1
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Prakash A, Fenner F, Shit B, Salminen TS, Monteith KM, Khan I, Vale PF. IMD-mediated innate immune priming increases Drosophila survival and reduces pathogen transmission. PLoS Pathog 2024; 20:e1012308. [PMID: 38857285 DOI: 10.1371/journal.ppat.1012308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2024] [Accepted: 05/31/2024] [Indexed: 06/12/2024] Open
Abstract
Invertebrates lack the immune machinery underlying vertebrate-like acquired immunity. However, in many insects past infection by the same pathogen can 'prime' the immune response, resulting in improved survival upon reinfection. Here, we investigated the mechanistic basis and epidemiological consequences of innate immune priming in the fruit fly Drosophila melanogaster when infected with the gram-negative bacterial pathogen Providencia rettgeri. We find that priming in response to P. rettgeri infection is long-lasting and sexually dimorphic response. We further explore the epidemiological consequences of immune priming and find it has the potential to curtail pathogen transmission by reducing pathogen shedding and spread. The enhanced survival of individuals previously exposed to a non-lethal bacterial inoculum coincided with a transient decrease in bacterial loads, and we provide strong evidence that the effect of priming requires the IMD-responsive antimicrobial-peptide Diptericin-B in the fat body. Further, we show that while Diptericin B is the main effector of bacterial clearance, it is not sufficient for immune priming, which requires regulation of IMD by peptidoglycan recognition proteins. This work underscores the plasticity and complexity of invertebrate responses to infection, providing novel experimental evidence for the effects of innate immune priming on population-level epidemiological outcomes.
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Affiliation(s)
- Arun Prakash
- Institute of Ecology and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Florence Fenner
- Institute of Ecology and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | | | - Tiina S Salminen
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Katy M Monteith
- Institute of Ecology and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | | | - Pedro F Vale
- Institute of Ecology and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
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2
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Liang W, Liu W, Xiong XP, Li JW, Li JL, Perera RJ, Zhou R. The circular RNA circATP8B(2) regulates ROS production and antiviral immunity in Drosophila. Cell Rep 2024; 43:113973. [PMID: 38507406 PMCID: PMC11081091 DOI: 10.1016/j.celrep.2024.113973] [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: 11/21/2023] [Revised: 02/04/2024] [Accepted: 02/29/2024] [Indexed: 03/22/2024] Open
Abstract
We identified and validated a collection of circular RNAs (circRNAs) in Drosophila melanogaster. We show that depletion of the pro-viral circRNA circATP8B(2), but not its linear siblings, compromises viral infection both in cultured Drosophila cells and in vivo. In addition, circATP8B(2) is enriched in the fly gut, and gut-specific depletion of circATP8B(2) attenuates viral replication in an oral infection model. Furthermore, circATP8B(2) depletion results in increased levels of reactive oxygen species (ROS) and enhanced expression of dual oxidase (Duox), which produces ROS. Genetic and pharmacological manipulations of circATP8B(2)-depleted flies that reduce ROS levels rescue the viral replication defects elicited by circATP8B(2) depletion. Mechanistically, circATP8B(2) associates with Duox, and circATP8B(2)-Duox interaction is crucial for circATP8B(2)-mediated modulation of Duox activity. In addition, Gαq, a G protein subunit required for optimal Duox activity, acts downstream of circATP8B(2). We conclude that circATP8B(2) regulates antiviral defense by modulating Duox expression and Duox-dependent ROS production.
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Affiliation(s)
- Weihong Liang
- Departments of Medicine, Biological Chemistry, & Oncology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Johns Hopkins All Children's Hospital, St. Petersburg, FL 33701, USA
| | - Wei Liu
- Departments of Medicine, Biological Chemistry, & Oncology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Johns Hopkins All Children's Hospital, St. Petersburg, FL 33701, USA
| | - Xiao-Peng Xiong
- Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Jennifer W Li
- Department of Medicine, Brown University, Providence, RI 02912, USA
| | - Jian-Liang Li
- Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA; National Institute of Environmental Health Sciences, Durham, NC 27709, USA
| | - Ranjan J Perera
- Departments of Medicine, Biological Chemistry, & Oncology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Johns Hopkins All Children's Hospital, St. Petersburg, FL 33701, USA; Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Rui Zhou
- Departments of Medicine, Biological Chemistry, & Oncology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Johns Hopkins All Children's Hospital, St. Petersburg, FL 33701, USA; Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA.
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3
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Hédelin L, Thiébaut A, Huang J, Li X, Lemoine A, Haas G, Meignin C, Cai H, Waterhouse RM, Martins N, Imler JL. Investigating the Evolution of Drosophila STING-Dependent Antiviral Innate Immunity by Multispecies Comparison of 2'3'-cGAMP Responses. Mol Biol Evol 2024; 41:msae032. [PMID: 38377349 PMCID: PMC10917227 DOI: 10.1093/molbev/msae032] [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: 10/13/2023] [Revised: 01/30/2024] [Accepted: 02/07/2024] [Indexed: 02/22/2024] Open
Abstract
Viruses represent a major threat to all animals, which defend themselves through induction of a large set of virus-stimulated genes that collectively control the infection. In vertebrates, these genes include interferons that play a critical role in the amplification of the response to infection. Virus- and interferon-stimulated genes include restriction factors targeting the different steps of the viral replication cycle, in addition to molecules associated with inflammation and adaptive immunity. Predictably, antiviral genes evolve dynamically in response to viral pressure. As a result, each animal has a unique arsenal of antiviral genes. Here, we exploit the capacity to experimentally activate the evolutionarily conserved stimulator of IFN genes (STING) signaling pathway by injection of the cyclic dinucleotide 2'3'-cyclic guanosine monophosphate-adenosine monophosphate into flies to define the repertoire of STING-regulated genes in 10 Drosophila species, spanning 40 million years of evolution. Our data reveal a set of conserved STING-regulated factors, including STING itself, a cGAS-like-receptor, the restriction factor pastel, and the antiviral protein Vago, but also 2 key components of the antiviral RNA interference pathway, Dicer-2, and Argonaute2. In addition, we identify unknown species- or lineage-specific genes that have not been previously associated with resistance to viruses. Our data provide insight into the core antiviral response in Drosophila flies and pave the way for the characterization of previously unknown antiviral effectors.
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Affiliation(s)
- Léna Hédelin
- CNRS UPR9022, Institut de Biologie Moléculaire et Cellulaire, Université de Strasbourg, Strasbourg, France
| | - Antonin Thiébaut
- Department of Ecology and Evolution, SIB Swiss Institute of Bioinformatics, University of Lausanne, Lausanne, Switzerland
| | - Jingxian Huang
- School of Basic Medical Science, Sino-French Hoffmann Institute, Guangzhou Medical University, Guangzhou, China
| | - Xiaoyan Li
- School of Basic Medical Science, Sino-French Hoffmann Institute, Guangzhou Medical University, Guangzhou, China
| | - Aurélie Lemoine
- CNRS UPR9022, Institut de Biologie Moléculaire et Cellulaire, Université de Strasbourg, Strasbourg, France
| | - Gabrielle Haas
- CNRS UPR9022, Institut de Biologie Moléculaire et Cellulaire, Université de Strasbourg, Strasbourg, France
| | - Carine Meignin
- CNRS UPR9022, Institut de Biologie Moléculaire et Cellulaire, Université de Strasbourg, Strasbourg, France
| | - Hua Cai
- School of Basic Medical Science, Sino-French Hoffmann Institute, Guangzhou Medical University, Guangzhou, China
| | - Robert M Waterhouse
- Department of Ecology and Evolution, SIB Swiss Institute of Bioinformatics, University of Lausanne, Lausanne, Switzerland
| | - Nelson Martins
- CNRS UPR9022, Institut de Biologie Moléculaire et Cellulaire, Université de Strasbourg, Strasbourg, France
| | - Jean-Luc Imler
- CNRS UPR9022, Institut de Biologie Moléculaire et Cellulaire, Université de Strasbourg, Strasbourg, France
- School of Basic Medical Science, Sino-French Hoffmann Institute, Guangzhou Medical University, Guangzhou, China
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4
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Goerlinger A, Develay C, Balourdet A, Rigaud T, Moret Y. Infection risk by oral contamination does not induce immune priming in the mealworm beetle ( Tenebrio molitor) but triggers behavioral and physiological responses. Front Immunol 2024; 15:1354046. [PMID: 38404577 PMCID: PMC10885348 DOI: 10.3389/fimmu.2024.1354046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Accepted: 01/29/2024] [Indexed: 02/27/2024] Open
Abstract
In invertebrates, immune priming is the ability of individuals to enhance their immune response based on prior immunological experiences. This adaptive-like immunity likely evolved due to the risk of repeated infections by parasites in the host's natural habitat. The expression of immune priming varies across host and pathogen species, as well as infection routes (oral or wounds), reflecting finely tuned evolutionary adjustments. Evidence from the mealworm beetle (Tenebrio molitor) suggests that Gram-positive bacterial pathogens play a significant role in immune priming after systemic infection. Despite the likelihood of oral infections by natural bacterial pathogens in T. molitor, it remains debated whether ingestion of contaminated food leads to systemic infection, and whether oral immune priming is possible is currently unknown. We first attempted to induce immune priming in both T. molitor larvae and adults by exposing them to food contaminated with living or dead Gram-positive and Gram-negative bacterial pathogens. We found that oral ingestion of living bacteria did not kill them, but septic wounds caused rapid mortality. Intriguingly, the consumption of either dead or living bacteria did not protect against reinfection, contrasting with injury-induced priming. We further examined the effects of infecting food with various living bacterial pathogens on variables such as food consumption, mass gain, and feces production in larvae. We found that larvae exposed to Gram-positive bacteria in their food ingested less food, gained less mass and/or produced more feces than larvae exposed to contaminated food with Gram-negative bacteria or control food. This suggests that oral contamination with Gram-positive bacteria induced both behavioral responses and peristalsis defense mechanisms, even though no immune priming was observed here. Considering that the oral route of infection neither caused the death of the insects nor induced priming, we propose that immune priming in T. molitor may have primarily evolved as a response to the infection risk associated with wounds rather than oral ingestion.
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Affiliation(s)
| | | | | | | | - Yannick Moret
- CNRS UMR 6282 Biogéosciences, Université de Bourgogne, Dijon, France
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5
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Kuyateh O, Obbard DJ. Viruses in Laboratory Drosophila and Their Impact on Host Gene Expression. Viruses 2023; 15:1849. [PMID: 37766256 PMCID: PMC10537266 DOI: 10.3390/v15091849] [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: 07/09/2023] [Revised: 08/18/2023] [Accepted: 08/28/2023] [Indexed: 09/29/2023] Open
Abstract
Drosophila melanogaster has one of the best characterized antiviral immune responses among invertebrates. However, relatively few easily transmitted natural virus isolates are available, and so many Drosophila experiments have been performed using artificial infection routes and artificial host-virus combinations. These may not reflect natural infections, especially for subtle phenotypes such as gene expression. Here, to explore the laboratory virus community and to better understand how natural virus infections induce changes in gene expression, we have analysed seven publicly available D. melanogaster transcriptomic sequencing datasets that were originally sequenced for projects unrelated to virus infection. We have found ten known viruses-including five that have not been experimentally isolated-but no previously unknown viruses. Our analysis of host gene expression revealed that numerous genes were differentially expressed in flies that were naturally infected with a virus. For example, flies infected with nora virus showed patterns of gene expression consistent with intestinal vacuolization and possible host repair via the upd3 JAK/STAT pathway. We also found marked sex differences in virus-induced differential gene expression. Our results show that natural virus infection in laboratory Drosophila does indeed induce detectable changes in gene expression, suggesting that this may form an important background condition for experimental studies in the laboratory.
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Affiliation(s)
- Oumie Kuyateh
- Institute of Ecology and Evolution, University of Edinburgh, Ashworth Laboratories, Charlotte Auerbach Road, Edinburgh EH9 3FL, UK;
- Parasites and Microbes, Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge CB10 1SA, UK
| | - Darren J. Obbard
- Institute of Ecology and Evolution, University of Edinburgh, Ashworth Laboratories, Charlotte Auerbach Road, Edinburgh EH9 3FL, UK;
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6
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Ferguson JM, González-González A, Kaiser JA, Winzer SM, Anast JM, Ridenhour B, Miura TA, Parent CE. Hidden variable models reveal the effects of infection from changes in host survival. PLoS Comput Biol 2023; 19:e1010910. [PMID: 36812266 PMCID: PMC9987815 DOI: 10.1371/journal.pcbi.1010910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 03/06/2023] [Accepted: 02/01/2023] [Indexed: 02/24/2023] Open
Abstract
The impacts of disease on host vital rates can be demonstrated using longitudinal studies, but these studies can be expensive and logistically challenging. We examined the utility of hidden variable models to infer the individual effects of infectious disease from population-level measurements of survival when longitudinal studies are not possible. Our approach seeks to explain temporal deviations in population-level survival after introducing a disease causative agent when disease prevalence cannot be directly measured by coupling survival and epidemiological models. We tested this approach using an experimental host system (Drosophila melanogaster) with multiple distinct pathogens to validate the ability of the hidden variable model to infer per-capita disease rates. We then applied the approach to a disease outbreak in harbor seals (Phoca vituline) that had data on observed strandings but no epidemiological data. We found that our hidden variable modeling approach could successfully detect the per-capita effects of disease from monitored survival rates in both the experimental and wild populations. Our approach may prove useful for detecting epidemics from public health data in regions where standard surveillance techniques are not available and in the study of epidemics in wildlife populations, where longitudinal studies can be especially difficult to implement.
