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Nie Z, Ao Y, Wang S, Shu X, Li M, Zhan X, Yu L, An X, Sun Y, Guo J, Zhao Y, He L, Zhao J. Erythrocyte Adhesion of Merozoite Surface Antigen 2c1 Expressed During Extracellular Stages of Babesia orientalis. Front Immunol 2021; 12:623492. [PMID: 34079537 PMCID: PMC8165267 DOI: 10.3389/fimmu.2021.623492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Accepted: 04/22/2021] [Indexed: 11/22/2022] Open
Abstract
Babesia orientalis, a major infectious agent of water buffalo hemolytic babesiosis, is transmitted by Rhipicephalus haemaphysaloides. However, no effective vaccine is available. Essential antigens that are involved in parasite invasion of host red blood cells (RBCs) are potential vaccine candidates. Therefore, the identification and the conduction of functional studies of essential antigens are highly desirable. Here, we evaluated the function of B. orientalis merozoite surface antigen 2c1 (BoMSA-2c1), which belongs to the variable merozoite surface antigen (VMSA) family in B. orientalis. We developed a polyclonal antiserum against the purified recombinant (r)BoMSA-2c1 protein. Immunofluorescence staining results showed that BoMSA-2c1 was expressed only on extracellular merozoites, whereas the antigen was undetectable in intracellular parasites. RBC binding assays suggested that BoMSA-2c1 specifically bound to buffalo erythrocytes. Cytoadherence assays using a eukaryotic expression system in vitro further verified the binding and inhibitory ability of BoMSA-2c1. We found that BoMSA-2c1 with a GPI domain was expressed on the surface of HEK293T cells that bound to water buffalo RBCs, and that the anti-rBoMSA2c1 antibody inhibited this binding. These results indicated that BoMSA-2c1 was involved in mediating initial binding to host erythrocytes of B. orientalis. Identification of the occurrence of binding early in the invasion process may facilitate understanding of the growth characteristics, and may help in formulating strategies for the prevention and control of this parasite.
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Affiliation(s)
- Zheng Nie
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture of the People's Republic of China, Wuhan, China
| | - Yangsiqi Ao
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture of the People's Republic of China, Wuhan, China
| | - Sen Wang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture of the People's Republic of China, Wuhan, China
| | - Xiang Shu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture of the People's Republic of China, Wuhan, China
| | - Muxiao Li
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture of the People's Republic of China, Wuhan, China
| | - Xueyan Zhan
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture of the People's Republic of China, Wuhan, China
| | - Long Yu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture of the People's Republic of China, Wuhan, China
| | - Xiaomeng An
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture of the People's Republic of China, Wuhan, China
| | - Yali Sun
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture of the People's Republic of China, Wuhan, China
| | - Jiaying Guo
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture of the People's Republic of China, Wuhan, China
| | - Yangnan Zhao
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture of the People's Republic of China, Wuhan, China
| | - Lan He
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture of the People's Republic of China, Wuhan, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
| | - Junlong Zhao
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture of the People's Republic of China, Wuhan, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
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2
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Ueti MW, Johnson WC, Kappmeyer LS, Herndon DR, Mousel MR, Reif KE, Taus NS, Ifeonu OO, Silva JC, Suarez CE, Brayton KA. Comparative analysis of gene expression between Babesia bovis blood stages and kinetes allowed by improved genome annotation. Int J Parasitol 2020; 51:123-136. [PMID: 33069745 DOI: 10.1016/j.ijpara.2020.08.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 07/29/2020] [Accepted: 08/04/2020] [Indexed: 12/23/2022]
Abstract
Throughout their life cycle, Babesia parasites alternate between a mammalian host, where they cause babesiosis, and the tick vector. Transition between hosts results in distinct environmental signals that influence patterns of gene expression, consistent with the morphological and functional changes operating in the parasites during their life stages. In addition, comparing differential patterns of gene expression among mammalian and tick parasite stages can provide clues for developing improved methods of control. Hereby, we upgraded the genome assembly of Babesia bovis, a bovine hemoparasite, closing a 139 kbp gap, and used RNA-Seq datasets derived from mammalian blood and tick kinete stages to update the genome annotation. Of the originally annotated genes, 1,254 required structural changes, and 326 new genes were identified, leading to a different predicted proteome compared to the original annotation. Next, the RNA-Seq data was used to identify B. bovis genes that were differentially expressed in the vertebrate and arthropod hosts. In blood stages, 28% of the genes were upregulated up to 300 fold, whereas 26% of the genes in kinetes, a tick stage, were upregulated up to >19,000 fold. We thus discovered differentially expressed genes that may play key biological roles and serve as suitable targets for the development of vaccines to control bovine babesiosis.
