Human Amniotic Fluid Stem Cells Exert Immunosuppressive Effects on T Lymphocytes in Allergic Rhinitis

The study aims to investigate the immunomodulatory effect of Amniotic fluid stem (AFS) cells to Th2-skewed allergic rhinitis (AR) on T-lymphocyte proliferation, viability, activation and cytokine production.

AFS cells can suppress peripheral blood mononuclear cells (PBMCs) proliferation and display immunomodulatory properties, but AFS cells' immunoregulation on AR has not been defined.

Human AFS cells were derived from magnetic cell sorting and co-cultured with PBMCs from AR patients stimulated by phytohemagglutinin (PHA). The AFS cells-associated suppressive proliferation was analyzed using CellTrace™ Violet assay; the T lymphocytes proliferation, viability, activation and the Foxp3⁺ Treg cells were determined by flow cytometry; cytokine levels were measured using an enzyme- linked immunosorbent assay.

We determined that AFS cells significantly inhibited PHA-induced CD3⁺ T lymphocyte proliferation at the ratio higher than 1:50 (AFS cells: PBMCs) (P<0.05); AFS cells obviously increased the T lymphocytes viability (P<0.01), inhibited the apoptosis of T lymphocytes (P<0.001), compared to PBMCs alone; AFS cells suppressed CD3⁺CD25⁺ T lymphocytes activated by PHA (P<0.05); AFS cells significantly promote Treg cells expansion in house dust mite (HDM)-stimulated PBMCs from AR patients (P<0.05). Compared with HDM-stimulated PBMCs, AFS cell co-culture predominantly decreased IL-4 level (P<0.05), but increased IFN-γ and IL-10 levels (P<0.01).

AFS cells modulate the T-cells' immune imbalance towards Th2 suppression in AR, which can be used as a new cell banking for allergic airway diseases.