1
|
Bergmann S, Graf E, Hoffmann P, Becker SC, Stern M. Localization of nitric oxide-producing hemocytes in Aedes and Culex mosquitoes infected with bacteria. Cell Tissue Res 2024; 395:313-326. [PMID: 38240845 PMCID: PMC10904431 DOI: 10.1007/s00441-024-03862-1] [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: 08/25/2023] [Accepted: 01/05/2024] [Indexed: 03/01/2024]
Abstract
Mosquitoes are significant vectors of various pathogens. Unlike vertebrates, insects rely solely on innate immunity. Hemocytes play a crucial role in the cellular part of the innate immune system. The gaseous radical nitric oxide (NO) produced by hemocytes acts against pathogens and also functions as a versatile transmitter in both the immune and nervous systems, utilizing cyclic guanosine monophosphate (cGMP) as a second messenger. This study conducted a parallel comparison of NO synthase (NOS) expression and NO production in hemocytes during Escherichia coli K12 infection in four vector species: Aedes aegypti, Aedes albopictus, Culex pipiens molestus, and Culex pipiens quinquefasciatus. Increased NOS expression by NADPH diaphorase (NADPHd) staining and NO production by immunofluorescence against the by-product L-citrulline were observed in infected mosquito hemocytes distributed throughout the abdomens. NADPHd activity and citrulline labeling were particularly found in periostial hemocytes near the heart, but also on the ventral nerve chord (VNC). Pericardial cells of Ae. aegypti and Cx. p. molestus showed increased citrulline immunofluorescence, suggesting their involvement in the immune response. Oenocytes displayed strong NADPHd and citrulline labeling independent of infection status. This comparative study, consistent with findings in other species, suggests a widespread phenomenon of NO's role in hemocyte responses during E. coli infection. Found differences within and between genera highlight the importance of species-specific investigations.
Collapse
Affiliation(s)
- Stella Bergmann
- Institute for Physiology and Cell Biology, University of Veterinary Medicine Hannover, 30173, Hannover, Germany
| | - Emily Graf
- Institute for Physiology and Cell Biology, University of Veterinary Medicine Hannover, 30173, Hannover, Germany
| | - Pascal Hoffmann
- Institute for Physiology and Cell Biology, University of Veterinary Medicine Hannover, 30173, 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
|
2
|
Xia J, Fei S, Wu H, Yang Y, Yu W, Zhang M, Guo Y, Swevers L, Sun J, Feng M. The piRNA pathway is required for nucleopolyhedrovirus replication in Lepidoptera. INSECT SCIENCE 2023; 30:1378-1392. [PMID: 36495071 DOI: 10.1111/1744-7917.13160] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 11/07/2022] [Accepted: 11/22/2022] [Indexed: 06/17/2023]
Abstract
The Piwi-interacting RNA (piRNA) pathway has been shown to be involved in the antiviral defense against RNA viruses, especially in mosquitoes, but its universality has been questioned. Here, we used the Bombyx mori nucleopolyhedrovirus (BmNPV) -infected silkworm as a model to explore the effects of the key factors of piRNA pathway, BmAgo3 and Siwi, on replication of a large DNA virus (belonging to the family of Baculoviridae). We demonstrated that BmAgo3 and Siwi could promote the replication of BmNPV through both overexpression and knockdown experiments in BmN cell lines and silkworm larvae. In addition, we also studied the effect of PIWI-class genes on Autographa californica nucleopolyhedrovirus (AcMNPV) replication in the Spodoptera frugiperda cell line Sf9. By knocking down the expression of PIWI-class genes in Sf9, we found that Piwi-like-1 and Piwi-like-2-3 could inhibit AcMNPV replication, while Piwi-like-4-5 promoted virus replication. Our study provides compelling evidence that the piRNA pathway affects host infection by exogenous viruses in Lepidoptera. Also, our results reflect the diversity of the roles of PIWI-class genes in virus infection of the host across species. This study is the first to explore the interaction of PIWI-class proteins with DNA viruses, providing new insights into the functional roles of the piRNA pathway.
Collapse
Affiliation(s)
- Junming Xia
- Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou, China
| | - Shigang Fei
- Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou, China
| | - Hongyun Wu
- Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou, China
| | - Yifan Yang
- Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou, China
| | - Wensheng Yu
- Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou, China
| | - Mengmeng Zhang
- Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou, China
| | - Yiyao Guo
- Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou, China
| | - Luc Swevers
- Insect Molecular Genetics and Biotechnology, National Center for Scientific Research Demokritos, Institute of Biosciences and Applications, Athens, Greece
| | - Jingchen Sun
- Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou, China
| | - Min Feng
- Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou, China
| |
Collapse
|
3
|
Samir M. Editorial: Host response to veterinary infectious diseases: role of coding and non-coding RNAs as biomarkers and disease modulators. Front Vet Sci 2023; 10:1275169. [PMID: 37711434 PMCID: PMC10497942 DOI: 10.3389/fvets.2023.1275169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Accepted: 08/14/2023] [Indexed: 09/16/2023] Open
Affiliation(s)
- Mohamed Samir
- The Immunogenetics Group, The Pirbright Institute, Woking, United Kingdom
- Department of Zoonoses, Faculty of Veterinary Medicine, Zagazig University, Zagazig, Egypt
| |
Collapse
|
4
|
Leggewie M, Scherer C, Altinli M, Gestuveo RJ, Sreenu VB, Fuss J, Vazeille M, Mousson L, Badusche M, Kohl A, Failloux AB, Schnettler E. The Aedes aegypti RNA interference response against Zika virus in the context of co-infection with dengue and chikungunya viruses. PLoS Negl Trop Dis 2023; 17:e0011456. [PMID: 37440582 DOI: 10.1371/journal.pntd.0011456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 06/12/2023] [Indexed: 07/15/2023] Open
Abstract
Since its detection in 2015 in Brazil, Zika virus (ZIKV) has remained in the spotlight of international public health and research as an emerging arboviral pathogen. In addition to single infection, ZIKV may occur in co-infection with dengue (DENV) and chikungunya (CHIKV) viruses, with whom ZIKV shares geographic distribution and the mosquito Aedes aegypti as a vector. The main mosquito immune response against arboviruses is RNA interference (RNAi). It is unknown whether or not the dynamics of the RNAi response differ between single arboviral infections and co-infections. In this study, we investigated the interaction of ZIKV and DENV, as well as ZIKV and CHIKV co-infections with the RNAi response in Ae. aegypti. Using small RNA sequencing, we found that the efficiency of small RNA production against ZIKV -a hallmark of antiviral RNAi-was mostly similar when comparing single and co-infections with either DENV or CHIKV. Silencing of key antiviral RNAi proteins, showed no change in effect on ZIKV replication when the cell is co-infected with ZIKV and DENV or CHIKV. Interestingly, we observed a negative effect on ZIKV replication during CHIKV co-infection in the context of Ago2-knockout cells, though his effect was absent during DENV co-infection. Overall, this study provides evidence that ZIKV single or co-infections with CHIKV or DENV are equally controlled by RNAi responses. Thus, Ae. aegypti mosquitoes and derived cells support co-infections of ZIKV with either CHIKV or DENV to a similar level than single infections, as long as the RNAi response is functional.
Collapse
Affiliation(s)
- Mayke Leggewie
- Bernhard-Nocht Institute for Tropical Medicine, Hamburg, Germany
- German Center for Infection; Research (DZIF), partner site Hamburg-Luebeck-Borstel-Riems, Germany
| | - Christina Scherer
- Bernhard-Nocht Institute for Tropical Medicine, Hamburg, Germany
- German Center for Infection; Research (DZIF), partner site Hamburg-Luebeck-Borstel-Riems, Germany
| | - Mine Altinli
- Bernhard-Nocht Institute for Tropical Medicine, Hamburg, Germany
- German Center for Infection; Research (DZIF), partner site Hamburg-Luebeck-Borstel-Riems, Germany
| | - Rommel J Gestuveo
- MRC-University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
- Division of Biological Sciences, University of the Philippines Visayas, Miagao, Iloilo, Philippines
| | - Vattipally B Sreenu
- MRC-University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
| | - Janina Fuss
- Institute of Clinical Molecular Biology (IKMB), Kiel University, Kiel, Germany
| | - Marie Vazeille
- Institut Pasteur, Université Paris Cité, Arboviruses and Insect Vectors, Paris, France
| | - Laurence Mousson
- Institut Pasteur, Université Paris Cité, Arboviruses and Insect Vectors, Paris, France
| | - Marlis Badusche
- Bernhard-Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Alain Kohl
- MRC-University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
| | - Anna-Bella Failloux
- Institut Pasteur, Université Paris Cité, Arboviruses and Insect Vectors, Paris, France
| | - Esther Schnettler
- Bernhard-Nocht Institute for Tropical Medicine, Hamburg, Germany
- German Center for Infection; Research (DZIF), partner site Hamburg-Luebeck-Borstel-Riems, Germany
- University Hamburg, Faculty of Mathematics, Informatics and Natural Sciences, Hamburg, Germany
| |
Collapse
|
5
|
Laureti M, Lee RX, Bennett A, Wilson LA, Sy VE, Kohl A, Dietrich I. Rift Valley Fever Virus Primes Immune Responses in Aedes aegypti Cells. Pathogens 2023; 12:563. [PMID: 37111448 PMCID: PMC10146816 DOI: 10.3390/pathogens12040563] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 03/25/2023] [Accepted: 04/03/2023] [Indexed: 04/29/2023] Open
Abstract
The ongoing global emergence of arthropod-borne (arbo) viruses has accelerated research into the interactions of these viruses with the immune systems of their vectors. Only limited information exists on how bunyaviruses, such as Rift Valley fever virus (RVFV), are sensed by mosquito immunity or escape detection. RVFV is a zoonotic phlebovirus (Bunyavirales; Phenuiviridae) of veterinary and human public health and economic importance. We have shown that the infection of mosquitoes with RVFV triggers the activation of RNA interference pathways, which moderately restrict viral replication. Here, we aimed to better understand the interactions between RVFV and other vector immune signaling pathways that might influence RVFV replication and transmission. For this, we used the immunocompetent Aedes aegypti Aag2 cell line as a model. We found that bacteria-induced immune responses restricted RVFV replication. However, virus infection alone did not alter the gene expression levels of immune effectors. Instead, it resulted in the marked enhancement of immune responses to subsequent bacterial stimulation. The gene expression levels of several mosquito immune pattern recognition receptors were altered by RVFV infection, which may contribute to this immune priming. Our findings imply that there is a complex interplay between RVFV and mosquito immunity that could be targeted in disease prevention strategies.
Collapse
Affiliation(s)
| | - Rui-Xue Lee
- MRC-University of Glasgow Centre for Virus Research, 464 Bearsden Road, Glasgow G61 1QH, UK
| | - Amelia Bennett
- The Pirbright Institute, Ash Road, Pirbright GU24 0NF, UK
- Department of Life Sciences, Faculty of Science, Claverton Down, University of Bath, Bath BA2 7AY, UK
| | - Lucas Aladar Wilson
- The Pirbright Institute, Ash Road, Pirbright GU24 0NF, UK
- Institute of Medical Sciences, School of Medicine, Medical Sciences and Nutrition, Foresterhill, University of Aberdeen, Aberdeen AB25 2ZD, UK
| | | | - Alain Kohl
- MRC-University of Glasgow Centre for Virus Research, 464 Bearsden Road, Glasgow G61 1QH, UK
| | - Isabelle Dietrich
- The Pirbright Institute, Ash Road, Pirbright GU24 0NF, UK
- MRC-University of Glasgow Centre for Virus Research, 464 Bearsden Road, Glasgow G61 1QH, UK
| |
Collapse
|
6
|
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
|
7
|
Qu J, Betting V, van Iterson R, Kwaschik FM, van Rij RP. Chromatin profiling identifies transcriptional readthrough as a conserved mechanism for piRNA biogenesis in mosquitoes. Cell Rep 2023; 42:112257. [PMID: 36930642 DOI: 10.1016/j.celrep.2023.112257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 12/21/2022] [Accepted: 02/27/2023] [Indexed: 03/18/2023] Open
Abstract
The piRNA pathway in mosquitoes differs substantially from other model organisms, with an expanded PIWI gene family and functions in antiviral defense. Here, we define core piRNA clusters as genomic loci that show ubiquitous piRNA expression in both somatic and germline tissues. These core piRNA clusters are enriched for non-retroviral endogenous viral elements (nrEVEs) in antisense orientation and depend on key biogenesis factors, Veneno, Tejas, Yb, and Shutdown. Combined transcriptome and chromatin state analyses identify transcriptional readthrough as a conserved mechanism for cluster-derived piRNA biogenesis in the vector mosquitoes Aedes aegypti, Aedes albopictus, Culex quinquefasciatus, and Anopheles gambiae. Comparative analyses between the two Aedes species suggest that piRNA clusters function as traps for nrEVEs, allowing adaptation to environmental challenges such as virus infection. Our systematic transcriptome and chromatin state analyses lay the foundation for studies of gene regulation, genome evolution, and piRNA function in these important vector species.
