title: The Babesia bovis merozoite surface antigen 1 hypervariable region induces surface-reactive antibodies that block merozoite invasion.
abstract: A hypervariable region (HVR) previously identified in the carboxy-terminal one-third of the Babesia bovis variable merozoite surface antigen family was more extensively analyzed in merozoite surface antigen 1 (MSA-1) from 16 strains and isolates. The MSA-1 HVR is proline rich and contains three semiconserved motifs nearly identical to those described for the related family member MSA-2. Two MSA-1-specific monoclonal antibodies previously shown to be reactive with the merozoite surface bound to a recombinant construct encoding the HVR, indicating that the HVR is surface exposed and accessible to antibody binding. Importantly, these surface-reactive, HVR-specific monoclonal antibodies were capable of inhibiting merozoite infectivity of the host erythrocyte in vivo. The results indicate that the MSA-1 HVR is involved in erythrocyte invasion and suggest that selection of MSA-1 variants may be driven by invasion-blocking antibodies.
authors.affiliation: Program in Vector-Borne Diseases, Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, Washington 99164-7040, USA. tleroith@vt.edu
authors.forename: Tanya
authors.initials: T
authors.lastname: LeRoith
authors.forename: Shawn J
authors.initials: SJ
authors.lastname: Berens
authors.forename: Kelly A
authors.initials: KA
authors.lastname: Brayton
authors.forename: Stephen A
authors.initials: SA
authors.lastname: Hines
authors.forename: Wendy C
authors.initials: WC
authors.lastname: Brown
authors.forename: Junzo
authors.initials: J
authors.lastname: Norimine
authors.forename: Terry F
authors.initials: TF
authors.lastname: McElwain
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000913:Antibodies, Protozoan / Q000276:immunology*; D016793:Babesia bovis / Q000276:immunology*; D020066:Merozoite Surface Protein 1 / Q000737:chemistry* / Q000276:immunology*; D008969:Molecular Sequence Data
chemical_list: D000911:Antibodies, Monoclonal; D000913:Antibodies, Protozoan; D020066:Merozoite Surface Protein 1