Journal article
CD4+ T-helper lymphocyte responses against Babesia bigemina rhoptry-associated protein 1
Infection and immunity, Vol.64(6), pp.2079-2087
06/1996
Handle:
https://hdl.handle.net/2376/110614
PMID: 8675310
Abstract
A multigene family of 58- to 60-kDa proteins, which are designated rhoptry-associated protein 1 (RAP-1) and which come from the parasites Babesia bigemina and Babesia bovis, is a target for vaccine development. The presence of multiple gene copies and conserved sequences and epitopes of RAP-1 implies that these proteins are functionally important for the survival of these parasites. Furthermore, it was previously shown that B. bigemina RAP-1 induced partial protection against challenge infection. However, the lack of correlation between protective immunity to B. bigemina infection and antibody titers against a merozoite surface-exposed, neutralization-sensitive epitope of B. bigemina RAP-1 indicated the potential importance of RAP-1-specific T helper (Th) cells in the observed protection. To begin to understand the mechanism of RAP-1-induced protective immunity, RAP-1-specific T-cell responses were characterized in cattle. Vigorous and sustained proliferative responses of peripheral blood mononuclear cells from native RAP-1-immunized cattle were observed. The anamnestic response in immunized cattle was specific for B. bigemina RAP-1 and predominantly comprised CD4+ T cells, which upon cloning expressed type 1 cytokine mRNA profiles and high levels of gamma interferon protein. The T cells responded to both native and recombinant forms of RAP-1, indicating the potential to use recombinant protein or epitopes derived therefrom as a vaccine that could evoke specific recall responses after exposure to natural infection. The differential responses of peripheral blood mononuclear cells and seven Th-cell clones derived from RAP-1-immunized cattle to different Central American strains of B bigemina indicated the presence of at least one conserved and one variable Th-cell epitope. The lack of response to B. bovis RAP-1 indicated that a strictly conserved 14-amino-acid peptide shared by the two babesial species was not immunogenic for Th cells in these experiments
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Details
- Title
- CD4+ T-helper lymphocyte responses against Babesia bigemina rhoptry-associated protein 1
- Creators
- S.D. RodriguezG.H PalmerT.F McElwainT.C McGuireB.J RuefC.G Chitko-McKownW.C Brown
- Publication Details
- Infection and immunity, Vol.64(6), pp.2079-2087
- Academic Unit
- Veterinary Microbiology and Pathology, Department of; Paul G. Allen School for Global Animal Health
- Identifiers
- 99900547394901842
- Language
- English
- Resource Type
- Journal article