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Zheng Y, Young ND, Song J, Gasser RB. Genome-Wide Analysis of Haemonchus contortus Proteases and Protease Inhibitors Using Advanced Informatics Provides Insights into Parasite Biology and Host-Parasite Interactions. Int J Mol Sci 2023; 24:12320. [PMID: 37569696 PMCID: PMC10418638 DOI: 10.3390/ijms241512320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 07/24/2023] [Accepted: 07/24/2023] [Indexed: 08/13/2023] Open
Abstract
Biodiversity within the animal kingdom is associated with extensive molecular diversity. The expansion of genomic, transcriptomic and proteomic data sets for invertebrate groups and species with unique biological traits necessitates reliable in silico tools for the accurate identification and annotation of molecules and molecular groups. However, conventional tools are inadequate for lesser-known organismal groups, such as eukaryotic pathogens (parasites), so that improved approaches are urgently needed. Here, we established a combined sequence- and structure-based workflow system to harness well-curated publicly available data sets and resources to identify, classify and annotate proteases and protease inhibitors of a highly pathogenic parasitic roundworm (nematode) of global relevance, called Haemonchus contortus (barber's pole worm). This workflow performed markedly better than conventional, sequence-based classification and annotation alone and allowed the first genome-wide characterisation of protease and protease inhibitor genes and gene products in this worm. In total, we identified 790 genes encoding 860 proteases and protease inhibitors representing 83 gene families. The proteins inferred included 280 metallo-, 145 cysteine, 142 serine, 121 aspartic and 81 "mixed" proteases as well as 91 protease inhibitors, all of which had marked physicochemical diversity and inferred involvements in >400 biological processes or pathways. A detailed investigation revealed a remarkable expansion of some protease or inhibitor gene families, which are likely linked to parasitism (e.g., host-parasite interactions, immunomodulation and blood-feeding) and exhibit stage- or sex-specific transcription profiles. This investigation provides a solid foundation for detailed explorations of the structures and functions of proteases and protease inhibitors of H. contortus and related nematodes, and it could assist in the discovery of new drug or vaccine targets against infections or diseases.
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Affiliation(s)
- Yuanting Zheng
- Melbourne Veterinary School, Faculty of Science, The University of Melbourne, Parkville, VIC 3010, Australia;
| | - Neil D. Young
- Melbourne Veterinary School, Faculty of Science, The University of Melbourne, Parkville, VIC 3010, Australia;
| | - Jiangning Song
- Department of Data Science and AI, Faculty of IT, Monash University, Melbourne, VIC 3800, Australia;
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Melbourne, VIC 3800, Australia
- Monash Data Futures Institute, Monash University, Melbourne, VIC 3800, Australia
| | - Robin B. Gasser
- Melbourne Veterinary School, Faculty of Science, The University of Melbourne, Parkville, VIC 3010, Australia;
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Adduci I, Sajovitz F, Hinney B, Lichtmannsperger K, Joachim A, Wittek T, Yan S. Haemonchosis in Sheep and Goats, Control Strategies and Development of Vaccines against Haemonchus contortus. Animals (Basel) 2022; 12:ani12182339. [PMID: 36139199 PMCID: PMC9495197 DOI: 10.3390/ani12182339] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 08/20/2022] [Accepted: 09/02/2022] [Indexed: 11/30/2022] Open
Abstract
Simple Summary Haemonchus contortus is the most pathogenic blood-feeding parasitic nematode in sheep and goats, threatening animal welfare and causing tremendous economic losses to the small ruminant industry. This comprehensive review article sums up current control strategies, worm-derived antigens and recent advances in anti-Haemonchus vaccine development. New insights into antigen engineering and general considerations for clinical trials are discussed here. Abstract The evolutionary success of parasitic worms causes significant economic losses and animal health problems, including in the small ruminant industry. The hematophagous nematode Haemonchus contortus is a common endoparasite that infects wild and domestic ruminants worldwide, especially in tropical and subtropical regions. To date, the most commonly applied control strategy is the administration of anthelminthic drugs. The main disadvantages of these chemicals are their ecotoxic effects, the necessary withdrawal period (especially important in dairy animals) and the increasing development of resistance. Vaccines offer an attractive alternative control strategy against Haemonchus infections. In previous years, several potential vaccine antigens prepared from H. contortus using the latest technologies have been assessed in clinical trials using different methods and strategies. This review highlights the current state of knowledge on anti-H. contortus vaccines (covering native, recombinant and DNA-based vaccines), including an evaluation, as well a discussion of the challenges and achievements in developing protective, efficient, and long-lasting vaccines to control H. contortus infection and haemonchosis in small ruminants. This paper also addresses novel developments tackling the challenge of glycosylation of putative candidates in recombinant form.
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Affiliation(s)
- Isabella Adduci
- Institute of Parasitology, Department of Pathobiology, University of Veterinary Medicine Vienna, Veterinärplatz 1, A-1210 Wien, Austria
| | - Floriana Sajovitz
- University Clinic for Ruminants, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, Veterinärplatz 1, A-1210 Wien, Austria
| | - Barbara Hinney
- Institute of Parasitology, Department of Pathobiology, University of Veterinary Medicine Vienna, Veterinärplatz 1, A-1210 Wien, Austria
| | - Katharina Lichtmannsperger
- University Clinic for Ruminants, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, Veterinärplatz 1, A-1210 Wien, Austria
| | - Anja Joachim
- Institute of Parasitology, Department of Pathobiology, University of Veterinary Medicine Vienna, Veterinärplatz 1, A-1210 Wien, Austria
| | - Thomas Wittek
- University Clinic for Ruminants, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, Veterinärplatz 1, A-1210 Wien, Austria
| | - Shi Yan
- Institute of Parasitology, Department of Pathobiology, University of Veterinary Medicine Vienna, Veterinärplatz 1, A-1210 Wien, Austria
- Correspondence:
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Immune reactivity and host modulatory roles of two novel Haemonchus contortus cathepsin B-like proteases. Parasit Vectors 2021; 14:580. [PMID: 34798906 PMCID: PMC8603344 DOI: 10.1186/s13071-021-05010-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Accepted: 09/09/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Haemonchus contortus is a blood-feeding, gastrointestinal nematode (GIN) that causes significant economic losses to the small ruminant industry worldwide. Despite extensive efforts, our understanding of the molecular mechanisms used by GIN to evade host immune responses is limited. Cathepsin B-like proteins (CBPs) are members of the cysteine protease family and are involved in parasite invasion and thus provide viable vaccine candidates. METHODS In silico comparative analysis was used to identify conserved proteins among a subset of clade V parasitic nematodes with emphasis on blood-feeding worms, among which CBPs appeared prominently. We identified and characterized two novel CBPs designated Hc-CBP-1 and Hc-CBP-2. Rabbit anti-recombinant (r) Hc-CBP-1 and rHc-CBP-2 were used to detect the presence of native proteins in the excretory secretory products (ESP) and in worm tissues of adult H. contortus. Peptide arrays of rHc-CBP-1 and rHc-CBP-2 were screened with the homologous and heterologous anti-sera and with sera from dexamethasone-treated (Dex+) and non-treated (Dex-) H. contortus-infected animals to identify key immunogenic peptides. Gene transcription of Hc-cbp-1 and Hc-cbp-2 was also performed on H. contortus-infected animals treated with Dex+. Finally, the mature recombinant proteins were used to assess their abilities to modulate cell functions. RESULTS Immunohistochemistry showed that both Hc-CBP-1 and Hc-CBP-2 are present on the brush borders of the intestine; Hc-CBP-2 was also present in the hypodermis of the body wall. Peptide displays screened with rabbit anti-rHc-CBP-1 and anti-rHc-CBP-2 revealed regions within the proteins where dominant and overlapping epitopes prevailed. ELISA results were consistent with only Hc-CBP-1 being present in H. contortus adult ESPs. H. contortus from Dex+ animals exhibited a threefold increase in Hc-cbp-2 transcript while Hc-cbp-1 expression did not change. In contrast, comparisons of immunoreactivities of rHc-CBP-1 and rHc-CBP-2 peptide arrays to sera from Dex+ and Dex- animals primarily showed changes in Hc-CBP-1 binding. Lastly, rHc-CBP-1 suppressed mRNA expression of bovine peripheral blood mononuclear cell cytokines/activation markers, including TNFα, IL-1, IL-6 and CD86. CONCLUSIONS These results suggest that as secreted and cryptic proteins, respectively, Hc-CBP-1 and Hc-CBP-2 influence cellular and immunological activities that have interesting dynamics during infection and may provide viable immune-related targets for attenuating H. contortus infectivity.
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Kumar S, Gupta S, Mohmad A, Fular A, Parthasarathi BC, Chaubey AK. Molecular tools-advances, opportunities and prospects for the control of parasites of veterinary importance. INTERNATIONAL JOURNAL OF TROPICAL INSECT SCIENCE 2021; 41:33-42. [PMID: 32837530 PMCID: PMC7387080 DOI: 10.1007/s42690-020-00213-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2020] [Accepted: 07/17/2020] [Indexed: 05/02/2023]
Abstract
The recent advancement in genome sequencing facilities, proteomics, transcriptomics, and metabolomics of eukaryotes have opened door for employment of molecular diagnostic techniques for early detection of parasites and determining target molecules for formulating control strategies. It further leads to the introduction of several purified vaccines in the field of veterinary parasitology. Earlier, the conventional diagnostic methods was entirely based upon morphological taxonomy for diagnosis of parasites but nowadays improved molecular techniques help in phylogenetic study and open an another area of molecular taxonomy of parasites with high precision. Control measures based upon targeting endosymbionts in parasites like Dirofilaria immitis is also under exploration in veterinary parasitology. Metagenomics have added an inside story of parasites bionomics which have created havoc in human and animals population since centuries. Omics era is playing a key role in opening the new approaches on parasite biology. Various newer generations of safer vaccines like edible vaccines and subunit vaccines and diagnostic techniques based upon purified immunologically active epitopes have become commercially available against the parasites (helminths, protozoa and arthropod borne diseases). Nowadays, a transgenic and gene knock out studies using RNA interference and CRISPR are also helping in understanding the functions of genes and screening of target genes, which are not available before the advent of molecular tools. Molecular techniques had paramount impact on increasing the sensitivity of diagnostic tools, epidemiological studies and more importantly in controlling these diseases. This review is about the advancements in veterinary parasitology and their impact on the control of these pathogens.
