Fig. 2: Cell density modulates the heterogeneity of macrophage activation.
From: Macrophages employ quorum licensing to regulate collective activation
a Reporter protein fluorescence was measured by flow cytometry for the indicated cell densities, time points, and ligand treatments (IL-10 and sTNFR treatments as in Fig. 1). Percentages of highly activated cells were determined using a threshold (dotted vertical line) at the nadir between the two modes (arrows) of mCherry distributions. b Reporter trajectories for n = 30 cells at high density after treatment with sTNFR and LPS. Cells are ordered by cumulative mCherry expression and color-coded by fluorescence magnitude within heat maps. c Single-cell trajectories for total EGFP-RelA expression. The mean is in bold. d–e Relationship between initial and cumulative total EGFP-RelA (R2 = 0.61, one-tailed permutation test p = 2 × 10−7) and between cumulative nuclear EGFP-RelA and cumulative mCherry (R2 = 0.59, one-tailed permutation test p = 3 × 10−7). Dotted lines are linear fits, and axes are linearly scaled. In c–e, color-coding denotes rank-ordered cumulative mCherry expression. f Single-cell mCherry trajectories, with the mean in bold. Values are in a.u. specific to each panel. g Effect of culture density-associated conditions on macrophage activation heterogeneity. Fluorescence units are comparable within each reporter protein and passaging density. Dotted vertical lines distinguish low and high activation. h Revised conceptual model for macrophage activation with differently activated cell density-dependent subpopulations. Source data are provided as a Source Data file.
