Figure 5.
Osx+ Cell Controls B Lymphopoiesis through a Microenvironment-Dependent Effect
(A–F) Transplantation of wild-type cells into mutant hosts. 1 × 106 total bone marrow cells from wild-type congenic SJL mice (CD45.1) were transplanted into lethally irradiated control or mutant OsxCre;iDTR recipients (CD45.2). (A) A similar rate of reconstitution was seen in both control and mutant groups. (B–F) As wild-type hematopoietic cells repopulated the new hosts over the next 12 weeks, we observed a gradual re-creation of the OsxCre;iDTR mutant hematopoietic phenotype in the mutant recipients but not in the control group.
(G–L) Transplantation of mutant cells into wild-type hosts. Bone marrow cells (5 × 105) from either control or mutant OsxCre;iDTR mice were competed with wild-type 5 × 105 SJL bone marrow competitors in a 1:1 ratio, and transplanted into lethally irradiated SJL hosts. (G) No functional disadvantage was seen in reconstitution when OsxCre;iDTR mutant cells competed with wild-type cells. (H–L) When hematopoietic cells from OsxCre;iDTR mutant donors were placed into a wild-type microenvironment, the hematopoietic defect was normalized over time.
Two independent experiments; n = 10/group/experiment. ∗p < 0.05, ∗∗p < 0.01. Error bars represent ± SEM.