Curcumin Reverses T Cell-Mediated Adaptive Immune Dysfunctions in Tumor-Bearing Hosts

Cell Mol Immunol. 2010 Jul;7(4):306-15. doi: 10.1038/cmi.2010.11. