射频消融联合原位疫苗联合调节性T细胞清除抑制肝癌复发的机制研究

To improve the survivals of the patients with hepatocellular carcinoma (HCC),the key is to prevent the recurrence and metastasis after therapy. Immunotherapy is the treatment of choice because it can discover and eradicate the tumor cells at any site. Studies have shown that thermal ablation can induce acitce immunogical reaction, whereas it can not last long. Depletion of Tregs has been proven to improve the antitumor immulogical effect. In this project, in situ vaccination after radiofrequency ablation (RFA) for HCC, in combination with the Tregs depletion is designed to achieve the specific immune effect towards HCC.The combined method will be established. The antitumor immune effect, immune protective effect, and antitumor specificity will be observed, including the growth rate of the tumor and the inoculated tumor, metastasis, and the survivals.The antitumor mechanisms will be elucidated by observing the DC activation ratio, and phenotype in the tumor, spleen, and draning lymph node; T lymphocytes infiltration;the tumor-specific killing effect of CTL cells; T cell proliferation test. The project will establish a new immunetherapy method for HCC. The novel treatment method will decrease the recurrence and metastasis after resection of HCC and improve the patient survival.

肝癌治疗后复发和转移是影响长期生存的关键，免疫治疗因能主动监视、识别和清除任何部位的肿瘤细胞成为最有希望控制肿瘤转移复发的治疗模式。前期研究发现肝癌热消融能诱导出机体主动抗肿瘤免疫反应，但作用时间短不能长效抑制肝癌复发，肿瘤原位疫苗可提高该免疫应答的时效性，清除 Tregs 能提高肿瘤免疫治疗如瘤苗的抗肿瘤疗效。据此提出肝癌射频消融原位疫苗联合Tregs清除增强机体抗肿瘤免疫应答，可望抑制肝癌复发。我们将用小鼠肿瘤模型经射频消融联合应用原位疫苗和Treg清除治疗，观察免疫保护效应、肿瘤免疫特异性、肿瘤组织免疫组化、血供和生长曲线、以及转移和小鼠生存期等指标，探索该疗法对抑制肝癌复发的效果。本研究对阐明肝癌射频消融后原位疫苗联合Tregs清除诱导机体主动抗癌免疫治疗的作用机制有重要意义，为降低肝癌治疗后的复发和转移提供了新的思路。

本项目中我们构建了小鼠肿瘤模型，研究了射频消融联合原位疫苗介导的免疫治疗在抑制小鼠肿瘤生长、抑制转移以及提高小鼠生存期方面的应用，通过肿瘤体积生长曲线和血供、免疫组化证实了该联合治疗方法可有效降低肿瘤中血管密度，阻断血供，同时诱发肿瘤细胞凋亡，最终极大地抑制肿瘤生长，同时有效的抑制肿瘤转移的发生，提高了裸鼠的生存周期和生活质量。进一步，我们通过免疫组化、免疫相关生物因子的检测等一系列分子生物学表征手段证明了肝癌射频消融联合原位疫苗可诱导机体主动抗癌免疫响应，明确了该联合治疗作用机制。