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Wang Z, Lin X, Shi W, Cao C. Nicotinic Acetylcholine Receptor Alpha6 Contributes to Antiviral Immunity via IMD Pathway in Drosophila melanogaster. Viruses 2024; 16:562. [PMID: 38675904 PMCID: PMC11054842 DOI: 10.3390/v16040562] [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: 03/06/2024] [Revised: 04/01/2024] [Accepted: 04/02/2024] [Indexed: 04/28/2024] Open
Abstract
Currently, insecticides that target nicotinic acetylcholine receptors (nAChR) are widely used. Studies on the sublethal effects of insecticides have found that they can affect the amount of virus in insects. The mechanism by which insecticides affect insect virus load remain unclear. Here, we show that nAChR targeting insecticide can affect viral replication through the immune deficiency (IMD) pathway. We demonstrate that a low dose of spinosad (6.8 ng/mL), acting as an antagonist to Drosophila melanogaster nicotinic acetylcholine receptor α6 (Dα6), significantly elevates Drosophila melanogaster sigmavirus (DMelSV) virus titers in adults of Drosophila melanogaster. Conversely, a high dose of spinosad (50 ng/mL), acting as an agonist to Dα6, substantially decreases viral load. This bidirectional regulation of virus levels is absent in Dα6-knockout flies, signifying the specificity of spinosad's action through Dα6. Furthermore, the knockdown of Dα6 results in decreased expression of genes in the IMD pathway, including dredd, imd, relish, and downstream antimicrobial peptide genes AttA and AttB, indicating a reduced innate immune response. Subsequent investigations reveal no significant difference in viral titers between relish mutant flies and Dα6-relish double mutants, suggesting that the IMD pathway's role in antiviral defense is dependent on Dα6. Collectively, our findings shed light on the intricate interplay between nAChR signaling and the IMD pathway in mediating antiviral immunity, highlighting the potential for nAChR-targeting compounds to inadvertently influence viral dynamics in insect hosts. This knowledge may inform the development of integrated pest management strategies that consider the broader ecological impact of insecticide use.
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Affiliation(s)
| | | | - Wangpeng Shi
- Department of Entomology, China Agricultural University, Beijing 100193, China; (Z.W.); (X.L.)
| | - Chuan Cao
- Department of Entomology, China Agricultural University, Beijing 100193, China; (Z.W.); (X.L.)
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2
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Estevez-Castro CF, Rodrigues MF, Babarit A, Ferreira FV, de Andrade EG, Marois E, Cogni R, Aguiar ERGR, Marques JT, Olmo RP. Neofunctionalization driven by positive selection led to the retention of the loqs2 gene encoding an Aedes specific dsRNA binding protein. BMC Biol 2024; 22:14. [PMID: 38273313 PMCID: PMC10809485 DOI: 10.1186/s12915-024-01821-4] [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: 02/07/2022] [Accepted: 01/10/2024] [Indexed: 01/27/2024] Open
Abstract
BACKGROUND Mosquito borne viruses, such as dengue, Zika, yellow fever and Chikungunya, cause millions of infections every year. These viruses are mostly transmitted by two urban-adapted mosquito species, Aedes aegypti and Aedes albopictus. Although mechanistic understanding remains largely unknown, Aedes mosquitoes may have unique adaptations that lower the impact of viral infection. Recently, we reported the identification of an Aedes specific double-stranded RNA binding protein (dsRBP), named Loqs2, that is involved in the control of infection by dengue and Zika viruses in mosquitoes. Preliminary analyses suggested that the loqs2 gene is a paralog of loquacious (loqs) and r2d2, two co-factors of the RNA interference (RNAi) pathway, a major antiviral mechanism in insects. RESULTS Here we analyzed the origin and evolution of loqs2. Our data suggest that loqs2 originated from two independent duplications of the first double-stranded RNA binding domain of loqs that occurred before the origin of the Aedes Stegomyia subgenus, around 31 million years ago. We show that the loqs2 gene is evolving under relaxed purifying selection at a faster pace than loqs, with evidence of neofunctionalization driven by positive selection. Accordingly, we observed that Loqs2 is localized mainly in the nucleus, different from R2D2 and both isoforms of Loqs that are cytoplasmic. In contrast to r2d2 and loqs, loqs2 expression is stage- and tissue-specific, restricted mostly to reproductive tissues in adult Ae. aegypti and Ae. albopictus. Transgenic mosquitoes engineered to express loqs2 ubiquitously undergo developmental arrest at larval stages that correlates with massive dysregulation of gene expression without major effects on microRNAs or other endogenous small RNAs, classically associated with RNA interference. CONCLUSIONS Our results uncover the peculiar origin and neofunctionalization of loqs2 driven by positive selection. This study shows an example of unique adaptations in Aedes mosquitoes that could ultimately help explain their effectiveness as virus vectors.
