The effect of Actinomycin D and cycloheximide on death ligand expression levels on CD4+ T cells and HB1.F3. (A) Actinomycin D (Act D) abolished induction of Fas ligand (FasL) transcription on CD4+ T cells at 12 hours, but TRAIL has no differences in the co-culture period. (B), (C) Intracellular FasL expression levels on co-cultured CD4+ T cells and CD8+ T cells, and HB1.F3 without cycloheximide (CHX−) and with cycloheximide (CHX+). Intracellular FasL expression on CD4+ T cells and co-cultured HB1.F3 were reduced about 50% (46.91 vs. 22.43, 13.14 vs. 6.66 (B)). On the other hand, intracellular FasL of CD8+ T cells and co-cultured HB1.F3 were increased slightly (3.04 vs. 17.82, 1.38 vs. 5.16 (C)).