1
|
Li Y, Wu SY. Entomopathogenic nematodes in insect pest biocontrol: Diversity and function of excretory/secretory proteins. J Invertebr Pathol 2024; 207:108205. [PMID: 39313094 DOI: 10.1016/j.jip.2024.108205] [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: 06/11/2024] [Revised: 09/18/2024] [Accepted: 09/18/2024] [Indexed: 09/25/2024]
Abstract
Entomopathogenic nematodes (EPNs) are obligate parasitic "biopesticides" that play a vital role in pest management. A thorough understanding of their pathogenic mechanisms is essential for promoting their widespread use in agricultural pest control. The pathogenicity of EPNs arises from two key factors: the pathogenicity of their symbiotic bacteria and the nematodes' intrinsic pathogenic mechanisms. This review concentrates on the latter, offering an exploration of the excretory/secretory products of EPNs, along with their pathogenic mechanisms and key components. Particular attention is given to specific excretory/secretory proteins (ESPs) identified in various EPN species. The aim is to provide a foundational reference for comprehending the role of these ESPs in pest control. Furthermore, the review discusses the potential of these findings to advance the development of eco-friendly biopesticides, thereby supporting sustainable agricultural practices.
Collapse
Affiliation(s)
- Yixuan Li
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Sheng-Yen Wu
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
| |
Collapse
|
2
|
Mallick S, Kenney E, Eleftherianos I. The Activin Branch Ligand Daw Regulates the Drosophila melanogaster Immune Response and Lipid Metabolism against the Heterorhabditis bacteriophora Serine Carboxypeptidase. Int J Mol Sci 2024; 25:7970. [PMID: 39063211 PMCID: PMC11277151 DOI: 10.3390/ijms25147970] [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: 06/11/2024] [Revised: 07/16/2024] [Accepted: 07/19/2024] [Indexed: 07/28/2024] Open
Abstract
Despite impressive advances in the broad field of innate immunity, our understanding of the molecules and signaling pathways that control the host immune response to nematode infection remains incomplete. We have shown recently that Transforming Growth Factor-β (TGF-β) signaling in the fruit fly Drosophila melanogaster is activated by nematode infection and certain TGF-β superfamily members regulate the D. melanogaster anti-nematode immune response. Here, we investigate the effect of an entomopathogenic nematode infection factor on host TGF-β pathway regulation and immune function. We find that Heterorhabditis bacteriophora serine carboxypeptidase activates the Activin branch in D. melanogaster adults and the immune deficiency pathway in Activin-deficient flies, it affects hemocyte numbers and survival in flies deficient for Activin signaling, and causes increased intestinal steatosis in Activin-deficient flies. Thus, insights into the D. melanogaster signaling pathways and metabolic processes interacting with H. bacteriophora pathogenicity factors will be applicable to entomopathogenic nematode infection of important agricultural insect pests and vectors of disease.
Collapse
Affiliation(s)
| | | | - Ioannis Eleftherianos
- Infection and Innate Immunity Lab, Department of Biological Sciences, The George Washington University, Washington, DC 20052, USA; (S.M.); (E.K.)
| |
Collapse
|
3
|
Chantab K, Rao Z, Zheng X, Han R, Cao L. Ascarosides and Symbiotic Bacteria of Entomopathogenic Nematodes Regulate Host Immune Response in Galleria mellonella Larvae. INSECTS 2024; 15:514. [PMID: 39057246 PMCID: PMC11277396 DOI: 10.3390/insects15070514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2024] [Revised: 06/20/2024] [Accepted: 06/27/2024] [Indexed: 07/28/2024]
Abstract
Insects protect themselves through their immune systems. Entomopathogenic nematodes and their bacterial symbionts are widely used for the biocontrol of economically important pests. Ascarosides are pheromones that regulate nematode behaviors, such as aggregation, avoidance, mating, dispersal, and dauer recovery and formation. However, whether ascarosides influence the immune response of insects remains unexplored. In this study, we co-injected ascarosides and symbiotic Photorhabdus luminescens subsp. kayaii H06 bacteria derived from Heterorhabditis bacteriophora H06 into the last instar larvae of Galleria mellonella. We recorded larval mortality and analyzed the expressions of AMPs, ROS/RNS, and LPSs. Our results revealed a process in which ascarosides, acting as enhancers of the symbiotic bacteria, co-induced G. mellonella immunity by significantly increasing oxidative stress responses and secreting AMPs (gallerimycin, gloverin, and cecropin). This led to a reduction in color intensity and the symbiotic bacteria load, ultimately resulting in delayed host mortality compared to either ascarosides or symbiotic bacteria. These findings demonstrate the cross-kingdom regulation of insects and symbiotic bacteria by nematode pheromones. Furthermore, our results suggest that G. mellonella larvae may employ nematode pheromones secreted by IJs to modulate insect immunity during early infection, particularly in the presence of symbiotic bacteria, for enhancing resistance to invasive bacteria in the hemolymph.
Collapse
Affiliation(s)
- Kanjana Chantab
- Guangdong Key Laboratory of Animal Conservation and Resource Utilization, Guangdong Public Laboratory of Wild Animal Conservation and Utilization, Institute of Zoology, Guangdong Academy of Science, Guangzhou 510260, China; (K.C.); (Z.R.); (X.Z.); (R.H.)
- Department of Plant Sciences, Faculty of Agriculture and Technology, Rajamangala University of Technology Isan, Surin 32000, Thailand
| | - Zhongchen Rao
- Guangdong Key Laboratory of Animal Conservation and Resource Utilization, Guangdong Public Laboratory of Wild Animal Conservation and Utilization, Institute of Zoology, Guangdong Academy of Science, Guangzhou 510260, China; (K.C.); (Z.R.); (X.Z.); (R.H.)
| | - Xuehong Zheng
- Guangdong Key Laboratory of Animal Conservation and Resource Utilization, Guangdong Public Laboratory of Wild Animal Conservation and Utilization, Institute of Zoology, Guangdong Academy of Science, Guangzhou 510260, China; (K.C.); (Z.R.); (X.Z.); (R.H.)
| | - Richou Han
- Guangdong Key Laboratory of Animal Conservation and Resource Utilization, Guangdong Public Laboratory of Wild Animal Conservation and Utilization, Institute of Zoology, Guangdong Academy of Science, Guangzhou 510260, China; (K.C.); (Z.R.); (X.Z.); (R.H.)
| | - Li Cao
- Guangdong Key Laboratory of Animal Conservation and Resource Utilization, Guangdong Public Laboratory of Wild Animal Conservation and Utilization, Institute of Zoology, Guangdong Academy of Science, Guangzhou 510260, China; (K.C.); (Z.R.); (X.Z.); (R.H.)
| |
Collapse
|
4
|
Bhat AH, Machado RAR, Abolafia J, Ruiz-Cuenca AN, Askary TH, Ameen F, Dass WM. Taxonomic and molecular characterization of a new entomopathogenic nematode species, Heterorhabditis casmirica n. sp., and whole genome sequencing of its associated bacterial symbiont. Parasit Vectors 2023; 16:383. [PMID: 37880744 PMCID: PMC10598981 DOI: 10.1186/s13071-023-05990-z] [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: 05/06/2023] [Accepted: 09/29/2023] [Indexed: 10/27/2023] Open
Abstract
BACKGROUND Nematodes of the genus Heterorhabditis are important biocontrol agents as they form a lethal combination with their symbiotic Photorhabdus bacteria against agricultural insect pests. This study describes a new species of Heterorhabditis. METHODS Six Heterorhabditis nematode populations were recovered from agricultural soils in Jammu and Kashmir, India. An initial examination using mitochondrial and nuclear genes showed that they belong to a new species. To describe this new species, a variety of analyses were conducted, including reconstructing phylogenetic relationships based on multiple genes, characterizing the nematodes at the morphological and morphometric levels, performing self-crossing and cross-hybridization experiments, and isolating and characterizing their symbiotic bacteria. RESULTS The newly discovered species, Heterorhabditis casmirica n. sp., shares 94% mitochondrial cytochrome C oxidase subunit I gene (COI) sequence identity with Heterorhabditis bacteriophora and Heterorhabditis ruandica, and 93% with Heterorhabditis zacatecana. Morphologically, it differs from H. bacteriophora in its infective juvenile phasmids (present vs. inconspicuous) and bacterial pouch visibility in the ventricular portion of the intestine (invisible vs. visible); genital papilla 1 (GP1) position (at manubrium level vs. more anterior), and in its b ratio (body length/neck length), c ratio (tail length/bulb width), and D% [(excretory pore/neck length) × 100]. Other morphological differences include anterior end to the nerve ring distance (77-100 vs. 121-130 μm), V% [(anterior end of vulva/body length) × 100] (46-57 vs. 41-47) in hermaphroditic females; rectum size (slightly longer than the anal body diameter vs. about three times longer), phasmids (smaller vs. inconspicuous), body length (0.13-2.0 vs. 0.32-0.39 mm), body diameter (73-150 vs. 160-220 μm), anterior end to the excretory pore distance (135-157 vs. 174-214 μm), and demanian ratios in amphimictic females. Morphological differences with H. ruandica and H. zacatecana were also observed. Furthermore, H. casmirica n. sp. did not mate or produce fertile progeny with other Heterorhabditis nematodes reported from India. It was also discovered that H. casmirica n. sp. is associated with Photorhabdus luminescence subsp. clarkei symbiotic bacteria. CONCLUSIONS The discovery of H. casmirica n. sp. provides novel insights into the diversity and evolution of Heterorhabditis nematodes and their symbiotic bacteria. This new species adds to the catalog of entomopathogenic nematodes in India.
Collapse
Affiliation(s)
- Aashaq Hussain Bhat
- Department of Biosciences, University Center for Research and Development, Chandigarh University, Gharuan, Mohali, Punjab, 140413, India.
- Experimental Biology Research Group, Institute of Biology, Faculty of Sciences, University of Neuchâtel, Neuchâtel, 2000, Switzerland.
| | - Ricardo A R Machado
- Experimental Biology Research Group, Institute of Biology, Faculty of Sciences, University of Neuchâtel, Neuchâtel, 2000, Switzerland
| | - Joaquín Abolafia
- Departamento de Biología Animal, Biología Vegetal y Ecología, Universidad de Jaén, Campus 'Las Lagunillas', Jaén, 23071, Spain
| | - Alba N Ruiz-Cuenca
- Departamento de Biología Animal, Biología Vegetal y Ecología, Universidad de Jaén, Campus 'Las Lagunillas', Jaén, 23071, Spain
| | - Tarique Hassan Askary
- Division of Entomology, Faculty of Agriculture, Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir, Wadura Campus, Sopore, 193201, Jammu and Kashmir, India
| | - Fuad Ameen
- Department of Botany and Microbiology, College of Science, King Saud University, 11451, Riyadh, Saudi Arabia
| | - Wasim Muzamil Dass
- Department of Zoology, University of Kashmir, Srinagar, 190006, Jammu and Kashmir, India
| |
Collapse
|
5
|
Huynh T, O'Halloran D, Hawdon J, Eleftherianos I. The nematode parasite Steinernema hermaphroditum is pathogenic to Drosophila melanogaster larvae without activating their immune response. MICROPUBLICATION BIOLOGY 2023; 2023:10.17912/micropub.biology.000944. [PMID: 37822685 PMCID: PMC10562934 DOI: 10.17912/micropub.biology.000944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Figures] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 08/20/2023] [Accepted: 08/24/2023] [Indexed: 10/13/2023]
Abstract
Entomopathogenic nematodes are commonly used to control insect pest populations in the field. They also contribute substantially to understanding the molecular basis of nematode pathogenicity and insect anti-nematode immunity. Here, we tested the effect of the entomopathogenic nematode Steinernema hermaphroditum on the survival and immune signaling regulation of Drosophila melanogaster wild type larvae. Our results indicate that S. hermaphroditum infective juveniles are pathogenic toward D. melanogaster larvae, but they fail to activate certain immune pathway readout genes. These findings imply that S. hermaphroditum employs mechanisms that allow these parasitic nematodes to interfere with the D. melanogaster immune system.
Collapse
Affiliation(s)
- Tien Huynh
- Department of Biological Sciences, The George Washington University, Washington, DC, USA
| | - Damien O'Halloran
- Department of Biological Sciences, The George Washington University, Washington, DC, USA
| | - John Hawdon
- Department of Microbiology, Immunology, and Tropical Medicine, The George Washington University, Washington, DC, USA
| | - Ioannis Eleftherianos
- Department of Biological Sciences, The George Washington University, Washington, DC, USA
| |
Collapse
|
6
|
Raval D, Daley L, Eleftherianos I. Drosophila melanogaster larvae are tolerant to oral infection with the bacterial pathogen Photorhabdus luminescens. MICROPUBLICATION BIOLOGY 2023; 2023:10.17912/micropub.biology.000938. [PMID: 37711508 PMCID: PMC10498274 DOI: 10.17912/micropub.biology.000938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Figures] [Subscribe] [Scholar Register] [Received: 07/29/2023] [Revised: 08/10/2023] [Accepted: 08/28/2023] [Indexed: 09/16/2023]
Abstract
The fruit fly Drosophila melanogaster is an excellent model for dissecting the molecular and functional bases of bacterial pathogenicity and host antibacterial immune response. The Gram-negative bacterium Photorhabdus luminescens is an insect-specific pathogen that forms a mutualistic relationship with the entomopathogenic nematode Heterorhabditis bacteriophora . Here we find that oral infection of D. melanogaster larvae with P. luminescens moderately reduces their survival ability while the bacteria replicate efficiently in the infected insects. This information will contribute towards understanding host gut immunity against potent bacterial pathogens.
