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van der Heijden EMDL, Lefevre L, Gossner A, Tzelos T, Connelley TK, Hassan MA. Comparative transcriptional analysis identifies genes associated with the attenuation of Theileria parva infected cells after long-term in vitro culture. Sci Rep 2024; 14:8976. [PMID: 38637584 PMCID: PMC11026401 DOI: 10.1038/s41598-024-59197-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Accepted: 04/08/2024] [Indexed: 04/20/2024] Open
Abstract
Autologous administration of attenuated Theileria parva-infected cells induces immunity to T. parva in cattle. The mechanism of attenuation, however, is largely unknown. Here, we used RNA sequencing of pathogenic and attenuated T. parva-infected T-cells to elucidate the transcriptional changes underpinning attenuation. We observed differential expression of several host genes, including TRAIL, PD-1, TGF-β and granzymes that are known to regulate inflammation and proliferation of infected cells. Importantly, many genes linked with the attenuation of the related T. annulata-infected cells were not dysregulated in this study. Furthermore, known T. parva antigens were not dysregulated in attenuated relative to pathogenic cells, indicating that attenuation is not due to enhanced immunogenicity. Overall this study suggests that attenuation is driven by a decrease in proliferation and restoration of the inflammatory profile of T. parva-infected cells. Additionally, it provides a foundation for future mechanistic studies of the attenuation phenotype in Theileria-infected cells.
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Affiliation(s)
- Elisabeth M D L van der Heijden
- Division of Infectious Diseases and Immunology, Department of Biomolecular Health Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.
| | - Lucas Lefevre
- Division of Immunology, The Roslin Institute, University of Edinburgh, Edinburgh, UK
| | - Anton Gossner
- Division of Immunology, The Roslin Institute, University of Edinburgh, Edinburgh, UK
| | - Thomas Tzelos
- Division of Immunology, The Roslin Institute, University of Edinburgh, Edinburgh, UK
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, EH26 0PZ, UK
| | - Timothy K Connelley
- Division of Immunology, The Roslin Institute, University of Edinburgh, Edinburgh, UK
- Centre for Tropical Livestock Genetics and Health, Easter Bush Campus, Edinburgh, UK
| | - Musa A Hassan
- Division of Immunology, The Roslin Institute, University of Edinburgh, Edinburgh, UK.
- Centre for Tropical Livestock Genetics and Health, Easter Bush Campus, Edinburgh, UK.
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Torina A, Blanda V, Villari S, Piazza A, La Russa F, Grippi F, La Manna MP, Di Liberto D, de la Fuente J, Sireci G. Immune Response to Tick-Borne Hemoparasites: Host Adaptive Immune Response Mechanisms as Potential Targets for Therapies and Vaccines. Int J Mol Sci 2020; 21:ijms21228813. [PMID: 33233869 PMCID: PMC7699928 DOI: 10.3390/ijms21228813] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 11/12/2020] [Accepted: 11/12/2020] [Indexed: 02/06/2023] Open
Abstract
Tick-transmitted pathogens cause infectious diseases in both humans and animals. Different types of adaptive immune mechanisms could be induced in hosts by these microorganisms, triggered either directly by pathogen antigens or indirectly through soluble factors, such as cytokines and/or chemokines, secreted by host cells as response. Adaptive immunity effectors, such as antibody secretion and cytotoxic and/or T helper cell responses, are mainly involved in the late and long-lasting protective immune response. Proteins and/or epitopes derived from pathogens and tick vectors have been isolated and characterized for the immune response induced in different hosts. This review was focused on the interactions between tick-borne pathogenic hemoparasites and different host effector mechanisms of T- and/or B cell-mediated adaptive immunity, describing the efforts to define immunodominant proteins or epitopes for vaccine development and/or immunotherapeutic purposes. A better understanding of these mechanisms of host immunity could lead to the assessment of possible new immunotherapies for these pathogens as well as to the prediction of possible new candidate vaccine antigens.
