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Koh C, Saleh MC. Translating mosquito viromes into vector management strategies. Trends Parasitol 2024; 40:10-20. [PMID: 38065789 DOI: 10.1016/j.pt.2023.11.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 11/06/2023] [Accepted: 11/07/2023] [Indexed: 01/06/2024]
Abstract
Mosquitoes are best known for transmitting human and animal viruses. However, they also harbour mosquito-specific viruses (MSVs) as part of their microbiota. These are a group of viruses whose diversity and prevalence overshadow their medically relevant counterparts. Although metagenomics sequencing has remarkably accelerated the discovery of these viruses, what we know about them is often limited to sequence information, leaving much of their fundamental biology to be explored. Understanding the biology and ecology of MSVs can enlighten our knowledge of virus-virus interactions and lead to new innovations in the management of mosquito-borne viral diseases. We retrace the history of their discovery and discuss research milestones that would line the path from mosquito virome knowledge to vector management strategies.
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Affiliation(s)
- Cassandra Koh
- Institut Pasteur, Université Paris Cité, CNRS UMR3569, Viruses and RNA Interference Unit, 75015 Paris, France.
| | - Maria-Carla Saleh
- Institut Pasteur, Université Paris Cité, CNRS UMR3569, Viruses and RNA Interference Unit, 75015 Paris, France
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2
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Körsten C, Reemtsma H, Ziegler U, Fischer S, Tews BA, Groschup MH, Silaghi C, Vasic A, Holicki CM. Cellular co-infections of West Nile virus and Usutu virus influence virus growth kinetics. Virol J 2023; 20:234. [PMID: 37833787 PMCID: PMC10576383 DOI: 10.1186/s12985-023-02206-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Accepted: 10/05/2023] [Indexed: 10/15/2023] Open
Abstract
The mosquito-borne flaviviruses West Nile virus (WNV) and Usutu virus (USUV) pose a significant threat to the health of humans and animals. Both viruses co-circulate in numerous European countries including Germany. Due to their overlapping host and vector ranges, there is a high risk of co-infections. However, it is largely unknown if WNV and USUV interact and how this might influence their epidemiology. Therefore, in-vitro infection experiments in mammalian (Vero B4), goose (GN-R) and mosquito cell lines (C6/36, CT) were performed to investigate potential effects of co-infections in vectors and vertebrate hosts. The growth kinetics of German and other European WNV and USUV strains were determined and compared. Subsequently, simultaneous co-infections were performed with selected WNV and USUV strains. The results show that the growth of USUV was suppressed by WNV in all cell lines. This effect was independent of the virus lineage but depended on the set WNV titre. The replication of WNV also decreased in co-infection scenarios on vertebrate cells. Overall, co-infections might lead to a decreased growth of USUV in mosquitoes and of both viruses in vertebrate hosts. These interactions can strongly affect the epidemiology of USUV and WNV in areas where they co-circulate.
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Affiliation(s)
- Christin Körsten
- Federal Research Institute for Animal Health, Institute of Infectology, Friedrich-Loeffler-Institut, 17493, Greifswald-Insel Riems, Germany
| | - Hannah Reemtsma
- Federal Research Institute for Animal Health, Institute of Novel and Emerging Infectious Diseases, Friedrich-Loeffler-Institut, 17493, Greifswald-Insel Riems, Germany
| | - Ute Ziegler
- Federal Research Institute for Animal Health, Institute of Novel and Emerging Infectious Diseases, Friedrich-Loeffler-Institut, 17493, Greifswald-Insel Riems, Germany
| | - Susanne Fischer
- Federal Research Institute for Animal Health, Institute of Infectology, Friedrich-Loeffler-Institut, 17493, Greifswald-Insel Riems, Germany
| | - Birke A Tews
- Federal Research Institute for Animal Health, Institute of Infectology, Friedrich-Loeffler-Institut, 17493, Greifswald-Insel Riems, Germany
| | - Martin H Groschup
- Federal Research Institute for Animal Health, Institute of Novel and Emerging Infectious Diseases, Friedrich-Loeffler-Institut, 17493, Greifswald-Insel Riems, Germany
| | - Cornelia Silaghi
- Federal Research Institute for Animal Health, Institute of Infectology, Friedrich-Loeffler-Institut, 17493, Greifswald-Insel Riems, Germany
| | - Ana Vasic
- Federal Research Institute for Animal Health, Institute of Infectology, Friedrich-Loeffler-Institut, 17493, Greifswald-Insel Riems, Germany
- Scientific Institute of Veterinary Medicine of Serbia, Belgrade, Serbia
| | - Cora M Holicki
- Federal Research Institute for Animal Health, Institute of Novel and Emerging Infectious Diseases, Friedrich-Loeffler-Institut, 17493, Greifswald-Insel Riems, Germany.
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3
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Agboli E, Schulze J, Jansen S, Cadar D, Sreenu VB, Leggewie M, Altinli M, Badusche M, Jöst H, Börstler J, Schmidt-Chanasit J, Schnettler E. Interaction of Mesonivirus and Negevirus with arboviruses and the RNAi response in Culex tarsalis-derived cells. Parasit Vectors 2023; 16:361. [PMID: 37833743 PMCID: PMC10576325 DOI: 10.1186/s13071-023-05985-w] [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: 04/03/2023] [Accepted: 09/26/2023] [Indexed: 10/15/2023] Open
Abstract
BACKGROUND Mosquito-specific viruses (MSVs) comprise a variety of different virus families, some of which are known to interfere with infections of medically important arboviruses. Viruses belonging to the family Mesoniviridae or taxon Negevirus harbor several insect-specific viruses, including MSVs, which are known for their wide geographical distribution and extensive host ranges. Although these viruses are regularly identified in mosquitoes all over the world, their presence in mosquitoes in Germany had not yet been reported. METHODS A mix of three MSVs (Yichang virus [Mesoniviridae] and two negeviruses [Daeseongdong virus and Dezidougou virus]) in a sample that contained a pool of Coquillettidia richiardii mosquitoes collected in Germany was used to investigate the interaction of these viruses with different arboviruses in Culex-derived cells. In addition, small RNA sequencing and analysis of different mosquito-derived cells infected with this MSV mix were performed. RESULTS A strain of Yichang virus (Mesoniviridae) and two negeviruses (Daeseongdong virus and Dezidougou virus) were identified in the Cq. richiardii mosquitoes sampled in Germany, expanding current knowledge of their circulation in central Europe. Infection of mosquito-derived cells with these three viruses revealed that they are targeted by the small interfering RNA (siRNA) pathway. In Culex-derived cells, co-infection by these three viruses had varying effects on the representative arboviruses from different virus families (Togaviridae: Semliki forest virus [SFV]; Bunyavirales: Bunyamwera orthobunyavirus [BUNV]; or Flaviviridae: Usutu virus [USUV]). Specifically, persistent MSV co-infection inhibited BUNV infection, as well as USUV infection (but the latter only at specific time points). However, the impact on SFV infection was only noticeable at low multiplicity of infection (MOI 0.1) and at specific time points in combination with the infection status. CONCLUSIONS Taken together, these results are important findings that will lead to a better understanding of the complex interactions of MSVs, mosquitoes and arboviruses.
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Affiliation(s)
- Eric Agboli
- Bernhard-Nocht-Institute for Tropical Medicine, 20359, Hamburg, Germany
- School of Basic and Biomedical Sciences, Department of Biomedical Sciences, University of Health and Allied Sciences, PMB 31, Ho, Ghana
| | - Jonny Schulze
- Bernhard-Nocht-Institute for Tropical Medicine, 20359, Hamburg, Germany
| | - Stephanie Jansen
- Bernhard-Nocht-Institute for Tropical Medicine, 20359, Hamburg, Germany
- Faculty of Mathematics, Informatics and Natural Sciences, University of Hamburg, 20148, Hamburg, Germany
| | - Daniel Cadar
- Bernhard-Nocht-Institute for Tropical Medicine, 20359, Hamburg, Germany
| | | | - Mayke Leggewie
- Bernhard-Nocht-Institute for Tropical Medicine, 20359, Hamburg, Germany
| | - Mine Altinli
- Bernhard-Nocht-Institute for Tropical Medicine, 20359, Hamburg, Germany
| | - Marlis Badusche
- Bernhard-Nocht-Institute for Tropical Medicine, 20359, Hamburg, Germany
| | - Hanna Jöst
- Bernhard-Nocht-Institute for Tropical Medicine, 20359, Hamburg, Germany
| | - Jessica Börstler
- Bernhard-Nocht-Institute for Tropical Medicine, 20359, Hamburg, Germany
| | - Jonas Schmidt-Chanasit
- Bernhard-Nocht-Institute for Tropical Medicine, 20359, Hamburg, Germany
- Faculty of Mathematics, Informatics and Natural Sciences, University of Hamburg, 20148, Hamburg, Germany
| | - Esther Schnettler
- Bernhard-Nocht-Institute for Tropical Medicine, 20359, Hamburg, Germany.
- Faculty of Mathematics, Informatics and Natural Sciences, University of Hamburg, 20148, Hamburg, Germany.
- German Center for Infection Research (DZIF), Partner Site Hamburg-Luebeck-Borstel-Riems, Hamburg, Germany.
