1
|
Wallace MA, Obbard DJ. Naturally occurring viruses of Drosophila reduce offspring number and lifespan. Proc Biol Sci 2024; 291:20240518. [PMID: 38747703 DOI: 10.1098/rspb.2024.0518] [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: 03/02/2024] [Accepted: 04/23/2024] [Indexed: 07/31/2024] Open
Abstract
Drosophila remains a pre-eminent insect model system for host-virus interaction, but the host range and fitness consequences of the drosophilid virome are poorly understood. Metagenomic studies have reported approximately 200 viruses associated with Drosophilidae, but few isolates are available to characterize the Drosophila immune response, and most characterization has relied on injection and systemic infection. Here, we use a more natural infection route to characterize the fitness effects of infection and to study a wider range of viruses. We exposed laboratory Drosophila melanogaster to 23 naturally occurring viruses from wild-collected drosophilids. We recorded transmission rates along with two components of female fitness: survival and the lifetime number of adult offspring produced. Nine different viruses transmitted during contact with laboratory D. melanogaster, although for the majority, rates of transmission were less than 20%. Five virus infections led to a significant decrease in lifespan (D. melanogaster Nora virus, D. immigrans Nora virus, Muthill virus, galbut virus and Prestney Burn virus), and three led to a reduction in the total number of offspring. Our findings demonstrate the utility of the Drosophila model for community-level studies of host-virus interactions, and suggest that viral infection could be a substantial fitness burden on wild flies.
Collapse
Affiliation(s)
- Megan A Wallace
- Institute of Ecology and Evolution, University of Edinburgh, Ashworth Laboratories, Charlotte Auerbach Road, Edinburgh EH9 3FL, UK
| | - Darren J Obbard
- Institute of Ecology and Evolution, University of Edinburgh, Ashworth Laboratories, Charlotte Auerbach Road, Edinburgh EH9 3FL, UK
| |
Collapse
|
2
|
Rodriguez-Andres J, Axford J, Hoffmann A, Fazakerley J. Mosquito transgenerational antiviral immunity is mediated by vertical transfer of virus DNA sequences and RNAi. iScience 2024; 27:108598. [PMID: 38155780 PMCID: PMC10753076 DOI: 10.1016/j.isci.2023.108598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Revised: 10/23/2023] [Accepted: 11/28/2023] [Indexed: 12/30/2023] Open
Abstract
Mosquitoes are important vectors for transmission of many viruses of public and veterinary health concern. These viruses most commonly have an RNA genome and infect mosquitoes for life. The principal mosquito antiviral response is the RNAi system which destroys virus RNA. Here, we confirm an earlier study that Aedes aegypti mosquitoes infected with positive-stranded RNA arboviruses can transmit specific immunity to their offspring. We show that this trans-generational immunity requires replication of virus RNA and reverse transcription of vRNA to vDNA in the infected parents and intergenerational transfer of vDNA. This vDNA is both genome-integrated and episomal. The episomal vDNA sequences are flanked by retrotransposon long-terminal repeats, predominantly Copia-like. Integrated vDNA sequences are propagated along several generations but specific immunity is effective only for a few generations and correlates with the presence of vRNA and episomal vDNA. This understanding raises new possibilities for the control of important mosquito-borne virus diseases.
Collapse
Affiliation(s)
- Julio Rodriguez-Andres
- Department of Microbiology and Immunology, Faculty of Medicine Dentistry and Health Sciences, University of Melbourne at the Peter Doherty Institute, Melbourne, VIC, Australia
| | - Jason Axford
- School of Biosciences, Faculty of Science at the Bio-21 Institute, University of Melbourne, Parkville, VIC, Australia
| | - Ary Hoffmann
- School of Biosciences, Faculty of Science at the Bio-21 Institute, University of Melbourne, Parkville, VIC, Australia
| | - John Fazakerley
- Department of Microbiology and Immunology, Faculty of Medicine Dentistry and Health Sciences, University of Melbourne at the Peter Doherty Institute, Melbourne, VIC, Australia
| |
Collapse
|
3
|
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.
Collapse
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;
| |
Collapse
|
4
|
Imrie RM, Walsh SK, Roberts KE, Lello J, Longdon B. Investigating the outcomes of virus coinfection within and across host species. PLoS Pathog 2023; 19:e1011044. [PMID: 37216391 DOI: 10.1371/journal.ppat.1011044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Accepted: 05/02/2023] [Indexed: 05/24/2023] Open
Abstract
Interactions between coinfecting pathogens have the potential to alter the course of infection and can act as a source of phenotypic variation in susceptibility between hosts. This phenotypic variation may influence the evolution of host-pathogen interactions within host species and interfere with patterns in the outcomes of infection across host species. Here, we examine experimental coinfections of two Cripaviruses-Cricket Paralysis Virus (CrPV), and Drosophila C Virus (DCV)-across a panel of 25 Drosophila melanogaster inbred lines and 47 Drosophilidae host species. We find that interactions between these viruses alter viral loads across D. melanogaster genotypes, with a ~3 fold increase in the viral load of DCV and a ~2.5 fold decrease in CrPV in coinfection compared to single infection, but we find little evidence of a host genetic basis for these effects. Across host species, we find no evidence of systematic changes in susceptibility during coinfection, with no interaction between DCV and CrPV detected in the majority of host species. These results suggest that phenotypic variation in coinfection interactions within host species can occur independently of natural host genetic variation in susceptibility, and that patterns of susceptibility across host species to single infections can be robust to the added complexity of coinfection.
Collapse
Affiliation(s)
- Ryan M Imrie
- Centre for Ecology & Conservation, Faculty of Environment, Science, and Economy, Biosciences, University of Exeter, Penryn Campus, Penryn, United Kingdom
| | - Sarah K Walsh
- Centre for Ecology & Conservation, Faculty of Environment, Science, and Economy, Biosciences, University of Exeter, Penryn Campus, Penryn, United Kingdom
| | - Katherine E Roberts
- Centre for Ecology & Conservation, Faculty of Environment, Science, and Economy, Biosciences, University of Exeter, Penryn Campus, Penryn, United Kingdom
| | - Joanne Lello
- School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | - Ben Longdon
- Centre for Ecology & Conservation, Faculty of Environment, Science, and Economy, Biosciences, University of Exeter, Penryn Campus, Penryn, United Kingdom
| |
Collapse
|
5
|
Bergmann S, Bohn MC, Dornbusch S, Becker SC, Stern M. Influence of RVFV Infection on Olfactory Perception and Behavior in Drosophila melanogaster. Pathogens 2023; 12:pathogens12040558. [PMID: 37111444 PMCID: PMC10142484 DOI: 10.3390/pathogens12040558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 03/31/2023] [Accepted: 04/03/2023] [Indexed: 04/08/2023] Open
Abstract
In blood-feeding dipterans, olfaction plays a role in finding hosts and, hence, in spreading pathogens. Several pathogens are known to alter olfactory responses and behavior in vectors. As a mosquito-borne pathogen, Rift Valley Fever Virus (RVFV) can affect humans and cause great losses in livestock. We test the influence of RVFV infection on sensory perception, olfactory choice behavior and activity on a non-biting insect, Drosophila melanogaster, using electroantennograms (EAG), Y-maze, and locomotor activity monitor. Flies were injected with RVFV MP12 strain. Replication of RVFV and its persistence for at least seven days was confirmed by quantitative reverse transcription-PCR (RT-qPCR). One day post injection, infected flies showed weaker EAG responses towards 1-hexanol, vinegar, and ethyl acetate. In the Y-maze, infected flies showed a significantly lower response for 1-hexanol compared to uninfected flies. At days six or seven post infection, no significant difference between infected and control flies could be found in EAG or Y-maze anymore. Activity of infected flies was reduced at both time points. We found an upregulation of the immune-response gene, nitric oxide synthase, in infected flies. An infection with RVFV is able to transiently reduce olfactory perception and attraction towards food-related odors in Drosophila, while effects on activity and immune effector gene expression persist. A similar effect in blood-feeding insects could affect vector competence in RVFV transmitting dipterans.
Collapse
Affiliation(s)
- Stella Bergmann
- Institute for Physiology and Cell Biology, University of Veterinary Medicine Hannover, 30173 Hannover, Germany
| | - Maja C. Bohn
- Institute for Physiology and Cell Biology, University of Veterinary Medicine Hannover, 30173 Hannover, Germany
| | - Susann Dornbusch
- Institute for Parasitology, University of Veterinary Medicine Hannover, 30559 Hannover, Germany
| | - Stefanie C. Becker
- Institute for Parasitology, University of Veterinary Medicine Hannover, 30559 Hannover, Germany
| | - Michael Stern
- Institute for Physiology and Cell Biology, University of Veterinary Medicine Hannover, 30173 Hannover, Germany
| |
Collapse
|
6
|
Vidal-Quist JC, Declercq J, Vanhee S, Lambrecht BN, Gómez-Rial J, Vidal C, Aydogdu E, Rombauts S, Hernández-Crespo P. RNA viruses alter house dust mite physiology and allergen production with no detected consequences for allergenicity. INSECT MOLECULAR BIOLOGY 2023; 32:173-186. [PMID: 36511188 DOI: 10.1111/imb.12822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Accepted: 12/05/2022] [Indexed: 06/17/2023]
Abstract
RNA viruses have recently been detected in association with house dust mites, including laboratory cultures, dust samples, and mite-derived pharmaceuticals used for allergy diagnosis. This study aimed to assess the incidence of viral infection on Dermatophagoides pteronyssinus physiology and on the allergenic performance of extracts derived from its culture. Transcriptional changes between genetically identical control and virus-infected mite colonies were analysed by RNAseq with the support of a new D. pteronyssinus high-quality annotated genome (56.8 Mb, 108 scaffolds, N50 = 2.73 Mb, 96.7% BUSCO-completeness). Extracts of cultures and bodies from both colonies were compared by inspecting major allergen accumulation by enzyme-linked immunosorbent assay (ELISA), allergen-related enzymatic activities by specific assays, airway inflammation in a mouse model of allergic asthma, and binding to allergic patient's sera IgE by ImmunoCAP. Viral infection induced a significant transcriptional response, including several immunity and stress-response genes, and affected the expression of seven allergens, putative isoallergens and allergen orthologs. Major allergens were unaffected except for Der p 23 that was upregulated, increasing ELISA titers up to 29% in infected-mite extracts. By contrast, serine protease allergens Der p 3, 6 and 9 were downregulated, being trypsin and chymotrypsin enzymatic activities reduced up to 21% in extracts. None of the parameters analysed in our mouse model, nor binding to human IgE were significantly different when comparing control and infected-mite extracts. Despite the described physiological impact of viral infection on the mites, no significant consequences for the allergenicity of derived extracts or their practical use in allergy diagnosis have been detected.
