Fig. 2.

CD4 T cells express ATP-selective P2X and ADP-selective P2Y receptors. a P2 receptor mRNA levels in purified CD4 T cells were determined with qPCR using CD4 T cells isolated from healthy human subjects or Jurkat T cells (mean ± SD, n = 3; n.d., not detected). b Total protein expression of P2Y1 and P2Y12 receptors in human CD4 T cells before and after TCR/CD28 stimulation. The results shown are representative of n = 3 experiments with cells from different subjects. c–d Cell surface expression of P2Y1 and P2Y12 receptors on human CD4 T cells was assessed with flow cytometry before or 72 h after TCR/CD28 stimulation. Representative histograms (c) and summarized data (d) of unstimulated (n = 5) or stimulated (n = 4) cell preparations with cells from different donors are shown (*p < 0.05, Mann-Whitney test). e Polarized P2Y1 receptor expression and translocation to the immune synapse during T cell stimulation. The cell surface expression of P2Y1 and P2Y12 receptors on Jurkat T cells was analyzed with immunofluorescence imaging before and after stimulation of cells with anti-CD3/CD28 antibody-coated beads (indicated with asterisks) to mimic the formation of an immune synapse. Images are representative of separate experiments (n = 3) comprising at least 50 cells. Scale bar 10 μm; ×100 oil objective