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Moustafa A, Perbandt M, Liebau E, Betzel C, Falke S. Crystal structure of an extracellular superoxide dismutase from Onchocerca volvulus and implications for parasite-specific drug development. Acta Crystallogr F Struct Biol Commun 2022; 78:232-240. [PMID: 35647680 PMCID: PMC9158661 DOI: 10.1107/s2053230x22005350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Accepted: 05/19/2022] [Indexed: 11/17/2022] Open
Abstract
An extracellular Cu/Zn superoxide dismutase from Onchocerca volvulus, the causative agent of human onchocerciasis, was purified and crystallized and the structure was solved at 1.55 Å resolution. The solution structure of the dimeric protein was verified using small-angle X-ray scattering. Initial docking studies utilizing previously identified superoxide dismutase inhibitors indicate the potential for future drug development targeting structural features outside the active site. Superoxide dismutases (SODs) are metalloproteins that are responsible for the dismutation of superoxide anion radicals. SODs are consequently protective against oxidative damage to cellular components. Among other protective mechanisms, the filarial parasite Onchocerca volvulus has a well developed defense system to scavenge toxic free radicals using SODs during migration and sojourning of the microfilariae and adult worms in the human body. O. volvulus is responsible for the neglected disease onchocerciasis or ‘river blindness’. In the present study, an extracellular Cu/Zn-SOD from O. volvulus (OvEC-SOD) was cloned, purified and crystallized to obtain structural insight into an attractive drug target with the potential to combat onchocerciasis. The recombinant OvEC-SOD forms a dimer and the protein structure was solved and refined to 1.55 Å resolution by X-ray crystallography. Interestingly, a sulfate ion supports the coordination of the conserved copper ion. The overall protein shape was verified by small-angle X-ray scattering. The enzyme shows a different surface charge distribution and different termini when compared with the homologous human SOD. A distinct hydrophobic cleft to which both protomers of the dimer contribute was utilized for a docking approach with compounds that have previously been identified as SOD inhibitors to highlight the potential for individual structure-based drug development.
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Zhan B, Bottazzi ME, Hotez PJ, Lustigman S. Advancing a Human Onchocerciasis Vaccine From Antigen Discovery to Efficacy Studies Against Natural Infection of Cattle With Onchocerca ochengi. Front Cell Infect Microbiol 2022; 12:869039. [PMID: 35444961 PMCID: PMC9015098 DOI: 10.3389/fcimb.2022.869039] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Accepted: 03/07/2022] [Indexed: 11/19/2022] Open
Abstract
Human onchocerciasis is a devastating neglected tropical disease caused by infection of the filarial nematode Onchocerca volvulus. The infection can cause irreversible visual impairment or blindness and stigmatizing dermatitis. More than 32 million people were estimated to be infected with O. volvulus in Africa, and 385,000 suffered from blindness. Even though the implementation of mass drug administration (MDA) with ivermectin has reduced the global prevalence of onchocerciasis, O. volvulus infection remains challenging to control because MDA with ivermectin cannot be implemented in endemic areas co-endemic with loiasis due to the risk of severe adverse events. There is also emerging drug resistance to ivermectin that further complicates the elimination of onchocerciasis. Thus, the development of a vaccine that would induce protective immunity and reduce infection burden is essential. Efforts to develop prophylactic and/or therapeutic vaccines for onchocerciasis have been explored since the late 1980s by many researchers and entities, and here we summarize the recent advances made in the development of vaccines against the infection of O. volvulus and onchocerciasis.
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Affiliation(s)
- Bin Zhan
- Texas Children’s Hospital Center for Vaccine Development, Baylor College of Medicine, Houston, TX, United States
- *Correspondence: Bin Zhan,
| | - Maria Elena Bottazzi
- Texas Children’s Hospital Center for Vaccine Development, Baylor College of Medicine, Houston, TX, United States
| | - Peter J. Hotez
- Texas Children’s Hospital Center for Vaccine Development, Baylor College of Medicine, Houston, TX, United States
| | - Sara Lustigman
- Laboratory of Molecular Parasitology, Lindsley F. Kimball Research Institute, New York Blood Center, New York, NY, United States
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Mohd-Shaharuddin N, Lim YAL, Ngui R, Nathan S. Expression of Ascaris lumbricoides putative virulence-associated genes when infecting a human host. Parasit Vectors 2021; 14:176. [PMID: 33757548 PMCID: PMC7985925 DOI: 10.1186/s13071-021-04680-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 03/11/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Ascaris lumbricoides is the most common causative agent of soil-transmitted helminth infections worldwide, with an estimated 450 million people infected with this nematode globally. It is suggested that helminths are capable of evading and manipulating the host immune system through the release of a spectrum of worm proteins which underpins their long-term survival in the host. We hypothesise that the worm overexpresses these proteins when infecting adults compared to children to cirvumvent the more robust defence mechanisms of adults. However, little is known about the parasite's genes and encoded proteins involved during A. lumbricoides infection. Hence, this study was conducted to assess the expression profile of putative virulence-associated genes during an active infection of adults and children. METHODS In this study, quantitative PCR was performed to evaluate the expression profile of putative virulence-associated genes in A. lumbricoides isolated from infected children and adults. The study was initiated by collecting adult worms expelled from adults and children following anthelminthic treatment. High-quality RNA was successfully extracted from each of six adult worms expelled by three adults and three children, respectively. Eleven putative homologues of helminth virulence-associated genes reported in previous studies were selected, primers were designed and specific amplicons of A. lumbricoides genes were noted. The expression profiles of these putative virulence-associated genes in A. lumbricoides from infected adults were compared to those in A. lumbricoides from infected children. RESULTS The putative virulence-associated genes VENOM, CADHERIN and PEBP were significantly upregulated at 166-fold, 13-fold and fivefold, respectively, in adults compared to children. Conversely, the transcription of ABA-1 (fourfold), CATH-L (threefold) and INTEGRIN (twofold) was significantly suppressed in A. lumbricoides from infected adults. CONCLUSIONS On the basis of the expression profile of the putative virulence-associated genes, we propose that the encoded proteins have potential roles in evasion mechanisms, which could guide the development of therapeutic interventions.
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Affiliation(s)
| | - Yvonne Ai Lian Lim
- Department of Parasitology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Romano Ngui
- Department of Parasitology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Sheila Nathan
- Department of Biological Sciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Selangor, Malaysia.
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Gaikwad AS, Hu J, Chapple DG, O'Bryan MK. The functions of CAP superfamily proteins in mammalian fertility and disease. Hum Reprod Update 2020; 26:689-723. [PMID: 32378701 DOI: 10.1093/humupd/dmaa016] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 03/11/2020] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Members of the cysteine-rich secretory proteins (CRISPS), antigen 5 (Ag5) and pathogenesis-related 1 (Pr-1) (CAP) superfamily of proteins are found across the bacterial, fungal, plant and animal kingdoms. Although many CAP superfamily proteins remain poorly characterized, over the past decade evidence has accumulated, which provides insights into the functional roles of these proteins in various processes, including fertilization, immune defence and subversion, pathogen virulence, venom toxicology and cancer biology. OBJECTIVE AND RATIONALE The aim of this article is to summarize the current state of knowledge on CAP superfamily proteins in mammalian fertility, organismal homeostasis and disease pathogenesis. SEARCH METHODS The scientific literature search was undertaken via PubMed database on all articles published prior to November 2019. Search terms were based on following keywords: 'CAP superfamily', 'CRISP', 'Cysteine-rich secretory proteins', 'Antigen 5', 'Pathogenesis-related 1', 'male fertility', 'CAP and CTL domain containing', 'CRISPLD1', 'CRISPLD2', 'bacterial SCP', 'ion channel regulator', 'CatSper', 'PI15', 'PI16', 'CLEC', 'PRY proteins', 'ASP proteins', 'spermatogenesis', 'epididymal maturation', 'capacitation' and 'snake CRISP'. In addition to that, reference lists of primary and review article were reviewed for additional relevant publications. OUTCOMES In this review, we discuss the breadth of knowledge on CAP superfamily proteins with regards to their protein structure, biological functions and emerging significance in reproduction, health and disease. We discuss the evolution of CAP superfamily proteins from their otherwise unembellished prokaryotic predecessors into the multi-domain and neofunctionalized members found in eukaryotic organisms today. At least in part because of the rapid evolution of these proteins, many inconsistencies in nomenclature exist within the literature. As such, and in part through the use of a maximum likelihood phylogenetic analysis of the vertebrate CRISP subfamily, we have attempted to clarify this confusion, thus allowing for a comparison of orthologous protein function between species. This framework also allows the prediction of functional relevance between species based on sequence and structural conservation. WIDER IMPLICATIONS This review generates a picture of critical roles for CAP proteins in ion channel regulation, sterol and lipid binding and protease inhibition, and as ligands involved in the induction of multiple cellular processes.
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Affiliation(s)
- Avinash S Gaikwad
- School of Biological Sciences, Monash University, Clayton, Victoria, 3800, Australia
| | - Jinghua Hu
- School of Biological Sciences, Monash University, Clayton, Victoria, 3800, Australia
| | - David G Chapple
- School of Biological Sciences, Monash University, Clayton, Victoria, 3800, Australia
| | - Moira K O'Bryan
- School of Biological Sciences, Monash University, Clayton, Victoria, 3800, Australia
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Lagatie O, Verheyen A, Van Dorst B, Batsa Debrah L, Debrah A, Stuyver LJ. Linear epitopes in Onchocerca volvulus vaccine candidate proteins and excretory-secretory proteins. Parasite Immunol 2018; 40:e12587. [PMID: 30188578 PMCID: PMC6220944 DOI: 10.1111/pim.12587] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 08/21/2018] [Accepted: 09/04/2018] [Indexed: 11/27/2022]
Abstract
In our previous study, a proteome‐wide screen was conducted to identify linear epitopes in this parasite's proteome, resulting in the discovery of three immunodominant motifs. Here, we investigated whether such antigenic peptides were found in proteins that were already known as vaccine candidates and excretome/secretome proteins for Onchocerca volvulus This approach led to the identification of 71 immunoreactive stretches in 46 proteins. A deep‐dive into the immunoreactivity profiles of eight vaccine candidates that were chosen as most promising candidates for further development (Ov‐CPI‐2, Ov‐ALT‐1, Ov‐RAL‐2, Ov‐ASP‐1, Ov‐103, Ov‐RBP‐1, Ov‐CHI‐1, and Ov‐B20), resulted in the identification of a poly‐glutamine stretch in Ov‐RAL‐2 that has properties for use as a serodiagnostic marker for O. volvulus infection. A peptide ELISA was developed, and the performance of this assay was evaluated. Based on this assessment, it was found that this assay has a sensitivity of 75.0% [95% CI: 64.9%‐83.5%] and a specificity of 98.5% [95% CI: 94.6%‐99.8%]. Furthermore, 8.7% reactivity in Asian parasite‐infected individuals (8 out of 92) was observed. Besides this identification of a linear epitope marker, the information on the presence of linear epitopes in vaccine candidate proteins might be useful in the study of vaccines for river blindness.
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Affiliation(s)
- Ole Lagatie
- Janssen Diagnostics, Janssen R&D, Beerse, Belgium
| | - Ann Verheyen
- Janssen Diagnostics, Janssen R&D, Beerse, Belgium
| | | | - Linda Batsa Debrah
- Department of Clinical Microbiology, School of Medical Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Alex Debrah
- Faculty of Allied Health Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
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Melouane A, Ghanemi A, Aubé S, Yoshioka M, St-Amand J. Differential gene expression analysis in ageing muscle and drug discovery perspectives. Ageing Res Rev 2018; 41:53-63. [PMID: 29102726 DOI: 10.1016/j.arr.2017.10.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Revised: 10/31/2017] [Accepted: 10/31/2017] [Indexed: 12/12/2022]
Abstract
Identifying therapeutic target genes represents the key step in functional genomics-based therapies. Within this context, the disease heterogeneity, the exogenous factors and the complexity of genomic structure and function represent important challenges. The functional genomics aims to overcome such obstacles via identifying the gene functions and therefore highlight disease-causing genes as therapeutic targets. Genomic technologies promise to reshape the research on ageing muscle, exercise response and drug discovery. Herein, we describe the functional genomics strategies, mainly differential gene expression methods microarray, serial analysis of gene expression (SAGE), massively parallel signature sequence (MPSS), RNA sequencing (RNA seq), representational difference analysis (RDA), and suppression subtractive hybridization (SSH). Furthermore, we review these illustrative approaches that have been used to discover new therapeutic targets for some complex diseases along with the application of these tools to study the modulation of the skeletal muscle transcriptome.
