High opsonic phagocytosis activity and growth inhibition of merozoites are associated with RON4 antibody levels and protect against febrile malaria in Ghanaian children
Date
2023
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Frontiers in Immunology
Abstract
Background: Naturally acquired immunity to malaria may involve different
immune mechanisms working in concert, however, their respective
contributions and potential antigenic targets have not been clearly established.
Here, we assessed the roles of opsonic phagocytosis and antibody-mediated
merozoite growth inhibition in Plasmodium falciparum (P. falciparum) infection
outcomes in Ghanaian children.
Methods: The levels of merozoite opsonic phagocytosis, growth inhibition
activities and six P. falciparum antigen-specific IgG of plasma samples from
children (n=238, aged 0.5 to 13 years) were measured at baseline prior to the
malaria seasons in southern Ghana. The children were then actively and passively
followed up for febrile malaria and asymptomatic P. falciparum infection
detection in a 50-week longitudinal cohort. P. falciparum infection outcome
was modelled as a function of the measured immune parameters while
accounting for important demographic factors.
Results: High plasma activity of opsonic phagocytosis [adjusted odds ratio (aOR)=
0.16; 95%CI= 0.05 - 0.50, p = 0.002], and growth inhibition (aOR=0.15; 95% CI =
0.04-0.47; p = 0.001) were individually associated with protection against febrile malaria. There was no evidence of correlation (b= 0.13; 95% CI= -0.04-0.30;
p=0.14) between the two assays. IgG antibodies against MSPDBL1 correlated with
opsonic phagocytosis (OP) while IgG against PfRh2a correlated with growth
inhibition. Notably, IgG antibodies against RON4 correlated with both assays.
Conclusion: Opsonic phagocytosis and growth inhibition are protective
immune mechanisms against malaria that may be acting independently to
confer overall protection. Vaccines incorporating RON4 may benefit from both
immune mechanisms.
Description
Research Article
Keywords
malaria, opsonic phagocytosis, growth inhibition
Citation
Kyei-Baafour E, Kusi KA, Arthur FKN, Tiendrebeogo RW, Owusu-Yeboa E, Singh SK, Friedrich S, Gerds TA, Dodoo D, Theisen M and Adu B (2023) High opsonic phagocytosis activity and growth inhibition of merozoites are associated with RON4 antibody levels and protect against febrile malaria in Ghanaian children. Front. Immunol. 14:1161301. doi: 10.3389/fimmu.2023.1161301