Collapse
Affiliation(s)
- Jieqiong Qu
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, P.O. Box 9101, 6500 HB Nijmegen, the Netherlands
| | - Valerie Betting
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, P.O. Box 9101, 6500 HB Nijmegen, the Netherlands
| | - Ruben van Iterson
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, P.O. Box 9101, 6500 HB Nijmegen, the Netherlands
| | - Florence M Kwaschik
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, P.O. Box 9101, 6500 HB Nijmegen, the Netherlands
| | - Ronald P van Rij
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, P.O. Box 9101, 6500 HB Nijmegen, the Netherlands.
| |
Collapse
|
8
|
Alexander AJT, Salvemini M, Sreenu VB, Hughes J, Telleria EL, Ratinier M, Arnaud F, Volf P, Brennan B, Varjak M, Kohl A. Characterisation of the antiviral RNA interference response to Toscana virus in sand fly cells. PLoS Pathog 2023; 19:e1011283. [PMID: 36996243 PMCID: PMC10112792 DOI: 10.1371/journal.ppat.1011283] [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: 12/13/2022] [Revised: 04/18/2023] [Accepted: 03/09/2023] [Indexed: 04/01/2023] Open
Abstract
Toscana virus (TOSV) (Bunyavirales, Phenuiviridae, Phlebovirus, Toscana phlebovirus) and other related human pathogenic arboviruses are transmitted by phlebotomine sand flies. TOSV has been reported in nations bordering the Mediterranean Sea among other regions. Infection can result in febrile illness as well as meningitis and encephalitis. Understanding vector-arbovirus interactions is crucial to improving our knowledge of how arboviruses spread, and in this context, immune responses that control viral replication play a significant role. Extensive research has been conducted on mosquito vector immunity against arboviruses, with RNA interference (RNAi) and specifically the exogenous siRNA (exo-siRNA) pathway playing a critical role. However, the antiviral immunity of phlebotomine sand flies is less well understood. Here we were able to show that the exo-siRNA pathway is active in a Phlebotomus papatasi-derived cell line. Following TOSV infection, distinctive 21 nucleotide virus-derived small interfering RNAs (vsiRNAs) were detected. We also identified the exo-siRNA effector Ago2 in this cell line, and silencing its expression rendered the exo-siRNA pathway largely inactive. Thus, our data show that this pathway is active as an antiviral response against a sand fly transmitted bunyavirus, TOSV.
Collapse
Affiliation(s)
| | - Marco Salvemini
- Department of Biology, University of Naples Federico II, Italy
| | | | - Joseph Hughes
- MRC-University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
| | - Erich L. Telleria
- Department of Parasitology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Maxime Ratinier
- IVPC UMR754, INRAE, Univ Lyon, Université Claude Bernard Lyon1, EPHE, PSL Research University, Lyon, France
| | - Frédérick Arnaud
- IVPC UMR754, INRAE, Univ Lyon, Université Claude Bernard Lyon1, EPHE, PSL Research University, Lyon, France
| | - Petr Volf
- Department of Parasitology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Benjamin Brennan
- MRC-University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
| | - Margus Varjak
- Institute of Technology, University of Tartu, Tartu, Estonia
| | - Alain Kohl
- MRC-University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
| |
Collapse
|
9
|
Santos D, Feng M, Kolliopoulou A, Taning CNT, Sun J, Swevers L. What Are the Functional Roles of Piwi Proteins and piRNAs in Insects? INSECTS 2023; 14:insects14020187. [PMID: 36835756 PMCID: PMC9962485 DOI: 10.3390/insects14020187] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2023] [Revised: 02/09/2023] [Accepted: 02/11/2023] [Indexed: 06/01/2023]
Abstract
Research on Piwi proteins and piRNAs in insects has focused on three experimental models: oogenesis and spermatogenesis in Drosophila melanogaster, the antiviral response in Aedes mosquitoes and the molecular analysis of primary and secondary piRNA biogenesis in Bombyx mori-derived BmN4 cells. Significant unique and complementary information has been acquired and has led to a greater appreciation of the complexity of piRNA biogenesis and Piwi protein function. Studies performed in other insect species are emerging and promise to add to the current state of the art on the roles of piRNAs and Piwi proteins. Although the primary role of the piRNA pathway is genome defense against transposons, particularly in the germline, recent findings also indicate an expansion of its functions. In this review, an extensive overview is presented of the knowledge of the piRNA pathway that so far has accumulated in insects. Following a presentation of the three major models, data from other insects were also discussed. Finally, the mechanisms for the expansion of the function of the piRNA pathway from transposon control to gene regulation were considered.
Collapse
Affiliation(s)
- Dulce Santos
- Research Group of Molecular Developmental Physiology and Signal Transduction, Division of Animal Physiology and Neurobiology, Department of Biology, KU Leuven, Naamsestraat 59, 3000 Leuven, Belgium
| | - Min Feng
- Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou 510642, China
| | - Anna Kolliopoulou
- Insect Molecular Genetics and Biotechnology, Institute of Biosciences & Applications, National Centre for Scientific Research “Demokritos”, Aghia Paraskevi, 15341 Athens, Greece
| | - Clauvis N. T. Taning
- Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, 9000 Ghent, Belgium
| | - Jingchen Sun
- Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou 510642, China
| | - Luc Swevers
- Insect Molecular Genetics and Biotechnology, Institute of Biosciences & Applications, National Centre for Scientific Research “Demokritos”, Aghia Paraskevi, 15341 Athens, Greece
| |
Collapse
|
10
|
Antiviral RNAi Response in Culex quinquefasciatus-Derived HSU Cells. Viruses 2023; 15:v15020436. [PMID: 36851650 PMCID: PMC9968050 DOI: 10.3390/v15020436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 01/20/2023] [Accepted: 01/31/2023] [Indexed: 02/09/2023] Open
Abstract
Culex spp. mosquitoes are important vectors of viruses, such as West Nile virus, Eastern equine encephalitis virus and Rift valley fever virus. However, their interactions with innate antiviral immunity, especially RNA interference (RNAi), are not well known. Most research on RNAi pathways in mosquitoes is focused on the tropical vector mosquito Aedes aegypti. Here, we investigated the production of arbovirus-specific small RNAs in Cx. quinquefasciatus-derived HSU cells. Furthermore, by silencing RNAi-related proteins, we investigated the antiviral role of these proteins for two different arboviruses: Semliki Forest virus (SFV) and Bunyamwera orthobunyavirus (BUNV). Our results showed an expansion of Ago2 and Piwi6 in Cx. quinquefasciatus compared to Ae. aegypti. While silencing Ago2a and Ago2b increased BUNV replication, only Ago2b showed antiviral activity against SFV. Our results suggest differences in the function of Cx. quinquefasciatus and Ae. aegypti RNAi proteins and highlight the virus-specific function of these proteins in Cx. quinquefasciatus.
Collapse
|
11
|
Culex Mosquito Piwi4 Is Antiviral against Two Negative-Sense RNA Viruses. Viruses 2022; 14:v14122758. [PMID: 36560761 PMCID: PMC9781653 DOI: 10.3390/v14122758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 12/06/2022] [Accepted: 12/07/2022] [Indexed: 12/14/2022] Open
Abstract
Culex spp. mosquitoes transmit several pathogens concerning public health, including West Nile virus and Saint Louis encephalitis virus. Understanding the antiviral immune system of Culex spp. mosquitoes is important for reducing the transmission of these viruses. Mosquitoes rely on RNA interference (RNAi) to control viral replication. While the siRNA pathway in mosquitoes is heavily studied, less is known about the piRNA pathway. The piRNA pathway in mosquitoes has recently been connected to mosquito antiviral immunity. In Aedes aegypti, Piwi4 has been implicated in antiviral responses. The antiviral role of the piRNA pathway in Culex spp. mosquitoes is understudied compared to Ae. aegypti. Here, we aimed to identify the role of PIWI genes and piRNAs in Culex quinquefasciatus and Culex tarsalis cells during virus infection. We examined the effect of PIWI gene silencing on virus replication of two arboviruses and three insect-specific viruses in Cx. quinquefasciatus derived cells (Hsu) and Cx. tarsalis derived (CT) cells. We show that Piwi4 is antiviral against the La Crosse orthobunyavirus (LACV) in Hsu and CT cells, and the insect-specific rhabdovirus Merida virus (MERDV) in Hsu cells. None of the silenced PIWI genes impacted replication of the two flaviviruses Usutu virus (USUV) and Calbertado virus, or the phasivirus Phasi-Charoen-like virus. We further used small RNA sequencing to determine that LACV-derived piRNAs, but not USUV-derived piRNAs were generated in Hsu cells and that PIWI gene silencing resulted in a small reduction in vpiRNAs. Finally, we determined that LACV-derived DNA was produced in Hsu cells during infection, but whether this viral DNA is required for vpiRNA production remains unclear. Overall, we expanded our knowledge on the piRNA pathway and how it relates to the antiviral response in Culex spp mosquitoes.
Collapse
|
12
|
Intact Type I Interferon Receptor Signaling Prevents Hepatocellular Necrosis but Not Encephalitis in a Dose-Dependent Manner in Rift Valley Fever Virus Infected Mice. Int J Mol Sci 2022; 23:ijms232012492. [DOI: 10.3390/ijms232012492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 09/30/2022] [Accepted: 10/11/2022] [Indexed: 11/17/2022] Open
Abstract
Rift Valley fever (RVF) is a zoonotic and emerging disease, caused by the RVF virus (RVFV). In ruminants, it leads to “abortion storms” and enhanced mortality rates in young animals, whereas in humans it can cause symptoms like severe hemorrhagic fever or encephalitis. The role of the innate and adaptive immune response in disease initiation and progression is still poorly defined. The present study used the attenuated RVFV strain clone 13 to investigate viral spread, tissue tropism, and histopathological lesions after intranasal infection in C57BL/6 wild type (WT) and type I interferon (IFN-I) receptor I knockout (IFNAR−/−) mice. In WT mice, 104 PFU RVFV (high dose) resulted in a fatal encephalitis, but no hepatitis 7–11 days post infection (dpi), whereas 103 PFU RVFV (low dose) did not cause clinical disease or significant histopathological lesions in liver and the central nervous system (CNS). In contrast, IFNAR−/− mice infected with 103 PFU RVFV developed hepatocellular necrosis resulting in death at 2–5 dpi and lacked encephalitis. These results show that IFNAR signaling prevents systemic spread of the attenuated RVFV strain clone 13, but not the dissemination to the CNS and subsequent fatal disease. Consequently, neurotropic viruses may be able to evade antiviral IFN-I signaling pathways by using the transneuronal instead of the hematogenous route.
Collapse
|
13
|
Benoit I, Di Curzio D, Civetta A, Douville RN. Drosophila as a Model for Human Viral Neuroinfections. Cells 2022; 11:cells11172685. [PMID: 36078091 PMCID: PMC9454636 DOI: 10.3390/cells11172685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 08/21/2022] [Accepted: 08/22/2022] [Indexed: 11/16/2022] Open
Abstract
The study of human neurological infection faces many technical and ethical challenges. While not as common as mammalian models, the use of Drosophila (fruit fly) in the investigation of virus–host dynamics is a powerful research tool. In this review, we focus on the benefits and caveats of using Drosophila as a model for neurological infections and neuroimmunity. Through the examination of in vitro, in vivo and transgenic systems, we highlight select examples to illustrate the use of flies for the study of exogenous and endogenous viruses associated with neurological disease. In each case, phenotypes in Drosophila are compared to those in human conditions. In addition, we discuss antiviral drug screening in flies and how investigating virus–host interactions may lead to novel antiviral drug targets. Together, we highlight standardized and reproducible readouts of fly behaviour, motor function and neurodegeneration that permit an accurate assessment of neurological outcomes for the study of viral infection in fly models. Adoption of Drosophila as a valuable model system for neurological infections has and will continue to guide the discovery of many novel virus–host interactions.
Collapse
Affiliation(s)
- Ilena Benoit
- Department of Biology, University of Winnipeg, 599 Portage Avenue, Winnipeg, MB R3B 2G3, Canada
- Division of Neurodegenerative Disorders, St. Boniface Hospital Albrechtsen Research Centre, 351 Taché Ave, Winnipeg, MB R2H 2A6, Canada
| | - Domenico Di Curzio
- Division of Neurodegenerative Disorders, St. Boniface Hospital Albrechtsen Research Centre, 351 Taché Ave, Winnipeg, MB R2H 2A6, Canada
| | - Alberto Civetta
- Department of Biology, University of Winnipeg, 599 Portage Avenue, Winnipeg, MB R3B 2G3, Canada
| | - Renée N. Douville
- Department of Biology, University of Winnipeg, 599 Portage Avenue, Winnipeg, MB R3B 2G3, Canada
- Division of Neurodegenerative Disorders, St. Boniface Hospital Albrechtsen Research Centre, 351 Taché Ave, Winnipeg, MB R2H 2A6, Canada
- Correspondence:
| |
Collapse
|
14
|
Cerqueira de Araujo A, Huguet E, Herniou EA, Drezen JM, Josse T. Transposable element repression using piRNAs, and its relevance to endogenous viral elements (EVEs) and immunity in insects. CURRENT OPINION IN INSECT SCIENCE 2022; 50:100876. [PMID: 35065285 DOI: 10.1016/j.cois.2022.100876] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 01/07/2022] [Accepted: 01/13/2022] [Indexed: 06/14/2023]
Abstract
The piRNA system controls transposable element (TE) mobility by transcriptional gene silencing and post-transcriptional gene silencing. Dispersed in insect genomes, piRNA clusters contain TE copies, from which they produce piRNAs (specific small RNAs). These piRNAs can both target the nascent transcripts produced by active TE copies and directly repress them by heterochromatinization. They can also target mature transcripts and cleave them following amplification by the so-called 'ping-pong' loop mechanism. Moreover, piRNA clusters contain endogenous viral elements (EVEs), from which they produce piRNAs. The current idea is that these piRNAs could participate in the antiviral response against exogenous viral infection. In this review, we show that among insects, to date, this antiviral response by the piRNA system appears mainly restricted to mosquitoes, but this could be due to the focus of most studies on arboviruses.
