Bone Marrow Mesenchymal Stem Cells Enhance the Differentiation of Human Switched Memory B Lymphocytes into Plasma Cells in Serum-Free Medium

Figure 1

In vitro expansion of switched B lymphocytes in medium containing FBS or in serum-free medium. Five samples of switched memory B lymphocytes were cultured in the presence of IL-2, IL-4, and IL-10 and CD154⁺ cells (L4.5 cells) at a ratio of five B lymphocytes per L4.5. Cells were cultured in parallel in medium containing FBS or in serum-free medium. (a) and (b) show, respectively, the proliferation rate and viability of B lymphocytes after 12 days of culture. (c) The cells were kept in culture for 9 supplemental days to determine the secretion level of IgG and IgA. (d) Redox potential of cell culture supernatants (day 8) and media was measured on 5 independent samples. (e) The proportions of cells expressing CD38 and CD138 markers were determined on gated CD19⁺ B lymphocytes on day 12 ( indicates , unpaired Student’s -test). All data are from 5 independent experiments, except for the monitoring of CD31 and CD39 in (e), which was done on 4 independent samples. Data are presented as means ± SEM.

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