Establishment of New Immunotheapy using Dendritic Cells and Evaluation of Its Inhibitory Effect on Tumor Relapse.

树突状细胞（DC）是一种有效的抗原提呈细胞，可引起原发性免疫反应。近年来，利用树突状细胞的新型免疫疗法被应用于恶性淋巴瘤和恶性黑色素瘤的治疗，取得了可喜的成果。在本研究中，我们尝试将这种新的免疫学方法用于其他恶性肿瘤，特别是胃肠道肿瘤。根据我们的结果，确定了DC分离和肿瘤抗原纯化的最佳方法。通过小鼠肿瘤转移模型的体内抗肿瘤作用的研究，比较了重组小鼠GM-CSF腹腔注射组、转GM-CSF基因肝细胞预处理组（脾内注射）和对照组，发现GM-CSF的局部供应对于激发肝脏的抗肿瘤免疫是重要的。我们希望我们的研究结果将有助于建立人类抗肿瘤免疫治疗，可以抑制肿瘤术后复发。

Dendritic cell (DC) is known to be a potent antigen presenting cell which can elicit primary immunoreaction. New immunotherapy using DCs are recently applied to malignant lymphoma and malignant melanoma, showing hopeful results. In this study, we tried to use this new immunological method to other malignancies, with special regard to gastrointestinal cancers. From our results, the optimal method of DC separation and tumor antigen purification was determined. Using murine tumor metastasis model, we evaluated the in vivo antitumor effect of this therapy.Comparing three groups, intraperitoneal injection of recombinant murine GM-CSF, pretreatment with GM-CSF gene transduced hepatocytes (intrasplenic injection), and control group, we found that the local supply of GM-CSF is important for eliciting strong antitumor immunity in the liver. We hope our findings would be helpful for the establishment of human antitumor immunotherapy that can inhibit tumor relapse after surgery.