Developing a Gene Expression Signature For T Cells Resident in Human Skin

Human skin contains various populations of memory T cells in permanent residence and in transit. The most well characterized subset of resident memory T cell is the CD8+ CD103+ T cell. In order to investigate the remaining subsets, we isolated skin-tropic helper T cells, T regulatory cells, and CD8+ CD103- T cells from skin and from blood by fluorescence activated cell sorting. We extracted RNA and performed a microarray analysis to compare the transcriptional profile of these groups. We found that despite expressing the same marker for skin tropism, the T cells of skin origin were significantly different from those from blood. Total RNA obtained from CLA+ Tregulatory cells, CLA+ helper T cells, and CLA+ CD8+ CD103- T cells isolated from human skin compared to CLA+ Tregulatory cells, CLA+ memory helper T cells, and CLA+ memory CD8+ T cells from human blood. 5 replicates of each; each replicate contains pooled cells from 3 subjects; total 15 subjects.