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Dishaw LJ, Litman GW, Liberti A. Tethering of soluble immune effectors to mucin and chitin reflects a convergent and dynamic role in gut immunity. Philos Trans R Soc Lond B Biol Sci 2024; 379:20230078. [PMID: 38497268 PMCID: PMC10945408 DOI: 10.1098/rstb.2023.0078] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Accepted: 12/04/2023] [Indexed: 03/19/2024] Open
Abstract
The immune system employs soluble effectors to shape luminal spaces. Antibodies are soluble molecules that effect immunological responses, including neutralization, opsonization, antibody-dependent cytotoxicity and complement activation. These molecules are comprised of immunoglobulin (Ig) domains. The N-terminal Ig domains recognize antigen, and the C-terminal domains facilitate their elimination through phagocytosis (opsonization). A less-recognized function mediated by the C-terminal Ig domains of the IgG class of antibodies (Fc region) involves the formation of multiple low-affinity bonds with the mucus matrix. This association anchors the antibody molecule to the matrix to entrap potential pathogens. Even though invertebrates are not known to have antibodies, protochordates have a class of secreted molecules containing Ig domains that can bind bacteria and potentially serve a similar purpose. The VCBPs (V region-containing chitin-binding proteins) possess a C-terminal chitin-binding domain that helps tether them to chitin-rich mucus gels, mimicking the IgG-mediated Fc trapping of microbes in mucus. The broad functional similarity of these structurally divergent, Ig-containing, secreted effectors makes a case for a unique form of convergent evolution within chordates. This opinion essay highlights emerging evidence that divergent secreted immune effectors with Ig-like domains evolved to manage immune recognition at mucosal surfaces in strikingly similar ways. This article is part of the theme issue 'Sculpting the microbiome: how host factors determine and respond to microbial colonization'.
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Affiliation(s)
- L. J. Dishaw
- Morsani College of Medicine, Department of Pediatrics, University of South Florida, Children's Research Institute, St. Petersburg, FL 33701, USA
| | - G. W. Litman
- Morsani College of Medicine, Department of Pediatrics, University of South Florida, Children's Research Institute, St. Petersburg, FL 33701, USA
| | - A. Liberti
- Biology and Evolution of Marine Organisms (BEOM), Stazione Zoologica Anton Dohrn, 80122 Naples, Italy
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Barbole RS, Sharma S, Patil Y, Giri AP, Joshi RS. Chitinase inhibition induces transcriptional dysregulation altering ecdysteroid-mediated control of Spodoptera frugiperda development. iScience 2024; 27:109280. [PMID: 38444606 PMCID: PMC10914475 DOI: 10.1016/j.isci.2024.109280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 01/30/2024] [Accepted: 02/16/2024] [Indexed: 03/07/2024] Open
Abstract
Chitinases and ecdysteroid hormones are vital for insect development. Crosstalk between chitin and ecdysteroid metabolism regulation is enigmatic. Here, we examined chitinase inhibition effect on Spodoptera frugiperda ecdysteroid metabolism. In vitro studies suggested that berberine inhibits S. frugiperda chitinase 5 (SfCht5). The Berberine feeding resulted in defective S. frugiperda development. Berberine-fed insects showed higher SfCht5 and Chitinase 7 expression and cumulative chitinase activity. Chitinase inhibition led to overexpression of chitinases, ecdysteroid biosynthesis, and responsive genes. SfCht5 silencing and overexpression resulted in ecdysone receptor deregulation. Transcription factors, like Broad Complex Z4, regulate the ecdysteroid metabolism and showed high expression upon berberine ingestion. Broad Complex Z4 binding in 5' UTR of Ecdysone receptor, SfCht5, Chitinase 7, Phantom, Neverland, and other ecdysteroid biosynthesis genes might lead to their upregulation in berberine-fed insects. As a result, berberine-fed insects showed ecdysone overaccumulation. These findings underscore chitinase activity's impact on ecdysone biosynthesis and its transcriptional crosstalk.
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Affiliation(s)
- Ranjit S. Barbole
- Biochemical Sciences Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411008, Maharashtra, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, Uttar Pradesh, India
| | - Shivani Sharma
- Biochemical Sciences Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411008, Maharashtra, India
| | - Yogita Patil
- Biochemical Sciences Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411008, Maharashtra, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, Uttar Pradesh, India
| | - Ashok P. Giri
- Biochemical Sciences Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411008, Maharashtra, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, Uttar Pradesh, India
| | - Rakesh S. Joshi
- Biochemical Sciences Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411008, Maharashtra, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, Uttar Pradesh, India
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3
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Talyuli OAC, Oliveira JHM, Bottino-Rojas V, Silveira GO, Alvarenga PH, Barletta ABF, Kantor AM, Paiva-Silva GO, Barillas-Mury C, Oliveira PL. The Aedes aegypti peritrophic matrix controls arbovirus vector competence through HPx1, a heme-induced peroxidase. PLoS Pathog 2023; 19:e1011149. [PMID: 36780872 PMCID: PMC9956595 DOI: 10.1371/journal.ppat.1011149] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 02/24/2023] [Accepted: 01/25/2023] [Indexed: 02/15/2023] Open
Abstract
Aedes aegypti mosquitoes are the main vectors of arboviruses. The peritrophic matrix (PM) is an extracellular layer that surrounds the blood bolus. It acts as an immune barrier that prevents direct contact of bacteria with midgut epithelial cells during blood digestion. Here, we describe a heme-dependent peroxidase, hereafter referred to as heme peroxidase 1 (HPx1). HPx1 promotes PM assembly and antioxidant ability, modulating vector competence. Mechanistically, the heme presence in a blood meal induces HPx1 transcriptional activation mediated by the E75 transcription factor. HPx1 knockdown increases midgut reactive oxygen species (ROS) production by the DUOX NADPH oxidase. Elevated ROS levels reduce microbiota growth while enhancing epithelial mitosis, a response to tissue damage. However, simultaneous HPx1 and DUOX silencing was not able to rescue bacterial population growth, as explained by increased expression of antimicrobial peptides (AMPs), which occurred only after double knockdown. This result revealed hierarchical activation of ROS and AMPs to control microbiota. HPx1 knockdown produced a 100-fold decrease in Zika and dengue 2 midgut infection, demonstrating the essential role of the mosquito PM in the modulation of arbovirus vector competence. Our data show that the PM connects blood digestion to midgut immunological sensing of the microbiota and viral infections.
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Affiliation(s)
- Octavio A. C. Talyuli
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Jose Henrique M. Oliveira
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de Santa Catarina, Florianópolis, Brazil
| | - Vanessa Bottino-Rojas
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
- Departments of Microbiology and Molecular Genetics and of Molecular Biology and Biochemistry, University of California, Irvine, California, United States of America
| | - Gilbert O. Silveira
- Laboratório de Expressão Genica em Eucariotos, Instituto Butantan and Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| | - Patricia H. Alvarenga
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Rio de Janeiro, Brazil
| | - Ana Beatriz F. Barletta
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Asher M. Kantor
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Gabriela O. Paiva-Silva
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Rio de Janeiro, Brazil
| | - Carolina Barillas-Mury
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Pedro L. Oliveira
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Rio de Janeiro, Brazil
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4
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Liu D, De Schutter K, Far J, Staes A, Dewettinck K, Quinton L, Gevaert K, Smagghe G. RNAi of Mannosidase-Ia in the Colorado potato beetle and changes in the midgut and peritrophic membrane. PEST MANAGEMENT SCIENCE 2022; 78:5071-5079. [PMID: 36053804 DOI: 10.1002/ps.7145] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 08/03/2022] [Accepted: 08/23/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND In addition to its role in the digestive system, the peritrophic membrane (PM) provides a physical barrier protecting the intestine from abrasion and against pathogens. Because of its sensitivity to RNA interference (RNAi), the notorious pest insect, the Colorado potato beetle (CPB, Leptinotarsa decemlineata), has become a model insect for functional studies. Previously, RNAi-mediated silencing of Mannosidase-Ia (ManIa), a key enzyme in the transition from high-mannose glycan moieties to paucimannose N-glycans, was shown to disrupt the transition from larva to pupa and the metamorphosis into adult beetles. While these effects at the organismal level were interesting in a pest control context, the effects at the organ or tissue level and also immune effects have not been investigated yet. To fill this knowledge gap, we performed an analysis of the midgut and PM in ManIa-silenced insects. RESULTS As marked phenotype, the ManIaRNAi insects, the PM pore size was found to be decreased when compared to the control GFPRNAi insects. These smaller pores are related to the observation of thinner microvilli (Mv) on the epithelial cells of the midgut of ManIaRNAi insects. A midgut and PM proteome study and reverse transcription quantitative polymerase chain reaction (RT-qPCR) analysis with a selection of marker genes was performed to characterize the midgut cells and understand their response to the silencing of ManIa. In agreement with the loss of ManIa activity, an accumulation of high-mannose N-glycans was observed in the ManIa-silenced insects. As a pathogen-associated molecular pattern (PAMP), the presence of these glycan structures could trigger the activation of the immune pathways. CONCLUSION The observed decrease in PM pore size could be a response to prevent potential pathogens to access the midgut epithelium. This hypothesis is supported by the strong increase in transcription levels of the anti-fungal peptide drosomycin-like in ManIaRNAi insects, although further research is required to elucidate this possibility. The potential immune response in the midgut and the smaller pore size in the PM shed a light on the function of the PM as a physical barrier and provide evidence for the relation between the Mv and PM. © 2022 Society of Chemical Industry.
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Affiliation(s)
- Dongdong Liu
- Laboratory of Agrozoology, Department Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Kristof De Schutter
- Laboratory of Agrozoology, Department Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Johann Far
- Mass Spectrometry Laboratory, MolSys Research Unit, University of Liège, Liège, Belgium
| | - An Staes
- VIB Center for Medical Biotechnology, Ghent University, Ghent, Belgium
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
| | - Koen Dewettinck
- Food Structure and Function Research Group, Department of Food Technology, Safety and Health, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Loic Quinton
- Mass Spectrometry Laboratory, MolSys Research Unit, University of Liège, Liège, Belgium
| | - Kris Gevaert
- VIB Center for Medical Biotechnology, Ghent University, Ghent, Belgium
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
| | - Guy Smagghe
- Laboratory of Agrozoology, Department Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
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Li J, Chen C, Zha X. Midgut and Head Transcriptomic Analysis of Silkworms Reveals the Physiological Effects of Artificial Diets. INSECTS 2022; 13:insects13030291. [PMID: 35323589 PMCID: PMC8948783 DOI: 10.3390/insects13030291] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Revised: 03/06/2022] [Accepted: 03/11/2022] [Indexed: 02/04/2023]
Abstract
Silkworms, a model lepidopteran insect, have a very simple diet. Artificial diets as an alternative nutrient source for silkworms are gradually being developed. To understand the effects of various nutrients on the growth and development of silkworms, we studied the transcriptomic differences in the midgut and head tissues of male and female silkworms fed either fresh mulberry leaves or artificial diets. In the artificial diet group, compared with the control group (fed mulberry leaves), 923 and 619 differentially expressed genes (DEGs) were identified from the midgut, and 2969 and 3427 DEGs were identified from the head, in female and male silkworms. According to our analysis, the DEGs were mainly involved in the digestion and absorption of nutrients and silkworm innate immunity. These experimental results provide insights into the effects of different foods, such as artificial diets or fresh mulberry leaves, on silkworms.
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Affiliation(s)
- Juan Li
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China; (J.L.); (C.C.)
- School of Life Sciences, Southwest University, Chongqing 400715, China
| | - Chunbing Chen
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China; (J.L.); (C.C.)
| | - Xingfu Zha
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China; (J.L.); (C.C.)
- Correspondence: ; Tel.: +86-023-68251573
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6
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De Vooght L, De Ridder K, Hussain S, Stijlemans B, De Baetselier P, Caljon G, Van Den Abbeele J. Targeting the tsetse-trypanosome interplay using genetically engineered Sodalis glossinidius. PLoS Pathog 2022; 18:e1010376. [PMID: 35271685 PMCID: PMC8939806 DOI: 10.1371/journal.ppat.1010376] [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: 11/08/2021] [Revised: 03/22/2022] [Accepted: 02/15/2022] [Indexed: 11/18/2022] Open
Abstract
Sodalis glossinidius, a secondary bacterial symbiont of the tsetse fly, is currently considered as a potential delivery system for anti-trypanosomal components interfering with African trypanosome transmission (i.e. paratransgenesis). Nanobodies (Nbs) have been proposed as potential candidates to target the parasite during development in the tsetse fly. In this study, we have generated an immune Nb-library and developed a panning strategy to select Nbs against the Trypanosoma brucei brucei procyclic developmental stage present in the tsetse fly midgut. Selected Nbs were expressed, purified, assessed for binding and tested for their impact on the survival and growth of in vitro cultured procyclic T. b. brucei parasites. Next, we engineered S. glossinidius to express the selected Nbs and validated their ability to block T. brucei development in the tsetse fly midgut. Genetically engineered S. glossinidius expressing Nb_88 significantly compromised parasite development in the tsetse fly midgut both at the level of infection rate and parasite load. Interestingly, expression of Nb_19 by S. glossinidius resulted in a significantly enhanced midgut establishment. These data are the first to show in situ delivery by S. glossinidius of effector molecules that can target the trypanosome-tsetse fly crosstalk, interfering with parasite development in the fly. These proof-of-principle data represent a major step forward in the development of a control strategy based on paratransgenic tsetse flies. Finally, S. glossinidius-based Nb delivery can also be applied as a powerful laboratory tool to unravel the molecular determinants of the parasite-vector association.
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Affiliation(s)
- Linda De Vooght
- Department of Biomedical Sciences, Trypanosoma Unit, Institute of Tropical Medicine Antwerp, Antwerp, Belgium
- Laboratory of Microbiology, Parasitology and Hygiene (LMPH), University of Antwerp, Wilrijk, Belgium
- * E-mail: (LDV); (JVDA)
| | - Karin De Ridder
- Department of Biomedical Sciences, Trypanosoma Unit, Institute of Tropical Medicine Antwerp, Antwerp, Belgium
| | - Shahid Hussain
- Unit of Cellular and Molecular Immunology, Vrije Universiteit Brussel, Brussels, Belgium
| | - Benoît Stijlemans
- Unit of Cellular and Molecular Immunology, Vrije Universiteit Brussel, Brussels, Belgium
- Myeloid Cell Immunology Lab, VIB Inflammation Research Center, Gent, Belgium
| | - Patrick De Baetselier
- Unit of Cellular and Molecular Immunology, Vrije Universiteit Brussel, Brussels, Belgium
| | - Guy Caljon
- Laboratory of Microbiology, Parasitology and Hygiene (LMPH), University of Antwerp, Wilrijk, Belgium
| | - Jan Van Den Abbeele
- Department of Biomedical Sciences, Trypanosoma Unit, Institute of Tropical Medicine Antwerp, Antwerp, Belgium
- * E-mail: (LDV); (JVDA)
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7
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McKenna CH, Asgari D, Crippen TL, Zheng L, Sherman RA, Tomberlin JK, Meisel RP, Tarone AM. Gene expression in Lucilia sericata (Diptera: Calliphoridae) larvae exposed to Pseudomonas aeruginosa and Acinetobacter baumannii identifies shared and microbe-specific induction of immune genes. INSECT MOLECULAR BIOLOGY 2022; 31:85-100. [PMID: 34613655 DOI: 10.1111/imb.12740] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 09/24/2021] [Accepted: 09/26/2021] [Indexed: 06/13/2023]
Abstract
Antibiotic resistance is a continuing challenge in medicine. There are various strategies for expanding antibiotic therapeutic repertoires, including the use of blow flies. Their larvae exhibit strong antibiotic and antibiofilm properties that alter microbiome communities. One species, Lucilia sericata, is used to treat problematic wounds due to its debridement capabilities and its excretions and secretions that kill some pathogenic bacteria. There is much to be learned about how L. sericata interacts with microbiomes at the molecular level. To address this deficiency, gene expression was assessed after feeding exposure (1 h or 4 h) to two clinically problematic pathogens: Pseudomonas aeruginosa and Acinetobacter baumannii. The results identified immunity-related genes that were differentially expressed when exposed to these pathogens, as well as non-immune genes possibly involved in gut responses to bacterial infection. There was a greater response to P. aeruginosa that increased over time, while few genes responded to A. baumannii exposure, and expression was not time-dependent. The response to feeding on pathogens indicates a few common responses and features distinct to each pathogen, which is useful in improving the wound debridement therapy and helps to develop biomimetic alternatives.
