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Shi C, Lin TH, Qu C. The role of pattern recognition receptors in the innate immune system of Chinese mitten crab (Eriocheir sinensis). FISH & SHELLFISH IMMUNOLOGY 2024; 154:109946. [PMID: 39370020 DOI: 10.1016/j.fsi.2024.109946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2024] [Revised: 09/09/2024] [Accepted: 10/04/2024] [Indexed: 10/08/2024]
Abstract
Eriocheir sinensis (Chinese mitten crab) is one of the main economic species in China, which has evolved an extremely sophisticated innate immune system to fend off disease invasions. However, bacterial and viral infections have caused significant financial losses for the E. sinensis aquaculture in recent years. Making well-informed judgments for the control microbial infections would require a thorough understanding and clarification of the intricate innate immune system of E. sinensis. Innate immunity is essential for the host's defense against invasive pathogens. Pattern recognition receptors (PRRs) initially recognize pathogen-associated molecular patterns (PAMPs) and trigger an innate immune response, causing the generation of inflammatory cytokine and promoting the clearance and control of pathogens. In E. sinensis, Toll/Toll-like receptors, lipopolysaccharide and β-1,3-glucan binding proteins, C-type lectins, galactoside-binding lectins, L-type lectins, scavenger receptors, and down syndrome cell adhesion molecules have been identified to be PRRs that are involved in the recognition of bacteria, fungi, and viruses. In this review, we give a comprehensive overview of the literature regarding PRRs' roles in the immunological defenses of E. sinensis, with the aim of providing clues to the mechanisms of innate immunity.
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Affiliation(s)
- Chenchen Shi
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, Fujian, 361102, China
| | - Ta-Hui Lin
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, Fujian, 361102, China; Fujian Provincial Key Laboratory of Functional and Clinical Translational Medicine, Xiamen Medical College, Xiamen, Fujian, 361023, China.
| | - Chen Qu
- Department of Chemical Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong, 518055, China.
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2
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Liu J, Chen W, Situ J, Li J, Chen J, Lai M, Huang F, Li B. BmToll9-1 Is a Positive Regulator of the Immune Response in the Silkworm Bombyx mori. INSECTS 2024; 15:643. [PMID: 39336611 PMCID: PMC11432072 DOI: 10.3390/insects15090643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2024] [Revised: 08/21/2024] [Accepted: 08/26/2024] [Indexed: 09/30/2024]
Abstract
Toll receptors are involved in the development and innate immunity of insects. BmToll9-1 is an important immune receptor in the Toll pathway. Previous studies have focused on its role as a receptor in immune response. In this study, we aimed to investigate the role of BmToll9-1 as a regulator in the immune response. The expression profiles demonstrated that BmToll9-1 was predominantly expressed in the midgut. RNA interference (RNAi) of BmToll9-1 was found to be effective in the midgut via the injection of dsRNA, which resulted in smaller and lighter larvae and cocoons. Most signaling genes in the Toll pathway and downstream effector genes were downregulated after the RNAi of BmToll9-1. The hemolymph from BmToll9-1-silenced larvae showed decreased antibacterial activity against Escherichia coli, either in growth curve or inhibition zone experiments. The above results indicate that BmToll9-1 might be positively involved in the immune pathway of silkworm. As a positive regulator, BmToll9-1 might function mainly in the gut to maintain microbial homeostasis to regulate the growth of silkworms. Silencing of BmToll9-1 downregulates the signaling genes in the Toll pathway and antimicrobial peptide (AMP) production, resulting in decreased antibacterial activity in the hemolymph.
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Affiliation(s)
- Jisheng Liu
- School of Life Sciences, Guangzhou University, Guangzhou 510006, China
| | - Weijian Chen
- School of Life Sciences, Guangzhou University, Guangzhou 510006, China
| | - Jinrong Situ
- School of Life Sciences, Guangzhou University, Guangzhou 510006, China
| | - Jiaxuan Li
- School of Life Sciences, Guangzhou University, Guangzhou 510006, China
| | - Jiahua Chen
- School of Life Sciences, Guangzhou University, Guangzhou 510006, China
| | - Minchun Lai
- School of Life Sciences, Guangzhou University, Guangzhou 510006, China
| | - Fengyi Huang
- School of Life Sciences, Guangzhou University, Guangzhou 510006, China
| | - Baoqi Li
- School of Life Sciences, Guangzhou University, Guangzhou 510006, China
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3
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Liu J, Yang W, Liao W, Huang Y, Chen W, Bu X, Huang S, Jiang W, Swevers L. Immunological function of Bombyx Toll9-2 in the silkworm (Bombyx mori) larval midgut: Activation by Escherichia coli/lipopolysaccharide and regulation of growth. ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2024; 116:e22130. [PMID: 39118437 DOI: 10.1002/arch.22130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Revised: 06/18/2024] [Accepted: 06/29/2024] [Indexed: 08/10/2024]
Abstract
Toll receptors are important regulators of insects' innate immune system which, upon binding of pathogen molecules, activate a conserved signal transduction cascade known as the Toll pathway. RNA interference (RNAi) is a powerful tool to study the function of genes via reverse genetics. However, due to the reported refractory of RNAi efficiency in lepidopteran insects, successful reports of silencing of Toll receptors in the silkworm Bombyx mori have not been reported yet. In this study, a Toll receptor of the silkworm Bombyx Toll9-2 (BmToll9-2) was cloned and its expression and function were analyzed. The results showed that BmToll9-2 contains an ectodomain (ECD) with a signal peptide and nine leucine-rich repeats, a transmembrane helix, and a cytoplasmic region with a Toll/interleukin-1 domain. Phylogenetic analysis indicates that BmToll9-2 clusters with other insect Toll9 receptors and mammalian Toll-like receptor 4. Oral infection of exogenous pathogens showed that the Gram-negative bacterium Escherichia coli and its main cell wall component lipopolysaccharide (LPS), as well as the Gram-positive bacterium Staphylococcus aureus and its main cell wall component peptidoglycan, significantly induce BmToll9-2 expression in vivo. LPS also induced the expression of BmToll9-2 in BmN4 cells in vitro. These observations indicate its role as a sensor in the innate immunity to exogenous pathogens and as a pathogen-associated receptor that is responsive to LPS. RNAi of BmToll9-2 was effective in the midgut and epidermis. RNAi-mediated knock-down of BmToll9-2 reduced the weight and growth of the silkworm. Bacterial challenge following RNAi upregulated the expression of BmToll9-2 and rescued the weight differences of the silkworm, which may be related to its participation in the immune response and the regulation of the microbiota in the midgut lumen of the silkworm larvae.