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7
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Lustigman S, Makepeace BL, Klei TR, Babayan SA, Hotez P, Abraham D, Bottazzi ME. Onchocerca volvulus: The Road from Basic Biology to a Vaccine. Trends Parasitol 2017; 34:64-79. [PMID: 28958602 DOI: 10.1016/j.pt.2017.08.011] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 08/27/2017] [Accepted: 08/30/2017] [Indexed: 11/18/2022]
Abstract
Human onchocerciasis - commonly known as river blindness - is one of the most devastating yet neglected tropical diseases, leaving many millions in sub-Saharan Africa blind and/or with chronic disabilities. Attempts to eliminate onchocerciasis, primarily through the mass drug administration of ivermectin, remains challenging and has been heightened by the recent news that drug-resistant parasites are developing in some populations after years of drug treatment. Needed, and needed now, in the fight to eliminate onchocerciasis are new tools, such as preventive and therapeutic vaccines. This review summarizes the progress made to advance the onchocerciasis vaccine from the research laboratory into the clinic.
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Affiliation(s)
- Sara Lustigman
- Laboratory of Molecular Parasitology, Lindsley F Kimball Research Institute, New York Blood Center, New York, NY, USA.
| | - Benjamin L Makepeace
- Department of Infection Biology, Institute of Infection and Global Health, University of Liverpool, Liverpool, UK
| | - Thomas R Klei
- Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA, USA
| | - Simon A Babayan
- Institute of Biodiversity, Animal Health & Comparative Medicine, College of Medical, Veterinary & Life Sciences, University of Glasgow and Moredun Research Institute, Glasgow, UK
| | - Peter Hotez
- Texas Children's Hospital Center for Vaccine Development, Department of Pediatrics, Section of Pediatric Tropical Medicine, National School of Tropical Medicine, Baylor College of Medicine, Houston, TX, USA
| | - David Abraham
- Department of Microbiology and Immunology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
| | - Maria Elena Bottazzi
- Texas Children's Hospital Center for Vaccine Development, Department of Pediatrics, Section of Pediatric Tropical Medicine, National School of Tropical Medicine, Baylor College of Medicine, Houston, TX, USA
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8
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Cotton JA, Bennuru S, Grote A, Harsha B, Tracey A, Beech R, Doyle SR, Dunn M, Hotopp JCD, Holroyd N, Kikuchi T, Lambert O, Mhashilkar A, Mutowo P, Nursimulu N, Ribeiro JMC, Rogers MB, Stanley E, Swapna LS, Tsai IJ, Unnasch TR, Voronin D, Parkinson J, Nutman TB, Ghedin E, Berriman M, Lustigman S. The genome of Onchocerca volvulus, agent of river blindness. Nat Microbiol 2016; 2:16216. [PMID: 27869790 PMCID: PMC5310847 DOI: 10.1038/nmicrobiol.2016.216] [Citation(s) in RCA: 78] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Accepted: 09/26/2016] [Indexed: 01/08/2023]
Abstract
Human onchocerciasis is a serious neglected tropical disease caused by the filarial nematode Onchocerca volvulus that can lead to blindness and chronic disability. Control of the disease relies largely on mass administration of a single drug, and the development of new drugs and vaccines depends on a better knowledge of parasite biology. Here, we describe the chromosomes of O. volvulus and its Wolbachia endosymbiont. We provide the highest-quality sequence assembly for any parasitic nematode to date, giving a glimpse into the evolution of filarial parasite chromosomes and proteomes. This resource was used to investigate gene families with key functions that could be potentially exploited as targets for future drugs. Using metabolic reconstruction of the nematode and its endosymbiont, we identified enzymes that are likely to be essential for O. volvulus viability. In addition, we have generated a list of proteins that could be targeted by Federal-Drug-Agency-approved but repurposed drugs, providing starting points for anti-onchocerciasis drug development.
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Affiliation(s)
- James A Cotton
- Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire CB10 1SA, UK
| | - Sasisekhar Bennuru
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, Maryland 20892, USA
| | - Alexandra Grote
- Center for Genomics and Systems Biology, Department of Biology, New York University, New York, New York 10003, USA
| | - Bhavana Harsha
- Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire CB10 1SA, UK
| | - Alan Tracey
- Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire CB10 1SA, UK
| | - Robin Beech
- Institute of Parasitology, McGill University, Montreal, Quebec H9X 3V9, Canada
| | - Stephen R Doyle
- Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire CB10 1SA, UK
| | - Matthew Dunn
- Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire CB10 1SA, UK
| | - Julie C Dunning Hotopp
- Institute for Genome Sciences, Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA
| | - Nancy Holroyd
- Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire CB10 1SA, UK
| | - Taisei Kikuchi
- Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire CB10 1SA, UK
| | - Olivia Lambert
- Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire CB10 1SA, UK
| | - Amruta Mhashilkar
- Global Health Infectious Disease Research Program, Department of Global Health, College of Public Health, University of South Florida, Tampa, Florida 33612, USA
| | - Prudence Mutowo
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire CB10 1SD, UK
| | - Nirvana Nursimulu
- Department of Computer Science, University of Toronto, Toronto M5S 3G4, Canada.,Division of Molecular Structure and Function, Research Institute, Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada
| | - Jose M C Ribeiro
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, Maryland 20892, USA
| | - Matthew B Rogers
- Children's Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15224, USA
| | - Eleanor Stanley
- Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire CB10 1SA, UK
| | - Lakshmipuram S Swapna
- Division of Molecular Structure and Function, Research Institute, Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada
| | - Isheng J Tsai
- Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire CB10 1SA, UK
| | - Thomas R Unnasch
- Global Health Infectious Disease Research Program, Department of Global Health, College of Public Health, University of South Florida, Tampa, Florida 33612, USA
| | - Denis Voronin
- New York Blood Center, New York, New York 10065, USA
| | - John Parkinson
- Department of Computer Science, University of Toronto, Toronto M5S 3G4, Canada.,Division of Molecular Structure and Function, Research Institute, Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada.,Departments of Biochemistry and Molecular Genetics, University of Toronto, M5S 1A8, Canada
| | - Thomas B Nutman
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, Maryland 20892, USA
| | - Elodie Ghedin
- Center for Genomics and Systems Biology, Department of Biology, New York University, New York, New York 10003, USA.,College of Global Public Health, New York University, New York, New York 10003, USA
| | - Matthew Berriman
- Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire CB10 1SA, UK
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Liu Y, Chen S, Pan B, Guan Z, Yang Z, Duan L, Cai H. A subunit vaccine based on rH-NS induces protection against Mycobacterium tuberculosis infection by inducing the Th1 immune response and activating macrophages. Acta Biochim Biophys Sin (Shanghai) 2016; 48:909-922. [PMID: 27563010 DOI: 10.1093/abbs/gmw078] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Accepted: 07/07/2016] [Indexed: 11/12/2022] Open
Abstract
Mycobacterium tuberculosis (Mtb) is a Gram-positive pathogen which causes tuberculosis in both animals and humans. All tested rH-NS formulations induced a specific Th1 response, as indicated by increased production of interferon γ (IFN-γ) and interleukin 2 (IL-2) by lymphocytes in the spleen of mice which were immunized with rH-NS alone or with rH-NS and the adjuvant cyclic GMP-AMP (cGAMP). Serum from mice immunized with rH-NS with or without adjuvant also had higher levels of IL-12p40 and TNF-α, compared with those from control mice immunized with phosphate-buffered saline. Both vaccines increased protective efficacy in mice which were challenged with Mtb H37Rv, as measured by reduced relative CFU counts in the lungs. We found that rH-NS induced the production of TNF-α, IL-6, and IL-12p40, which relied on the activation of mitogen-activated protein kinases by stimulating the rapid phosphorylation of ERK1/2, p38, and JNK, and on the activation of transcription factor NF-κB in macrophages. Additionally, we also found that rH-NS could interact with TLR2 but not TLR4 in pull-down assays. The rH-NS-induced cytokine production from TLR2-silenced RAW264.7 cells was lower than that from BALB/c macrophages. Prolonged exposure (>24 h) of RAW264.7 cells to rH-NS resulted in a significant enhancement in IFN-γ-induced MHC II expression, which was not found in shTLR2-treated RAW264.7 cells. These results suggest that rH-NS is a TLR2 agonist which induces the production of cytokines by macrophages and up-regulates macrophage function.
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Affiliation(s)
- Yuan Liu
- State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing 100871, China
| | - Suting Chen
- National Clinical Laboratory on Tuberculosis, Beijing Key Laboratory on Drug-Resistant Tuberculosis Research, Beijing Chest Hospital, Capital Medical University, Beijing Tuberculosis and Thoracic Tumor Institute, Beijing 101149, China
| | - Bowen Pan
- State Key Laboratory of Natural and Biomimetic Drugs, Peking Universtiy Health Science Center, Beijing 100191, China
| | - Zhu Guan
- State Key Laboratory of Natural and Biomimetic Drugs, Peking Universtiy Health Science Center, Beijing 100191, China
| | - Zhenjun Yang
- State Key Laboratory of Natural and Biomimetic Drugs, Peking Universtiy Health Science Center, Beijing 100191, China
| | - Linfei Duan
- State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing 100871, China
| | - Hong Cai
- State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing 100871, China
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10
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Vaccination of Gerbils with Bm-103 and Bm-RAL-2 Concurrently or as a Fusion Protein Confers Consistent and Improved Protection against Brugia malayi Infection. PLoS Negl Trop Dis 2016; 10:e0004586. [PMID: 27045170 PMCID: PMC4821550 DOI: 10.1371/journal.pntd.0004586] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Accepted: 03/08/2016] [Indexed: 12/26/2022] Open
Abstract
Background The Brugia malayi Bm-103 and Bm-RAL-2 proteins are orthologous to Onchocerca volvulus Ov-103 and Ov-RAL-2, and which were selected as the best candidates for the development of an O. volvulus vaccine. The B. malayi gerbil model was used to confirm the efficacy of these Ov vaccine candidates on adult worms and to determine whether their combination is more efficacious. Methodology and Principle Findings Vaccine efficacy of recombinant Bm-103 and Bm-RAL-2 administered individually, concurrently or as a fusion protein were tested in gerbils using alum as adjuvant. Vaccination with Bm-103 resulted in worm reductions of 39%, 34% and 22% on 42, 120 and 150 days post infection (dpi), respectively, and vaccination with Bm-RAL-2 resulted in worm reductions of 42%, 22% and 46% on 42, 120 and 150 dpi, respectively. Vaccination with a fusion protein comprised of Bm-103 and Bm-RAL-2 resulted in improved efficacy with significant reduction of worm burden of 51% and 49% at 90 dpi, as did the concurrent vaccination with Bm-103 and Bm-RAL-2, with worm reduction of 61% and 56% at 90 dpi. Vaccination with Bm-103 and Bm-RAL-2 as a fusion protein or concurrently not only induced a significant worm reduction of 61% and 42%, respectively, at 150 dpi, but also significantly reduced the fecundity of female worms as determined by embryograms. Elevated levels of antigen-specific IgG were observed in all vaccinated gerbils. Serum from gerbils vaccinated with Bm-103 and Bm-RAL-2 individually, concurrently or as a fusion protein killed third stage larvae in vitro when combined with peritoneal exudate cells. Conclusion Although vaccination with Bm-103 and Bm-RAL-2 individually conferred protection against B. malayi infection in gerbils, a more consistent and enhanced protection was induced by vaccination with Bm-103 and Bm-RAL-2 fusion protein and when they were used concurrently. Further characterization and optimization of these filarial vaccines are warranted. Onchocerciasis and Lymphatic filariasis (LF) are debilitating neglected tropical diseases (NTDs). Practical challenges in implementation of mass drug administration (MDA) such as prolonged treatment regime requirements and the possible emergence of drug resistance will likely impede the elimination of these NTDs. Hence, the availability of an efficacious prophylactic vaccine would be an invaluable tool. The objective of the present studies was to use the B. malayi-gerbil model of filariasis as a surrogate system to test the efficacy of filarial molecules as vaccine targets for an onchocerciasis vaccine. The vaccine efficacy of Onchocerca volvulus recombinant proteins Ov-RAL-2 and Ov-103 was recently demonstrated using a mouse diffusion chamber model. In this communication, we provide encouraging results on the vaccine efficacy of Bm-RAL-2 and Bm-103, individually or in combination. Our data demonstrate that vaccination with Bm-RAL-2 and Bm-103 concurrently and as a fusion protein confers not only a consistent and significant protection against B. malayi infection in gerbils, but also reduces the fecundity of female worms as demonstrated in embryogram analyses. Our results support the contention that Ov-RAL-2 and Ov-103 are excellent onchocerciasis vaccine candidates and that further investigations leading to their development as a vaccine are warranted.
