Expression data from human T cell populations

Murine T cell populations have been described that are generated upon strong TCR activation, a process referred to as agonist selection. This murine population is phenotypically and functionally characterized and lacks coreceptors CD4 and CD8 (double negative or DN). The existence of a human equivalent of this population is not clear. We identified a population based on expression of PD-1, CD10 and lower expression of CD3 that shows characteristics resemblant of mouse DN T cells. Here, we perform transcriptional profiling of this particular PD-1+ T cell population in human thymus and cord blood and compare it to conventional CD8 T cells (that are PD-1 negative) as well as innate TCRgammadelta+ T cells. We purified PD-1- CD8+and PD-1+CD8+ populations from human donor post-natal thymus and cord blood as well as TCRgd+T cells from human post-natal thymus. Purification was based on ex vivo fluorescence-activated cell sorting (FACS) of mononuclear cell fractions obtained from donor samples. For each population 3 donors were used and obtained fractions were pooled for further analysis.