Collapse
Affiliation(s)
- Alexandra Cerqueira de Araujo
- Institut de Recherche sur la Biologie de l'Insecte (IRBI), UMR 7261, CNRS - Université de Tours, 37200 Tours, France
| | - Elisabeth Huguet
- Institut de Recherche sur la Biologie de l'Insecte (IRBI), UMR 7261, CNRS - Université de Tours, 37200 Tours, France
| | - Elisabeth A Herniou
- Institut de Recherche sur la Biologie de l'Insecte (IRBI), UMR 7261, CNRS - Université de Tours, 37200 Tours, France
| | - Jean-Michel Drezen
- Institut de Recherche sur la Biologie de l'Insecte (IRBI), UMR 7261, CNRS - Université de Tours, 37200 Tours, France
| | - Thibaut Josse
- Institut de Recherche sur la Biologie de l'Insecte (IRBI), UMR 7261, CNRS - Université de Tours, 37200 Tours, France.
| |
Collapse
|
15
|
Antiviral RNAi Response against the Insect-Specific Agua Salud Alphavirus. mSphere 2022; 7:e0100321. [PMID: 35171691 PMCID: PMC8849343 DOI: 10.1128/msphere.01003-21] [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] [Indexed: 11/20/2022] Open
Abstract
Arboviruses transmitted by mosquitoes are responsible for the death of millions of people each year. In addition to arboviruses, many insect-specific viruses (ISVs) have been discovered in mosquitoes in the last decade. ISVs, in contrast to arboviruses transmitted by mosquitoes to vertebrates, cannot replicate in vertebrate cells even when they are evolutionarily closely related to arboviruses. The alphavirus genus includes many arboviruses, although only a few ISVs have been discovered from this genus so far. Here, we investigate the interactions of a recently isolated insect-specific alphavirus, Agua Salud alphavirus (ASALV), with its mosquito host. RNA interference (RNAi) is one of the essential antiviral responses against arboviruses, although there is little knowledge on the interactions of RNAi with ISVs. Through the knockdown of transcripts of the different key RNAi pathway (small interfering RNA [siRNA], microRNA [miRNA], and P-element-induced wimpy testis [PIWI]-interacting RNA [piRNA]) proteins, we show the antiviral role of Ago2 (siRNA), Ago1 (miRNA), and Piwi4 proteins against ASALV in Aedes aegypti-derived cells. ASALV replication was increased in Dicer2 and Ago2 knockout cells, confirming the antiviral role of the siRNA pathway. In infected cells, mainly ASALV-specific siRNAs are produced, while piRNA-like small RNAs, with the characteristic nucleotide bias resulting from ping-pong amplification, are produced only in Dicer2 knockout cells. Taken together, ASALV interactions with the mosquito RNAi response differ from those of arthropod-borne alphaviruses in some aspects, although they also share some commonalities. Further research is needed to understand whether the identified differences can be generalized to other insect-specific alphaviruses. IMPORTANCE Mosquitoes are efficient vectors for many arboviruses that cause emergent infectious diseases in humans. Many insect-specific viruses (ISVs) that can infect mosquitoes but cannot infect vertebrates have been discovered in the last decade. ISVs have attracted great attention due to their potential use in mosquito or arbovirus control, by either decreasing mosquito fitness or restricting arbovirus replication and transmission to humans. However, ISV-mosquito interactions are not well understood. RNA interference (RNAi) is the most important innate immune response against many arboviruses, while it is unknown if it is antiviral against ISVs. Here, we investigate in detail the antiviral effect of the RNAi response in mosquitoes against an ISV for the first time. Using a recently isolated insect-specific alphavirus, we show that the regulation of virus replication was different from that for arthropod-borne alphaviruses despite some similarities. The differences in mosquito-virus interactions could drive the different transmission modes, which could eventually drive the evolution of arboviruses. Hence, an understanding of mosquito-ISV interactions can shed light on the ecology and evolution of both ISVs and the medically important arboviruses.
Collapse
|
16
|
Chikungunya virus non-structural protein nsP3 interacts with Aedes aegypti DEAD-box helicase RM62F. Virusdisease 2021; 32:657-665. [PMID: 34901322 DOI: 10.1007/s13337-021-00734-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Accepted: 07/22/2021] [Indexed: 10/20/2022] Open
Abstract
The non-structural proteins (nsPs) of the chikungunya virus (CHIKV) form the virus's replication complex. They are known to participate in several functions that allow efficient replication of the virus in diverse host systems. One such function is evading the host defense system such as RNA interference (RNAi). Two nsPs of CHIKV, namely, nsP2 and nsP3, were found to suppress the host/vector RNAi machinery and exhibit RNAi suppressor activity. The present study was undertaken to identify interacting partners of CHIKV-nsP3 in Aedes aegypti. We performed pull-down assays with the mass spectrometry approach and showed the interaction of CHIKV-nsP3 with several Aedes proteins. Further co-immunoprecipitation assays revealed that CHIKV-nsP3 interacts with RM62F, a DEAD-box containing RNA known to play roles in multiple gene regulatory processes such as alternative splicing, RNA release, and also is a component of Ago2-RISC complex. Supplementary Information The online version contains supplementary material available at 10.1007/s13337-021-00734-y.
Collapse
|
17
|
NO Synthesis in Immune-Challenged Locust Hemocytes and Potential Signaling to the CNS. INSECTS 2021; 12:insects12100951. [PMID: 34680720 PMCID: PMC8539611 DOI: 10.3390/insects12100951] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 10/13/2021] [Accepted: 10/15/2021] [Indexed: 01/22/2023]
Abstract
Simple Summary Insects, in the same way as vertebrates, are exposed to a broad variety of pathogens but lack their adaptive immune system. Relying on their innate immune system, they respond to pathogens by phagocytosis, melanization, and the synthesis of antimicrobial or cytotoxic compounds. In this study, we evaluated the production of the cytotoxic gaseous radical nitric oxide (NO) in hemocytes, the immune cells of the model insect Locusta migratoria in response to various immune stimuli. Both sessile and circulating hemocytes responded to gram-negative Escherichia coli and gram-positive Streptococcus suis injection with a strong increase in NO production. In contrast, the gram-positive bacterium Staphylococcus aureus elicited only a minor response. In addition, bacteria were encapsulated by hemocytes. Since NO is an important neurotransmitter, NO-producing hemocytes were tested on the locust central nervous system (CNS) in an embryo culture model. CNS neurons responded with a distinct increase in production of the second messenger, cGMP. This is indicative of the influence of the immune response on the CNS. Our findings show that NO production in hemocytes and capsule formation need complex stimuli and contribute to the understanding of neuroimmune interactions in insects. Abstract Similar to vertebrates, insects are exposed to a broad variety of pathogens. The innate insect immune system provides several response mechanisms such as phagocytosis, melanization, and the synthesis of antimicrobial or cytotoxic compounds. The cytotoxic nitric oxide (NO), which is also a neurotransmitter, is involved in the response to bacterial infections in various insects but has rarely been shown to be actually produced in hemocytes. We quantified the NO production in hemocytes of Locusta migratoria challenged with diverse immune stimuli by immunolabeling the by-product of NO synthesis, citrulline. Whereas in untreated adult locusts less than 5% of circulating hemocytes were citrulline-positive, the proportion rose to over 40% after 24 hours post injection of heat-inactivated bacteria. Hemocytes surrounded and melanized bacteria in locust nymphs by forming capsules. Such sessile hemocytes also produced NO. As in other insect species, activated hemocytes were found dorsally, close to the heart. In addition, we frequently observed citrulline-positive hemocytes and capsules near the ventral nerve cord. Neurites in the CNS of sterile locust embryos responded with elevation of the second messenger cGMP after contact with purified adult NO-producing hemocytes as revealed by immunofluorescence. We suggest that hemocytes can mediate a response in the CNS of an infected animal via the NO/cGMP signaling pathway.
Collapse
|
18
|
Rosendo Machado S, van der Most T, Miesen P. Genetic determinants of antiviral immunity in dipteran insects - Compiling the experimental evidence. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2021; 119:104010. [PMID: 33476667 DOI: 10.1016/j.dci.2021.104010] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 01/08/2021] [Accepted: 01/09/2021] [Indexed: 06/12/2023]
Abstract
The genetic basis of antiviral immunity in dipteran insects is extensively studied in Drosophila melanogaster and advanced technologies for genetic manipulation allow a better characterization of immune responses also in non-model insect species. Especially, immunity in vector mosquitoes is recently in the spotlight, due to the medical impact that these insects have by transmitting viruses and other pathogens. Here, we review the current state of experimental evidence that supports antiviral functions for immune genes acting in different cellular pathways. We discuss the well-characterized RNA interference mechanism along with the less well-defined JAK-STAT, Toll, and IMD signaling pathways. Furthermore, we highlight the initial evidence for antiviral activity observed for the autophagy pathway, transcriptional pausing, as well as piRNA production from endogenous viral elements. We focus our review on studies from Drosophila and mosquito species from the lineages Aedes, Culex, and Anopheles, which contain major vector species responsible for virus transmission.
Collapse
Affiliation(s)
- Samara Rosendo Machado
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Nijmegen Medical Center, P.O. Box 9101, 6500 HB, Nijmegen, the Netherlands
| | - Tom van der Most
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Nijmegen Medical Center, P.O. Box 9101, 6500 HB, Nijmegen, the Netherlands
| | - Pascal Miesen
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Nijmegen Medical Center, P.O. Box 9101, 6500 HB, Nijmegen, the Netherlands.
| |
Collapse
|
19
|
Rift Valley fever virus detection in susceptible hosts with special emphasis in insects. Sci Rep 2021; 11:9822. [PMID: 33972596 PMCID: PMC8110843 DOI: 10.1038/s41598-021-89226-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 04/15/2021] [Indexed: 11/09/2022] Open
Abstract
Rift Valley fever phlebovirus (RVFV, Phenuiviridae) is an emerging arbovirus that can cause potentially fatal disease in many host species including ruminants and humans. Thus, tools to detect this pathogen within tissue samples from routine diagnostic investigations or for research purposes are of major interest. This study compares the immunohistological usefulness of several mono- and polyclonal antibodies against RVFV epitopes in tissue samples derived from natural hosts of epidemiologic importance (sheep), potentially virus transmitting insect species (Culex quinquefasciatus, Aedes aegypti) as well as scientific infection models (mouse, Drosophila melanogaster, C6/36 cell pellet). While the nucleoprotein was the epitope most prominently detected in mammal and mosquito tissue samples, fruit fly tissues showed expression of glycoproteins only. Antibodies against non-structural proteins exhibited single cell reactions in salivary glands of mosquitoes and the C6/36 cell pellet. However, as single antibodies exhibited a cross reactivity of varying degree in non-infected specimens, a careful interpretation of positive reactions and consideration of adequate controls remains of critical importance. The results suggest that primary antibodies directed against viral nucleoproteins and glycoproteins can facilitate RVFV detection in mammals and insects, respectively, and therefore will allow RVFV detection for diagnostic and research purposes.
Collapse
|
20
|
Cheng L, Liu WL, Tsou YT, Li JC, Chien CH, Su MP, Liu KL, Huang YL, Wu SC, Tsai JJ, Hsieh SL, Chen CH. Transgenic Expression of Human C-Type Lectin Protein CLEC18A Reduces Dengue Virus Type 2 Infectivity in Aedes aegypti. Front Immunol 2021; 12:640367. [PMID: 33767710 PMCID: PMC7985527 DOI: 10.3389/fimmu.2021.640367] [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: 12/11/2020] [Accepted: 02/17/2021] [Indexed: 01/15/2023] Open
Abstract
The C-type lectins, one family of lectins featuring carbohydrate binding domains which participate in a variety of bioprocesses in both humans and mosquitoes, including immune response, are known to target DENV. A human C-type lectin protein CLEC18A in particular shows extensive glycan binding abilities and correlates with type-I interferon expression, making CLEC18A a potential player in innate immune responses to DENV infection; this potential may provide additional regulatory point in improving mosquito immunity. Here, we established for the first time a transgenic Aedes aegypti line that expresses human CLEC18A. This expression enhanced the Toll immune pathway responses to DENV infection. Furthermore, viral genome and virus titers were reduced by 70% in the midgut of transgenic mosquitoes. We found significant changes in the composition of the midgut microbiome in CLEC18A expressing mosquitoes, which may result from the Toll pathway enhancement and contribute to DENV inhibition. Transgenic mosquito lines offer a compelling option for studying DENV pathogenesis, and our analyses indicate that modifying the mosquito immune system via expression of a human immune gene can significantly reduce DENV infection.
