Switches in expression of Plasmodium falciparum var genes correlate with changes in antigenic and cytoadherent phenotypes of infected erythrocytes.
Plasmodium falciparum expresses on the host erythrocyte surface clonally variant antigens and ligands that mediate adherence to endothelial receptors. Both are central to pathogenesis, since they allow chronicity of infection and lead to concentration of infected erythrocytes in cerebral vessels. Here we show that expression of variant antigenic determinants is correlated with expression of individual members of a large, multigene family named var. Each var gene contains copies of a motif that has been previously shown to bind diverse host receptors; expression of a specific var gene correlated with binding to ICAM-1. Thus, our findings are consistent with the involvement of var genes in antigenic variation and binding to endothelium.
Smith
J D
JD
Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA.
Chitnis
C E
CE
Craig
A G
AG
Roberts
D J
DJ
Hudson-Taylor
D E
DE
Peterson
D S
DS
Pinches
R
R
Newbold
C I
CI
Miller
L H
LH
D000595:Amino Acid Sequence; D000818:Animals; D000940:Antigenic Variation / Q000235:genetics*; D000953:Antigens, Protozoan / Q000235:genetics* / Q000276:immunology; D001483:Base Sequence; D015815:Cell Adhesion Molecules / Q000378:metabolism; D003001:Cloning, Molecular; D017931:DNA Primers; D004910:Erythrocyte Membrane / Q000469:parasitology*; D005786:Gene Expression Regulation / Q000235:genetics*; D015321:Gene Rearrangement / Q000235:genetics; D017125:Genes, Protozoan / Q000235:genetics*; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism; D008969:Molecular Sequence Data; D005810:Multigene Family / Q000235:genetics; D010963:Plasmodium falciparum / Q000235:genetics* / Q000276:immunology; D012333:RNA, Messenger / Q000032:analysis; D016053:RNA, Protozoan / Q000032:analysis; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA
D000953:Antigens, Protozoan; D015815:Cell Adhesion Molecules; D017931:DNA Primers; D012333:RNA, Messenger; D016053:RNA, Protozoan; D018799:Intercellular Adhesion Molecule-1