CD8⁺ T cells are considered a critical component of antitumor immunity. However, tumor-infiltrating CD8⁺ T cells may express more than one checkpoint molecules that have the potential to inhibit effector responses alone or cooperatively. Here, we focused on the expression dynamic of TIGIT and PD-1 in CD8⁺ T cells. TIGIT⁺ subset presented significantly higher PD-1 expression than TIGIT⁻ subset in circulating CD8⁺ T cells. The expression dynamic of TIGIT and PD-1 was then tracked. In total CD8⁺ T cells, TIGIT mRNA increased more rapidly than PD-1 mRNA, and TIGIT⁺ CD8⁺ T cells upregulated PD-1 more rapidly than TIGIT⁻ CD8⁺ T cells. Next, 24-h-stimulated CD8⁺ T cells were re-sorted into TIGIT⁺ and TIGIT⁻ subsets, and the TIGIT⁺ cells that came from TIGIT⁻ cells also presented significantly more rapid PD-1 induction than persistent TIGIT⁻ CD8⁺ T cells. In non-small cell lung cancer (NSCLC) patients, the expression of PD-1 was more enriched in TIGIT⁺ cells than in TIGIT⁻ cells in both circulating CD8⁺ T cells and tumor-infiltrating CD8⁺ T cells. Function analysis revealed that TIGIT⁺ CD8 T cells presented lower interferon-gamma, perforin 1, and granzyme B upregulation than TIGIT⁻ CD8 T cells, especially in NSCLC patients. Overall, these data indicated that TIGIT presented earlier expression dynamic than PD-1 in activated CD8⁺ T cells and was upregulated in NSCLC patients.

CD8 ⁺ T细胞被认为是抗肿瘤免疫力的重要组成部分。但是，浸润肿瘤的CD8 ⁺ T细胞可能表达一种以上的检查点分子，这些分子有可能单独或协同抑制效应子反应。在这里，我们专注于TIGIT和PD-1在CD8 ⁺ T细胞中的表达动态。TIGIT ⁺子集呈现显著更高PD-1的表达比TIGIT ^-在循环CD8子⁺ T细胞。然后跟踪TIGIT和PD-1的表达动态。在CD8 ⁺ T细胞总数中，TIGIT mRNA的增长速度比PD-1 mRNA和TIGIT ⁺ CD8 ⁺T细胞比TIGIT ^- CD8 ⁺ T细胞更快地上调PD-1 。接下来，24小时的刺激的CD8 ⁺ T细胞重新分为TIGIT ⁺和TIGIT ^-子集，和TIGIT ⁺从TIGIT传来细胞^-细胞也呈现PD-1诱导比持续TIGIT显著更快速^- CD8 ⁺ ŧ细胞。在非小细胞肺癌（NSCLC）患者，表达PD-1更富含TIGIT ⁺细胞中比在TIGIT ^-细胞在这两个循环CD8 ⁺ T细胞和肿瘤浸润性CD8 ⁺T细胞。功能分析表明，TIGIT ⁺ CD8 T细胞的干扰素-γ，穿孔素1和颗粒酶B的上调低于TIGIT ^- CD8 T细胞，尤其是在NSCLC患者中。总体而言，这些数据表明，在活化的CD8 ⁺ T细胞中，TIGIT的表达动力学比PD-1早，并且在NSCLC患者中表达上调。