Cellular Localization of Babesia bovis Merozoite Rhoptry-Associated Protein 1 and Its Erythrocyte-Binding Activity
AUTOR(ES)
Yokoyama, Naoaki
FONTE
American Society for Microbiology
RESUMO
The cellular localization of Babesia bovis rhoptry-associated protein 1 (RAP-1) and its erythrocyte-binding affinity were examined with anti-RAP-1 antibodies. In an indirect immunofluorescent antibody test, RAP-1 was detectable in all developmental stages of merozoites and in extracellular merozoites. In the early stage of merozoite development, RAP-1 appears as a dense accumulation, which later thins out and blankets the host cell cytoplasm, but retains a denser mass around newly formed parasite nuclei. The preferential accumulations of RAP-1 on the inner surface of a host cell membrane and bordering the parasite's outer surface were demonstrable by immunoelectron microscopy. An erythrocyte-binding assay with the lysate of merozoites demonstrated RAP-1 binding to both bovine and equine erythrocytes. Anti-RAP-1 monoclonal antibody 1C1 prevented the interaction of RAP-1 with bovine erythrocytes and significantly inhibited parasite proliferation in vitro. With the recombinant RAP-1, the addition of increasing concentrations of Ca2+ accentuated its binding affinity with bovine erythrocytes. The present findings lend support to an earlier proposition of an erythrocytic binding role for RAP-1 expressed in B. bovis merozoites and, possibly, its involvement in the escape of newly formed merozoites from host cells.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=128354Documentos Relacionados
- Specific T-cell recognition of the merozoite proteins rhoptry-associated protein 1 and erythrocyte-binding antigen 1 of Plasmodium falciparum.
- Babesia bovis Merozoite Surface Antigen 1 and Rhoptry-Associated Protein 1 Are Expressed in Sporozoites, and Specific Antibodies Inhibit Sporozoite Attachment to Erythrocytes
- Immunogenic B-cell epitopes of Babesia bovis rhoptry-associated protein 1 are distinct from sequences conserved between species.
- Competitive Enzyme-Linked Immunosorbent Assay Based on a Rhoptry-Associated Protein 1 Epitope Specifically Identifies Babesia bovis-Infected Cattle
- CD4+ T-helper lymphocyte responses against Babesia bigemina rhoptry-associated protein I.