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Toledo R, Cociancic P, Fiallos E, Esteban JG, Muñoz-Antoli C. Immunology and pathology of echinostomes and other intestinal trematodes. ADVANCES IN PARASITOLOGY 2024; 124:1-55. [PMID: 38754926 DOI: 10.1016/bs.apar.2024.02.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2024]
Abstract
Intestinal trematodes constitute a major group of helminths that parasitize humans and animals with relevant morbidity and mortality. Despite the importance of the intestinal trematodes in medical and veterinary sciences, immunology and pathology of these helminth infections have been neglected for years. Apart from the work focused on the members of the family Echnistomatidae, there are only very isolated and sporadic studies on the representatives of other families of digeneans, which makes a compilation of all these studies necessary. In the present review, the most salient literature on the immunology and pathology of intestinal trematodes in their definitive hosts in examined. Emphasis will be placed on members of the echinostomatidae family, since it is the group in which the most work has been carried out. However, we also review the information on selected species of the families Brachylaimidae, Diplostomidae, Gymnophallidae, and Heterophyidae. For most of these families, coverage is considered under the following headings: (i) Background; (ii) Pathology of the infection; (iii) Immunology of the infection; and (iv) Human infections.
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Affiliation(s)
- Rafael Toledo
- Department of Pharmacy and Pharmaceutical Technology and Parasitology, Faculty of Pharmacy, University of Valencia, Valencia, Spain.
| | - Paola Cociancic
- Department of Pharmacy and Pharmaceutical Technology and Parasitology, Faculty of Pharmacy, University of Valencia, Valencia, Spain
| | - Emma Fiallos
- Department of Pharmacy and Pharmaceutical Technology and Parasitology, Faculty of Pharmacy, University of Valencia, Valencia, Spain
| | - J Guillermo Esteban
- Department of Pharmacy and Pharmaceutical Technology and Parasitology, Faculty of Pharmacy, University of Valencia, Valencia, Spain
| | - Carla Muñoz-Antoli
- Department of Pharmacy and Pharmaceutical Technology and Parasitology, Faculty of Pharmacy, University of Valencia, Valencia, Spain
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Salvia R, Rico LG, Ward MD, Bradford JA, Petriz J. Functional Flow Cytometry to Predict PD-L1 Conformational Changes. Curr Protoc 2023; 3:e944. [PMID: 38100257 DOI: 10.1002/cpz1.944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2023]
Abstract
The programmed cell death protein 1/programmed cell death protein ligand 1 (PD-1/PD-L1) axis is one of the most widely recognized targets for cancer immunotherapy. Importantly, PD-L1 conformational changes can hinder target binding when living cells are used. Antibody affinity, equilibrium binding, association and dissociation rates, and other affinity-related constants are fundamental to ensure target saturation. Here, PD-L1 changes in conformation and their potential impact on PD-L1 function and mutation are explored. Specifically, we present detailed flow cytometry procedures to analyze PD-L1 reactivity in myeloid-derived suppressor cells (MDSCs). This approach can also be used to study the contribution of protein conformational changes in living cells. © 2023 Wiley Periodicals LLC. Basic Protocol 1: Sample preparation for PD-L1+ myeloid-derived suppressor cells detection by flow cytometry Basic Protocol 2: Protocol preparation, sample acquisition, and gating strategy for flow cytometric screening of PD-L1+ myeloid-derived suppressor cells in patients with lung cancer Support Protocol 1: Bioinformatic tools for the analysis of flow cytometric data.