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Affiliation(s)
- Jake M. Ferguson
- Department of Biology, University of Hawaiʻi at Mānoa, Honolulu, Hawaii, United States of America
- Institute for Modeling Collaboration and Innovation, University of Idaho, Moscow, Idaho, United States of America
| | - Andrea González-González
- Institute for Modeling Collaboration and Innovation, University of Idaho, Moscow, Idaho, United States of America
- Department of Biology, University of Florida, Gainesville, Florida, United States of America
- Department of Biological Sciences, University of Idaho, Moscow, Idaho, United States of America
| | - Johnathan A. Kaiser
- Department of Biological Sciences, University of Idaho, Moscow, Idaho, United States of America
| | - Sara M. Winzer
- Department of Biological Sciences, University of Idaho, Moscow, Idaho, United States of America
| | - Justin M. Anast
- Department of Biological Sciences, University of Idaho, Moscow, Idaho, United States of America
| | - Ben Ridenhour
- Department of Mathematics, University of Idaho, Moscow, Idaho, United States of America
| | - Tanya A. Miura
- Institute for Modeling Collaboration and Innovation, University of Idaho, Moscow, Idaho, United States of America
- Department of Biological Sciences, University of Idaho, Moscow, Idaho, United States of America
| | - Christine E. Parent
- Institute for Modeling Collaboration and Innovation, University of Idaho, Moscow, Idaho, United States of America
- Department of Biological Sciences, University of Idaho, Moscow, Idaho, United States of America
- Institute for Interdisciplinary Data Sciences, University of Idaho, Moscow, Idaho, United States of America
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7
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Feng C, Torimaru K, Lim MYT, Chak LL, Shiimori M, Tsuji K, Tanaka T, Iida J, Okamura K. A novel eukaryotic RdRP-dependent small RNA pathway represses antiviral immunity by controlling an ERK pathway component in the black-legged tick. PLoS One 2023; 18:e0281195. [PMID: 36996253 PMCID: PMC10062562 DOI: 10.1371/journal.pone.0281195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 01/17/2023] [Indexed: 04/01/2023] Open
Abstract
Small regulatory RNAs (sRNAs) are involved in antiviral defense and gene regulation. Although roles of RNA-dependent RNA Polymerases (RdRPs) in sRNA biology are extensively studied in nematodes, plants and fungi, understanding of RdRP homologs in other animals is still lacking. Here, we study sRNAs in the ISE6 cell line, which is derived from the black-legged tick, an important vector of human and animal pathogens. We find abundant classes of ~22nt sRNAs that require specific combinations of RdRPs and sRNA effector proteins (Argonautes or AGOs). RdRP1-dependent sRNAs possess 5'-monophosphates and are mainly derived from RNA polymerase III-transcribed genes and repetitive elements. Knockdown of some RdRP homologs misregulates genes including RNAi-related genes and the regulator of immune response Dsor1. Sensor assays demonstrate that Dsor1 is downregulated by RdRP1 through the 3'UTR that contains a target site of RdRP1-dependent repeat-derived sRNAs. Consistent with viral gene repression by the RNAi mechanism using virus-derived small interfering RNAs, viral transcripts are upregulated by AGO knockdown. On the other hand, RdRP1 knockdown unexpectedly results in downregulation of viral transcripts. This effect is dependent on Dsor1, suggesting that antiviral immunity is enhanced by RdRP1 knockdown through Dsor1 upregulation. We propose that tick sRNA pathways control multiple aspects of immune response via RNAi and regulation of signaling pathways.
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Affiliation(s)
- Canran Feng
- Nara Institute of Science and Technology, Nara, Japan
| | | | - Mandy Yu Theng Lim
- Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore, Singapore
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Li-Ling Chak
- Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore, Singapore
| | | | - Kosuke Tsuji
- Nara Institute of Science and Technology, Nara, Japan
| | - Tetsuya Tanaka
- Joint Faculty of Veterinary Medicine, Laboratory of Infectious Diseases, Kagoshima University, Kagoshima, Japan
| | - Junko Iida
- Nara Institute of Science and Technology, Nara, Japan
| | - Katsutomo Okamura
- Nara Institute of Science and Technology, Nara, Japan
- Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore, Singapore
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
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8
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9
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Wang L, Tracy L, Su W, Yang F, Feng Y, Silverman N, Zhang ZZZ. Retrotransposon activation during Drosophila metamorphosis conditions adult antiviral responses. Nat Genet 2022; 54:1933-1945. [PMID: 36396707 PMCID: PMC9795486 DOI: 10.1038/s41588-022-01214-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Accepted: 09/29/2022] [Indexed: 11/18/2022]
Abstract
Retrotransposons are one type of mobile genetic element that abundantly reside in the genomes of nearly all animals. Their uncontrolled activation is linked to sterility, cancer and other pathologies, thereby being largely considered detrimental. Here we report that, within a specific time window of development, retrotransposon activation can license the host's immune system for future antiviral responses. We found that the mdg4 (also known as Gypsy) retrotransposon selectively becomes active during metamorphosis at the Drosophila pupal stage. At this stage, mdg4 activation educates the host's innate immune system by inducing the systemic antiviral function of the nuclear factor-κB protein Relish in a dSTING-dependent manner. Consequently, adult flies with mdg4, Relish or dSTING silenced at the pupal stage are unable to clear exogenous viruses and succumb to viral infection. Altogether, our data reveal that hosts can establish a protective antiviral response that endows a long-term benefit in pathogen warfare due to the developmental activation of mobile genetic elements.
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Affiliation(s)
- Lu Wang
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, NC, USA.
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China.
| | - Lauren Tracy
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, NC, USA
| | - Weijia Su
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, NC, USA
| | - Fu Yang
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, NC, USA
| | - Yu Feng
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China
| | - Neal Silverman
- Division of Infectious Diseases and Immunology, Department of Medicine, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Z Z Zhao Zhang
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, NC, USA.
- Duke Regeneration Center, Duke University School of Medicine, Durham, NC, USA.
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10
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Arch M, Vidal M, Koiffman R, Melkie ST, Cardona PJ. Drosophila melanogaster as a model to study innate immune memory. Front Microbiol 2022; 13:991678. [PMID: 36338030 PMCID: PMC9630750 DOI: 10.3389/fmicb.2022.991678] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 10/03/2022] [Indexed: 09/12/2023] Open
Abstract
Over the last decades, research regarding innate immune responses has gained increasing importance. A growing body of evidence supports the notion that the innate arm of the immune system could show memory traits. Such traits are thought to be conserved throughout evolution and provide a survival advantage. Several models are available to study these mechanisms. Among them, we find the fruit fly, Drosophila melanogaster. This non-mammalian model has been widely used for innate immune research since it naturally lacks an adaptive response. Here, we aim to review the latest advances in the study of the memory mechanisms of the innate immune response using this animal model.
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Affiliation(s)
- Marta Arch
- Tuberculosis Research Unit, Germans Trias i Pujol Research Institute (IGTP), Badalona, Spain
- Department of Genetics and Microbiology, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - Maria Vidal
- Tuberculosis Research Unit, Germans Trias i Pujol Research Institute (IGTP), Badalona, Spain
- Department of Genetics and Microbiology, Universitat Autònoma de Barcelona, Bellaterra, Spain
- Comparative Medicine and Bioimage Centre of Catalonia (CMCiB), Germans Trias I Pujol Research Institute (IGTP), Badalona, Spain
- Microbiology Department, Laboratori Clínic Metropolitana Nord, Germans Trias i Pujol University Hospital, Badalona, Spain
| | - Romina Koiffman
- Tuberculosis Research Unit, Germans Trias i Pujol Research Institute (IGTP), Badalona, Spain
- UCBL, UnivLyon, Université Claude Bernard Lyon 1 (UCBL1), Villeurbanne, France
| | - Solomon Tibebu Melkie
- Tuberculosis Research Unit, Germans Trias i Pujol Research Institute (IGTP), Badalona, Spain
- UCBL, UnivLyon, Université Claude Bernard Lyon 1 (UCBL1), Villeurbanne, France
| | - Pere-Joan Cardona
- Tuberculosis Research Unit, Germans Trias i Pujol Research Institute (IGTP), Badalona, Spain
- Department of Genetics and Microbiology, Universitat Autònoma de Barcelona, Bellaterra, Spain
- Comparative Medicine and Bioimage Centre of Catalonia (CMCiB), Germans Trias I Pujol Research Institute (IGTP), Badalona, Spain
- Microbiology Department, Laboratori Clínic Metropolitana Nord, Germans Trias i Pujol University Hospital, Badalona, Spain
- Centro de Investigación Biomédica en Red en Enfermedades Respiratorias (CIBERES), Instituto de Salud Carlos III (ISCIII), Madrid, Spain
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11
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Armitage SAO, Milutinović B. Editorial overview: Evolutionary ecology of insect immunity. CURRENT OPINION IN INSECT SCIENCE 2022; 53:100948. [PMID: 35777617 DOI: 10.1016/j.cois.2022.100948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Affiliation(s)
- Sophie A O Armitage
- Institute of Biology, Freie Universität Berlin, Königin-Luise-Straße 1-3, 14195 Berlin, Germany.
| | - Barbara Milutinović
- Laboratory of Evolutionary Genetics, Division of Molecular Biology, Ruđer Bošković Institute, 10000 Zagreb, Croatia
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12
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Santos D, Verdonckt TW, Mingels L, Van den Brande S, Geens B, Van Nieuwerburgh F, Kolliopoulou A, Swevers L, Wynant N, Vanden Broeck J. PIWI Proteins Play an Antiviral Role in Lepidopteran Cell Lines. Viruses 2022; 14:v14071442. [PMID: 35891422 PMCID: PMC9321812 DOI: 10.3390/v14071442] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 06/27/2022] [Accepted: 06/27/2022] [Indexed: 01/27/2023] Open
Abstract
Insect antiviral immunity primarily relies on RNAi mechanisms. While a key role of small interfering (si)RNAs and AGO proteins has been well established in this regard, the situation for PIWI proteins and PIWI-interacting (pi)RNAs is not as clear. In the present study, we investigate whether PIWI proteins and viral piRNAs are involved in the immunity against single-stranded RNA viruses in lepidopteran cells, where two PIWIs are identified (Siwi and Ago3). Via loss- and gain-of-function studies in Bombyx mori BmN4 cells and in Trichoplusia ni High Five cells, we demonstrated an antiviral role of Siwi and Ago3. However, small RNA analysis suggests that viral piRNAs can be absent in these lepidopteran cells. Together with the current literature, our results support a functional diversification of PIWI proteins in insects.
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Affiliation(s)
- Dulce Santos
- Research Group of Molecular Developmental Physiology and Signal Transduction, Division of Animal Physiology and Neurobiology, Department of Biology, KU Leuven, Naamsestraat 59, 3000 Leuven, Belgium; (T.-W.V.); (L.M.); (S.V.d.B.); (B.G.); (N.W.); (J.V.B.)