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Affiliation(s)
- Sachin Kumar
- Division of Parasitology, ICAR-Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh 243122 India
- Department of Zoology, Choudhary Charan Singh University, Meerut, Uttar Pradesh 250001 India
| | - Snehil Gupta
- Department of Veterinary Parasitology, Lala Lajpat Rai University of Veterinary and Animal Sciences, Hisar, Haryana 125001 India
| | - Aquil Mohmad
- Division of Parasitology, ICAR-Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh 243122 India
| | - Ashutosh Fular
- Division of Parasitology, ICAR-Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh 243122 India
| | - B. C. Parthasarathi
- Division of Parasitology, ICAR-Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh 243122 India
| | - Ashok Kumar Chaubey
- Department of Zoology, Choudhary Charan Singh University, Meerut, Uttar Pradesh 250001 India
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Ehsan M, Hu RS, Liang QL, Hou JL, Song X, Yan R, Zhu XQ, Li X. Advances in the Development of Anti- Haemonchus contortus Vaccines: Challenges, Opportunities, and Perspectives. Vaccines (Basel) 2020; 8:vaccines8030555. [PMID: 32971770 PMCID: PMC7565421 DOI: 10.3390/vaccines8030555] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 09/13/2020] [Accepted: 09/16/2020] [Indexed: 02/06/2023] Open
Abstract
The gastrointestinal nematode parasite Haemonchus contortus (H. contortus) is a resident of tropical and subtropical regions worldwide that imposes significant production losses, economic losses, and animal health issues in the small ruminant industry, particularly sheep and goats. Considerable efforts have been made to understand how immunity is elicited against H. contortus infection. Various potential vaccine antigens have been tested by different methods and strategies applied in animal models, and significant progress has been made in the development of vaccines against H. contortus. This review highlighted and shared the knowledge about the current understanding of host immune responses to H. contortus and ongoing challenges in the development of a protective, effective, and long-lasting vaccine against H. contortus infection. We have also pinpointed some achievements and failures in the development and testing of vaccines, which will establish a road map for future research directions to explore new effective vaccine candidates for controlling and preventing H. contortus infection.
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Affiliation(s)
- Muhammad Ehsan
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou 730046, China; (M.E.); (R.-S.H.); (Q.-L.L.); (J.-L.H.)
| | - Rui-Si Hu
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou 730046, China; (M.E.); (R.-S.H.); (Q.-L.L.); (J.-L.H.)
| | - Qin-Li Liang
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou 730046, China; (M.E.); (R.-S.H.); (Q.-L.L.); (J.-L.H.)
| | - Jun-Ling Hou
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou 730046, China; (M.E.); (R.-S.H.); (Q.-L.L.); (J.-L.H.)
| | - Xiaokai Song
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China; (X.S.); (R.Y.); (X.L.)
| | - Ruofeng Yan
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China; (X.S.); (R.Y.); (X.L.)
| | - Xing-Quan Zhu
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou 730046, China; (M.E.); (R.-S.H.); (Q.-L.L.); (J.-L.H.)
- College of Veterinary Medicine, Shanxi Agricultural University, Taigu 030801, China
- Correspondence: or ; Tel.: +86-354-628-8993
| | - Xiangrui Li
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China; (X.S.); (R.Y.); (X.L.)
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Tjondro HC, Loke I, Chatterjee S, Thaysen-Andersen M. Human protein paucimannosylation: cues from the eukaryotic kingdoms. Biol Rev Camb Philos Soc 2019; 94:2068-2100. [PMID: 31410980 DOI: 10.1111/brv.12548] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 07/10/2019] [Accepted: 07/17/2019] [Indexed: 12/11/2022]
Abstract
Paucimannosidic proteins (PMPs) are bioactive glycoproteins carrying truncated α- or β-mannosyl-terminating asparagine (N)-linked glycans widely reported across the eukaryotic domain. Our understanding of human PMPs remains limited, despite findings documenting their existence and association with human disease glycobiology. This review comprehensively surveys the structures, biosynthetic routes and functions of PMPs across the eukaryotic kingdoms with the aim of synthesising an improved understanding on the role of protein paucimannosylation in human health and diseases. Convincing biochemical, glycoanalytical and biological data detail a vast structural heterogeneity and fascinating tissue- and subcellular-specific expression of PMPs within invertebrates and plants, often comprising multi-α1,3/6-fucosylation and β1,2-xylosylation amongst other glycan modifications and non-glycan substitutions e.g. O-methylation. Vertebrates and protists express less-heterogeneous PMPs typically only comprising variable core fucosylation of bi- and trimannosylchitobiose core glycans. In particular, the Manα1,6Manβ1,4GlcNAc(α1,6Fuc)β1,4GlcNAcβAsn glycan (M2F) decorates various human neutrophil proteins reportedly displaying bioactivity and structural integrity demonstrating that they are not degradation products. Less-truncated paucimannosidic glycans (e.g. M3F) are characteristic glycosylation features of proteins expressed by human cancer and stem cells. Concertedly, these observations suggest the involvement of human PMPs in processes related to innate immunity, tumorigenesis and cellular differentiation. The absence of human PMPs in diverse bodily fluids studied under many (patho)physiological conditions suggests extravascular residence and points to localised functions of PMPs in peripheral tissues. Absence of PMPs in Fungi indicates that paucimannosylation is common, but not universally conserved, in eukaryotes. Relative to human PMPs, the expression of PMPs in plants, invertebrates and protists is more tissue-wide and constitutive yet, similar to their human counterparts, PMP expression remains regulated by the physiology of the producing organism and PMPs evidently serve essential functions in development, cell-cell communication and host-pathogen/symbiont interactions. In most PMP-producing organisms, including humans, the N-acetyl-β-hexosaminidase isoenzymes and linkage-specific α-mannosidases are glycoside hydrolases critical for generating PMPs via N-acetylglucosaminyltransferase I (GnT-I)-dependent and GnT-I-independent truncation pathways. However, the identity and structure of many species-specific PMPs in eukaryotes, their biosynthetic routes, strong tissue- and development-specific expression, and diverse functions are still elusive. Deep exploration of these PMP features involving, for example, the characterisation of endogenous PMP-recognising lectins across a variety of healthy and N-acetyl-β-hexosaminidase-deficient human tissue types and identification of microbial adhesins reactive to human PMPs, are amongst the many tasks required for enhanced insight into the glycobiology of human PMPs. In conclusion, the literature supports the notion that PMPs are significant, yet still heavily under-studied biomolecules in human glycobiology that serve essential functions and create structural heterogeneity not dissimilar to other human N-glycoprotein types. Human PMPs should therefore be recognised as bioactive glycoproteins that are distinctly different from the canonical N-glycoprotein classes and which warrant a more dedicated focus in glycobiological research.
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Affiliation(s)
- Harry C Tjondro
- Department of Molecular Sciences, Macquarie University, Sydney, New South Wales, 2109, Australia
| | - Ian Loke
- Department of Molecular Sciences, Macquarie University, Sydney, New South Wales, 2109, Australia.,Department of Biological Sciences, National University of Singapore, Singapore 117543, Singapore
| | - Sayantani Chatterjee
- Department of Molecular Sciences, Macquarie University, Sydney, New South Wales, 2109, Australia
| | - Morten Thaysen-Andersen
- Department of Molecular Sciences, Macquarie University, Sydney, New South Wales, 2109, Australia
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In silico homology modelling and prediction of novel epitopic peptides from P24 protein of Haemonchus contortus. Gene 2019; 703:102-111. [DOI: 10.1016/j.gene.2019.03.056] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 03/23/2019] [Accepted: 03/25/2019] [Indexed: 01/02/2023]
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Trials with the Haemonchus vaccine, Barbervax ®, in ewes and lambs in a tropical environment: Nutrient supplementation improves protection in periparturient ewes. Vet Parasitol 2018; 264:52-57. [PMID: 30503092 DOI: 10.1016/j.vetpar.2018.11.006] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Revised: 11/05/2018] [Accepted: 11/08/2018] [Indexed: 11/23/2022]
Abstract
Haemonchus contortus is an economic problem in sheep farms worldwide, mainly in the tropics and subtropics. A vaccine against haemonchosis, called Barbervax®, was evaluated in ewes under two nutritional status, naturally infected with gastrointestinal nematodes. Ewes were divided into four groups: Supplemented Diet - Vaccine; Supplemented Diet - No vaccine; Basal Diet - Vaccine and Basal Diet - No vaccine. Their lambs were divided in Vaccinated and No vaccine. Ewes were immunised six times starting about 1 month of pregnancy with the first three doses at 3 week intervals and the last three shots at 4 week intervals. Supplemented ewes had higher body weight, body score and packed cell volume compared with those fed a basal diet. Both groups of vaccinated ewes showed a similar response in circulating anti-vaccine antibodies but the vaccine had no discernible effect on either body weight, body score and packed cell volume. There was a marked group difference in the number of ewes that received precautionary treatments with anthelmintic. All 14 Basal Diet - No vaccine ewes required treatment. In contrast only 7 ewes, in the Supplemented Diet - Vaccine group required anthelmintic treatment. In the Basal Diet - Vaccine and in the Supplemented Diet - No Vaccine groups, 12 and 13 ewes needed anthelmintic treatment, respectively. Vaccinated lambs showed much higher antibody titres resulting in 80% less Haemonchus spp. egg counts comparing with no vaccine lambs. Taken together these results clearly suggest that in pregnant and lactating ewes a combined protective effect between vaccination and improved nutrition resulted in fewer precautionary anthelmintic treatments. Thus, it was possible to achieve a more sustainable level of control of the haemonchosis, less dependent on anthelmintic drugs.
