CD38 gene-modified dendritic cells inhibit murine asthma development by increasing IL-12 production and promoting Th1 cell differentiation

Predominant T helper (Th)2 and impaired Th1 cell polarization has a crucial role in the development of asthma. Cluster of differentiation (CD) 38 is associated with the increased release of interleukin (IL)-12 from dendritic cells (DCs) and DC-induced Th1 cell polarization. However, whether CD38 expression affects DC function in asthma development remains unknown. In the current study, adenoviruses were constructed containing the murine CD38 gene. Overexpression of CD38 protein level in DCs induced from bone-marrow derived DCs (BMDCs) by recombinant mouse granulocyte macrophage colony-stimulating factor and IL-4 was achieved through 24 h adenovirus infection. The results demonstrated that BMDCs with CD38 overexpression exhibited no phenotypic change; however, following stimulation with lipopolysaccharide (LPS), maturation and IL-12 secretion were increased. In addition, CD38-overexpressing BMDCs stimulated with LPS exhibited more effective Th1 cell differentiation. Mice that were administered CD38-overexpressing BMDCs exhibited milder symptoms of asthma. Furthermore, decreased IL-4, IL-5 and IL-13 levels were detected in bronchoalveolar lavage fluid (BALF), reduced immunoglobulin E levels were measured in the sera, and increased interferon-gamma was detected in BALF from the recipients of CD38-overexpressing BMDCs. Increased phosphorylated-p38 expression was also detected in LPS-stimulated CD38-overexpressing BMDCs, whereas pretreatment with a p38-specific inhibitor was able to abolish the effects of LPS stimulation and CD38 overexpression on IL-12 release and Th1 cell differentiation in BMDCs. These results suggested that CD38 may be involved in the DC function of alleviating asthma via restoration of the Th1/Th2 balance, thus providing a novel strategy for asthma therapy.