The ability to safely control transgene expression with simple synthetic gene switches is critical for effective gene- and cell-based therapies. In the present study, the signaling pathway controlled by human transient receptor potential (TRP) melastatin 8 (hTRPM8), a TRP channel family member¹, is harnessed to control transgene expression. Human TRPM8 signaling is stimulated by menthol, an innocuous, natural, cooling compound, or by exposure to a cool environment (15–18 °C). By functionally linking hTRPM8-induced signaling to a synthetic promoter containing elements that bind nuclear factor of activated T cells, a synthetic gene circuit was designed that can be adjusted by exposure to either a cool environment or menthol. It was shown that this gene switch is functional in various cell types and human primary cells, as well as in mice implanted with engineered cells. In response to transdermal delivery of menthol, microencapsulated cell implants harboring this gene circuit, coupled to expression of either of two therapeutic proteins, insulin or a modified, activin type IIB, receptor ligand trap protein (mActRIIB^ECD-hFc), could alleviate hyperglycemia in alloxan-treated mice (a model of type 1 diabetes) or reverse muscle atrophy in dexamethasone-treated mice (a model of muscle wasting), respectively. This fully human-derived orthogonal transgene switch should be amenable to a wide range of clinical applications.

使用简单的合成基因开关安全控制转基因表达的能力对于有效的基于基因和细胞的治疗至关重要。在本研究中，由人类瞬时受体电位 (TRP) melastatin 8 (hTRPM8) 控制的信号通路，TRP 通道家族成员¹，用于控制转基因表达。人类 TRPM8 信号传导受到薄荷醇（一种无害、天然、凉爽的化合物）或暴露于凉爽环境 (15–18 °C) 的刺激。通过将 hTRPM8 诱导的信号与含有结合活化 T 细胞核因子的元件的合成启动子功能性地连接起来，设计了一种合成基因回路，该回路可以通过暴露于凉爽的环境或薄荷醇来进行调整。结果表明，这种基因开关在各种细胞类型和人类原代细胞以及植入工程细胞的小鼠中都起作用。为响应薄荷醇的透皮递送，含有该基因回路的微囊化细胞植入物与两种治疗性蛋白质（胰岛素或修饰的激活素 IIB 型受体配体捕获蛋白（mActRIIB）中的任何一种的表达偶联）^ECD -hFc) 可分别缓解四氧嘧啶治疗小鼠（一种 1 型糖尿病模型）的高血糖或逆转地塞米松治疗小鼠的肌肉萎缩（一种肌肉萎缩模型）。这种完全由人类衍生的正交转基因开关应该适用于广泛的临床应用。