Collapse
Affiliation(s)
- José Cristian Vidal-Quist
- Entomología Aplicada a la Agricultura y la Salud, Departamento de Biotecnología Microbiana y de Plantas, Centro de Investigaciones Biológicas Margarita Salas (CIB), CSIC, Madrid, Spain
| | - Jozefien Declercq
- Laboratory of Immunoregulation and Mucosal Immunology, VIB Center for Inflammation Research, Ghent, Belgium
- Department of Internal Medicine and Pediatrics, Ghent University, Ghent, Belgium
| | - Stijn Vanhee
- Laboratory of Immunoregulation and Mucosal Immunology, VIB Center for Inflammation Research, Ghent, Belgium
- Department of Internal Medicine and Pediatrics, Ghent University, Ghent, Belgium
| | - Bart N Lambrecht
- Laboratory of Immunoregulation and Mucosal Immunology, VIB Center for Inflammation Research, Ghent, Belgium
- Department of Internal Medicine and Pediatrics, Ghent University, Ghent, Belgium
| | - José Gómez-Rial
- Laboratorio de Inmunogenética, Unidad de Inmunología, Complejo Hospitalario Universitario de Santiago (CHUS), Santiago de Compostela, Spain
| | - Carmen Vidal
- Servicio de Alergología, Complejo Hospitalario Universitario de Santiago (CHUS), Santiago de Compostela, Spain
| | - Eylem Aydogdu
- Center for Plant Systems Biology, VIB, Ghent, Belgium
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
| | - Stephane Rombauts
- Center for Plant Systems Biology, VIB, Ghent, Belgium
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
| | - Pedro Hernández-Crespo
- Entomología Aplicada a la Agricultura y la Salud, Departamento de Biotecnología Microbiana y de Plantas, Centro de Investigaciones Biológicas Margarita Salas (CIB), CSIC, Madrid, Spain
| |
Collapse
|
7
|
Kutzer MAM, Gupta V, Neophytou K, Doublet V, Monteith KM, Vale PF. Intraspecific genetic variation in host vigour, viral load and disease tolerance during Drosophila C virus infection. Open Biol 2023; 13:230025. [PMID: 36854375 PMCID: PMC9974301 DOI: 10.1098/rsob.230025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2023] Open
Abstract
Genetic variation for resistance and disease tolerance has been described in a range of species. In Drosophila melanogaster, genetic variation in mortality following systemic Drosophila C virus (DCV) infection is driven by large-effect polymorphisms in the restriction factor pastrel (pst). However, it is unclear if pst contributes to disease tolerance. We investigated systemic DCV challenges spanning nine orders of magnitude, in males and females of 10 Drosophila Genetic Reference Panel lines carrying either a susceptible (S) or resistant (R) pst allele. We find among-line variation in fly survival, viral load and disease tolerance measured both as the ability to maintain survival (mortality tolerance) and reproduction (fecundity tolerance). We further uncover novel effects of pst on host vigour, as flies carrying the R allele exhibited higher survival and fecundity even in the absence of infection. Finally, we found significant genetic variation in the expression of the JAK-STAT ligand upd3 and the epigenetic regulator of JAK-STAT G9a. However, while G9a has been previously shown to mediate tolerance of DCV infection, we found no correlation between the expression of either upd3 or G9a on fly tolerance or resistance. Our work highlights the importance of both resistance and tolerance in viral defence.
Collapse
Affiliation(s)
- Megan A. M. Kutzer
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, UK
| | - Vanika Gupta
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, UK
| | - Kyriaki Neophytou
- Institute of Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, UK
| | - Vincent Doublet
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, UK
| | - Katy M. Monteith
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, UK
| | - Pedro F. Vale
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, UK
| |
Collapse
|
8
|
Roberts KE, Longdon B. Heterogeneities in infection outcomes across species: sex and tissue differences in virus susceptibility. PEER COMMUNITY JOURNAL 2023; 3:pcjournal.242. [PMID: 36811030 PMCID: PMC7614206 DOI: 10.24072/pcjournal.242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
Species vary in their susceptibility to pathogens, and this can alter the ability of a pathogen to infect a novel host. However, many factors can generate heterogeneity in infection outcomes, obscuring our ability to understand pathogen emergence. Such heterogeneities can alter the consistency of responses across individuals and host species. For example, sexual dimorphism in susceptibility means males are often intrinsically more susceptible than females (although this can vary by host and pathogen). Further, we know little about whether the tissues infected by a pathogen in one host are the same in another species, and how this relates to the harm a pathogen does to its host. Here, we first take a comparative approach to examine sex differences in susceptibility across 31 species of Drosophilidae infected with Drosophila C Virus (DCV). We found a strong positive inter-specific correlation in viral load between males and females, with a close to 1:1 relationship, suggesting that susceptibility to DCV across species is not sex specific. Next, we made comparisons of the tissue tropism of DCV across seven species of fly. We found differences in viral load between the tissues of the seven host species, but no evidence of tissues showing different patterns of susceptibility in different host species. We conclude that, in this system, patterns of viral infectivity across host species are robust between males and females, and susceptibility in a given host is general across tissue types.
Collapse
Affiliation(s)
- Katherine E Roberts
- Centre for Ecology and Conservation, University of Exeter, Penryn Campus, TR10 9FE, UK
| | - Ben Longdon
- Centre for Ecology and Conservation, University of Exeter, Penryn Campus, TR10 9FE, UK,corresponding author
| |
Collapse
|
9
|
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.
Collapse
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
| |
Collapse
|
10
|
Harsh S, Tafesh-Edwards G, Eleftherianos I. Zika virus infection triggers the melanization response in Drosophila. Biochim Biophys Acta Mol Basis Dis 2022; 1868:166424. [DOI: 10.1016/j.bbadis.2022.166424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2022] [Accepted: 04/20/2022] [Indexed: 11/30/2022]
|
11
|
Zhang J, Wang F, Yuan B, Yang L, Yang Y, Fang Q, Kuhn JH, Song Q, Ye G. A novel cripavirus of an ectoparasitoid wasp increases pupal duration and fecundity of the wasp's Drosophila melanogaster host. THE ISME JOURNAL 2021; 15:3239-3257. [PMID: 34007060 PMCID: PMC8528920 DOI: 10.1038/s41396-021-01005-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 04/21/2021] [Accepted: 04/30/2021] [Indexed: 02/03/2023]
Abstract
We identified a 9332-nucleotide-long novel picornaviral genome sequence in the transcriptome of an agriculturally important parasitoid wasp (Pachycrepoideus vindemmiae (Rondani, 1875)). The genome of the novel virus, Rondani's wasp virus 1 (RoWV-1), contains two long open reading frames encoding a nonstructural and a structural protein, respectively, and is 3'-polyadenylated. Phylogenetic analyses firmly place RoWV-1 into the dicistrovirid genus Cripavirus. We detected RoWV-1 in various tissues and life stages of the parasitoid wasp, with the highest virus load measured in the larval digestive tract. We demonstrate that RoWV-1 is transmitted horizontally from infected to uninfected wasps but not vertically to wasp offspring. Comparison of several important biological parameters between the infected and uninfected wasps indicates that RoWV-1 does not have obvious detrimental effects on wasps. We further demonstrate that RoWV-1 also infects Drosophila melanogaster (Meigen, 1830), the hosts of the pupal ectoparasitoid wasps, and thereby increases its pupal developmental duration and fecundity, but decreases the eclosion rate. Together, these results suggest that RoWV-1 may have a potential benefit to the wasp by increasing not only the number of potential wasp hosts but also the developmental time of the hosts to ensure proper development of wasp offspring.
Collapse
Affiliation(s)
- Jiao Zhang
- State Key Laboratory of Rice Biology & Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Fei Wang
- State Key Laboratory of Rice Biology & Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Bo Yuan
- State Key Laboratory of Rice Biology & Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Lei Yang
- State Key Laboratory of Rice Biology & Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Yi Yang
- State Key Laboratory of Rice Biology & Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Qi Fang
- State Key Laboratory of Rice Biology & Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Jens H Kuhn
- Integrated Research Facility at Fort Detrick, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Fort Detrick, Frederick, MD, USA
| | - Qisheng Song
- Division of Plant Sciences, College of Agriculture, Food and Natural Resources, University of Missouri, Columbia, MO, USA.
| | - Gongyin Ye
- State Key Laboratory of Rice Biology & Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, Zhejiang Province, China.
| |
Collapse
|
12
|
Imrie RM, Roberts KE, Longdon B. Between virus correlations in the outcome of infection across host species: Evidence of virus by host species interactions. Evol Lett 2021; 5:472-483. [PMID: 34621534 PMCID: PMC8484721 DOI: 10.1002/evl3.247] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 06/15/2021] [Accepted: 06/28/2021] [Indexed: 12/24/2022] Open
Abstract
Virus host shifts are a major source of outbreaks and emerging infectious diseases, and predicting the outcome of novel host and virus interactions remains a key challenge for virus research. The evolutionary relationships between host species can explain variation in transmission rates, virulence, and virus community composition between hosts, but it is unclear if correlations exist between related viruses in infection traits across novel hosts. Here, we measure correlations in viral load of four Cripavirus isolates across experimental infections of 45 Drosophilidae host species. We find positive correlations between every pair of viruses tested, suggesting that some host clades show broad susceptibility and could act as reservoirs and donors for certain types of viruses. Additionally, we find evidence of virus by host species interactions, highlighting the importance of both host and virus traits in determining the outcome of virus host shifts. Of the four viruses tested here, those that were more closely related tended to be more strongly correlated, providing tentative evidence that virus evolutionary relatedness may be a useful proxy for determining the likelihood of novel virus emergence, which warrants further research.
Collapse
Affiliation(s)
- Ryan M. Imrie
- Centre for Ecology and Conservation, Biosciences, College of Life and Environmental SciencesUniversity of ExeterPenrynTR10 9FEUnited Kingdom
| | - Katherine E. Roberts
- Centre for Ecology and Conservation, Biosciences, College of Life and Environmental SciencesUniversity of ExeterPenrynTR10 9FEUnited Kingdom
| | - Ben Longdon
- Centre for Ecology and Conservation, Biosciences, College of Life and Environmental SciencesUniversity of ExeterPenrynTR10 9FEUnited Kingdom
| |
Collapse
|
13
|
de Brito TF, Coelho VL, Cardoso MA, Brito IADA, Berni MA, Zenk FL, Iovino N, Pane A. Transovarial transmission of a core virome in the Chagas disease vector Rhodnius prolixus. PLoS Pathog 2021; 17:e1009780. [PMID: 34407148 PMCID: PMC8372912 DOI: 10.1371/journal.ppat.1009780] [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: 10/18/2020] [Accepted: 07/02/2021] [Indexed: 01/09/2023] Open
Abstract
Triatomine assassin bugs comprise hematophagous insect vectors of Trypanosoma cruzi, the causative agent of Chagas disease. Although the microbiome of these species has been investigated to some extent, only one virus infecting Triatoma infestans has been identified to date. Here, we describe for the first time seven (+) single-strand RNA viruses (RpV1-7) infecting Rhodnius prolixus, a primary vector of Chagas disease in Central and South America. We show that the RpVs belong to the Iflaviridae, Permutotetraviridae and Solemoviridae and are vertically transmitted from the mothers to the progeny via transovarial transmission. Consistent with this, all the RpVs, except RpV2 that is related to the entomopathogenic Slow bee paralysis virus, established persistent infections in our R. prolixus colony. Furthermore, we show that R. prolixus ovaries express 22-nucleotide viral siRNAs (vsiRNAs), but not viral piRNAs, that originate from the processing of dsRNA intermediates during viral replication of the RpVs. Interestingly, the permutotetraviruses and sobemoviruses display shared pools of vsiRNAs that might provide the basis for a cross-immunity system. The vsiRNAs are maternally deposited in the eggs, where they likely contribute to reduce the viral load and protect the developing embryos. Our results unveil for the first time a complex core virome in R. prolixus and begin to shed light on the RNAi-based antiviral defenses in triatomines.
Collapse
Affiliation(s)
| | - Vitor Lima Coelho
- Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Maira Arruda Cardoso
- Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | | | - Mateus Antonio Berni
- Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Fides Lea Zenk
- Department of Chromatin Regulation, Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
| | - Nicola Iovino
- Department of Chromatin Regulation, Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
| | - Attilio Pane
- Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| |
Collapse
|
14
|
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.