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Affiliation(s)
- Alessandra Torina
- Area Diagnostica Sierologica, Istituto Zooprofilattico Sperimentale della Sicilia, via Gino Marinuzzi 3, 90129 Palermo, Italy; (A.T.); (F.G.)
- Laboratorio di Riferimento OIE Theileriosi, Istituto Zooprofilattico Sperimentale della Sicilia, via Gino Marinuzzi 3, 90129 Palermo, Italy
| | - Valeria Blanda
- Laboratorio di Riferimento OIE Theileriosi, Istituto Zooprofilattico Sperimentale della Sicilia, via Gino Marinuzzi 3, 90129 Palermo, Italy
- Laboratorio di Entomologia e Controllo Vettori Ambientali, Istituto Zooprofilattico Sperimentale della Sicilia, Via Gino Marinuzzi 3, 90129 Palermo, Italy; (S.V.); (A.P.); (F.L.R.)
- Correspondence:
| | - Sara Villari
- Laboratorio di Entomologia e Controllo Vettori Ambientali, Istituto Zooprofilattico Sperimentale della Sicilia, Via Gino Marinuzzi 3, 90129 Palermo, Italy; (S.V.); (A.P.); (F.L.R.)
| | - Antonio Piazza
- Laboratorio di Entomologia e Controllo Vettori Ambientali, Istituto Zooprofilattico Sperimentale della Sicilia, Via Gino Marinuzzi 3, 90129 Palermo, Italy; (S.V.); (A.P.); (F.L.R.)
| | - Francesco La Russa
- Laboratorio di Entomologia e Controllo Vettori Ambientali, Istituto Zooprofilattico Sperimentale della Sicilia, Via Gino Marinuzzi 3, 90129 Palermo, Italy; (S.V.); (A.P.); (F.L.R.)
| | - Francesca Grippi
- Area Diagnostica Sierologica, Istituto Zooprofilattico Sperimentale della Sicilia, via Gino Marinuzzi 3, 90129 Palermo, Italy; (A.T.); (F.G.)
| | - Marco Pio La Manna
- Central Laboratory of Advanced Diagnostic and Biological Research (CLADIBIOR), BIND, University Hospital “Paolo Giaccone”, Università degli studi di Palermo, Via del Vespro 129, 90100 Palermo, Italy; (M.P.L.M.); (D.D.L.); (G.S.)
| | - Diana Di Liberto
- Central Laboratory of Advanced Diagnostic and Biological Research (CLADIBIOR), BIND, University Hospital “Paolo Giaccone”, Università degli studi di Palermo, Via del Vespro 129, 90100 Palermo, Italy; (M.P.L.M.); (D.D.L.); (G.S.)
| | - José de la Fuente
- SaBio, Instituto de Investigación en Recursos Cinegéticos IREC-CSIC-UCLM-JCCM, Ronda de Toledo s/n, 13005 Ciudad Real, Spain;
- Department of Veterinary Pathobiology, Center for Veterinary Health Sciences, Oklahoma State University, Stillwater, OK 74078, USA
| | - Guido Sireci
- Central Laboratory of Advanced Diagnostic and Biological Research (CLADIBIOR), BIND, University Hospital “Paolo Giaccone”, Università degli studi di Palermo, Via del Vespro 129, 90100 Palermo, Italy; (M.P.L.M.); (D.D.L.); (G.S.)
