Responses to anti-PD-1 immunotherapy occur but are infrequent in bladder cancer. The specific T cells that mediate tumor rejection are unknown. T cells from human bladder tumors and non-malignant tissue were assessed with single-cell RNA and paired T cell receptor (TCR) sequencing of 30,604 T cells from 7 patients. We find that the states and repertoires of CD8⁺ T cells are not distinct in tumors compared with non-malignant tissues. In contrast, single-cell analysis of CD4⁺ T cells demonstrates several tumor-specific states, including multiple distinct states of regulatory T cells. Surprisingly, we also find multiple cytotoxic CD4⁺ T cell states that are clonally expanded. These CD4⁺ T cells can kill autologous tumors in an MHC class II-dependent fashion and are suppressed by regulatory T cells. Further, a gene signature of cytotoxic CD4⁺ T cells in tumors predicts a clinical response in 244 metastatic bladder cancer patients treated with anti-PD-L1.

对抗 PD-1 免疫疗法有反应，但在膀胱癌中并不常见。介导肿瘤排斥的特定 T 细胞是未知的。来自人类膀胱肿瘤和非恶性组织的 T 细胞通过对 7 名患者的 30,604 个 T 细胞的单细胞 RNA 和配对 T 细胞受体 (TCR) 测序进行了评估。我们发现，与非恶性组织相比，CD8 ⁺ T 细胞的状态和库在肿瘤中并不明显。相比之下，CD4 ⁺ T 细胞的单细胞分析显示了几种肿瘤特异性状态，包括调节性 T 细胞的多种不同状态。令人惊讶的是，我们还发现了多种细胞毒性 CD4 ⁺ T 细胞状态，这些状态被克隆扩展。这些 CD4 ⁺T 细胞可以以 MHC II 类依赖性方式杀死自体肿瘤，并被调节性 T 细胞抑制。此外，肿瘤中细胞毒性 CD4 ⁺ T 细胞的基因特征预测了 244 名接受抗 PD-L1 治疗的转移性膀胱癌患者的临床反应。