The processes that keep a cell alive are constantly challenged by unpredictable changes in its environment. Cells manage to counteract these changes by employing sophisticated regulatory strategies that maintain a steady internal milieu. Recently, the antithetic integral feedback motif has been demonstrated to be a minimal and universal biological regulatory strategy that can guarantee robust perfect adaptation for noisy gene regulatory networks in Escherichia coli. Here, we present a realization of the antithetic integral feedback motif in a synthetic gene circuit in mammalian cells. We show that the motif robustly maintains the expression of a synthetic transcription factor at tunable levels even when it is perturbed by increased degradation or its interaction network structure is perturbed by a negative feedback loop with an RNA-binding protein. We further demonstrate an improved regulatory strategy by augmenting the antithetic integral motif with additional negative feedback to realize antithetic proportional-integral control. We show that this motif produces robust perfect adaptation while also reducing the variance of the regulated synthetic transcription factor. We demonstrate that the integral and proportional-integral feedback motifs can mitigate the impact of gene expression burden, and we computationally explore their use in cell therapy. We believe that the engineering of precise and robust perfect adaptation will enable substantial advances in industrial biotechnology and cell-based therapeutics.

中文翻译：

---

用于稳健和精确基因调控的遗传哺乳动物比例积分反馈控制电路。

使细胞保持活力的过程不断受到其环境中不可预测的变化的挑战。细胞通过采用维持稳定内部环境的复杂调节策略来设法抵消这些变化。最近，对立的积分反馈基序已被证明是一种最小且通用的生物调控策略，可以保证对大肠杆菌中嘈杂的基因调控网络的稳健完美适应。在这里，我们提出了哺乳动物细胞合成基因回路中对立的积分反馈基序的实现。我们表明该基序将合成转录因子的表达稳健地维持在可调水平，即使它受到降解增加的干扰，或其相互作用网络结构受到带有 RNA 结合蛋白的负反馈环的干扰。我们进一步展示了一种改进的监管策略，通过增加对立积分基序和额外的负反馈来实现对立比例积分控制。我们表明，该基序产生了强大的完美适应，同时还减少了受监管的合成转录因子的方差。我们证明积分和比例积分反馈基序可以减轻基因表达负担的影响，我们通过计算探索它们在细胞治疗中的用途。我们相信，精确而稳健的完美适应工程将使工业生物技术和基于细胞的疗法取得重大进展。我们表明，该基序产生了强大的完美适应，同时还减少了受监管的合成转录因子的方差。我们证明积分和比例积分反馈基序可以减轻基因表达负担的影响，我们通过计算探索它们在细胞治疗中的用途。我们相信，精确而稳健的完美适应工程将使工业生物技术和基于细胞的疗法取得重大进展。我们表明，该基序产生了强大的完美适应，同时还减少了受监管的合成转录因子的方差。我们证明积分和比例积分反馈基序可以减轻基因表达负担的影响，我们通过计算探索它们在细胞治疗中的用途。我们相信，精确而稳健的完美适应工程将使工业生物技术和基于细胞的疗法取得重大进展。