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Affiliation(s)
- Jisheng Liu
- School of Life Sciences, Guangzhou University, Guangzhou, China
| | - Weifeng Yang
- School of Life Sciences, Guangzhou University, Guangzhou, China
| | - Wenli Liao
- School of Life Sciences, Guangzhou University, Guangzhou, China
| | - Yanling Huang
- School of Life Sciences, Guangzhou University, Guangzhou, China
| | - Weijian Chen
- School of Life Sciences, Guangzhou University, Guangzhou, China
| | - Xiaoling Bu
- School of Life Sciences, Guangzhou University, Guangzhou, China
| | - Shiyi Huang
- School of Life Sciences, Guangzhou University, Guangzhou, China
| | - Wanyi Jiang
- School of Life Sciences, Guangzhou University, Guangzhou, China
| | - Luc Swevers
- Institute of Biosciences and Applications, National Centre for Scientific Research Demokritos, Athens, Greece
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4
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Ali Mohammadie Kojour M, Jang HA, Lee YS, Jo YH, Han YS. Innate Immune Response of TmToll-3 Following Systemic Microbial Infection in Tenebrio molitor. Int J Mol Sci 2023; 24:ijms24076751. [PMID: 37047723 PMCID: PMC10095136 DOI: 10.3390/ijms24076751] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 03/28/2023] [Accepted: 03/29/2023] [Indexed: 04/08/2023] Open
Abstract
Although Toll-like receptors have been widely identified and functionally characterized in mammalian models and Drosophila, the immunological function of these receptors in other insects remains unclear. Here, we explored the relevant innate immune response of Tenebrio molitor (T. molitor) Toll-3 against Gram-negative bacteria, Gram-positive bacteria, and fungal infections. Our findings indicated that TmToll-3 expression was mainly induced by Candida albicans infections in the fat bodies, gut, Malpighian tubules, and hemolymph of young T. molitor larvae. Surprisingly, Escherichia coli systemic infection caused mortality after TmToll-3 knockdown via RNA interference (RNAi) injection, which was not observed in the control group. Further analyses indicated that in the absence of TmToll-3, the final effector of the Toll signaling pathway, antimicrobial peptide (AMP) genes and relevant transcription factors were significantly downregulated after E. coli challenge. Our results indicated that the expression of almost all AMP genes was suppressed in silenced individuals, whereas the expression of relevant genes was positively regulated after fungal injection. Therefore, this study revealed the immunological involvement of TmToll-3 in T. molitor in response to systematic infections.
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Affiliation(s)
- Maryam Ali Mohammadie Kojour
- Department of Applied Biology, Institute of Environmentally-Friendly Agriculture (IEFA), College of Agriculture and Life Sciences, Chonnam National University, Gwangju 61186, Republic of Korea
| | - Ho Am Jang
- Department of Biology, College of Natural Sciences, Soonchunhyang University, Asan 31538, Republic of Korea
| | - Yong Seok Lee
- Department of Biology, College of Natural Sciences, Soonchunhyang University, Asan 31538, Republic of Korea
| | - Yong Hun Jo
- Department of Biology, College of Natural Sciences, Soonchunhyang University, Asan 31538, Republic of Korea
| | - Yeon Soo Han
- Department of Applied Biology, Institute of Environmentally-Friendly Agriculture (IEFA), College of Agriculture and Life Sciences, Chonnam National University, Gwangju 61186, Republic of Korea
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5
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Sakakibara Y, Yamashiro R, Chikamatsu S, Hirota Y, Tsubokawa Y, Nishijima R, Takei K, Sekiya M, Iijima KM. Drosophila Toll-9 is induced by aging and neurodegeneration to modulate stress signaling and its deficiency exacerbates tau-mediated neurodegeneration. iScience 2023; 26:105968. [PMID: 36718365 PMCID: PMC9883205 DOI: 10.1016/j.isci.2023.105968] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 12/06/2022] [Accepted: 01/10/2023] [Indexed: 01/15/2023] Open
Abstract
Drosophila Toll-9 is most closely related to mammalian Toll-like receptors; however, physiological functions of Toll-9 remain elusive. We examined the roles of Toll-9 in fly brains in aging and neurodegeneration. Toll-9 mRNA levels were increased in aged fly heads accompanied by activation of nuclear factor-kappa B (NF-kB) and stress-activated protein kinase (SAPK) signaling, and many of these changes were modulated by Toll-9 in glial cells. The loss of Toll-9 did not affect lifespan or brain integrity, whereas it exacerbated hydrogen peroxide-induced lethality. Toll-9 expression was also induced by nerve injury but did not affect acute stress response or glial engulfment activity, suggesting Toll-9 may modulate subsequent neurodegeneration. In a fly tauopathy model, Toll-9 deficiency enhanced neurodegeneration and disease-related tau phosphorylation with reduced SAPK activity, and blocking SAPK enhanced tau phosphorylation and neurodegeneration. In sum, Toll-9 is induced upon aging and nerve injury and affects neurodegeneration by modulating stress kinase signaling.