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Affiliation(s)
- C H McKenna
- Department of Entomology, Texas A&M University, College Station, TX, USA
| | - D Asgari
- Department of Biology and Biochemistry, University of Houston, Houston, TX, USA
| | - T L Crippen
- Southern Plains Agricultural Research Center, Agricultural Research Service, US Department of Agriculture, College Station, TX, USA
| | - L Zheng
- Department of Entomology, Texas A&M University, College Station, TX, USA
| | - R A Sherman
- BioTherapeutics, Education and Research (BTER) Foundation, Irvine, CA, USA
- Monarch Labs, Irvine, CA, USA
| | - J K Tomberlin
- Department of Entomology, Texas A&M University, College Station, TX, USA
| | - R P Meisel
- Department of Biology and Biochemistry, University of Houston, Houston, TX, USA
| | - A M Tarone
- Department of Entomology, Texas A&M University, College Station, TX, USA
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Characteristics of the Peritrophic Matrix of the Silkworm, Bombyx mori and Factors Influencing Its Formation. INSECTS 2021; 12:insects12060516. [PMID: 34199436 PMCID: PMC8227122 DOI: 10.3390/insects12060516] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 05/25/2021] [Accepted: 05/28/2021] [Indexed: 11/16/2022]
Abstract
Simple Summary The insect midgut is an important digestive organ with the peritrophic matrix (PM) being a semi-permeable membrane secreted by the midgut cells. The PM plays an important role in improving midgut digestion efficiency and protecting the midgut from food particles and exogenous pathogens. The silkworm, Bombyx mori, is an economically important insect. Understanding the structure of the PM is necessary for studying its function, but characteristics of PM in B. mori have been rarely reported. In this study, we conducted a comprehensive study on the PM structure of the PM in silkworms and found its thickness increased gradually during growth, but there was no difference in the thickness comparing the anterior, middle, and posterior regions. Permeability of the PM gradually decreased from the anterior to posterior regions. In addition, we found the formation of the PM was influenced by food ingestion and the gut microbiota. Abstract The peritrophic matrix (PM) secreted by the midgut cells of insects is formed by the binding of PM proteins to chitin fibrils. The PM envelops the food bolus, serving as a barrier between the content of the midgut lumen and its epithelium, and plays a protective role for epithelial cells against mechanical damage, pathogens, toxins, and other harmful substances. However, few studies have investigated the characteristics and synthesis factors of the PM in the silkworm, Bombyx mori. Here, we examined the characteristics of the PM in the silkworms. The PM thickness of the silkworms increased gradually during growth, while there was no significant difference in thickness along the entire PM region. Permeability of the PM decreased gradually from the anterior to posterior PM. We also found that PM synthesis was affected by food ingestion and the gut microbiota. Our results are beneficial for future studies regarding the function of the PM in silkworms.
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Yang L, Weiss BL, Williams AE, Aksoy E, de Silva Orfano A, Son JH, Wu Y, Vigneron A, Karakus M, Aksoy S. Paratransgenic manipulation of a tsetse microRNA alters the physiological homeostasis of the fly's midgut environment. PLoS Pathog 2021; 17:e1009475. [PMID: 34107000 PMCID: PMC8216540 DOI: 10.1371/journal.ppat.1009475] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 06/21/2021] [Accepted: 05/13/2021] [Indexed: 12/27/2022] Open
Abstract
Tsetse flies are vectors of parasitic African trypanosomes, the etiological agents of human and animal African trypanosomoses. Current disease control methods include fly-repelling pesticides, fly trapping, and chemotherapeutic treatment of infected people and animals. Inhibiting tsetse's ability to transmit trypanosomes by strengthening the fly's natural barriers can serve as an alternative approach to reduce disease. The peritrophic matrix (PM) is a chitinous and proteinaceous barrier that lines the insect midgut and serves as a protective barrier that inhibits infection with pathogens. African trypanosomes must cross tsetse's PM in order to establish an infection in the fly, and PM structural integrity negatively correlates with trypanosome infection outcomes. Bloodstream form trypanosomes shed variant surface glycoproteins (VSG) into tsetse's gut lumen early during the infection establishment, and free VSG molecules are internalized by the fly's PM-producing cardia. This process results in a reduction in the expression of a tsetse microRNA (miR275) and a sequential molecular cascade that compromises PM integrity. miRNAs are small non-coding RNAs that are critical in regulating many physiological processes. In the present study, we investigated the role(s) of tsetse miR275 by developing a paratransgenic expression system that employs tsetse's facultative bacterial endosymbiont, Sodalis glossinidius, to express tandem antagomir-275 repeats (or miR275 sponges). This system induces a constitutive, 40% reduction in miR275 transcript abundance in the fly's midgut and results in obstructed blood digestion (gut weights increased by 52%), a significant increase (p-value < 0.0001) in fly survival following infection with an entomopathogenic bacteria, and a 78% increase in trypanosome infection prevalence. RNA sequencing of cardia and midgut tissues from paratransgenic tsetse confirmed that miR275 regulates processes related to the expression of PM-associated proteins and digestive enzymes as well as genes that encode abundant secretory proteins. Our study demonstrates that paratransgenesis can be employed to study microRNA regulated pathways in arthropods that house symbiotic bacteria.
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Affiliation(s)
- Liu Yang
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, United States of America
| | - Brian L. Weiss
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, United States of America
| | - Adeline E. Williams
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, United States of America
- Department of Microbiology, Immunology, Pathology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Emre Aksoy
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, United States of America
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States of America
| | - Alessandra de Silva Orfano
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, United States of America
| | - Jae Hak Son
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, United States of America
| | - Yineng Wu
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, United States of America
| | - Aurelien Vigneron
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, United States of America
- Department of Evolutionary Ecology, Institute for Organismic and Molecular Evolution, Johannes Gutenberg University, Mainz, Germany
| | - Mehmet Karakus
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, United States of America
- Department of Medical Microbiology, Faculty of Medicine, University of Health Sciences, Istanbul, Turkey
| | - Serap Aksoy
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, United States of America
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10
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Medina Munoz M, Brenner C, Richmond D, Spencer N, Rio RVM. The holobiont transcriptome of teneral tsetse fly species of varying vector competence. BMC Genomics 2021; 22:400. [PMID: 34058984 PMCID: PMC8166097 DOI: 10.1186/s12864-021-07729-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Accepted: 05/21/2021] [Indexed: 12/13/2022] Open
Abstract
Background Tsetse flies are the obligate vectors of African trypanosomes, which cause Human and Animal African Trypanosomiasis. Teneral flies (newly eclosed adults) are especially susceptible to parasite establishment and development, yet our understanding of why remains fragmentary. The tsetse gut microbiome is dominated by two Gammaproteobacteria, an essential and ancient mutualist Wigglesworthia glossinidia and a commensal Sodalis glossinidius. Here, we characterize and compare the metatranscriptome of teneral Glossina morsitans to that of G. brevipalpis and describe unique immunological, physiological, and metabolic landscapes that may impact vector competence differences between these two species. Results An active expression profile was observed for Wigglesworthia immediately following host adult metamorphosis. Specifically, ‘translation, ribosomal structure and biogenesis’ followed by ‘coenzyme transport and metabolism’ were the most enriched clusters of orthologous genes (COGs), highlighting the importance of nutrient transport and metabolism even following host species diversification. Despite the significantly smaller Wigglesworthia genome more differentially expressed genes (DEGs) were identified between interspecific isolates (n = 326, ~ 55% of protein coding genes) than between the corresponding Sodalis isolates (n = 235, ~ 5% of protein coding genes) likely reflecting distinctions in host co-evolution and adaptation. DEGs between Sodalis isolates included genes involved in chitin degradation that may contribute towards trypanosome susceptibility by compromising the immunological protection provided by the peritrophic matrix. Lastly, G. brevipalpis tenerals demonstrate a more immunologically robust background with significant upregulation of IMD and melanization pathways. Conclusions These transcriptomic differences may collectively contribute to vector competence differences between tsetse species and offers translational relevance towards the design of novel vector control strategies. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-021-07729-5.
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Affiliation(s)
- Miguel Medina Munoz
- Department of Biology, Eberly College of Arts and Sciences, West Virginia University, Morgantown, WV, 26505, USA
| | - Caitlyn Brenner
- Department of Biology, Washington and Jefferson College, Washington, PA, 15301, USA
| | - Dylan Richmond
- Department of Biology, Eberly College of Arts and Sciences, West Virginia University, Morgantown, WV, 26505, USA
| | - Noah Spencer
- Department of Biology, Eberly College of Arts and Sciences, West Virginia University, Morgantown, WV, 26505, USA
| | - Rita V M Rio
- Department of Biology, Eberly College of Arts and Sciences, West Virginia University, Morgantown, WV, 26505, USA.
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11
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Physical and Chemical Barriers in the Larval Midgut Confer Developmental Resistance to Virus Infection in Drosophila. Viruses 2021; 13:v13050894. [PMID: 34065985 PMCID: PMC8151258 DOI: 10.3390/v13050894] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 05/05/2021] [Accepted: 05/06/2021] [Indexed: 01/23/2023] Open
Abstract
Insects can become lethally infected by the oral intake of a number of insect-specific viruses. Virus infection commonly occurs in larvae, given their active feeding behaviour; however, older larvae often become resistant to oral viral infections. To investigate mechanisms that contribute to resistance throughout the larval development, we orally challenged Drosophila larvae at different stages of their development with Drosophila C virus (DCV, Dicistroviridae). Here, we showed that DCV-induced mortality is highest when infection initiates early in larval development and decreases the later in development the infection occurs. We then evaluated the peritrophic matrix as an antiviral barrier within the gut using a Crystallin-deficient fly line (Crys-/-), whose PM is weakened and becomes more permeable to DCV-sized particles as the larva ages. This phenotype correlated with increasing mortality the later in development oral challenge occurred. Lastly, we tested in vitro the infectivity of DCV after incubation at pH conditions that may occur in the midgut. DCV virions were stable in a pH range between 3.0 and 10.5, but their infectivity decreased at least 100-fold below (1.0) and above (12.0) this range. We did not observe such acidic conditions in recently hatched larvae. We hypothesise that, in Drosophila larvae, the PM is essential for containing ingested virions separated from the gut epithelium, while highly acidic conditions inactivate the majority of the virions as they transit.
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12
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Lin YB, Rong JJ, Wei XF, Sui ZX, Xiao J, Huang DW. Proteomics and ultrastructural analysis of Hermetia illucens (Diptera: Stratiomyidae) larval peritrophic matrix. Proteome Sci 2021; 19:7. [PMID: 33836751 PMCID: PMC8035744 DOI: 10.1186/s12953-021-00175-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Accepted: 04/03/2021] [Indexed: 02/01/2023] Open
Abstract
BACKGROUND The black soldier fly (Hermetia illucens) has significant economic potential. The larvae can be used in financially viable waste management systems, as they are voracious feeders able to efficiently convert low-quality waste into valuable biomass. However, most studies on H. illucens in recent decades have focused on optimizing their breeding and bioconversion conditions, while information on their biology is limited. METHODS About 200 fifth instar well-fed larvae were sacrificed in this work. The liquid chromatography-tandem mass spectrometry and scanning electron microscopy were employed in this study to perform a proteomic and ultrastructural analysis of the peritrophic matrix (PM) of H. illucens larvae. RESULTS A total of 565 proteins were identified in the PM samples of H. illucen, of which 177 proteins were predicted to contain signal peptides, bioinformatics analysis and manual curation determined 88 proteins may be associated with the PM, with functions in digestion, immunity, PM modulation, and others. The ultrastructure of the H. illucens larval PM observed by scanning electron microscopy shows a unique diamond-shaped chitin grid texture. CONCLUSIONS It is the first and most comprehensive proteomics research about the PM of H. illucens larvae to date. All the proteins identified in this work has been discussed in details, except several unnamed or uncharacterized proteins, which should not be ignored and need further study. A comparison of the ultrastructure between H. illucens larval PM and those of other insects as observed by SEM indicates that the PM displays diverse textures on an ultra-micro scale and we suscept a unique diamond-shaped chitin grid texture may help H. illucens larval to hold more food. This work deepens our understanding of the molecular architecture and ultrastructure of the H. illucens larval PM.
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Affiliation(s)
- Yu-Bo Lin
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jing-Jing Rong
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xun-Fan Wei
- Institute of Entomology, College of Life Sciences, Nankai University, Tianjin, 300071, China
| | - Zhuo-Xiao Sui
- Institute of Entomology, College of Life Sciences, Nankai University, Tianjin, 300071, China
| | - Jinhua Xiao
- Institute of Entomology, College of Life Sciences, Nankai University, Tianjin, 300071, China
| | - Da-Wei Huang
- Institute of Entomology, College of Life Sciences, Nankai University, Tianjin, 300071, China.
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13
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Talyuli OAC, Bottino-Rojas V, Polycarpo CR, Oliveira PL, Paiva-Silva GO. Non-immune Traits Triggered by Blood Intake Impact Vectorial Competence. Front Physiol 2021; 12:638033. [PMID: 33737885 PMCID: PMC7960658 DOI: 10.3389/fphys.2021.638033] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Accepted: 02/08/2021] [Indexed: 11/13/2022] Open
Abstract
Blood-feeding arthropods are considered an enormous public health threat. They are vectors of a plethora of infectious agents that cause potentially fatal diseases like Malaria, Dengue fever, Leishmaniasis, and Lyme disease. These vectors shine due to their own physiological idiosyncrasies, but one biological aspect brings them all together: the requirement of blood intake for development and reproduction. It is through blood-feeding that they acquire pathogens and during blood digestion that they summon a collection of multisystemic events critical for vector competence. The literature is focused on how classical immune pathways (Toll, IMD, and JAK/Stat) are elicited throughout the course of vector infection. Still, they are not the sole determinants of host permissiveness. The dramatic changes that are the hallmark of the insect physiology after a blood meal intake are the landscape where a successful infection takes place. Dominant processes that occur in response to a blood meal are not canonical immunological traits yet are critical in establishing vector competence. These include hormonal circuitries and reproductive physiology, midgut permeability barriers, midgut homeostasis, energy metabolism, and proteolytic activity. On the other hand, the parasites themselves have a role in the outcome of these blood triggered physiological events, consistently using them in their favor. Here, to enlighten the knowledge on vector-pathogen interaction beyond the immune pathways, we will explore different aspects of the vector physiology, discussing how they give support to these long-dated host-parasite relationships.
