1
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Rhodes VL, Waterhouse RM, Michel K. The Molecular Toll Pathway Repertoire in Anopheline Mosquitoes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.09.12.612760. [PMID: 39345384 PMCID: PMC11429875 DOI: 10.1101/2024.09.12.612760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 10/01/2024]
Abstract
Innate immunity in mosquitoes has received much attention due to its potential impact on vector competence for vector-borne disease pathogens, including malaria parasites. The nuclear factor (NF)-κB-dependent Toll pathway is a major regulator of innate immunity in insects. In mosquitoes, this pathway controls transcription of the majority of the known canonical humoral immune effectors, mediates anti-bacterial, anti-fungal and anti-viral immune responses, and contributes to malaria parasite killing. However, besides initial gene annotation of putative Toll pathway members and genetic analysis of the contribution of few key components to immunity, the molecular make-up and function of the Toll pathway in mosquitoes is largely unexplored. To facilitate functional analyses of the Toll pathway in mosquitoes, we report here manually annotated and refined gene models of Toll-like receptors and all putative components of the intracellular signal transduction cascade across 19 anopheline genomes, and in two culicine genomes. In addition, based on phylogenetic analyses, we identified differing levels of evolutionary constraint across the intracellular Toll pathway members, and identified a recent radiation of TOLL1/5 within the An. gambiae complex. Together, this study provides insight into the evolution of TLRs and the putative members of the intracellular signal transduction cascade within the genus Anopheles.
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Affiliation(s)
- Victoria L. Rhodes
- Division of Biology, Kansas State University, Manhattan, KS 66506, USA
- Biology Department, Missouri Southern University, Joplin, MO 64801, USA
| | | | - Kristin Michel
- Division of Biology, Kansas State University, Manhattan, KS 66506, USA
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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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Hixson B, Huot L, Morejon B, Yang X, Nagy P, Michel K, Buchon N. The transcriptional response in mosquitoes distinguishes between fungi and bacteria but not Gram types. BMC Genomics 2024; 25:353. [PMID: 38594632 PMCID: PMC11003161 DOI: 10.1186/s12864-024-10153-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Accepted: 02/22/2024] [Indexed: 04/11/2024] Open
Abstract
Mosquitoes are prolific vectors of human pathogens, therefore a clear and accurate understanding of the organization of their antimicrobial defenses is crucial for informing the development of transmission control strategies. The canonical infection response in insects, as described in the insect model Drosophila melanogaster, is pathogen type-dependent, with distinct stereotypical responses to Gram-negative bacteria and Gram-positive bacteria/fungi mediated by the activation of the Imd and Toll pathways, respectively. To determine whether this pathogen-specific discrimination is shared by mosquitoes, we used RNAseq to capture the genome-wide transcriptional response of Aedes aegypti and Anopheles gambiae (s.l.) to systemic infection with Gram-negative bacteria, Gram-positive bacteria, yeasts, and filamentous fungi, as well as challenge with heat-killed Gram-negative, Gram-positive, and fungal pathogens. From the resulting data, we found that Ae. aegypti and An. gambiae both mount a core response to all categories of infection, and this response is highly conserved between the two species with respect to both function and orthology. When we compared the transcriptomes of mosquitoes infected with different types of bacteria, we observed that the intensity of the transcriptional response was correlated with both the virulence and growth rate of the infecting pathogen. Exhaustive comparisons of the transcriptomes of Gram-negative-challenged versus Gram-positive-challenged mosquitoes yielded no difference in either species. In Ae. aegypti, however, we identified transcriptional signatures specific to bacterial infection and to fungal infection. The bacterial infection response was dominated by the expression of defensins and cecropins, while the fungal infection response included the disproportionate upregulation of an uncharacterized family of glycine-rich proteins. These signatures were also observed in Ae. aegypti challenged with heat-killed bacteria and fungi, indicating that this species can discriminate between molecular patterns that are specific to bacteria and to fungi.
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Affiliation(s)
- Bretta Hixson
- Cornell Institute of Host-Microbe Interactions and Disease, Department of Entomology, Cornell University, Ithaca, NY, 14853, USA
| | - Louise Huot
- Cornell Institute of Host-Microbe Interactions and Disease, Department of Entomology, Cornell University, Ithaca, NY, 14853, USA
| | - Bianca Morejon
- Division of Biology, Kansas State University, Manhattan, KS, 66506, USA
| | - Xiaowei Yang
- Cornell Institute of Host-Microbe Interactions and Disease, Department of Entomology, Cornell University, Ithaca, NY, 14853, USA
- Current address: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute for Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Peter Nagy
- Cornell Institute of Host-Microbe Interactions and Disease, Department of Entomology, Cornell University, Ithaca, NY, 14853, USA
| | - Kristin Michel
- Division of Biology, Kansas State University, Manhattan, KS, 66506, USA
| | - Nicolas Buchon
- Cornell Institute of Host-Microbe Interactions and Disease, Department of Entomology, Cornell University, Ithaca, NY, 14853, USA.
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Jiang S, Bao J, Chen Y, Liu Z, Liu R, Cheng Y, Zhang L, Jiang X, Kong H. Immunological regulation by Toll-1 and Spätzle-4 in larval density-dependent prophylaxis of the oriental armyworm, Mythimna separata. Int J Biol Macromol 2024; 264:130778. [PMID: 38467221 DOI: 10.1016/j.ijbiomac.2024.130778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2023] [Revised: 02/19/2024] [Accepted: 03/08/2024] [Indexed: 03/13/2024]
Abstract
High population density has been shown to alter insect prophylactic immunity. Toll-Spätzle pathway performs a key function in insect innate immune response. To determine the role of Toll and Spätzle, two main components of Toll-Spätzle pathway, in the density-dependent prophylaxis of Mythimna separata. We identified full-length cDNA encoding the Toll-1 and Spätzle-4 genes in M. separata (designed MsToll-1 and Ms Spätzle-4). Both MsToll-1 and MsSpätzle-4 were expressed throughout all developmental stages. MsToll-1 expression was highly in fat body and brain and MsSpätzle-4 was highly expressed in brain and Malpighian tubule. With increased larval density, MsToll-1 expression was markedly up-regulated. MsSpätzle-4 expression was found to be raised in larvae that were fed in high density (5 and 10 larvae per jar). Co-immunoprecipitation assays demonstrated that MsToll-1 interacted with MsSpätzle-4. Immune-related genes transcriptions were considerably reduced in high-density larvae MsToll-1 (or MsSpätzle-4) was silenced by dsRNA injection. Meanwhile, a discernible reduction in the survival rate of the larvae exposed to Bacillus thuringiensis infection with silence of MsToll-1 (or MsSpätzle-4) was observed. This study implies that prophylactic immunity was influenced by crowded larvae via modulating the Toll-Spätzle pathway in M. separata and allow for a new understanding of into density-dependent prophylaxis in insects.
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Affiliation(s)
- Suwan Jiang
- College of Plant Protection, Yangzhou University, Wenhui East Road, NO. 48, Yangzhou 225009, PR China
| | - Jianqiang Bao
- College of Plant Protection, Yangzhou University, Wenhui East Road, NO. 48, Yangzhou 225009, PR China
| | - Yuxuan Chen
- College of Plant Protection, Yangzhou University, Wenhui East Road, NO. 48, Yangzhou 225009, PR China
| | - Zhonglin Liu
- College of Plant Protection, Yangzhou University, Wenhui East Road, NO. 48, Yangzhou 225009, PR China
| | - Rui Liu
- College of Plant Protection, Yangzhou University, Wenhui East Road, NO. 48, Yangzhou 225009, PR China
| | - Yunxia Cheng
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, NO. 2 of West Yuanmingyuan Road, Beijing 100193, PR China
| | - Lei Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, NO. 2 of West Yuanmingyuan Road, Beijing 100193, PR China
| | - Xingfu Jiang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, NO. 2 of West Yuanmingyuan Road, Beijing 100193, PR China.
| | - Hailong Kong
- College of Plant Protection, Yangzhou University, Wenhui East Road, NO. 48, Yangzhou 225009, PR China.
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Garrigós M, Ylla G, Martínez-de la Puente J, Figuerola J, Ruiz-López MJ. Two avian Plasmodium species trigger different transcriptional responses on their vector Culex pipiens. Mol Ecol 2023:e17240. [PMID: 38108558 DOI: 10.1111/mec.17240] [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: 06/10/2023] [Revised: 11/01/2023] [Accepted: 11/27/2023] [Indexed: 12/19/2023]
Abstract
Malaria is a mosquito-borne disease caused by protozoans of the genus Plasmodium that affects both humans and wildlife. The fitness consequences of infections by avian malaria are well known in birds, however, little information exists on its impact on mosquitoes. Here we study how Culex pipiens mosquitoes transcriptionally respond to infection by two different Plasmodium species, P. relictum and P. cathemerium, differing in their virulence (mortality rate) and transmissibility (parasite presence in exposed mosquitoes' saliva). We studied the mosquito response to the infection at three critical stages of parasite development: the formation of ookinetes at 24 h post-infection (hpi), the release of sporozoites into the hemocoel at 10 days post-infection (dpi), and the storage of sporozoites in the salivary glands at 21 dpi. For each time point, we characterized the gene expression of mosquitoes infected with each P. relictum and P. cathemerium and mosquitoes fed on an uninfected bird and, subsequently, compared their transcriptomic responses. Differential gene expression analysis showed that most transcriptomic changes occurred during the early infection stage (24 hpi), especially when comparing P. relictum and P. cathemerium-infected mosquitoes. Differentially expressed genes in mosquitoes infected with each species were related mainly to the metabolism of the immune response, trypsin, and other serine-proteases. We conclude that these differences in response may partly play a role in the differential virulence and transmissibility previously observed between P. relictum and P. cathemerium in Cx. pipiens.
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Affiliation(s)
- Marta Garrigós
- Department of Parasitology, University of Granada, Granada, Spain
| | - Guillem Ylla
- Bioinformatics and Genome Biology Lab, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
| | - Josué Martínez-de la Puente
- Department of Parasitology, University of Granada, Granada, Spain
- CIBER Epidemiologia y Salud Pública (CIBERESP), Madrid, Spain
| | - Jordi Figuerola
- CIBER Epidemiologia y Salud Pública (CIBERESP), Madrid, Spain
- Department of Wetland Ecology, Estación Biológica de Doñana, CSIC, Sevilla, Spain
| | - María José Ruiz-López
- CIBER Epidemiologia y Salud Pública (CIBERESP), Madrid, Spain
- Department of Wetland Ecology, Estación Biológica de Doñana, CSIC, Sevilla, Spain
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Yang L, Li J, Yang L, Wang X, Xiao S, Xiong S, Xu X, Xu J, Ye G. Altered Gene Expression of the Parasitoid Pteromalus puparum after Entomopathogenic Fungus Beauveria bassiana Infection. Int J Mol Sci 2023; 24:17030. [PMID: 38069352 PMCID: PMC10707577 DOI: 10.3390/ijms242317030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 11/28/2023] [Accepted: 11/29/2023] [Indexed: 12/18/2023] Open
Abstract
Both parasitoids and entomopathogenic fungi are becoming increasingly crucial for managing pest populations. Therefore, it is essential to carefully consider the potential impact of entomopathogenic fungi on parasitoids due to their widespread pathogenicity and the possible overlap between these biological control tools during field applications. However, despite their importance, little research has been conducted on the pathogenicity of entomopathogenic fungi on parasitoids. In our study, we aimed to address this knowledge gap by investigating the interaction between the well-known entomopathogenic fungus Beauveria bassiana, and the pupal endoparasitoid Pteromalus puparum. Our results demonstrated that the presence of B. bassiana significantly affected the survival rates of P. puparum under laboratory conditions. The pathogenicity of B. bassiana on P. puparum was dose- and time-dependent, as determined via through surface spraying or oral ingestion. RNA-Seq analysis revealed that the immune system plays a primary and crucial role in defending against B. bassiana. Notably, several upregulated differentially expressed genes (DEGs) involved in the Toll and IMD pathways, which are key components of the insect immune system, and antimicrobial peptides were rapidly induced during both the early and late stages of infection. In contrast, a majority of genes involved in the activation of prophenoloxidase and antioxidant mechanisms were downregulated. Additionally, we identified downregulated DEGs related to cuticle formation, olfactory mechanisms, and detoxification processes. In summary, our study provides valuable insights into the interactions between P. puparum and B. bassiana, shedding light on the changes in gene expression during fungal infection. These findings have significant implications for the development of more effective and sustainable strategies for pest management in agriculture.
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Affiliation(s)
- Lei Yang
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Key Laboratory of Traceability for Agricultural Genetically Modified Organisms, Ministry of Agriculture and Rural Affairs, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China
| | - Jinting Li
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Key Laboratory of Traceability for Agricultural Genetically Modified Organisms, Ministry of Agriculture and Rural Affairs, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China
| | - Lei Yang
- State Key Laboratory of Rice Biology and Breeding & Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou 310058, China
| | - Xiaofu Wang
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Key Laboratory of Traceability for Agricultural Genetically Modified Organisms, Ministry of Agriculture and Rural Affairs, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China
| | - Shan Xiao
- State Key Laboratory of Rice Biology and Breeding & Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou 310058, China
| | - Shijiao Xiong
- State Key Laboratory of Rice Biology and Breeding & Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou 310058, China
| | - Xiaoli Xu
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Key Laboratory of Traceability for Agricultural Genetically Modified Organisms, Ministry of Agriculture and Rural Affairs, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China
| | - Junfeng Xu
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Key Laboratory of Traceability for Agricultural Genetically Modified Organisms, Ministry of Agriculture and Rural Affairs, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China
| | - Gongyin Ye
- State Key Laboratory of Rice Biology and Breeding & Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou 310058, China
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7
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Yan J, Kim CH, Chesser L, Ramirez JL, Stone CM. Nutritional stress compromises mosquito fitness and antiviral immunity, while enhancing dengue virus infection susceptibility. Commun Biol 2023; 6:1123. [PMID: 37932414 PMCID: PMC10628303 DOI: 10.1038/s42003-023-05516-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Accepted: 10/27/2023] [Indexed: 11/08/2023] Open
Abstract
Diet-induced nutritional stress can influence pathogen transmission potential in mosquitoes by impacting life history traits, infection susceptibility, and immunity. To investigate these effects, we manipulate mosquito diets at larval and adult stages, creating two nutritional levels (low and normal), and expose adults to dengue virus (DENV). We observe that egg number is reduced by nutritional stress at both stages and viral exposure separately and jointly, while the likelihood of laying eggs is exclusively influenced by adult nutritional stress. Adult nutritional stress alone shortens survival, while any pairwise combination between both-stage stress and viral exposure have a synergistic effect. Additionally, adult nutritional stress increases susceptibility to DENV infection, while larval nutritional stress likely has a similar effect operating via smaller body size. Furthermore, adult nutritional stress negatively impacts viral titers in infected mosquitoes; however, some survive and show increased titers over time. The immune response to DENV infection is overall suppressed by larval and adult nutritional stress, with specific genes related to Toll, JAK-STAT, and Imd immune signaling pathways, and antimicrobial peptides being downregulated. Our findings underscore the importance of nutritional stress in shaping mosquito traits, infection outcomes, and immune responses, all of which impact the vectorial capacity for DENV transmission.
