Figure 5. Animals experiencing a return of transplantation tolerance can successfully develop protective immunity to a lethal challenge of Lm.

Tolerant (Tol) mice received a primary lethal (L) challenge of Lm (1.2 × 10⁷ CFU; 1° L-Lm, n=10) or a sublethal Lm infection on day 0 (D0) followed by graft rejection and subsequent re-infection with a secondary lethal Lm challenge (2° L-Lm) on D14 or D56 after the first infection (n=7–9 per group). Data are pooled from two independent experiments. (a) Experimental design. (b) Data are presented as percent animal survival after lethal Lm challenge (P<0.001 for 2° L-Lm on D14 or D56 compared with 1° L-Lm by log-rank test).