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Affiliation(s)
- Massaro W Ueti
- Animal Diseases Research Unit, USDA-ARS, Pullman, Washington, USA; Program in Vector-borne Diseases, Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, Washington, USA; Paul G. Allen School for Global Animal Health, Washington State University, Pullman, Washington, USA.
| | | | | | - David R Herndon
- Animal Diseases Research Unit, USDA-ARS, Pullman, Washington, USA
| | - Michelle R Mousel
- Animal Diseases Research Unit, USDA-ARS, Pullman, Washington, USA; Paul G. Allen School for Global Animal Health, Washington State University, Pullman, Washington, USA
| | - Kathryn E Reif
- Animal Diseases Research Unit, USDA-ARS, Pullman, Washington, USA; Program in Vector-borne Diseases, Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, Washington, USA
| | - Naomi S Taus
- Animal Diseases Research Unit, USDA-ARS, Pullman, Washington, USA; Program in Vector-borne Diseases, Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, Washington, USA
| | - Olukemi O Ifeonu
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Joana C Silva
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland, USA; Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Carlos E Suarez
- Animal Diseases Research Unit, USDA-ARS, Pullman, Washington, USA; Program in Vector-borne Diseases, Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, Washington, USA
| | - Kelly A Brayton
- Program in Vector-borne Diseases, Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, Washington, USA; Paul G. Allen School for Global Animal Health, Washington State University, Pullman, Washington, USA.
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Simas PVM, Bassetto CC, Giglioti R, Okino CH, de Oliveira HN, de Sena Oliveira MC. Use of molecular markers can help to understand the genetic diversity of Babesia bovis. INFECTION GENETICS AND EVOLUTION 2019; 79:104161. [PMID: 31881358 DOI: 10.1016/j.meegid.2019.104161] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 12/13/2019] [Accepted: 12/23/2019] [Indexed: 11/16/2022]
Abstract
Cattle babesiosis is a tick-borne disease responsible for significant losses for the livestock industries in tropical areas of the world. These piroplasms are under constant control of the host immune system, which lead to a strong selective pressure for arising more virulent or attenuated phenotypes. Aiming to better understand the most critical genetic modifications in Babesia bovis genome, related to virulence, an in silico analysis was performed using DNA sequences from GenBank. Fourteen genes (sbp-2, sbp-4, trap, msa-1, msa-2b, msa-2c, Bv80 (or Bb-1), 18S rRNA, acs-1, ama-1, β-tub, cp-2, p0, rap-1a) related to parasite infection and immunogenicity and ITS region were selected for alignment and comparison of several isolates of Babesia bovis from different geographic regions around the world. Among the 15 genes selected for the study of diversity, only 7 genes (sbp-2, sbp-4, trap, msa-1, msa-2b, msa-2c, Bv80) and the ITS region presented sufficient genetic variation for the studies of phylogeny. Despite this genetic diversity observed into groups, there was not sufficient information available to associate molecular markers with virulence of isolates. However, some genetic groups no were correlated with geographic region what could indicate some typical evolutionary characteristics in the relation between parasite-host. Further studies using these genes in herds presenting diverse clinical conditions are required. The better understanding of evolutionary mechanisms of the parasite may contribute to improve prophylactic and therapeutic measures. In this way, we suggest that genes used in our study are potential markers of virulence and attenuation and have to be analyzed with the use of sequences from animals that present clinical signs of babesiosis and asymptomatic carriers.
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Affiliation(s)
- Paulo Vitor Marques Simas
- Faculdade de Ciências Agrárias e Veterinárias, Universidade Estadual Paulista Júlio de Mesquita Filho, Jaboticabal, São Paulo, Brazil; Embrapa Pecuária Sudeste, São Carlos, São Paulo, Brazil.