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Affiliation(s)
- Octavio A C Talyuli
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Vanessa Bottino-Rojas
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Carla R Polycarpo
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.,Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Rio de Janeiro, Brazil
| | - Pedro L Oliveira
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.,Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Rio de Janeiro, Brazil
| | - Gabriela O Paiva-Silva
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.,Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Rio de Janeiro, Brazil
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14
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Wang Y, Cheng J, Luo M, Wu J, Guo G. Identifying and Characterizing a Novel Peritrophic Matrix Protein (MdPM-17) Associated With Antibacterial Response From the Housefly, Musca domestica (Diptera: Muscidae). JOURNAL OF INSECT SCIENCE (ONLINE) 2020; 20:6042885. [PMID: 33347588 PMCID: PMC7751770 DOI: 10.1093/jisesa/ieaa135] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Indexed: 06/12/2023]
Abstract
Peritrophic matrix/membrane (PM) critically prevents the midgut of insects from external invasion by microbes. The proteins in the peritrophic membrane are its major structural components. Additionally, they determine the formation and function of this membrane. However, the role of PM proteins in immune regulation is unclear. Herein, we isolated a novel PM protein (MdPM-17) from Musca domestica larvae. Further, the function of MdPM-17 in regulating host innate immunity was identified. Results showed that the cDNA of MdPM-17 full is 635 bp in length. Moreover, it consists of a 477-bp open reading frame encoding 158 amino acid residues. These amino acid residues are composed of two Chitin-binding type-2 domain (ChtBD2) and 19 amino acids as a signal peptide. Moreover, tissue distribution analysis indicates that MdPM-17 was enriched expressed in midgut, and moderate levels in the fat body, foregut, and malpighian tubule. Notably, MdPM-17 recombinant protein showed high chitin-binding capacity, thus belongs to the Class III PM protein group. MdPM-17 protein silencing via RNA interference resulted in the expression of antimicrobial peptide (defensin, cecropins, and diptericin) genes, and this occurred after oral inoculation with exogenous microbes Escherichia coli (Enterobacteriales:Enterobacteriaceae), Staphylococcus aureus (Bacillales:Staphylococcaceae), and Candida albicans (Endomycetales:Saccharomycetaceae)). Therefore, all the antimicrobial peptide (AMP) gene expression levels are high in MdPM-17-depleted larvae during microbial infection compared to controls. Consequently, these findings indicate that MdPM-17 protein is associated with the antibacterial response from the housefly.
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Affiliation(s)
- Yu Wang
- Department of Clinical laboratory, The First People’s Hospital of Guiyang, Guizhou, PR China
- School of Basic Medical Sciences, Guizhou Medical University, Guiyang, PR China
| | - Jinzhi Cheng
- School of Basic Medical Sciences, Guizhou Medical University, Guiyang, PR China
| | - Man Luo
- School of Basic Medical Sciences, Guizhou Medical University, Guiyang, PR China
| | - Jianwei Wu
- School of Basic Medical Sciences, Guizhou Medical University, Guiyang, PR China
| | - Guo Guo
- School of Basic Medical Sciences, Guizhou Medical University, Guiyang, PR China
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15
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Transcriptomic profiling of the digestive tract of the rat flea, Xenopsylla cheopis, following blood feeding and infection with Yersinia pestis. PLoS Negl Trop Dis 2020; 14:e0008688. [PMID: 32946437 PMCID: PMC7526888 DOI: 10.1371/journal.pntd.0008688] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 09/30/2020] [Accepted: 08/10/2020] [Indexed: 01/29/2023] Open
Abstract
Yersinia pestis, the causative agent of plague, is a highly lethal pathogen transmitted by the bite of infected fleas. Once ingested by a flea, Y. pestis establish a replicative niche in the gut and produce a biofilm that promotes foregut colonization and transmission. The rat flea Xenopsylla cheopis is an important vector to several zoonotic bacterial pathogens including Y. pestis. Some fleas naturally clear themselves of infection; however, the physiological and immunological mechanisms by which this occurs are largely uncharacterized. To address this, RNA was extracted, sequenced, and distinct transcript profiles were assembled de novo from X. cheopis digestive tracts isolated from fleas that were either: 1) not fed for 5 days; 2) fed sterile blood; or 3) fed blood containing ~5x108 CFU/ml Y. pestis KIM6+. Analysis and comparison of the transcript profiles resulted in identification of 23 annotated (and 11 unknown or uncharacterized) digestive tract transcripts that comprise the early transcriptional response of the rat flea gut to infection with Y. pestis. The data indicate that production of antimicrobial peptides regulated by the immune-deficiency pathway (IMD) is the primary flea immune response to infection with Y. pestis. The remaining infection-responsive transcripts, not obviously associated with the immune response, were involved in at least one of 3 physiological themes: 1) alterations to chemosensation and gut peristalsis; 2) modification of digestion and metabolism; and 3) production of chitin-binding proteins (peritrophins). Despite producing several peritrophin transcripts shortly after feeding, including a subset that were infection-responsive, no thick peritrophic membrane was detectable by histochemistry or electron microscopy of rat flea guts for the first 24 hours following blood-feeding. Here we discuss the physiological implications of rat flea infection-responsive transcripts, the function of X. cheopis peritrophins, and the mechanisms by which Y. pestis may be cleared from the flea gut. The goal of this study was to characterize the transcriptional response of the digestive tract of the rat flea, Xenopsylla cheopis, to infection with Yersinia pestis, the causative agent of plague. This flea is generally considered the most prevalent and efficient vector of Y. pestis. Because most pathogens transmitted by fleas, including Y. pestis, reside in the insect digestive tract prior to transmission, the transcriptional program induced in the gut epithelium likely influences bacterial colonization of the flea. To determine the specific response to infection, RNA profiles were generated from fleas that were either unfed, fed sterile blood, or fed blood containing Y. pestis. Comparative analyses of the transcriptomes resulted in identification of 34 infection-responsive transcripts. The functions of these differentially regulated genes indicate that infection of fleas with Y. pestis induces a limited immune response and potentially alters the insect’s behavior, metabolism, and other aspects of its physiology. Based on these data, we describe potential mechanisms fleas use to eliminate bacteria and the corresponding strategies Y. pestis uses to resist elimination. These findings may be helpful for developing targeted strategies to make fleas resistant to microbial infection and thereby reduce the incidence of diseases they spread.
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16
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Ferreira PG, Tesla B, Horácio ECA, Nahum LA, Brindley MA, de Oliveira Mendes TA, Murdock CC. Temperature Dramatically Shapes Mosquito Gene Expression With Consequences for Mosquito-Zika Virus Interactions. Front Microbiol 2020; 11:901. [PMID: 32595607 PMCID: PMC7303344 DOI: 10.3389/fmicb.2020.00901] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Accepted: 04/16/2020] [Indexed: 12/20/2022] Open
Abstract
Vector-borne flaviviruses are emerging threats to human health. For successful transmission, the virus needs to efficiently enter mosquito cells and replicate within and escape several tissue barriers while mosquitoes elicit major transcriptional responses to flavivirus infection. This process will be affected not only by the specific mosquito-pathogen pairing but also by variation in key environmental variables such as temperature. Thus far, few studies have examined the molecular responses triggered by temperature and how these responses modify infection outcomes, despite substantial evidence showing strong relationships between temperature and transmission in a diversity of systems. To define the host transcriptional changes associated with temperature variation during the early infection process, we compared the transcriptome of mosquito midgut samples from mosquitoes exposed to Zika virus (ZIKV) and non-exposed mosquitoes housed at three different temperatures (20, 28, and 36°C). While the high-temperature samples did not show significant changes from those with standard rearing conditions (28°C) 48 h post-exposure, the transcriptome profile of mosquitoes housed at 20°C was dramatically different. The expression of genes most altered by the cooler temperature involved aspects of blood-meal digestion, ROS metabolism, and mosquito innate immunity. Further, we did not find significant differences in the viral RNA copy number between 24 and 48 h post-exposure at 20°C, suggesting that ZIKV replication is limited by cold-induced changes to the mosquito midgut environment. In ZIKV-exposed mosquitoes, vitellogenin, a lipid carrier protein, was most up-regulated at 20°C. Our results provide a deeper understanding of the temperature-triggered transcriptional changes in Aedes aegypti and can be used to further define the molecular mechanisms driven by environmental temperature variation.
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Affiliation(s)
| | - Blanka Tesla
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA, United States
| | - Elvira Cynthia Alves Horácio
- René Rachou Institute, Oswaldo Cruz Foundation, Belo Horizonte, Brazil.,Department of Genetics, Ecology and Evolution, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Laila Alves Nahum
- René Rachou Institute, Oswaldo Cruz Foundation, Belo Horizonte, Brazil.,Department of Genetics, Ecology and Evolution, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil.,Promove College of Technology, Belo Horizonte, Brazil
| | - Melinda Ann Brindley
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA, United States.,Department of Population Health, College of Veterinary Medicine, University of Georgia, Athens, GA, United States.,Center for Vaccines and Immunology, University of Georgia, Athens, GA, United States
| | | | - Courtney Cuinn Murdock
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA, United States.,Center for Vaccines and Immunology, University of Georgia, Athens, GA, United States.,Odum School of Ecology, University of Georgia, Athens, GA, United States.,Center for the Ecology of Infectious Diseases, University of Georgia, Athens, GA, United States.,Center for Emerging and Global Tropical Diseases, University of Georgia, Athens, GA, United States.,River Basin Center, University of Georgia, Athens, GA, United States.,Department of Entomology, College of Agriculture and Life Sciences, Cornell University, Ithaca, NY, United States
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17
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Rose C, Casas-Sánchez A, Dyer NA, Solórzano C, Beckett AJ, Middlehurst B, Marcello M, Haines LR, Lisack J, Engstler M, Lehane MJ, Prior IA, Acosta-Serrano Á. Trypanosoma brucei colonizes the tsetse gut via an immature peritrophic matrix in the proventriculus. Nat Microbiol 2020; 5:909-916. [DOI: 10.1038/s41564-020-0707-z] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Accepted: 03/09/2020] [Indexed: 01/10/2023]
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18
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Qin J, Tong Z, Zhan Y, Buisson C, Song F, He K, Nielsen-LeRoux C, Guo S. A Bacillus thuringiensis Chitin-Binding Protein is Involved in Insect Peritrophic Matrix Adhesion and Takes Part in the Infection Process. Toxins (Basel) 2020; 12:toxins12040252. [PMID: 32294913 PMCID: PMC7232397 DOI: 10.3390/toxins12040252] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 04/07/2020] [Accepted: 04/10/2020] [Indexed: 11/16/2022] Open
Abstract
Bacillus thuringiensis (Bt) is used for insect pest control, and its larvicidal activity is primarily attributed to Cry toxins. Other factors participate in infection, and limited information is available regarding factors acting on the peritrophic matrix (PM). This study aimed to investigate the role of a Bt chitin-binding protein (CBPA) that had been previously shown to be expressed at pH 9 in vitro and could therefore be expressed in the alkaline gut of lepidopteron larvae. A ∆cbpA mutant was generated that was 10-fold less virulent than wild-type Bt HD73 towards Ostrinia furnacalis neonate larvae, indicating its important role in infection. Purified recombinant Escherichia coli CBPA was shown to have a chitin affinity, thus indicating a possible interaction with the chitin-rich PM. A translational GFP-CBPA fusion elucidated the localization of CBPA on the bacterial surface, and the transcriptional activity of the promoter PcbpA was immediately induced and confirmed at pH 9. Next, in order to connect surface expression and possible in vivo gut activity, last instar Galleria mellonella (Gm) larvae (not susceptible to Bt HD-73) were used as a model to follow CBPA in gut expression, bacterial transit, and PM adhesion. CBPA-GFP was quickly expressed in the Gm gut lumen, and more Bt HD73 strain bacteria adhered to the PM than those of the ∆cbpA mutant strain. Therefore, CBPA may help to retain the bacteria, via the PM binding, close to the gut surface and thus takes part in the early steps of Bt gut interactions.
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Affiliation(s)
- Jiaxin Qin
- School of Life Science, Beijing Institute of Technology, Beijing 100081, China
| | - Zongxing Tong
- School of Life Science, Beijing Institute of Technology, Beijing 100081, China
| | - Yiling Zhan
- School of Life Science, Beijing Institute of Technology, Beijing 100081, China
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Christophe Buisson
- Micalis Institute, INRAE, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France
| | - Fuping Song
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Kanglai He
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Christina Nielsen-LeRoux
- Micalis Institute, INRAE, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France
- Correspondence: (C.N.-L.); (S.G.); Tel.: +33-01-3465-2101 (C.N.-L.); +86-10-6891-4495 (S.G.)
| | - Shuyuan Guo
- School of Life Science, Beijing Institute of Technology, Beijing 100081, China
- Correspondence: (C.N.-L.); (S.G.); Tel.: +33-01-3465-2101 (C.N.-L.); +86-10-6891-4495 (S.G.)
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19
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Li F, Li M, Wang H, Mao T, Chen J, Lu Z, Qu J, Fang Y, Li B. Effects of phoxim pesticide on the immune system of silkworm midgut. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2020; 164:58-64. [PMID: 32284137 DOI: 10.1016/j.pestbp.2019.12.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 12/11/2019] [Accepted: 12/26/2019] [Indexed: 06/11/2023]
Abstract
Silkworm (Bombyx mori) is an important economic insect. Bombyx mori, which is exposed to sublethal doses of pesticides, has a low or no mortality rate, while it is susceptible to infections triggered by foreign pathogens. The immune regulatory mechanism of silkworms caused by trace pesticides still remains unclear. The midgut is the major organ of silkworm for digestion and nutrient absorption, and it plays a critical defensive role against pathogens. In the present study, the silkworm was susceptible to Enterobacter cloacae sp. (E. cloacae) after exposure to sublethal dose of phoxim. The body weight and survival rate of the phoxim-E. cloacae co-treatment group were significantly decreased after 120 h of treatment compared with the phoxim treatment group. The immune responses and expressions of immune-related genes were dysregulated in the midgut of silkworm following exposure to phoxim. Digital gene expression (DGE) analysis revealed that 44 immune response-related and immune defense-related genes were differentially expressed. qRT-PCR results indicated that the transcriptional levels of antimicrobial peptide genes Bmdefensin1, BmcecA, Bmglv1, Bmglv2, Bmmoricin and BmmoricinB3 were down-regulated by 0.77-, 0.37-, 0.05-, 0.19-, 0.34- and 0.54-fold, respectively. The transcriptional levels of Toll signaling pathway genes Bmcactus, Bmspatzle and Bmrel were down-regulated by 0.4-, 0.37- and 0.96-fold, respectively. Peritrophic membrane (PM) protein-related genes BmCBP-02, BmPM-41, BmPM-43 and BmCDA7 were down-regulated by 0.18-, 0.02-, 0.66- and 0.16-fold, respectively. The expressions of Toll signaling pathway genes were down-regulated at 48 h and 72 h. Immune deficiency (IMD) and Janus kinase and signal transducer and activator of transcription (JAK/STAT) signaling pathway genes were dysregulated after phoxim exposure. These results indicated that phoxim might cause damage to the PM and reduce the immune response of the silkworm, leading to susceptibility of silkworm to disease and damage from foreign pathogens.
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Affiliation(s)
- Fanchi Li
- School of Basic Medicine and Biological Sciences, Soochow University, Suzhou, Jiangsu 215123, PR China; Sericulture Institute of Soochow University, Suzhou, Jiangsu 215123, PR China
| | - Mengxue Li
- School of Basic Medicine and Biological Sciences, Soochow University, Suzhou, Jiangsu 215123, PR China
| | - Hui Wang
- School of Basic Medicine and Biological Sciences, Soochow University, Suzhou, Jiangsu 215123, PR China
| | - Tingting Mao
- School of Basic Medicine and Biological Sciences, Soochow University, Suzhou, Jiangsu 215123, PR China
| | - Jian Chen
- School of Basic Medicine and Biological Sciences, Soochow University, Suzhou, Jiangsu 215123, PR China
| | - Zhengting Lu
- School of Basic Medicine and Biological Sciences, Soochow University, Suzhou, Jiangsu 215123, PR China
| | - Jianwei Qu
- School of Basic Medicine and Biological Sciences, Soochow University, Suzhou, Jiangsu 215123, PR China
| | - Yilong Fang
- School of Basic Medicine and Biological Sciences, Soochow University, Suzhou, Jiangsu 215123, PR China
| | - Bing Li
- School of Basic Medicine and Biological Sciences, Soochow University, Suzhou, Jiangsu 215123, PR China; Sericulture Institute of Soochow University, Suzhou, Jiangsu 215123, PR China.