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Affiliation(s)
- Carlos F Estevez-Castro
- Department of Biochemistry and Immunology, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-901, Brazil
- CNRS UPR9022, Inserm U1257, Université de Strasbourg, 67084, Strasbourg, France
| | - Murillo F Rodrigues
- Institute of Ecology and Evolution, University of Oregon, Eugene, OR, 97403-5289, USA
| | - Antinéa Babarit
- CNRS UPR9022, Inserm U1257, Université de Strasbourg, 67084, Strasbourg, France
| | - Flávia V Ferreira
- Department of Biochemistry and Immunology, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-901, Brazil
| | - Elisa G de Andrade
- Department of Biochemistry and Immunology, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-901, Brazil
- CNRS UPR9022, Inserm U1257, Université de Strasbourg, 67084, Strasbourg, France
| | - Eric Marois
- CNRS UPR9022, Inserm U1257, Université de Strasbourg, 67084, Strasbourg, France
| | - Rodrigo Cogni
- Department of Ecology, Institute of Biosciences, University of São Paulo, São Paulo, 05508-090, Brazil
| | - Eric R G R Aguiar
- Department of Biological Science, Center of Biotechnology and Genetics, State University of Santa Cruz, Ilhéus, 45662-900, Brazil
| | - João T Marques
- Department of Biochemistry and Immunology, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-901, Brazil.
- CNRS UPR9022, Inserm U1257, Université de Strasbourg, 67084, Strasbourg, France.
| | - Roenick P Olmo
- Department of Biochemistry and Immunology, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-901, Brazil.
- CNRS UPR9022, Inserm U1257, Université de Strasbourg, 67084, Strasbourg, France.
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3
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Mantilla-Granados JS, Castellanos JE, Velandia-Romero ML. A tangled threesome: understanding arbovirus infection in Aedes spp. and the effect of the mosquito microbiota. Front Microbiol 2024; 14:1287519. [PMID: 38235434 PMCID: PMC10792067 DOI: 10.3389/fmicb.2023.1287519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Accepted: 12/05/2023] [Indexed: 01/19/2024] Open
Abstract
Arboviral infections transmitted by Aedes spp. mosquitoes are a major threat to human health, particularly in tropical regions but are expanding to temperate regions. The ability of Aedes aegypti and Aedes albopictus to transmit multiple arboviruses involves a complex relationship between mosquitoes and the virus, with recent discoveries shedding light on it. Furthermore, this relationship is not solely between mosquitoes and arboviruses, but also involves the mosquito microbiome. Here, we aimed to construct a comprehensive review of the latest information about the arbovirus infection process in A. aegypti and A. albopictus, the source of mosquito microbiota, and its interaction with the arbovirus infection process, in terms of its implications for vectorial competence. First, we summarized studies showing a new mechanism for arbovirus infection at the cellular level, recently described innate immunological pathways, and the mechanism of adaptive response in mosquitoes. Second, we addressed the general sources of the Aedes mosquito microbiota (bacteria, fungi, and viruses) during their life cycle, and the geographical reports of the most common microbiota in adults mosquitoes. How the microbiota interacts directly or indirectly with arbovirus transmission, thereby modifying vectorial competence. We highlight the complexity of this tripartite relationship, influenced by intrinsic and extrinsic conditions at different geographical scales, with many gaps to fill and promising directions for developing strategies to control arbovirus transmission and to gain a better understanding of vectorial competence. The interactions between mosquitoes, arboviruses and their associated microbiota are yet to be investigated in depth.
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Affiliation(s)
- Juan S. Mantilla-Granados
- Saneamiento Ecológico, Salud y Medio Ambiente, Universidad El Bosque, Vicerrectoría de Investigaciones, Bogotá, Colombia
| | - Jaime E. Castellanos
- Grupo de Virología, Universidad El Bosque, Vicerrectoría de Investigaciones, Bogotá, Colombia
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4
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Labropoulou V, Wang L, Magkrioti C, Smagghe G, Swevers L. Single domain von Willebrand factor type C "cytokines" and the regulation of the stress/immune response in insects. ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2024; 115:e22071. [PMID: 38288483 DOI: 10.1002/arch.22071] [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: 09/07/2023] [Revised: 10/25/2023] [Accepted: 11/01/2023] [Indexed: 02/01/2024]
Abstract
The single domain von Willebrand factor type C (SVWC) appears in small secreted peptides that are arthropod-specific and are produced following environmental stress or pathogen exposure. Most research has focused on proteins with SVWC domain that are induced after virus infection and are hypothesized to function as "cytokines" to regulate the innate immune response. The expansion of SVWC genes in insect species indicates that many other functions remain to be discovered. Research in shrimp has elucidated the adaptability of Vago-like peptides in the innate immune response against bacteria, fungi and viruses after activation by Jak-STAT and/or Toll/Imd pathways in which they can act as pathogen-recognition receptors or cytokine-like signaling molecules. SVWC factors also appear in scorpion venoms and tick saliva, underlining their versatility to acquire new functions. This review discusses the discovery and function of SVWC peptides from insects to crustaceans and chelicerates and reveals the enormous gaps in knowledge that remain to be filled to understand this enigmatic group of secreted peptides.
