In:
PLOS Neglected Tropical Diseases, Public Library of Science (PLoS), Vol. 16, No. 6 ( 2022-6-17), p. e0010493-
Abstract:
Plasmodium vivax blood-stage invasion into reticulocyte is critical for parasite development. Thus, validation of novel parasite invasion ligands is essential for malaria vaccine development. Recently, we demonstrated that EBP2, a Duffy binding protein (DBP) paralog, is antigenically distinct from DBP and could not be functionally inhibited by anti-DBP antibodies. Here, we took advantage of a small outbreak of P . vivax malaria, located in a non-malarious area of Brazil, to investigate for the first time IgM/IgG antibodies against EBP2 and DEKnull-2 (an engineering DBPII vaccine) among individuals who had their first and brief exposure to P . vivax (16 cases and 22 non-cases). Our experimental approach included 4 cross sectional surveys at 3-month interval (12-month follow-up). The results demonstrated that while a brief initial P . vivax infection was not efficient to induce IgM/ IgG antibodies to either EBP2 or DEKnull-2, IgG antibodies against DEKnull-2 (but not EBP2) were boosted by recurrent blood-stage infections following treatment. Of interest, in most recurrent P . vivax infections (4 out of 6 patients) DEKnull-2 IgG antibodies were sustained for 6 to 12 months. Polymorphisms in the ebp2 gene does not seem to explain EBP2 low immunogenicity as the ebp2 allele associated with the P . vivax outbreak presented high identity to the original EBP2 isolate used as recombinant protein. Although EBP2 antibodies were barely detectable after a primary episode of P . vivax infection, EBP2 was highly recognized by serum IgG from long-term malaria-exposed Amazonians (range from 35 to 92% according to previous malaria episodes). Taken together, the results showed that individuals with a single and brief exposure to P . vivax infection develop very low anti-EBP2 antibodies, which tend to increase after long-term malaria exposure. Finally, the findings highlighted the potential of DEKnull-2 as a vaccine candidate, as in non-immune individuals anti-DEKnull-2 IgG antibodies were boosted even after a brief exposure to P . vivax blood stages.
Type of Medium:
Online Resource
ISSN:
1935-2735
DOI:
10.1371/journal.pntd.0010493
DOI:
10.1371/journal.pntd.0010493.g001
DOI:
10.1371/journal.pntd.0010493.g002
DOI:
10.1371/journal.pntd.0010493.g003
DOI:
10.1371/journal.pntd.0010493.g004
DOI:
10.1371/journal.pntd.0010493.g005
DOI:
10.1371/journal.pntd.0010493.t001
DOI:
10.1371/journal.pntd.0010493.s001
DOI:
10.1371/journal.pntd.0010493.s002
DOI:
10.1371/journal.pntd.0010493.s003
DOI:
10.1371/journal.pntd.0010493.s004
DOI:
10.1371/journal.pntd.0010493.s005
Language:
English
Publisher:
Public Library of Science (PLoS)
Publication Date:
2022
detail.hit.zdb_id:
2429704-5
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