ELISPOT assay as a tool to study the effects of stem cells on cytokine secretion

Mesenchymal stem cells (MSCs) have many regulatory effects (e.g., T-cell suppression) on various immune cells. As aberrant T-cell activation is a primary cause of many diseases, understanding the underlying mechanisms of how MSCs exert immunosuppression is an important issue with potential therapeutic implications. A group of cytokines was shown to be involved as soluble mediators in the immunosuppressive effects of MSCs. An enzyme-linked immunospot (ELISPOT) assay is an ideal method to find potential mediators involved in the MSC-immunosupporessive pathway; additionally, the ELISPOT assay can measure changes in the full spectrum of cytokines produced during T-cell activation in the presence of MSCs. Here, we show that during a mixed lymphocyte reaction, interleukin-10 (IL-10)-secreting splenocytes increased in number in the presence of MSC-conditioned media; the increase in IL-10 levels in the supernatant was confirmed by an independent enzyme-linked immunosorbent assay (ELISA).