Natural immune response to Plasmodium vivax alpha-helical coiled coil protein motifs and its association with the risk of P. vivax malaria

Nora Céspedes (1) , Connie S.N. Li Wai Suen (2, 3) , Cristian Koepfli (2, 3) , Camila T. França (2, 3) , Ingrid Felger (4) , Issa Nebie (5) , M. Arévalo-Herrera (1) , Ivo Mueller (6, 2, 3, 7, 8) , Giampietro Corradin (9) , Socrates Herrera (10)

1 Univalle - Universidad del Valle [Cali]
2 WEHI - The Walter and Eliza Hall Institute of Medical Research
3 University of Melbourne
4 Swiss Tropical and Public Health Institute [Basel]
5 CNRFP - Centre National de Recherche et de Formation sur le Paludisme [Ouagadougou, Burkina Faso]
6 IP - Institut Pasteur [Paris]
7 ISGlobal - Instituto de Salud Global - Institute For Global Health [Barcelona]
8 Malaria : parasites et hôtes - Malaria : parasites and hosts
9 UNIL - Université de Lausanne = University of Lausanne
10 Caucaseco scientific research center = Centro de Investigación Científica Caucaseco

Protein α-helical coiled coil structures are known to induce antibodies able to block critical functions in different pathogens. In a previous study, a total of 50 proteins of Plasmodium vivax erythrocytic asexual stages containing ?-helical coiled coil structural motifs were identified in silico, and the corresponding peptides were chemically synthesized. A total of 43 peptides were recognized by naturally acquired antibodies in plasma samples from both Papua New Guinea (PNG) and Colombian adult donors. In this study, the association between IgG antibodies to these peptides and clinical immunity was further explored by measuring total IgG antibody levels to 24 peptides in baseline samples from a longitudinal study of children aged 1–3 years (n = 164) followed for 16 months. Samples were reactive to all peptides tested. Eight peptides were recognized by \textgreater50% of individuals, whereas only one peptide had \textless 20% reactivity. Children infected at baseline were seropositive to 23/24 peptides. No significant association was observed between antibody titers and age or molecular force of infection, suggesting that antibody levels had already reached an equilibrium. There was a strong association between antibody levels to all peptides and protection against P. vivax clinical episodes during the 16 months follow-up. These results suggest that the selected coiled coil antigens might be good markers of both exposure and acquired immunity to P. vivax malaria, and further preclinical investigation should be performed to determine their potential as P. vivax vaccine antigens. Copyright: © 2017 Céspedes et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Mots clés: Infectious disease control; Plasmodium; Antibodies; Malaria; Malarial parasites; Immunity; Antibody response; Parasitic diseases

Domaines: Immunologie; Maladies infectieuses

Nora Céspedes, Connie S.N. Li Wai Suen, Cristian Koepfli, Camila T. França, Ingrid Felger, et al.. Natural immune response to Plasmodium vivax alpha-helical coiled coil protein motifs and its association with the risk of P. vivax malaria. PLoS ONE, 2017, 12 (6), pp.e0179863. ⟨10.1371/journal.pone.0179863⟩. ⟨pasteur-01570236⟩