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Affiliation(s)
- Vassiliki Labropoulou
- Insect Molecular Genetics and Biotechnology, Institute of Biosciences & Applications, Athens, Greece
| | - Luoluo Wang
- Red Imported Fire Ant Research Center, South China Agricultural University, Guangzhou, China
| | - Christiana Magkrioti
- Insect Molecular Genetics and Biotechnology, Institute of Biosciences & Applications, Athens, Greece
| | - Guy Smagghe
- Department of Biology, Vrije Universiteit Brussel (VUB), Brussels, Belgium
- Institute of Entomology, Guizhou University, Guizhou, China
- Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Luc Swevers
- Insect Molecular Genetics and Biotechnology, Institute of Biosciences & Applications, Athens, Greece
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5
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Merkling SH, Crist AB, Henrion-Lacritick A, Frangeul L, Couderc E, Gausson V, Blanc H, Bergman A, Baidaliuk A, Romoli O, Saleh MC, Lambrechts L. Multifaceted contributions of Dicer2 to arbovirus transmission by Aedes aegypti. Cell Rep 2023; 42:112977. [PMID: 37573505 DOI: 10.1016/j.celrep.2023.112977] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 06/20/2023] [Accepted: 07/28/2023] [Indexed: 08/15/2023] Open
Abstract
Arthropod-borne viruses (arboviruses) transmitted by Aedes aegypti mosquitoes are an increasing threat to global health. The small interfering RNA (siRNA) pathway is considered the main antiviral immune pathway of insects, but its effective impact on arbovirus transmission is surprisingly poorly understood. Here, we use CRISPR-Cas9-mediated gene editing in vivo to mutate Dicer2, a gene encoding the RNA sensor and key component of the siRNA pathway. The loss of Dicer2 enhances early viral replication and systemic viral dissemination of four medically significant arboviruses (chikungunya, Mayaro, dengue, and Zika viruses) representing two viral families. However, Dicer2 mutants and wild-type mosquitoes display overall similar levels of vector competence. In addition, Dicer2 mutants undergo significant virus-induced mortality during infection with chikungunya virus. Together, our results define a multifaceted role for Dicer2 in the transmission of arboviruses by Ae. aegypti mosquitoes and pave the way for further mechanistic investigations.
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Affiliation(s)
- Sarah Hélène Merkling
- Institut Pasteur, Université Paris Cité, CNRS UMR2000, Insect-Virus Interactions Unit, 75015 Paris, France
| | - Anna Beth Crist
- Institut Pasteur, Université Paris Cité, CNRS UMR2000, Insect-Virus Interactions Unit, 75015 Paris, France
| | - Annabelle Henrion-Lacritick
- Institut Pasteur, Université Paris Cité, CNRS UMR3569, Viruses and RNA Interference Unit, 75015 Paris, France
| | - Lionel Frangeul
- Institut Pasteur, Université Paris Cité, CNRS UMR3569, Viruses and RNA Interference Unit, 75015 Paris, France
| | - Elodie Couderc
- Institut Pasteur, Université Paris Cité, CNRS UMR2000, Insect-Virus Interactions Unit, 75015 Paris, France; Sorbonne Université, Collège Doctoral, 75005 Paris, France
| | - Valérie Gausson
- Institut Pasteur, Université Paris Cité, CNRS UMR3569, Viruses and RNA Interference Unit, 75015 Paris, France
| | - Hervé Blanc
- Institut Pasteur, Université Paris Cité, CNRS UMR3569, Viruses and RNA Interference Unit, 75015 Paris, France
| | - Alexander Bergman
- Institut Pasteur, Université Paris Cité, CNRS UMR2000, Insect-Virus Interactions Unit, 75015 Paris, France
| | - Artem Baidaliuk
- Institut Pasteur, Université Paris Cité, CNRS UMR2000, Insect-Virus Interactions Unit, 75015 Paris, France; Sorbonne Université, Collège Doctoral, 75005 Paris, France
| | - Ottavia Romoli
- 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.
| | - Louis Lambrechts
- Institut Pasteur, Université Paris Cité, CNRS UMR2000, Insect-Virus Interactions Unit, 75015 Paris, France.
