Fig. 4. IFN-γ produced by Th1 polarized CD4⁺ T cells activates macrophages in cutaneous sarcoidosis.

a UMAP projection of scRNA-seq data showing T cell clusters in sarcoidosis (shades of red) compared to healthy controls (grey). b Histograms showing contribution of each condition (sarcoidosis: shades of red, grey: controls) to each T cell cluster. c Volcano plot showing the most differentially expressed genes between CD4⁺ SAR-1 (clusters 2,7,12) versus CD4⁺ CTRL (clusters 0,5), corresponding to Fig. 4a. p value determined using Wilcon Rank-Sum test, two-tailed. d Heatmap showing expression of selected transcripts in CD4⁺FOXP3^- T cell clusters. e Histogram showing selected predicted upstream regulators of CD4⁺ SAR-1 clusters (2,7,12) versus CD4⁺ CTRL clusters (0, 5) as determined by IPA. Significance cutoff of p < 0.001 is shown by a dotted horizontal line and determined using Fisher exact test, right-tailed. f UMAP projection of scRNA-seq data showing myeloid cell clusters in sarcoidosis (shades of red) compared to healthy controls (grey). g Histograms showing contribution of each condition (sarcoidosis: shades of red, grey: controls) to each myeloid cluster. h Volcano plot showing the most differentially expressed genes between Mac SAR-1 (clusters 0,1,4,6,9,10) versus control myeloid (clusters 2,8,13). p value determined using Wilcon Rank-Sum test, two-tailed. i Heatmap showing expression of selected transcripts in myeloid clusters. j Histogram showing selected predicted upstream regulators in Mac SAR-1 and Mac SAR-2 (clusters 0,1,3,4,6,7,9,10,11) versus myeloid cells in controls (clusters 2,8,13) as determined by IPA. Significance cutoff of p < 0.001 is shown by a dotted horizontal line, as determined using Fisher exact test, right-tailed.