Esser-Kahn Lab, Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL, United States.
Front Immunol. 2024 Jan 23;15:1340384. doi: 10.3389/fimmu.2024.1340384. eCollection 2024.
The innate immune system initiates early response to infection by sensing molecular patterns of infection through pattern-recognition receptors (PRRs). Previous work on PRR stimulation of macrophages revealed significant heterogeneity in single cell responses, suggesting the importance of individual macrophage stimulation. Current methods either isolate individual macrophages or stimulate a whole culture and measure individual readouts. We probed single cell NF-κB responses to localized stimuli within a naïve culture with Fluidic Force Microscopy (FluidFM). Individual cells stimulated in naïve culture were more sensitive compared to individual cells in uniformly stimulated cultures. In cluster stimulation, NF-κB activation decreased with increased cell density or decreased stimulation time. Our results support the growing body of evidence for cell-to-cell communication in macrophage activation, and limit potential mechanisms. Such a mechanism might be manipulated to tune macrophage sensitivity, and the density-dependent modulation of sensitivity to PRR signals could have relevance to biological situations where macrophage density increases.
先天免疫系统通过模式识别受体 (PRR) 感知感染的分子模式，从而启动对感染的早期反应。先前关于 PRR 刺激巨噬细胞的研究表明，单细胞反应存在显著异质性，这表明单个巨噬细胞刺激的重要性。目前的方法要么分离单个巨噬细胞，要么刺激整个培养物并测量单个读出值。我们使用流体力显微镜 (FluidFM) 探测了原始培养物中局部刺激对单个 NF-κB 的反应。与均匀刺激培养物中的单个细胞相比，原始培养物中刺激的单个细胞更敏感。在簇刺激中，NF-κB 激活随细胞密度增加或刺激时间减少而降低。我们的结果支持越来越多的证据表明巨噬细胞激活中的细胞间通讯，并限制了潜在的机制。这种机制可能被操纵以调节巨噬细胞的敏感性，并且对 PRR 信号敏感性的密度依赖性调节可能与巨噬细胞密度增加的生物学情况有关。