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20
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Roma JS, D’Souza S, Somers PJ, Cabo LF, Farsin R, Aksoy S, Runyen-Janecky LJ, Weiss BL. Thermal stress responses of Sodalis glossinidius, an indigenous bacterial symbiont of hematophagous tsetse flies. PLoS Negl Trop Dis 2019; 13:e0007464. [PMID: 31738754 PMCID: PMC6887450 DOI: 10.1371/journal.pntd.0007464] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Revised: 12/02/2019] [Accepted: 10/24/2019] [Indexed: 11/22/2022] Open
Abstract
Tsetse flies (Diptera: Glossinidae) house a taxonomically diverse microbiota that includes environmentally acquired bacteria, maternally transmitted symbiotic bacteria, and pathogenic African trypanosomes. Sodalis glossinidius, which is a facultative symbiont that resides intra and extracellularly within multiple tsetse tissues, has been implicated as a mediator of trypanosome infection establishment in the fly’s gut. Tsetse’s gut-associated population of Sodalis are subjected to marked temperature fluctuations each time their ectothermic fly host imbibes vertebrate blood. The molecular mechanisms that Sodalis employs to deal with this heat stress are unknown. In this study, we examined the thermal tolerance and heat shock response of Sodalis. When grown on BHI agar plates, the bacterium exhibited the most prolific growth at 25oC, and did not grow at temperatures above 30oC. Growth on BHI agar plates at 31°C was dependent on either the addition of blood to the agar or reduction in oxygen levels. Sodalis was viable in liquid cultures for 24 hours at 30oC, but began to die upon further exposure. The rate of death increased with increased temperature. Similarly, Sodalis was able to survive for 48 hours within tsetse flies housed at 30oC, while a higher temperature (37oC) was lethal. Sodalis’ genome contains homologues of the heat shock chaperone protein-encoding genes dnaK, dnaJ, and grpE, and their expression was up-regulated in thermally stressed Sodalis, both in vitro and in vivo within tsetse fly midguts. Arrested growth of E. coli dnaK, dnaJ, or grpE mutants under thermal stress was reversed when the cells were transformed with a low copy plasmid that encoded the Sodalis homologues of these genes. The information contained in this study provides insight into how arthropod vector enteric commensals, many of which mediate their host’s ability to transmit pathogens, mitigate heat shock associated with the ingestion of a blood meal. Microorganisms associated with insects must cope with fluctuating temperatures. Because symbiotic bacteria influence the biology of their host, how they respond to temperature changes will have an impact on the host and other microorganisms in the host. The tsetse fly and its symbionts represent an important model system for studying thermal tolerance because the fly feeds exclusively on vertebrate blood and is thus exposed to dramatic temperature shifts. Tsetse flies house a microbial community that can consist of symbiotic and environmentally acquired bacteria, viruses, and parasitic African trypanosomes. This work, which makes use of tsetse’s commensal endosymbiont, Sodalis glossinidius, is significance because it represents the only examination of thermal tolerance mechanisms in a bacterium that resides indigenously within an arthropod disease vector. A better understanding of the biology of thermal tolerance in Sodalis provides insight into thermal stress survival in other insect symbionts and may yield information to help control vector-borne disease.
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Affiliation(s)
- Jose Santinni Roma
- Department of Biology, University of Richmond, Richmond, Virginia, United States of America
| | - Shaina D’Souza
- Department of Biology, University of Richmond, Richmond, Virginia, United States of America
| | - Patrick J. Somers
- Department of Biology, University of Richmond, Richmond, Virginia, United States of America
| | - Leah F. Cabo
- Department of Biology, University of Richmond, Richmond, Virginia, United States of America
| | - Ruhan Farsin
- Department of Biology, University of Richmond, Richmond, Virginia, United States of America
| | - Serap Aksoy
- Yale School of Public Health, Department of Epidemiology of Microbial Diseases, New Haven, Connecticut, United States of America
| | - Laura J. Runyen-Janecky
- Department of Biology, University of Richmond, Richmond, Virginia, United States of America
- * E-mail: (LJR-J); (BLW)
| | - Brian L. Weiss
- Yale School of Public Health, Department of Epidemiology of Microbial Diseases, New Haven, Connecticut, United States of America
- * E-mail: (LJR-J); (BLW)
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Aksoy S. Tsetse peritrophic matrix influences for trypanosome transmission. JOURNAL OF INSECT PHYSIOLOGY 2019; 118:103919. [PMID: 31425686 PMCID: PMC6853167 DOI: 10.1016/j.jinsphys.2019.103919] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Revised: 08/09/2019] [Accepted: 08/09/2019] [Indexed: 06/10/2023]
Abstract
Tsetse flies are important vectors of parasitic African trypanosomes, agents of human and animal trypanosomiasis. Easily administrable and effective tools for disease control in the mammalian host are still lacking but reduction of the tsetse vector populations can reduce disease. An alternative approach is to reduce the transmission of trypanosomes in the tsetse vector. The gut peritrophic matrix (PM) has emerged as an important regulator of parasite transmission success in tsetse. Tsetse has a Type II PM that is constitutively produced by cells in the cardia organ. Tsetse PM lines the entire gut and functions as an immunological barrier to prevent the gut epithelia from responding to commensal environmental microbes present in the gut lumen. Tsetse PM also functions as a physical barrier to trypanosome infections that enter into the gut lumen in an infective blood meal. For persistence in the gut, African trypanosomes have developed an adaptive manipulative process to transiently reduce PM efficacy. The process is mediated by mammalian trypanosome surface coat proteins, Variant Surface Glycoproteins (VSGs) which are shed in the gut lumen and taken up by cardia cells. The mechanism of PM reduction involves a tsetse microRNA (miR-275) which acts thru the Wnt signaling pathway. The PM efficacy is once again reduced later in the infection process to enable the gut established parasites to reenter into the gut lumen to colonize the salivary glands, an essential process for transmission. The ability to modulate PM integrity can lead to innovative approaches to reduce disease transmission.
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Affiliation(s)
- Serap Aksoy
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, 60 College St, LEPH 624, New Haven, CT 06520, United States.
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22
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Matetovici I, De Vooght L, Van Den Abbeele J. Innate immunity in the tsetse fly (Glossina), vector of African trypanosomes. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2019; 98:181-188. [PMID: 31075296 DOI: 10.1016/j.dci.2019.05.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 05/05/2019] [Accepted: 05/06/2019] [Indexed: 06/09/2023]
Abstract
Tsetse flies (Glossina sp.) are medically and veterinary important vectors of African trypanosomes, protozoan parasites that cause devastating diseases in humans and livestock in sub-Saharan Africa. These flies feed exclusively on vertebrate blood and harbor a limited diversity of obligate and facultative bacterial commensals. They have a well-developed innate immune system that plays a key role in protecting the fly against invading pathogens and in modulating the fly's ability to transmit African trypanosomes. In this review, we briefly summarize our current knowledge on the tsetse fly innate immune system and its interaction with the bacterial commensals and the trypanosome parasite.
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Affiliation(s)
- Irina Matetovici
- Department of Biomedical Sciences, Institute of Tropical Medicine Antwerp, Nationalestraat 155, B-2000, Antwerp, Belgium
| | - Linda De Vooght
- Department of Biomedical Sciences, Institute of Tropical Medicine Antwerp, Nationalestraat 155, B-2000, Antwerp, Belgium
| | - Jan Van Den Abbeele
- Department of Biomedical Sciences, Institute of Tropical Medicine Antwerp, Nationalestraat 155, B-2000, Antwerp, Belgium.
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23
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Guo W, Kain W, Wang P. Effects of disruption of the peritrophic membrane on larval susceptibility to Bt toxin Cry1Ac in cabbage loopers. JOURNAL OF INSECT PHYSIOLOGY 2019; 117:103897. [PMID: 31199901 DOI: 10.1016/j.jinsphys.2019.103897] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Revised: 06/05/2019] [Accepted: 06/10/2019] [Indexed: 06/09/2023]
Abstract
The insect midgut peritrophic membrane (or peritrophic matrix) (PM) is an extracellular structure, lining the midgut epithelium. The PM facilitates the food digestion process and plays important roles in insect-microbe interactions as a barrier against microbial pathogens. The soil bacterium, Bacillus thuringiensis (Bt), and its proteinaceous toxins are widely used for insect control. To understand the protective role of PM in insects against Bt toxins, the effect of PM on larval susceptibility to Bt toxin Cry1Ac was examined in Cry1Ac-susceptible and -resistant strains of the cabbage looper, Trichoplusia ni. The PM in T. ni was disrupted, using a baculovirus enhancin (TnGV enhancin) to degrade the major PM mucin protein IIM and a chitin binding chemical, Calcofluor, to inhibit the binding of PM proteins to chitin. Bioassays of the susceptibility of T. ni larvae to Cry1Ac with treatment of TnGV enhancin showed significantly increased larval mortality in both the Cry1Ac susceptible and resistant strains, confirming that the PM is a protective barrier to the passage of Cry1Ac and plays a protective role against the toxin. However, treatment of T. ni larvae with Calcofluor significantly reduced the larval susceptibility to Cry1Ac. The level of mortality reduction by treatment with Calcofluor was more significant in the resistant T. ni strains than in the susceptible strain. The mechanism for the decrease of susceptibility to Cry1Ac in T. ni treated with Calcofluor needs to be understood. It may result from binding of the toxin to the over expressed PM proteins, preventing the Cry1Ac from reaching the midgut receptor for the toxin or from potential binding of Calcofluor to the midgut receptor for Cry1Ac, leading to inhibition of the toxicity of Cry1Ac in larvae.
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Affiliation(s)
- Wei Guo
- Department of Entomology, Cornell University, Geneva, NY 14456, USA
| | - Wendy Kain
- Department of Entomology, Cornell University, Geneva, NY 14456, USA
| | - Ping Wang
- Department of Entomology, Cornell University, Geneva, NY 14456, USA.
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24
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Erlandson MA, Toprak U, Hegedus DD. Role of the peritrophic matrix in insect-pathogen interactions. JOURNAL OF INSECT PHYSIOLOGY 2019; 117:103894. [PMID: 31175854 DOI: 10.1016/j.jinsphys.2019.103894] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 05/27/2019] [Accepted: 06/05/2019] [Indexed: 05/12/2023]
Abstract
The peritrophic matrix (PM) is an acellular chitin and glycoprotein layer that lines the invertebrate midgut. The PM has long been considered a physical as well as a biochemical barrier, protecting the midgut epithelium from abrasive food particles, digestive enzymes and pathogens infectious per os. This short review will focus on the latter function, as a barrier to pathogens infectious per os. We focus on the evidence confirming the role of the PM as protective barrier against pathogenic microorganisms of insects, mainly bacteria and viruses, as well as the evolution of a variety of mechanisms used by pathogens to overcome the PM barrier.
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Affiliation(s)
- Martin A Erlandson
- Saskatoon Research and Development Centre, Agriculture and Agri-Food Canada, Saskatoon, Saskatchewan, Canada; Department of Biology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
| | - Umut Toprak
- Molecular Entomology Laboratory, Faculty of Agriculture, Ankara University, Ankara, Turkey
| | - Dwayne D Hegedus
- Saskatoon Research and Development Centre, Agriculture and Agri-Food Canada, Saskatoon, Saskatchewan, Canada; Department of Food and Bioproduct Science, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
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25
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Weiss BL, Maltz MA, Vigneron A, Wu Y, Walter KS, O’Neill MB, Wang J, Aksoy S. Colonization of the tsetse fly midgut with commensal Kosakonia cowanii Zambiae inhibits trypanosome infection establishment. PLoS Pathog 2019; 15:e1007470. [PMID: 30817773 PMCID: PMC6394900 DOI: 10.1371/journal.ppat.1007470] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Accepted: 12/27/2018] [Indexed: 11/18/2022] Open
Abstract
Tsetse flies (Glossina spp.) vector pathogenic trypanosomes (Trypanosoma spp.) in sub-Saharan Africa. These parasites cause human and animal African trypanosomiases, which are debilitating diseases that inflict an enormous socio-economic burden on inhabitants of endemic regions. Current disease control strategies rely primarily on treating infected animals and reducing tsetse population densities. However, relevant programs are costly, labor intensive and difficult to sustain. As such, novel strategies aimed at reducing tsetse vector competence require development. Herein we investigated whether Kosakonia cowanii Zambiae (Kco_Z), which confers Anopheles gambiae with resistance to Plasmodium, is able to colonize tsetse and induce a trypanosome refractory phenotype in the fly. Kco_Z established stable infections in tsetse’s gut and exhibited no adverse effect on the fly’s survival. Flies with established Kco_Z infections in their gut were significantly more refractory to infection with two distinct trypanosome species (T. congolense, 6% infection; T. brucei, 32% infection) than were age-matched flies that did not house the exogenous bacterium (T. congolense, 36% infected; T. brucei, 70% infected). Additionally, 52% of Kco_Z colonized tsetse survived infection with entomopathogenic Serratia marcescens, compared with only 9% of their wild-type counterparts. These parasite and pathogen refractory phenotypes result from the fact that Kco_Z acidifies tsetse’s midgut environment, which inhibits trypanosome and Serratia growth and thus infection establishment. Finally, we determined that Kco_Z infection does not impact the fecundity of male or female tsetse, nor the ability of male flies to compete with their wild-type counterparts for mates. We propose that Kco_Z could be used as one component of an integrated strategy aimed at reducing the ability of tsetse to transmit pathogenic trypanosomes. Tsetse flies transmit pathogenic African trypanosomes, which are the causative agents of socio-economically devastating human and animal African trypanosomiases. These diseases are currently controlled in large part by reducing the population size of tsetse vectors through the use of insecticides, traps and sterile insect technique. However, logistic and monetary hurdles often preclude the prolonged application of procedures necessary to maintain these control programs. Thus, novel strategies, including those aimed at sustainably reducing the ability of tsetse to transmit trypanosomes, are presently under development. Herein we stably colonize tsetse flies with a bacterium (Kosakonia cowanii Zambiae, Kco_Z) that acidifies their midgut, thus rendering the environment inhospitable to infection with two distinct, epidemiologically important trypanosome strains as well as an entomopathogenic bacteria. In addition to inducing a trypanosome refractory phenotype, colonization of tsetse with Kco_Z exerts only a modest fitness cost on the fly. Taken together, these findings suggest that Kco_Z could be applied to enhance the effectiveness of currently employed tsetse control programs.
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Affiliation(s)
- Brian L. Weiss
- Yale School of Public Health, Department of Epidemiology of Microbial Diseases, New Haven, Connecticut, United States of America
- * E-mail: (BLW); (SA)
| | - Michele A. Maltz
- Southern Connecticut State University, New Haven, Connecticut, United States of America
| | - Aurélien Vigneron
- Yale School of Public Health, Department of Epidemiology of Microbial Diseases, New Haven, Connecticut, United States of America
| | - Yineng Wu
- Yale School of Public Health, Department of Epidemiology of Microbial Diseases, New Haven, Connecticut, United States of America
| | - Katharine S. Walter
- Yale School of Public Health, Department of Epidemiology of Microbial Diseases, New Haven, Connecticut, United States of America
| | - Michelle B. O’Neill
- Yale School of Public Health, Department of Epidemiology of Microbial Diseases, New Haven, Connecticut, United States of America
| | - Jingwen Wang
- Yale School of Public Health, Department of Epidemiology of Microbial Diseases, New Haven, Connecticut, United States of America
| | - Serap Aksoy
- Yale School of Public Health, Department of Epidemiology of Microbial Diseases, New Haven, Connecticut, United States of America
- * E-mail: (BLW); (SA)
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26
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Kariithi HM, Meki IK, Schneider DI, De Vooght L, Khamis FM, Geiger A, Demirbaş-Uzel G, Vlak JM, iNCE IA, Kelm S, Njiokou F, Wamwiri FN, Malele II, Weiss BL, Abd-Alla AMM. Enhancing vector refractoriness to trypanosome infection: achievements, challenges and perspectives. BMC Microbiol 2018; 18:179. [PMID: 30470182 PMCID: PMC6251094 DOI: 10.1186/s12866-018-1280-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
With the absence of effective prophylactic vaccines and drugs against African trypanosomosis, control of this group of zoonotic neglected tropical diseases depends the control of the tsetse fly vector. When applied in an area-wide insect pest management approach, the sterile insect technique (SIT) is effective in eliminating single tsetse species from isolated populations. The need to enhance the effectiveness of SIT led to the concept of investigating tsetse-trypanosome interactions by a consortium of researchers in a five-year (2013-2018) Coordinated Research Project (CRP) organized by the Joint Division of FAO/IAEA. The goal of this CRP was to elucidate tsetse-symbiome-pathogen molecular interactions to improve SIT and SIT-compatible interventions for trypanosomoses control by enhancing vector refractoriness. This would allow extension of SIT into areas with potential disease transmission. This paper highlights the CRP's major achievements and discusses the science-based perspectives for successful mitigation or eradication of African trypanosomosis.
