Fig. 1: Severe COVID-19 is characterized by progressive lung fibrosis along with an accumulation of immune cells.
From: Distinct tissue niches direct lung immunopathology via CCL18 and CCL21 in severe COVID-19
a–d Tissue sections of lung samples from a non-COVID-related pneumonia donor and COVID-19 donors at different time-points after disease onset were analyzed using spatially resolved techniques (n = 12 tissue sections). Each column represents a series of consecutive sections from the same donor. a HE staining shows tissue structure in whole sections. Dotted lines represent areas analyzed by confocal microscopy (b) and by spatial transcriptomics (ST; c). Small squares depict areas analyzed by multiplex microscopy (d). b Corresponding immunofluorescence (IF) images showing CD45 in yellow, DAPI in magenta, Collagen I (Col.I) in cyan and Collagen IV (Col.IV) in blue. c Relative expression of COL1A1, shown as Log2 fold change between the 5th and the 95th quantile and displayed on the spots, as analyzed by ST. d Corresponding IF images showing DAPI in magenta, CD45 in yellow and Collagen IV in cyan. e Light sheet fluorescence microscopy (LSFM) acquisition of an acute and a prolonged COVID-19 lung samples stained with the fibroblast marker ER-TR7 (yellow) (n = 4 samples). See also Supplementary Movie 1 and 2. Dot plot depicting the absolute cell numbers (f) and CD45+ cell counts (g) per field of view (FOV), which represent 665 ×665 µm, analyzed by multiplex microscopy. Data (M ± SD) are analyzed by one-way ANOVA with Fisher´s LSD test, F (3, 28) = 5.09, p = 0.006 (f), and F (3, 28) = 3.391, p = 0.03 (g). Various filled-symbols represent distinct donors. Source data are provided as a Source Data file. (d, f and g) (n = 32 FOVs). See also Supplementary Figs. 1 and 2.