- Correspondence:
| | - Thomas-Wolf Verdonckt
- Research Group of Molecular Developmental Physiology and Signal Transduction, Division of Animal Physiology and Neurobiology, Department of Biology, KU Leuven, Naamsestraat 59, 3000 Leuven, Belgium; (T.-W.V.); (L.M.); (S.V.d.B.); (B.G.); (N.W.); (J.V.B.)
| | - Lina Mingels
- Research Group of Molecular Developmental Physiology and Signal Transduction, Division of Animal Physiology and Neurobiology, Department of Biology, KU Leuven, Naamsestraat 59, 3000 Leuven, Belgium; (T.-W.V.); (L.M.); (S.V.d.B.); (B.G.); (N.W.); (J.V.B.)
| | - Stijn Van den Brande
- Research Group of Molecular Developmental Physiology and Signal Transduction, Division of Animal Physiology and Neurobiology, Department of Biology, KU Leuven, Naamsestraat 59, 3000 Leuven, Belgium; (T.-W.V.); (L.M.); (S.V.d.B.); (B.G.); (N.W.); (J.V.B.)
| | - Bart Geens
- Research Group of Molecular Developmental Physiology and Signal Transduction, Division of Animal Physiology and Neurobiology, Department of Biology, KU Leuven, Naamsestraat 59, 3000 Leuven, Belgium; (T.-W.V.); (L.M.); (S.V.d.B.); (B.G.); (N.W.); (J.V.B.)
| | - Filip Van Nieuwerburgh
- Laboratory of Pharmaceutical Biotechnology, Gent University, Ottergemsesteenweg 460, 9000 Gent, Belgium;
| | - Anna Kolliopoulou
- Insect Molecular Genetics and Biotechnology, Institute of Biosciences and Applications, National Center for Scientific Research “Demokritos”, Aghia Paraskevi Attikis, 153 10 Athens, Greece; (A.K.); (L.S.)
| | - Luc Swevers
- Insect Molecular Genetics and Biotechnology, Institute of Biosciences and Applications, National Center for Scientific Research “Demokritos”, Aghia Paraskevi Attikis, 153 10 Athens, Greece; (A.K.); (L.S.)
| | - Niels Wynant
- Research Group of Molecular Developmental Physiology and Signal Transduction, Division of Animal Physiology and Neurobiology, Department of Biology, KU Leuven, Naamsestraat 59, 3000 Leuven, Belgium; (T.-W.V.); (L.M.); (S.V.d.B.); (B.G.); (N.W.); (J.V.B.)
| | - Jozef Vanden Broeck
- Research Group of Molecular Developmental Physiology and Signal Transduction, Division of Animal Physiology and Neurobiology, Department of Biology, KU Leuven, Naamsestraat 59, 3000 Leuven, Belgium; (T.-W.V.); (L.M.); (S.V.d.B.); (B.G.); (N.W.); (J.V.B.)
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13
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Wu G, Liu J, Li M, Xiao Y, Yi Y. Prior infection of Galleria mellonella with sublethal dose of Bt elicits immune priming responses but incurs metabolic changes. JOURNAL OF INSECT PHYSIOLOGY 2022; 139:104401. [PMID: 35636486 DOI: 10.1016/j.jinsphys.2022.104401] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 05/16/2022] [Accepted: 05/25/2022] [Indexed: 06/15/2023]
Abstract
Invertebrate immune priming has attracted wide attention of biologists in recent years because it challenges core notions about the disparate nature of acquired and innate immunity. However, the metabolic switch and energetic cost during eliciting immune priming are poorly investigated issues, which could widen and deepen our understanding of the physiological mechanism of immune priming. In this study, using sublethal dose of Bacillus thuringiensis (Bt) as an elicitor, we detected typical immune priming responses in Galleria mellonella. We found that the intensity of immune priming is positively correlated with the levels of antimicrobial peptides and phagocytosis ability of hemocytes. Subsequently, we employed LC-MS/MS-based untargeted metabolomics techniques to analyze the metabolic changes in the fat body of G. mellonella larvae during immune priming. The results showed that there were 74 and 56 significantly altered metabolites in positive and negative ion mode, respectively, after Bt priming. Most of the differential metabolites were enriched in the following metabolic pathways: amino acid biosynthesis, carbon metabolism, aminoacyl-tRNA biosynthesis and ABC transporters. The energetic cost of immune priming was depicted mainly in the slow growth of body mass and decreased levels of sucrose, lactose, D-ribulose 1,5-bisphosphate, Glycerate-3P and isocitric acid, which are enriched in carbon metabolism and involved in energy production. Meanwhile, correlation and interaction network analysis showed negative correlations between carbohydrates and metabolites involved in amino acid biosynthesis, suggesting that amino acids acted as the main energy source and helped the organisms synthesize immune effectors to participate in the immune priming response. Our results pave the way for uncovering the physiological mechanism of insect immune priming and discovering novel targets for Bt insecticide.
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Affiliation(s)
- Gongqing Wu
- School of Chemistry and Chemical Engineering, Guangdong Pharmaceutical University, Zhongshan 528458, PR China; Guangdong Cosmetics Engineering & Technology Research Center, Zhongshan 528458, PR China
| | - Jiajie Liu
- School of Chemistry and Chemical Engineering, Guangdong Pharmaceutical University, Zhongshan 528458, PR China
| | - Mei Li
- University of Electronic Science and Technology of China, Zhongshan Institute, Zhongshan 528402, PR China
| | - Yang Xiao
- Sericultural & Agri-Food Research Institute, Guangdong Academy of Agricultural Science, Guangzhou 510610, PR China
| | - Yunhong Yi
- School of Chemistry and Chemical Engineering, Guangdong Pharmaceutical University, Zhongshan 528458, PR China.
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14
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Innate immune pathways act synergistically to constrain RNA virus evolution in Drosophila melanogaster. Nat Ecol Evol 2022; 6:565-578. [PMID: 35273366 PMCID: PMC7612704 DOI: 10.1038/s41559-022-01697-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Accepted: 12/14/2021] [Indexed: 02/05/2023]
Abstract
Host-pathogen interactions impose recurrent selective pressures that lead to constant adaptation and counter-adaptation in both competing species. Here, we sought to study this evolutionary arms-race and assessed the impact of the innate immune system on viral population diversity and evolution, using Drosophila melanogaster as model host and its natural pathogen Drosophila C virus (DCV). We isogenized eight fly genotypes generating animals defective for RNAi, Imd and Toll innate immune pathways as well as pathogen sensing and gut renewal pathways. Wild-type or mutant flies were then orally infected with DCV, and the virus was serially passaged ten times via reinfection in naïve flies. Viral population diversity was studied after each viral passage by high-throughput sequencing, and infection phenotypes were assessed at the beginning and at the end of the evolution experiment. We found that the absence of any of the various immune pathways studied increased viral genetic diversity while attenuating virulence. Strikingly, these effects were observed in a range of host factors described as having mainly antiviral or antibacterial functions. Together, our results indicate that the innate immune system as a whole, and not specific antiviral defense pathways in isolation, generally constrains viral diversity and evolution.
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15
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Cai H, Meignin C, Imler JL. cGAS-like receptor-mediated immunity: the insect perspective. Curr Opin Immunol 2022; 74:183-189. [PMID: 35149240 DOI: 10.1016/j.coi.2022.01.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 01/17/2022] [Accepted: 01/19/2022] [Indexed: 12/18/2022]
Abstract
The cGAS-STING pathway plays a central role in the detection of DNA in the cytosol of mammalian cells and activation of immunity. Although the early evolutionary origin of this pathway in animals has been noted, its ancestral functions have remained elusive so far. We review here new findings in invertebrates establishing a role in sensing and signaling infection, triggering potent transcriptional responses, in addition to autophagy. Results from flies and moths/butterflies point to the importance of STING signaling in antiviral immunity in insects. The recent characterization of cGAS-like receptors in Drosophila reveals the plasticity of this family of pattern-recognition receptors, able to accommodate ligands different from DNA and to produce cyclic dinucleotides beyond 2'3'-cGAMP.
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Affiliation(s)
- Hua Cai
- Sino-French Hoffmann Institute, School of Basic Medical Science, Guangzhou Medical University, Guangzhou, China
| | - Carine Meignin
- Université de Strasbourg, CNRS UPR9022, Institut de Biologie Moléculaire et Cellulaire, Strasbourg, France
| | - Jean-Luc Imler
- Sino-French Hoffmann Institute, School of Basic Medical Science, Guangzhou Medical University, Guangzhou, China; Université de Strasbourg, CNRS UPR9022, Institut de Biologie Moléculaire et Cellulaire, Strasbourg, France.
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16
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Lanz-Mendoza H, Contreras-Garduño J. Innate immune memory in invertebrates: Concept and potential mechanisms. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2022; 127:104285. [PMID: 34626688 DOI: 10.1016/j.dci.2021.104285] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Revised: 09/19/2021] [Accepted: 10/01/2021] [Indexed: 06/13/2023]
Abstract
Invertebrates are the protagonists of a recent paradigm shift because they now show that vertebrates are not the only group with immune memory. This review discusses the concept of immune priming, its characteristics, and differences with trained immunity and immune enhancement. We include an update of the current status of immune priming within generations in different groups of invertebrates which now include work in 5 Phyla: Ctenophora, Cnidaria, Mollusca, Nematoda, and Arthropoda. Clearly, few Phyla have been studied. We also resume and discuss the effector mechanism related to immune memory, including integrating viral elements into the genome, endoreplication, and epigenetics. The roles of other elements are incorporated, such as hemocytes, immune pathways, and metabolisms. We conclude that taking care of the experimental procedure will discern if results provide or do not support the invertebrates' immune memory and that regarding mechanisms, indeed, there are no studies on the immune memory mechanisms, this is how specificity is reached, and how and where the immune memory is stored and how is recall upon subsequent encounters. Finally, we discuss the possibility of having more than one mechanism working in different groups of invertebrates depending on the environmental conditions.
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Affiliation(s)
- Humberto Lanz-Mendoza
- Centro de Investigaciones sobre Enfermedades Infecciosas, INSP, Cuernavaca, Morelos, Mexico.
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17
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Sensing microbial infections in the Drosophila melanogaster genetic model organism. Immunogenetics 2022; 74:35-62. [DOI: 10.1007/s00251-021-01239-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Accepted: 11/20/2021] [Indexed: 12/17/2022]
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18
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Prigot-Maurice C, Beltran-Bech S, Braquart-Varnier C. Why and how do protective symbionts impact immune priming with pathogens in invertebrates? DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2022; 126:104245. [PMID: 34453995 DOI: 10.1016/j.dci.2021.104245] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 07/29/2021] [Accepted: 08/24/2021] [Indexed: 06/13/2023]
Abstract
Growing evidence demonstrates that invertebrates display adaptive-like immune abilities, commonly known as "immune priming". Immune priming is a process by which a host improves its immune defences following an initial pathogenic exposure, leading to better protection after a subsequent infection with the same - or different - pathogens. Nevertheless, beneficial symbionts can enhance similar immune priming processes in hosts, such as when they face repeated infections with pathogens. This "symbiotic immune priming" protects the host against pathogenic viruses, bacteria, fungi, or eukaryotic parasites. In this review, we explore the extent to which protective symbionts interfere and impact immune priming against pathogens from both a mechanical (proximal) and an evolutionary (ultimate) point of view. We highlight that the immune priming of invertebrates is the cornerstone of the tripartite interaction of hosts/symbionts/pathogens. The main shared mechanism of immune priming (induced by symbionts or pathogens) is the sustained immune response at the beginning of host-microbial interactions. However, the evolutionary outcome of immune priming leads to a specific discrimination, which provides enhanced tolerance or resistance depending on the type of microbe. Based on several studies testing immune priming against pathogens in the presence or absence of protective symbionts, we observed that both types of immune priming could overlap and affect each other inside the same hosts. As protective symbionts could be an evolutionary force that influences immune priming, they may help us to better understand the heterogeneity of pathogenic immune priming across invertebrate populations and species.
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Affiliation(s)
- Cybèle Prigot-Maurice
- Université de Poitiers - UFR Sciences Fondamentales et Appliquées, Laboratoire Écologie et Biologie des Interactions - UMR CNRS 7267, Bâtiment B8-B35, 5 rue Albert Turpin, TSA 51106, F, 86073, POITIERS Cedex 9, France.
| | - Sophie Beltran-Bech
- Université de Poitiers - UFR Sciences Fondamentales et Appliquées, Laboratoire Écologie et Biologie des Interactions - UMR CNRS 7267, Bâtiment B8-B35, 5 rue Albert Turpin, TSA 51106, F, 86073, POITIERS Cedex 9, France
| | - Christine Braquart-Varnier
- Université de Poitiers - UFR Sciences Fondamentales et Appliquées, Laboratoire Écologie et Biologie des Interactions - UMR CNRS 7267, Bâtiment B8-B35, 5 rue Albert Turpin, TSA 51106, F, 86073, POITIERS Cedex 9, France
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19
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Prakash A, Khan I. Why do insects evolve immune priming? A search for crossroads. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2022; 126:104246. [PMID: 34453994 DOI: 10.1016/j.dci.2021.104246] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Accepted: 08/25/2021] [Indexed: 06/13/2023]
Abstract
Until recently, it was assumed that insects lack immune memory since they do not have vertebrate-like specialized memory cells. Therefore, their most well studied evolutionary response against pathogens was increased basal immunity. However, growing evidence suggests that many insects also exhibit a form of immune memory (immune priming), where prior exposure to a low dose of infection confers protection against subsequent infection by the same pathogen that acts both within and across generations. Most strikingly, they can rapidly evolve as a highly parallel and mutually exclusive strategy from basal immunity, under different selective conditions and with divergent evolutionary trade-offs. However, the relative importance of priming as an optimal immune strategy also has contradictions, primarily because supporting mechanisms are still unclear. In this review, we adopt a comparative approach to highlight several emerging evolutionary, ecological and mechanistic features of priming vs basal immune responses that warrant immediate attention for future research.