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Zaheer R, Klima CL, McAllister TA. Expeditious screening of candidate proteins for microbial vaccines. J Microbiol Methods 2015; 116:53-9. [PMID: 26149626 DOI: 10.1016/j.mimet.2015.06.018] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Revised: 06/26/2015] [Accepted: 06/27/2015] [Indexed: 11/18/2022]
Abstract
Advancements in high-throughput "omics" technologies have revolutionized the way vaccine candidates are identified. Now every surface expressed protein that an organism produces can be identified in silico and possibly made available for the rapid development of recombinant/subunit vaccines. However, evaluating the antigenicity of a large number of candidate proteins is an immense challenge, typically requiring cloning of several hundred candidates followed by immunogenicity screening. Here we report the development of a rapid, high-throughput method for screening candidate proteins for vaccines. This method involves utilizing a coupled, cell-free transcription-translation system to screen tagged proteins that are captured at the C-termini using appropriate ligand coated wells in 96 well ELISA plates. The template DNA for the cell-free expression is generated by two sequential PCRs and includes gene coding sequences, promoter, terminator, other necessary cis-acting elements and appropriate tag sequences. The process generates expressible candidate proteins containing two different peptide tags at the N- and the C-termini of the protein molecules. Proteins are screened in parallel for their quantity and immunoreactivity with N-terminal tag antibodies and antisera raised against the pathogen of interest, respectively. Normalization against the total detectable bound protein in the control wells allows for the identification of highly immunoreactive candidates. For this study we selected 30 representatives of >300 potential candidate proteins from Mannheimia haemolytica, a bacterial agent of pneumonia in feedlot cattle for expression with N-terminal Strep-II and C-terminal His(x6)-tag and evaluated their relative immunoreactivities using Strep-tactin-HRP and rabbit antisera generated against M. haemolytica. Using this system we were able to swiftly and quantitatively analyze and rank the suitability of proteins to identify potentially viable vaccine candidates, with the majority of the high ranking candidates being associated with virulence and pathogenicity. The system is adaptable to any bacterial target and presents an alternative to conventional laborious cloning, expression and screening procedures.
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Affiliation(s)
- Rahat Zaheer
- Lethbridge Research Centre, Agriculture and Agri-Food Canada, Lethbridge, AB T1J 4B1 Canada
| | - Cassidy L Klima
- Lethbridge Research Centre, Agriculture and Agri-Food Canada, Lethbridge, AB T1J 4B1 Canada
| | - Tim A McAllister
- Lethbridge Research Centre, Agriculture and Agri-Food Canada, Lethbridge, AB T1J 4B1 Canada.
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12
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Gooyit M, Harris TL, Tricoche N, Javor S, Lustigman S, Janda KD. Onchocerca volvulus Molting Inhibitors Identified through Scaffold Hopping. ACS Infect Dis 2015; 1:198-202. [PMID: 27622649 DOI: 10.1021/acsinfecdis.5b00017] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The anthelmintic closantel has shown promise in abrogating the L3 molting of Onchocerca volvulus, the causative agent of the infectious disease onchocerciasis. In our search for alternative scaffolds, we utilized a fragment replacement/modification approach to generate novel chemotypes with improved chitinase inhibitory properties. Further evaluation of the compounds unveiled the potential of urea-tropolones as potent inhibitors of O. volvulus L3 molting.
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Affiliation(s)
- Major Gooyit
- Departments
of Chemistry and Immunology and Microbial Science, The Skaggs Institute
for Chemical Biology, and The Worm Institute of Research and Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Tyler L. Harris
- Departments
of Chemistry and Immunology and Microbial Science, The Skaggs Institute
for Chemical Biology, and The Worm Institute of Research and Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Nancy Tricoche
- Lindsley F. Kimball Research Institute, New York Blood Center, New York, New York 10065, United States
| | - Sacha Javor
- Departments
of Chemistry and Immunology and Microbial Science, The Skaggs Institute
for Chemical Biology, and The Worm Institute of Research and Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Sara Lustigman
- Lindsley F. Kimball Research Institute, New York Blood Center, New York, New York 10065, United States
| | - Kim D. Janda
- Departments
of Chemistry and Immunology and Microbial Science, The Skaggs Institute
for Chemical Biology, and The Worm Institute of Research and Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
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13
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Gooyit M, Tricoche N, Javor S, Lustigman S, Janda KD. Exploiting the Polypharmacology of ß-Carbolines to Disrupt O. volvulus Molting. ACS Med Chem Lett 2015; 6:339-43. [PMID: 25815157 DOI: 10.1021/ml500516r] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Accepted: 01/20/2015] [Indexed: 01/22/2023] Open
Abstract
Onchocerciasis is an infection caused by the filarial worm Onchocerca volvulus, which can eventually result in blindness. The lack of an effective macrofilaricide and the possible development of ivermectin-resistant strains of O. volvulus necessitate the need for alternative treatment strategies. We have shown that targeting the L3-stage-specific chitinase OvCHT1 impairs the shedding of the filarial cuticle. In our continued efforts to discover OvCHT1 inhibitors, we identified the β-carboline alkaloid scaffolding as a chitinase inhibitor that is capable of penetrating the worm cuticle. Herein, we disclose the rich polypharmacology of the β-carboline class of compounds as an approach to abrogate the molting of the parasite and thus the initiation of infection in the human host.
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Affiliation(s)
- Major Gooyit
- Departments
of Chemistry and Immunology and Microbial Science, The Skaggs Institute
for Chemical Biology, and The Worm Institute of Research and Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Nancy Tricoche
- Lindsley
F. Kimball Research Institute, New York Blood Center, New York, New York 10065, United States
| | - Sacha Javor
- Departments
of Chemistry and Immunology and Microbial Science, The Skaggs Institute
for Chemical Biology, and The Worm Institute of Research and Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Sara Lustigman
- Lindsley
F. Kimball Research Institute, New York Blood Center, New York, New York 10065, United States
| | - Kim D. Janda
- Departments
of Chemistry and Immunology and Microbial Science, The Skaggs Institute
for Chemical Biology, and The Worm Institute of Research and Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
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14
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Mahalakshmi N, Aparnaa R, Kaliraj P. Evaluation of immune response elicited by inulin as an adjuvant with filarial antigens in mice model. Scand J Immunol 2014; 80:261-70. [PMID: 25041426 DOI: 10.1111/sji.12208] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Accepted: 06/25/2014] [Indexed: 11/30/2022]
Abstract
Filariasis caused by infectious parasitic nematodes has been identified as the second leading source of permanent and long-term disability in Sub-Saharan Africa, Asia and Latin America. Several vaccine candidates were identified from infective third-stage larvae (L3) which involves in the critical transition from arthropod to human. Hitherto studies of these antigens in combination with alum adjuvant have shown to elicit its characteristic Th2 responses. Inulin is a safe, non-toxic adjuvant that principally stimulates the innate immune response through the alternative complement pathway. In the present study, the immune response elicited by inulin and alum as adjuvants were compared with filarial antigens from different aetiological agents: secreted larval acidic protein 1 (SLAP1) from Onchocerca volvulus and venom allergen homologue (VAH) from Brugia malayi as single or as cocktail vaccines in mice model. The study revealed that inulin can induce better humoral response against these antigens than alum adjuvant. Antibody isotyping disclosed inulin's ability to elevate the levels of IgG2a and IgG3 antibodies which mediates in complement-dependent cytotoxicity and antibody-dependent cell-mediated cytotoxicity (ADCC), respectively, in mice. Splenocyte analysis showed that T cells prestimulated with inulin have higher stimulation index (P < 0.05) than alum except for BmVAH antigen. In vitro ADCC assay showed that inulin formulation had induced higher cytotoxicity with filarial antigens (as single P < 0.01 and as cocktail P < 0.05, respectively) than alum. The results had confirmed the capability of inulin to deplete the levels of Treg and brought a balance in Th1/Th2 arms against filarial antigens in mice.
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Affiliation(s)
- N Mahalakshmi
- Centre for Biotechnology, Anna University, Guindy, Chennai, Tamilnadu, India
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15
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Kim DW, Yoo WG, Lee MR, Yang HW, Kim YJ, Cho SH, Lee WJ, Ju JW. Transcriptome sequencing and analysis of the zoonotic parasite Spirometra erinacei spargana (plerocercoids). Parasit Vectors 2014; 7:368. [PMID: 25128015 PMCID: PMC4262225 DOI: 10.1186/1756-3305-7-368] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Accepted: 07/22/2014] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Although spargana, which are the plerocercoids of Spirometra erinacei, are of biological and clinical importance, expressed sequence tags (ESTs) from this parasite have not been explored. To understand molecular and biological features of this parasite, sparganum ESTs were examined by large-scale EST sequencing and multiple bioinformatics tools. METHODS Total RNA was isolated from spargana and then ESTs were generated, assembled and sequenced. Many biological aspects of spargana were investigated using multi-step bioinformatics tools. RESULTS A total of 5,634 ESTs were collected from spargana. After clustering and assembly, the functions of 1,794 Sparganum Assembled ESTs (SpAEs) including 934 contigs and 860 singletons were analyzed. A total of 1,351 (75%) SpAEs were annotated using a hybrid of BLASTX and InterProScan. Of these genes, 1,041 (58%) SpAEs had high similarity to tapeworms. In the context of the biology of sparganum, our analyses reveal: (i) a highly expressed fibronectin 1, a ubiquitous and abundant glycoprotein; (ii) up-regulation of enzymes related with glycolysis pathway; (iii) most frequent domains of protein kinase and RNA recognition motif domain; (iv) a set of helminth-parasitic and spargana-specific genes that may offer a number of antigen candidates. CONCLUSIONS Our transcriptomic analysis of S. erinacei spargana demonstrates biological aspects of a parasite that invades and travels through subcutaneous tissue in intermediate hosts. Future studies should include comparative analyses using combinations of transcriptome and proteome data collected from the entire life cycle of S. erinacei.
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Affiliation(s)
| | | | | | | | | | | | - Won-Ja Lee
- Division of Malaria and Parasitic Diseases, Centre for Immunology and Pathology, Korea National Institute of Health, Chungbuk 363-951, Republic of Korea.
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16
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Metuge JA, Nyongbela KD, Mbah JA, Samje M, Fotso G, Babiaka SB, Cho-Ngwa F. Anti-Onchocerca activity and phytochemical analysis of an essential oil from Cyperus articulatus L. BMC COMPLEMENTARY AND ALTERNATIVE MEDICINE 2014; 14:223. [PMID: 24998345 PMCID: PMC4099029 DOI: 10.1186/1472-6882-14-223] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/26/2013] [Accepted: 06/30/2014] [Indexed: 11/10/2022]
Abstract
BACKGROUND The lack of a safe and effective adult worm drug and the emergence of resistant animal parasite strains to the only recommended drug, the microfilaricide, ivermectin put many at risk of the devastating effects of the onchocerciasis. The present study was undertaken to investigate the acclaimed anti-Onchocerca activity of the roots/rhizomes of Cyperus articulatus in the traditional treatment of onchocerciasis in North Western Cameroon and to assess the plant as a new source of potential filaricidal lead compounds. METHODS Crude extracts were prepared from the dried plant parts using hexane, methylene chloride and methanol. The antifilarial activity was evaluated in vitro on microfilariae (Mfs) and adult worms of the bovine derived Onchocerca ochengi, a close relative of Onchocerca volvulus. The viabilities of microfilariae and adult male worms were determined based on motility reduction, while for the adult female worms the viability was based on the standard MTT/formazan assay. Cytotoxicity of the active extract was assessed on monkey kidney epithelial cells in vitro and the selectivity indices (SI) were determined. Acute toxicity of the promising extract was investigated in mice. Chemical composition of the active extract was unraveled by GC/MS analysis. RESULTS Only the hexane extract, an essential oil exhibited anti-Onchocerca activity. The oil killed both the microfilariae and adult worms of O. ochengi in a dose manner dependently, with IC50s of 23.4 μg/ml on the Mfs, 23.4 μg/ml on adult male worms and 31.25 μg/ml on the adult female worms. Selectivity indices were 4, 4, and 2.99 for Mfs, adult males and adult females, respectively. At a single limit dose of 2000 mg/kg body weight, none of 6 mice that received the essential oil by gavage died. GC/MS analysis revealed the presence of terpenoids, hydrocarbons and fatty acids or fatty acid derivatives as components of the oil. CONCLUSIONS The essential oil from the roots/rhizomes of Cyperus articulatus is active against O. ochengi microfilariae and adult worms in vitro in a dose dependent manner, hence may provide a source of new anti-filarial compounds. The results also support the traditional use of C. articulatus in the treatment of human onchocerciasis.