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Affiliation(s)
- Yasufumi Sakakibara
- Department of Neurogenetics, Center for Development of Advanced Medicine for Dementia, National Center for Geriatrics and Gerontology, Obu, Aichi 474-8511, Japan
| | - Risa Yamashiro
- Department of Experimental Gerontology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya 467-8603, Japan
| | - Sachie Chikamatsu
- Department of Neurogenetics, Center for Development of Advanced Medicine for Dementia, National Center for Geriatrics and Gerontology, Obu, Aichi 474-8511, Japan,Department of Experimental Gerontology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya 467-8603, Japan
| | - Yu Hirota
- Department of Neurogenetics, Center for Development of Advanced Medicine for Dementia, National Center for Geriatrics and Gerontology, Obu, Aichi 474-8511, Japan,Reseach Fellow of Japan Society for the Promotion of Science, Tokyo, Japan
| | - Yoko Tsubokawa
- Department of Neurogenetics, Center for Development of Advanced Medicine for Dementia, National Center for Geriatrics and Gerontology, Obu, Aichi 474-8511, Japan
| | - Risa Nishijima
- Department of Neurogenetics, Center for Development of Advanced Medicine for Dementia, National Center for Geriatrics and Gerontology, Obu, Aichi 474-8511, Japan
| | - Kimi Takei
- Department of Neurogenetics, Center for Development of Advanced Medicine for Dementia, National Center for Geriatrics and Gerontology, Obu, Aichi 474-8511, Japan
| | - Michiko Sekiya
- Department of Neurogenetics, Center for Development of Advanced Medicine for Dementia, National Center for Geriatrics and Gerontology, Obu, Aichi 474-8511, Japan,Department of Experimental Gerontology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya 467-8603, Japan,Corresponding author
| | - Koichi M. Iijima
- Department of Neurogenetics, Center for Development of Advanced Medicine for Dementia, National Center for Geriatrics and Gerontology, Obu, Aichi 474-8511, Japan,Department of Experimental Gerontology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya 467-8603, Japan,Corresponding author
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6
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Shields A, Amcheslavsky A, Brown E, Lee TV, Nie Y, Tanji T, Ip YT, Bergmann A. Toll-9 interacts with Toll-1 to mediate a feedback loop during apoptosis-induced proliferation in Drosophila. Cell Rep 2022; 39:110817. [PMID: 35584678 PMCID: PMC9211775 DOI: 10.1016/j.celrep.2022.110817] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2020] [Revised: 02/25/2022] [Accepted: 04/22/2022] [Indexed: 11/30/2022] Open
Abstract
Drosophila Toll-1 and all mammalian Toll-like receptors regulate innate immunity. However, the functions of the remaining eight Toll-related proteins in Drosophila are not fully understood. Here, we show that Drosophila Toll-9 is necessary and sufficient for a special form of compensatory proliferation after apoptotic cell loss (undead apoptosis-induced proliferation [AiP]). Mechanistically, for AiP, Toll-9 interacts with Toll-1 to activate the intracellular Toll-1 pathway for nuclear translocation of the NF-κB-like transcription factor Dorsal, which induces expression of the pro-apoptotic genes reaper and hid. This activity contributes to the feedback amplification loop that operates in undead cells. Given that Toll-9 also functions in loser cells during cell competition, we define a general role of Toll-9 in cellular stress situations leading to the expression of pro-apoptotic genes that trigger apoptosis and apoptosis-induced processes such as AiP. This work identifies conceptual similarities between cell competition and AiP.
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Affiliation(s)
- Alicia Shields
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Alla Amcheslavsky
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Elizabeth Brown
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Tom V Lee
- Department of Neurology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Yingchao Nie
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Takahiro Tanji
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Y Tony Ip
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Andreas Bergmann
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA 01605, USA.