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ARAVIND M, SARAVANAN BC, MANJUNATHACHAR HV, SANKAR M, SARAVANAN R, PRASAD A, MILTON AAP, PRIYA GBHUVANA. Molecular expression and characterization of GCP7 gene of Haemonchus contortus. THE INDIAN JOURNAL OF ANIMAL SCIENCES 2017. [DOI: 10.56093/ijans.v87i11.75853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/03/2023]
Abstract
Haemonchus contortus is a highly pathogenic and most economically important parasite of sheep and goats worldwide. The cysteine proteases from H. contortus are prime targets for vaccine development. In the present communication we report the molecular expression and characterization of cathepsin B-like cysteine protease, GCP7 gene of H. contortus to study its efficiency as target protein for immunoprophylaxis against haemonchosis in sheep and goats. The complete ORF of GCP7 gene, devoid of the signal sequence, was amplified by RT-PCR from mRNA isolated from H. contortus and was cloned initially into pTZ57R/T cloning vector and then sub-cloned in the pET32a(+) expression vector to produce GCP7 antigen. The nucleotide and deduced amino acid sequence of the GCP7 was aligned against the related sequences of H. contortus available in public domain for in silico analysis by DNA STAR and MEGA version 4.0 softwares. The nucleotide sequence revealed that the GCP7 gene of H.contortus (Indian isolate) encodes 324 amino acids (devoid of signal sequence) and its nucleotide sequence had 95.9% to 99.4% sequence homology with that of U.S.A. and previously published Indian isolates. A high level expression of recombinant (r) GCP7 protein was observed in the molecular range (Mr) of 55 kDa. The rGCP7 protein was confirmed by its specific immunoreactivity against known reference positive sheep sera.
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Wang C, Li F, Zhang Z, Yang X, Ahmad AA, Li X, Du A, Hu M. Recent Research Progress in China on Haemonchus contortus. Front Microbiol 2017; 8:1509. [PMID: 28883809 PMCID: PMC5574212 DOI: 10.3389/fmicb.2017.01509] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Accepted: 07/27/2017] [Indexed: 11/23/2022] Open
Abstract
Haemonchus contortus is one of the most important parasites of ruminants with worldwide distribution that can bring huge economic losses to the breeding industry of cattle, sheep, and goats. In recent 20 years, studies on H. contortus in China mainly focused on the epidemiology, population genetics, anthelmintic resistance, structural and functional studies of important genes regulating the development of this parasite, interaction between parasite molecules and host cells and vaccine development against haemonchosis, and achieved good progress. However, there is no systematic review about the studies by Chinese researchers on H. contortus in China. The purpose of this review is to bring together the findings from the studies on H. contortus in China in order to obtain the knowledge gained from the recent studies in China and provide foundation for identifying future research directions to establish novel diagnostic methods, discover new drug targets and vaccine candidates for use in preventing and controlling H. contortus in China.
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Affiliation(s)
- Chunqun Wang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural UniversityWuhan, China
| | - Fangfang Li
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural UniversityWuhan, China
| | - Zongze Zhang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural UniversityWuhan, China
| | - Xin Yang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural UniversityWuhan, China
| | - Awais A. Ahmad
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural UniversityWuhan, China
| | - Xiangrui Li
- College of Veterinary Medicine, Nanjing Agricultural UniversityNanjing, China
| | - Aifang Du
- College of Animal Sciences, Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Zhejiang UniversityHangzhou, China
| | - Min Hu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural UniversityWuhan, China
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Latchumikanthan A, Prasad A, Sankar M, Pavan Kumar P, Jithin MV, Aravind M. Polymerase chain reaction (PCR) based amplification of hmcp3 and hmcp6 cysteine protease genes of Haemonchus contortus from small ruminants. J Parasit Dis 2016; 40:1313-1316. [PMID: 27876938 DOI: 10.1007/s12639-015-0679-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Accepted: 03/10/2015] [Indexed: 11/27/2022] Open
Abstract
Haemonchus contortus is a haematophagous nematode in small ruminants population and causes anaemia, weakness and mortality especially in young animals. In the present study, hmcp3 partial gene of 836 bp and hmcp6 full length gene of 1041 bp were amplified from the cDNA of Bareilly isolate of adult male H. contortus by polymerase chain reaction. Further gene characterization and expression studies are warranted to know the immunoprophylactic potential of hmcp3 and hmcp6 proteins of H. contortus.
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Affiliation(s)
- A Latchumikanthan
- Division of Veterinary Parasitology, Indian Veterinary Research Institute, Izatnagar, Bareilly, 243 122 UP India
| | - A Prasad
- Division of Veterinary Parasitology, Indian Veterinary Research Institute, Izatnagar, Bareilly, 243 122 UP India
| | - M Sankar
- Division of Temperate Animal Husbandry, Indian Veterinary Research Institute, Mukteshwar, Nainital, 263 138 Uttarakhand India
| | - Pesingi Pavan Kumar
- Division of Veterinary Public Health, Indian Veterinary Research Institute, Izatnagar, Bareilly, 243 122 UP India
| | - M V Jithin
- Division of Veterinary Medicine, Indian Veterinary Research Institute, Izatnagar, Bareilly, 243 122 UP India
| | - M Aravind
- Division of Veterinary Parasitology, Indian Veterinary Research Institute, Izatnagar, Bareilly, 243 122 UP India
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Abstract
Sheep are capable of developing protective immunity to Haemonchus contortus through repeated exposure to this parasite, although this immune protection is the result of a complex interaction among age, gender, physiological status, pregnancy, lactation, nutrition and innate and adaptive immunity in the host animal. There are multiple effectors of the protective immune response, which differ depending on the developmental stage of the parasite being targeted, and our understanding of the effector mechanisms has developed considerably in the 2000s. The rational design of vaccines based on 'natural' or 'exposed' antigens depends on an understanding of this exposure-induced immunity. However, the most effective current vaccines rely on protection via the induction of high circulating antibody levels to 'hidden' gut antigens of H. contortus. The success of this latter strategy has resulted in the launch of a vaccine, which is based on extracts of the parasite's gut, to aid in the control of Haemonchus in Australia. The development of recombinant subunit vaccines based on the components of the successful native vaccine has not yet been achieved and most of the recent successes with recombinant subunit vaccines have focussed on antigens unrelated to the gut antigens. The future integration of an understanding of the immunobiology of this parasite with advances in antigen identification, expression (or synthesis) and presentation is likely to be pivotal to the further development of these recombinant subunit vaccines. Recent progress in each of the components underpinning this integrated approach is summarized in this review.
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Tak IR, Dar JS, Dar SA, Ganai BA, Chishti MZ, Ahmad F. A comparative analysis of various antigenic proteins found in Haemonchus contortus—a review. Mol Biol 2015. [DOI: 10.1134/s0026893315060217] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Mohandas N, Young ND, Jabbar A, Korhonen PK, Koehler AV, Hall RS, Hu M, Hofmann A, Gasser RB. The complement of family M1 aminopeptidases of Haemonchus contortus--Biotechnological implications. Biotechnol Adv 2015; 34:65-76. [PMID: 26597954 DOI: 10.1016/j.biotechadv.2015.10.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2015] [Revised: 10/04/2015] [Accepted: 10/10/2015] [Indexed: 01/03/2023]
Abstract
Although substantial research has been focused on the 'hidden antigen' H11 of Haemonchus contortus as a vaccine against haemonchosis in small ruminants, little is know about this and related aminopeptidases. In the present article, we reviewed genomic and transcriptomic data sets to define, for the first time, the complement of aminopeptidases (designated Hc-AP-1 to Hc-AP-13) of the family M1 with homologues in Caenorhabditis elegans, characterised by zinc-binding (HEXXH) and exo-peptidase (GAMEN) motifs. The three previously published H11 isoforms (accession nos. X94187, FJ481146 and AJ249941) had most sequence similarity to Hc-AP-2 and Hc-AP-8, whereas unpublished isoforms (accession nos. AJ249942 and AJ311316) were both most similar to Hc-AP-3. The aminopeptidases characterised here had homologues in C. elegans. Hc-AP-1 to Hc-AP-8 were most similar in amino acid sequence (28-41%) to C. elegans T07F10.1; Hc-AP-9 and Hc-AP-10 to C. elegans PAM-1 (isoform b) (53-54% similar); Hc-AP-11 and Hc-AP-12 to C. elegans AC3.5 and Y67D8C.9 (26% and 50% similar, respectively); and Hc-AP-13 to C. elegans C42C1.11 and ZC416.6 (50-58% similar). Comparative analysis suggested that Hc-AP-1 to Hc-AP-8 play roles in digestion, metabolite excretion, neuropeptide processing and/or osmotic regulation, with Hc-AP-4 and Hc-AP-7 having male-specific functional roles. The analysis also indicated that Hc-AP-9 and Hc-AP-10 might be involved in the degradation of cyclin (B3) and required to complete meiosis. Hc-AP-11 represents a leucyl/cystinyl aminopeptidase, predicted to have metallopeptidase and zinc ion binding activity, whereas Hc-AP-12 likely encodes an aminopeptidase Q homologue also with these activities and a possible role in gonad function. Finally, Hc-AP-13 is predicted to encode an aminopeptidase AP-1 homologue of C. elegans with hydrolase activity, suggested to operate, possibly synergistically with a PEPT-1 ortholog, as an oligopeptide transporter in the gut for protein uptake and normal development and/or reproduction of the worm. An appraisal of structure-based amino acid sequence alignments revealed that all conceptually translated Hc-AP proteins, with the exception of Hc-AP-12, adopt a topology similar to those observed for the two subgroups of mammalian M1 aminopeptidases, which possess either three (I, II and IV) or four (I-IV) domains. In contrast, Hc-AP-12 lacks the N-terminal domain (I), but possesses a substantially expanded domain III. Although further work needs to be done to assess amino acid sequence conservation of the different aminopeptidases among individual worms within and among H. contortus populations, we hope that these insights will support future localisation, structural and functional studies of these molecules in H. contortus as well as facilitate future assessments of a recombinant subunit or cocktail vaccine against haemonchosis.
