The effects of hyperthermia on the immunomodulatory properties of human umbilical cord vein mesenchymal stem cells (MSCs)

Purpose: Hyperthermia can modulate inflammation and the immune response. Based on the recruitment of mesenchymal stem cells (MSCs) to inflamed tissues and the immunomodulatory properties of these cells, the aim of this study was to examine the effects of hyperthermia on the immunomodulatory properties of MSCs in a mixed lymphocyte reaction (MLR).

Materials and methods: Passages 4–6 of human umbilical cord vein mesenchymal stem cells were co-cultured in a two-way MLR. Cells in the hyperthermia groups were incubated at 41?°C for 45?min. A colorimetric assay was employed to examine the effects of MSCs on cell proliferation. The levels of IL-4 and TNF-α proteins in the cell culture supernatant were measured, and non-adherent cells were used for RNA extraction, which was then used for cDNA synthesis. RT-PCR was utilised to assess levels of IL-10, IL-17A, IL-4, TNF-α, TGF-β1, FOX P₃, IFN-γ, CXCL12 and β-actin mRNA expression.

Results: UCV-MSCs co-cultured in an MLR reduced lymphocyte proliferation at 37?°C, whereas hyperthermia attenuated this effect. Hyperthermia increased expression of IL-10, TGF-β1 and FOXP3 mRNAs in co-culture; however, no effects on IL-17A and IFN-γ were observed, and it reduced CXCL12 expression. In co-culture, IL-4 mRNA and protein increased at 37?°C, an effect that was reduced by hyperthermia. No considerable change in TNF-α mRNA expression was found in hyperthermia-treated cells.

Conclusion: Hyperthermia increases cell proliferation of the peripheral blood mononuclear cells and modifies the cytokine profile in the presence of UCV-MSCs.