| | - César Cristiano Bassetto
- Faculdade de Ciências Agrárias e Veterinárias, Universidade Estadual Paulista Júlio de Mesquita Filho, Jaboticabal, São Paulo, Brazil; Embrapa Pecuária Sudeste, São Carlos, São Paulo, Brazil
| | - Rodrigo Giglioti
- Centro de Pesquisa de Genética e Reprodução Animal, Instituto de Zootecnia, Nova Odessa, São Paulo, Brazil
| | | | - Henrique Nunes de Oliveira
- Faculdade de Ciências Agrárias e Veterinárias, Universidade Estadual Paulista Júlio de Mesquita Filho, Jaboticabal, São Paulo, Brazil
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Matos CA, Gonçalves LR, Alvarez DO, Freschi CR, Silva JBD, Val-Moraes SP, Mendes NS, André MR, Machado RZ. Longitudinal evaluation of humoral immune response and merozoite surface antigen diversity in calves naturally infected with Babesia bovis, in São Paulo, Brazil. ACTA ACUST UNITED AC 2018; 26:479-490. [PMID: 29211135 DOI: 10.1590/s1984-29612017069] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Accepted: 11/07/2017] [Indexed: 11/21/2022]
Abstract
Babesiosis is an economically important infectious disease affecting cattle worldwide. In order to longitudinally evaluate the humoral immune response against Babesia bovis and the merozoite surface antigen diversity of B. bovis among naturally infected calves in Taiaçu, Brazil, serum and DNA samples from 15 calves were obtained quarterly, from their birth to 12 months of age. Anti-B. bovis IgG antibodies were detected by means of the indirect fluorescent antibody test (IFAT) and enzyme-linked immunosorbent assay (ELISA). The polymerase chain reaction (PCR) was used to investigate the genetic diversity of B. bovis, based on the genes that encode merozoite surface antigens (MSA-1, MSA-2b and MSA-2c). The serological results demonstrated that up to six months of age, all the calves developed active immunity against B. bovis. Among the 75 DNA samples evaluated, 2, 4 and 5 sequences of the genes msa-1, msa-2b and msa-2c were obtained. The present study demonstrated that the msa-1 and msa-2b genes sequences amplified from blood DNA of calves positive to B. bovis from Taiaçu were genetically distinct, and that msa-2c was conserved. All animals were serologically positive to ELISA and IFAT, which used full repertoire of parasite antigens in despite of the genetic diversity of MSAs.
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Affiliation(s)
- Carlos António Matos
- Laboratório de Imunoparasitologia, Departamento de Patologia Veterinária, Universidade Estadual Paulista - UNESP, Jaboticabal, SP, Brasil.,Direcção de Ciências Animais, Maputo, Moçambique
| | - Luiz Ricardo Gonçalves
- Laboratório de Imunoparasitologia, Departamento de Patologia Veterinária, Universidade Estadual Paulista - UNESP, Jaboticabal, SP, Brasil
| | | | - Carla Roberta Freschi
- Laboratório de Imunoparasitologia, Departamento de Patologia Veterinária, Universidade Estadual Paulista - UNESP, Jaboticabal, SP, Brasil
| | - Jenevaldo Barbosa da Silva
- Laboratório de Imunoparasitologia, Departamento de Patologia Veterinária, Universidade Estadual Paulista - UNESP, Jaboticabal, SP, Brasil
| | - Silvana Pompeia Val-Moraes
- Laboratório de Imunoparasitologia, Departamento de Patologia Veterinária, Universidade Estadual Paulista - UNESP, Jaboticabal, SP, Brasil
| | - Natalia Serra Mendes
- Laboratório de Imunoparasitologia, Departamento de Patologia Veterinária, Universidade Estadual Paulista - UNESP, Jaboticabal, SP, Brasil
| | - Marcos Rogério André
- Laboratório de Imunoparasitologia, Departamento de Patologia Veterinária, Universidade Estadual Paulista - UNESP, Jaboticabal, SP, Brasil
| | - Rosangela Zacarias Machado
- Laboratório de Imunoparasitologia, Departamento de Patologia Veterinária, Universidade Estadual Paulista - UNESP, Jaboticabal, SP, Brasil
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Zhou M, Cao S, Luo Y, Liu M, Wang G, Moumouni PFA, Jirapattharasate C, Iguchi A, Vudriko P, Terkawi MA, Löwenstein M, Kern A, Nishikawa Y, Suzuki H, Igarashi I, Xuan X. Molecular identification and antigenic characterization of a merozoite surface antigen and a secreted antigen of Babesia canis (BcMSA1 and BcSA1). Parasit Vectors 2016; 9:257. [PMID: 27141812 PMCID: PMC4855366 DOI: 10.1186/s13071-016-1518-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Accepted: 04/18/2016] [Indexed: 11/29/2022] Open
Abstract
Background Babesia canis is an apicomplexan tick-transmitted hemoprotozoan responsible for causing canine babesiosis in Europe and west Asia. Despite its importance, there is no known rapid diagnostic kit detection of B. canis infection in dogs. The present study identified two novel antigens of B. canis and used the recombinant antigens to establish a rapid, specific and sensitive serodiagnostic technique for detection of B. canis infection. Methods A complementary DNA (cDNA) expression library was constructed from the mRNA of B. canis and immunoscreened using B. canis-infected dog sera. The cDNAs encoding a merozoite surface antigen and a secreted antigen protein were identified and designated as BcMSA1 and BcSA1, respectively. The recombinant BcMSA1 and BcSA1 (rBcMSA1 and rBcSA1) expressed in Escherichia coli were purified and injected into mice for production of anti-sera. The native proteins were characterized by Western blot analysis and immunofluorescence. Furthermore, indirect enzyme-linked immunosorbent assays (iELISA) and rapid immunochromatographic tests (ICT) based on rBcMSA1 or rBcSA1 were established and evaluated to test specific antibodies in consecutive plasma samples from two B. canis-infected dogs. Results Antiserum raised against rBcMSA1 and rBcSA1 recognized the 39 kDa and 44 kDa native proteins by Western blot analysis, respectively. In addition, immunofluorescence and confocal microscopic observations revealed that BcMSA1 was found on the surface of parasites. However, BcSA1 localized in the matrix of the merozoites. The ELISA and ICT based on rBcMSA1 or rBcSA1 could detect specific antibodies in consecutive plasma samples from two B. canis-infected dogs. They showed no cross-reactions against the serum samples collected from dogs experimentally infected with closely related parasites. Conclusion Taken together, the current results indicated that the rBcMSA1 and rBcSA1 are promising serodiagnostic antigens for developing iELISA and ICT to detect B. canis infection. To our knowledge, this study is the first to report BcMSA1 and BcSA1 as potential antigenic proteins for serodiagnosis of B. canis infection in dogs.