Collapse
Affiliation(s)
- Dhaivat Raval
- Department of Biological Sciences, The George Washington University, Washington, DC, USA
| | - Lillia Daley
- Department of Biological Sciences, The George Washington University, Washington, DC, USA
| | - Ioannis Eleftherianos
- Department of Biological Sciences, The George Washington University, Washington, DC, USA
| |
Collapse
|
7
|
Ozakman Y, Raval D, Eleftherianos I. Drosophila melanogaster Imd signaling interacts with insulin signaling and alters feeding rate upon parasitic nematode infection. Heliyon 2023; 9:e16139. [PMID: 37251825 PMCID: PMC10208921 DOI: 10.1016/j.heliyon.2023.e16139] [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: 10/06/2022] [Revised: 03/15/2023] [Accepted: 05/06/2023] [Indexed: 05/31/2023] Open
Abstract
Significant progress has been made in recent years on exploring immunometabolism, a field that integrates two processes essential for maintaining tissue and organismal homeostasis, immunity and metabolism. The nematode parasite Heterorhabditis gerrardi, its mutualistic bacteria Photorhabdus asymbiotica, and the fruit fly Drosophila melanogaster constitute a unique system to investigate the molecular basis of host immunometabolic response to nematode-bacterial complexes. In this study, we explored the contribution of the two major immune signaling pathways, Toll and Imd, to sugar metabolism in D. melanogaster larvae during infection with H. gerrardi nematodes. We infected Toll or Imd signaling loss-of-function mutant larvae with H. gerrardi nematodes and assessed larval survival ability, feeding rate, and sugar metabolism. We found no significant differences in the survival ability or levels of sugar metabolites in any of the mutant larvae when responding to H. gerrardi infection. However, we found that the Imd mutant larvae have higher feeding rate than controls during the early stages of infection. In addition, feeding rates are lower in Imd mutants relative to the control larvae as the infection progresses. We further showed that Dilp2 and Dilp3 gene expression increases in Imd mutants compared to controls early in the infection, but their expression levels decrease at later times. These findings indicate that Imd signaling activity regulates the feeding rate and Dilp2 and Dilp3 expression in D. melanogaster larvae infected with H. gerrardi. Results from this study facilitate our understanding of the link between host innate immunity and sugar metabolism in the context of infectious diseases caused by parasitic nematodes.
Collapse
Affiliation(s)
- Yaprak Ozakman
- Infection and Innate Immunity Laboratory, Department of Biological Sciences, The George Washington University, Washington DC, 20052, USA
| | - Dhaivat Raval
- Infection and Innate Immunity Laboratory, Department of Biological Sciences, The George Washington University, Washington DC, 20052, USA
| | - Ioannis Eleftherianos
- Infection and Innate Immunity Laboratory, Department of Biological Sciences, The George Washington University, Washington DC, 20052, USA
| |
Collapse
|
8
|
Bland ML. Regulating metabolism to shape immune function: Lessons from Drosophila. Semin Cell Dev Biol 2023; 138:128-141. [PMID: 35440411 PMCID: PMC10617008 DOI: 10.1016/j.semcdb.2022.04.002] [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: 10/05/2021] [Revised: 02/21/2022] [Accepted: 04/03/2022] [Indexed: 12/14/2022]
Abstract
Infection with pathogenic microbes is a severe threat that hosts manage by activating the innate immune response. In Drosophila melanogaster, the Toll and Imd signaling pathways are activated by pathogen-associated molecular patterns to initiate cellular and humoral immune processes that neutralize and kill invaders. The Toll and Imd signaling pathways operate in organs such as fat body and gut that control host nutrient metabolism, and infections or genetic activation of Toll and Imd signaling also induce wide-ranging changes in host lipid, carbohydrate and protein metabolism. Metabolic regulation by immune signaling can confer resistance to or tolerance of infection, but it can also lead to pathology and susceptibility to infection. These immunometabolic phenotypes are described in this review, as are changes in endocrine signaling and gene regulation that mediate survival during infection. Future work in the field is anticipated to determine key variables such as sex, dietary nutrients, life stage, and pathogen characteristics that modify immunometabolic phenotypes and, importantly, to uncover the mechanisms used by the immune system to regulate metabolism.
Collapse
Affiliation(s)
- Michelle L Bland
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA, 22908, United States.
| |
Collapse
|
9
|
Garriga A, Toubarro D, Simões N, Morton A, García-Del-Pino F. The modulation effect of the Steinernema carpocapsae - Xenorhabdus nematophila complex on immune-related genes in Drosophila suzukii larvae. J Invertebr Pathol 2023; 196:107870. [PMID: 36493843 DOI: 10.1016/j.jip.2022.107870] [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: 04/06/2022] [Revised: 10/31/2022] [Accepted: 12/01/2022] [Indexed: 12/12/2022]
Abstract
Larvae of the invasive pest Drosophila suzukii are susceptible to the Steinernema carpocapsae - Xenorhabdus nematophila complex and an assessment of the immune-regulatory system activation in this insect was performed to understand the response to the nematode infection. The expressions of 14 immune-related genes of different pathways (Imd, Toll, Jak-STAT, ProPO, JNK, TGF-β) were analyzed using qRT-PCR to determine variations after nematode penetration (90 min and 4 h) and after bacterial release (14 h). Before the bacteria were present, the nematodes were not recognized by the immune system of the larvae and practically none of the analyzed pathways presented variations when compared with the non-infected larvae. However, after the X. nematophila were released, PGRP-LC was activated leading to the gene upregulation of antimicrobial peptides of both the Toll and Imd pathways. Interestingly, the cellular response was inactive during the infection course as Jak/STAT and pro-phenoloxidase genes remained unresponsive to the presence of both pathogens. These results illustrate how D. suzukii immune pathways responded differently to the nematode and bacteria along the infection course.
Collapse
Affiliation(s)
- A Garriga
- Departament de Biologia Animal, Biologia Vegetal i Ecologia, Facultat de Biociències, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain
| | - D Toubarro
- Centro de Biotecnologia dos Açores, Departamento de Biologia, Universidade dos Açores, Ponta Delgada, Portugal
| | - N Simões
- Centro de Biotecnologia dos Açores, Departamento de Biologia, Universidade dos Açores, Ponta Delgada, Portugal
| | - A Morton
- Departament de Biologia Animal, Biologia Vegetal i Ecologia, Facultat de Biociències, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain
| | - F García-Del-Pino
- Departament de Biologia Animal, Biologia Vegetal i Ecologia, Facultat de Biociències, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain.
| |
Collapse
|
10
|
Kundu A, Jaiswal N, Rao U, Somvanshi VS. Stringent in-silico identification of putative G-protein-coupled receptors (GPCRs) of the entomopathogenic nematode Heterorhabditis bacteriophora. J Nematol 2023; 55:20230038. [PMID: 38026552 PMCID: PMC10670001 DOI: 10.2478/jofnem-2023-0038] [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: 02/17/2023] [Indexed: 12/01/2023] Open
Abstract
The infective juveniles (IJs) of entomopathogenic nematode (EPN) Heterorhabditis bacteriophora find and infect their host insects in heterogeneous soil ecosystems by sensing a universal host cue (CO2) or insect/plant-derived odorants, which bind to various sensory receptors, including G protein-coupled receptors (GPCRs). Nematode chemosensory GPCRs (NemChRs) bind to a diverse set of ligands, including odor molecules. However, there is a lack of information on the NemChRs in EPNs. Here we identified 21 GPCRs in the H. bacteriophora genome sequence in a triphasic manner, combining various transmembrane detectors and GPCR predictors based on different algorithms, and considering inherent properties of GPCRs. The pipeline was validated by reciprocal BLAST, InterProscan, GPCR-CA, and NCBI CDD search. Functional classification of predicted GPCRs using Pfam revealed the presence of four NemChRs. Additionally, GPCRs were classified into various families based on the reciprocal BLAST approach into a frizzled type, a secretin type, and 19 rhodopsin types of GPCRs. Gi/o is the most abundant kind of G-protein, having a coupling specificity to all the fetched GPCRs. As the 21 GPCRs identified are expected to play a crucial role in the host-seeking behavior, these might be targeted to develop novel insect-pest management strategies by tweaking EPN IJ behavior, or to design novel anthelminthic drugs. Our new and stringent GPCR detection pipeline may also be used to identify GPCRs from the genome sequence of other organisms.
Collapse
Affiliation(s)
- Artha Kundu
- Division of Nematology, ICAR-Indian Agricultural Research Institute, New Delhi-12, India
| | - Nisha Jaiswal
- Division of Nematology, ICAR-Indian Agricultural Research Institute, New Delhi-12, India
| | - Uma Rao
- Division of Nematology, ICAR-Indian Agricultural Research Institute, New Delhi-12, India
| | - Vishal Singh Somvanshi
- Division of Nematology, ICAR-Indian Agricultural Research Institute, New Delhi-12, India
| |
Collapse
|
11
|
Lillis PE, Kennedy IP, Carolan JC, Griffin CT. Low-temperature exposure has immediate and lasting effects on the stress tolerance, chemotaxis and proteome of entomopathogenic nematodes. Parasitology 2022; 150:1-14. [PMID: 36328953 PMCID: PMC10090647 DOI: 10.1017/s0031182022001445] [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: 08/09/2022] [Revised: 10/03/2022] [Accepted: 10/07/2022] [Indexed: 11/07/2022]
Abstract
Temperature is one of the most important factors affecting soil organisms, including the infective stages of parasites and entomopathogenic nematodes, which are important biological control agents. We investigated the response of 2 species of entomopathogenic nematodes to different storage regimes: cold (9°C), culture temperature (20°C) and temperature swapped from 9 to 20°C. For Steinernema carpocapsae, cold storage had profound effects on chemotaxis, stress tolerance and protein expression that were retained in temperature-swapped individuals. These effects included reversal of chemotactic response for 3 (prenol, methyl salicylate and hexanol) of the 4 chemicals tested, and enhanced tolerance to freezing (−10°C) and desiccation (75% RH). Label-free quantitative proteomics showed that cold storage induced widespread changes in S. carpocapsae, including an increase in heat-shock proteins and late embryogenesis abundant proteins. For Heterorhabditis megidis, cold storage had a less dramatic effect on chemotaxis (as previously shown for proteomic expression) and changes were not maintained on return to 20°C. Thus, cold temperature exposure has significant effects on entomopathogenic nematodes, but the nature of the change depends on the species. Steinernema carpocapsae, in particular, displays significant plasticity, and its behaviour and stress tolerance may be manipulated by brief exposure to low temperatures, with implications for its use as a biological control agent.
Collapse
Affiliation(s)
- Peter E. Lillis
- Department of Biology, Maynooth University, Maynooth, County Kildare, Ireland
| | - Ian P. Kennedy
- Department of Biology, Maynooth University, Maynooth, County Kildare, Ireland
| | - James C. Carolan
- Department of Biology, Maynooth University, Maynooth, County Kildare, Ireland
| | | |
Collapse
|
12
|
Swart Z, Duong TA, Wingfield BD, Postma A, Slippers B. The relevance of studying insect-nematode interactions for human disease. Pathog Glob Health 2022; 116:140-145. [PMID: 34726122 PMCID: PMC9090338 DOI: 10.1080/20477724.2021.1996796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
Abstract
Vertebrate-parasitic nematodes cause debilitating, chronic infections in millions of people worldwide. The burden of these so-called 'neglected tropical diseases' is often carried by poorer socioeconomic communities in part because research on parasitic nematodes and their vertebrate hosts is challenging and costly. However, complex biological and pathological processes can be modeled in simpler organisms. Here, we consider how insight into the interactions between entomopathogenic nematodes (EPN), their insect hosts and bacterial symbionts may reveal novel treatment targets for parasitic nematode infections. We argue that a combination of approaches that target nematodes, as well as the interaction of pathogens with insect vectors and bacterial symbionts, offer potentially effective, but underexplored opportunities.
