Ig production and gene expression of TFs involved in B cells to PC differentiation. (A) MBCs were cultured as described in Figure 1, and culture supernatants were harvested at day 4, day 7, and day 10 to assay for IgM, IgA, and IgG concentrations using nephelometry. The rate of Ig production per cell and per day was calculated by dividing the amount of Igs in the culture supernatant by the number of viable cells at the time of culture supernatant harvesting and by the number of days of culture. Data are the mean ± SD of the rates of Ig production determined in 5 separate experiments. *The rate of Ig productions is different from those at day 4. **The rate of Ig productions is different from those at day 7. (B) D0 MBCs, D4 actBCs, D7 PBs, and D10 PCs were FACS sorted, and the expression of PAX5, BCL6, IRF4, PRDM1, and XBP1 genes was evaluated by real-time RT-PCR. The gene expression in the different cell populations was compared assigning the arbitrary value 1 to the maximal expression. Data are the mean value ± SD of gene expression determined in 5 separate experiments. *The mean expression is different from that in D0 MBCs. **The mean expression is different from that in D4 actBCs. ***The mean expression is different from that in D7 PBs.