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6
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Prince BC, Walsh E, Torres TZB, Rückert C. Recognition of Arboviruses by the Mosquito Immune System. Biomolecules 2023; 13:1159. [PMID: 37509194 PMCID: PMC10376960 DOI: 10.3390/biom13071159] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 07/12/2023] [Accepted: 07/18/2023] [Indexed: 07/30/2023] Open
Abstract
Arthropod-borne viruses (arboviruses) pose a significant threat to both human and animal health worldwide. These viruses are transmitted through the bites of mosquitoes, ticks, sandflies, or biting midges to humans or animals. In humans, arbovirus infection often results in mild flu-like symptoms, but severe disease and death also occur. There are few vaccines available, so control efforts focus on the mosquito population and virus transmission control. One area of research that may enable the development of new strategies to control arbovirus transmission is the field of vector immunology. Arthropod vectors, such as mosquitoes, have coevolved with arboviruses, resulting in a balance of virus replication and vector immune responses. If this balance were disrupted, virus transmission would likely be reduced, either through reduced replication, or even through enhanced replication, resulting in mosquito mortality. The first step in mounting any immune response is to recognize the presence of an invading pathogen. Recent research advances have been made to tease apart the mechanisms of arbovirus detection by mosquitoes. Here, we summarize what is known about arbovirus recognition by the mosquito immune system, try to generate a comprehensive picture, and highlight where there are still gaps in our current understanding.
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Affiliation(s)
- Brian C Prince
- Department of Biochemistry and Molecular Biology, College of Agriculture, Biotechnology & Natural Resources, University of Nevada, Reno, NV 89557, USA
| | - Elizabeth Walsh
- Department of Biochemistry and Molecular Biology, College of Agriculture, Biotechnology & Natural Resources, University of Nevada, Reno, NV 89557, USA
| | - Tran Zen B Torres
- Department of Biochemistry and Molecular Biology, College of Agriculture, Biotechnology & Natural Resources, University of Nevada, Reno, NV 89557, USA
| | - Claudia Rückert
- Department of Biochemistry and Molecular Biology, College of Agriculture, Biotechnology & Natural Resources, University of Nevada, Reno, NV 89557, USA
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7
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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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8
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Unraveling the Role of Antimicrobial Peptides in Insects. Int J Mol Sci 2023; 24:ijms24065753. [PMID: 36982826 PMCID: PMC10059942 DOI: 10.3390/ijms24065753] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 03/14/2023] [Accepted: 03/15/2023] [Indexed: 03/19/2023] Open
Abstract
Antimicrobial peptides (AMPs) are short, mainly positively charged, amphipathic molecules. AMPs are important effectors of the immune response in insects with a broad spectrum of antibacterial, antifungal, and antiparasitic activity. In addition to these well-known roles, AMPs exhibit many other, often unobvious, functions in the host. They support insects in the elimination of viral infections. AMPs participate in the regulation of brain-controlled processes, e.g., sleep and non-associative learning. By influencing neuronal health, communication, and activity, they can affect the functioning of the insect nervous system. Expansion of the AMP repertoire and loss of their specificity is connected with the aging process and lifespan of insects. Moreover, AMPs take part in maintaining gut homeostasis, regulating the number of endosymbionts as well as reducing the number of foreign microbiota. In turn, the presence of AMPs in insect venom prevents the spread of infection in social insects, where the prey may be a source of pathogens.
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9
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Orbán TI. One locus, several functional RNAs-emerging roles of the mechanisms responsible for the sequence variability of microRNAs. Biol Futur 2023:10.1007/s42977-023-00154-7. [PMID: 36847925 DOI: 10.1007/s42977-023-00154-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Accepted: 02/08/2023] [Indexed: 03/01/2023]
Abstract
With the development of modern molecular genetics, the original "one gene-one enzyme" hypothesis has been outdated. For protein coding genes, the discovery of alternative splicing and RNA editing provided the biochemical background for the RNA repertoire of a single locus, which also serves as an important pillar for the enormous protein variability of the genomes. Non-protein coding RNA genes were also revealed to produce several RNA species with distinct functions. The loci of microRNAs (miRNAs), encoding for small endogenous regulatory RNAs, were also found to produce a population of small RNAs, rather than a single defined product. This review aims to present the mechanisms contributing to the astonishing variability of miRNAs revealed by the new sequencing technologies. One important source is the careful balance of arm selection, producing sequentially different 5p- or 3p-miRNAs from the same pre-miRNA, thereby broadening the number of regulated target RNAs and the phenotypic response. In addition, the formation of 5', 3' and polymorphic isomiRs, with variable end and internal sequences also leads to a higher number of targeted sequences, and increases the regulatory output. These miRNA maturation processes, together with other known mechanisms such as RNA editing, further increase the potential outcome of this small RNA pathway. By discussing the subtle mechanisms behind the sequence diversity of miRNAs, this review intends to reveal this engaging aspect of the inherited "RNA world", how it contributes to the almost infinite molecular variability among living organisms, and how this variability can be exploited to treat human diseases.
