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

Abstract

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_c 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.