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Affiliation(s)
- Mo Zhou
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, 080-8555, Japan
| | - Shinuo Cao
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, 080-8555, Japan.,Harbin Veterinary Research Institute, CAAS-Michigan State University Joint Laboratory of Innate Immunity, State Key Laboratory of Veterinary Biotechnology, Chinese Academy of Agricultural Sciences, Maduan Street 427, Nangang District, Harbin, 150001, PR China
| | - Yuzi Luo
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, 080-8555, Japan
| | - Mingming Liu
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, 080-8555, Japan
| | - Guanbo Wang
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, 080-8555, Japan
| | - Paul Franck Adjou Moumouni
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, 080-8555, Japan
| | - Charoonluk Jirapattharasate
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, 080-8555, Japan
| | - Aiko Iguchi
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, 080-8555, Japan
| | - Patrick Vudriko
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, 080-8555, Japan
| | - Mohamad Alaa Terkawi
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, 080-8555, Japan
| | | | - Angela Kern
- Megacor Diagnostik GmbH, Hoerbranz, Vorarlberg, A-6912, Austria
| | - Yoshifumi Nishikawa
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, 080-8555, Japan
| | - Hiroshi Suzuki
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, 080-8555, Japan
| | - Ikuo Igarashi
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, 080-8555, Japan
| | - Xuenan Xuan
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, 080-8555, Japan.
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Laughery JM, Knowles DP, Schneider DA, Bastos RG, McElwain TF, Suarez CE. Targeted surface expression of an exogenous antigen in stably transfected Babesia bovis. PLoS One 2014; 9:e97890. [PMID: 24840336 PMCID: PMC4026526 DOI: 10.1371/journal.pone.0097890] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Accepted: 04/25/2014] [Indexed: 11/18/2022] Open
Abstract
Babesia bovis is a tick-borne intraerythocytic protozoan responsible for acute disease in cattle which can be controlled by vaccination with attenuated B. bovis strains. Emerging B. bovis transfection technologies may increase the usefulness of these live vaccines. One use of transfected B. bovis parasites may be as a vaccine delivery platform. Previous transfection methods for B. bovis were limited by single expression sites and intracellular expression of transfected antigens. This study describes a novel transfection system in which two exogenous genes are expressed: one for selection and the other for a selected antigen designed to be delivered to the surface of the parasites. The strategy for duplicating the number of transfected genes was based on the use of the putative bidirectional promoter of the B. bovis 1.4 Kb ef-1α intergenic region. The ability of this region to regulate two independent expression sites was demonstrated using a luciferase assay on transiently transfected B. bovis parasites and then incorporated into a stable transfection plasmid to control independent expression of the selectable marker GFP-BSD and another gene of interest. A chimeric gene was synthetized using sequences from the protective B-cell epitopes of Rhipicephalus microplus tick antigen Bm86 along with sequences from the surface exposed B. bovis major surface antigen-1. This chimeric gene was then cloned into the additional expression site of the transfection plasmid. Transfection of the B. bovis Mo7 strain with this plasmid resulted in stable insertion into the ef-1α locus and simultaneous expression of both exogenous genes. Expression of the Bm86 epitopes on the surface of transfected merozoites was demonstrated using immunofluorescence analyses. The ability to independently express multiple genes by the inclusion of a bidirectional promoter and the achievement of surface expression of foreign epitopes advances the potential of transfected B. bovis as a future vaccine delivery platform.