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3
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Atchou K, Ongus J, Machuka E, Juma J, Tiambo C, Djikeng A, Silva JC, Pelle R. Comparative Transcriptomics of the Bovine Apicomplexan Parasite Theileria parva Developmental Stages Reveals Massive Gene Expression Variation and Potential Vaccine Antigens. Front Vet Sci 2020; 7:287. [PMID: 32582776 PMCID: PMC7296165 DOI: 10.3389/fvets.2020.00287] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Accepted: 04/28/2020] [Indexed: 01/10/2023] Open
Abstract
Theileria parva is a protozoan parasite that causes East Coast fever (ECF), an economically important disease of cattle in Africa. It is transmitted mainly by the tick Rhipicephalus appendiculatus. Research efforts to develop a subunit vaccine based on parasite neutralizing antibodies and cytotoxic T-lymphocytes have met with limited success. The molecular mechanisms underlying T. parva life cycle stages in the tick vector and bovine host are poorly understood, thus limiting progress toward an effective and efficient control of ECF. Transcriptomics has been used to identify candidate vaccine antigens or markers associated with virulence and disease pathology. Therefore, characterization of gene expression throughout the parasite's life cycle should shed light on host-pathogen interactions in ECF and identify genes underlying differences in parasite stages as well as potential, novel therapeutic targets. Recently, the first gene expression profiling of T. parva was conducted for the sporoblast, sporozoite, and schizont stages. The sporozoite is infective to cattle, whereas the schizont is the major pathogenic form of the parasite. The schizont can differentiate into piroplasm, which is infective to the tick vector. The present study was designed to extend the T. parva gene expression profiling to the piroplasm stage with reference to the schizont. Pairwise comparison revealed that 3,279 of a possible 4,084 protein coding genes were differentially expressed, with 1,623 (49%) genes upregulated and 1,656 (51%) downregulated in the piroplasm relative to the schizont. In addition, over 200 genes were stage-specific. In general, there were more molecular functions, biological processes, subcellular localizations, and pathways significantly enriched in the piroplasm than in the schizont. Using known antigens as benchmarks, we identified several new potential vaccine antigens, including TP04_0076 and TP04_0640, which were highly immunogenic in naturally T. parva-infected cattle. All the candidate vaccine antigens identified have yet to be investigated for their capacity to induce protective immune response against ECF.
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Affiliation(s)
- Kodzo Atchou
- Institute for Basic Sciences, Technology and Innovation, Pan African University, Nairobi, Kenya.,Biosciences eastern and central Africa-International Livestock Research Institute (BecA-ILRI), Nairobi, Kenya
| | - Juliette Ongus
- Institute for Basic Sciences, Technology and Innovation, Pan African University, Nairobi, Kenya
| | - Eunice Machuka
- Institute for Basic Sciences, Technology and Innovation, Pan African University, Nairobi, Kenya.,Biosciences eastern and central Africa-International Livestock Research Institute (BecA-ILRI), Nairobi, Kenya
| | - John Juma
- Biosciences eastern and central Africa-International Livestock Research Institute (BecA-ILRI), Nairobi, Kenya
| | - Christian Tiambo
- Biosciences eastern and central Africa-International Livestock Research Institute (BecA-ILRI), Nairobi, Kenya
| | - Appolinaire Djikeng
- Centre for Tropical Livestock Genetics and Health, The Roslin Institute and Royal (Dick) School of Veterinary Studies, The University of Edinburgh, Scotland, United Kingdom
| | - Joana C Silva
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, United States.,Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Roger Pelle
- Biosciences eastern and central Africa-International Livestock Research Institute (BecA-ILRI), Nairobi, Kenya
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Evolution and diversity of the EMA families of the divergent equid parasites, Theileria equi and T. haneyi. INFECTION GENETICS AND EVOLUTION 2019; 68:153-160. [DOI: 10.1016/j.meegid.2018.12.020] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Revised: 12/04/2018] [Accepted: 12/17/2018] [Indexed: 11/30/2022]
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Nyagwange J, Tijhaar E, Ternette N, Mobegi F, Tretina K, Silva JC, Pelle R, Nene V. Characterization of the Theileria parva sporozoite proteome. Int J Parasitol 2017; 48:265-273. [PMID: 29258832 PMCID: PMC5854367 DOI: 10.1016/j.ijpara.2017.09.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Revised: 08/16/2017] [Accepted: 09/21/2017] [Indexed: 12/29/2022]
Abstract
2007 Theileria parva proteins expressed in the sporozoite were identified. Proteins include known T. parva antigens targeted by antibodies and cytotoxic T cells. Proteins predicted to be orthologs of Plasmodium falciparum sporozoite surface molecules were identified. Proteins predicted to be orthologs of P. falciparum invasion organelle proteins were identified. Proteins that may contribute to the phenomenon of bovine lymphocyte transformation were identified.
