Programmable Probiotics for Cancer

 描述(申请人提供)：在过去的十年里，微生物组数据揭示了人体内微生物的惊人流行，改变了长期以来认为细菌是病原体的观点。这些细菌不仅存在于众所周知的区域，如肠道，还存在于包括肿瘤在内的多种组织类型中。鉴于这种流行，微生物代表着一个天然的平台，用于开发诊断和治疗方法，这些方法旨在感知它们的环境并将药物输送到肿瘤。当前与指导研究：我们的初步结果表明，口服益生菌可以在结直肠肝转移瘤中定植，并酶切可以在尿液中检测到的注射底物(Danino等人，科学转化医学，修订中)。在这一结果的基础上，为了提高敏感性和特异性，我们将设计一个基因电路，在肿瘤环境中以阈值种群密度裂解，并释放尿液诊断肽。电路参数将通过数学建模进行预测，以微流控测量为特征，并通过基因拷贝数和核糖体结合强度进行实验调整，以优化小鼠模型中诊断肽的检测。独立阶段研究：随着工程诊断电路的初步表征，我们将评估在更现实的结直肠癌原位和基因工程小鼠模型中的定植。我们将确定细菌定植发生的最早阶段，并同时测量尿液中诊断肽的浓度。我们将以我们的益生菌为靶标，使用肿瘤归宿多肽，表达促凋亡多肽作为治疗药物，并监测肿瘤的进展随时间的变化。总之，可编程益生菌平台将允许对癌症进行更复杂的微生物诊断和治疗，并为合成生物学的体内应用建立一个工程框架。

 DESCRIPTION (provided by applicant): Over the past decade, the long-held view of bacteria as pathogens has been transformed by microbiome data revealing an astounding prevalence of microbes within the human body. These bacteria exist not only in well- known regions such as the intestines, but also in a multitude of tissue types including tumors. Given this prevalence, microbes represent a natural platform for the development of diagnostics and therapies engineered to sense their environment and deliver drugs to tumors. Current & Mentored Research: Our preliminary results have shown that oral delivery of probiotic bacteria can colonize colorectal liver metastases and enzymatically cleave an injected substrate that can be detected in the urine (Danino et al., Science Translational Medicine, in revision). Building upon this result to improve sensitivity and specificity, we will engineer a gene circuit to lyse at a threshold population density within the tumor environment and release a urine diagnostic peptide. Circuit parameters will be predicted by mathematical modeling, characterized by microfluidic measurements, and experimentally tuned by genetic copy number and ribosome binding strengths to optimize for detection of the diagnostic peptide in mouse models. Independent Phase Research: Following initial characterization of the engineered diagnostic circuit, we will assess colonization in more realistic orthotopic and genetically engineered mouse models of colorectal cancer. We will determine earliest stages at which bacteria colonization occurs and simultaneously measure diagnostic peptide concentrations in the urine. We will target our probiotics with tumor-homing peptides, express pro- apoptotic peptides as therapeutics, and monitor progression of tumors as a function of time. Altogether, the programmable probiotic platform will allow for more sophisticated microbial diagnostics and therapeutics for cancer and establish an engineering framework for in vivo applications for synthetic biology.