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Affiliation(s)
- Namitha Mohandas
- The University of Melbourne, Faculty of Veterinary and Agricultural Sciences, Parkville, Victoria 3010, Australia
| | - Neil D Young
- The University of Melbourne, Faculty of Veterinary and Agricultural Sciences, Parkville, Victoria 3010, Australia
| | - Abdul Jabbar
- The University of Melbourne, Faculty of Veterinary and Agricultural Sciences, Parkville, Victoria 3010, Australia
| | - Pasi K Korhonen
- The University of Melbourne, Faculty of Veterinary and Agricultural Sciences, Parkville, Victoria 3010, Australia
| | - Anson V Koehler
- The University of Melbourne, Faculty of Veterinary and Agricultural Sciences, Parkville, Victoria 3010, Australia
| | - Ross S Hall
- The University of Melbourne, Faculty of Veterinary and Agricultural Sciences, Parkville, Victoria 3010, Australia
| | - Min Hu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, Hubei, China
| | - Andreas Hofmann
- The University of Melbourne, Faculty of Veterinary and Agricultural Sciences, Parkville, Victoria 3010, Australia; Structural Chemistry Program, Eskitis Institute for Drug Discovery, Griffith University, Brisbane, Queensland 4111, Australia.
| | - Robin B Gasser
- The University of Melbourne, Faculty of Veterinary and Agricultural Sciences, Parkville, Victoria 3010, Australia; State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, Hubei, China.
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Heim C, Hertzberg H, Butschi A, Bleuler-Martinez S, Aebi M, Deplazes P, Künzler M, Štefanić S. Inhibition of Haemonchus contortus larval development by fungal lectins. Parasit Vectors 2015; 8:425. [PMID: 26283415 PMCID: PMC4539729 DOI: 10.1186/s13071-015-1032-x] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Accepted: 08/05/2015] [Indexed: 11/10/2022] Open
Abstract
Background Lectins are carbohydrate-binding proteins that are involved in fundamental intra- and extracellular biological processes. They occur ubiquitously in nature and are especially abundant in plants and fungi. It has been well established that certain higher fungi produce lectins in their fruiting bodies and/or sclerotia as a part of their natural resistance against free-living fungivorous nematodes and other pests. Despite relatively high diversity of the glycan structures in nature, many of the glycans targeted by fungal lectins are conserved among organisms of the same taxon and sometimes even among different taxa. Such conservation of glycans between free-living and parasitic nematodes is providing us with a useful tool for discovery of novel chemotherapeutic and vaccine targets. In our study, a subset of fungal lectins emanating from toxicity screens on Caenorhabditis elegans was tested for their potential to inhibit larval development of Haemonchus contortus. Methods The effect of Coprinopsis cinerea lectins - CCL2, CGL2, CGL3; Aleuria aurantia lectin – AAL; Marasmius oreades agglutinin - MOA; and Laccaria bicolor lectin – Lb-Tec2, on cultivated Haemonchus contortus larval stages was investigated using a larval development test (LDT). To validate the results of the toxicity assay and determine lectin binding capacity to the nematode digestive tract, biotinylated versions of lectins were fed to pre-infective larval stages of H. contortus and visualized by fluorescent microscopy. Lectin histochemistry on fixed adult worms was performed to investigate the presence and localisation of lectin binding sites in the disease-relevant developmental stage. Results Using an improved larval development test we found that four of the six tested lectins: AAL, CCL2, MOA and CGL2, exhibited a dose-dependent toxicity in LDT, as measured by the number of larvae developing to the L3 stage. In the case of AAL, CGL2 and MOA lectin, doses as low as 5 μg/ml caused >95 % inhibition of larval development while 40 μg/ml were needed to achieve the same inhibition by CCL2 lectin. MOA was the only lectin tested that caused larval death while other toxic lectins had larvistatic effect manifesting as L1 growth arrest. Using lectin histochemistry we demonstrate that of all lectins tested, only the four toxic ones displayed binding to the larvae’s gut and likewise were found to interact with glycans localized to the gastrodermal tissue of adults. Conclusion The results of our study suggest a correlation between the presence of target glycans of lectins in the digestive tract and the lectin-mediated toxicity in Haemonchus contortus. We demonstrate that binding to the structurally conserved glycan structures found in H. contortus gastrodermal tissue by the set of fungal lectins has detrimental effect on larval development. Some of these glycan structures might represent antigens which are not exposed to the host immune system (hidden antigens) and thus have a potential for vaccine or drug development. Nematotoxic fungal lectins prove to be a useful tool to identify such targets in parasitic nematodes. Electronic supplementary material The online version of this article (doi:10.1186/s13071-015-1032-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Christian Heim
- Institute of Parasitology, University of Zurich, Winterthurerstrasse 266a, 8057, Zurich, Switzerland.
| | - Hubertus Hertzberg
- Institute of Parasitology, University of Zurich, Winterthurerstrasse 266a, 8057, Zurich, Switzerland.
| | - Alex Butschi
- Malcisbo AG, Wagistrasse 27a, 8952, Schlieren, Switzerland.
| | - Silvia Bleuler-Martinez
- Institute of Microbiology, Swiss Federal Institute of Technology (ETH) Zürich, 8093, Zürich, Switzerland.
| | - Markus Aebi
- Institute of Microbiology, Swiss Federal Institute of Technology (ETH) Zürich, 8093, Zürich, Switzerland.
| | - Peter Deplazes
- Institute of Parasitology, University of Zurich, Winterthurerstrasse 266a, 8057, Zurich, Switzerland.
| | - Markus Künzler
- Institute of Microbiology, Swiss Federal Institute of Technology (ETH) Zürich, 8093, Zürich, Switzerland.
| | - Saša Štefanić
- Institute of Parasitology, University of Zurich, Winterthurerstrasse 266a, 8057, Zurich, Switzerland.
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Comparative immunoprophylactic efficacy of Haemonchus contortus recombinant enolase (rHcENO) and Con A purified native glycoproteins in sheep. Exp Parasitol 2015; 154:98-107. [PMID: 25913090 DOI: 10.1016/j.exppara.2015.04.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Revised: 04/07/2015] [Accepted: 04/19/2015] [Indexed: 01/13/2023]
Abstract
Haemonchus contortus is the most economically important blood feeding nematode parasite of sheep and goats all over the world. Enolase in helminth parasites is a multi-functional enzyme which involves in glycolysis and host tissue invasion. In this study, the recombinant H. contortus enolase (rHcENO) was evaluated for its immunoprophylactic efficacy in sheep along with Con A purified native glycoproteins in a vaccine challenge trial. Group I and Group II experimental sheep were immunized thrice with rHcENO and Con A purified native glycoproteins along with Montanide ISA 61 VG adjuvant. The animals were challenged with 5000 L3 stage active H. contortus larvae after 21 days of third immunization. A significant increase in the IgG titre was observed in rHcENO and Con A purified native glycoproteins immunized animals as compared to the control animals. Immunoprotective efficacy of Con A purified native glycoproteins was comparatively higher than rHcENO antigen.
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Bassetto C, Picharillo M, Newlands G, Smith W, Fernandes S, Siqueira E, Amarante A. Attempts to vaccinate ewes and their lambs against natural infection with Haemonchus contortus in a tropical environment. Int J Parasitol 2014; 44:1049-54. [DOI: 10.1016/j.ijpara.2014.07.007] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Revised: 07/22/2014] [Accepted: 07/23/2014] [Indexed: 11/24/2022]
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Abstract
Helminth parasites infect over one fourth of the human population and are highly prevalent in livestock worldwide. In model systems, parasites are strongly immunomodulatory, but the immune system can be driven to expel them by prior vaccination. However, no vaccines are currently available for human use. Recent advances in vaccination with recombinant helminth antigens have been successful against cestode infections of livestock and new vaccines are being tested against nematode parasites of animals. Numerous vaccine antigens are being defined for a wide range of helminth parasite species, but greater understanding is needed to define the mechanisms of vaccine-induced immunity, to lay a rational platform for new vaccines and their optimal design. With human trials underway for hookworm and schistosomiasis vaccines, a greater integration between veterinary and human studies will highlight the common molecular and mechanistic pathways, and accelerate progress towards reducing the global health burden of helminth infection.
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Zhou QJ, Yang Y, Guo XL, Duan LJ, Chen XQ, Yan BL, Zhang HL, Du AF. Expression of Caenorhabditis elegans-expressed Trans-HPS, partial aminopeptidase H11 from Haemonchus contortus. Exp Parasitol 2014; 145:87-98. [PMID: 25128369 DOI: 10.1016/j.exppara.2014.08.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2014] [Revised: 06/29/2014] [Accepted: 08/04/2014] [Indexed: 01/26/2023]
Abstract
Aminopeptidase H11 present in the surface of intestine microvilli in Haemonchus contortus was identified as the most effective antigen candidate. However, its recombinant forms produced in Escherichiacoli, insect cells and yeast could not provide promising protection against H. contortus challenge, probably due to the inappropriate glycosylation and/or conformational folding. Herein, partial H11 containing the potential zinc-binding domain and two predicted glycosylation sites (nt 1 bp-1710 bp, Trans-HPS) was subcloned downstream of 5' flanking region of Caenorhabditis elegans cpr-1 gene in pPD95.77 vector, with the deletion of GFP gene. The recombinant was expressed in C. elegans and verified by blotting with anti-H11 and anti-Trans-HPS rabbit polyclonal antibodies and anti-His monoclonal antibody. Stably inherited Trans-HPS in worm descendants was achieved by integration using UV irradiation. Immunization with the crude Trans-HPS extracted from transgenic worms resulted in 37.71% reduction in faecal egg counts (FEC) (P<0.05) and 24.91% reduction in worm burden, but an upward curve with moderate rate of daily FEC in goats. These results suggested an apparent delay against H. contortus egg-laying in goats, which differed from that with bacteria-origin form of partial H11 (nt 670 bp-1710 bp, HPS) (26.04% reduction in FEC and 18.46% reduction in worm burden). These findings indicate the feasibility of sufficient C. elegans-expressed H11 for the immunological research and vaccine development.
