Cerebral malaria (CM) is the most severe complication of Plasmodium falciparum (Pf) infection in humans. This syndrome occurs in approximately 1% of Pf infected subjects, mainly children living in sub-Saharan Africa. Although the mechanisms through which Pf infection evolves to CM remain incompletely understood, it has recently been proposed that microparticles (MPs) may play an important role in CM pathogenesis. Their number is, in fact, increased in CM patients’ circulation and mice unable to produce MPs are protected from the disease. These submicron extracellular vesicles are involved in various biological processes including cell-cell interactions.
In the present work we hypothesise that the characterisation of the protein cargo of plasma MPs obtained in P. berghei ANKA (PbA) infected DBA/1 mice, the murine model of CM, will help better understand CM pathophysiology and reveal new potential disease biomarkers.
To achieve our objective, we established a qualitative and a quantitative (based on TMT® isobaric labelling) proteomics workflow, to efficiently identify and quantify MPs proteins.
Our first data on MP proteins from one single mouse led to the identification by LC-MS/MS of 205 proteins (2 unique peptides, FDR<1%). The gene ontology and pathway analyses of the dataset, highlighted a significant involvement of the identified proteins in actin cytoskeleton regulation and a significant representation of membrane proteins (including important cell-specific surface markers), in addition to proteins involved in the immune response and complement activation. Plasmodium peptides could also be detected. Quantitative comparisons between MPs form infected (n=3) and non-infected (n=3) mice are currently ongoing, in order to identify and quantify proteins significantly differentially expressed between the two conditions. These data, once verified, together with similar work on the microRNA content of MP in the context of CM pathogenesis, will improve our understanding of the mechanisms leading to this deadly disease.