title: Mapping the T cell epitopes of the Babesia bovis antigen 12D3: implications for vaccine design.
abstract: The Babesia bovis antigen 12D3 was analysed to identify potential T-cell epitopes. Two predictive algorithms identified 13 possible sites but there was minimal agreement between the different predictive methods. Experimental determination of the T-cell epitopes recognized by nine cattle was achieved using a panel of overlapping peptides which identified seven different epitopes, five of which were clustered together around residues 210-320 of the molecule. No T cell epitopes were located within the tightly disulphide bonded core of 12D3. Using a series of truncated peptides, the location of two of the epitopes was mapped to residues 35-43 and 266-275. The sequences of these two epitopes was compared with a database of previously described binding motifs for MHC II alleles and each epitope was found to contain three sequence motifs recognized by HLA-DR alleles. The BoLA-DRB3 alleles occurring in these cattle were determined by a sequence specific oligonucleotide hybridization assay. Within those cattle whose T cells proliferated in response to 12D3, there was a consistent pattern of epitope recognition and presence of particular DRB3 alleles. The implications for effective vaccine design are discussed.
authors.affiliation: Department of Parasitology, University of Queensland, Brisbane, Australia.
authors.forename: R A
authors.initials: RA
authors.lastname: Court
authors.forename: K
authors.initials: K
authors.lastname: Sitte
authors.forename: J P
authors.initials: JP
authors.lastname: Opdebeeck
authors.forename: I J
authors.initials: IJ
authors.lastname: East
mesh_terms: D000483:Alleles; D000595:Amino Acid Sequence; D000818:Animals; D000953:Antigens, Protozoan / Q000235:genetics* / Q000276:immunology*; D016793:Babesia bovis / Q000276:immunology*; D001404:Babesiosis / Q000276:immunology*; D002417:Cattle; D002418:Cattle Diseases / Q000276:immunology*; D002455:Cell Division; D002478:Cells, Cultured; D018604:Epitope Mapping; D000939:Epitopes / Q000235:genetics / Q000276:immunology; D006684:HLA-DR Antigens / Q000235:genetics / Q000276:immunology; D059826:HLA-DRB3 Chains; D000949:Histocompatibility Antigens Class II / Q000235:genetics / Q000276:immunology; D006650:Histocompatibility Testing; D007963:Leukocytes, Mononuclear / Q000276:immunology; D008297:Male; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D010455:Peptides / Q000138:chemical synthesis / Q000235:genetics / Q000276:immunology; D016052:Protozoan Vaccines / Q000276:immunology; D016415:Sequence Alignment; D017421:Sequence Analysis; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology*; D014614:Vaccines, Synthetic / Q000235:genetics / Q000276:immunology
chemical_list: D000953:Antigens, Protozoan; D000939:Epitopes; D006684:HLA-DR Antigens; D059826:HLA-DRB3 Chains; D000949:Histocompatibility Antigens Class II; D010455:Peptides; D016052:Protozoan Vaccines; D014614:Vaccines, Synthetic; C108421:antigen 12D3