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Affiliation(s)
- Tamás I Orbán
- Institute of Enzymology, Research Centre for Natural Sciences, Eötvös Loránd Research Network, Magyar Tudósok Körútja 2, Budapest, 1117, Hungary.
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10
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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: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2023] [Revised: 02/09/2023] [Accepted: 02/11/2023] [Indexed: 06/01/2023]
Abstract
Research on Piwi proteins and piRNAs in insects has focused on three experimental models: oogenesis and spermatogenesis in Drosophila melanogaster, the antiviral response in Aedes mosquitoes and the molecular analysis of primary and secondary piRNA biogenesis in Bombyx mori-derived BmN4 cells. Significant unique and complementary information has been acquired and has led to a greater appreciation of the complexity of piRNA biogenesis and Piwi protein function. Studies performed in other insect species are emerging and promise to add to the current state of the art on the roles of piRNAs and Piwi proteins. Although the primary role of the piRNA pathway is genome defense against transposons, particularly in the germline, recent findings also indicate an expansion of its functions. In this review, an extensive overview is presented of the knowledge of the piRNA pathway that so far has accumulated in insects. Following a presentation of the three major models, data from other insects were also discussed. Finally, the mechanisms for the expansion of the function of the piRNA pathway from transposon control to gene regulation were considered.
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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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Huang Z, Wang W, Xu P, Gong S, Hu Y, Liu Y, Su F, Anjum KM, Deng WM, Yang S, Liu J, Jiao R, Chen J. Drosophila Ectoderm-expressed 4 modulates JAK/STAT pathway and protects flies against Drosophila C virus infection. Front Immunol 2023; 14:1135625. [PMID: 36817462 PMCID: PMC9937023 DOI: 10.3389/fimmu.2023.1135625] [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: 01/01/2023] [Accepted: 01/23/2023] [Indexed: 02/05/2023] Open
Abstract
Sterile alpha and HEAT/Armadillo motif-containing protein (SARM) is conserved in evolution and negatively regulates TRIF-dependent Toll signaling in mammals. The SARM protein from Litopenaeus vannamei and its Drosophila orthologue Ectoderm-expressed (Ect4) are also involved in immune defense against pathogen infection. However, the functional mechanism of the protective effect remains unclear. In this study, we show that Ect4 is essential for the viral load in flies after a Drosophila C virus (DCV) infection. Viral load is increased in Ect4 mutants resulting in higher mortality rates than wild-type. Overexpression of Ect4 leads to a suppression of virus replication and thus improves the survival rate of the animals. Ect4 is required for the viral induction of STAT-responsive genes, TotA and TotM. Furthermore, Ect4 interacts with Stat92E, affecting the tyrosine phosphorylation and nuclear translocation of Stat92E in S2 cells. Altogether, our study identifies the adaptor protein Ect4 of the Toll pathway contributes to resistance to viral infection and regulates JAK/STAT signaling pathway.