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Affiliation(s)
- Jiayue Yan
- Illinois Natural History Survey, University of Illinois at Urbana-Champaign, Champaign, IL, USA.
| | - Chang-Hyun Kim
- Illinois Natural History Survey, University of Illinois at Urbana-Champaign, Champaign, IL, USA
| | - Leta Chesser
- Illinois Natural History Survey, University of Illinois at Urbana-Champaign, Champaign, IL, USA
| | - Jose L Ramirez
- USDA, Agricultural Research Service, National Center for Agricultural Utilization Research, Crop Bioprotection Research Unit, Peoria, IL, USA
| | - Chris M Stone
- Illinois Natural History Survey, University of Illinois at Urbana-Champaign, Champaign, IL, USA
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Palli SR. RNAi turns 25:contributions and challenges in insect science. FRONTIERS IN INSECT SCIENCE 2023; 3:1209478. [PMID: 38469536 PMCID: PMC10926446 DOI: 10.3389/finsc.2023.1209478] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Accepted: 05/26/2023] [Indexed: 03/13/2024]
Abstract
Since its discovery in 1998, RNA interference (RNAi), a Nobel prize-winning technology, made significant contributions to advances in biology because of its ability to mediate the knockdown of specific target genes. RNAi applications in medicine and agriculture have been explored with mixed success. The past 25 years of research on RNAi resulted in advances in our understanding of the mechanisms of its action, target specificity, and differential efficiency among animals and plants. RNAi played a major role in advances in insect biology. Did RNAi technology fully meet insect pest and disease vector management expectations? This review will discuss recent advances in the mechanisms of RNAi and its contributions to insect science. The remaining challenges, including delivery to the target site, differential efficiency, potential resistance development and possible solutions for the widespread use of this technology in insect management.
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Affiliation(s)
- Subba Reddy Palli
- Department of Entomology, Martin-Gatton College of Agriculture, Food and Environment, University of Kentucky, Lexington, KY, United States
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Yang L, Yang L, Wang X, Peng C, Chen X, Wei W, Xu X, Ye G, Xu J. Toll and IMD Immune Pathways Are Important Antifungal Defense Components in a Pupal Parasitoid, Pteromalus puparum. Int J Mol Sci 2023; 24:14088. [PMID: 37762389 PMCID: PMC10531655 DOI: 10.3390/ijms241814088] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2023] [Revised: 09/03/2023] [Accepted: 09/07/2023] [Indexed: 09/29/2023] Open
Abstract
Insects employ multifaceted strategies to combat invading fungi, with immunity being a promising mechanism. Immune pathways function in signal transduction and amplification, ultimately leading to the activation of antimicrobial peptides (AMPs). Although several studies have shown that immune pathways are responsible for defending against fungi, the roles of parasitoid immune pathways involved in antifungal responses remain unknown. In this study, we evaluated the roles of the Toll and IMD pathways of a pupal parasitoid, Pteromalus puparum (Hymenoptera: Pteromalidae), in fighting against Beauveria bassiana (Hypocreales: Cordycipitaceae). Successful colonization of B. bassiana on P. puparum adults was confirmed by scanning electron microscopy (SEM). AMPs were induced upon B. bassiana infection. The knockdown of key genes, PpTollA and PpIMD, in Toll and IMD signaling pathways, respectively, significantly compromised insect defense against fungal infection. The knockdown of either PpTollA or PpIMD in P. puparum dramatically promoted the proliferation of B. bassiana, resulting in a decreased survival rate and downregulated expression levels of AMPs against B. bassiana compared to controls. These data indicated that PpTollA and PpIMD participate in Toll and IMD-mediated activation of antifungal responses, respectively. In summary, this study has greatly broadened our knowledge of the parasitoid antifungal immunity against fungi.
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Affiliation(s)
- Lei Yang
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Key Laboratory of Traceability for Agricultural Genetically Modified Organisms, Ministry of Agriculture and Rural Affairs, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China
| | - Lei Yang
- State Key Laboratory of Rice Biology and Breeding & Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou 310058, China
| | - Xiaofu Wang
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Key Laboratory of Traceability for Agricultural Genetically Modified Organisms, Ministry of Agriculture and Rural Affairs, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China
| | - Cheng Peng
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Key Laboratory of Traceability for Agricultural Genetically Modified Organisms, Ministry of Agriculture and Rural Affairs, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China
| | - Xiaoyun Chen
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Key Laboratory of Traceability for Agricultural Genetically Modified Organisms, Ministry of Agriculture and Rural Affairs, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China
| | - Wei Wei
- State Key Laboratory of Rice Biology and Breeding & Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou 310058, China
| | - Xiaoli Xu
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Key Laboratory of Traceability for Agricultural Genetically Modified Organisms, Ministry of Agriculture and Rural Affairs, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China
| | - Gongyin Ye
- State Key Laboratory of Rice Biology and Breeding & Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou 310058, China
| | - Junfeng Xu
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Key Laboratory of Traceability for Agricultural Genetically Modified Organisms, Ministry of Agriculture and Rural Affairs, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China
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10
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Hixson B, Huot L, Morejon B, Yang X, Nagy P, Michel K, Buchon N. The transcriptional response in mosquitoes distinguishes between fungi and bacteria but not Gram types. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.26.550663. [PMID: 37546902 PMCID: PMC10402080 DOI: 10.1101/2023.07.26.550663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/08/2023]
Abstract
Mosquitoes are prolific vectors of human pathogens; a clear and accurate understanding of the organization of their antimicrobial defenses is crucial for informing the development of transmission control strategies. The canonical infection response in insects, as described in the insect model Drosophila melanogaster , is pathogen type-dependent, with distinct stereotypical responses to Gram-negative bacteria and Gram-positive bacteria/fungi mediated by the activation of the Imd and Toll pathways, respectively. To determine whether this pathogen-specific discrimination is shared by mosquitoes, we used RNAseq to capture the genome-wide transcriptional response of Aedes aegypti and Anopheles gambiae ( s.l. ) to systemic infection with Gram-negative bacteria, Gram-positive bacteria, yeasts, and filamentous fungi, as well as challenge with heat-killed Gram-negative, Gram-positive, and fungal pathogens. From the resulting data, we found that Ae. aegypti and An. gambiae both mount a core response to all categories of infection, and this response is highly conserved between the two species with respect to both function and orthology. When we compared the transcriptomes of mosquitoes infected with different types of bacteria, we observed that the intensity of the transcriptional response was correlated with both the virulence and growth rate of the infecting pathogen. Exhaustive comparisons of the transcriptomes of Gram-negative-challenged versus Gram-positive-challenged mosquitoes yielded no difference in either species. In Ae. aegypti , however, we identified transcriptional signatures specific to bacterial infection and to fungal infection. The bacterial infection response was dominated by the expression of defensins and cecropins, while the fungal infection response included the disproportionate upregulation of an uncharacterized family of glycine-rich proteins. These signatures were also observed in Ae. aegypti challenged with heat-killed bacteria and fungi, indicating that this species can discriminate between molecular patterns that are specific to bacteria and to fungi.
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11
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Wrońska AK, Kaczmarek A, Boguś MI, Kuna A. Lipids as a key element of insect defense systems. Front Genet 2023; 14:1183659. [PMID: 37359377 PMCID: PMC10289264 DOI: 10.3389/fgene.2023.1183659] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Accepted: 05/31/2023] [Indexed: 06/28/2023] Open
Abstract
The relationship between insect pathogenic fungi and their insect hosts is a classic example of a co-evolutionary arms race between pathogen and target host: parasites evolve towards mechanisms that increase their advantage over the host, and the host increasingly strengthens its defenses. The present review summarizes the literature data describing the direct and indirect role of lipids as an important defense mechanism during fungal infection. Insect defense mechanisms comprise anatomical and physiological barriers, and cellular and humoral response mechanisms. The entomopathogenic fungi have the unique ability to digest the insect cuticle by producing hydrolytic enzymes with chitin-, lipo- and proteolytic activity; besides the oral tract, cuticle pays the way for fungal entry within the host. The key factor in insect resistance to fungal infection is the presence of certain types of lipids (free fatty acids, waxes or hydrocarbons) which can promote or inhibit fungal attachment to cuticle, and might also have antifungal activity. Lipids are considered as an important source of energy, and as triglycerides are stored in the fat body, a structure analogous to the liver and adipose tissue in vertebrates. In addition, the fat body plays a key role in innate humoral immunity by producing a range of bactericidal proteins and polypeptides, one of which is lysozyme. Energy derived from lipid metabolism is used by hemocytes to migrate to the site of fungal infection, and for phagocytosis, nodulation and encapsulation. One polyunsaturated fatty acid, arachidonic acid, is used in the synthesis of eicosanoids, which play several crucial roles in insect physiology and immunology. Apolipoprotein III is important compound with antifungal activity, which can modulate insect cellular response and is considered as important signal molecule.
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Affiliation(s)
- Anna Katarzyna Wrońska
- Museum and Institute of Zoology, Polish Academy of Science, Warszawa, Poland
- Witold Stefański Institute of Parasitology, Polish Academy of Sciences, Warsaw, Poland
| | - Agata Kaczmarek
- Museum and Institute of Zoology, Polish Academy of Science, Warszawa, Poland
- Witold Stefański Institute of Parasitology, Polish Academy of Sciences, Warsaw, Poland
| | - Mieczysława Irena Boguś
- Museum and Institute of Zoology, Polish Academy of Science, Warszawa, Poland
- Witold Stefański Institute of Parasitology, Polish Academy of Sciences, Warsaw, Poland
| | - Anna Kuna
- Independent Researcher, Warsaw, Poland
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12
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Laureti M, Lee RX, Bennett A, Wilson LA, Sy VE, Kohl A, Dietrich I. Rift Valley Fever Virus Primes Immune Responses in Aedes aegypti Cells. Pathogens 2023; 12:563. [PMID: 37111448 PMCID: PMC10146816 DOI: 10.3390/pathogens12040563] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 03/25/2023] [Accepted: 04/03/2023] [Indexed: 04/29/2023] Open
Abstract
The ongoing global emergence of arthropod-borne (arbo) viruses has accelerated research into the interactions of these viruses with the immune systems of their vectors. Only limited information exists on how bunyaviruses, such as Rift Valley fever virus (RVFV), are sensed by mosquito immunity or escape detection. RVFV is a zoonotic phlebovirus (Bunyavirales; Phenuiviridae) of veterinary and human public health and economic importance. We have shown that the infection of mosquitoes with RVFV triggers the activation of RNA interference pathways, which moderately restrict viral replication. Here, we aimed to better understand the interactions between RVFV and other vector immune signaling pathways that might influence RVFV replication and transmission. For this, we used the immunocompetent Aedes aegypti Aag2 cell line as a model. We found that bacteria-induced immune responses restricted RVFV replication. However, virus infection alone did not alter the gene expression levels of immune effectors. Instead, it resulted in the marked enhancement of immune responses to subsequent bacterial stimulation. The gene expression levels of several mosquito immune pattern recognition receptors were altered by RVFV infection, which may contribute to this immune priming. Our findings imply that there is a complex interplay between RVFV and mosquito immunity that could be targeted in disease prevention strategies.
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Affiliation(s)
| | - Rui-Xue Lee
- MRC-University of Glasgow Centre for Virus Research, 464 Bearsden Road, Glasgow G61 1QH, UK
| | - Amelia Bennett
- The Pirbright Institute, Ash Road, Pirbright GU24 0NF, UK
- Department of Life Sciences, Faculty of Science, Claverton Down, University of Bath, Bath BA2 7AY, UK
| | - Lucas Aladar Wilson
- The Pirbright Institute, Ash Road, Pirbright GU24 0NF, UK
- Institute of Medical Sciences, School of Medicine, Medical Sciences and Nutrition, Foresterhill, University of Aberdeen, Aberdeen AB25 2ZD, UK
| | | | - Alain Kohl
- MRC-University of Glasgow Centre for Virus Research, 464 Bearsden Road, Glasgow G61 1QH, UK
| | - Isabelle Dietrich
- The Pirbright Institute, Ash Road, Pirbright GU24 0NF, UK
- MRC-University of Glasgow Centre for Virus Research, 464 Bearsden Road, Glasgow G61 1QH, UK
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13
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Expression of mosquito miRNAs in entomopathogenic fungus induces pathogen-mediated host RNA interference and increases fungal efficacy. Cell Rep 2022; 41:111527. [PMID: 36288711 DOI: 10.1016/j.celrep.2022.111527] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2022] [Revised: 08/18/2022] [Accepted: 09/28/2022] [Indexed: 11/21/2022] Open
Abstract
The growing threat of insecticide resistance prompts the urgent need to develop additional tools for mosquito control. Entomopathogenic fungi provide an eco-friendly alternative to chemical insecticides. One limitation to the use of mycoinsecticides is their relatively low virulence. Here, we report an approach for suppressing mosquito immunity and increasing fungal virulence. We engineered Beauveria bassiana to express Aedes immunosuppressive microRNAs (miRNAs) to induce host RNA interference (RNAi) immune responses. We show that engineered strains can produce and deliver the miRNAs into host cells to activate cross-kingdom RNAi during infection and suppress mosquito immunity by targeting multiple host genes, thereby dramatically increasing fungal virulence against Aedes aegypti and Galleria mellonella larvae. Importantly, expressing host miRNAs also significantly increases fungal virulence against insecticide-resistant mosquitoes, creating potential for insecticide-resistance management. This pathogen-mediated RNAi (pmRNAi)-based approach provides an innovative strategy to enhance the efficacy of fungal insecticides and eliminate the likelihood of resistance development.
