CD4⁺ CD25⁺ regulatory T (Treg) cells express the transcription factor FOXP3 and play an essential role in preventing autoimmunity. Abundant Treg cell accumulation in tumors and tumor draining lymph nodes (TDLNs) has been reported to correlate with both poor and favorable prognosis in various cancers, which suggests that Tregs may have multiple effects on antitumor immunity. However, the heterogeneity of tumor- and TDLN-infiltrating Treg cells remains unclear. Here we provide heterogeneity analysis of tumor infiltrating human CD4⁺ Treg cells and their matched adjacent tissues and TDLNs. We defined three different subpopulations of tumor- and TDLN-infiltrating Treg cells by Helios and CCR8 expression in pancreatic ductal adenocarcinoma (PDAC) and confirmed their functional heterogeneity. Helios⁺ CCR8⁺ Treg cells with potent suppressor function and limited IL-2 and IFN-γ secretion were identified in tumors and TDLNs. On the contrary, Helios⁻ CCR8⁻ Treg cells have impaired suppressive activity, and elevated expression of pro-inflammatory cytokines. More advanced grades of PDAC have predominantly Helios⁺ CCR8⁺ Treg cells and few Helios⁻ CCR8⁻ Treg cells both in tumors and TDLNs that suggests poor prognosis. These data could help further define the role of Treg cells and their functional role in tumors and TDLNs.

CD4 ⁺ CD25 ⁺调节性 T (Treg) 细胞表达转录因子 FOXP3，并在预防自身免疫方面发挥重要作用。据报道，肿瘤和肿瘤引流淋巴结 (TDLN) 中大量的 Treg 细胞积聚与各种癌症的不良预后和良好预后相关，这表明 Treg 可能对抗肿瘤免疫具有多种影响。然而，肿瘤和 TDLN 浸润性 Treg 细胞的异质性仍不清楚。在这里，我们提供肿瘤浸润人 CD4 ^{+的异质性分析}Treg 细胞及其匹配的相邻组织和 TDLN。我们通过胰腺导管腺癌 (PDAC) 中的 Helios 和 CCR8 表达定义了肿瘤和 TDLN 浸润性 Treg 细胞的三个不同亚群，并证实了它们的功能异质性。在肿瘤和 TDLN 中鉴定出具有有效抑制功能和有限的 IL-2 和 IFN-γ 分泌的Helios ⁺ CCR8 ⁺ Treg 细胞。相反，Helios ⁻ CCR8 ⁻ Treg 细胞的抑制活性受损，促炎细胞因子的表达升高。更高级的 PDAC 主要有 Helios ⁺ CCR8 ⁺ Treg 细胞和少量 Helios ^- CCR8 ^-肿瘤和 TDLN 中的 Treg 细胞表明预后不良。这些数据有助于进一步确定 Treg 细胞的作用及其在肿瘤和 TDLN 中的功能作用。