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Affiliation(s)
- Arun Prakash
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, EH9 3FL, United Kingdom.
| | - Imroze Khan
- Department of Biology, Ashoka University, Plot No. 2, Rajiv Gandhi Education City, P.O. Rai, Sonepat, Haryana, 131029, India.
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20
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Segrist E, Dittmar M, Gold B, Cherry S. Orally acquired cyclic dinucleotides drive dSTING-dependent antiviral immunity in enterocytes. Cell Rep 2021; 37:110150. [PMID: 34965418 DOI: 10.1016/j.celrep.2021.110150] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 11/12/2021] [Accepted: 11/30/2021] [Indexed: 11/19/2022] Open
Abstract
Enteric pathogens overcome barrier immunity within the intestinal environment that includes the endogenous flora. The microbiota produces diverse ligands, and the full spectrum of microbial products that are sensed by the epithelium and prime protective immunity is unknown. Using Drosophila, we find that the gut presents a high barrier to infection, which is partially due to signals from the microbiota, as loss of the microbiota enhances oral viral infection. We report cyclic dinucleotide (CDN) feeding is sufficient to protect microbiota-deficient flies from enhanced oral infection, suggesting that bacterial-derived CDNs induce immunity. Mechanistically, we find CDN protection is dSTING- and dTBK1-dependent, leading to NF-kB-dependent gene expression. Furthermore, we identify the apical nucleoside transporter, CNT2, as required for oral CDN protection. Altogether, our studies define a role for bacterial products in priming immune defenses in the gut.
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Affiliation(s)
- Elisha Segrist
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Mark Dittmar
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Beth Gold
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Sara Cherry
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
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21
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Xu Y, Zhong Z, Ren Y, Ma L, Ye Z, Gao C, Wang J, Li Y. Antiviral RNA interference in disease vector (Asian longhorned) ticks. PLoS Pathog 2021; 17:e1010119. [PMID: 34860862 PMCID: PMC8673602 DOI: 10.1371/journal.ppat.1010119] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 12/15/2021] [Accepted: 11/16/2021] [Indexed: 11/18/2022] Open
Abstract
Disease vectors such as mosquitoes and ticks play a major role in the emergence and re-emergence of human and animal viral pathogens. Compared to mosquitoes, however, much less is known about the antiviral responses of ticks. Here we showed that Asian longhorned ticks (Haemaphysalis longicornis) produced predominantly 22-nucleotide virus-derived siRNAs (vsiRNAs) in response to severe fever with thrombocytopenia syndrome virus (SFTSV, an emerging tick-borne virus), Nodamura virus (NoV), or Sindbis virus (SINV) acquired by blood feeding. Notably, experimental acquisition of NoV and SINV by intrathoracic injection also initiated viral replication and triggered the production of vsiRNAs in H. longicornis. We demonstrated that a mutant NoV deficient in expressing its viral suppressor of RNAi (VSR) replicated to significantly lower levels than wildtype NoV in H. longicornis, but accumulated to higher levels after knockdown of the tick Dicer2-like protein identified by phylogeny comparison. Moreover, the expression of a panel of known animal VSRs in cis from the genome of SINV drastically enhanced the accumulation of the recombinant viruses. This study establishes a novel model for virus-vector-mouse experiments with longhorned ticks and provides the first in vivo evidence for an antiviral function of the RNAi response in ticks. Interestingly, comparing the accumulation levels of SINV recombinants expressing green fluorescent protein or SFTSV proteins identified the viral non-structural protein as a putative VSR. Elucidating the function of ticks’ antiviral RNAi pathway in vivo is critical to understand the virus-host interaction and the control of tick-borne viral pathogens. Tick-borne diseases (TBDs) are the most common illnesses transmitted by ticks, and the annual number of reported TBD cases continues to increase. The Asian longhorned tick, a vector associated with at least 30 human pathogens, is native to eastern Asia and recently reached the USA as an emerging disease threat. Newly identified tick-transmitted pathogens continue to be reported, raising concerns about how TBDs occur. Interestingly, tick can harbor pathogens without being affected themselves. For viral infections, ticks have their own immune systems that protect them from infection. Meanwhile, tick-borne viruses have evolved to avoid these defenses as they establish themselves within the vector. Here, we show in detail that infecting longhorned ticks with distinct arthropod-borne RNA viruses through two approaches natural blood feeding and injection, all induce the production of vsiRNAs. Dicer2-like homolog plays a role in regulating antiviral RNAi responses as knocking down of this gene enhanced viral replication. Furthermore, we demonstrate that tick antiviral RNAi responses are inhibited through expression heterologous VSR proteins in recombinant SINV. We identify both the virus and tick factors are critical components to understanding TBDs. Importantly, our study introduces a novel, in vivo virus-vector-mouse model system for exploring TBDs in the future.
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Affiliation(s)
- Yan Xu
- CAS Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, China
| | - Zhengwei Zhong
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, China
| | - Yanxin Ren
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, China
| | - Liting Ma
- CAS Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, China
| | - Zhi Ye
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, China
| | - Chuang Gao
- CAS Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Jingwen Wang
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, China
- * E-mail: (JW); (YL)
| | - Yang Li
- CAS Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, China
- * E-mail: (JW); (YL)
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22
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Li W. Dscam in arthropod immune priming: What is known and what remains unknown. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2021; 125:104231. [PMID: 34390752 DOI: 10.1016/j.dci.2021.104231] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 08/09/2021] [Accepted: 08/10/2021] [Indexed: 06/13/2023]
Abstract
A popular view in the current academic circle is that invertebrates have no adaptive immunity. However, the immune memory and specificity of invertebrates pose a serious challenge to this view and constitute immune priming based on innate immunity. The Down syndrome cell adhesion molecule (Dscam) gene of invertebrates, with approximately 10,000 alternatively spliced isoforms, has a unique characteristic: it specifically binds to different types of bacteria and promotes cell phagocytosis; owing to its antibody-like function, Dscam is a key candidate protein for immune priming. However, the high molecular diversity of Dscam and the gaps and inconsistencies in the existing research make the study of regulation of immune priming by Dscam challenging. In recent years, significant research has been conducted on the Dscam-regulated immune functions in insects and crustaceans, providing preliminary results for Dscam-regulated innate immunity and immune priming, but some important questions remain unresolved. In this review, we summarize the existing knowledge about Dscam-regulated immunity and discuss three yet unanswered questions, the study of which may improve the understanding of the role of Dscam-regulated immune priming in invertebrates.
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Affiliation(s)
- Weiwei Li
- Laboratory of Invertebrate Immunological Defense, School of Life Sciences, East China Normal University, Shanghai, 200241, China.
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23
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Carrau T, Thümecke S, Silva LMR, Perez-Bravo D, Gärtner U, Taubert A, Hermosilla C, Vilcinskas A, Lee KZ. The Cellular Innate Immune Response of the Invasive Pest Insect Drosophila suzukii against Pseudomonas entomophila Involves the Release of Extracellular Traps. Cells 2021; 10:cells10123320. [PMID: 34943828 PMCID: PMC8699444 DOI: 10.3390/cells10123320] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 11/17/2021] [Accepted: 11/25/2021] [Indexed: 01/02/2023] Open
Abstract
Drosophila suzukii is a neobiotic invasive pest that causes extensive damage to fruit crops worldwide. The biological control of this species has been unsuccessful thus far, in part because of its robust cellular innate immune system, including the activity of professional phagocytes known as hemocytes and plasmatocytes. The in vitro cultivation of primary hemocytes isolated from D. suzukii third-instar larvae is a valuable tool for the investigation of hemocyte-derived effector mechanisms against pathogens such as wasp parasitoid larvae, bacteria, fungi and viruses. Here, we describe the morphological characteristics of D. suzukii hemocytes and evaluate early innate immune responses, including extracellular traps released against the entomopathogen Pseudomonas entomophila and lipopolysaccharides. We show for the first time that D. suzukii plasmatocytes cast extracellular traps to combat P. entomophila, along with other cell-mediated reactions, such as phagocytosis and the formation of filopodia.
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Affiliation(s)
- Tessa Carrau
- Department Pests and Vector Insect Control, Fraunhofer Institute for Molecular Biology and Applied Ecology, Ohlebergsweg 12, D-35394 Giessen, Germany; (T.C.); (A.V.)
| | - Susanne Thümecke
- Institute for Insect Biotechnology, Justus Liebig University, Heinrich Buff Ring 26-32, D-35392 Giessen, Germany;
| | - Liliana M. R. Silva
- Institute of Parasitology, Justus Liebig University, Schubert Strasse 81, D-35392 Giessen, Germany; (A.T.); (C.H.)
- Correspondence: (L.M.R.S.); (K.-Z.L.)
| | - David Perez-Bravo
- Department of Internal Medicine (Pulmonology), University of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Aulweg 123, D-35394 Giessen, Germany;
| | - Ulrich Gärtner
- Institute of Anatomy and Cell Biology, Justus Liebig University, Aulweg 123, D-35392 Giessen, Germany;
| | - Anja Taubert
- Institute of Parasitology, Justus Liebig University, Schubert Strasse 81, D-35392 Giessen, Germany; (A.T.); (C.H.)
| | - Carlos Hermosilla
- Institute of Parasitology, Justus Liebig University, Schubert Strasse 81, D-35392 Giessen, Germany; (A.T.); (C.H.)
| | - Andreas Vilcinskas
- Department Pests and Vector Insect Control, Fraunhofer Institute for Molecular Biology and Applied Ecology, Ohlebergsweg 12, D-35394 Giessen, Germany; (T.C.); (A.V.)
- Institute for Insect Biotechnology, Justus Liebig University, Heinrich Buff Ring 26-32, D-35392 Giessen, Germany;
| | - Kwang-Zin Lee
- Department Pests and Vector Insect Control, Fraunhofer Institute for Molecular Biology and Applied Ecology, Ohlebergsweg 12, D-35394 Giessen, Germany; (T.C.); (A.V.)
- Correspondence: (L.M.R.S.); (K.-Z.L.)
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24
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Nigg JC, Mongelli V, Blanc H, Saleh MC. Innovative Toolbox for the Quantification of Drosophila C Virus, Drosophila A Virus, and Nora Virus. J Mol Biol 2021; 434:167308. [PMID: 34678301 DOI: 10.1016/j.jmb.2021.167308] [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: 06/28/2021] [Revised: 09/28/2021] [Accepted: 10/12/2021] [Indexed: 11/29/2022]
Abstract
Quantification of viral replication underlies investigations into host-virus interactions. In Drosophila melanogaster, persistent infections with Drosophila C virus, Drosophila A virus, and Nora virus are commonly observed in nature and in laboratory fly stocks. However, traditional endpoint dilution assays to quantify infectious titers are not compatible with persistently infecting isolates of these viruses that do not cause cytopathic effects in cell culture. Here we present a novel assay based on immunological detection of Drosophila C virus infection that allows quantification of infectious titers for a wider range of Drosophila C virus isolates. We also describe strand specific RT-qPCR assays for quantification of viral negative strand RNA produced during Drosophila C virus, Drosophila A virus, and Nora virus infection. Finally, we demonstrate the utility of these assays for quantification of viral replication during oral infections and persistent infections with each virus.
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Affiliation(s)
- Jared C Nigg
- Viruses and RNA Interference Unit, Institut Pasteur, CNRS UMR 3569, 75724 Paris CEDEX 15, France.
| | - Vanesa Mongelli
- Viruses and RNA Interference Unit, Institut Pasteur, CNRS UMR 3569, 75724 Paris CEDEX 15, France.
| | - Hervé Blanc
- Viruses and RNA Interference Unit, Institut Pasteur, CNRS UMR 3569, 75724 Paris CEDEX 15, France.
| | - Maria-Carla Saleh
- Viruses and RNA Interference Unit, Institut Pasteur, CNRS UMR 3569, 75724 Paris CEDEX 15, France.
