Interaction vesicles as emerging mediators of host-pathogen molecular crosstalk and their implications for infection dynamics.

Extracellular vesicles (EVs) are critical in cell communication, transfer of biomolecules, and host-pathogen interaction. A newly identified subset, "interaction vesicles" (iEVs), forms through host-pathogen contact, merging membrane elements from both. These iEVs may arise through multiple mechanisms, including direct cell-cell contact, membrane contact sites, uptake and repackaging of foreign EVs, and post-release fusion of EVs. These hybrid vesicles enable pathogens to modify host environments, aiding immune evasion and infection persistence. However, iEVs may also act in favor of the host, contributing to pathogen recognition and elimination. Advanced techniques, including proteomics and high-resolution microscopy, are beginning to clarify their composition and fusion. Yet, isolating these hybrid EVs remains challenging. Overcoming these barriers could enhance understanding of infection mechanisms and support diagnostic and therapeutic innovation.