Dendritic cells (DCs) and macrophages (MΦs) are antigen-presenting phagocytic cells found in many peripheral tissues of the human body, including the blood, lymph nodes, skin, and lung. They are vital to maintaining steady-state respiration in the human lung based on their ability to clear airways while also directing tolerogenic or inflammatory responses based on specific stimuli. Over the past three decades, studies have determined that there are multiple subsets of these two general cell types that exist in the airways and interstitium. Identifying these numerous subsets has proven challenging, especially with the unique microenvironments present in the lung. Cells found in the vasculature are not the same subsets found in the skin or the lung, as demonstrated by surface marker expression. By transcriptional profiling, these subsets show similarities but also major differences. Primary human lung cells and/ or tissues are difficult to acquire, particularly in a healthy condition. Additionally, surface marker screening and transcriptional profiling are continually identifying new DC and MΦ subsets. While the overall field is moving forward, we emphasize that more attention needs to focus on replicating the steady-state microenvironment of the lung to reveal the physiological functions of these subsets.

中文翻译：

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静息人肺中的气道巨噬细胞和树突状细胞亚群。

树突状细胞（DC）和巨噬细胞（MΦ）是在人体许多外周组织（包括血液，淋巴结，皮肤和肺）中发现的抗原呈递吞噬细胞。它们具有清除气道的能力，同时还可以根据特定的刺激来指导致耐受性或炎症反应，对于维持人肺的稳态呼吸至关重要。在过去的三十年中，研究已经确定，气道和间质中存在这两种普通细胞类型的多个子集。事实证明，鉴定这些众多子集具有挑战性，尤其是在肺部存在独特的微环境的情况下。表面标记表达证明，在脉管系统中发现的细胞与在皮肤或肺中发现的细胞不同。通过转录分析，这些子集显示出相似之处，但也存在主要差异。人原发性肺细胞和/或组织很难获得，尤其是在健康状况下。此外，表面标记物筛选和转录谱分析正在不断识别新的DC和MΦ亚组。在整个领域向前发展的同时，我们强调需要更多地关注复制肺的稳态微环境以揭示这些亚群的生理功能。