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Affiliation(s)
- Roser Salvia
- Functional Cytomics Lab, Germans Trias i Pujol Research Institute (IGTP), Universitat Autònoma de Barcelona, Badalona, Barcelona, Spain
| | - Laura G Rico
- Functional Cytomics Lab, Germans Trias i Pujol Research Institute (IGTP), Universitat Autònoma de Barcelona, Badalona, Barcelona, Spain
| | | | | | - Jordi Petriz
- Functional Cytomics Lab, Germans Trias i Pujol Research Institute (IGTP), Universitat Autònoma de Barcelona, Badalona, Barcelona, Spain
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3
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Feng X, BaiMaYangJin, Mo X, Zhang F, Hu W, Feng Z, Zhang T, Wei L, Lu H. IgG glycomic profiling identifies potential biomarkers for diagnosis of echinococcosis. J Chromatogr B Analyt Technol Biomed Life Sci 2023; 1227:123838. [PMID: 37540936 DOI: 10.1016/j.jchromb.2023.123838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 06/25/2023] [Accepted: 07/18/2023] [Indexed: 08/06/2023]
Abstract
Echinococcosis caused by larval stage of the genus Echinococcus, is a serious and potentially fatal parasitic zoonosis distributed globally. The two types of the disease in human are cystic echinococcosis (CE) and alveolar echinococcosis (AE). As the biological and encysting characteristics of the parasite, early diagnosis remains to address. In the present study, we demonstrate the value of Immunoglobulin G (IgG) glycome as a potential diagnostic biomarker for echinococcosis. Serum IgG glycome profiles were analyzed by ultra-performance liquid chromatography in a cohort comprised of 127 echinococcosis patients, of them 98 were diagnosed as CE and 29 as AE. IgG N-glycome analysis in pretreatment serum of echinococcosis patients presents 25 glycans and 64 derived traits. Compared with IgG glycans of healthy control group, neutral glycans, fucosylation and agalactosylated N-glycans increased while sialylation and galactosylation decreased in echinococcosis patients. Combined with a machine-learning-based approach, we built three biomarker combinations to distinguish CE, AE and healthy controls. Meanwhile, galactosylation, sialylation and A2BG2S1 in IgG glycan profiles were evidently associated with different types of CE (from CE1 to CE5). Our findings suggest that the alterations in IgG N-glycome may be of value in CE and AE diagnosis and follow-up CE disease progress. The role of IgG N-glycans as diagnostic biomarker remains to be verified in future study.
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Affiliation(s)
- Xiaoxiao Feng
- The Fifth People's Hospital of Shanghai, Institutes of Biomedical Sciences, Shanghai Cancer Center, Department of Chemistry & NHC Key Laboratory of Glycoconjugates Research, Fudan University, Shanghai 200032, People's Republic of China
| | - BaiMaYangJin
- National Health Commission Key Laboratory of Echinococcosis Prevention and Control, Xizang Center for Disease Control and Prevention, Lhasa 850000, Tibet Autonomous Region, People's Republic of China
| | - Xiaojin Mo
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention (Chinese Center for Tropical Diseases Research), NHC Key Laboratory of Parasite and Vector Biology, WHO Collaborating Center for Tropical Diseases, National Center for International Research on Tropical Diseases, Shanghai 200025, People's Republic of China
| | - Fangyan Zhang
- Waters Technologies, Pudong New District, Shanghai 201203, People's Republic of China
| | - Wei Hu
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention (Chinese Center for Tropical Diseases Research), NHC Key Laboratory of Parasite and Vector Biology, WHO Collaborating Center for Tropical Diseases, National Center for International Research on Tropical Diseases, Shanghai 200025, People's Republic of China
| | - Zheng Feng
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention (Chinese Center for Tropical Diseases Research), NHC Key Laboratory of Parasite and Vector Biology, WHO Collaborating Center for Tropical Diseases, National Center for International Research on Tropical Diseases, Shanghai 200025, People's Republic of China
| | - Ting Zhang
- National Health Commission Key Laboratory of Echinococcosis Prevention and Control, Xizang Center for Disease Control and Prevention, Lhasa 850000, Tibet Autonomous Region, People's Republic of China; National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention (Chinese Center for Tropical Diseases Research), NHC Key Laboratory of Parasite and Vector Biology, WHO Collaborating Center for Tropical Diseases, National Center for International Research on Tropical Diseases, Shanghai 200025, People's Republic of China.
| | - Liming Wei
- The Fifth People's Hospital of Shanghai, Institutes of Biomedical Sciences, Shanghai Cancer Center, Department of Chemistry & NHC Key Laboratory of Glycoconjugates Research, Fudan University, Shanghai 200032, People's Republic of China.
| | - Haojie Lu
- The Fifth People's Hospital of Shanghai, Institutes of Biomedical Sciences, Shanghai Cancer Center, Department of Chemistry & NHC Key Laboratory of Glycoconjugates Research, Fudan University, Shanghai 200032, People's Republic of China.