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7
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Liu H, Yang M, Tang X, Liu J, Zheng L, Xu D, Chi C, Lv Z. Molecular insights of a novel fish Toll-like receptor 9 homologue in Nibea albiflora to reveal its function as PRRs. FISH & SHELLFISH IMMUNOLOGY 2021; 118:321-332. [PMID: 34555530 DOI: 10.1016/j.fsi.2021.09.021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 08/29/2021] [Accepted: 09/18/2021] [Indexed: 06/13/2023]
Abstract
Toll-like receptors (TLRs) are an important class of molecules involved in non-specific immunity, and they are also the bridge connecting between non-specific immunity and specific immunity. As a vital member of TLR family TLR9 can be activated by bacterial DNA and induce the production of inflammatory cytokines. In this study, a full length of TLR9 homologue of 3677 bp in Nibea albiflora (named as NaTLR9, GenBank accession no: MN125017.1) was characterized, and its ORF was 3180 bp encoding 1059 amino acid residues with a calculated molecular weight of 121.334 kDa (pI = 6.29). Several leucine-rich repeated sequences (LRR domain) and conservative TIR domain were found in NaTLR9, which was mainly expressed in dendritic cells and macrophages. The phylogenetic and synteny analysis further revealed high sequence identity of NaTLR9 with its counterparts of other teleost, confirming their correct nomenclature and conservative during evolution as an important pattern recognition receptor. The NaTLR9-TIR-pEGFP-N1 fusion protein showed green fluorescence and mainly distributed in the cytoplasm. After co-transfection of NaTLR9-TIR-pEGFP-N1 and NaMyD88-pDsRED-Monomer-N1, green fluorescence obviously overlapped with red and changed into yellowish-green, which suggested that there might be the interaction between homologous NaTLR9-TIR and MyD88. Based on this result the pCDNA3.1-NaTLR9-TIR-flag and pcMV-NaMyD88-TIR-Myc plasmids were co-transfected into 293T cells for the immunoprecipitation test. According to Western blot, TLR9 and MyD88 protein could interact with each other. Furthermore, NaTLR9 was ubiquitously expressed in all the investigated tissues, most abundantly in head kidney, followed by stomach, spleen, liver and gill, but lower in muscle. The vitro immune stimulation experiments revealed that Pseudomonas plecoglossicida and polyinosinic-polycytidylic acid [Poly (I:C)] induced higher levels of NaTLR9 mRNA expression with the peaks of 9.52 times at 2 h and 39.91 times at 24 h compared with the control group respectively. The functional domains (LRRs and TIR, named NaTLR9-TIR and NaTLR9-LRR respectively) of NaTLR9 were expressed and purified, the recombinant proteins both could bind three kinds of typical aquatic pathogenic bacteria (Vibrio. parahaemolyticus, Vibrio alginolyticus, and Vibrio harveyi), which showed that NaTLR9 could couple to bacteria by its function domains. The aforementioned results indicated that NaTLR9 played a significant role in the defense against pathogenic bacteria infection in innate immune response of sciaenidae fish, which may provide some further understandings of the regulatory mechanisms in the teleostean innate immune system.
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Affiliation(s)
- Huihui Liu
- National and Provincial Joint Laboratory of Exploration and Utilization of Marine Aquatic Genetic Resources, National Engineering Research Center of Marine Facilities Aquaculture, Zhejiang Ocean University, Zhoushan, 316022, PR China.
| | - Meijun Yang
- National and Provincial Joint Laboratory of Exploration and Utilization of Marine Aquatic Genetic Resources, National Engineering Research Center of Marine Facilities Aquaculture, Zhejiang Ocean University, Zhoushan, 316022, PR China
| | - Xiuqin Tang
- National and Provincial Joint Laboratory of Exploration and Utilization of Marine Aquatic Genetic Resources, National Engineering Research Center of Marine Facilities Aquaculture, Zhejiang Ocean University, Zhoushan, 316022, PR China
| | - Jiaxin Liu
- National and Provincial Joint Laboratory of Exploration and Utilization of Marine Aquatic Genetic Resources, National Engineering Research Center of Marine Facilities Aquaculture, Zhejiang Ocean University, Zhoushan, 316022, PR China
| | - Libing Zheng
- National and Provincial Joint Laboratory of Exploration and Utilization of Marine Aquatic Genetic Resources, National Engineering Research Center of Marine Facilities Aquaculture, Zhejiang Ocean University, Zhoushan, 316022, PR China
| | - Dongdong Xu
- Marine Fishery Institute of Zhejiang Province, Key Lab of Mariculture and Enhancement of Zhejiang Province, Zhoushan, 316100, PR China
| | - Changfeng Chi
- National and Provincial Joint Laboratory of Exploration and Utilization of Marine Aquatic Genetic Resources, National Engineering Research Center of Marine Facilities Aquaculture, Zhejiang Ocean University, Zhoushan, 316022, PR China
| | - Zhenming Lv
- National and Provincial Joint Laboratory of Exploration and Utilization of Marine Aquatic Genetic Resources, National Engineering Research Center of Marine Facilities Aquaculture, Zhejiang Ocean University, Zhoushan, 316022, PR China
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8
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Chowdhury M, Li CF, He Z, Lu Y, Liu XS, Wang YF, Ip YT, Strand MR, Yu XQ. Toll family members bind multiple Spätzle proteins and activate antimicrobial peptide gene expression in Drosophila. J Biol Chem 2019; 294:10172-10181. [PMID: 31088910 DOI: 10.1074/jbc.ra118.006804] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 05/10/2019] [Indexed: 12/31/2022] Open
Abstract
The Toll signaling pathway in Drosophila melanogaster regulates several immune-related functions, including the expression of antimicrobial peptide (AMP) genes. The canonical Toll receptor (Toll-1) is activated by the cytokine Spätzle (Spz-1), but Drosophila encodes eight other Toll genes and five other Spz genes whose interactions with one another and associated functions are less well-understood. Here, we conducted in vitro assays in the Drosophila S2 cell line with the Toll/interleukin-1 receptor (TIR) homology domains of each Toll family member to determine whether they can activate a known target of Toll-1, the promoter of the antifungal peptide gene drosomycin. All TIR family members activated the drosomycin promoter, with Toll-1 and Toll-7 TIRs producing the highest activation. We found that the Toll-1 and Toll-7 ectodomains bind Spz-1, -2, and -5, and also vesicular stomatitis virus (VSV) virions, and that Spz-1, -2, -5, and VSV all activated the promoters of drosomycin and several other AMP genes in S2 cells expressing full-length Toll-1 or Toll-7. In vivo experiments indicated that Toll-1 and Toll-7 mutants could be systemically infected with two bacterial species (Enterococcus faecalis and Pseudomonas aeruginosa), the opportunistic fungal pathogen Candida albicans, and VSV with different survival times in adult females and males compared with WT fly survival. Our results suggest that all Toll family members can activate several AMP genes. Our results further indicate that Toll-1 and Toll-7 bind multiple Spz proteins and also VSV, but they differentially affect adult survival after systemic infection, potentially because of sex-specific differences in Toll-1 and Toll-7 expression.
