Experimental study of the cancer vaccine prepared by fusions of esophageal carcinoma cell line with dendritic cell derived from cord blood after cryopreservation

Objective:To develop fusion vaccine of esophageal carcinoma cell and DC, and study the biological characteristics and induction antitumor immunity after cryopreservation. Methods: Fusion vaccine was produced by traditional PEG fusing, cytokine inducing, CD34+ magnetic microbead marker sorting, and MACS. The fused cells were frozen and stored at -80 degrees C for three weeks. Both the flash vaccine and the cryopreservated vaccine were assayed for their immunophenotypes by flow cytometry. Oncogenicity of the cord blood derived DC based esophageal carcinoma vaccine after cryopreservation were tested. Lymphocytes proliferation reaction and the CTL cytotoxicity were examined with MTT assay both for the flash vaccine and the cryopreservated vaccine. Results: The fusion cells after cryopreservation was expressed highly with FR and CD80. No tumor was found in spleen, lung and liver after the injection of fusion vaccine after cryopreservation;The specific CTL activity was well preserved after cryopreservation, and there was no statistic significant difference when compared with that of the fresh fused vaccine (P0.05). Conclusion: Cryopreservation does not cause significant changes in the phenotypes of the fused vaccine cells. The fusion vaccine after thawing have no oncogenicity in vivo. A simple method of freezing and storage at -80℃ is practical. It can well preserve the phenotypes and morphology of the fusion cells. It will be a new storage method for cord blood derived DC-based vaccine.