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Affiliation(s)
- Zongliang Huang
- Fujian Key Laboratory on Conservation and Sustainable Utilization of Marine Biodiversity, Fuzhou Institute of Oceanography, Minjiang University, Fuzhou, Fujian, China,Sino-French Hoffmann Institute, School of Basic Sciences, Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Wei Wang
- Fujian Key Laboratory on Conservation and Sustainable Utilization of Marine Biodiversity, Fuzhou Institute of Oceanography, Minjiang University, Fuzhou, Fujian, China,Department of Bioengineering and Biotechnology, College of Chemical Engineering, Huaqiao University, Xiamen, Fujian, China
| | - Pengpeng Xu
- Sino-French Hoffmann Institute, School of Basic Sciences, Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Shangyu Gong
- Sino-French Hoffmann Institute, School of Basic Sciences, Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Yingshan Hu
- Sino-French Hoffmann Institute, School of Basic Sciences, Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Yan Liu
- Sino-French Hoffmann Institute, School of Basic Sciences, Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Fang Su
- Sino-French Hoffmann Institute, School of Basic Sciences, Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Khalid Mahmood Anjum
- Department of Wildlife and Ecology, University of Veterinary and Animal Sciences, Lahore, Punjab, Pakistan
| | - Wu-Min Deng
- Department of Biological Science, Florida State University, Tallahassee, FL, United States
| | - Suping Yang
- Department of Bioengineering and Biotechnology, College of Chemical Engineering, Huaqiao University, Xiamen, Fujian, China
| | - Jiyong Liu
- Sino-French Hoffmann Institute, School of Basic Sciences, Guangzhou Medical University, Guangzhou, Guangdong, China,*Correspondence: Jiyong Liu, ; Renjie Jiao, ; Jianming Chen,
| | - Renjie Jiao
- Sino-French Hoffmann Institute, School of Basic Sciences, Guangzhou Medical University, Guangzhou, Guangdong, China,*Correspondence: Jiyong Liu, ; Renjie Jiao, ; Jianming Chen,
| | - Jianming Chen
- Fujian Key Laboratory on Conservation and Sustainable Utilization of Marine Biodiversity, Fuzhou Institute of Oceanography, Minjiang University, Fuzhou, Fujian, China,Sino-French Hoffmann Institute, School of Basic Sciences, Guangzhou Medical University, Guangzhou, Guangdong, China,*Correspondence: Jiyong Liu, ; Renjie Jiao, ; Jianming Chen,
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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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13
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Rosendo Machado S, Qu J, Koopman WJH, Miesen P. The DEAD-box RNA helicase Dhx15 controls glycolysis and arbovirus replication in Aedes aegypti mosquito cells. PLoS Pathog 2022; 18:e1010694. [PMID: 36441781 PMCID: PMC9731432 DOI: 10.1371/journal.ppat.1010694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 12/08/2022] [Accepted: 11/11/2022] [Indexed: 11/30/2022] Open
Abstract
Aedes aegypti mosquitoes are responsible for the transmission of arthropod-borne (arbo)viruses including dengue and chikungunya virus (CHIKV) but in contrast to human hosts, arbovirus-infected mosquitoes are able to efficiently control virus replication to sub-pathological levels. Yet, our knowledge of the molecular interactions of arboviruses with their mosquito hosts is incomplete. Here, we aimed to identify and characterize novel host genes that control arbovirus replication in Aedes mosquitoes. RNA binding proteins (RBPs) are well-known to regulate immune signaling pathways in all kingdoms of life. We therefore performed a knockdown screen targeting 461 genes encoding predicted RBPs in Aedes aegypti Aag2 cells and identified 15 genes with antiviral activity against Sindbis virus. Amongst these, the three DEAD-box RNA helicases AAEL004419/Dhx15, AAEL008728, and AAEL004859 also acted as antiviral factors in dengue and CHIKV infections. Here, we explored the mechanism of Dhx15 in regulating an antiviral transcriptional response in mosquitoes by silencing Dhx15 in Aag2 cells followed by deep-sequencing of poly-A enriched RNAs. Dhx15 knockdown in uninfected and CHIKV-infected cells resulted in differential expression of 856 and 372 genes, respectively. Interestingly, amongst the consistently downregulated genes, glycolytic process was the most enriched gene ontology (GO) term as the expression of all core enzymes of the glycolytic pathway was reduced, suggesting that Dhx15 regulates glycolytic function. A decrease in lactate production indicated that Dhx15 silencing indeed functionally impaired glycolysis. Modified rates of glycolytic metabolism have been implicated in controlling the replication of several classes of viruses and strikingly, infection of Aag2 cells with CHIKV by itself also resulted in the decrease of several glycolytic genes. Our data suggests that Dhx15 regulates replication of CHIKV, and possibly other arboviruses, by controlling glycolysis in mosquito cells.
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Affiliation(s)
- Samara Rosendo Machado
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Jieqiong Qu
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Werner J. H. Koopman
- Department of Pediatrics, Amalia Children’s Hospital, Radboud Institute for Molecular Life Sciences, Radboud Center for Mitochondrial Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Pascal Miesen
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
- * E-mail:
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14
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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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15
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Cheung YP, Park S, Pagtalunan J, Maringer K. The antiviral role of NF-κB-mediated immune responses and their antagonism by viruses in insects. J Gen Virol 2022; 103. [PMID: 35510990 DOI: 10.1099/jgv.0.001741] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The antiviral role of innate immune responses mediated by the NF-κB family of transcription factors is well established in vertebrates but was for a long time less clear in insects. Insects encode two canonical NF-κB pathways, the Toll and Imd ('immunodeficiency') pathways, which are best characterised for their role in antibacterial and antifungal defence. An increasing body of evidence has also implicated NF-κB-mediated innate immunity in antiviral responses against some, but not all, viruses. Specific pattern recognition receptors (PRRs) and molecular events leading to NF-κB activation by viral pathogen-associated molecular patterns (PAMPs) have been elucidated for a number of viruses and insect species. Particularly interesting are recent findings indicating that the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway detects viral RNA to activate NF-κB-regulated gene expression. We summarise the literature on virus-NF-κB pathway interactions across the class Insecta, with a focus on the dipterans Drosophila melanogaster and Aedes aegypti. We discuss potential reasons for differences observed between different virus-host combinations, and highlight similarities and differences between cGAS-STING signalling in insects versus vertebrates. Finally, we summarise the increasing number of known molecular mechanisms by which viruses antagonise NF-κB responses, which suggest that NF-κB-mediated immunity exerts strong evolutionary pressures on viruses. These developments in our understanding of insect antiviral immunity have relevance to the large number of insect species that impact on humans through their transmission of human, livestock and plant diseases, exploitation as biotechnology platforms, and role as parasites, pollinators, livestock and pests.
