Stability of T1 and T2 global cytokine polarity after syngeneic or allogeneic BMT. Ly5.1 B6 T1 and T2 populations were generated in vitro through CD3/CD28 costimulation and were injected into lethally irradiated syngeneic B6 or allogeneic CB6F1 hosts (n = 4 per treatment group). On day 5 after BMT, splenic cells were isolated and restimulated with CD3/CD28-coated beads for 24 hours. Resultant supernatants were evaluated for cytokine content using ELISA. Results shown are mean ± SEM for each treatment group.