Differential Production of Th1- and Th2-Type Chemokines by Mouse Langerhans Cells and Splenic Dendritic Cells

Some chemokines specifically attract T helper 1 (Th1) cells, whereas others attract T helper 2 (Th2) cells. In this study, we investigated the capacity of Langerhans cells (LC) to produce Th1- and Th2-type chemokines in comparison with that of splenic CD11c+ dendritic cells (DC). We prepared highly purified (>95%) LC from BALB/c mouse skin using the panning method. With regard to Th1-type chemokines, exogenous stimulus, such as interferon-γ (IFN-γ), lipopolysaccharide, or polyinosinic-polycytidylic acid, was mandatory for the production of substantial amounts of CXCL10, CXCL9, and CXCL11 both in LC and splenic DC. LC, as a whole, exhibited low ability to produce Th1-type chemokines in comparison with splenic DC. As for Th2-type chemokines, LC, but not splenic DC, produced high levels of CCL22 and CCL17 constitutively during culture even without exogenous stimuli. The production of Th2-type chemokines was regulated in a complicated manner. In particular, interleukin-4 upregulated, and IFN-γ downregulated both CCL22 and CCL17 production by LC. Of note, LC produced much more amounts of Th2-type chemokines than splenic DC under any conditions tested. Finally, Th1- and Th2-type chemokines produced by LC were shown to be functional using chemokine receptor-transfected-2B4 T cells. The high production of CC chemokine receptor 4 ligands by LC in the absence of IFN-γ may be an important character discriminating LC from other DC.