Influence of Adipose Mesenchymal Stem Cell-Derived Exosomes on the Th2/Treg Cells in Peripheral Blood of the Patients with Allergic Rhinitis and its Mechanism

Background At present, there are many therapeutic regimens for allergic rhinitis (AR), but their therapeutic effects are not better. Therefore, it is a focus to find new therapeutic targets by exploring AR immune regulation. Objective To explore the possible mechanism that adipose mesenchymal stem cell-derived exosomes (AMSC-exos) regulate the balance of Th2/Treg cells by mTOR pathway in AR patients. Methods Thirty patients with AR and 30 patients with deviated nasal septum alone were selected as AR group and control group. From each patient, 10 ml of peripheral blood were collected for determining the levels of blood plasma IL-4 and TGF- β as well as protein levels of p-PI3K (P85), p-AKT (Ser473), p-mTOR (Ser2448) and p-p70S6K (Thr389) in peripheral blood mononuclear cells (MCs) and the proportions of Th2 and Treg cells. And then MCs from AR patients were divided into two groups. One group was as AR cell group. Another group was co-cultured with AMSC-exos and served as AR cell + exos group. The levels of IL-4 and TGF- β in supernatant, the protein levels of p-PI3K (P85), p-AKT (Ser473), p-mTOR (Ser2448) and p-p70S6K (Thr389) in MCs and the proportions of Th2 and Treg cells were also determined. Results The levels of p-PI3K (P85), p-AKT (Ser473), p-mTOR (Ser2448) and p-p70S6K (Thr389), the IL-4 level and the proportion of Th2 cells were significantly higher in the AR group than in the control group (all P < 0.05). However, the levels of p-PI3K (P85), p-AKT (Ser473), p-mTOR (Ser2448) and p-p70S6K (Thr389), the IL-4 level and the proportion of Th2 cells were significantly lower in the AR cell + exos group than in the AR cell group (all P < 0.05). Conclusions AMSC-exos may regulate the balance between Th2 and Treg cells by PI3K/AKT/mTOR/p70S6K pathways in vitro.