Percent donor-derived chimerism in 1°LT and 2°LT recipients of BM-homed donor cells from irradiated or nonirradiated 1°ST recipients.
Irradiated or nonirradiated 1°ST recipients received 1-3 × 105 Sca-1+lin−CD62L− or Sca-1+lin−CD49e+ cells, killed 20 hours later, and 50 to 200 BM-homed donor cells were transplanted competitively into lethally irradiated 1°LT recipients. Percent donor-derived chimerism in 1°LT recipients 6 months after transplantation is shown in panel A, where bars represent mean ± SEM chimerism; n = 13 for irradiated, n = 5 for nonirradiated. In some experiments, 2-5 × 106 LDBM cells from 1°LT recipients 7 months after transplantation were transplanted without competition into lethally irradiated 2°LT recipients (panel B). In panel B, 1°LT recipients had received 50 or 100 BM-homed cells of Sca-1+lin−CD62L− origin. Data in panel B represent mean ± SEM chimerism; n = 3-5 mice at each time point. Data in both A and B were analyzed using repeated measures analysis of variance. *P < .05. Source of graft cells: ■ indicates irradiated 1°ST; ▪, nonirradiated 1°ST.