Collapse
Affiliation(s)
- Zorada Swart
- Department of Biochemistry Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute, University of Pretoria, South Africa
| | - Tuan A. Duong
- Department of Biochemistry Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute, University of Pretoria, South Africa
| | - Brenda D. Wingfield
- Department of Biochemistry Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute, University of Pretoria, South Africa
| | - Alisa Postma
- Department of Biochemistry Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute, University of Pretoria, South Africa
| | - Bernard Slippers
- Department of Biochemistry Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute, University of Pretoria, South Africa
| |
Collapse
|
13
|
Okakpu OK, Dillman AR. Review of the Role of Parasitic Nematode Excretory/Secretory Proteins in Host Immunomodulation. J Parasitol 2022; 108:199-208. [DOI: 10.1645/21-33] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Affiliation(s)
- Ogadinma K. Okakpu
- University of California, Riverside 900 University Avenue, Riverside, California 92521
| | - Adler R. Dillman
- University of California, Riverside 900 University Avenue, Riverside, California 92521
| |
Collapse
|
14
|
Influence of the ascarosides on the recovery, yield and dispersal of entomopathogenic nematodes. J Invertebr Pathol 2022; 188:107717. [PMID: 35031295 DOI: 10.1016/j.jip.2022.107717] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 01/08/2022] [Accepted: 01/09/2022] [Indexed: 11/23/2022]
Abstract
Recovery, yield, and dispersal are crucial developmental and behavioral indices for the infective juveniles of entomopathogenic nematodes, which are used as biocontrol agents against a variety of agricultural pests. Ascarosides and isopropylstilbene (ISO) function as nematode pheromones with developmental and behavioral effects. In this study, 11 synthesized ascarosides identified from Caenorhabditis elegans, together with ISO identified from Photorhabdus luminescens, were used to determine their influence on the IJ recovery, growth on agar plates, and dispersal of S. carpocapsae All, H. bacteriophora H06 and H. indica LN2 nematodes. Compared with the controls, significant differences in IJ recovery of three nematode species were detected from the supernatants of their corresponding bacterial cultures with almost all ascarosides or isopropylstilbene (ISO) at 0.04 nM in 6 days. The highest IJ recovery percentages was obtained from ISO and ascr#3 for All strain, ascr#5 and ascr#6 for LN2 strain, and ISO and ascr#12 for H06 strain. The ISO detected from Photorhabdus bacteria also induced IJ recovery of S. carpocapsae All. IJ yields was significantly stimulated by all synthesized compounds for S. carpocapsae All, and by most compounds for H. bacteriophora H06. The higher IJ yields varied with ascarosides. Ascr#7 and DMSO was common for the improved IJ yields of both nematode species. The three nematode species showed marked differences in dispersal behavior. In response to the ascarosides or ISO, S. carpocapsae All IJs actively moved with different dispersal rates, H. indica LN2 IJs in very low dispersal rates, and H. bacteriophora H06 IJs in variable and even suppressed rates on the agar plates at least during the assay period. Based on the synthesized standards, ascr#1, ascr#9 and ascr#10 were detected from three nematode species, ascr#5 and ascr#11 also from S. carpocapsae All and H. bacteriophora H06, and ascr#12 also from H. bacteriophora H06 and H. indica LN2. Ascr#9 was most abundant in three nematode species. Compared with the sterile PBS, significantly more ascr#1, ascr#9 and ascr#10 were detected from S. carpocapsae All and H. indica LN2, but less ascr#5 and ascr#11 from S. carpocapsae All, ascr#1, ascr#5, ascr#11 and ascr#12 from H. bacteriophora H06, in the corresponding bacterial supernatant. It seems that the bacterial supernatants could regulate the ascaroside secretion by the three nematode species. These results will provide useful clues for selecting suitable ascarosides to induce the recovery, improve the yield, and enhance the dispersal of the IJs of these nematodes.
Collapse
|
15
|
Dulovic A, Norman M, Harbecke D, Streit A. Chemotactic and temperature-dependent responses of the Strongyloidoidea superfamily of nematodes. Parasitology 2022; 149:116-123. [PMID: 35184785 PMCID: PMC11010508 DOI: 10.1017/s003118202100161x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 09/07/2021] [Accepted: 09/13/2021] [Indexed: 01/08/2023]
Abstract
Host-seeking behaviour and how a parasite identifies the correct host to infect remains a poorly understood area of parasitology. What is currently known is that host sensation and seeking behaviour is formed from a complex mixture of chemo-, thermo- and mechanosensory behaviours, of which chemosensation is the best studied. Previous studies of olfaction in parasitic nematodes suggested that this behaviour appears to be more closely related to target host and infection mode than phylogeny. However, there has not yet been a study comparing the chemotactic and temperature-dependent behaviours of very closely related parasitic and non-parasitic nematodes. To this end, we examined the temperature-dependent and chemotactic responses of the Strongyloidoidea superfamily of nematodes. We found differences in temperature response between the different species and within infective larvae. Chemotactic responses were highly divergent, with different attraction profiles between all species studied. When examining direct stimulation with fur, we found that it was insufficient to cause an attractive response. Overall, our results support the notion that olfactory sensation is more closely related to lifestyle and host range than phylogeny, and that multiple cues are required to initiate host-seeking behaviour.
Collapse
Affiliation(s)
- Alex Dulovic
- Max Planck Institute for Developmental Biology, Tübingen, Baden Württemberg, Germany
- NMI Natural and Medical Sciences Institute at the University of Tübingen, Tübingen, Baden Württemberg, Germany
| | - Mat Norman
- Max Planck Institute for Developmental Biology, Tübingen, Baden Württemberg, Germany
- UBC Faculty of Medicine, Vancouver, British Columbia, Canada
| | - Dorothee Harbecke
- Max Planck Institute for Developmental Biology, Tübingen, Baden Württemberg, Germany
| | - Adrian Streit
- Max Planck Institute for Developmental Biology, Tübingen, Baden Württemberg, Germany
| |
Collapse
|
16
|
Ozakman Y, Raval D, Eleftherianos I. Activin and BMP Signaling Activity Affects Different Aspects of Host Anti-Nematode Immunity in Drosophila melanogaster. Front Immunol 2021; 12:795331. [PMID: 35003118 PMCID: PMC8727596 DOI: 10.3389/fimmu.2021.795331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Accepted: 12/06/2021] [Indexed: 11/13/2022] Open
Abstract
The multifaceted functions ranging from cellular and developmental mechanisms to inflammation and immunity have rendered TGF-ß signaling pathways as critical regulators of conserved biological processes. Recent studies have indicated that this evolutionary conserved signaling pathway among metazoans contributes to the Drosophila melanogaster anti-nematode immune response. However, functional characterization of the interaction between TGF-ß signaling activity and the mechanisms activated by the D. melanogaster immune response against parasitic nematode infection remains unexplored. Also, it is essential to evaluate the precise effect of entomopathogenic nematode parasites on the host immune system by separating them from their mutualistic bacteria. Here, we investigated the participation of the TGF-ß signaling branches, activin and bone morphogenetic protein (BMP), to host immune function against axenic or symbiotic Heterorhabditis bacteriophora nematodes (parasites lacking or containing their mutualistic bacteria, respectively). Using D. melanogaster larvae carrying mutations in the genes coding for the TGF-ß extracellular ligands Daw and Dpp, we analyzed the changes in survival ability, cellular immune response, and phenoloxidase (PO) activity during nematode infection. We show that infection with axenic H. bacteriophora decreases the mortality rate of dpp mutants, but not daw mutants. Following axenic or symbiotic H. bacteriophora infection, both daw and dpp mutants contain only plasmatocytes. We further detect higher levels of Dual oxidase gene expression in dpp mutants upon infection with axenic nematodes and Diptericin and Cecropin gene expression in daw mutants upon infection with symbiotic nematodes compared to controls. Finally, following symbiotic H. bacteriophora infection, daw mutants have higher PO activity relative to controls. Together, our findings reveal that while D. melanogaster Dpp/BMP signaling activity modulates the DUOX/ROS response to axenic H. bacteriophora infection, Daw/activin signaling activity modulates the antimicrobial peptide and melanization responses to axenic H. bacteriophora infection. Results from this study expand our current understanding of the molecular and mechanistic interplay between nematode parasites and the host immune system, and the involvement of TGF-ß signaling branches in this process. Such findings will provide valuable insight on the evolution of the immune role of TGF-ß signaling, which could lead to the development of novel strategies for the effective management of human parasitic nematodes.
Collapse
|
17
|
Erdogan H, Cruzado-Gutierrez K, Stevens G, Shapiro-Ilan D, Kaplan F, Alborn H, Lewis E. Nematodes Follow a Leader. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.740351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Aggregated movement and population structure are known in entomopathogenic nematodes, which are obligate insect parasites. Aggregation behavior in the absence of external stimuli suggests communication among individuals, often in the form of trail-following, which has not been shown by nematodes of any kind. Interactions among individuals are an essential basis of following behaviors and can have significant fitness consequences. We explored intraspecific and interspecific interactions among three Steinernema species (S. glaseri, S. carpocapsae, and S. feltiae) in terms of trail following, and fitness outcomes of following heterospecific individuals. We found that the following behavior is context dependent. Following behavior among conspecifics was significantly increased when the lead nematode had prior contact with host cuticle. However, we did not find a clear association between the following response to heterospecific IJs and their reproductive success in a co-infected host.
Collapse
|
18
|
Parks SC, Nguyen S, Nasrolahi S, Bhat C, Juncaj D, Lu D, Ramaswamy R, Dhillon H, Fujiwara H, Buchman A, Akbari OS, Yamanaka N, Boulanger MJ, Dillman AR. Parasitic nematode fatty acid- and retinol-binding proteins compromise host immunity by interfering with host lipid signaling pathways. PLoS Pathog 2021; 17:e1010027. [PMID: 34714893 PMCID: PMC8580252 DOI: 10.1371/journal.ppat.1010027] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 11/10/2021] [Accepted: 10/11/2021] [Indexed: 12/19/2022] Open
Abstract
Parasitic nematodes cause significant morbidity and mortality globally. Excretory/secretory products (ESPs) such as fatty acid- and retinol- binding proteins (FARs) are hypothesized to suppress host immunity during nematode infection, yet little is known about their interactions with host tissues. Leveraging the insect parasitic nematode, Steinernema carpocapsae, we describe here the first in vivo study demonstrating that FARs modulate animal immunity, causing an increase in susceptibility to bacterial co-infection. Moreover, we show that FARs dampen key components of the fly immune response including the phenoloxidase cascade and antimicrobial peptide (AMP) production. Our data also reveal that FARs deplete lipid signaling precursors in vivo as well as bind to these fatty acids in vitro, suggesting that FARs elicit their immunomodulatory effects by altering the availability of lipid signaling molecules necessary for an efficient immune response. Collectively, these data support a complex role for FARs in immunosuppression in animals and provide detailed mechanistic insight into parasitism in phylum Nematoda.
Collapse
Affiliation(s)
- Sophia C. Parks
- Department of Nematology, University of California, Riverside, California, United States of America
| | - Susan Nguyen
- Department of Nematology, University of California, Riverside, California, United States of America
| | - Shyon Nasrolahi
- Department of Nematology, University of California, Riverside, California, United States of America
| | - Chaitra Bhat
- Department of Nematology, University of California, Riverside, California, United States of America
| | - Damian Juncaj
- Department of Nematology, University of California, Riverside, California, United States of America
| | - Dihong Lu
- Department of Nematology, University of California, Riverside, California, United States of America
| | - Raghavendran Ramaswamy
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada
| | - Harpal Dhillon
- Department of Nematology, University of California, Riverside, California, United States of America
| | - Hideji Fujiwara
- Division of Endocrinology, Metabolism, and Lipid Research, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Anna Buchman
- Division of Biological Sciences, Section of Cell and Developmental Biology, University of California, San Diego, California, United States of America
| | - Omar S. Akbari
- Division of Biological Sciences, Section of Cell and Developmental Biology, University of California, San Diego, California, United States of America
| | - Naoki Yamanaka
- Department of Entomology, University of California, Riverside, California, United States of America
| | - Martin J. Boulanger
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada
| | - Adler R. Dillman
- Department of Nematology, University of California, Riverside, California, United States of America
- * E-mail:
| |
Collapse
|
19
|
Ozakman Y, Eleftherianos I. Nematode infection and antinematode immunity in Drosophila. Trends Parasitol 2021; 37:1002-1013. [PMID: 34154933 DOI: 10.1016/j.pt.2021.06.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 05/28/2021] [Accepted: 06/01/2021] [Indexed: 12/15/2022]
Abstract
The entomopathogenic nematodes Heterorhabditis and Steinernema form mutualistic complexes with Gram-negative bacteria. These insect parasites have emerged as excellent research tools for studying nematode pathogenicity and elucidating the features that allow them to persist and multiply within the host. A better understanding of the molecular mechanisms of nematode infection and host antinematode processes will lead to the development of novel means for parasitic nematode control. Recent work has demonstrated the power of using the Drosophila infection model to identify novel parasitic nematode infection factors and elucidate the genetic and functional bases of host antinematode defense. Here, we aim to highlight the recent advances and address their contribution to the development of novel means for parasitic nematode control.
