Enhanced IL-2 sensitivity of Tregs
Human PBMCs were stained with Alexa Fluor® 647 Anti-Human CD127 antibody during a 15-minute stimulation with 0-, 0.01-, 0.1-, 1-, 10-, or 100-ng/mL doses of recombinant human IL-2. Cells were fixed using BD Cytofix fixation buffer, permeabilized using BD Phosflow perm buffer III, and stained with fluorescent antibodies specific for Stat5 (pY694), CD4, CD8, and CD25. Samples were acquired using a BD LSRFortessa™ flow cytometry system and analyzed using Cytobank software. CD4 T-cell subsets were identified as shown. Compared to other T cells, Tregs phosphorylate Stat5 in response to much lower concentrations of IL-2.