Analysis of human antibodies to erythrocyte binding antigen 175 of Plasmodium falciparum.
Invasion of human erythrocytes by Plasmodium falciparum merozoites is a multistep process. For many strains of the parasite, part of this process requires that the erythrocyte binding antigen 175 (EBA-175) of the merozoite binds to sialic acid residues of glycophorin A on the erythrocyte surface, a receptor-ligand interaction which represents a potential target for inhibition by antibodies. This study characterizes the reactivity of naturally acquired human antibodies with four recombinant proteins representing parts of EBA-175 (region II, regions III to V, and the dimorphic C and F segment region) in populations in which the organism is endemic. Serum immunoglobulin G (IgG) recognizing the recombinant proteins is predominantly of the IgG1 and IgG3 subclasses, and its prevalence increases with age. In a large population study in The Gambia, serum positivity for IgG or IgG1 and IgG3 subclass antibodies to each of the EBA-175 recombinant antigens was not significantly associated with subsequent protection from clinical malaria. However, there was a trend indicating that individuals with high levels of IgG to region II may have some protection.
Okenu
D M
DM
Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London WC1E 7HT, United Kingdom.
Riley
E M
EM
Bickle
Q D
QD
Agomo
P U
PU
Barbosa
A
A
Daugherty
J R
JR
Lanar
D E
DE
Conway
D J
DJ
D000328:Adult; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood* / Q000276:immunology; D000953:Antigens, Protozoan; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology; D016778:Malaria, Falciparum / Q000276:immunology* / Q000469:parasitology; D010963:Plasmodium falciparum / Q000276:immunology*; D015800:Protozoan Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D011817:Rabbits; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism
D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D002352:Carrier Proteins; D007074:Immunoglobulin G; D015800:Protozoan Proteins; D011993:Recombinant Fusion Proteins; C065668:erythrocyte-binding antigen 175, Plasmodium