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4
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González-Flores AM, Salas-Benito M, Rosales-García VH, Zárate-Segura PB, Del Ángel RM, De Nova-Ocampo MA, Salas-Benito JS. Characterization of Viral Interference in Aedes albopictus C6/36 Cells Persistently Infected with Dengue Virus 2. Pathogens 2023; 12:1135. [PMID: 37764943 PMCID: PMC10536104 DOI: 10.3390/pathogens12091135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 08/29/2023] [Accepted: 08/31/2023] [Indexed: 09/29/2023] Open
Abstract
Arboviruses are an important group of pathogens that cause diseases of medical and veterinary concern worldwide. The interactions of these viruses with their host cells are complex, and frequently, the coexistence of two different viruses in the same cell results in the inhibition of replication in one of the viruses, which is a phenomenon called viral interference. This phenomenon can be exploited to develop antiviral strategies. Insect cell lines persistently infected with arboviruses are useful models with which to study viral interference. In this work, a model of C6/36-HT cells (from Aedes albopictus mosquitoes) persistently infected with Dengue virus, serotype 2, was used. Viral interference was evaluated via plaque and flow cytometry assays. The presence of heterotypic interference against the other serotypes of the same virus and homologous interference against yellow fever virus was determined; however, this cell line did not display heterologous viral interference against Sindbis virus. The mechanisms responsible for viral interference have not been fully elucidated, but small RNAs could be involved. However, the silencing of Ago3, a key protein in the genome-derived P-element-induced wimpy testis pathway, did not alter the viral interference process, suggesting that viral interference occurs independent of this pathway.
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Affiliation(s)
| | - Mariana Salas-Benito
- Escuela Nacional de Medicina y Homeopatía, Instituto Politécnico Nacional, Mexico City 07320, Mexico; (M.S.-B.); (M.A.D.N.-O.)
| | - Victor Hugo Rosales-García
- Laboratorios Centrales, Centro de Investigación y de Estudios Avanzados del IPN, Mexico City 07360, Mexico;
| | | | - Rosa María Del Ángel
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del IPN, Mexico City 07360, Mexico;
| | - Mónica Ascención De Nova-Ocampo
- Escuela Nacional de Medicina y Homeopatía, Instituto Politécnico Nacional, Mexico City 07320, Mexico; (M.S.-B.); (M.A.D.N.-O.)
| | - Juan Santiago Salas-Benito
- Escuela Nacional de Medicina y Homeopatía, Instituto Politécnico Nacional, Mexico City 07320, Mexico; (M.S.-B.); (M.A.D.N.-O.)
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5
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Abel SM, Hong Z, Williams D, Ireri S, Brown MQ, Su T, Hung KY, Henke JA, Barton JP, Le Roch KG. Small RNA sequencing of field Culex mosquitoes identifies patterns of viral infection and the mosquito immune response. Sci Rep 2023; 13:10598. [PMID: 37391513 PMCID: PMC10313667 DOI: 10.1038/s41598-023-37571-6] [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: 02/08/2023] [Accepted: 06/23/2023] [Indexed: 07/02/2023] Open
Abstract
Mosquito-borne disease remains a significant burden on global health. In the United States, the major threat posed by mosquitoes is transmission of arboviruses, including West Nile virus by mosquitoes of the Culex genus. Virus metagenomic analysis of mosquito small RNA using deep sequencing and advanced bioinformatic tools enables the rapid detection of viruses and other infecting organisms, both pathogenic and non-pathogenic to humans, without any precedent knowledge. In this study, we sequenced small RNA samples from over 60 pools of Culex mosquitoes from two major areas of Southern California from 2017 to 2019 to elucidate the virome and immune responses of Culex. Our results demonstrated that small RNAs not only allowed the detection of viruses but also revealed distinct patterns of viral infection based on location, Culex species, and time. We also identified miRNAs that are most likely involved in Culex immune responses to viruses and Wolbachia bacteria, and show the utility of using small RNA to detect antiviral immune pathways including piRNAs against some pathogens. Collectively, these findings show that deep sequencing of small RNA can be used for virus discovery and surveillance. One could also conceive that such work could be accomplished in various locations across the world and over time to better understand patterns of mosquito infection and immune response to many vector-borne diseases in field samples.
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Affiliation(s)
- Steven M Abel
- Department of Molecular, Cell and Systems Biology, Center for Infection Disease and Vector Research, University of California, Riverside, CA, 92521, USA
| | - Zhenchen Hong
- Department of Physics and Astronomy, University of California, Riverside, CA, 92521, USA
| | - Desiree Williams
- Department of Molecular, Cell and Systems Biology, Center for Infection Disease and Vector Research, University of California, Riverside, CA, 92521, USA
| | - Sally Ireri
- Department of Molecular, Cell and Systems Biology, Center for Infection Disease and Vector Research, University of California, Riverside, CA, 92521, USA
| | - Michelle Q Brown
- West Valley Mosquito & Vector Control District, Ontario, CA, 91761, USA
| | - Tianyun Su
- West Valley Mosquito & Vector Control District, Ontario, CA, 91761, USA
| | - Kim Y Hung
- Coachella Valley Mosquito & Vector Control District, Indio, CA, 92201, USA
| | - Jennifer A Henke
- Coachella Valley Mosquito & Vector Control District, Indio, CA, 92201, USA
| | - John P Barton
- Department of Physics and Astronomy, University of California, Riverside, CA, 92521, USA
| | - Karine G Le Roch
- Department of Molecular, Cell and Systems Biology, Center for Infection Disease and Vector Research, University of California, Riverside, CA, 92521, USA.
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6
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Chang T, Hunt BPV, Hirai J, Suttle CA. Divergent RNA viruses infecting sea lice, major ectoparasites of fish. PLoS Pathog 2023; 19:e1011386. [PMID: 37347729 DOI: 10.1371/journal.ppat.1011386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Accepted: 04/25/2023] [Indexed: 06/24/2023] Open
Abstract
Sea lice, the major ectoparasites of fish, have significant economic impacts on wild and farmed finfish, and have been implicated in the decline of wild salmon populations. As blood-feeding arthropods, sea lice may also be reservoirs for viruses infecting fish. However, except for two groups of negative-strand RNA viruses within the order Mononegavirales, nothing is known about viruses of sea lice. Here, we used transcriptomic data from three key species of sea lice (Lepeophtheirus salmonis, Caligus clemensi, and Caligus rogercresseyi) to identify 32 previously unknown RNA viruses. The viruses encompassed all the existing phyla of RNA viruses, with many placed in deeply branching lineages that likely represent new families and genera. Importantly, the presence of canonical virus-derived small interfering RNAs (viRNAs) indicates that most of these viruses infect sea lice, even though in some cases their closest classified relatives are only known to infect plants or fungi. We also identified both viRNAs and PIWI-interacting RNAs (piRNAs) from sequences of a bunya-like and two qin-like viruses in C. rogercresseyi. Our analyses showed that most of the viruses found in C. rogercresseyi occurred in multiple life stages, spanning from planktonic to parasitic stages. Phylogenetic analysis revealed that many of the viruses infecting sea lice were closely related to those that infect a wide array of eukaryotes with which arthropods associate, including fungi and parasitic tapeworms, implying that over evolutionary time there has been cross-phylum and cross-kingdom switching of viruses between arthropods and other eukaryotes. Overall, this study greatly expands our view of virus diversity in crustaceans, identifies viruses that infect and replicate in sea lice, and provides evidence that over evolutionary time, viruses have switched between arthropods and eukaryotic hosts in other phyla and kingdoms.
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Affiliation(s)
- Tianyi Chang
- Department of Earth, Ocean and Atmospheric Sciences, University of British Columbia, Vancouver, Canada
| | - Brian P V Hunt
- Department of Earth, Ocean and Atmospheric Sciences, University of British Columbia, Vancouver, Canada
- Institute for the Oceans and Fisheries, University of British Columbia, Vancouver, Canada
- Hakai Institute, Campbell River, Canada
| | - Junya Hirai
- Atmosphere and Ocean Research Institute, The University of Tokyo, Kashiwa, Japan
| | - Curtis A Suttle
- Department of Earth, Ocean and Atmospheric Sciences, University of British Columbia, Vancouver, Canada
- Institute for the Oceans and Fisheries, University of British Columbia, Vancouver, Canada
- Hakai Institute, Campbell River, Canada
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, Canada
- Department of Botany, University of British Columbia, Vancouver, Canada
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7
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Jagtap SV, Brink J, Frank SC, Badusche M, Leggewie M, Sreenu VB, Fuss J, Schnettler E, Altinli M. Agua Salud Alphavirus Infection, Dissemination and Transmission in Aedes aegypti Mosquitoes. Viruses 2023; 15:1113. [PMID: 37243199 PMCID: PMC10223791 DOI: 10.3390/v15051113] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 04/25/2023] [Accepted: 04/28/2023] [Indexed: 05/28/2023] Open
Abstract
Mosquitoes are competent vectors for many important arthropod-borne viruses (arboviruses). In addition to arboviruses, insect-specific viruses (ISV) have also been discovered in mosquitoes. ISVs are viruses that replicate in insect hosts but are unable to infect and replicate in vertebrates. They have been shown to interfere with arbovirus replication in some cases. Despite the increase in studies on ISV-arbovirus interactions, ISV interactions with their hosts and how they are maintained in nature are still not well understood. In the present study, we investigated the infection and dissemination of the Agua Salud alphavirus (ASALV) in the important mosquito vector Aedes aegypti through different infection routes (per oral infection, intrathoracic injection) and its transmission. We show here that ASALV infects the female Ae. aegypti and replicates when mosquitoes are infected intrathoracically or orally. ASALV disseminated to different tissues, including the midgut, salivary glands and ovaries. However, we observed a higher virus load in the brain than in the salivary glands and carcasses, suggesting a tropism towards brain tissues. Our results show that ASALV is transmitted horizontally during adult and larval stages, although we did not observe vertical transmission. Understanding ISV infection and dissemination dynamics in Ae. aegypti and their transmission routes could help the use of ISVs as an arbovirus control strategy in the future.
