Objective: To isolate and purify exosomes derived from human bladder transitional cell carcinoma T24 cells, analyze the morphology and protein composition, and investigate the antitumor effect of specific cytotoxic T lymphocytes induced by exosomes.
Methods: Exosomes were isolated and purified by ultrafiltration and sucrose gradient centrifugation, and characterized by electron microscopy and Western blot. Dendritic cells were amplified and purified from peripheral blood and pulsed with exosomes. Then they were co-cultured with T cells, and divided into 3 groups: exosome-pulsed DC group, unplused DC group and control group. Alamar-Blue assay was used to evaluate the specific cytolytic activity.
Results: The exosomes were in size about 30 approximately 90 nm saucer-shaped membranous vesicles. HSP70, ICAM-1 and CK20 were detected by Western blot. The CTL induced by DC pulsed with exosomes had significant cytolytic activity (P < 0.01).
Conclusion: The exosomes derived from T24 cells are loaded with immunoprotein HSP70 and ICAM-1, and DC pulsed with exosomes can promote the anti-tumor effect of CTLs in vitro.