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Affiliation(s)
- Munmun Chowdhury
- From the Division of Cell Biology and Biophysics, School of Biological Sciences, University of Missouri-Kansas City, Kansas City, Missouri 64110
| | - Chun-Feng Li
- From the Division of Cell Biology and Biophysics, School of Biological Sciences, University of Missouri-Kansas City, Kansas City, Missouri 64110.,the State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400716, China
| | - Zhen He
- From the Division of Cell Biology and Biophysics, School of Biological Sciences, University of Missouri-Kansas City, Kansas City, Missouri 64110.,the School of Life Sciences, Central China Normal University, Wuhan 430079, China
| | - Yuzhen Lu
- the Guangzhou Key Laboratory of Insect Development Regulation and Application Research, Institute of Insect Science and Technology and School of Life Sciences, South China Normal University, Guangzhou 510631, China
| | - Xu-Sheng Liu
- the School of Life Sciences, Central China Normal University, Wuhan 430079, China
| | - Yu-Feng Wang
- the School of Life Sciences, Central China Normal University, Wuhan 430079, China
| | - Y Tony Ip
- the Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts 01605
| | - Michael R Strand
- the Department of Entomology, University of Georgia, Athens, Georgia 30602, and
| | - Xiao-Qiang Yu
- From the Division of Cell Biology and Biophysics, School of Biological Sciences, University of Missouri-Kansas City, Kansas City, Missouri 64110, .,the School of Life Sciences, Central China Normal University, Wuhan 430079, China.,the Guangzhou Key Laboratory of Insect Development Regulation and Application Research, Institute of Insect Science and Technology and School of Life Sciences, South China Normal University, Guangzhou 510631, China
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9
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Abstract
Like humans, insects face the threat of viral infection. Despite having repercussions on human health and disease, knowledge gaps exist for how insects cope with viral pathogens. Drosophila melanogaster serves as an ideal insect model due to its genetic tractability. When encountering a pathogen, two major approaches to fight disease are resistance strategies and tolerance strategies. Disease resistance strategies promote the health of the infected host by reducing pathogen load. Multiple disease resistance mechanisms have been identified in Drosophila: RNA interference, Jak/STAT signaling, Toll signaling, IMD signaling, and autophagy. Disease tolerance mechanisms, in contrast, do not reduce pathogen load directly, but rather mitigate the stress and damage incurred by infection. The main benefit of tolerance mechanisms may therefore be to provide the host with time to engage antiviral resistance mechanisms that eliminate the threat. In this review, antiviral resistance mechanisms used by Drosophila will be described and compared to mammalian antiviral mechanisms. Disease tolerance will then be explained in a broader context as this is a burgeoning field of study.
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Affiliation(s)
- Jonathan Chow
- Division of Gastroenterology, Harvard Medical School, Boston Children's Hospital, Boston, MA, United States
| | - Jonathan C Kagan
- Division of Gastroenterology, Harvard Medical School, Boston Children's Hospital, Boston, MA, United States.
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10
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Levin TC, Malik HS. Rapidly Evolving Toll-3/4 Genes Encode Male-Specific Toll-Like Receptors in Drosophila. Mol Biol Evol 2017; 34:2307-2323. [PMID: 28541576 PMCID: PMC5850136 DOI: 10.1093/molbev/msx168] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Animal Toll-like receptors (TLRs) have evolved through a pattern of duplication and divergence. Whereas mammalian TLRs directly recognize microbial ligands, Drosophila Tolls bind endogenous ligands downstream of both developmental and immune signaling cascades. Here, we find that most Toll genes in Drosophila evolve slowly with little gene turnover (gains/losses), consistent with their important roles in development and indirect roles in microbial recognition. In contrast, we find that the Toll-3/4 genes have experienced an unusually rapid rate of gene gains and losses, resulting in lineage-specific Toll-3/4s and vastly different gene repertoires among Drosophila species, from zero copies (e.g., D. mojavensis) to nineteen copies (e.g., D. willistoni). In D. willistoni, we find strong evidence for positive selection in Toll-3/4 genes, localized specifically to an extracellular region predicted to overlap with the binding site of Spätzle, the only known ligand of insect Tolls. However, because Spätzle genes are not experiencing similar selective pressures, we hypothesize that Toll-3/4s may be rapidly evolving because they bind to a different ligand, akin to TLRs outside of insects. We further find that most Drosophila Toll-3/4 genes are either weakly expressed or expressed exclusively in males, specifically in the germline. Unlike other Toll genes in D. melanogaster, Toll-3, and Toll-4 have apparently escaped from essential developmental roles, as knockdowns have no substantial effects on viability or male fertility. Based on these findings, we propose that the Toll-3/4 genes represent an exceptionally rapidly evolving lineage of Drosophila Toll genes, which play an unusual, as-yet-undiscovered role in the male germline.