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Affiliation(s)
- Qian-Jin Zhou
- School of Marine Science, Ningbo University, Ningbo 315211, China; Institute of Preventive Veterinary Medicine, Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Zhejiang University, Hangzhou 310058, China
| | - Yi Yang
- Institute of Preventive Veterinary Medicine, Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Zhejiang University, Hangzhou 310058, China
| | - Xiao-Lu Guo
- Institute of Preventive Veterinary Medicine, Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Zhejiang University, Hangzhou 310058, China
| | - Li-Jun Duan
- Institute of Preventive Veterinary Medicine, Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Zhejiang University, Hangzhou 310058, China
| | - Xue-Qiu Chen
- Institute of Preventive Veterinary Medicine, Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Zhejiang University, Hangzhou 310058, China
| | - Bao-Long Yan
- Institute of Preventive Veterinary Medicine, Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Zhejiang University, Hangzhou 310058, China
| | - Hong-Li Zhang
- Institute of Preventive Veterinary Medicine, Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Zhejiang University, Hangzhou 310058, China
| | - Ai-Fang Du
- Institute of Preventive Veterinary Medicine, Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Zhejiang University, Hangzhou 310058, China.
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Fitzpatrick J. Global food security: The impact of veterinary parasites and parasitologists. Vet Parasitol 2013; 195:233-48. [DOI: 10.1016/j.vetpar.2013.04.005] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Knox D. Proteases in blood-feeding nematodes and their potential as vaccine candidates. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2011; 712:155-76. [PMID: 21660664 DOI: 10.1007/978-1-4419-8414-2_10] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Parasitic nematodes express and secrete a variety of proteases which they use for many purposes including the penetration of host tissues, digestion of host protein for nutrients, evasion of host immune responses and for internal processes such as tissue catabolism and apoptosis. For these broad reasons they have been examined as possible parasite control targets. Blood-feeding nematodes such as the barber-pole worm Haemonchus contortus that infect sheep and goats and the hookworms, Ancylostoma spp. and Necator americanus, affecting man, use an array of endo- and exopeptidases to digest the blood meal. Haemoglobin digestion occurs by an ordered and partly conserved proteolytic cascade. These proteases are accessible to host immune responses which can block enzyme function and lead to parasite expulsion and/or death. Thus they are receiving attention as components of vaccines against several parasitic nematodes of social and economic importance.
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Affiliation(s)
- David Knox
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, Midlothian, Scotland, UK.
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Pearson MS, Ranjit N, Loukas A. Blunting the knife: development of vaccines targeting digestive proteases of blood-feeding helminth parasites. Biol Chem 2010; 391:901-11. [DOI: 10.1515/bc.2010.074] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
AbstractProteases are pivotal to parasitism, mediating biological processes crucial to worm survival including larval migration through tissue, immune evasion/modulation and nutrient acquisition by the adult parasite. In haematophagous parasites, many of these proteolytic enzymes are secreted from the intestine (nematodes) or gastrodermis (trematodes) where they act to degrade host haemoglobin and serum proteins as part of the feeding process. These proteases are exposed to components of the immune system of the host when the worms ingest blood, and therefore present targets for the development of anti-helminth vaccines. The protective effects of current vaccine antigens against nematodes that infect humans (hookworm) and livestock (barber's pole worm) are based on haemoglobin-degrading intestinal proteases and act largely as a result of the neutralisation of these proteases by antibodies that are ingested with the blood-meal. In this review, we survey the current status of helminth proteases that show promise as vaccines and describe their vital contribution to a parasitic existence.
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The gene structure and promoter region of the vaccine target aminopeptidase H11 from the blood-sucking nematode parasite of ruminants, Haemonchus contortus. Funct Integr Genomics 2010; 10:589-601. [DOI: 10.1007/s10142-010-0172-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2010] [Revised: 03/29/2010] [Accepted: 04/01/2010] [Indexed: 12/17/2022]
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Donald D, Chen Y, Hartman D, Zawadzki JL. Haemonchus contortus: evaluation of two signal sequence trapping systems for detection of secreted molecules. Exp Parasitol 2008; 119:49-57. [PMID: 18267320 DOI: 10.1016/j.exppara.2007.12.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2007] [Revised: 11/23/2007] [Accepted: 12/17/2007] [Indexed: 10/22/2022]
Abstract
Given that signal sequences between secreted proteins of different species can be interchanged, it is reasonable to expect that both mammalian and yeast signal sequence trapping (SST) systems would secrete Haemonchus contortus proteins with similar efficiency and quality. To determine if H. contortus cDNAs that contain a signal sequence could re-establish secretion of a reporter protein, mammalian and yeast SST vectors were designed, 10 H. contortus genes selected, and their respective cDNAs cloned into these two SST vectors. The selected molecules included genes known to code for excretory/secretory or membrane-bound proteins as potential test 'positives', and genes known to code for non-secreted proteins as test 'negatives'. While differentiation between secretion and non-secretion was evident in both systems, the results indicated greater efficiency was achieved when the mammalian system was used. Therefore, mammalian SST using COS cells would be a more useful tool to screen H. contortus cDNA libraries for potential secreted and type-1 integral membrane proteins than yeast SST.
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Affiliation(s)
- Debbie Donald
- Department of Primary Industries Victoria, 475 Mickleham Road, Attwood, Vic. 3049, Australia
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Jensen J, Vieira-Bressan M. Protection against high-dose homologous infection in calves immunized with intestine or membrane extracts from Haemonchus placei. Vet Parasitol 2008; 151:344-50. [DOI: 10.1016/j.vetpar.2007.10.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2007] [Revised: 10/10/2007] [Accepted: 10/18/2007] [Indexed: 10/22/2022]
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Nisbet AJ, Redmond DL, Matthews JB, Watkins C, Yaga R, Jones JT, Nath M, Knox DP. Stage-specific gene expression in Teladorsagia circumcincta (Nematoda: Strongylida) infective larvae and early parasitic stages. Int J Parasitol 2007; 38:829-38. [PMID: 18062971 DOI: 10.1016/j.ijpara.2007.10.016] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2007] [Revised: 10/10/2007] [Accepted: 10/16/2007] [Indexed: 10/22/2022]
Abstract
Suppression subtractive hybridisation was used to enrich genes expressed in a stage-specific manner in infective, exsheathed L3s (xL3) versus early L4s of the ovine nematode, Teladorsagia circumcincta prior to gene expression profiling by microarray. The 769 cDNA sequences obtained from the xL3-enriched library contained 361 unique sequences, with 292 expressed sequence tags (ESTs) being represented once ("singletons") and 69 sequences which were represented more than once (overlapping and non-overlapping "contigs"). The L4-enriched EST dataset contained 472 unique sequences, with 314 singletons and 158 contigs. Of these 833 sequences, 85% of the xL3 sequences and 86% of the L4 sequences exhibited homology to known genes or ESTs derived from other species of nematode. Quantitative differential expression (P<0.05) was demonstrated for 563 (68%) of the ESTs by microarray. Within the L3-specific dataset, more than 30% of the transcripts represented the enzyme, guanosine-5'-triphosphate (GTP)-cyclohydrolase, which is the first and rate-limiting enzyme of the tetrahydrobiopterin synthesis pathway and may be involved in critical elements of larval development. In L4s, proteolytic enzymes were highly up-regulated, as were collagens and a number of previously characterised secretory proteins, reflecting the rapid growth of these larvae in abomasal glands. Nucleotide sequence data reported in this paper are available in the EMBL, GenBank and DDJB databases under accession numbers AM 743198-AM 744942.
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Affiliation(s)
- Alasdair J Nisbet
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, UK.
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27
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Reszka N, Rijsewijk FAM, Zelnik V, Moskwa B, Bieńkowska-Szewczyk K. Haemonchus contortus: characterization of the baculovirus expressed form of aminopeptidase H11. Exp Parasitol 2007; 117:208-13. [PMID: 17482594 DOI: 10.1016/j.exppara.2007.03.018] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2006] [Revised: 03/21/2007] [Accepted: 03/27/2007] [Indexed: 11/16/2022]
Abstract
Recombinant form of Haemonchus contortus aminopeptidase H11, an intestinal membrane glycoprotein considered to be in its native form the most promising vaccine candidate, was produced in insect cells, characterised and tested in pilot vaccination-challenge trial on sheep. The sequence of the cloned gene, obtained by RT PCR isolated from adult worms, showed 97% identity to the highly immunogenic H11 clone, described by Graham et al., (database accession number AJ249941.1). A 1305 bp fragment of H11 was expressed in E. coli and used to raise a specific antiserum, which recognized recombinant forms of H11 and 110 kDa protein from H. contortus extract. H11 was expressed by baculovirus recombinants in insect cells in full length and as a fusion protein with H. contortus glutathione S-transferase (GST). The baculovirus produced recombinant antigens were used without adjuvants to immunize sheep, which resulted in 30% (full length H11) and 20% (GST-H11) reduction of worm burden. These animal experiments indicated that, although the protection induced by in vitro produced protein is lower than in case of H11 isolated from worms, recombinant forms of aminopeptidase may be considered as antigens for the control of haemonchosis.
