Study on the Mechanisms of Modulatory Effects of Mesenchymal Stem Cells on Airway Inflammation in Murine Model of Asthma

Asthma is one of the most common allergic diseases in children and its prevalence has been increased in recent decades. Allergic asthma is characterized by the induction of T helper 2 cells, airway hyperresponsiveness, eosinophil infiltration, increased mucus secretion and even airway remodeling. Mesenchymal stem cells (MSCs) are a self-renewing population of multipotent stem cells present in bone marrow and can differentiate into a variety of tissues or cell lineages. Recent studies have demonstrated that MSCs could exert an immunosuppressive function. This study was performed to investigate whether MSCs could inhibit OVA-induced allergic airway inflammation in murine model. First, MSCs were isolated from mouse bone marrow, characterized by their phenotypes, and differentiated into osteocytes and adipocytes in the appropriate induction media. In addition, the immunosuppressive function of MSCs was determined in vitro. The results indicated that MSCs exerted effectively inhibitory effect on the proliferation of lymphocytes under ConA stimulation or the mixed lymphocyte reaction. Furthermore, to investigate the effect of MSCs on the allergic asthma, the female BALB/c mice were sensitized with ovalbumin (OVA) by intraperitoneal injection, 1×106 MSCs were injected intravenously before each OVA challenge. In the study, we found that the airway hyperresponsiveness, eosinophilic inflammation in bronchoalveolar lavage fluid, and OVA-sprcific IgE in serum were diminished after MSCs administration. Additionally, MSCs delivered in mice not only inhibited the proliferation of OVA-specific lymphocytes but also increased the levels of IL-10 and IFN-γ. Therefore, we demonstrated that administration of MSCs could alleviate airway inflammation in OVA-induced murine model of asthma. In the future, it will be interesting to clarify the immunomodulatory mechanisms of MSCs.