Finding Sleeping Beauty: T Cell Biosensors for Dormant Cancer Detection

项目总结 某些类型的癌症，如雌激素受体阳性的乳腺癌，可以复发为转移性癌症。 在患者没有临床表现的休眠期后许多年甚至几十年的疾病 症状。晚期复发被认为是由最初未被杀死的播散性肿瘤细胞(DTC)引起的 治疗和转移部位，如骨髓，一直处于休眠状态，直到它们苏醒。令人惊讶的是，Meta- 对60,000多名接受内分泌治疗的早期ER阳性乳腺癌患者的分析显示 复发的相对风险在至少20年内逐渐增加，这表明 没有疾病证据的完全缓解患者可能潜伏着癌症，并仍有患癌症的风险 在他们的余生中转移复发。目前，还没有广泛使用的方法来监控休眠状态 国家或它的重新觉醒。癌症免疫疗法的到来揭示了使用 将T细胞改造成活的药物。具有肿瘤靶向受体和复杂基因的T细胞 电路已经在某些类型的癌症患者中导致了显著的治疗反应，这些癌症以前是 无法治愈。这一时刻不仅是一个机会，不仅可以建立一个T细胞被设计成治疗方法的未来， 而且还可以作为活传感器，可以检测癌症，具有比目前更高的灵敏度和特异度 有可能。处于休眠状态的肿瘤细胞的激活和生长为微转移需要标志 蛋白水解酶在血管生成等关键步骤中的表达。为了利用蛋白水解酶的失调，这个项目 将开发能够感知蛋白质分解的工程化受体来检测苏醒。它们含有一种胞外物质 一种单链抗体，被多肽模拟表位阻断，从而可以与其同源抗原结合 只有在通过蛋白分解去除封闭多肽后，才会将T细胞的激活限制在特定的条件下 同源蛋白酶和肿瘤抗原都存在的地方。激活后，T细胞传感器放大 释放合成生物标志物(血液、尿液和成像)进行检测。基因编码库(&gt；10^4) 将允许在体内筛选1000个候选T细胞传感器以阳性 和负值选择可以报告不同微环境中唤醒的构造，例如 骨髓和肺。具有记忆表型的T细胞传感器的过继转移可能导致终生 持续监测未来疾病的T细胞传感器。这些技术突破将产生巨大的影响 对了解休眠细胞如何以及何时苏醒并指导治疗干预的启示 重新激活的最早阶段。

PROJECT SUMMARY Some types of cancers, as exemplified by estrogen receptor positive breast cancer, can recur as metastatic disease many years or even decades following a dormancy period where the patient displays no clinical symptoms. Late recurrence is thought to arise from disseminated tumor cells (DTCs) that were not killed by initial treatment and that lie dormant at metastatic sites such as the bone marrow until they reawaken. Strikingly, meta- analysis of over 60,000 early-stage ER-positive breast cancer patients treated with endocrine therapy revealed that the relative risk of recurrence progressively increases over a period of at least 20 years, indicating that patients in complete remission with no evidence of disease could harbor dormant cancer and remain at risk of metastatic relapse for the remainder of their life. Currently, there is no widely used method to monitor the dormant state nor its reawakening. The arrival of cancer immunotherapy has revealed exciting possibilities using engineered T cells as living medicines. T cells designed with tumor-targeting receptors and sophisticated genetic circuits have led to striking treatment responses in patients with certain types of cancers that were previously untreatable. This moment is an opportunity to not only build a future where T cells are engineered as therapies, but also as living sensors that can detect cancer with sensitivities and specificities beyond what is currently possible. The activation and growth of dormant tumor cells into micro-metastases require the hallmark expression of proteases during key steps such as angiogenesis. To exploit protease dysregulation, this project will develop engineered receptors that sense proteolysis to detect reawakening. These contain an extracellular single chain antibody that is blocked by a peptide mimotope such that they can bind to their cognate antigens only after the blocking peptide is removed by proteolysis, restricting T cell activation to the specific condition where the cognate protease and tumor antigen are both present. Following activation, T cell sensors amplify the release of synthetic biomarkers (blood, urine and imaging) for detection. Genetically encoded libraries (>10^4) of protease-activatable receptors will allow in vivo screening of 1000s of candidate T cell sensors to positively and negatively select for constructs that can report on awakening in different microenvironments such as the bone marrow and lungs. The adoptive transfer of T cell sensors with memory phenotype could lead to life-long T cell sensors that continuously monitor for future disease. These technological breakthroughs will have huge implications in understanding how and when dormant cells reawaken and guide therapeutic interventions at the earliest stages of reactivation.