Modeling transplantation of multiple allogeneic progenitors. (A) Cell dose titration by survival assay in congenic mouse transplantation. C57BL/6 (B6-Ly5.2, H2b) mice received cell grafts; congenic B6-Ly5.1 mice (H2b) were principal donors. Recipient mice were transplanted with the indicated dose of KSL cells after lethal irradiation (4.9 Gy × 2). A Kaplan-Meier plot shows recipient survival rates. n = 5 in each group. Data were analyzed by log-rank testing. P = 0.0026. P < 0.008, Bonferroni-corrected threshold, was considered statistically significant. *, P < indicated Bonferroni-corrected threshold. (B) Kaplan-Meier plot showing survival rates of recipient B6 mice transplanted with the indicated grafts. n = 6 in each group. (C) A model of transplantation using multiple-donor–derived KSL cells. Recipient mice are B6-Ly5.2; principal donor mice are B6-Ly5.1. The four allogeneic mouse strains shown are used as additional graft donors. (D) Kaplan-Meier plot showing survival among mice transplanted with congenic KSL 2,500 cells (red) and with mixed allogeneic KSL 2,500 cells (blue). P < 0.05 was considered statistically significant. ns, not significant. n = 6 in each group. (E) Results of complete blood counts in PB from recipients transplanted with congenic KSL 2,500 cells (red) and with mixed allogeneic KSL 2,500 cells (blue) at indicated times. Mann-Whitney testing was used for statistical analysis. Mean values are indicated as bars. P < 0.05 was considered statistically significant. n = 6 in each group. (F) Percentages of peripheral donor granulocyte and BM chimerism in individual recipients after transplantation. n = 6 in each group (some death observed at 24 wk). Mean values are indicated as bars. Representative data are shown from at least two independent experiments for each panel.