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14
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Saucereau Y, Wilson TH, Tang MCK, Moncrieffe MC, Hardwick SW, Chirgadze DY, Soares SG, Marcaida MJ, Gay NJ, Gangloff M. Structure and dynamics of Toll immunoreceptor activation in the mosquito Aedes aegypti. Nat Commun 2022; 13:5110. [PMID: 36042238 PMCID: PMC9427763 DOI: 10.1038/s41467-022-32690-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 08/09/2022] [Indexed: 11/09/2022] Open
Abstract
Aedes aegypti has evolved to become an efficient vector for arboviruses but the mechanisms of host-pathogen tolerance are unknown. Immunoreceptor Toll and its ligand Spaetzle have undergone duplication which may allow neofunctionalization and adaptation. Here we present cryo-EM structures and biophysical characterisation of low affinity Toll5A complexes that display transient but specific interactions with Spaetzle1C, forming asymmetric complexes, with only one ligand clearly resolved. Loop structures of Spaetzle1C and Toll5A intercalate, temporarily bridging the receptor C-termini to promote signalling. By contrast unbound receptors form head-to-head homodimers that keep the juxtamembrane regions far apart in an inactive conformation. Interestingly the transcriptional signature of Spaetzle1C differs from other Spaetzle cytokines and controls genes involved in innate immunity, metabolism and tissue regeneration. Taken together our results explain how upregulation of Spaetzle1C in the midgut and Toll5A in the salivary gland shape the concomitant immune response.
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Affiliation(s)
- Yoann Saucereau
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge, CB2 1GA, UK
| | - Thomas H Wilson
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge, CB2 1GA, UK
| | - Matthew C K Tang
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge, CB2 1GA, UK
| | - Martin C Moncrieffe
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge, CB2 1GA, UK
| | - Steven W Hardwick
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge, CB2 1GA, UK
| | - Dimitri Y Chirgadze
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge, CB2 1GA, UK
| | - Sandro G Soares
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge, CB2 1GA, UK
| | - Maria Jose Marcaida
- Institute of Bioengineering, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Nicholas J Gay
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge, CB2 1GA, UK
| | - Monique Gangloff
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge, CB2 1GA, UK.
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15
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Bae YM, Jo YH, Patnaik BB, Kim BB, Park KB, Edosa TT, Keshavarz M, Kojour MAM, Lee YS, Han YS. Tenebrio molitor Spätzle 1b Is Required to Confer Antibacterial Defense Against Gram-Negative Bacteria by Regulation of Antimicrobial Peptides. Front Physiol 2021; 12:758859. [PMID: 34867464 PMCID: PMC8637286 DOI: 10.3389/fphys.2021.758859] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Accepted: 10/28/2021] [Indexed: 11/13/2022] Open
Abstract
Innate immunity is the ultimate line of defense against invading pathogens in insects. Unlike in the mammalian model, in the insect model, invading pathogens are recognized by extracellular receptors, which activate the Toll signaling pathway through an extracellular serine protease cascade. In the Toll-NF-κB pathway, the extracellular spätzle protein acts as a downstream ligand for Toll receptors in insects. In this study, we identified a novel Spätzle isoform (TmSpz1b) from RNA sequencing database of Tenebrio molitor. TmSpz1b was bioinformatically analyzed, and functionally characterized for the antimicrobial function by RNA interference (RNAi). The 702 bp open reading frame of TmSpz1b encoded a putative protein of 233 amino acid residues. A conserved cystine-knot domain with seven cysteine residues in TmSpz1b was involved in three disulfide bridges and the formation of a spätzle dimer. TmSpz1b was mostly expressed in the hemocytes of T. molitor late instar larvae. The mRNA expression of TmSpz1b was highly induced in the hemocytes after Escherichia coli, Staphylococcus aureus, and Candida albicans stimulation of T. molitor larvae. TmSpz1b silenced larvae were significantly more susceptible to E. coli infection. In addition, RNAi-based functional assay characterized TmSpz1b to be involved in the positive regulation of antimicrobial peptide genes in hemocytes and fat bodies. Further, the TmDorX2 transcripts were downregulated in TmSpz1b silenced individuals upon E. coli challenge suggesting the relationship to Toll signaling pathway. These results indicate that TmSpz1b is involved in the T. molitor innate immunity, causes the sequestration of Gram-negative bacteria by the regulatory action of antimicrobial peptides, and enhances the survival of T. molitor larvae.
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Affiliation(s)
- Young Min Bae
- Department of Applied Biology, Institute of Environmentally-Friendly Agriculture (IEFA), College of Agriculture and Life Sciences, Chonnam National University, Gwangju, South Korea
| | - Yong Hun Jo
- Department of Applied Biology, Institute of Environmentally-Friendly Agriculture (IEFA), College of Agriculture and Life Sciences, Chonnam National University, Gwangju, South Korea
| | - Bharat Bhusan Patnaik
- Department of Bio-Science and Bio-Technology, Fakir Mohan University, Balasore, India
| | - Bo Bae Kim
- Department of Applied Biology, Institute of Environmentally-Friendly Agriculture (IEFA), College of Agriculture and Life Sciences, Chonnam National University, Gwangju, South Korea
| | - Ki Beom Park
- Department of Applied Biology, Institute of Environmentally-Friendly Agriculture (IEFA), College of Agriculture and Life Sciences, Chonnam National University, Gwangju, South Korea
| | - Tariku Tesfaye Edosa
- Department of Applied Biology, Institute of Environmentally-Friendly Agriculture (IEFA), College of Agriculture and Life Sciences, Chonnam National University, Gwangju, South Korea.,Ethiopian Institute of Agricultural Research, Ambo Agricultural Research Center, Ambo, Ethiopia
| | - Maryam Keshavarz
- Department of Applied Biology, Institute of Environmentally-Friendly Agriculture (IEFA), College of Agriculture and Life Sciences, Chonnam National University, Gwangju, South Korea.,Department of Evolutionary Biology, Institute for Biology-Zoology, Free University of Berlin, Berlin, Germany
| | - Maryam Ali Mohammadie Kojour
- Department of Applied Biology, Institute of Environmentally-Friendly Agriculture (IEFA), College of Agriculture and Life Sciences, Chonnam National University, Gwangju, South Korea
| | - Yong Seok Lee
- Department of Biology, College of Natural Sciences, Soonchunhyang University, Asan, South Korea
| | - Yeon Soo Han
- Department of Applied Biology, Institute of Environmentally-Friendly Agriculture (IEFA), College of Agriculture and Life Sciences, Chonnam National University, Gwangju, South Korea
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16
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TmSpz-like Plays a Fundamental Role in Response to E. coli but Not S. aureus or C. albican Infection in Tenebrio molitor via Regulation of Antimicrobial Peptide Production. Int J Mol Sci 2021; 22:ijms221910888. [PMID: 34639230 PMCID: PMC8509142 DOI: 10.3390/ijms221910888] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 09/29/2021] [Accepted: 10/04/2021] [Indexed: 11/25/2022] Open
Abstract
The cystine knot protein Spätzle is a Toll receptor ligand that modulates the intracellular signaling cascade involved in the nuclear factor kappa B (NF-κB)-mediated regulation of antimicrobial peptide (AMP)-encoding genes. Spätzle-mediated activation of the Toll pathway is critical for the innate immune responses of insects against Gram-positive bacteria and fungi. In this study, the open reading frame (ORF) sequence of Spätzle-like from T. molitor (TmSpz-like) identified from the RNA sequencing dataset was cloned and sequenced. The 885-bp TmSpz-like ORF encoded a polypeptide of 294 amino acid residues. TmSpz-like comprised a cystine knot domain with six conserved cysteine residues that formed three disulfide bonds. Additionally, TmSpz-like exhibited the highest amino acid sequence similarity with T. castaneum Spätzle (TcSpz). In the phylogenetic tree, TmSpz-like and TcSpz were located within a single cluster. The expression of TmSpz-like was upregulated in the Malpighian tubules and gut tissues of T. molitor. Additionally, the expression of TmSpz-like in the whole body and gut of the larvae was upregulated at 24 h post-E. coli infection. The results of RNA interference experiments revealed that TmSpz-like is critical for the viability of E. coli-infected T. molitor larvae. Eleven AMP-encoding genes were downregulated in the E. coli-infected TmSpz-like knockdown larvae, which suggested that TmSpz-like positively regulated these genes. Additionally, the NF-κB-encoding genes (TmDorX1, TmDorX2, and TmRelish) were downregulated in the E. coli-infected TmSpz-like knockdown larvae. Thus, TmSpz-like plays a critical role in the regulation of AMP production in T. molitor in response to E. coli infection.
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17
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Angleró-Rodríguez YI, Tikhe CV, Kang S, Dimopoulos G. Aedes aegypti Toll pathway is induced through dsRNA sensing in endosomes. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2021; 122:104138. [PMID: 34022257 DOI: 10.1016/j.dci.2021.104138] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 05/13/2021] [Accepted: 05/14/2021] [Indexed: 06/12/2023]
Abstract
Mosquito anti-pathogen immune responses, including those controlling infection with arboviruses are regulated by multiple signal transduction pathways. While the Toll pathway is critical in the defense against arboviruses such as dengue and Zika viruses, the factors and mechanisms involved in virus recognition leading to the activation of the Toll pathway are not fully understood. In this study we evaluated the role of virus-produced double-stranded RNA (dsRNA) intermediates in mosquito immune activation by utilizing the synthetic dsRNA analog polyinosinic-polycytidylic acid (poly I:C). Poly I:C treatment of Aedes aegypti mosquitoes and Aag2 cells reduced DENV infection. Transcriptomic analyses of Aag2 cell responses to poly I:C indicated putative activation of the Toll pathway. We found that poly I:C is translocated to the endosomal compartment of Aag2 cells, and that the A. aegypti Toll 6 receptor is a putative dsRNA recognition receptor. This study elucidates the role of dsRNAs in the immune activation of non-RNAi pathways in mosquitoes.
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Affiliation(s)
| | - Chinmay V Tikhe
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, United States
| | - Seokyoung Kang
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, United States
| | - George Dimopoulos
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, United States.
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18
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Mollah MMI, Ahmed S, Kim Y. Immune mediation of HMG-like DSP1 via Toll-Spätzle pathway and its specific inhibition by salicylic acid analogs. PLoS Pathog 2021; 17:e1009467. [PMID: 33765093 PMCID: PMC8023496 DOI: 10.1371/journal.ppat.1009467] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 04/06/2021] [Accepted: 03/11/2021] [Indexed: 12/22/2022] Open
Abstract
Xenorhabdus hominickii, an entomopathogenic bacterium, inhibits eicosanoid biosynthesis of target insects to suppress their immune responses by inhibiting phospholipase A2 (PLA2) through binding to a damage-associated molecular pattern (DAMP) molecule called dorsal switch protein 1 (DSP1) from Spodoptera exigua, a lepidopteran insect. However, the signalling pathway between DSP1 and PLA2 remains unknown. The objective of this study was to determine whether DSP1 could activate Toll immune signalling pathway to activate PLA2 activation and whether X. hominickii metabolites could inhibit DSP1 to shutdown eicosanoid biosynthesis. Toll-Spätzle (Spz) signalling pathway includes two Spz (SeSpz1 and SeSpz2) and 10 Toll receptors (SeToll1-10) in S. exigua. Loss-of-function approach using RNA interference showed that SeSpz1 and SeToll9 played crucial roles in connecting DSP1 mediation to activate PLA2. Furthermore, a deletion mutant against SeToll9 using CRISPR/Cas9 abolished DSP1 mediation and induced significant immunosuppression. Organic extracts of X. hominickii culture broth could bind to DSP1 at a low micromolar range. Subsequent sequential fractionations along with binding assays led to the identification of seven potent compounds including 3-ethoxy-4-methoxyphenol (EMP). EMP could bind to DSP1 and prevent its translocation to plasma in response to bacterial challenge and suppress the up-regulation of PLA2 activity. These results suggest that X. hominickii inhibits DSP1 and prevents its DAMP role in activating Toll immune signalling pathway including PLA2 activation, leading to significant immunosuppression of target insects. Immune responses of insects are highly effective in defending various entomopathogens. Xenorhabdus hominickii is an entomopathogenic bacterium that uses a pathogenic strategy of suppressing host insect immunity by inhibiting phospholipase A2 (PLA2) which catalyzes the committed step for eicosanoid biosynthesis. Eicosanoids mediate both cellular and humoral immune responses in insects. This study discovers an upstream signalling pathway to activate PLA2 in response to bacterial challenge. Se-DSP1 is an insect homolog of vertebrate HMGB1 that acts as a damage-associated molecular pattern. Upon bacterial infection, Se-DSP1 is released to the circulatory system to activate Spätzle, an insect cytokine that can bind to Toll receptor. Toll immune signalling pathway can activate antimicrobial peptide gene expression and PLA2. A deletion mutant against a Toll gene abolished immune responses mediated by Se-DSP1. Indeed, X. hominickii can produce and secrete secondary metabolites including salicylic acid analogs that can strongly bind to Se-DSP1. These bacterial metabolites prevented the release of Se-DSP1, which impaired the activation of PLA2 and resulted in a significant immunosuppression of target insects against bacterial infection.
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Affiliation(s)
- Md. Mahi Imam Mollah
- Department of Plant Medicals, College of Life Sciences, Andong National University, Andong, Korea
| | - Shabbir Ahmed
- Department of Plant Medicals, College of Life Sciences, Andong National University, Andong, Korea
| | - Yonggyun Kim
- Department of Plant Medicals, College of Life Sciences, Andong National University, Andong, Korea
- * E-mail:
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19
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Wei Y, Wang J, Wei YH, Song Z, Hu K, Chen Y, Zhou G, Zhong D, Zheng X. Vector Competence for DENV-2 Among Aedes albopictus (Diptera: Culicidae) Populations in China. Front Cell Infect Microbiol 2021; 11:649975. [PMID: 33834007 PMCID: PMC8021855 DOI: 10.3389/fcimb.2021.649975] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 03/08/2021] [Indexed: 11/21/2022] Open
Abstract
Aedes albopictus is a vector of over 20 arboviruses that has spread throughout the world, mainly in the second half of the twentieth century. Approximately 50–100 million people are infected with dengue virus (DENV) transmitted by Aedes mosquitoes each year, leading to heavy economic burdens for both governments and individuals, among countless other negative consequences. Understanding the vector competence of vector species is critical for effectively preventing and controlling vector-borne diseases. Accordingly, in this study, vector competence was evaluated by quantitative analysis of DENV-2 loads in mosquito tissues (midguts, heads, and salivary glands) and whole mosquitoes through real-time quantitative polymerase chain reaction (RT-qPCR) analysis. Wolbachia and the expression of immune-associated genes (Rel1, Rel2, Dicer2, and STAT) in mosquitoes were also detected by RT-qPCR to explore their impact on vector competence. The amount of DENV-2 in the mosquito midguts, heads, and salivary glands from southern-western China were found to be lower than those from eastern-central-northern China. The DENV-2 loads in whole mosquitoes showed a negative correlation with Rel1 gene (r = -0.285, P = 0.011) and STAT gene expression levels (r = -0.289, P = 0.009). In terms of Wolbachia strains, the density of the wAlbB strain was found to be significantly higher than that of the wAlbA strain in the eight Ae. albopictus populations, and the relative density of the wAlbB strain in mosquitoes from southern-western China was higher than those from eastern-central-northern China. The relative density of the wAlbB strain showed a negative correlation with the mean loads of DENV-2 in the heads (r = -0.729, P = 0.040), salivary glands (r = -0.785, P = 0.021), and whole mosquitoes (r = -0.909, P = 0.002). Thus, there are lower DENV-2 loads in the mosquitoes from southern-western China, which may be related to the innate immunity of mosquitoes as affected by Rel1 in the Toll pathway, STAT in the JAK-STAT pathway, and the relative density of the wAlbB strain.
