement of the p38 MAP kinase pathway in the Drosophila immune response. Two genes that are highly homologous to the mammalian p38 MAP kinase were molecularly cloned and characterized. Furthermore, genes that encode two novel Drosophila MAP kinase kinases, D-MKK3 and D-MKK4, were identified. D-MKK3 is an efficient activator of both Drosophila p38 MAP kinases, while D-MKK4 is an activator of D-JNK but not D-p38. These data establish that Drosophila indeed possesses a conserved p38 MAP kinase signaling pathway. We have examined the role of the D-p38 MAP kinases in the regulation of insect immunity. The results revealed that one of the functions of D-p38 is to attenuate antimicrobial peptide gene expression following exposure to lipopolysaccharide.
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Affiliation(s)
- Z S Han
- Program in Molecular Medicine, Department of Biochemistry and Molecular Biology, Howard Hughes Medical Institute, Worcester, Massachusetts 01605, USA
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29
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Wu LP, Anderson KV. Regulated nuclear import of Rel proteins in the Drosophila immune response. Nature 1998; 392:93-7. [PMID: 9510254 DOI: 10.1038/32195] [Citation(s) in RCA: 267] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The Drosophila immune response uses many of the same components as the mammalian innate immune response, including signalling pathways that activate transcription factors of the Rel/NK-kappaB family. In response to infection, two Rel proteins, Dif and Dorsal, translocate from the cytoplasm to the nuclei of larval fat-body cells. The Toll signalling pathway, which controls dorsal-ventral patterning during Drosophila embryogenesis, regulates the nuclear import of Dorsal in the immune response, but here we show that the Toll pathway is not required for nuclear import of Dif. Cytoplasmic retention of both Dorsal and Dif depends on Cactus protein; nuclear import of Dorsal and Dif is accompanied by degradation of Cactus. Therefore the two signalling pathways that target Cactus for degradation must discriminate between Cactus-Dorsal and Cactus-Dif complexes. We identified new genes that are required for normal induction of transcription of an antibacterial peptide during the immune response. Mutations in three of these genes prevent nuclear import of Dif in response to infection, and define new components of signalling pathways involving Rel. Mutations in three other genes cause constitutive nuclear localization of Dif; these mutations may block Rel protein activity by a novel mechanism.
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Affiliation(s)
- L P Wu
- Molecular Biology Program, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA
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30
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Williams MJ, Rodriguez A, Kimbrell DA, Eldon ED. The 18-wheeler mutation reveals complex antibacterial gene regulation in Drosophila host defense. EMBO J 1997; 16:6120-30. [PMID: 9321392 PMCID: PMC1326296 DOI: 10.1093/emboj/16.20.6120] [Citation(s) in RCA: 204] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Mammals and insects employ similar Rel/NF-kappaB signaling cascades in their humoral immune responses. The mammalian interleukin-1 type I receptor (IL-1R) is one way of activating this cascade. The Drosophila Toll protein, whose cytoplasmic domain shows striking similarity to that of the IL-1R, acts in the humoral antimicrobial response. Here we demonstrate that a second IL-1R-related Drosophila protein, 18-Wheeler (18W), is a critical component of the humoral immune response. 18-wheeler is expressed in the larval fat body, the primary organ of antimicrobial peptide synthesis. In the absence of the 18W receptor, larvae are more susceptible to bacterial infection. Nuclear translocation of the Rel protein Dorsal-like immunity factor (Dif) is inhibited, though nuclear translocation of another Rel protein, Dorsal, is unaffected. Induction of several antibacterial genes is reduced following infection, relative to wild-type: attacin is reduced by 95%, cecropin by 65% and diptericin by 12%. Finally, 18-wheeler (18w) expression is induced in response to infection and, in addition to the receptor form, four immune-specific transcripts and proteins are produced.
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Affiliation(s)
- M J Williams
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556-5645, USA
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