Epithelial and Mesenchymal Stromal Cells From the Amniotic Membrane: Both Potent Immunomodulators

Abstract Different in vitro and in vivo studies have demonstrated that cells isolated from the amniotic membrane possess broad immunomodulatory activities. Indeed, both amniotic epithelial cells (hAECs) and amniotic mesenchymal stromal cells (hAMSCs) suppress B cell and T cell proliferation, generation of Th1, Th17, and cytotoxic T cells, and production of inflammatory cytokines. Moreover, both hAMSCs and hAECs suppress inflammatory activities of monocytes, macrophages, dendritic cells, neutrophils, and natural killer cells, while promoting the induction of cells with regulatory functions such as regulatory T cells and antiinflammatory M2 macrophages. Increasing evidence shows that these immunomodulatory properties are the mechanism through which amniotic cells can exert the therapeutic effect observed in the preclinical setting of diseases characterized by an exacerbated inflammatory response. In this chapter, we will comprehensively review in vitro and in vivo studies of the immunomodulatory properties of hAECs and hAMSCs and discuss differences between the two cell populations.