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Abstract
In the present paper, we review two of the most neglected intestinal food-borne trematodiases: echinostomiasis, caused by members of the family Echinostomatidae, and gastrodiscoidiasis produced by the amphistome Gastrodiscoides hominis. Both parasitic infections are important intestinal food-borne diseases. Humans become infected after ingestion of raw or insufficiently cooked molluscs, fish, crustaceans, amphibians or aquatic vegetables. Thus, eating habits are essential to determine the distribution of these parasitic diseases and, traditionally, they have been considered as minor diseases confined to low-income areas, mainly in Asia. However, this scenario is changing and the population at risk are currently expanding in relation to factors such as new eating habits in developed countries, growing international markets, improved transportation systems and demographic changes. These aspects determine the necessity of a better understanding of these parasitic diseases. Herein, we review the main features of human echinostomiasis and gastrodiscoidiasis in relation to their biology, epidemiology, immunology, clinical aspects, diagnosis and treatment.
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Salazar ML, Jiménez JM, Villar J, Rivera M, Báez M, Manubens A, Becker MI. N-Glycosylation of mollusk hemocyanins contributes to their structural stability and immunomodulatory properties in mammals. J Biol Chem 2019; 294:19546-19564. [PMID: 31719148 PMCID: PMC6926458 DOI: 10.1074/jbc.ra119.009525] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 10/29/2019] [Indexed: 12/16/2022] Open
Abstract
Hemocyanins are widely used as carriers, adjuvants, and nonspecific immunostimulants in cancer because they promote Th1 immunity in mammals. Hemocyanins also interact with glycan-recognizing innate immune receptors on antigen-presenting cells, such as the C-type lectin immune receptors mannose receptor (MR), macrophage galactose lectin (MGL), and the Toll-like receptors (TLRs), stimulating proinflammatory cytokine secretion. However, the role of N-linked oligosaccharides on the structural and immunological properties of hemocyanin is unclear. Mollusk hemocyanins, such as Concholepas concholepas (CCH), Fissurella latimarginata (FLH), and Megathura crenulata (KLH), are oligomeric glycoproteins with complex dodecameric quaternary structures and heterogeneous glycosylation patterns, primarily consisting of mannose-rich N-glycans. Here, we report that enzyme-catalyzed N-deglycosylation of CCH, FLH, and KLH disrupts their quaternary structure and impairs their immunogenic effects. Biochemical analyses revealed that the deglycosylation does not change hemocyanin secondary structure but alters their refolding mechanism and dodecameric structure. Immunochemical analyses indicated decreased binding of N-deglycosylated hemocyanins to the MR and MGL receptors and TLR4 and reduced endocytosis concomitant with an impaired production of tumor necrosis factor α, and interleukins 6 and 12 (IL-6 and IL-12p40, respectively) in macrophages. Evaluating the function of N-deglycosylated hemocyanins in the humoral immune response and their nonspecific antitumor effects in the B16F10 melanoma model, we found that compared with native hemocyanins N-deglycosylated hemocyanins elicited reduced antibody titers, as well as partially diminished antitumor effects and altered carrier activities. In conclusion, the glycan content of hemocyanins is, among other structural characteristics, critically required for their immunological activities and should be considered in biomedical applications.