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Affiliation(s)
- Yin P Cheung
- The Pirbright Institute, Pirbright, Surrey, GU24 0NF, UK.,Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey, GU2 7XH, UK
| | - Sohyun Park
- The Pirbright Institute, Pirbright, Surrey, GU24 0NF, UK.,Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey, GU2 7XH, UK
| | - Justine Pagtalunan
- The Pirbright Institute, Pirbright, Surrey, GU24 0NF, UK.,Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey, GU2 7XH, UK
| | - Kevin Maringer
- The Pirbright Institute, Pirbright, Surrey, GU24 0NF, UK
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16
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Feitosa-Suntheimer F, Zhu Z, Mameli E, Dayama G, Gold AS, Broos-Caldwell A, Troupin A, Rippee-Brooks M, Corley RB, Lau NC, Colpitts TM, Londoño-Renteria B. Dengue Virus-2 Infection Affects Fecundity and Elicits Specific Transcriptional Changes in the Ovaries of Aedes aegypti Mosquitoes. Front Microbiol 2022; 13:886787. [PMID: 35814655 PMCID: PMC9260120 DOI: 10.3389/fmicb.2022.886787] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 05/23/2022] [Indexed: 11/13/2022] Open
Abstract
Dengue fever (DF), caused by the dengue virus (DENV), is the most burdensome arboviral disease in the world, with an estimated 400 million infections each year. The Aedes aegypti mosquito is the main vector of DENV and transmits several other human pathogens, including Zika, yellow fever, and chikungunya viruses. Previous studies have shown that the pathogen infection of mosquitoes can alter reproductive fitness, revealing specific vector-pathogen interactions that are key determinants of vector competence. However, only a handful of studies have examined the effect of DENV infection in A. aegypti, showing a reduction in lifespan and fecundity over multiple blood meals. To provide a more comprehensive analysis of the impact of DENV infection on egg laying and fecundity, we assessed egg laying timing in DENV-2 blood-fed mosquitoes (infected group) compared to mock blood-fed mosquitoes (control group). We confirmed a significant decrease in fecundity during the first gonadotrophic cycle. To further investigate this phenotype and the underlying DENV-2 infection-dependent changes in gene expression, we conducted a transcriptomic analysis for differentially expressed genes in the ovaries of A. aegypti infected with DENV-2 vs. mock-infected mosquitoes. This analysis reveals several DENV-2-regulated genes; among them, we identified a group of 12 metabolic genes that we validated using reverse transcription-quantitative PCR (RT-qPCR). Interestingly, two genes found to be upregulated in DENV-infected mosquito ovaries exhibited an antiviral role for DENV-2 in an Aedes cell line. Altogether, this study offers useful insights into the virus-vector interface, highlighting the importance of gene expression changes in the mosquito's ovary during DENV-2 infection in the first gonadotrophic cycle, triggering antiviral responses that may possibly interfere with mosquito reproduction. This information is extremely relevant for further investigation of A. aegypti's ability to tolerate viruses since virally infected mosquitoes in nature constitute a powerful source of supporting viruses during intra-epidemic periods, causing a huge burden on the public health system.
