Upregulation of FasL expression on CD8+ T cells. A cell suspension containing 6 × 107 B6.SJL T cells was injected into unirradiated B6AF1 recipients. (A) Increased FasL expression on donor (Ly5.1+) CD8+ T cells on day 8. Cells were first labeled with hamster anti-FasL antibody, then with biotin-coupled goat antihamster antibody, and lastly with PE-conjugated streptavidin together with FITC-labeled anti-Ly5.1 and Cy-chrome–labeled anti-CD4 or anti-CD8 antibodies; only the last two steps were performed in staining control. FasL staining is represented by a shaded histogram and staining control as a clear histogram. The value shown in each box represents the specific staining of FasL+ cells. Results from one representative experiment of three are shown. (B) Time course evaluation of FasL expression. Mean ± SD, N = 3. **P < .01, ****P< .001 relative to control.
