P. falciparum and P. vivax orthologous coiled-coil candidates for a potential cross-protective vaccine

Over the last four decades, significant efforts have been invested to develop vaccines against malaria. Although most efforts are focused on the development of; P. falciparum; vaccines, the current availability of the parasite genomes, bioinformatics tools, and high throughput systems for both recombinant and synthetic antigen production have helped to accelerate vaccine development against the; P. vivax; parasite. We have previously; in silico; identified several; P. falciparum; and; P. vivax; proteins containing α-helical coiled-coil motifs that represent novel putative antigens for vaccine development since they are highly immunogenic and have been associated with protection in many; in vitro; functional assays. Here, we selected five pairs of; P. falciparum; and; P. vivax; orthologous peptides to assess their sero-reactivity using plasma samples collected in; P. falciparum-; endemic African countries.; Pf-Pv; cross-reactivity was also investigated. The pairs; Pf27/Pv27, Pf43/Pv43; , and; Pf45/Pv45; resulted to be the most promising candidates for a cross-protective vaccine because they showed a high degree of recognition in direct and competition ELISA assays and cross-reactivity with their respective ortholog. The recognition of; P. vivax; peptides by plasma of; P. falciparum; infected individuals indicates the existence of a high degree of cross-reactivity between these two; Plasmodium; species. The design of longer polypeptides combining these epitopes will allow the assessment of their immunogenicity and protective efficacy in animal models.