Programmable bacteria detect and record an environmental signal in the mammalian gut
Programmable bacteria detect and record an environmental signal in the mammalian gut
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DOI：
10.1073/pnas.1321321111
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发表时间：
2014-04-01
影响因子：
11.1
通讯作者：
Silver, Pamela A.
中科院分区：
文献类型：
--
作者：
Kotula, Jonathan W.;Kerns, S. Jordan;Silver, Pamela A.
哺乳动物肠道是一个动态的共生微生物群落，它们与宿主相互作用，影响健康、疾病和代谢。我们构建了在哺乳动物肠道中存活的工程细菌，它们能感知、记忆并报告它们的经历。基于先前的遗传记忆系统，我们构建了一个由两部分组成的系统，其中一个“触发元件”是由四环素诱导的启动子转录的lambda Cro基因，另一个“记忆元件”来自噬菌体lambda的cI/Cro区域。记忆元件具有非常稳定的cI状态和对许多细胞分裂稳定的Cro状态。当携带记忆系统的大肠杆菌被给予无水四环素治疗的小鼠时，恢复的细菌都切换到Cro状态，而那些给予未治疗的小鼠的细菌仍然处于cI状态。将触发元件和记忆元件从大肠杆菌K12转移到新分离的小鼠大肠杆菌菌株中；记忆元件的稳定性和开关特性在体外和小鼠传代过程中基本相同，但经过工程改造的小鼠大肠杆菌在小鼠肠道中更稳定地建立。这项工作为在复杂、不明确的环境中使用合成遗传电路作为监测系统奠定了基础，并可能导致活体诊断和治疗的发展。
The mammalian gut is a dynamic community of symbiotic microbes that interact with the host to impact health, disease, and metabolism. We constructed engineered bacteria that survive in the mammalian gut and sense, remember, and report on their experiences. Based on previous genetic memory systems, we constructed a two-part system with a "trigger element" in which the lambda Cro gene is transcribed from a tetracycline-inducible promoter, and a "memory element" derived from the cI/Cro region of phage lambda. The memory element has an extremely stable cI state and a Cro state that is stable for many cell divisions. When Escherichia coli bearing the memory system are administered to mice treated with anhydrotetracycline, the recovered bacteria all have switched to the Cro state, whereas those administered to untreated mice remain in the cI state. The trigger and memory elements were transferred from E. coli K12 to a newly isolated murine E. coli strain; the stability and switching properties of the memory element were essentially identical in vitro and during passage through mice, but the engineered murine E. coli was more stably established in the mouse gut. This work lays a foundation for the use of synthetic genetic circuits as monitoring systems in complex, ill-defined environments, and may lead to the development of living diagnostics and therapeutics.