Abstract：Exosomes are vesicles secreted by cells, rich in nucleic acids and proteins, which play an important role in the transmission of information and the regulation of immune function. In this study, macrophages and dendritic cells were cultured, the supernatant was collected, and the exosomes were extracted by the kit method and ultracentrifugation method, and the exosomes were identified by the TEM electron microscope method and the Western blot method. The extracted exosomes were transfected with fluorescent markers and incubated with lymphocytes for 24 h；miR-155 containing fluorescent markers was used to transfect macrophages and dendritic cells respectively, and the exosomes from the cell supernatant were extracted and combined with the lymphocytes and were incubated together for 24 h. The results showed that the exosomes extracted by ultracentrifugation were more pure, but the exosomes extracted by the SBI kit were more suitable for the next experiment. After the exosomes secreted by macrophages and dendritic cells were co-cultured with lymphocytes with fluorescent labels, the fluorescence of lymphocytes increased. Co-culture of fluorescently labeled miR-155 exosomes and lymphocytes can increase the fluorescence of lymphocytes. This study confirmed that the exosomes secreted by dendritic cells and macrophages and the miR-155 contained therein can act on lymphocytes and participate in the communication between immune cells, laying a theoretical foundation for further elucidating the mechanism of exosomes.
2021, Vol. 34 