Collapse
Affiliation(s)
- Yaprak Ozakman
- Infection and Innate Immunity Lab, Department of Biological Sciences, Institute for Biomedical Sciences, The George Washington University, Science and Engineering Hall, 800 22nd Street NW, Washington, DC 20052, USA
| | - Ioannis Eleftherianos
- Infection and Innate Immunity Lab, Department of Biological Sciences, Institute for Biomedical Sciences, The George Washington University, Science and Engineering Hall, 800 22nd Street NW, Washington, DC 20052, USA.
| |
Collapse
|
20
|
Chemogenomic approach to identifying nematode chemoreceptor drug targets in the entomopathogenic nematode Heterorhabditis bacteriophora. Comput Biol Chem 2021; 92:107464. [PMID: 33667976 DOI: 10.1016/j.compbiolchem.2021.107464] [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: 10/28/2020] [Revised: 02/18/2021] [Accepted: 02/22/2021] [Indexed: 11/21/2022]
Abstract
Parasitic nematodes constitute one of the major threats to human health, causing diseases of major socioeconomic importance worldwide. Recent estimates indicate that more than 1 billion people are infected with parasitic nematodes around the world. Current measures to combat parasitic nematode infections include anthelmintic drugs. However, heavy exposure to anthelmintics has selected populations of livestock parasitic nematodes that are no longer susceptible to the drugs, rendering several anthelmintics useless for parasitic nematode control in many areas of the world. The rapidity with which anthelmintic resistance developed in response to these drugs suggests that increasing the selective pressure on human parasitic nematodes will also rapidly generate resistant worm populations. Therefore, development of new anthelmintics is of major importance before resistance becomes widespread in human parasitic nematode populations. G-Protein Coupled Receptors (GPCRs) represent an important target for many pharmacological interventions due to their ubiquitous expression in various cell types. GPCRs contribute to numerous physiological processes, and their ligand binding sites located on cell surfaces make them accessible targets and attractive substrates in terms of druggability. In fact, ∼35 % of Food and Drug Administration (FDA) and European Medicines Agency (EMA) approved drugs target GPCRs and their associated proteins, with over 300 additional drugs targeting GPCRs at the clinical trial stage. Nematode Chemosensory GPCRs (NemChRs) are unique to nematodes, and therefore represent ideal substrates for target-based drug discovery. Here we set out to identify NemChRs that are transcriptionally active inside the host, and to use these NemChRs in a reverse pharmacological screen to impede parasitic development. Our data identified several NemChRs, and we focused on one that was expressed in neuronal cells and exhibited the highest fold change in transcription after host activation. Next, we performed homology modelling and molecular dynamics simulations of this NemChR in order to conduct a virtual screening campaign to identify candidate drug targets which were ranked and selected for experimental testing in bioassays. Taken together, our results identify and characterize a candidate NemChR drug target, and provide a chemogenomic pipeline for identifying nematicide substrates.
Collapse
|
21
|
Kenney E, Yaparla A, Hawdon JM, O' Halloran DM, Grayfer L, Eleftherianos I. A putative lysozyme and serine carboxypeptidase from Heterorhabditis bacteriophora show differential virulence capacities in Drosophila melanogaster. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2021; 114:103820. [PMID: 32791175 DOI: 10.1016/j.dci.2020.103820] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2020] [Revised: 07/30/2020] [Accepted: 07/31/2020] [Indexed: 06/11/2023]
Abstract
Nematode virulence factors are of interest for a variety of applications including biocontrol against insect pests and the alleviation of autoimmune diseases with nematode-derived factors. In silico "omics" techniques have generated a wealth of candidate factors that may be important in the establishment of nematode infections, although the challenge of characterizing these individual factors in vivo remains. Here we provide a fundamental characterization of a putative lysozyme and serine carboxypeptidase from the host-induced transcriptome of Heterorhabditis bacteriophora. Both factors accelerated the mortality rate following Drosophila melanogaster infections with Photorhabdus luminescens, and both factors suppressed phenoloxidase activity in D. melanogaster hemolymph. Furthermore, the serine carboxypeptidase was lethal to a subpopulation of flies and suppressed the upregulation of antimicrobial peptides as well as phagocytosis. Together, our findings suggest that this serine carboxypeptidase possess both toxic and immunomodulatory properties while the lysozyme is likely to confer immunomodulatory, but not toxic effects.
Collapse
Affiliation(s)
- Eric Kenney
- Department of Biological Sciences, The George Washington University, Washington, DC, 20052, USA
| | - Amulya Yaparla
- Department of Biological Sciences, The George Washington University, Washington, DC, 20052, USA
| | - John M Hawdon
- Department of Microbiology, Immunology, and Tropical Medicine, The George Washington University, Washington, DC, USA
| | - Damien M O' Halloran
- Department of Biological Sciences, The George Washington University, Washington, DC, 20052, USA
| | - Leon Grayfer
- Department of Biological Sciences, The George Washington University, Washington, DC, 20052, USA
| | - Ioannis Eleftherianos
- Department of Biological Sciences, The George Washington University, Washington, DC, 20052, USA.
| |
Collapse
|
22
|
Kundu A, Jaiswal N, Bhat CG, Phani V, Chatterjee M, Dash M, Rao U, Somvanshi VS. Expression of various odorant-response defective (odr) genes in the entomopathogenic nematode Heterorhabditis bacteriophora (Nematoda: Heterorhabditidae). GENE REPORTS 2020. [DOI: 10.1016/j.genrep.2020.100818] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
23
|
Billard B, Gimond C, Braendle C. [Genetics and evolution of developmental plasticity in the nematode C. elegans: Environmental induction of the dauer stage]. Biol Aujourdhui 2020; 214:45-53. [PMID: 32773029 DOI: 10.1051/jbio/2020006] [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: 06/13/2020] [Indexed: 12/28/2022]
Abstract
Adaptive developmental plasticity is a common phenomenon across diverse organisms and allows a single genotype to express multiple phenotypes in response to environmental signals. Developmental plasticity is thus thought to reflect a key adaptation to cope with heterogenous habitats. Adaptive plasticity often relies on highly regulated processes in which organisms sense environmental cues predictive of unfavourable environments. The integration of such cues may involve sophisticated neuro-endocrine signaling pathways to generate subtle or complete developmental shifts. A striking example of adaptive plasticity is found in the nematode C. elegans, which can undergo two different developmental trajectories depending on the environment. In favourable conditions, C. elegans develops through reproductive growth to become an adult in three days at 20 °C. In contrast, in unfavourable conditions (high population density, food scarcity, elevated temperature) larvae can adopt an alternative developmental stage, called dauer. dauer larvae are highly stress-resistant and exhibit specific anatomical, metabolic and behavioural features that allow them to survive and disperse. In C. elegans, the sensation of environmental cues is mediated by amphid ciliated sensory neurons by means of G-coupled protein receptors. In favourable environments, the perception of pro-reproductive cues, such as food and the absence of pro-dauer cues, upregulates insulin and TGF-β signaling in the nervous system. In unfavourable conditions, pro-dauer cues lead to the downregulation of insulin and TGF-β signaling. In favourable conditions, TGF-β and insulin act in parallel to promote synthesis of dafachronic acid (DA) in steroidogenic tissues. Synthetized DA binds to the DAF-12 nuclear receptor throughout the whole body. DA-bound DAF-12 positively regulates genes of reproductive development in all C. elegans tissues. In poor conditions, the inhibition of insulin and TGF-β signaling prevents DA synthesis, thus the unliganded DAF-12 and co-repressor DIN-1 repress genes of reproductive development and promote dauer formation. Wild C. elegans have often been isolated as dauer larvae suggesting that dauer formation is very common in nature. Natural populations of C. elegans have colonized a great variety of habitats across the planet, which may differ substantially in environmental conditions. Consistent with divergent adaptation to distinct ecological niches, wild isolates of C. elegans and other nematode species isolated from different locations show extensive variation in dauer induction. Quantitative genetic and population-genomic approaches have identified many quantitative trait loci (QTL) associated with differences in dauer induction as well as a few underlying causative molecular variants. In this review, we summarize how C. elegans dauer formation is genetically regulated and how this trait evolves- both within and between species.
Collapse
|
24
|
A putative UDP-glycosyltransferase from Heterorhabditis bacteriophora suppresses antimicrobial peptide gene expression and factors related to ecdysone signaling. Sci Rep 2020; 10:12312. [PMID: 32704134 PMCID: PMC7378173 DOI: 10.1038/s41598-020-69306-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 07/12/2020] [Indexed: 12/20/2022] Open
Abstract
Insect pathogens have adopted an array of mechanisms to subvert the immune pathways of their respective hosts. Suppression may occur directly at the level of host-pathogen interactions, for instance phagocytic capacity or phenoloxidase activation, or at the upstream signaling pathways that regulate these immune effectors. Insect pathogens of the family Baculoviridae, for example, are known to produce a UDP-glycosyltransferase (UGT) that negatively regulates ecdysone signaling. Normally, ecdysone positively regulates both molting and antimicrobial peptide production, so the inactivation of ecdysone by glycosylation results in a failure of host larvae to molt, and probably a reduced antimicrobial response. Here, we examine a putative ecdysteroid glycosyltransferase, Hba_07292 (Hb-ugt-1), which was previously identified in the hemolymph-activated transcriptome of the entomopathogenic nematode Heterorhabditis bacteriophora. Injection of recombinant Hb-ugt-1 (rHb-ugt-1) into Drosophila melanogaster flies resulted in diminished upregulation of antimicrobial peptides associated with both the Toll and Immune deficiency pathways. Ecdysone was implicated in this suppression by a reduction in Broad Complex expression and reduced pupation rates in r Hb-ugt-1-injected larvae. In addition to the finding that H. bacteriophora excreted-secreted products contain glycosyltransferase activity, these results demonstrate that Hb-ugt-1 is an immunosuppressive factor and that its activity likely involves the inactivation of ecdysone.
Collapse
|
25
|
Bruno P, Machado RAR, Glauser G, Köhler A, Campos-Herrera R, Bernal J, Toepfer S, Erb M, Robert CAM, Arce CCM, Turlings TCJ. Entomopathogenic nematodes from Mexico that can overcome the resistance mechanisms of the western corn rootworm. Sci Rep 2020; 10:8257. [PMID: 32427834 PMCID: PMC7237494 DOI: 10.1038/s41598-020-64945-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Accepted: 02/28/2020] [Indexed: 12/30/2022] Open
Abstract
Natural enemies of herbivores are expected to adapt to the defence strategies of their preys or hosts. Such adaptations may also include their capacity to cope with plant metabolites that herbivores sequester as a defence. In this study, we evaluated the ability of Mexican entomopathogenic nematodes (EPN) to resist benzoxazinoids that are sequestered from maize roots by the western corn rootworm (WCR, Diabrotica virgifera virgifera; Coleoptera: Chrysomelidae), an important maize pest in America and Europe. From maize fields throughout Mexico, we retrieved 40 EPN isolates belonging to five different species, with a majority identified as Heterorhabditis bacteriophora. In the laboratory, all nematodes readily infected non-sequestering larvae of the banded cucumber beetle (D. balteata), while infectivity varied strongly for WCR larvae. While some H. bacteriophora isolates seemed negatively affected by benzoxazinoids, most showed to be resistant. Thus, EPN from Mexican maize fields can cope with these plant defence metabolites, but the results also indicate that WCR larvae possess other mechanisms that help to resist EPN. This work contributes to a better understanding of the capacity of herbivore natural enemies to resist plant defence metabolites. Furthermore, it identifies several benzoxazinoid-resistant EPN isolates that may be used to control this important maize pest.
Collapse
Affiliation(s)
- Pamela Bruno
- Laboratory of Fundamental and Applied Research in Chemical Ecology, University of Neuchâtel, Emile-Argand 11, 2000, Neuchâtel, Switzerland
| | | | - Gaétan Glauser
- Neuchâtel Platform of Analytical Chemistry, University of Neuchâtel, Neuchâtel, Switzerland
| | - Angela Köhler
- Laboratory of Fundamental and Applied Research in Chemical Ecology, University of Neuchâtel, Emile-Argand 11, 2000, Neuchâtel, Switzerland
- Friedrich Schiller University Jena, Jena, Germany
| | - Raquel Campos-Herrera
- Instituto de Ciencias de la Vid y del Vino (Universidad de La Rioja, CSIC, Gobierno de La Rioja), Logroño, La Rioja, Spain
| | - Julio Bernal
- Department of Entomology, Texas A&M University, Texas, USA
| | - Stefan Toepfer
- CABI, c/o Plant Protection and Soil Conservation Directorate, Hódmezővásárhely, Hungary
| | - Matthias Erb
- Institute of Plant Sciences, University of Bern, Bern, Switzerland
| | | | - Carla C M Arce
- Laboratory of Fundamental and Applied Research in Chemical Ecology, University of Neuchâtel, Emile-Argand 11, 2000, Neuchâtel, Switzerland.
| | - Ted C J Turlings
- Laboratory of Fundamental and Applied Research in Chemical Ecology, University of Neuchâtel, Emile-Argand 11, 2000, Neuchâtel, Switzerland.
| |
Collapse
|
26
|
Colgan TJ, Carolan JC, Sumner S, Blaxter ML, Brown MJF. Infection by the castrating parasitic nematode Sphaerularia bombi changes gene expression in Bombus terrestris bumblebee queens. INSECT MOLECULAR BIOLOGY 2020; 29:170-182. [PMID: 31566835 DOI: 10.1111/imb.12618] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Revised: 08/20/2019] [Accepted: 09/13/2019] [Indexed: 06/10/2023]
Abstract
Parasitism can result in dramatic changes in host phenotype, which are themselves underpinned by genes and their expression. Understanding how hosts respond at the molecular level to parasites can therefore reveal the molecular architecture of an altered host phenotype. The entomoparasitic nematode Sphaerularia bombi is a parasite of bumblebee (Bombus) hosts where it induces complex behavioural changes and host castration. To examine this interaction at the molecular level, we performed genome-wide transcriptional profiling using RNA-Sequencing (RNA-Seq) of S. bombi-infected Bombus terrestris queens at two critical time-points: during and just after overwintering diapause. We found that infection by S. bombi affects the transcription of genes underlying host biological processes associated with energy usage, translation, and circadian rhythm. We also found that the parasite affects the expression of immune genes, including members of the Toll signalling pathway providing evidence for a novel interaction between the parasite and the host immune response. Taken together, our results identify host biological processes and genes affected by an entomoparasitic nematode providing the first steps towards a molecular understanding of this ecologically important host-parasite interaction.