East Coast fever is a lymphoproliferative disease caused by the tick-borne protozoan parasite Theileria parva. The sporozoite stage of this parasite, harboured and released from the salivary glands of the tick Rhipicephalus appendiculatus during feeding, invades and establishes infection in bovine lymphocytes. Blocking this initial stage of invasion presents a promising vaccine strategy for control of East Coast fever and can in part be achieved by targeting the major sporozoite surface protein p67. To support research on the biology of T. parva and the identification of additional candidate vaccine antigens, we report on the sporozoite proteome as defined by LC–MS/MS analysis. In total, 4780 proteins were identified in an enriched preparation of sporozoites. Of these, 2007 were identified as T. parva proteins, representing close to 50% of the total predicted parasite proteome. The remaining 2773 proteins were derived from the tick vector. The identified sporozoite proteins include a set of known T. parva antigens targeted by antibodies and cytotoxic T cells from cattle that are immune to East Coast fever. We also identified proteins predicted to be orthologs of Plasmodium falciparum sporozoite surface molecules and invasion organelle proteins, and proteins that may contribute to the phenomenon of bovine lymphocyte transformation. Overall, these data establish a protein expression profile of T. parva sporozoites as an important starting point for further study of a parasitic species which has considerable agricultural impact.
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Affiliation(s)
- James Nyagwange
- International Livestock Research Institute, P.O. Box 30709, Nairobi, Kenya; Cell Biology and Immunology Group, Wageningen University, The Netherlands
| | - Edwin Tijhaar
- Cell Biology and Immunology Group, Wageningen University, The Netherlands
| | - Nicola Ternette
- The Jenner Institute, Nuffield Department of Medicine, University of Oxford, UK
| | - Fredrick Mobegi
- Department of Infection and Immunity, South Australian Health and Medical Research Institute, North Terrace, Adelaide 5000, South Australia, Australia
| | - Kyle Tretina
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Joana C Silva
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, USA; Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Roger Pelle
- International Livestock Research Institute, P.O. Box 30709, Nairobi, Kenya
| | - Vishvanath Nene
- International Livestock Research Institute, P.O. Box 30709, Nairobi, Kenya.
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The biology of Theileria parva and control of East Coast fever – Current status and future trends. Ticks Tick Borne Dis 2016; 7:549-64. [DOI: 10.1016/j.ttbdis.2016.02.001] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Revised: 02/01/2016] [Accepted: 02/02/2016] [Indexed: 01/02/2023]
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Sivakumar T, Hayashida K, Sugimoto C, Yokoyama N. Evolution and genetic diversity of Theileria. INFECTION GENETICS AND EVOLUTION 2014; 27:250-63. [PMID: 25102031 DOI: 10.1016/j.meegid.2014.07.013] [Citation(s) in RCA: 137] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2014] [Revised: 07/11/2014] [Accepted: 07/15/2014] [Indexed: 11/16/2022]
Abstract
Theileria parasites infect a wide range of domestic and wild ruminants worldwide, causing diseases with varying degrees of severity. A broad classification, based on the parasite's ability to transform the leukocytes of host animals, divides Theileria into two groups, consisting of transforming and non-transforming species. The evolution of transforming Theileria has been accompanied by drastic changes in its genetic makeup, such as acquisition or expansion of gene families, which are thought to play critical roles in the transformation of host cells. Genetic variation among Theileria parasites is sometimes linked with host specificity and virulence in the parasites. Immunity against Theileria parasites primarily involves cell-mediated immune responses in the host. Immunodominance and major histocompatibility complex class I phenotype-specificity result in a host immunity that is tightly focused and strain-specific. Immune escape in Theileria is facilitated by genetic diversity in its antigenic determinants, which potentially results in a loss of T cell receptor recognition in its host. In the recent past, several reviews have focused on genetic diversity in the transforming species, Theileriaparva and Theileriaannulata. In contrast, genetic diversity in Theileriaorientalis, a benign non-transforming parasite, which occasionally causes disease outbreaks in cattle, has not been extensively examined. In this review, therefore, we provide an outline of the evolution of Theileria, which includes T. orientalis, and discuss the possible mechanisms generating genetic diversity among parasite populations. Additionally, we discuss the potential implications of a genetically diverse parasite population in the context of Theileria vaccine development.
