Identification of a conserved var gene in different Plasmodium falciparum strains.

Background: The multicopy var gene family of Plasmodium falciparum is of crucial importance for pathogenesis and antigenic variation. So far only var2csa, the var gene responsible for placental malaria, was found to be highly conserved among all P. falciparum strains.

In Vitro Variant Surface Antigen Expression in Plasmodium falciparum Parasites from a Semi-Immune Individual Is Not Correlated with Var Gene Transcription.

Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) is considered to be the main variant surface antigen (VSA) of Plasmodium falciparum and is mainly localized on electron-dense knobs in the membrane of the infected erythrocyte. Switches in PfEMP1 expression provide the basis for antigenic variation and are thought to be critical for parasite persistence during chronic infections. Recently, strain transcending anti-PfEMP1 immunity has been shown to develop early in life, challenging the role of PfEMP1 in antigenic variation during chronic infections.

Var Gene promoter activation in clonal Plasmodium falciparum isolates follows a hierarchy and suggests a conserved switching program that is independent of genetic background.

Antigenic variation of Plasmodium falciparum is mediated by a mutually exclusive expression mechanism that limits expression to an individual member of the multicopy var gene family. This process determines the antigenic and adhesive phenotype of the infected red blood cell. Previously, we showed that var gene switching is influenced by chromosomal position.

Antigenic variation in Plasmodium falciparum: moving beyond the laboratory strains.

Antigenic variation in Plasmodium falciparum malaria is mediated by the multicopy var gene gene family. Each parasite carries approximately 60 different var genes. A system of mutually exclusive expression ensures that only one gene is expressed in each individual cell.