Macrophages have previously been characterized based on phenotypical and functional differences into suggested simplified subtypes of MØ, M1, M2a and M2c. These macrophage subtypes can be generated in a well-established primary monocyte culture model that produces cells expressing accepted subtype surface markers. To determine how these subtypes retain functional similarities and better understand their formation, we generated all four subtypes from the same donors. Comparative whole-cell proteomics confirmed that four distinct macrophage subtypes could be induced from the same donor material, with > 50% of 5435 identified proteins being significantly altered in abundance between subtypes. Functional assessment highlighted that these distinct protein expression profiles are primed to enable specific cell functions, indicating that this shifting proteome is predictive of meaningful changes in cell characteristics. Importantly, the 2552 proteins remained consistent in abundance across all macrophage subtypes examined, demonstrating maintenance of a stable core proteome that likely enables swift polarity changes. We next explored the cross-polarization capabilities of preactivated M1 macrophages treated with dexamethasone. Importantly, these treated cells undergo a partial repolarization toward the M2c surface markers but still retain the M1 functional phenotype. Our investigation of polarized macrophage subtypes therefore provides evidence of a sliding scale of macrophage functionality, with these data sets providing a valuable benchmark resource for further studies of macrophage polarity, with relevance for cell therapy development and drug discovery.

中文翻译：

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定义培养巨噬细胞的蛋白质组景观及其极化连续体

之前根据表型和功能差异将巨噬细胞分为建议的简化亚型 MØ、M1、M2a 和 M2c。这些巨噬细胞亚型可以在完善的原代单核细胞培养模型中产生，该模型产生表达可接受的亚型表面标记的细胞。为了确定这些亚型如何保留功能相似性并更好地了解它们的形成，我们从同一供体生成了所有四种亚型。比较全细胞蛋白质组学证实，可以从相同的供体材料诱导出四种不同的巨噬细胞亚型，在 5435 个已识别蛋白质中，超过 50% 的蛋白质在亚型之间丰度显着改变。功能评估强调，这些不同的蛋白质表达谱能够实现特定的细胞功能，表明这种变化的蛋白质组可以预测细胞特征的有意义的变化。重要的是，2552 个蛋白质在所有检查的巨噬细胞亚型中保持丰度一致，这表明维持了稳定的核心蛋白质组，这可能导致快速的极性变化。接下来我们探讨了用地塞米松处理的预激活 M1 巨噬细胞的交叉极化能力。重要的是，这些处理过的细胞经历了向 M2c 表面标记的部分复极化，但仍然保留了 M1 功能表型。因此，我们对极化巨噬细胞亚型的研究提供了巨噬细胞功能滑动尺度的证据，这些数据集为巨噬细胞极性的进一步研究提供了宝贵的基准资源，与细胞疗法开发和药物发现相关。