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25
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Sułek M, Kordaczuk J, Wojda I. Current understanding of immune priming phenomena in insects. J Invertebr Pathol 2021; 185:107656. [PMID: 34464656 DOI: 10.1016/j.jip.2021.107656] [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] [Received: 03/03/2021] [Revised: 08/21/2021] [Accepted: 08/24/2021] [Indexed: 10/20/2022]
Abstract
It may seem that the most important issues related to insect immunity have already been described. However, novel phenomena observed in recent years shed new light on the understanding of the immune response in insects.The adaptive abilities of insects helped them to populate all ecological land niches.One important adaptive ability of insects that facilitates their success is the plasticity of their immune system. Although they only have innate immune mechanisms, insects can increase their resistance after the first encounter with the pathogen. In recent years, this phenomenon,namedimmunepriming, has become a "hot topic" in immunobiology.Priming can occur within or across generations. In the first case, the resistance of a given individual can increase after surviving a previous infection. Transstadial immune priming occurs when infection takes place at one of the initial developmental stages and increased resistance is observed at the pupal or imago stages. Priming across generations (transgenerationalimmune priming, TGIP) relies on the increased resistance of the offspring when one or both parents are infected during their lifetime.Despite the attention that immune priming has received, basic questions remain to be answered, such as regulation of immune priming at the molecular level. Research indicates that pathogen recognition receptors (PRRs) can be involved in the priming phenomenon. Recent studies have highlighted the special role of microRNAs and epigenetics, which can influence expression of genes that can be transmitted through generations although they are not encoded in the nucleotide sequence. Considerable amounts of research are required to fully understand the mechanisms that regulate priming phenomena. The aim of our work is to analyse thoroughly the most important information on immune priming in insects and help raise pertinent questions such that a greater understanding of this phenomenon can be obtained in the future.
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Affiliation(s)
- Michał Sułek
- Maria Curie-Skłodowska University, Institute of Biological Sciences, Department of Immunobiology, Akademicka 19, Lublin 20-033, Poland.
| | - Jakub Kordaczuk
- Maria Curie-Skłodowska University, Institute of Biological Sciences, Department of Immunobiology, Akademicka 19, Lublin 20-033, Poland
| | - Iwona Wojda
- Maria Curie-Skłodowska University, Institute of Biological Sciences, Department of Immunobiology, Akademicka 19, Lublin 20-033, Poland.
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Endogenous reverse transcriptase and RNase H-mediated antiviral mechanism in embryonic stem cells. Cell Res 2021; 31:998-1010. [PMID: 34158624 PMCID: PMC8217788 DOI: 10.1038/s41422-021-00524-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 05/26/2021] [Indexed: 02/06/2023] Open
Abstract
Nucleic acid-based systems play important roles in antiviral defense, including CRISPR/Cas that adopts RNA-guided DNA cleavage to prevent DNA phage infection and RNA interference (RNAi) that employs RNA-guided RNA cleavage to defend against RNA virus infection. Here, we report a novel type of nucleic acid-based antiviral system that exists in mouse embryonic stem cells (mESCs), which suppresses RNA virus infection by DNA-mediated RNA cleavage. We found that the viral RNA of encephalomyocarditis virus can be reverse transcribed into complementary DNA (vcDNA) by the reverse transcriptase (RTase) encoded by endogenous retrovirus-like elements in mESCs. The vcDNA is negative-sense single-stranded and forms DNA/RNA hybrid with viral RNA. The viral RNA in the heteroduplex is subsequently destroyed by cellular RNase H1, leading to robust suppression of viral growth. Furthermore, either inhibition of the RTase activity or depletion of endogenous RNase H1 results in the promotion of virus proliferation. Altogether, our results provide intriguing insights into the antiviral mechanism of mESCs and the antiviral function of endogenized retroviruses and cellular RNase H. Such a natural nucleic acid-based antiviral mechanism in mESCs is referred to as ERASE (endogenous RTase/RNase H-mediated antiviral system), which is an addition to the previously known nucleic acid-based antiviral mechanisms including CRISPR/Cas in bacteria and RNAi in plants and invertebrates.
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Rosendo Machado S, van der Most T, Miesen P. Genetic determinants of antiviral immunity in dipteran insects - Compiling the experimental evidence. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2021; 119:104010. [PMID: 33476667 DOI: 10.1016/j.dci.2021.104010] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 01/08/2021] [Accepted: 01/09/2021] [Indexed: 06/12/2023]
Abstract
The genetic basis of antiviral immunity in dipteran insects is extensively studied in Drosophila melanogaster and advanced technologies for genetic manipulation allow a better characterization of immune responses also in non-model insect species. Especially, immunity in vector mosquitoes is recently in the spotlight, due to the medical impact that these insects have by transmitting viruses and other pathogens. Here, we review the current state of experimental evidence that supports antiviral functions for immune genes acting in different cellular pathways. We discuss the well-characterized RNA interference mechanism along with the less well-defined JAK-STAT, Toll, and IMD signaling pathways. Furthermore, we highlight the initial evidence for antiviral activity observed for the autophagy pathway, transcriptional pausing, as well as piRNA production from endogenous viral elements. We focus our review on studies from Drosophila and mosquito species from the lineages Aedes, Culex, and Anopheles, which contain major vector species responsible for virus transmission.
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Affiliation(s)
- Samara Rosendo Machado
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Nijmegen Medical Center, P.O. Box 9101, 6500 HB, Nijmegen, the Netherlands
| | - Tom van der Most
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Nijmegen Medical Center, P.O. Box 9101, 6500 HB, Nijmegen, the Netherlands
| | - Pascal Miesen
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Nijmegen Medical Center, P.O. Box 9101, 6500 HB, Nijmegen, the Netherlands.
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28
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Physical and Chemical Barriers in the Larval Midgut Confer Developmental Resistance to Virus Infection in Drosophila. Viruses 2021; 13:v13050894. [PMID: 34065985 PMCID: PMC8151258 DOI: 10.3390/v13050894] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 05/05/2021] [Accepted: 05/06/2021] [Indexed: 01/23/2023] Open
Abstract
Insects can become lethally infected by the oral intake of a number of insect-specific viruses. Virus infection commonly occurs in larvae, given their active feeding behaviour; however, older larvae often become resistant to oral viral infections. To investigate mechanisms that contribute to resistance throughout the larval development, we orally challenged Drosophila larvae at different stages of their development with Drosophila C virus (DCV, Dicistroviridae). Here, we showed that DCV-induced mortality is highest when infection initiates early in larval development and decreases the later in development the infection occurs. We then evaluated the peritrophic matrix as an antiviral barrier within the gut using a Crystallin-deficient fly line (Crys-/-), whose PM is weakened and becomes more permeable to DCV-sized particles as the larva ages. This phenotype correlated with increasing mortality the later in development oral challenge occurred. Lastly, we tested in vitro the infectivity of DCV after incubation at pH conditions that may occur in the midgut. DCV virions were stable in a pH range between 3.0 and 10.5, but their infectivity decreased at least 100-fold below (1.0) and above (12.0) this range. We did not observe such acidic conditions in recently hatched larvae. We hypothesise that, in Drosophila larvae, the PM is essential for containing ingested virions separated from the gut epithelium, while highly acidic conditions inactivate the majority of the virions as they transit.
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Schneider J, Imler JL. Sensing and signalling viral infection in drosophila. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2021; 117:103985. [PMID: 33358662 DOI: 10.1016/j.dci.2020.103985] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 12/16/2020] [Accepted: 12/17/2020] [Indexed: 06/12/2023]
Abstract
The fruitfly Drosophila melanogaster is a valuable model to unravel mechanisms of innate immunity, in particular in the context of viral infections. RNA interference, and more specifically the small interfering RNA pathway, is a major component of antiviral immunity in drosophila. In addition, the contribution of inducible transcriptional responses to the control of viruses in drosophila and other invertebrates is increasingly recognized. In particular, the recent discovery of a STING-IKKβ-Relish signalling cassette in drosophila has confirmed that NF-κB transcription factors play an important role in the control of viral infections, in addition to bacterial and fungal infections. Here, we review recent developments in the field, which begin to shed light on the mechanisms involved in sensing of viral infections and in signalling leading to production of antiviral effectors.
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Affiliation(s)
- Juliette Schneider
- Université de Strasbourg, CNRS UPR9022, Institut de Biologie Moléculaire et Cellulaire, Strasbourg, France
| | - Jean-Luc Imler
- Université de Strasbourg, CNRS UPR9022, Institut de Biologie Moléculaire et Cellulaire, Strasbourg, France; Sino-French Hoffmann Institute, School of Basic Medical Science, Guangzhou Medical University, Guangzhou 511436, China.
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30
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Wallace MA, Coffman KA, Gilbert C, Ravindran S, Albery GF, Abbott J, Argyridou E, Bellosta P, Betancourt AJ, Colinet H, Eric K, Glaser-Schmitt A, Grath S, Jelic M, Kankare M, Kozeretska I, Loeschcke V, Montchamp-Moreau C, Ometto L, Onder BS, Orengo DJ, Parsch J, Pascual M, Patenkovic A, Puerma E, Ritchie MG, Rota-Stabelli O, Schou MF, Serga SV, Stamenkovic-Radak M, Tanaskovic M, Veselinovic MS, Vieira J, Vieira CP, Kapun M, Flatt T, González J, Staubach F, Obbard DJ. The discovery, distribution, and diversity of DNA viruses associated with Drosophila melanogaster in Europe. Virus Evol 2021; 7:veab031. [PMID: 34408913 PMCID: PMC8363768 DOI: 10.1093/ve/veab031] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Drosophila melanogaster is an important model for antiviral immunity in arthropods, but very few DNA viruses have been described from the family Drosophilidae. This deficiency limits our opportunity to use natural host-pathogen combinations in experimental studies, and may bias our understanding of the Drosophila virome. Here, we report fourteen DNA viruses detected in a metagenomic analysis of 6668 pool-sequenced Drosophila, sampled from forty-seven European locations between 2014 and 2016. These include three new nudiviruses, a new and divergent entomopoxvirus, a virus related to Leptopilina boulardi filamentous virus, and a virus related to Musca domestica salivary gland hypertrophy virus. We also find an endogenous genomic copy of galbut virus, a double-stranded RNA partitivirus, segregating at very low frequency. Remarkably, we find that Drosophila Vesanto virus, a small DNA virus previously described as a bidnavirus, may be composed of up to twelve segments and thus represent a new lineage of segmented DNA viruses. Two of the DNA viruses, Drosophila Kallithea nudivirus and Drosophila Vesanto virus are relatively common, found in 2 per cent or more of wild flies. The others are rare, with many likely to be represented by a single infected fly. We find that virus prevalence in Europe reflects the prevalence seen in publicly available datasets, with Drosophila Kallithea nudivirus and Drosophila Vesanto virus the only ones commonly detectable in public data from wild-caught flies and large population cages, and the other viruses being rare or absent. These analyses suggest that DNA viruses are at lower prevalence than RNA viruses in D.melanogaster, and may be less likely to persist in laboratory cultures. Our findings go some way to redressing an earlier bias toward RNA virus studies in Drosophila, and lay the foundation needed to harness the power of Drosophila as a model system for the study of DNA viruses.