Collapse
Affiliation(s)
- Lie Cheng
- National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Miaoli, Taiwan.,Tropical Medicine Center, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
| | - Wei-Liang Liu
- National Mosquito-Borne Diseases Control Research Center, National Health Research Institutes, Miaoli, Taiwan
| | - Yun-Ting Tsou
- Institute of Microbiology and Immunology, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Jian-Chiuan Li
- National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Miaoli, Taiwan
| | - Chia-Hao Chien
- Institute of Molecular and Genomic Medicine, National Health Research Institutes, Miaoli, Taiwan
| | - Matthew P Su
- Department of Biological Science, Nagoya University, Nagoya, Japan
| | - Kun-Lin Liu
- National Mosquito-Borne Diseases Control Research Center, National Health Research Institutes, Miaoli, Taiwan
| | - Ya-Lang Huang
- Genomics Research Center, Academia Sinica, Taipei, Taiwan
| | - Shih-Cheng Wu
- National Mosquito-Borne Diseases Control Research Center, National Health Research Institutes, Miaoli, Taiwan
| | - Jih-Jin Tsai
- Tropical Medicine Center, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.,Division of Infectious Diseases, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.,School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Shie-Liang Hsieh
- Genomics Research Center, Academia Sinica, Taipei, Taiwan.,Institute of Clinical Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan.,Department of Medical Research, Taipei Veterans General Hospital, Taipei, Taiwan.,Institute for Cancer Biology and Drug Discovery, Taipei Medical University, Taipei, Taiwan
| | - Chun-Hong Chen
- National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Miaoli, Taiwan.,National Mosquito-Borne Diseases Control Research Center, National Health Research Institutes, Miaoli, Taiwan
| |
Collapse
|
21
|
Núñez AI, Esteve-Codina A, Gómez-Garrido J, Brustolin M, Talavera S, Berdugo M, Dabad M, Alioto T, Bensaid A, Busquets N. Alteration in the Culex pipiens transcriptome reveals diverse mechanisms of the mosquito immune system implicated upon Rift Valley fever phlebovirus exposure. PLoS Negl Trop Dis 2020; 14:e0008870. [PMID: 33301456 PMCID: PMC7755283 DOI: 10.1371/journal.pntd.0008870] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 12/22/2020] [Accepted: 10/10/2020] [Indexed: 01/02/2023] Open
Abstract
Rift Valley fever phlebovirus (RVFV) causes an emerging zoonotic disease and is mainly transmitted by Culex and Aedes mosquitoes. While Aedes aegypti-dengue virus (DENV) is the most studied model, less is known about the genes involved in infection-responses in other mosquito-arboviruses pairing. The main objective was to investigate the molecular responses of Cx. pipiens to RVFV exposure focusing mainly on genes implicated in innate immune responses. Mosquitoes were fed with blood spiked with RVFV. The fully-engorged females were pooled at 3 different time points: 2 hours post-exposure (hpe), 3- and 14-days post-exposure (dpe). Pools of mosquitoes fed with non-infected blood were also collected for comparisons. Total RNA from each mosquito pool was subjected to RNA-seq analysis and a de novo transcriptome was constructed. A total of 451 differentially expressed genes (DEG) were identified. Most of the transcriptomic alterations were found at an early infection stage after RVFV exposure. Forty-eight DEG related to immune infection-response were characterized. Most of them were related with the RNAi system, Toll and IMD pathways, ubiquitination pathway and apoptosis. Our findings provide for the first time a comprehensive view on Cx. pipiens-RVFV interactions at the molecular level. The early depletion of RNAi pathway genes at the onset of the RVFV infection would allow viral replication in mosquitoes. While genes from the Toll and IMD immune pathways were altered in response to RVFV none of the DEG were related to the JAK/STAT pathway. The fact that most of the DEG involved in the Ubiquitin-proteasome pathway (UPP) or apoptosis were found at an early stage of infection would suggest that apoptosis plays a regulatory role in infected Cx. pipiens midguts. This study provides a number of target genes that could be used to identify new molecular targets for vector control.
Collapse
Affiliation(s)
- Ana I. Núñez
- IRTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA-UAB), Campus de la Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - Anna Esteve-Codina
- CNAG-CRG, Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Barcelona, Catalonia, Spain
| | - Jèssica Gómez-Garrido
- CNAG-CRG, Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Barcelona, Catalonia, Spain
| | - Marco Brustolin
- IRTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA-UAB), Campus de la Universitat Autònoma de Barcelona, Bellaterra, Spain
- Department of Entomology, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Sandra Talavera
- IRTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA-UAB), Campus de la Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - Miguel Berdugo
- Instituto de Biología Evolutiva, Universitat Pompeu i Fabra-CSIC, Dr. Aigüader 88, Barcelona, Spain
| | - Marc Dabad
- CNAG-CRG, Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Barcelona, Catalonia, Spain
| | - Tyler Alioto
- CNAG-CRG, Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Barcelona, Catalonia, Spain
- Universitat Pompeu i Fabra (UPF), Barcelona, Catalonia, Spain
| | - Albert Bensaid
- IRTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA-UAB), Campus de la Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - Núria Busquets
- IRTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA-UAB), Campus de la Universitat Autònoma de Barcelona, Bellaterra, Spain
| |
Collapse
|
22
|
Endogenous Viral Element-Derived Piwi-Interacting RNAs (piRNAs) Are Not Required for Production of Ping-Pong-Dependent piRNAs from Diaphorina citri Densovirus. mBio 2020; 11:mBio.02209-20. [PMID: 32994324 PMCID: PMC7527727 DOI: 10.1128/mbio.02209-20] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Piwi-interacting RNAs (piRNAs) are a class of small RNAs primarily responsible for silencing transposons in the animal germ line. The ping-pong cycle, the posttranscriptional silencing branch of the piRNA pathway, relies on piRNAs produced from endogenous transposon remnants to direct cleavage of transposon RNA via association with Piwi-family Argonaute proteins. In some mosquito species and mosquito-derived cell lines expressing a functionally expanded group of Piwi-family Argonaute proteins, both RNA and DNA viruses are targeted by piRNAs in a manner thought to involve direct processing of exogenous viral RNA into piRNAs. Whether viruses are targeted by piRNAs in nonmosquito species is unknown. Partial integrations of DNA and nonretroviral RNA virus genomes, termed endogenous viral elements (EVEs), are abundant in arthropod genomes and often produce piRNAs that are speculated to target cognate viruses through the ping-pong cycle. Here, we describe a Diaphorina citri densovirus (DcDV)-derived EVE in the genome of Diaphorina citri We found that this EVE gives rise to DcDV-specific primary piRNAs and is unevenly distributed among D. citri populations. Unexpectedly, we found that DcDV is targeted by ping-pong-dependent virus-derived piRNAs (vpiRNAs) in D. citri lacking the DcDV-derived EVE, while four naturally infecting RNA viruses of D. citri are not targeted by vpiRNAs. Furthermore, a recombinant Cricket paralysis virus containing a portion of the DcDV genome corresponding to the DcDV-derived EVE was not targeted by vpiRNAs during infection in D. citri harboring the EVE. These results demonstrate that viruses can be targeted by piRNAs in a nonmosquito species independently of endogenous piRNAs.IMPORTANCE Small RNAs serve as specificity determinants of antiviral responses in insects. Piwi-interacting RNAs (piRNAs) are a class of small RNAs found in animals, and their primary role is to direct antitransposon responses. These responses require endogenous piRNAs complementary to transposon RNA. Additionally, piRNAs have been shown to target RNA and DNA viruses in some mosquito species. In contrast to transposons, targeting of viruses by the piRNA pathway in these mosquito species does not require endogenous piRNAs. Here, we show that piRNAs target a DNA virus, but not RNA viruses, in an agricultural insect pest. We found that targeting of this DNA virus did not require endogenous piRNAs and that endogenous piRNAs did not mediate targeting of an RNA virus with which they shared complementary sequence. Our results highlight differences between mosquitoes and our experimental system and raise the possibility that DNA viruses may be targeted by piRNAs in other species.
Collapse
|
23
|
Li T, Xia Y, Xu X, Wei G, Wang L. Functional analysis of Dicer-2 gene in Bombyx mori resistance to BmNPV virus. ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2020; 105:e21724. [PMID: 32623793 DOI: 10.1002/arch.21724] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Revised: 06/22/2020] [Accepted: 06/23/2020] [Indexed: 06/11/2023]
Abstract
Bombyx mori nucleopolyhedrovirus (BmNPV) is a primary pathogen in silkworm, and the molecular mechanism of B. mori defense to BmNPV infection is still unclear. RNA interference (RNAi) is well-known as an intracellular conserved mechanism that is critical in gene regulation and cell defense. The antiviral RNAi pathway processes viral double-stranded RNA (dsRNA) into viral small interfering RNAs that guide the recognition and cleavage of complementary viral target RNAs. In this study, a Dicer-2 (Dcr2) gene was identified in B. mori and its antiviral function was explored. Dcr2 messenger RNA (mRNA) expression was the highest in hemocytes and expressed in all stages of silkworm growth. After infection with BmNPV, the expression of Dcr2 mRNA was significantly increased after infection in midgut and hemocytes. The expression of Dcr2 was significantly upregulated by injecting dsRNA (dsBmSPH-1) into silkworm after 48 hr. Knocking down the expression level of Dcr2 using specific dsRNA in silkworm, which modestly enhanced the production of viral genomic DNA. Our results suggested that the Dcr2 gene in B. mori plays an important role in against BmNPV invasion.
Collapse
Affiliation(s)
- Taohong Li
- School of Life Science, Anhui Agricultural University, Hefei, China
| | - Yuchen Xia
- School of Life Science, Anhui Agricultural University, Hefei, China
| | - Xinyue Xu
- School of Life Science, Anhui Agricultural University, Hefei, China
| | - Guoqing Wei
- School of Life Science, Anhui Agricultural University, Hefei, China
| | - Lei Wang
- School of Life Science, Anhui Agricultural University, Hefei, China
| |
Collapse
|
24
|
aBravo Is a Novel Aedes aegypti Antiviral Protein that Interacts with, but Acts Independently of, the Exogenous siRNA Pathway Effector Dicer 2. Viruses 2020; 12:v12070748. [PMID: 32664591 PMCID: PMC7411624 DOI: 10.3390/v12070748] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 07/03/2020] [Accepted: 07/08/2020] [Indexed: 12/12/2022] Open
Abstract
Mosquitoes, such as Aedes aegypti, can transmit arboviruses to humans. The exogenous short interfering RNA (exo-siRNA) pathway plays a major antiviral role in controlling virus infection in mosquito cells. The Dicer 2 (Dcr2) nuclease is a key effector protein in this pathway, which cleaves viral double-stranded RNA into virus-derived siRNAs that are further loaded onto an effector called Argonaute 2 (Ago2), which as part of the multiprotein RNA-induced silencing complex (RISC) targets and cleaves viral RNA. In order to better understand the effector protein Dcr2, proteomics experiments were conducted to identify interacting cellular partners. We identified several known interacting partners including Ago2, as well as two novel and previously uncharacterized Ae. aegypti proteins. The role of these two proteins was further investigated, and their interactions with Dcr2 verified by co-immunoprecipitation. Interestingly, despite their ability to interact with Ago2 and Piwi4, neither of these proteins was found to affect exo-siRNA silencing in a reporter assay. However, one of these proteins, Q0IFK9, subsequently called aBravo (aedine broadly active antiviral protein), was found to mediate antiviral activity against positive strand RNA arboviruses. Intriguingly the presence of Dcr2 was not necessary for this effect, suggesting that this interacting antiviral effector may act as part of protein complexes with potentially separate antiviral activities.
Collapse
|
25
|
Parry R, Naccache F, Ndiaye EH, Fall G, Castelli I, Lühken R, Medlock J, Cull B, Hesson JC, Montarsi F, Failloux AB, Kohl A, Schnettler E, Diallo M, Asgari S, Dietrich I, Becker SC. Identification and RNAi Profile of a Novel Iflavirus Infecting Senegalese Aedes vexans arabiensis Mosquitoes. Viruses 2020; 12:E440. [PMID: 32295109 PMCID: PMC7232509 DOI: 10.3390/v12040440] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2020] [Revised: 04/10/2020] [Accepted: 04/11/2020] [Indexed: 01/16/2023] Open
Abstract
The inland floodwater mosquito Aedes vexans (Meigen, 1830) is a competent vector of numerous arthropod-borne viruses such as Rift Valley fever virus (Phenuiviridae) and Zika virus (Flaviviridae). Aedes vexans spp. have widespread Afrotropical distribution and are common European cosmopolitan mosquitoes. We examined the virome of Ae. vexans arabiensis samples from Barkédji village, Senegal, with small RNA sequencing, bioinformatic analysis, and RT-PCR screening. We identified a novel 9494 nt iflavirus (Picornaviridae) designated here as Aedes vexans iflavirus (AvIFV). Annotation of the AvIFV genome reveals a 2782 amino acid polyprotein with iflavirus protein domain architecture and typical iflavirus 5' internal ribosomal entry site and 3' poly-A tail. Aedes vexans iflavirus is most closely related to a partial virus sequence from Venturia canescens (a parasitoid wasp) with 56.77% pairwise amino acid identity. Analysis of AvIFV-derived small RNAs suggests that AvIFV is targeted by the exogenous RNA interference pathway but not the PIWI-interacting RNA response, as ~60% of AvIFV reads corresponded to 21 nt Dicer-2 virus-derived small RNAs and the 24-29 nt AvIFV read population did not exhibit a "ping-pong" signature. The RT-PCR screens of archival and current (circa 2011-2020) Ae. vexans arabiensis laboratory samples and wild-caught mosquitoes from Barkédji suggest that AvIFV is ubiquitous in these mosquitoes. Further, we screened wild-caught European Ae. vexans samples from Germany, the United Kingdom, Italy, and Sweden, all of which tested negative for AvIFV RNA. This report provides insight into the diversity of commensal Aedes viruses and the host RNAi response towards iflaviruses.
Collapse
Affiliation(s)
- Rhys Parry
- Australian Infectious Diseases Research Centre, School of Biological Sciences, The University of Queensland, Brisbane, QLD 4072, Australia; (R.P.); (S.A.)
| | - Fanny Naccache
- Institute for Parasitology, University of Veterinary Medicine Hannover, 30559 Hannover, Germany;
- Research Center for Emerging Infections and Zoonoses, University of Veterinary Medicine Hannover, 30559 Hannover, Germany
| | - El Hadji Ndiaye
- Pole de Zoologie Médicale, Institut Pasteur de Dakar, Dakar BP 220, Senegal; (E.H.N.); (M.D.)
| | - Gamou Fall
- Pole de Virologie, Unité des Arbovirus et Virus de Fièvres Hémorragiques, Institut Pasteur de Dakar, Dakar BP 220, Senegal;
| | - Ilaria Castelli
- Arboviruses and Insect Vectors, Department of Virology, Institut Pasteur, 75724 Paris, France; (I.C.); (A.-B.F.)
| | - Renke Lühken
- Faculty of Mathematics, Informatics and Natural Sciences, Universiät Hamburg, 20148 Hamburg, Germany; (R.L.); (E.S.)