Collapse
Affiliation(s)
- T J Colgan
- Department of Zoology, School of Natural Sciences, University of Dublin, Trinity College, Dublin, Ireland
- School of Biological and Chemical Sciences, Queen Mary University of London, London, UK
- School of Biological, Earth and Environmental Sciences, University College Cork, Cork, Ireland
| | - J C Carolan
- Department of Biology, Maynooth University, Maynooth, County Kildare, Ireland
| | - S Sumner
- Centre for Biodiversity and Environment Research, University College London, London, UK
| | - M L Blaxter
- School of Biological Sciences, Institute of Evolutionary Biology, University of Edinburgh, Edinburgh, UK
| | - M J F Brown
- Centre of Ecology, Evolution and Behaviour, Department of Biological Sciences, Royal Holloway University of London, Egham, UK
| |
Collapse
|
27
|
Abstract
Different model systems have, over the years, contributed to our current understanding of the molecular mechanisms underpinning the various types of interaction between bacteria and their animal hosts. The genus
Photorhabdus
comprises Gram-negative insect pathogenic bacteria that are normally found as symbionts that colonize the gut of the infective juvenile stage of soil-dwelling nematodes from the family Heterorhabditis. The nematodes infect susceptible insects and release the bacteria into the insect haemolymph where the bacteria grow, resulting in the death of the insect. At this stage the nematodes feed on the bacterial biomass and, following several rounds of reproduction, the nematodes develop into infective juveniles that leave the insect cadaver in search of new hosts. Therefore
Photorhabdus
has three distinct and obligate roles to play during this life-cycle: (1)
Photorhabdus
must kill the insect host; (2)
Photorhabdus
must be capable of supporting nematode growth and development; and (3)
Photorhabdus
must be able to colonize the gut of the next generation of infective juveniles before they leave the insect cadaver. In this review I will discuss how genetic analysis has identified key genes involved in mediating, and regulating, the interaction between
Photorhabdus
and each of its invertebrate hosts. These studies have resulted in the characterization of several new families of toxins and a novel inter-kingdom signalling molecule and have also uncovered an important role for phase variation in the regulation of these different roles.
Collapse
Affiliation(s)
- David J Clarke
- School of Microbiology and APC Microbiome Ireland, University College Cork, Cork, Ireland
| |
Collapse
|
28
|
Elucidating the molecular and developmental biology of parasitic nematodes: Moving to a multiomics paradigm. ADVANCES IN PARASITOLOGY 2020; 108:175-229. [PMID: 32291085 DOI: 10.1016/bs.apar.2019.12.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
In the past two decades, significant progress has been made in the sequencing, assembly, annotation and analyses of genomes and transcriptomes of parasitic worms of socioeconomic importance. This progress has somewhat improved our knowledge and understanding of these pathogens at the molecular level. However, compared with the free-living nematode Caenorhabditis elegans, the areas of functional genomics, transcriptomics, proteomics and metabolomics of parasitic nematodes are still in their infancy, and there are major gaps in our knowledge and understanding of the molecular biology of parasitic nematodes. The information on signalling molecules, molecular pathways and microRNAs (miRNAs) that are known to be involved in developmental processes in C. elegans and the availability of some molecular resources (draft genomes, transcriptomes and some proteomes) for selected parasitic nematodes provide a basis to start exploring the developmental biology of parasitic nematodes. Indeed, some studies have identified molecules and pathways that might associate with developmental processes in related, parasitic nematodes, such as Haemonchus contortus (barber's pole worm). However, detailed information is often scant and 'omics resources are limited, preventing a proper integration of 'omic data sets and comprehensive analyses. Moreover, little is known about the functional roles of pheromones, hormones, signalling pathways and post-transcriptional/post-translational regulations in the development of key parasitic nematodes throughout their entire life cycles. Although C. elegans is an excellent model to assist molecular studies of parasitic nematodes, its use is limited when it comes to explorations of processes that are specific to parasitism within host animals. A deep understanding of parasitic nematodes, such as H. contortus, requires substantially enhanced resources and the use of integrative 'omics approaches for analyses. The improved genome and well-established in vitro larval culture system for H. contortus provide unprecedented opportunities for comprehensive studies of the transcriptomes (mRNA and miRNA), proteomes (somatic, excretory/secretory and phosphorylated proteins) and lipidomes (e.g., polar and neutral lipids) of this nematode. Such resources should enable in-depth explorations of its developmental biology at a level, not previously possible. The main aims of this review are (i) to provide a background on the development of nematodes, with a particular emphasis on the molecular aspects involved in the dauer formation and exit in C. elegans; (ii) to critically appraise the current state of knowledge of the developmental biology of parasitic nematodes and identify key knowledge gaps; (iii) to cover salient aspects of H. contortus, with a focus on the recent advances in genomics, transcriptomics, proteomics and lipidomics as well as in vitro culturing systems; (iv) to review recent advances in our knowledge and understanding of the molecular and developmental biology of H. contortus using an integrative multiomics approach, and discuss the implications of this approach for detailed explorations of signalling molecules, molecular processes and pathways likely associated with nematode development, adaptation and parasitism, and for the identification of novel intervention targets against these pathogens. Clearly, the multiomics approach established recently is readily applicable to exploring a wide range of interesting and socioeconomically significant parasitic worms (including also trematodes and cestodes) at the molecular level, and to elucidate host-parasite interactions and disease processes.
Collapse
|
29
|
Drosophila melanogaster Responses against Entomopathogenic Nematodes: Focus on Hemolymph Clots. INSECTS 2020; 11:insects11010062. [PMID: 31963772 PMCID: PMC7023112 DOI: 10.3390/insects11010062] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 01/11/2020] [Accepted: 01/14/2020] [Indexed: 12/28/2022]
Abstract
Several insect innate immune mechanisms are activated in response to infection by entomopathogenic nematodes (EPNs). In this review, we focus on the coagulation of hemolymph, which acts to stop bleeding after injury and prevent access of pathogens to the body cavity. After providing a general overview of invertebrate coagulation systems, we discuss recent findings in Drosophila melanogaster which demonstrate that clots protect against EPN infections. Detailed analysis at the cellular level provided insight into the kinetics of the secretion of Drosophila coagulation factors, including non-classical modes of secretion. Roughly, clot formation can be divided into a primary phase in which crosslinking of clot components depends on the activity of Drosophila transglutaminase and a secondary, phenoloxidase (PO)-dependent phase, characterized by further hardening and melanization of the clot matrix. These two phases appear to play distinct roles in two commonly used EPN infection models, namely Heterorhabditis bacteriophora and Steinernema carpocapsae. Finally, we discuss the implications of the coevolution between parasites such as EPNs and their hosts for the dynamics of coagulation factor evolution.
Collapse
|
30
|
High-Resolution Infection Kinetics of Entomopathogenic Nematodes Entering Drosophila melanogaster. INSECTS 2020; 11:insects11010060. [PMID: 31963655 PMCID: PMC7023307 DOI: 10.3390/insects11010060] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 01/10/2020] [Accepted: 01/11/2020] [Indexed: 12/26/2022]
Abstract
Entomopathogenic nematodes (EPNs) have been a useful model for studying wound healing in insects due to their natural mechanism of entering an insect host either through the cuticle or an orifice. While many experiments have shed light on nematode and host behavior, as well as the host immune response, details regarding early nematode entry and proliferative events have been limited. Using high-resolution microscopy, we provide data on the early infection kinetics of Heterorhabditis bacteriophora and its symbiotic bacteria, Photorhabdus luminescens. EPNs appendage themselves to the host and enter through the host cuticle with a drill-like mechanism while leaving their outer sheath behind. EPNs immediately release their symbiotic bacteria in the host which leads to changes in host behavior and septicemia within 6 h while EPNs travel through the host in a predictable manner, congregating in the anterior end of the host. This paper sheds light on the entry and proliferative events of EPN infection, which will further aid in our understanding of wound healing and host immune activation at a high spatiotemporal resolution.
Collapse
|
31
|
Kenney E, Hawdon JM, O'Halloran D, Eleftherianos I. Heterorhabditis bacteriophora Excreted-Secreted Products Enable Infection by Photorhabdus luminescens Through Suppression of the Imd Pathway. Front Immunol 2019; 10:2372. [PMID: 31636642 PMCID: PMC6787769 DOI: 10.3389/fimmu.2019.02372] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2019] [Accepted: 09/20/2019] [Indexed: 12/14/2022] Open
Abstract
Upon entering the hemocoel of its insect host, the entomopathogenic nematode Heterorhabditis bacteriophora releases its symbiotic bacteria Photorhabdus luminescens, which is also a strong insect pathogen. P. luminescens is known to suppress the insect immune response independently following its release, but the nematode appears to enact its own immunosuppressive mechanisms during the earliest phases of an infection. H. bacteriophora was found to produce a unique set of excreted-secreted proteins in response to host hemolymph, and while basal secretions are immunogenic with regard to Diptericin expression through the Imd pathway, host-induced secretions suppress this expression to a level below that of controls in Drosophila melanogaster. This effect is consistent in adults, larvae, and isolated larval fat bodies, and the magnitude of suppression is dose-dependent. By reducing the expression of Diptericin, an antimicrobial peptide active against Gram-negative bacteria, the activated excreted-secreted products enable a more rapid propagation of P. luminescens that corresponds to more rapid host mortality. The identification and isolation of the specific proteins responsible for this suppression represents an exciting field of study with potential for enhancing the biocontrol of insect pests and treatment of diseases associated with excessive inflammation.
Collapse
Affiliation(s)
- Eric Kenney
- Infection and Innate Immunity Lab, Department of Biological Sciences, George Washington University, Washington, DC, United States
| | - John M Hawdon
- Department of Microbiology, Immunology, and Tropical Medicine, George Washington University, Washington, DC, United States
| | - Damien O'Halloran
- Infection and Innate Immunity Lab, Department of Biological Sciences, George Washington University, Washington, DC, United States.,Institute for Neuroscience, Department of Biological Sciences, George Washington University, Washington, DC, United States
| | - Ioannis Eleftherianos
- Infection and Innate Immunity Lab, Department of Biological Sciences, George Washington University, Washington, DC, United States
| |
Collapse
|
32
|
Participation of the Serine Protease Jonah66Ci in the Drosophila Antinematode Immune Response. Infect Immun 2019; 87:IAI.00094-19. [PMID: 31182620 DOI: 10.1128/iai.00094-19] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 05/29/2019] [Indexed: 01/27/2023] Open
Abstract
Serine proteases and serine protease homologs form the second largest gene family in the Drosophila melanogaster genome. Certain genes in the Jonah multigene family encoding serine proteases have been implicated in the fly antiviral immune response. Here, we report the involvement of Jonah66Ci in the Drosophila immune defense against Steinernema carpocapsae nematode infection. We find that Drosophila Jonah66Ci is upregulated in response to symbiotic (carrying the mutualistic bacterium Xenorhabdus nematophila) or axenic (lacking Xenorhabdus) Steinernema nematodes and is expressed exclusively in the gut of Drosophila larvae. Inactivation of Jonah66Ci provides a survival advantage to larvae against axenic nematodes and results in differential expression of Toll and Imd pathway effector genes, specifically in the gut. Also, inactivation of Jonah66Ci increases the numbers of enteroendocrine and mitotic cells in the gut of uninfected larvae, and infection with Steinernema nematodes reduces their numbers, whereas the numbers of intestinal stem cells are unaffected by nematode infection. Jonah66Ci knockdown further reduces nitric oxide levels in response to infection with symbiotic Steinernema nematodes. Finally, we show that Jonah66Ci knockdown does not alter the feeding rates of uninfected Drosophila larvae; however, infection with axenic Steinernema nematodes lowers larval feeding. In conclusion, we report that Jonah66Ci participates in maintaining homeostasis of certain physiological processes in Drosophila larvae in the context of Steinernema nematode infection. Similar findings will take us a step further toward understanding the molecular and physiological mechanisms that take place during parasitic nematode infection in insects.