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Affiliation(s)
- Henry M Kariithi
- Biotechnology Research Institute, Kenya Agricultural & Livestock Research Organization, P.O Box 57811, 00200, Kaptagat Rd, Loresho, Nairobi, Kenya
| | - Irene K Meki
- Insect Pest Control Laboratory, FAO/IAEA Agriculture & Biotechnology Laboratory, IAEA Laboratories Seibersdorf, A-2444 Seibersdorf, Austria
- Laboratory of Virology, Wageningen University and Research, Wageningen, 6708 PB The Netherlands
| | - Daniela I Schneider
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, 60 College Street, New Haven, CT 06510 USA
| | - Linda De Vooght
- Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
| | - Fathiya M Khamis
- International Centre of Insect Physiology and Ecology, P.O. Box 30772, 00100, Nairobi, Kenya
| | - Anne Geiger
- INTERTRYP, Institut de Recherche pour le Développement, University of Montpellier, Montpellier, France
| | - Guler Demirbaş-Uzel
- Insect Pest Control Laboratory, FAO/IAEA Agriculture & Biotechnology Laboratory, IAEA Laboratories Seibersdorf, A-2444 Seibersdorf, Austria
| | - Just M Vlak
- Laboratory of Virology, Wageningen University and Research, Wageningen, 6708 PB The Netherlands
| | - ikbal Agah iNCE
- Institute of Chemical, Environmental & Biological Engineering, Research Area Biochemical Technology, Vienna University of Technology, Gumpendorfer Straße 1a, 1060 Vienna, Austria
| | - Sorge Kelm
- Department of Medical Microbiology, Acıbadem Mehmet Ali Aydınlar University, School of Medicine, 34752, Ataşehir, Istanbul, Turkey
| | - Flobert Njiokou
- Centre for Biomolecular Interactions Bremen, Faculty for Biology & Chemistry, Universität Bremen, Bibliothekstraße 1, 28359 Bremen, Germany
| | - Florence N Wamwiri
- Laboratory of Parasitology and Ecology, Faculty of Sciences, Department of Animal Biology and Physiology, University of Yaoundé 1, Yaoundé, BP 812 Cameroon
| | - Imna I Malele
- Trypanosomiasis Research Centre, Kenya Agricultural & Livestock Research Organization, P.O. Box 362-00902, Kikuyu, Kenya
| | - Brian L Weiss
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, 60 College Street, New Haven, CT 06510 USA
| | - Adly M M Abd-Alla
- Molecular Department, Vector and Vector Borne Diseases Institute, Tanzania Veterinary Laboratory Agency, Majani Mapana, Off Korogwe Road, Box, 1026 Tanga, Tanzania
- Insect Pest Control Laboratory, FAO/IAEA Agriculture & Biotechnology Laboratory, IAEA Laboratories Seibersdorf, A-2444 Seibersdorf, Austria
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27
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Radwanska M, Vereecke N, Deleeuw V, Pinto J, Magez S. Salivarian Trypanosomosis: A Review of Parasites Involved, Their Global Distribution and Their Interaction With the Innate and Adaptive Mammalian Host Immune System. Front Immunol 2018; 9:2253. [PMID: 30333827 PMCID: PMC6175991 DOI: 10.3389/fimmu.2018.02253] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 09/11/2018] [Indexed: 01/27/2023] Open
Abstract
Salivarian trypanosomes are single cell extracellular parasites that cause infections in a wide range of hosts. Most pathogenic infections worldwide are caused by one of four major species of trypanosomes including (i) Trypanosoma brucei and the human infective subspecies T. b. gambiense and T. b. rhodesiense, (ii) Trypanosoma evansi and T. equiperdum, (iii) Trypanosoma congolense and (iv) Trypanosoma vivax. Infections with these parasites are marked by excessive immune dysfunction and immunopathology, both related to prolonged inflammatory host immune responses. Here we review the classification and global distribution of these parasites, highlight the adaptation of human infective trypanosomes that allow them to survive innate defense molecules unique to man, gorilla, and baboon serum and refer to the discovery of sexual reproduction of trypanosomes in the tsetse vector. With respect to the immunology of mammalian host-parasite interactions, the review highlights recent findings with respect to the B cell destruction capacity of trypanosomes and the role of T cells in the governance of infection control. Understanding infection-associated dysfunction and regulation of both these immune compartments is crucial to explain the continued failures of anti-trypanosome vaccine developments as well as the lack of any field-applicable vaccine based anti-trypanosomosis intervention strategy. Finally, the link between infection-associated inflammation and trypanosomosis induced anemia is covered in the context of both livestock and human infections.
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Affiliation(s)
- Magdalena Radwanska
- Laboratory for Biomedical Research, Ghent University Global Campus, Incheon, South Korea
| | - Nick Vereecke
- Laboratory for Biomedical Research, Ghent University Global Campus, Incheon, South Korea.,Laboratory of Cellular and Molecular Immunology, Vrije Universiteit Brussel, Brussels, Belgium
| | - Violette Deleeuw
- Laboratory of Cellular and Molecular Immunology, Vrije Universiteit Brussel, Brussels, Belgium
| | - Joar Pinto
- Laboratory of Cellular and Molecular Immunology, Vrije Universiteit Brussel, Brussels, Belgium
| | - Stefan Magez
- Laboratory for Biomedical Research, Ghent University Global Campus, Incheon, South Korea.,Laboratory of Cellular and Molecular Immunology, Vrije Universiteit Brussel, Brussels, Belgium
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A fine-tuned vector-parasite dialogue in tsetse's cardia determines peritrophic matrix integrity and trypanosome transmission success. PLoS Pathog 2018; 14:e1006972. [PMID: 29614112 PMCID: PMC5898766 DOI: 10.1371/journal.ppat.1006972] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Revised: 04/13/2018] [Accepted: 03/13/2018] [Indexed: 01/19/2023] Open
Abstract
Arthropod vectors have multiple physical and immunological barriers that impede the development and transmission of parasites to new vertebrate hosts. These barriers include the peritrophic matrix (PM), a chitinous barrier that separates the blood bolus from the midgut epithelia and modulates vector-pathogens interactions. In tsetse flies, a sleeve-like PM is continuously produced by the cardia organ located at the fore- and midgut junction. African trypanosomes, Trypanosoma brucei, must bypass the PM twice; first to colonize the midgut and secondly to reach the salivary glands (SG), to complete their transmission cycle in tsetse. However, not all flies with midgut infections develop mammalian transmissible SG infections—the reasons for which are unclear. Here, we used transcriptomics, microscopy and functional genomics analyses to understand the factors that regulate parasite migration from midgut to SG. In flies with midgut infections only, parasites fail to cross the PM as they are eliminated from the cardia by reactive oxygen intermediates (ROIs)—albeit at the expense of collateral cytotoxic damage to the cardia. In flies with midgut and SG infections, expression of genes encoding components of the PM is reduced in the cardia, and structural integrity of the PM barrier is compromised. Under these circumstances trypanosomes traverse through the newly secreted and compromised PM. The process of PM attrition that enables the parasites to re-enter into the midgut lumen is apparently mediated by components of the parasites residing in the cardia. Thus, a fine-tuned dialogue between tsetse and trypanosomes at the cardia determines the outcome of PM integrity and trypanosome transmission success. Insects are responsible for transmission of parasites that cause deadly diseases in humans and animals. Understanding the key factors that enhance or interfere with parasite transmission processes can result in new control strategies. Here, we report that a proportion of tsetse flies with African trypanosome infections in their midgut can prevent parasites from migrating to the salivary glands, albeit at the expense of collateral damage. In a subset of flies with gut infections, the parasites manipulate the integrity of a midgut barrier, called the peritrophic matrix, and reach the salivary glands for transmission to the next mammal. Either targeting parasite manipulative processes or enhancing peritrophic matrix integrity could reduce parasite transmission.
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Variations in the Peritrophic Matrix Composition of Heparan Sulphate from the Tsetse Fly, Glossina morsitans morsitans. Pathogens 2018; 7:pathogens7010032. [PMID: 29562674 PMCID: PMC5874758 DOI: 10.3390/pathogens7010032] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2018] [Revised: 03/16/2018] [Accepted: 03/17/2018] [Indexed: 01/01/2023] Open
Abstract
Tsetse flies are the principal insect vectors of African trypanosomes—sleeping sickness in humans and Nagana in cattle. One of the tsetse fly species, Glossina morsitans morsitans, is host to the parasite, Trypanosoma brucei, a major cause of African trypanosomiasis. Precise details of the life cycle have yet to be established, but the parasite life cycle involves crossing the insect peritrophic matrix (PM). The PM consists of the polysaccharide chitin, several hundred proteins, and both glycosamino- and galactosaminoglycan (GAG) polysaccharides. Owing to the technical challenges of detecting small amounts of GAG polysaccharides, their conclusive identification and composition have not been possible until now. Following removal of PMs from the insects and the application of heparinases (bacterial lyase enzymes that are specific for heparan sulphate (HS) GAG polysaccharides), dot blots with a HS-specific antibody showed heparan sulphate proteoglycans (HSPGs) to be present, consistent with Glossina morsitans morsitans genome analysis, as well as the likely expression of the HSPGs syndecan and perlecan. Exhaustive HS digestion with heparinases, fluorescent labeling of the resulting disaccharides with BODIPY fluorophore, and separation by strong anion exchange chromatography then demonstrated the presence of HS for the first time and provided the disaccharide composition. There were no significant differences in the type of disaccharide species present between genders or between ages (24 vs. 48 h post emergence), although the HS from female flies was more heavily sulphated overall. Significant differences, which may relate to differences in infection between genders or ages, were evident, however, in overall levels of 2-O-sulphation between sexes and, for females, between 24 and 48 h post-emergence, implying a change in expression or activity for the 2-O-sulphotransferase enzyme. The presence of significant quantities of disaccharides containing the monosaccharide GlcNAc6S contrasts with previous findings in Drosophila melanogaster and suggests subtle differences in HS fine structure between species of the Diptera.
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30
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Baia-da-Silva DC, Alvarez LCS, Lizcano OV, Costa FTM, Lopes SCP, Orfanó AS, Pascoal DO, Nacif-Pimenta R, Rodriguez IC, Guerra MDGVB, Lacerda MVG, Secundino NFC, Monteiro WM, Pimenta PFP. The role of the peritrophic matrix and red blood cell concentration in Plasmodium vivax infection of Anopheles aquasalis. Parasit Vectors 2018; 11:148. [PMID: 29510729 PMCID: PMC5840820 DOI: 10.1186/s13071-018-2752-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Accepted: 02/26/2018] [Indexed: 12/31/2022] Open
Abstract
Background Plasmodium vivax is predominant in the Amazon region, and enhanced knowledge of its development inside a natural vector, Anopheles aquasalis, is critical for future strategies aimed at blocking parasite development. The peritrophic matrix (PM), a chitinous layer produced by the mosquito midgut in response to blood ingestion, is a protective barrier against pathogens. Plasmodium can only complete its life-cycle, and consequently be transmitted to a new host, after successfully passing this barrier. Interestingly, fully engorged mosquitoes that had a complete blood meal form a thicker, well-developed PM than ones that feed in small amounts. The amount of red blood cells (RBC) in the blood meal directly influences the production of digestive enzymes and can protect parasites from being killed during the meal digestion. A specific study interrupting the development of the PM associated with the proteolytic activity inhibition, and distinct RBC concentrations, during the P. vivax infection of the New World malaria vector An. aquasalis is expected to clarify whether these factors affect the parasite development. Results Absence of PM in the vector caused a significant reduction in P. vivax infection. However, the association of chitinase with trypsin inhibitor restored infection rates to those of mosquitoes with a structured PM. Also, only the ingestion of trypsin inhibitor by non-chitinase treated mosquitoes increased the infection intensity. Moreover, the RBC concentration in the infected P. vivax blood meal directly influenced the infection rate and its intensity. A straight correlation was observed between RBC concentrations and infection intensity. Conclusions This study established that there is a balance between the PM role, RBC concentration and digestive enzyme activity influencing the establishment and development of P. vivax infection inside An. aquasalis. Our results indicate that the absence of PM in the midgut facilitates digestive enzyme dispersion throughout the blood meal, causing direct damage to P. vivax. On the other hand, high RBC concentrations support a better and thick, well-developed PM and protect P. vivax from being killed. Further studies of this complex system may provide insights into other details of the malaria vector response to P. vivax infection.
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Affiliation(s)
- Djane Clarys Baia-da-Silva
- Diretoria de Ensino e Pesquisa, Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, AM, Brazil.,Programa de Pós-Graduação em Medicina Tropical, Universidade do Estado do Amazonas, Manaus, AM, Brazil
| | - Luis Carlos Salazar Alvarez
- Diretoria de Ensino e Pesquisa, Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, AM, Brazil.,Programa de Pós-Graduação em Medicina Tropical, Universidade do Estado do Amazonas, Manaus, AM, Brazil
| | - Omaira Vera Lizcano
- Grupo de Investigación QUIBIO, Departamento de Biología, Universidad Santiago de Cali, Valle del Cauca, Colombia
| | - Fabio Trindade Maranhão Costa
- Department of Genetics, Evolution and Bioagents, Institute of Biology, Universidade Estadual de Campinas, Campinas, SP, Brazil
| | - Stefanie Costa Pinto Lopes
- Programa de Pós-Graduação em Medicina Tropical, Universidade do Estado do Amazonas, Manaus, AM, Brazil.,Instituto Leônidas & Maria Deane, Fiocruz, Manaus, AM, Brazil
| | - Alessandra Silva Orfanó
- Instituto de Pesquisas René Rachou, Fundação Oswaldo Cruz-Minas Gerais, Belo Horizonte, MG, Brazil
| | - Denner Oliveira Pascoal
- Diretoria de Ensino e Pesquisa, Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, AM, Brazil
| | - Rafael Nacif-Pimenta
- Instituto de Pesquisas René Rachou, Fundação Oswaldo Cruz-Minas Gerais, Belo Horizonte, MG, Brazil
| | - Iria Cabral Rodriguez
- Diretoria de Ensino e Pesquisa, Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, AM, Brazil
| | - Maria das Graças Vale Barbosa Guerra
- Diretoria de Ensino e Pesquisa, Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, AM, Brazil.,Programa de Pós-Graduação em Medicina Tropical, Universidade do Estado do Amazonas, Manaus, AM, Brazil
| | - Marcus Vinicius Guimarães Lacerda
- Programa de Pós-Graduação em Medicina Tropical, Universidade do Estado do Amazonas, Manaus, AM, Brazil.,Instituto Leônidas & Maria Deane, Fiocruz, Manaus, AM, Brazil
| | | | - Wuelton Marcelo Monteiro
- Diretoria de Ensino e Pesquisa, Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, AM, Brazil.,Programa de Pós-Graduação em Medicina Tropical, Universidade do Estado do Amazonas, Manaus, AM, Brazil
| | - Paulo Filemon Paolucci Pimenta
- Diretoria de Ensino e Pesquisa, Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, AM, Brazil. .,Programa de Pós-Graduação em Medicina Tropical, Universidade do Estado do Amazonas, Manaus, AM, Brazil. .,Instituto de Pesquisas René Rachou, Fundação Oswaldo Cruz-Minas Gerais, Belo Horizonte, MG, Brazil.
