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Biological function of Dictyocaulus viviparus asparaginyl peptidase legumain-1 and its suitability as a vaccine target. Parasitology 2017; 145:378-392. [PMID: 28942744 DOI: 10.1017/s0031182017001573] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The present study characterized the biological function of the asparaginyl peptidase legumain-1 (LEG-1) of the bovine lungworm Dictyocaulus viviparus and its suitability as a recombinant vaccine against dictyocaulosis. Quantitative real-time PCR and immunoblot analysis revealed LEG-1 to be almost exclusively transcribed and expressed in parasitic lungworm stages. Immunohistochemistry localized the enzyme in the parasite's gut, which was confirmed by immunoblots detecting LEG-1 in the gut as well as male testes. LEG-1 was recombinantly (rLEG-1) expressed in the yeast Pichia pastoris and subsequently analysed in activity assays for its enzyme functions and substrate specificity. For sufficient functionality, rLEG-1 needed trans-activation through D. viviparus cathepsin L-2, indicating a novel mechanism of legumain activation. After trans-activation, rLEG-1 worked best at pH 5·5 and 35-39 °C and cleaved a legumain-specific artificial substrate as well as the natural substrates bovine collagen types I and II. In a clinical vaccination trial, rLEG-1 did not protect against challenge infection. Results of in vitro characterization, transcription pattern and localization enhance the presumption that LEG-1 participates in digestion processes of D. viviparus. Since rLEG-1 needs trans-activation through a cathepsin, it is probably involved in an enzyme cascade and therefore remains interesting as a candidate in a multi-component vaccine.
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McNulty SN, Strübe C, Rosa BA, Martin JC, Tyagi R, Choi YJ, Wang Q, Hallsworth Pepin K, Zhang X, Ozersky P, Wilson RK, Sternberg PW, Gasser RB, Mitreva M. Dictyocaulus viviparus genome, variome and transcriptome elucidate lungworm biology and support future intervention. Sci Rep 2016; 6:20316. [PMID: 26856411 PMCID: PMC4746573 DOI: 10.1038/srep20316] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Accepted: 10/26/2015] [Indexed: 11/12/2022] Open
Abstract
The bovine lungworm, Dictyocaulus viviparus (order Strongylida), is an important parasite of livestock that causes substantial economic and production losses worldwide. Here we report the draft genome, variome, and developmental transcriptome of D. viviparus. The genome (161 Mb) is smaller than those of related bursate nematodes and encodes fewer proteins (14,171 total). In the first genome-wide assessment of genomic variation in any parasitic nematode, we found a high degree of sequence variability in proteins predicted to be involved host-parasite interactions. Next, we used extensive RNA sequence data to track gene transcription across the life cycle of D. viviparus, and identified genes that might be important in nematode development and parasitism. Finally, we predicted genes that could be vital in host-parasite interactions, genes that could serve as drug targets, and putative RNAi effectors with a view to developing functional genomic tools. This extensive, well-curated dataset should provide a basis for developing new anthelmintics, vaccines, and improved diagnostic tests and serve as a platform for future investigations of drug resistance and epidemiology of the bovine lungworm and related nematodes.
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Affiliation(s)
- Samantha N McNulty
- The McDonnell Genome Institute, Washington University in St Louis, MO 63108, USA
| | - Christina Strübe
- Institute for Parasitology, University of Veterinary Medicine Hannover, Hannover 30559, Germany
| | - Bruce A Rosa
- The McDonnell Genome Institute, Washington University in St Louis, MO 63108, USA
| | - John C Martin
- The McDonnell Genome Institute, Washington University in St Louis, MO 63108, USA
| | - Rahul Tyagi
- The McDonnell Genome Institute, Washington University in St Louis, MO 63108, USA
| | - Young-Jun Choi
- The McDonnell Genome Institute, Washington University in St Louis, MO 63108, USA
| | - Qi Wang
- The McDonnell Genome Institute, Washington University in St Louis, MO 63108, USA
| | | | - Xu Zhang
- The McDonnell Genome Institute, Washington University in St Louis, MO 63108, USA
| | - Philip Ozersky
- The McDonnell Genome Institute, Washington University in St Louis, MO 63108, USA
| | - Richard K Wilson
- The McDonnell Genome Institute, Washington University in St Louis, MO 63108, USA
| | - Paul W Sternberg
- HHMI, Division of Biology, California Institute of Technology, Pasadena, CA 91125, USA
| | - Robin B Gasser
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Victoria 3010, Australia
| | - Makedonka Mitreva
- The McDonnell Genome Institute, Washington University in St Louis, MO 63108, USA.,Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
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Mangiola S, Young ND, Sternberg PW, Strube C, Korhonen PK, Mitreva M, Scheerlinck JP, Hofmann A, Jex AR, Gasser RB. Analysis of the transcriptome of adult Dictyocaulus filaria and comparison with Dictyocaulus viviparus, with a focus on molecules involved in host-parasite interactions. Int J Parasitol 2014; 44:251-61. [PMID: 24487001 DOI: 10.1016/j.ijpara.2013.12.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Revised: 12/11/2013] [Accepted: 12/18/2013] [Indexed: 01/09/2023]
Abstract
Parasitic nematodes cause diseases of major economic importance in animals. Key representatives are species of Dictyocaulus (=lungworms), which cause bronchitis (=dictyocaulosis, commonly known as "husk") and have a major adverse impact on the health of livestock. In spite of their economic importance, very little is known about the immunomolecular biology of these parasites. Here, we conducted a comprehensive investigation of the adult transcriptome of Dictyocaulus filaria of small ruminants and compared it with that of Dictyocaulus viviparus of bovids. We then identified a subset of highly transcribed molecules inferred to be linked to host-parasite interactions, including cathepsin B peptidases, fatty-acid and/or retinol-binding proteins, β-galactoside-binding galectins, secreted protein 6 precursors, macrophage migration inhibitory factors, glutathione peroxidases, a transthyretin-like protein and a type 2-like cystatin. We then studied homologues of D. filaria type 2-like cystatin encoded in D. viviparus and 24 other nematodes representing seven distinct taxonomic orders, with a particular focus on their proposed role in immunomodulation and/or metabolism. Taken together, the present study provides new insights into nematode-host interactions. The findings lay the foundation for future experimental studies and could have implications for designing new interventions against lungworms and other parasitic nematodes. The future characterisation of the genomes of Dictyocaulus spp. should underpin these endeavours.
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Affiliation(s)
- Stefano Mangiola
- Faculty of Veterinary Science, The University of Melbourne, Victoria, Australia
| | - Neil D Young
- Faculty of Veterinary Science, The University of Melbourne, Victoria, Australia.
| | - Paul W Sternberg
- HHMI, Division of Biology, California Institute of Technology, Pasadena, CA, USA
| | - Christina Strube
- Institute for Parasitology, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Pasi K Korhonen
- Faculty of Veterinary Science, The University of Melbourne, Victoria, Australia
| | - Makedonka Mitreva
- The Genome Institute, Washington University School of Medicine, St. Louis, MO, USA; Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | | | - Andreas Hofmann
- Faculty of Veterinary Science, The University of Melbourne, Victoria, Australia; Eskitis Institute for Cell & Molecular Therapies, Griffith University, Brisbane, Australia
| | - Aaron R Jex
- Faculty of Veterinary Science, The University of Melbourne, Victoria, Australia
| | - Robin B Gasser
- Faculty of Veterinary Science, The University of Melbourne, Victoria, Australia; Institute of Parasitology and Tropical Veterinary Medicine, Berlin, Germany.
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