Collapse
|
33
|
Chevée V, Sachar U, Yadav S, Heryanto C, Eleftherianos I. The peptidoglycan recognition protein PGRP-LE regulates the Drosophila immune response against the pathogen Photorhabdus. Microb Pathog 2019; 136:103664. [PMID: 31404632 DOI: 10.1016/j.micpath.2019.103664] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 08/09/2019] [Accepted: 08/09/2019] [Indexed: 12/15/2022]
Abstract
Photorhabdus bacteria are potent pathogens of insects and humans. To elucidate the infection strategies Photorhabdus employs to subvert the host innate immune response, it is critical to use model organisms that permit the genetic dissection of the dynamics involved in host-pathogen interactions. Here, we employed the fruit fly Drosophila melanogaster to interrogate the role of the immune deficiency (Imd) pathway receptor peptidoglycan recognition protein LE (PGRP-LE) in the regulation of the fly's response to the insect pathogen Photorhabdus luminescens and the insect/human pathogen P. asymbiotica. We show that PGRP-LE is upregulated in response to injection of Photorhabdus bacteria in background control flies, and that loss-of-function PGRP-LE mutant flies are more sensitive specifically to P. luminescens infection and harbor a higher bacterial burden of this species compared to background controls. Also, our results indicate that the absence of functional PGRP-LE alters the transcriptional pathway activity of Imd and Jnk signaling upon infection with P. asymbiotica, while infection with P. luminescens modifies the activity of Jak/Stat signaling. These findings denote the participation of the PGRP-LE receptor in the response of D. melanogaster to Photorhabdus challenge and contribute to a better understanding of pathogen detection and host immune regulation against virulent microbial invaders.
Collapse
Affiliation(s)
- Victoria Chevée
- Infection and Innate Immunity Lab, Department of Biological Sciences, 800 22nd Street NW, Washington, DC, 200 52, USA
| | - Upasana Sachar
- Infection and Innate Immunity Lab, Department of Biological Sciences, 800 22nd Street NW, Washington, DC, 200 52, USA
| | - Shruti Yadav
- Infection and Innate Immunity Lab, Department of Biological Sciences, 800 22nd Street NW, Washington, DC, 200 52, USA
| | - Christa Heryanto
- Infection and Innate Immunity Lab, Department of Biological Sciences, 800 22nd Street NW, Washington, DC, 200 52, USA
| | - Ioannis Eleftherianos
- Infection and Innate Immunity Lab, Department of Biological Sciences, 800 22nd Street NW, Washington, DC, 200 52, USA.
| |
Collapse
|
34
|
Harsh S, Heryanto C, Eleftherianos I. Intestinal lipid droplets as novel mediators of host-pathogen interaction in Drosophila. Biol Open 2019; 8:bio.039040. [PMID: 31278163 PMCID: PMC6679391 DOI: 10.1242/bio.039040] [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] [Indexed: 01/23/2023] Open
Abstract
Lipid droplets (LDs) are lipid-carrying multifunctional organelles, which might also interact with pathogens and influence the host immune response. However, the exact nature of these interactions remains currently unexplored. Here we show that systemic infection of Drosophila adult flies with non-pathogenic Escherichia coli, the extracellular bacterial pathogen Photorhabdus luminescens or the facultative intracellular pathogen Photorhabdus asymbiotica results in intestinal steatosis marked by lipid accumulation in the midgut. Accumulation of LDs in the midgut also correlates with increased whole-body lipid levels characterized by increased expression of genes regulating lipogenesis. The lipid-enriched midgut further displays reduced expression of the enteroendocrine-secreted hormone, Tachykinin. The observed lipid accumulation requires the Gram-negative cell wall pattern recognition molecule, PGRP-LC, but not PGRP-LE, for the humoral immune response. Altogether, our findings indicate that Drosophila LDs are inducible organelles, which can serve as markers for inflammation and, depending on the nature of the challenge, they can dictate the outcome of the infection. Summary: Lipid droplets are inducible organelles, act as inflammatory markers and, depending on the nature of challenge, can dictate the outcome of the infection.
Collapse
Affiliation(s)
- Sneh Harsh
- Department of Biological Sciences, Institute for Biomedical Sciences, The George Washington University, Washington DC 20052, USA
| | - Christa Heryanto
- Department of Biological Sciences, Institute for Biomedical Sciences, The George Washington University, Washington DC 20052, USA
| | - Ioannis Eleftherianos
- Department of Biological Sciences, Institute for Biomedical Sciences, The George Washington University, Washington DC 20052, USA
| |
Collapse
|
35
|
Ozakman Y, Eleftherianos I. TGF-β Signaling Interferes With the Drosophila Innate Immune and Metabolic Response to Parasitic Nematode Infection. Front Physiol 2019; 10:716. [PMID: 31316388 PMCID: PMC6611403 DOI: 10.3389/fphys.2019.00716] [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: 02/10/2019] [Accepted: 05/23/2019] [Indexed: 01/23/2023] Open
Abstract
The common fruit fly, Drosophila melanogaster, is an outstanding model to study the molecular basis of anti-pathogen immunity. The parasitic nematode Heterorhabditis gerrardi, together with its mutualistic bacteria Photorhabdus asymbiotica, infects a wide range of insects, including D. melanogaster. Recently, we have shown that transforming growth factor-β (TGF-ß) signaling in D. melanogaster is regulated in response to parasitic nematode infection. In the current study, we investigated the contribution of two TGF-ß signaling branches, the activin and the bone morphogenetic protein (BMP), to D. melanogaster immune function against H. gerrardi. We used D. melanogaster larvae carrying mutations in the genes coding for the TGF-ß extracellular ligands daw and dpp. We have demonstrated that the number of circulating hemocytes in uninfected daw and dpp mutants decreases twofold compared to background controls, yet no significant changes in hemocyte numbers and survival of the TGF-ß mutants are observed upon nematode infection. However, we have shown that nematode-infected daw mutants express Dual oxidase at higher levels and phenoloxidase activity at lower levels compared to their background controls. To elucidate the contribution of TGF-ß signaling in the metabolic response of D. melanogaster to parasitic nematodes, we estimated lipid and carbohydrate levels in daw and dpp mutant larvae infected with H. gerrardi. We have found that both nematode-infected mutants contain lipid droplets of larger size, with daw mutant larvae also containing elevated glycogen levels. Overall, our findings indicate that the regulation of activin and BMP branches of TGF-ß signaling can alter the immune and metabolic processes in D. melanogaster during response to parasitic nematode infection. Results from this study shed light on the molecular signaling pathways insects activate to regulate mechanisms for fighting potent nematode parasites, which could lead to the identification of novel management strategies for the control of damaging pests.
Collapse
Affiliation(s)
- Yaprak Ozakman
- Infection and Innate Immunity Laboratory, Department of Biological Sciences, The George Washington University, Washington, DC, United States
| | - Ioannis Eleftherianos
- Infection and Innate Immunity Laboratory, Department of Biological Sciences, The George Washington University, Washington, DC, United States
| |
Collapse
|
36
|
Forger LV, Woolf MS, Simmons TL, Swall JL, Singh B. A eukaryotic community succession based method for postmortem interval (PMI) estimation of decomposing porcine remains. Forensic Sci Int 2019; 302:109838. [PMID: 31233889 DOI: 10.1016/j.forsciint.2019.05.054] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 05/24/2019] [Accepted: 05/26/2019] [Indexed: 10/26/2022]
Abstract
Recent, short-term studies on porcine and human models (albeit with few replicates) demonstrated that the succession of the microbial community of remains may be used to estimate time since death. Using a porcine model (N=6) over an extended period of time (1703 ADD, or two months), this study characterized the eukaryote community of decomposing remains. Skin microbial samples were collected from the torso of each set of remains every day during the first week, on alternate days during the second week, and once a week for the remainder of the 60-day period; all collection intervals were recorded in accumulated degree days (ADD). The eukaryote community of each sample was determined using 18S ribosomal DNA (rDNA) MiSeq high throughput sequencing; data were analyzed in the Mothur pipeline (v1.39.5) and in IBM SPSS and R statistical packages. The relative abundance of eukaryote taxa across ADD/Days and an Analysis of Molecular Variance (AMOVA) indicated similarities between sequential ADD/Days, but significant differences in the eukaryote communities as broad stage 'milestones' of decomposition were reached. Fresh remains (0-57 ADD/0-2 Days; exhibiting a total body score (TBS) of 0-10) were characterized by the combined presence of Saccharomycetaceae, Debaryomycetaceae, Trichosporonaceae, Rhabditida, and Trichostomatia. During bloat and active decay (87-209 ADD/3-7 Days; exhibiting TBS of 11-20), Diptera was the most abundant eukaryotic taxa. During advanced decay stage (267-448 ADD/9-15 Days; exhibiting TBS of 21-25), Rhabditida was the most dominant eukaryote. Dry/skeletal remains (734-1703 ADD/26-61 Days; TBS≥26) were dominated by fungal families Dipodascaceae, Debaryomycetaceae, Trichosporonaceae, and Sporidiobolaceae. Using the family-level eukaryote taxonomic data for the entire study, random forest modelling explained 89.58% of the variation in ADD/Days, with a root mean square error (RMSE) of 177.55 ADD (≈6 days). Overall, these results highlight the importance of the microbial eukaryote community during the process of decomposition and in estimation of PMI.
Collapse
Affiliation(s)
- Luisa V Forger
- Department of Forensic Science, Virginia Commonwealth University, Richmond, VA, United States; Visiting Scientist Program, Oak Ridge Institute for Science and Education, Stafford, VA, United States
| | - Michael S Woolf
- Department of Forensic Science, Virginia Commonwealth University, Richmond, VA, United States; Department of Chemistry, University of Virginia, Charlottesville, VA, United States
| | - Tal L Simmons
- Department of Forensic Science, Virginia Commonwealth University, Richmond, VA, United States
| | - Jenise L Swall
- Department of Statistical Sciences and Operations Research, Virginia Commonwealth University, Richmond, VA, United States
| | - Baneshwar Singh
- Department of Forensic Science, Virginia Commonwealth University, Richmond, VA, United States.
| |
Collapse
|
37
|
Patrnogic J, Heryanto C, Ozakman Y, Eleftherianos I. Transcript analysis reveals the involvement of NF-κB transcription factors for the activation of TGF-β signaling in nematode-infected Drosophila. Immunogenetics 2019; 71:501-510. [PMID: 31147740 DOI: 10.1007/s00251-019-01119-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2018] [Accepted: 05/11/2019] [Indexed: 11/27/2022]
Abstract
The common fruit fly Drosophila melanogaster is a powerful model for studying signaling pathway regulation. Conserved signaling pathways underlying physiological processes signify evolutionary relationship between organisms and the nature of the mechanisms they control. This study explores the cross-talk between the well-characterized nuclear factor kappa B (NF-κB) innate immune signaling pathways and transforming growth factor beta (TGF-β) signaling pathway in response to parasitic nematode infection in Drosophila. To understand the link between signaling pathways, we followed on our previous studies by performing a transcript-level analysis of different TGF-β signaling components following infection of immune-compromised Drosophila adult flies with the nematode parasites Heterorhabditis gerrardi and H. bacteriophora. Our findings demonstrate the requirement of NF-κB transcription factors for activation of TGF-β signaling pathway in Drosophila in the context of parasitic nematode infection. We observe significant decrease in transcript level of glass bottom boat (gbb) and screw (scw), components of the bone morphogenic protein (BMP) branch, as well as Activinβ (actβ) which is a component of the Activin branch of the TGF-β signaling pathway. These results are observed only in H. gerrardi nematode-infected flies compared to uninfected control. Also, this significant decrease in transcript level is found only for extracellular ligands. Future research examining the mechanisms regulating the interaction of these signaling pathways could provide further insight into Drosophila anti-nematode immune function against infection with potent parasitic nematodes.