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Affiliation(s)
- Natalia Reszka
- University of Gdańsk, Department of Molecular Virology, Kładki 24, 80-822 Gdańsk, Poland
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Bethony JM, Loukas A, Hotez PJ, Knox DP. Vaccines against blood-feeding nematodes of humans and livestock. Parasitology 2007; 133 Suppl:S63-79. [PMID: 17274849 DOI: 10.1017/s0031182006001818] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
This paper summarises the progress towards vaccine development against the major blood-feeding nematodes of man and livestock, the hookworms and Haemonchus contortus, respectively. The impact of the diseases and the drivers for vaccine development are summarized as well as the anticipated impact of the host immune response on vaccine design. The performance requirements are discussed and progress towards these objectives using defined larval and adult antigens, many of these being shared between species. Specific examples include the Ancylostoma secreted proteins and homologues in Haemonchus as well as proteases used for digestion of the blood meal. This discussion shows that many of the major vaccine candidates are shared between these blood-feeding species, not only those from the blood-feeding stages but also those expressed by infective L3s in the early stages of infection. Challenges for the future include: exploiting the expanding genome information for antigen discovery, use of different recombinant protein expression systems, formulation with new adjuvants, and novel methods of field testing vaccine efficacy.
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Affiliation(s)
- J M Bethony
- Centro de Pesquisas René Rachou/CPqRR, A FIOCRUZ em Minas Gerais. Rene Rachou Research Center/CPqRR, The Oswaldo Cruz Foundation, Minas Gerais, Brazil.
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29
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Smith WD, Zarlenga DS. Developments and hurdles in generating vaccines for controlling helminth parasites of grazing ruminants. Vet Parasitol 2006; 139:347-59. [PMID: 16750599 DOI: 10.1016/j.vetpar.2006.04.024] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
As a direct consequence of rising drug resistance among common nematodes of grazing animals, efforts toward state-of-the-art vaccine development have clearly intensified in recent years, fuelled primarily by the advent of newer technologies in gene discovery, by advancements in antigen identification, characterisation and production. In this regard, it is appropriate to review progress that has been made in generating helminth vaccines and in particular, vaccines against common nematodes of production animals for consumption. In like manner, it is prudent to evaluate barriers that have hindered progress in the past and continue to present obstacles that must be solved when utilizing and depending on host immunity to attenuate parasitic infections.
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Affiliation(s)
- W D Smith
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, Scotland, UK.
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POKHAREL DR, RATHAUR S. Helminth proteases: the leading vaccine candidates against helminth infections. Parasite Immunol 2006. [DOI: 10.1111/j.1365-3024.2006.00855.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Abstract
The increasing prevalence of anthelmintic resistance has provided a spur for research into 'alternative/novel' approaches to the control of helminthoses that are intended to reduce our reliance upon using chemoprophylaxis. The different approaches either target the parasite population in the host or on pasture, but the goal of all of them is to restrict host parasite contact to levels which minimise the impact of helminths on host welfare and/or performance. Infrapopulation regulation can be achieved through methods that enhance immunity such as optimised nutrition (immunonutrition), genetic selection and vaccination, or by an 'anthelmintic' route using bioactive forages, copper oxide wire particles, or use of targeted selective treatment strategies such as FAMACHA, which reduce the selection pressure for the development of resistance by maintaining a population in refugia. Suprapopulation control can be achieved through grazing management, or by using predacious fungi such as Duddingtonia flagrans. All of these approaches have been developed beyond the proof of concept stage and some are capable of being employed currently. However, some still require knowledge transfer, or commercialisation before they can be tested and widely applied in the field. All of the different approaches present unique challenges to the researchers engaged in developing them, and in comparison to simple prescriptive anthelmintic treatments, their use appears complex and requires some expertise on behalf of the advisor and/or end user. At present, most of our data are derived from trials using single approaches, but it is apparent that we need to move towards integrating some of these technologies which again represents a further challenge to the extension/advisory services. Progress in establishing different approaches requires not only the funding to support their scientific development but also to support the development of computer based models which can be used to highlight deficiencies in our understanding of the control mechanisms and to identify impediments to their introduction. It is inevitable that some of the approaches currently under investigation will fail to become widely applied for a variety of reasons that are not solely financial. These include issues concerned with practicability/applicability, affordability/appropriateness, availability/deliverability and above all, the failure to provide a consistent, reliable effect when used under commercial farming conditions.
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Affiliation(s)
- Frank Jackson
- Moredun Research Institute, Department of Parasitology, Bush Loan, Pentland Science Park, Edinburgh, Scotland, UK.
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Newlands GFJ, Skuce PJ, Nisbet AJ, Redmond DL, Smith SK, Pettit D, Smith WD. Molecular characterization of a family of metalloendopeptidases from the intestinal brush border of Haemonchus contortus. Parasitology 2006; 133:357-68. [PMID: 16740178 DOI: 10.1017/s0031182006000217] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2006] [Revised: 02/27/2006] [Accepted: 02/27/2006] [Indexed: 11/07/2022]
Abstract
Substantial protection against the economically important parasitic nematode Haemonchus contortus has been achieved by immunizing sheep with a glycoprotein fraction isolated from the intestinal membranes of the worm (H-gal-GP). Previous studies showed that one of the major components of H-gal-GP is a family of at least 4 zinc metalloendopeptidases, designated MEPs 1–4. This paper describes aspects of the molecular architecture of this protease family, including the proteomic analysis of the MEP fraction of the H-gal-GP complex. These enzymes belong to the M13 zinc metalloendopeptidase family (EC 3.4.24.11), also known as neutral endopeptidases or neprilysins. The sequences of MEPs 1 and 3 suggested a typical Type II integral membrane protein structure, whilst MEPs 2 and 4 had putative cleavable signal peptides, typical of secreted proteins. Proteomic analysis of H-gal-GP indicated that the extracellular domain of all 4 MEPs had been cleaved close to the transmembrane region/signal peptide with additional cleavage sites mid-way along the polypeptide. MEP3 was present as a homo-dimer in H-gal-GP, whereas MEP1 or MEP2 formed hetero-dimers with MEP4. It was found that expression of MEP3 was confined to developing 4th-stage larvae and to adult worms, the stages of Haemonchus which feed on blood. MEP-like activity was detected in the H-gal-GP complex over a broad pH range (5–9). Since all 4 MEPs must share a similar microenvironment in the complex, this suggests that each might have a different substrate specificity.
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Affiliation(s)
- G F J Newlands
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, Midlothian EH26 OPZ, Scotland.
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Nikolaou S, Hartman D, Nisbet AJ, Gasser RB. Haemonchus contortus: prokaryotic expression and enzyme activity of recombinant HcSTK, a serine/threonine protein kinase. Exp Parasitol 2006; 113:207-14. [PMID: 16500645 DOI: 10.1016/j.exppara.2006.01.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2005] [Revised: 01/09/2006] [Accepted: 01/10/2006] [Indexed: 11/19/2022]
Abstract
Members of the PAR-1/MARK serine/threonine protein kinase (STK) subfamily are important regulators of the cytoskeleton, and their characterization can provide insights into a number of critical processes relating to the development and survival of an organism. We previously investigated the mRNA expression for and organization of a gene (hcstk) representing HcSTK, an STK from the parasitic nematode Haemonchus contortus. In the present study, a recombinant form of HcSTK was expressed and characterized. Affinity-purified anti-HcSTK antibodies reacted with native HcSTK in protein homogenates extracted from third-stage larvae (L3) of H. contortus and were also used to immunolocalize the protein around the nuclei of ovarian and intestinal tissues of adult H. contortus. The enzyme activity of the recombinant HcSTK protein was also demonstrated. The findings show that recombinant HcSTK is a functional protein kinase, with activity directed to KXGS motifs, consistent with other members of the PAR-1/MARK STK subfamily.
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Affiliation(s)
- Sia Nikolaou
- Primary Industries Research Victoria (Animal Genetics and Genomics), 475 Mickleham Road, Attwood, Vic. 3049, Australia
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Lilley CJ, Goodchild SA, Atkinson HJ, Urwin PE. Cloning and characterisation of a Heterodera glycines aminopeptidase cDNA. Int J Parasitol 2005; 35:1577-85. [PMID: 16216247 DOI: 10.1016/j.ijpara.2005.07.017] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2005] [Revised: 06/21/2005] [Accepted: 07/28/2005] [Indexed: 11/28/2022]
Abstract
An aminopeptidase full-length cDNA (Hg-amp-1) was cloned from the adult female soybean cyst nematode Heterodera glycines by heterologous screening of a cDNA library with a Caenorhabditis elegans EST sequence. The predicted open reading frame encoded an 882-amino acid protein containing the conserved zinc-binding domain and GAMEN motif that are characteristic of M1 family aminopeptidases. The putative protein lacks any subcellular targeting signals and displays strong similarity to puromycin-sensitive aminopeptidases from C. elegans, Drosophila and mammals. Hg-amp-1 is expressed in juvenile nematodes and both male and female adults, with highest expression in gravid females. In situ mRNA hybridisation localised the Hg-amp-1 transcript to the genital primordium of pre-parasitic juvenile nematodes and the reproductive tract of adult females. Suppression of Hg-amp-1 transcript level by RNA-interference led to a 61% reduction in the number of female nematodes parasitising soybean roots 21 days post infection with infective juvenile nematodes that had been exposed to double-stranded RNA.
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35
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Redmond DL, Windham R. Characterization of proteinases in different isolates of adult Haemonchus contortus. Parasitology 2004; 130:429-35. [PMID: 15830817 DOI: 10.1017/s0031182004006687] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
A high degree of intra- and inter-geographical variation has been demonstrated previously in the excretory/secretory proteinases released by adult Haemonchus contortus. Proteinase activity has also been associated with host-protective ‘hidden’ antigens isolated from the gut of adult H. contortus. If similar geographical strain variation also exists within the gut-associated proteinases, this will have important implications for the development of a globally effective vaccine. The proteinases active in integral-membrane protein extracts from 3 different strains of adult H. contortus were characterized on the basis of their pH optima and molecular size. Although enzyme activity was detected over a wide pH range, the majority of proteinase activity was detected at acidic pH. Differences in specific activity and size of enzymes were observed between the 3 different parasite strains at different pH values. A high degree of conservation in reactive peptides was observed when protein extracts were probed with antisera raised to the protective hidden gut-antigen complexes isolated from the Moredun strain of H. contortus, or to bacterially expressed subcomponents thereof. Therefore, despite the observed differences in membrane-bound proteinase profiles, the similarity of the immunogenic response against these hidden antigens may be sufficient to prove protective against different geographical isolates of H. contortus.
