(a) (d) 2 ① Anergic Fixed genes APC IL-2 gene Fixed 2 A (b) Anergic Normal allogeneic genes Normal APC AP℃ 00 Fab B7 anti-CD28 (e) (c) Anergic T cell IL 2 gene Fixed Normal ② APC APC No response Anti-CD28 T细胞必须在双信号作用下才能活化的试验设计 T细胞必须在双信号作用下才能活化的试验设计