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Affiliation(s)
- Swati V. Jagtap
- Bernhard-Nocht-Institute for Tropical Medicine, 20359 Hamburg, Germany; (S.V.J.)
- German Center for Infection Research, Partner Site Hamburg-Lübeck-Borstel-Riems, 20359 Hamburg, Germany
| | - Jorn Brink
- Bernhard-Nocht-Institute for Tropical Medicine, 20359 Hamburg, Germany; (S.V.J.)
| | - Svea C. Frank
- Bernhard-Nocht-Institute for Tropical Medicine, 20359 Hamburg, Germany; (S.V.J.)
| | - Marlis Badusche
- Bernhard-Nocht-Institute for Tropical Medicine, 20359 Hamburg, Germany; (S.V.J.)
| | - Mayke Leggewie
- Bernhard-Nocht-Institute for Tropical Medicine, 20359 Hamburg, Germany; (S.V.J.)
| | | | - Janina Fuss
- Institute of Clinical Molecular Biology (IKMB), Kiel University, 24105 Kiel, Germany
| | - Esther Schnettler
- Bernhard-Nocht-Institute for Tropical Medicine, 20359 Hamburg, Germany; (S.V.J.)
- German Center for Infection Research, Partner Site Hamburg-Lübeck-Borstel-Riems, 20359 Hamburg, Germany
- Faculty of Mathematics, Informatics and Natural Sciences, University Hamburg, 20148 Hamburg, Germany
| | - Mine Altinli
- Bernhard-Nocht-Institute for Tropical Medicine, 20359 Hamburg, Germany; (S.V.J.)
- German Center for Infection Research, Partner Site Hamburg-Lübeck-Borstel-Riems, 20359 Hamburg, Germany
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8
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Blair CD. A Brief History of the Discovery of RNA-Mediated Antiviral Immune Defenses in Vector Mosquitos. Microbiol Mol Biol Rev 2023; 87:e0019121. [PMID: 36511720 PMCID: PMC10029339 DOI: 10.1128/mmbr.00191-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Arthropod-borne viruses (arboviruses) persist in a natural cycle that includes infections of humans or other vertebrates and transmission between vertebrates by infected arthropods, most commonly mosquitos. Arboviruses can cause serious, sometimes fatal diseases in humans and other vertebrates but cause little pathology in their mosquito vectors. Knowledge of the interactions between mosquito vectors and the arboviruses that they transmit is an important facet of developing schemes to control transmission. Mosquito innate immune responses to virus infection modulate virus replication in the vector, and understanding the components and mechanisms of the immune response could lead to improved methods for interrupting the transmission cycle. The most important aspect of mosquito antiviral defense is the exogenous small interfering RNA (exo-siRNA) pathway, one arm of the RNA interference (RNAi) silencing response. Our research as well as that of many other groups over the past 25 years to define this pathway are reviewed here. A more recently recognized but less well-understood RNA-mediated mosquito defense against arbovirus infections, the PIWI-interacting RNA (piRNA) pathway, is also described.
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Affiliation(s)
- Carol D Blair
- Center for Vector-Borne Infectious Diseases, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, USA
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9
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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.
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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.
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10
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Asad S, Mehdi AM, Pujhari S, Rückert C, Ebel GD, Rasgon JL. Identification of MicroRNAs in the West Nile Virus Vector Culex tarsalis (Diptera: Culicidae). JOURNAL OF MEDICAL ENTOMOLOGY 2023; 60:182-293. [PMID: 36477983 DOI: 10.1093/jme/tjac182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Indexed: 05/28/2023]
Abstract
MicroRNAs (miRNAs) are a group of small noncoding RNAs that regulate gene expression during important biological processes including development and pathogen defense in most living organisms. Presently, no miRNAs have been identified in the mosquito Culex tarsalis (Diptera: Culicidae), one of the most important vectors of West Nile virus (WNV) in North America. We used small RNA sequencing data and in vitro and in vivo experiments to identify and validate a repertoire of miRNAs in Cx. tarsalis mosquitoes. Using bioinformatic approaches we analyzed small RNA sequences from the Cx. tarsalis CT embryonic cell line to discover orthologs for 86 miRNAs. Consistent with other mosquitoes such as Aedes albopictus and Culex quinquefasciatus, miR-184 was found to be the most abundant miRNA in Cx. tarsalis. We also identified 20 novel miRNAs from the recently sequenced Cx. tarsalis genome, for a total of 106 miRNAs identified in this study. The presence of selected miRNAs was biologically validated in both the CT cell line and in adult Cx. tarsalis mosquitoes using RT-qPCR and sequencing. These results will open new avenues of research into the role of miRNAs in Cx. tarsalis biology, including development, metabolism, immunity, and pathogen infection.
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Affiliation(s)
- Sultan Asad
- Department of Entomology, The Center for Infectious Disease Dynamics, and the Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA, USA
| | - Ahmed M Mehdi
- The University of Queensland, Brisbane, Australia Diamantina Institute, Faculty of Medicine, The University of Queensland, Translational Research Institute, Brisbane, QLD, Australia
| | - Sujit Pujhari
- Department of Entomology, The Center for Infectious Disease Dynamics, and the Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA, USA
- Department of Pharmacology Physiology and Neuroscience, University of South Carolina School of Medicine, Columbia, SC, USA
| | - Claudia Rückert
- Department of Biochemistry and Molecular Biology, University of Nevada Reno, Reno, NV, 89557, USA
- Department of Microbiology, Immunology and Pathology, Center for Vector-borne Infectious Diseases, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, 80523, USAand
| | - Gregory D Ebel
- Department of Microbiology, Immunology and Pathology, Center for Vector-borne Infectious Diseases, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, 80523, USAand
| | - Jason L Rasgon
- Department of Entomology, The Center for Infectious Disease Dynamics, and the Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA, USA
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Cable J, Denison MR, Kielian M, Jackson WT, Bartenschlager R, Ahola T, Mukhopadhyay S, Fremont DH, Kuhn RJ, Shannon A, Frazier MN, Yuen KY, Coyne CB, Wolthers KC, Ming GL, Guenther CS, Moshiri J, Best SM, Schoggins JW, Jurado KA, Ebel GD, Schäfer A, Ng LFP, Kikkert M, Sette A, Harris E, Wing PAC, Eggenberger J, Krishnamurthy SR, Mah MG, Meganck RM, Chung D, Maurer-Stroh S, Andino R, Korber B, Perlman S, Shi PY, Bárcena M, Aicher SM, Vu MN, Kenney DJ, Lindenbach BD, Nishida Y, Rénia L, Williams EP. Positive-strand RNA viruses-a Keystone Symposia report. Ann N Y Acad Sci 2023; 1521:46-66. [PMID: 36697369 PMCID: PMC10347887 DOI: 10.1111/nyas.14957] [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] [Indexed: 01/27/2023]
Abstract
Positive-strand RNA viruses have been the cause of several recent outbreaks and epidemics, including the Zika virus epidemic in 2015, the SARS outbreak in 2003, and the ongoing SARS-CoV-2 pandemic. On June 18-22, 2022, researchers focusing on positive-strand RNA viruses met for the Keystone Symposium "Positive-Strand RNA Viruses" to share the latest research in molecular and cell biology, virology, immunology, vaccinology, and antiviral drug development. This report presents concise summaries of the scientific discussions at the symposium.
