英国曼彻斯特大学和MedImmune公司、阿斯利康公司全球生物制剂研究和开发部门研究人员发现，免疫治疗和放射治疗两者结合的新疗法可帮助免疫系统追捕和摧毁那些乳腺癌、皮肤癌和肠癌小鼠体内初始放疗后没有杀死的癌细胞。
对于多种癌症，放射治疗是一个非常成功的治疗方法，但放射治疗不能杀死的肿瘤细胞表面会开启PD-L1蛋白，能“诱骗”身体的防御系统，使其认为癌细胞没有构成威胁。
免疫治疗通过阻断这些“标志”，揭示癌细胞的真实身份，使免疫系统“看看”他们是什么并摧毁他们。这种结合疗法能改善小鼠生存和抵御疾病的复发。曼彻斯特大学研究员Simon Dovedi说：使用人体自身的防御系统，对治疗癌症有巨大的潜力，早期阶段的临床试验展示患者可得到很大益处，但我们在了解如何最好地使用这些类型的治疗中仍处于早期阶段。
而特定免疫疗法与结合放疗可以更加有效治疗癌症，我们现在正在试图开展临床试验以测试这个新疗法，看看到底它可以带来多大意义。（生物谷Bioon.com）
Acquired resistance to fractionated radiotherapy can be overcome by concurrent PD-L1 blockade.
Dovedi SJ，et al.
Radiotherapy is a major part in the treatment of most common cancers, but many patients experience local recurrence with metastatic disease. In evaluating response biomarkers, we found that low doses of fractionated radiotherapy led to PD-L1 upregulation on tumor cells in a variety of syngeneic mouse models of cancer. Notably, fractionated radiotherapy delivered in combination with αPD-1 or αPD-L1 mAbs generated efficacious CD8(+) T-cell responses that improved local tumor control, long-term survival, and protection against tumor rechallenge. These favorable outcomes were associated with induction of a tumor antigen-specific memory immune response. Mechanistic investigations showed that IFNγ produced by CD8(+) T cells was responsible for mediating PD-L1 upregulation on tumor cells after delivery of fractionated radiotherapy. Scheduling of anti-PD-L1 mAb was important for therapeutic outcome, with concomitant but not sequential administration with fractionated radiotherapy required to improve survival. Taken together, our results reveal the mechanistic basis for an adaptive response by tumor cells that mediates resistance to fractionated radiotherapy and its treatment failure. With attention to scheduling, combination
