Fig. 1: Type I IFN-producing macrophages surround damaged endothelial cells in COVID-19 skin lesions.
From: The cGAS–STING pathway drives type I IFN immunopathology in COVID-19
a, Immune gene expression profiles of skin lesions from individuals with COVID-19 (n = 10) and individuals with CLE (n = 11), and skin from healthy donors (HD; n = 5). Unbiased clustering was performed. b, Immunohistochemistry quantification of macrophages, neutrophils, plasmacytoid dendritic cells (pDCs) and T cells (stained for CD163, MPO, CD123 and CD3) in CLE (n = 5) and COVID-19 (n = 10) skin lesions. c, Confocal microscopy images of representative COVID-19 skin lesion stained for CD163 (green) and IFNβ (red). Scale bars, 20 μm. d, Contribution of CD163+ macrophages and CD31+ endothelial cells to IFNβ expression in CLE (n = 5) and COVID-19 (n = 10). e, Confocal microscopy images of representative COVID-19 skin lesion stained for CD31 (green) and IFNβ (red). Scale bars, 20 μm. f, Proportions of CD163+ macrophages, CD31+ endothelial cells and other cells among IFNβ-producing cells for each CLE and COVID-19 sample. g, Confocal microscopy images of a representative COVID-19 skin sample stained for CD163 (green) and CD31 (red) to depict macrophages and endothelial cells. Scale bar, 50 μm. h, Transmission electron microscopy of dermal vessels in purpuro-necrotic (left) and maculopapular (middle) COVID-19 skin lesions, and in healthy skin (right). Arrows show disrupted endothelial cells (COVID-19 skin lesions) and intact endothelial cells (healthy skin). Scale bars, 2 μm (left); 5 μm (middle); 1 μm (right). i, Immunohistochemistry for cleaved caspase-3 (cl. caspase-3) in COVID-19 skin lesions (nuclear staining indicated by arrow). Scale bar, 20 μm. j, Percentage of CD31+ endothelial cells with cleaved caspase-3 staining in healthy skin (n = 8) and in CLE (n = 6) and COVID-19 (n = 10) skin lesions. k, Correlation between cleaved-caspase-3-positive nuclei and overall staining intensity of IFNβ measured in COVID-19 skin samples (n = 8). Spearman correlation and two-tailed statistical significance were performed. Data are mean ± s.d. (b, d, j). P values obtained with two-tailed Student’s t-test and one-way ANOVA followed by Tukey’s multiple comparisons test (b, d, j).
