Gibbings Sophie L, Jakubzick Claudia V
Department of Pediatrics, National Jewish Health, Denver, CO, USA.
Department of Microbiology and Immunology, University of Colorado, Denver, CO, USA.
Methods Mol Biol. 2018;1799:381-395. doi: 10.1007/978-1-4939-7896-0_28.
Mononuclear phagocytes (MP) consist of macrophages, dendritic cells (DCs), and monocytes. In all organs, including the lung, there are multiple subtypes within these categories. The existence of all these cell types suggest that there is a clear division of labor and delicate balance between the MPs under steady state and inflammatory conditions. Although great strides have been made to understand MPs in the mouse lung, and human blood, little is known about the MPs that exist in the human lung and lung-draining lymph nodes (LNs), and even less is known about their functional roles, studies of which will require a large number of sorted cells. We have comprehensively examined cell surface markers previously used in a variety of organs to identify human pulmonary MPs. In the lung, we consistently identify five extravascular pulmonary MPs and three LN MPs. These MPs were present in over 100 lungs regardless of age or gender. Notably, the human blood CD141 DCs, as described in the literature, were not observed in non-diseased lungs or their draining LNs. In the lung and draining LNs, expression of CD141 was only observed on HLADR CD11c CD14 extravascular monocytes (often confused in the LN as resident DCs based on the level of HLADR expression and mouse LN data). In the human lung and LNs there are at least two DC subtypes expressing HLADR, DEC205 and CD1c, along with circulating monocytes that behave as either antigen-presenting cells or macrophages. Furthermore, we demonstrate how to distinguish between alveolar macrophages and interstitial macrophage subtypes. It still remains unclear how the human pulmonary MPs identified here align with mouse MPs. Clearly, we are now past the stage of cell surface marker characterization, and future studies will need to move toward understanding what these cell types are and how they function. Our hope is that the strategy described here can help the pulmonary community take this next step.
单核吞噬细胞（MP）由巨噬细胞、树突状细胞（DC）和单核细胞组成。在包括肺在内的所有器官中，这些类别都存在多种亚型。所有这些细胞类型的存在表明，在稳态和炎症条件下，MP之间存在明确的分工和微妙的平衡。尽管在理解小鼠肺和人血液中的MP方面已经取得了很大进展，但对于存在于人类肺和肺引流淋巴结（LN）中的MP却知之甚少，关于它们的功能作用更是了解甚少，而对其进行研究需要大量分选的细胞。我们全面检查了先前在各种器官中用于鉴定人类肺MP的细胞表面标志物。在肺中，我们始终鉴定出五种血管外肺MP和三种LN MP。无论年龄或性别如何，这些MP都存在于100多个肺中。值得注意的是，文献中描述的人血CD141 DC在未患病的肺或其引流的LN中未观察到。在肺和引流的LN中，仅在HLADR CD11c CD14血管外单核细胞上观察到CD141的表达（基于HLADR表达水平和小鼠LN数据，在LN中常被误认为是驻留DC）。在人类肺和LN中，至少有两种表达HLADR、DEC205和CD1c的DC亚型，以及作为抗原呈递细胞或巨噬细胞的循环单核细胞。此外，我们展示了如何区分肺泡巨噬细胞和间质巨噬细胞亚型。目前仍不清楚这里鉴定出的人类肺MP与小鼠MP如何对应。显然，我们现在已经超越了细胞表面标志物表征的阶段，未来的研究需要朝着了解这些细胞类型是什么以及它们如何发挥功能的方向发展。我们希望这里描述的策略能够帮助肺部研究领域迈出下一步。
