Naturally acquired inhibitory antibodies to Plasmodium vivax Duffy binding protein are short-lived and allele-specific following a single malaria infection.
The Duffy binding protein of Plasmodium vivax (DBP) is a critical adhesion ligand that participates in merozoite invasion of human Duffy-positive erythrocytes. A small outbreak of P. vivax malaria, in a village located in a non-malarious area of Brazil, offered us an opportunity to investigate the DBP immune responses among individuals who had their first and brief exposure to malaria. Thirty-three individuals participated in the five cross-sectional surveys, 15 with confirmed P. vivax infection while residing in the outbreak area (cases) and 18 who had not experienced malaria (non-cases). In the present study, we found that only 20% (three of 15) of the individuals who experienced their first P. vivax infection developed an antibody response to DBP; a secondary boosting can be achieved with a recurrent P. vivax infection. DNA sequences from primary/recurrent P. vivax samples identified a single dbp allele among the samples from the outbreak area. To investigate inhibitory antibodies to the ligand domain of the DBP (cysteine-rich region II, DBP(II)), we performed in vitro assays with mammalian cells expressing DBP(II) sequences which were homologous or not to those from the outbreak isolate. In non-immune individuals, the results of a 12-month follow-up period provided evidence that naturally acquired inhibitory antibodies to DBP(II) are short-lived and biased towards a specific allele.
Centro de Pesquisas René Rachou, Fundação Oswaldo Cruz, FIOCRUZ, Malaria Laboratory, Belo Horizonte, MG, Brazil. lhcarvalho@cpqrr.fiocruz.br
I P
IP
Ceravolo
B A M
BA
Sanchez
T N
TN
Sousa
B M
BM
Guerra
I S
IS
Soares
E M
EM
Braga
A M
AM
McHenry
J H
JH
Adams
C F A
CF
Brito
L H
LH
Carvalho
D000328:Adult; D000483:Alleles; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood*; D000953:Antigens, Protozoan / Q000235:genetics / Q000276:immunology*; D001938:Brazil / Q000453:epidemiology; D003430:Cross-Sectional Studies; D016054:DNA, Protozoan / Q000235:genetics; D004196:Disease Outbreaks; D006801:Humans; D016780:Malaria, Vivax / Q000453:epidemiology / Q000276:immunology* / Q000469:parasitology; D020066:Merozoite Surface Protein 1 / Q000276:immunology; D008875:Middle Aged; D010966:Plasmodium vivax / Q000235:genetics / Q000276:immunology*; D015800:Protozoan Proteins / Q000235:genetics / Q000276:immunology*; D011956:Receptors, Cell Surface / Q000235:genetics / Q000276:immunology*; D055815:Young Adult
D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D016054:DNA, Protozoan; C066001:Duffy antigen binding protein, Plasmodium; D020066:Merozoite Surface Protein 1; D015800:Protozoan Proteins; D011956:Receptors, Cell Surface