A review of Extracellular Vesicles in Parasitic Diseases: Mechanisms and Translational Opportunities

Extracellular vesicles (EVs) are membrane-delimited particles secreted by cells in all domains of life, and are now widely regarded as core mediators of intercellular communication in health and disease. Within the field of parasitology, EV studies have deepened our understanding of how protozoa and helminths communicate with host tissue, evade immune responses, and orchestrate parasite-to-parasite signalling. Concurrently, this review reflects on recent results on the biogenesis and molecular cargo of EVs and reiterates methodological rigour and standardization as recommended by the Minimal Information for Studies of Extracellular Vesicles (MISEV) guidelines. We explore mechanisms through EVs derived from major protozoan pathogens (Plasmodium spp., Trypanosoma brucei, Leishmania spp., and Giardia duodenalis) and from helminths in showing how vesicular proteins, lipids, and small RNAs drive host innate and adaptive responses. We conclude by reviewing host EVs produced by parasitic infection in terms of inflammatory signaling, endothelial activation, anemia, and tissue remodeling. The translational components examine EVs as candidate biomarkers, vaccine components, and delivery platforms and note technical and biological limitations in this regard, especially EV heterogeneity, co-isolation of contaminants, and variability between in vitro and in vivo systems. Last, we provide a regional perspective with reference to recent reports of parasitological surveys and molecular diagnostics conducted in Kirkuk Province (Iraq), presenting ongoing burdens of intestinal parasitism and zoonotic transmission at the human-animal interface. Integrating these parasite-EV examinations with robust reporting mechanisms and appropriate sampling methods guided by the science of medicine can facilitate a successful translation of this mechanistic insight to a comprehensive idea of diagnostics and intervention.