Anti-GARP:TGF-β1 mAbs induce an IFNγ signature in murine PMF. (A) MPL^W508A/GFP⁺ WBC counts on day 34 in mice from experiment in Figure 2. Data points: individual mice; horizontal lines: median + SEM per group. MPL^W508A mice responding to 58A2 (n = 5, blue symbols) are defined as mice with a low tumor burden (cut-off: median MPL^W508A/GFP⁺ WBC counts in the 58A2 group). Controls correspond to nontreated (mIgG2a) MPL^W508A mice with a high tumor burden (n = 7, orange symbols). (B) GSEA of RNAseq data from spleens collected from MPL^W508A mice on days 13, 20, or 34. White bars: ES of the indicated signatures in the list of transcripts ordered by mean fold-change between day 20 and 13 in nontreated controls. Black bars: ES in transcripts ordered by mean fold-change between 58A2 responders and non-treated controls. Green bars: FDR obtained by calculating ES for 1000-gene-set permutations. Right panel shows representative GSEA plots, with black vertical bars indicating position of genes from various gene sets in the ordered transcript list for the responder vs control comparison. EMT, epithelial mesenchymal transition. (C) Heatmap representation of the expression of genes in the leading edge of the IFNγ response signature. Each row represents a gene and each column a mouse. Black boxes on the right indicate genes that are also present in IFNα response signature. (D) Correlation between expression of IFN-induced genes by RNAseq analysis and number of MPL^W508A/GFP⁺ WBCs in all mice.