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Affiliation(s)
- Megan A Wallace
- The European Drosophila Population Genomics Consortium (DrosEU)
- Ashworth Laboratories, Institute of Evolutionary Biology, University of Edinburgh, Charlotte Auerbach Road, Edinburgh EH9 3FL, UK
| | - Kelsey A Coffman
- Department of Entomology, University of Georgia, Athens, GA, USA
| | - Clément Gilbert
- The European Drosophila Population Genomics Consortium (DrosEU)
- Université Paris-Saclay, CNRS, IRD, UMR Évolution, Génomes, Comportement et Écologie, 91198 Gif-sur-Yvette, France
| | - Sanjana Ravindran
- Ashworth Laboratories, Institute of Evolutionary Biology, University of Edinburgh, Charlotte Auerbach Road, Edinburgh EH9 3FL, UK
| | - Gregory F Albery
- Department of Biology, Georgetown University, Washington, DC, USA
| | - Jessica Abbott
- The European Drosophila Population Genomics Consortium (DrosEU)
- Department of Biology, Section for Evolutionary Ecology, Lund University, Sölvegatan 37, Lund 223 62, Sweden
| | - Eliza Argyridou
- The European Drosophila Population Genomics Consortium (DrosEU)
- Division of Evolutionary Biology, Faculty of Biology, Ludwig-Maximilians-Universität München, Planegg, Germany
| | - Paola Bellosta
- The European Drosophila Population Genomics Consortium (DrosEU)
- Department of Cellular, Computational and Integrative Biology, CIBIO University of Trento, Via Sommarive 9, Trento 38123, Italy
- Department of Medicine & Endocrinology, NYU Langone Medical Center, 550 First Avenue, New York, NY 10016, USA
| | - Andrea J Betancourt
- The European Drosophila Population Genomics Consortium (DrosEU)
- Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK
| | - Hervé Colinet
- The European Drosophila Population Genomics Consortium (DrosEU)
- UMR CNRS 6553 ECOBIO, Université de Rennes1, Rennes, France
| | - Katarina Eric
- The European Drosophila Population Genomics Consortium (DrosEU)
- Institute for Biological Research “Sinisa Stankovic”, National Institute of Republic of Serbia, University of Belgrade, Bulevar despota Stefana 142, Belgrade, Serbia
| | - Amanda Glaser-Schmitt
- The European Drosophila Population Genomics Consortium (DrosEU)
- Division of Evolutionary Biology, Faculty of Biology, Ludwig-Maximilians-Universität München, Planegg, Germany
| | - Sonja Grath
- The European Drosophila Population Genomics Consortium (DrosEU)
- Division of Evolutionary Biology, Faculty of Biology, Ludwig-Maximilians-Universität München, Planegg, Germany
| | - Mihailo Jelic
- The European Drosophila Population Genomics Consortium (DrosEU)
- Faculty of Biology, University of Belgrade, Studentski trg 16, Belgrade, Serbia
| | - Maaria Kankare
- The European Drosophila Population Genomics Consortium (DrosEU)
- Department of Biological and Environmental Science, University of Jyväskylä, Finland
| | - Iryna Kozeretska
- The European Drosophila Population Genomics Consortium (DrosEU)
- National Antarctic Scientific Center of Ukraine, 16 Shevchenko Avenue, Kyiv, 01601, Ukraine
| | - Volker Loeschcke
- The European Drosophila Population Genomics Consortium (DrosEU)
- Department of Biology, Genetics, Ecology and Evolution, Aarhus University, Ny Munkegade 116, Aarhus C DK-8000, Denmark
| | - Catherine Montchamp-Moreau
- The European Drosophila Population Genomics Consortium (DrosEU)
- Université Paris-Saclay, CNRS, IRD, UMR Évolution, Génomes, Comportement et Écologie, 91198 Gif-sur-Yvette, France
| | - Lino Ometto
- The European Drosophila Population Genomics Consortium (DrosEU)
- Department of Biology and Biotechnology, University of Pavia, Pavia 27100, Italy
| | - Banu Sebnem Onder
- The European Drosophila Population Genomics Consortium (DrosEU)
- Department of Biology, Faculty of Science, Hacettepe University, Ankara, Turkey
| | - Dorcas J Orengo
- The European Drosophila Population Genomics Consortium (DrosEU)
- Departament de Genètica, Microbiologia i Estadística and Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona, Barcelona, Spain
| | - John Parsch
- The European Drosophila Population Genomics Consortium (DrosEU)
- Division of Evolutionary Biology, Faculty of Biology, Ludwig-Maximilians-Universität München, Planegg, Germany
| | - Marta Pascual
- The European Drosophila Population Genomics Consortium (DrosEU)
- Departament de Genètica, Microbiologia i Estadística and Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona, Barcelona, Spain
| | - Aleksandra Patenkovic
- The European Drosophila Population Genomics Consortium (DrosEU)
- Institute for Biological Research “Sinisa Stankovic”, National Institute of Republic of Serbia, University of Belgrade, Bulevar despota Stefana 142, Belgrade, Serbia
| | - Eva Puerma
- The European Drosophila Population Genomics Consortium (DrosEU)
- Departament de Genètica, Microbiologia i Estadística and Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona, Barcelona, Spain
| | - Michael G Ritchie
- The European Drosophila Population Genomics Consortium (DrosEU)
- Centre for Biological Diversity, St Andrews University, St Andrews HY15 4SS, UK
| | - Omar Rota-Stabelli
- The European Drosophila Population Genomics Consortium (DrosEU)
- Research and Innovation Center, Fondazione E. Mach, San Michele all’Adige (TN) 38010, Italy
- Centre Agriculture Food Environment, University of Trento, San Michele all’Adige (TN) 38010, Italy
| | - Mads Fristrup Schou
- The European Drosophila Population Genomics Consortium (DrosEU)
- Department of Biology, Section for Evolutionary Ecology, Lund University, Sölvegatan 37, Lund 223 62, Sweden
- Department of Bioscience, Aarhus University, Aarhus, Denmark
| | - Svitlana V Serga
- The European Drosophila Population Genomics Consortium (DrosEU)
- National Antarctic Scientific Center of Ukraine, 16 Shevchenko Avenue, Kyiv, 01601, Ukraine
- Taras Shevchenko National University of Kyiv, 64 Volodymyrska str, Kyiv 01601, Ukraine
| | - Marina Stamenkovic-Radak
- The European Drosophila Population Genomics Consortium (DrosEU)
- Faculty of Biology, University of Belgrade, Studentski trg 16, Belgrade, Serbia
| | - Marija Tanaskovic
- The European Drosophila Population Genomics Consortium (DrosEU)
- Institute for Biological Research “Sinisa Stankovic”, National Institute of Republic of Serbia, University of Belgrade, Bulevar despota Stefana 142, Belgrade, Serbia
| | - Marija Savic Veselinovic
- The European Drosophila Population Genomics Consortium (DrosEU)
- Faculty of Biology, University of Belgrade, Studentski trg 16, Belgrade, Serbia
| | - Jorge Vieira
- The European Drosophila Population Genomics Consortium (DrosEU)
- Instituto de Biologia Molecular e Celular (IBMC), University of Porto, Porto, Portugal
- Instituto de Investigação e Inovação em Saúde, University of Porto, i3S, Porto, Portugal
| | - Cristina P Vieira
- The European Drosophila Population Genomics Consortium (DrosEU)
- Instituto de Biologia Molecular e Celular (IBMC), University of Porto, Porto, Portugal
- Instituto de Investigação e Inovação em Saúde, University of Porto, i3S, Porto, Portugal
| | - Martin Kapun
- The European Drosophila Population Genomics Consortium (DrosEU)
- Department of Evolutionary Biology and Environmental Studies, University of Zürich, Zürich, Switzerland
- Division of Cell & Developmental Biology, Medical University of Vienna, Vienna, Austria
| | - Thomas Flatt
- The European Drosophila Population Genomics Consortium (DrosEU)
- Department of Biology, University of Fribourg, Fribourg CH-1700, Switzerland
| | - Josefa González
- The European Drosophila Population Genomics Consortium (DrosEU)
- Institute of Evolutionary Biology (CSIC-UPF), Barcelona, Spain
| | - Fabian Staubach
- The European Drosophila Population Genomics Consortium (DrosEU)
- Department of Evolution and Ecology, University of Freiburg, Freiburg 79104, Germany
| | - Darren J Obbard
- The European Drosophila Population Genomics Consortium (DrosEU)
- Ashworth Laboratories, Institute of Evolutionary Biology, University of Edinburgh, Charlotte Auerbach Road, Edinburgh EH9 3FL, UK
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Evidence For Long-Lasting Transgenerational Antiviral Immunity in Insects. Cell Rep 2020; 33:108506. [PMID: 33326778 PMCID: PMC7758158 DOI: 10.1016/j.celrep.2020.108506] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 08/04/2020] [Accepted: 11/17/2020] [Indexed: 12/14/2022] Open
Abstract
Transgenerational immune priming (TGIP) allows memory-like immune responses to be transmitted from parents to offspring in many invertebrates. Despite increasing evidence for TGIP in insects, the mechanisms involved in the transfer of information remain largely unknown. Here, we show that Drosophila melanogaster and Aedes aegypti transmit antiviral immunological memory to their progeny that lasts throughout generations. We observe that TGIP, which is virus and sequence specific but RNAi independent, is initiated by a single exposure to disparate RNA viruses and also by inoculation of a fragment of viral double-stranded RNA. The progeny, which inherit a viral DNA that is only a fragment of the viral RNA used to infect the parents, display enriched expression of genes related to chromatin and DNA binding. These findings represent a demonstration of TGIP for RNA viruses in invertebrates, broadly increasing our understanding of the immune response, host genome plasticity, and antiviral memory of the germline.
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32
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Dekmak AS, Yang X, Zu Dohna H, Buchon N, Osta MA. The Route of Infection Influences the Contribution of Key Immunity Genes to Antibacterial Defense in Anopheles gambiae. J Innate Immun 2020; 13:107-126. [PMID: 33207342 DOI: 10.1159/000511401] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Accepted: 09/01/2020] [Indexed: 12/13/2022] Open
Abstract
Insect systemic immune responses to bacterial infections have been mainly studied using microinjections, whereby the microbe is directly injected into the hemocoel. While this methodology has been instrumental in defining immune signaling pathways and enzymatic cascades in the hemolymph, it remains unclear whether and to what extent the contribution of systemic immune defenses to host microbial resistance varies if bacteria invade the hemolymph after crossing the midgut epithelium subsequent to an oral infection. Here, we address this question using the pathogenic Serratia marcescens (Sm) DB11 strain to establish systemic infections of the malaria vector Anopheles gambiae, either by septic Sm injections or by midgut crossing after feeding on Sm. Using functional genetic studies by RNAi, we report that the two humoral immune factors, thioester-containing protein 1 and C-type lectin 4, which play key roles in defense against Gram-negative bacterial infections, are essential for defense against systemic Sm infections established through injection, but they become dispensable when Sm infects the hemolymph following oral infection. Similar results were observed for the mosquito Rel2 pathway. Surprisingly, blocking phagocytosis by cytochalasin D treatment did not affect mosquito susceptibility to Sm infections established through either route. Transcriptomic analysis of mosquito midguts and abdomens by RNA-seq revealed that the transcriptional response in these tissues is more pronounced in response to feeding on Sm. Functional classification of differentially expressed transcripts identified metabolic genes as the most represented class in response to both routes of infection, while immune genes were poorly regulated in both routes. We also report that Sm oral infections are associated with significant downregulation of several immune genes belonging to different families, specifically the clip-domain serine protease family. In sum, our findings reveal that the route of infection not only alters the contribution of key immunity genes to host antimicrobial defense but is also associated with different transcriptional responses in midguts and abdomens, possibly reflecting different adaptive strategies of the host.
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Affiliation(s)
- Amira San Dekmak
- Biology Department, American University of Beirut, Beirut, Lebanon
| | - Xiaowei Yang
- Entomology Department, Cornell Institute for Host-Microbe Interactions and Disease, Cornell University, Ithaca, New York, USA
| | | | - Nicolas Buchon
- Entomology Department, Cornell Institute for Host-Microbe Interactions and Disease, Cornell University, Ithaca, New York, USA
| | - Mike A Osta
- Biology Department, American University of Beirut, Beirut, Lebanon,
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33
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Endogenous Viral Element-Derived Piwi-Interacting RNAs (piRNAs) Are Not Required for Production of Ping-Pong-Dependent piRNAs from Diaphorina citri Densovirus. mBio 2020; 11:mBio.02209-20. [PMID: 32994324 PMCID: PMC7527727 DOI: 10.1128/mbio.02209-20] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Piwi-interacting RNAs (piRNAs) are a class of small RNAs primarily responsible for silencing transposons in the animal germ line. The ping-pong cycle, the posttranscriptional silencing branch of the piRNA pathway, relies on piRNAs produced from endogenous transposon remnants to direct cleavage of transposon RNA via association with Piwi-family Argonaute proteins. In some mosquito species and mosquito-derived cell lines expressing a functionally expanded group of Piwi-family Argonaute proteins, both RNA and DNA viruses are targeted by piRNAs in a manner thought to involve direct processing of exogenous viral RNA into piRNAs. Whether viruses are targeted by piRNAs in nonmosquito species is unknown. Partial integrations of DNA and nonretroviral RNA virus genomes, termed endogenous viral elements (EVEs), are abundant in arthropod genomes and often produce piRNAs that are speculated to target cognate viruses through the ping-pong cycle. Here, we describe a Diaphorina citri densovirus (DcDV)-derived EVE in the genome of Diaphorina citri We found that this EVE gives rise to DcDV-specific primary piRNAs and is unevenly distributed among D. citri populations. Unexpectedly, we found that DcDV is targeted by ping-pong-dependent virus-derived piRNAs (vpiRNAs) in D. citri lacking the DcDV-derived EVE, while four naturally infecting RNA viruses of D. citri are not targeted by vpiRNAs. Furthermore, a recombinant Cricket paralysis virus containing a portion of the DcDV genome corresponding to the DcDV-derived EVE was not targeted by vpiRNAs during infection in D. citri harboring the EVE. These results demonstrate that viruses can be targeted by piRNAs in a nonmosquito species independently of endogenous piRNAs.IMPORTANCE Small RNAs serve as specificity determinants of antiviral responses in insects. Piwi-interacting RNAs (piRNAs) are a class of small RNAs found in animals, and their primary role is to direct antitransposon responses. These responses require endogenous piRNAs complementary to transposon RNA. Additionally, piRNAs have been shown to target RNA and DNA viruses in some mosquito species. In contrast to transposons, targeting of viruses by the piRNA pathway in these mosquito species does not require endogenous piRNAs. Here, we show that piRNAs target a DNA virus, but not RNA viruses, in an agricultural insect pest. We found that targeting of this DNA virus did not require endogenous piRNAs and that endogenous piRNAs did not mediate targeting of an RNA virus with which they shared complementary sequence. Our results highlight differences between mosquitoes and our experimental system and raise the possibility that DNA viruses may be targeted by piRNAs in other species.