Collapse
|
15
|
Jimenez-Guri E, Roberts KE, García FC, Tourmente M, Longdon B, Godley BJ. Transgenerational effects on development following microplastic exposure in Drosophila melanogaster. PeerJ 2021; 9:e11369. [PMID: 34012729 PMCID: PMC8109007 DOI: 10.7717/peerj.11369] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 04/07/2021] [Indexed: 01/22/2023] Open
Abstract
Background Plastic pollution affects all ecosystems, and detrimental effects to animals have been reported in a growing number of studies. However, there is a paucity of evidence for effects on terrestrial animals in comparison to those in the marine realm. Methods We used the fly Drosophila melanogaster to study the effects that exposure to plastics may have on life history traits and immune response. We reared flies in four conditions: In media containing 1% virgin polyethylene, with no chemical additives; in media supplemented with 1% or 4% polyvinyl chloride, known to have a high content of added chemicals; and control flies in non-supplemented media. Plastic particle size ranged from 23–500 µm. We studied fly survival to viral infection, the length of the larval and pupal stage, sex ratios, fertility and the size of the resultant adult flies. We then performed crossings of F1 flies in non-supplemented media and looked at the life history traits of the F2. Results Flies treated with plastics in the food media showed changes in fertility and sex ratio, but showed no differences in developmental times, adult size or the capacity to fight infections in comparison with controls. However, the offspring of treated flies reared in non-supplemented food had shorter life cycles, and those coming from both polyvinyl chloride treatments were smaller than those offspring of controls.
Collapse
Affiliation(s)
- Eva Jimenez-Guri
- Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter Cornwall Campus, University of Exeter, Penryn, Cornwall, United Kingdom.,Biology and Evolution of Marine Organisms (BEOM), Stazione Zoologica Anton Dhorn, Naples, Italy
| | - Katherine E Roberts
- Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter Cornwall Campus, University of Exeter, Penryn, Cornwall, United Kingdom
| | - Francisca C García
- Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter Cornwall Campus, University of Exeter, Penryn, Cornwall, United Kingdom
| | - Maximiliano Tourmente
- Institute for Biological and Technological Research (IIByT), National Scientific and Technical Research Council (CONICET), Córdoba, Argentina.,Centre for Cell and Molecular Biology. Faculty of Exact, Physical, and Natural Sciences, University of Córdoba, Córdoba, Argentina
| | - Ben Longdon
- Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter Cornwall Campus, University of Exeter, Penryn, Cornwall, United Kingdom
| | - Brendan J Godley
- Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter Cornwall Campus, University of Exeter, Penryn, Cornwall, United Kingdom
| |
Collapse
|
16
|
Roberts KE, Longdon B. Viral susceptibility across host species is largely independent of dietary protein to carbohydrate ratios. J Evol Biol 2021; 34:746-756. [PMID: 33586293 PMCID: PMC8436156 DOI: 10.1111/jeb.13773] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 02/02/2021] [Accepted: 02/07/2021] [Indexed: 12/23/2022]
Abstract
The likelihood of a successful host shift of a parasite to a novel host species can be influenced by environmental factors that can act on both the host and parasite. Changes in nutritional resource availability have been shown to alter pathogen susceptibility and the outcome of infection in a range of systems. Here, we examined how dietary protein to carbohydrate altered susceptibility in a large cross-infection experiment. We infected 27 species of Drosophilidae with an RNA virus on three food types of differing protein to carbohydrate ratios. We then measured how viral load and mortality across species was affected by changes in diet. We found that changes in the protein:carbohydrate in the diet did not alter the outcomes of infection, with strong positive inter-species correlations in both viral load and mortality across diets, suggesting no species-by-diet interaction. Mortality and viral load were strongly positively correlated, and this association was consistent across diets. This suggests changes in diet may give consistent outcomes across host species, and may not be universally important in determining host susceptibility to pathogens.
Collapse
Affiliation(s)
- Katherine E. Roberts
- Centre for Ecology & ConservationCollege of Life and Environmental SciencesUniversity of ExeterPenrynUK
| | - Ben Longdon
- Centre for Ecology & ConservationCollege of Life and Environmental SciencesUniversity of ExeterPenrynUK
| |
Collapse
|
17
|
Sheffield L, Sciambra N, Evans A, Hagedorn E, Goltz C, Delfeld M, Kuhns H, Fierst JL, Chtarbanova S. Age-dependent impairment of disease tolerance is associated with a robust transcriptional response following RNA virus infection in Drosophila. G3-GENES GENOMES GENETICS 2021; 11:6219303. [PMID: 33836060 PMCID: PMC8495950 DOI: 10.1093/g3journal/jkab116] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 03/26/2021] [Indexed: 12/18/2022]
Abstract
Advanced age in humans is associated with greater susceptibility to and higher mortality rates from infections, including infections with some RNA viruses. The underlying innate immune mechanisms, which represent the first line of defense against pathogens, remain incompletely understood. Drosophila melanogaster is able to mount potent and evolutionarily conserved innate immune defenses against a variety of microorganisms including viruses and serves as an excellent model organism for studying host–pathogen interactions. With its relatively short lifespan, Drosophila also is an organism of choice for aging studies. Despite numerous advantages that this model offers, Drosophila has not been used to its full potential to investigate the response of the aged host to viral infection. Here, we show that, in comparison to younger flies, aged Drosophila succumb more rapidly to infection with the RNA-containing Flock House virus due to an age-dependent defect in disease tolerance. Relative to younger individuals, we find that older Drosophila mount transcriptional responses characterized by differential regulation of more genes and genes regulated to a greater extent. We show that loss of disease tolerance to Flock House virus with age associates with a stronger regulation of genes involved in apoptosis, some genes of the Drosophila immune deficiency NF-kB pathway, and genes whose products function in mitochondria and mitochondrial respiration. Our work shows that Drosophila can serve as a model to investigate host–virus interactions during aging and furthermore sets the stage for future analysis of the age-dependent mechanisms that govern survival and control of virus infections at older age.
Collapse
Affiliation(s)
- Lakbira Sheffield
- Department of Biological Sciences, University of Alabama, 300, Hackberry lane, Tuscaloosa, AL-35487, USA.,Graduate Biomedical Sciences program, University of Alabama at Birmingham, Birmingham, AL- 35294, USA
| | - Noah Sciambra
- Department of Biological Sciences, University of Alabama, 300, Hackberry lane, Tuscaloosa, AL-35487, USA
| | - Alysa Evans
- Department of Biological Sciences, University of Alabama, 300, Hackberry lane, Tuscaloosa, AL-35487, USA
| | - Eli Hagedorn
- Department of Biological Sciences, University of Alabama, 300, Hackberry lane, Tuscaloosa, AL-35487, USA
| | - Casey Goltz
- Department of Biological Sciences, University of Alabama, 300, Hackberry lane, Tuscaloosa, AL-35487, USA
| | - Megan Delfeld
- Department of Biological Sciences, University of Alabama, 300, Hackberry lane, Tuscaloosa, AL-35487, USA
| | - Haley Kuhns
- Department of Biological Sciences, University of Alabama, 300, Hackberry lane, Tuscaloosa, AL-35487, USA
| | - Janna L Fierst
- Department of Biological Sciences, University of Alabama, 300, Hackberry lane, Tuscaloosa, AL-35487, USA
| | - Stanislava Chtarbanova
- Department of Biological Sciences, University of Alabama, 300, Hackberry lane, Tuscaloosa, AL-35487, USA
| |
Collapse
|
18
|
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.
Collapse
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.
| |
Collapse
|
19
|
Siva-Jothy JA, Vale PF. Dissecting genetic and sex-specific sources of host heterogeneity in pathogen shedding and spread. PLoS Pathog 2021; 17:e1009196. [PMID: 33465160 PMCID: PMC7846003 DOI: 10.1371/journal.ppat.1009196] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2019] [Revised: 01/29/2021] [Accepted: 11/30/2020] [Indexed: 11/18/2022] Open
Abstract
Host heterogeneity in disease transmission is widespread but precisely how different host traits drive this heterogeneity remains poorly understood. Part of the difficulty in linking individual variation to population-scale outcomes is that individual hosts can differ on multiple behavioral, physiological and immunological axes, which will together impact their transmission potential. Moreover, we lack well-characterized, empirical systems that enable the quantification of individual variation in key host traits, while also characterizing genetic or sex-based sources of such variation. Here we used Drosophila melanogaster and Drosophila C Virus as a host-pathogen model system to dissect the genetic and sex-specific sources of variation in multiple host traits that are central to pathogen transmission. Our findings show complex interactions between genetic background, sex, and female mating status accounting for a substantial proportion of variance in lifespan following infection, viral load, virus shedding, and viral load at death. Two notable findings include the interaction between genetic background and sex accounting for nearly 20% of the variance in viral load, and genetic background alone accounting for ~10% of the variance in viral shedding and in lifespan following infection. To understand how variation in these traits could generate heterogeneity in individual pathogen transmission potential, we combined measures of lifespan following infection, virus shedding, and previously published data on fly social aggregation. We found that the interaction between genetic background and sex explained ~12% of the variance in individual transmission potential. Our results highlight the importance of characterising the sources of variation in multiple host traits to understand the drivers of heterogeneity in disease transmission.
Collapse
Affiliation(s)
- Jonathon A. Siva-Jothy
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Pedro F. Vale
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
- Centre for Immunity, Infection and Evolution, University of Edinburgh, Edinburgh, United Kingdom
| |
Collapse
|
20
|
White LA, Siva-Jothy JA, Craft ME, Vale PF. Genotype and sex-based host variation in behaviour and susceptibility drives population disease dynamics. Proc Biol Sci 2020; 287:20201653. [PMID: 33171094 DOI: 10.1098/rspb.2020.1653] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Host heterogeneity in pathogen transmission is widespread and presents a major hurdle to predicting and minimizing disease outbreaks. Using Drosophila melanogaster infected with Drosophila C virus as a model system, we integrated experimental measurements of social aggregation, virus shedding, and disease-induced mortality from different genetic lines and sexes into a disease modelling framework. The experimentally measured host heterogeneity produced substantial differences in simulated disease outbreaks, providing evidence for genetic and sex-specific effects on disease dynamics at a population level. While this was true for homogeneous populations of single sex/genetic line, the genetic background or sex of the index case did not alter outbreak dynamics in simulated, heterogeneous populations. Finally, to explore the relative effects of social aggregation, viral shedding and mortality, we compared simulations where we allowed these traits to vary, as measured experimentally, to simulations where we constrained variation in these traits to the population mean. In this context, variation in infectiousness, followed by social aggregation, was the most influential component of transmission. Overall, we show that host heterogeneity in three host traits dramatically affects population-level transmission, but the relative impact of this variation depends on both the susceptible population diversity and the distribution of population-level variation.
Collapse
Affiliation(s)
- Lauren A White
- National Socio-Environmental Synthesis Center SESYNC, 1 Park Place, Suite 300, Annapolis, MD 21401, USA.,Department of Veterinary Population Medicine, University of Minnesota, St Paul, MN 55126, USA
| | - Jonathon A Siva-Jothy
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Ashworth Labs, Charlotte Auerbach Road, Edinburgh EH9 3JT, UK
| | - Meggan E Craft
- Department of Veterinary Population Medicine, University of Minnesota, St Paul, MN 55126, USA
| | - Pedro F Vale
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Ashworth Labs, Charlotte Auerbach Road, Edinburgh EH9 3JT, UK
| |
Collapse
|
21
|
Zhou X, Ding G, Li J, Xiang X, Rushworth E, Song W. Physiological and Pathological Regulation of Peripheral Metabolism by Gut-Peptide Hormones in Drosophila. Front Physiol 2020; 11:577717. [PMID: 33117196 PMCID: PMC7552570 DOI: 10.3389/fphys.2020.577717] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 09/07/2020] [Indexed: 12/18/2022] Open
Abstract
The gastrointestinal (GI) tract in both vertebrates and invertebrates is now recognized as a major source of signals modulating, via gut-peptide hormones, the metabolic activities of peripheral organs, and carbo-lipid balance. Key advances in the understanding of metabolic functions of gut-peptide hormones and their mediated interorgan communication have been made using Drosophila as a model organism, given its powerful genetic tools and conserved metabolic regulation. Here, we summarize recent studies exploring peptide hormones that are involved in the communication between the midgut and other peripheral organs/tissues during feeding conditions. We also highlight the emerging impacts of fly gut-peptide hormones on stress sensing and carbo-lipid metabolism in various disease models, such as energy overload, pathogen infection, and tumor progression. Due to the functional similarity of intestine and its derived peptide hormones between Drosophila and mammals, it can be anticipated that findings obtained in the fly system will have important implications for the understanding of human physiology and pathology.
