c-Met是肿瘤细胞表面的重要靶点，然而目前针对c-Met的小分子抑制剂和单克隆抗体杀伤肿瘤的效果多不理想。PDL-1作为肿瘤细胞逃避免疫监视的重要信号分子，是肿瘤免疫治疗的重点靶标。尽管目前针对PDL-1的药物在临床上已经显示出一定的疗效，但仍然存在靶向性不强等缺点。究其原因，很可能是由于传统的小分子抑制剂和单抗药物所采取的单一靶向性所造成的，因此，针对双信号通路的靶向策略已经受到国内外同行的高度重视。本课题拟从c-Met和PDL-1着手，利用“纳米抗体”的众多特点，创造性地将抗c-Met介导的肿瘤靶向治疗与抗PDL-1介导的肿瘤免疫治疗结合起来，通过筛选、构建针对c-Met和PDL-1的双靶点纳米抗体，研究抗c-Met/PDL-1双靶点纳米抗体在肿瘤靶向免疫治疗中的作用及机制，探索基于纳米抗体的双靶向抑制肿瘤的可行性，为临床应用提供坚实的理论基础和技术支持。

c-Met is one of the most important targets on the surface of cancer cell, but at present, the effects of small molecule inhibitors and monoclonal antibodies for c-Met on killing cancer are not ideal. On the other side, as a pivotal signal molecule in cancer cell evading immunosurveillance, PDL-1 is the central target of cancer immunotherapy. Despite the current drugs for PDL-1 in clinic have shown certain effects, but it still exists shortcomings, such as off-targeting. It should be due to the defects of traditional small molecule inhibitors and monoclonal antibodies, which is caused by single targeting. Therefore, the strategy of bispecific targeting has been attached great importance to researchers. This project is based on various characteristics of nanobody, which could creatively connect anti-c-Met mediated cancer targeted therapy and anti-PDL-1 mediated cancer immunotherapy, through screening and parparing anti-c-Met/PDL-1 bispecific nanobody, figuring out its role and mechanism in cancer targeted immunotherapy, to explore the feasibility of bispecific nanobody in suppressing cancer, hoping to provide the strong theoretical basis and technical support for the clinical application.