BACKGROUND: CD14 (Monocyte identifying Toll-Like Receptor) and CD16 (FcyRIII co-receptor, marker of inflammatory monocytes) were used to define 3 subpopulations of circulating monocytes with different attributes in terms of inflammatory and phagocytic capabilities. There are contradictory reports regarding response of circulating monocytes to pro-inflammatory or non-inflammatory stimuli in vitro. Here we aimed to analyze the phenotypic changes in circulating monocytes when stimulated with pro and non-inflammatory stimuli. METHODS: Whole blood from 9 healthy donors was extracted and studied. Monocyte subpopulations were directly measured using flow cytometry with PBMC Ficoll extraction method. Pro-inflammatory interleukin IL-1β was measured by intracellular cytometry. Whole blood-extracted monocytes were stimulated using LPS and IL-4 as previously described. Changes against non-stimulated (N-S) populations were statistically analyzed. RESULTS: Compared to N-S, LPS-stimulated monocytes display a singular milieu of markers, with higher levels of intracellular IL-1β in parallel raise of CD14+CD163-/CD14+CD163+ ratio. CD163 shows positive correlation with levels of IL-1β. In t-SNE (T-distributed Stochastic Neighbor Embedding) analysis, after LPS stimulation, subpopulation CD14+CD16-CD163-, containing mainly classical monocytes, show a higher number of IL-1β+ cells. CONCLUSION: Classical monocytes, the non-inflammatory subset, show higher levels of IL-1β in response to LPS narrowing down to a new subpopulation of monocytes CD14+CD16-CD163-, which correlates better with this interleukin response than widely used monocytes classification. Using CD163 in addition to CD16, we were able to show that classical monocytes display the most intense response to LPS. Additionally, CD163 appears to be a suitable addition to CD14-CD16 classification to improve its performance.

中文翻译：

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体外用LPS刺激的非炎性经典单核细胞的促炎反应。

背景：使用CD14（单核细胞识别Toll样受体）和CD16（FcγRIII共受体，炎性单核细胞的标志物）来定义循环单核细胞的3个亚群，这些亚群具有不同的炎症和吞噬能力。关于循环单核细胞对体外促炎性或非炎性刺激的反应存在矛盾的报道。在这里，我们旨在分析当用亲和非炎性刺激刺激时循环单核细胞的表型变化。方法：从9名健康供者的全血中提取和研究。使用流式细胞仪和PBMC Ficoll提取法直接测量单核细胞亚群。通过细胞内流式细胞术测量促炎性白介素IL-1β。如先前所述，使用LPS和IL-4刺激全血提取的单核细胞。对非刺激（NS）人群的变化进行统计分析。结果：与NS相比，LPS刺激的单核细胞显示出独特的标志物环境，伴随CD14 + CD163- / CD14 + CD163 +比值的平行升高，细胞内IL-1β含量更高。CD163与IL-1β水平呈正相关。在t-SNE（T分布随机邻居嵌入）分析中，LPS刺激后，主要包含经典单核细胞的亚群CD14 + CD16-CD163-显示出更高数量的IL-1β+细胞。结论：经典单核细胞（非炎性亚群）在LPS缩小为单核细胞CD14 + CD16-CD163-的新亚群后，表现出较高的IL-1β水平，与广泛使用的单核细胞分类相比，与白介素反应的相关性更好。除CD16外，使用CD163，我们能够证明经典单核细胞对LPS的反应最强烈。另外，CD163似乎是CD14-CD16分类的合适补充，以改善其性能。