Dynamics of asymptomatic Plasmodium vivax infections and Duffy binding protein polymorphisms in relation to parasitemia levels in Papua New Guinean children.
The interaction between Plasmodium vivax Duffy binding protein II (PvDBPII) and human erythrocyte Duffy antigen is necessary for blood stage infections. However, PvDBPII is highly polymorphic. We recently observed that certain recombinant DBPII variants bind better to erythrocytes in vitro. To examine the hypothesis that haplotypes with enhanced binding have increased parasitemia levels, we followed 206 Papua New Guinean children biweekly for six months with a total of 713 P. vivax samples genotyped. Twenty-seven PvDBPII haplotypes were identified, and 3 haplotypes accounted for 57% of the infections. The relative frequencies of dominant haplotypes remained stable throughout the study. There was no significant association with PvDBPII alleles or haplotypes with P. vivax parasitemia. The dominant haplotype (26% of samples), however, corresponded to a high-binding haplotype. Thus, common haplotypes are not likely to have arisen from increased fitness as measured by greater parasitemia levels. The restricted number of common haplotypes increases the feasibility of a PvDBPII-based vaccine.
Cole-Tobian
Jennifer L
JL
Center for Global Health and Diseases, Case Western Reserve University, Cleveland, Ohio 44106, USA. jtobian@gmail.com
Michon
Pascal
P
Dabod
Elijah
E
Mueller
Ivo
I
King
Christopher L
CL
D000293:Adolescent; D000595:Amino Acid Sequence; D000818:Animals; D000953:Antigens, Protozoan / Q000235:genetics*; D000962:Antimalarials / Q000627:therapeutic use; D037621:Artemisinins / Q000627:therapeutic use; D000077332:Artesunate; D002648:Child; D002675:Child, Preschool; D006239:Haplotypes; D006801:Humans; D016780:Malaria, Vivax / Q000097:blood* / Q000188:drug therapy; D010219:Papua New Guinea; D018512:Parasitemia / Q000097:blood* / Q000469:parasitology*; D010802:Phylogeny; D010966:Plasmodium vivax; D011110:Polymorphism, Genetic; D015800:Protozoan Proteins / Q000235:genetics*; D011956:Receptors, Cell Surface / Q000235:genetics*; D012717:Sesquiterpenes / Q000627:therapeutic use
D000953:Antigens, Protozoan; D000962:Antimalarials; D037621:Artemisinins; C066001:Duffy antigen binding protein, Plasmodium; D015800:Protozoan Proteins; D011956:Receptors, Cell Surface; D012717:Sesquiterpenes; D000077332:Artesunate