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Affiliation(s)
- Jonathan Alunge Metuge
- ANDI Centre of Excellence, Biotechnology Unit, Faculty of Science, University of Buea, P.O. Box 63, Buea, Cameroon
| | - Kennedy D Nyongbela
- Department of Chemistry, Faculty of Science, University of Buea, Buea, Cameroon
| | - James A Mbah
- Department of Chemistry, Faculty of Science, University of Buea, Buea, Cameroon
| | - Moses Samje
- ANDI Centre of Excellence, Biotechnology Unit, Faculty of Science, University of Buea, P.O. Box 63, Buea, Cameroon
| | - Ghislain Fotso
- Department of Organic chemistry, Faculty of Science, University of Yaoundé I, Cameroon
| | - Smith B Babiaka
- Department of Chemistry, Faculty of Science, University of Buea, Buea, Cameroon
| | - Fidelis Cho-Ngwa
- ANDI Centre of Excellence, Biotechnology Unit, Faculty of Science, University of Buea, P.O. Box 63, Buea, Cameroon
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17
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Li F, Lok JB, Gasser RB, Korhonen PK, Sandeman MR, Shi D, Zhou R, Li X, Zhou Y, Zhao J, Hu M. Hc-daf-2 encodes an insulin-like receptor kinase in the barber's pole worm, Haemonchus contortus, and restores partial dauer regulation. Int J Parasitol 2014; 44:485-96. [PMID: 24727120 PMCID: PMC4516220 DOI: 10.1016/j.ijpara.2014.03.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Revised: 03/14/2014] [Accepted: 03/16/2014] [Indexed: 01/25/2023]
Abstract
Infective L3s (iL3s) of parasitic nematodes share common behavioural, morphological and developmental characteristics with the developmentally arrested (dauer) larvae of the free-living nematode Caenorhabditis elegans. It is proposed that similar molecular mechanisms regulate entry into or exit from the dauer stage in C. elegans, and the transition from free-living to parasitic forms of parasitic nematodes. In C. elegans, one of the key factors regulating the dauer transition is the insulin-like receptor (designated Ce-DAF-2) encoded by the gene Ce-daf-2. However, nothing is known about DAF-2 homologues in most parasitic nematodes. Here, using a PCR-based approach, we identified and characterised a gene (Hc-daf-2) and its inferred product (Hc-DAF-2) in Haemonchus contortus (a socioeconomically important parasitic nematode of ruminants). The sequence of Hc-DAF-2 displays significant sequence homology to insulin receptors (IR) in both vertebrates and invertebrates, and contains conserved structural domains. A sequence encoding an important proteolytic motif (RKRR) identified in the predicted peptide sequence of Hc-DAF-2 is consistent with that of the human IR, suggesting that it is involved in the formation of the IR complex. The Hc-daf-2 gene was transcribed in all life stages of H. contortus, with a significant up-regulation in the iL3 compared with other stages. To compare patterns of expression between Hc-daf-2 and Ce-daf-2, reporter constructs fusing the Ce-daf-2 or Hc-daf-2 promoter to sequence encoding GFP were microinjected into the N2 strain of C. elegans, and transgenic lines were established and examined. Both genes showed similar patterns of expression in amphidial (head) neurons, which relate to sensation and signal transduction. Further study by heterologous genetic complementation in a daf-2-deficient strain of C. elegans (CB1370) showed partial rescue of function by Hc-daf-2. Taken together, these findings provide a first insight into the roles of Hc-daf-2/Hc-DAF-2 in the biology and development of H. contortus, particularly in the transition to parasitism.
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Affiliation(s)
- Facai Li
- State Key Laboratory of Agricultural Microbiology, Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture, College of Veterinary Medicine, Huazhong Agricultural University, 1 Shizishan Street, Wuhan 430070, Hubei, China
| | - James B Lok
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, 3800 Spruce Street, Philadelphia, PA 19104, USA
| | - Robin B Gasser
- Faculty of Veterinary Science, The University of Melbourne, Corner of Flemington Road and Park Drive, Parkville, Victoria 3010, Australia; Institute of Parasitology and Tropical Veterinary Medicine, Freie Universität Berlin, 16-18 Kaiserswerther Street, Berlin 14195, Germany
| | - Pasi K Korhonen
- Faculty of Veterinary Science, The University of Melbourne, Corner of Flemington Road and Park Drive, Parkville, Victoria 3010, Australia
| | - Mark R Sandeman
- School of Applied Sciences and Engineering, Monash University, Northways Road, Churchill, Victoria 3842, Australia
| | - Deshi Shi
- State Key Laboratory of Agricultural Microbiology, Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture, College of Veterinary Medicine, Huazhong Agricultural University, 1 Shizishan Street, Wuhan 430070, Hubei, China
| | - Rui Zhou
- State Key Laboratory of Agricultural Microbiology, Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture, College of Veterinary Medicine, Huazhong Agricultural University, 1 Shizishan Street, Wuhan 430070, Hubei, China
| | - Xiangrui Li
- College of Veterinary Medicine, Nanjing Agricultural University, 1 Weigang, Nanjing 210095, Jiangsu, China
| | - Yanqin Zhou
- State Key Laboratory of Agricultural Microbiology, Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture, College of Veterinary Medicine, Huazhong Agricultural University, 1 Shizishan Street, Wuhan 430070, Hubei, China
| | - Junlong Zhao
- State Key Laboratory of Agricultural Microbiology, Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture, College of Veterinary Medicine, Huazhong Agricultural University, 1 Shizishan Street, Wuhan 430070, Hubei, China
| | - Min Hu
- State Key Laboratory of Agricultural Microbiology, Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture, College of Veterinary Medicine, Huazhong Agricultural University, 1 Shizishan Street, Wuhan 430070, Hubei, China.
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18
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Beaumier CM, Gillespie PM, Hotez PJ, Bottazzi ME. New vaccines for neglected parasitic diseases and dengue. Transl Res 2013; 162:144-55. [PMID: 23578479 DOI: 10.1016/j.trsl.2013.03.006] [Citation(s) in RCA: 111] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Revised: 03/15/2013] [Accepted: 03/16/2013] [Indexed: 01/13/2023]
Abstract
Neglected tropical diseases (NTDs) are a significant source of morbidity and socioeconomic burden among the world's poor. Virtually all of the 2.4 billion people who live on less than $2 per d, more than a third of the world's population, are at risk for these debilitating NTDs. Although chemotherapeutic measures exist for many of these pathogens, they are not sustainable countermeasures on their own because of rates of reinfection, risk of drug resistance, and inconsistent maintenance of drug treatment programs. Preventative and therapeutic NTD vaccines are needed as long-term solutions. Because there is no market in the for-profit sector of vaccine development for these pathogens, much of the effort to develop vaccines is driven by nonprofit entities, mostly through product development partnerships. This review describes the progress of vaccines under development for many of the NTDs, with a specific focus on those about to enter or that are currently in human clinical trials. Specifically, we report on the progress on dengue, hookworm, leishmaniasis, schistosomiasis, Chagas disease, and onchocerciasis vaccines. These products will be some of the first with specific objectives to aid the world's poorest populations.
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Affiliation(s)
- Coreen M Beaumier
- Sabin Vaccine Institute and Texas Children's Hospital Center for Vaccine Development, National School of Tropical Medicine, Baylor College of Medicine, Houston 77030, Tex., USA
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19
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Nematode-derived proteins suppress proliferation and cytokine production of antigen-specific T cells via induction of cell death. PLoS One 2013; 8:e68380. [PMID: 23861729 PMCID: PMC3693813 DOI: 10.1371/journal.pone.0068380] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2013] [Accepted: 05/28/2013] [Indexed: 01/08/2023] Open
Abstract
In order to establish long-lasting infections in their mammalian host, filarial
nematodes have developed sophisticated strategies to dampen their host’s immune
response. Proteins that are actively secreted by the parasites have been shown
to induce the expansion of regulatory T cells and to directly interfere with
effector T cell function. Here, we analyze the suppressive capacity of
Onchocercavolvulus-derived excreted/secreted
proteins. Addition of two recombinant O. volvulus proteins, abundant larval
transcript-2 (OvALT-2) and novel larval transcript-1
(OvNLT-1) to cell cultures of T cell receptor transgenic
CD4+ and CD8+ T cells suppressed antigen-specific
stimulation in vitro. Ovalbumin-specific CD4+
DO11.10 and OT-II T cells that had been stimulated with their cognate antigen in
the presence of OvALT-2 or OvNLT-1 displayed
reduced DNA synthesis quantified by 3H-thymidine incorporation and
reduced cell division quantified by CFSE dilution. Furthermore, the IL-2 and
IFN-γ response of ovalbumin-specific CD8+ OT-I T cells was suppressed
by OvALT-2 and OvNLT-1. In contrast, another
recombinant O.
volvulus protein,
microfilariae surface-associated antigen (Ov103), did not
modulate T cell activation, thus serving as internal control for
non-ESP-mediated artifacts. Suppressive capacity of the identified ESP was
associated with induction of apoptosis in T cells demonstrated by increased
exposure of phosphatidylserine on the plasma membrane. Of note, the digestion of
recombinant proteins with proteinase K did not abolish the suppression of
antigen-specific proliferation although the suppressive capacity of the
identified excreted/secreted products was not mediated by low molecular weight
contaminants in the undigested preparations. In summary, we identified two
suppressive excreted/secreted products from O. volvulus, which interfere with the
function of antigen-specific T cells in vitro.
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20
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Ajonina-Ekoti I, Ndjonka D, Tanyi MK, Wilbertz M, Younis AE, Boursou D, Kurosinski MA, Eberle R, Lüersen K, Perbandt M, Breloer M, Brattig NW, Liebau E. Functional characterization and immune recognition of the extracellular superoxide dismutase from the human pathogenic parasite Onchocerca volvulus (OvEC-SOD). Acta Trop 2012; 124:15-26. [PMID: 22677600 DOI: 10.1016/j.actatropica.2012.05.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2012] [Revised: 05/23/2012] [Accepted: 05/28/2012] [Indexed: 01/04/2023]
Abstract
Onchocerca volvulus is a human pathogenic filarial nematode causing chronic onchocerciasis, a disease characterized by chronic skin and eye lesions. Despite attempts to control this infection from many perspectives, it still remains a threat to public health because of adverse effects of available drugs and recent reports of drug resistance. Under control of an intact immune system, O. volvulus survives for a long time in the host by employing a variety of strategies including the utility of antioxidant enzymes. In the present study, we focus on the extracellular superoxide dismutase from O. volvulus (OvEC-SOD) found in the excretory/secretory products of adult worms. Contrary to previous studies, the OvEC-SOD was found to have a 19 amino acid long signal peptide that is cleaved off during the process of maturation. To validate this result, we designed a novel method based on Caenorhabditis elegans cup5(ar465) mutants to specifically evaluate signal peptide-mediated secretion of nematodal proteins. Following purification, the recombinant OvEC-SOD was active as a dimer. Site-directed mutagenesis of the three cysteines present in the OvEC-SOD shows that enzyme activity is markedly reduced in the Cys-192 mutant. A homology model of the OvEC-SOD underlines the importance of Cys-192 for the stabilization of the adjacent active site channel. The generation of a humoral immune response to secretory OvEC-SOD was indicated by demonstrating IgG reactivity in sera from patients infected with O. volvulus while the cross-reactivity of IgG in plasma samples from cows, infected with the most closely related parasite Onchocerca ochengi, occurred only marginally. High IgG1 and IgM titres were recorded in sera from mice infected with the filaria Litomosoides sigmodontis, however, low or no cellular proliferative responses were observed. Thus, the present data suggest that secretory OvEC-SOD is a target of the humoral immune response in human onchocerciasis and induced strongest IgG responses in hyperreactive onchocerciasis. Furthermore, humoral response during murine infection induced SOD-specific IgG that cross-reacted with OvEC-SOD.
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21
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Blaxter M, Kumar S, Kaur G, Koutsovoulos G, Elsworth B. Genomics and transcriptomics across the diversity of the Nematoda. Parasite Immunol 2012; 34:108-20. [PMID: 22044053 DOI: 10.1111/j.1365-3024.2011.01342.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The diversity of biology in nematodes is reflected in the diversity of their genomes. Parasitic species in particular have evolved mechanisms to invade and outwit their hosts, and these offer opportunities for the development of control measures. Genomic analyses can reveal the molecular underpinnings of phenotypes such as parasitism and thus, initiate and support research programmes that explore the manipulation of host and parasite physiologies to achieve favourable outcomes. Wide sampling across nematode diversity allows phylogenetically informed formulation of research hypotheses, identification of core features shared by all species or important evolutionary novelties present in isolated clades. Many nematode species have been investigated through the use of the expressed sequence tag approach, which samples from the transcribed genome. Gene catalogues generated in this way can be explored to reveal the patterns of expression associated with parasitism and candidates for testing as drug targets or vaccine components. Analysis environments, such as NEMBASE facilitate exploitation of these data. The development of new high-throughput DNA-sequencing technologies has facilitated transcriptomic and genomic approaches to parasite biology. Whole genome sequencing offers more complete catalogues of genes and assists a systems approach to phenotype dissection. These efforts are being coordinated through the 959 Nematode Genomes initiative.
