| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
* Centre for Medical Parasitology at Department of International Health, Immunology, and Microbiology, University of Copenhagen, and Department of Infectious Diseases, Copenhagen University Hospital, Copenhagen, Denmark;
Center for International Health Research, Rhode Island Hospital, Brown University School of Medicine, Providence, RI 02903; and
National Institute for Medical Research, Tanga Centre, Tanga, Tanzania
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.
The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
1 This study received financial support from a grant from the Foundation for the National Institute of Health through the Grand Challenges in Global Health initiative and the Danish International Development Agency (DANIDA) and the Novo Nordisk Foundation (Grant 10335). G. Kennedy and J. Lusingu were supported by the Gates Malaria Partnership. The study was conducted under the auspices of the Joint Malaria Programme, a collaborative research initiative between National Institute for Medical Research, Tanzania, Kilimanjaro Christian Medical College, London School of Hygiene and Tropical Medicine, and the University of Copenhagen.
2 Address correspondence and reprint requests to Gerald K. K. Cham, Centre for Medical Parasitology, University of Copenhagen, CSS Building 22-23, 
ster Farimagsgade 5, PO Box 2099, 1014 Copenhagen K, Denmark. E-mail address: gerald{at}sund.ku.dk
3 Abbreviations used in this paper: PfEMP1, P. falciparum erythrocyte membrane protein 1; CIDR, cysteine-rich interdomain region; DBL, duffy binding ligand; PP, point prevalence; VSA, variant surface Ag.
4 The online version of this article contains supplemental material.
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
