PO.CL01.05 · 临床研究
外周LAG-3+CD8+ T细胞的特征分析：一类与免疫治疗耐药相关的免疫细胞群
Profiling of peripheral LAG-3+CD8+ T cells: An immune cell population associated with immunotherapy resistance
作者与单位 Authors & Affiliations
摘要 Abstract
中文摘要
尽管免疫检查点阻断（ICB）取得成功，许多患者仍无应答，凸显了对预测性生物标志物的需求。我们此前使用11色流式细胞术检测板，鉴定了接受ICB治疗患者外周血单个核细胞（PBMC）的治疗前差异。这些差异将患者分为3种不同的免疫表型或免疫型（Shen等，Sci Trans Med，2021）。免疫型1（IT-1）以较高数量的LAG-3+CD8+ T细胞为特征，与抗PD-1治疗后的不良应答和总生存期（OS）相关。IT-2以较低的LAG-3+CD8+和较好的结局为特征；IT-3以存在IT-1或IT-2中不存在的额外细胞群为特征。在此，我们旨在更深入地理解LAG-3+CD8+ T细胞——IT-1表型的决定性细胞群。
我们采用28色光谱流式细胞术检测，分析了此前被评估为IT-1、IT-2或IT-3的黑色素瘤（n=30）和尿路上皮癌（UC，n=48）患者库存的治疗前PBMC样本，并对一个代表性IT-1样本进行了单细胞RNA测序。
与LAG-3-CD8+细胞相比，LAG-3+CD8+ T细胞表现出较高的细胞毒性、终末分化标志物（GzmB、CD57、T-bet、Eomes）表达，以及较低的归巢（CCR4、CXCR5、CCR7）和共刺激分子（ICOS、CD27、CD28、CD127）表达。与我们的流式细胞术数据一致，转录组分析揭示GZMB、B3GAT1、TBX21和EOMES上调，以及CCR4、CCR7、ICOS、CD27、CD28和IL7R下调。这些发现在一个独立的黑色素瘤scRNA-seq数据集中得到进一步验证（Huuhtanen等，J. Clin. Invest，2023）。最后，我们评估了IT-2/3表型患者的样本，证实此模式为IT-1所独有。
我们的结果揭示了定义LAG-3+CD8+ T细胞（IT-1的标志）的独特表型特征。这些发现完善了IT-1的定义，凸显了IT-1与IT-2/3之间的免疫表型差异，并提示了诸如共刺激和迁移改变等构成ICB耐药基础的机制。
查看英文原文 English abstract
Despite the success of immune checkpoint blockade (ICB), many patients fail to respond, highlighting a need for predictive biomarkers. We previously identified pre-treatment differences in peripheral blood mononuclear cells (PBMCs) from patients treated with ICB using an 11-color flow cytometry panel. These differences grouped patients into 3 distinct immune phenotypes, or immunotypes (Shen et al Sci Trans Med, 2021). Immunotype 1 (IT-1) was characterized by higher numbers of LAG-3 + CD8 + T cells and associated with poor response and overall survival (OS) after anti-PD-1 therapy. IT-2 was characterized by lower LAG-3 + CD8 + and better outcomes; IT-3, by the presence of additional cell populations not present in IT-1 or IT-2. Here, we aim to establish a deeper understanding of LAG-3 + CD8 + T cells, the defining cell population of the IT-1 phenotype.
We analyzed banked pre-treatment PBMC samples from patients with melanoma (n=30) and urothelial carcinoma (UC, n=48) previously assessed to have IT-1, IT-2, or IT-3, using a 28-color spectral flow cytometry assay, with single-cell RNA sequencing of a representative IT-1 sample.
Compared with LAG-3 - CD8 + cells, LAG-3 + CD8 + T cells displayed higher expression of cytotoxic, terminal differentiation markers (GzmB, CD57, T-bet, Eomes) and lower expression of homing (CCR4, CXCR5, CCR7) and costimulatory molecules (ICOS, CD27, CD28, CD127). Consistent with our flow cytometry data, transcriptomic profiling revealed upregulation of GZMB, B3GAT1, TBX21, and EOMES, as well as downregulation of CCR4, CCR7, ICOS, CD27, CD28, and IL7R. These findings were further validated in an independent melanoma scRNA-seq dataset (Huuhtanen et al J. Clin. Invest, 2023). Finally, we evaluated samples from patients with the IT-2/3 phenotypes, confirming this pattern to be unique to IT-1.
Our results reveal a distinct phenotypic signature defining LAG-3 + CD8 + T cells, the hallmark of IT-1. These findings refine the definition of IT-1, highlight immune-phenotype differences between the IT-1 and IT-2/3, and suggest mechanisms, such as altered costimulation and trafficking, that underlie ICB resistance.
利益披露 Disclosure
A. Kogan Zajdman, None..
C. A. Brennick, None..
K. J. Foster, None..
S. A. Riddick, None..
T. Shcheglova, None..
M. Adamow, None..
J. Lee, None..
R. Shen, None..
K. S. Panageas, None..
X. Peng, None..
M. K. Callahan, None.