Parasite histones are toxic to brain endothelium and link blood barrier breakdown and thrombosis in cerebral malaria.



Moxon, Christopher A, Alhamdi, Yasir, Storm, Janet, Toh, Julien MH, McGuinness, Dagmara, Ko, Joo Yeon, Murphy, George, Lane, Steven, Taylor, Terrie E, Seydel, Karl B
et al (show 10 more authors) (2020) Parasite histones are toxic to brain endothelium and link blood barrier breakdown and thrombosis in cerebral malaria. Blood advances, 4 (13). 2851 - 2864.

WarningThere is a more recent version of this item available.
[img] Text
200426_Hist in CM_manuscript_clean_full.pdf - Author Accepted Manuscript
Access to this file is restricted: this item is under permanent embargo.

Download (6MB)

Abstract

Microvascular thrombosis and blood-brain barrier (BBB) breakdown are key components of cerebral malaria (CM) pathogenesis in African children and are implicated in fatal brain swelling. How Plasmodium falciparum infection causes this endothelial disruption and why this occurs, particularly in the brain, is not fully understood. In this study, we have demonstrated that circulating extracellular histones, equally of host and parasite origin, are significantly elevated in CM patients. Higher histone levels are associated with brain swelling on magnetic resonance imaging. On postmortem brain sections of CM patients, we found that histones are colocalized with P falciparum-infected erythrocytes sequestered inside small blood vessels, suggesting that histones might be expelled locally during parasite schizont rupture. Histone staining on the luminal vascular surface colocalized with thrombosis and leakage, indicating a possible link between endothelial surface accumulation of histones and coagulation activation and BBB breakdown. Supporting this, patient sera or purified P falciparum histones caused disruption of barrier function and were toxic to cultured human brain endothelial cells, which were abrogated with antihistone antibody and nonanticoagulant heparin. Overall, our data support a role for histones of parasite and host origin in thrombosis, BBB breakdown, and brain swelling in CM, processes implicated in the causal pathway to death. Neutralizing histones with agents such as nonanticoagulant heparin warrant exploration to prevent brain swelling in the development or progression of CM and thereby to improve outcomes.

Item Type: Article
Depositing User: Symplectic Admin
Date Deposited: 19 May 2020 08:52
Last Modified: 18 Jan 2023 23:51
DOI: 10.1182/bloodadvances.2019001258
URI: https://livrepository.liverpool.ac.uk/id/eprint/3087912

Available Versions of this Item