Comparative Analysis of Human Epidermal and Peripheral Blood gammadelta T Cell Cytokine Profiles

ABSTRACT

BACKGROUND: Human epidermal gammadelta T cells are known to play crucial roles in the defense and homeostasis of the skin. However, their precise mechanism of action in skin inflammation remains less clear. OBJECTIVE: In this study, we analyzed the cytokine expression profile of human epidermal gammadelta T cells and compared it to that of peripheral blood gammadelta T cells to investigate the specific activity of epidermal gammadelta T cells in modulating skin inflammation. METHODS: We isolated gammadelta T cells from epidermal tissue or peripheral blood obtained from healthy volunteers. Isolated gammadelta T cells were stimulated using immobilized anti-CD3 antibody and interleukin-2 plus phytohaemagglutinin, and were then analyzed using a cytokine array kit. RESULTS: Both epidermal and peripheral blood gammadelta T cells produced comparable levels of granulocyte-macrophage colony-stimulating factor, I-309, interferon-gamma, macrophage migration inhibitory factor, macrophage inflammatory protein-1alpha, and chemokine (C-C) ligand 5. The epidermal gammadelta T cells produced significantly higher levels of interleukin-4, -8, -13, and macrophage inflammatory protein-1beta than the peripheral blood gammadelta T cells did. Notably, the epidermal gammadelta T cells produced several hundred-fold higher levels of interleukin-13 than interleukin-4. CONCLUSION: These results suggest that the epidermal gammadelta T cells have a stronger potential to participate in the Th2-type response than the peripheral blood gammadelta T cells do. Furthermore, epidermal gammadelta T cells might play an important role in the pathogenesis of Th2-dominant skin diseases because of their active production of interleukin-13.