Plasmodium falciparum: pfalhesin and CD36 form an adhesin/receptor pair that is responsible for the pH-dependent portion of cytoadherence/sequestration

Abstract

The cytoadherent behavior of two Plasmodium falciparum (human malaria) cell lines, FCR-3 and ITO4 (a cell line with elevated ICAM-1 adherence), was studied using CHO cells transfected with CD36 or ICAM-1 receptors as target cells. ICAM-1-mediated adherence was found to be relatively pH insensitive, whereas CD36-mediated adherence was pH sensitive and inhibited by monoclonal antibodies and peptides based on a region found in human band 3 protein and named pfalhesin. Immobilized pfalhesin was used as an affinity matrix to purify CD36 from extracts of C32 amelanotic melanoma cells, which have ICAM-1 as well as CD36 receptors, and bind both parasite cell lines. We conclude that pfalhesin and CD36 constitute an adhesin/receptor pair.