CD36 binding of CIDR-1 recombinant proteins.

CIDR-1 recombinant proteins from CD36-adherent parasites, but not CSA-adherent parasites, bind CD36. Soluble CD36 was immobilized to beads coated with M1 anti-FLAG mAb. Coated beads were incubated with COS-7 cells grown on coverslips and transfected with different constructs. After washing and fixation, the colocalization of beads and transfected cells was quantified by means of a specific monoclonal antibody against an epitope tag incorporated carboxy terminal to the cell-surface–expressed protein. The degree of bead association was examined under immunofluorescence and phase microscopy. CD36-coated beads specifically bound COS-7 cells expressing CIDR-1 from CD36-adherent strains (MC, A4, A4tres, and FVO) but not CIDR-1 from CSA-adherent strains (FCR3-CSA and ItG2-CS2).