Department of Obstetrics and Gynecology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
Cell Commun Signal. 2024 Sep 28;22(1):459. doi: 10.1186/s12964-024-01834-0.
Clinical trials have shown that immunotherapy based on Vγ9Vδ2 T cells (Vδ2 T cells) is safe and well-tolerated for various cancers including cervical cancer (CC), but its overall treatment efficacy remains limited. Therefore, exploring the mechanisms underlying the suboptimal efficacy of Vδ2 T cell-based cancer immunotherapy is crucial for enabling its successful clinical translation.
Tumor samples from CC patients and CC cell line-derived xenograft (CDX) mice were analyzed using flow cytometry to examine the exhausted phenotype of tumor-infiltrating Vδ2 T cells. The interrelationship between BTN3A1 expression and Vδ2 T cells in CC, along with their correlation with patient prognosis, was analyzed using data from The Cancer Genome Atlas (TCGA) database. CC cell lines with BTN3A1 knockout (KO) and overexpression (OE) were constructed through lentivirus transduction, which were then co-cultured with expanded Vδ2 T cells, followed by detecting the function of Vδ2 T cells using flow cytometry. The pathways and transcription factors (TFs) related to BTN3A1-induced Vδ2 T cells exhaustion and the factors affecting BTN3A1 expression were identified by RNA-seq analysis, which was confirmed by flow cytometry, Western Blot, and gene manipulation.
Tumor-infiltrating Vδ2 T cells exhibited an exhausted phenotype in both CC patients and CDX mice. BTN3A1 expressed in CC is highly enhancing exhaustion markers, while reducing the secretion of effector molecules in Vδ2 T cells. Blocking TCR or knocking down nuclear receptor subfamily 4 group A (NR4A) 2/3 can reverse BTN3A1-induced exhaustion in Vδ2 T cells. On the other hand, IFN-γ secreted by Vδ2 T cells promoted the expression of BTN3A1 and PD-L1.
Through binding γδ TCRs, BTN3A1 expressed on tumor cells, which is induced by IFN-γ, can promote Vδ2 T cells to upregulate the expression of TFs NR4A2/3, thereby affecting their activation and expression of exhaustion-related molecules in the tumor microenvironment (TME). Therefore, targeting BTN3A1 might overcome the immunosuppressive effect of the TME on Vδ2 T cells in CC.
临床试验表明，基于 Vγ9Vδ2 T 细胞（Vδ2 T 细胞）的免疫疗法对于包括宫颈癌（CC）在内的多种癌症是安全且耐受良好的，但总体治疗效果仍然有限。因此，探索 Vδ2 T 细胞为基础的癌症免疫疗法疗效不佳的机制对于实现其成功的临床转化至关重要。
使用流式细胞术分析 CC 患者的肿瘤样本和源自 CC 细胞系的异种移植（CDX）小鼠，以检查肿瘤浸润 Vδ2 T 细胞的耗竭表型。使用癌症基因组图谱（TCGA）数据库中的数据分析 BTN3A1 表达与 CC 中的 Vδ2 T 细胞之间的相互关系，以及它们与患者预后的相关性。通过慢病毒转导构建 BTN3A1 敲除（KO）和过表达（OE）的 CC 细胞系，然后将其与扩增的 Vδ2 T 细胞共培养，使用流式细胞术检测 Vδ2 T 细胞的功能。通过 RNA-seq 分析鉴定与 BTN3A1 诱导的 Vδ2 T 细胞耗竭相关的途径和转录因子（TFs），以及影响 BTN3A1 表达的因素，通过流式细胞术、Western Blot 和基因操作进行验证。
在 CC 患者和 CDX 小鼠中，肿瘤浸润的 Vδ2 T 细胞表现出耗竭表型。CC 中表达的 BTN3A1 高度增强了 Vδ2 T 细胞的耗竭标志物，同时减少了效应分子的分泌。阻断 TCR 或敲低核受体亚家族 4 组 A（NR4A）2/3 可以逆转 BTN3A1 诱导的 Vδ2 T 细胞耗竭。另一方面，Vδ2 T 细胞分泌的 IFN-γ促进了 BTN3A1 和 PD-L1 的表达。
通过与 γδ TCR 结合，肿瘤细胞上表达的 BTN3A1 被 IFN-γ诱导，可促进 Vδ2 T 细胞上调 TF NR4A2/3 的表达，从而影响其在肿瘤微环境（TME）中的激活和耗竭相关分子的表达。因此，靶向 BTN3A1 可能克服 CC 中 TME 对 Vδ2 T 细胞的免疫抑制作用。
