Amniotic Membrane Mesenchymal Cells-Derived Factors Skew T Cell Polarization Toward Treg and Downregulate Th1 and Th17 Cells Subsets

Abstract

We previously demonstrated that cells derived from the mesenchymal layer of the human amniotic membrane (hAMSC) and their conditioned medium (CM-hAMSC) modulate lymphocyte proliferation in a dose-dependent manner. In order to understand the mechanisms involved in immune regulation exerted by hAMSC, we analyzed the effects of CM-hAMSC on T-cell polarization towards Th1, Th2, Th17, and T-regulatory (Treg) subsets. We show that CM-hAMSC equally suppresses the proliferation of both CD4+ T-helper (Th) and CD8+ cytotoxic T-lymphocytes. Moreover, we prove that the CM-hAMSC inhibitory ability affects both central (CD45RO+CD62L+) and effector memory (CD45RO+CD62L−) subsets. We evaluated the phenotype of CD4+ cells in the MLR setting and showed that CM-hAMSC significantly reduced the expression of markers associated to the Th1 (T-bet+CD119+) and Th17 (RORγt+CD161+) populations, while having no effect on the Th2 population (GATA3+CD193+/GATA3+CD294+cells). T-cell subset modulation was substantiated through the analysis of cytokine release for 6 days during co-culture with alloreactive T-cells, whereby we observed a decrease in specific subset-related cytokines, such as a decrease in pro-inflammatory, Th1-related (TNFα, IFNγ, IL-1β), Th2 (IL-5, IL-6), Th9 (IL-9), and Th17 (IL-17A, IL-22). Furthermore, CM-hAMSC significantly induced the Treg compartment, as shown by an induction of proliferating CD4+FoxP3+ cells, and an increase of CD25+FoxP3+ and CD39+FoxP3+ Treg in the CD4+ population. Induction of Treg cells was corroborated by the increased secretion of TGF-β. Taken together, these data strengthen the findings regarding the immunomodulatory properties of CM-hAMSC derived from human amniotic membrane MSC, and in particular provide insights into their effect on regulation of T cell polarization.

TNF-α modulates the immunosuppressive effects of MSCs on dendritic cells and T cells

“…Also, MSCs induce trimethylation at promoter of Foxp3 resulting to suppress of ROR-C trimethylation through IL-10 production. These evidence lead to decrease T H 17 as well as increase of Treg frequencies [26]. Enhanced immune suppressive effects of IFN-γ treated MSCs are partially associated to induce of IDO and PGE2 production in MSCs by IFN-γ.…”

Conditioned medium derived from rat amniotic epithelial cells confers protection against inflammation, cancer, and senescence

“…Human AECs exert immunomodulatory effects on lymphocytes by fostering the Th2 anti-inflammatory phenotype over Th1, both by acting directing with lymphocytes and through the conditioned medium, which contains secreted factors [36]. Amniotic cells dose-dependently inhibit the proliferation of activated peripheral blood mononuclear cells (PBMCs) [10, 19], but only few studies have focused on the effects of AECs on macrophages [37, 38, 39].…”

Immunomodulatory oligonucleotide IMT504: Effects on mesenchymal stem cells as a first-in-class immunoprotective/immunoregenerative therapy

“…Abundant information has been published on the relationship between MSC 2 and resolution of the inflammatory setting, and tissue protection and repair[24-34]. Some of the well-known anti-inflammatory effects mediated by MSC 2 are skewing macrophages to the M2 immunosuppressive alternative phenotype[35-41], promoting T cells to T regulatory (T reg ) cell differentiation[42-48], skewing monocyte-derived dendritic cells to a regulatory phenotype[49-54], inhibiting neutrophil influx and respiratory burst while maintaining or even increasing its phagocytic capacity[55-59], inhibiting mast cell degranulation[60-62], and inhibiting pro-inflammatory activities of T cells[63-72], natural killer (NK) cells[73-79] and B cells[80-84]. Furthermore, throughout the numerous reports describing the regulatory role of MSCs attenuating (at some point) inflammation, several intercellular molecular signals have consistently emerged as relevant.…”