Human umbilical cord derived mesenchymal stem cells promote interleukin‐17 production from human peripheral blood mononuclear cells of healthy donors and systemic lupus erythematosus patients

Summary Inflammation instigated by interleukin (IL)‐17‐producing cells is central to the development and pathogenesis of several human autoimmune diseases and animal models of autoimmunity. The expansion of IL‐17‐producing cells from healthy donors is reportedly promoted by mesenchymal stem cells derived from fetal bone marrow. In the present study, human umbilical cord‐derived mesenchymal stem cells (hUC‐MSCs) were examined for their effects on lymphocytes from healthy donors and from patients with systemic lupus erythematosus (SLE). Significantly higher levels of IL‐17 were produced when CD4 + T cells from healthy donors were co‐cultured with hUC‐MSCs than those that were cultured alone. Blocking experiments identified that this effect might be mediated partially through prostaglandin E 2 (PGE 2 ) and IL‐1β, without IL‐23 involvement. We then co‐cultured hUC‐MSCs with human CD4 + T cells from systemic lupus erythematosus patients. Ex‐vivo inductions of IL‐17 by hUC‐MSCs in stimulated lymphocytes were significantly higher in SLE patients than in healthy donors. This effect was not observed for IL‐23. Taken together, our results represent that hUC‐MSCs can promote the IL‐17 production from CD4 + T cells in both healthy donor and SLE patients. PGE 2 and IL‐1β might also be partially involved in the promotive effect of hUC‐MSCs.