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Affiliation(s)
- Yong Wei
- Department of Pathogen Biology, School of Public Health, Southern Medical University, Guangzhou, China
| | - Jiatian Wang
- Department of Pathogen Biology, School of Public Health, Southern Medical University, Guangzhou, China
| | - Yuan-Huan Wei
- Department of Clinical Nutrition, Huazhong University of Science and Technology Union Shenzhen Hospital, Shenzhen, China
| | - Zhangyao Song
- Department of Pathogen Biology, School of Public Health, Southern Medical University, Guangzhou, China
| | - Ke Hu
- Department of Pathogen Biology, School of Public Health, Southern Medical University, Guangzhou, China
| | - Yulan Chen
- Department of Pathogen Biology, School of Public Health, Southern Medical University, Guangzhou, China
| | - Guofa Zhou
- Program in Public Health, College of Health Sciences, University of California, Irvine, Irvine, CA, United States
| | - Daibin Zhong
- Program in Public Health, College of Health Sciences, University of California, Irvine, Irvine, CA, United States
| | - Xueli Zheng
- Department of Pathogen Biology, School of Public Health, Southern Medical University, Guangzhou, China
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20
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Bitencourt RDOB, Salcedo-Porras N, Umaña-Diaz C, da Costa Angelo I, Lowenberger C. Antifungal immune responses in mosquitoes (Diptera: Culicidae): A review. J Invertebr Pathol 2020; 178:107505. [PMID: 33238166 DOI: 10.1016/j.jip.2020.107505] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 10/27/2020] [Accepted: 11/17/2020] [Indexed: 02/08/2023]
Abstract
Mosquitoes transmit many parasites and pathogens to humans that cause significant morbidity and mortality. As such, we are constantly looking for new methods to reduce mosquito populations, including the use of effective biological controls. Entomopathogenic fungi are excellent candidate biocontrol agents to control mosquitoes. Understanding the complex ecological, environmental, and molecular interactions between hosts and pathogens are essential to create novel, effective and safe biocontrol agents. Understanding how mosquitoes recognize and eliminate pathogens such as entomopathogenic fungi may allow us to create insect-order specific biocontrol agents to reduce pest populations. Here we summarize the current knowledge of fungal infection, colonization, development, and replication within mosquitoes and the innate immune responses of the mosquitoes towards the fungal pathogens, emphasizing those features required for an effective mosquito biocontrol agent.
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Affiliation(s)
- Ricardo de Oliveira Barbosa Bitencourt
- Program in Veterinary Science, Institute of Veterinary Science, Rural Federal University of Rio de Janeiro, Seropédica, RJ, Brazil; Centre for Cell Biology, Development and Disease, Department of Biological Sciences, Simon Fraser University, Burnaby BC V5A 1S6, British Columbia, Canada.
| | - Nicolas Salcedo-Porras
- Centre for Cell Biology, Development and Disease, Department of Biological Sciences, Simon Fraser University, Burnaby BC V5A 1S6, British Columbia, Canada
| | - Claudia Umaña-Diaz
- Centre for Cell Biology, Development and Disease, Department of Biological Sciences, Simon Fraser University, Burnaby BC V5A 1S6, British Columbia, Canada
| | - Isabele da Costa Angelo
- Department of Epidemiology and Public Health, Veterinary Institute, Rural Federal University of Rio de Janeiro, Seropédica, RJ, Brazil
| | - Carl Lowenberger
- Centre for Cell Biology, Development and Disease, Department of Biological Sciences, Simon Fraser University, Burnaby BC V5A 1S6, British Columbia, Canada.
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21
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González-González A, Wayne ML. Immunopathology and immune homeostasis during viral infection in insects. Adv Virus Res 2020; 107:285-314. [PMID: 32711732 DOI: 10.1016/bs.aivir.2020.06.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Organisms clear infections by mounting an immune response that is normally turned off once the pathogens have been cleared. However, sometimes this immune response is not properly or timely arrested, resulting in the host damaging itself. This immune dysregulation may be referred to as immunopathology. While our knowledge of immune and metabolic pathways in insects, particularly in response to viral infections, is growing, little is known about the mechanisms that regulate this immune response and hence little is known about immunopathology in this important and diverse group of organisms. In this chapter we focus both on documenting the molecular mechanisms described involved in restoring immune homeostasis in insects after viral infections and on identifying potential mechanisms for future investigation. We argue that learning about the immunopathological consequences of an improperly regulated immune response in insects will benefit both insect and human health.
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Affiliation(s)
| | - Marta L Wayne
- Department of Biology, University of Florida, Gainesville, FL, United States
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Muhammad A, Habineza P, Wang X, Xiao R, Ji T, Hou Y, Shi Z. Spätzle Homolog-Mediated Toll-Like Pathway Regulates Innate Immune Responses to Maintain the Homeostasis of Gut Microbiota in the Red Palm Weevil, Rhynchophorus ferrugineus Olivier (Coleoptera: Dryophthoridae). Front Microbiol 2020; 11:846. [PMID: 32523559 PMCID: PMC7261851 DOI: 10.3389/fmicb.2020.00846] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2019] [Accepted: 04/08/2020] [Indexed: 11/13/2022] Open
Abstract
Spätzle (Spz) is a dimeric ligand that responds to the Gram-positive bacterial or fungal infection by binding Toll receptors to induce the secretion of antimicrobial peptides. However, whether the Toll-like signaling pathway mediates the innate immunity of Rhynchophorus ferrugineus to modulate the homeostasis of gut microbiota has not been determined. In this study, we found that a Spz homolog, RfSpätzle, is a secretory protein comprising a signal peptide and a conservative Spz domain. RT-qPCR analysis revealed that RfSpätzle was significantly induced to be expressed in the fat body and gut by the systemic and oral infection with pathogenic microbes. The expression levels of two antimicrobial peptide genes, RfColeoptericin and RfCecropin, were downregulated significantly by RfSpätzle knockdown, indicating that their secretion is under the regulation of the RfSpätzle-mediated signaling pathway. After being challenged by pathogenic microbes, the cumulative mortality rate of RfSpätzle-silenced individuals was drastically increased as compared to that of the controls. Further analysis indicated that these larvae possessed the diminished antibacterial activity. Moreover, RfSpätzle knockdown altered the relative abundance of gut bacteria at the phylum and family levels. Taken together, these findings suggest that RfSpätzle is involved in RPW immunity to confer protection and maintain the homeostasis of gut microbiota by mediating the production of antimicrobial peptides.
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Affiliation(s)
- Abrar Muhammad
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou, China.,Fujian Provincial Key Laboratory of Insect Ecology, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Prosper Habineza
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou, China.,Fujian Provincial Key Laboratory of Insect Ecology, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Xinghong Wang
- Guizhou Institute of Biology, Guizhou Academy of Sciences, Guiyang, China
| | - Rong Xiao
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou, China.,Fujian Provincial Key Laboratory of Insect Ecology, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Tianliang Ji
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou, China.,Fujian Provincial Key Laboratory of Insect Ecology, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Youming Hou
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou, China.,Fujian Provincial Key Laboratory of Insect Ecology, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Zhanghong Shi
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou, China.,Fujian Provincial Key Laboratory of Insect Ecology, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, China
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23
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TmSpz4 Plays an Important Role in Regulating the Production of Antimicrobial Peptides in Response to Escherichia coli and Candida albicans Infections. Int J Mol Sci 2020; 21:ijms21051878. [PMID: 32182940 PMCID: PMC7084639 DOI: 10.3390/ijms21051878] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Revised: 02/19/2020] [Accepted: 03/07/2020] [Indexed: 12/20/2022] Open
Abstract
Spätzle family proteins activate the Toll pathway and induce antimicrobial peptide (AMP) production against microbial infections. However, the functional importance of Tmspätzle4 (TmSpz4) in the immune response of Tenebrio molitor has not been reported. Therefore, here, we have identified and functionally characterized the role of TmSpz4 against bacterial and fungal infections. We showed that TmSpz4 expression was significantly induced in hemocytes at 6 h post-injection with Escherichia coli, Staphylococcus aureus, and Candida albicans. TmSpz4 knock-down significantly reduced larval survival against E. coli and C. albicans. To understand the reason for the survivability difference, the role of TmSpz4 in AMP production was examined in TmSpz4-silenced larvae following microbe injection. The AMPs that are active against Gram-negative bacteria, including TmTenecin-2, TmTenecin-4, TmAttacin-1a, TmDefensin-2, and TmCecropin-2, were significantly downregulated in response to E. coli in TmSpz4-silenced larvae. Similarly, the expression of TmTenecin-1, TmTenecin-3, TmThaumatin-like protein-1 and -2, TmDefensin-1, TmDefensin-2, and TmCecropin-2 were downregulated in response to C. albicans in TmSpz4-silenced larvae. In addition, the transcription factor NF-κB (TmDorX1 and TmDorX2) expression was significantly suppression in TmSpz4-silenced larvae. In conclusion, these results suggest that TmSpz4 plays a key role in regulating immune responses of T. molitor against to E. coli and C. albicans.
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24
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Edosa TT, Jo YH, Keshavarz M, Bae YM, Kim DH, Lee YS, Han YS. TmSpz6 Is Essential for Regulating the Immune Response to Escherichia Coli and Staphylococcus Aureus Infection in Tenebrio Molitor. INSECTS 2020; 11:insects11020105. [PMID: 32033290 PMCID: PMC7074004 DOI: 10.3390/insects11020105] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 02/02/2020] [Accepted: 02/03/2020] [Indexed: 12/20/2022]
Abstract
Spätzle is an extracellular protein that activates the Toll receptor during embryogenesis and immune responses in Drosophila. However, the functions of the spätzle proteins in the innate immune response against bacteria or fungi in T. molitor are not well understood. Therefore, in this study, the open reading frame (ORF) of TmSpz6 was identified and its function in the response to bacterial and fungal infections in T. molitor was investigated using RNAi. The highest expression of TmSpz6 was in prepupae, and 3- and 6-day-old pupae, while remarkable expression was also observed in other stages. The tissue-specific expression analysis showed that TmSpz6 expression was highest in the hemocytes of larvae. TmSpz6 expression was highly induced when challenged with Escherichia coli, Staphylococcus aureus, or Candida albicans at 6 h post-injection; however, TmSpz6-silenced larvae were significantly more susceptible to only E. coli and S. aureus infection. The antimicrobial peptides (AMPs) gene expression analysis results show that TmSpz6 mainly positively regulated the expression of TmTencin-2 and -3 in response to E. coli and S. aureus infection. Collectively, these results suggest that TmSpz6 plays an important role in regulating AMP expression and increases the survival of T. molitor against E. coli and S. aureus.
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Affiliation(s)
- Tariku Tesfaye Edosa
- Department of Applied Biology, Institute of Environmentally-Friendly Agriculture (IEFA), College of Agriculture and Life Sciences, Chonnam National University, Gwangju 61186, Korea; (T.T.E.); (Y.H.J.); (M.K.); (Y.M.B.); (D.H.K.)
- Ethiopian Institute of Agricultural Research, Ambo Agricultural Research Center, Ambo 37, Ethiopia
| | - Yong Hun Jo
- Department of Applied Biology, Institute of Environmentally-Friendly Agriculture (IEFA), College of Agriculture and Life Sciences, Chonnam National University, Gwangju 61186, Korea; (T.T.E.); (Y.H.J.); (M.K.); (Y.M.B.); (D.H.K.)
| | - Maryam Keshavarz
- Department of Applied Biology, Institute of Environmentally-Friendly Agriculture (IEFA), College of Agriculture and Life Sciences, Chonnam National University, Gwangju 61186, Korea; (T.T.E.); (Y.H.J.); (M.K.); (Y.M.B.); (D.H.K.)
| | - Young Min Bae
- Department of Applied Biology, Institute of Environmentally-Friendly Agriculture (IEFA), College of Agriculture and Life Sciences, Chonnam National University, Gwangju 61186, Korea; (T.T.E.); (Y.H.J.); (M.K.); (Y.M.B.); (D.H.K.)
| | - Dong Hyun Kim
- Department of Applied Biology, Institute of Environmentally-Friendly Agriculture (IEFA), College of Agriculture and Life Sciences, Chonnam National University, Gwangju 61186, Korea; (T.T.E.); (Y.H.J.); (M.K.); (Y.M.B.); (D.H.K.)
| | - Yong Seok Lee
- Department of Life Science and Biotechnology, College of Natural Sciences, Soonchunhyang University, Asan 31538, 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, Korea; (T.T.E.); (Y.H.J.); (M.K.); (Y.M.B.); (D.H.K.)
- Correspondence: ; Tel.: +82-62-530-2072
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25
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Tawidian P, Rhodes VL, Michel K. Mosquito-fungus interactions and antifungal immunity. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2019; 111:103182. [PMID: 31265904 PMCID: PMC6639037 DOI: 10.1016/j.ibmb.2019.103182] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Accepted: 06/28/2019] [Indexed: 05/14/2023]
Abstract
The mosquito immune system has evolved in the presence of continuous encounters with fungi that range from food to foes. Herein, we review the field of mosquito-fungal interactions, providing an overview of current knowledge and topics of interest. Mosquitoes encounter fungi in their aquatic and terrestrial habitats. Mosquito larvae are exposed to fungi on plant detritus, within the water column, and at the water surface. Adult mosquitoes are exposed to fungi during indoor and outdoor resting, blood and sugar feeding, mating, and oviposition. Fungi enter the mosquito body through different routes, including ingestion and through active or passive breaches in the cuticle. Oral uptake of fungi can be beneficial to mosquitoes, as yeasts hold nutritional value and support larval development. However, ingestion of or surface contact with fungal entomopathogens leads to colonization of the mosquito with often lethal consequences to the host. The mosquito immune system recognizes fungi and mounts cellular and humoral immune responses in the hemocoel, and possibly epithelial immune responses in the gut. These responses are regulated transcriptionally through multiple signal transduction pathways. Proteolytic protease cascades provide additional regulation of antifungal immunity. Together, these immune responses provide an efficient barrier to fungal infections, which need to be overcome by entomopathogens. Therefore, fungi constitute an excellent tool to examine the molecular underpinnings of mosquito immunity and to identify novel antifungal peptides. In addition, recent advances in mycobiome analyses can now be used to examine the contribution of fungi to various mosquito traits, including vector competence.
