1
|
Abstract
INTRODUCTION : Human infections with helminth worm parasites are extraordinarily prevalent across tropical and subtropical parts of the world, and control relies primarily on drugs that offer short-term suppression of infection. There is an urgent need for new vaccines that would confer long-lived immunity, protecting children in particular and minimizing community transmission. AREAS COVERED : This article discusses the development of helminth vaccines, from the first successful veterinary vaccines that demonstrated the feasibility of inducing protective immunity to helminths, to more recent initiatives to test human helminth antigens. The field has focussed primarily on evaluating individual antigens that could constitute targets amenable to antibody attack to inhibit parasite establishment. In a new direction, vaccines employing extracellular vesicles released by helminths have also given exciting results. EXPERT OPINION : Taking into account the complex life cycles and sophisticated immune evasion strategies of many helminths, a combination of antigens and approaches designed to target essential functional pathways of the parasite will be required to achieve a high level of protection in future anti-helminth vaccines.
Collapse
Affiliation(s)
- Rick M. Maizels
- Wellcome Centre for Integrative Parasitology; Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, UK,CONTACT Rick M. Maizels Wellcome Centre for Integrative Parasitology; Institute of Infection, Immunity and Inflammation, University of Glasgow, 120 University Place, GlasgowG12 8TA, UK
| |
Collapse
|
2
|
Guimarães-Peixoto RPM, Pinto PSA, Santos MR, Zilch TJ, Apolinário PF, Silva-Júnior A. Development of the multi-epitope chimeric antigen rqTSA-25 from Taenia saginata for serological diagnosis of bovine cysticercosis. PLoS Negl Trop Dis 2018; 12:e0006371. [PMID: 29649259 PMCID: PMC6078323 DOI: 10.1371/journal.pntd.0006371] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 08/06/2018] [Accepted: 03/07/2018] [Indexed: 11/30/2022] Open
Abstract
Bovine cysticercosis is a worldwide distributed zoonosis caused by the larval form of Taenia saginata present in bovine muscles. The diagnosis is based on the postmortem inspection at slaughterhouses and consists of the macroscopic visualization of lesions caused by cysticercosis in muscle sites. However, parasitized animals can pass unnoticed during sanitary inspection. Thus, the objective of this study was to characterize and evaluate the performance of different peptides from different regions of T. saginata for the cysticercosis diagnosis using enzyme-linked immunosorbent assay. We generated and evaluated a new recombinant protein chimera derived from the fusion of different peptides. We selected three distinct regions of T. saginata and predicted six peptides with antigenic potential (EP2–EP7). These peptides were analyzed individually and selected for generating a new chimeric recombinant protein. The new protein was termed rqTSA-25, and its performance rates were: 93.3% sensitivity (confidence interval (CI) = 76–98%), 95.3% specificity (CI = 82–99%), 93% positive predictive value (CI = 76–98%), 95% negative predictive value (CI = 82–99%), and 95% accuracy. In the immunoblot, this protein showed no false positive or false negative reaction. Thus, the use of rqTSA-25 is recommended for the diagnosis of bovine cysticercosis. Taenia saginata cysticercosis occurs worldwide. The prevalence related is higher mainly in developing countries, causing damage to public health and economic losses. Through our study, a new antigen with high diagnostic potential was developed for use in laboratory serological tests, aiming at the detection of bovine cysticercosis. In this way, it was possible to contribute significantly to the improvement of the diagnosis of this disease.
