Treatment of Atopic Dermatitis by Bone Marrow-derived Clonal Mesenchymal Stem Cells (119.3)

Mesenchymal stem cells (MSCs) can perform immunomodulatory activities, including suppression of T- and B-cell proliferation. MSCs have been primarily studied for their suppression of pro-inflammatory Th1 responses, but their therapeutic effects on atopic dermatitis (AD), which is a Th2-dominant disease, have not been reported. In this study, using an ovalbumin-induced mouse AD model, we investigated whether MSCs reduce the allergic inflammation in AD. We used mouse bone marrow-derived clonal mesenchymal stem cells (mcMSCs) isolated by our newly established isolation protocol termed the subfractionation culturing method (SCM). When injected intravenously into animals between antigen challenges, mcMSCs were found to inhibit the majority of AD-specific pathological changes by decreasing cell infiltration in skin lesions and reducing serum level of IgE. To explore the mechanism of this effect, we investigated the effects of mcMSCs on IgE production in B cells. We found that mcMSCs significantly inhibited IgE production when B cells were stimulated either by lipopolysaccharide (LPS) or anti-CD40 antibodies in the presence of interleukin (IL)-4. In addition, allogeneic mcMSCs can inhibit both isotype class switching and terminal differentiation of B cells probably by inhibiting NF-κB activation. These results suggest that mcMSC-based cell therapy is a promising therapeutic modality for AD treatment.