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Song X, Wang M, Dong L, Zhu H, Wang J. PGRP-LD mediates A. stephensi vector competency by regulating homeostasis of microbiota-induced peritrophic matrix synthesis. PLoS Pathog 2018; 14:e1006899. [PMID: 29489896 PMCID: PMC5831637 DOI: 10.1371/journal.ppat.1006899] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 01/23/2018] [Indexed: 12/02/2022] Open
Abstract
Peptidoglycan recognition proteins (PGRPs) and commensal microbes mediate pathogen infection outcomes in insect disease vectors. Although PGRP-LD is retained in multiple vectors, its role in host defense remains elusive. Here we report that Anopheles stephensi PGRP-LD protects the vector from malaria parasite infection by regulating gut homeostasis. Specifically, knock down of PGRP-LD (dsLD) increased susceptibility to Plasmodium berghei infection, decreased the abundance of gut microbiota and changed their spatial distribution. This outcome resulted from a change in the structural integrity of the peritrophic matrix (PM), which is a chitinous and proteinaceous barrier that lines the midgut lumen. Reduction of microbiota in dsLD mosquitoes due to the upregulation of immune effectors led to dysregulation of PM genes and PM fragmentation. Elimination of gut microbiota in antibiotic treated mosquitoes (Abx) led to PM loss and increased vectorial competence. Recolonization of Abx mosquitoes with indigenous Enterobacter sp. restored PM integrity and decreased mosquito vectorial capacity. Silencing PGRP-LD in mosquitoes without PM didn’t influence their vector competence. Our results indicate that PGPR-LD protects the gut microbiota by preventing hyper-immunity, which in turn promotes PM structurally integrity. The intact PM plays a key role in limiting P. berghei infection. Malaria parasites must overcome several obstacles to complete their development in mosquito. Understanding the interactions between parasites and mosquitoes will provide potential targets to control malaria transmission. PGRP-LD is a peptidoglycan recognition protein, of which limit information is available in insects. Here we show that A. stephensi PGRP-LD mediates malaria parasite infection outcomes by influencing homeostasis of the gut microbiota. Reduction of the gut microbiota density, resulting from upregulation of immune activities in PGRP-LD knock down mosquitoes, changes expression of PM genes and causes PM fragmentation. The compromised PM leads to increasing susceptibility to parasite infection. We also discovered that the PM is lost in mosquitoes in which the gut microbiota is removed by antibiotic treatment. Knock down of PGRP-LD in these mosquitoes doesn’t increase their vector competence. Altogether, these results indicate that capacity of Anopheles mosquito to transmit parasites is determined by a finely tuned balance between host immunity, gut microbiota and peritrophic matrix. PGRP-LD is a key mediator in regulating this balance. Our results expand knowledge on interactions between immune system, gut microbiota and Plasmodium, and will shed light on equivalent processes in other disease transmitting vectors.
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Affiliation(s)
- Xiumei Song
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, P. R. China
- Ministry of Education Key Laboratory of Contemporary Anthropology, School of Life Sciences, Fudan University, Shanghai, P. R. China
| | - Mengfei Wang
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, P. R. China
- Ministry of Education Key Laboratory of Contemporary Anthropology, School of Life Sciences, Fudan University, Shanghai, P. R. China
| | - Li Dong
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, P. R. China
- Ministry of Education Key Laboratory of Contemporary Anthropology, School of Life Sciences, Fudan University, Shanghai, P. R. China
| | - Huaimin Zhu
- The 2nd Military Medical University, Shanghai, P. R. China
| | - Jingwen Wang
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, P. R. China
- Ministry of Education Key Laboratory of Contemporary Anthropology, School of Life Sciences, Fudan University, Shanghai, P. R. China
- * E-mail:
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32
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Bateta R, Wang J, Wu Y, Weiss BL, Warren WC, Murilla GA, Aksoy S, Mireji PO. Tsetse fly (Glossina pallidipes) midgut responses to Trypanosoma brucei challenge. Parasit Vectors 2017; 10:614. [PMID: 29258576 PMCID: PMC5738168 DOI: 10.1186/s13071-017-2569-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Accepted: 12/04/2017] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Tsetse flies (Glossina spp.) are the prominent vector of African trypanosome parasites (Trypanosoma spp.) in sub-Saharan Africa, and Glossina pallidipes is the most widely distributed species in Kenya. This species displays strong resistance to infection by parasites, which are typically eliminated in the midgut shortly after acquisition from the mammalian host. Although extensive molecular information on immunity for the related species Glossina morsitans morsitans exists, similar information is scarce for G. pallidipes. METHODS To determine temporal transcriptional responses of G. pallidipes to Trypanosoma brucei brucei challenge, we conducted Illumina based RNA-seq on midgut organ and carcass from teneral females G. pallidipes at 24 and 48 h post-challenge (hpc) with T. b. brucei relative to their respective controls that received normal blood meals (without the parasite). We used a suite of bioinformatics tools to determine differentially expressed and enriched transcripts between and among tissues, and to identify expanded transcripts in G. pallidipes relative to their orthologs G. m. morsitans. RESULTS Midgut transcripts induced at 24 hpc encoded proteins were associated with lipid remodelling, proteolysis, collagen metabolism, apoptosis, and cell growth. Midgut transcripts induced at 48 hpc encoded proteins linked to embryonic growth and development, serine endopeptidases and proteosomal degradation of the target protein, mRNA translation and neuronal development. Temporal expression of immune responsive transcripts at 48 relative to 24 hpc was pronounced, indicative of a gradual induction of host immune responses the following challenge. We also searched for G. m. morsitans orthologous groups that may have experienced expansions in the G. pallidipes genome. We identified ten expanded groups in G. pallidipes with putative immunity-related functions, which may play a role in the higher refractoriness exhibited by this species. CONCLUSIONS There appears to be a lack of strong immune responses elicited by gut epithelia of teneral adults. This in combination with a compromised peritrophic matrix at this stage during the initial phase of T. b. brucei challenge may facilitate the increased parasite infection establishment noted in teneral flies relative to older adults. Although teneral flies are more susceptible than older adults, the majority of tenerals are still able to eliminate parasite infections. Hence, robust responses elicited at a later time point, such as 72 hpc, may clear parasite infections from the majority of flies. The expanded G. m. morsitans orthologous groups in G. pallidipes may also be functionally associated with the enhanced refractoriness to trypanosome infections reported in G. pallidipes relative to G. m. morsitans.
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Affiliation(s)
- Rosemary Bateta
- Department of Biochemistry, Biotechnology Research Institute, Kenya Agricultural and Livestock Research Organization, P.O. Box 362, Kikuyu, Kenya
- Department of Biochemistry and Molecular Biology, Egerton University, P.O. Box 536, Njoro, Kenya
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT USA
| | - Jingwen Wang
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT USA
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, 200433 China
- Ministry of Education Key Laboratory of Contemporary Anthropology, School of Life Sciences, Fudan University, Shanghai, 200433 China
| | - Yineng Wu
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT USA
| | - Brian L. Weiss
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT USA
| | - Wesley C. Warren
- McDonnell Genome Institute, Washington University School of Medicine, 4444 Forest Park Ave., Campus Box 8501, St Louis, MO 63108 USA
| | - Grace A. Murilla
- Department of Biochemistry, Biotechnology Research Institute, Kenya Agricultural and Livestock Research Organization, P.O. Box 362, Kikuyu, Kenya
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT USA
| | - Serap Aksoy
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT USA
| | - Paul O. Mireji
- Department of Biochemistry, Biotechnology Research Institute, Kenya Agricultural and Livestock Research Organization, P.O. Box 362, Kikuyu, Kenya
- Department of Biochemistry and Molecular Biology, Egerton University, P.O. Box 536, Njoro, Kenya
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT USA
- Centre for Geographic Medicine Research - Coast, Kenya Medical Research Institute, P. O. Box 428-80108, Kilifi, Kenya
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33
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Awuoche EO, Weiss BL, Vigneron A, Mireji PO, Aksoy E, Nyambega B, Attardo GM, Wu Y, O’Neill M, Murilla G, Aksoy S. Molecular characterization of tsetse's proboscis and its response to Trypanosoma congolense infection. PLoS Negl Trop Dis 2017; 11:e0006057. [PMID: 29155830 PMCID: PMC5695773 DOI: 10.1371/journal.pntd.0006057] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Accepted: 10/20/2017] [Indexed: 12/18/2022] Open
Abstract
Tsetse flies (Glossina spp.) transmit parasitic African trypanosomes (Trypanosoma spp.), including Trypanosoma congolense, which causes animal African trypanosomiasis (AAT). AAT detrimentally affects agricultural activities in sub-Saharan Africa and has negative impacts on the livelihood and nutrient availability for the affected communities. After tsetse ingests an infectious blood meal, T. congolense sequentially colonizes the fly’s gut and proboscis (PB) organs before being transmitted to new mammalian hosts during subsequent feedings. Despite the importance of PB in blood feeding and disease transmission, little is known about its molecular composition, function and response to trypanosome infection. To bridge this gap, we used RNA-seq analysis to determine its molecular characteristics and responses to trypanosome infection. By comparing the PB transcriptome to whole head and midgut transcriptomes, we identified 668 PB-enriched transcripts that encoded proteins associated with muscle tissue, organ development, chemosensation and chitin-cuticle structure development. Moreover, transcripts encoding putative mechanoreceptors that monitor blood flow during tsetse feeding and interact with trypanosomes were also expressed in the PB. Microscopic analysis of the PB revealed cellular structures associated with muscles and cells. Infection with T. congolense resulted in increased and decreased expression of 38 and 88 transcripts, respectively. Twelve of these differentially expressed transcripts were PB-enriched. Among the transcripts induced upon infection were those encoding putative proteins associated with cell division function(s), suggesting enhanced tissue renewal, while those suppressed were associated with metabolic processes, extracellular matrix and ATP-binding as well as immunity. These results suggest that PB is a muscular organ with chemosensory and mechanosensory capabilities. The mechanoreceptors may be point of PB-trypanosomes interactions. T. congolense infection resulted in reduced metabolic and immune capacity of the PB. The molecular knowledge on the composition and putative functions of PB forms the foundation to identify new targets to disrupt tsetse’s ability to feed and parasite transmission. Tsetse flies are economically important insects responsible for transmitting African trypanosomes, which cause debilitating and fatal diseases in humans and animals in sub-Saharan Africa. In the tsetse vector, trypanosomes undergo complex developmental processes in the midgut, culminating with the generation of mammalian infective forms in the salivary glands for Trypanosoma brucei spp. and in the proboscis (PB) for Trypanosoma congolense and Trypanosoma vivax. Molecular studies on tsetse’s PB, and its interactions with trypanosomes, are limited. We used RNA-seq analysis to obtain molecular information on the putative products associated with tsetse’s PB and characterized PB responses to infection with T. congolense. Based on the predicted putative protein profile, the PB appears to be a muscular organ with mechanoreceptors and may have the capacity to sense and respond to chemical cues. Parasite infections of the PB lead to decreased expression of genes whose products are associated with metabolic and immune functions. These data provide insights into tsetse-trypanosome interactions in the PB organ and identify potential candidate targets that can be further explored to develop biotechnological strategies to reduce transmission of trypanosomes by tsetse flies.
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Affiliation(s)
- Erick O. Awuoche
- Department of Biochemistry, Biotechnology Research Institute, Kenya Agricultural and Livestock Research Organization, Kikuyu. Kenya
- Department of Biomedical Science and Technology, School of Public Health and Community Development, Maseno University, Private Bag, Maseno, Kenya
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, United States of America
- Department of Agriculture, School of Agriculture and Food Science, Meru University of Science and Technology, Meru, Kenya
- * E-mail:
| | - Brian L. Weiss
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, United States of America
| | - Aurélien Vigneron
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, United States of America
| | - Paul O. Mireji
- Department of Biochemistry, Biotechnology Research Institute, Kenya Agricultural and Livestock Research Organization, Kikuyu. Kenya
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, United States of America
- Centre for Geographic Medicine Research—Coast, Kenya Medical Research Institute, Kilifi. Kenya
| | - Emre Aksoy
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, United States of America
| | - Benson Nyambega
- Department of Medical Biochemistry, School of Medicine, Maseno University, Private Bag, Maseno, Kenya
| | - Geoffrey M. Attardo
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, United States of America
| | - Yineng Wu
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, United States of America
| | - Michelle O’Neill
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, United States of America
| | - Grace Murilla
- Department of Biochemistry, Biotechnology Research Institute, Kenya Agricultural and Livestock Research Organization, Kikuyu. Kenya
| | - Serap Aksoy
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, United States of America
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Jacob F, Melachio TT, Njitchouang GR, Gimonneau G, Njiokou F, Abate L, Christen R, Reveillaud J, Geiger A. Intestinal Bacterial Communities of Trypanosome-Infected and Uninfected Glossina palpalis palpalis from Three Human African Trypanomiasis Foci in Cameroon. Front Microbiol 2017; 8:1464. [PMID: 28824591 PMCID: PMC5541443 DOI: 10.3389/fmicb.2017.01464] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Accepted: 07/20/2017] [Indexed: 11/27/2022] Open
Abstract
Glossina sp. the tsetse fly that transmits trypanosomes causing the Human or the Animal African Trypanosomiasis (HAT or AAT) can harbor symbiotic bacteria that are known to play a crucial role in the fly's vector competence. We hypothesized that other bacteria could be present, and that some of them could also influence the fly's vector competence. In this context the objectives of our work were: (a) to characterize the bacteria that compose the G. palpalis palpalis midgut bacteriome, (b) to evidence possible bacterial community differences between trypanosome-infected and non-infected fly individuals from a given AAT and HAT focus or from different foci using barcoded Illumina sequencing of the hypervariable V3-V4 region of the 16S rRNA gene. Forty G. p. palpalis flies, either infected by Trypanosoma congolense or uninfected were sampled from three trypanosomiasis foci in Cameroon. A total of 143 OTUs were detected in the midgut samples. Most taxa were identified at the genus level, nearly 50% at the species level; they belonged to 83 genera principally within the phyla Actinobacteria, Bacteroidetes, Firmicutes, and Proteobacteria. Prominent representatives included Wigglesworthia (the fly's obligate symbiont), Serratia, and Enterobacter hormaechei. Wolbachia was identified for the first time in G. p. palpalis. The average number of bacterial species per tsetse sample was not significantly different regarding the fly infection status, and the hierarchical analysis based on the differences in bacterial community structure did not provide a clear clustering between infected and non-infected flies. Finally, the most important result was the evidence of the overall very large diversity of intestinal bacteria which, except for Wigglesworthia, were unevenly distributed over the sampled flies regardless of their geographic origin and their trypanosome infection status.
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Affiliation(s)
- Franck Jacob
- UMR INTERTRYP, Institut de Recherche pour le Développement-CIRAD, CIRAD TA A-17/GMontpellier, France
| | - Trésor T Melachio
- Parasitology and Ecology Laboratory, Department of Animal Biology and Physiology, Faculty of Science, University of Yaounde 1Yaounde, Cameroon
| | - Guy R Njitchouang
- Parasitology and Ecology Laboratory, Department of Animal Biology and Physiology, Faculty of Science, University of Yaounde 1Yaounde, Cameroon
| | - Geoffrey Gimonneau
- UMR INTERTRYP, Institut de Recherche pour le Développement-CIRAD, CIRAD TA A-17/GMontpellier, France
| | - Flobert Njiokou
- Parasitology and Ecology Laboratory, Department of Animal Biology and Physiology, Faculty of Science, University of Yaounde 1Yaounde, Cameroon
| | - Luc Abate
- UMR MIVEGEC, Institut de Recherche pour le Développement 224-Centre National de la Recherche Scientifique 5290Montpellier, France
| | - Richard Christen
- UMR 7138, Systématique Adaptation Evolution, Université de Nice-Sophia AntipolisNice, France
| | - Julie Reveillaud
- Institut National de la Recherche Agronomique, UMR 1309 ASTREMontpellier, France.,CIRAD, UMR ASTREMontpellier, France
| | - Anne Geiger
- UMR INTERTRYP, Institut de Recherche pour le Développement-CIRAD, CIRAD TA A-17/GMontpellier, France
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Sterkel M, Oliveira JHM, Bottino-Rojas V, Paiva-Silva GO, Oliveira PL. The Dose Makes the Poison: Nutritional Overload Determines the Life Traits of Blood-Feeding Arthropods. Trends Parasitol 2017; 33:633-644. [PMID: 28549573 DOI: 10.1016/j.pt.2017.04.008] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2017] [Revised: 04/20/2017] [Accepted: 04/27/2017] [Indexed: 12/21/2022]
Abstract
Vertebrate blood composition is heavily biased towards proteins, and hemoglobin, which is a hemeprotein, is by far the most abundant protein. Typically, hematophagous insects ingest blood volumes several times their weight before the blood meal. This barbarian feast offers an abundance of nutrients, but the degradation of blood proteins generates toxic concentrations of amino acids and heme, along with unparalleled microbiota growth. Despite this challenge, hematophagous arthropods have successfully developed mechanisms that bypass the toxicity of these molecules. While these adaptations allow hematophagous arthropods to tolerate their diet, they also constitute a unique mode of operation for cell signaling, immunity, and metabolism, the study of which may offer insights into the biology of disease vectors and may lead to novel vector-specific control methods.
