Differential Effect of Extracellular Vesicles Derived from Plasmodium falciparum-Infected Red Blood Cells on Monocyte Polarization

Nanoparticle tracking analysis of natural hemozoin from Plasmodium parasites

BACKGROUND

Hemozoin is a byproduct of hemoglobin digestion crucial for parasite survival. It forms crystals that can be of interest as drug targets or biomarkers of malaria infection. However, hemozoin has long been considered as an amorphous crystal of simple morphology. Studying the consequences of biomineralization of this crystal during the parasite growth may provide more comprehensive evidence of its role during malaria.

OBJECTIVES

This study aimed to investigate the interest of nanoparticles tracker analysis for measuring the concentration and size of hemozoin particles produced from different parasite sources and conditions.

METHODS

Hemozoin was extracted from several clones of Plasmodium falciparum both asexual and sexual parasites. Hemozoin was also extracted from blood samples of malaria patients and from saliva of asymptomatic malaria carriers. Nanoparticles tracking analysis (NTA) was performed to assess the size and concentration of hemozoin.

RESULTS

NTA data showed variation in hemozoin concentration, size, and crystal clusters between parasite clones, species, and stages. Among parasite clones, hemozoin concentration ranged from 131 to 2663 particles/infected red blood cell (iRBC) and size ranged from 149.6 ± 6.3 nm to 234.8 ± 40.1 nm. The mean size was lower for Plasmodium vivax (176 ± 79.2 nm) than for Plasmodium falciparum (254.8 ± 74.0 nm). Sexual NF54 parasites showed a 7.5-fold higher concentration of hemozoin particles (28.7 particles/iRBC) compared to asexual parasites (3.8 particles/iRBC). In addition, the mean hemozoin size also increased by approximately 60 % for sexual parasites. Compared to in vitro cultures of parasites, blood samples showed low hemozoin concentrations.

CONCLUSIONS

This study highlights the potential of NTA as a useful method for analyzing hemozoin, demonstrating its ability to provide detailed information on hemozoin characterization. However, further research is needed to adapt the NTA for hemozoin analysis.

Red Blood Cell-Derived Extracellular Vesicles: An Overview of Current Research Progress, Challenges, and Opportunities

Red blood cell-derived extracellular vesicles (RBC EVs) are small, spherical fragments released from red blood cells. These vesicles, similar to EVs derived from other cell types, are crucial for intercellular communication processes and have been implicated in various physiological and pathological processes. The diagnostic and therapeutic potential of RBC EVs has garnered increasing attention in recent years, revealing their valuable role in the field of medicine. In this review, we aim to provide a comprehensive analysis of the current research status of RBC EVs. We summarize existing studies and highlight the progress made in understanding the characteristics and functions of RBC EVs, with a particular focus on their biological roles in different diseases. We also discuss their potential utility as diagnostic and prognostic biomarkers in diseases and as vectors for drug delivery. Furthermore, we emphasize the need for further research to achieve selective purification of RBC EVs and unravel their heterogeneity, which will allow for a deeper understanding of their diverse functions and exploration of their potential applications in diagnostics and therapeutics.

Exosome-derived long noncoding RNAs: Mediators of host-Plasmodium parasite communication

Overcoming challenges associated with malaria eradication proves to be a formidable task due to the complicated life cycle exhibited by the malaria parasite and the lack of safe and enduring vaccines against malaria. Investigating the interplay between Plasmodium parasites and their mammalian hosts is crucial for the development of novel vaccines. Long noncoding RNAs (lncRNAs) derived from Plasmodium parasites or host cells have emerged as potential signaling molecules involved in the trafficking of proteins, RNA (mRNAs, miRNAs, and ncRNAs), and DNA. These lncRNAs facilitate the interaction between hosts and parasites, impacting normal physiology or pathology in malaria-infected individuals. Moreover, they possess the capacity to regulate immune responses and associated signaling pathways, thus potentially influencing chromatin organization, epigenetic modifications, mRNA processing, splicing, and translation. However, the functional role of exosomal lncRNAs in malaria remains poorly understood. This review offers a comprehensive analysis of lncRNA and exosomal lncRNA profiles during malaria infection. It presents an overview of recent progress in elucidating the involvement of exosomal lncRNAs in host-parasite interactions. Additionally, potential exosomal lncRNAs linked to the domains of innate and adaptive immunity in the context of malaria are proposed. These findings may contribute to the discovery of new diagnostic and therapeutic strategies for malaria. Furthermore, the need for additional research was highlighted that aimed to elucidate the mechanisms underlying lncRNA transportation into host cells and their targeting of specific genes to regulate the host's immune response. This knowledge gap presents an opportunity for future investigations, offering innovative approaches to enhance malarial control. This article is categorized under: RNA Interactions with Proteins and Other Molecules > Small Molecule-RNA Interactions RNA Interactions with Proteins and Other Molecules > Protein-RNA Interactions: Functional Implications RNA in Disease and Development > RNA in Disease.

Extracellular Vesicles in Microbes, Pathogens, and Infectious Diseases

Extracellular vesicles (EVs) are nanosized lipid bilayer particles that are produced by all kinds of organisms, including both pathogenic and non-pathogenic archaea, bacteria, fungi, and parasites [...].