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Affiliation(s)
- Tera C Levin
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA
| | - Harmit S Malik
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA.,Howard Hughes Medical Institute, Fred Hutchinson Cancer Research Center, Seattle, WA
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Liu Q, Xu D, Jiang S, Huang J, Zhou F, Yang Q, Jiang S, Yang L. Toll-receptor 9 gene in the black tiger shrimp (Penaeus monodon) induced the activation of the TLR-NF-κB signaling pathway. Gene 2017; 639:27-33. [PMID: 28982619 DOI: 10.1016/j.gene.2017.09.060] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Revised: 09/22/2017] [Accepted: 09/26/2017] [Indexed: 12/11/2022]
Abstract
Toll receptors are important pathogen recognition receptors (PRRs) in shrimps, which play a vital role in defending against virus and bacterial challenge. In this paper, the characterization and functional analysis of a Toll9 receptor gene from Penaeus monodon was performed in HEK293T cells. Data showed that PmToll9 can activate the NF-κB promoter activities of TLR pathway, while ISRE and IFN-β promoter cannot be activated obviously in HEK293T cells using dual-luciferase reporter system. The downstream immune factors of IL-8, IκB-α, and TRAF6 were activated by PmToll9 and IL-8 showed the most significant up-regulation in expression levels, indicating the activities of NF-κB can be mediated by PmToll9. Six LRRs-deletion mutants were constructed and results showed these mutants had obvious declines in luciferase activities, among which the mutant pCMV-DeLRR4 showed the most significant decline. qPCR data indicated LRRs-deletion mutants efficiently impaired the activities of the downstream immune factors IL-8, IκB-α, and TRAF6. It demonstrates that LRRs-deletion mutants could result in the weaken abilities of PmToll9 in signaling transduction. Overexpression of PmToll9-GFP fusion protein in Hela cells revealed the primary cellular localization of PmToll9 is in the cytoplasm.
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Affiliation(s)
- Qian Liu
- South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510300, China; College of Aqua-life Science and Technology, Shanghai Ocean University, Shanghai 201306, China; Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture, Guangzhou 510300, China
| | - Dan Xu
- College of Aqua-life Science and Technology, Shanghai Ocean University, Shanghai 201306, China
| | - Shigui Jiang
- South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510300, China; Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture, Guangzhou 510300, China
| | - Jianhua Huang
- South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510300, China
| | - Falin Zhou
- South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510300, China
| | - Qibin Yang
- South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510300, China
| | - Song Jiang
- South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510300, China
| | - Lishi Yang
- South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510300, China.
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12
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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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13
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Valanne S. Functional genomic analysis of the Drosophila immune response. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2014; 42:93-101. [PMID: 23707784 DOI: 10.1016/j.dci.2013.05.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2013] [Revised: 05/13/2013] [Accepted: 05/13/2013] [Indexed: 06/02/2023]
Abstract
Drosophila melanogaster has been widely used as a model organism for over a century now, and also as an immunological research model for over 20 years. With the emergence of RNA interference (RNAi) in Drosophila as a robust tool to silence genes of interest, large-scale or genome-wide functional analysis has become a popular way of studying the Drosophila immune response in cell culture. Drosophila immunity is composed of cellular and humoral immunity mechanisms, and especially the systemic, humoral response pathways have been extensively dissected using the functional genomic approach. Although most components of the main immune pathways had already been found using traditional genetic screening techniques, important findings including pathway components, positive and negative regulators and modifiers have been made with RNAi screening. Additionally, RNAi screening has produced new information on host-pathogen interactions related to the pathogenesis of many microbial species.
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Affiliation(s)
- Susanna Valanne
- Institute of Biomedical Technology and BioMediTech, Tampere University, 33520 Tampere, Finland.
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14
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Pavlidis P, Jensen JD, Stephan W, Stamatakis A. A critical assessment of storytelling: gene ontology categories and the importance of validating genomic scans. Mol Biol Evol 2012; 29:3237-48. [PMID: 22617950 DOI: 10.1093/molbev/mss136] [Citation(s) in RCA: 159] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
In the age of whole-genome population genetics, so-called genomic scan studies often conclude with a long list of putatively selected loci. These lists are then further scrutinized to annotate these regions by gene function, corresponding biological processes, expression levels, or gene networks. Such annotations are often used to assess and/or verify the validity of the genome scan and the statistical methods that have been used to perform the analyses. Furthermore, these results are frequently considered to validate "true-positives" if the identified regions make biological sense a posteriori. Here, we show that this approach can be potentially misleading. By simulating neutral evolutionary histories, we demonstrate that it is possible not only to obtain an extremely high false-positive rate but also to make biological sense out of the false-positives and construct a sensible biological narrative. Results are compared with a recent polymorphism data set from Drosophila melanogaster.
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Affiliation(s)
- Pavlos Pavlidis
- The Exelixis Lab, Scientific Computing Group, Heidelberg Institute for Theoretical Studies (HITS gGmbH), Heidelberg, Germany.
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15
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Keebaugh ES, Schlenke TA. Adaptive evolution of a novel Drosophila lectin induced by parasitic wasp attack. Mol Biol Evol 2011; 29:565-77. [PMID: 21873297 DOI: 10.1093/molbev/msr191] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Drosophila melanogaster has long been used as a model for the molecular genetics of innate immunity. Such work has uncovered several immune receptors that recognize bacterial and fungal pathogens by binding unique components of their cell walls and membranes. Drosophila also act as hosts to metazoan pathogens such as parasitic wasps, which can infect a majority of individuals in natural populations, but many aspects of their immune responses against these more closely related pathogens are poorly understood. Here, we present data describing the transcriptional induction and molecular evolution of a candidate Drosophila anti-wasp immunity gene, lectin-24A. Lectin-24A has a secretion signal sequence and its lectin domain suggests a function in sugar group binding. Transcript levels of lectin-24A were induced significantly stronger and faster following wasp attack than following wounding or bacterial infection, demonstrating lectin-24A is not a general stress response or defense response gene but is instead part of a specific response against wasps. The major site of lectin-24A transcript production is the fat body, the main humoral immune tissue of flies. Interestingly, lectin-24A is a new gene of the D. melanogaster/Drosophila simulans clade, displaying very little homology to any other Drosophila lectins. Population genetic analyses of lectin-24A DNA sequence data from African and North American populations of D. melanogaster and D. simulans revealed gene length polymorphisms segregating at high frequencies as well as strong evidence of repeated and recent selective sweeps. Thus, lectin-24A is a rapidly evolving new gene that has seemingly developed functional importance for fly resistance against infection by parasitic wasps.