Collapse
Affiliation(s)
- Xiaoya Zhou
- Department of Oncology, Renmin Hospital of Wuhan University, Wuhan, China.,Frontier Science Center for Immunology and Metabolism, Medical Research Institute, Wuhan University, Wuhan, China
| | - Guangming Ding
- Department of Oncology, Renmin Hospital of Wuhan University, Wuhan, China.,Frontier Science Center for Immunology and Metabolism, Medical Research Institute, Wuhan University, Wuhan, China
| | - Jiaying Li
- Department of Oncology, Renmin Hospital of Wuhan University, Wuhan, China.,Frontier Science Center for Immunology and Metabolism, Medical Research Institute, Wuhan University, Wuhan, China
| | - Xiaoxiang Xiang
- Department of Oncology, Renmin Hospital of Wuhan University, Wuhan, China.,Frontier Science Center for Immunology and Metabolism, Medical Research Institute, Wuhan University, Wuhan, China
| | - Elisabeth Rushworth
- Department of Oncology, Renmin Hospital of Wuhan University, Wuhan, China.,Frontier Science Center for Immunology and Metabolism, Medical Research Institute, Wuhan University, Wuhan, China
| | - Wei Song
- Department of Oncology, Renmin Hospital of Wuhan University, Wuhan, China.,Frontier Science Center for Immunology and Metabolism, Medical Research Institute, Wuhan University, Wuhan, China
| |
Collapse
|
22
|
Kaur R, Martinez J, Rota-Stabelli O, Jiggins FM, Miller WJ. Age, tissue, genotype and virus infection regulate Wolbachia levels in Drosophila. Mol Ecol 2020; 29:2063-2079. [PMID: 32391935 DOI: 10.1111/mec.15462] [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] [Received: 12/20/2018] [Accepted: 04/28/2020] [Indexed: 12/13/2022]
Abstract
The bacterial symbiont Wolbachia can protect insects against viral pathogens, and the varying levels of antiviral protection are correlated with the endosymbiont load within the insects. To understand why Wolbachia strains differ in their antiviral effects, we investigated the factors controlling Wolbachia density in five closely related strains in their natural Drosophila hosts. We found that Wolbachia density varied greatly across different tissues and between flies of different ages, and these effects depended on the host-symbiont association. Some endosymbionts maintained largely stable densities as flies aged while others increased, and these effects in turn depended on the tissue being examined. Measuring Wolbachia rRNA levels in response to viral infection, we found that viral infection itself also altered Wolbachia levels, with Flock House virus causing substantial reductions in symbiont loads late in the infection. This effect, however, was virus-specific as Drosophila C virus had little impact on Wolbachia in all of the five host systems. Because viruses have strong tissue tropisms and antiviral protection is thought to be cell-autonomous, these effects are likely to affect the virus-blocking phenomenon. However, we were unable to find any evidence of a correlation between Wolbachia and viral titres within the same tissues. We conclude that Wolbachia levels within flies are regulated in a complex host-symbiont-virus-dependent manner and this trinity is likely to influence the antiviral effects of Wolbachia.
Collapse
Affiliation(s)
- Rupinder Kaur
- Division of Cell and Developmental Biology, Medical University of Vienna, Vienna, Austria.,Department of Sustainable Agro-Ecosystems and Bioresources, Fondazione Edmund Mach, San Michele all'Adige, Italy.,Department of Neurobiology, University of Vienna, Vienna, Austria.,Instituto Gulbenkian de Ciência, Oeiras, Portugal
| | - Julien Martinez
- MRC-University of Glasgow Centre for Virus Research, University of Glasgow, Glasgow, UK
| | - Omar Rota-Stabelli
- Department of Sustainable Agro-Ecosystems and Bioresources, Fondazione Edmund Mach, San Michele all'Adige, Italy
| | | | - Wolfgang J Miller
- Division of Cell and Developmental Biology, Medical University of Vienna, Vienna, Austria
| |
Collapse
|
23
|
Abstract
Two areas of research that have greatly increased in attention are: dipterans as vectors and the microbes they are capable of vectoring. Because it is the front-end of the fly that first encounters these microbes, this review focuses on the legs, mouthparts, and foregut, which includes the crop as major structures involved in dipteran vectoring ability. The legs and mouthparts are generally involved in mechanical transmission of microbes. However, the crop is involved in more than just mechanical transmission, for it is within the lumen of the crop that microbes are taken up with the meal of the fly, stored, and it is within the lumen that horizontal transmission of bacterial resistance has been demonstrated. In addition to storage of microbes, the crop is also involved in depositing the microbes via a process known as regurgitation. Various aspects of crop regulation are discussed and specific examples of crop involvement with microorganisms are discussed. The importance of biofilm and biofilm formation are presented, as well as, some physical parameters of the crop that might either facilitate or inhibit biofilm formation. Finally, there is a brief discussion of dipteran model systems for studying crop microbe interactions.
Collapse
Affiliation(s)
- John G Stoffolano
- Stockbridge School of Agriculture, University of Massachusetts, Amherst, MA, United States
| |
Collapse
|
24
|
Xi J, Cai J, Cheng Y, Fu Y, Wei W, Zhang Z, Zhuang Z, Hao Y, Lilly MA, Wei Y. The TORC1 inhibitor Nprl2 protects age-related digestive function in Drosophila. Aging (Albany NY) 2019; 11:9811-9828. [PMID: 31712450 PMCID: PMC6874466 DOI: 10.18632/aging.102428] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2019] [Accepted: 10/28/2019] [Indexed: 01/23/2023]
Abstract
Aging and age-related diseases occur in almost all organisms. Recently, it was discovered that the inhibition of target of rapamycin complex 1 (TORC1), a conserved complex that mediates nutrient status and cell metabolism, can extend an individual’s lifespan and inhibit age-related diseases in many model organisms. However, the mechanism whereby TORC1 affects aging remains elusive. Here, we use a loss-of-function mutation in nprl2, a component of GATOR1 that mediates amino acid levels and inhibits TORC1 activity, to investigate the effect of increased TORC1 activity on the occurrence of age-related digestive dysfunction in Drosophila. We found that the nprl2 mutation decreased Drosophila lifespan. Furthermore, the nprl2 mutant had a distended crop, with food accumulation at an early age. Interestingly, the inappropriate food distribution and digestion along with decreased crop contraction in nprl2 mutant can be rescued by decreasing TORC1 activity. In addition, nprl2-mutant flies exhibited age-related phenotypes in the midgut, including short gut length, a high rate of intestinal stem cell proliferation, and metabolic dysfunction, which could be rescued by inhibiting TORC1 activity. Our findings showed that the gastrointestinal tract aging process is accelerated in nprl2-mutant flies, owing to high TORC1 activity, which suggested that TORC1 promotes digestive tract senescence.
Collapse
Affiliation(s)
- Junmeng Xi
- College of Bioscience and Biotechnology, Yangzhou University, Yangzhou, China.,Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou, China.,Institute of Reproduction and Metabolism, Yangzhou University, Yangzhou, China
| | - Jiadong Cai
- College of Bioscience and Biotechnology, Yangzhou University, Yangzhou, China.,Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou, China.,Institute of Reproduction and Metabolism, Yangzhou University, Yangzhou, China
| | - Yang Cheng
- College of Bioscience and Biotechnology, Yangzhou University, Yangzhou, China.,Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou, China
| | - Yuanyuan Fu
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou, China
| | - Wanhong Wei
- College of Bioscience and Biotechnology, Yangzhou University, Yangzhou, China
| | - Zhenbo Zhang
- Reproductive Medicine Center, Department of Obstetrics and Gynecology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Ziheng Zhuang
- School of Pharmaceutical Engineering and Life Sciences, Changzhou University, Changzhou, China
| | - Yue Hao
- Key Laboratory of Pollinating Insect Biology, Ministry of Agriculture, Beijing, China
| | - Mary A Lilly
- Cell Biology and Neurobiology Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Youheng Wei
- College of Bioscience and Biotechnology, Yangzhou University, Yangzhou, China.,Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou, China.,Institute of Reproduction and Metabolism, Yangzhou University, Yangzhou, China
| |
Collapse
|
25
|
Identification of Regulatory Host Genes Involved in Sigma Virus Replication Using RNAi Knockdown in Drosophila. INSECTS 2019; 10:insects10100339. [PMID: 31614679 PMCID: PMC6835446 DOI: 10.3390/insects10100339] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Revised: 10/01/2019] [Accepted: 10/08/2019] [Indexed: 01/15/2023]
Abstract
The Drosophila melanogaster sigma virus, a member of the Rhabdoviridae family, specifically propagates itself in D. melanogaster. It contains six genes in the order of 3′-N–P–X–M–G–L-5′. The sigma virus is the only arthropod-specific virus of the Rhabdoviridae family. Sigma-virus-infected Drosophila may suffer from irreversible paralysis when exposed to a high CO2 concentration, but generally, no other symptoms are reported. A recent study reported that host gene expression in immune pathways was not changed in sigma-virus-infected Drosophila, which does not necessarily suggest that they are not involved in virus–host interactions. The present study aimed to identify host genes associated with sigma virus replication. Immune pathways JAK-STAT and IMD were selected for detailed study. The results showed that the genome copy number of the sigma virus increased after knocking down the immune pathway genes domeless and PGRP-LC in Drosophila S2 cells. The knocking down of domeless and PGRP-LC significantly up-regulated the expression of the L gene compared to the other viral genes. We propose that the immune pathways respond to sigma virus infection by altering L expression, hence suppressing viral replication. This effect was further tested in vivo, when D. melanogaster individuals injected with dsdome and dsPGRP-LC showed not only an increase in sigma virus copy number, but also a reduced survival rate when treated with CO2. Our study proved that host immunity influences viral replication, even in persistent infection. Knocking down the key components of the immune process deactivates immune controls, thus facilitating viral expression and replication. We propose that the immunity system of D. melanogaster regulates the replication of the sigma virus by affecting the L gene expression. Studies have shown minimal host–virus interaction in persistent infection. However, our study demonstrated that the immunity continued to affect viral replication even in persistent infection because knocking down the key components of the immune process disabled the relevant immune controls and facilitated viral expression and replication.
Collapse
|
26
|
Participation of the Serine Protease Jonah66Ci in the Drosophila Antinematode Immune Response. Infect Immun 2019; 87:IAI.00094-19. [PMID: 31182620 DOI: 10.1128/iai.00094-19] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 05/29/2019] [Indexed: 01/27/2023] Open
Abstract
Serine proteases and serine protease homologs form the second largest gene family in the Drosophila melanogaster genome. Certain genes in the Jonah multigene family encoding serine proteases have been implicated in the fly antiviral immune response. Here, we report the involvement of Jonah66Ci in the Drosophila immune defense against Steinernema carpocapsae nematode infection. We find that Drosophila Jonah66Ci is upregulated in response to symbiotic (carrying the mutualistic bacterium Xenorhabdus nematophila) or axenic (lacking Xenorhabdus) Steinernema nematodes and is expressed exclusively in the gut of Drosophila larvae. Inactivation of Jonah66Ci provides a survival advantage to larvae against axenic nematodes and results in differential expression of Toll and Imd pathway effector genes, specifically in the gut. Also, inactivation of Jonah66Ci increases the numbers of enteroendocrine and mitotic cells in the gut of uninfected larvae, and infection with Steinernema nematodes reduces their numbers, whereas the numbers of intestinal stem cells are unaffected by nematode infection. Jonah66Ci knockdown further reduces nitric oxide levels in response to infection with symbiotic Steinernema nematodes. Finally, we show that Jonah66Ci knockdown does not alter the feeding rates of uninfected Drosophila larvae; however, infection with axenic Steinernema nematodes lowers larval feeding. In conclusion, we report that Jonah66Ci participates in maintaining homeostasis of certain physiological processes in Drosophila larvae in the context of Steinernema nematode infection. Similar findings will take us a step further toward understanding the molecular and physiological mechanisms that take place during parasitic nematode infection in insects.
