In vitro treatment of murine splenocytes with extracellular vesicles derived from mesenchymal stem cells altered the mRNA levels of the master regulator genes of T helper cell subsets.

Abstract

The purpose of the current study was to evaluate the effect of mesenchymal stem cells-derived extracellular vesicles (MSC-EVs) on the production of cytokines and expression of genes, which are corresponded to the subsets of T helper cells. The supernatant of the second passage of MSCs that had been isolated from C57BL/6 mice abdominal adipose tissue was used to collect the MSC-EV. Splenocytes of healthy mice were activated using anti-CD3 and anti-CD28 antibodies and simultaneously were treated using the MSC-EVs. The proliferation rate of lymphocytes and the frequency of regulatory T cells were measured using flow cytometry. In addition, the expressions of T helper cell subset-specific transcription factors were evaluated using a real-time PCR assay. To appraise the effects of MSC-EV on splenocytes, the levels of IFN-γ, IL-17A, IL-10, and TGF-β were measured using ELISA. The results showed that the treatment of the CD3/CD28-activated splenocytes with MSC-EV did not statistically change the proliferation of CD3+ splenocytes. However, after the treatment, the mRNA levels of Foxp3 and Elf4 as well as the frequency of regulatory T cells was significantly higher when compared to the control group. The expression levels of Gata3, Rorc, and Tbx21 were down-regulated while, the corresponding cytokines levels did not alter. The results revealed that the in vitro treatment of MSC-EV was associated with the increase in the frequency of CD4+CD25+FOXP3+ T cells and upregulation of Foxp3 mRNA level.