- Bernhard-Nocht-Institute for Tropical Medicine, 20359 Hamburg, Germany
| | - Jolyon Medlock
- Health Protection Research Unit in Emerging and Zoonotic Infection, Public Health England, Porton Down, Salisbury SP4 0JG, UK;
- Medical Entomology & Zoonoses Ecology, Emergency Response Department Science & Technology, Public Health England, Porton Down, Salisbury SP4 0JG, UK; or
| | - Benjamin Cull
- Medical Entomology & Zoonoses Ecology, Emergency Response Department Science & Technology, Public Health England, Porton Down, Salisbury SP4 0JG, UK; or
| | - Jenny C. Hesson
- Department of Medical Biochemistry and Microbiology/Zoonosis Science Center, Uppsala University, 75237 Uppsala, Sweden;
| | - Fabrizio Montarsi
- Laboratory of Parasitology, Istituto Zooprofilattico Sperimentale delle Venezie, 35020 Legnaro (Padua), Italy;
| | - Anna-Bella Failloux
- Arboviruses and Insect Vectors, Department of Virology, Institut Pasteur, 75724 Paris, France; (I.C.); (A.-B.F.)
| | - Alain Kohl
- MRC-University of Glasgow Centre for Virus Research, Glasgow G61 1QH, UK;
| | - Esther Schnettler
- Faculty of Mathematics, Informatics and Natural Sciences, Universiät Hamburg, 20148 Hamburg, Germany; (R.L.); (E.S.)
- Bernhard-Nocht-Institute for Tropical Medicine, 20359 Hamburg, Germany
- German Centre for Infection Research, partner site Hamburg-Lübeck-Borstel-Riems, 20359 Hamburg, Germany
| | - Mawlouth Diallo
- Pole de Zoologie Médicale, Institut Pasteur de Dakar, Dakar BP 220, Senegal; (E.H.N.); (M.D.)
| | - Sassan Asgari
- Australian Infectious Diseases Research Centre, School of Biological Sciences, The University of Queensland, Brisbane, QLD 4072, Australia; (R.P.); (S.A.)
| | | | - Stefanie C. Becker
- Institute for Parasitology, University of Veterinary Medicine Hannover, 30559 Hannover, Germany;
- Research Center for Emerging Infections and Zoonoses, University of Veterinary Medicine Hannover, 30559 Hannover, Germany
| |
Collapse
|
26
|
McFarlane M, Almire F, Kean J, Donald CL, McDonald A, Wee B, Lauréti M, Varjak M, Terry S, Vazeille M, Gestuveo RJ, Dietrich I, Loney C, Failloux AB, Schnettler E, Pondeville E, Kohl A. The Aedes aegypti Domino Ortholog p400 Regulates Antiviral Exogenous Small Interfering RNA Pathway Activity and ago-2 Expression. mSphere 2020; 5:e00081-20. [PMID: 32269152 PMCID: PMC7142294 DOI: 10.1128/msphere.00081-20] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 03/13/2020] [Indexed: 02/03/2023] Open
Abstract
Arboviruses are pathogens of humans and animals. A better understanding of the interactions between these pathogens and the arthropod vectors, such as mosquitoes, that transmit them is necessary to develop novel control measures. A major antiviral pathway in the mosquito vector is the exogenous small interfering RNA (exo-siRNA) pathway, which is induced by arbovirus-derived double-stranded RNA in infected cells. Although recent work has shown the key role played by Argonaute-2 (Ago-2) and Dicer-2 (Dcr-2) in this pathway, the regulatory mechanisms that govern these pathways have not been studied in mosquitoes. Here, we show that the Domino ortholog p400 has antiviral activity against the alphavirus Semliki Forest virus (Togaviridae) both in Aedes aegypti-derived cells and in vivo Antiviral activity of p400 was also demonstrated against chikungunya virus (Togaviridae) and Bunyamwera virus (Peribunyaviridae) but not Zika virus (Flaviviridae). p400 was found to be expressed across mosquito tissues and regulated ago-2 but not dcr-2 transcript levels in A. aegypti mosquitoes. These findings provide novel insights into the regulation of an important aedine exo-siRNA pathway effector protein, Ago-2, by the Domino ortholog p400. They add functional insights to previous observations of this protein's antiviral and RNA interference regulatory activities in Drosophila melanogasterIMPORTANCE Female Aedes aegypti mosquitoes are vectors of human-infecting arthropod-borne viruses (arboviruses). In recent decades, the incidence of arthropod-borne viral infections has grown dramatically. Vector competence is influenced by many factors, including the mosquito's antiviral defenses. The exogenous small interfering RNA (siRNA) pathway is a major antiviral response restricting arboviruses in mosquitoes. While the roles of the effectors of this pathway, Argonaute-2 and Dicer-2 are well characterized, nothing is known about its regulation in mosquitoes. In this study, we demonstrate that A. aegypti p400, whose ortholog Domino in Drosophila melanogaster is a chromatin-remodeling ATPase member of the Tip60 complex, regulates siRNA pathway activity and controls ago-2 expression levels. In addition, we found p400 to have antiviral activity against different arboviruses. Therefore, our study provides new insights into the regulation of the antiviral response in A. aegypti mosquitoes.
Collapse
Affiliation(s)
- Melanie McFarlane
- MRC-University of Glasgow Centre for Virus Research, Glasgow, Scotland
| | - Floriane Almire
- MRC-University of Glasgow Centre for Virus Research, Glasgow, Scotland
| | - Joy Kean
- MRC-University of Glasgow Centre for Virus Research, Glasgow, Scotland
| | - Claire L Donald
- MRC-University of Glasgow Centre for Virus Research, Glasgow, Scotland
| | - Alma McDonald
- MRC-University of Glasgow Centre for Virus Research, Glasgow, Scotland
| | - Bryan Wee
- Usher Institute for Population Health Sciences & Informatics, University of Edinburgh, Edinburgh, United Kingdom
| | - Mathilde Lauréti
- MRC-University of Glasgow Centre for Virus Research, Glasgow, Scotland
| | - Margus Varjak
- MRC-University of Glasgow Centre for Virus Research, Glasgow, Scotland
| | - Sandra Terry
- MRC-University of Glasgow Centre for Virus Research, Glasgow, Scotland
| | - Marie Vazeille
- Arboviruses and Insect Vectors Unit, Department of Virology, Institut Pasteur, Paris, France
| | - Rommel J Gestuveo
- MRC-University of Glasgow Centre for Virus Research, Glasgow, Scotland
- Division of Biological Sciences, University of the Philippines Visayas, Miagao, Philippines
| | - Isabelle Dietrich
- MRC-University of Glasgow Centre for Virus Research, Glasgow, Scotland
| | - Colin Loney
- MRC-University of Glasgow Centre for Virus Research, Glasgow, Scotland
| | - Anna-Bella Failloux
- Arboviruses and Insect Vectors Unit, Department of Virology, Institut Pasteur, Paris, France
| | - Esther Schnettler
- MRC-University of Glasgow Centre for Virus Research, Glasgow, Scotland
| | - Emilie Pondeville
- MRC-University of Glasgow Centre for Virus Research, Glasgow, Scotland
| | - Alain Kohl
- MRC-University of Glasgow Centre for Virus Research, Glasgow, Scotland
| |
Collapse
|
27
|
Abstract
Protection against microbial infection in eukaryotes is provided by diverse cellular and molecular mechanisms. Here, we present a comparative view of the antiviral activity of virus-derived small interfering RNAs in fungi, plants, invertebrates and mammals, detailing the mechanisms for their production, amplification and activity. We also highlight the recent discovery of viral PIWI-interacting RNAs in animals and a new role for mobile host and pathogen small RNAs in plant defence against eukaryotic pathogens. In turn, viruses that infect plants, insects and mammals, as well as eukaryotic pathogens of plants, have evolved specific virulence proteins that suppress RNA interference (RNAi). Together, these advances suggest that an antimicrobial function of the RNAi pathway is conserved across eukaryotic kingdoms.
Collapse
|
28
|
Blair CD. Deducing the Role of Virus Genome-Derived PIWI-Associated RNAs in the Mosquito-Arbovirus Arms Race. Front Genet 2019; 10:1114. [PMID: 31850054 PMCID: PMC6901949 DOI: 10.3389/fgene.2019.01114] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Accepted: 10/16/2019] [Indexed: 01/26/2023] Open
Abstract
The P-element-induced wimpy testis (PIWI)-associated RNA (piRNA) pathway is known for its role in the protection of genome integrity in the germline of Drosophila melanogaster by silencing transposable elements. The piRNAs that target transposons originate from piRNA clusters in transposon-rich regions of the Drosophila genome and are processed by three PIWI family proteins. In Aedes aegypti and Aedes albopictus mosquitoes, which are two of the most important vectors of arthropod-borne viruses (arboviruses), the number of PIWI family genes has expanded and some are expressed in somatic, as well as germline, tissues. These discoveries have led to active research to explore the possible expanded functional roles of the piRNA pathway in vector mosquitoes. Virus genome-derived piRNAs (which will be referred to as (virus name) vpiRNAs) have been demonstrated in Aedes spp. cultured cells and mosquitoes after infection by arthropod-borne alpha-, bunya-, and flaviviruses. However, although Culex quinquefasciatus also is an important arbovirus vector and has an expansion of PIWI family genes, vpiRNAs have seldom been documented in this genus after arbovirus infection. Generation of complementary DNA (cDNA) fragments from RNA genomes of alpha-, bunya-, and flaviviruses (viral-derived cDNAs, vDNAs) has been demonstrated in cultured Aedes spp. cells and mosquitoes, and endogenous viral elements (EVEs), cDNA fragments of non-retroviral RNA virus genomes, are found more abundantly in genomes of Ae. aegypti and Ae. albopictus than other vector mosquitoes. These observations have led to speculation that vDNAs are integrated into vector genomes to form EVEs, which serve as templates for the transcription of antiviral vpiRNA precursors. However, no EVEs derived from alphavirus genomes have been demonstrated in genomes of any vector mosquito. In addition, although EVEs have been shown to be a source of piRNAs, the preponderance of EVEs described in Aedes spp. vectors are more closely related to the genomes of persistently infecting insect-specific viruses than to acutely infecting arboviruses. Furthermore, the signature patterns of the “ping-pong” amplification cycle that maintains transposon-targeting piRNAs in Drosophila are also evident in alphavirus and bunyavirus vpiRNAs, but not in vpiRNAs of flaviviruses. These divergent observations have rendered deciphering the mechanism(s) of biogenesis and potential role of vpiRNAs in the mosquito–arbovirus arms race difficult, and the focus of this review will be to assemble major findings regarding vpiRNAs and antiviral immunity in the important arbovirus vectors from Aedes and Culex genera.
Collapse
Affiliation(s)
- Carol D Blair
- Arthropod-borne and Infectious Diseases Laboratory, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO, United States
| |
Collapse
|
29
|
Tassetto M, Kunitomi M, Whitfield ZJ, Dolan PT, Sánchez-Vargas I, Garcia-Knight M, Ribiero I, Chen T, Olson KE, Andino R. Control of RNA viruses in mosquito cells through the acquisition of vDNA and endogenous viral elements. eLife 2019; 8:41244. [PMID: 31621580 PMCID: PMC6797480 DOI: 10.7554/elife.41244] [Citation(s) in RCA: 80] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2018] [Accepted: 09/10/2019] [Indexed: 01/02/2023] Open
Abstract
Aedes aegypti transmit pathogenic arboviruses while the mosquito itself tolerates the infection. We examine a piRNA-based immunity that relies on the acquisition of viral derived cDNA (vDNA) and how this pathway discriminates between self and non-self. The piRNAs derived from these vDNAs are essential for virus control and Piwi4 has a central role in the pathway. Piwi4 binds preferentially to virus-derived piRNAs but not to transposon-targeting piRNAs. Analysis of episomal vDNA from infected cells reveals that vDNA molecules are acquired through a discriminatory process of reverse-transcription and recombination directed by endogenous retrotransposons. Using a high-resolution Ae. aegypti genomic sequence, we found that vDNAs integrated in the host genome as endogenous viral elements (EVEs), produce antisense piRNAs that are preferentially loaded onto Piwi4. Importantly, EVE-derived piRNAs are specifically loaded onto Piwi4 to inhibit virus replication. Thus, Ae. aegypti employs a sophisticated antiviral mechanism that promotes viral persistence and generates long-lasting adaptive immunity.