Collapse
|
27
|
Kerr CH, Wang QS, Moon KM, Keatings K, Allan DW, Foster LJ, Jan E. IRES-dependent ribosome repositioning directs translation of a +1 overlapping ORF that enhances viral infection. Nucleic Acids Res 2019; 46:11952-11967. [PMID: 30418631 PMCID: PMC6294563 DOI: 10.1093/nar/gky1121] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Accepted: 10/23/2018] [Indexed: 12/16/2022] Open
Abstract
RNA structures can interact with the ribosome to alter translational reading frame maintenance and promote recoding that result in alternative protein products. Here, we show that the internal ribosome entry site (IRES) from the dicistrovirus Cricket paralysis virus drives translation of the 0-frame viral polyprotein and an overlapping +1 open reading frame, called ORFx, via a novel mechanism whereby a subset of ribosomes recruited to the IRES bypasses 37 nucleotides downstream to resume translation at the +1-frame 13th non-AUG codon. A mutant of CrPV containing a stop codon in the +1 frame ORFx sequence, yet synonymous in the 0-frame, is attenuated compared to wild-type virus in a Drosophila infection model, indicating the importance of +1 ORFx expression in promoting viral pathogenesis. This work demonstrates a novel programmed IRES-mediated recoding strategy to increase viral coding capacity and impact virus infection, highlighting the diversity of RNA-driven translation initiation mechanisms in eukaryotes.
Collapse
Affiliation(s)
- Craig H Kerr
- Department of Biochemistry and Molecular Biology, Life Sciences Institute, University of British Columbia, Vancouver, BC V6T 1Z3, Canada.,Centre for High-Throughput Biology, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Qing S Wang
- Department of Biochemistry and Molecular Biology, Life Sciences Institute, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Kyung-Mee Moon
- Department of Biochemistry and Molecular Biology, Life Sciences Institute, University of British Columbia, Vancouver, BC V6T 1Z3, Canada.,Centre for High-Throughput Biology, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Kathleen Keatings
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Douglas W Allan
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Leonard J Foster
- Department of Biochemistry and Molecular Biology, Life Sciences Institute, University of British Columbia, Vancouver, BC V6T 1Z3, Canada.,Centre for High-Throughput Biology, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Eric Jan
- Department of Biochemistry and Molecular Biology, Life Sciences Institute, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| |
Collapse
|
28
|
Rahmatika D, Kuroda N, Min Z, Nainu F, Nagaosa K, Nakanishi Y. Inhibitory effects of viral infection on cancer development. Virology 2018; 528:48-53. [PMID: 30576859 DOI: 10.1016/j.virol.2018.12.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Revised: 12/08/2018] [Accepted: 12/10/2018] [Indexed: 12/30/2022]
Abstract
Immune responses evoked on viral infections prevent the dissemination of infection that otherwise leads to the development of diseases in host organisms. In the present study, we investigated whether viral infection influences tumorigenesis in cancer-bearing animals using a Drosophila model of cancer. Cancer was induced in the posterior part of wing imaginal discs through the simultaneous inhibition of apoptosis and cell-cycle checkpoints. The larvae and embryos of cancer-induced flies were infected with Drosophila C virus, a natural pathogen to Drosophila, and larval wing discs and adult wings were morphologically examined for cancer characteristics relative to uninfected controls. We found that viral infections brought about an approximately 30% reduction in the rate of cancer development in both wing discs and wings. These inhibitory effects were not observed when growth-defective virus was used to infect animals. These results indicate that productive viral infections repress tumorigenesis in Drosophila.
Collapse
Affiliation(s)
- Dini Rahmatika
- Graduate School of Medical Sciences, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan
| | - Nanae Kuroda
- School of Pharmacy, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan
| | - Zhang Min
- Graduate School of Medical Sciences, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan
| | - Firzan Nainu
- Faculty of Pharmacy, Hasanuddin University, Tamalanrea, Kota Makassar, Sulawesi Selatan 90245, Indonesia
| | - Kaz Nagaosa
- Section of Food Sciences, Institute of Regional Innovation, Hirosaki University, Yanagawa, Aomori 038-0012, Japan
| | - Yoshinobu Nakanishi
- Graduate School of Medical Sciences, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan; School of Pharmacy, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan.
| |
Collapse
|
29
|
Siva-Jothy JA, Monteith KM, Vale PF. Navigating infection risk during oviposition and cannibalistic foraging in a holometabolous insect. Behav Ecol 2018; 29:1426-1435. [PMID: 30510395 PMCID: PMC6257210 DOI: 10.1093/beheco/ary106] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 06/20/2018] [Indexed: 01/03/2023] Open
Abstract
Deciding where to eat and raise offspring carries important fitness consequences for all animals, especially if foraging, feeding, and reproduction increase pathogen exposure. In insects with complete metamorphosis, foraging mainly occurs during the larval stage, while oviposition decisions are made by adult females. Selection for infection avoidance behaviors may therefore be developmentally uncoupled. Using a combination of experimental infections and behavioral choice assays, we tested if Drosophila melanogaster fruit flies avoid infectious environments at distinct developmental stages. When given conspecific fly carcasses as a food source, larvae did not discriminate between carcasses that were clean or infected with the pathogenic Drosophila C Virus (DCV), even though cannibalism was a viable route of DCV transmission. When laying eggs, DCV-infected females did not discriminate between infectious and noninfectious carcasses, and laying eggs near potentially infectious carcasses was always preferred to sites containing only fly food. Healthy mothers, however, laid more eggs near a clean rather than an infectious carcass. Avoidance during oviposition changed over time: after an initial oviposition period, healthy mothers stopped avoiding infectious carcasses. We interpret this result as a possible trade-off between managing infection risk and maximizing reproduction. Our findings suggest infection avoidance contributes to how mothers provision their offspring and underline the need to consider infection avoidance behaviors at multiple life-stages.
Collapse
Affiliation(s)
- Jonathon A Siva-Jothy
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - Katy M Monteith
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - Pedro F Vale
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
- Centre for Immunity, Infection and Evolution, University of Edinburgh, Edinburgh, UK
| |
Collapse
|
30
|
Harsh S, Ozakman Y, Kitchen SM, Paquin-Proulx D, Nixon DF, Eleftherianos I. Dicer-2 Regulates Resistance and Maintains Homeostasis against Zika Virus Infection in Drosophila. THE JOURNAL OF IMMUNOLOGY 2018; 201:3058-3072. [PMID: 30305326 DOI: 10.4049/jimmunol.1800597] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Accepted: 09/17/2018] [Indexed: 12/13/2022]
Abstract
Zika virus (ZIKV) outbreaks pose a massive public health threat in several countries. We have developed an in vivo model to investigate the host-ZIKV interaction in Drosophila We have found that a strain of ZIKV replicates in wild-type flies without reducing their survival ability. We have shown that ZIKV infection triggers RNA interference and that mutating Dicer-2 results in enhanced ZIKV load and increased susceptibility to ZIKV infection. Using a flavivirus-specific Ab, we have found that ZIKV is localized in the gut and fat body cells of the infected wild-type flies and results in their perturbed homeostasis. In addition, Dicer-2 mutants display severely reduced insulin activity, which could contribute toward the increased mortality of these flies. Our work establishes the suitability of Drosophila as the model system to study host-ZIKV dynamics, which is expected to greatly advance our understanding of the molecular and physiological processes that determine the outcome of this disease.
Collapse
Affiliation(s)
- Sneh Harsh
- Department of Biological Sciences, The Institute for Biomedical Sciences, The George Washington University, Washington, DC 20052; and
| | - Yaprak Ozakman
- Department of Biological Sciences, The Institute for Biomedical Sciences, The George Washington University, Washington, DC 20052; and
| | - Shannon M Kitchen
- Department of Microbiology, Immunology, and Tropical Medicine, GW School of Medicine & Health Sciences, The George Washington University, Washington, DC 20052
| | - Dominic Paquin-Proulx
- Department of Microbiology, Immunology, and Tropical Medicine, GW School of Medicine & Health Sciences, The George Washington University, Washington, DC 20052
| | - Douglas F Nixon
- Department of Microbiology, Immunology, and Tropical Medicine, GW School of Medicine & Health Sciences, The George Washington University, Washington, DC 20052
| | - Ioannis Eleftherianos
- Department of Biological Sciences, The Institute for Biomedical Sciences, The George Washington University, Washington, DC 20052; and
| |
Collapse
|
31
|
Miguel-Aliaga I, Jasper H, Lemaitre B. Anatomy and Physiology of the Digestive Tract of Drosophila melanogaster. Genetics 2018; 210:357-396. [PMID: 30287514 PMCID: PMC6216580 DOI: 10.1534/genetics.118.300224] [Citation(s) in RCA: 247] [Impact Index Per Article: 41.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 07/26/2018] [Indexed: 12/15/2022] Open
Abstract
The gastrointestinal tract has recently come to the forefront of multiple research fields. It is now recognized as a major source of signals modulating food intake, insulin secretion and energy balance. It is also a key player in immunity and, through its interaction with microbiota, can shape our physiology and behavior in complex and sometimes unexpected ways. The insect intestine had remained, by comparison, relatively unexplored until the identification of adult somatic stem cells in the Drosophila intestine over a decade ago. Since then, a growing scientific community has exploited the genetic amenability of this insect organ in powerful and creative ways. By doing so, we have shed light on a broad range of biological questions revolving around stem cells and their niches, interorgan signaling and immunity. Despite their relatively recent discovery, some of the mechanisms active in the intestine of flies have already been shown to be more widely applicable to other gastrointestinal systems, and may therefore become relevant in the context of human pathologies such as gastrointestinal cancers, aging, or obesity. This review summarizes our current knowledge of both the formation and function of the Drosophila melanogaster digestive tract, with a major focus on its main digestive/absorptive portion: the strikingly adaptable adult midgut.
Collapse
Affiliation(s)
- Irene Miguel-Aliaga
- Medical Research Council London Institute of Medical Sciences, Imperial College London, W12 0NN, United Kingdom
| | - Heinrich Jasper
- Buck Institute for Research on Aging, Novato, California 94945-1400
- Immunology Discovery, Genentech, Inc., San Francisco, California 94080
| | - Bruno Lemaitre
- Global Health Institute, School of Life Sciences, École polytechnique fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| |
Collapse
|
32
|
Roberts KE, Hadfield JD, Sharma MD, Longdon B. Changes in temperature alter the potential outcomes of virus host shifts. PLoS Pathog 2018; 14:e1007185. [PMID: 30339695 PMCID: PMC6209381 DOI: 10.1371/journal.ppat.1007185] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Revised: 10/31/2018] [Accepted: 10/02/2018] [Indexed: 12/26/2022] Open
Abstract
Host shifts-where a pathogen jumps between different host species-are an important source of emerging infectious disease. With on-going climate change there is an increasing need to understand the effect changes in temperature may have on emerging infectious disease. We investigated whether species' susceptibilities change with temperature and ask if susceptibility is greatest at different temperatures in different species. We infected 45 species of Drosophilidae with an RNA virus and measured how viral load changes with temperature. We found the host phylogeny explained a large proportion of the variation in viral load at each temperature, with strong phylogenetic correlations between viral loads across temperature. The variance in viral load increased with temperature, while the mean viral load did not. This suggests that as temperature increases the most susceptible species become more susceptible, and the least susceptible less so. We found no significant relationship between a species' susceptibility across temperatures, and proxies for thermal optima (critical thermal maximum and minimum or basal metabolic rate). These results suggest that whilst the rank order of species susceptibilities may remain the same with changes in temperature, some species may become more susceptible to a novel pathogen, and others less so.