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Affiliation(s)
| | - Mark R Denison
- Department of Pediatrics and Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center; and Vanderbilt Institute for Infection, Immunology, and Inflammation, Nashville, Tennessee, USA
| | - Margaret Kielian
- Department of Cell Biology, Albert Einstein College of Medicine, New York, New York, USA
| | - William T Jackson
- Department of Microbiology and Immunology and Center for Pathogen Research, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Ralf Bartenschlager
- Department of Infectious Diseases, Molecular Virology, Heidelberg University and German Cancer Research Center (DKFZ), Research Division Virus-associated Carcinogenesis, Heidelberg, Germany
| | - Tero Ahola
- Department of Microbiology, Faculty of Agriculture and Forestry, University of Helsinki, Helsinki, Finland
| | | | - Daved H Fremont
- Department of Pathology & Immunology; Department of Molecular Microbiology; and Department of Biochemistry & Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Richard J Kuhn
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana, USA
| | - Ashleigh Shannon
- Architecture et Fonction des Macromolécules Biologiques, CNRS and Aix Marseille Université, Marseille, France
| | - Meredith N Frazier
- Signal Transduction Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, North Carolina, USA
| | - Kwok-Yung Yuen
- Department of Microbiology, Li Ka Shing Faculty of Medicine and State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Hong Kong, People's Republic of China
- Centre for Virology, Vaccinology and Therapeutics, Hong Kong Science and Technology Park, Hong Kong, People's Republic of China
| | - Carolyn B Coyne
- Department of Molecular Genetics and Microbiology, Duke University, Durham, North Carolina, USA
| | - Katja C Wolthers
- Department of Medical Microbiology, Amsterdam UMC, University of Amsterdam and Amsterdam Institute for Infection and Immunity, OrganoVIR Labs, Amsterdam, The Netherlands
| | - Guo-Li Ming
- Department of Neuroscience and Mahoney Institute for Neurosciences, Institute for Regenerative Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | | | - Jasmine Moshiri
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, USA
| | - Sonja M Best
- Laboratory of Virology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, USA
| | - John W Schoggins
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Kellie Ann Jurado
- Department of Microbiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Gregory D Ebel
- Center for Vector-borne Infectious Diseases, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, USA
| | - Alexandra Schäfer
- Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Lisa F P Ng
- ASTAR Infectious Diseases Labs (A*STAR ID Labs), Agency for Science Technology and Research (A*STAR), Singapore City, Singapore
- National Institute of Health Research, Health Protection Research Unit in Emerging and Zoonotic Infections; Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, UK
| | - Marjolein Kikkert
- Department of Medical Microbiology, Leiden University Medical Center, Leiden, The Netherlands
| | - Alessandro Sette
- Center for Infectious Disease and Vaccine Research, La Jolla Institute for Immunology, La Jolla, California, USA
- Division of Infectious Diseases and Global Public Health, Department of Medicine, University of California, San Diego, La Jolla, California, USA
| | - Eva Harris
- Division of Infectious Diseases and Vaccinology, School of Public Health, University of California, Berkeley, California, USA
| | - Peter A C Wing
- Nuffield Department of Medicine and Chinese Academy of Medical Sciences Oxford Institute, University of Oxford, Oxford, UK
| | - Julie Eggenberger
- Department of Immunology, University of Washington School of Medicine, Seattle, Washington, USA
| | - Siddharth R Krishnamurthy
- Metaorganism Immunity Section, Laboratory of Immune System Biology and NIAID Microbiome Program, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Marcus G Mah
- Programme in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore City, Singapore
| | - Rita M Meganck
- Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Donghoon Chung
- Department of Experimental Therapeutics, MD Anderson Cancer Center, Houston, Texas, USA
| | - Sebastian Maurer-Stroh
- Yong Loo Lin School of Medicine and Department of Biological Sciences, National University of Singapore, Singapore City, Singapore
- Bioinformatics Institute, Agency for Science, Technology and Research, Singapore City, Singapore
| | - Raul Andino
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, California, USA
| | - Bette Korber
- Los Alamos National Laboratory, Los Alamos, New Mexico, USA
| | - Stanley Perlman
- Department of Microbiology and Immunology, and Department of Pediatrics, University of Iowa, Iowa City, Iowa, USA
| | - Pei-Yong Shi
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Montserrat Bárcena
- Section Electron Microscopy, Department of Cell and Chemical Biology, Leiden University Medical Center, Leiden, The Netherlands
| | - Sophie-Marie Aicher
- Institut Pasteurgrid, Université de Paris Cité, Virus Sensing and Signaling Unit, Paris, France
| | - Michelle N Vu
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Devin J Kenney
- Department of Microbiology and National Emerging Infectious Diseases Laboratories, Boston University School of Medicine, Boston, Massachusetts, USA
| | - Brett D Lindenbach
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Yukiko Nishida
- Chugai Pharmaceutical, Co., Tokyo, Japan
- Lee Kong Chian School of Medicine and School of Biological Sciences, Nanyang Technological University, Singapore City, Singapore
| | - Laurent Rénia
- ASTAR Infectious Diseases Labs (A*STAR ID Labs), Agency for Science Technology and Research (A*STAR), Singapore City, Singapore
| | - Evan P Williams
- Department of Microbiology, Immunology, and Biochemistry, The University of Tennessee Health Science Center, Memphis, Tennessee, USA
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12
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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: 5] [Impact Index Per Article: 5.0] [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.
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Affiliation(s)
- Dulce Santos
- Research Group of Molecular Developmental Physiology and Signal Transduction, Division of Animal Physiology and Neurobiology, Department of Biology, KU Leuven, Naamsestraat 59, 3000 Leuven, Belgium
| | - 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
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13
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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.
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14
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Schirtzinger EE, Jasperson DC, Swanson DA, Mitzel D, Drolet BS, Richt JA, Wilson WC. Establishment of a Culex tarsalis (Diptera: Culicidae) Cell Line and its Permissiveness to Arbovirus Infection. JOURNAL OF MEDICAL ENTOMOLOGY 2023; 60:239-244. [PMID: 36260075 PMCID: PMC10091495 DOI: 10.1093/jme/tjac155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Indexed: 05/25/2023]
Abstract
A cell line was established from Culex tarsalis Coquillett embryonated eggs and designated as CxTr. The cell line is heterogeneous, composed predominantly of small, round cells, and spindle-shaped cells with a doubling time of approximately 52-60 h. The identity of the cell line was verified as Cx. tarsalis by sequencing of cytochrome oxidase I and the cells were found to be free of contaminating cells, bacteria, fungi, and mycoplasma. The permissiveness of CxTr cells to arbovirus infection was investigated with vaccine and wildtype arboviruses from four viral families: Flaviviridae (Japanese encephalitis virus), Phenuiviridae (Rift Valley fever phlebovirus), Rhabdoviridae (vesicular stomatitis virus), and Togaviridae (Mayaro virus). All viruses were able to infect and replicate within CxTr cells.
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Affiliation(s)
- Erin E Schirtzinger
- Arthropod-borne Animal Diseases Research Unit, USDA, ARS, Manhattan, KS, USA
- Department of Diagnostic Medicine/Pathology, College of Veterinary Medicine, Kansas State University, Manhattan, KS, USA
| | - Dane C Jasperson
- Arthropod-borne Animal Diseases Research Unit, USDA, ARS, Manhattan, KS, USA
| | - Dustin A Swanson
- Arthropod-borne Animal Diseases Research Unit, USDA, ARS, Manhattan, KS, USA
| | - Dana Mitzel
- Foreign Arthropod-borne Animal Diseases Research Unit, National Bio- and Agro-Defense Facility, USDA, ARS, Manhattan, KS, USA
| | - Barbara S Drolet
- Arthropod-borne Animal Diseases Research Unit, USDA, ARS, Manhattan, KS, USA
| | - Juergen A Richt
- Department of Diagnostic Medicine/Pathology, College of Veterinary Medicine, Kansas State University, Manhattan, KS, USA
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15
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Suzuki Y. [Endogenous viral emelement limit cognate virus replication in mosquito vectors]. Uirusu 2023; 72:159-166. [PMID: 38220204 DOI: 10.2222/jsv.72.159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2024]
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16
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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.
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17
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Antiviral RNAi Mechanisms to Arboviruses in Mosquitoes: microRNA Profile of Aedes aegypti and Culex quinquefasciatus from Grenada, West Indies. Appl Microbiol 2022. [DOI: 10.3390/applmicrobiol2020029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Mosquito-borne arboviruses, such as dengue virus, West Nile virus, Zika virus and yellow fever virus, impose a tremendous cost on the health of populations around the world. As a result, much effort has gone into the study of the impact of these viruses on human infections. Comparatively less effort, however, has been made to study the way these viruses interact with mosquitoes themselves. As ingested arboviruses infect their midgut and subsequently other tissue, the mosquito mounts a multifaceted innate immune response. RNA interference, the central intracellular antiviral defense mechanism in mosquitoes and other invertebrates can be induced and modulated through outside triggers (small RNAs) and treatments (transgenesis or viral-vector delivery). Accordingly, modulation of this facet of the mosquito’s immune system would thereby suggest a practical strategy for vector control. However, this requires a detailed understanding of mosquitoes’ endogenous small RNAs and their effects on the mosquito and viral proliferation. This paper provides an up-to-date overview of the mosquito’s immune system along with novel data describing miRNA profiles for Aedes aegypti and Culex quinquefasiatus in Grenada, West Indies.
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18
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Fiorillo C, Yen PS, Colantoni A, Mariconti M, Azevedo N, Lombardo F, Failloux AB, Arcà B. MicroRNAs and other small RNAs in Aedes aegypti saliva and salivary glands following chikungunya virus infection. Sci Rep 2022; 12:9536. [PMID: 35681077 PMCID: PMC9184468 DOI: 10.1038/s41598-022-13780-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Accepted: 05/27/2022] [Indexed: 11/10/2022] Open
Abstract
Mosquito saliva facilitates blood feeding through the anti-haemostatic, anti-inflammatory and immunomodulatory properties of its proteins. However, the potential contribution of non-coding RNAs to host manipulation is still poorly understood. We analysed small RNAs from Aedes aegypti saliva and salivary glands and show here that chikungunya virus-infection triggers both the siRNA and piRNA antiviral pathways with limited effects on miRNA expression profiles. Saliva appears enriched in specific miRNA subsets and its miRNA content is well conserved among mosquitoes and ticks, clearly pointing to a non-random sorting and occurrence. Finally, we provide evidence that miRNAs from Ae. aegypti saliva may target human immune and inflammatory pathways, as indicated by prediction analysis and searching for experimentally validated targets of identical human miRNAs. Overall, we believe these observations convincingly support a scenario where both proteins and miRNAs from mosquito saliva are injected into vertebrates during blood feeding and contribute to the complex vector-host-pathogen interactions.
