Plasmodium vivax Pv12 B-cell epitopes and HLA-DRβ1*-dependent T-cell epitopes in vitro antigenicity

PLoS One. 2018 Sep 10;13(9):e0203715. doi: 10.1371/journal.pone.0203715. eCollection 2018.

Abstract

Malaria is an infectious disease caused by parasites from the genus Plasmodium (P. falciparum and P. vivax are responsible for 90% of all clinical cases); it is widely distributed throughout the world's tropical and subtropical regions. The P. vivax Pv12 protein is involved in invasion, is expressed on merozoite surface and has been recognised by antibodies from individuals exposed to the disease. In this study, B- and T-cell epitopes from Pv12 were predicted and characterised to advance in the design of a peptide-based vaccine against malaria. For evaluating the humoral response of individuals exposed to natural P. vivax infection from two endemic areas in Colombia, BepiPred-1.0 software was used for selecting B-cell epitopes. B-cell epitope 39038 displayed the greatest recognition by naturally-acquired antibodies and induced an IgG2/IgG4 response. NetMHCIIpan-3.1 prediction software was used for selecting peptides having high affinity binding for HLA-DRβ1* allele lineages and this was confirmed by in-vitro binding assays. T-epitopes 39113 and 39117 triggered a memory T-cell response (Stimulation Index≥2) and significant cytokine production. Combining in-silico, in-vitro and functional assays, two Pv12 protein regions (containing peptides 39038, 39040, 39113 and 39117) have thus been characterised as promising vaccine candidates against P. vivax malaria.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Colombia / epidemiology
  • Computational Biology
  • Enzyme-Linked Immunosorbent Assay
  • Epitopes, B-Lymphocyte / immunology*
  • Epitopes, T-Lymphocyte / immunology*
  • HLA-DR beta-Chains / immunology*
  • Humans
  • Immunity, Humoral
  • Plasmodium vivax / immunology*

Substances

  • Epitopes, B-Lymphocyte
  • Epitopes, T-Lymphocyte
  • HLA-DR beta-Chains

Grants and funding

This work was financed by the Departamento Administrativo de Ciencia, Tecnología e Innovación (COLCIENCIAS) through grant RC # 0309-2013. CL received support from Colciencias within the framework of the Convocatoria Nacional para Estudios de Doctorado en Colombia (call for candidates # 6172).