Collapse
Affiliation(s)
- Katherine E. Roberts
- Biosciences, College of Life & Environmental Sciences, University of Exeter, Penryn Campus, Penryn, Cornwall, United Kingdom
| | - Jarrod D. Hadfield
- Institute of Evolutionary Biology, School of Biological Sciences, The University of Edinburgh, Ashworth Laboratories, Edinburgh, United Kingdom
| | - Manmohan D. Sharma
- Biosciences, College of Life & Environmental Sciences, University of Exeter, Penryn Campus, Penryn, Cornwall, United Kingdom
| | - Ben Longdon
- Biosciences, College of Life & Environmental Sciences, University of Exeter, Penryn Campus, Penryn, Cornwall, United Kingdom
| |
Collapse
|
33
|
Goto A, Okado K, Martins N, Cai H, Barbier V, Lamiable O, Troxler L, Santiago E, Kuhn L, Paik D, Silverman N, Holleufer A, Hartmann R, Liu J, Peng T, Hoffmann JA, Meignin C, Daeffler L, Imler JL. The Kinase IKKβ Regulates a STING- and NF-κB-Dependent Antiviral Response Pathway in Drosophila. Immunity 2018; 49:225-234.e4. [PMID: 30119996 DOI: 10.1016/j.immuni.2018.07.013] [Citation(s) in RCA: 100] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Revised: 05/08/2018] [Accepted: 07/16/2018] [Indexed: 12/22/2022]
Abstract
Antiviral immunity in Drosophila involves RNA interference and poorly characterized inducible responses. Here, we showed that two components of the IMD pathway, the kinase dIKKβ and the transcription factor Relish, were required to control infection by two picorna-like viruses. We identified a set of genes induced by viral infection and regulated by dIKKβ and Relish, which included an ortholog of STING. We showed that dSTING participated in the control of infection by picorna-like viruses, acting upstream of dIKKβ to regulate expression of Nazo, an antiviral factor. Our data reveal an antiviral function for STING in an animal model devoid of interferons and suggest an evolutionarily ancient role for this molecule in antiviral immunity.
Collapse
Affiliation(s)
- Akira Goto
- Université de Strasbourg, CNRS, Insect Models of Innate Immunity (M3I; UPR9022), 67084 Strasbourg, France; Sino-French Hoffmann Institute, School of Basic Medical Science, Guangzhou Medical University, Guangzhou 511436, China.
| | - Kiyoshi Okado
- Université de Strasbourg, CNRS, Insect Models of Innate Immunity (M3I; UPR9022), 67084 Strasbourg, France
| | - Nelson Martins
- Université de Strasbourg, CNRS, Insect Models of Innate Immunity (M3I; UPR9022), 67084 Strasbourg, France; Sino-French Hoffmann Institute, School of Basic Medical Science, Guangzhou Medical University, Guangzhou 511436, China
| | - Hua Cai
- Université de Strasbourg, CNRS, Insect Models of Innate Immunity (M3I; UPR9022), 67084 Strasbourg, France; Sino-French Hoffmann Institute, School of Basic Medical Science, Guangzhou Medical University, Guangzhou 511436, China
| | - Vincent Barbier
- Université de Strasbourg, CNRS, Insect Models of Innate Immunity (M3I; UPR9022), 67084 Strasbourg, France
| | - Olivier Lamiable
- Université de Strasbourg, CNRS, Insect Models of Innate Immunity (M3I; UPR9022), 67084 Strasbourg, France
| | - Laurent Troxler
- Université de Strasbourg, CNRS, Insect Models of Innate Immunity (M3I; UPR9022), 67084 Strasbourg, France
| | - Estelle Santiago
- Université de Strasbourg, CNRS, Insect Models of Innate Immunity (M3I; UPR9022), 67084 Strasbourg, France
| | - Lauriane Kuhn
- Université de Strasbourg, CNRS, Plateforme Protéomique Strasbourg-Esplanade, 67000 Strasbourg, France
| | - Donggi Paik
- Division of Infectious Diseases and Immunology, Department of Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Neal Silverman
- Division of Infectious Diseases and Immunology, Department of Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Andreas Holleufer
- Center for Structural Biology, Aarhus University, 8000 Aarhus C, Denmark
| | - Rune Hartmann
- Center for Structural Biology, Aarhus University, 8000 Aarhus C, Denmark
| | - Jiyong Liu
- Sino-French Hoffmann Institute, School of Basic Medical Science, Guangzhou Medical University, Guangzhou 511436, China
| | - Tao Peng
- Sino-French Hoffmann Institute, School of Basic Medical Science, Guangzhou Medical University, Guangzhou 511436, China
| | - Jules A Hoffmann
- Université de Strasbourg, CNRS, Insect Models of Innate Immunity (M3I; UPR9022), 67084 Strasbourg, France; Sino-French Hoffmann Institute, School of Basic Medical Science, Guangzhou Medical University, Guangzhou 511436, China; University of Strasbourg Institute for Advanced Study, 67000 Strasbourg, France
| | - Carine Meignin
- Université de Strasbourg, CNRS, Insect Models of Innate Immunity (M3I; UPR9022), 67084 Strasbourg, France
| | - Laurent Daeffler
- Université de Strasbourg, CNRS, Insect Models of Innate Immunity (M3I; UPR9022), 67084 Strasbourg, France
| | - Jean-Luc Imler
- Université de Strasbourg, CNRS, Insect Models of Innate Immunity (M3I; UPR9022), 67084 Strasbourg, France; Sino-French Hoffmann Institute, School of Basic Medical Science, Guangzhou Medical University, Guangzhou 511436, China.
| |
Collapse
|
34
|
Swevers L, Liu J, Smagghe G. Defense Mechanisms against Viral Infection in Drosophila: RNAi and Non-RNAi. Viruses 2018; 10:E230. [PMID: 29723993 PMCID: PMC5977223 DOI: 10.3390/v10050230] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2018] [Revised: 04/20/2018] [Accepted: 04/27/2018] [Indexed: 12/20/2022] Open
Abstract
RNAi is considered a major antiviral defense mechanism in insects, but its relative importance as compared to other antiviral pathways has not been evaluated comprehensively. Here, it is attempted to give an overview of the antiviral defense mechanisms in Drosophila that involve both RNAi and non-RNAi. While RNAi is considered important in most viral infections, many other pathways can exist that confer antiviral resistance. It is noted that very few direct recognition mechanisms of virus infections have been identified in Drosophila and that the activation of immune pathways may be accomplished indirectly through cell damage incurred by viral replication. In several cases, protection against viral infection can be obtained in RNAi mutants by non-RNAi mechanisms, confirming the variability of the RNAi defense mechanism according to the type of infection and the physiological status of the host. This analysis is aimed at more systematically investigating the relative contribution of RNAi in the antiviral response and more specifically, to ask whether RNAi efficiency is affected when other defense mechanisms predominate. While Drosophila can function as a useful model, this issue may be more critical for economically important insects that are either controlled (agricultural pests and vectors of diseases) or protected from parasite infection (beneficial insects as bees) by RNAi products.
Collapse
Affiliation(s)
- Luc Swevers
- Institute of Biosciences & Applications, NCSR "Demokritos", 15341 Athens, Greece.
| | - Jisheng Liu
- School of Life Sciences, Guangzhou University, 510006 Guangzhou, China.
| | - Guy Smagghe
- Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, 9000 Ghent, Belgium.
| |
Collapse
|
35
|
Thioester-Containing Proteins 2 and 4 Affect the Metabolic Activity and Inflammation Response in Drosophila. Infect Immun 2018; 86:IAI.00810-17. [PMID: 29463615 DOI: 10.1128/iai.00810-17] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Accepted: 02/06/2018] [Indexed: 12/17/2022] Open
Abstract
Drosophila melanogaster is an outstanding model for studying host antipathogen defense. Although substantial progress has been made in understanding how metabolism and immunity are interrelated in flies, little information has been obtained on the molecular players that regulate metabolism and inflammation in Drosophila during pathogenic infection. Recently, we reported that the inactivation of thioester-containing protein 2 (Tep2) and Tep4 promotes survival and decreases the bacterial burden in flies upon infection with the virulent pathogens Photorhabdus luminescens and Photorhabdus asymbiotica Here, we investigated physiological and pathological defects in tep mutant flies in response to Photorhabdus challenge. We find that tep2 and tep4 loss-of-function mutant flies contain increased levels of carbohydrates and triglycerides in the presence or absence of Photorhabdus infection. We also report that Photorhabdus infection leads to higher levels of nitric oxide and reduced transcript levels of the apical caspase-encoding gene Dronc in tep2 and tep4 mutants. We show that Tep2 and Tep4 are upregulated mainly in the fat body rather than the gut in Photorhabdus-infected wild-type flies and that tep mutants contain decreased numbers of Photorhabdus bacteria in both tissue types. We propose that the inactivation of Tep2 or Tep4 in adult Drosophila flies results in lower levels of inflammation and increased energy reserves in response to Photorhabdus, which could confer a survival-protective effect during the initial hours of infection.
Collapse
|
36
|
Damase TR, Miura TA, Parent CE, Allen PB. Application of the Open qPCR Instrument for the in Vitro Selection of DNA Aptamers against Epidermal Growth Factor Receptor and Drosophila C Virus. ACS COMBINATORIAL SCIENCE 2018; 20:45-54. [PMID: 29293309 DOI: 10.1021/acscombsci.7b00138] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The low-cost Open qPCR instrument can be used for different tasks in the aptamer selection process: quantification of DNA, cycle course optimization, screening, and final binding characterization. We have selected aptamers against whole Drosophila C virus (DCV) particles and recombinant epidermal growth factor receptor (EGFR). We performed systematic evolution of ligands by exponential enrichment (SELEX) using the Open qPCR to optimize each amplification step. The Open qPCR instrument identified the best aptamer candidate. The Open qPCR has the capacity to perform melt curves, and we used this function to perform thermofluorimetric analysis (TFA) to quantify target-aptamer binding. We confirmed target-aptamer binding using flow cytometry. A sandwich type luminescence bioassay based on our anti-DCV aptamer was sensitive to DCV and did not respond to a related virus, demonstrating that our selected anti-DCV aptamer can be used to specifically detect DCV.
Collapse
Affiliation(s)
- Tulsi Ram Damase
- University of Idaho, Department of Chemistry, 875 Perimeter Drive, Moscow, Idaho 83844-2343, United States
| | - Tanya A. Miura
- University of Idaho, Department of Biological Sciences, 875 Perimeter Drive, MS 3051, Moscow, Idaho 83844-3051, United States
| | - Christine E. Parent
- University of Idaho, Department of Biological Sciences, 875 Perimeter Drive, MS 3051, Moscow, Idaho 83844-3051, United States
| | - Peter B. Allen
- University of Idaho, Department of Chemistry, 875 Perimeter Drive, Moscow, Idaho 83844-2343, United States
| |
Collapse
|
37
|
Panthu B, Ohlmann T, Perrier J, Schlattner U, Jalinot P, Elena-Herrmann B, Rautureau GJP. Cell-Free Protein Synthesis Enhancement from Real-Time NMR Metabolite Kinetics: Redirecting Energy Fluxes in Hybrid RRL Systems. ACS Synth Biol 2018; 7:218-226. [PMID: 28915016 DOI: 10.1021/acssynbio.7b00280] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
A counterintuitive cell-free protein synthesis (CFPS) strategy, based on reducing the ribosomal fraction in rabbit reticulocyte lysate (RRL), triggers the development of hybrid systems composed of RRL ribosome-free supernatant complemented with ribosomes from different mammalian cell-types. Hybrid RRL systems maintain translational properties of the original ribosome cell types, and deliver protein expression levels similar to RRL. Here, we show that persistent ribosome-associated metabolic activity consuming ATP is a major obstacle for maximal protein yield. We provide a detailed picture of hybrid CFPS systems energetic metabolism based on real-time nuclear magnetic resonance (NMR) investigation of metabolites kinetics. We demonstrate that protein synthesis capacity has an upper limit at native ribosome concentration and that lower amounts of the ribosomal fraction optimize energy fluxes toward protein translation, consequently increasing CFPS yield. These results provide a rationalized strategy for further mammalian CFPS developments and reveal the potential of real-time NMR metabolism phenotyping for optimization of cell-free protein expression systems.