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Affiliation(s)
- M Blaxter
- Institute of Evolutionary Biology, The University of Edinburgh, Edinburgh EH9 3JT, UK.
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22
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Cantacessi C, Gasser RB. SCP/TAPS proteins in helminths--where to from now? Mol Cell Probes 2011; 26:54-9. [PMID: 22005034 DOI: 10.1016/j.mcp.2011.10.001] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2011] [Revised: 10/03/2011] [Accepted: 10/03/2011] [Indexed: 10/16/2022]
Abstract
A diverse array of proteins belonging to the SCP/TAPS 'family' has been described for various eukaryotic organisms, including parasites. Although SCP/TAPS proteins have been hypothesized to play key roles in various fundamental biological processes, such as host-pathogen interactions and defence mechanisms, there is still a limited understanding of the precise roles of these proteins. Here, we review current knowledge of key SCP/TAPS proteins of helminths and their proposed roles in parasite-host interactions. Molecular investigations of these molecules in parasites and the integration of structural and functional data could lead to new and innovative approaches for the treatment and control of parasitic diseases, with important biotechnological outcomes.
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Affiliation(s)
- Cinzia Cantacessi
- Faculty of Veterinary Science, The University of Melbourne, Parkville, Victoria 3010, Australia
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Ebensen T, Libanova R, Schulze K, Yevsa T, Morr M, Guzmán CA. Bis-(3',5')-cyclic dimeric adenosine monophosphate: strong Th1/Th2/Th17 promoting mucosal adjuvant. Vaccine 2011; 29:5210-20. [PMID: 21619907 DOI: 10.1016/j.vaccine.2011.05.026] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2010] [Revised: 04/07/2011] [Accepted: 05/11/2011] [Indexed: 12/24/2022]
Abstract
New effective adjuvants are required to improve the performance of subunit vaccines. Here, we showed that bis-(3',5')-cyclic dimeric adenosine monophosphate (c-di-AMP), a second messenger molecule in bacteria and archaea, exerts strong adjuvant activities when delivered by mucosal route. In vitro studies showed that c-di-AMP was able to both stimulate pre-activated murine macrophages and promote the activation and maturation of dendritic cells of murine and human origin. Co-administration of c-di-AMP with β-galactosidase (β-Gal) by intranasal route to BALB/c mice resulted in the elicitation of significantly higher serum antigen-specific IgG titres than in controls. The induction of local immune responses was shown by the production of antigen-specific secretory IgA in different mucosal territories. In addition, strong cellular immune responses were observed against both the β-Gal protein and a peptide encompassing its MHC class I-restricted epitope. The ratio of β-Gal-specific antibodies and the secreted cytokine profiles by in vitro re-stimulated splenocytes suggested that a balanced Th1/Th2/Th17 response pattern is promoted by c-di-AMP. When C57BL/6 mice were immunized with OVA and c-di-AMP, vigorous in vivo CTL responses were also observed. These results indicated that c-di-AMP exhibits a high potential as adjuvant for the development of mucosal vaccines, in particular when cellular immunity is needed.
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Affiliation(s)
- Thomas Ebensen
- Department of Vaccinology and Applied Microbiology, Helmholtz Centre for Infection Research, Braunschweig, Germany.
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Screening the Schistosoma mansoni transcriptome for genes differentially expressed in the schistosomulum stage in search for vaccine candidates. Parasitol Res 2010; 108:123-35. [PMID: 20852890 DOI: 10.1007/s00436-010-2045-1] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2010] [Accepted: 08/29/2010] [Indexed: 12/17/2022]
Abstract
Schistosomiasis affects more than 200 million people worldwide; another 600 million are at risk of infection. The schistosomulum stage is believed to be the target of protective immunity in the attenuated cercaria vaccine model. In an attempt to identify genes up-regulated in the schistosomulum stage in relation to cercaria, we explored the Schistosoma mansoni transcriptome by looking at the relative frequency of reads in EST libraries from both stages. The 400 genes potentially up-regulated in schistosomula were analyzed as to their Gene Ontology categorization, and we have focused on those encoding-predicted proteins with no similarity to proteins of other organisms, assuming they could be parasite-specific proteins important for survival in the host. Up-regulation in schistosomulum relative to cercaria was validated with real-time reverse transcription polymerase chain reaction (RT-PCR) for five out of nine selected genes (56%). We tested their protective potential in mice through immunization with DNA vaccines followed by a parasite challenge. Worm burden reductions of 16-17% were observed for one of them, indicating its protective potential. Our results demonstrate the value and caveats of using stage-associated frequency of ESTs as an indication of differential expression coupled to DNA vaccine screening in the identification of novel proteins to be further investigated as potential vaccine candidates.
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Cho-Ngwa F, Liu J, Lustigman S. The Onchocerca volvulus cysteine proteinase inhibitor, Ov-CPI-2, is a target of protective antibody response that increases with age. PLoS Negl Trop Dis 2010; 4:e800. [PMID: 20808763 PMCID: PMC2927424 DOI: 10.1371/journal.pntd.0000800] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2009] [Accepted: 07/23/2010] [Indexed: 11/18/2022] Open
Abstract
Background Despite considerable efforts, a suitable vaccine against Onchocerca volvulus infection has remained elusive. Herein, we report on the use of molecular tools to identify and characterize O. volvulus antigens that are possibly associated with the development of concomitant immunity in onchocerciasis. Methodology/Principal Findings Third-stage larvae (L3) and molting L3 (mL3) O. volvulus stage-specific cDNA libraries were screened with a pool of sera from chronically infected patients who had likely developed such immunity. The 87 immunoreactive clones isolated were grouped into 20 distinct proteins of which 12 had already been cloned and/or characterized before and 4 had been proven to be protective in a small O. volvulus animal model. One of these, onchocystatin (Ov-CPI-2), a previously characterized O. volvulus cysteine proteinase inhibitor was, overall, the most abundant clone recognized by the immune sera in both the L3 and mL3 cDNA libraries. To further characterize its association with protective immunity, we measured the IgG subclass and IgE class specific responses to the antigen in putatively immune (PI) and infected (INF) individuals living in a hyperendemic area in Cameroon. It appeared that both groups had similar IgG3 and IgE responses to the antigen, but the INF had significantly higher IgG1 and IgG4 responses than the PI individuals (p<0.05). In the INF group, the IgG3 levels increased significantly with the age of the infected individuals (r = 0.241; p<0.01). The IgG1 responses in the INF were high regardless of age. Notably, culturing L3 in vitro in the presence of anti-Ov-CPI-2 monospecific human antibodies and naïve neutrophils resulted in almost complete inhibition of molting of L3 to L4 and to cytotoxicity to the larvae. Conclusions/Significance These results add to the knowledge of protective immunity in onchocerciasis and support the possible involvement of anti-Ov-CPI-2 IgG1 and/or IgG3 cytophilic antibodies in the development of protective immunity in the PI and the INF. The results further support the consideration of Ov-CPI-2 as a leading target for an anti-L3 vaccine. Onchocerciasis is a chronic and highly debilitating disease of humans caused by a worm called Onchocerca volvulus. This worm can live in the human body for over 15 years. The disease affects mainly the skin and eyes and is the second leading infectious cause of blindness worldwide. There is currently no vaccine to prevent the infection. Available drugs can give short-term relief but cannot cure the infection. To prevent infection, a vaccine against the third-stage infective larva, L3, or the developing larva is required. These stages were shown to be the targets of protective immunity that develops in individuals who live in onchocerciasis endemic regions. One type of protective immunity has been shown to develop with age and is called concomitant immunity. In the present study, we have identified a number of larval antigens that may be associated with the development of such immunity. The most prominent of these antigens was Ov-CPI-2, also called onchocystatin, which had previously been shown to be a promising vaccine candidate. This antigen was further characterized and confirmed to be possibly also a target of immune protection that develops in the infected individuals with age and is referred to as concomitant immunity.
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Affiliation(s)
- Fidelis Cho-Ngwa
- Laboratory of Molecular Parasitology, Lindsley F. Kimball Research Institute, New York Blood Center, New York, New York, United States of America.
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Cantacessi C, Campbell BE, Visser A, Geldhof P, Nolan MJ, Nisbet AJ, Matthews JB, Loukas A, Hofmann A, Otranto D, Sternberg PW, Gasser RB. A portrait of the "SCP/TAPS" proteins of eukaryotes--developing a framework for fundamental research and biotechnological outcomes. Biotechnol Adv 2009; 27:376-88. [PMID: 19239923 DOI: 10.1016/j.biotechadv.2009.02.005] [Citation(s) in RCA: 120] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2008] [Revised: 02/05/2009] [Accepted: 02/11/2009] [Indexed: 01/17/2023]
Abstract
A wide range of proteins belonging to the SCP/TAPS "family" has been described for various eukaryotic organisms, including plants and animals (vertebrates and invertebrates, such as helminths). Although SCP/TAPS proteins have been proposed to play key roles in a number of fundamental biological processes, such as host-pathogen interactions and defence mechanisms, there is a paucity of information on their genetic relationships, structures and functions, and there is no standardised nomenclature for these proteins. A detailed analysis of the relationships of members of the SCP/TAPS family of proteins, based on key protein signatures, could provide a foundation for investigating these areas. In this article, we review the current state of knowledge of key SCP/TAPS proteins of eukaryotes, with an emphasis on those from parasitic helminths, and undertake a comprehensive, systematic phylogenetic analysis of currently available full-length protein sequence data (considering characteristic protein signatures or motifs) to infer relationships and provide a framework (based on statistical support) for the naming of these proteins. This framework is intended to guide genomic and molecular biological explorations of key SCP/TAPS molecules associated with infectious diseases of plants and animals. In particular, fundamental investigations of these molecules in parasites and the integration of structural and functional data could lead to new and innovative approaches for the control of parasitic diseases, with important biotechnological outcomes.
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Affiliation(s)
- C Cantacessi
- Department of Veterinary Science, The University of Melbourne, Australia
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Screening of different classes of proteases in microfilarial and adult stages of Setaria cervi. Parasitol Res 2009; 104:1399-405. [PMID: 19184106 DOI: 10.1007/s00436-009-1336-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2008] [Accepted: 01/08/2009] [Indexed: 10/21/2022]
Abstract
Many of the filarial proteases involved in critical physiological functions are expressed in stage-specific manner and belong to various mechanistic classes. Setaria cervi, a bovine filarial parasite express different classes of proteases. This parasite shows strong antigenic cross-reactivity with human filarial parasites Wuchereria bancrofti and Brugia malayi. Somatic extracts of S. cervi microfilariae (mf) and adult stages as well as their excretory-secretory (ES) products were screened for the presence of different classes of proteases using general (casein, bovine hemoglobin) and class specific substrates. Detergent-soluble extracts of male and female worms were also screened. Significant enzyme activity was detected in ES products both at pH 5.0 and 7.0 with casein. Cathepsin B-like activity was found to be much higher in membrane-bound extract than in the crude-soluble extract. However, it was also found to be actively secreted by both mf and adult worms. Cathepsin D-like activity assayed at pH 3.0 was very low both in somatic extract as well as in ES products. Collagenase activity at neutral pH showed higher levels, both in somatic extract and ES products. Cathepsin L-like activity was detected only in crude-soluble extract but was below detectable limit in ES products. Leucine aminopeptidase activity was significant both in crude-soluble extract and ES products. This study, thus, might be helpful for a better understanding of host-parasite interaction and identification of appropriate virulence factors that may be targeted as vaccine and/or drug targets against lymphatic filariasis.
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Wang Z, Martin J, Abubucker S, Yin Y, Gasser RB, Mitreva M. Systematic analysis of insertions and deletions specific to nematode proteins and their proposed functional and evolutionary relevance. BMC Evol Biol 2009; 9:23. [PMID: 19175938 PMCID: PMC2644674 DOI: 10.1186/1471-2148-9-23] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2008] [Accepted: 01/28/2009] [Indexed: 11/25/2022] Open
Abstract
Background Amino acid insertions and deletions in proteins are considered relatively rare events, and their associations with the evolution and adaptation of organisms are not yet understood. In this study, we undertook a systematic analysis of over 214,000 polypeptides from 32 nematode species and identified insertions and deletions unique to nematode proteins in more than 1000 families and provided indirect evidence that these alterations are linked to the evolution and adaptation of nematodes. Results Amino acid alterations in sequences of nematodes were identified by comparison with homologous sequences from a wide range of eukaryotic (metzoan) organisms. This comparison revealed that the proteins inferred from transcriptomic datasets for nematodes contained more deletions than insertions, and that the deletions tended to be larger in length than insertions, indicating a decreased size of the transcriptome of nematodes compared with other organisms. The present findings showed that this reduction is more pronounced in parasitic nematodes compared with the free-living nematodes of the genus Caenorhabditis. Consistent with a requirement for conservation in proteins involved in the processing of genetic information, fewer insertions and deletions were detected in such proteins. On the other hand, more insertions and deletions were recorded for proteins inferred to be involved in the endocrine and immune systems, suggesting a link with adaptation. Similarly, proteins involved in multiple cellular pathways tended to display more deletions and insertions than those involved in a single pathway. The number of insertions and deletions shared by a range of plant parasitic nematodes were higher for proteins involved in lipid metabolism and electron transport compared with other nematodes, suggesting an association between metabolic adaptation and parasitism in plant hosts. We also identified three sizable deletions from proteins found to be specific to and shared by parasitic nematodes, which, given their uniqueness, might serve as target candidates for drug design. Conclusion This study illustrates the significance of using comparative genomics approaches to identify molecular elements unique to parasitic nematodes, which have adapted to a particular host organism and mode of existence during evolution. While the focus of this study was on nematodes, the approach has applicability to a wide range of other groups of organisms.