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Affiliation(s)
- Carmine Fiorillo
- Department of Public Health and Infectious Diseases - Division of Parasitology, "Sapienza" University, Piazzale Aldo Moro 5, 00185, Rome, Italy
| | - Pei-Shi Yen
- Arboviruses and Insect Vectors Unit, Institute Pasteur, 25 rue Dr. Roux, 75724, Paris Cedex 15, France
| | - Alessio Colantoni
- Department of Biology and Biotechnology, "Sapienza" University, Piazzale Aldo Moro 5, 00185, Rome, Italy
| | - Marina Mariconti
- Arboviruses and Insect Vectors Unit, Institute Pasteur, 25 rue Dr. Roux, 75724, Paris Cedex 15, France
| | - Nayara Azevedo
- Genomics Core Facility, European Molecular Biology Laboratory, Meyerhofstrasse 1, 69117, Heidelberg, Germany
| | - Fabrizio Lombardo
- Department of Public Health and Infectious Diseases - Division of Parasitology, "Sapienza" University, Piazzale Aldo Moro 5, 00185, Rome, Italy
| | - Anna-Bella Failloux
- Arboviruses and Insect Vectors Unit, Institute Pasteur, 25 rue Dr. Roux, 75724, Paris Cedex 15, France
| | - Bruno Arcà
- Department of Public Health and Infectious Diseases - Division of Parasitology, "Sapienza" University, Piazzale Aldo Moro 5, 00185, Rome, Italy.
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19
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Wang ZZ, Ye XQ, Huang JH, Chen XX. Virus and endogenous viral element-derived small non-coding RNAs and their roles in insect-virus interaction. CURRENT OPINION IN INSECT SCIENCE 2022; 49:85-92. [PMID: 34974161 DOI: 10.1016/j.cois.2021.12.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 12/20/2021] [Accepted: 12/21/2021] [Indexed: 06/14/2023]
Abstract
RNA interference pathways mediated by different types of small non-coding RNAs (siRNAs, miRNAs and piRNAs) are conserved biological responses to exotic stresses, including viral infection. Aside from the well-established siRNA pathway, the miRNA pathway and the piRNA pathway process viral sequences, exogenously or endogenously, into miRNAs and piRNAs, respectively. During the host-virus interaction, viral sequences, including both coding and non-coding sequences, can be integrated as endogenous viral elements (EVEs) and thereby become present within the germline of a non-viral organism. In recent years, significant progress has been made in characterizing the biogenesis and function of viruses and EVEs associated with snRNAs. Overall, the siRNA pathway acts as the primarily antiviral defense against a wide range of exogenous viruses; the miRNA pathways associated with viruses or EVEs function in antiviral response and host gene regulation; EVE derived piRNAs with a ping-pong signature have the potential to limit cognate viral infection.
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Affiliation(s)
- Zhi-Zhi Wang
- Institute of Insect Sciences, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, China; Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insect Pests, Zhejiang University, Hangzhou 310058, China; Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Zhejiang University, Hangzhou 310058, China
| | - Xi-Qian Ye
- Institute of Insect Sciences, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, China; Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insect Pests, Zhejiang University, Hangzhou 310058, China; Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Zhejiang University, Hangzhou 310058, China
| | - Jian-Hua Huang
- Institute of Insect Sciences, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, China; Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insect Pests, Zhejiang University, Hangzhou 310058, China; Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Zhejiang University, Hangzhou 310058, China
| | - Xue-Xin Chen
- Institute of Insect Sciences, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, China; Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insect Pests, Zhejiang University, Hangzhou 310058, China; Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Zhejiang University, Hangzhou 310058, China; State Key Lab of Rice Biology, Zhejiang University, Hangzhou 310058, China.
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20
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Cell Line Platforms Support Research into Arthropod Immunity. INSECTS 2021; 12:insects12080738. [PMID: 34442304 PMCID: PMC8397109 DOI: 10.3390/insects12080738] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 08/10/2021] [Accepted: 08/12/2021] [Indexed: 12/21/2022]
Abstract
Simple Summary Many insect and tick species are serious pests, because insects damage crop plants and, along with ticks, transmit a wide range of human and animal diseases. One way of controlling these pests is by impairing their immune system, which protects them from bacterial, fungal, and viral infections. An important tool for studying immunity is using long-lasting cell cultures, known as cell lines. These lines can be frozen and thawed at will to be used in automated tests, and they provide consistent results over years. Questions that can be asked using cell lines include: How do insects or ticks recognize when they have been infected and by what organism? What kinds of defensive strategies do they use to contain or kill infectious agents? This article reviews research with insect or tick cell lines to answer these questions, as well as other questions relating to immunity. This review also discusses future research strategies for working with cell lines. Abstract Innate immune responses are essential to maintaining insect and tick health and are the primary defense against pathogenic viruses, bacteria, and fungi. Cell line research is a powerful method for understanding how invertebrates mount defenses against pathogenic organisms and testing hypotheses on how these responses occur. In particular, immortal arthropod cell lines are valuable tools, providing a tractable, high-throughput, cost-effective, and consistent platform to investigate the mechanisms underpinning insect and tick immune responses. The research results inform the controls of medically and agriculturally important insects and ticks. This review presents several examples of how cell lines have facilitated research into multiple aspects of the invertebrate immune response to pathogens and other foreign agents, as well as comments on possible future research directions in these robust systems.
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21
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Parry R, James ME, Asgari S. Uncovering the Worldwide Diversity and Evolution of the Virome of the Mosquitoes Aedes aegypti and Aedes albopictus. Microorganisms 2021; 9:microorganisms9081653. [PMID: 34442732 PMCID: PMC8398489 DOI: 10.3390/microorganisms9081653] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2021] [Revised: 07/13/2021] [Accepted: 07/27/2021] [Indexed: 12/16/2022] Open
Abstract
Aedes aegypti, the yellow fever mosquito, and Aedes albopictus, the Asian tiger mosquito, are the most significant vectors of dengue, Zika, and Chikungunya viruses globally. Studies examining host factors that control arbovirus transmission demonstrate that insect-specific viruses (ISVs) can modulate mosquitoes’ susceptibility to arbovirus infection in both in vivo and in vitro co-infection models. While research is ongoing to implicate individual ISVs as proviral or antiviral factors, we have a limited understanding of the composition and diversity of the Aedes virome. To address this gap, we used a meta-analysis approach to uncover virome diversity by analysing ~3000 available RNA sequencing libraries representing a worldwide geographic range for both mosquitoes. We identified ten novel viruses and previously characterised viruses, including mononegaviruses, orthomyxoviruses, negeviruses, and a novel bi-segmented negev-like group. Phylogenetic analysis suggests close relatedness to mosquito viruses implying likely insect host range except for one arbovirus, the multi-segmented Jingmen tick virus (Flaviviridae) in an Italian colony of Ae. albopictus. Individual mosquito transcriptomes revealed remarkable inter-host variation of ISVs within individuals from the same colony and heterogeneity between different laboratory strains. Additionally, we identified striking virus diversity in Wolbachia infected Aedes cell lines. This study expands our understanding of the virome of these important vectors. It provides a resource for further assessing the ecology, evolution, and interaction of ISVs with their mosquito hosts and the arboviruses they transmit.
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Affiliation(s)
- Rhys Parry
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia
- Correspondence:
| | - Maddie E James
- School of Biological Sciences, The University of Queensland, Brisbane, QLD 4072, Australia; (M.E.J.); (S.A.)
| | - Sassan Asgari
- School of Biological Sciences, The University of Queensland, Brisbane, QLD 4072, Australia; (M.E.J.); (S.A.)
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22
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Azlan A, Halim MA, Mohamad F, Azzam G. Identification and characterization of long noncoding RNAs and their association with acquisition of blood meal in Culex quinquefasciatus. INSECT SCIENCE 2021; 28:917-928. [PMID: 32621332 DOI: 10.1111/1744-7917.12847] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 06/20/2020] [Accepted: 06/22/2020] [Indexed: 06/11/2023]
Abstract
The Southern house mosquito, Culex quinquefasciatus (Cx. quinquefasciatus) is an important vector that transmit multiple diseases including West Nile encephalitis, Japanese encephalitis, St. Louis encephalitis and lymphatic filariasis. Long noncoding RNAs (lncRNAs) involve in many biological processes such as development, infection, and virus-host interaction. However, there is no systematic identification and characterization of lncRNAs in Cx. quinquefasciatus. Here, we report the first lncRNA identification in Cx. quinquefasciatus. By using 31 public RNA-seq datasets, a total of 4763 novel lncRNA transcripts were identified, of which 3591, 569, and 603 were intergenic, intronic, and antisense respectively. Examination of genomic features revealed that Cx. quinquefasciatus shared similar characteristics with other species such as short in length, low GC content, low sequence conservation, and low coding potential. Furthermore, compared to protein-coding genes, Cx. quinquefasciatus lncRNAs had lower expression values, and tended to be expressed in temporally specific fashion. In addition, weighted correlation network and functional annotation analyses showed that lncRNAs may have roles in blood meal acquisition of adult female Cx. quinquefasciatus mosquitoes. This study presents the first systematic identification and analysis of Cx. quinquefasciatus lncRNAs and their association with blood feeding. Results generated from this study will facilitate future investigation on the function of Cx. quinquefasciatus lncRNAs.