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Affiliation(s)
- P Tawidian
- Division of Biology, Kansas State University, 267 Chalmers Hall, Manhattan, KS, 66506, USA
| | - V L Rhodes
- Missouri Southern State University, Biology Department, Reynolds Hall 220, 3950 E. Newman Rd., Joplin, MO, 64801-1595, USA
| | - K Michel
- Division of Biology, Kansas State University, 267 Chalmers Hall, Manhattan, KS, 66506, USA.
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26
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Lee WS, Webster JA, Madzokere ET, Stephenson EB, Herrero LJ. Mosquito antiviral defense mechanisms: a delicate balance between innate immunity and persistent viral infection. Parasit Vectors 2019; 12:165. [PMID: 30975197 PMCID: PMC6460799 DOI: 10.1186/s13071-019-3433-8] [Citation(s) in RCA: 71] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Accepted: 04/04/2019] [Indexed: 01/24/2023] Open
Abstract
Mosquito-borne diseases are associated with major global health burdens. Aedes spp. and Culex spp. are primarily responsible for the transmission of the most medically important mosquito-borne viruses, including dengue virus, West Nile virus and Zika virus. Despite the burden of these pathogens on human populations, the interactions between viruses and their mosquito hosts remain enigmatic. Viruses enter the midgut of a mosquito following the mosquito’s ingestion of a viremic blood meal. During infection, virus recognition by the mosquito host triggers their antiviral defense mechanism. Of these host defenses, activation of the RNAi pathway is the main antiviral mechanism, leading to the degradation of viral RNA, thereby inhibiting viral replication and promoting viral clearance. However, whilst antiviral host defense mechanisms limit viral replication, the mosquito immune system is unable to effectively clear the virus. As such, these viruses can establish persistent infection with little or no fitness cost to the mosquito vector, ensuring life-long transmission to humans. Understanding of the mosquito innate immune response enables the discovery of novel antivectorial strategies to block human transmission. This review provides an updated and concise summary of recent studies on mosquito antiviral immune responses, which is a key determinant for successful virus transmission. In addition, we will also discuss the factors that may contribute to persistent infection in mosquito hosts. Finally, we will discuss current mosquito transmission-blocking strategies that utilize genetically modified mosquitoes and Wolbachia-infected mosquitoes for resistance to pathogens.
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Affiliation(s)
- Wai-Suet Lee
- Institute for Glycomics, Griffith University, Gold Coast Campus, Southport, QLD, 4215, Australia
| | - Julie A Webster
- Institute for Glycomics, Griffith University, Gold Coast Campus, Southport, QLD, 4215, Australia
| | - Eugene T Madzokere
- Institute for Glycomics, Griffith University, Gold Coast Campus, Southport, QLD, 4215, Australia
| | - Eloise B Stephenson
- Institute for Glycomics, Griffith University, Gold Coast Campus, Southport, QLD, 4215, Australia.,Environmental Futures Research Institute, Griffith University, Gold Coast Campus, Southport, QLD, 4215, Australia
| | - Lara J Herrero
- Institute for Glycomics, Griffith University, Gold Coast Campus, Southport, QLD, 4215, Australia.
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27
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Vaniksampanna A, Longyant S, Charoensapsri W, Sithigorngul P, Chaivisuthangkura P. Molecular isolation and characterization of a spätzle gene from Macrobrachium rosenbergii. FISH & SHELLFISH IMMUNOLOGY 2019; 84:441-450. [PMID: 30308293 DOI: 10.1016/j.fsi.2018.10.015] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Revised: 09/30/2018] [Accepted: 10/05/2018] [Indexed: 06/08/2023]
Abstract
Spätzle protein is an extracellular ligand of Toll receptor in Toll signaling pathway involved in the embryonic dorsoventral patterning and in the innate immunity. In this study, a spätzle gene of freshwater prawn, Macrobrachium rosenbergii (MrSpz) was isolated and characterized. The open reading frame of MrSpz consisted of 747 nucleotides encoding 248 amino acid residues containing a signal peptide and C-terminal spätzle activated domain. MrSpz shared high similarity to spätzle of Fenneropenaeus chinensis (FcSpz) at 92% identity and Marsupenaeus japonicus (MjSpz) at 83% identity. Phylogenetic analysis was performed and the results revealed that MrSpz was a member of the clade containing LvSpz3 of Litopenaeus vannamei, FcSpz and Penaeus monodon spätzle protein. The expression distribution at transcriptional level in various tissues of normal prawn revealed that the MrSpz was detected in gills, heart and hepatopancreas while no expression was observed in hemocyte, muscle and stomach. In the Aeromonas caviae challenged prawn, the expression level of MrSpz in hemocyte was increased gradually at 6, 12 and 24 h post-injection. Furthermore, in MrSpz knocked down prawn injected with Aeromonas caviae, the mortality rate were higher than that of non-related dsRNA group and control group. These results suggest that MrSpz protein may play a key role in the innate immunity of M. rosenbergii, especially in response to Gram-negative bacteria A. caviae invasion.
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Affiliation(s)
| | - Siwaporn Longyant
- Department of Biology, Srinakharinwirot University, Bangkok, 10110, Thailand; Center of Excellence for Animal, Plant and Parasite Biotechnology, Srinakharinwirot University, Bangkok, 10110, Thailand
| | - Walaiporn Charoensapsri
- National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Pathum Thani, Thailand; Center of Excellence for Shrimp Molecular Biology and Biotechnology (Centex Shrimp), Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Paisarn Sithigorngul
- Department of Biology, Srinakharinwirot University, Bangkok, 10110, Thailand; Center of Excellence for Animal, Plant and Parasite Biotechnology, Srinakharinwirot University, Bangkok, 10110, Thailand
| | - Parin Chaivisuthangkura
- Department of Biology, Srinakharinwirot University, Bangkok, 10110, Thailand; Center of Excellence for Animal, Plant and Parasite Biotechnology, Srinakharinwirot University, Bangkok, 10110, Thailand.
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28
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Li M, Christen JM, Dittmer NT, Cao X, Zhang X, Jiang H, Kanost MR. The Manduca sexta serpinome: Analysis of serpin genes and proteins in the tobacco hornworm. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2018; 102:21-30. [PMID: 30237077 PMCID: PMC6249112 DOI: 10.1016/j.ibmb.2018.09.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Revised: 09/14/2018] [Accepted: 09/16/2018] [Indexed: 06/02/2023]
Abstract
Members of the serpin superfamily of proteins occur in animals, plants, bacteria, archaea and some viruses. They adopt a variety of physiological functions, including regulation of immune system, modulation of apoptosis, hormone transport and acting as storage proteins. Most members of the serpin family are inhibitors of serine proteinases. In this study, we searched the genome of Manduca sexta and identified 32 serpin genes. We analyzed the structure of these genes and the sequences of their encoded proteins. Three M. sexta genes (serpin-1, serpin-15, and serpin-28) have mutually exclusive alternatively spliced exons encoding the carboxyl-terminal reactive center loop of the protein, which is the site of interaction with target proteases. We discovered that MsSerpin-1 has 14 splicing isoforms, including two undiscovered in previous studies. Twenty-eight of the 32 M. sexta serpins include a putative secretion signal peptide and are predicted to be extracellular proteins. Phylogenetic analysis of serpins in M. sexta and Bombyx mori indicates that 17 are orthologous pairs, perhaps carrying out essential physiological functions. Analysis of the reactive center loop and hinge regions of the protein sequences indicates that 16 of the serpin genes encode proteins that may lack proteinase inhibitor activity. Our annotation and analysis of these serpin genes and their transcript profiles should lead to future advances in experimental study of their functions in insect biochemistry.
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Affiliation(s)
- Miao Li
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, KS 66506, USA
| | - Jayne M Christen
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, KS 66506, USA
| | - Neal T Dittmer
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, KS 66506, USA
| | - Xiaolong Cao
- Department of Entomology and Plant Pathology, Oklahoma State University, Stillwater, OK 74078, USA
| | - Xiufeng Zhang
- Department of Entomology and Plant Pathology, Oklahoma State University, Stillwater, OK 74078, USA
| | - Haobo Jiang
- Department of Entomology and Plant Pathology, Oklahoma State University, Stillwater, OK 74078, USA
| | - Michael R Kanost
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, KS 66506, USA.
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29
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The Effect of Permethrin Resistance on Aedes aegypti Transcriptome Following Ingestion of Zika Virus Infected Blood. Viruses 2018; 10:v10090470. [PMID: 30200481 PMCID: PMC6165428 DOI: 10.3390/v10090470] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Revised: 08/24/2018] [Accepted: 08/26/2018] [Indexed: 01/02/2023] Open
Abstract
Aedes aegypti (L.) is the primary vector of many emerging arboviruses. Insecticide resistance among mosquito populations is a consequence of the application of insecticides for mosquito control. We used RNA-sequencing to compare transcriptomes between permethrin resistant and susceptible strains of Florida Ae. aegypti in response to Zika virus infection. A total of 2459 transcripts were expressed at significantly different levels between resistant and susceptible Ae. aegypti. Gene ontology analysis placed these genes into seven categories of biological processes. The 863 transcripts were expressed at significantly different levels between the two mosquito strains (up/down regulated) more than 2-fold. Quantitative real-time PCR analysis was used to validate the Zika-infection response. Our results suggested a highly overexpressed P450, with AAEL014617 and AAEL006798 as potential candidates for the molecular mechanism of permethrin resistance in Ae. aegypti. Our findings indicated that most detoxification enzymes and immune system enzymes altered their gene expression between the two strains of Ae. aegypti in response to Zika virus infection. Understanding the interactions of arboviruses with resistant mosquito vectors at the molecular level allows for the possible development of new approaches in mitigating arbovirus transmission. This information sheds light on Zika-induced changes in insecticide resistant Ae. aegypti with implications for mosquito control strategies.
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30
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Rhodes VL, Thomas MB, Michel K. The interplay between dose and immune system activation determines fungal infection outcome in the African malaria mosquito, Anopheles gambiae. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2018; 85:125-133. [PMID: 29649553 PMCID: PMC5935592 DOI: 10.1016/j.dci.2018.04.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Revised: 04/05/2018] [Accepted: 04/06/2018] [Indexed: 05/27/2023]
Abstract
The Toll pathway is a central regulator of antifungal immunity in insects. In mosquitoes, the Toll pathway affects infections with the fungal entomopathogen, Beauveria bassiana, which is considered a potential mosquito biopesticide. We report here the use of B. bassiana strain I93-825 in Anopheles gambiae to analyze the impact of Toll pathway modulation on mosquito survival. Exposure to a narrow dose range of conidia by direct contact decreased mosquito longevity and median survival. In addition, fungal exposure dose correlated positively and linearly with hazard ratio. Increased Toll signaling by knockdown of its inhibitor, cactus, decreased survivorship of uninfected females, increased mosquito survival after low dose B. bassiana exposure, but had little effect following exposure to higher doses. This observed trade-off could have implications for development of B. bassiana as a prospective vector control tool. On the one hand, selection for small increases in mosquito immune signaling across a narrow dose range could impair efficacy of B. bassiana. On the other hand, costs of immunity and the capacity for higher doses of fungus to overwhelm immune responses could limit evolution of resistance.
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Affiliation(s)
- Victoria L Rhodes
- Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Matthew B Thomas
- Department of Entomology and Center for Infectious Disease Dynamics, The Pennsylvania State University, University Park, PA 16802, USA
| | - Kristin Michel
- Division of Biology, Kansas State University, Manhattan, KS 66506, USA.
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31
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Wang YH, Chang MM, Wang XL, Zheng AH, Zou Z. The immune strategies of mosquito Aedes aegypti against microbial infection. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2018; 83:12-21. [PMID: 29217264 DOI: 10.1016/j.dci.2017.12.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 11/30/2017] [Accepted: 12/03/2017] [Indexed: 06/07/2023]
Abstract
Yellow fever mosquito Aedes aegypti transmits many devastating arthropod-borne viruses (arboviruses), such as dengue virus, yellow fever virus, Chikungunya virus, and Zika virus, which cause great concern to human health. Mosquito control is an effective method to block the spread of infectious diseases. Ae. aegypti uses its innate immune system to fight against arboviruses, parasites, and fungi. In this review, we briefly summarize the recent findings in the immune response of Ae. aegypti against arboviral and entomopathogenic infections. This review enriches our understanding of the mosquito immune system and provides evidence to support the development of novel mosquito control strategies.
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Affiliation(s)
- Yan-Hong Wang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Meng-Meng Chang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xue-Li Wang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Ai-Hua Zheng
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Zhen Zou
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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32
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Qu S, Wang S. Interaction of entomopathogenic fungi with the host immune system. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2018; 83:96-103. [PMID: 29355579 DOI: 10.1016/j.dci.2018.01.010] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Revised: 01/14/2018] [Accepted: 01/15/2018] [Indexed: 06/07/2023]
Abstract
Entomopathogenic fungi can invade wide range of insect hosts in the natural world and have been used as environmentally friendly alternatives to chemical insecticides for pest control. Studies of host-pathogen interactions provide valuable insights into the coevolutionay arms race between fungal pathogens and their hosts. Entomopathogenic fungi have evolved a series of sophisticated strategies to counter insect immune defenses. In response to fungal infection, insect hosts rely on behavior avoidance, physical barrier and innate immune defenses in the fight against invading pathogens. The insect cuticle acts as the first physical barrier against pathogens. It is an inhospitable physiological environment that contains chemicals (e.g., antimicrobial peptides and reactive oxygen species), which inhibit fungal growth. In addition, innate immune responses, including cellular immunity and humoral immunity, play critical roles in preventing fungal infection. In this review, we outline the current state of our knowledge of insect defenses to fungal infection and discuss the strategies by which entomopathogenic fungi counter the host immune system. Increased knowledge regarding the molecular interactions between entomopathogenic fungi and the insect host could provide new strategies for pest management.
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Affiliation(s)
- Shuang Qu
- Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Sibao Wang
- Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China.
