Immunotherapy And Mechanisms Of Ad5-CCL20 Combined With Hyperthermia Therapy For Colorectal Cancer

As the first of global top ten science and technology breakthroughs,tumor immunotherapy has been extensively concerned in recent years,and exploring new modes of immunotherapy has been one of the hot researches in oncology.Recently,cancer therapeutic vaccine which is based on dendritic cells has achieved good progress.However,because of the variability of tumor antigens as well as the complexity of operations when transfusing the pulsed dendritic cells in vitro,most of the dendritic cell vaccines are still in the experimental and preclinical stage.This study aims to explore the method of pulsed dendritic cells in vivo,inducing anti-tumor immune response.We restructured a recombinant adenoviral vector with chemokine CCL20 cDNA,which was transfected into the colorectal cancer cell CT-26 in vitro to express chemokine CCL20.After transfection,expression of CCL20 at different time periods were detected by Elisa and the results showed that the transfected CT-26 highly expressed chemokine CCL20 and expression level was proportionate to the increased time.The chemokine CCL20 could remarkably chemotaxis immature dendritic cells.The expression of heat shock protein(HSP)was detected by Western blot after CT-26 cells were induced by 42 ?.We found that the HSP70,Gp96 expression was significantly increased in heat-induced CT-26 cells.Researches of biological effect among HSP,dendritic cells and T lymphocyte indicated that heat-induced CT-26 could significantly increase the expression of MHC-II,CD80,CD86,CCR6,which were maturation phenotypes of dendritic cells,and secret lots of cytokines like TNF-?,IL-1?,IL-2,IL-6.The supernatant of heat-induced CT26 cells showed significant chemotactic activity to T lymphocytes and the ability to promote IFN-? high secretion.By intratumoral injection of recombinant adenovirus Ad5-CCL20 combined with ex vivo hyperthermia,tumor growth in tumor-bearing mice was significantly inhibited and survival was significantly prolonged.This experiment has proved that recombinant adenovirus which expressed chemokine CCL20 combined with hyperthermia,could effectively inhibit the growth of colon cancer in mice and prolong the survival time,providing a new strategy for the cancer therapy.