Analysis of the role of TpUB05 antigen from Theileria parva in immune responses to malaria in humans compared to its homologue in Plasmodium falciparum; UB05 antigen

Abstract

Despite the amount of resources deployed and technological advancements in Molecular Biology, vaccinology, immunology, genetics, and biotechnology, there is still no effective vaccines against malaria. Immunity to either malaria or East Coast fever is usually seen as species- and/or strain-specific. But there is growing body of evidence suggesting the possibility of the existence of cross strain, cross species and cross genus immune responses in apicomplexans. The principle of gene conservations indicates that homologues play similar role in closely related organisms. UB05 antigen (XP_001347656.2) from Plasmodium falciparum is part of chimeric UB05-09 antigen; a potential vaccine candidate has been demonstrated to be a marker of protective immunity in malaria. The homologue of UB05 in Theileria parva is TpUB05 (XP_763711.1) which was also tested and shown to be a potential marker of protective immunity in ECF as well. In a bid to identify potent markers of protective immunity to aid malaria vaccine development, TpUB05 was tested in malaria caused by Plasmodium falciparum . UB05 antigen was tested in malaria using ELISpot, ELISA, and Growth Inhibition assays with samples from a malaria endemic region, and published. During these same experiments, TpUB05 antigen was tested alongside UB05, in separate wells but on the same plates and exposed to the same experimental conditions and the result presented here. Here we compare the performance of TpUB05 to that of UB05 in terms of the type and magnitude of immune responses provoked in malaria. It was observed that TpUB05 provoked stronger immune responses in malaria compared to UB05 antigen ex-vivo . This suggests that TpUB05 from Theileria parva is a better marker of protective immunity in malaria compared to its homologue UB05 from Plasmodium falciparum .