Plasmodium falciparum HRP2-induced damage to brain cortical organoids damage is Toll-Like Receptor dependent and is attenuated via Neuregulin-1/ErbB4 signaling

Human cerebral malaria (HCM) is a severe complication of Plasmodium falciparum (P.f.) infection that is characterized by capillary occlusions, rupture of the blood-brain barrier (BBB) and perivascular cellular injury. P.f. histidine-rich protein 2 (HRP2), a byproduct of parasitized red blood cell (pRBC) lysis, crosses the BBB when compromised to cause brain injury. We hypothesized that HRP2-induced neuronal damage can be attenuated by Neuregulin 1 (NRG1), an anti-inflammatory neuroprotective factor. Using brain cortical organoids, we determined that HRP2 upregulated cell death and inflammatory markers and disorganized brain organoid tissue. We identified Toll Like Receptors (TLR1 and 2) as potential mediators of HRP2-induced cellular damage and inflammation. Exogenous treatment of organoids with NRG1 attenuated HRP2 effects. The results indicate that HRP2 mediates malaria-associated HRP2-induced brain injury and inflammation and that NRG1 may be an effective therapy against HRP2 effects in the brain. In the study presented here, we assessed the inflammatory genes induced by HRP2 using the Immunology Panel on the nCounter system (NanoString) and results were analyzed using nSolver softaware. We treated 50 days old cortical organoids (n=3) for 26 hours with 4.2 μg/ml HRP2 with or without 100 ng/ml NRG1, while untreated (n=3) organoids were used as control.