Requirement for Early KL and FL Activation for Optimal ProB-Cell Formation From Lin−/loSca1+c-kit+flt3−Cells
| Cytokines . | No. of B220+ Cells Produced per Lin−/loSca1+c-kit+flt3−Cell . | |
|---|---|---|
| 0 to 40 Hours . | 40 Hours to 12 Days . | |
| Medium | KL + FL + IL-7 | 3 (2) |
| KL | KL + FL + IL-7 | 56 (30) |
| FL | KL + FL + IL-7 | 23 (12) |
| KL + FL | KL + FL + IL-7 | 289 (40) |
| Cytokines . | No. of B220+ Cells Produced per Lin−/loSca1+c-kit+flt3−Cell . | |
|---|---|---|
| 0 to 40 Hours . | 40 Hours to 12 Days . | |
| Medium | KL + FL + IL-7 | 3 (2) |
| KL | KL + FL + IL-7 | 56 (30) |
| FL | KL + FL + IL-7 | 23 (12) |
| KL + FL | KL + FL + IL-7 | 289 (40) |
Lin−/loSca1+c-kit+flt3−cells were preincubated in serum-depleted medium alone or in the presence of KL, FL, or KL + FL for 40 hours before being supplemented with KL + FL + IL-7 for the rest of the 12-day culture period. After a total of 12 days cells were harvested, counted, and analyzed for the expression of B220. The data represent the mean (±SEM) from 4 individual experiments.