title: Improved immunogenicity of novel baculovirus-derived Theileria parva p67 subunit antigens.
abstract: East Coast fever (ECF) in cattle is caused by the tick-borne protozoan parasite Theileria parva. The major sporozoite surface antigen of T. parva (p67) is an important candidate for inclusion in a subunit vaccine. Recently, we reported the expression and production of different parts of p67 as fusions to either GFP or to the baculovirus GP64 envelope glycoprotein in insect cells, which resulted in stable proteins recognized by a monoclonal specific for native p67. The immunogenicity of these fusion proteins was examined in out-bred mice and cattle. In mice, the full length p67 molecule without its signal peptide and transmembrane region, but fused to GFP (GFP:p67deltaSS) was the best immunogen followed by the C-terminus of p67 fused to GP64 (GP64:p67C). These two immunogens also provoked a high level of sero-conversion in cattle when formulated in a water-in-oil or saponin-derived adjuvant with only 100 microg of protein and a single booster. The vaccine-elicited antibodies efficiently inhibited the infectivity of T. parva sporozoites in in vitro neutralization assays. This study demonstrated that these new baculovirus-derived p67 vaccines were highly immunogenic, and that in combination with a suitable adjuvant, they have a clear potential to induce protective immunity in cattle.
authors.affiliation: Laboratory of Virology, Wageningen University, The Netherlands.
authors.forename: Stephen A
authors.initials: SA
authors.lastname: Kaba
authors.forename: Dick
authors.initials: D
authors.lastname: Schaap
authors.forename: Els C
authors.initials: EC
authors.lastname: Roode
authors.forename: Vishvanath
authors.initials: V
authors.lastname: Nene
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Musoke
authors.forename: Just M
authors.initials: JM
authors.lastname: Vlak
authors.forename: Monique M
authors.initials: MM
authors.lastname: van Oers
mesh_terms: D000276:Adjuvants, Immunologic; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D016367:Baculoviridae / Q000235:genetics; D015153:Blotting, Western / Q000662:veterinary; D002417:Cattle; D002418:Cattle Diseases / Q000276:immunology / Q000469:parasitology*; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D005260:Female; D049452:Green Fluorescent Proteins; D007114:Immunization / Q000379:methods / Q000662:veterinary; D008164:Luminescent Proteins; D051379:Mice; D009500:Neutralization Tests / Q000662:veterinary; D015800:Protozoan Proteins / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*; D016052:Protozoan Vaccines / Q000235:genetics / Q000276:immunology; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology; D016797:Theileria parva / Q000276:immunology*; D013801:Theileriasis / Q000276:immunology* / Q000469:parasitology / Q000517:prevention & control; D022223:Vaccines, Subunit / Q000235:genetics / Q000276:immunology
chemical_list: D000276:Adjuvants, Immunologic; D000913:Antibodies, Protozoan; D008164:Luminescent Proteins; D015800:Protozoan Proteins; D016052:Protozoan Vaccines; D011993:Recombinant Fusion Proteins; D022223:Vaccines, Subunit; C114309:p67 antigen, Theileria; D049452:Green Fluorescent Proteins