Collapse
Affiliation(s)
- Jelena Patrnogic
- Infection and Innate Immunity Laboratory, Department of Biological Sciences, Institute for Biomedical Sciences, The George Washington University, Washington, DC, USA
| | - Christa Heryanto
- Infection and Innate Immunity Laboratory, Department of Biological Sciences, Institute for Biomedical Sciences, The George Washington University, Washington, DC, USA
| | - Yaprak Ozakman
- Infection and Innate Immunity Laboratory, Department of Biological Sciences, Institute for Biomedical Sciences, The George Washington University, Washington, DC, USA
| | - Ioannis Eleftherianos
- Infection and Innate Immunity Laboratory, Department of Biological Sciences, Institute for Biomedical Sciences, The George Washington University, Washington, DC, USA.
| |
Collapse
|
38
|
Wang GJ, Zhuo XR, Wang WW, Liu XS, Wang GX, Wang JL. Molecular characterization of immune responses of Helicoverpa armigera to infection with the mermithid nematode Ovomermis sinensis. BMC Genomics 2019; 20:161. [PMID: 30813894 PMCID: PMC6391810 DOI: 10.1186/s12864-019-5544-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Accepted: 02/18/2019] [Indexed: 01/02/2023] Open
Abstract
Background Mermithid nematodes, such as Ovomermis sinensis, display a broad host range including some lepidopteran pests. Infective juveniles penetrate their host through the cuticle, complete their growth within the hemocoel and eventually kill the host upon their emergence. Hence, mermithid nematodes are considered potential biological control agents of insect pests. Our previous data indicate that the infection rate of O. sinensis on cotton bollworm (Helicoverpa armigera) is low, which may be largely due to the strong immune system of the host. However, current knowledge on the interactions of mermithid nematodes with their hosts and the mechanisms employed by hosts to defend themselves against mermithid nematodes is limited. Results Here, we investigated the response of H. armigera to O. sinensis infection. Parasitism by O. sinensis caused a sharp decline in the survival rate of H. armigera. The hemocytic phagocytosis ability, antibacterial activity, and phenoloxidase (PO) activity in plasma of H. armigera increased at 1 d post parasitism (dpp) but decreased at 3 dpp. Further, we investigated gene expression in the fat body of parasitized and non-parasitized H. armigera larvae at 1, 3, and 5 dpp using a digital gene expression system. In total, 41, 60 and 68 immune-related differentially expressed genes were identified at 1, 3, and 5 dpp, respectively. These genes encoded pattern recognition receptors (PRRs), antimicrobial peptides (AMPs), serine proteases (SPs), SP inhibitors, mucins and other immune-related proteins. The expression of most PRRs, AMPs, SPs, and mucins was upregulated in the fat body of larvae at 1 dpp, downregulated at 3 dpp, and then again upregulated at 5 dpp by O. sinensis. The increased expression of SP inhibitors may contribute to the inhibited PO activity at 5 dpp. Conclusions This study demonstrates that parasitism by O. sinensis modulates the immune reaction of the host H. armigera by altering the expression of immune-related genes. Our data provide a basis for future investigation of the molecular mechanisms employed by the mermithid nematode O. sinensis to modulate the immunity of the host H. armigera. These data will also likely facilitate the improvement of success in parasitism of H. armigera by O. sinensis. Electronic supplementary material The online version of this article (10.1186/s12864-019-5544-1) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Gui-Jie Wang
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, 430079, China
| | - Xiao-Rong Zhuo
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, 430079, China
| | - Wen-Wen Wang
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, 430079, China
| | - Xu-Sheng Liu
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, 430079, China
| | - Guo-Xiu Wang
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, 430079, China
| | - Jia-Lin Wang
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, 430079, China.
| |
Collapse
|
39
|
O'Halloran DM. Genome aware CRISPR gRNA target prediction for parasitic nematodes. Mol Biochem Parasitol 2019; 227:25-28. [PMID: 30529475 DOI: 10.1016/j.molbiopara.2018.12.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 12/05/2018] [Accepted: 12/05/2018] [Indexed: 01/03/2023]
Abstract
The pace of research towards a genetic model to understand the unique molecular biology of parasitic nematodes has increased recently. This research has developed a diverse suite of genetic tools for a variety of parasitic nematodes. CRISPR/Cas9 technology in particular offers much promise as a game changing tool for researchers studying parasitic nematodes. Unlike RNAi, which depends on diverse nematode effectors to silence gene expression, the effectors for CRISPR/Cas9 mutations are typically supplied by the experimenter, making gene editing via CRISPR/Cas9 ideal for testing on genetically intractable nematode systems. To facilitate the development of CRISPR/Cas9 technology for parasitic nematodes, I here describe a tool for identifying gRNA targets and diagnostic primers to a user supplied sequence. The software attempts to minimize non-specific targets by interrogating the genomes of parasitic nematodes. This software is freely available online and features an intuitive interface to help researchers design effective CRISPR experiments for parasitic nematodes.
Collapse
Affiliation(s)
- Damien M O'Halloran
- Department of Biological Sciences, George Washington University, Science and Engineering Hall, Suite 6000, 800 22nd Street NW, Washington DC 20052, USA; Institute for Neuroscience, George Washington University, 636A Ross Hall, 2300 I Street NW, Washington DC 20052, USA.
| |
Collapse
|
40
|
Cellular immunity in the insect Galleria mellonella against insect non-parasitic nematodes. Parasitology 2018; 146:708-715. [DOI: 10.1017/s003118201800210x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
AbstractImmunity to microbial infections is well understood; however, information regarding the immunity to parasitic multicellular organisms remains lacking. To understand innate host cellular immunity to nematodes, we compared the cellular response of the greater wax moth (Galleria mellonella) larvae against the non-parasitic, bacterial-feeding nematode Caenorhabditis elegans and pathogenic nematode Heterorhabditis bacteriophora. When intact first-instar or dauer larvae of C. elegans were injected into a G. mellonella larva, most of the nematodes were alive and not confined by the surrounding reaction by insect haemocytes (encapsulation), similarly as the pathogenic nematode, whereas most of the heat-killed nematodes of both species were severely encapsulated by 24 h after inoculation. Other non-parasitic nematodes were also not encapsulated. Surprisingly, C. elegans injected into the insect haemocoel grew and propagated in the live insect, resulting in death of the host insect. Our results suggest that C. elegans has some basic mechanisms to evade immunity of G. mellonenlla and grow in the haemocoel.
Collapse
|
41
|
Mastore M, Quadroni S, Toscano A, Mottadelli N, Brivio MF. Susceptibility to entomopathogens and modulation of basal immunity in two insect models at different temperatures. J Therm Biol 2018; 79:15-23. [PMID: 30612676 DOI: 10.1016/j.jtherbio.2018.11.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Revised: 10/31/2018] [Accepted: 11/12/2018] [Indexed: 11/30/2022]
Abstract
In this work, we analysed the efficacy of different commercial bio-insecticides (Steinernema feltiae, Steinernema carpocapsae, Heterorhabditis bacteriophora and Bacillus thuringiensis) by valuating the mortality induced on two insect models, Galleria mellonella (Lepidoptera) and Sarcophaga africa (Diptera) after exposure to different temperatures (10, 20 and 30 °C). Moreover, we investigated the effects of temperature on the basal humoral immunity of the two target insects; particularly, phenoloxidase (PO) and lysozyme activity. Our results show that G. mellonella is susceptible to all bio-insecticides at all the examined temperatures, except when infected at 10 °C with S. carpocapsae and at 30 °C with S. feltiae and B. thuringiensis. S. africa is more susceptible at 30 °C to all bioinsecticides; whereas, when infected at 10 and 20 °C, H. bacteriophora is the most efficient. Temperature modulates PO activity of both G. mellonella and S. africa, otherwise variations in lysozyme activity is observed only in G. mellonella. Except for a possible correlation between the increased lysozyme activity and the delayed Bt efficacy recorded on G. mellonella at 30 °C, a different resistance to bio-insecticides at different temperatures does not seem to be associated to variations of the host basal immunity, probably due to immunoevasive and immunodepressive strategies of these entomopathogens.
Collapse
Affiliation(s)
- Maristella Mastore
- Lab. of Comparative Immunology and Parasitology, Dept. of Theoretical and Applied Sciences, University of Insubria, Varese, Italy
| | - Silvia Quadroni
- Lab. of Ecology, Dept. of Science and High Technology, University of Insubria, Varese, Italy
| | - Andrea Toscano
- Lab. of Comparative Immunology and Parasitology, Dept. of Theoretical and Applied Sciences, University of Insubria, Varese, Italy
| | - Nicolò Mottadelli
- Lab. of Comparative Immunology and Parasitology, Dept. of Theoretical and Applied Sciences, University of Insubria, Varese, Italy
| | - Maurizio F Brivio
- Lab. of Comparative Immunology and Parasitology, Dept. of Theoretical and Applied Sciences, University of Insubria, Varese, Italy.
| |
Collapse
|
42
|
Patrnogic J, Castillo JC, Shokal U, Yadav S, Kenney E, Heryanto C, Ozakman Y, Eleftherianos I. Pre-exposure to non-pathogenic bacteria does not protect Drosophila against the entomopathogenic bacterium Photorhabdus. PLoS One 2018; 13:e0205256. [PMID: 30379824 PMCID: PMC6209181 DOI: 10.1371/journal.pone.0205256] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 09/22/2018] [Indexed: 01/27/2023] Open
Abstract
Immune priming in insects involves an initial challenge with a non-pathogenic microbe or exposure to a low dose of pathogenic microorganisms, which provides a certain degree of protection against a subsequent pathogenic infection. The protective effect of insect immune priming has been linked to the activation of humoral or cellular features of the innate immune response during the preliminary challenge, and these effects might last long enough to promote the survival of the infected animal. The fruit fly Drosophila melanogaster is a superb model to dissect immune priming processes in insects due to the availability of molecular and genetic tools, and the comprehensive understanding of the innate immune response in this organism. Previous investigations have indicated that the D. melanogaster immune system can be primed efficiently. Here we have extended these studies by examining the result of immune priming against two potent entomopathogenic bacteria, Photorhabdus luminescens and P. asymbiotica. We have found that rearing D. melanogaster on diet containing a non-pathogenic strain of Escherichia coli alone or in combination with Micrococcus luteus upregulates the antibacterial peptide immune response in young adult flies, but it does not prolong fly life span. Also, subsequent intrathoracic injection with P. luminescens or P. asymbiotica triggers the Immune deficiency and Toll signaling pathways in flies previously exposed to a live or heat-killed mix of the non-pathogenic bacteria, but the immune activation fails to promote fly survival against the pathogens. These findings suggest that immune priming in D. melanogaster, and probably in other insects, is determined by the type of microbes involved as well as the mode of microbial exposure, and possibly requires a comprehensive and precise alteration of immune signaling and function to provide efficient protection against pathogenic infection.
Collapse
Affiliation(s)
- Jelena Patrnogic
- Infection and Innate Immunity Lab, Department of Biological Sciences, George Washington University, Washington, District of Columbia, United States of America
| | - Julio Cesar Castillo
- Infection and Innate Immunity Lab, Department of Biological Sciences, George Washington University, Washington, District of Columbia, United States of America
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Upasana Shokal
- Infection and Innate Immunity Lab, Department of Biological Sciences, George Washington University, Washington, District of Columbia, United States of America
| | - Shruti Yadav
- Infection and Innate Immunity Lab, Department of Biological Sciences, George Washington University, Washington, District of Columbia, United States of America
| | - Eric Kenney
- Infection and Innate Immunity Lab, Department of Biological Sciences, George Washington University, Washington, District of Columbia, United States of America
| | - Christa Heryanto
- Infection and Innate Immunity Lab, Department of Biological Sciences, George Washington University, Washington, District of Columbia, United States of America
| | - Yaprak Ozakman
- Infection and Innate Immunity Lab, Department of Biological Sciences, George Washington University, Washington, District of Columbia, United States of America
| | - Ioannis Eleftherianos
- Infection and Innate Immunity Lab, Department of Biological Sciences, George Washington University, Washington, District of Columbia, United States of America
- * E-mail:
| |
Collapse
|
43
|
The infection of Harmonia axyridis by a parasitic nematode is mediated by entomopathogenic bacteria and triggers sex-specific host immune responses. Sci Rep 2018; 8:15938. [PMID: 30374104 PMCID: PMC6206131 DOI: 10.1038/s41598-018-34278-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Accepted: 10/11/2018] [Indexed: 01/19/2023] Open
Abstract
The harlequin ladybird Harmonia axyridis is native to Asia but has been introduced into many countries as a biological control agent. It is now considered an invasive pest, threatening the biodiversity of native ladybirds globally, in part because of its superior immune system. H. axyridis is infected and killed by the parasitic nematode Parasitylenchus bifurcatus, which could therefore be developed as a biological strategy to counter the spread of this insect pest. However, effective control requires an understanding of the tripartite relationship between H. axyridis, P. bifurcatus and their potential bacterial mutualists. Here we describe the isolation of two species of nematode-associated bacteria (Serratia marcescens and Providencia rettgeri) which were highly virulent against H. axyridis in survival experiments. In addition, contact between the nematodes and beetles led to the sex-specific modulation of multiple host immunity-related genes after 24 and 48 h, with many genes encoding antimicrobial peptides rapidly and stably repressed in females whereas the same genes were initially induced in males before suppression at the later time point. These data provide evidence that the female immune system responds much more strongly to the nematodes and provokes, in turn, a more robust invasion strategy involving the bacterial mutualists.