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Affiliation(s)
- Jacob M. Laughery
- Program in Vector-Borne Diseases, Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, Washington, United States of America
| | - Donald P. Knowles
- Program in Vector-Borne Diseases, Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, Washington, United States of America
- Animal Disease Research Unit, Agricultural Research Service, United States Department of Agriculture, Pullman, Washington, United States of America
| | - David A. Schneider
- Animal Disease Research Unit, Agricultural Research Service, United States Department of Agriculture, Pullman, Washington, United States of America
| | - Reginaldo G. Bastos
- Program in Vector-Borne Diseases, Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, Washington, United States of America
| | - Terry F. McElwain
- Program in Vector-Borne Diseases, Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, Washington, United States of America
- Paul G. Allen School for Global Animal Health, College of Veterinary Medicine, Washington State University, Pullman, Washington, United States of America
| | - Carlos E. Suarez
- Program in Vector-Borne Diseases, Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, Washington, United States of America
- Animal Disease Research Unit, Agricultural Research Service, United States Department of Agriculture, Pullman, Washington, United States of America
- * E-mail:
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7
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Rodriguez AE, Florin-Christensen M, Flores DA, Echaide I, Suarez CE, Schnittger L. The glycosylphosphatidylinositol-anchored protein repertoire of Babesia bovis and its significance for erythrocyte invasion. Ticks Tick Borne Dis 2014; 5:343-8. [DOI: 10.1016/j.ttbdis.2013.12.011] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Revised: 12/23/2013] [Accepted: 12/29/2013] [Indexed: 11/26/2022]
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The molecular prevalence and MSA-2b gene-based genetic diversity of Babesia bovis in dairy cattle in Thailand. Vet Parasitol 2013; 197:642-8. [PMID: 23953761 DOI: 10.1016/j.vetpar.2013.07.015] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Revised: 07/08/2013] [Accepted: 07/09/2013] [Indexed: 11/20/2022]
Abstract
Bovine babesiosis is an economically significant disease that affects dairy farming operations in Thailand. In the present study, 1824 blood-DNA samples prepared from cattle bred in 4 different regions of the country (North, Northeast, Central, and South) were screened using a nested PCR for the specific detection of Babesia bovis. While the overall prevalence of B. bovis was 8.8%, the Central region of Thailand was found to be a high-risk area of the country, as the prevalence of the parasite was 15.0%. The positive rate was relatively higher among the animals of 1-5 years of age. The genetic diversity among the B. bovis parasites was also studied based on their MSA-2b gene, and the findings showed that the Thai sequences were dispersed across 8 of 13 total clades observed in the phylogram. Three of these clades were formed only of Thai sequences. Similarity among the deduced MSA-2b amino acid sequences determined in the present study was 68.3-100%. In conclusion, the present study found that all the locations surveyed were infected with B. bovis and that the parasite populations in Thailand were genetically diverse. Our findings highlight the need for further studies in Thailand to generate more information before a sound control strategy could be implemented against B. bovis.
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Nagano D, Sivakumar T, De De Macedo ACC, Inpankaew T, Alhassan A, Igarashi I, Yokoyama N. The genetic diversity of merozoite surface antigen 1 (MSA-1) among Babesia bovis detected from cattle populations in Thailand, Brazil and Ghana. J Vet Med Sci 2013; 75:1463-70. [PMID: 23856760 PMCID: PMC3942984 DOI: 10.1292/jvms.13-0251] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
In the present study, we screened blood DNA samples obtained from cattle bred in Brazil
(n=164) and Ghana (n=80) for Babesia bovis using a diagnostic PCR assay
and found prevalences of 14.6% and 46.3%, respectively. Subsequently, the genetic
diversity of B. bovis in Thailand, Brazil and Ghana was analyzed, based
on the DNA sequence of merozoite surface antigen-1 (MSA-1). In Thailand,
MSA-1 sequences were relatively conserved and found in a single clade
of the phylogram, while Brazilian MSA-1 sequences showed high genetic
diversity and were dispersed across three different clades. In contrast, the sequences
from Ghanaian samples were detected in two different clades, one of which contained only a
single Ghanaian sequence. The identities among the MSA-1 sequences from
Thailand, Brazil and Ghana were 99.0–100%, 57.5–99.4% and 60.3–100%, respectively, while
the similarities among the deduced MSA-1 amino acid sequences within the respective
countries were 98.4–100%, 59.4–99.7% and 58.7–100%, respectively. These observations
suggested that the genetic diversity of B. bovis based on
MSA-1 sequences was higher in Brazil and Ghana than in Thailand. The
current data highlight the importance of conducting extensive studies on the genetic
diversity of B. bovis before designing immune control strategies in each
surveyed country.
