Induction of IL-12 Experession in Bone Marrow-derived Mouse Dendritic Cells

Youn, Jung Koo; Kim, Hyung Il; Kim, Ae Yung; Park, Sun; Lee, Milli Na

Abstract

Dendritic cells (DCs) are the most potent antigen presenting cells that can activate naive T cells. Mature DCs exress high levels of MHC and costimulatory molecules on their surface and have capacity to produce IL-12, a 75 kDa heterodimeric cytokine composed of p35 and p40 subunit. IL-12 is currently thought to be one of most critical determinants for skewing the immune response towards Th1. Expression of IL-12 in dendritic cells seems to be regulated by various stimuli including CD40L. In the present study we investigated expression of IL-12 in mature DCs, which were cultured from bone marrow cells in the presence of GM-CSF. Maturity of the DCs was confirmed by morphologic characteristics, immunophenotypes, and allostimulatory activities. Exprssion levels of IL-12 p40 in the DCs were measured by semi-quantitative RT-PCR. Increases in IL-12 p40 expression were observed after treatment with lipopolysaccharide (LPS), an anti-MHC class II monoclonal antibody, or an anti-CD40 monoclonal antibody. The most remarkable increases, however, were observed in the DCs treated with an anti-CD40 monoclonal antibody. These results support a previous notion that signals through CD40/CD40L interaction may be important for the production of IL-12 by DCs. Moreover, results of this study show a possibility of using monoclonal antibodies against CD40 molecules for preparing DCs producing high amount of IL-12, which can be used for anti-tumor or anti-viral immunotherapy.