Protein Profiling of Malaria-Derived Extracellular Vesicles Reveals Distinct Subtypes

Abstract

Malaria is caused by obligate intracellular parasites belonging to the genus Plasmodium. Red blood cells (RBCs) infected with different stages of Plasmodium spp. release extracellular vesicles (EVs). Extensive studies have recently shown that these EVs are involved in key aspects of the parasite’s biology and disease pathogenesis. However, they are yet to be fully characterized. The blood stages of Plasmodium spp., namely the rings, trophozoites and schizonts, are phenotypically distinct, hence, may induce the release of characteristically different EVs from infected RBCs. To gain insights into the biology and biogenesis of malaria EVs, it is important to characterize their biophysical and biochemical properties. By differential centrifugation, we isolated EVs from in vitro cultures of RBCs infected with different stages of Plasmodium falciparum. We performed a preliminary characterization of these EVs and observed that important EV markers were differentially expressed in EVs with different sedimentation properties as well as across EVs released from ring-, trophozoite- or schizont-infected RBCs. Our findings show that RBCs infected with different stages of malaria parasites release EVs with distinct protein expression profiles.

Chloroquine induces eryptosis inP. falciparum-infectedred blood cells and the release of extracellular vesicles with a unique protein profile

“…EVs from uRBCs were predominantly smaller and quite abundant. Previous studies stated that RBCs stored above 2 weeks released significantly more EVs with high protein levels which proportionally increase with the age of the cell (27)(28)(29). For this study, we worked with RBCs within the first 3 weeks after collection.…”

Extracellular Vesicles in Malaria: Shedding Light on Pathogenic Depths

“…Recent studies have revealed that EVs produced by RBCs infected with P. falciparum at different stages of the parasite’s life cycle contain a variety of protein cargos, further supporting this notion. 61 , 65 Recently, Abou Karam et al (2022) have identified 132 proteins of which there were 23 P. falciparum -derived proteins along with 109 human proteins, including proteins that may promote the fusion of vesicles. 62 There were 66 proteins that exhibited varying levels of abundance between the two EVs fractions: 6 P. falciparum proteins as well as 60 human proteins, suggesting that F3-EVs (30–70 nm) and F4-EVs (70–300 nm) contain distinct protein cargos that is inclusive of parasite as well as human-derived components.…”

Extracellular Vesicles and Their Impact on the Biology of Protozoan Parasites

“…EVs from Plasmodium -infected RBCs (iRBCs) have been very well characterized and were found to contain a variety of molecules mediating pathogenesis and intercellular communication between the host cells, and between the host and the parasite [ 64 ]. Interestingly, Pf -iRBC-EVs from RBCs infected with different stages of malaria parasites had distinct protein expression profiles, which indicates the tight control of the EV cargo by the intracellular parasites [ 65 ]. Different proteomic analyses have confirmed that virulence-associated proteins such as PfPTP2 and MSP-1 are enriched in these EVs, and they were shown to have a role in EV-mediated communication [ 66 , 67 , 68 ].…”