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Affiliation(s)
- Daisuke Nagano
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Obihiro, Hokkaido 080-8555, Japan
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Smith DB, Vanek J, Ramalingam S, Johannessen I, Templeton K, Simmonds P. Evolution of the hepatitis E virus hypervariable region. J Gen Virol 2012; 93:2408-2418. [PMID: 22837418 PMCID: PMC3542125 DOI: 10.1099/vir.0.045351-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
The presence of a hypervariable (HVR) region within the genome of hepatitis E virus (HEV) remains unexplained. Previous studies have described the HVR as a proline-rich spacer between flanking functional domains of the ORF1 polyprotein. Others have proposed that the region has no function, that it reflects a hypermutable region of the virus genome, that it is derived from the insertion and evolution of host sequences or that it is subject to positive selection. This study attempts to differentiate between these explanations by documenting the evolutionary processes occurring within the HVR. We have measured the diversity of HVR sequences within acutely infected individuals or amongst sequences derived from epidemiologically linked samples and, surprisingly, find relative homogeneity amongst these datasets. We found no evidence of positive selection for amino acid substitution in the HVR. Through an analysis of published sequences, we conclude that the range of HVR diversity observed within virus genotypes can be explained by the accumulation of substitutions and, to a much lesser extent, through deletions or duplications of this region. All published HVR amino acid sequences display a relative overabundance of proline and serine residues that cannot be explained by a local bias towards cytosine in this part of the genome. Although all published HVRs contain one or more SH3-binding PxxP motifs, this motif does not occur more frequently than would be expected from the proportion of proline residues in these sequences. Taken together, these observations are consistent with the hypothesis that the HVR has a structural role that is dependent upon length and amino acid composition, rather than a specific sequence.
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Affiliation(s)
- Donald B Smith
- Centre for Immunity, Infection and Evolution, University of Edinburgh, Ashworth Building, King's Buildings, Edinburgh EH9 3JF, UK
| | - Jeff Vanek
- Department of Laboratory Medicine, Royal Infirmary of Edinburgh, Little France, Edinburgh EH16 4SA, UK
| | - Sandeep Ramalingam
- Department of Laboratory Medicine, Royal Infirmary of Edinburgh, Little France, Edinburgh EH16 4SA, UK
| | - Ingolfur Johannessen
- Department of Laboratory Medicine, Royal Infirmary of Edinburgh, Little France, Edinburgh EH16 4SA, UK
| | - Kate Templeton
- Department of Laboratory Medicine, Royal Infirmary of Edinburgh, Little France, Edinburgh EH16 4SA, UK
| | - Peter Simmonds
- Centre for Immunity, Infection and Evolution, University of Edinburgh, Ashworth Building, King's Buildings, Edinburgh EH9 3JF, UK
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11
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Ferreri LM, Brayton KA, Sondgeroth KS, Lau AO, Suarez CE, McElwain TF. Expression and strain variation of the novel "small open reading frame" (smorf) multigene family in Babesia bovis. Int J Parasitol 2011; 42:131-8. [PMID: 22138017 PMCID: PMC3459096 DOI: 10.1016/j.ijpara.2011.10.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2011] [Revised: 09/11/2011] [Accepted: 10/05/2011] [Indexed: 11/19/2022]
Abstract
Small open reading frame (smorf) genes comprise the second largest Babesia bovis multigene family. All known 44 variant smorf genes are located in close chromosomal proximity to ves1 genes, which encode proteins that mediate cytoadhesion and contribute to immune evasion. In this study, we characterised the general topology of smorf genes and investigated the gene repertoire, transcriptional profile and SMORF expression in two distinct strains, T2Bo and Mo7. Sequence analysis using degenerate primers identified additional smorf genes in each strain and demonstrated that the smorf gene repertoire varies between strains, with conserved and unique genes in both. Smorf genes have multiple semi-conserved and variable blocks, and a large hypervariable insertion in 20 of the 44 genes defines two major branches of the family, termed smorf A and smorf B. A total of 32 smorf genes are simultaneously transcribed in T2Bo strain B. bovis merozoites obtained from deep brain tissue of an acutely infected animal. SMORF peptide-specific antiserum bound in immunoblots to multiple proteins with a range of sizes predicted by smorf genes, confirming translation of smorf gene products from these transcripts. These results indicate that the smorf multigene family is larger than previously described and demonstrate that smorf genes are expressed and are undergoing variation, both within strains and in a lineage-specific pattern independent of strain specificity. The function of these novel proteins is unknown.