Collapse
Affiliation(s)
- Michel Tassetto
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, United States
| | - Mark Kunitomi
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, United States
| | - Zachary J Whitfield
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, United States
| | - Patrick T Dolan
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, United States
| | - Irma Sánchez-Vargas
- Department of Microbiology, Immunology and Pathology, Arthropod-borne and Infectious Diseases Laboratory, Colorado State University, Fort Collins, United States
| | - Miguel Garcia-Knight
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, United States
| | - Isabel Ribiero
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, United States
| | - Taotao Chen
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, United States
| | - Ken E Olson
- Department of Microbiology, Immunology and Pathology, Arthropod-borne and Infectious Diseases Laboratory, Colorado State University, Fort Collins, United States
| | - Raul Andino
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, United States
| |
Collapse
|
30
|
Sun Y, Zhang Y, Zhang X. Synonymous SNPs of viral genes facilitate virus to escape host antiviral RNAi immunity. RNA Biol 2019; 16:1697-1710. [PMID: 31416386 DOI: 10.1080/15476286.2019.1656026] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
Synonymous single nucleotide polymorphisms (SNPs) are involved in codon usage preference or mRNA splicing. Up to date, however, the role of synonymous SNPs in immunity remains unclear. To address this issue, the SNPs of white spot syndrome virus (WSSV) were characterized in shrimp in the present study. Our results indicated that there existed synonymous SNPs in the mRNAs of wsv151 and wsv226, two viral genes of WSSV. In the presence of SNP siRNA, wild-type siRNA, wild-type mRNA and SNP mRNA of wsv151 or wsv226, RNAi was significantly suppressed, showing that the synonymous SNPs of wsv151 and wsv226 played negative roles in host siRNA pathway due to mismatch of siRNA with its target. In insect cells, the mismatch, caused by synonymous SNPs of wsv151 or wsv226, between siRNA and its target inhibited the host RNAi. Furthermore, the data revealed that the co-injection of SNP siRNA and wild-type siRNA of wsv151 or wsv226 into WSSV-infected shrimp led to a significant increase of WSSV copies compared with that of SNP siRNA alone or wild-type siRNA alone, indicating that the synonymous SNPs of viral genes could be a strategy of virus escaping host siRNA pathway in shrimp in vivo. Therefore, our study provided novel insights into the underlying mechanism of virus escaping host antiviral RNAi immunity by synonymous SNPs of viral genes.
Collapse
Affiliation(s)
- Yuechao Sun
- College of Life Sciences and Laboratory for Marine Biology and Biotechnology of Qingdao National Laboratory for Marine Science and Technology, Zhejiang University, Hangzhou, People's Republic of China
| | - Yu Zhang
- College of Life Sciences and Laboratory for Marine Biology and Biotechnology of Qingdao National Laboratory for Marine Science and Technology, Zhejiang University, Hangzhou, People's Republic of China
| | - Xiaobo Zhang
- College of Life Sciences and Laboratory for Marine Biology and Biotechnology of Qingdao National Laboratory for Marine Science and Technology, Zhejiang University, Hangzhou, People's Republic of China
| |
Collapse
|
31
|
Liu J, Swevers L, Kolliopoulou A, Smagghe G. Arboviruses and the Challenge to Establish Systemic and Persistent Infections in Competent Mosquito Vectors: The Interaction With the RNAi Mechanism. Front Physiol 2019; 10:890. [PMID: 31354527 PMCID: PMC6638189 DOI: 10.3389/fphys.2019.00890] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Accepted: 06/27/2019] [Indexed: 12/15/2022] Open
Abstract
Arboviruses are capable to establish long-term persistent infections in mosquitoes that do not affect significantly the physiology of the insect vectors. Arbovirus infections are controlled by the RNAi machinery via the production of viral siRNAs and the formation of RISC complexes targeting viral genomes and mRNAs. Engineered arboviruses that contain cellular gene sequences can therefore be transformed to "viral silencing vectors" for studies of gene function in reverse genetics approaches. More specifically, "ideal" viral silencing vectors must be competent to induce robust RNAi effects while other interactions with the host immune system should be kept at a minimum to reduce non-specific effects. Because of their inconspicuous nature, arboviruses may approach the "ideal" viral silencing vectors in insects and it is therefore worthwhile to study the mechanisms by which the interactions with the RNAi machinery occur. In this review, an analysis is presented of the antiviral RNAi response in mosquito vectors with respect to the major types of arboviruses (alphaviruses, flaviviruses, bunyaviruses, and others). With respect to antiviral defense, the exo-RNAi pathway constitutes the major mechanism while the contribution of both miRNAs and viral piRNAs remains a contentious issue. However, additional mechanisms exist in mosquitoes that are capable to enhance or restrict the efficiency of viral silencing vectors such as the amplification of RNAi effects by DNA forms, the existence of incorporated viral elements in the genome and the induction of a non-specific systemic response by Dicer-2. Of significance is the observation that no major "viral suppressors of RNAi" (VSRs) seem to be encoded by arboviral genomes, indicating that relatively tight control of the activity of the RNA-dependent RNA polymerase (RdRp) may be sufficient to maintain the persistent character of arbovirus infections. Major strategies for improvement of viral silencing vectors therefore are proposed to involve engineering of VSRs and modifying of the properties of the RdRp. Because of safety issues (pathogen status), however, arbovirus-based silencing vectors are not well suited for practical applications, such as RNAi-based mosquito control. In that case, related mosquito-specific viruses that also establish persistent infections and may cause similar RNAi responses may represent a valuable alternative solution.
Collapse
Affiliation(s)
- Jisheng Liu
- School of Life Sciences, Guangzhou University, Guangzhou, China
| | - Luc Swevers
- Institute of Biosciences and Applications, National Centre of Scientific Research “Demokritos”, Athens, Greece
| | - Anna Kolliopoulou
- Institute of Biosciences and Applications, National Centre of Scientific Research “Demokritos”, Athens, Greece
| | - Guy Smagghe
- Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| |
Collapse
|
32
|
Kolliopoulou A, Santos D, Taning CNT, Wynant N, Vanden Broeck J, Smagghe G, Swevers L. PIWI pathway against viruses in insects. WILEY INTERDISCIPLINARY REVIEWS-RNA 2019; 10:e1555. [PMID: 31183996 DOI: 10.1002/wrna.1555] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 05/06/2019] [Accepted: 05/07/2019] [Indexed: 12/26/2022]
Abstract
Piwi-interacting RNAs (piRNAs) are an animal-specific class of small non-coding RNAs that are generated via a biogenesis pathway distinct from small interfering RNAs (siRNAs) and microRNAs (miRNAs). There are variations in piRNA biogenesis that depend on several factors, such as the cell type (germline or soma), the organism, and the purpose for which they are being produced, such as transposon-targeting, viral-targeting, or gene-derived piRNAs. Interestingly, the genes involved in the PIWI/piRNA pathway are more rapidly evolving compared with other RNA interference (RNAi) genes. In this review, the role of the piRNA pathway in the antiviral response is reviewed based on recent findings in insect models such as Drosophila, mosquitoes, midges and the silkworm, Bombyx mori. We extensively discuss the special features that characterize host-virus piRNA responses with respect to the proteins and the genes involved, the viral piRNAs' sequence characteristics, the target strand orientation biases as well as the viral piRNA target hotspots across the viral genomes. This article is categorized under: Regulatory RNAs/RNAi/Riboswitches > RNAi: Mechanisms of Action Regulatory RNAs/RNAi/Riboswitches > Biogenesis of Effector Small RNAs.
Collapse
Affiliation(s)
- Anna Kolliopoulou
- Insect Molecular Genetics and Biotechnology, Institute of Biosciences and Applications, National Centre for Scientific Research "Demokritos", Athens, Greece
| | - Dulce Santos
- Molecular Developmental Physiology and Signal Transduction Research Group, Animal Physiology and Neurobiology Division, Department of Biology, KU Leuven, Leuven, Belgium
| | - Clauvis Nji Tizi Taning
- Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Niels Wynant
- Molecular Developmental Physiology and Signal Transduction Research Group, Animal Physiology and Neurobiology Division, Department of Biology, KU Leuven, Leuven, Belgium
| | - Jozef Vanden Broeck
- Molecular Developmental Physiology and Signal Transduction Research Group, Animal Physiology and Neurobiology Division, Department of Biology, KU Leuven, Leuven, Belgium
| | - Guy Smagghe
- Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Luc Swevers
- Insect Molecular Genetics and Biotechnology, Institute of Biosciences and Applications, National Centre for Scientific Research "Demokritos", Athens, Greece
| |
Collapse
|
33
|
Olmo RP, Martins NE, Aguiar ERGR, Marques JT, Imler JL. The insect reservoir of biodiversity for viruses and for antiviral mechanisms. AN ACAD BRAS CIENC 2019; 91 Suppl 3:e20190122. [PMID: 31166476 DOI: 10.1590/0001-3765201920190122] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 03/23/2019] [Indexed: 01/13/2023] Open
Abstract
Insects are the most diverse group of animals. They can be infected by an extraordinary diversity of viruses. Among them, arthropod-borne viruses (arboviruses) can be transmitted to humans. High-throughput sequencing of small RNAs from insects provides insight into their virome, which may help understand the dynamics of vector borne infectious diseases. Furthermore, investigating the mechanisms that restrict viral infections in insects points to genetic innovations that may inspire novel antiviral strategies.
Collapse
Affiliation(s)
- Roenick P Olmo
- Institut de Biologie Moléculaire et Cellulaire, Université de Strasbourg, Strasbourg, France
| | - Nelson Eduardo Martins
- Institut de Biologie Moléculaire et Cellulaire, Université de Strasbourg, Strasbourg, France
| | - Eric Roberto G R Aguiar
- Department of Biochemistry and Immunology, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - João T Marques
- Department of Biochemistry and Immunology, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Jean-Luc Imler
- Institut de Biologie Moléculaire et Cellulaire, Université de Strasbourg, Strasbourg, France
| |
Collapse
|
34
|
Rückert C, Prasad AN, Garcia-Luna SM, Robison A, Grubaugh ND, Weger-Lucarelli J, Ebel GD. Small RNA responses of Culex mosquitoes and cell lines during acute and persistent virus infection. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2019; 109:13-23. [PMID: 30959110 PMCID: PMC6516063 DOI: 10.1016/j.ibmb.2019.04.008] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Revised: 04/01/2019] [Accepted: 04/02/2019] [Indexed: 05/31/2023]
Abstract
RNA interference is a crucial antiviral mechanism in arthropods, including in mosquito vectors of arthropod-borne viruses (arboviruses). Although the exogenous small interfering RNA (siRNA) pathway constitutes an efficient antiviral response in mosquitoes, virus-derived P-element induced wimpy testis (PIWI)-interacting RNAs (piRNAs) have been implicated in the response to alpha-, bunya- and flaviviruses in Aedes spp. mosquitoes. Culex mosquitoes transmit several medically important viruses including West Nile virus (WNV), but are considerably less well studied than Aedes mosquitoes and little is known about antiviral RNA interference in Culex mosquitoes. Therefore, we sequenced small RNA (sRNA) libraries from different Culex cell lines and tissues infected with WNV. The clear majority of virus-derived sRNA reads were 21 nt siRNAs in all cell lines and tissues tested, with no evidence for a role of WNV-derived piRNAs. Additionally, we aligned sRNA reads from Culex quinquefasciatus Hsu cells to the insect-specific rhabdovirus, Merida virus, which persistently replicates in these cells. We found that a significant proportion of the sRNA response to Merida virus consisted of piRNAs. Since viral DNA forms have been implicated in siRNA and piRNA responses of Aedes spp. mosquitoes, we also tested for viral DNA forms in WNV infected Culex cells. We detected viral DNA in Culex tarsalis cells infected with WNV and, to a lesser amount, WNV and Merida virus-derived DNA in Culex quinquefasciatus Hsu cells. In conclusion, Hsu cells generated Merida virus-derived piRNAs, but our data suggests that the major sRNA response of Culex cells and mosquitoes to WNV infection is the exogenous siRNA response. It is also evident that sRNA responses differ significantly between specific virus-mosquito combinations. Future work using additional Culex-borne viruses may further elucidate how virus-derived piRNAs are generated in Culex cells and what role they may play in controlling replication of different viruses.
Collapse
Affiliation(s)
- Claudia Rückert
- Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, 80523, USA.
| | - Abhishek N Prasad
- Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, 80523, USA; Department of Pathology, Galveston National Laboratory, University of Texas Medical Branch, Galveston, TX, USA
| | - Selene M Garcia-Luna
- Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, 80523, USA; Department of Entomology, Texas A&M University, College Station, TX, USA
| | - Alexis Robison
- Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, 80523, USA
| | - Nathan D Grubaugh
- Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, 80523, USA; Yale School of Public Health, Department of Epidemiology of Microbial Diseases, Laboratory of Epidemiology of Public Health, New Haven, CT, USA
| | - James Weger-Lucarelli
- Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, 80523, USA; Department of Biomedical Sciences and Pathobiology, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
| | - Gregory D Ebel
- Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, 80523, USA.
| |
Collapse
|
35
|
Martins NE, Olmo RP, Aguiar ERGR, Marques JT, Imler JL. [Insects: An exceptional reservoir for viruses and antiviral genes]. Biol Aujourdhui 2019; 212:101-106. [PMID: 30973139 DOI: 10.1051/jbio/2019008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Indexed: 11/14/2022]
Abstract
Insects are the most diverse group of animals. They can be infected by an extraordinary diversity of viruses. Among them, arthropod-borne viruses (arboviruses) can be transmitted to humans. High-throughput sequencing of small RNAs from insects provides insight on their virome, which may help understand the dynamics of vector borne infectious diseases. Furthermore, investigating the mechanisms that restrict viral infections in insects points to genetic innovations that may inspire novel antiviral strategies.
