To characterize the molecular mechanisms by which P. falciparum-infected erythrocytes adhere to brain endothelial cells, shed light on the pathogenic mechanisms associated with cerebral malaria, and may suggest anti-adhesive strategies or new treatment options to improve cerebral malaria outcomes.
- To determine if EPCR-binding parasites inhibit the protein C-EPCR interaction.
- To determine if EPCR-binding parasites affect the cytoprotective and pro-barrier function of EPCR on endothelial cells and
- To determine the combination of host receptors that act in concert with EPCR to mediate high affinity binding of DC8 variants to brain endothelial cells.
Rationale and Abstract
Cerebral malaria is a deadly complication of Plasmodium falciparum infection that is associated with the massive accumulation of infected erythrocytes in cerebral microvasculature. Parasite binding is mediated by the P. falciparum erythrocyte membrane protein 1 (PfEMP1) family. Recently, we discovered that parasites expressing DC8 and DC13 PfEMP1 are associated with cerebral malaria and showed that they bind to endothelial protein C receptor (EPCR) via the cysteine-rich interdomain region (CIDR) domain in PfEMP1. The finding that DC8 and DC13 PfEMP1 bind EPCR has important implications for cerebral malaria pathogenesis. EPCR is a receptor for activated protein C and plays a key role in regulating coagulation and endothelial barrier properties. These findings suggest there may be causal links between parasite cytoadhesion and microvascular pathology, such as a blockade of the protein C-EPCR interaction by DC8 or DC13-expressing infected erythrocytes. While this mechanism provides an appealing explanation for many of the pathophysiological correlates of cerebral malaria, a number of critical questions remain unanswered including to what extent DC8 and DC13 PfEMP1 inhibit EPCR function and identifying the combination of host receptors mediating cerebral binding.