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Affiliation(s)
- Zhengyuan Wang
- The Genome Center, Department of Genetics, Washington University School of Medicine, St Louis, MO 63110, USA.
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Gnanasekar M, Anand SB, Ramaswamy K. Identification and cloning of a novel tetraspanin (TSP) homologue from Brugia malayi. ACTA ACUST UNITED AC 2008; 19:151-6. [PMID: 17852334 PMCID: PMC3121260 DOI: 10.1080/10425170701517614] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
This is the first report of a tetraspanin (TSP)-like molecule in the lymphatic filarial parasites. Expressed sequence tag (EST) database search for TSP like molecules in the filarial genome resulted in three significant EST hits (two partial ESTs from Brugia malayi and one full length EST from Wuchereria bancrofti). The full length gene cloned from B. malayi showed significant similarity to Caenorhabditis elegans TSP and human TSP and hence the gene was named B. malayi TSP (BmTSP). Subsequent Genbank analysis with the predicted ORF of BmTSP showed additional homologous genes reported from Schistosoma mansoni and Taenia solium parasites. Structural analyses showed that BmTSP has four transmembrane domains and other conserved domains such as CCG and two other critical cysteine residues present within the large extracellular loop similar to other reported TSPs. In addition, putative post-translational modifications such as N-glycosylation, protein kinase c phosphorylation, casein kinase II phosphorylation and N-myristoylation sites have been found in BmTSP sequence. Further, PCR analyses showed that BmTSP is differentially transcribed, with highest level of expression being present in the adult stages followed by L3 and mf stages. This study thus describes a novel TSP cloned from B. malayi, its putative functions in cuticle biogenesis and role in protective immunity.
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Affiliation(s)
- Munirathinam Gnanasekar
- Department of Biomedical Sciences, College of Medicine, University of Illinois, 1601 Parkview Avenue, Rockford, IL 61107, USA
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Analysis of the transthyretin-like (TTL) gene family in Ostertagia ostertagi--comparison with other strongylid nematodes and Caenorhabditis elegans. Int J Parasitol 2008; 38:1545-56. [PMID: 18571174 DOI: 10.1016/j.ijpara.2008.04.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2008] [Revised: 04/07/2008] [Accepted: 04/10/2008] [Indexed: 11/21/2022]
Abstract
The transthyretin-like (ttl) gene family is one of the largest conserved nematode-specific gene families, coding for a group of proteins with significant sequence similarity to transthyretins (TTR) and transthyretin-related proteins (TRP). In the present study, we investigated the ttl family in Ostertagia ostertagi (a nematode of the abomasum of cattle). Mining of expressed sequence tag (EST) databases revealed the presence of at least 18 ttl genes in O. ostertagi (Oo-ttl), most of which are constitutively transcribed from the free-living, third larval stage onwards. The full-length cDNA of one of these genes (Oo-ttl-1) was amplified and cloned for recombinant expression. Western blot analysis using a specific antiserum showed that the native protein Oo-TTL-1 was highly present in the excretory-secretory (ES) products of adults of O. ostertagi. The protein was immunolocalized to the pseudocoelomic fluid of adult worms. A phylogenetic-bioinformatic analysis of all amino acid sequence data for TTL proteins from a range of strongylid nematodes showed that they could be divided into at least five different classes. This classification was based on conserved amino acids in the first TTL signature domain and the number and location of cysteine residues. The biological role(s) of the TTLs in nematode biology is still unclear. A theoretical three-dimensional model of Oo-TTL-1 indicated that it had a similar structure to TTRs (i.e., containing β-sheets, arranged in a β-sandwich). In contrast to TTRs, competitive binding studies using recombinant Oo-TTL-1 indicated that the protein was devoid of any hydrophobic ligand- or thyroid hormone-binding properties. Finally, combinatorial analysis by double-stranded RNA interference of five ttl genes in the free-living nematode Caenorhabditis elegans did not reveal any visible phenotypes. More information on the transcription profile and tissue distribution of TTLs in nematodes is needed to provide new insights into the biological role of this gene family.
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Molecular cloning, purification and characterisation of myosin of human lymphatic filarial parasite Brugia malayi. Parasitol Res 2007; 102:481-9. [PMID: 18064491 DOI: 10.1007/s00436-007-0786-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2007] [Accepted: 10/30/2007] [Indexed: 10/22/2022]
Abstract
Global efforts have been made towards development of vaccine for prevention of lymphatic filariasis. However, lack of thorough knowledge about developmental biology and pathogenesis of filarial parasite restricts us from developing an effective vaccine. A limited number of immunodominant antigens of human lymphatic filariid Brugia malayi have been characterised; however, none of these recombinant antigens so far induced significant degree of protective immunity to challenge infection. In the present study, we identified a approximately 2.0 Kb cDNA clone by immunoscreening of cDNA library of adult female Brugia malayi. The nucleotide sequence of the identified clone showed 94.3% homology with C-terminal part of myosin heavy chain gene of Brugia malayi. This cDNA insert was sub-cloned into pET28b vector and expressed in BL21(DE3). The recombinant protein was purified to near homogeneity by immobilised metal affinity chromatography (IMAC) with yield of approximately 25 mg/l. The purified protein was recognised in western blot with anti-His tag antibody as also with the antibodies present in the sera of human W. bancrofti patients of all categories and infected/immunized rodent serum demonstrating its functional role. Recombinant myosin induced marked cellular immune response as observed by lymphoproliferation assay. The present findings demonstrate the usefulness of B. malayi recombinant myosin as vaccine candidate against human lymphatic filariasis.
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Townson S, Ramirez B, Fakorede F, Mouries MA, Nwaka S. Challenges in drug discovery for novel antifilarials. Expert Opin Drug Discov 2007; 2:S63-73. [DOI: 10.1517/17460441.2.s1.s63] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Ebensen T, Link C, Riese P, Schulze K, Morr M, Guzmán CA. A pegylated derivative of alpha-galactosylceramide exhibits improved biological properties. THE JOURNAL OF IMMUNOLOGY 2007; 179:2065-73. [PMID: 17675464 DOI: 10.4049/jimmunol.179.4.2065] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The glycolipid alpha-galactosylceramide (alphaGalCer) has immunomodulatory properties, which have been exploited to combat cancer, chronic inflammatory diseases, and infections. However, its poor solubility makes alphaGalCer a suboptimal compound for in vivo applications. In this study, a pegylated derivative of alphaGalCer is characterized, which exhibits improved physical and biological properties. The new compound, alphaGalCerMPEG, is water-soluble and retains the specificity for the CD1d receptor of alphaGalCer. The in vitro stimulatory properties on immune cells (e.g., dendritic cells and splenocytes) are maintained intact, even when tested at a 33-fold lower concentration of the active moiety than alphaGalCer. NK cells isolated from mice treated with alphaGalCerMPEG also had stronger cytotoxic activity on YAC-1 cells than those obtained from animals receiving either alphaGalCer or CpG. Intranasal immunization studies performed in mice showed that alphaGalCerMPEG exerts stronger adjuvant activities than the parental compound alphaGalCer when tested at 0.35 vs 11.7 nM/dose. Coadministration of beta-galactosidase with alphaGalCerMPEG resulted not only in high titers of Ag-specific Abs in serum (i.e., 1:512,000), but also in the stimulation of stronger Th2 and secretory IgA responses, both at local and remote mucosal effector sites (i.e., nose, lung, and vagina). The new synthetic derivative alphaGalCerMPEG represents a promising tool for the development of immune interventions against infectious and noninfectious diseases.
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Affiliation(s)
- Thomas Ebensen
- Department of Vaccinology, Helmholtz Centre for Infection Research, Braunschweig, Germany
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Ebensen T, Schulze K, Riese P, Morr M, Guzmán CA. The bacterial second messenger cdiGMP exhibits promising activity as a mucosal adjuvant. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2007; 14:952-8. [PMID: 17567766 PMCID: PMC2044480 DOI: 10.1128/cvi.00119-07] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The development of mucosal adjuvants is still a critical need in vaccinology. In the present work, we show that bis(3',5')-cyclic dimeric GMP (cdiGMP), a second messenger that modulates cell surface properties of several microorganisms, exerts potent activity as a mucosal adjuvant. BALB/c mice were immunized intranasally with the model antigen beta-galactosidase (beta-Gal) coadministered with cdiGMP. Animals receiving cdiGMP as an adjuvant showed significantly higher anti-beta-Gal immunoglobulin G (IgG) titers in sera than controls (i.e., 512-fold [P < 0.05]). Coadministration of cdiGMP also stimulated efficient beta-Gal-specific secretory IgA production in the lung (P < 0.016) and vagina (P < 0.036). Cellular immune responses were observed in response to both the beta-Gal protein and a peptide encompassing its major histocompatibility complex class I-restricted epitope. The IgG1-to-IgG2a ratio of anti-beta-Gal antibodies and the observed profiles of secreted cytokines suggest that a dominant Th1 response pattern is promoted by mucosal coadministration of cdiGMP. Finally, the use of cdiGMP as a mucosal adjuvant also led to the stimulation of in vivo cytotoxic T-lymphocyte responses in C57BL/6 mice intranasally immunized with ovalbumin and cdiGMP (up to 30% of specific lysis). The results obtained indicate that cdiGMP is a promising tool for the development of mucosal vaccines.
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Affiliation(s)
- Thomas Ebensen
- Department of Vaccinology, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, D-38124 Braunschweig, Germany
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Fenn K, Conlon C, Jones M, Quail MA, Holroyd NE, Parkhill J, Blaxter M. Phylogenetic relationships of the Wolbachia of nematodes and arthropods. PLoS Pathog 2006; 2:e94. [PMID: 17040125 PMCID: PMC1599763 DOI: 10.1371/journal.ppat.0020094] [Citation(s) in RCA: 114] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2006] [Accepted: 08/21/2006] [Indexed: 11/18/2022] Open
Abstract
Wolbachia are well known as bacterial symbionts of arthropods, where they are reproductive parasites, but have also been described from nematode hosts, where the symbiotic interaction has features of mutualism. The majority of arthropod Wolbachia belong to clades A and B, while nematode Wolbachia mostly belong to clades C and D, but these relationships have been based on analysis of a small number of genes. To investigate the evolution and relationships of Wolbachia symbionts we have sequenced over 70 kb of the genome of wOvo, a Wolbachia from the human-parasitic nematode Onchocerca volvulus, and compared the genes identified to orthologues in other sequenced Wolbachia genomes. In comparisons of conserved local synteny, we find that wBm, from the nematode Brugia malayi, and wMel, from Drosophila melanogaster, are more similar to each other than either is to wOvo. Phylogenetic analysis of the protein-coding and ribosomal RNA genes on the sequenced fragments supports reciprocal monophyly of nematode and arthropod Wolbachia. The nematode Wolbachia did not arise from within the A clade of arthropod Wolbachia, and the root of the Wolbachia clade lies between the nematode and arthropod symbionts. Using the wOvo sequence, we identified a lateral transfer event whereby segments of the Wolbachia genome were inserted into the Onchocerca nuclear genome. This event predated the separation of the human parasite O. volvulus from its cattle-parasitic sister species, O. ochengi. The long association between filarial nematodes and Wolbachia symbionts may permit more frequent genetic exchange between their genomes. Filarial nematode worms cause hundreds of millions of cases of disease in humans worldwide. As part of efforts to identify new drug targets in these parasites, the Filarial Genome Project rediscovered that these worms carry within them a symbiotic bacterium, which may be a novel target. Fenn et al. investigated the relationships of these bacteria, from the genus Wolbachia, to those previously identified in arthropods using a new dataset of genome sequence data from the human parasite Onchocerca volvulus. O. volvulus causes river blindness in West Africa. The authors found that the Wolbachia strains found in nematodes are more closely related to each other than they are to the Wolbachia in insects, suggesting that the nematodes and their bacterial partners have been coevolving for some considerable evolutionary time and may indeed be good targets. In addition, the authors identified a fragment of Wolbachia DNA that was inserted in the genome of its nematode host and has subsequently degenerated. The insertion occurred before O. volvulus diverged from another nematode species, O. ochengi, found in cattle.