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Affiliation(s)
- Azali Azlan
- School of Biological Sciences, Universiti Sains Malaysia, Penang, Malaysia
| | | | - Faisal Mohamad
- School of Biological Sciences, Universiti Sains Malaysia, Penang, Malaysia
| | - Ghows Azzam
- School of Biological Sciences, Universiti Sains Malaysia, Penang, Malaysia
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23
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Abstract
Narnaviruses are RNA viruses detected in diverse fungi, plants, protists, arthropods, and nematodes. Though initially described as simple single-gene nonsegmented viruses encoding RNA-dependent RNA polymerase (RdRp), a subset of narnaviruses referred to as "ambigrammatic" harbor a unique genomic configuration consisting of overlapping open reading frames (ORFs) encoded on opposite strands. Phylogenetic analysis supports selection to maintain this unusual genome organization, but functional investigations are lacking. Here, we establish the mosquito-infecting Culex narnavirus 1 (CxNV1) as a model to investigate the functional role of overlapping ORFs in narnavirus replication. In CxNV1, a reverse ORF without homology to known proteins covers nearly the entire 3.2-kb segment encoding the RdRp. Additionally, two opposing and nearly completely overlapping novel ORFs are found on the second putative CxNV1 segment, the 0.8-kb "Robin" RNA. We developed a system to launch CxNV1 in a naive mosquito cell line and then showed that functional RdRp is required for persistence of both segments, and an intact reverse ORF is required on the RdRp segment for persistence. Mass spectrometry of persistently CxNV1-infected cells provided evidence for translation of this reverse ORF. Finally, ribosome profiling yielded a striking pattern of footprints for all four CxNV1 RNA strands that was distinct from actively translating ribosomes on host mRNA or coinfecting RNA viruses. Taken together, these data raise the possibility that the process of translation itself is important for persistence of ambigrammatic narnaviruses, potentially by protecting viral RNA with ribosomes, thus suggesting a heretofore undescribed viral tactic for replication and transmission. IMPORTANCE Fundamental to our understanding of RNA viruses is a description of which strand(s) of RNA are transmitted as the viral genome relative to which encode the viral proteins. Ambigrammatic narnaviruses break the mold. These viruses, found broadly in fungi, plants, and insects, have the unique feature of two overlapping genes encoded on opposite strands, comprising nearly the full length of the viral genome. Such extensive overlap is not seen in other RNA viruses and comes at the cost of reduced evolutionary flexibility in the sequence. The present study is motivated by investigating the benefits which balance that cost. We show for the first time a functional requirement for the ambigrammatic genome configuration in Culex narnavirus 1, which suggests a model for how translation of both strands might benefit this virus. Our work highlights a new blueprint for viral persistence, distinct from strategies defined by canonical definitions of the coding strand.
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Rosendo Machado S, van der Most T, Miesen P. Genetic determinants of antiviral immunity in dipteran insects - Compiling the experimental evidence. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2021; 119:104010. [PMID: 33476667 DOI: 10.1016/j.dci.2021.104010] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 01/08/2021] [Accepted: 01/09/2021] [Indexed: 06/12/2023]
Abstract
The genetic basis of antiviral immunity in dipteran insects is extensively studied in Drosophila melanogaster and advanced technologies for genetic manipulation allow a better characterization of immune responses also in non-model insect species. Especially, immunity in vector mosquitoes is recently in the spotlight, due to the medical impact that these insects have by transmitting viruses and other pathogens. Here, we review the current state of experimental evidence that supports antiviral functions for immune genes acting in different cellular pathways. We discuss the well-characterized RNA interference mechanism along with the less well-defined JAK-STAT, Toll, and IMD signaling pathways. Furthermore, we highlight the initial evidence for antiviral activity observed for the autophagy pathway, transcriptional pausing, as well as piRNA production from endogenous viral elements. We focus our review on studies from Drosophila and mosquito species from the lineages Aedes, Culex, and Anopheles, which contain major vector species responsible for virus transmission.
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Affiliation(s)
- Samara Rosendo Machado
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Nijmegen Medical Center, P.O. Box 9101, 6500 HB, Nijmegen, the Netherlands
| | - Tom van der Most
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Nijmegen Medical Center, P.O. Box 9101, 6500 HB, Nijmegen, the Netherlands
| | - Pascal Miesen
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Nijmegen Medical Center, P.O. Box 9101, 6500 HB, Nijmegen, the Netherlands.
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25
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Differential miRNA Expression Profiling Reveals Correlation of miR125b-5p with Persistent Infection of Japanese Encephalitis Virus. Int J Mol Sci 2021; 22:ijms22084218. [PMID: 33921710 PMCID: PMC8073291 DOI: 10.3390/ijms22084218] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 04/13/2021] [Accepted: 04/14/2021] [Indexed: 12/13/2022] Open
Abstract
MicroRNAs (miRNAs) play versatile roles in multiple biological processes. However, little is known about miRNA’s involvement in flavivirus persistent infection. Here, we used an miRNA array analysis of Japanese encephalitis virus (JEV)-infected cells to search for persistent infection-associated miRNAs in comparison to acute infection. Among all differentially expressed miRNAs, the miR-125b-5p is the most significantly increased one. The high level of miR-125b-5p in persistently JEV-infected cells was confirmed by Northern analysis and real-time quantitative polymerase chain reaction. As soon as the cells established a persistent infection, a significantly high expression of miR-125b-5p was readily observed. Transfecting excess quantities of a miR-125b-5p mimic into acutely infected cells reduced genome replication and virus titers. Host targets of miR125b-5p were analyzed by target prediction algorithms, and six candidates were confirmed by a dual-luciferase reporter assay. These genes were upregulated in the acutely infected cells and sharply declined in the persistently infected cells. The transfection of the miR125b-5p mimic reduced the expression levels of Stat3, Map2k7, and Triap1. Our studies indicated that miR-125b-5p targets both viral and host sequences, suggesting its role in coordinating viral replication and host antiviral responses. This is the first report to characterize the potential roles of miR-125b-5p in persistent JEV infections.
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Ma Q, Srivastav SP, Gamez S, Dayama G, Feitosa-Suntheimer F, Patterson EI, Johnson RM, Matson EM, Gold AS, Brackney DE, Connor JH, Colpitts TM, Hughes GL, Rasgon JL, Nolan T, Akbari OS, Lau NC. A mosquito small RNA genomics resource reveals dynamic evolution and host responses to viruses and transposons. Genome Res 2021; 31:512-528. [PMID: 33419731 PMCID: PMC7919454 DOI: 10.1101/gr.265157.120] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Accepted: 01/06/2021] [Indexed: 12/14/2022]
Abstract
Although mosquitoes are major transmission vectors for pathogenic arboviruses, viral infection has little impact on mosquito health. This immunity is caused in part by mosquito RNA interference (RNAi) pathways that generate antiviral small interfering RNAs (siRNAs) and Piwi-interacting RNAs (piRNAs). RNAi also maintains genome integrity by potently repressing mosquito transposon activity in the germline and soma. However, viral and transposon small RNA regulatory pathways have not been systematically examined together in mosquitoes. Therefore, we developed an integrated mosquito small RNA genomics (MSRG) resource that analyzes the transposon and virus small RNA profiles in mosquito cell cultures and somatic and gonadal tissues across four medically important mosquito species. Our resource captures both somatic and gonadal small RNA expression profiles within mosquito cell cultures, and we report the evolutionary dynamics of a novel Mosquito-Conserved piRNA Cluster Locus (MCpiRCL) made up of satellite DNA repeats. In the larger culicine mosquito genomes we detected highly regular periodicity in piRNA biogenesis patterns coinciding with the expansion of Piwi pathway genes. Finally, our resource enables detection of cross talk between piRNA and siRNA populations in mosquito cells during a response to virus infection. The MSRG resource will aid efforts to dissect and combat the capacity of mosquitoes to tolerate and spread arboviruses.
