Role of Extracellular Vesicles in Shaping Immune Responses in the Lymph Node Microenvironment

Extracellular vesicles (EV) secreted by living cells are important players in cell-to-cell communication, particularly in the diffuse immune system, where they contribute to local and systemic coordination. Indeed, EV are in the ideal size range for diffusion in interstitial and lymphatic fluids, which is the main route of tissue EV trafficking towards secondary lymphoid organs that orchestrate immune responses. In the lymph nodes, EV interact with multiple immune and stromal cell populations sensitive to antigens and co-delivered tissue messages via degradative and non-degradative pathways. Natural conveyers of bioactive compounds inherited from their mother cells and their surroundings, EV modulate innate and adaptive immune responses in health and disease. The aim of this scoping review is to aggregate information from the literature on cellular effectors and molecular pathways of EV-mediated immune responses in the lymph node environment and to gain insight into practices using EV for immune intervention .