Collapse
Affiliation(s)
- Rafaella P. M. Guimarães-Peixoto
- Laboratório de Inspeção de Produtos de Origem Animal, Departamento de Veterinária, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
- * E-mail:
| | - Paulo S. A. Pinto
- Laboratório de Inspeção de Produtos de Origem Animal, Departamento de Veterinária, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
| | - Marcus R. Santos
- Laboratório de Virologia Animal, Departamento de Veterinária, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
| | - Tiago J. Zilch
- Laboratório de Virologia Animal, Departamento de Veterinária, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
| | - Paula F. Apolinário
- Laboratório de Inspeção de Produtos de Origem Animal, Departamento de Veterinária, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
| | - Abelardo Silva-Júnior
- Laboratório de Virologia Animal, Departamento de Veterinária, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
| |
Collapse
|
3
|
Díaz A, Casaravilla C, Barrios AA, Ferreira AM. Parasite molecules and host responses in cystic echinococcosis. Parasite Immunol 2016; 38:193-205. [PMID: 26425838 DOI: 10.1111/pim.12282] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Accepted: 09/22/2015] [Indexed: 01/03/2023]
Abstract
Cystic echinococcosis is the infection by the larvae of cestode parasites belonging to the Echinococcus granulosus sensu lato species complex. Local host responses are strikingly subdued in relation to the size and persistence of these larvae, which develop within mammalian organs as 'hydatid cysts' measuring up to tens of cm in diameter. In a context in which helminth-derived immune-suppressive, as well as Th2-inducing, molecules garner much interest, knowledge on the interactions between E. granulosus molecules and the immune system lags behind. Here, we discuss what is known and what are the open questions on E. granulosus molecules and structures interacting with the innate and adaptive immune systems, potentially or in demonstrated form. We attempt a global biological approach on molecules that have been given consideration primarily as protective (Eg95) or diagnostic antigens (antigen B, antigen 5). We integrate glycobiological information, which traverses the discussions on antigen 5, the mucin-based protective laminated layer and immunologically active preparations from protoscoleces. We also highlight some less well-known molecules that appear as promising candidates to possess immune-regulatory activities. Finally, we point out gaps in the molecular-level knowledge of this infectious agent that hinder our understanding of its immunology.
Collapse
Affiliation(s)
- A Díaz
- Cátedra de Inmunología, Departamento de Biociencias (Facultad de Química) and Instituto de Química Biológica (Facultad de Ciencias), Universidad de la República, Montevideo, Uruguay
| | - C Casaravilla
- Cátedra de Inmunología, Departamento de Biociencias (Facultad de Química) and Instituto de Química Biológica (Facultad de Ciencias), Universidad de la República, Montevideo, Uruguay
| | - A A Barrios
- Cátedra de Inmunología, Departamento de Biociencias (Facultad de Química) and Instituto de Química Biológica (Facultad de Ciencias), Universidad de la República, Montevideo, Uruguay
| | - A M Ferreira
- Cátedra de Inmunología, Departamento de Biociencias (Facultad de Química) and Instituto de Química Biológica (Facultad de Ciencias), Universidad de la República, Montevideo, Uruguay
| |
Collapse
|
4
|
Olson PD, Zarowiecki M, Kiss F, Brehm K. Cestode genomics - progress and prospects for advancing basic and applied aspects of flatworm biology. Parasite Immunol 2012; 34:130-50. [PMID: 21793855 DOI: 10.1111/j.1365-3024.2011.01319.x] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Characterization of the first tapeworm genome, Echinococcus multilocularis, is now nearly complete, and genome assemblies of E. granulosus, Taenia solium and Hymenolepis microstoma are in advanced draft versions. These initiatives herald the beginning of a genomic era in cestodology and underpin a diverse set of research agendas targeting both basic and applied aspects of tapeworm biology. We discuss the progress in the genomics of these species, provide insights into the presence and composition of immunologically relevant gene families, including the antigen B- and EG95/45W families, and discuss chemogenomic approaches toward the development of novel chemotherapeutics against cestode diseases. In addition, we discuss the evolution of tapeworm parasites and introduce the research programmes linked to genome initiatives that are aimed at understanding signalling systems involved in basic host-parasite interactions and morphogenesis.
Collapse
Affiliation(s)
- P D Olson
- Department of Zoology, The Natural History Museum, London, UK
| | | | | | | |
Collapse
|
5
|
Gauci C, Lightowlers MW. Genes encoding homologous antigens in taeniid cestode parasites: Implications for development of recombinant vaccines produced in Escherichia coli. Bioengineered 2012; 4:168-71. [PMID: 23090389 DOI: 10.4161/bioe.22576] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Recombinant vaccine antigens are being evaluated for their ability to protect livestock animals against cysticercosis and related parasitic infections. Practical use of some of these vaccines is expected to reduce parasite transmission, leading to a reduction in the incidence of neurocysticercosis and hydatid disease in humans. We recently showed that an antigen (TSOL16), expressed in Escherichia coli, confers high levels of protection against Taenia solium cysticercosis in pigs, which provides a strategy for control of T. solium parasite transmission. Here, we discuss the characteristics of this antigen that may affect the utility of TSOL16 and related antigens for development as recombinant vaccines. We also report that genes encoding antigens closely related to TSOL16 from T. solium also occur in other related species of parasites. These highly homologous antigens have the potential to be used as vaccines and may provide protection against related species of Taenia that cause infection in other hosts.
