Conservation of the sporozoite p67 vaccine antigen in cattle-derived Theileria parva stocks with different cross-immunity profiles.

AUTOR(ES)

Nene, V

RESUMO

Immunity to Theileria parva infection in cattle is often parasite stock specific. The antigenic diversity which is expressed at the schizont stage of the parasite together with a wild reservoir of the organism in buffalo has complicated the development of effective disease control by immunization. We have previously shown that about 70% of cattle inoculated with recombinant forms of p67, a sporozoite stage-specific surface antigen from the cattle-derived Muguga stock of the parasite, are immune to a homologous challenge. Thus, immune responses to p67 can play a role in immunity. The genes encoding this protein in five other parasite stocks have been sequenced. Here, we report that the p67 molecule encoded by four cattle-derived parasite stocks (Boleni, Uganda, Mariakani, and Marikebuni) that fall into different cross-immunity groups is identical in sequence to Muguga p67. The protein encoded by a buffalo-derived parasite exhibits 95% sequence identity with Muguga p67, the major difference being the presence of a 43-residue peptide insert. As predicted by these data, cattle inoculated with recombinant p67 can resist a heterologous cattle-derived parasite challenge. Seven of 12 cattle receiving a homologous Muguga challenge and 6 of 11 cattle receiving a heterologous Marikebuni challenge were immune to East Coast fever. These results extend earlier data suggesting that p67 is a conserved molecule and confirm its potential as a broad-spectrum vaccine antigen for the control of T. parva infection.

Documentos Relacionados

• Delivery of the p67 Sporozoite Antigen of Theileria parva by Using Recombinant Salmonella dublin: Secretion of the Product Enhances Specific Antibody Responses in Cattle†
• Characterization of an insect cell-derived Theileria parva sporozoite vaccine antigen and immunogenicity in cattle.
• Linear Peptide Specificity of Bovine Antibody Responses to p67 of Theileria parva and Sequence Diversity of Sporozoite-Neutralizing Epitopes: Implications for a Vaccine†
• A recombinant sporozoite surface antigen of Theileria parva induces protection in cattle.
• Bovine Leukocyte Antigen Major Histocompatibility Complex Class II DRB3*2703 and DRB3*1501 Alleles Are Associated with Variation in Levels of Protection against Theileria parva Challenge following Immunization with the Sporozoite p67 Antigen