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Affiliation(s)
- Qicheng Ma
- Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts 02118, USA
| | - Satyam P Srivastav
- Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts 02118, USA
| | - Stephanie Gamez
- Division of Biological Sciences, Section of Cell and Developmental Biology, University of California San Diego, La Jolla, California 92093, USA
| | - Gargi Dayama
- Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts 02118, USA
| | - Fabiana Feitosa-Suntheimer
- Department of Microbiology and the National Emerging Infectious Disease Laboratory, Boston University School of Medicine, Boston, Massachusetts 02118, USA
| | - Edward I Patterson
- Departments of Vector Biology and Tropical Disease Biology, Centre for Neglected Tropical Diseases, Liverpool School of Tropical Medicine, Liverpool L3 5QA, United Kingdom
| | - Rebecca M Johnson
- Department of Entomology, Center for Infectious Disease Dynamics, and the Huck Institutes for the Life Sciences, Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Erik M Matson
- Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts 02118, USA
| | - Alexander S Gold
- Department of Microbiology and the National Emerging Infectious Disease Laboratory, Boston University School of Medicine, Boston, Massachusetts 02118, USA
| | - Douglas E Brackney
- Department of Environmental Sciences, The Connecticut Agricultural Experiment Station, New Haven, Connecticut 06511, USA
| | - John H Connor
- Department of Microbiology and the National Emerging Infectious Disease Laboratory, Boston University School of Medicine, Boston, Massachusetts 02118, USA
| | - Tonya M Colpitts
- Department of Microbiology and the National Emerging Infectious Disease Laboratory, Boston University School of Medicine, Boston, Massachusetts 02118, USA
| | - Grant L Hughes
- Departments of Vector Biology and Tropical Disease Biology, Centre for Neglected Tropical Diseases, Liverpool School of Tropical Medicine, Liverpool L3 5QA, United Kingdom
| | - Jason L Rasgon
- Department of Entomology, Center for Infectious Disease Dynamics, and the Huck Institutes for the Life Sciences, Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Tony Nolan
- Departments of Vector Biology and Tropical Disease Biology, Centre for Neglected Tropical Diseases, Liverpool School of Tropical Medicine, Liverpool L3 5QA, United Kingdom
| | - Omar S Akbari
- Division of Biological Sciences, Section of Cell and Developmental Biology, University of California San Diego, La Jolla, California 92093, USA
| | - Nelson C Lau
- Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts 02118, USA
- Boston University Genome Science Institute and the National Emerging Infectious Disease Laboratory, Boston, Massachusetts 02118, USA
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27
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The Antiviral Small-Interfering RNA Pathway Induces Zika Virus Resistance in Transgenic Aedes aegypti. Viruses 2020; 12:v12111231. [PMID: 33142991 PMCID: PMC7692394 DOI: 10.3390/v12111231] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 10/27/2020] [Accepted: 10/28/2020] [Indexed: 01/21/2023] Open
Abstract
The resurgence of arbovirus outbreaks across the globe, including the recent Zika virus (ZIKV) epidemic in 2015–2016, emphasizes the need for innovative vector control methods. In this study, we investigated ZIKV susceptibility to transgenic Aedes aegypti engineered to target the virus by means of the antiviral small-interfering RNA (siRNA) pathway. The robustness of antiviral effector expression in transgenic mosquitoes is strongly influenced by the genomic insertion locus and transgene copy number; we therefore used CRISPR/Cas9 to re-target a previously characterized locus (Chr2:321382225) and engineered mosquitoes expressing an inverted repeat (IR) dsRNA against the NS3/4A region of the ZIKV genome. Small RNA analysis revealed that the IR effector triggered the mosquito’s siRNA antiviral pathway in bloodfed females. Nearly complete (90%) inhibition of ZIKV replication was found in vivo in both midguts and carcasses at 7 or 14 days post-infection (dpi). Furthermore, significantly fewer transgenic mosquitoes contained ZIKV in their salivary glands (p = 0.001), which led to a reduction in the number of ZIKV-containing saliva samples as measured by transmission assay. Our work shows that Ae. aegypti innate immunity can be co-opted to engineer mosquitoes resistant to ZIKV.
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28
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Gamez S, Srivastav S, Akbari OS, Lau NC. Diverse Defenses: A Perspective Comparing Dipteran Piwi-piRNA Pathways. Cells 2020; 9:E2180. [PMID: 32992598 PMCID: PMC7601171 DOI: 10.3390/cells9102180] [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: 09/02/2020] [Revised: 09/22/2020] [Accepted: 09/23/2020] [Indexed: 02/07/2023] Open
Abstract
Animals face the dual threat of virus infections hijacking cellular function and transposons proliferating in germline genomes. For insects, the deeply conserved RNA interference (RNAi) pathways and other chromatin regulators provide an important line of defense against both viruses and transposons. For example, this innate immune system displays adaptiveness to new invasions by generating cognate small RNAs for targeting gene silencing measures against the viral and genomic intruders. However, within the Dipteran clade of insects, Drosophilid fruit flies and Culicids mosquitoes have evolved several unique mechanistic aspects of their RNAi defenses to combat invading transposons and viruses, with the Piwi-piRNA arm of the RNAi pathways showing the greatest degree of novel evolution. Whereas central features of Piwi-piRNA pathways are conserved between Drosophilids and Culicids, multiple lineage-specific innovations have arisen that may reflect distinct genome composition differences and specific ecological and physiological features dividing these two branches of Dipterans. This perspective review focuses on the most recent findings illuminating the Piwi/piRNA pathway distinctions between fruit flies and mosquitoes, and raises open questions that need to be addressed in order to ameliorate human diseases caused by pathogenic viruses that mosquitoes transmit as vectors.
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Affiliation(s)
- Stephanie Gamez
- Division of Biological Sciences, Section of Cell and Developmental Biology, University of California, San Diego, CA 92093, USA; (S.G.); (O.S.A.)
| | - Satyam Srivastav
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853-2703, USA;
| | - Omar S. Akbari
- Division of Biological Sciences, Section of Cell and Developmental Biology, University of California, San Diego, CA 92093, USA; (S.G.); (O.S.A.)
| | - Nelson C. Lau
- Department of Biochemistry and Genome Science Institute, Boston University School of Medicine, Boston, MA 02118, USA
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29
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MacLeod HJ, Dimopoulos G. Detailed Analyses of Zika Virus Tropism in Culex quinquefasciatus Reveal Systemic Refractoriness. mBio 2020; 11:e01765-20. [PMID: 32817107 PMCID: PMC7439479 DOI: 10.1128/mbio.01765-20] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 07/15/2020] [Indexed: 01/01/2023] Open
Abstract
The role of Culex quinquefasciatus in Zika virus transmission has been debated since the epidemic of Zika occurred in the Americas in 2015 to 2016. The majority of studies have found no evidence that C. quinquefasciatus or other Culex species are competent vectors of Zika virus, and the few studies that have proposed Zika vector status for C. quinquefasciatus have relied predominantly on quantitative real-time PCR (qRT-PCR) for viral detection. We assessed the infectious range of pre- and post-epidemic Zika virus isolates in order to classify mosquito samples based on titer infectiousness and demonstrated that two strains of C. quinquefasciatus, including one previously found to be competent, are highly resistant to infection with these Zika isolates compared to Aedes aegypti and are not competent for virus transmission. Further dissection of the dynamics of Zika exposure in both A. aegypti and C. quinquefasciatus revealed that while virus transmission by C. quinquefasciatus is blocked at the levels of the midgut and salivary glands, viral RNA persists in these tissues for prolonged periods post-exposure. We assessed Zika entry dynamics in both Aedes and Culex cells, and our results suggest that Zika virus infection in Culex cells may be blocked downstream of cell entry. These findings strongly suggest that C. quinquefasciatus is not a vector of Zika virus and additionally inform the use of qRT-PCR in vector competence assays as well as our understanding of barriers to arbovirus infection in non-susceptible mosquito species.IMPORTANCE Understanding which mosquito species transmit an emerging arbovirus is critical to effective vector control. During the Zika virus epidemic in 2015 to 2016, Aedes mosquitoes were confirmed as vectors. However, studies addressing the vector status of Culex quinquefasciatus mosquitoes presented conflicting evidence and remain an outstanding source of confusion in the field. Here, we established a robust cell-based assay to identify infectious titers of Zika virus and assessed the virus titers in C. quinquefasciatus by quantitative real-time PCR (qRT-PCR). We found that while low levels of virus were detected in C. quinquefasciatus, these titers did not correspond to infectious virus, and these mosquitoes did not transmit virus in the saliva. We also present evidence that the virus may enter Culex cells before infection is disrupted. Our findings are important for future studies incriminating vector species using qRT-PCR for virus detection and offer new information on how virus transmission is blocked by mosquitoes.
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Affiliation(s)
- Hannah J MacLeod
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, USA
| | - George Dimopoulos
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, USA
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30
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Qasim M, Xiao H, He K, Omar MAA, Liu F, Ahmed S, Li F. Genetic engineering and bacterial pathogenesis against the vectorial capacity of mosquitoes. Microb Pathog 2020; 147:104391. [PMID: 32679245 DOI: 10.1016/j.micpath.2020.104391] [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: 06/04/2020] [Revised: 07/05/2020] [Accepted: 07/09/2020] [Indexed: 12/19/2022]
Abstract
Mosquitoes are the main vector of multiple diseases worldwide and transmit viral (malaria, chikungunya, encephalitis, yellow fever, as well as dengue fever), as well as bacterial diseases (tularemia). To manage the outbreak of mosquito populations, various management programs include the application of chemicals, followed by biological and genetic control. Here we aimed to focus on the role of bacterial pathogenesis and molecular tactics for the management of mosquitoes and their vectorial capacity. Bacterial pathogenesis and molecular manipulations have a substantial impact on the biology of mosquitoes, and both strategies change the gene expression and regulation of disease vectors. The strategy for genetic modification is also proved to be excellent for the management of mosquitoes, which halt the development of population via incompatibility of different sex. Therefore, the purpose of the present discussion is to illustrate the impact of both approaches against the vectorial capacity of mosquitoes. Moreover, it could be helpful to understand the relationship of insect-pathogen and to manage various insect vectors as well as diseases.
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Affiliation(s)
- Muhammad Qasim
- Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, College of Agriculture & Biotechnology, Zhejiang University, Hangzhou, 310058, China.
| | - Huamei Xiao
- Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, College of Agriculture & Biotechnology, Zhejiang University, Hangzhou, 310058, China; College of Life Sciences and Resource Environment, Key Laboratory of Crop Growth and Development Regulation of Jiangxi Province, Yichun University, Yichun, 336000, China
| | - Kang He
- Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, College of Agriculture & Biotechnology, Zhejiang University, Hangzhou, 310058, China
| | - Mohamed A A Omar
- Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, College of Agriculture & Biotechnology, Zhejiang University, Hangzhou, 310058, China
| | - Feiling Liu
- Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, College of Agriculture & Biotechnology, Zhejiang University, Hangzhou, 310058, China
| | - Sohail Ahmed
- Department of Entomology, University of Agriculture, Faisalabad, 38040, Pakistan
| | - Fei Li
- Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, College of Agriculture & Biotechnology, Zhejiang University, Hangzhou, 310058, China.
