The Effect Of Exosomes Derived From Dendritic Cells With Cyclophosphamide And Poly I: C In Antitumor Chemoimmunotherpy

The aim of this experiment is to prove that exosomes combined with Poly I:C and CTX are efficient in antitumor chemoimmunotherpy.DCs derived from bone marrow were loaded with L1210 tumor cells frozen-thaw peptide, then exosomes were secreted from DC. The exosomes were isolated by ultracentrifugation and ultrafiltration. In order to analyse wether Poly I:C could stimulate DC mature, Poly I:C was added to the culture system of imDC, and then DC was analysed by flow cytometry. From the experiment, we could see the surface molecules,including MHC-I/II,CD11c,CD80,CD86, were uploaded. To analysis the antitumor effects, the spleen cells proliferation and the cytotoxicity of antigen-specific spleen cells which were stimulated by exosomes were measured. Exosomes are potent for inducing spleen cells proliferation. The absorption value of spleen cell proliferation test was (0.90±0.22) while spleen cells without exosomes was(0.53±0.13).(30.56±3.85)%,(21.19±3.99)% L1210 cells were killed when the effector target ratio is 10:1 and 5:1 when use spleen cells pulsed with exosomes , while spleen cells without pulsing with exosomes are (19.38±4.68)%,(17.54±4.48)%. Compared with mice treated with PBS or CTX or CTX+Poly I:C, mice injected with exosomes lived longer. Mice treated with exosomes+CTX+Poly I:C lived much longer than those treated with exosomes and the tumor on them grew much slow. We have improved that exosomes are potent in killing L1210 and can prolong the survival time of tumor model.Exosomes together with CTX and Poly I:C is efficient in suppressing tumor growth and prolonging survival time.