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Abstract
The Drosophila genome encodes a total of nine Toll and related proteins. The immune and developmental functions of Toll and 18Wheeler (18W) have been analyzed extensively, while the in vivo functions of the other Toll-related proteins require further investigation. We performed transgenic experiments and found that overexpression of Toll-related genes caused different extents of lethality and developmental defects. Moreover, 18w, Toll-6, Toll-7 and Toll-8 often caused related phenotypic changes, consistent with the idea that these four genes have more conserved molecular structure and thus may regulate similar processes in vivo. Deletion alleles of Toll-6, Toll-7 and Toll-8 were generated by targeted homologous recombination or P element excision. These mutant alleles were viable, fertile, and had no detectable defect in the inducible expression of antimicrobial peptide genes except for the Toll-8 mutant had some defects in leg development. The expression of 18w, Toll-7 and Toll-8 mRNA showed wide and overlapping patterns in imaginal discs and the 18w, Toll-8 double and Toll-7, Toll-8 double mutants showed substantially increased lethality. Overall our results suggest that some of the Toll-related proteins, such as 18W, Toll-7 and Toll-8, may have redundant functions in regulating developmental processes.
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Affiliation(s)
- Yoshimasa Yagi
- Division of Biological Science, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan.
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17
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Narbonne-Reveau K, Charroux B, Royet J. Lack of an antibacterial response defect in Drosophila Toll-9 mutant. PLoS One 2011; 6:e17470. [PMID: 21386906 PMCID: PMC3046252 DOI: 10.1371/journal.pone.0017470] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2010] [Accepted: 02/02/2011] [Indexed: 01/12/2023] Open
Abstract
Toll and Toll-like receptors represent families of receptors involved in mediating innate immunity response in insects and mammals. Although Drosophila proteome contains multiple Toll paralogs, Toll-1 is, so far, the only receptor to which an immune role has been attributed. In contrast, every single mammalian TLR is a key membrane receptor upstream of the vertebrate immune signaling cascades. The prevailing view is that TLR-mediated immunity is ancient. Structural analysis reveals that Drosophila Toll-9 is the most closely related to vertebrate TLRs and utilizes similar signaling components as Toll-1. This suggests that Toll-9 could be an ancestor of TLR-like receptors and could have immune function. Consistently, it has been reported that over-expression of Toll-9 in immune tissues is sufficient to induce the expression of some antimicrobial peptides in flies. These results have led to the idea that Toll-9 could be a constitutively active receptor that maintain significant levels of antimicrobial molecules and therefore provide constant basal protection against micro-organisms. To test theses hypotheses, we generated and analyzed phenotypes associated with a complete loss-of-function allele of Toll-9. Our results suggest that Toll-9 is neither required to maintain a basal anti-microbial response nor to mount an efficient immune response to bacterial infection.
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Affiliation(s)
- Karine Narbonne-Reveau
- Institut de Biologie du Développement de Marseille-Luminy (IBDML), CNRS UMR 6216/Aix-Marseille II University, Campus de Luminy, Marseille, France
| | - Bernard Charroux
- Institut de Biologie du Développement de Marseille-Luminy (IBDML), CNRS UMR 6216/Aix-Marseille II University, Campus de Luminy, Marseille, France
| | - Julien Royet
- Institut de Biologie du Développement de Marseille-Luminy (IBDML), CNRS UMR 6216/Aix-Marseille II University, Campus de Luminy, Marseille, France
- * E-mail:
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18
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Valanne S, Wang JH, Rämet M. The Drosophila Toll signaling pathway. THE JOURNAL OF IMMUNOLOGY 2011; 186:649-56. [PMID: 21209287 DOI: 10.4049/jimmunol.1002302] [Citation(s) in RCA: 600] [Impact Index Per Article: 46.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The identification of the Drosophila melanogaster Toll pathway cascade and the subsequent characterization of TLRs have reshaped our understanding of the immune system. Ever since, Drosophila NF-κB signaling has been actively studied. In flies, the Toll receptors are essential for embryonic development and immunity. In total, nine Toll receptors are encoded in the Drosophila genome, including the Toll pathway receptor Toll. The induction of the Toll pathway by gram-positive bacteria or fungi leads to the activation of cellular immunity as well as the systemic production of certain antimicrobial peptides. The Toll receptor is activated when the proteolytically cleaved ligand Spatzle binds to the receptor, eventually leading to the activation of the NF-κB factors Dorsal-related immunity factor or Dorsal. In this study, we review the current literature on the Toll pathway and compare the Drosophila and mammalian NF-κB pathways.
