调节性T细胞（Tregs）是免疫系统中的关键细胞类型。在肿瘤微环境（TME）中，Tregs的存在对免疫反应和肿瘤发展具有重要意义。对于肺腺癌（LUAD）中Tregs的作用了解甚少。我们使用单细胞RNA测序（scRNA-seq）分析鉴定了Tregs，并研究了Tregs与TME中其他细胞之间的相互作用。接下来，我们使用多个批量RNA测序数据集基于Tregs的标记基因构建了危险模型，并探索了高风险组和低风险组之间在预后、突变谱、免疫细胞浸润和免疫治疗方面的差异，最后，我们进行了qRT-PCR和细胞功能实验以验证模型基因。Cellchat分析显示，MIF-(CD74+CXCR4)对在Tregs与其他细胞亚群之间的相互作用中起关键作用，并且Tregs相关的标记基因（TRAS）可以将多个LUAD队列很好地分类为高风险组和低风险组。根据其较强的生存能力、免疫细胞浸润增加以及免疫检查点表达增强，低风险组可能获得较大的免疫治疗潜力。最后，实验验证了模型基因LTB和PTTG1在癌组织中相对高表达，而PTPRC在癌旁组织中相对高表达。克隆形成实验证实，PTTG1的沉默减少了LUAD细胞的增殖能力。使用scRNA-seq和批量RNA测序构建了TRAS以区分患者风险亚组，这可能对LUAD患者的临床管理提供帮助。版权所有© 2023 Zhang，Zhang，Cui，Gong，Wang和Lin。

Regulatory T cells (Tregs), are a key class of cell types in the immune system. In the tumor microenvironment (TME), the presence of Tregs has important implications for immune response and tumor development. Relatively little is known about the role of Tregs in lung adenocarcinoma (LUAD).Tregs were identified using but single-cell RNA sequencing (scRNA-seq) analysis and interactions between Tregs and other cells in the TME were investigated. Next, we used multiple bulk RNA-seq datasets to construct risk models based on marker genes of Tregs and explored differences in prognosis, mutational landscape, immune cell infiltration and immunotherapy between high- and low-risk groups, and finally, qRT-PCR and cell function experiments were performed to validate the model genes.The cellchat analysis showed that MIF-(CD74+CXCR4) pairs play a key role in the interaction of Tregs with other cell subpopulations, and the Tregs-associated signatures (TRAS) could well classify multiple LUAD cohorts into high- and low-risk groups. Immunotherapy may offer greater potential benefits to the low-risk group, as indicated by their superior survival, increased infiltration of immune cells, and heightened expression of immune checkpoints. Finally, the experiment verified that the model genes LTB and PTTG1 were relatively highly expressed in cancer tissues, while PTPRC was relatively highly expressed in paracancerous tissues. Colony Formation assay confirmed that knockdown of PTTG1 reduced the proliferation ability of LUAD cells.TRAS were constructed using scRNA-seq and bulk RNA-seq to distinguish patient risk subgroups, which may provide assistance in the clinical management of LUAD patients.Copyright © 2023 Zhang, Zhang, Cui, Gong, Wang and Lin.