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Xu P, Yang L, Yang X, Li T, Graham RI, Wu K, Wilson K. Novel partiti-like viruses are conditional mutualistic symbionts in their normal lepidopteran host, African armyworm, but parasitic in a novel host, Fall armyworm. PLoS Pathog 2020; 16:e1008467. [PMID: 32569314 PMCID: PMC7332103 DOI: 10.1371/journal.ppat.1008467] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 07/02/2020] [Accepted: 03/08/2020] [Indexed: 11/18/2022] Open
Abstract
Recent advances in next generation sequencing (NGS) (e.g. metagenomic and transcriptomic sequencing) have facilitated the discovery of a large number of new insect viruses, but the characterization of these viruses is still in its infancy. Here, we report the discovery, using RNA-seq, of three new partiti-like viruses from African armyworm, Spodoptera exempta (Lepidoptera: Noctuidae), which are all vertically-transmitted transovarially from mother to offspring with high efficiency. Experimental studies show that the viruses reduce their host's growth rate and reproduction, but enhance their resistance to a nucleopolyhedrovirus (NPV). Via microinjection, these partiti-like viruses were transinfected into a novel host, a newly-invasive crop pest in sub-Saharan Africa (SSA), the Fall armyworm, S. frugiperda. This revealed that in this new host, these viruses appear to be deleterious without any detectable benefit; reducing their new host's reproductive rate and increasing their susceptibility to NPV. Thus, the partiti-like viruses appear to be conditional mutualistic symbionts in their normal host, S. exempta, but parasitic in the novel host, S. frugiperda. Transcriptome analysis of S. exempta and S. frugiperda infected, or not, with the partiti-like viruses indicates that the viruses may regulate pathways related to immunity and reproduction. These findings suggest a possible pest management strategy via the artificial host-shift of novel viruses discovered by NGS.
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Affiliation(s)
- Pengjun Xu
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, China
- Lancaster Environment Centre, Lancaster University, Lancaster, United Kingdom
| | - Liyu Yang
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, China
| | - Xianming Yang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Tong Li
- Institute of Plant Protection, Henan Academy of Agricultural Sciences, Zhengzhou, China
| | - Robert I. Graham
- Department of Animal and Agriculture, Hartpury University, Gloucester, United Kingdom
| | - Kongming Wu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Kenneth Wilson
- Lancaster Environment Centre, Lancaster University, Lancaster, United Kingdom
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Vargas V, Cime-Castillo J, Lanz-Mendoza H. Immune priming with inactive dengue virus during the larval stage of Aedes aegypti protects against the infection in adult mosquitoes. Sci Rep 2020; 10:6723. [PMID: 32317699 PMCID: PMC7174395 DOI: 10.1038/s41598-020-63402-z] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2019] [Accepted: 02/27/2020] [Indexed: 02/07/2023] Open
Abstract
Several studies have observed that the immune response in insects can be conserved, a phenomenon known as immune priming, which has been mostly tested in adult stages. However, it is unknown if induction of immune priming in larval stages protects against dengue virus (DENV) infections in adult mosquitoes. In this work, we primed larval instar 3rd of Aedes aegypti with inactive dengue virus, producing adult mosquitoes with i) an enhanced antiviral-immune response; ii) a reduction in the load and replication of RNA of dengue virus (DENV); iii) a decline in viral infective particles production. Adult mosquitoes previously primed during larval stages over-expressed RNA interference (RNAi) markers Argonaute-2 (AGO-2) and Dicer-2 (DCR-2). We also observed inter-individual variations of DENV infection in adult mosquitoes, indicating a heterogeneous response to DENV infection in the same mosquito strain. However, mosquitoes primed during larval stages appear to control the infection, reducing the viral load. The over-expression of interferon-like factors (VAGO) and AGO-2 in the pupa stage suggests a fast activation of antiviral mechanisms after immune priming in larvae, creating a condition in which adult mosquitoes are resistant to the pathogen in the posterior exposure.
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Affiliation(s)
- Valeria Vargas
- National Institute of Public Health, Center for Research on Infectious Diseases, Santa María Ahuacatitlán, Cuernavaca, 62100, Morelos, Mexico.,Postgraduate in Biological Sciences, National Autonomous University of Mexico, Av. Ciudad Universitaria 3000, Coyoacán, C.P. 04510, Mexico
| | - Jorge Cime-Castillo
- National Institute of Public Health, Center for Research on Infectious Diseases, Santa María Ahuacatitlán, Cuernavaca, 62100, Morelos, Mexico
| | - Humberto Lanz-Mendoza
- National Institute of Public Health, Center for Research on Infectious Diseases, Santa María Ahuacatitlán, Cuernavaca, 62100, Morelos, Mexico.
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Drosophila melanogaster as a model for arbovirus infection of adult salivary glands. Virology 2020; 543:1-6. [DOI: 10.1016/j.virol.2020.01.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 01/21/2020] [Accepted: 01/22/2020] [Indexed: 12/19/2022]
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Segrist E, Cherry S. Using Diverse Model Systems to Define Intestinal Epithelial Defenses to Enteric Viral Infections. Cell Host Microbe 2020; 27:329-344. [PMID: 32164844 DOI: 10.1016/j.chom.2020.02.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The intestine is an essential physical and immunological barrier comprised of a monolayer of diverse and specialized epithelial cells that perform functions ranging from nutrient absorption to pathogen sensing and intestinal homeostasis. The intestinal barrier prevents translocation of intestinal microbes into internal compartments. The microbiota is comprised of a complex community largely populated by diverse bacterial species that provide metabolites, nutrients, and immune stimuli that promote intestinal and organismal health. Although commensal organisms promote health, enteric pathogens, including a diverse plethora of enteric viruses, cause acute and chronic diseases. The barrier epithelium plays fundamental roles in immune defenses against enteric viral infections by integrating diverse signals, including those from the microbiota, to prevent disease. Importantly, many model systems have contributed to our understanding of this complex interface. This review will focus on the antiviral mechanisms at play within the intestinal epithelium and how these responses are shaped by the microbiota.
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Affiliation(s)
- Elisha Segrist
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA; Department of Microbiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA; Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Sara Cherry
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA; Department of Microbiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA; Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
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Torri A, Mongelli V, Mondotte JA, Saleh MC. Viral Infection and Stress Affect Protein Levels of Dicer 2 and Argonaute 2 in Drosophila melanogaster. Front Immunol 2020; 11:362. [PMID: 32194567 PMCID: PMC7065269 DOI: 10.3389/fimmu.2020.00362] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 02/14/2020] [Indexed: 12/21/2022] Open
Abstract
The small interfering RNA (siRNA) pathway of Drosophila melanogaster, mainly characterized by the activity of the enzymes Dicer 2 (Dcr-2) and Argonaute 2 (Ago-2), has been described as the major antiviral immune response. Several lines of evidence demonstrated its pivotal role in conferring resistance against viral infections at cellular and systemic level. However, only few studies have addressed the regulation and induction of this system upon infection and knowledge on stability and turnover of the siRNA pathway core components transcripts and proteins remains scarce. In the current work, we explore whether the siRNA pathway is regulated following viral infection in D. melanogaster. After infecting different fly strains with two different viruses and modes of infection, we observed changes in Dcr-2 and Ago-2 protein concentrations that were not related with changes in gene expression. This response was observed either upon viral infection or upon stress-related experimental procedure, indicating a bivalent function of the siRNA system operating as a general gene regulation rather than a specific antiviral system.
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Affiliation(s)
- Alessandro Torri
- Viruses and RNA Interference Unit, CNRS Unité Mixte de Recherche, Institut Pasteur, Paris, France
| | - Vanesa Mongelli
- Viruses and RNA Interference Unit, CNRS Unité Mixte de Recherche, Institut Pasteur, Paris, France
| | - Juan A Mondotte
- Viruses and RNA Interference Unit, CNRS Unité Mixte de Recherche, Institut Pasteur, Paris, France
| | - Maria-Carla Saleh
- Viruses and RNA Interference Unit, CNRS Unité Mixte de Recherche, Institut Pasteur, Paris, France
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Frochaux MV, Bou Sleiman M, Gardeux V, Dainese R, Hollis B, Litovchenko M, Braman VS, Andreani T, Osman D, Deplancke B. cis-regulatory variation modulates susceptibility to enteric infection in the Drosophila genetic reference panel. Genome Biol 2020; 21:6. [PMID: 31948474 PMCID: PMC6966807 DOI: 10.1186/s13059-019-1912-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Accepted: 12/05/2019] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Resistance to enteric pathogens is a complex trait at the crossroads of multiple biological processes. We have previously shown in the Drosophila Genetic Reference Panel (DGRP) that resistance to infection is highly heritable, but our understanding of how the effects of genetic variants affect different molecular mechanisms to determine gut immunocompetence is still limited. RESULTS To address this, we perform a systems genetics analysis of the gut transcriptomes from 38 DGRP lines that were orally infected with Pseudomonas entomophila. We identify a large number of condition-specific, expression quantitative trait loci (local-eQTLs) with infection-specific ones located in regions enriched for FOX transcription factor motifs. By assessing the allelic imbalance in the transcriptomes of 19 F1 hybrid lines from a large round robin design, we independently attribute a robust cis-regulatory effect to only 10% of these detected local-eQTLs. However, additional analyses indicate that many local-eQTLs may act in trans instead. Comparison of the transcriptomes of DGRP lines that were either susceptible or resistant to Pseudomonas entomophila infection reveals nutcracker as the only differentially expressed gene. Interestingly, we find that nutcracker is linked to infection-specific eQTLs that correlate with its expression level and to enteric infection susceptibility. Further regulatory analysis reveals one particular eQTL that significantly decreases the binding affinity for the repressor Broad, driving differential allele-specific nutcracker expression. CONCLUSIONS Our collective findings point to a large number of infection-specific cis- and trans-acting eQTLs in the DGRP, including one common non-coding variant that lowers enteric infection susceptibility.
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Affiliation(s)
- Michael V. Frochaux
- Laboratory of Systems Biology and Genetics, Institute of Bioengineering, Ecole Polytechnique Fédérale de Lausanne (EPFL) and Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Maroun Bou Sleiman
- Laboratory of Systems Biology and Genetics, Institute of Bioengineering, Ecole Polytechnique Fédérale de Lausanne (EPFL) and Swiss Institute of Bioinformatics, Lausanne, Switzerland
- Current Address: Laboratory of Integrative Systems Physiology, Institute of Bioengineering, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Vincent Gardeux
- Laboratory of Systems Biology and Genetics, Institute of Bioengineering, Ecole Polytechnique Fédérale de Lausanne (EPFL) and Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Riccardo Dainese
- Laboratory of Systems Biology and Genetics, Institute of Bioengineering, Ecole Polytechnique Fédérale de Lausanne (EPFL) and Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Brian Hollis
- Laboratory of Systems Biology and Genetics, Institute of Bioengineering, Ecole Polytechnique Fédérale de Lausanne (EPFL) and Swiss Institute of Bioinformatics, Lausanne, Switzerland
- Current Address: Department of Biological Sciences, University of South Carolina, Columbia, South Carolina USA
| | - Maria Litovchenko
- Laboratory of Systems Biology and Genetics, Institute of Bioengineering, Ecole Polytechnique Fédérale de Lausanne (EPFL) and Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Virginie S. Braman
- Laboratory of Systems Biology and Genetics, Institute of Bioengineering, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Tommaso Andreani
- Computational Biology and Data Mining Group, Institute of Molecular Biology, Johannes Gutenberg-Universität Mainz, Mainz, Germany
| | - Dani Osman
- Faculty of Sciences III and Azm Center for Research in Biotechnology and its Applications, LBA3B, EDST, Lebanese University, Tripoli, 1300 Lebanon
| | - Bart Deplancke
- Laboratory of Systems Biology and Genetics, Institute of Bioengineering, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
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Nigg JC, Falk BW. Diaphorina citri densovirus is a persistently infecting virus with a hybrid genome organization and unique transcription strategy. J Gen Virol 2019; 101:226-239. [PMID: 31855134 DOI: 10.1099/jgv.0.001371] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Diaphorina citri densovirus (DcDV) is an ambisense densovirus with a 5071 nt genome. Phylogenetic analysis places DcDV in an intermediate position between those in the Ambidensovirus and Iteradensovirus genera, a finding that is consistent with the observation that DcDV possesses an Iteradensoviris-like non-structural (NS) protein-gene cassette, but a capsid-protein (VP) gene cassette resembling those of other ambisense densoviruses. DcDV is maternally transmitted to 100 % of the progeny of infected female Diaphorina citri, and the progeny of infected females carry DcDV as a persistent infection without outward phenotypic effects. We were unable to infect naïve individuals by oral inoculation, however low levels of transient viral replication are detected following intrathoracic injection of DcDV virions into uninfected D. citri insects. Transcript mapping indicates that DcDV produces one transcript each from the NS and VP gene cassettes and that these transcripts are polyadenylated at internal sites to produce a ~2.2 kb transcript encoding the NS proteins and a ~2.4 kb transcript encoding the VP proteins. Additionally, we found that transcriptional readthrough leads to the production of longer non-canonical transcripts from both genomic strands.
