Determination of the acquisition and frequency of alloreactive T cells in T1 and T2 recipients. (A, B) On day 5 after syngeneic (CB6F1 → CB6F1) or allogeneic (Ly5.1 B6 → CB6F1) BMT, splenic cells were obtained and restimulated in vitro for 24 hours in the presence of either syngeneic B6 or allogeneic CB6F1 DC (10:1 T cell/DC ratio). The restimulated T cells were harvested and stained for either surface CD4 (A) or CD8 (B) in combination with a bispecific antibody specific for CD45 and IFN-γ capture. Results shown are the mean ± SEM of each treatment group (n = 5) and culture condition. Results for IL-4 capture assay were negative for each condition.