Collapse
Affiliation(s)
- Baptiste Panthu
- Univ. Lyon, ENS de Lyon, Univ. Claude Bernard, CNRS UMR 5239, INSERM U1210, Laboratory of Biology and Modelling of the Cell, 46 allée d’Italie Site Jacques Monod, F-69007 Lyon, France
| | - Théophile Ohlmann
- CIRI, Inserm, U1111, Université Claude Bernard Lyon 1, CNRS, UMR5308, ENS de Lyon, Univ. Lyon, F-69007 Lyon, France
| | - Johan Perrier
- Univ. Lyon, CNRS, Université Claude Bernard Lyon 1, ENS de Lyon, Institut des Sciences Analytiques, UMR 5280, 5 rue de la Doua, F-69100 Villeurbanne, France
| | - Uwe Schlattner
- Univ. Grenoble Alpes, Laboratory of Fundamental and Applied Bioenergetics (LBFA), 38058 Grenoble cedex, France
| | - Pierre Jalinot
- Univ. Lyon, ENS de Lyon, Univ. Claude Bernard, CNRS UMR 5239, INSERM U1210, Laboratory of Biology and Modelling of the Cell, 46 allée d’Italie Site Jacques Monod, F-69007 Lyon, France
| | - Bénédicte Elena-Herrmann
- Univ. Lyon, CNRS, Université Claude Bernard Lyon 1, ENS de Lyon, Institut des Sciences Analytiques, UMR 5280, 5 rue de la Doua, F-69100 Villeurbanne, France
| | - Gilles J. P. Rautureau
- Univ. Lyon, CNRS, Université Claude Bernard Lyon 1, ENS de Lyon, Institut des Sciences Analytiques, UMR 5280, 5 rue de la Doua, F-69100 Villeurbanne, France
| |
Collapse
|
38
|
Mondotte JA, Saleh MC. Antiviral Immune Response and the Route of Infection in Drosophila melanogaster. Adv Virus Res 2017; 100:247-278. [PMID: 29551139 DOI: 10.1016/bs.aivir.2017.10.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The use of Drosophila as a model organism has made an important contribution to our understanding of the function and regulation of innate immunity in insects. Indeed, insects can discriminate between different types of pathogens and mount specific and effective responses. Strikingly, the same pathogen can trigger a different immune response in the same organism, depending solely on the route of infection by which the pathogen is delivered. In this review, we recapitulate what is known about antiviral responses in Drosophila, and how they are triggered depending on the route and the mode used for the virus to infect its host.
Collapse
Affiliation(s)
- Juan A Mondotte
- Institut Pasteur, Viruses and RNA Interference Unit, CNRS Unité Mixte de Recherche 3569, Paris, France
| | - Maria-Carla Saleh
- Institut Pasteur, Viruses and RNA Interference Unit, CNRS Unité Mixte de Recherche 3569, Paris, France.
| |
Collapse
|
39
|
Gupta V, Vale PF. Nonlinear disease tolerance curves reveal distinct components of host responses to viral infection. ROYAL SOCIETY OPEN SCIENCE 2017; 4:170342. [PMID: 28791163 PMCID: PMC5541558 DOI: 10.1098/rsos.170342] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Accepted: 05/31/2017] [Indexed: 05/07/2023]
Abstract
The ability to tolerate infection is a key component of host defence and offers potential novel therapeutic approaches for infectious diseases. To yield successful targets for therapeutic intervention, it is important that the analytical tools employed to measure disease tolerance are able to capture distinct host responses to infection. Here, we show that commonly used methods that estimate tolerance as a linear relationship should be complemented with more flexible, nonlinear estimates of this relationship which may reveal variation in distinct components such as host vigour, sensitivity to increases in pathogen loads, and the severity of the infection. To illustrate this, we measured the survival of Drosophila melanogaster carrying either a functional or non-functional regulator of the JAK-STAT immune pathway (G9a) when challenged with a range of concentrations of Drosophila C virus (DCV). While classical linear model analyses indicated that G9a affected tolerance only in females, a more powerful nonlinear logistic model showed that G9a mediates viral tolerance to different extents in both sexes. This analysis also revealed that G9a acts by changing the sensitivity to increasing pathogen burdens, but does not reduce the ultimate severity of disease. These results indicate that fitting nonlinear models to host health-pathogen burden relationships may offer better and more detailed estimates of disease tolerance.
Collapse
Affiliation(s)
- Vanika Gupta
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, EH9 3FL Edinburgh, UK
| | - Pedro F. Vale
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, EH9 3FL Edinburgh, UK
- Centre for Immunity, Infection and Evolution, University of Edinburgh, EH9 3FL Edinburgh, UK
- Author for correspondence: Pedro F. Vale e-mail:
| |
Collapse
|
40
|
Complex Coding and Regulatory Polymorphisms in a Restriction Factor Determine the Susceptibility of Drosophila to Viral Infection. Genetics 2017. [PMID: 28630113 PMCID: PMC5560813 DOI: 10.1534/genetics.117.201970] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
It is common to find that major-effect genes are an important cause of variation in susceptibility to infection. Here we have characterized natural variation in a gene called pastrel that explains over half of the genetic variance in susceptibility to the Drosophila C virus (DCV) in populations of Drosophila melanogaster We found extensive allelic heterogeneity, with a sample of seven alleles of pastrel from around the world conferring four phenotypically distinct levels of resistance. By modifying candidate SNPs in transgenic flies, we show that the largest effect is caused by an amino acid polymorphism that arose when an ancestral threonine was mutated to alanine, greatly increasing resistance to DCV. Overexpression of the ancestral, susceptible allele provides strong protection against DCV; indicating that this mutation acted to improve an existing restriction factor. The pastrel locus also contains complex structural variation and cis-regulatory polymorphisms altering gene expression. We find that higher expression of pastrel is associated with increased survival after DCV infection. To understand why this variation is maintained in populations, we investigated genetic variation surrounding the amino acid variant that is causing flies to be resistant. We found no evidence of natural selection causing either recent changes in allele frequency or geographical variation in frequency, suggesting that this is an old polymorphism that has been maintained at a stable frequency. Overall, our data demonstrate how complex genetic variation at a single locus can control susceptibility to a virulent natural pathogen.
Collapse
|
41
|
Mussabekova A, Daeffler L, Imler JL. Innate and intrinsic antiviral immunity in Drosophila. Cell Mol Life Sci 2017; 74:2039-2054. [PMID: 28102430 PMCID: PMC5419870 DOI: 10.1007/s00018-017-2453-9] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Revised: 12/11/2016] [Accepted: 01/03/2017] [Indexed: 02/07/2023]
Abstract
The fruit fly Drosophila melanogaster has been a valuable model to investigate the genetic mechanisms of innate immunity. Initially focused on the resistance to bacteria and fungi, these studies have been extended to include antiviral immunity over the last decade. Like all living organisms, insects are continually exposed to viruses and have developed efficient defense mechanisms. We review here our current understanding on antiviral host defense in fruit flies. A major antiviral defense in Drosophila is RNA interference, in particular the small interfering (si) RNA pathway. In addition, complex inducible responses and restriction factors contribute to the control of infections. Some of the genes involved in these pathways have been conserved through evolution, highlighting loci that may account for susceptibility to viral infections in humans. Other genes are not conserved and represent species-specific innovations.
Collapse
Affiliation(s)
- Assel Mussabekova
- Institut de Biologie Moléculaire et Cellulaire, CNRS UPR9022, Université de Strasbourg, 15 rue René Descartes, 67000, Strasbourg, France.
| | - Laurent Daeffler
- Institut de Biologie Moléculaire et Cellulaire, CNRS UPR9022, Université de Strasbourg, 15 rue René Descartes, 67000, Strasbourg, France
| | - Jean-Luc Imler
- Institut de Biologie Moléculaire et Cellulaire, CNRS UPR9022, Université de Strasbourg, 15 rue René Descartes, 67000, Strasbourg, France
- Faculté des Sciences de la Vie, Université de Strasbourg, 28 rue Goethe, 67000, Strasbourg, France
| |
Collapse
|
42
|
Gupta V, Stewart CO, Rund SSC, Monteith K, Vale PF. Costs and benefits of sublethal Drosophila C virus infection. J Evol Biol 2017; 30:1325-1335. [PMID: 28425174 DOI: 10.1111/jeb.13096] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Revised: 04/10/2017] [Accepted: 04/12/2017] [Indexed: 01/24/2023]
Abstract
Viruses are major evolutionary drivers of insect immune systems. Much of our knowledge of insect immune responses derives from experimental infections using the fruit fly Drosophila melanogaster. Most experiments, however, employ lethal pathogen doses through septic injury, frequently overwhelming host physiology. While this approach has revealed several immune mechanisms, it is less informative about the fitness costs hosts may experience during infection in the wild. Using both systemic and oral infection routes, we find that even apparently benign, sublethal infections with the horizontally transmitted Drosophila C virus (DCV) can cause significant physiological and behavioural morbidity that is relevant for host fitness. We describe DCV-induced effects on fly reproductive output, digestive health and locomotor activity, and we find that viral morbidity varies according to the concentration of pathogen inoculum, host genetic background and sex. Notably, sublethal DCV infection resulted in a significant increase in fly reproduction, but this effect depended on host genotype. We discuss the relevance of sublethal morbidity for Drosophila ecology and evolution, and more broadly, we remark on the implications of deleterious and beneficial infections for the evolution of insect immunity.
Collapse
Affiliation(s)
- V Gupta
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, Scotland
| | - C O Stewart
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, Scotland
| | - S S C Rund
- Centre for Immunity, Infection and Evolution, University of Edinburgh, Edinburgh, Scotland
| | - K Monteith
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, Scotland
| | - P F Vale
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, Scotland.,Centre for Immunity, Infection and Evolution, University of Edinburgh, Edinburgh, Scotland
| |
Collapse
|
43
|
Disruption of Stress Granule Formation by the Multifunctional Cricket Paralysis Virus 1A Protein. J Virol 2017; 91:JVI.01779-16. [PMID: 28003491 DOI: 10.1128/jvi.01779-16] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2016] [Accepted: 12/15/2016] [Indexed: 12/26/2022] Open
Abstract
Stress granules (SGs) are cytosolic ribonucleoprotein aggregates that are induced during cellular stress. Several viruses modulate SG formation, suggesting that SGs have an impact on virus infection. However, the mechanisms and impact of modulating SG assembly in infected cells are not completely understood. In this study, we identify the dicistrovirus cricket paralysis virus 1A (CrPV-1A) protein that functions to inhibit SG assembly during infection. Moreover, besides inhibiting RNA interference, CrPV-1A also inhibits host transcription, which indirectly modulates SG assembly. Thus, CrPV-1A is a multifunctional protein. We identify a key R146A residue that is responsible for these effects, and mutant CrPV(R146A) virus infection is attenuated in Drosophila melanogaster S2 cells and adult fruit flies and results in increased SG formation. Treatment of CrPV(R146A)-infected cells with actinomycin D, which represses transcription, restores SG assembly suppression and viral yield. In summary, CrPV-1A modulates several cellular processes to generate a cellular environment that promotes viral translation and replication.IMPORTANCE RNA viruses encode a limited set of viral proteins to modulate an array of cellular processes in order to facilitate viral replication and inhibit antiviral defenses. In this study, we identified a viral protein, called CrPV-1A, within the dicistrovirus cricket paralysis virus that can inhibit host transcription, modulate viral translation, and block a cellular process called stress granule assembly. We also identified a specific amino acid within CrPV-1A that is important for these cellular processes and that mutant viruses containing mutations of CrPV-1A attenuate virus infection. We also demonstrate that the CrPV-1A protein can also modulate cellular processes in human cells, suggesting that the mode of action of CrPV-1A is conserved. We propose that CrPV-1A is a multifunctional, versatile protein that creates a cellular environment in virus-infected cells that permits productive virus infection.
