B-lineage cells harvested from FTOC do not respond to bone marrow stromal cell signals
| Week after seeding on S17 stroma . | Frequency of CD45R+cells . | ||||
|---|---|---|---|---|---|
| S17 stroma (× 104) . | FTOC S17 stroma (× 104) . | ||||
| d2 | d7 | d11 | d16 | ||
| 1 | 11.8 | 3.9 | 1.9 | 0.3 | ND |
| 2 | 6.6 | 4.7 | < 0.2 | 5.7 | ND |
| 3 | 11.1 | 28.1 | < 0.1 | 0.6 | < 0.1 |
| Week after seeding on S17 stroma . | Frequency of CD45R+cells . | ||||
|---|---|---|---|---|---|
| S17 stroma (× 104) . | FTOC S17 stroma (× 104) . | ||||
| d2 | d7 | d11 | d16 | ||
| 1 | 11.8 | 3.9 | 1.9 | 0.3 | ND |
| 2 | 6.6 | 4.7 | < 0.2 | 5.7 | ND |
| 3 | 11.1 | 28.1 | < 0.1 | 0.6 | < 0.1 |
CD45R+ sIgM− cells were isolated from the bone marrow. Aliquots of 5 × 104 cells from this pool were used to establish long-term cultures on S17 stroma (“S17 stroma”) or to seed FTOC. Following 2, 7, 11, or 16 days of incubation in these FTOCs, cells were harvested and reseeded on S17 stroma (“FTOC → S17 stroma”). At weekly intervals for 3 weeks thereafter, cells were harvested from the cultures and examined for CD45R+ expression by flow cytometry. Data are representative of 5 independent experiments. ND indicates that no cells were harvested, as too few cells were present in the cultures.