Fig. 2. Allograft rejection in adoptive hosts of CD8 T_CM and T_EM.

Sorted CD8 T_CM (1.5 × 10⁶ – 2 × 10⁶) or T_EM (0.4 × 10⁶ – 0.6 × 10⁶) containing similar numbers of BALB/c-reactive IFNγ⁺ T cells were transferred into wt and aly/aly-spleen adoptive hosts followed by BALB/c-skin transplantation 2-days later. (A) Skin allograft rejection mediated by CD8 T_CM and T_EM in wt hosts. BALB/c-skin allograft survival was tested in wt recipients of CD8 T_CM or T_EM and compared to unimmunized naïve mice (Naïve, no cells) and sensitized mice (Sensitized, no cells) harboring endogenous memory T cells that had rejected BALB/c-skin allografts 8 – 12 weeks earlier (n = 3 – 4 mice/grp). (B) Skin allograft rejection mediated by CD8 T_CM and T_EM in wt hosts treated with co-stimulation blockade. Wt recipients of CD8 T_CM or CD8 T_EM, unimmunized naïve mice (Naïve, no cells) and sensitized mice (Sensitized, no cells) were treated with CTLA4-Ig and anti-CD40L, 0.25mg each (i.p.), on day 0, 2, 4 and 6 after BALB/c-skin transplantation and allograft survival was compared (n = 4 – 6 mice/grp). (C) Skin allograft rejection mediated by CD8 T_CM and T_EM in aly/aly-spleen hosts. Aly/aly-spleen recipients of CD8 T_CM or CD8 T_EM or unfractionated CD8 memory T cells (1 × 10⁶) (CD8 memory) and aly/aly-spleen naïve mice without memory T cell transfer (Naïve, no cells) underwent BALB/c-skin transplantation and allograft survival was compared (n = 4 – 7 mice/grp).