Expression of the common cytokine receptor γ chain by murine dendritic cells including epidermal Langerhans cells

The common cytokine receptor γ chain (γ(c)) is an indispensable component of interleukin (IL)-2, IL-4, IL-7, IL-9, and IL-15 receptors, and its expression has been detected in several leukocyte populations, including T cells, B cells, monocytes, natural killer cells, and neutrophils. The purpose of this study was to determine whether γ receptors are expressed by dendritic cells (DC). Constitutive γ(c) mRNA expression was observed by reverse transcription polymerase chain reaction and/or Northern blotting for: (a) Ia⁺ epidermal Langerhans cells (LC), (b) 4F7⁺ splenic DC, (c) granulocyte/macrophage colony-stimulated factor-propagated bone marrow-derived DC, and (d) the epidermal-derived DC line, XS52, which retains important functions of epidermal LC. Exposure of XS52 cells to recombinant IL-4 induced a rapid up-regulation of c-myc mRNA expression, and this IL-4-dependent signaling was blocked almost completely by anti-γ(c) monoclonal antibody (mAb) TUGm2 in a soluble form. Moreover, c-myc up-regulation was inducible in XS52 cells by the same mAb in an immobilized form. These results imply that molecules recognized by this antibody (i.e. γ(c) receptors) are expressed on XS52 cell surfaces. We thus conclude that DC express functional γ(c) receptors, which then mediate cytokine-dependent regulation of DC functions.