IL-23 stimulation of peripheral blood lymphocytes activates STAT proteins with inter-individual variability in IL-23 responsiveness.

<p>Peripheral whole blood was stimulated with 100ng/ml IL-23 for 15 minutes and IL-23-mediated pSTAT induction was assessed by phospho-flow assays for STAT1, 3, 4 and 5. (A) IL-23-mediated pSTAT induction in CD8+CD45RO+ memory T cells. Gray line and black lines represent pSTAT in un-stimulated and IL-23 stimulated samples, respectively. (B) IL-23-mediated pSTAT3 induction in CD8+ naïve (CD45RO-) and memory (CD45RO+) T cells, NK cells (CD3−CD56+), and NKT (CD3+CD56+) cells. (C) Representative individuals showing low (subject #1) or high (subject #2) IL-23 responsiveness.