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Affiliation(s)
- Katelyn Fenn
- Institutes of Evolutionary Biology and Immunology and Infection Research, University of Edinburgh, Edinburgh, United Kingdom
| | - Claire Conlon
- Institutes of Evolutionary Biology and Immunology and Infection Research, University of Edinburgh, Edinburgh, United Kingdom
| | - Martin Jones
- Institutes of Evolutionary Biology and Immunology and Infection Research, University of Edinburgh, Edinburgh, United Kingdom
| | - Michael A Quail
- The Wellcome Trust Sanger Institute, Hinxton, Cambridge, United Kingdom
| | - Nancy E Holroyd
- The Wellcome Trust Sanger Institute, Hinxton, Cambridge, United Kingdom
| | - Julian Parkhill
- The Wellcome Trust Sanger Institute, Hinxton, Cambridge, United Kingdom
| | - Mark Blaxter
- Institutes of Evolutionary Biology and Immunology and Infection Research, University of Edinburgh, Edinburgh, United Kingdom
- * To whom correspondence should be addressed. E-mail:
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Zheng CJ, Han LY, Yap CW, Ji ZL, Cao ZW, Chen YZ. Therapeutic targets: progress of their exploration and investigation of their characteristics. Pharmacol Rev 2006; 58:259-79. [PMID: 16714488 DOI: 10.1124/pr.58.2.4] [Citation(s) in RCA: 132] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Modern drug discovery is primarily based on the search and subsequent testing of drug candidates acting on a preselected therapeutic target. Progress in genomics, protein structure, proteomics, and disease mechanisms has led to a growing interest in and effort for finding new targets and more effective exploration of existing targets. The number of reported targets of marketed and investigational drugs has significantly increased in the past 8 years. There are 1535 targets collected in the therapeutic target database compared with approximately 500 targets reported in a 1996 review. Knowledge of these targets is helpful for molecular dissection of the mechanism of action of drugs and for predicting features that guide new drug design and the search for new targets. This article summarizes the progress of target exploration and investigates the characteristics of the currently explored targets to analyze their sequence, structure, family representation, pathway association, tissue distribution, and genome location features for finding clues useful for searching for new targets. Possible "rules" to guide the search for druggable proteins and the feasibility of using a statistical learning method for predicting druggable proteins directly from their sequences are discussed.
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Affiliation(s)
- C J Zheng
- Bioinformatics and Drug Design Group, Department of Computational Science, National University of Singapore, Singapore, Singapore
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Ebensen T, Schulze K, Riese P, Link C, Morr M, Guzmán CA. The bacterial second messenger cyclic diGMP exhibits potent adjuvant properties. Vaccine 2006; 25:1464-9. [PMID: 17187906 DOI: 10.1016/j.vaccine.2006.10.033] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2006] [Revised: 10/16/2006] [Accepted: 10/18/2006] [Indexed: 01/09/2023]
Abstract
The identification of new adjuvants is a critical need in vaccinology. In this work, it is demonstrated that bis-(3',5')-cyclic dimeric guanosine monophosphate (cdiGMP) exhibits potent adjuvant properties. Subcutaneous co-administration of cdiGMP with beta-galactosidase (beta-Gal) to mice resulted in the elicitation of significantly higher antigen-specific serum IgG titres than in animals receiving beta-Gal alone. Strong cellular immune responses, which were characterized by a balanced Th1/Th2 pattern, were also observed in response to the beta-Gal protein and a peptide encompassing its MHC class I-restricted epitope in immunized animals. These results suggest that cdiGMP represents a promising adjuvant for vaccine development.
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Affiliation(s)
- Thomas Ebensen
- Department of Vaccinology, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, 38124 Braunschweig, Germany
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Li BW, Rush AC, Weil GJ, McCarter JP, Mitreva M. Brugia malayi: Effects of radiation and culture on gene expression in infective larvae. Mol Biochem Parasitol 2006; 149:201-7. [PMID: 16824625 DOI: 10.1016/j.molbiopara.2006.05.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2006] [Revised: 05/26/2006] [Accepted: 05/31/2006] [Indexed: 11/13/2022]
Abstract
Third-stage infective larvae (L3i) of Brugia malayi are developmentally arrested in mosquitoes but must quickly adapt to a new environment when they enter mammalian hosts to initiate infections. These changes can be studied by in vitro culture of L3 (L3c) under conditions that permit molting of L3-L4. Irradiated L3 (L3ir) have stunted growth and limited lifespan in mammalian hosts, and they induce high levels of immunity to challenge infections in animal models. This study explored differences in gene expression in L3i, L3c and L3ir by expressed sequence tag EST generation and qRT-PCR. 2506 ESTs generated from cDNA libraries constructed from L3i, L3c and L3ir were grouped into 1309 gene clusters. Despite extensive prior sampling from B. malayi (>22,000 ESTs in dbEST), 73% of the L3 clusters described here are novel. Sixty-three percentage of the clusters have homology to proteins from other species including 187 specific to nematodes and 141 that have to date only been described in non-nematode species. The transcript levels of 62 candidates for up- or down-regulation in L3i, L3c and L3ir based on EST frequencies were evaluated by qRT-PCR. Twenty-eight were confirmed to have > or = 3-fold differences in expression. Genes coding for proteins believed to be involved in establishment of infection, host adaptation and targets of protective immunity were confirmed to have higher expression in L3i than in L3c. Some of the genes that were down-regulated in L3c were highly expressed in L3ir. This study provides an improved description of the adaptations that accompany the transition from L3i to L3c and the special ability of L3ir to induce protective immunity.
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Affiliation(s)
- Ben-Wen Li
- Infectious Diseases Division, Campus Box 8051, Washington University School of Medicine, 660 S. Euclid Avenue, St. Louis, MO 63110, USA.
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Abstract
Ticks are distributed worldwide and impact human and animal health, as well as food animal production. Control of ticks has been primarily by application of acaricides, which has resulted in selection of resistant ticks and environmental pollution. Vaccines have been shown to be a feasible tick control method that offers a cost-effective, environmentally friendly alternative to chemical control. However, identification of tick-protective antigens remains the limiting step in vaccine development. Tick antigens exposed naturally to the host during tick feeding and those concealed have both shown promise as candidate vaccine antigens. Development of vaccines against multiple tick species may be possible using highly conserved tick-protective antigens or by antigens showing immune cross-reaction to different tick species. Vaccines made from a combination of key protective antigens may greatly enhance vaccine efficacy. Preliminary studies have suggested the possibility of vaccine strategies directed toward both tick control and the blocking of pathogen transmission. Characterization of the tick genomes will have a great impact on the discovery of new protective antigens. The future of research directed toward tick vaccine development is exciting because of new and emerging technologies for gene discovery, and vaccine formulation and delivery.
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Affiliation(s)
- J de la Fuente
- Department of Veterinary Pathobiology, Center for Veterinary pathobiology, Oklahoma State University, Stillwater, OK 74078-2007, USA.
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Ford L, Guiliano DB, Oksov Y, Debnath AK, Liu J, Williams SA, Blaxter ML, Lustigman S. Characterization of a Novel Filarial Serine Protease Inhibitor, Ov-SPI-1, from Onchocerca volvulus, with Potential Multifunctional Roles during Development of the Parasite. J Biol Chem 2005; 280:40845-56. [PMID: 16186127 DOI: 10.1074/jbc.m504434200] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A novel filarial serine protease inhibitor (SPI) from the human parasitic nematode Onchocerca volvulus, Ov-SPI-1, was identified through the analysis of a molting third-stage larvae expressed sequence tag dataset. Subsequent analysis of the expressed sequence tag datasets of O. volvulus and other filariae identified four other members of this family. These proteins are related to the low molecular weight SPIs originally isolated from Ascaris suum where they are believed to protect the parasite from host intestinal proteases. The two Ov-spi transcripts are up-regulated in the molting larvae and adult stages of the development of the parasite. Recombinant Ov-SPI-1 is an active inhibitor of serine proteases, specifically elastase, chymotrypsin, and cathepsin G. Immunolocalization of the Ov-SPI proteins demonstrates that the endogenous proteins are localized to the basal layer of the cuticle of third-stage, molting third-stage, and fourth-stage larvae, the body channels and multivesicular bodies of third-stage larvae and the processed material found between the two cuticles during molting. In O. volvulus adult worms the Ov-SPI proteins are localized to the sperm and to eggshells surrounding the developing embryos. RNA interference targeting the Ov-spi genes resulted in the specific knockdown of the transcript levels of both Ov-spi-1 and Ov-spi-2, a loss of native proteins, and a significant reduction in both molting and viability of third-stage larvae. We suggest the Ov-SPI proteins play a vital role in nematode molting by controlling the activity of an endogenous serine protease(s). The localization data in adults also indicate that these inhibitors may be involved in other processes such as embryogenesis and spermatogenesis.
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Affiliation(s)
- Louise Ford
- Laboratory of Molecular Parasitology, Lindsley F. Kimball Research Institute, New York Blood Center, New York, New York 10021, USA
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Almazán C, Blas-Machado U, Kocan KM, Yoshioka JH, Blouin EF, Mangold AJ, de la Fuente J. Characterization of three Ixodes scapularis cDNAs protective against tick infestations. Vaccine 2005; 23:4403-16. [PMID: 16005748 DOI: 10.1016/j.vaccine.2005.04.012] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2004] [Revised: 03/30/2005] [Accepted: 04/06/2005] [Indexed: 11/18/2022]
Abstract
cDNA expression library immunization (ELI) and analysis of expressed sequenced tags (EST) in a mouse model of tick infestations was used to identified cDNA clones that affected I. scapularis. Three protective antigens against larval tick infestations, 4F8, with homology to a nucleotidase, and 4D8 and 4E6 of unknown function, were selected for further characterization. All three antigens were expressed in all I. scapularis stages and localized in adult tick tissues. 4D8 was shown to be conserved in six other tick species. Based on immunization trials with synthetic polypeptides against larvae and nymphs and on artificial feeding experiments of adults, these antigens, especially 4D8, appear to be good candidates for continued development of a vaccine for control of tick infestations and may be useful in a formulation to target multiple species of ticks.
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Affiliation(s)
- Consuelo Almazán
- Department of Veterinary Pathobiology, Center for Veterinary Health Sciences, Oklahoma State University, Stillwater, OK 74078, USA
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Abstract
This is the first of a projected series of canonic reviews covering all invertebrate muscle literature prior to 2005 and covers muscle genes and proteins except those involved in excitation-contraction coupling (e.g., the ryanodine receptor) and those forming ligand- and voltage-dependent channels. Two themes are of primary importance. The first is the evolutionary antiquity of muscle proteins. Actin, myosin, and tropomyosin (at least, the presence of other muscle proteins in these organisms has not been examined) exist in muscle-like cells in Radiata, and almost all muscle proteins are present across Bilateria, implying that the first Bilaterian had a complete, or near-complete, complement of present-day muscle proteins. The second is the extraordinary diversity of protein isoforms and genetic mechanisms for producing them. This rich diversity suggests that studying invertebrate muscle proteins and genes can be usefully applied to resolve phylogenetic relationships and to understand protein assembly coevolution. Fully achieving these goals, however, will require examination of a much broader range of species than has been heretofore performed.
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Affiliation(s)
- Scott L Hooper
- Neuroscience Program, Department of Biological Sciences, Irvine Hall, Ohio University, Athens, Ohio 45701, USA.
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Gnanasekar M, Padmavathi B, Ramaswamy K. Cloning and characterization of a novel immunogenic protein 3 (NIP3) from Brugia malayi by immuno screening of a phage-display cDNA expression library. Parasitol Res 2005; 97:49-58. [PMID: 15952042 PMCID: PMC1307516 DOI: 10.1007/s00436-005-1375-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2004] [Accepted: 03/16/2005] [Indexed: 10/25/2022]
Abstract
Iterative screening of a phage display cDNA expression library of the third-stage larvae (L3) of Brugia malayi with sera from putatively immune individuals (endemic normal, EN) identified a novel clone with insert showing significant homology to Onchocerca volvulus novel immunogenic protein-3 (Ov-NIP3) gene and Caenorhabditis elegans NIP3-like protein and hence the gene was designated Brugia malayi NIP3-like protein (BmNIP3). EST database analysis showed that ESTs from several gastrointestinal nematodes such as Ancylostoma caninum, Teladorsagia circumcincta, Haemonchus contortus and Strongyloides stercoralis has BmNIP3 homologues, but the gene has not been described from these parasites. Sequence analyses showed that BmNIP3 has three potential mucin-type O-glycosylation sites and several serine/threonine phosphorylation sites. As expected, BmNIP3 protein isolated from the parasite was serine/threonine phosphorylated. Further analyses showed that BmNIP3 is differentially transcribed, with highest level of expression present in the larval (L3 and L4) stages. Mice immunized with rBmNIP3 developed strong antibody responses predominantly of the IgG1 and IgG2a subtype. A similar analyses of the sera samples from EN individuals showed that they also carry high levels of IgG1 and IgG2 antibodies against BmNIP3, whereas, chronically infected patients carry largely IgG3 antibodies and MF individuals carry high levels of IgG1 antibodies against BmNIP3. This study thus describes a novel protein from B. malayi that appears to be highly immunogenic in both humans and mice.