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31
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Suzuki Y, Baidaliuk A, Miesen P, Frangeul L, Crist AB, Merkling SH, Fontaine A, Lequime S, Moltini-Conclois I, Blanc H, van Rij RP, Lambrechts L, Saleh MC. Non-retroviral Endogenous Viral Element Limits Cognate Virus Replication in Aedes aegypti Ovaries. Curr Biol 2020; 30:3495-3506.e6. [PMID: 32679098 PMCID: PMC7522710 DOI: 10.1016/j.cub.2020.06.057] [Citation(s) in RCA: 71] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 06/06/2020] [Accepted: 06/16/2020] [Indexed: 12/27/2022]
Abstract
Endogenous viral elements (EVEs) are viral sequences integrated in host genomes. A large number of non-retroviral EVEs was recently detected in Aedes mosquito genomes, leading to the hypothesis that mosquito EVEs may control exogenous infections by closely related viruses. Here, we experimentally investigated the role of an EVE naturally found in Aedes aegypti populations and derived from the widespread insect-specific virus, cell-fusing agent virus (CFAV). Using CRISPR-Cas9 genome editing, we created an Ae. aegypti line lacking the CFAV EVE. Absence of the EVE resulted in increased CFAV replication in ovaries, possibly modulating vertical transmission of the virus. Viral replication was controlled by targeting of viral RNA by EVE-derived P-element-induced wimpy testis-interacting RNAs (piRNAs). Our results provide evidence that antiviral piRNAs are produced in the presence of a naturally occurring EVE and its cognate virus, demonstrating a functional link between non-retroviral EVEs and antiviral immunity in a natural insect-virus interaction. Aedes aegypti harbors EVEs with high sequence identity to a contemporary RNA virus EVE-derived piRNAs target genomic viral RNA in infected mosquitoes Ablation of EVE results in increased viral replication in Aedes aegypti ovaries piRNA pathway fulfills antiviral function in presence of EVE and cognate virus
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Affiliation(s)
- Yasutsugu Suzuki
- Viruses and RNA Interference Unit, Institut Pasteur, UMR3569, CNRS, Paris, France
| | - Artem Baidaliuk
- Insect-Virus Interactions Unit, Institut Pasteur, UMR2000, CNRS, Paris, France; Collège Doctoral, Sorbonne Université, 75005 Paris, France
| | - Pascal Miesen
- Viruses and RNA Interference Unit, Institut Pasteur, UMR3569, CNRS, Paris, France; Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Lionel Frangeul
- Viruses and RNA Interference Unit, Institut Pasteur, UMR3569, CNRS, Paris, France
| | - Anna B Crist
- Insect-Virus Interactions Unit, Institut Pasteur, UMR2000, CNRS, Paris, France
| | - Sarah H Merkling
- Insect-Virus Interactions Unit, Institut Pasteur, UMR2000, CNRS, Paris, France
| | - Albin Fontaine
- Insect-Virus Interactions Unit, Institut Pasteur, UMR2000, CNRS, Paris, France
| | - Sebastian Lequime
- Laboratory of Clinical and Epidemiological Virology, Rega Institute, Department of Microbiology and Immunology, KU Leuven, Leuven, Belgium
| | | | - Hervé Blanc
- Viruses and RNA Interference Unit, Institut Pasteur, UMR3569, CNRS, Paris, France
| | - Ronald P van Rij
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Louis Lambrechts
- Insect-Virus Interactions Unit, Institut Pasteur, UMR2000, CNRS, Paris, France.
| | - Maria-Carla Saleh
- Viruses and RNA Interference Unit, Institut Pasteur, UMR3569, CNRS, Paris, France.
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32
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Differential Small RNA Responses against Co-Infecting Insect-Specific Viruses in Aedes albopictus Mosquitoes. Viruses 2020; 12:v12040468. [PMID: 32326240 PMCID: PMC7232154 DOI: 10.3390/v12040468] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 04/15/2020] [Accepted: 04/17/2020] [Indexed: 12/23/2022] Open
Abstract
The mosquito antiviral response has mainly been studied in the context of arthropod-borne virus (arbovirus) infection in female mosquitoes. However, in nature, both female and male mosquitoes are frequently infected with insect-specific viruses (ISVs). ISVs are capable of infecting the reproductive organs of both sexes and are primarily maintained by vertical transmission. Since the RNA interference (RNAi)-mediated antiviral response plays an important antiviral role in mosquitoes, ISVs constitute a relevant model to study sex-dependent antiviral responses. Using a naturally generated viral stock containing three distinct ISVs, Aedes flavivirus (AEFV), Menghai rhabdovirus (MERV), and Shinobi tetra virus (SHTV), we infected adult Aedes albopictus females and males and generated small RNA libraries from ovaries, testes, and the remainder of the body. Overall, both female and male mosquitoes showed unique small RNA profiles to each co-infecting ISV regardless of the sex or tissue tested. While all three ISVs generated virus-derived siRNAs, only MERV generated virus-derived piRNAs. We also studied the expression of PIWI genes in reproductive tissues and carcasses. In contrast to Piwi5-9, Piwi1-4 were abundantly expressed in ovaries and testes, suggesting that Piwi5-9 are involved in exogenous viral piRNA production. Together, our results show that ISV-infected Aedes albopictus produce viral small RNAs in a virus-specific manner and that male mosquitoes mount a similar small RNA-mediated antiviral response to that of females.
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33
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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.
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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
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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.
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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
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35
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piRNA-Guided CRISPR-like Immunity in Eukaryotes. Trends Immunol 2019; 40:998-1010. [DOI: 10.1016/j.it.2019.09.003] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Revised: 09/17/2019] [Accepted: 09/17/2019] [Indexed: 02/07/2023]
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Santos D, Mingels L, Vogel E, Wang L, Christiaens O, Cappelle K, Wynant N, Gansemans Y, Van Nieuwerburgh F, Smagghe G, Swevers L, Vanden Broeck J. Generation of Virus- and dsRNA-Derived siRNAs with Species-Dependent Length in Insects. Viruses 2019; 11:v11080738. [PMID: 31405199 PMCID: PMC6723321 DOI: 10.3390/v11080738] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 08/07/2019] [Accepted: 08/08/2019] [Indexed: 01/01/2023] Open
Abstract
Double-stranded RNA (dsRNA) molecules of viral origin trigger a post-transcriptional gene-silencing mechanism called RNA interference (RNAi). Specifically, virally derived dsRNA is recognized and cleaved by the enzyme Dicer2 into short interfering RNAs (siRNAs), which further direct sequence-specific RNA silencing, ultimately silencing replication of the virus. Notably, RNAi can also be artificially triggered by the delivery of gene-specific dsRNA, thereby leading to endogenous gene silencing. This is a widely used technology that holds great potential to contribute to novel pest control strategies. In this regard, research efforts have been set to find methods to efficiently trigger RNAi in the field. In this article, we demonstrate the generation of dsRNA- and/or virus-derived siRNAs—the main RNAi effectors—in six insect species belonging to five economically important orders (Lepidoptera, Orthoptera, Hymenoptera, Coleoptera, and Diptera). In addition, we describe that the siRNA length distribution is species-dependent. Taken together, our results reveal interspecies variability in the (antiviral) RNAi mechanism in insects and show promise to contribute to future research on (viral-based) RNAi-triggering mechanisms in this class of animals.
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Affiliation(s)
- Dulce Santos
- Research Group of Molecular Developmental Physiology and Signal Transduction, KU Leuven, 3000 Leuven, Belgium.
| | - Lina Mingels
- Research Group of Molecular Developmental Physiology and Signal Transduction, KU Leuven, 3000 Leuven, Belgium
| | - Elise Vogel
- Research Group of Molecular Developmental Physiology and Signal Transduction, KU Leuven, 3000 Leuven, Belgium
| | - Luoluo Wang
- Laboratory of Agrozoology, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, 9000 Ghent, Belgium
| | - Olivier Christiaens
- Laboratory of Agrozoology, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, 9000 Ghent, Belgium
| | - Kaat Cappelle
- Laboratory of Agrozoology, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, 9000 Ghent, Belgium
| | - Niels Wynant
- Research Group of Molecular Developmental Physiology and Signal Transduction, KU Leuven, 3000 Leuven, Belgium
| | - Yannick Gansemans
- Laboratory of Pharmaceutical Biotechnology, Faculty of Pharmaceutical Sciences, Ghent University, 9000 Ghent, Belgium
| | - Filip Van Nieuwerburgh
- Laboratory of Pharmaceutical Biotechnology, Faculty of Pharmaceutical Sciences, Ghent University, 9000 Ghent, Belgium
| | - Guy Smagghe
- Laboratory of Agrozoology, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, 9000 Ghent, Belgium
| | - Luc Swevers
- Insect Molecular Genetics and Biotechnology Group, Institute of Biosciences and Applications, National Center for Scientific Research "Demokritos", 15310 Athens, Greece
| | - Jozef Vanden Broeck
- Research Group of Molecular Developmental Physiology and Signal Transduction, KU Leuven, 3000 Leuven, Belgium
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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.
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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
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38
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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.
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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
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