East Coast fever, a devastating disease of cattle, can be controlled partially by vaccination with live T. parva sporozoites. The antigens responsible for conferring immunity are not fully characterized. Recently it was shown that the Plasmodium falciparum immunodominant protein UB05 is highly conserved in T. parva, the causative agent of East Coast fever. The aim of the present investigation was to determine the role of the homologue TpUB05 in protective immunity to East Coast fever.
The cloning, sequencing and expression of TpUB05 were done according to standard protocols. Bioinformatics analysis of TpUB05 gene was carried out using algorithms found in the public domain. Polyclonal antiserum against recombinant TpUB05 were raised in rabbits and used for further analysis by Western blotting, ELISA, immunolocalization and in vitro infection neutralization assay. The ability of recombinant TpUB05 (r-TpUB05) to stimulate bovine PBMCs ex-vivo to produce IFN-gamma or to proliferate was tested using ELISpot and [3H]-thymidine incorporation assays, respectively.
All the 20 cattle immunised by the infection and treatment method (ITM) developed significantly higher levels of TpUB05 specific antibodies (p
It was concluded that TpUB05 is a potential marker of protective immunity in ECF worth investigating further.