Preventive Effects of a Human Hematopoietic Mesenchymal Stem Cell (hHMSC) Therapy in Ovalbumin-Induced Food Allergy

No effective therapeutic strategies have been developed against food allergies. Im-munomodulation during early infant period could prevent the development of food allergies. We investigated the preventive effects of human hematopoietic mesenchymal stem cells (hHMSCs) in mice with ovalbumin (OVA)-induced food allergy. BALB/c mice with OVA-induced food allergy were divided into 3 groups, and each group was treated with hHMSCs or hHMSC culture medium (hHMSC-CM) or saline. Ear thickness, allergy score, rectal temperature, and diarrhea occurrence were checked. Total IgE, OVA-specific IgE, and mucosal mast cell protease-1 (mMCP-1) were measured by ELISA. Other allergic parameters were analyzed using histology specimens, RT-PCR, and flow cytometry. Treatment with hHMSCs or hHMSC-CM significantly suppressed the frequency of anaphylactic response and rectal temperature decline, reduced diarrhea, total IgE, OVA-specific IgE, and mMCP-1. While the treatment decreased the level of Th2 cytokines, it enhanced IL-10 and TGF-β1 mRNA. Exposure to hHMSC or hHMSC-CM did not generate regulatory T cells, but reduced mast cells. The immunomodulatory effect on the Th2 cytokines was greater in hHMSC-CM than in hHMSCs. hHMSC treatment may be a promising preventive intervention against food allergy. Further studies are needed to elucidate the key substances released from hHMSC to induce immune tolerance.