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Affiliation(s)
- Munirathinam Gnanasekar
- Department of Biomedical Sciences, University of Illinois College of Medicine, 1601 Parkview Avenue, Rockford, IL 61107, USA
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Lustigman S, Zhang J, Liu J, Oksov Y, Hashmi S. RNA interference targeting cathepsin L and Z-like cysteine proteases of Onchocerca volvulus confirmed their essential function during L3 molting. Mol Biochem Parasitol 2005; 138:165-70. [PMID: 15555728 DOI: 10.1016/j.molbiopara.2004.08.003] [Citation(s) in RCA: 130] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2004] [Accepted: 08/02/2004] [Indexed: 11/17/2022]
Abstract
We describe the successful use of RNA interference (RNAi) to investigate gene function in the human filarial parasite Onchocerca volvulus third-stage larvae (L3). We targeted two specific gene products, the O. volvulus cathepsin L (Ov-CPL) and cathepsin Z-like (Ov-CPZ) cysteine proteases, which were proposed to function during O. volvulus L3 molting. We show that fluorescent-labeled Cy3-dsRNA corresponding to cpl or cpz regions encoding the mature enzymes can enter the larvae. The molting rate of larvae treated overnight with 0.5 mg ml(-1) cpl was reduced by 92% and 86% in comparison to normal control worms. It appeared that although the larvae started the molting process the last stage of molting, ecdysis was inhibited. The effect was gene specific, as larvae that did not molt in the presence of cpl or cpz dsRNA expressed the other cysteine protease, CPZ and CPL, respectively. This was confirmed by immunoelectron microscopy using antibodies directed against each enzyme. Our present study validate conclusively that both enzymes are essential for the molting of O. volvulus L3 to fourth-stage larvae. We also confirmed that the activity of the enzymes is specific to the changes that occur during the molting process on days 1-3, when the separation between the cuticles is in progress. The development of RNAi in O. volvulus L3 could further help study many of the abundant L3 and molting L3 genes identified through the filarial genome project, many of which, although have no attributed function, were identified as vaccine candidates or potential drug targets.
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Affiliation(s)
- Sara Lustigman
- Laboratory of Molecular Parasitology, Lindsley F. Kimball Research Institute, New York Blood Center, 310 East 67th Street, New York, NY 10021, USA.
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Parkinson J, Mitreva M, Whitton C, Thomson M, Daub J, Martin J, Schmid R, Hall N, Barrell B, Waterston RH, McCarter JP, Blaxter ML. A transcriptomic analysis of the phylum Nematoda. Nat Genet 2004; 36:1259-67. [PMID: 15543149 DOI: 10.1038/ng1472] [Citation(s) in RCA: 192] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2004] [Accepted: 10/15/2004] [Indexed: 11/09/2022]
Abstract
The phylum Nematoda occupies a huge range of ecological niches, from free-living microbivores to human parasites. We analyzed the genomic biology of the phylum using 265,494 expressed-sequence tag sequences, corresponding to 93,645 putative genes, from 30 species, including 28 parasites. From 35% to 70% of each species' genes had significant similarity to proteins from the model nematode Caenorhabditis elegans. More than half of the putative genes were unique to the phylum, and 23% were unique to the species from which they were derived. We have not yet come close to exhausting the genomic diversity of the phylum. We identified more than 2,600 different known protein domains, some of which had differential abundances between major taxonomic groups of nematodes. We also defined 4,228 nematode-specific protein families from nematode-restricted genes: this class of genes probably underpins species- and higher-level taxonomic disparity. Nematode-specific families are particularly interesting as drug and vaccine targets.
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Affiliation(s)
- John Parkinson
- Hospital for Sick Children, 555 University Avenue, Departments of Biochemistry and Medical Genetics and Microbiology, University of Toronto, Toronto, Ontario M5G 1X8, Canada.
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47
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Guiliano DB, Hong X, McKerrow JH, Blaxter ML, Oksov Y, Liu J, Ghedin E, Lustigman S. A gene family of cathepsin L-like proteases of filarial nematodes are associated with larval molting and cuticle and eggshell remodeling. Mol Biochem Parasitol 2004; 136:227-42. [PMID: 15478801 DOI: 10.1016/j.molbiopara.2004.03.015] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Cysteine proteinases are involved in a variety of important biological processes and have been implicated in molting and tissue remodeling in free living and parasitic nematodes. We show that in the lymphatic filarial nematode Brugia pahangi molting of third-stage larvae (L3) to fourth-stage larvae is dependent on the activity of a cathepsin L-like cysteine protease (CPL), which can be detected in the excretory/secretory (ES) products of molting L3. Directed cloning of a cysteine protease gene in B. pahangi and analysis of the expressed sequence tag (EST) and genomic sequences of the closely related human lymphatic filarial nematode Brugia malayi have identified a family of CPLs. One group of these enzymes, Bm-cpl-1, -4, -5 and Bp-cpl-4, is highly expressed in the B. malayi and B. pahangi infective L3 larvae. Immunolocalization indicates that the corresponding enzymes are synthesized and stored in granules of the glandular esophagus of L3 and released during the molting process. Functional analysis of these genes in Brugia and closely related CPL genes identified in the filarial nematode Onchocerca volvulus and the free living model nematode Caenorhabditis elegans indicate that these genes are also involved in cuticle and eggshell remodeling.
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Affiliation(s)
- David B Guiliano
- Department of Biological Sciences, Imperial College of Science and Technology, London SW7 2AY, UK
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48
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Harcus YM, Parkinson J, Fernández C, Daub J, Selkirk ME, Blaxter ML, Maizels RM. Signal sequence analysis of expressed sequence tags from the nematode Nippostrongylus brasiliensis and the evolution of secreted proteins in parasites. Genome Biol 2004; 5:R39. [PMID: 15186490 PMCID: PMC463072 DOI: 10.1186/gb-2004-5-6-r39] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2003] [Revised: 04/14/2004] [Accepted: 04/29/2004] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Parasitism is a highly successful mode of life and one that requires suites of gene adaptations to permit survival within a potentially hostile host. Among such adaptations is the secretion of proteins capable of modifying or manipulating the host environment. Nippostrongylus brasiliensis is a well-studied model nematode parasite of rodents, which secretes products known to modulate host immunity. RESULTS Taking a genomic approach to characterize potential secreted products, we analyzed expressed sequence tag (EST) sequences for putative amino-terminal secretory signals. We sequenced ESTs from a cDNA library constructed by oligo-capping to select full-length cDNAs, as well as from conventional cDNA libraries. SignalP analysis was applied to predicted open reading frames, to identify potential signal peptides and anchors. Among 1,234 ESTs, 197 (~16%) contain predicted 5' signal sequences, with 176 classified as conventional signal peptides and 21 as signal anchors. ESTs cluster into 742 distinct genes, of which 135 (18%) bear predicted signal-sequence coding regions. Comparisons of clusters with homologs from Caenorhabditis elegans and more distantly related organisms reveal that the majority (65% at P < e-10) of signal peptide-bearing sequences from N. brasiliensis show no similarity to previously reported genes, and less than 10% align to conserved genes recorded outside the phylum Nematoda. Of all novel sequences identified, 32% contained predicted signal peptides, whereas this was the case for only 3.4% of conserved genes with sequence homologies beyond the Nematoda. CONCLUSIONS These results indicate that secreted proteins may be undergoing accelerated evolution, either because of relaxed functional constraints, or in response to stronger selective pressure from host immunity.
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Affiliation(s)
- Yvonne M Harcus
- Institute of Cell, Animal and Population Biology, University of Edinburgh, Edinburgh, EH9 3JT, UK
| | - John Parkinson
- Institute of Cell, Animal and Population Biology, University of Edinburgh, Edinburgh, EH9 3JT, UK
- Current address: Program in Genetics and Genomic Biology, Hospital for Sick Children, University Avenue, Toronto, Ontario M5G 1X8, Canada
| | - Cecilia Fernández
- Institute of Cell, Animal and Population Biology, University of Edinburgh, Edinburgh, EH9 3JT, UK
- Current address: Facultad de Química, Cátedra de Inmunología, Universita de la Republica, Montevideo 11300, Uruguay
| | - Jennifer Daub
- Institute of Cell, Animal and Population Biology, University of Edinburgh, Edinburgh, EH9 3JT, UK
| | - Murray E Selkirk
- Department of Biological Sciences, Imperial College London, London SW7 2AZ, UK
| | - Mark L Blaxter
- Institute of Cell, Animal and Population Biology, University of Edinburgh, Edinburgh, EH9 3JT, UK
| | - Rick M Maizels
- Institute of Cell, Animal and Population Biology, University of Edinburgh, Edinburgh, EH9 3JT, UK
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Pellerone FI, Archer SK, Behm CA, Grant WN, Lacey MJ, Somerville AC. Trehalose metabolism genes in Caenorhabditis elegans and filarial nematodes. Int J Parasitol 2004; 33:1195-206. [PMID: 13678635 DOI: 10.1016/s0020-7519(03)00173-5] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The sugar trehalose is claimed to be important in the physiology of nematodes where it may function in sugar transport, energy storage and protection against environmental stresses. In this study we investigated the role of trehalose metabolism in nematodes, using Caenorhabditis elegans as a model, and also identified complementary DNA clones putatively encoding genes involved in trehalose pathways in filarial nematodes. In C. elegans two putative trehalose-6-phosphate synthase (tps) genes encode the enzymes that catalyse trehalose synthesis and five putative trehalase (tre) genes encode enzymes catalysing hydrolysis of the sugar. We showed by RT-PCR or Northern analysis that each of these genes is expressed as mRNA at all stages of the C. elegans life cycle. Database searches and sequencing of expressed sequence tag clones revealed that at least one tps gene and two tre genes are expressed in the filarial nematode Brugia malayi, while one tps gene and at least one tre gene were identified for Onchocerca volvulus. We used the feeding method of RNA interference in C. elegans to knock down temporarily the expression of each of the tps and tre genes. Semiquantitative RT-PCR analysis confirmed that expression of each gene was silenced by RNA interference. We did not observe an obvious phenotype for any of the genes silenced individually but gas-chromatographic analysis showed >90% decline in trehalose levels when both tps genes were targeted simultaneously. This decline in trehalose content did not affect viability or development of the nematodes.
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Affiliation(s)
- F I Pellerone
- School of Biochemistry & Molecular Biology, Faculty of Science, Australian National University, ACT 0200, Canberra, Australia
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50
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MacDonald AJ, Tawe W, Leon O, Cao L, Liu J, Oksov Y, Abraham D, Lustigman S. Ov-ASP-1, the Onchocerca volvulus homologue of the activation associated secreted protein family is immunostimulatory and can induce protective anti-larval immunity. Parasite Immunol 2004; 26:53-62. [PMID: 15198646 DOI: 10.1111/j.0141-9838.2004.00685.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Vaccination of mice with a recombinant protein, Ov-ASP-1, the Onchocerca volvulus homologue of the activation associated secreted gene family stimulated very high titres of both IgG1 and IgG2a without adjuvant. rOv-ASP-1 was also immuno-reactive with IgG isotypes from both O. volvulus-infected (INF) and putatively immune (PI) humans, with higher IgG4 in the former group. The protein also stimulated IFN-gamma secretion by PBMC from INF and PI and IL-5 only in INF. Using a mouse diffusion chamber model, vaccination with rOv-ASP-1 resulted in partial but significant protection against challenge with infective third-stage larvae (L3) but only when formulated with Freund's complete adjuvant (FCA) or alum. Protection was Th1-dependent (highly elevated IgG2a) with FCA and contingent on a strongly Th2-skewed (IgG1) response with alum. IgE responses to rOv-ASP-1 with or without adjuvant were weak or absent. When immunization using rOv-ASP-1 in adjuvant failed to induce adequate Th1 (FCA) or Th2 (alum) responses, protection efficacy was compromised. The recombinant protein appears to stimulate a mixed Th1/Th2 response but the outcome in terms of protective immunity is the result of a subtle interplay of its intrinsic and adjuvant-augmented properties. Ov-ASP-1 is potentially secreted based on its localization in the secretory granules of L3.
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Affiliation(s)
- A J MacDonald
- Laboratory of Molecular Parasitology, Lindsley F. Kimball Research Institute, New York Blood Center, New York, NY 10021, USA.
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