Collapse
Affiliation(s)
- Nelson Eduardo Martins
- CNRS UPR9022, INSERM U1257, Institut de Biologie Moléculaire et Cellulaire, Université de Strasbourg, 15, rue René Descartes, 67084 Strasbourg, France
| | - Roenick Proveti Olmo
- CNRS UPR9022, INSERM U1257, Institut de Biologie Moléculaire et Cellulaire, Université de Strasbourg, 15, rue René Descartes, 67084 Strasbourg, France
| | - Eric Roberto Guimarães Rocha Aguiar
- Department of Biochemistry and Immunology, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, 6627, Av. Antônio Carlos, 31270-901 Belo Horizonte/MG, Brazil - Instituto de Ciências da Saúde, Universidade Federal da Bahia, Salvador, BA, Brazil
| | - João Trindade Marques
- CNRS UPR9022, INSERM U1257, Institut de Biologie Moléculaire et Cellulaire, Université de Strasbourg, 15, rue René Descartes, 67084 Strasbourg, France - Department of Biochemistry and Immunology, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, 6627, Av. Antônio Carlos, 31270-901 Belo Horizonte/MG, Brazil
| | - Jean-Luc Imler
- CNRS UPR9022, INSERM U1257, Institut de Biologie Moléculaire et Cellulaire, Université de Strasbourg, 15, rue René Descartes, 67084 Strasbourg, France
| |
Collapse
|
36
|
Göertz GP, Miesen P, Overheul GJ, van Rij RP, van Oers MM, Pijlman GP. Mosquito Small RNA Responses to West Nile and Insect-Specific Virus Infections in Aedes and Culex Mosquito Cells. Viruses 2019; 11:v11030271. [PMID: 30889941 PMCID: PMC6466260 DOI: 10.3390/v11030271] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 03/12/2019] [Accepted: 03/14/2019] [Indexed: 12/15/2022] Open
Abstract
Small RNA mediated responses are essential for antiviral defence in mosquitoes, however, they appear to differ per virus-vector combination. To further investigate the diversity of small RNA responses against viruses in mosquitoes, we applied a small RNA deep sequencing approach on five mosquito cell lines: Culex tarsalis CT cells, Aedes albopictus U4.4 and C6/36 cells, Ae. aegypti Aag2 cells (cleared from cell fusing agent virus and Culex Y virus (CYV) by repetitive dsRNA transfections) and Ae. pseudoscutellaris AP-61 cells. De novo assembly of small RNAs revealed the presence of Phasi Charoen-like virus (PCLV), Calbertado virus, Flock House virus and a novel narnavirus in CT cells, CYV in U4.4 cells, and PCLV in Aag2 cells, whereas no insect-specific viruses (ISVs) were detected in C6/36 and AP-61 cells. Next, we investigated the small RNA responses to the identified ISVs and to acute infection with the arthropod-borne West Nile virus (WNV). We demonstrate that AP-61 and C6/36 cells do not produce siRNAs to WNV infection, suggesting that AP-61, like C6/36, are Dicer-2 deficient. CT cells produced a strong siRNA response to the persistent ISVs and acute WNV infection. Interestingly, CT cells also produced viral PIWI-interacting (pi)RNAs to PCLV, but not to WNV or any of the other ISVs. In contrast, in U4.4 and Aag2 cells, WNV siRNAs, and pi-like RNAs without typical ping-pong piRNA signature were observed, while this signature was present in PCLV piRNAs in Aag2 cells. Together, our results demonstrate that mosquito small RNA responses are strongly dependent on both the mosquito cell type and/or the mosquito species and family of the infecting virus.
Collapse
Affiliation(s)
- Giel P Göertz
- Laboratory of Virology, Wageningen University & Research, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands.
| | - Pascal Miesen
- Department of Medical Microbiology, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Geert Grooteplein Zuid 28, 6525 GA Nijmegen, The Netherlands.
| | - Gijs J Overheul
- Department of Medical Microbiology, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Geert Grooteplein Zuid 28, 6525 GA Nijmegen, The Netherlands.
| | - Ronald P van Rij
- Department of Medical Microbiology, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Geert Grooteplein Zuid 28, 6525 GA Nijmegen, The Netherlands.
| | - Monique M van Oers
- Laboratory of Virology, Wageningen University & Research, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands.
| | - Gorben P Pijlman
- Laboratory of Virology, Wageningen University & Research, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands.
| |
Collapse
|
37
|
Donald CL, Varjak M, Aguiar ERGR, Marques JT, Sreenu VB, Schnettler E, Kohl A. Antiviral RNA Interference Activity in Cells of the Predatory Mosquito, Toxorhynchites amboinensis. Viruses 2018; 10:v10120694. [PMID: 30563205 PMCID: PMC6316411 DOI: 10.3390/v10120694] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 11/19/2018] [Accepted: 12/04/2018] [Indexed: 12/13/2022] Open
Abstract
Arthropod vectors control the replication of arboviruses through their innate antiviral immune responses. In particular, the RNA interference (RNAi) pathways are of notable significance for the control of viral infections. Although much has been done to understand the role of RNAi in vector populations, little is known about its importance in non-vector mosquito species. In this study, we investigated the presence of an RNAi response in Toxorhynchites amboinensis, which is a non-blood feeding species proposed as a biological control agent against pest mosquitoes. Using a derived cell line (TRA-171), we demonstrate that these mosquitoes possess a functional RNAi response that is active against a mosquito-borne alphavirus, Semliki Forest virus. As observed in vector mosquito species, small RNAs are produced that target viral sequences. The size and characteristics of these small RNAs indicate that both the siRNA and piRNA pathways are induced in response to infection. Taken together, this data suggests that Tx. amboinensis are able to control viral infections in a similar way to natural arbovirus vector mosquito species. Understanding their ability to manage arboviral infections will be advantageous when assessing these and similar species as biological control agents.
Collapse
Affiliation(s)
- Claire L Donald
- MRC-University of Glasgow Centre for Virus Research, Glasgow, Scotland G61 1QH, UK.
| | - Margus Varjak
- MRC-University of Glasgow Centre for Virus Research, Glasgow, Scotland G61 1QH, UK.
| | - Eric Roberto Guimarães Rocha Aguiar
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, 6627-Pampulha-Belo Horizonte-MG, CEP 31270-901, Brazil.
| | - João T Marques
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, 6627-Pampulha-Belo Horizonte-MG, CEP 31270-901, Brazil.
| | - Vattipally B Sreenu
- MRC-University of Glasgow Centre for Virus Research, Glasgow, Scotland G61 1QH, UK.
| | - Esther Schnettler
- MRC-University of Glasgow Centre for Virus Research, Glasgow, Scotland G61 1QH, UK.
| | - Alain Kohl
- MRC-University of Glasgow Centre for Virus Research, Glasgow, Scotland G61 1QH, UK.
| |
Collapse
|
38
|
Leggewie M, Schnettler E. RNAi-mediated antiviral immunity in insects and their possible application. Curr Opin Virol 2018; 32:108-114. [DOI: 10.1016/j.coviro.2018.10.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 10/16/2018] [Accepted: 10/23/2018] [Indexed: 01/09/2023]
|
39
|
Karamipour N, Fathipour Y, Talebi AA, Asgari S, Mehrabadi M. Small interfering RNA pathway contributes to antiviral immunity in Spodoptera frugiperda (Sf9) cells following Autographa californica multiple nucleopolyhedrovirus infection. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2018; 101:24-31. [PMID: 30075239 DOI: 10.1016/j.ibmb.2018.07.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2018] [Revised: 07/22/2018] [Accepted: 07/29/2018] [Indexed: 06/08/2023]
Abstract
Autographa californica multiple nucleopolyhedrovirus (AcMNPV) is a well-known virus in the Baculoviridae family. Presence of the p35 gene in the AcMNPV genome as a suppressor of the short interfering RNA (siRNA) pathway is a strong reason for the importance of the siRNA pathway in the host cellular defense. Given that, here we explored the roles of Dicer-2 (Dcr2) and Argonaute 2 (Ago2) genes, key factors in the siRNA pathway in response to AcMNPV infection in Spodoptera frugiperda Sf9 cells. The results showed that the transcript levels of Dcr2 and Ago2 increased in response to AcMNPV infection particularly over 16 h post infection suggesting induction of the siRNA pathway. Reductions in the expression levels of Dcr2 and Ago2 by using specific dsRNAs in Sf9 cells modestly enhanced production of viral genomic DNA which indicated their role in the host antiviral defense. Using deep sequencing, our previous study showed a large number of small reads (siRNAs of ∼20 nucleotides) from AcMNPV-infected Sf9 cells that were mapped to some of the viral genes (hot spots). Down-regulation of Dcr2 in Sf9 cells resulted in enhanced expression levels of the selected virus hotspot genes (i.e. ORF-9 and ORF-148), while the transcript levels of virus cold spots (i.e. ORF-18 and ORF-25) with no or few siRNAs mapped to them did not change. Overexpression of AcMNPV p35 as a suppressor of RNAi and anti-apoptosis gene in Sf9 cells increased virus replication. Also, replication of mutant AcMNPV lacking the p35 gene was significantly increased in Sf9 cells with reduced transcript levels of Dcr2 and Ago2, highlighting the antiviral role of the siRNA pathway in Sf9 cells. Together, our results demonstrate that Dcr2 and Ago2 genes contribute in efficient antiviral response of Sf9 cells towards AcMNPV, and in turn, the AcMNPV p35 suppresses the siRNA pathway, besides being an antiapoptotic protein.
Collapse
Affiliation(s)
- Naeime Karamipour
- Department of Entomology, Faculty of Agriculture, Tarbiat Modares University, Tehran, Iran
| | - Yaghoub Fathipour
- Department of Entomology, Faculty of Agriculture, Tarbiat Modares University, Tehran, Iran
| | - Ali Asghar Talebi
- Department of Entomology, Faculty of Agriculture, Tarbiat Modares University, Tehran, Iran
| | - Sassan Asgari
- Australian Infectious Disease Research Centre, School of Biological Sciences, The University of Queensland, Brisbane, QLD, Australia
| | - Mohammad Mehrabadi
- Department of Entomology, Faculty of Agriculture, Tarbiat Modares University, Tehran, Iran.
| |
Collapse
|
40
|
Monsanto-Hearne V, Johnson KN. miRNAs in Insects Infected by Animal and Plant Viruses. Viruses 2018; 10:E354. [PMID: 29970868 PMCID: PMC6071220 DOI: 10.3390/v10070354] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 06/29/2018] [Accepted: 06/29/2018] [Indexed: 12/13/2022] Open
Abstract
Viruses vectored by insects cause severe medical and agricultural burdens. The process of virus infection of insects regulates and is regulated by a complex interplay of biomolecules including the small, non-coding microRNAs (miRNAs). Considered an anomaly upon its discovery only around 25 years ago, miRNAs as a class have challenged the molecular central dogma which essentially typifies RNAs as just intermediaries in the flow of information from DNA to protein. miRNAs are now known to be common modulators or fine-tuners of gene expression. While recent years has seen an increased emphasis on understanding the role of miRNAs in host-virus associations, existing literature on the interaction between insects and their arthropod-borne viruses (arboviruses) is largely restricted to miRNA abundance profiling. Here we analyse the commonalities and contrasts between miRNA abundance profiles with different host-arbovirus combinations and outline a suggested pipeline and criteria for functional analysis of the contribution of miRNAs to the insect vector-virus interaction. Finally, we discuss the potential use of the model organism, Drosophila melanogaster, in complementing research on the role of miRNAs in insect vector-virus interaction.
Collapse
Affiliation(s)
- Verna Monsanto-Hearne
- School of Biological Sciences, The University of Queensland, Brisbane 4072, Australia.
| | - Karyn N Johnson
- School of Biological Sciences, The University of Queensland, Brisbane 4072, Australia.
| |
Collapse
|
41
|
Ferreira FV, Aguiar ERGR, Olmo RP, de Oliveira KPV, Silva EG, Sant'Anna MRV, Gontijo NDF, Kroon EG, Imler JL, Marques JT. The small non-coding RNA response to virus infection in the Leishmania vector Lutzomyia longipalpis. PLoS Negl Trop Dis 2018; 12:e0006569. [PMID: 29864168 PMCID: PMC6002125 DOI: 10.1371/journal.pntd.0006569] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2017] [Revised: 06/14/2018] [Accepted: 05/30/2018] [Indexed: 12/30/2022] Open
Abstract
Sandflies are well known vectors for Leishmania but also transmit a number of arthropod-borne viruses (arboviruses). Few studies have addressed the interaction between sandflies and arboviruses. RNA interference (RNAi) mechanisms utilize small non-coding RNAs to regulate different aspects of host-pathogen interactions. The small interfering RNA (siRNA) pathway is a broad antiviral mechanism in insects. In addition, at least in mosquitoes, another RNAi mechanism mediated by PIWI interacting RNAs (piRNAs) is activated by viral infection. Finally, endogenous microRNAs (miRNA) may also regulate host immune responses. Here, we analyzed the small non-coding RNA response to Vesicular stomatitis virus (VSV) infection in the sandfly Lutzoymia longipalpis. We detected abundant production of virus-derived siRNAs after VSV infection in adult sandflies. However, there was no production of virus-derived piRNAs and only mild changes in the expression of vector miRNAs in response to infection. We also observed abundant production of virus-derived siRNAs against two other viruses in Lutzomyia Lulo cells. Together, our results suggest that the siRNA but not the piRNA pathway mediates an antiviral response in sandflies. In agreement with this hypothesis, pre-treatment of cells with dsRNA against VSV was able to inhibit viral replication while knock-down of the central siRNA component, Argonaute-2, led to increased virus levels. Our work begins to elucidate the role of RNAi mechanisms in the interaction between L. longipalpis and viruses and should also open the way for studies with other sandfly-borne pathogens. Sandflies are important insect vectors that transmit many species of Leishmania, bacteria and viruses. We know very little about how this insect vector responds to viral infection. RNA interference (RNAi) utilizes small non-coding RNAs to regulate different aspects of animal physiology, including immune responses. Small interfering RNAs (siRNAs) mediate a major antiviral response in insects. Virus-derived PIWI-interacting RNAs (piRNAs) can also be generated during infection, at least in some insects. Finally, endogenous microRNAs (miRNA) can regulate the host response to infection. Here we show that virus infection triggers activation of the siRNA pathway but not production of piRNAs in the sandfly Lutzomyia longipalpis. Furthermore, activation or inhibition of the siRNA pathway had a direct effect on viral replication. We also show that virus infection caused mild changes to the expression of endogenous miRNAs. Our work describes for the first time a model to study virus infection in sandflies and highlights the importance of the siRNA pathway for the control of virus infection in L. longipalpis. The framework described here can be used to explore other aspects of the vector-pathogen interactions.