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Affiliation(s)
- Lucas M. Ferreri
- Department of Veterinary Microbiology and Pathology and School for Global Animal Health, College of Veterinary Medicine, Washington State University, Pullman, WA 99164-6040, USA
| | - Kelly A. Brayton
- Department of Veterinary Microbiology and Pathology and School for Global Animal Health, College of Veterinary Medicine, Washington State University, Pullman, WA 99164-6040, USA
| | - Kerry S. Sondgeroth
- Department of Veterinary Microbiology and Pathology and School for Global Animal Health, College of Veterinary Medicine, Washington State University, Pullman, WA 99164-6040, USA
| | - Audrey O.T. Lau
- Department of Veterinary Microbiology and Pathology and School for Global Animal Health, College of Veterinary Medicine, Washington State University, Pullman, WA 99164-6040, USA
| | - Carlos E. Suarez
- Animal Disease Research Unit, United States Department of Agriculture, Agricultural Research Service, Pullman, WA 99164, USA
| | - Terry F. McElwain
- Department of Veterinary Microbiology and Pathology and School for Global Animal Health, College of Veterinary Medicine, Washington State University, Pullman, WA 99164-6040, USA
- Corresponding author. Tel.: +1 509 335 6342; fax: +1 509 335 7424.
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12
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Schneider DA, Yan H, Bastos RG, Johnson WC, Gavin PR, Allen AJ, Barrington GM, Herrmann-Hoesing LM, Knowles DP, Goff WL. Dynamics of bovine spleen cell populations during the acute response to Babesia bovis infection: an immunohistological study. Parasite Immunol 2011; 33:34-44. [PMID: 21155841 DOI: 10.1111/j.1365-3024.2010.01249.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The spleen is a critical organ in defence against haemoparasitic diseases like babesiosis. Many in vitro and ex vivo studies have identified splenic cells working in concert to activate mechanisms required for successful resolution of infection. The techniques used in those studies, however, remove cells from the anatomical context in which cell interaction and trafficking take place. In this study, an immunohistological approach was used to monitor the splenic distribution of defined cells during the acute response of naïve calves to Babesia bovis infection. Splenomegaly was characterized by disproportionate hyperplasia of large versus small leucocytes and altered distribution of several cell types thought to be important in mounting an effective immune response. In particular, the results suggest that the initial crosstalk between NK cells and immature dendritic cells occurs within the marginal zone and that immature dendritic cells are first redirected to encounter pathogens as they enter the spleen and then mature as they process antigen and migrate to T-cell-rich areas. The results of this study are remarkably similar to those observed in a mouse model of malarial infection, suggesting these dynamic events may be central to the acute response of naïve animals to haemoparasitic infection.
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Affiliation(s)
- D A Schneider
- Animal Disease Research Unit, USDA-ARS, Washington State University, Pullman, Washington 99164-6630, USA.
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13
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Freeman JM, Kappmeyer LS, Ueti MW, McElwain TF, Baszler TV, Echaide I, Nene VM, Knowles DP. A Babesia bovis gene syntenic to Theileria parva p67 is expressed in blood and tick stage parasites. Vet Parasitol 2010; 173:211-8. [DOI: 10.1016/j.vetpar.2010.06.024] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2009] [Revised: 06/17/2010] [Accepted: 06/17/2010] [Indexed: 11/29/2022]
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14
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Genotypic diversity of merozoite surface antigen 1 of Babesia bovis within an endemic population. Mol Biochem Parasitol 2010; 172:107-12. [PMID: 20371255 PMCID: PMC2941823 DOI: 10.1016/j.molbiopara.2010.03.017] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2010] [Revised: 03/26/2010] [Accepted: 03/29/2010] [Indexed: 11/21/2022]
Abstract
Multiple genetically distinct strains of a pathogen circulate and compete for dominance within populations of animal reservoir hosts. Understanding the basis for genotypic strain structure is critical for predicting how pathogens respond to selective pressures and how shifts in pathogen population structure can lead to disease outbreaks. Evidence from related Apicomplexans such as Plasmodium, Toxoplasma, Cryptosporidium and Theileria suggests that various patterns of population dynamics exist, including but not limited to clonal, oligoclonal, panmictic and epidemic genotypic strain structures. In Babesia bovis, genetic diversity of variable merozoite surface antigen (VMSA) genes has been associated with disease outbreaks, including in previously vaccinated animals. However, the extent of VMSA diversity within a defined population in an endemic area has not been examined. We analyzed genotypic diversity and temporal change of MSA-1, a member of the VMSA family, in individual infected animals within a reservoir host population. Twenty-eight distinct MSA-1 genotypes were identified within the herd. All genotypically distinct MSA-1 sequences clustered into three groups based on sequence similarity. Two thirds of the animals tested changed their dominant MSA-1 genotypes during a 6-month period. Five animals within the population contained multiple genotypes. Interestingly, the predominant genotypes within those five animals also changed over the 6-month sampling period, suggesting ongoing transmission or emergence of variant MSA-1 genotypes within the herd. This study demonstrated an unexpected level of diversity for a single copy gene in a haploid genome, and illustrates the dynamic genotype structure of B. bovis within an individual animal in an endemic region. Co-infection with multiple diverse MSA-1 genotypes provides a basis for more extensive genotypic shifts that characterizes outbreak strains.