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Affiliation(s)
- Thillaiampalam Sivakumar
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan; Veterinary Research Institute, Peradeniya, Sri Lanka
| | - Kyoko Hayashida
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan
| | - Chihiro Sugimoto
- Division of Collaboration and Education, Research Center for Zoonosis Control, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Naoaki Yokoyama
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan.
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Hayashida K, Abe T, Weir W, Nakao R, Ito K, Kajino K, Suzuki Y, Jongejan F, Geysen D, Sugimoto C. Whole-genome sequencing of Theileria parva strains provides insight into parasite migration and diversification in the African continent. DNA Res 2013; 20:209-20. [PMID: 23404454 PMCID: PMC3686427 DOI: 10.1093/dnares/dst003] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The disease caused by the apicomplexan protozoan parasite Theileria parva, known as East Coast fever or Corridor disease, is one of the most serious cattle diseases in Eastern, Central, and Southern Africa. We performed whole-genome sequencing of nine T. parva strains, including one of the vaccine strains (Kiambu 5), field isolates from Zambia, Uganda, Tanzania, or Rwanda, and two buffalo-derived strains. Comparison with the reference Muguga genome sequence revealed 34 814–121 545 single nucleotide polymorphisms (SNPs) that were more abundant in buffalo-derived strains. High-resolution phylogenetic trees were constructed with selected informative SNPs that allowed the investigation of possible complex recombination events among ancestors of the extant strains. We further analysed the dN/dS ratio (non-synonymous substitutions per non-synonymous site divided by synonymous substitutions per synonymous site) for 4011 coding genes to estimate potential selective pressure. Genes under possible positive selection were identified that may, in turn, assist in the identification of immunogenic proteins or vaccine candidates. This study elucidated the phylogeny of T. parva strains based on genome-wide SNPs analysis with prediction of possible past recombination events, providing insight into the migration, diversification, and evolution of this parasite species in the African continent.
