title: Differential antibody recognition of FC27-like Plasmodium falciparum merozoite surface protein MSP2 antigens which lack 12 amino acid repeats.
abstract: Three alleles of the FC27-type allelic family of the MSP2 gene of the malaria parasite Plasmodium falciparum have been sequenced from parasites from the field (The Gambia and Tanzania). These alleles lack the 12 amino acid repeat units which are usual in this family of MSP2 alleles. We have investigated the recognition by sera from an endemic area (The Gambia) of three recombinant MSP2 proteins that have 5, 1 and no copies of this repeat region. Antibody recognition of these recombinant proteins varied according to the number of repeats present. High titre antibody levels were seen with most sera using the recombinant protein with 5 x 12-mer repeats, whereas only low responses were measured using proteins containing 1 or no 12-mer repeats. Several sera entirely failed to recognise the protein which lacked 12-mer repeats. The data suggest that variation in the number of tandem repeat sequences could allow the parasite to avoid high avidity antibody binding and this may allow escape from immune recognition.
authors.affiliation: Institute of Cell, Animal and Population Biology, University of Edinburgh, Scotland, UK.
authors.forename: L C
authors.initials: LC
authors.lastname: Ranford-Cartwright
authors.forename: R R
authors.initials: RR
authors.lastname: Taylor
authors.forename: N
authors.initials: N
authors.lastname: Asgari-Jirhandeh
authors.forename: D B
authors.initials: DB
authors.lastname: Smith
authors.forename: P E
authors.initials: PE
authors.lastname: Roberts
authors.forename: V I
authors.initials: VI
authors.lastname: Robinson
authors.forename: H A
authors.initials: HA
authors.lastname: Babiker
authors.forename: E M
authors.initials: EM
authors.lastname: Riley
authors.forename: D
authors.initials: D
authors.lastname: Walliker
authors.forename: J S
authors.initials: JS
authors.lastname: McBride
mesh_terms: D000483:Alleles; D000595:Amino Acid Sequence; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D000915:Antibody Affinity; D000940:Antigenic Variation; D000953:Antigens, Protozoan / Q000235:genetics*; D000954:Antigens, Surface / Q000235:genetics*; D001483:Base Sequence; D002648:Child; D017931:DNA Primers / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics; D005714:Gambia; D006801:Humans; D016778:Malaria, Falciparum / Q000276:immunology / Q000469:parasitology; D008969:Molecular Sequence Data; D010963:Plasmodium falciparum / Q000235:genetics* / Q000276:immunology*; D015800:Protozoan Proteins / Q000235:genetics* / Q000276:immunology*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000276:immunology; D012091:Repetitive Sequences, Nucleic Acid; D017384:Sequence Deletion; D013636:Tanzania
chemical_list: D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D000954:Antigens, Surface; D017931:DNA Primers; D015800:Protozoan Proteins; D011993:Recombinant Fusion Proteins; C065974:merozoite surface protein 2, Plasmodium