Department of Regenerative and Cancer Cell Biology, Albany Medical College, Albany, NY, United States.
Department of Biomedical Engineering, Rensselaer Polytechnic Institute, Troy, NY, United States.
Front Immunol. 2020 Feb 21;11:269. doi: 10.3389/fimmu.2020.00269. eCollection 2020.
Macrophages are a heterogeneous and plastic population of cells whose phenotype changes in response to their environment. Macrophage biologists utilize peritoneal (pMAC) and bone marrow-derived macrophages (BMDM) for studies. Given that pMACs mature while BMDM are differentiated from stem cells, it is likely that their responses differ under experimental conditions. Surprisingly little is known about how BMDM and pMACs responses compare under the same experimental conditionals. While morphologically similar with respect to forward and side scatter by flow cytometry, reports in the literature suggest that pMACs are more mature than their BMDM counterparts. Given the dearth of information comparing BMDM and pMACs, this work was undertaken to test the hypothesis that elicited pMACs are more responsive to defined conditions, including phagocytosis, respiratory burst, polarization, and cytokine and chemokine release. In all cases, our hypothesis was disproved. At steady state, BMDM are more phagocytic (both rate and extent) than elicited pMACs. In response to polarization, they upregulate chemokine and cytokine gene expression and release more cytokines. The results demonstrate that BMDM are generally more responsive and poised to respond to their environment, while pMAC responses are, in comparison, less pronounced. BMDM responses are a function of intrinsic differences, while pMAC responses reflect their differentiation in the context of the whole animal. This distinction may be important in knockout animals, where the pMAC phenotype may be influenced by the absence of the gene of interest.
巨噬细胞是一种异质且具有可塑性的细胞群体，其表型会根据其所处的环境而发生变化。巨噬细胞生物学家利用腹腔（pMAC）和骨髓来源的巨噬细胞（BMDM）进行研究。鉴于 pMAC 在成熟，而 BMDM 则从干细胞分化而来，因此它们在实验条件下的反应可能不同。令人惊讶的是，人们对 BMDM 和 pMAC 在相同实验条件下的反应如何比较知之甚少。虽然在流式细胞术方面，前向散射和侧向散射的形态相似，但文献中的报道表明，pMAC 比其 BMDM 对应物更成熟。鉴于比较 BMDM 和 pMAC 的信息匮乏，这项工作旨在检验以下假设：即诱导的 pMAC 对定义条件（包括吞噬作用、呼吸爆发、极化以及细胞因子和趋化因子的释放）的反应更敏感。在所有情况下，我们的假设都被证明是错误的。在稳定状态下，BMDM 的吞噬作用（无论是速率还是程度）都比诱导的 pMAC 更强。对极化的反应，它们上调趋化因子和细胞因子基因的表达，并释放更多的细胞因子。结果表明，BMDM 通常更敏感，并且能够更好地对其环境做出反应，而 pMAC 的反应则相对不那么明显。BMDM 的反应是内在差异的函数，而 pMAC 的反应则反映了它们在整个动物环境中的分化。这种区别在敲除动物中可能很重要，因为 pMAC 表型可能会受到感兴趣基因缺失的影响。
