AUTHOR=Ayadi Imen , Balam Saidou , Audran Régine , Bikorimana Jean-Pierre , Nebie Issa , Diakité Mahamadou , Felger Ingrid , Tanner Marcel , Spertini François , Corradin Giampietro , Arevalo Myriam , Herrera Socrates , Agnolon Valentina 

TITLE=P. falciparum and P. vivax Orthologous Coiled-Coil Candidates for a Potential Cross-Protective Vaccine

JOURNAL=Frontiers in Immunology

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2020.574330

DOI=10.3389/fimmu.2020.574330

ISSN=1664-3224

ABSTRACT=<p>Over the last four decades, significant efforts have been invested to develop vaccines against malaria. Although most efforts are focused on the development of <italic>P. falciparum</italic> 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 <italic>P. vivax</italic> parasite. We have previously <italic>in silico</italic> identified several <italic>P. falciparum</italic> and <italic>P. vivax</italic> 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 <italic>in vitro</italic> functional assays. Here, we selected five pairs of <italic>P. falciparum</italic> and <italic>P. vivax</italic> orthologous peptides to assess their sero-reactivity using plasma samples collected in <italic>P. falciparum-</italic> endemic African countries. <italic>Pf-Pv</italic> cross-reactivity was also investigated. The pairs <italic>Pf27/Pv27, Pf43/Pv43</italic>, and <italic>Pf45/Pv45</italic> 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 <italic>P. vivax</italic> peptides by plasma of <italic>P. falciparum</italic> infected individuals indicates the existence of a high degree of cross-reactivity between these two <italic>Plasmodium</italic> species. The design of longer polypeptides combining these epitopes will allow the assessment of their immunogenicity and protective efficacy in animal models.</p>