CD36 Mediates the Phagocytosis of Plasmodium falciparum-Infected Erythrocytes by Rodent Macrophages

Abstract

Phagocytic cells represent an important line of innate defense against malaria; however, little is known of the mechanism by which macrophages recognize Plasmodium falciparum-parasitized erythrocytes (PEs). Using macrophages from CD36 wild-type (WT), CD36-null, and CD36 transgenically- rescued rodents, we demonstrate a major role for CD36 in the phagocytosis of PEs. WT macrophages display enhanced phagocytic capacity for nonopsonized PEs, compared with that for CD36-null mouse and rat macrophages. Transgenic rescue of CD36-deficient rats restored macrophage phagocytic capacity for PEs. CD36 receptor blockade with monoclonal antibodies and proteolytic cleavage of CD36 ligands from the surface of PEs inhibited the uptake of PEs. Upregulation of rodent CD36 by use of peroxisome proliferator-activated receptor (PPAR-γ) agonists increased the phagocytosis of PEs. CD36-mediated uptake of PEs did not result in increased tumor necrosis factor-α secretion, of which high levels are associated with adverse outcomes in malaria. These studies support the use of these rodent models to examine PE-CD36 interactions.