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Affiliation(s)
- Michelle L Salazar
- Fundación Ciencia y Tecnología para el Desarrollo (FUCITED), Santiago 7750269, Chile
| | - José M Jiménez
- Fundación Ciencia y Tecnología para el Desarrollo (FUCITED), Santiago 7750269, Chile
| | - Javiera Villar
- Fundación Ciencia y Tecnología para el Desarrollo (FUCITED), Santiago 7750269, Chile
| | - Maira Rivera
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santiago 8380494, Chile
| | - Mauricio Báez
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santiago 8380494, Chile
| | - Augusto Manubens
- Departamento de Investigación y Desarrollo, Biosonda Corp., Santiago 7750269, Chile
| | - María Inés Becker
- Fundación Ciencia y Tecnología para el Desarrollo (FUCITED), Santiago 7750269, Chile .,Departamento de Investigación y Desarrollo, Biosonda Corp., Santiago 7750269, Chile
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Benabdessalem C, Othman H, Ouni R, Ghouibi N, Dahman A, Riahi R, Larguach B, Srairi-Abid N, Barbouche MR, Fathallah MD. N-glycosylation and homodimeric folding significantly enhance the immunoreactivity of Mycobacterium tuberculosis virulence factor CFP32 when produced in the yeast Pichia pastoris. Biochem Biophys Res Commun 2019; 516:845-850. [PMID: 31262446 DOI: 10.1016/j.bbrc.2019.06.140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Accepted: 06/25/2019] [Indexed: 11/18/2022]
Abstract
We previously reported that immunoreactivity of recombinant CFP32 (Rv0577), a virulence factor of Mycobacterium tuberculosis, was higher when produced in transformed Pichia pastoris as compared to transformed E. coli. In this study, we show that this difference is partly due to the N-glycosylation of the recombinant CFP32 (rCFP32) by the yeast Pichia pastoris. In addition, SDS-PAGE and western blotting analysis of Mycobacterium bovis BCG and yeast-produced rCFP32 showed the presence of a band corresponding to a homodimeric state of the protein, unlike that of rCFP32 produced in E. coli. Computational modeling indicates that a single cysteine residue at position 193 of each monomer might bond to stabilize the homodimeric state of CFP32. Computational study showed that this residue is buried inside the protein core of E. coli-produced rCFP32 suggesting that rCFP32 may adopt a different folding in P. pastoris and BCG, in which C193 is solvent exposed. Surprisingly, an enzyme-linked immunosorbent assay using a generated monoclonal antibody (14D4) reveals the presence of a differential epitope that appears to be the consequence of the protein dimerization of the yeast- and BCG-, but not E.coli- produced, CFP32 recombinant form. We conclude that, in addition to N-glycosylation, homodimeric folding significantly enhances the immunoreactivity of rCFP32 and may these post-translational modifications may factor into the structure and function of native M. tuberculosis CFP32.
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Affiliation(s)
- Chaouki Benabdessalem
- Laboratory of Transmission, Control and Immunobiology of Infection - LR11IPT-02, Institut Pasteur de Tunis, Tunisia; University Tunis El Manar, Tunisia.
| | - Houcemeddine Othman
- Université de Tunis El Manar, Institut Pasteur de Tunis, LR16IPT08 Venins et Biomolécules Thérapeutiques, 1002, Tunis, Tunisia
| | - Rym Ouni
- Laboratory of Transmission, Control and Immunobiology of Infection - LR11IPT-02, Institut Pasteur de Tunis, Tunisia; University of Carthage, Tunisia
| | - Nabila Ghouibi
- Laboratory of Transmission, Control and Immunobiology of Infection - LR11IPT-02, Institut Pasteur de Tunis, Tunisia; University Tunis El Manar, Tunisia
| | - Amira Dahman
- Laboratory of Transmission, Control and Immunobiology of Infection - LR11IPT-02, Institut Pasteur de Tunis, Tunisia
| | - Rachid Riahi
- Laboratory of Transmission, Control and Immunobiology of Infection - LR11IPT-02, Institut Pasteur de Tunis, Tunisia
| | - Beya Larguach
- Laboratory of Transmission, Control and Immunobiology of Infection - LR11IPT-02, Institut Pasteur de Tunis, Tunisia
| | - Najet Srairi-Abid
- Université de Tunis El Manar, Institut Pasteur de Tunis, LR16IPT08 Venins et Biomolécules Thérapeutiques, 1002, Tunis, Tunisia; University Tunis El Manar, Tunisia
| | - Mohamed-Ridha Barbouche