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Affiliation(s)
- D L Redmond
- Moredun Research Institute, International Research Centre, Pentlands Science Park, Bush Loan, Penicuik, Midlothian EH26 0PZ, Scotland, UK.
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36
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Knox DP, Redmond DL, Newlands GF, Skuce PJ, Pettit D, Smith WD. The nature and prospects for gut membrane proteins as vaccine candidates for Haemonchus contortus and other ruminant trichostrongyloids. Int J Parasitol 2004; 33:1129-37. [PMID: 13678629 DOI: 10.1016/s0020-7519(03)00167-x] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Substantial progress has been made in the last decade in identifying several antigens from Haemonchus contortus which, in their native form, stimulate useful levels of protective immunity (70-95% reductions in faecal egg output) in the ovine host. Much work has focussed on proteins/protein complexes expressed on the surface of the worm gut which are exposed to the blood meal, and, hence, antibody ingested with it. The antigens generally, but not in all cases, show protease activity and antibody is thought to mediate protective immunity by blocking the activity of enzymes involved in digestion within the worm. This review summarises the protective efficacy, as well as the biochemical and molecular properties, of the principal candidate antigens which are expressed in the gut of these parasites. Of course, such antigens will have to be expressed as recombinant proteins to be sufficiently cost-effective for use in a commercial vaccine and the current status of recombinant antigen expression is discussed with particular reference to conformation and glycosylation. There is a need for continued antigen definition even in the confines of gut antigens and potential targets can be selected from the rapidly expanding genome/EST datasets on the basis of predicted functional homology. Gene knockout technologies such as RNA interference have the potential to provide high throughput, rapid and inexpensive methods to define whether the protein product of a particular gene would be a suitable vaccine candidate.
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Affiliation(s)
- David P Knox
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, Scotland, EH 26 0PZ, Midlothian, UK.
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Williamson AL, Brindley PJ, Knox DP, Hotez PJ, Loukas A. Digestive proteases of blood-feeding nematodes. Trends Parasitol 2003; 19:417-23. [PMID: 12957519 DOI: 10.1016/s1471-4922(03)00189-2] [Citation(s) in RCA: 145] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Blood-feeding parasites employ a battery of proteolytic enzymes to digest the contents of their bloodmeal. Host haemoglobin is a major substrate for these proteases and, therefore, a driving force in the evolution of parasite-derived proteolytic enzymes. This review will focus on the digestive proteases of the major blood-feeding nematodes - hookworms (Ancylostoma spp. and Necator americanus) and the ruminant parasite, Haemonchus contortus - but also compares and contrasts these proteases with recent findings from schistosomes and malaria parasites. Haematophagous nematodes express proteases of different mechanistic classes in their intestines, many of which have proven or putative roles in degradation of haemoglobin and other proteins involved in nutrition. Moreover, the fine specificity of the relationships between digestive proteases and their substrate proteins provides a new molecular paradigm for understanding host-parasite co-evolution. Numerous laboratories are actively investigating these molecules as antiparasite vaccine targets.
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Affiliation(s)
- Angela L Williamson
- Department of Microbiology and Tropical Medicine, George Washington University Medical Center, Washington DC 20037, USA
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Maehashi K, Abe T, Yasuhara T, Yamasato K, Yamamoto Y, Udaka S. Purification and characterization of a novel glutamyl aminopeptidase from chicken meat. Meat Sci 2003; 64:163-8. [DOI: 10.1016/s0309-1740(02)00175-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2002] [Revised: 06/20/2002] [Accepted: 06/20/2002] [Indexed: 10/27/2022]
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Newton SE, Meeusen ENT. Progress and new technologies for developing vaccines against gastrointestinal nematode parasites of sheep. Parasite Immunol 2003; 25:283-96. [PMID: 12969446 DOI: 10.1046/j.1365-3024.2003.00631.x] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Despite the identification of highly effective native antigens for vaccination against Haemonchus contortus, particularly 'hidden' antigens derived from the intestine of adult worms, to date similar efficacy has not been shown with recombinant antigens. In addition, progress towards identification of protective antigens from other sheep gastrointestinal (GI) nematode species is limited. Coupled with this is an incomplete understanding of the mechanism of natural immunity to GI nematodes, making selection of appropriate immunization strategies and adjuvants for evaluation of candidate 'natural' antigens problematic. The current explosion in new high-throughput technologies, arising from human studies, for analysis of the genome, transcriptome, proteome and glycome offers the opportunity to gain a better understanding of the molecular pathways underlying pathogen biology, the host immune system and the host-pathogen interaction. An overview is provided on how these technologies can be applied to parasite research and how they may aid in overcoming some of the current problems in development of commercial vaccines against GI nematode parasites.
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Affiliation(s)
- S E Newton
- Victorian Institute of Animal Science, 475 Mickleham Road, Attwood, Victoria, 3049, Australia
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40
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Abstract
The study of gene function in parasitic worms is technically demanding due to difficulties associated with life-cycle propagation and, hence, molecular genetics. Exploitation of the free-living nematode, Caenorhabditis elegans, coupled with recent major advances in molecular studies of parasitic nematodes, have opened up new avenues for understanding the biology of these parasites and present opportunities for novel strategies of therapeutic intervention and control.
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Affiliation(s)
- Darren R Brooks
- Faculty of Biological Sciences, University of Leeds, West Yorkshire, Leeds LS2 9JT, UK.
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41
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Jones BF, Hotez PJ. Molecular cloning and characterization of Ac-mep-1, a developmentally regulated gut luminal metalloendopeptidase from adult Ancylostoma caninum hookworms. Mol Biochem Parasitol 2002; 119:107-16. [PMID: 11755191 DOI: 10.1016/s0166-6851(01)00409-1] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
A zinc metalloendopeptidase cDNA (Ac-mep-1) was cloned from Ancylostoma caninum adult hookworms. Ac-mep-1 is encoded by a 2.8 kb mRNA with a predicted open reading frame (ORF) of 870 amino acids (predicted pI=5.5, m.w.=98.7 kDa) that contains four potential N-linked glycosylation sites and predicted zinc-binding domains (HExxH and ENxADxGG). These domains represent signature sequences of the Neutral Endopeptidase 24.11 (neprilysin) family of enzymes. The ORF corresponding to Ac-MEP-1 exhibited strong similarity to metalloproteases from the trichostrongyle Haemonchus contortus as well as Caenorhabditis elegans. RT-PCR analysis of A. caninum eggs, L1, non-activated and activated L3 and adult cDNA identify transcription of Ac-MEP-1 only in the adult stage of the parasite. Mouse antibody raised to the expressed protein recognized proteins of approximately 90 and 100 kDa in adult hookworm extracts. Adult worm sections probed with these antisera localized Ac-mep-1 to the microvilli of the worm gastrointestinal tract suggesting a possible role for this enzyme in digestion of the parasite blood meal.
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Affiliation(s)
- Brian F Jones
- Medical Helminthology Laboratory, Department of Epidemiology and Public Health, Yale University School of Medicine, New Haven, CT 06510, USA
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42
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Knox DP, Redmond DL, Skuce PJ, Newlands GF. The contribution of molecular biology to the development of vaccines against nematode and trematode parasites of domestic ruminants. Vet Parasitol 2001; 101:311-35. [PMID: 11707304 DOI: 10.1016/s0304-4017(01)00558-1] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Rapid developments in molecular biology have had an enormous impact on the prospects for the development of vaccines to control the major nematode and trematode infestations of livestock. Vaccine candidates are purified using conventional protein chemistry techniques but the limitations imposed by the scarcity of parasite material provide an insurmountable barrier for commercial vaccine production by this means. The ability to purify mRNA from different parasite life-cycle stages and to prepare cDNA expression libraries from it has proven central to the identification of immunogenic parasite proteins. Potentially, protective parasite antigens can now be produced in recombinant form in a variety of vectors and this represents a key breakthrough on the road to commercial vaccine production. The contribution of molecular biology to this process is discussed using several examples, particularly in vaccine development against the pathogenic abomasal nematode of sheep and goats, Haemonchus contortus, and the liver fluke of sheep and cattle, Fasciola hepatica. The difficulties of producing recombinant proteins in the correct form, with appropriate post-translational modification and conformation, are discussed as well as emerging means of antigen delivery including DNA vaccination. The opportunities offered by genome and expressed sequence tag analyses programmes for antigen targeting are discussed in association with developing microarray and proteomics technologies which offer the prospect of large scale, rapid antigen screening and identification.
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Affiliation(s)
- D P Knox
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, Midlothian EH26 0PZ, UK.
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Knox DP, Smith WD. Vaccination against gastrointestinal nematode parasites of ruminants using gut-expressed antigens. Vet Parasitol 2001; 100:21-32. [PMID: 11522403 DOI: 10.1016/s0304-4017(01)00480-0] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
To date, proteins isolated from the surface of the gut of gastrointestinal nematodes, particularly Haemonchus contortus, have generally proved to be useful protective antigens and several are being progressed towards recombinant protein-based vaccines. This paper describes the properties of some of the most promising antigens and summarises their performance in laboratory and field based trials. The antigens described include contortin, H11, H-gal-GP, GPI and cysteine proteinases. In addition, the discussion addresses the utility of selected antigens to protect against co-infecting nematode species such as Teladorsagia circumcincta and against related nematode infections such as Ostertagia ostertagi in cattle.
