Exosome-mediated immune regulation and its clinical application

Abstract

Immune system is a precise mechanism for maintenance of homeostasis by lymphocyte-mediated elimination of extracellular and intercellular pathogens, and abnormal cells in cytokine-, chemokine-, antibody-, and cytotoxic granuledependent manners. Extracellular vesicles, e.g. exosomes, released from multivesicular endosome in immune cells have been known to be a part of the immune system. Exosomes released by antigen-presenting cells (APCs)

Engineered exosomes for studies in tumor immunology

“…Generally, T cells are more efficiently activated by mature DCs than immature DCs, and mature DCs release exosomes to facilitate immune-stimulatory responses, whereas immature DC exosomes exhibit a potent immune-suppressive response. 72,73 Immunosuppressive molecules, such as TGFβ, NKG2D, and death ligand FasL expressed by immature DCs following response to tumors, can inhibit natural killer (NK) cells, macrophages, and neutrophils. 74,75 Furthermore, DCderived exosomes expressing HLA-B associated transcript-3 (BAT3) bound to NKp30 receptor in NK cells and stimulate the secretion of TNFα and IFNγ.…”

“…Although DC‐derived exosomes can activate T cells through stable interactions with TCR complexes, the extent of the activation depends on DC developmental stage. Generally, T cells are more efficiently activated by mature DCs than immature DCs, and mature DCs release exosomes to facilitate immune‐stimulatory responses, whereas immature DC exosomes exhibit a potent immune‐suppressive response 72,73 . Immunosuppressive molecules, such as TGF‐β, NKG2D, and death ligand FasL expressed by immature DCs following response to tumors, can inhibit natural killer (NK) cells, macrophages, and neutrophils 74,75 .…”