Collapse
|
44
|
Martins N, Imler JL, Meignin C. Discovery of novel targets for antivirals: learning from flies. Curr Opin Virol 2016; 20:64-70. [PMID: 27657660 DOI: 10.1016/j.coviro.2016.09.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 08/24/2016] [Accepted: 09/06/2016] [Indexed: 12/15/2022]
Abstract
Developing antiviral drugs is challenging due to the small number of targets in viruses, and the rapid evolution of viral genes. Animals have evolved a number of efficient antiviral defence mechanisms, which can serve as a source of inspiration for novel therapies. The genetically tractable insect Drosophila belongs to the most diverse group of animals. Genetic and transcriptomic analyses have recently identified Drosophila genes encoding viral restriction factors. Some of them represent evolutionary novelties and their characterization may provide hints for the design of directly acting antivirals. In addition, functional screens revealed conserved host factors required for efficient viral translation, such as the ribosomal protein RACK1 and the release factor Pelo. These proteins are promising candidates for host-targeted antivirals.
Collapse
Affiliation(s)
- 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; Faculté des Sciences de la Vie, Université de Strasbourg, Strasbourg, France
| | - Carine Meignin
- CNRS UPR9022, Institut de Biologie Moléculaire et Cellulaire, Université de Strasbourg, Strasbourg, France; Faculté des Sciences de la Vie, Université de Strasbourg, Strasbourg, France.
| |
Collapse
|
45
|
Vale PF, Jardine MD. Infection avoidance behavior: Viral exposure reduces the motivation to forage in female Drosophila melanogaster. Fly (Austin) 2016; 11:3-9. [PMID: 27362557 PMCID: PMC5354229 DOI: 10.1080/19336934.2016.1207029] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Infection avoidance behaviors are the first line of defense against pathogenic encounters. Behavioral plasticity in response to internal or external cues of infection can therefore generate potentially significant heterogeneity in infection. We tested whether Drosophila melanogaster exhibits infection avoidance behavior, and whether this behavior is modified by prior exposure to Drosophila C Virus (DCV) and by the risk of DCV encounter. We examined 2 measures of infection avoidance: (1) the motivation to seek out food sources in the presence of an infection risk and (2) the preference to land on a clean food source over a potentially infectious source. While we found no evidence for preference of clean food sources over potentially infectious ones, previously exposed female flies showed lower motivation to pick a food source when presented with a risk of encountering DCV. We discuss the relevance of behavioral plasticity during foraging for host fitness and pathogen spread.
Collapse
Affiliation(s)
- Pedro F Vale
- a Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh , Edinburgh , UK.,b Centre for Immunity, Infection and Evolution, University of Edinburgh , Edinburgh , UK
| | - Michael D Jardine
- a Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh , Edinburgh , UK
| |
Collapse
|
46
|
Ekström JO, Hultmark D. A Novel Strategy for Live Detection of Viral Infection in Drosophila melanogaster. Sci Rep 2016; 6:26250. [PMID: 27189868 PMCID: PMC4870574 DOI: 10.1038/srep26250] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Accepted: 04/29/2016] [Indexed: 02/07/2023] Open
Abstract
We have created a transgenic reporter for virus infection, and used it to study Nora virus infection in Drosophila melanogaster. The transgenic construct, Munin, expresses the yeast transcription factor Gal4, tethered to a transmembrane anchor via a linker that can be cleaved by a viral protease. In infected cells, liberated Gal4 will then transcribe any gene that is linked to a promoter with a UAS motif, the target for Gal4 transcription. For instance, infected cells will glow red in the offspring of a cross between the Munin stock and flies with a UAS-RFP(nls) transgene (expressing a red fluorescent protein). In such flies we show that after natural infection, via the faecal-oral route, 5-15% of the midgut cells are infected, but there is little if any infection elsewhere. By contrast, we can detect infection in many other tissues after injection of virus into the body cavity. The same principle could be applied for other viruses and it could also be used to express or suppress any gene of interest in infected cells.
Collapse
Affiliation(s)
- Jens-Ola Ekström
- Department of Molecular Biology, Umeå University, S-90187 Umeå, Sweden
- BioMediTech, FI-33014 University of Tampere, Finland
| | - Dan Hultmark
- Department of Molecular Biology, Umeå University, S-90187 Umeå, Sweden
- BioMediTech, FI-33014 University of Tampere, Finland
| |
Collapse
|
47
|
Wong ZS, Brownlie JC, Johnson KN. Impact of ERK activation on fly survival and Wolbachia-mediated protection during virus infection. J Gen Virol 2016; 97:1446-1452. [PMID: 26977591 DOI: 10.1099/jgv.0.000456] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Elevated levels of reactive oxygen species (ROS) provide protection against virus-induced mortality in Drosophila. In addition to contributing to oxidative stress, ROS are known to activate a number of signalling pathways including the extracellular signal-regulated kinases (ERK) signalling cascade. It was recently shown that ERK signalling is important for resistance against viral replication and invasion in cultured Drosophila cells and the gut epithelium of adult flies. Here, using a Drosophila loss-of-function ERK (rolled) mutant we demonstrated that ERK is important for fly survival during virus infection. ERK mutant flies subjected to Drosophila C virus (DCV) oral and systemic infection were more susceptible to virus-induced mortality as compared with wild-type flies. We have demonstrated experimentally that ERK activation is important for fly survival during oral and systemic virus infection. Given that elevated ROS correlates with Wolbachia-mediated antiviral protection, we also investigated the involvement of ERK in antiviral protection in flies infected by Wolbachia. The results indicate that ERK activation is increased in the presence of Wolbachia but this does not appear to influence Wolbachia-mediated antiviral protection, at least during systemic infection.
Collapse
Affiliation(s)
- Zhee Sheen Wong
- School of Biological Sciences, University of Queensland, St Lucia, Brisbane, Australia
| | - Jeremy C Brownlie
- School of Natural Sciences, Griffith University, Brisbane, Australia
| | - Karyn N Johnson
- School of Biological Sciences, University of Queensland, St Lucia, Brisbane, Australia
| |
Collapse
|
48
|
Temporal Regulation of Distinct Internal Ribosome Entry Sites of the Dicistroviridae Cricket Paralysis Virus. Viruses 2016; 8:v8010025. [PMID: 26797630 PMCID: PMC4728584 DOI: 10.3390/v8010025] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Revised: 01/08/2016] [Accepted: 01/11/2016] [Indexed: 01/04/2023] Open
Abstract
Internal ribosome entry is a key mechanism for viral protein synthesis in a subset of RNA viruses. Cricket paralysis virus (CrPV), a member of Dicistroviridae, has a positive-sense single strand RNA genome that contains two internal ribosome entry sites (IRES), a 5′untranslated region (5′UTR) and intergenic region (IGR) IRES, that direct translation of open reading frames (ORF) encoding the viral non-structural and structural proteins, respectively. The regulation of and the significance of the CrPV IRESs during infection are not fully understood. In this study, using a series of biochemical assays including radioactive-pulse labelling, reporter RNA assays and ribosome profiling, we demonstrate that while 5′UTR IRES translational activity is constant throughout infection, IGR IRES translation is delayed and then stimulated two to three hours post infection. The delay in IGR IRES translation is not affected by inhibiting global translation prematurely via treatment with Pateamine A. Using a CrPV replicon that uncouples viral translation and replication, we show that the increase in IGR IRES translation is dependent on expression of non-structural proteins and is greatly stimulated when replication is active. Temporal regulation by distinct IRESs within the CrPV genome is an effective viral strategy to ensure optimal timing and expression of viral proteins to facilitate infection.
Collapse
|
49
|
Drosophila melanogaster does not exhibit a behavioural fever response when infected with Drosophila C virus. J Gen Virol 2015; 96:3667-3671. [DOI: 10.1099/jgv.0.000296] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Behavioural fever is a widely conserved response to infection. The host increases body temperature (T
b) by altering their preferred temperature (T
p), generating a fever and delaying or avoiding pathogen-induced mortality. This response is not ubiquitous in insects, however, although few studies have investigated this response to viral infection. Here, we examined the change in T
p of Drosophila in response to virus infection using a thermal gradient. No difference in T
p was observed. We suggest that the lack of behavioural fever could be due to the increased energy cost of maintaining a higher T
b whilst the immune response is active. To the best of our knowledge, this is the first study to assay for changes in T
p of infected Drosophila.
Collapse
|
50
|
Nainu F, Tanaka Y, Shiratsuchi A, Nakanishi Y. Protection of Insects against Viral Infection by Apoptosis-Dependent Phagocytosis. THE JOURNAL OF IMMUNOLOGY 2015; 195:5696-706. [PMID: 26546607 DOI: 10.4049/jimmunol.1500613] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Accepted: 10/14/2015] [Indexed: 11/19/2022]
Abstract
We investigated whether phagocytosis participates in the protection of insects from viral infection using the natural host-virus interaction between Drosophila melanogaster and Drosophila C virus (DCV). Drosophila S2 cells were induced to undergo apoptotic cell death upon DCV infection. However, UV-inactivated virus was unable to cause apoptosis, indicating the need for productive infection for apoptosis induction. S2 cells became susceptible to phagocytosis by hemocyte-derived l(2)mbn cells after viral infection, and the presence of phagocytes in S2 cell cultures reduced viral proliferation. Phagocytosis depended, in part, on caspase activity in S2 cells, as well as the engulfment receptors Draper and integrin βν in phagocytes. To validate the in vivo situation, adult flies were abdominally infected with DCV, followed by the analysis of fly death and viral growth. DCV infection killed flies in a dose-responding manner, and the activation of effector caspases was evident, as revealed by the cleavage of a target protein ectopically expressed in flies. Furthermore, hemocytes isolated from infected flies contained DCV-infected cells, and preinjection of latex beads to inhibit the phagocytic activity of hemocytes accelerated fly death after viral infection. Likewise, viral virulence was exaggerated in flies lacking the engulfment receptors, and was accompanied by the augmented proliferation of virus. Finally, phagocytosis of DCV-infected cells in vitro was inhibited by phosphatidylserine-containing liposome, and virus-infected flies died early when a phosphatidylserine-binding protein was ectopically expressed. Collectively, our study demonstrates that the apoptosis-dependent, phosphatidylserine-mediated phagocytosis of virus-infected cells plays an important role in innate immune responses against viral infection in Drosophila.
Collapse
Affiliation(s)
- Firzan Nainu
- Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Ishikawa 920-1192, Japan; Faculty of Pharmacy, Hasanuddin University, Makassar, South Sulawesi 90245, Indonesia; and
| | - Yumiko Tanaka
- School of Pharmacy, Kanazawa University, Kanazawa, Ishikawa 920-1192, Japan
| | - Akiko Shiratsuchi
- Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Ishikawa 920-1192, Japan; School of Pharmacy, Kanazawa University, Kanazawa, Ishikawa 920-1192, Japan
| | - Yoshinobu Nakanishi
- Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Ishikawa 920-1192, Japan; School of Pharmacy, Kanazawa University, Kanazawa, Ishikawa 920-1192, Japan
| |
Collapse
|