Dendritic cells (DCs) are a heterogeneous group of antigen-presenting innate immune cells that regulate adaptive immunity, including against cancer. Therefore, understanding the precise activities of DCs in tumours and patients with cancer is important. The classification of DC subsets has historically been based on ontogeny; however, single-cell analyses are now additionally revealing a diversity of functional states of DCs in cancer. DCs can promote the activation of potent antitumour T cells and immune responses via numerous mechanisms, although they can also be hijacked by tumour-mediated factors to contribute to immune tolerance and cancer progression. Consequently, DC activities are often key determinants of the efficacy of immunotherapies, including immune-checkpoint inhibitors. Potentiating the antitumour functions of DCs or using them as tools to orchestrate short-term and long-term anticancer immunity has immense but as-yet underexploited therapeutic potential. In this Review, we outline the nature and emerging complexity of DC states as well as their functions in regulating adaptive immunity across different cancer types. We also describe how DCs are required for the success of current immunotherapies and explore the inherent potential of targeting DCs for cancer therapy. We focus on novel insights on DCs derived from patients with different cancers, single-cell studies of DCs and their relevance to therapeutic strategies.

树突状细胞 (DC) 是一组异质的抗原呈递先天免疫细胞，可调节适应性免疫，包括对抗癌症。因此，了解 DC 在肿瘤和癌症患者中的精确活性非常重要。DC子集的分类历来是基于个体发育的；然而，单细胞分析现在还揭示了癌症中 DC 的多种功能状态。DC 可以通过多种机制促进强效抗肿瘤 T 细胞的激活和免疫反应，尽管它们也可能被肿瘤介导的因子劫持，从而促进免疫耐受和癌症进展。因此，DC 活性通常是免疫疗法（包括免疫检查点抑制剂）疗效的关键决定因素。增强树突状细胞的抗肿瘤功能或使用它们作为协调短期和长期抗癌免疫的工具具有巨大但尚未充分开发的治疗潜力。在这篇综述中，我们概述了 DC 状态的性质和新出现的复杂性，以及它们在调节不同癌症类型的适应性免疫中的功能。我们还描述了当前免疫疗法的成功如何需要 DC，并探索靶向 DC 进行癌症治疗的内在潜力。我们专注于对来自不同癌症患者的 DC 的新见解、DC 的单细胞研究及其与治疗策略的相关性。