Febrile temperature enhances Plasmodium falciparum and neutrophil adhesion by disrupting the endothelial glycocalyx

Abstract

Fever, a universal host defense response in infection and inflammation, paradoxically contributes to neurological complications in malaria. Febrile temperatures are known to enhance parasite virulence protein expression, but direct effects on the human endothelium remain unknown. We found that a 1-hour exposure to 40 {degrees}C, representative of fever in children with cerebral malaria, increased adhesion of Plasmodium falciparum-infected red blood cells and neutrophils to 3D brain microvascular models displaying a wide wall shear stress gradient. Mechanistically, this brief hyperthermia triggered rapid endothelial glycocalyx shedding, exposing endothelial receptors for binding. This response was more pronounced in brain than in pulmonary microvessels, revealing a greater vulnerability of the cerebral vasculature to fever. Pharmacological inhibition of matrix metalloproteinase activity preserved glycocalyx integrity and abolished the temperature-induced increase in adhesion. These findings identify fever as a host-specific amplifier of malaria-associated microvascular pathology, highlighting the importance of antipyretic strategies to mitigate disease severity.