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Affiliation(s)
- D P Knox
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, Midlothian, Scotland EH26 0PZ, UK.
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Jasmer DP, Roth J, Myler PJ. Cathepsin B-like cysteine proteases and Caenorhabditis elegans homologues dominate gene products expressed in adult Haemonchus contortus intestine. Mol Biochem Parasitol 2001; 116:159-69. [PMID: 11522349 DOI: 10.1016/s0166-6851(01)00312-7] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Proteins expressed by nematode intestinal cells are potential targets for parasite control by immune or chemical based strategies. To expand our knowledge on nematode intestinal proteins, expressed sequence tags were generated for 131 cDNA clones from the intestine of adult female Haemonchus contortus. An estimated 55 distinct protein genes or gene families were identified. Predicted proteins represented diverse functions. Several predicted polypeptides were related to H. contortus proteins implicated in inducing protective immunity against challenge infections of this parasite. The dominant intestinal transcripts were represented by cathepsin B-like cysteine protease genes (cbl) (17% of protein coding expressed sequence tags (ESTs) analyzed). An estimated 11 previously undescribed cbl genes were identified, doubling the recognized members of this gene family. Multiple C-type lectin sequences were identified. Other notable sequences included a predicted Y-box binding protein, serine/threonine kinases and a cyclin E-like sequence. Predicted protein homologues were found in Caenorhabditis elegans for all but one H. contortus sequence (99%), while fewer homologues from other parasitic nematodes were found. Many of the proteases, lipase and C-type lectin homologues in C. elegans had apparent signal peptides, suggesting that they are secreted. Several gene products had no obvious similarity outside the phylum Nematoda. The ESTs identified intestinal genes with potential application to immune control, understanding of basic intestinal regulatory processes and refinement of nematode genomic resources.
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Affiliation(s)
- D P Jasmer
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA 99164-7040, USA.
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Smith WD, van Wyk JA, van Strijp MF. Preliminary observations on the potential of gut membrane proteins of Haemonchus contortus as candidate vaccine antigens in sheep on naturally infected pasture. Vet Parasitol 2001; 98:285-97. [PMID: 11423186 DOI: 10.1016/s0304-4017(01)00400-9] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
In a trial lasting 11 months in South Africa, faecal egg counts and haematocrits of sheep vaccinated with gut membrane proteins of adult Haemonchus contortus were compared with unvaccinated controls grazing pasture contaminated with the parasite. Vaccination reduced egg output by >82% on average during one 4 month period of the trial and simultaneously significantly reduced the degree of anaemia and deaths due to haemonchosis. Although vaccine immunity was not sufficiently long lasting to prevent a surge in egg output which occurred after the onset of a period of irrigation, re-vaccinating the sheep at this point cleared their newly acquired infection and rapidly restored protection to approximately the level observed beforehand. It was clear that a vaccine based on parasite gut membrane proteins could offer substantial benefits in the control of natural haemonchosis.
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Affiliation(s)
- W D Smith
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, Scotland EH26 OPZ, Midlothian, UK.
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46
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Abstract
The tools of molecular biology are increasingly relevant to veterinary parasitology. The sequencing of the complete genomes of Caenorhabditis elegans and other helminths and protozoa is allowing great advances in studying the biology, and improving diagnosis and control of parasites. Unique DNA sequences provide very high levels of specificity for the diagnosis and identification of parasite species and strains, and PCR allows extremely high levels of sensitivity. New techniques, such as the use of uniquely designed molecular beacons and DNA microarrays will eventually allow rapid screening for specific parasite genotypes and assist in diagnostic and epidemiological studies of veterinary parasites. The ability to use genome data to clone and sequence genes which when expressed will provide antigens for vaccine screening and receptors and enzymes for mechanism-based chemotherapy screening will increase our options for parasite control. In addition, DNA vaccines can have desirable characteristics, such as sustained stimulation of the host immune system compared with protein based vaccines. One of the greatest threats to parasite control has been the development of drug resistance in parasites. Our knowledge of the basis of drug resistance and our ability to monitor its development with highly sensitive and specific DNA-based assays for 'resistance'-alleles will help maintain the effectiveness of existing antiparasitic drugs and provide hope that we can maintain control of parasitic disease outbreaks.
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Affiliation(s)
- R Prichard
- Institute of Parasitology, McGill University, 21, 111 Lakeshore Road, Ste Anne-de-Bellevue, Pointe-Claire, Que., H9S 5G5, Canada.
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Abstract
Over the last decade, the anti-parasitics market has been the fastest growing sector of the overall $18 billion animal health market. While drugs for the treatment of parasites of livestock still dominate this sector and will continue to be developed or re-formulated, because of consumer demands for chemical-free food and of concerns regarding the environment and animal welfare there is a growing interest in the development of safe and effective vaccines. There is also a call for vaccines in the lucrative $3 billion-plus companion animal market. These demands for vaccines will add a greater impetus to an area that has seen tremendous success in the last 15 years. A number of anti-parasite vaccines have been developed, e.g. the recombinant 45w and EG95 oncosphere proteins against Taenia ovis and Echinococcus granulosis, respectively, and the Bm86 vaccine against Boophilus microplus. In addition, the cathepsin L vaccines against the liver fluke, Fasciola hepatica, and the H11 vaccine against Haemonchus contortus are progressing well. There are also many additional vaccine candidates for H. contortus and for other nematodes such as Ostertagia and Trichostrongylus spp. that may ultimately lead to broad-spectrum gastrointestinal worm vaccines. Live or attenuated-live vaccines are available for the control of avian coccidiosis, toxplasmosis in sheep and anaplasmosis in cattle, although molecular vaccines against protozoans are still proving elusive. The wealth of information in genomics, proteomics and immunology that has been forthcoming together will new methods of vaccine production and delivery should see many new vaccines reach the marketplace in the near future.
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Affiliation(s)
- J P Dalton
- School of Biotechnology, Dublin City University, Dublin 9, Ireland.
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48
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Redmond DL, Clucas C, Johnstone IL, Knox DP. Expression of Haemonchus contortus pepsinogen in Caenorhabditis elegans. Mol Biochem Parasitol 2001; 112:125-31. [PMID: 11166393 DOI: 10.1016/s0166-6851(00)00357-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A genomic copy of a gut-expressed Haemonchus contortus candidate vaccine antigen, pepsinogen, was isolated using the polymerase chain reaction (PCR). The isolated sequence was 4 kb in length and contained eight introns ranging in size from 54 to 1475 base pairs. This sequence, together with its 3' non-coding DNA region containing a polyadenylation signal sequence, was cloned into the Bluescript SK(+) vector immediately downstream of the Caenorhabditis elegans cpr-5 gene promoter. This promoter has been shown previously to direct protein expression to the gut of C. elegans. The construct was micro-injected into DR96 unc-76(e911) mutant C. elegans together with a rescue plasmid and transgenic worms identified by reversion back to wild-type phenotype. Two transgenic lines of C. elegans were established. The presence of the injected construct and of the Haemonchus pepsinogen transcript in transgenic worms was confirmed by PCR analysis. Correct splicing of intronic sequences was observed. Immunohistochemistry showed expression of the Haemonchus pepsinogen protein in the gut of transgenic C. elegans, with reactivity evident in the larval and adult stages. Expression of the Haemonchus pepsinogen in C. elegans affirms the role of C. elegans as a model for parasitic nematodes and demonstrates its potential as a vector for expression of candidate vaccine antigens from parasitic nematodes.
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Affiliation(s)
- D L Redmond
- Moredun Research Institute, International Research Centre, Pentlands Science Park, Midlothian EH26 0PZ, Penicuik, UK
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Gasser RB, Newton SE. Genomic and genetic research on bursate nematodes: significance, implications and prospects. Int J Parasitol 2000; 30:509-34. [PMID: 10731573 DOI: 10.1016/s0020-7519(00)00021-7] [Citation(s) in RCA: 89] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Molecular genetic research on parasitic nematodes (order Strongylida) is of major significance for many fundamental and applied areas of medical and veterinary parasitology. The advent of gene technology has led to some progress for this group of nematodes, particularly in studying parasite systematics, drug resistance and population genetics, and in the development of diagnostic assays and the characterisation of potential vaccine and drug targets. This paper gives an account of the molecular biology and genetics of strongylid nematodes, mainly of veterinary socio-economic importance, indicates the implications of such research and gives a perspective on genome research for this important parasite group, in light of recent technological advances and knowledge of the genomes of other metazoan organisms.
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Affiliation(s)
- R B Gasser
- Department of Veterinary Science, The University of Melbourne, 250 Princes Highway, Werribee, Victoria, Australia.
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Gal-Garber O, Uni Z. Chicken intestinal aminopeptidase: partial sequence of the gene, expression and activity. Poult Sci 2000; 79:41-5. [PMID: 10685887 DOI: 10.1093/ps/79.1.41] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Aminopeptidases are members of a membrane-bound metallopeptidase family that are expressed at a high level on the brush-border membrane of enterocytes. Because the rapid growth of meat-type chickens depends on the dietary supply of amino acids, a study of intestinal aminopeptidases, which play a central role in protein digestion, is important. This study is the first reported isolation of the partial cDNA of chicken intestinal aminopeptidase and sequencing of a 1.7-kb cDNA fragment. The gene was isolated by reverse transcriptase polymerase chain reaction using six primers chosen from conserved regions of the aminopeptidase genes. Amplified fragments were extracted from the gel, purified, and sequenced. By using this chicken cDNA as a probe, northern blot analysis revealed a transcript of approximately 3.5 kb in the chicken duodenum, jejunum, and ileum tissues. Higher RNA expression and activity of aminopeptidase were found in the ileum tissue compared with the duodenum and jejunum segments.
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Affiliation(s)
- O Gal-Garber
- Department of Animal Sciences, Faculty of Agricultural, Food and Environmental Quality Sciences, The Hebrew University of Jerusalem, Rehovot, Israel
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