- Laboratory of Transmission, Control and Immunobiology of Infection - LR11IPT-02, Institut Pasteur de Tunis, Tunisia; University Tunis El Manar, Tunisia
| | - M Dahmani Fathallah
- Laboratory of Transmission, Control and Immunobiology of Infection - LR11IPT-02, Institut Pasteur de Tunis, Tunisia
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Schistosome-Derived Molecules as Modulating Actors of the Immune System and Promising Candidates to Treat Autoimmune and Inflammatory Diseases. J Immunol Res 2016; 2016:5267485. [PMID: 27635405 PMCID: PMC5011209 DOI: 10.1155/2016/5267485] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2016] [Revised: 06/29/2016] [Accepted: 07/13/2016] [Indexed: 12/27/2022] Open
Abstract
It is long known that some parasite infections are able to modulate specific pathways of host's metabolism and immune responses. This modulation is not only important in order to understand the host-pathogen interactions and to develop treatments against the parasites themselves but also important in the development of treatments against autoimmune and inflammatory diseases. Throughout the life cycle of schistosomes the mammalian hosts are exposed to several biomolecules that are excreted/secreted from the parasite infective stage, named cercariae, from their tegument, present in adult and larval stages, and finally from their eggs. These molecules can induce the activation and modulation of innate and adaptive responses as well as enabling the evasion of the parasite from host defense mechanisms. Immunomodulatory effects of helminth infections and egg molecules are clear, as well as their ability to downregulate proinflammatory cytokines, upregulate anti-inflammatory cytokines, and drive a Th2 type of immune response. We believe that schistosomes can be used as a model to understand the potential applications of helminths and helminth-derived molecules against autoimmune and inflammatory diseases.
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Veríssimo CM, Morassutti AL, von Itzstein M, Sutov G, Hartley-Tassell L, McAtamney S, Dell A, Haslam SM, Graeff-Teixeira C. Characterization of the N-glycans of female Angiostrongylus cantonensis worms. Exp Parasitol 2016; 166:137-43. [PMID: 27107931 DOI: 10.1016/j.exppara.2016.04.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2015] [Revised: 04/04/2016] [Accepted: 04/19/2016] [Indexed: 12/29/2022]
Abstract
Glycoconjugates play a crucial role in the host-parasite relationships of helminthic infections, including angiostrongyliasis. It has previously been shown that the antigenicity of proteins from female Angiostrongylus cantonensis worms may depend on their associated glycan moieties. Here, an N-glycan profile of A. cantonensis is reported. A total soluble extract (TE) was prepared from female A. cantonensis worms and was tested by western blot before and after glycan oxidation or N- and O-glycosidase treatment. The importance of N-glycans for the immunogenicity of A. cantonensis was demonstrated when deglycosylation of the TE with PNGase F completely abrogated IgG recognition. The TE was also fractionated using various lectin columns [Ulex europaeus (UEA), concanavalin A (Con A), Arachis hypogaea (PNA), Triticum vulgaris (WGA) and Lycopersicon esculentum (LEA)], and then each fraction was digested with PNGase F. Released N-glycans were analyzed with matrix-assisted laser desorption ionization (MALDI)-time-of-flight (TOF)-mass spectrometry (MS) and MALDI-TOF/TOF-MS/MS. Complex-type, high mannose, and truncated glycan structures were identified in all five fractions. Sequential MALDI-TOF-TOF analysis of the major MS peaks identified complex-type structures, with a α1-6 fucosylated core and truncated antennas. Glycoproteins in the TE were labeled with BodipyAF558-SE dye for a lectin microarray analysis. Fluorescent images were analyzed with ProScanArray imaging software followed by statistical analysis. A total of 29 lectins showed positive binding to the TE. Of these, Bandeiraea simplicifolia (BS-I), PNA, and Wisteria floribunda (WFA), which recognize galactose (Gal) and N-acetylgalactosamine (GalNAc), exhibited high affinity binding. Taken together, our findings demonstrate that female A. cantonensis worms have characteristic helminth N-glycans.