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33
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Bartholomay LC, Michel K. Mosquito Immunobiology: The Intersection of Vector Health and Vector Competence. ANNUAL REVIEW OF ENTOMOLOGY 2018; 63:145-167. [PMID: 29324042 DOI: 10.1146/annurev-ento-010715-023530] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
As holometabolous insects that occupy distinct aquatic and terrestrial environments in larval and adult stages and utilize hematophagy for nutrient acquisition, mosquitoes are subjected to a wide variety of symbiotic interactions. Indeed, mosquitoes play host to endosymbiotic, entomopathogenic, and mosquito-borne organisms, including protozoa, viruses, bacteria, fungi, fungal-like organisms, and metazoans, all of which trigger and shape innate infection-response capacity. Depending on the infection or interaction, the mosquito may employ, for example, cellular and humoral immune effectors for septic infections in the hemocoel, humoral infection responses in the midgut lumen, and RNA interference and programmed cell death for intracellular pathogens. These responses often function in concert, regardless of the infection type, and provide a robust front to combat infection. Mosquito-borne pathogens and entomopathogens overcome these immune responses, employing avoidance or suppression strategies. Burgeoning methodologies are capitalizing on this concerted deployment of immune responses to control mosquito-borne disease.
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Affiliation(s)
- Lyric C Bartholomay
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Wisconsin 53706;
| | - Kristin Michel
- Division of Biology, Kansas State University, Manhattan, Kansas 66506;
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Boonrawd S, Mani R, Ponprateep S, Supungul P, Masrinoul P, Tassanakajon A, Rimphanitchayakit V. Characterization of PmSpӓtzle 1 from the black tiger shrimp Peneaus monodon. FISH & SHELLFISH IMMUNOLOGY 2017; 65:88-95. [PMID: 28400214 DOI: 10.1016/j.fsi.2017.04.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Revised: 04/02/2017] [Accepted: 04/07/2017] [Indexed: 06/07/2023]
Abstract
Spätzle is a signaling ligand in innate immune response that signals pathogenic infection via Toll receptor and Toll pathway into the cells for the synthesis of antimicrobial proteins. Herein, three PmSpӓtzle isoforms were identified in Penaeus monodon, namely PmSpz1, 2 and 3. The PmSpz1 was chosen for detailed study. The PmSpz1 gene was expressed in all nine tissues tested including the hemocytes, stomach, hepatopancreas, gill, lymphoid tissue, eyestalk, muscle, intestine and heart. Its expression was up-regulated upon white spot syndrome virus (WSSV) infection. Western blot analysis of hemolymph showed that the PmSpz1 mostly existed as a cleaved active form awaiting to activate the Toll pathway. Injection of a recombinant PmSpz1 rendered the shrimp less susceptible to the WSSV infection. Injection of a recombinant active form of PmSpz1 into a normal shrimp activated the synthesis of crustinPm1, crustinPm7, ALFPm3, penaeidin3 but not penaeidin5 indicating that the expression of all antimicrobial proteins but not penaeidin5 was under the regulation of Toll pathway.
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Affiliation(s)
- Sittichai Boonrawd
- Center of Excellence for Molecular Biology and Genomics of Shrimp, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Phyathai Road, Bangkok 10330, Thailand
| | - Ravi Mani
- Department of Biotechnology, Sathyabama University, Jeppiaar Nagar, Rajiv Gandhi Road, Chennai, Tamil Nadu 600119, India
| | - Sirikwan Ponprateep
- Department of Chemistry, Faculty of Science, Srinakharinwirot University, 114 Sukhumvit 23 Road, Bangkok 10110, Thailand
| | - Premruethai Supungul
- National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), Pathum Thani 10120, Thailand
| | - Promsin Masrinoul
- Institute of Molecular Biosciences, Mahidol University, 25/25 Phuttamonthon 4 Road, Salaya, Nakhon Pathom 73170, Thailand
| | - Anchalee Tassanakajon
- Center of Excellence for Molecular Biology and Genomics of Shrimp, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Phyathai Road, Bangkok 10330, Thailand
| | - Vichien Rimphanitchayakit
- Center of Excellence for Molecular Biology and Genomics of Shrimp, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Phyathai Road, Bangkok 10330, Thailand.
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Yuan K, Yuan FH, Weng SP, He JG, Chen YH. Identification and functional characterization of a novel Spätzle gene in Litopenaeus vannamei. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2017; 68:46-57. [PMID: 27884706 DOI: 10.1016/j.dci.2016.11.016] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Revised: 11/18/2016] [Accepted: 11/18/2016] [Indexed: 06/06/2023]
Abstract
Shrimp innate immunity is the first line of resistance against pathogenic bacteria. The Toll-like receptor (TLR)-NF-κB pathway is vital in this immunity process. In this study, a novel Spätzle gene (LvSpz4) of Litopenaeus vannamei was cloned and functionally characterized. The open reading frame of LvSpz4 was 918 bp, which encoded a putative protein with 305 amino acids. LvSpz4 was most expressed in the gills of L. vannamei. This expression was induced by Vibrio alginolyticus or Staphylococcus aureus infection or lipopolysaccharide stimulation. The reporter gene assay showed that LvSpz4 could activate the promoters of Pen4, Drs, AttA, Mtk, and white spot syndrome virus immediate early gene1 in Drosophila Schneider 2 (S2) cells. Knockdown LvSpz4 increased the cumulative mortality of L. vannamei upon V. alginolyticus infection. The unfolded protein response (UPR) induced the expression of LvSpz4 in L. vannamei. Moreover, the promoter of LvSpz4 was activated by L. vannamei X-Box binding protein 1 and activating transcription factor 4 in S2 cells. These results suggested that LvSpz4 was involved in L. vannamei innate immunity and caused the crosstalk between the TLR-NF-κB pathway and UPR.
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Affiliation(s)
- Kai Yuan
- School of Life Sciences, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, PR China; State Key Laboratory for Biocontrol, MOE Key Laboratory of Aquatic Product Safety, Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, PR China
| | - Feng-Hua Yuan
- School of Life Sciences, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, PR China; State Key Laboratory for Biocontrol, MOE Key Laboratory of Aquatic Product Safety, Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, PR China
| | - Shao-Ping Weng
- School of Life Sciences, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, PR China; State Key Laboratory for Biocontrol, MOE Key Laboratory of Aquatic Product Safety, Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, PR China
| | - Jian-Guo He
- Key Laboratory of Marine Resources and Coastal Engineering in Guangdong Province, South China Sea Bio-Resource Exploitation and Protection Collaborative Innovation Center (SCS-REPIC), School of Marine Sciences, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, PR China; School of Life Sciences, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, PR China; State Key Laboratory for Biocontrol, MOE Key Laboratory of Aquatic Product Safety, Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, PR China
| | - Yi-Hong Chen
- Key Laboratory of Marine Resources and Coastal Engineering in Guangdong Province, South China Sea Bio-Resource Exploitation and Protection Collaborative Innovation Center (SCS-REPIC), School of Marine Sciences, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, PR China; State Key Laboratory for Biocontrol, MOE Key Laboratory of Aquatic Product Safety, Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, PR China.
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Barletta ABF, Nascimento-Silva MCL, Talyuli OAC, Oliveira JHM, Pereira LOR, Oliveira PL, Sorgine MHF. Microbiota activates IMD pathway and limits Sindbis infection in Aedes aegypti. Parasit Vectors 2017; 10:103. [PMID: 28231846 PMCID: PMC5324288 DOI: 10.1186/s13071-017-2040-9] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2016] [Accepted: 02/16/2017] [Indexed: 01/18/2023] Open
Abstract
BACKGROUND Aedes aegypti is the main vector of important arboviruses such as dengue, Zika and chikungunya. During infections mosquitoes can activate the immune pathways Toll, IMD and JAK/STAT to limit pathogen replication. RESULTS Here, we evaluate the immune response profile of Ae. aegypti against Sindbis virus (SINV). We analyzed gene expression of components of Toll, IMD and JAK/STAT pathways and showed that a blood meal and virus infection upregulated aaREL2 in a microbiota-dependent fashion, since this induction was prevented by antibiotic. The presence of the microbiota activates IMD and impaired the replication of SINV in the midgut. Constitutive activation of the IMD pathway, by Caspar depletion, leads to a decrease in microbiota levels and an increase in SINV loads. CONCLUSION Together, these results suggest that a blood meal is able to activate innate immune pathways, through a nutrient induced growth of microbiota, leading to upregulation of aaREL2 and IMD activation. Microbiota levels seemed to have a reciprocal interaction, where the proliferation of the microbiota activates IMD pathway that in turn controls bacterial levels, allowing SINV replication in Ae. aegypti mosquitoes. The activation of the IMD pathway seems to have an indirect effect in SINV levels that is induced by the microbiota.
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Affiliation(s)
- Ana Beatriz Ferreira Barletta
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
| | | | - Octávio A C Talyuli
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - José Henrique M Oliveira
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
| | | | - Pedro L Oliveira
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Marcos Henrique F Sorgine
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
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Yu M, Zhang Y, Tang X, Ren J, Zhang Y. The first mollusk spätzle homolog gene in the clam, Paphia undulate. FISH & SHELLFISH IMMUNOLOGY 2015; 47:712-716. [PMID: 26477575 DOI: 10.1016/j.fsi.2015.10.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 10/12/2015] [Accepted: 10/12/2015] [Indexed: 06/05/2023]
Abstract
Spätzle, is the only identified endogenous Toll receptor ligand, plays a critical role in initiatinge innate immune responses and controlling dorsal-ventral axis formation in Drosophila. Here we identified the first spätzle gene homolog, Pu-Spz, in the marine mollusk Paphia undulate. The full-length of Pu-Spz cDNA is 1248 bp, including an open reading frame (ORF) of 702 bp, a 5'-untranslated region (UTR) of 26 bp and a 3'-UTR of 203 bp. The ORF encodes a 233-amino-acid protein with conserved domains; it includes a putative signal peptide and a C-terminal cystine-knot. Sequence alignment revealed that the cystine-knot domain of Pu-Spz contains six highly conserved Cys residues, which maintain a molecular conformation suitable for Toll receptor binding. Unlike Spätzle, Pu-Spz lacks a seventh Cys residue, which is essential for forming intermolecular disulfide bridge. Phylogenetic analysis revealed that Pu-Spz is closer to the homologs found in crustaceans than to those in the insect branch. Transcript abundance of Pu-Spz was increased after challenging P. undulate with either heat-killed Listeria monocytogenes or heat-killed Vibrio alginolyticus, suggesting Spätzle is involved in P. undulate host defense. Our results demonstrate convergent evolution of the spätzle-Toll system between the mollusk and arthropod lineages.
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Affiliation(s)
- Mingjia Yu
- Engineering Research Center of Marine Biological Resource Comprehensive Utilization, Third Institute of Oceanography, State Oceanic Administration, Xiamen, 361005, China
| | - Yuehuan Zhang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China
| | - Xu Tang
- Engineering Research Center of Marine Biological Resource Comprehensive Utilization, Third Institute of Oceanography, State Oceanic Administration, Xiamen, 361005, China
| | - Jun Ren
- Department of Surgery, University of Wisconsin-Madison, Madison, WI, 53705, USA
| | - Yang Zhang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China.
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Ren Y, Zhang H, Pan B, Yan C. A Kazal-type serine proteinase inhibitor from Cyclina sinensis is involved in immune response and signal pathway initiation. FISH & SHELLFISH IMMUNOLOGY 2015; 47:110-116. [PMID: 26327114 DOI: 10.1016/j.fsi.2015.08.026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Revised: 08/21/2015] [Accepted: 08/26/2015] [Indexed: 06/04/2023]
Abstract
Serine protease inhibitors (SPIs) are an important group of protease inhibitors involved in a variety of biological processes. In the present study, a Kazal-type serine protease inhibitor homolog gene (designated as CsKPI) was identified from a Cyclina sinensis cDNA library. The open reading frame consists of 456 bp and encodes a protein of 151 amino acid residues with a theoretical molecular mass of 16.85 kDa and an isoelectric point of 5.74. Furthermore, using quantitative real-time PCR, we focused on the expression patterns of CsKPI found in tissues and on the stimulation of this gene's expression by bacteria. The results show that a higher-level mRNA expression of CsKPI was detected in hemocytes (P < 0.05) and was significantly upregulated at 3 h (P < 0.01) upon receiving bacterial challenges with Vibrio anguillarum. In addition, after the CsKPI gene was silenced by RNA interference, the expression of the CsTLR2 and CsMyD88 genes was extremely significantly decreased (P < 0.01) in C. sinensis. Finally, the recombinant CsKPI (rCsKPI) protein was purified and shown to exhibit less inhibitory activity than C-lyz against V. anguillarum in vitro. Hence, we propose that CsKPI plays an important role in the innate immunity and mediates TLR2 and MyD88-dependent pathway initiation in C. sinensis.
