title: Characterization of the antibody response against Plasmodium falciparum erythrocyte membrane protein 1 in human volunteers.
abstract: The immune response against the Plasmodium falciparum variant surface antigen P. falciparum erythrocyte membrane protein 1 (PfEMP1) is a key component of clinical immunity against falciparum malaria. In this study, we used sera from human volunteers who had been infected with the P. falciparum 3D7 strain to investigate the development, specificity, and dynamics of anti-PfEMP1 antibodies measured against six different strain 3D7 Duffy binding-like domain 1alpha (DBL1alpha) fusion proteins. We observed that a parasitemia of 20 to 200 infected erythrocytes per mul was required to trigger an antibody response to DBL1alpha and that antibodies against one DBL1alpha variant cross-react with other DBL1alpha variants. Both serum and purified immunoglobulin Gs (IgGs) were able to agglutinate infected erythrocytes, and purified anti-DBL1alpha IgGs bound to the live infected red blood cell surface in a punctate surface pattern, confirming that the IgGs recognize native PfEMP1. Analysis of sera from tourists naturally infected with P. falciparum suggests that the anti-PfEMP1 antibodies often persisted for more than 100 days after a single infection. These results help to further our understanding of the development of acquired immunity to P. falciparum infections.
authors.affiliation: Malaria Drug Resistance and Chemotherapy, Infectious Diseases and Immunology Division, The Queensland Institute of Medical Research, Post Office Royal Brisbane Hospital, Qld 4029, Australia.
authors.forename: Darren R
authors.initials: DR
authors.lastname: Krause
authors.forename: Michelle L
authors.initials: ML
authors.lastname: Gatton
authors.forename: Sarah
authors.initials: S
authors.lastname: Frankland
authors.forename: Damon P
authors.initials: DP
authors.lastname: Eisen
authors.forename: Michael F
authors.initials: MF
authors.lastname: Good
authors.forename: Leann
authors.initials: L
authors.lastname: Tilley
authors.forename: Qin
authors.initials: Q
authors.lastname: Cheng
mesh_terms: D000818:Animals; D000913:Antibodies, Protozoan / Q000096:biosynthesis* / Q000276:immunology; D000953:Antigens, Protozoan / Q000276:immunology*; D004912:Erythrocytes / Q000276:immunology / Q000469:parasitology; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology; D007075:Immunoglobulin M / Q000097:blood / Q000276:immunology; D016778:Malaria, Falciparum / Q000097:blood / Q000276:immunology* / Q000469:parasitology; D018512:Parasitemia / Q000097:blood / Q000276:immunology / Q000469:parasitology; D010963:Plasmodium falciparum / Q000276:immunology*; D015800:Protozoan Proteins / Q000276:immunology*; D011956:Receptors, Cell Surface / Q000276:immunology*; D012397:Rosette Formation; D014195:Travel
chemical_list: D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; C066001:Duffy antigen binding protein, Plasmodium; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D015800:Protozoan Proteins; D011956:Receptors, Cell Surface; C085731:erythrocyte membrane protein 1, Plasmodium falciparum