CM is a serious complication of Plasmodium falciparum infection, and has a profoundly devastating effect especially on children, non-immune travelers and military personnel. Clinically, CM can result in several neurological problems, which include seizures, reversible coma and is associated with a high mortality of up to 30%, with the highest rate in children. Acute neurological symptoms include impaired consciousness, coma, delirium, seizures, and increased intracranial hypertension. The hallmark of CM pathology is the intra-vascular sequestration of parasitized red blood cells (PRBC) inside high endothelial venules throughout the brain. PRBC bind to the blood brain barrier (BBB) endothelium in both WM and gray matter (GM) but do not invade into the brain. Interestingly, the PRBC sequestration in blood vessels leads to a distinctly different pathology between WM and GM. Recent postmortem studies reveal a clear hemorrhagic pathology within WM. Our previous data showed highly inflammatory responses associated with GM endothelium. Yet, little is known of the factors that cause these differences of the brain endothelium residing in GM versus WM and how any potential differences could relate to divergent responses in CM. Therefore, we hypothesize that, due to differences in the direct physiological environment of GM and WM (e.g. astrocyte-neuronal versus pericyte-oligodendrocytes), the vessel endothelium in these different brain tissues exhibit differing properties. In combination with a specific var-gene expressing Plasmodium binding pattern, these different endothelial properties result in diverging CM pathologies. Here, we propose to study the underlying WM versus GM endothelial differences and responses to PRBC by using in vitro models of human BBB, and compare these differences to in situ human brain samples and vascular responses in an in vivo experimental CM model. This application is response to RFA-HL-15-023 Vascular Dysfunction in the Pathogenesis of Severe Malaria (R01). These studies will provide an improved understanding of the BBB and could provide new understandings of the molecular mechanisms of the brain vessels differentiation in WM versus GM that may also be implicated in other neurological diseases.
In CM, Plasmodium infected red blood cells (PRBC) clog small blood vessels and postmortem studies show that hemorrhagic pathology is abundant in blood vessels in white matter but scarce in gray matter. Since very little is known of the differences between gray and white matter blood vessels and how that relates to their responses in CM we propose to study these differences using human tissues, in-vitro human blood brain barrier models and in vivo experimental models for CM. This will be relevant for understanding of CM pathogenesis discovering adjunctive treatment for CM and potentially also for other neurological diseases. (End of Abstract)
