Helper T-cell epitopes encoded by the Babesia bigemina rap-1 gene family in the constant and variant domains are conserved among parasite strains
Abstract
Among important candidates for babesial vaccines are apical complex proteins, including rhoptry-associated protein 1 (RAP-1) from Babesia bovis and B. bigemina, which have been shown to induce partial immunity. Four variant B. bigemina rap-1 transcripts identified in a clone of the Mexico strain have highly conserved sequence in the central region but vary in sequence at the amino and carboxy termini (NT and CT) of the predicted proteins, resulting in different combinations of NT and CT domains in the individual gene products. Cattle were immunized with native protein consisting of the RAP-alpha1 variant, which contains NT-1 and CT-1 domains, and T-cell responses were characterized. We previously reported the identification of two T helper (Th) cell epitopes in B. bigemina RAP-1alpha1 protein (I. Hötzel, W. C. Brown, T. F. McElwain, S. D. Rodriguez, and G. H. Palmer, Mol. Biochem. Parasitol. 81:89-99, 1996). One epitope mapped to the constant domain of RAP-1 (amino acids [aa] 144 to 187), and one mapped to the CT-1 variable domain (aa 386 to 480). Th1-like clones responding to these epitopes proliferated differentially to different strains of B. bigemina, raising the possibilities that the T-cell epitopes may vary antigenically...Continue Reading
References
Citations
Related Concepts
Related Feeds
Babesiosis (ASM)
Babesiosis is caused by parasites of the genus babesia, which are transmitted in nature by the bite of an infected tick. Discover the latest research on babesiosis here.