Mass spectrometry identification of biomarkers in extracellular vesicles from Plasmodium vivax liver hypnozoite infections

ABSTRACT: Plasmodium vivax is a protozoan parasite responsible for the great majority of Malaria cases outside Sub-Saharan Africa. This parasite is characterized by the presence of latent liver stage forms called hypnozoites which cause relapsing blood infections estimated to contribute up to 79% of vivax malaria cases in endemic regions. P. vivax hypnozoites are considered a major bottleneck for the malaria elimination goal not only due to symptomatic recurrent blood infections experienced by individuals carrying this parasite form but also for continue silent parasite transmission among the population. Importantly, diagnose of hypnozoites cannot be achieved with the current diagnostic tools. Extracellular vesicles (EVs) are nanovesicles secreted by all cell types involved in intercellular communication. EVs are characterized by the presence of molecules from the cell of origin being thus considered as a fingerprint of cell physiological status. Due to this property and to the great EVs stability in biofluids, they are emerging as promising biomarkers for non-invasive diagnosis of a large range of diseases. We have previously reported that plasma-derived EVs from P. vivax infected liver chimeric mice (FRG huHep), a model of liver stage infection of this parasite, contain P. vivax proteins. In this project, we have performed a proteomic characterization of EVs derived from liver chimeric FRG huHEP mice. Pharmacological treatment of FRG huHep mice with a schizontycidal experimental drug (MMV48) was performed to generate infections enriched with latent hypnozoites, an unexplored approach to study EVs specific from this liver stage. The identification of parasite proteins associated to EVs in this model represents a significant advance in the road to identify P. vivax hypnozoite biomarkers that can be implemented for the future diagnose of hypnozoites carriers in endemic regions. Biological samples used • P. vivax FRG huHep mice in vivo model: Female FRG KO mice engrafted with human hepatocytes (FRG KO huHep) were infected with P. vivax as previously described[8]. Mice were divided in 5 experimental groups. Group 1 (3 mice) was uninfected, Group 2 (6 mice) was inoculated with P. vivax sporozoites by the bite of 20 mosquitos and euthanized after 8 days post-inoculation; Group 3 (6 mice) was infected by intravenous injection of P. vivax sporozoites (0.8 million) and euthanized after 8 days post-infection; Group 4 (6 mice) was infected by intravenous injection of P. vivax sporozoites (1 million sporozoites) and euthanized after 21 days post-infection; Group 5 (3 mice) was infected by intravenous injection (1 million sporozoites) and treated with Tafenoquine (10 mg/kg) at 14 dpi and euthanized at 21 days post-infection. MMV048 mice treatment (30 mg/kg) was performed as follows: 3 mice of Group 2 and 3 received intravenous injections of the drug at 4 days post-infection. 3 mice of Group 4 received intravenous injections of the drug at 17 days post-infection. 3 DMSO-treated animals were used as controls in groups 2, 3 and 4. After euthanasia, whole blood was extracted by cardiac venipuncture for plasma collection as previously described. Plasma-derived EVs were purified as follows: Plasma were thawed on ice, centrifuged at 2000 x g for 10 min and supernatant collected. EVs were purified by SEC using commercial Sepharose (iZON) following manufacturer instructions. SEC fractions were characterized for the presence of EV markers CD9 and plasma-derived EVs marker CD5L in a BBA and by NTA. Protein concentration was determined by BCA (Thermo Scientific).

INSTRUMENT(S): Orbitrap Fusion Lumos

ORGANISM(S): Plasmodium Vivax

DISEASE(S): Plasmodium Vivax Malaria

SUBMITTER: Eva Borràs  

LAB HEAD: Eduard Sabido

PROVIDER: PXD035719 | Pride | 2022-08-26

REPOSITORIES: Pride