Studies on the roles of extracellular vesicles from biological fluids as a intercellular communicasome on immune response

DoctorRespiratory and gastrointestinal track as the outside of our body anatomically, are always exposed to environmental pathogen or non-pathogenic foreign antigens. Therefore, immune mechanisms of these organs are well established depending on their functions, compared with other organs existing inside the body. These tracks have specific physical barrier as known as mucus which secreted goblet cells to protect against foreign pathogen and epithelial layer, various kinds of immune cells exist for innate or adaptive immune response. Immune response has to be controlled in a very delicate manner to prevent the onset of inflammatory response wrongly. Because different immune cells elicits different functions, communication between the immune cells are important in order to rightly orchestrate the immune response. In this context, soluble proteins, small chemical, and direct interaction between cells are the known means of intercellular communication. Extracellular vesicles (EVs) are 50-200nm sized spherical particles composed of lipid bilayer, which contain proteins, DNA and RNA. Recent evidences indicate that EVs are intercellular communicasome between the cells to transfer insoluble molecules or ligand. It is reported that various types of immune cells such as dendritic cell, mast cell and B cell secret EVs and presence of EVs was observed in several kinds of biological fluid. However, the functions of EVs are not clear. In this present study, we show that EVs from BAL fluid of mice intranasally administrated with LPS induce Th1 and Th17 immune response to inert antigen and EVs from small intestinal lamina propria of orally administrated antigens reduce Th2 immune response in the antigen specific manner. These findings indicate that EVs, which exist on the biological fluids are not passively secreted particles and that EVs are highly insoluble molecular intercellular communicasomes that transfer the intercellular signals depending on the status of environmen