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Affiliation(s)
- Kyoko Hayashida
- Division of Collaboration and Education, Research Center for Zoonosis Control, Hokkaido University, Sapporo-shi, Hokkaido 001-0020, Japan
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Kappmeyer LS, Thiagarajan M, Herndon DR, Ramsay JD, Caler E, Djikeng A, Gillespie JJ, Lau AO, Roalson EH, Silva JC, Silva MG, Suarez CE, Ueti MW, Nene VM, Mealey RH, Knowles DP, Brayton KA. Comparative genomic analysis and phylogenetic position of Theileria equi. BMC Genomics 2012; 13:603. [PMID: 23137308 PMCID: PMC3505731 DOI: 10.1186/1471-2164-13-603] [Citation(s) in RCA: 88] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2012] [Accepted: 10/29/2012] [Indexed: 12/03/2022] Open
Abstract
Background Transmission of arthropod-borne apicomplexan parasites that cause disease and result in death or persistent infection represents a major challenge to global human and animal health. First described in 1901 as Piroplasma equi, this re-emergent apicomplexan parasite was renamed Babesia equi and subsequently Theileria equi, reflecting an uncertain taxonomy. Understanding mechanisms by which apicomplexan parasites evade immune or chemotherapeutic elimination is required for development of effective vaccines or chemotherapeutics. The continued risk of transmission of T. equi from clinically silent, persistently infected equids impedes the goal of returning the U. S. to non-endemic status. Therefore comparative genomic analysis of T. equi was undertaken to: 1) identify genes contributing to immune evasion and persistence in equid hosts, 2) identify genes involved in PBMC infection biology and 3) define the phylogenetic position of T. equi relative to sequenced apicomplexan parasites. Results The known immunodominant proteins, EMA1, 2 and 3 were discovered to belong to a ten member gene family with a mean amino acid identity, in pairwise comparisons, of 39%. Importantly, the amino acid diversity of EMAs is distributed throughout the length of the proteins. Eight of the EMA genes were simultaneously transcribed. As the agents that cause bovine theileriosis infect and transform host cell PBMCs, we confirmed that T. equi infects equine PBMCs, however, there is no evidence of host cell transformation. Indeed, a number of genes identified as potential manipulators of the host cell phenotype are absent from the T. equi genome. Comparative genomic analysis of T. equi revealed the phylogenetic positioning relative to seven apicomplexan parasites using deduced amino acid sequences from 150 genes placed it as a sister taxon to Theileria spp. Conclusions The EMA family does not fit the paradigm for classical antigenic variation, and we propose a novel model describing the role of the EMA family in persistence. T. equi has lost the putative genes for host cell transformation, or the genes were acquired by T. parva and T. annulata after divergence from T. equi. Our analysis identified 50 genes that will be useful for definitive phylogenetic classification of T. equi and closely related organisms.
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Affiliation(s)
- Lowell S Kappmeyer
- Animal Disease Research Unit, Agricultural Research Service, USDA, Pullman, WA 99164-7030, USA
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Comparative genome analysis of three eukaryotic parasites with differing abilities to transform leukocytes reveals key mediators of Theileria-induced leukocyte transformation. mBio 2012; 3:e00204-12. [PMID: 22951932 PMCID: PMC3445966 DOI: 10.1128/mbio.00204-12] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We sequenced the genome of Theileria orientalis, a tick-borne apicomplexan protozoan parasite of cattle. The focus of this study was a comparative genome analysis of T. orientalis relative to other highly pathogenic Theileria species, T. parva and T. annulata. T. parva and T. annulata induce transformation of infected cells of lymphocyte or macrophage/monocyte lineages; in contrast, T. orientalis does not induce uncontrolled proliferation of infected leukocytes and multiplies predominantly within infected erythrocytes. While synteny across homologous chromosomes of the three Theileria species was found to be well conserved overall, subtelomeric structures were found to differ substantially, as T. orientalis lacks the large tandemly arrayed subtelomere-encoded variable secreted protein-encoding gene family. Moreover, expansion of particular gene families by gene duplication was found in the genomes of the two transforming Theileria species, most notably, the TashAT/TpHN and Tar/Tpr gene families. Gene families that are present only in T. parva and T. annulata and not in T. orientalis, Babesia bovis, or Plasmodium were also identified. Identification of differences between the genome sequences of Theileria species with different abilities to transform and immortalize bovine leukocytes will provide insight into proteins and mechanisms that have evolved to induce and regulate this process. The T. orientalis genome database is available at http://totdb.czc.hokudai.ac.jp/.