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Affiliation(s)
- Marcos Sterkel
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, Brazil
| | - José Henrique M Oliveira
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
| | - Vanessa Bottino-Rojas
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, Brazil
| | - Gabriela O Paiva-Silva
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, Brazil; Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Brazil
| | - Pedro L Oliveira
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, Brazil; Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Brazil.
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Rodgers FH, Gendrin M, Wyer CAS, Christophides GK. Microbiota-induced peritrophic matrix regulates midgut homeostasis and prevents systemic infection of malaria vector mosquitoes. PLoS Pathog 2017; 13:e1006391. [PMID: 28545061 PMCID: PMC5448818 DOI: 10.1371/journal.ppat.1006391] [Citation(s) in RCA: 97] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Revised: 05/30/2017] [Accepted: 04/28/2017] [Indexed: 12/22/2022] Open
Abstract
Manipulation of the mosquito gut microbiota can lay the foundations for novel methods for disease transmission control. Mosquito blood feeding triggers a significant, transient increase of the gut microbiota, but little is known about the mechanisms by which the mosquito controls this bacterial growth whilst limiting inflammation of the gut epithelium. Here, we investigate the gut epithelial response to the changing microbiota load upon blood feeding in the malaria vector Anopheles coluzzii. We show that the synthesis and integrity of the peritrophic matrix, which physically separates the gut epithelium from its luminal contents, is microbiota dependent. We reveal that the peritrophic matrix limits the growth and persistence of Enterobacteriaceae within the gut, whilst preventing seeding of a systemic infection. Our results demonstrate that the peritrophic matrix is a key regulator of mosquito gut homeostasis and establish functional analogies between this and the mucus layers of the mammalian gastrointestinal tract. When a female mosquito takes a blood meal from a human, the bacteria residing within its gut grow significantly. Following a blood meal, female mosquitoes produce a barrier within their gut, known as the peritrophic matrix, which physically separates the blood meal from the cells of the epithelium. Here, we show that the presence of bacteria in the gut is required for the synthesis of the peritrophic matrix. By experimentally disrupting this barrier, we find that this structure plays a role in limiting the extent to which bacteria of one particular family are able to grow and persist in the mosquito gut. We also find that the peritrophic matrix ensures that bacteria remain within the gut, preventing them from invading the mosquito body cavity. These results will be useful in designing disease control strategies that depend on the ability of bacteria to colonize and persist in relevant tissues in the mosquito host.
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Affiliation(s)
- Faye H. Rodgers
- Vector Immunogenomics and Infection Laboratory, Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Mathilde Gendrin
- Vector Immunogenomics and Infection Laboratory, Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Claudia A. S. Wyer
- Vector Immunogenomics and Infection Laboratory, Department of Life Sciences, Imperial College London, London, United Kingdom
| | - George K. Christophides
- Vector Immunogenomics and Infection Laboratory, Department of Life Sciences, Imperial College London, London, United Kingdom
- * E-mail:
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Romoli O, Saviane A, Bozzato A, D'Antona P, Tettamanti G, Squartini A, Cappellozza S, Sandrelli F. Differential sensitivity to infections and antimicrobial peptide-mediated immune response in four silkworm strains with different geographical origin. Sci Rep 2017; 7:1048. [PMID: 28432358 PMCID: PMC5430696 DOI: 10.1038/s41598-017-01162-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Accepted: 03/27/2017] [Indexed: 01/19/2023] Open
Abstract
The domesticated silkworm Bombyx mori has an innate immune system, whose main effectors are the antimicrobial peptides (AMPs). Silkworm strains are commonly grouped into four geographical types (Japanese, Chinese, European and Tropical) and are generally characterised by a variable susceptibility to infections. To clarify the genetic and molecular mechanisms on which the different responses to infections are based, we exposed one silkworm strain for each geographical area to oral infections with the silkworm pathogens Enterococcus mundtii or Serratia marcescens. We detected a differential susceptibility to both bacteria, with the European strain displaying the lowest sensitivity to E. mundtii and the Indian one to S. marcescens. We found that all the strains were able to activate the AMP response against E. mundtii. However, the highest tolerance of the European strain appeared to be related to the specific composition of its AMP cocktail, containing more effective variants such as a peculiar Cecropin B6 isoform. The resistance of the Indian strain to S. marcescens seemed to be associated with its prompt capability to activate the systemic transcription of AMPs. These data suggest that B. mori strains with distinct genetic backgrounds employ different strategies to counteract bacterial infections, whose efficacy appears to be pathogen-dependent.
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Affiliation(s)
- Ottavia Romoli
- Department of Biology, University of Padova, Padova, Italy
| | - Alessio Saviane
- CREA - Honey Bee and Silkworm Research Unit, Padova Seat, Padova, Italy
| | - Andrea Bozzato
- Department of Biology, University of Padova, Padova, Italy
| | - Paola D'Antona
- Department of Biotechnology and Life Sciences, University of Insubria, Varese, Italy
| | - Gianluca Tettamanti
- Department of Biotechnology and Life Sciences, University of Insubria, Varese, Italy
| | - Andrea Squartini
- Department of Agronomy, Food, Natural Resources, Animals and Environment, University of Padova, Padova, Italy
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Hamidou Soumana I, Tchicaya B, Rialle S, Parrinello H, Geiger A. Comparative Genomics of Glossina palpalis gambiensis and G. morsitans morsitans to Reveal Gene Orthologs Involved in Infection by Trypanosoma brucei gambiense. Front Microbiol 2017; 8:540. [PMID: 28421044 PMCID: PMC5376623 DOI: 10.3389/fmicb.2017.00540] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Accepted: 03/14/2017] [Indexed: 11/22/2022] Open
Abstract
Blood-feeding Glossina palpalis gambiense (Gpg) fly transmits the single-celled eukaryotic parasite Trypanosoma brucei gambiense (Tbg), the second Glossina fly African trypanosome pair being Glossina morsitans/T.brucei rhodesiense. Whatever the T. brucei subspecies, whereas the onset of their developmental program in the zoo-anthropophilic blood feeding flies does unfold in the fly midgut, its completion is taking place in the fly salivary gland where does emerge a low size metacyclic trypomastigote population displaying features that account for its establishment in mammals-human individuals included. Considering that the two Glossina—T. brucei pairs introduced above share similarity with respect to the developmental program of this African parasite, we were curious to map on the Glossina morsitans morsitans (Gmm), the Differentially Expressed Genes (DEGs) we listed in a previous study. Briefly, using the gut samples collected at days 3, 10, and 20 from Gpg that were fed or not at day 0 on Tbg—hosting mice, these DGE lists were obtained from RNA seq—based approaches. Here, post the mapping on the quality controlled DEGs on the Gmm genome, the identified ortholog genes were further annotated, the resulting datasets being compared. Around 50% of the Gpg DEGs were shown to have orthologs in the Gmm genome. Under one of the three Glossina midgut sampling conditions, the number of DEGs was even higher when mapping on the Gmm genome than initially recorded. Many Gmm genes annotated as “Hypothetical” were mapped and annotated on many distinct databases allowing some of them to be properly identified. We identify Glossina fly candidate genes encoding (a) a broad panel of proteases as well as (b) chitin—binding proteins, (c) antimicrobial peptide production—Pro3 protein, transferrin, mucin, atttacin, cecropin, etc—to further select in functional studies, the objectives being to probe and validated fly genome manipulation that prevents the onset of the developmental program of one or the other T. brucei spp. stumpy form sampled by one of the other bloodfeeding Glossina subspecies.
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Affiliation(s)
| | - Bernadette Tchicaya
- UMR 177, Institut de Recherche pour le Développement-CIRAD, CIRAD TA A-17/GMontpellier, France
| | - Stéphanie Rialle
- Centre National de la Recherche Scientifique Unité Mixte de Recherche 5203, Institut de Génomique FonctionnelleMontpellier, France.,Institut National de la Santé Et de la Recherche Médicale U661Montpellier, France.,Universités de Montpellier 1 and 2, UMR 5203Montpellier, France.,Montpellier GenomiX, c/o Institut de Génomique FonctionnelleMontpellier, France
| | - Hugues Parrinello
- Centre National de la Recherche Scientifique Unité Mixte de Recherche 5203, Institut de Génomique FonctionnelleMontpellier, France.,Institut National de la Santé Et de la Recherche Médicale U661Montpellier, France.,Universités de Montpellier 1 and 2, UMR 5203Montpellier, France.,Montpellier GenomiX, c/o Institut de Génomique FonctionnelleMontpellier, France
| | - Anne Geiger
- UMR 177, Institut de Recherche pour le Développement-CIRAD, CIRAD TA A-17/GMontpellier, France
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Shanbhag SR, Vazhappilly AT, Sane A, D'Silva NM, Tripathi S. Electrolyte transport pathways induced in the midgut epithelium of Drosophila melanogaster larvae by commensal gut microbiota and pathogens. J Physiol 2016; 595:523-539. [PMID: 27373966 DOI: 10.1113/jp272617] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Accepted: 06/20/2016] [Indexed: 02/01/2023] Open
Abstract
KEY POINTS The digestive tract of larval and adult Drosophila is an excellent analogue of the mammalian gut. Enterocytes of the posterior midgut are separated by septa, with no paracellular path, and therefore perform both immune and transport functions. Using microperfusion electrophysiology, we show that larvae emerging from the embryo into sterile medium have symmetrical apical and basal membrane conductances while larvae emerging into non-sterile medium have apical membranes fivefold more conductive than basal membranes. The channels inserted into the apical membranes could originate in microbiata or host and mediate recognition of microbes. Entomopathogenic cyclic peptide toxins deplete intracellular ions reversibly, forming transient ion channels that do not conduct water, unlike an ionophore like nystatin that depletes ions irreversibly. We show the feasibility of studying the interaction of a single microbial species, or tractable combinatorials of microbial species, with only enterocytes in the primary epithelial barrier. ABSTRACT Microbiota colonizing exposed epithelial surfaces are vital for sustenance of metazoan life, but communication between microbiota, epithelial cells and the host immune system is only beginning to be understood. We address this issue in the posterior midgut epithelium of Drosophila larvae where nutrient transport and immune functions are exclusively transcellular. We showed that larvae emerging into a sterile post-embryonic environment have symmetrical apical and basal membranes. In contrast, larvae emerging into non-sterile media, the source of microbiota, have markedly asymmetrical membranes, with apical membrane conductance more than fivefold higher than the basal membrane. As an example of pathogen action, we showed that the entomopathogenic fungal toxin destruxin A (Dx) depleted intracellular ions. Reversibility of action of Dx was verified by bilayer reconstitution in forming transient non-specific channels that conduct ions but not water. Dx was also less effective from the apical side as compared to the basal side of the epithelium. We also showed that intercellular septa are not conductive in non-sterile cells, even though most cells are isopotential. Luminal microbiota therefore impart asymmetry to the epithelium, by activation of apical membrane conductance, enhancing inter-enterocyte communication, separated by insulating septa, via the gut lumen. These results also open the possibility of studying the basis of bidirectional molecular conversation specifically between enterocytes and microbiota that enables discrimination between commensals and pathogens, establishment of the former, and elimination of the latter.
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Affiliation(s)
- Shubha R Shanbhag
- Tata Institute of Fundamental Research, Colaba, Mumbai, 400 005, India
| | | | - Abhay Sane
- Tata Institute of Fundamental Research, Colaba, Mumbai, 400 005, India
| | - Natalie M D'Silva
- Tata Institute of Fundamental Research, Colaba, Mumbai, 400 005, India
| | - Subrata Tripathi
- Tata Institute of Fundamental Research, Colaba, Mumbai, 400 005, India.,Institute of Physics, Sachivalaya Marg, Bhubaneswar, 751 005, India
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Peacock L, Bailey M, Gibson W. Dynamics of gamete production and mating in the parasitic protist Trypanosoma brucei. Parasit Vectors 2016; 9:404. [PMID: 27439767 PMCID: PMC4955137 DOI: 10.1186/s13071-016-1689-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 07/10/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Sexual reproduction in Plasmodium falciparum and Trypanosoma brucei occurs in the insect vector and is important in generating hybrid strains with different combinations of parental characteristics. Production of hybrid parasite genotypes depends on the likelihood of co-infection of the vector with multiple strains. In mosquitoes, existing infection with Plasmodium facilitates the establishment of a second infection, although the asynchronicity of gamete production subsequently prevents mating. In the trypanosome/tsetse system, flies become increasingly refractory to infection as they age, so the likelihood of a fly acquiring a second infection also decreases. This effectively restricts opportunities for trypanosome mating to co-infections picked up by the fly on its first feed, unless an existing infection increases the chance of successful second infection as in the Plasmodium/mosquito system. RESULTS Using green and red fluorescent trypanosomes, we compared the rates of trypanosome infection and hybrid production in flies co-infected on the first feed, co-infected on a subsequent feed 18 days after emergence, or fed sequentially with each trypanosome clone 18 days apart. Infection rates were highest in the midguts and salivary glands (SG) of flies that received both trypanosome clones in their first feed, and were halved when the infected feed was delayed to day 18. In flies fed the two trypanosome clones sequentially, the second clone often failed to establish a midgut infection and consequently was not present in the SG. Nevertheless, hybrids were recovered from all three groups of infected flies. Meiotic stages and gametes were produced continuously from day 11 to 42 after the infective feed, and in sequentially infected flies, the co-occurrence of gametes led to hybrid formation. CONCLUSIONS We found that a second trypanosome strain can establish infection in the tsetse SG 18 days after the first infected feed, with co-mingling of gametes and production of trypanosome hybrids. Establishment of the second strain was severely compromised by the strong immune response of the fly to the existing infection. Although sequential infection provides an opportunity for trypanosome mating, the easiest way for a tsetse fly to acquire a mixed infection is by feeding on a co-infected host.
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Affiliation(s)
- Lori Peacock
- School of Biological Sciences, University of Bristol, Bristol, BS8 1TQ, UK.,School of Clinical Veterinary Science, University of Bristol, Langford, Bristol, BS40 7DU, UK
| | - Mick Bailey
- School of Clinical Veterinary Science, University of Bristol, Langford, Bristol, BS40 7DU, UK
| | - Wendy Gibson
- School of Biological Sciences, University of Bristol, Bristol, BS8 1TQ, UK.
