Adult enriched BMSCs support plasmablast survival. (A-C) Purified PBs (5 × 103) were added on adult enriched BMSCs or 2-week enriched BMSCs, or incubated with medium or IL-6. (A) The viability of recovered cells was analyzed by FACS 48 hours after culture using propidium iodide exclusion. Results are expressed as the mean (± SD) of 4 independent cultures per condition. *P < .05 versus 2-week enriched BMSCs. **P < .05 versus medium. (B) FACS panels for expression of B220 and CD138 for one culture per each condition representing 4 independent cultures. Percentages of each subset gated on live cells are shown on the plots. (C) Percentage of each subset gated on live cells determined by FACS staining as described in panel A. Results are expressed as the mean (± SD) of 4 independent cultures per each condition. *P < .05 versus 2-week enriched BMSCs. **P < .05 versus medium. (D) The expression of Bcl-XL and Blimp-1 by PBs was evaluated by quantitative real-time RT-PCR at onset (ex vivo) and after 24 hours of culture. Results are expressed as the fold change of transcript expression for each condition of culture compared with t0 (mean ± SD) obtained from 3 independent cultures each representing a pool of 10 mice. *P < .05 versus 2-week enriched BMSCs. **P < .05 versus medium.
