Cerebral malaria (CM), a severe complication of Plasmodium falciparum infection, is characterised by pleomorphic endothelial cell activation, adhesion of parasitised erythrocytes, leucocytes and platelets to vessel walls and subsequent blockade of post-capillary venules, notably in the brain. We previously showed that infected erythrocytes, together with host cells, lead to profound endothelial alterations. In turn, brain endothelial cell activation, notably via extracellular vesicles (EV), can trigger immunopathological changes.
EV have emerged as important elements in cell-cell communication and as key players in disease pathogenesis via transmission of their cargo between several cell types. During the last decade, various techniques have been developed to investigate the relative differences in biophysical and biomolecular properties of various populations of extracellular vesicles.
Here, using various vibrational spectroscopic techniques, we characterised EV released in the supernates of human brain microvascular endothelial cells co-cultured with P. falciparum-infected erythrocytes, an in vitro model of CM. Specifically, Fourier-transform infra-red (FTIR), attenuated total reflection (bio-ATR) and atomic force microscope infrared spectroscopies (AFM-IR) were used to assess biochemical changes in the heterogeneous population of bulk and individual EV derived from brain endothelial cells when co-cultured with infected or non-infected erythrocytes.
Using this technology, we identified differences in the biomolecular content of EV derived from brain endothelial cells co-cultured with ICAM-1 binder versus CD36 binder strains of P. falciparum. These results provide pivotal insight on the mechanisms of EV formation, as well as on their role in the pathophysiology of CM.