Melanoma skews dendritic cells to facilitate a T helper 2 profile

Surgery. 2005 Aug;138(2):321-8. doi: 10.1016/j.surg.2005.06.011.


Background: Patients with progressing melanoma have a circulating cytokine profile reflecting a T helper cell type 2 (Th2) imbalance, while patients responding to therapy favor a Th1 profile. The aim of this study was to determine the role of circulating dendritic cells (DCs) in mediating this imbalance.

Methods: Isolated human peripheral blood mononuclear cells (PBMCs) were exposed to cell-free melanoma-conditioned medium (MCM) or control fibroblast-conditioned medium before stimulation. In separate experiments, isolated circulating DCs were exposed to MCM before addition of T cells. DC maturation and function were determined. Mixed leukocyte response T-cell proliferation was quantified and supernatants were assayed for Th1 (interleukin [IL]-2 and interferon gamma) and Th2 (IL-4, IL-5, and IL-10) cytokines.

Results: PBMCs exposed to MCM produced significantly more Th2-type cytokines (IL-4, IL-5, and IL-10) over time than those exposed to control medium. DCs exposed to MCM before addition of T cells, produced a similar pattern of a sustained longer term Th2 response after an initial burst of IL-2. Exposure to MCM did not significantly affect DC maturation or IL-12 production. T-cell proliferation did not change significantly in the mixed leukocyte response, however, the percentage of viable CD4+ T cells in the MCM-treated group was significantly less than control (37 vs 50%, P < .05).

Conclusions: Exposure of PBMCs to melanoma produces a Th2-type cytokine profile, which may be, in part, facilitated by DCs.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Cell Differentiation / immunology
  • Cell Division / immunology
  • Culture Media, Conditioned / pharmacology
  • Cytokines / metabolism
  • Dendritic Cells / cytology
  • Dendritic Cells / immunology*
  • Fibroblasts / cytology
  • Humans
  • In Vitro Techniques
  • Lymphocyte Culture Test, Mixed
  • Melanoma / immunology*
  • Skin Neoplasms / immunology*
  • Th2 Cells / cytology
  • Th2 Cells / immunology*
  • Th2 Cells / metabolism
  • Tumor Cells, Cultured


  • Culture Media, Conditioned
  • Cytokines