title: Sequential, ordered acquisition of antibodies to Plasmodium falciparum erythrocyte membrane protein 1 domains.
abstract: The binding of erythrocytes infected with mature blood stage parasites to the vascular bed is key to the pathogenesis of malignant malaria. The binding is mediated by members of Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) family. PfEMP1s can be divided into groups, and it has previously been suggested that parasites expressing group A or B/A PfEMP1s are most pathogenic. To test the hypothesis that the first malaria infections in infants and young children are dominated by parasites expressing A and B/A PfEMP1s, we measured the plasma Ab level against 48 recombinant PfEMP1 domains of different groupings in 1342 individuals living in five African villages characterized by markedly different malaria transmission. We show that children progressively acquire a broader repertoire of anti-PfEMP1 Abs, but that the rate of expansion is governed by transmission intensity. However, independently of transmission intensity, Abs are first acquired to particular Duffy binding ligand-like domains belonging to group A or B/A PfEMP1s. The results support the view that anti-PfEMP1 Ab responses effectively structure the expenditure of the repertoire of PfEMP1 maintained by the parasite. Parasites expressing certain group A and B/A PfEMP1s are responded to first by individuals with limited previous exposure, and the resulting Abs reduce the fitness and pathogenicity of these parasites during subsequent infections. This allows parasites expressing less pathogenic PFEMP1s to dominate during later infections. The identification of PfEMP1 domains expressed by parasites causing disease in infants and young children is important for development of vaccines protecting against severe malaria.
authors.affiliation: Centre for Medical Parasitology at Department of International Health, Immunology, and Microbiology, University of Copenhagen, Copenhagen University Hospital, Copenhagen, Denmark. gerald@sund.ku.dk
authors.forename: Gerald K K
authors.initials: GK
authors.lastname: Cham
authors.forename: Louise
authors.initials: L
authors.lastname: Turner
authors.forename: John
authors.initials: J
authors.lastname: Lusingu
authors.forename: Lasse
authors.initials: L
authors.lastname: Vestergaard
authors.forename: Bruno P
authors.initials: BP
authors.lastname: Mmbando
authors.forename: Jonathan D
authors.initials: JD
authors.lastname: Kurtis
authors.forename: Anja T R
authors.initials: AT
authors.lastname: Jensen
authors.forename: Ali
authors.initials: A
authors.lastname: Salanti
authors.forename: Thomas
authors.initials: T
authors.lastname: Lavstsen
authors.forename: Thor G
authors.initials: TG
authors.lastname: Theander
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000818:Animals; D000913:Antibodies, Protozoan / Q000096:biosynthesis* / Q000097:blood; D000953:Antigens, Protozoan / Q000097:blood / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D004910:Erythrocyte Membrane / Q000276:immunology* / Q000469:parasitology; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D016778:Malaria, Falciparum / Q000276:immunology / Q000469:parasitology / Q000635:transmission; D008875:Middle Aged; D018512:Parasitemia / Q000097:blood / Q000276:immunology / Q000469:parasitology; D010963:Plasmodium falciparum / Q000276:immunology* / Q000472:pathogenicity; D015995:Prevalence; D017434:Protein Structure, Tertiary; D015800:Protozoan Proteins / Q000097:blood / Q000276:immunology*; D055815:Young Adult
chemical_list: D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D015800:Protozoan Proteins; C085731:erythrocyte membrane protein 1, Plasmodium falciparum