Effect of Rac1 carboxy-terminal peptide treatment on T-cell cytokine production. Splenocytes obtained from mice (n = 6) on day 19 following priming with bovine collagen type II in complete Freund's adjuvant were preincubated for 15 minutes with Ctrl or Rac1 peptide (200 μg/mL) and stimulated for 24 hours with anti-CD3 and anti-CD28 antibodies. Brefeldin A was included for the last 4 hours of stimulation, and cells were stained for CD3, CD4, CD8, interleukin (IL)-2, tumor necrosis factor-alpha (TNFα), interferon-gamma (IFNγ), and IL-17. The percentages of CD3+CD4+ and CD3+CD8+ T cells expressing each cytokine were determined by fluorescence-activated cell sorting analysis. Data points within each column represent values obtained from splenocytes of individual mice, and the bar indicates the median value. *P ≤ 0.05. Ctrl, control.