Collapse
Affiliation(s)
- Charles Gauci
- University of Melbourne, Faculty of Veterinary Science, Werribee, VIC, Australia.
| | | |
Collapse
|
6
|
Chile N, Evangelista J, Gilman RH, Arana Y, Palma S, Sterling CR, Garcia HH, Gonzalez A, Verastegui M. Standardization of a fluorescent-based quantitative adhesion assay to study attachment of Taenia solium oncosphere to epithelial cells in vitro. J Immunol Methods 2012; 376:89-96. [PMID: 22178422 DOI: 10.1016/j.jim.2011.12.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2011] [Revised: 12/01/2011] [Accepted: 12/01/2011] [Indexed: 11/18/2022]
Abstract
To fully understand the preliminary stages of Taenia solium oncosphere attachment in the gut, adequate tools and assays are necessary to observe and quantify this event that leads to infection. A fluorescent-based quantitative adhesion assay, using biotinylated activated-oncospheres and monolayers of Chinese hamster ovary cells (CHO-K1) or human intestinal monolayer cells (INT-407, HCT-8 or HT-29), was developed to study initial events during the infection of target cells and to rapidly quantify the in vitro adhesion of T. solium oncospheres. Fluorescein streptavidin was used to identify biotinylated activated-oncospheres adhered to cells. This adherence was quantified using an automated fluorescence plate reader, and the results were expressed as fluorescence intensity values. A series of three assays were performed. The first was to identify the optimum number of biotinylated activated-oncospheres to be used in the adhesion assay. The goal of the second assay was to validate this novel method with the established oncosphere-binding system using the immunofluorescent-antibody assay (IFA) method to quantify oncosphere adhesion. A total of 10,000 biotinylated activated-oncospheres were utilized to assess the role of sera and laminin (LM) in oncosphere adherence to a CHO-K1 cell monolayer. The findings that sera and LM increase the adhesion of oncospheres to monolayer cells were similar to results that were previously obtained using the IFA method. The third assay compared the adherence of biotinylated activated-oncospheres to different types of human intestinal monolayer cells. In this case, the fluorescence intensity was greatest when using the INT-407 cell monolayer. We believe this new method of quantification offers the potential for rapid, large-scale screening to study and elucidate specific molecules and mechanisms involved in oncosphere-host cell attachment.
Collapse
Affiliation(s)
- Nancy Chile
- Laboratory of Infectious Diseases Research, Department of Cellular and Molecular Sciences, School of Sciences and Philosophy Universidad Peruana Cayetano Heredia, PO Box 5045, Lima, Peru
| | | | | | | | | | | | | | | | | |
Collapse
|
7
|
Martinez-Ocaña J, Romero-Valdovinos M, de Kaminsky RG, Maravilla P, Flisser A. Immunolocalization of TSOL18 and TSOL45-1A, the successful protective peptides against porcine cysticercosis, in Taenia solium oncospheres. Parasit Vectors 2011; 4:3. [PMID: 21211050 PMCID: PMC3024966 DOI: 10.1186/1756-3305-4-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2010] [Accepted: 01/06/2011] [Indexed: 11/10/2022] Open
Abstract
Taenia solium life cycle includes humans as definitive hosts and pigs as intermediate hosts. One of the measures to stop the life cycle of this parasite is by vaccination of pigs. In experiments performed in pigs with TSOL18 and TSOL45-1A, two recombinant T. solium proteins, 99.5% and 97.0% protection was induced, respectively. The purpose of this paper was to localize these antigens in all stages of the parasite (adult worms, oncospheres and cysticerci) by immunofluorescence, with the use of antibodies against TSOL18 and TSOL45-1A that were obtained from the pigs used in the vaccination experiment. Results show that TSOL18 and TSOL45-1A are expressed on the surface of T. solium oncospheres and not in tapeworms or cysticerci, indicating that they are stage-specific antigens. This, therefore, might explain the high level of protection these antigens induce against pig cysticercosis.
Collapse
Affiliation(s)
- Joel Martinez-Ocaña
- Hospital General Dr. Manuel Gea Gonzalez, SSA. Calzada de Tlalpan 4800, Col Seccion XVI, Tlalpan, Mexico 14080 DF, Mexico
| | | | | | | | | |
Collapse
|