Rote of nonimmune IgG bound to PfEMP1 in placental malaria

Infections with Plasmodium falciparum during pregnancy lead to the accumula tion of parasitized red blood cells (infected erythrocytes, IEs) in the pla centa. IEs of A falciparum isolates that infect the human placenta were fou nd to bind immunoglobulin G (IgG). A strain of P. falciparum cloned for IgG binding adhered massively to placental syncytiotrophoblasts in a pattern s imilar to that of natural infections. Adherence was inhibited by IgG-bindin g proteins, but not by glycosaminoglycans or enzymatic digestion of chondro itin sulfate A or hyaluronic acid. Normal, nonimmune IgG that is bound to a duffy binding-like domain beta of the P. falciparum erythrocyte membrane p rotein 1 (PfEMP1) might at the IE surface act as a bridge to neonatal Fc re ceptors of the placenta.