Activation of murine epidermal γδ T cells through surface 2B4

Dendritic epidermal T cells (DETC) are γδ T cells that normally reside in murine skin. They express on their surface the 2B4 molecule, a 66‐kDa glycoprotein of the immunoglobulin gene superfamily thought to be associated with anti‐tumor cytotoxicity by natural killer and lymphokine‐activated killer cells. Here, we show that ligation of surface 2B4 transduces cell activation signals in DETC. Treatment with anti‐2B4 monoclonal antibodies triggers the secretion of interferon‐γ and interleukin‐2 by DETC lines, induces proliferation of resting DETC lines, amplifies anti‐CD3‐dependent proliferation of DETC freshly isolated from mouse skin; and up‐regulates egr‐1 and c‐fos mRNA expression. These results indicate a unique pathway for DETC activation.