Dynamics of IgM and IgG responses to the next generation of engineered Duffy binding protein II immunogen: Strain-specific and strain-transcending immune responses over a nine-year period.
PLoS One
; 15(5): e0232786, 2020.
Article
en En
| MEDLINE
| ID: mdl-32379804
ABSTRACT
BACKGROUND:
A low proportion of P. vivax-exposed individuals acquire protective strain-transcending neutralizing IgG antibodies that are able to block the interaction between the Duffy binding protein II (DBPII) and its erythrocyte-specific invasion receptor. In a recent study, a novel surface-engineered DBPII-based vaccine termed DEKnull-2, whose antibody response target conserved DBPII epitopes, was able to induce broadly binding-inhibitory IgG antibodies (BIAbs) that inhibit P. vivax reticulocyte invasion. Toward the development of DEKnull-2 as an effective P. vivax blood-stage vaccine, we investigate the relationship between naturally acquired DBPII-specific IgM response and the profile of IgG antibodies/BIAbs activity over time. METHODOLOGY/PRINCIPALFINDINGS:
A nine-year follow-up study was carried-out among long-term P. vivax-exposed Amazonian individuals and included six cross-sectional surveys at periods of high and low malaria transmission. DBPII immune responses associated with either strain-specific (Sal1, natural DBPII variant circulating in the study area) or conserved epitopes (DEKnull-2) were monitored by conventional serology (ELISA-detected IgM and IgG antibodies), with IgG BIAbs activity evaluated by functional assays (in vitro inhibition of DBPII-erythrocyte binding). The results showed a tendency of IgM antibodies toward Sal1-specific response; the profile of Sal1 over DEKnull-2 was not associated with acute malaria and sustained throughout the observation period. The low malaria incidence in two consecutive years allowed us to demonstrate that variant-specific IgG (but not IgM) antibodies waned over time, which resulted in IgG skewed to the DEKnull-2 response. A persistent DBPII-specific IgM response was not associated with the presence (or absence) of broadly neutralizing IgG antibody response. CONCLUSIONS/SIGNIFICANCE:
The current study demonstrates that long-term exposure to low and unstable levels of P. vivax transmission led to a sustained DBPII-specific IgM response against variant-specific epitopes, while sustained IgG responses are skewed to conserved epitopes. Further studies should investigate on the role of a stable and persistent IgM antibody response in the immune response mediated by DBPII.
Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Plasmodium vivax
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Inmunoglobulina G
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Inmunoglobulina M
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Proteínas Protozoarias
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Malaria Vivax
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Vacunas contra la Malaria
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Receptores de Superficie Celular
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Antígenos de Protozoos
Tipo de estudio:
Observational_studies
/
Prognostic_studies
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Risk_factors_studies
Límite:
Adult
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Female
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Humans
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Male
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Middle aged
Idioma:
En
Revista:
PLoS One
Asunto de la revista:
CIENCIA
/
MEDICINA
Año:
2020
Tipo del documento:
Article
País de afiliación:
Brasil