Engineering tumor-targeting bacteria to sense and deliver therapeutics

项目摘要 将活细胞设计为智能治疗剂的能力有望改变目前的癌症治疗 范例。基于某些天然和外源性细菌对实体瘤的固有生长专一性， 微生物已经被探索为向肿瘤环境输送治疗药物的程序化载体。然而， 开发这种下一代生活疗法的一个普遍挑战是缺乏研究动力的工具-- 细菌和癌细胞的相互作用群体。因此，过去的绝大多数研究都是 依赖于只测试少数几个候选治疗药物的动物模型，并提供有限的时空 信息。为了应对这一挑战，我最近开发了一个3D多细胞共培养平台，它能够- BLES高通量表征肿瘤球体中的细菌，评估多细胞间的动力学 体内作用及疗效预测。 在这个提案中，我将利用3D共培养技术和合成生物学工具来构建新的 感知和表达治疗药物的细菌系统，特别是在肿瘤中。在F99阶段，我将设计 肿瘤归巢细菌动态调节细胞毒分子的产生，以应对肿瘤的缩小。 具体地说，随着癌细胞死亡增加了肿瘤核心中的氧气水平，我将设计一种细菌 生物传感器电路用于监测肿瘤微环境的这种变化。通过检测氧气水平的上升， 这表明了广泛的治疗进展，这种基因循环将降低产生的治疗水平， 将偏离目标的毒性降至最低。在K00阶段，我将重新调整肿瘤归宿细菌的用途，以瞄准并根除 结直肠癌中的致癌核假单胞菌。我将应用3D共培养平台来筛选抗F。核形 细菌递送到肿瘤球体的多肽。将使用正交异性小鼠癌症模型来评估 F.核酸盐消除，对共生微生物区系的影响，以及癌症进展。总的来说，建议的 这项工作将利用一种新的工程框架来开发有效的细菌癌症疗法，并将其推向临床 翻译。

Project Summary The ability to engineer living cells as intelligent therapeutic agents is poised to transform current cancer treatment paradigms. Based on the inherent growth specificity of some natural and exogenous bacteria to solid tumors, microbes have been explored as programmed vehicles to deliver therapeutics to tumor environments. However, a universal challenge for developing this next-generation living therapy is the lack of tools to study the dynami- cally interacting population of bacteria and cancer cells. Consequently, the vast majority of the past studies have relied on animal models that only test a handful of therapeutic candidates and provide limited spatiotemporal information. To address this challenge, I have recently developed a 3D multicellular coculture platform that ena- bles high-throughput characterization of bacteria in tumor spheroids, assessing dynamics of multicellular inter- actions and predicting therapeutic efficacy in vivo. In this proposal, I will leverage the 3D coculture technologies and synthetic biology tools to construct novel bacterial systems that sense and express therapeutics specifically in tumors. In the F99 phase, I will engineer tumor-homing bacteria to dynamically regulate production of cytotoxic molecules in response to tumor shrinkage. Specifically, as the cancer cell death increases the level of oxygen in the tumor core, I will engineer a bacterial biosensor circuit to monitor this change in the tumor microenvironment. By detecting rises in oxygen levels, which indicate extensive therapeutic progression, this gene circuit will reduce the therapeutic level produced, minimizing off-target toxicity. In the K00 phase, I will repurpose tumor-homing bacteria to target and eradicate oncogenic F. nucleatum in colorectal cancer. I will apply the 3D coculture platform to screen anti-F. nucleatum peptides delivered by bacteria to tumor spheroids. Orthotropic mouse cancer models will be used to assess the F. nucleatum elimination, effect on commensal microbiota, and cancer progression. Collectively, the proposed work will utilize a novel engineering framework to develop effective bacterial cancer therapies towards clinical translation.