一些患者对免疫治疗的反应混合，其生物机制和临床影响至今尚无定论。我们从同一患者的淋巴结转移病灶中获得了两个肿瘤样本。通过对两种肿瘤进行全外显子组测序和单细胞测序分析肿瘤浸润淋巴细胞 （TIL） 的差异，我们发现两种肿瘤的克隆性和 TIL 特征，特别是疲劳 T 细胞克隆型，存在显著差异，虽然在肿瘤细胞和 T 细胞克隆之间存在密切关系，但在同时对同一新抗原产生重叠疲劳 T 细胞克隆的响应下出现了差异。为了模拟临床环境，我们建立了来自同一肿瘤细胞系的几个克隆的小鼠模型。同样，不同的肿瘤克隆含有不同的 TILs，在这个模型中，其中一个克隆对 PD-1 抑制剂有反应，而另一个则没有反应。我们进一步进行了队列研究（n = 503），使用 PD-1 抑制单药治疗，以调查混合反应的结果。我们队列中 PD-1 抑制剂混合反应的患者预后不佳。特别是，在经历抗 PD-1 靶向药物治疗后仅在淋巴结转移病灶中出现疾病进展的患者，原发灶和淋巴结转移灶之间的肿瘤和 T 细胞克隆存在显著差异。我们的结果强调了异种肿瘤的异质性即使在同一个患者中也会改变 TILs 的特征，导致免疫治疗的混合反应，并导致结果差异显著。 有几位患者对免疫治疗产生混合反应，但生物学机制和临床意义仍不清楚。我们的临床和小鼠研究结果强调异种肿瘤的异质性即使在同一个患者中也会改变 TILs 的特征，导致对免疫治疗的混合反应，并导致结果差异显著。版权所有 © 2022 AACR。

Some patients experience mixed response to immunotherapy, whose biological mechanisms and clinical impact have been obscure. We obtained two tumor samples from lymph node (LN) metastatic lesions in a same patient. Whole exome sequencing for the both tumors and single-cell sequencing for the both tumor-infiltrating lymphocytes (TIL) demonstrated a significant difference in tumor clonality and TILs' characteristics, especially exhausted T-cell clonotypes, although a close relationship between the tumor cell and T-cell clones were observed as a response of an overlapped exhausted T-cell clone to an overlapped neoantigen. To mimic the clinical setting, we generated a mouse model of several clones from a same tumor cell line. Similarly, differential tumor clones harbored distinct TILs, and one responded to programmed cell death protein 1 (PD-1) blockade but the other did not in this model. We further conducted cohort study (n = 503) treated with PD-1 blockade monotherapies to investigate the outcome of mixed response. Patients with mixed responses to PD-1 blockade had a poor prognosis in our cohort. Particularly, there were significant differences in both tumor and T-cell clones between the primary and LN lesions in a patient who experienced tumor response to anti-PD-1 mAb followed by disease progression in only LN metastasis. Our results underscore that intertumoral heterogeneity alters characteristics of TILs even in the same patient, leading to mixed response to immunotherapy and significant difference in the outcome.Several patients experience mixed responses to immunotherapies, but the biological mechanisms and clinical significance remain unclear. Our results from clinical and mouse studies underscore that intertumoral heterogeneity alters characteristics of TILs even in the same patient, leading to mixed response to immunotherapy and significant difference in the outcome.© 2022 The Authors; Published by the American Association for Cancer Research.