Spherical Body Protein 4 from <i>Babesia bigemina</i>: A Novel Gene That Contains Conserved B-Cell Epitopes and Induces Cross-Reactive Neutralizing Antibodies in <i>Babesia ovata</i>
Juan Mosqueda,
Diego Josimar Hernandez-Silva,
Massaro W. Ueti,
Adolfo Cruz-Reséndiz,
Ricardo Marquez-Cervantez,
Uriel Mauricio Valdez-Espinoza,
Minh-Anh Dang-Trinh,
Thu-Thuy Nguyen,
Minerva Camacho-Nuez,
Miguel Angel Mercado-Uriostegui,
Gabriela Aguilar-Tipacamú,
Juan Alberto Ramos-Aragon,
Ruben Hernandez-Ortiz,
Shin-ichiro Kawazu,
Ikuo Igarashi
Affiliations
Juan Mosqueda
Immunology and Vaccines Laboratory, C. A. Facultad de Ciencias Naturales, Universidad Autonoma de Queretaro, Carretera a Chichimequillas, Ejido Bolaños, Queretaro 76140, Mexico
Diego Josimar Hernandez-Silva
Immunology and Vaccines Laboratory, C. A. Facultad de Ciencias Naturales, Universidad Autonoma de Queretaro, Carretera a Chichimequillas, Ejido Bolaños, Queretaro 76140, Mexico
Massaro W. Ueti
Animal Diseases Research Unit, Agricultural Research Service, US Department of Agriculture, Pullman, WA 99164, USA
Adolfo Cruz-Reséndiz
Immunology and Vaccines Laboratory, C. A. Facultad de Ciencias Naturales, Universidad Autonoma de Queretaro, Carretera a Chichimequillas, Ejido Bolaños, Queretaro 76140, Mexico
Ricardo Marquez-Cervantez
Immunology and Vaccines Laboratory, C. A. Facultad de Ciencias Naturales, Universidad Autonoma de Queretaro, Carretera a Chichimequillas, Ejido Bolaños, Queretaro 76140, Mexico
Uriel Mauricio Valdez-Espinoza
Immunology and Vaccines Laboratory, C. A. Facultad de Ciencias Naturales, Universidad Autonoma de Queretaro, Carretera a Chichimequillas, Ejido Bolaños, Queretaro 76140, Mexico
Minh-Anh Dang-Trinh
National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro 080-8555, Japan
Thu-Thuy Nguyen
National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro 080-8555, Japan
Minerva Camacho-Nuez
Posgrado en Ciencias Genomicas, Universidad Autonoma de la Ciudad de Mexico, San Lorenzo 290, Esquina Roberto Gayol, Col. del Valle Sur, Delegacion Benito Juarez, Mexico City 03100, Mexico
Miguel Angel Mercado-Uriostegui
Immunology and Vaccines Laboratory, C. A. Facultad de Ciencias Naturales, Universidad Autonoma de Queretaro, Carretera a Chichimequillas, Ejido Bolaños, Queretaro 76140, Mexico
Gabriela Aguilar-Tipacamú
C.A. Salud Animal y Microbiologia Ambiental, Facultad de Ciencias Naturales, Universidad Autonoma de Queretaro, Av. de las Ciencias s/n Col Juriquilla, Queretaro 76230, Mexico
Juan Alberto Ramos-Aragon
CENID-Salud Animal e Inocuidad/INIFAP, Carretera Federal Cuernavaca-Cuautla #8534, Col. Progreso, Jiutepec 62574, Mexico
Ruben Hernandez-Ortiz
CENID-Salud Animal e Inocuidad/INIFAP, Carretera Federal Cuernavaca-Cuautla #8534, Col. Progreso, Jiutepec 62574, Mexico
Shin-ichiro Kawazu
National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro 080-8555, Japan
Ikuo Igarashi
National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro 080-8555, Japan
Bovine babesiosis is a tick-transmitted disease caused by intraerythrocytic protozoan parasites of the genus Babesia. Its main causative agents in the Americas are Babesia bigemina and Babesia bovis, while Babesia ovata affects cattle in Asia. All Babesia species secrete proteins stored in organelles of the apical complex, which are involved in all steps of the invasion process of vertebrate host cells. Unlike other apicomplexans, which have dense granules, babesia parasites instead have large, round intracellular organelles called spherical bodies. Evidence suggests that proteins from these organelles are released during the process of invading red blood cells, where spherical body proteins (SBPs) play an important role in cytoskeleton reorganization. In this study, we characterized the gene that encodes SBP4 in B. bigemina. This gene is transcribed and expressed in the erythrocytic stages of B. bigemina. The sbp4 gene consists of 834 nucleotides without introns that encode a protein of 277 amino acids. In silico analysis predicted a signal peptide that is cleaved at residue 20, producing a 28.88-kDa protein. The presence of a signal peptide and the absence of transmembrane domains suggest that this protein is secreted. Importantly, when cattle were immunized with recombinant B. bigemina SBP4, antibodies identified B. bigemina and B. ovata merozoites according to confocal microscopy observations and were able to neutralize parasite multiplication in vitro for both species. Four peptides with predicted B-cell epitopes were identified to be conserved in 17 different isolates from six countries. Compared with the pre-immunization sera, antibodies against these conserved peptides reduced parasite invasion in vitro by 57%, 44%, 42%, and 38% for peptides 1, 2, 3, and 4, respectively (p B. bigemina cattle contained antibodies that recognized the individual peptides. All these results support the concept of spb4 as a new gene in B. bigemina that should be considered a candidate for a vaccine to control bovine babesiosis.