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Affiliation(s)
- Carolina M Veríssimo
- Laboratório de Parasitologia Molecular, Instituto de Pesquisas Biomédicas and Laboratório de Biologia Parasitária, Faculdade de Biociências da Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre, RS 90060-900, Brazil; Institute for Glycomics, Griffith University, Gold Coast Campus, Queensland, 4222, Australia.
| | - Alessandra L Morassutti
- Laboratório de Parasitologia Molecular, Instituto de Pesquisas Biomédicas and Laboratório de Biologia Parasitária, Faculdade de Biociências da Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre, RS 90060-900, Brazil
| | - Mark von Itzstein
- Institute for Glycomics, Griffith University, Gold Coast Campus, Queensland, 4222, Australia
| | - Grigorij Sutov
- Department of Life Sciences, Faculty of Natural Sciences, Imperial College London, London, SW7 2AZ, United Kingdom
| | - Lauren Hartley-Tassell
- Institute for Glycomics, Griffith University, Gold Coast Campus, Queensland, 4222, Australia
| | - Sarah McAtamney
- Institute for Glycomics, Griffith University, Gold Coast Campus, Queensland, 4222, Australia
| | - Anne Dell
- Department of Life Sciences, Faculty of Natural Sciences, Imperial College London, London, SW7 2AZ, United Kingdom
| | - Stuart M Haslam
- Department of Life Sciences, Faculty of Natural Sciences, Imperial College London, London, SW7 2AZ, United Kingdom
| | - Carlos Graeff-Teixeira
- Laboratório de Parasitologia Molecular, Instituto de Pesquisas Biomédicas and Laboratório de Biologia Parasitária, Faculdade de Biociências da Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre, RS 90060-900, Brazil
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Tegument Glycoproteins and Cathepsins of Newly Excysted Juvenile Fasciola hepatica Carry Mannosidic and Paucimannosidic N-glycans. PLoS Negl Trop Dis 2016; 10:e0004688. [PMID: 27139907 PMCID: PMC4854454 DOI: 10.1371/journal.pntd.0004688] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2016] [Accepted: 04/14/2016] [Indexed: 11/19/2022] Open
Abstract
Recently, the prevalence of Fasciola hepatica in some areas has increased considerably and the availability of a vaccine to protect livestock from infection would represent a major advance in tools available for controlling this disease. To date, most vaccine-target discovery research on this parasite has concentrated on proteomic and transcriptomic approaches whereas little work has been carried out on glycosylation. As the F. hepatica tegument (Teg) may contain glycans potentially relevant to vaccine development and the Newly Excysted Juvenile (NEJ) is the first lifecycle stage in contact with the definitive host, our work has focused on assessing the glycosylation of the NEJTeg and identifying the NEJTeg glycoprotein repertoire. After in vitro excystation, NEJ were fixed and NEJTeg was extracted. Matrix-assisted laser desorption ionisation-time of flight-mass spectrometry (MALDI-TOF-MS) analysis of released N-glycans revealed that oligomannose and core-fucosylated truncated N-glycans were the most dominant glycan types. By lectin binding studies these glycans were identified mainly on the NEJ surface, together with the oral and ventral suckers. NEJTeg glycoproteins were affinity purified after targeted biotinylation of the glycans and identified using liquid chromatography and tandem mass spectrometry (LC-MS/MS). From the total set of proteins previously identified in NEJTeg, eighteen were also detected in the glycosylated fraction, including the F. hepatica Cathepsin B3 (FhCB3) and two of the Cathepsin L3 (FhCL3) proteins, among others. To confirm glycosylation of cathepsins, analysis at the glycopeptide level by LC-ESI-ion-trap-MS/MS with collision-induced dissociation (CID) and electron-transfer dissociation (ETD) was carried out. We established that cathepsin B1 (FhCB1) on position N80, and FhCL3 (BN1106_s10139B000014, scaffold10139) on position N153, carry unusual paucimannosidic Man2GlcNAc2 glycans. To our knowledge, this is the first description of F. hepatica NEJ glycosylation and the first report of N-glycosylation of F. hepatica cathepsins. The significance of these findings for immunological studies and vaccine development is discussed.
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