Umbilical cord mesenchymal stem cells suppress B-cell proliferation and differentiation

Mesenchymal stem cells (MSCs) may be obtained from umbilical cord as an abundant and noninvasive source. However, the immunomodulatory properties of umbilical cord–MSCs (UC–MSCs) were poorly studied. In this study, we aimed to investigate the effects of UC–MSCs on B-cell proliferation and differentiation. UC–MSCs were found to suppress the proliferation of B cells isolated from murine spleen. Moreover, UC–MSCs markedly suppressed B-cell differentiation as shown by the decreased number of CD138 + cells and reduced levels of IgM and IgG production in coculture. As revealed by transwell experiments, soluble factors produced by UC–MSCs might be involved in mediating B-cell suppression. The Blimp-1 mRNA expression was suppressed whereas the PAX-5 mRNA expression was induced in coculture. Finally, UC–MSCs modified the phosphorylation pattern of Akt and p38 pathways, which were involved in B-cell proliferation and differentiation. These results may further support the potential therapeutic use of UC–MSCs in treating autoimmune disorders.