Intratumoral immune cells are crucial for tumor control and antitumor responses during immunotherapy. Immune cell trafficking into tumors is mediated by binding of specific immune cell receptors to chemokines, a class of secreted chemotactic cytokines. To broadly characterize chemokine expression and function in melanoma, we used multiplexed mass cytometry–based imaging of protein markers and RNA transcripts to analyze the chemokine landscape and immune infiltration in metastatic melanoma samples. Tumors that lacked immune infiltration were devoid of most of the profiled chemokines and exhibited low levels of antigen presentation and markers of inflammation. Infiltrated tumors were characterized by expression of multiple chemokines. CXCL9 and CXCL10 were often localized in patches associated with dysfunctional T cells expressing the B lymphocyte chemoattractant CXCL13. In tumors with B cells but no B cell follicles, T cells were the sole source of CXCL13 , suggesting that T cells play a role in B cell recruitment and potentially in B cell follicle formation. B cell patches and follicles were also enriched with TCF7 + naïve-like T cells, a cell type that is predictive of response to immune checkpoint blockade. Our data highlight the strength of targeted RNA and protein codetection to analyze tumor immune microenvironments based on chemokine expression and suggest that the formation of tertiary lymphoid structures may be accompanied by naïve and naïve-like T cell recruitment, which may contribute to antitumor activity.

中文翻译：

---

黑色素瘤中趋化因子环境的多路成像质谱流式细胞术表征了对免疫治疗的反应特征

肿瘤内免疫细胞对于免疫治疗期间的肿瘤控制和抗肿瘤反应至关重要。免疫细胞向肿瘤的运输是通过特异性免疫细胞受体与趋化因子（一类分泌的趋化细胞因子）结合来介导的。为了广泛表征黑色素瘤中趋化因子的表达和功能，我们使用基于多路复用质谱的蛋白质标记和 RNA 转录物成像来分析转移性黑色素瘤样本中的趋化因子景观和免疫浸润。缺乏免疫浸润的肿瘤缺乏大多数已分析的趋化因子，并且表现出低水平的抗原呈递和炎症标志物。浸润性肿瘤的特征在于多种趋化因子的表达。CXCL9和CXCL10通常位于与表达 B 淋巴细胞趋化因子的功能失调的 T 细胞相关的斑块中CXCL13。在有 B 细胞但没有 B 细胞滤泡的肿瘤中，T 细胞是唯一来源CXCL13，表明 T 细胞在 B 细胞募集中发挥作用，并可能在 B 细胞滤泡形成中发挥作用。B 细胞斑块和毛囊也富含 TCF7+幼稚样 T 细胞，一种可预测对免疫检查点阻断反应的细胞类型。我们的数据突出了靶向 RNA 和蛋白质共同检测基于趋化因子表达分析肿瘤免疫微环境的强度，并表明三级淋巴结构的形成可能伴随着幼稚和幼稚样 T 细胞募集，这可能有助于抗肿瘤活性。