Figure 4. Comparison of the human and mouse TRM transcriptome.

(A) PCA was performed using RNA-Seq data presented here (black symbols) compared to mouse herpes simplex virus (HSV)-specific CD8⁺ TRM from skin and CD8⁺TEM from spleen (“mouse HSV”, yellow) and LCMV-specific CD8⁺TRM from intestine and CD8⁺TEM from spleen (“Mouse LCMV”, red) (Mackay et al. 2016). Left: PCA comparing whole transcriptomes of each dataset comprising 15571 common genes between human and mouse. Right: PCA comparing the core human gene signature (Fig. 3) to the mouse datasets. (B) Gene set enrichment analysis (GSEA) comparing our human CD8⁺ (left) and CD4⁺ (left) gene sets to published microarray data of CD103⁺ brain TRM vs. spleen TEM (top row), gut TRM vs. spleen TEM (middle row), and lung TRM vs. spleen TEM (middle row) (Wakim et al. 2012; Mackay et al. 2013). In each plot, the x-axis shows the genes ranked with absolute value of log fold change between TRM vs. TEM and y-axis shows running enrichment score (ES) comparing the ranked list of genes with indicated p values. (C) Comparison of Hobit gene expression in mouse and human datasets. Violin plots show Z score of gene expression levels from mouse TRM (from Mackay et al. 2016) and human CD69⁺ memory T cells (this study). Red dots represent Hobit, blue dots represent the housekeeping gene GAPDH, green dots represent CD69, and the white dot represents median gene expression.