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Gharbi M, Darghouth MA, Weir W, Katzer F, Boulter N, Adamson R, Gilbert SC, Jongejan F, Westbroek I, Hall R, Tait A, Shiels B. Prime-boost immunisation against tropical theileriosis with two parasite surface antigens: Evidence for protection and antigen synergy. Vaccine 2011; 29:6620-8. [DOI: 10.1016/j.vaccine.2011.06.109] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2011] [Revised: 05/05/2011] [Accepted: 06/28/2011] [Indexed: 11/30/2022]
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McKeever DJ. Bovine immunity - a driver for diversity in Theileria parasites? Trends Parasitol 2009; 25:269-76. [PMID: 19423397 DOI: 10.1016/j.pt.2009.03.005] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2008] [Revised: 03/10/2009] [Accepted: 03/16/2009] [Indexed: 10/20/2022]
Abstract
Theileria parva and Theileria annulata are tick-borne parasites of cattle that infect and transform leukocytes, causing severe and often fatal parasitic leukoses. Both species provoke strong immunity against subsequent infection. However, considerable diversity is observed in field populations of each parasite and protection is only assured against homologous challenge. The life cycles of these parasites are complex and involve prolonged exposure to host and vector defence mechanisms. Although the relevant vector mechanisms are poorly defined, protective responses of cattle seem to be tightly focused and variable in their specificity between individuals. This review considers whether bovine immunity acts as a driver for diversity in T. parva and T. annulata and explores other factors that might underlie genetic variation in these parasites.
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Affiliation(s)
- Declan J McKeever
- Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Hertfordshire, AL9 7TA, UK.
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Lau AOT. An overview of the Babesia, Plasmodium and Theileria genomes: a comparative perspective. Mol Biochem Parasitol 2008; 164:1-8. [PMID: 19110007 DOI: 10.1016/j.molbiopara.2008.11.013] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2008] [Revised: 11/21/2008] [Accepted: 11/24/2008] [Indexed: 11/30/2022]
Abstract
Babesia, Plasmodium and Theileria form a triad of apicomplexan hemoparasites and are accountable for significant mortality and morbidity to humans and animals globally. Understanding the pathobiology of these three genera is crucial as multiple drug resistant strains continue to arise in endemic areas along with pesticide and acaricide resistant vector hosts. Vastly improved sequencing technology has produced whole genome sequences of several apicomplexan species and subsequent comparative analyses of these genomes have identified unique as well as common features among the different species, information that will help in the pursuit of alternative therapies, management and perhaps elimination of the disease. This review, therefore, summarizes comparisons of genome structure, protein families, metabolic pathways and organelle biology in these three apicomplexans and how such knowledge has and will continue to enhance the field.
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Affiliation(s)
- Audrey O T Lau
- Program in Genomics, Department of Veterinary Microbiology and Pathology, School for Global Animal Health, College of Veterinary Medicine, Washington State University, Pullman, WA 99164-7040, USA.
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Bakheit M, Scholzen T, Ahmed JS, Seitzer U. Identification of potential antigenic proteins of Theileria lestoquardi. Ann N Y Acad Sci 2007; 1081:463-4. [PMID: 17135549 DOI: 10.1196/annals.1373.065] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
A PCR strategy was used to identify potential antigenic proteins of T. lestoquardi suitable for the development of an ELISA by searching for homologous proteins previously identified in other theilierial parasites to be antigenic.
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Affiliation(s)
- Mohammed Bakheit
- Department of Parasitology, University of Khartoum, Khartoum North, Sudan
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Bakheit MA, Scholzen T, Ahmed JS, Seitzer U. Molecular characterization of a Theileria lestoquardi gene encoding for immunogenic protein splice variants. Parasitol Res 2006; 100:161-70. [PMID: 16896652 DOI: 10.1007/s00436-006-0255-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2005] [Accepted: 06/01/2006] [Indexed: 01/17/2023]
Abstract
A Theileria lestoquardi schizont cDNA library was screened using sera collected from sheep recovering from a natural malignant theileriosis infection. An immunogenic clone (clone-5) was isolated and its full sequence was obtained using rapid amplification of cDNA ends polymerase chain reaction (PCR) technique. PCR experiments and sequencing demonstrated the presence of two transcript forms of the gene, resulting from splicing variation at the single intron found in the gene. Both gene products, clone-5 long and clone-5 short variants with calculated molecular weights of 99.9 and 72.7 kDa, respectively, were expressed in a T. lestoquardi-infected cell line. BLAST searches suggested the presence of homologues of the gene in both the Theileria parva and Theileria annulata genomes, with identities of 53 and 62% on the DNA level, respectively. The intron was preserved in size, sequence, and location within the gene in these parasites. Analysis of the subcellular localization of the clone-5 proteins showed a predominant parasite membrane association in T. lestoquardi-infected cells. Both recombinantly produced forms were found to be reactive with sera from infected animals. Bioinformatic analyses were employed to address the possible function of the gene products in the biology of T. lestoquardi.
