Intranasal delivery of mesenchymal stem cell exosomes modulates the immune response of allergic rhinitis via the MAPK pathway in a mouse model

Background: Allergic rhinitis (AR) is a non-infectious chronic inflammatory disease of the nasal mucosa, which is mainly mediated by IgE after the body is exposed to allergens. It has been shown that transplantation of human mesenchymal stem cells (MSCs) into AR animal models can improve the AR behavioral phenotype. Furthermore, there are recent studies that states exosomes are the main mediators of MSC therapy. However, the effect of exosomes on AR has not been investigated. Methods: In the established AR mouse model, different concentrations of MSC-derived exosomes (MSCs-Exo) were applied via intranasal delivery. The AR symptom scores, the eosinophils in the nasal mucosal section, the inflammation infiltration in the spleen section, and IgE, ovalbumin-specific IgE (OVA-sIgE), histamine, IgG1, IgG2a and other Th1/Th2 related inflammatory factors were evaluated by Hematoxylin–eosin staining, Elisa, real-time PCR. Results: We found that intranasal administration of MSCs-Exo could not only reduce the behavior of nasal scratching and sneezing in mice, but also cause a decline in related immune indicators via the MAPK pathway, including the spleen index, tissue staining, and the expression of inflammation-related cytokines. Moreover, we found that the optimal concentration of MSCs-Exo was 4×10 8 /mL. Conclusion: The significant beneficial effects of exosomes may be exploited to develop a new, non-invasive treatment strategy for AR.