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Affiliation(s)
- Jared C Nigg
- Department of Plant Pathology, University of California, Davis, CA, USA
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41
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Niu J, Yang WJ, Tian Y, Fan JY, Ye C, Shang F, Ding BY, Zhang J, An X, Yang L, Chang TY, Christiaens O, Smagghe G, Wang JJ. Topical dsRNA delivery induces gene silencing and mortality in the pea aphid. PEST MANAGEMENT SCIENCE 2019; 75:2873-2881. [PMID: 31038279 DOI: 10.1002/ps.5457] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2019] [Revised: 04/16/2019] [Accepted: 04/30/2019] [Indexed: 05/10/2023]
Abstract
BACKGROUND With the growing number of available aphid genomes and transcriptomes, an efficient and easy-to-adapt tool for gene function study is urgently required. RNA interference (RNAi), as a post-transcriptional gene silencing mechanism, is important as a research tool for determining gene functions and has potential as a novel insect control strategy. However, these applications have been hampered by the lack of effective dsRNA delivery approaches in aphids. RESULTS Here, we developed a convenient and efficient dsRNA delivery method, topical RNAi, in aphids. An investigation of its dose and time-dependent RNAi efficiencies revealed that with as little as 60 ng dsRNA per adult pea aphid (Acyrthosiphon pisum), the indicator gene, Aphunchback, could be significantly silenced within 2 h of exposure. The method was further validated by successfully silencing other different genes, and it was also efficient toward two other aphid species, Aphis citricidus and Myzus persicae. Furthermore, a noticeable mortality was also observed in pea aphids using topical RNAi-mediated gene silencing, within 4 days post-dsRNA application for four out of seven tested genes. CONCLUSION Compared with the currently used dsRNA delivery methods in aphids, microinjection and ingestion, topical RNAi is time- and cost-effective, which could greatly influence RNAi-based gene functional studies and potential candidate gene selection for developing RNAi-based aphid control strategies in the future. © 2019 Society of Chemical Industry.
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Affiliation(s)
- Jinzhi Niu
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing, China
- International Joint Laboratory on China-Belgium Sustainable Crop Pest Control, Academy of Agricultural Sciences, Southwest University, Chongqing, China
| | - Wan-Jun Yang
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing, China
- International Joint Laboratory on China-Belgium Sustainable Crop Pest Control, Academy of Agricultural Sciences, Southwest University, Chongqing, China
| | - Yuan Tian
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing, China
- International Joint Laboratory on China-Belgium Sustainable Crop Pest Control, Academy of Agricultural Sciences, Southwest University, Chongqing, China
| | - Jia-Yao Fan
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing, China
- International Joint Laboratory on China-Belgium Sustainable Crop Pest Control, Academy of Agricultural Sciences, Southwest University, Chongqing, China
| | - Chao Ye
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing, China
- International Joint Laboratory on China-Belgium Sustainable Crop Pest Control, Academy of Agricultural Sciences, Southwest University, Chongqing, China
| | - Feng Shang
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing, China
- International Joint Laboratory on China-Belgium Sustainable Crop Pest Control, Academy of Agricultural Sciences, Southwest University, Chongqing, China
| | - Bi-Yue Ding
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing, China
- International Joint Laboratory on China-Belgium Sustainable Crop Pest Control, Academy of Agricultural Sciences, Southwest University, Chongqing, China
| | - Jun Zhang
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing, China
- International Joint Laboratory on China-Belgium Sustainable Crop Pest Control, Academy of Agricultural Sciences, Southwest University, Chongqing, China
| | - Xin An
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing, China
- International Joint Laboratory on China-Belgium Sustainable Crop Pest Control, Academy of Agricultural Sciences, Southwest University, Chongqing, China
| | - Li Yang
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing, China
- International Joint Laboratory on China-Belgium Sustainable Crop Pest Control, Academy of Agricultural Sciences, Southwest University, Chongqing, China
| | - Teng-Yu Chang
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing, China
- International Joint Laboratory on China-Belgium Sustainable Crop Pest Control, Academy of Agricultural Sciences, Southwest University, Chongqing, China
| | - Olivier Christiaens
- Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Guy Smagghe
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing, China
- International Joint Laboratory on China-Belgium Sustainable Crop Pest Control, Academy of Agricultural Sciences, Southwest University, Chongqing, China
- Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Jin-Jun Wang
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing, China
- International Joint Laboratory on China-Belgium Sustainable Crop Pest Control, Academy of Agricultural Sciences, Southwest University, Chongqing, China
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Hammer TJ, Moran NA. Links between metamorphosis and symbiosis in holometabolous insects. Philos Trans R Soc Lond B Biol Sci 2019; 374:20190068. [PMID: 31438811 PMCID: PMC6711286 DOI: 10.1098/rstb.2019.0068] [Citation(s) in RCA: 75] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/16/2019] [Indexed: 01/23/2023] Open
Abstract
Many animals depend on microbial symbionts to provide nutrition, defence or other services. Holometabolous insects, as well as other animals that undergo metamorphosis, face unique constraints on symbiont maintenance. Microbes present in larvae encounter a radical transformation of their habitat and may also need to withstand chemical and immunological challenges. Metamorphosis also provides an opportunity, in that symbiotic associations can be decoupled over development. For example, some holometabolous insects maintain the same symbiont as larvae and adults, but house it in different tissues; in other species, larvae and adults may harbour entirely different types or numbers of microbes, in accordance with shifts in host diet or habitat. Such flexibility may provide an advantage over hemimetabolous insects, in which selection on adult-stage microbial associations may be constrained by its negative effects on immature stages, and vice versa. Additionally, metamorphosis itself can be directly influenced by symbionts. Across disparate insect taxa, microbes protect hosts from pathogen infection, supply nutrients essential for rebuilding the adult body and provide cues regulating pupation. However, microbial associations remain completely unstudied for many families and even orders of Holometabola, and future research will undoubtedly reveal more links between metamorphosis and microbiota, two widespread features of animal life. This article is part of the theme issue 'The evolution of complete metamorphosis'.
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Affiliation(s)
- Tobin J. Hammer
- Department of Integrative Biology, University of Texas at Austin, Austin, TX 78712, USA
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43
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Ben-Ami F. Host Age Effects in Invertebrates: Epidemiological, Ecological, and Evolutionary Implications. Trends Parasitol 2019; 35:466-480. [PMID: 31003758 DOI: 10.1016/j.pt.2019.03.008] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 03/19/2019] [Accepted: 03/21/2019] [Indexed: 12/26/2022]
Abstract
In most species, variation in age among individuals is the strongest and most visible form of phenotypic variation. Individual-level age effects on disease traits, caused by differences in the age at exposure of the host or its parents, have been widely documented in invertebrates. They can influence diverse traits, such as host susceptibility, virulence, parasite reproduction and further transmission, and may cascade to the population level, influencing disease prevalence and within-host competition. Here, I summarize what is known about the relationship between individual-level age/stage effects and infectious disease in invertebrates. I also attempt to link age effects to the theory of aging (senescence), and highlight the importance of population age structure to disease epidemiology and evolution. I conclude by identifying gaps in our understanding of individual- and population-level age effects in invertebrates. As the age structure of populations varies across space and time, age effects have strong epidemiological, ecological, and evolutionary implications for explaining variation in infectious diseases of invertebrates.
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Affiliation(s)
- Frida Ben-Ami
- School of Zoology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel.
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44
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Kutzer MAM, Kurtz J, Armitage SAO. A multi-faceted approach testing the effects of previous bacterial exposure on resistance and tolerance. J Anim Ecol 2019; 88:566-578. [PMID: 30697699 PMCID: PMC6487967 DOI: 10.1111/1365-2656.12953] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Accepted: 12/03/2018] [Indexed: 01/03/2023]
Abstract
Hosts can alter their strategy towards pathogens during their lifetime; that is, they can show phenotypic plasticity in immunity or life history. Immune priming is one such example, where a previous encounter with a pathogen confers enhanced protection upon secondary challenge, resulting in reduced pathogen load (i.e., resistance) and improved host survival. However, an initial encounter might also enhance tolerance, particularly to less virulent opportunistic pathogens that establish persistent infections. In this scenario, individuals are better able to reduce the negative fecundity consequences that result from a high pathogen burden. Finally, previous exposure may also lead to life‐history adjustments, such as terminal investment into reproduction. Using different Drosophila melanogaster host genotypes and two bacterial pathogens, Lactococcus lactis and Pseudomonas entomophila, we tested whether previous exposure results in resistance or tolerance and whether it modifies immune gene expression during an acute‐phase infection (one day post‐challenge). We then asked whether previous pathogen exposure affects chronic‐phase pathogen persistence and longer‐term survival (28 days post‐challenge). We predicted that previous exposure would increase host resistance to an early stage bacterial infection while it might come at a cost to host fecundity tolerance. We reasoned that resistance would be due in part to stronger immune gene expression after challenge. We expected that previous exposure would improve long‐term survival, that it would reduce infection persistence, and we expected to find genetic variation in these responses. We found that previous exposure to P. entomophila weakened host resistance to a second infection independent of genotype and had no effect on immune gene expression. Fecundity tolerance showed genotypic variation but was not influenced by previous exposure. However, L. lactis persisted as a chronic infection, whereas survivors cleared the more pathogenic P. entomophila infection. To our knowledge, this is the first study that addresses host tolerance to bacteria in relation to previous exposure, taking a multi‐faceted approach to address the topic. Our results suggest that previous exposure comes with transient costs to resistance during the early stage of infection in this host–pathogen system and that infection persistence may be bacterium‐specific.
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Affiliation(s)
- Megan A M Kutzer
- Institute for Evolution and Biodiversity, University of Münster, Münster, Germany.,IST Austria, Klosterneuburg, Austria
| | - Joachim Kurtz
- Institute for Evolution and Biodiversity, University of Münster, Münster, Germany
| | - Sophie A O Armitage
- Institute for Evolution and Biodiversity, University of Münster, Münster, Germany.,Institute of Biology, Freie Universität Berlin, Berlin, Germany
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Schulz NKE, Sell MP, Ferro K, Kleinhölting N, Kurtz J. Transgenerational Developmental Effects of Immune Priming in the Red Flour Beetle Tribolium castaneum. Front Physiol 2019; 10:98. [PMID: 30837885 PMCID: PMC6389831 DOI: 10.3389/fphys.2019.00098] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2018] [Accepted: 01/28/2019] [Indexed: 11/13/2022] Open
Abstract
Immune priming, the increased chance to survive a secondary encounter with a pathogen, has been described for many invertebrate species, which lack the classical adaptive immune system of vertebrates. Priming can be specific even for closely related bacterial strains, last up to the entire lifespan of an individual, and in some species, it can also be transferred to the offspring and is then called transgenerational immune priming (TGIP). In the red flour beetle Tribolium castaneum, a pest of stored grains, TGIP has even been shown to be transferred paternally after injection of adult beetles with heat-killed Bacillus thuringiensis. Here we studied whether TGIP in T. castaneum is also transferred to the second filial generation, whether it can also occur after oral and injection priming of larvae and whether it has effects on offspring development. We found that paternal priming with B. thuringiensis does not only protect the first but also the second offspring generation. Also, fitness costs of the immune priming became apparent, when the first filial generation produced fewer offspring. Furthermore, we used two different routes of exposure to prime larvae, either by injecting them with heat-killed bacteria or orally feeding them B. thuringiensis spore culture supernatant. Neither of the parental larval priming methods led to any direct benefits regarding offspring resistance. However, the injections slowed down development of the injected individuals, while oral priming with both a pathogenic and a non-pathogenic strain of B. thuringiensis delayed offspring development. The long-lasting transgenerational nature of immune priming and its impact on offspring development indicate that potentially underlying epigenetic modifications might be stable over several generations. Therefore, this form of phenotypic plasticity might impact pest control and should be considered when using products of bacterial origin against insects.
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Affiliation(s)
- Nora K E Schulz
- Institute for Evolution and Biodiversity, University of Münster, Münster, Germany
| | - Marie Pauline Sell
- Institute for Evolution and Biodiversity, University of Münster, Münster, Germany
| | - Kevin Ferro
- Institute for Evolution and Biodiversity, University of Münster, Münster, Germany
| | - Nico Kleinhölting
- Institute for Evolution and Biodiversity, University of Münster, Münster, Germany
| | - Joachim Kurtz
- Institute for Evolution and Biodiversity, University of Münster, Münster, Germany
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