ABSTRACT
Objective To extract exosomes from dendritic cell (DC)and investigate antitumor effect of the special cytotoxic T lymphocytes activated by exosomes against 769-P.Methods Monocytes from peripheral blood of healthy donors were cultured to induce DC in intro and their phenotypes were analyzed by FACS.The exosomes were extracted from DC by ultrafiltration and ultracentrifugation and observed under electric microscope.Proliferation of T cells and the cytotoxicities of CTL against 769-P induced by exosome were measured by MTT.Results The exosomes could be separated from culture supernatant of DC by ultrafiltration and ultracentrifugation.The combination of the exosomes from DC and the 769-P antigen could effectively stimulate T cell proliferation and enhance their cytotoxicity, the absorption value of T cell proliferation(1.68±0.22), the cytotoxicity of CTL(38.23±2.16)%.Conclusion The exosomes extracted by ultrafiltration and ultracentrifugation can present tumor antigen to T cells and induce the cytotoxicity of CTL.
ABSTRACT
Objective To analyze the relationship between the expression of MHC class I chain-related gene A/B(MICA/B) on different human cancer cells and their sensitivity to NK cell cytotoxicity.Methods Hie expression MICA/B in K562,Bcap37,769P and A549 cells was measured by FACS.Isolation of NK cells were obtained by the modified RosetteSep~((R)) procedure.Cytotoxicity of NK cells at different ef0.50)%,(90.72±0.64)%,(55.59±0.55)%,and(3.84±0.10)% respectively.The purity of NK cells obtained by the modified RosetteSep~((R)) procedure was(96.52±2.42)%,whereas the cytotoxicity of NK cells against K562,Bcap39 and 769P was much higher than that of A549(P<0.01).The expression of MICA/B was significantly correlated with the cytotoxicity of NK cells at E:T ratios of 5:1,10:1 and 20:1 respectively(P<0.01).Conclusion The MICA/B expression on cancer cell lines was correlated with NK cell-mediated cytolysis and influenced the cytotoxicity of NK cells.