Collapse
|
44
|
Yadav S, Eleftherianos I. The Imaginal Disc Growth Factors 2 and 3 participate in the Drosophila response to nematode infection. Parasite Immunol 2018; 40:e12581. [PMID: 30107045 DOI: 10.1111/pim.12581] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2018] [Revised: 07/11/2018] [Accepted: 08/09/2018] [Indexed: 01/13/2023]
Abstract
The Drosophila imaginal disc growth factors (IDGFs) induce the proliferation of imaginal disc cells and terminate cell proliferation at the end of larval development. However, the participation of Idgf-encoding genes in other physiological processes of Drosophila including the immune response to infection is not fully understood. Here, we show the contribution of Idgf2 and Idgf3 in the Drosophila response to infection with Steinernema carpocapsae nematodes carrying or lacking their mutualistic Xenorhabdus nematophila bacteria (symbiotic or axenic nematodes, respectively). We find that Idgf2 and Idgf3 are upregulated in Drosophila larvae infected with symbiotic or axenic Steinernema and inactivation of Idgf2 confers a survival advantage to Drosophila larvae against axenic nematodes. Inactivation of Idgf2 induces the Imd and Jak/Stat pathways, whereas inactivation of Idgf3 induces the Imd, Toll and Jak/Stat pathways. We also show that inactivation of the Imd pathway receptor PGRP-LE upregulates Idgf2 against Steinernema nematode infection. Finally, we demonstrate that inactivation of Idgf3 induces the recruitment of larval haemocytes in response to Steinernema. Our results indicate that Idgf2 and Idgf3 might be involved in different yet crucial immune functions in the Drosophila antinematode immune response. Similar findings will promote the development of new targets for species-specific pest control strategies.
Collapse
Affiliation(s)
- Shruti Yadav
- Department of Biological Sciences, The George Washington University, Washington, District of Columbia
| | - Ioannis Eleftherianos
- Department of Biological Sciences, The George Washington University, Washington, District of Columbia
| |
Collapse
|
45
|
Entomopathogenic nematode Steinernema carpocapsae surpasses the cellular immune responses of the hispid beetle, Octodonta nipae (Coleoptera: Chrysomelidae). Microb Pathog 2018; 124:337-345. [PMID: 30172903 DOI: 10.1016/j.micpath.2018.08.063] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 08/29/2018] [Accepted: 08/29/2018] [Indexed: 12/29/2022]
Abstract
The Nipa palm hispid, Octodonta nipae (Maulik) is an important invasive pest of palm trees particularly in Southern China. How this beetle interacts with invading pathogens via its immune system remains to be dissected. Steinernema carpocapsae is a pathogenic nematode that attacks a number of insects of economic importance. The present study systematically investigates the cellular immune responses of O. nipae against S. carpocapsae infection using combined immunological, biochemical and transcriptomics approaches. Our data reveal that S. carpocapsae efficiently resists being encapsulated and melanized within the host's hemolymph and most of the nematodes were observed moving freely in the hemolymph even at 24 h post incubation. Consistently, isolated cuticles from the parasite also withstand encapsulation by the O. nipae hemocytes at all-time points. However, significant encapsulation and melanization of the isolated cuticles were recorded following heat treatment of the cuticles. The host's phenoloxidase activity was found to be slightly suppressed due to S. carpocapsae infection. Furthermore, the expression levels of some antimicrobial peptide (AMP) genes were significantly up-regulated in the S. carpocapsae-challenged O. nipae. Taken together, our data suggest that S. carpocapsae modulates and surpasses the O. nipae immune responses and hence can serve as an excellent biological control agent of the pest.
Collapse
|
46
|
Patrnogic J, Heryanto C, Eleftherianos I. Transcriptional up-regulation of the TGF-β intracellular signaling transducer Mad of Drosophila larvae in response to parasitic nematode infection. Innate Immun 2018; 24:349-356. [PMID: 30049242 PMCID: PMC6830907 DOI: 10.1177/1753425918790663] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The common fruit fly Drosophila melanogaster is an exceptional
model for dissecting innate immunity. However, our knowledge on responses to
parasitic nematode infections still lags behind. Recent studies have
demonstrated that the well-conserved TGF-β signaling pathway participates in
immune processes of the fly, including the anti-nematode response. To elucidate
the molecular basis of TGF-β anti-nematode activity, we performed a transcript
level analysis of different TGF-β signaling components following infection of
D. melanogaster larvae with the nematode parasite
Heterorhabditis gerrardi. We found no significant changes
in the transcript level of most extracellular ligands in both bone morphogenic
protein (BMP) and activin branches of the TGF-β signaling pathway between
nematode-infected larvae and uninfected controls. However, extracellular ligand,
Scw, and Type I receptor, Sax, in the BMP pathway as well as the Type I
receptor, Babo, in the activin pathway were substantially up-regulated following
H. gerrardi infection. Our results suggest that receptor
up-regulation leads to transcriptional up-regulation of the intracellular
component Mad in response to H. gerrardi following changes in
gene expression of intracellular receptors of both TGF-β signaling branches.
These findings identify the involvement of certain TGF-β signaling pathway
components in the immune signal transduction of D. melanogaster
larvae against parasitic nematodes.
Collapse
Affiliation(s)
- Jelena Patrnogic
- Infection and Innate Immunity Laboratory, Department of Biological Sciences, The George Washington University, Washington DC, USA
| | - Christa Heryanto
- Infection and Innate Immunity Laboratory, Department of Biological Sciences, The George Washington University, Washington DC, USA
| | - Ioannis Eleftherianos
- Infection and Innate Immunity Laboratory, Department of Biological Sciences, The George Washington University, Washington DC, USA
| |
Collapse
|
47
|
Thioester-Containing Proteins 2 and 4 Affect the Metabolic Activity and Inflammation Response in Drosophila. Infect Immun 2018; 86:IAI.00810-17. [PMID: 29463615 DOI: 10.1128/iai.00810-17] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Accepted: 02/06/2018] [Indexed: 12/17/2022] Open
Abstract
Drosophila melanogaster is an outstanding model for studying host antipathogen defense. Although substantial progress has been made in understanding how metabolism and immunity are interrelated in flies, little information has been obtained on the molecular players that regulate metabolism and inflammation in Drosophila during pathogenic infection. Recently, we reported that the inactivation of thioester-containing protein 2 (Tep2) and Tep4 promotes survival and decreases the bacterial burden in flies upon infection with the virulent pathogens Photorhabdus luminescens and Photorhabdus asymbiotica Here, we investigated physiological and pathological defects in tep mutant flies in response to Photorhabdus challenge. We find that tep2 and tep4 loss-of-function mutant flies contain increased levels of carbohydrates and triglycerides in the presence or absence of Photorhabdus infection. We also report that Photorhabdus infection leads to higher levels of nitric oxide and reduced transcript levels of the apical caspase-encoding gene Dronc in tep2 and tep4 mutants. We show that Tep2 and Tep4 are upregulated mainly in the fat body rather than the gut in Photorhabdus-infected wild-type flies and that tep mutants contain decreased numbers of Photorhabdus bacteria in both tissue types. We propose that the inactivation of Tep2 or Tep4 in adult Drosophila flies results in lower levels of inflammation and increased energy reserves in response to Photorhabdus, which could confer a survival-protective effect during the initial hours of infection.
Collapse
|
48
|
Yadav S, Gupta S, Eleftherianos I. Differential Regulation of Immune Signaling and Survival Response in Drosophila melanogaster Larvae upon Steinernema carpocapsae Nematode Infection. INSECTS 2018; 9:insects9010017. [PMID: 29419764 PMCID: PMC5872282 DOI: 10.3390/insects9010017] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/09/2017] [Revised: 01/27/2018] [Accepted: 02/01/2018] [Indexed: 01/11/2023]
Abstract
Drosophila melanogaster is an excellent model to dissect the molecular components and pathways of the innate anti-pathogen immune response. The nematode parasite Steinernema carpocapsae and its mutualistic bacterium Xenorhabdus nematophila form a complex that is highly pathogenic to insects, including D. melanogaster. We have used symbiotic (carrying X. nematophila) and axenic (lacking X. nematophila) nematodes to probe the regulation of genes belonging to different immune signaling pathways in D. melanogaster larvae and assess the survival response of certain mutants to these pathogens. We found that both types of S. carpocapsae upregulate MyD88 (Toll), but not PGRP-LE (Imd); whereas axenic S. carpocapsae strongly upregulate Wengen (Jnk), Domeless (Jak/Stat), Dawdle (TGFβ, Activin), and Decapentaplegic (TGFβ, BMP). We further found that inactivation of Wengen and Decapentaplegic confers a survival advantage to larvae infected with axenic S. carpocapsae, whereas mutating PGRP-LE promotes the survival of larvae infected with symbiotic nematodes.
Collapse
Affiliation(s)
- Shruti Yadav
- Insect Infection and Immunity Lab., Department of Biological Sciences, The George Washington University, Washington, DC 20052, USA.
| | - Sonali Gupta
- Insect Infection and Immunity Lab., Department of Biological Sciences, The George Washington University, Washington, DC 20052, USA.
| | - Ioannis Eleftherianos
- Insect Infection and Immunity Lab., Department of Biological Sciences, The George Washington University, Washington, DC 20052, USA.
| |
Collapse
|
49
|
Eleftherianos I, Yadav S, Kenney E, Cooper D, Ozakman Y, Patrnogic J. Role of Endosymbionts in Insect-Parasitic Nematode Interactions. Trends Parasitol 2017; 34:430-444. [PMID: 29150386 DOI: 10.1016/j.pt.2017.10.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Revised: 09/12/2017] [Accepted: 10/19/2017] [Indexed: 12/12/2022]
Abstract
Endosymbiotic bacteria exist in many animals where they develop relationships that affect certain physiological processes in the host. Insects and their nematode parasites form great models for understanding the genetic and molecular basis of immune and parasitic processes. Both organisms contain endosymbionts that possess the ability to interfere with certain mechanisms of immune function and pathogenicity. This review summarizes recent information on the involvement of insect endosymbionts in the response to parasitic nematode infections, and the influence of nematode endosymbionts on specific aspects of the insect immune system. Analyzing this information will be particularly useful for devising endosymbiont-based strategies to intervene in insect immunity or nematode parasitism for the efficient management of noxious insects in the field.
Collapse
Affiliation(s)
- Ioannis Eleftherianos
- Insect Infection and Immunity Laboratory, Department of Biological Sciences, The George Washington University, Science and Engineering Hall, 800 22nd Street NW, Washington, DC 20052, USA.
| | - Shruti Yadav
- Insect Infection and Immunity Laboratory, Department of Biological Sciences, The George Washington University, Science and Engineering Hall, 800 22nd Street NW, Washington, DC 20052, USA
| | - Eric Kenney
- Insect Infection and Immunity Laboratory, Department of Biological Sciences, The George Washington University, Science and Engineering Hall, 800 22nd Street NW, Washington, DC 20052, USA
| | - Dustin Cooper
- Insect Infection and Immunity Laboratory, Department of Biological Sciences, The George Washington University, Science and Engineering Hall, 800 22nd Street NW, Washington, DC 20052, USA
| | - Yaprak Ozakman
- Insect Infection and Immunity Laboratory, Department of Biological Sciences, The George Washington University, Science and Engineering Hall, 800 22nd Street NW, Washington, DC 20052, USA
| | - Jelena Patrnogic
- Insect Infection and Immunity Laboratory, Department of Biological Sciences, The George Washington University, Science and Engineering Hall, 800 22nd Street NW, Washington, DC 20052, USA
| |
Collapse
|
50
|
Androwski RJ, Flatt KM, Schroeder NE. Phenotypic plasticity and remodeling in the stress-induced Caenorhabditis elegans dauer. WILEY INTERDISCIPLINARY REVIEWS. DEVELOPMENTAL BIOLOGY 2017; 6:10.1002/wdev.278. [PMID: 28544390 PMCID: PMC5626018 DOI: 10.1002/wdev.278] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2017] [Revised: 03/23/2017] [Accepted: 04/14/2017] [Indexed: 12/22/2022]
Abstract
Organisms are often capable of modifying their development to better suit their environment. Under adverse conditions, the nematode Caenorhabditis elegans develops into a stress-resistant alternative larval stage called dauer. The dauer stage is the primary survival stage for C. elegans in nature. Large-scale tissue remodeling during dauer conveys resistance to harsh environments. The environmental and genetic regulation of the decision to enter dauer has been extensively studied. However, less is known about the mechanisms regulating tissue remodeling. Changes to the cuticle and suppression of feeding in dauers lead to an increased resistance to external stressors. Meanwhile reproductive development arrests during dauer while preserving the ability to reproduce once favorable environmental conditions return. Dramatic remodeling of neurons, glia, and muscles during dauer likely facilitate dauer-specific behaviors. Dauer-specific pulsation of the excretory duct likely mediates a response to osmotic stress. The power of C. elegans genetics has uncovered some of the molecular pathways regulating dauer tissue remodeling. In addition to genes that regulate single remodeling events, several mutants result in pleiotropic defects in dauer remodeling. This review details the individual aspects of morphological changes that occur during dauer formation and discusses molecular mechanisms regulating these processes. The dauer stage provides us with an excellent model for understanding phenotypic plasticity and remodeling from the individual cell to an entire animal. WIREs Dev Biol 2017, 6:e278. doi: 10.1002/wdev.278 For further resources related to this article, please visit the WIREs website.
Collapse
Affiliation(s)
- Rebecca J Androwski
- Neuroscience Program, University of Illinois at Urbana-Champaign, Champaign, IL, USA
| | - Kristen M Flatt
- Neuroscience Program, University of Illinois at Urbana-Champaign, Champaign, IL, USA
| | - Nathan E Schroeder
- Neuroscience Program and Department of Crop Sciences, University of Illinois at Urbana-Champaign, Champaign, IL, USA
| |
Collapse
|