In the absence of conditioning, thymopoiesis by transplanted semiallogeneic BM progenitors is only sustained after intrathymic administration. ZAP-70−/− mice were transplanted with 2 × 105 semiallogeneic BM progenitors isolated from C57Bl/6JxCBA/J WT mice, in the absence of any preconditioning. Progenitors were administered by either intravenous or intrathymic routes. (A) Bar graph quantification of the percentages of CD45.1+ donor cells detected in the thymi of intravenous- and intrathymic-transplanted mice 28 weeks posttransplantation (mean ± SD). (B) The phenotype of donor thymocytes generated after intravenous and intrathymic transplantation of semiallogeneic progenitors was assessed by CD4/CD8 staining. Representative dot plots of transplanted mice, gated on donor thymocytes, as well as donor and recipient controls are shown. (C) Bar graph quantification of the percentages of donor cells (CD45.1+) in the LN of intravenous- and intrathymic-transplanted mice (mean ± SD; *P < .05). (D) The phenotype of donor cells in the periphery of transplanted mice was assessed by CD3/CD19 staining of lymph nodes. Dot plots show the phenotype of gated donor cells compared with WT and ZAP-70−/− controls. Data are representative of 3 independent experiments.