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Perez-Llaneza A, Caballero M, Baravalle E, Mesplet M, Mosqueda J, Suarez CE, Echaide I, Katzer F, Pacheco GM, Florin-Christensen M, Schnittger L. Development of a tandem repeat-based multilocus typing system distinguishing Babesia bovis geographic isolates. Vet Parasitol 2010; 167:196-204. [DOI: 10.1016/j.vetpar.2009.09.021] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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16
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Dominguez M, Echaide I, Echaide STD, Mosqueda J, Cetrá B, Suarez CE, Florin-Christensen M. In silico predicted conserved B-cell epitopes in the merozoite surface antigen-2 family of B. bovis are neutralization sensitive. Vet Parasitol 2009; 167:216-26. [PMID: 19850413 DOI: 10.1016/j.vetpar.2009.09.023] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The merozoite surface antigens MSA-2 of Babesia bovis constitute a family of polymorphic GPI-anchored glycoproteins located at the parasite cell surface, that contain neutralization-sensitive B-cell epitopes. These are therefore putative vaccine candidates for bovine babesiosis. It was previously shown that (i) the MSA-2 antigens of the biologically cloned Mo7 strain are encoded by four tandemly organized genes: msa-2a(1), a(2), b and c, and (ii) at least one allele of each of these genes is present in the Argentine R1A strain with a moderate degree of polymorphism. The present work was aimed at defining neutralization-sensitive B-cell epitopes in the MSA-2 family, that are conserved among different B. bovis geographical isolates. To this end, msa-2a, b and c alleles from different isolates from Argentina, USA and Mexico were amplified by PCR, cloned and sequenced. Bioinformatic analysis by ClustalW alignments and B-cell epitope prediction algorithms performed on these sequences allowed the identification of several regions containing putative conserved B-cell epitopes. Four peptides representing these regions: (KDYKTMVKFCN from msa-2a(1); YYKKHIS, from msa-2b; and THDALKAVKQLIKT and ELLKLLIEA from msa-2c) were chemically synthesized, conjugated to keyhole limpet hemocyanin and used to inoculate mice to obtain immune sera. Anti-peptide antibodies recognized B. bovis merozoite extracts in all cases in ELISA tests. In addition, these sera reacted with the surface of merozoites of an Argentine and a Mexican B. bovis strains in immunofluorescence assays, and sera against two of the selected peptides inhibited invasion of erythrocytes by in vitro cultured merozoites. Taken together, the results show that the peptide sequences selected by bioinformatic analysis represent expressed and geographically conserved B. bovis B-cell epitopes that might be strong candidates for development of subunit vaccines.
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Affiliation(s)
- M Dominguez
- Institute of Pathobiology, Center of Agriculture and Veterinary Research, National Institute of Agriculture Technology, Castelar, Argentina
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Berens SJ, Brayton KA, McElwain TF. Coinfection with antigenically and genetically distinct virulent strains of Babesia bovis is maintained through all phases of the parasite life cycle. Infect Immun 2007; 75:5769-76. [PMID: 17893136 PMCID: PMC2168326 DOI: 10.1128/iai.00802-07] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Antigenic polymorphism is a defining characteristic of the Babesia bovis variable merozoite surface antigen (VMSA) family. Sequence analysis strongly suggests that recombination between virulent strains contributes to VMSA diversity. While meiosis during the aneuploid stage of the parasite's life cycle in the tick vector Rhipicephalus (Boophilus) microplus is the most probable source of interstrain recombination, there is no definitive evidence that coinfection of the mammalian host or R. microplus ticks with more than one virulent strain occurs. Using allele-specific real-time quantitative PCR, we tested the hypotheses that cattle could support coinfection of two antigenically variant virulent tick-transmissible strains of B. bovis and that R. microplus ticks could acquire and transmit these two divergent strains. The results indicate that both calves and ticks can support virulent B. bovis coinfection through all phases of the hemoparasite's life cycle. Neither strain dominated in either the mammalian or invertebrate host, and larval tick progeny, which could be coinfected individually, were also able to transmit both strains, resulting in virulent babesiosis in recipients. While coinfection of the tick vector provides the context in which allelic antigenic diversity can be generated, recombination of VMSA genes could not be confirmed, suggesting that VMSA allelic changes are slow to accumulate.
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Affiliation(s)
- Shawn J Berens
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA 99164-7040, USA.
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