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Affiliation(s)
- Yipeng Ren
- Tianjin Key Laboratory of Animal and Plant Resistance, School of Life Sciences, Tianjin Normal University, Tianjin, 300387, PR China; Institute of Entomology, College of Life Sciences, Nankai University, Tianjin, 300071, PR China
| | - Hao Zhang
- Tianjin Key Laboratory of Animal and Plant Resistance, School of Life Sciences, Tianjin Normal University, Tianjin, 300387, PR China; State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin 300071, PR China
| | - Baoping Pan
- Tianjin Key Laboratory of Animal and Plant Resistance, School of Life Sciences, Tianjin Normal University, Tianjin, 300387, PR China.
| | - Chuncai Yan
- Tianjin Key Laboratory of Animal and Plant Resistance, School of Life Sciences, Tianjin Normal University, Tianjin, 300387, PR China
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Redmond SN, Eiglmeier K, Mitri C, Markianos K, Guelbeogo WM, Gneme A, Isaacs AT, Coulibaly B, Brito-Fravallo E, Maslen G, Mead D, Niare O, Traore SF, Sagnon N, Kwiatkowski D, Riehle MM, Vernick KD. Association mapping by pooled sequencing identifies TOLL 11 as a protective factor against Plasmodium falciparum in Anopheles gambiae. BMC Genomics 2015; 16:779. [PMID: 26462916 PMCID: PMC4603968 DOI: 10.1186/s12864-015-2009-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Accepted: 10/03/2015] [Indexed: 11/16/2022] Open
Abstract
Background The genome-wide association study (GWAS) techniques that have been used for genetic mapping in other organisms have not been successfully applied to mosquitoes, which have genetic characteristics of high nucleotide diversity, low linkage disequilibrium, and complex population stratification that render population-based GWAS essentially unfeasible at realistic sample size and marker density. Methods We designed a novel mapping strategy for the mosquito system that combines the power of linkage mapping with the resolution afforded by genetic association. We established founder colonies from West Africa, controlled for diversity, linkage disequilibrium and population stratification. Colonies were challenged by feeding on the infectious stage of the human malaria parasite, Plasmodium falciparum, mosquitoes were phenotyped for parasite load, and DNA pools for phenotypically similar mosquitoes were Illumina sequenced. Phenotype-genotype mapping was carried out in two stages, coarse and fine. Results In the first mapping stage, pooled sequences were analysed genome-wide for intervals displaying relativereduction in diversity between phenotype pools, and candidate genomic loci were identified for influence upon parasite infection levels. In the second mapping stage, focused genotyping of SNPs from the first mapping stage was carried out in unpooled individual mosquitoes and replicates. The second stage confirmed significant SNPs in a locus encoding two Toll-family proteins. RNAi-mediated gene silencing and infection challenge revealed that TOLL 11 protects mosquitoes against P. falciparum infection. Conclusions We present an efficient and cost-effective method for genetic mapping using natural variation segregating in defined recent Anopheles founder colonies, and demonstrate its applicability for mapping in a complex non-model genome. This approach is a practical and preferred alternative to population-based GWAS for first-pass mapping of phenotypes in Anopheles. This design should facilitate mapping of other traits involved in physiology, epidemiology, and behaviour. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-2009-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Seth N Redmond
- Department of Parasites and Insect Vectors, Institut Pasteur, Unit of Insect Vector Genetics and Genomics, 28 rue du Docteur Roux, Paris, 75015, France. .,CNRS Unit of Hosts, Vectors and Pathogens, Paris, France (URA3012), 28 rue du Docteur Roux, Paris, 75015, France.
| | - Karin Eiglmeier
- Department of Parasites and Insect Vectors, Institut Pasteur, Unit of Insect Vector Genetics and Genomics, 28 rue du Docteur Roux, Paris, 75015, France. .,CNRS Unit of Hosts, Vectors and Pathogens, Paris, France (URA3012), 28 rue du Docteur Roux, Paris, 75015, France.
| | - Christian Mitri
- Department of Parasites and Insect Vectors, Institut Pasteur, Unit of Insect Vector Genetics and Genomics, 28 rue du Docteur Roux, Paris, 75015, France. .,CNRS Unit of Hosts, Vectors and Pathogens, Paris, France (URA3012), 28 rue du Docteur Roux, Paris, 75015, France.
| | - Kyriacos Markianos
- Program in Genomics, Boston Children's Hospital, Harvard Medical School, 3 Blackfan Street, Boston, MA, 02115, USA.
| | - Wamdaogo M Guelbeogo
- Centre National de Recherche et de Formation sur le Paludisme, 1487 Avenue de l'Oubritenga, 01 BP 2208, Ouagadougou, Burkina Faso.
| | - Awa Gneme
- Centre National de Recherche et de Formation sur le Paludisme, 1487 Avenue de l'Oubritenga, 01 BP 2208, Ouagadougou, Burkina Faso.
| | - Alison T Isaacs
- Department of Parasites and Insect Vectors, Institut Pasteur, Unit of Insect Vector Genetics and Genomics, 28 rue du Docteur Roux, Paris, 75015, France. .,CNRS Unit of Hosts, Vectors and Pathogens, Paris, France (URA3012), 28 rue du Docteur Roux, Paris, 75015, France.
| | - Boubacar Coulibaly
- Malaria Research and Training Centre, Faculty of Medicine and Dentistry, University of Mali, Point G, Bamako, Mali.
| | - Emma Brito-Fravallo
- Department of Parasites and Insect Vectors, Institut Pasteur, Unit of Insect Vector Genetics and Genomics, 28 rue du Docteur Roux, Paris, 75015, France. .,CNRS Unit of Hosts, Vectors and Pathogens, Paris, France (URA3012), 28 rue du Docteur Roux, Paris, 75015, France.
| | - Gareth Maslen
- Wellcome Trust Sanger Institute, Hinxton, Cambridge, UK. .,Wellcome Trust Centre for Human Genetics, Oxford, UK.
| | - Daniel Mead
- Wellcome Trust Sanger Institute, Hinxton, Cambridge, UK. .,Wellcome Trust Centre for Human Genetics, Oxford, UK.
| | - Oumou Niare
- Malaria Research and Training Centre, Faculty of Medicine and Dentistry, University of Mali, Point G, Bamako, Mali.
| | - Sekou F Traore
- Malaria Research and Training Centre, Faculty of Medicine and Dentistry, University of Mali, Point G, Bamako, Mali.
| | - N'Fale Sagnon
- Centre National de Recherche et de Formation sur le Paludisme, 1487 Avenue de l'Oubritenga, 01 BP 2208, Ouagadougou, Burkina Faso.
| | - Dominic Kwiatkowski
- Wellcome Trust Sanger Institute, Hinxton, Cambridge, UK. .,Wellcome Trust Centre for Human Genetics, Oxford, UK.
| | - Michelle M Riehle
- Department of Microbiology, University of Minnesota, 1500 Gortner Avenue, Saint Paul, MN 55108, USA.
| | - Kenneth D Vernick
- Department of Parasites and Insect Vectors, Institut Pasteur, Unit of Insect Vector Genetics and Genomics, 28 rue du Docteur Roux, Paris, 75015, France. .,CNRS Unit of Hosts, Vectors and Pathogens, Paris, France (URA3012), 28 rue du Docteur Roux, Paris, 75015, France. .,Malaria Research and Training Centre, Faculty of Medicine and Dentistry, University of Mali, Point G, Bamako, Mali.
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Kanost MR, Jiang H. Clip-domain serine proteases as immune factors in insect hemolymph. CURRENT OPINION IN INSECT SCIENCE 2015; 11:47-55. [PMID: 26688791 PMCID: PMC4680995 DOI: 10.1016/j.cois.2015.09.003] [Citation(s) in RCA: 161] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
CLIP proteases are non-digestive serine proteases present in hemolymph of insects and other arthropods. They are composed of one or more amino-terminal clip domains followed by a linker sequence and a carboxyl-terminal S1A family serine protease domain. The genes for CLIP proteases have evolved as four clades (CLIPA, CLIPB, CLIPC, CLIPD), each present as multigene families in insect genomes. CLIP proteases in hemolymph function in innate immune responses. These include proteolytic activation of the cytokine Spätzle, to form an active Toll ligand leading to synthesis of antimicrobial peptides, and specific activation of prophenoloxidase, required for the melanization response. CLIP proteases act in cascade pathways. In the immune pathways that have been characterized, microbial surface molecules stimulate activation of an initiating modular serine protease, which then activates a CLIPC, which in turn activates a CLIPB. The active CLIPB then cleaves and activates an effector molecule (proSpätzle or prophenoloxidase). CLIPA proteins are pseudoproteases, lacking proteolytic activity, but some can function as regulators of the activity of other CLIP proteases and form high molecular weight immune complexes. A few three dimensional structures for CLIP proteases are now available for structure-function analysis of these immune factors, revealing structural features that may act in specific activation or in formation of immune complexes. The functions of most CLIP proteases are unknown, even in well studied insect species. It is very likely that additional proteins activated by CLIP proteases and acting in immunity remain to be discovered.
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Affiliation(s)
- Michael R. Kanost
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, KS 66506 USA
- Communicating author: Michael R. Kanost, Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, KS 66506 USA, 785-532-6964,
| | - Haobo Jiang
- Department of Entomology and Plant Pathology, Oklahoma State University, Stillwater, OK, 74078 USA
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Liu D, Wang L, Yang L, Qian C, Wei G, Dai L, Li J, Zhu B, Liu C. Serpin-15 from Bombyx mori inhibits prophenoloxidase activation and expression of antimicrobial peptides. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2015; 51:22-28. [PMID: 25720980 DOI: 10.1016/j.dci.2015.02.013] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Revised: 02/17/2015] [Accepted: 02/17/2015] [Indexed: 06/04/2023]
Abstract
Serine protease inhibitors (SPIs) play a key role in physiological responses by controlling protease activities. In this study, we studied the biochemical functions of serpin-15, an SPI, from Bombyx mori (Bmserpin-15). Recombinant Bmserpin-15 was expressed in Escherichia coli cells and used to raise rabbit anti-Bmserpin-15 polyclonal antibodies. Bmserpin-15 mRNA and protein expression was detected in all tested tissues, particularly in the fat body and silk gland. After challenge with four different microorganisms (Escherichia coli, Beauveria bassiana, Micrococcus luteus and B. mori nuclear polyhedrosis virus), the expressions of Bmserpin-15 mRNA and protein were induced significantly, particularly by B. bassiana and M. luteus. Recombinant Bmserpin-15 inhibited prophenoloxidase activation, but did not affect phenoloxidase activity, in B. mori hemolymph. Injection of recombinant Bmserpin-15 into B. mori larvae reduced significantly the transcript levels of antimicrobial peptides in fat body. Our results suggested that Bmserpin-15 plays an important role in the innate immunity of B. mori.
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Affiliation(s)
- Dongran Liu
- College of Life Science, Anhui Agricultural University, Hefei 230036, China
| | - Lei Wang
- College of Life Science, Anhui Agricultural University, Hefei 230036, China
| | - Liu Yang
- College of Life Science, Anhui Agricultural University, Hefei 230036, China
| | - Cen Qian
- College of Life Science, Anhui Agricultural University, Hefei 230036, China
| | - Guoqing Wei
- College of Life Science, Anhui Agricultural University, Hefei 230036, China
| | - Lishang Dai
- College of Life Science, Anhui Agricultural University, Hefei 230036, China
| | - Jun Li
- College of Life Science, Anhui Agricultural University, Hefei 230036, China
| | - Baojian Zhu
- College of Life Science, Anhui Agricultural University, Hefei 230036, China
| | - Chaoliang Liu
- College of Life Science, Anhui Agricultural University, Hefei 230036, China.
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Xiong GH, Xing LS, Lin Z, Saha TT, Wang C, Jiang H, Zou Z. High throughput profiling of the cotton bollworm Helicoverpa armigera immunotranscriptome during the fungal and bacterial infections. BMC Genomics 2015; 16:321. [PMID: 26001831 PMCID: PMC4490664 DOI: 10.1186/s12864-015-1509-1] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Accepted: 03/31/2015] [Indexed: 12/03/2022] Open
Abstract
Background Innate immunity is essential in defending against invading pathogens in invertebrates. The cotton bollworm, Helicoverpa armigera (Hübner) is one of the most destructive lepidopteran pests, which causes enormous economic losses in agricultural production worldwide. The components of the immune system are largely unknown in this insect. The application of entomopathogens is considered as an alternative to the chemical insecticides for its control. However, few studies have focused on the molecular mechanisms of host-pathogen interactions between pest insects and their pathogens. Here, we investigated the immunotranscriptome of H. armigera larvae and examined gene expression changes after pathogen infections. This study provided insights into the potential immunity-related genes and pathways in H. armigera larvae. Results Here, we adopted a high throughput RNA-seq approach to determine the immunotranscriptome of H. armigera larvae injected with buffer, fungal pathogen Beauveria bassiana, or Gram-negative bacterium Enterobacter cloacae. Based on sequence similarity to those homologs known to participate in immune responses in other insects, we identified immunity-related genes encoding pattern recognition receptors, signal modulators, immune effectors, and nearly all members of the Toll, IMD and JAK/STAT pathways. The RNA-seq data indicated that some immunity-related genes were activated in fungus- and bacterium-challenged fat body while others were suppressed in B. bassiana challenged hemocytes, including the putative IMD and JAK-STAT pathway members. Bacterial infection elevated the expression of recognition and modulator genes in the fat body and signal pathway genes in hemocytes. Although fat body and hemocytes both are important organs involved in the immune response, our transcriptome analysis revealed that more immunity-related genes were induced in the fat body than that hemocytes. Furthermore, quantitative real-time PCR analysis confirmed that, consistent with the RNA-seq data, the transcript abundances of putative PGRP-SA1, Serpin1, Toll-14, and Spz2 genes were elevated in fat body upon B. bassiana infection, while the mRNA levels of defensin, moricin1, and gloverin1 were up-regulated in hemocytes. Conclusions In this study, a global survey of the host defense against fungal and bacterial infection was performed on the non-model lepidopteran pest species. The comprehensive sequence resource and expression profiles of the immunity-related genes in H. armigera are acquired. This study provided valuable information for future functional investigations as well as development of specific and effective agents to control this pest. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-1509-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Guang-Hua Xiong
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China. .,University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Long-Sheng Xing
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China. .,University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Zhe Lin
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.
| | - Tusar T Saha
- Department of Entomology, University of California Riverside, Riverside, CA, 92521, USA.
| | - Chengshu Wang
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200032, China.
| | - Haobo Jiang
- Department of Entomology and Plant Pathology, Oklahoma State University, 127 NRC, Stillwater, OK, 74078, USA.
| | - Zhen Zou
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.
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Juneja P, Ariani CV, Ho YS, Akorli J, Palmer WJ, Pain A, Jiggins FM. Exome and transcriptome sequencing of Aedes aegypti identifies a locus that confers resistance to Brugia malayi and alters the immune response. PLoS Pathog 2015; 11:e1004765. [PMID: 25815506 PMCID: PMC4376896 DOI: 10.1371/journal.ppat.1004765] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Accepted: 02/25/2015] [Indexed: 11/18/2022] Open
Abstract
Many mosquito species are naturally polymorphic for their abilities to transmit parasites, a feature which is of great interest for controlling vector-borne disease. Aedes aegypti, the primary vector of dengue and yellow fever and a laboratory model for studying lymphatic filariasis, is genetically variable for its capacity to harbor the filarial nematode Brugia malayi. The genome of Ae. aegypti is large and repetitive, making genome resequencing difficult and expensive. We designed exome captures to target protein-coding regions of the genome, and used association mapping in a wild Kenyan population to identify a single, dominant, sex-linked locus underlying resistance. This falls in a region of the genome where a resistance locus was previously mapped in a line established in 1936, suggesting that this polymorphism has been maintained in the wild for the at least 80 years. We then crossed resistant and susceptible mosquitoes to place both alleles of the gene into a common genetic background, and used RNA-seq to measure the effect of this locus on gene expression. We found evidence for Toll, IMD, and JAK-STAT pathway activity in response to early stages of B. malayi infection when the parasites are beginning to die in the resistant genotype. We also found that resistant mosquitoes express anti-microbial peptides at the time of parasite-killing, and that this expression is suppressed in susceptible mosquitoes. Together, we have found that a single resistance locus leads to a higher immune response in resistant mosquitoes, and we identify genes in this region that may be responsible for this trait.