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Affiliation(s)
- M A Bakheit
- Division of Veterinary Infectiology and Immunology, Research Center Borstel, Parkallee 22, 23845, Borstel, Germany
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Katzer F, McKellar S, Ferguson MAJ, d'Oliveira C, Shiels BR. A role for tertiary structure in the generation of antigenic diversity and molecular association of the Tams1 polypeptide in Theileria annulata. Mol Biochem Parasitol 2002; 122:55-67. [PMID: 12076770 DOI: 10.1016/s0166-6851(02)00078-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The major merozoite-piroplasm surface antigen (mMPSA) of Theileria annulata, Tams1, is known to be antigenically diverse. The possession of variable N-linked glycosylation sites and removal of monoclonal antibody 5E1 reactivity by mild periodate treatment suggested, previously, that divergent epitopes may be conferred by secondary modification. This study has shown that monoclonal antibody 5E1 and polyspecific antisera raised against the native protein react against divergent amino acid epitopes that are dependent on a molecular conformation that is sensitive to periodate. Therefore, no experimental evidence exists to confirm the sequence prediction that Tams1 undergoes N-linked glycosylation. Data is also presented indicating that the conformation of the antigen results in presentation of divergent regions on the external surface of the molecule, while conserved regions are more likely to be internal and hidden. In addition, non-reducing SDS-PAGE analysis demonstrated that Tams1 can undergo molecular association to form homo-dimers, trimers and multimers. The potential influence of tertiary structure and inter-molecular association on Tams1 diversity and function is discussed.
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Affiliation(s)
- Frank Katzer
- Department of Veterinary Parasitology, Faculty of Veterinary Medicine, University of Glasgow, Glasgow, UK
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Abstract
Protozoa are responsible for considerable morbidity and mortality in domestic and companion animals. Preventing infection may involve deliberate exposure to virulent or attenuated parasites so that immunity to natural infection is established early in life. This is the basis for vaccines against theilerosis and avian coccidiosis. Vaccination may not be effective or practical with diseases, such as cryptosporidiosis, that primarily afflict the immune-compromised or individuals with an incompletely developed immune system. Strategies for combating these diseases often rely on passive immunotherapy using serum or colostrums containing antibodies to parasite surface proteins. Subunit vaccines offer an attractive alternative to virulent or attenuated parasites for several reasons. These include the use of bacteria or lower eukaryotes to produce recombinant proteins in batch culture, the relative stability of recombinant proteins compared to live parasites, and the flexibility to incorporate only those antigens that elicit "protective" immune responses. Although subunit vaccines offer many theoretical advantages, our lack of understanding of immune mechanisms to primary and secondary infection and the capacity of many protozoa to evade host immunity remain obstacles to developing effective vaccines. This review examines the progress made on developing recombinant proteins of Eimeria, Giardia, Cryptosporidium, Toxoplasma, Neospora, Trypanosoma, Babesia, and Theileria and attempts to use these antigens for vaccinating animals against the associated diseases.
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Affiliation(s)
- M C Jenkins
- Immunology and Disease Resistance Laboratory, Agricultural Research Service, US Department of Agriculture (USDA), Beltsville, MA 20705, USA.
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