Macrophages infiltrating tumour tissues or residing in the microenvironment of solid tumours are known as tumour-associated macrophages (TAMs). These specialized immune cells play crucial roles in tumour growth, angiogenesis, immune regulation, metastasis, and chemoresistance. TAMs encompass various subpopulations, primarily classified into M1 and M2 subtypes based on their differentiation and activities. M1 macrophages, characterized by a pro-inflammatory phenotype, exert anti-tumoural effects, while M2 macrophages, with an anti-inflammatory phenotype, function as protumoural regulators. These highly versatile cells respond to stimuli from tumour cells and other constituents within the tumour microenvironment (TME), such as growth factors, cytokines, chemokines, and enzymes. These stimuli induce their polarization towards one phenotype or another, leading to complex interactions with TME components and influencing both pro-tumour and anti-tumour processes. This review comprehensively and deeply covers the literature on macrophages, their origin and function as well as the intricate interplay between macrophages and the TME, influencing the dual nature of TAMs in promoting both pro- and anti-tumour processes. Moreover, the review delves into the primary pathways implicated in macrophage polarization, examining the diverse stimuli that regulate this process. These stimuli play a crucial role in shaping the phenotype and functions of macrophages. In addition, the advantages and limitations of current macrophage based clinical interventions are reviewed, including enhancing TAM phagocytosis, inducing TAM exhaustion, inhibiting TAM recruitment, and polarizing TAMs towards an M1-like phenotype. In conclusion, while the treatment strategies targeting macrophages in precision medicine show promise, overcoming several obstacles is still necessary to achieve an accessible and efficient immunotherapy.

中文翻译：

---

破译巨噬细胞在肿瘤微环境中的性能：呼吁精准免疫疗法


浸润肿瘤组织或驻留在实体瘤微环境中的巨噬细胞被称为肿瘤相关巨噬细胞 （TAM）。这些专门的免疫细胞在肿瘤生长、血管生成、免疫调节、转移和化疗耐药中起着至关重要的作用。TAM 包含各种亚群，主要根据其分化和活性分为 M1 和 M2 亚型。以促炎表型为特征的 M1 巨噬细胞发挥抗肿瘤作用，而具有抗炎表型的 M2 巨噬细胞则起促肿瘤调节剂的作用。这些高度通用的细胞对肿瘤细胞和肿瘤微环境 （TME） 内其他成分（如生长因子、细胞因子、趋化因子和酶）的刺激做出反应。这些刺激诱导它们向一种或另一种表型极化，导致与 TME 成分的复杂相互作用，并影响促肿瘤和抗肿瘤过程。本综述全面深入地涵盖了有关巨噬细胞、其起源和功能以及巨噬细胞与 TME 之间错综复杂的相互作用的文献，影响了 TAMs 在促进促肿瘤和抗肿瘤过程方面的双重性质。此外，该综述深入探讨了与巨噬细胞极化有关的主要途径，研究了调节这一过程的各种刺激。这些刺激在塑造巨噬细胞的表型和功能中起着至关重要的作用。此外，还综述了当前基于巨噬细胞的临床干预的优点和局限性，包括增强 TAM 吞噬作用、诱导 TAM 耗竭、抑制 TAM 募集以及将 TAM 极化为 M1 样表型。 总之，虽然精准医学中针对巨噬细胞的治疗策略显示出前景，但要实现可及且有效的免疫疗法，仍然需要克服一些障碍。