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Affiliation(s)
- Susanna Valanne
- Laboratory of Experimental Immunology, Institute of Medical Technology, University of Tampere, 33014 Tampere, Finland
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19
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Endocytosis is required for Toll signaling and shaping of the Dorsal/NF-kappaB morphogen gradient during Drosophila embryogenesis. Proc Natl Acad Sci U S A 2010; 107:18028-33. [PMID: 20921412 DOI: 10.1073/pnas.1009157107] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Dorsoventral cell fate in the Drosophila embryo is specified by activation of the Toll receptor, leading to a ventral-to-dorsal gradient across nuclei of the NF-κB transcription factor Dorsal. Toll receptor has been investigated genetically, molecularly, and immunohistologically, but much less is known about its dynamics in living embryos. Using live imaging of fluorescent protein chimeras, we find that Toll is recruited from the plasma membrane to Rab5(+) early endosomes. The distribution of a constitutively active form of Toll, Toll(10b), is shifted from the plasma membrane to early endosomes. Inhibition of endocytosis on the ventral side of the embryo attenuates Toll signaling ventrally and causes Dorsal to accumulate on the dorsal side of the embryo, essentially inverting the dorsal/ventral axis. Conversely, enhancing endocytosis laterally greatly potentiates Toll signaling locally, altering the shape of the Dorsal gradient. Photoactivation and fluorescence recovery after photobleaching studies reveal that Toll exhibits extremely limited lateral diffusion within the plasma membrane, whereas Toll is highly compartmentalized in endosomes. When endocytosis is blocked ventrally, creating an ectopic dorsal signaling center, Toll is preferentially endocytosed at the ectopic signaling center. We propose that Toll signals from an endocytic compartment rather than the plasma membrane. Our studies reveal that endocytosis plays a pivotal role in the spatial regulation of Toll receptor activation and signaling and in the correct shaping of the nuclear Dorsal concentration gradient.
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20
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Lessons from the fly: pattern recognition in Drosophila melanogaster. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2009; 653:162-74. [PMID: 19799118 DOI: 10.1007/978-1-4419-0901-5_11] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Drosophila have a variety of innate immune strategies for defending itself from infection, including humoral and cell mediated responses to invading microorganisms. At the front lines of these responses, are a diverse group of pattern recognition receptors that recognize pathogen associated molecular patterns. These patterns include bacterial lipopolysaccharides, peptidoglycans, and fungal beta-1,3 glucans. Some of the receptors catalytically modify the pathogenic determinant, but all are responsible for directly facilitating a signaling event that results in an immune response. Some of these events require multiple pattern recognition receptors acting sequentially to activate a pathway. In some cases, a signaling pathway may be activated by a variety of different pathogens, through parallel receptors detecting different pathogenic determinants. In this chapter, we review what is known about pattern recognition receptors in Drosophila, and how those lessons may be applied towards a broader understanding of immunity.
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21
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Tanji T, Ohashi-Kobayashi A, Natori S. Participation of a galactose-specific C-type lectin in Drosophila immunity. Biochem J 2006; 396:127-38. [PMID: 16475980 PMCID: PMC1450005 DOI: 10.1042/bj20051921] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
A galactose-specific C-type lectin has been purified from a pupal extract of Drosophila melanogaster. This lectin gene, named DL1 (Drosophila lectin 1), is part of a gene cluster with the other two galactose-specific C-type lectin genes, named DL2 (Drosophila lectin 2) and DL3 (Drosophila lectin 3). These three genes are expressed differentially in fruit fly, but show similar haemagglutinating activities. The present study characterized the biochemical and biological properties of the DL1 protein. The recombinant DL1 protein bound to Escherichia coli and Erwinia chrysanthemi, but not to other Gram-negative or any other kinds of microbial strains that have been investigated. In addition, DL1 agglutinated E. coli and markedly intensified the association of a Drosophila haemocytes-derived cell line with E. coli. For in vivo genetic analysis of the lectin genes, we also established a null-mutant Drosophila. The induction of inducible antibacterial peptide genes was not impaired in the DL1 mutant, suggesting that the galactose-specific C-type lectin does not participate in the induction of antibacterial peptides, but possibly participates in the immune response via the haemocyte-mediated mechanism.
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Affiliation(s)
- Takahiro Tanji
- *Department of Cell Biochemistry, Graduate School of Pharmaceutical Sciences, University of Tokyo, Tokyo, Japan
| | - Ayako Ohashi-Kobayashi
- †Laboratory of Biochemistry and Molecular Biology, Graduate School of Pharmaceutical Sciences, Osaka University, Osaka, Japan
- To whom correspondence should be addressed (email )
| | - Shunji Natori
- ‡The Institute of Physical and Chemical Research (RIKEN), Saitama, Japan
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22
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Wang L, Ligoxygakis P. Pathogen recognition and signalling in the Drosophila innate immune response. Immunobiology 2006; 211:251-61. [PMID: 16697918 DOI: 10.1016/j.imbio.2006.01.001] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2005] [Accepted: 01/18/2006] [Indexed: 01/09/2023]
Abstract
Genetic analysis of the innate immune response in Drosophila has provided important insights into the mechanism of microbial sensing and the subsequent host signalling events. The two major players following immune challenge are the Toll and Immune deficiency (IMD) pathways, which are essential for fruit flies to survive infection. These pathways are homologous to the mammalian Toll-like receptor and tumour necrosis factor pathways, respectively. Moreover, microbial pattern-recognition receptors upstream of Toll and IMD, such as the peptidoglycan recognition proteins, have been isolated and studied at the structural and functional level. In the present, we will review recent data pertaining to the genetic, genomic, RNAi and infection studies that have added new complexities to the system.
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Affiliation(s)
- Lihui Wang
- Genetics Unit, Department of Biochemistry, University of Oxford, South Parks Road Oxford, OX1 3QU, UK
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