Collapse
Affiliation(s)
- Flávia Viana Ferreira
- Department of Biochemistry and Immunology, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
- Department of Microbiology, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Eric Roberto Guimarães Rocha Aguiar
- Department of Biochemistry and Immunology, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Roenick Proveti Olmo
- Department of Biochemistry and Immunology, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Karla Pollyanna Vieira de Oliveira
- Department of Biochemistry and Immunology, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Emanuele Guimarães Silva
- Department of Biochemistry and Immunology, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Maurício Roberto Viana Sant'Anna
- Department of Parasitology, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Nelder de Figueiredo Gontijo
- Department of Parasitology, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Erna Geessien Kroon
- Department of Microbiology, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Jean Luc Imler
- Université de Strasbourg, CNRS M3I/UPR9022, Inserm MIR/U1257, Strasbourg, France
| | - João Trindade Marques
- Department of Biochemistry and Immunology, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
- * E-mail:
| |
Collapse
|
42
|
Hameed MS, Wang Z, Vasseur L, Yang G. Molecular Characterization and the Function of Argonaute3 in RNAi Pathway of Plutella xylostella. Int J Mol Sci 2018; 19:ijms19041249. [PMID: 29677157 PMCID: PMC5979473 DOI: 10.3390/ijms19041249] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Revised: 04/14/2018] [Accepted: 04/17/2018] [Indexed: 01/30/2023] Open
Abstract
Argonaute (Ago) protein family plays a key role in the RNA interference (RNAi) process in different insects including Lepidopteran. However, the role of Ago proteins in the RNAi pathway of Plutella xylostella is still unknown. We cloned an Argonaute3 gene in P. xylostella (PxAgo3) with the complete coding sequence of 2832 bp. The encoded protein had 935 amino acids with an expected molecular weight of 108.9 kDa and an isoelectric point of 9.29. It contained a PAZ (PIWI/Argonaute/Zwile) domain and PIWI (P-element-induced whimpy testes) domain. PxAgo3 was classified into the Piwi subfamily of Ago proteins with a high similarity of 93.0% with Bombyx mori Ago3 (BmAgo3). The suppression of PxAgo3 by dsPxAgo3 was observed 3 h after treatment and was maintained until 24 h. Knockdown of PxAgo3 decreased the suppression level of PxActin by dsPxActin in P. xylostella cells, while overexpression of PxAgo3 increased the RNAi efficiency. Our results suggest that PxAgo3 play a key role in the double stranded RNA (dsRNA)-regulated RNAi pathway in P. xylostella.
Collapse
Affiliation(s)
- Muhammad Salman Hameed
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
- Joint International Research Laboratory of Ecological Pest Control, Ministry of Education, Fuzhou 350002, China.
- Key Laboratory of Integrated Pest Management for Fujian-Taiwan Crops, Ministry of Agriculture, Fuzhou 350002, China.
- Key Laboratory of Green Pest Control (Fujian Agriculture and Forestry University), Fujian Province University, Fuzhou 350002, China.
| | - Zhengbing Wang
- Key Laboratory of Natural Pesticides and Chemical Biology of the Ministry of Education, South China Agricultural University, Guangzhou 510642, China.
| | - Liette Vasseur
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
- Department of Biological Sciences, Brock University, 500 Glenridge Avenue, St. Catharines, ON L2S 3A1, Canada.
| | - Guang Yang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
- Joint International Research Laboratory of Ecological Pest Control, Ministry of Education, Fuzhou 350002, China.
- Key Laboratory of Integrated Pest Management for Fujian-Taiwan Crops, Ministry of Agriculture, Fuzhou 350002, China.
- Key Laboratory of Green Pest Control (Fujian Agriculture and Forestry University), Fujian Province University, Fuzhou 350002, China.
| |
Collapse
|
43
|
Spindle-E Acts Antivirally Against Alphaviruses in Mosquito Cells. Viruses 2018; 10:v10020088. [PMID: 29463033 PMCID: PMC5850395 DOI: 10.3390/v10020088] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 02/14/2018] [Accepted: 02/15/2018] [Indexed: 12/11/2022] Open
Abstract
Mosquitoes transmit several human- and animal-pathogenic alphaviruses (Togaviridae family). In alphavirus-infected mosquito cells two different types of virus-specific small RNAs are produced as part of the RNA interference response: short-interfering (si)RNAs and PIWI-interacting (pi)RNAs. The siRNA pathway is generally thought to be the main antiviral pathway. Although an antiviral activity has been suggested for the piRNA pathway its role in host defences is not clear. Knock down of key proteins of the piRNA pathway (Ago3 and Piwi5) in Aedes aegypti-derived cells reduced the production of alphavirus chikungunya virus (CHIKV)-specific piRNAs but had no effect on virus replication. In contrast, knock down of the siRNA pathway key protein Ago2 resulted in an increase in virus replication. Similar results were obtained when expression of Piwi4 was silenced. Knock down of the helicase Spindle-E (SpnE), an essential co-factor of the piRNA pathway in Drosophila melanogaster, resulted in increased virus replication indicating that SpnE acts as an antiviral against alphaviruses such as CHIKV and the related Semliki Forest virus (SFV). Surprisingly, this effect was found to be independent of the siRNA and piRNA pathways in Ae. aegypti cells and specific for alphaviruses. This suggests a small RNA-independent antiviral function for this protein in mosquitoes.
Collapse
|
44
|
Mosquitoes as Arbovirus Vectors: From Species Identification to Vector Competence. PARASITOLOGY RESEARCH MONOGRAPHS 2018. [PMCID: PMC7122353 DOI: 10.1007/978-3-319-94075-5_9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Mosquitoes and other arthropods transmit a large number of medically important pathogens, in particular viruses. These arthropod-borne viruses (arboviruses) include a wide variety of RNA viruses belonging to the Flaviviridae family (West Nile virus (WNV), Usutu virus (USUV), Dengue virus (DENV), Japanese encephalitis virus (JEV), Zika virus (ZIKV)), the Togaviridae family (Chikungunya virus (CHIKV)), and Bunyavirales order (Rift Valley fever virus (RVFV)) (please refer also to Table 9.1). Arboviral transmission to humans and livestock constitutes a major threat to public health and economy as illustrated by the emergence of ZIKV in the Americas, RVFV outbreaks in Africa, and the worldwide outbreaks of DENV. To answer the question if those viral pathogens also pose a risk to Europe, we need to first answer the key questions (summarized in Fig. 9.1):Who could contribute to such an outbreak? Information about mosquito species resident or imported, potential hosts and viruses able to infect vectors and hosts in Germany is needed. Where would competent mosquito species meet favorable conditions for transmission? Information on the minimum requirements for efficient replication of the virus in a given vector species and subsequent transmission is needed. How do viruses and vectors interact to facilitate transmission? Information on the vector immunity, vector physiology, vector genetics, and vector microbiomes is needed.
Collapse
|
45
|
Varjak M, Donald CL, Mottram TJ, Sreenu VB, Merits A, Maringer K, Schnettler E, Kohl A. Characterization of the Zika virus induced small RNA response in Aedes aegypti cells. PLoS Negl Trop Dis 2017; 11:e0006010. [PMID: 29040304 PMCID: PMC5667879 DOI: 10.1371/journal.pntd.0006010] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Revised: 11/02/2017] [Accepted: 10/04/2017] [Indexed: 01/16/2023] Open
Abstract
RNA interference (RNAi) controls arbovirus infections in mosquitoes. Two different RNAi pathways are involved in antiviral responses: the PIWI-interacting RNA (piRNA) and exogenous short interfering RNA (exo-siRNA) pathways, which are characterized by the production of virus-derived small RNAs of 25–29 and 21 nucleotides, respectively. The exo-siRNA pathway is considered to be the key mosquito antiviral response mechanism. In Aedes aegypti-derived cells, Zika virus (ZIKV)-specific siRNAs were produced and loaded into the exo-siRNA pathway effector protein Argonaute 2 (Ago2); although the knockdown of Ago2 did not enhance virus replication. Enhanced ZIKV replication was observed in a Dcr2-knockout cell line suggesting that the exo-siRNA pathway is implicated in the antiviral response. Although ZIKV-specific piRNA-sized small RNAs were detected, these lacked the characteristic piRNA ping-pong signature motif and were bound to Ago3 but not Piwi5 or Piwi6. Silencing of PIWI proteins indicated that the knockdown of Ago3, Piwi5 or Piwi6 did not enhance ZIKV replication and only Piwi4 displayed antiviral activity. We also report that the expression of ZIKV capsid (C) protein amplified the replication of a reporter alphavirus; although, unlike yellow fever virus C protein, it does not inhibit the exo-siRNA pathway. Our findings elucidate ZIKV-mosquito RNAi interactions that are important for understanding its spread. The recent outbreak of Zika virus (ZIKV) in the Americas has resulted in a severe threat to public health. ZIKV is transmitted by Aedes aegypti mosquitoes, thus it is important to understand virus-vector interactions. Analysis of ZIKV infection in mosquito cells indicated that two RNA interference pathways are involved during infection: the exogenous short-interfering (si)RNA (exo-siRNA) and PIWI-interacting (pi)RNA pathways. If Dcr2, an enzyme responsible for cleaving dsRNA into siRNAs, is knocked out, ZIKV replication is increased compared to control cells. However, the knockdown of Ago2 expression had no significant enhancing effect on ZIKV replication. In the case of the PIWI pathway, only the Piwi4 protein was found to have significant antiviral activity. Furthermore, unlike the capsid (C) protein of yellow fever virus, ZIKV capsid protein does not suppress the siRNA pathway. These results suggest that ZIKV has mechanisms to evade mosquito innate immunity and it is therefore important to understand these virus-vector interactions and the implications they have on transmission.
Collapse
Affiliation(s)
- Margus Varjak
- MRC-University of Glasgow Centre for Virus Research, Glasgow, Scotland, United Kingdom
- * E-mail: (MV); (AK)
| | - Claire L. Donald
- MRC-University of Glasgow Centre for Virus Research, Glasgow, Scotland, United Kingdom
| | - Timothy J. Mottram
- MRC-University of Glasgow Centre for Virus Research, Glasgow, Scotland, United Kingdom
| | - Vattipally B. Sreenu
- MRC-University of Glasgow Centre for Virus Research, Glasgow, Scotland, United Kingdom
| | - Andres Merits
- Institute of Technology, University of Tartu, Nooruse 1, Tartu, Estonia
| | - Kevin Maringer
- Department of Microbial Sciences, Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
| | - Esther Schnettler
- Bernhard-Nocht-Institute for Tropical Medicine, Bernhard-Nocht-Strasse, Hamburg, Germany
| | - Alain Kohl
- MRC-University of Glasgow Centre for Virus Research, Glasgow, Scotland, United Kingdom
- * E-mail: (MV); (AK)
| |
Collapse
|
46
|
Saldaña MA, Etebari K, Hart CE, Widen SG, Wood TG, Thangamani S, Asgari S, Hughes GL. Zika virus alters the microRNA expression profile and elicits an RNAi response in Aedes aegypti mosquitoes. PLoS Negl Trop Dis 2017; 11:e0005760. [PMID: 28715413 PMCID: PMC5531668 DOI: 10.1371/journal.pntd.0005760] [Citation(s) in RCA: 90] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Revised: 07/27/2017] [Accepted: 06/29/2017] [Indexed: 01/18/2023] Open
Abstract
Zika virus (ZIKV), a flavivirus transmitted primarily by Aedes aegypti, has recently spread globally in an unprecedented fashion, yet we have a poor understanding of host-microbe interactions in this system. To gain insights into the interplay between ZIKV and the mosquito, we sequenced the small RNA profiles in ZIKV-infected and non-infected Ae. aegypti mosquitoes at 2, 7 and 14 days post-infection. ZIKA induced an RNAi response in the mosquito with virus-derived short interfering RNAs and PIWI-interacting RNAs dramatically increased in abundance post-infection. Further, we found 17 host microRNAs (miRNAs) that were modulated by ZIKV infection at all time points. Strikingly, many of these regulated miRNAs have been reported to have their expression altered by dengue and West Nile viruses, while the response was divergent from that induced by the alphavirus Chikungunya virus in mosquitoes. This suggests that conserved miRNA responses occur within mosquitoes in response to flavivirus infection. This study expands our understanding of ZIKV-vector interactions and provides potential avenues to be further investigated to target ZIKV in the mosquito host.
Collapse
Affiliation(s)
- Miguel A. Saldaña
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, United States of America
| | - Kayvan Etebari
- Australian Infectious Disease Research Centre, School of Biological Sciences, The University of Queensland, Brisbane, Australia
| | - Charles E. Hart
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, United States of America
| | - Steven G. Widen
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX, United States of America
| | - Thomas G. Wood
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX, United States of America
| | - Saravanan Thangamani
- Department of Pathology, Institute for Human Infections and Immunity, Center for Tropical Diseases, Center for Biodefense and Emerging Infectious Disease. University of Texas Medical Branch, Galveston, TX, United States of America
| | - Sassan Asgari
- Australian Infectious Disease Research Centre, School of Biological Sciences, The University of Queensland, Brisbane, Australia
- * E-mail: (SA); (GLH)
| | - Grant L. Hughes
- Department of Pathology, Institute for Human Infections and Immunity, Center for Tropical Diseases, Center for Biodefense and Emerging Infectious Disease. University of Texas Medical Branch, Galveston, TX, United States of America
- * E-mail: (SA); (GLH)
| |
Collapse
|