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Affiliation(s)
- Punita Juneja
- Department of Genetics, University of Cambridge, Cambridge, United Kingdom
| | - Cristina V. Ariani
- Department of Genetics, University of Cambridge, Cambridge, United Kingdom
| | - Yung Shwen Ho
- Biological and Environmental Sciences and Engineering (BESE) Division, King Abdullah University of Science & Technology, Thuwal, Kingdom of Saudi Arabia
| | - Jewelna Akorli
- Department of Genetics, University of Cambridge, Cambridge, United Kingdom
- Department of Parasitology, Noguchi Memorial Institute for Medical Research, Accra, Ghana
| | - William J. Palmer
- Department of Genetics, University of Cambridge, Cambridge, United Kingdom
| | - Arnab Pain
- Biological and Environmental Sciences and Engineering (BESE) Division, King Abdullah University of Science & Technology, Thuwal, Kingdom of Saudi Arabia
| | - Francis M. Jiggins
- Department of Genetics, University of Cambridge, Cambridge, United Kingdom
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Liu Y, Hou F, He S, Qian Z, Wang X, Mao A, Sun C, Liu X. Identification, characterization and functional analysis of a serine protease inhibitor (Lvserpin) from the Pacific white shrimp, Litopenaeus vannamei. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2014; 43:35-46. [PMID: 24211341 DOI: 10.1016/j.dci.2013.10.012] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2013] [Revised: 10/24/2013] [Accepted: 10/25/2013] [Indexed: 06/02/2023]
Abstract
As important arthropod immune responses, prophenoloxidase (proPO) activation and Toll pathway initiation are mediated by serine proteinase cascades and regulated by serpins. Herein, a serine protease inhibitor (Lvserpin), encoding for 415 amino acids with calculated molecular weight of 46,639 Da and isoelectric point of 7.03 was characterized from the Pacific white shrimp Litopenaeus vannamei. Multiple sequence alignment revealed that Lvserpin shared the highest similarity with Penaeus monodon serpin6 (87%). Quantitative real-time PCR (qRT-PCR) results showed that the transcripts of Lvserpin were detected in all the examined tissues and most highly expressed in gill. The expression profiles of Lvserpin were greatly fluctuated upon infection of Vibrio anguillarum, Micrococcus lysoleikticus or White Spot Syndrome Virus (WSSV). Double stranded RNA-mediated suppression of Lvserpin resulted in a significant increase in the transcripts of two clip-domain serine proteinases (PPAE and PPAF), prophenoloxidase (proPO), anti-lipopolysaccharide factor (ALF), Crustin and penaeidin3 (Pens3) and also increased the high cumulative mortality post V. anguillarum injection. Besides, the recombinant Lvserpin protein (rLvserpin) was purified and exhibited inhibitory activity against trypsin. Also the rLvserpin showed inhibition on prophenoloxidase activation and bacterial growth. Hence, we proposed that the Lvserpin played important role in the shrimp innate immunity.
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Affiliation(s)
- Yongjie Liu
- College of Animal Science and Technology, Northwest A&F University, Shaanxi Yangling 712100, China
| | - Fujun Hou
- College of Animal Science and Technology, Northwest A&F University, Shaanxi Yangling 712100, China
| | - Shulin He
- College of Animal Science and Technology, Northwest A&F University, Shaanxi Yangling 712100, China
| | - Zhaoying Qian
- College of Animal Science and Technology, Northwest A&F University, Shaanxi Yangling 712100, China
| | - Xianzong Wang
- College of Animal Science and Technology, Northwest A&F University, Shaanxi Yangling 712100, China
| | - Aitao Mao
- Fisheries College, Guangdong Ocean University, Guangdong Zhanjiang 524025, China
| | - Chengbo Sun
- Fisheries College, Guangdong Ocean University, Guangdong Zhanjiang 524025, China
| | - Xiaolin Liu
- College of Animal Science and Technology, Northwest A&F University, Shaanxi Yangling 712100, China.
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Gulley MM, Zhang X, Michel K. The roles of serpins in mosquito immunology and physiology. JOURNAL OF INSECT PHYSIOLOGY 2013; 59:138-47. [PMID: 22960307 PMCID: PMC3560325 DOI: 10.1016/j.jinsphys.2012.08.015] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2012] [Revised: 08/24/2012] [Accepted: 08/28/2012] [Indexed: 05/10/2023]
Abstract
In vector-borne diseases, the complex interplay between pathogen and its vector's immune system determines the outcome of infection and therefore disease transmission. Serpins have been shown in many animals to be key regulators of innate immune reactions. Their control over regulatory proteolytic cascades ultimately decides whether the recognition of a pathogen will lead to an appropriate immune response. In mosquitoes, serpins (SRPNs) regulate the activation of prophenoloxidase and thus melanization, contribute to malaria parasite lysis, and likely Toll pathway activation. Additionally, in culicine mosquitoes, SRPNs are able to regulate hemostasis in the vertebrate host, suggesting a crucial role during bloodfeeding. This review summarizes the annotation, transcriptional regulation, and current knowledge of SRPN function in the three mosquito species for which the complete genome sequence is available. Additionally, we give a brief overview of how SRPNs may be used to prevent transmission of vector-borne diseases.
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Affiliation(s)
| | | | - Kristin Michel
- Corresponding author: tel.: +1 (785) 532-0161, fax: +1 (785) 532-6653;
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Christen JM, Hiromasa Y, An C, Kanost MR. Identification of plasma proteinase complexes with serpin-3 in Manduca sexta. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2012; 42:946-55. [PMID: 23063421 PMCID: PMC3496060 DOI: 10.1016/j.ibmb.2012.09.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2012] [Revised: 09/26/2012] [Accepted: 09/30/2012] [Indexed: 05/09/2023]
Abstract
Extracellular serine proteinase cascades stimulate prophenoloxidase (proPO) activation and antimicrobial peptide production in insect innate immune responses. Serpins in plasma regulate such cascades by selective inhibition of proteinases, in reactions which result in the formation of covalent serpin-proteinase complexes. We carried out experiments to identify plasma proteinases that are inhibited by Manduca sexta serpin-3, an immune-inducible serpin known to regulate proPO activation. Immunoaffinity chromatography, using antiserum to serpin-3, yielded serpin-3 complexes with proteinases identified by immunoblot analysis as prophenoloxidase-activating proteinase (PAP)-1, PAP-2, PAP-3, and hemolymph proteinase 8 (HP8). HP8 can cleave and activate the Toll ligand, Spätzle, leading to synthesis of antimicrobial peptides. Analysis by mass spectrometry of tryptic peptides derived from the serpin-3 complexes confirmed the presence of PAP-1, PAP-3, and HP8. Purified recombinant serpin-3 and active HP8 formed an SDS-stable complex in vitro. Identification of serpin-3-proteinase complexes in plasma provides insight into proteinase targets of serpin-3 and extends the understanding of serpin/proteinase function in the immune response of M. sexta.
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Affiliation(s)
- Jayne M. Christen
- Department of Biochemistry, Kansas State University, Manhattan, KS 66506, USA
| | - Yasuaki Hiromasa
- Department of Biochemistry, Kansas State University, Manhattan, KS 66506, USA
| | - Chunju An
- Department of Entomology, China Agricultural University, Beijing 100193, China
| | - Michael R. Kanost
- Department of Biochemistry, Kansas State University, Manhattan, KS 66506, USA
- Send correspondence to: Michael R. Kanost, Department of Biochemistry, 141 Chalmers Hall, Kansas State University, Manhattan, KS 66506, Telephone: (785)-532-6964, Fax: (785)-532-7278,
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47
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Choi YJ, Fuchs JF, Mayhew GF, Yu HE, Christensen BM. Tissue-enriched expression profiles in Aedes aegypti identify hemocyte-specific transcriptome responses to infection. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2012; 42:729-38. [PMID: 22796331 PMCID: PMC3438353 DOI: 10.1016/j.ibmb.2012.06.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2012] [Revised: 06/18/2012] [Accepted: 06/23/2012] [Indexed: 05/16/2023]
Abstract
Hemocytes are integral components of mosquito immune mechanisms such as phagocytosis, melanization, and production of antimicrobial peptides. However, our understanding of hemocyte-specific molecular processes and their contribution to shaping the host immune response remains limited. To better understand the immunophysiological features distinctive of hemocytes, we conducted genome-wide analysis of hemocyte-enriched transcripts, and examined how tissue-enriched expression patterns change with the immune status of the host. Our microarray data indicate that the hemocyte-enriched trascriptome is dynamic and context-dependent. Analysis of transcripts enriched after bacterial challenge in circulating hemocytes with respect to carcass added a dimension to evaluating infection-responsive genes and immune-related gene families. We resolved patterns of transcriptional change unique to hemocytes from those that are likely shared by other immune responsive tissues, and identified clusters of genes preferentially induced in hemocytes, likely reflecting their involvement in cell type specific functions. In addition, the study revealed conserved hemocyte-enriched molecular repertoires, which might be implicated in core hemocyte function by cross-species meta-analysis of microarray expression data from Anopheles gambiae and Drosophila melanogaster.
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Affiliation(s)
| | | | | | | | - Bruce M. Christensen
- Corresponding author. Bruce M. Christensen, Department of Pathobiological Sciences, University of Wisconsin-Madison, 1656 Linden Drive, Madison, WI 53706, USA, Tel: + 1 608 262 3850, Fax: +1 608 262 7420,
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48
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Wang PH, Liang JP, Gu ZH, Wan DH, Weng SP, Yu XQ, He JG. Molecular cloning, characterization and expression analysis of two novel Tolls (LvToll2 and LvToll3) and three putative Spätzle-like Toll ligands (LvSpz1-3) from Litopenaeus vannamei. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2012; 36:359-371. [PMID: 21827783 DOI: 10.1016/j.dci.2011.07.007] [Citation(s) in RCA: 175] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2011] [Revised: 07/18/2011] [Accepted: 07/21/2011] [Indexed: 05/31/2023]
Abstract
Toll-like receptor-mediated NF-κB pathways are essential for inducing immune related-gene expression in the defense against bacterial, fungal and viral infections in insects and mammals. Although a Toll receptor (LvToll1) was cloned in Litopenaeus vannamei, relatively little is known about other types of Toll-like receptors and their endogenous cytokine-like ligand, Spätzle. Here, we report two novel Toll-like receptors (LvToll2 and LvToll3) and three Spätzle-like proteins (LvSpz1-3) from L. vannamei. LvToll2 has 1009 residues with an extracellular domain containing 18 leucine-rich repeats (LRRs) and a cytoplasmic Toll/interleukin-1 receptor (TIR) domain of 139 residues. LvToll3 is 1244 residues long with an extracellular domain containing 23 LRRs and a cytoplasmic TIR domain of 138 residues. The Spätzle-like proteins LvSpz1, LvSpz2 and LvSpz3 are 237, 245 and 275 residues in length, respectively, and all of them have a putative C-terminal cystine-knot domain. In Drosophila Schneider 2 (S2) cells, LvToll1 and LvToll3 were localized to the membrane and cytoplasm, and LvToll2 was confined to the cytoplasm. In Drosophila S2 cells, LvToll2 could significantly activate the promoters of NF-κB-pathway-controlled antimicrobial peptide genes, whereas LvToll1 and LvToll3 had no effect on them. LvSpz1 exerted some degree of inhibition on the promoter activities of Drosophila Attacin A and L. vannamei Penaeidin4. LvSpz3 also inhibited the Drosophila Attacin A promoter, but LvSpz2 could only slightly activate it. LvToll1, LvToll2 and LvToll3 were constitutive expressed in various tissues, while LvSpz1, LvSpz2 and LvSpz3 exhibited tissue-specific expression in the epithelium, eyestalk, intestine, gill and muscle. In the gill, after Vibrio alginolyticus challenge, LvToll1 was upregulated, but LvToll2 and LvToll3 showed no obvious changes. LvSpz1 and LvSpz3 were also strongly induced by V. alginolyticus challenge, but LvSpz2 only showed a slight downregulation. In the gill, after white spot syndrome virus (WSSV) challenge, LvToll1, LvToll2, LvToll3, LvSpz1 and LvSpz3 were upregulated, but LvSpz2 showed no obvious change, except for a slight downregulation at 12h post-injection of WSSV. These findings might be valuable in understanding the innate immune signal pathways of shrimp and enabling future studies on the host-pathogen interactions in V. alginolyticus and WSSV infections.
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Affiliation(s)
- Pei-Hui Wang
- MOE Key Laboratory of Aquatic Product Safety/State Key Laboratory of Biocontrol School of Life Sciences, Sun Yat-sen University, Guangzhou, People's Republic of China
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Dong Y, Morton JC, Ramirez JL, Souza-Neto JA, Dimopoulos G. The entomopathogenic fungus Beauveria bassiana activate toll and JAK-STAT pathway-controlled effector genes and anti-dengue activity in Aedes aegypti. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2012; 42:126-32. [PMID: 22198333 PMCID: PMC3462650 DOI: 10.1016/j.ibmb.2011.11.005] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2011] [Revised: 11/17/2011] [Accepted: 11/27/2011] [Indexed: 05/14/2023]
Abstract
Here we investigated the effect of Beauveria bassiana infection on the survival of Aedes aegypti mosquitoes and the modulation of their susceptibility to dengue virus infection. Application of B. bassiana caused a reduction in the life span of A. aegypti and hindered dengue virus replication in the mosquito midgut. Fungus infection induced the expression a variety anti-microbial and dengue virus restriction factor genes. Transient reverse genetic analyses showed that the JAK-STAT pathway is implicated anti-fungal defense of Aedes mosquitoes. Our data suggest that this B. bassiana-mediated anti-dengue activity is likely to be at least partly indirectly mediated through the activation of the mosquito's anti-dengue Toll and JAK-STAT pathways.
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Abstract
Parasitic diseases cause important losses in public and veterinary health worldwide. Novel drugs, more reliable diagnostic techniques and vaccine candidates are urgently needed. Due to the complexity of parasites and the intricate relationship with their hosts, development of successful tools to fight parasites has been very limited to date. The growing information on individual parasite genomes is now allowing the use of a broader range of potential strategies to gain deeper insights into the host-parasite relationship and has increased the possibilities to develop molecular-based tools in the field of parasitology. Nevertheless, functional studies of respective genes are still scarce. The RNA interference phenomenon resulting in the regulation of protein expression through the specific degradation of defined mRNAs, and more specifically the possibility of artificially induce it, has shown to be a powerful tool for the investigation of proteins function in many organisms. Recent advances in the design and delivery of targeting molecules allow efficient and highly specific gene silencing in different types of parasites, pointing out this technology as a powerful tool for the identification of novel vaccine candidates or drug targets at the high-throughput level in the near future, and could enable researchers to functionally annotate parasite genomes. The aim of this review is to provide a comprehensive overview on the current advances and pitfalls in gene silencing mechanisms, techniques, applications and prospects in animal parasites.
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