Human CD38^hiCD138⁺ Plasma Cells Can Be Generated In Vitro from CD40-Activated Switched-Memory B Lymphocytes

Figure 1

In vitro plasma cell generation and cytokine microenvironment. B lymphocytes were expanded for 19 days with IL-2, IL-4, and IL-10 at high interaction level with CD154. The same interleukin combination was used for the differentiation phase (filled symbols and bars) or the cells were cultured from day 19 with a combination of IL-6 and IL-10 (empty symbols and bars). The transition and differentiation phases lasted a total of 18 days with a low CD154 interaction. The results shown are the mean of 6 independent experiments. (a) Cell expansion, (b) cell viability, (c) IgG secretion rate in the differentiation environment, from D19 to D38, (d) IgG, A, and M secretion on day 33 supernatants, and (e) IgG subclasses secretion on day 33 supernatants. A significant difference was noticed in IgG1 secretion among the two interleukins combinations. Statistical analyses were done using the Bonferroni -test and the value was <0.05 (f) CD38 and CD38⁺CD138⁺ cells frequency. The IL-6-10 combination generated a larger CD38⁺ cell population on day 33, confirmed by a paired -test, value = 0.0188. All errors bars stand for SD and can be smaller than symbols.

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