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Affiliation(s)
- Fabiana Feitosa-Suntheimer
- Department of Microbiology, Boston University School of Medicine, Boston, MA, United States.,National Emerging Infectious Diseases Laboratories, Boston University, Boston, MA, United States
| | - Zheng Zhu
- National Emerging Infectious Diseases Laboratories, Boston University, Boston, MA, United States.,Department of Biochemistry, Boston University School of Medicine, Boston, MA, United States
| | - Enzo Mameli
- Department of Microbiology, Boston University School of Medicine, Boston, MA, United States.,National Emerging Infectious Diseases Laboratories, Boston University, Boston, MA, United States.,Department of Genetics, Harvard Medical School, Blavatnik Institute, Boston, MA, United States
| | - Gargi Dayama
- Department of Biochemistry, Boston University School of Medicine, Boston, MA, United States
| | - Alexander S Gold
- Department of Microbiology, Boston University School of Medicine, Boston, MA, United States.,National Emerging Infectious Diseases Laboratories, Boston University, Boston, MA, United States
| | - Aditi Broos-Caldwell
- Department of Microbiology, Boston University School of Medicine, Boston, MA, United States.,National Emerging Infectious Diseases Laboratories, Boston University, Boston, MA, United States
| | - Andrea Troupin
- School of Public Health and Tropical Medicine, Tulane University, New Orleans, LA, United States
| | - Meagan Rippee-Brooks
- Department of Biology, Missouri State University, Springfield, MO, United States
| | - Ronald B Corley
- Department of Microbiology, Boston University School of Medicine, Boston, MA, United States.,National Emerging Infectious Diseases Laboratories, Boston University, Boston, MA, United States
| | - Nelson C Lau
- National Emerging Infectious Diseases Laboratories, Boston University, Boston, MA, United States.,Department of Biochemistry, Boston University School of Medicine, Boston, MA, United States.,Genome Science Institute, Boston University, Boston, MA, United States
| | - Tonya M Colpitts
- Department of Microbiology, Boston University School of Medicine, Boston, MA, United States.,National Emerging Infectious Diseases Laboratories, Boston University, Boston, MA, United States
| | - Berlin Londoño-Renteria
- School of Public Health and Tropical Medicine, Tulane University, New Orleans, LA, United States.,Department of Entomology, Kansas State University, Manhattan, KS, United States
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17
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Impact of Microorganisms and Parasites on Neuronally Controlled Drosophila Behaviours. Cells 2021; 10:cells10092350. [PMID: 34571999 PMCID: PMC8472771 DOI: 10.3390/cells10092350] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 09/01/2021] [Accepted: 09/06/2021] [Indexed: 02/07/2023] Open
Abstract
Like all invertebrates, flies such as Drosophila lack an adaptive immune system and depend on their innate immune system to protect them against pathogenic microorganisms and parasites. In recent years, it appears that the nervous systems of eucaryotes not only control animal behavior but also cooperate and synergize very strongly with the animals’ immune systems to detect and fight potential pathogenic threats, and allow them to adapt their behavior to the presence of microorganisms and parasites that coexist with them. This review puts into perspective the latest progress made using the Drosophila model system, in this field of research, which remains in its infancy.
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18
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Spadar A, Phelan JE, Benavente ED, Campos M, Gomez LF, Mohareb F, Clark TG, Campino S. Flavivirus integrations in Aedes aegypti are limited and highly conserved across samples from different geographic regions unlike integrations in Aedes albopictus. Parasit Vectors 2021; 14:332. [PMID: 34174947 PMCID: PMC8235865 DOI: 10.1186/s13071-021-04828-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Accepted: 06/07/2021] [Indexed: 12/15/2022] Open
Abstract
Mosquitoes of the genus Aedes are the main vectors of many viruses, e.g. dengue and Zika, which affect millions of people each year and for which there are limited treatment options. Understanding how Aedes mosquitoes tolerate high viral loads may lead to better disease control strategies. Elucidating endogenous viral elements (EVEs) within vector genomes may give exploitable biological insights. Previous studies have reported the presence of a large number of EVEs in Aedes genomes. Here we investigated if flavivirus EVEs are conserved across populations and different Aedes species by using ~ 500 whole genome sequence libraries from Aedes aegypti and Aedes albopictus, sourced from colonies and field mosquitoes across continents. We found that nearly all flavivirus EVEs in the Ae. aegypti reference genome originate from four separate putative viral integration events, and that they are highly conserved across geographically diverse samples. By contrast, flavivirus EVEs in the Ae. albopictus reference genome originate from up to nine distinct integration events and show low levels of conservation, even within samples from narrow geographical ranges. Our analysis suggests that flaviviruses integrated as long sequences and were subsequently fragmented and shuffled by transposable elements. Given that EVEs of Ae. aegypti and Ae. albopictus belong to different phylogenetic clades and have very differing levels of conservation, they may have different evolutionary origins and potentially different functional roles.
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Affiliation(s)
- Anton Spadar
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
| | - Jody E Phelan
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
| | - Ernest Diez Benavente
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
| | - Monica Campos
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
| | - Lara Ferrero Gomez
- Unidade de Ciências da Natureza, da Vida e do Ambiente, Universidade Jean Piaget de Cabo Verde, Praia, Cabo Verde
| | - Fady Mohareb
- School of Water, Energy and Environment, Cranfield University, Bedford, UK
| | - Taane G Clark
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK.
- Faculty of Epidemiology and Population Health, London School of Hygiene & Tropical Medicine, London, UK.
| | - Susana Campino
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK.
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