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

Abstract

B lymphocyte differentiation into long-lived plasma cells is the keystone event for the production of long-term protective antibodies. CD40-CD154 and CD27-CD70 interactions are involved in human B lymphocyte differentiation into CD38hiCD138+ cells in vivo as well as in vitro. In this study, we have compared these interactions in their capacity to drive switched-memory B lymphocytes differentiation into CD38hiCD138+ plasma cells. The targeted B lymphocytes were isolated from human peripheral blood, expanded for 19 days, and then submitted to CD70 or CD154 interactions for 14 days. The expanded B lymphocytes were constitutively expressing CD39, whereas CD31's expression was noticed only following the in vitro differentiation step (day 5) and was exclusively present on the CD38hi cell population. Furthermore, the generated CD38hiCD138+ cells showed a higher proportion of CD31+ cells than the CD38hiCD138− cells. Besides, analyses done with human blood and bone marrow plasma cells showed that in vivo and de novo generated CD38hiCD138+ cells have a similar CD31 expression profile but are distinct according to their reduced CD39 expression level. Overall, we have evidences that in vitro generated plasma cells are heterogeneous and appear as CD39+ precursors to the ones present in bone marrow niches.

Theoretical Explanation for the Rarity of Antibody-Dependent Enhancement of Infection (ADE) in COVID-19

“…Parameters for the antigen–antibody complex formation were obtained from the average values for binding with monoclonal antibodies [ 59 ]. The ranges for time lags t memory and t naive were calculated from known data on lymphocyte physiology [ 60 , 61 ] and experimental results [ 34 ] (see Text S1 for the calculation details).…”

Integrated single-cell (phospho-)protein and RNA detection uncovers phenotypic characteristics of human antibody secreting cells

“…We adopted an in vitro differentiation protocol of human peripheral B-cells to generate human ASCs ( 6–8 ). Isolated B-cells from healthy donors were stimulated with CpG for 1 day.…”

“…Human PCs only represent ∼0.25% of total bone marrow cells and home to different tissues in the human body, making extensive molecular analysis and functional studies challenging ( 5 ). Protocols for in vitro differentiation of human peripheral B-cells into ASCs ( 6–8 ) form the basis for phenotypic and functional studies ( 9, 10 ). Studies in mice have shown divergent gene expression profiles for the different Ig class PCs ( 11 ) and different expression profiles were observed comparing human class-switched germinal center (GC) B-cells from human tonsils as compared to non-class switched cells ( 12 ).…”

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

“…B lymphocytes were pushed into differentiation in BPFM using a simple three-step model involving a shift in the L4.5 : B-cell ratio and modifications of cytokines, as previously described [47] (Figure 2(a)). As previously observed, CD38 and CD39 expression rapidly increased following B-cell activation (Figure 2(b), D8).…”

“…In our model, the source of B lymphocytes is also peripheral blood, but the selection method we use includes CD27 − IgG- and IgA-positive cells [49] and excludes CD27 + IgD + IgM + cells [64], which are, respectively, absent and present in Jourdan and Cocco culture systems. Our culture model was initiated by an 8-day expansion step generating CD40-activated memory B lymphocytes [47, 65]. The expansion rate we obtained was at least 20-fold; that is, starting with 1 × 10 6 switched memory B lymphocytes on day 0, we could generate up to 20 × 10 6 cells.…”