Effects Of Regulatory Dendritic Cells On The Airway Inflammation And Expression Of IL-12and Immunoglobulin E In Mice With Asthma

Dendritic cells (DC) is known the most powerful antigen-presenting cells (APC)in vivo, which not only can activate T cells and initiate the immuneresponse, but alsohavethe ability of regulating the immune response strength and inducting the immunetolerancerole. Our preliminary experiments confirmed that mature dendritic cells (mDC)in the lung matrix microenvironment can be induced to an immune phenotype ofCD11clowIalowCD11bhighregulatory dendritic cells (DCreg, rDC). This rDC is lack ofimportant signals (Ia, IL-12p70) which can activate T cells, but the hypersecrete Th2cellfactor IL-10which can inhibit the growth of immature DC mature. And we found, bytesting the MTT, the DCreg induced by allogeneic T cell proliferation was significantlylower than that in mDC group. From the above DCreg phenotype, cytokine secretion andfunction features we hypothesize that DCreg can induce immune tolerance. Bronchialasthma is a kind of chronic inflammatory airway diseases which mast cells,eosinophils,T lymphocytes and other cells, inflammatory factors are involved in. Itspathogenesis is relation to effects of T (CD4+T) cell activation and secretion of variouscytokines, leading to Th1and Th2imbalance.We confirmed the role of the DCreg inalleviating airway inflammation and the expecting of IL-12and IgE in asthmaticmice through experiments. The completion of this experiment provides a theoretical basisand clinical application by inducing specific immune tolerance to the treatment orprevention of respiratory allergic diseases.ObjectivesTo investigate the effects of regulatory dendritic cells which generated by co-cultureof pulmonary stromal cells supernatant and mature dendritic cells on the airwayinflammation and IL-12、IgE in a murine model of asthma, and to elucidate the possiblemechanism of regulatory dendritic cells in the induction of immune tolerance, and thereby- to provide new thoughts for the clinical prevention and treatment of asthma.Methods(1) Prepairation of regulatory dendritic cells (2) C57BL/6mice were divided into4groups,10in each group. On day21, all mice were sacrificed. The effects of rDC on theairway inflammation were studied.ResultsInfiltration of inflammatory cells into the lung and proportion of eosinophils(Eos)were notably reduced and high expression of Th1type cytokine interleukin(IL)-12and lowexpression IgE by injection of rDC than the asthma control group(P<0.01).ConclusionsInoculation of regulatory dendritic cells was a potential method to inhibit airwayinflammation in mice models, which is in relation to high expression Th1type cytokineinterleukin(IL)-12and low expression IgE.