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VSG overcomes an early barrier to survival of African trypanosomes in tsetse flies. Proc Natl Acad Sci U S A 2016; 113:6821-3. [PMID: 27286826 DOI: 10.1073/pnas.1607008113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Aksoy E, Vigneron A, Bing X, Zhao X, O'Neill M, Wu YN, Bangs JD, Weiss BL, Aksoy S. Mammalian African trypanosome VSG coat enhances tsetse's vector competence. Proc Natl Acad Sci U S A 2016; 113:6961-6. [PMID: 27185908 PMCID: PMC4922192 DOI: 10.1073/pnas.1600304113] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Tsetse flies are biological vectors of African trypanosomes, the protozoan parasites responsible for causing human and animal trypanosomiases across sub-Saharan Africa. Currently, no vaccines are available for disease prevention due to antigenic variation of the Variant Surface Glycoproteins (VSG) that coat parasites while they reside within mammalian hosts. As a result, interference with parasite development in the tsetse vector is being explored to reduce disease transmission. A major bottleneck to infection occurs as parasites attempt to colonize tsetse's midgut. One critical factor influencing this bottleneck is the fly's peritrophic matrix (PM), a semipermeable, chitinous barrier that lines the midgut. The mechanisms that enable trypanosomes to cross this barrier are currently unknown. Here, we determined that as parasites enter the tsetse's gut, VSG molecules released from trypanosomes are internalized by cells of the cardia-the tissue responsible for producing the PM. VSG internalization results in decreased expression of a tsetse microRNA (mir-275) and interferes with the Wnt-signaling pathway and the Iroquois/IRX transcription factor family. This interference reduces the function of the PM barrier and promotes parasite colonization of the gut early in the infection process. Manipulation of the insect midgut homeostasis by the mammalian parasite coat proteins is a novel function and indicates that VSG serves a dual role in trypanosome biology-that of facilitating transmission through its mammalian host and insect vector. We detail critical steps in the course of trypanosome infection establishment that can serve as novel targets to reduce the tsetse's vector competence and disease transmission.
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Affiliation(s)
- Emre Aksoy
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, Yale University, New Haven, CT 06520
| | - Aurélien Vigneron
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, Yale University, New Haven, CT 06520
| | - XiaoLi Bing
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, Yale University, New Haven, CT 06520
| | - Xin Zhao
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, Yale University, New Haven, CT 06520
| | - Michelle O'Neill
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, Yale University, New Haven, CT 06520
| | - Yi-Neng Wu
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, Yale University, New Haven, CT 06520
| | - James D Bangs
- Department of Microbiology and Immunology, University at Buffalo (SUNY), Buffalo, NY 14214
| | - Brian L Weiss
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, Yale University, New Haven, CT 06520;
| | - Serap Aksoy
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, Yale University, New Haven, CT 06520;
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Hillyer JF. Insect immunology and hematopoiesis. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2016; 58:102-18. [PMID: 26695127 PMCID: PMC4775421 DOI: 10.1016/j.dci.2015.12.006] [Citation(s) in RCA: 280] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Revised: 12/08/2015] [Accepted: 12/10/2015] [Indexed: 05/08/2023]
Abstract
Insects combat infection by mounting powerful immune responses that are mediated by hemocytes, the fat body, the midgut, the salivary glands and other tissues. Foreign organisms that have entered the body of an insect are recognized by the immune system when pathogen-associated molecular patterns bind host-derived pattern recognition receptors. This, in turn, activates immune signaling pathways that amplify the immune response, induce the production of factors with antimicrobial activity, and activate effector pathways. Among the immune signaling pathways are the Toll, Imd, Jak/Stat, JNK, and insulin pathways. Activation of these and other pathways leads to pathogen killing via phagocytosis, melanization, cellular encapsulation, nodulation, lysis, RNAi-mediated virus destruction, autophagy and apoptosis. This review details these and other aspects of immunity in insects, and discusses how the immune and circulatory systems have co-adapted to combat infection, how hemocyte replication and differentiation takes place (hematopoiesis), how an infection prepares an insect for a subsequent infection (immune priming), how environmental factors such as temperature and the age of the insect impact the immune response, and how social immunity protects entire groups. Finally, this review highlights some underexplored areas in the field of insect immunobiology.
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Affiliation(s)
- Julián F Hillyer
- Department of Biological Sciences, Vanderbilt University, VU Station B 35-1634, Nashville, TN 37235, USA.
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Zhu KY, Merzendorfer H, Zhang W, Zhang J, Muthukrishnan S. Biosynthesis, Turnover, and Functions of Chitin in Insects. ANNUAL REVIEW OF ENTOMOLOGY 2016; 61:177-96. [PMID: 26982439 DOI: 10.1146/annurev-ento-010715-023933] [Citation(s) in RCA: 211] [Impact Index Per Article: 26.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Chitin is a major component of the exoskeleton and the peritrophic matrix of insects. It forms complex structures in association with different assortments of cuticle and peritrophic matrix proteins to yield biocomposites with a wide range of physicochemical and mechanical properties. The growth and development of insects are intimately coupled with the biosynthesis, turnover, and modification of chitin. The genes encoding numerous enzymes of chitin metabolism and proteins that associate with and organize chitin have been uncovered by bioinformatics analyses. Many of these proteins are encoded by sets of large gene families. There is specialization among members within each family, which function in particular tissues or developmental stages. Chitin-containing matrices are dynamically modified at every developmental stage and are under developmental and/or physiological control. A thorough understanding of the diverse processes associated with the assembly and turnover of these chitinous matrices offers many strategies to achieve selective pest control.
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Affiliation(s)
| | | | - Wenqing Zhang
- State Key Laboratory of Biocontrol and School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China;
| | - Jianzhen Zhang
- Research Institute of Applied Biology, Shanxi University, Taiyuan, Shanxi 030006, China;
| | - Subbaratnam Muthukrishnan
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, Kansas 66506; ,
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Talyuli OAC, Bottino-Rojas V, Taracena ML, Soares ALM, Oliveira JHM, Oliveira PL. The use of a chemically defined artificial diet as a tool to study Aedes aegypti physiology. JOURNAL OF INSECT PHYSIOLOGY 2015; 83:1-7. [PMID: 26578294 DOI: 10.1016/j.jinsphys.2015.11.007] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Revised: 11/04/2015] [Accepted: 11/05/2015] [Indexed: 06/05/2023]
Abstract
Aedes aegypti mosquitoes obtain from vertebrate blood nutrients that are essential to oogenesis, such as proteins and lipids. As with all insects, mosquitoes do not synthesize cholesterol but take it from the diet. Here, we used a chemically defined artificial diet, hereafter referred to as Substitute Blood Meal (SBM), that was supplemented with cholesterol to test the nutritional role of cholesterol. SBM-fed and blood-fed mosquitoes were compared regarding several aspects of the insect physiology that are influenced by a blood meal, including egg laying, peritrophic matrix formation, gut microbiota proliferation, generation of reactive oxygen species (ROS) and expression of antioxidant genes, such as catalase and ferritin. Our results show that SBM induced a physiological response that was very similar to a regular blood meal. Depending on the nutritional life history of the mosquito since the larval stage, the presence of cholesterol in the diet increased egg development, suggesting that the teneral reserves of cholesterol in the newly hatched female are determinant of reproductive performance. We propose here the use of SBM as a tool to study other aspects of the physiology of mosquitoes, including their interaction with microbiota and pathogens.
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Affiliation(s)
- Octávio A C Talyuli
- Programa de Biologia Molecular e Biotecnologia, Instituto de Bioquímica Médica Leopoldo de Meis, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-590, Brazil; Instituto Biomédico, Universidade Federal do Estado do Rio de Janeiro, Brazil
| | - Vanessa Bottino-Rojas
- Programa de Biologia Molecular e Biotecnologia, Instituto de Bioquímica Médica Leopoldo de Meis, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-590, Brazil
| | - Mabel L Taracena
- Programa de Biologia Molecular e Biotecnologia, Instituto de Bioquímica Médica Leopoldo de Meis, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-590, Brazil
| | - Ana Luiza Macedo Soares
- Programa de Biologia Molecular e Biotecnologia, Instituto de Bioquímica Médica Leopoldo de Meis, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-590, Brazil; Instituto Biomédico, Universidade Federal do Estado do Rio de Janeiro, Brazil
| | - José Henrique M Oliveira
- Programa de Biologia Molecular e Biotecnologia, Instituto de Bioquímica Médica Leopoldo de Meis, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-590, Brazil
| | - Pedro L Oliveira
- Programa de Biologia Molecular e Biotecnologia, Instituto de Bioquímica Médica Leopoldo de Meis, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-590, Brazil; Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular (INCT-EM), Brazil.
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Hamidou Soumana I, Klopp C, Ravel S, Nabihoudine I, Tchicaya B, Parrinello H, Abate L, Rialle S, Geiger A. RNA-seq de novo Assembly Reveals Differential Gene Expression in Glossina palpalis gambiensis Infected with Trypanosoma brucei gambiense vs. Non-Infected and Self-Cured Flies. Front Microbiol 2015; 6:1259. [PMID: 26617594 PMCID: PMC4643127 DOI: 10.3389/fmicb.2015.01259] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Accepted: 10/29/2015] [Indexed: 12/24/2022] Open
Abstract
Trypanosoma brucei gambiense (Tbg), causing the sleeping sickness chronic form, completes its developmental cycle within the tsetse fly vector Glossina palpalis gambiensis (Gpg) before its transmission to humans. Within the framework of an anti-vector disease control strategy, a global gene expression profiling of trypanosome infected (susceptible), non-infected, and self-cured (refractory) tsetse flies was performed, on their midguts, to determine differential genes expression resulting from in vivo trypanosomes, tsetse flies (and their microbiome) interactions. An RNAseq de novo assembly was achieved. The assembled transcripts were mapped to reference sequences for functional annotation. Twenty-four percent of the 16,936 contigs could not be annotated, possibly representing untranslated mRNA regions, or Gpg- or Tbg-specific ORFs. The remaining contigs were classified into 65 functional groups. Only a few transposable elements were present in the Gpg midgut transcriptome, which may represent active transpositions and play regulatory roles. One thousand three hundred and seventy three genes differentially expressed (DEGs) between stimulated and non-stimulated flies were identified at day-3 post-feeding; 52 and 1025 between infected and self-cured flies at 10 and 20 days post-feeding, respectively. The possible roles of several DEGs regarding fly susceptibility and refractoriness are discussed. The results provide new means to decipher fly infection mechanisms, crucial to develop anti-vector control strategies.
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Affiliation(s)
| | - Christophe Klopp
- Institut National de la Recherche Agronomique, GenoToul, UR875 Castanet-Tolosan, France
| | - Sophie Ravel
- UMR 177, Institut de Recherche Pour le Développement-CIRAD, CIRAD TA A-17/G Montpellier, France
| | | | - Bernadette Tchicaya
- UMR 177, Institut de Recherche Pour le Développement-CIRAD, CIRAD TA A-17/G Montpellier, France
| | - Hugues Parrinello
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5203, Institut de Génomique Fonctionnelle Montpellier, France ; Institut National de la Santé et de la Recherche Médicale U661 Montpellier, France ; Universités de Montpellier 1 and 2, UMR 5203 Montpellier, France ; Montpellier GenomiX, Institut de Génomique Fonctionnelle Montpellier, France
| | - Luc Abate
- UMR MIVEGEC (Institut de Recherche pour le Développement 224-Centre National de la Recherche Scientifique 5290-UM1-UM2), Institut de Recherche pour le Développement Montpellier, France
| | - Stéphanie Rialle
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5203, Institut de Génomique Fonctionnelle Montpellier, France ; Institut National de la Santé et de la Recherche Médicale U661 Montpellier, France ; Universités de Montpellier 1 and 2, UMR 5203 Montpellier, France ; Montpellier GenomiX, Institut de Génomique Fonctionnelle Montpellier, France
| | - Anne Geiger
- UMR 177, Institut de Recherche Pour le Développement-CIRAD, CIRAD TA A-17/G Montpellier, France
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Abstract
Trypanosomatid parasites are significant causes of human disease and are ubiquitous in insects. Despite the importance of Drosophila melanogaster as a model of infection and immunity and a long awareness that trypanosomatid infection is common in the genus, no trypanosomatid parasites naturally infecting Drosophila have been characterized. Here, we establish a new model of trypanosomatid infection in Drosophila—Jaenimonas drosophilae, gen. et sp. nov. As far as we are aware, this is the first Drosophila-parasitic trypanosomatid to be cultured and characterized. Through experimental infections, we find that Drosophila falleni, the natural host, is highly susceptible to infection, leading to a substantial decrease in host fecundity. J. drosophilae has a broad host range, readily infecting a number of Drosophila species, including D. melanogaster, with oral infection of D. melanogaster larvae resulting in the induction of numerous immune genes. When injected into adult hemolymph, J. drosophilae kills D. melanogaster, although interestingly, neither the Imd nor the Toll pathway is induced and Imd mutants do not show increased susceptibility to infection. In contrast, mutants deficient in drosocrystallin, a major component of the peritrophic matrix, are more severely infected during oral infection, suggesting that the peritrophic matrix plays an important role in mediating trypanosomatid infection in Drosophila. This work demonstrates that the J. drosophilae-Drosophila system can be a powerful model to uncover the effects of trypanosomatids in their insect hosts. Trypanosomatid parasites are ubiquitous in insects and are significant causes of disease when vectored to humans by blood-feeding insects. In recent decades, Drosophila has emerged as the predominant insect model of infection and immunity and is also known to be infected by trypanosomatids at high rates in the wild. Despite this, there has been almost no work on their trypanosomatid parasites, in part because Drosophila-specific trypanosomatids have been resistant to culturing. Here, we present the first isolation and detailed characterization of a trypanosomatid from Drosophila, finding that it represents a new genus and species, Jaenimonas drosophilae. Using this parasite, we conducted a series of experiments that revealed many of the unknown aspects of trypanosomatid infection in Drosophila, including host range, transmission biology, dynamics of infection, and host immune response. Taken together, this work establishes J. drosophilae as a powerful new opportunity to study trypanosomatid infections in insects.
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TonB-dependent heme iron acquisition in the tsetse fly symbiont Sodalis glossinidius. Appl Environ Microbiol 2015; 81:2900-9. [PMID: 25681181 DOI: 10.1128/aem.04166-14] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Sodalis glossinidius is an intra- and extracellular symbiont of the tsetse fly (Glossina sp.), which feeds exclusively on vertebrate blood. S. glossinidius resides in a wide variety of tsetse tissues and may encounter environments that differ dramatically in iron content. The Sodalis chromosome encodes a putative TonB-dependent outer membrane heme transporter (HemR) and a putative periplasmic/inner membrane ABC heme permease system (HemTUV). Because these gene products mediate iron acquisition processes by other enteric bacteria, we characterized their regulation and physiological role in the Sodalis/tsetse system. Our results show that the hemR and tonB genes are expressed by S. glossinidius in the tsetse fly. Furthermore, transcription of hemR in Sodalis is repressed in a high-iron environment by the iron-responsive transcriptional regulator Fur. Expression of the S. glossinidius hemR and hemTUV genes in an Escherichia coli strain unable to use heme as an iron source stimulated growth in the presence of heme or hemoglobin as the sole iron source. This stimulation was dependent on the presence of either the E. coli or Sodalis tonB gene. Sodalis tonB and hemR mutant strains were defective in their ability to colonize the gut of tsetse flies that lacked endogenous symbionts, while wild-type S. glossinidius proliferated in this same environment. Finally, we show that the Sodalis HemR protein is localized to the bacterial membrane and appears to bind hemin. Collectively, this study provides strong evidence that TonB-dependent, HemR-mediated iron acquisition is important for the maintenance of symbiont homeostasis in the tsetse fly, and it provides evidence for the expression of bacterial high-affinity iron acquisition genes in insect symbionts.
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Aksoy S, Weiss BL, Attardo GM. Trypanosome Transmission Dynamics in Tsetse. CURRENT OPINION IN INSECT SCIENCE 2014; 3:43-49. [PMID: 25580379 PMCID: PMC4286356 DOI: 10.1016/j.cois.2014.07.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Tsetse flies (Diptera:Glossinidae) are vectors of African trypanosomes. Tsetse undergo viviparous reproductive biology, and depend on their obligate endosymbiont (genus Wigglesworthia) for the maintenance of fecundity and immune system development. Trypanosomes establish infections in the midgut and salivary glands of the fly. Tsetse's resistance to trypanosome infection increases as a function of age. Among the factors that mediate resistance to parasites are antimicrobial peptides (AMPs) produced by the Immune deficiency (Imd) signaling pathway, peptidoglycan recognition protein (PGRP) LB, tsetse-EP protein and the integrity of the midgut peritrophic matrix (PM) barrier. The presence of obligate Wigglesworthia during larval development is essential for adult immune system maturation and PM development. Thus, Wigglesworthia prominently influences the vector competency of it's tsetse host.
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