East Coast fever (ECF) is a lymphoproliferative disease caused by the protozoan parasite Theileria parva. It kills about one million cattle annually in Africa. Four groups of 5 BoLA-typed animals were immunized with the T. parva Tp1 antigen with or without leader sequence in the HAd5 viral vector and boosted with the same antigens in the MVA vector. Most animals generated CTL to the known epitope measured using tetramer staining, ELISpot and Cr-51-release assay. The CTL expressed perforin and lysed peptide pulsed PBMC. CD4 cells were shown to proliferate to the antigen. Challenge of the animals resulted in about 30% protection.
The parasite Theileria parva claims the life of approximately 1 million cattle every year. Immune animals to the parasite develop a lifelong immunity based on a cytotoxic T lymphocyte (CTL) response with a strong immunodominance restricted by the bovine leukocyte antigen (BoLA) class I molecules. In our goal of developing a next-generation vaccine against T. parva, we have undertaken to identify new CTL inducing antigens that can be included in a recombinant vaccine. A peptide library of 18-mer peptides overlapping by 12 amino acids and covering 500 genes of the whole parasite genome was synthesized; giving approximately 40,000 peptides aliquoted in pools of 50 peptides.
East Coast fever (ECF) is a lymphoproliferative disease caused by the protozoan parasite Theileria parva. It kills about one million cattle annually in Africa. The sporozoite stage of this parasite, harbored in the salivary glands of the tick Rhipicephalus appendiculatus, invades and establishes infection in the bovine lymphocytes during tick feeding. However, little is known about the parasite molecules involved in this infection process. It is therefore necessary to elucidate the protein composition of the sporozoites to identify novel targets for blocking invasion. Blocking this initial stage of invasion presents a promising vaccine strategy for the control of ECF.
A sub-group of the members of the ECF Consortium held a two-day meeting in Oxford to discuss one of the Consortium objectives, “To induce T-cell mediated immunity by targeting the schizont stage of the parasite.”
To be held 22-26 May 2016 in Cape Town, an important component of this Keystone Symposia meeting will be to stimulate crosstalk between the human and veterinary vaccine communities by highlighting cross-cutting technical advances and new science and knowledge from laboratory and field research.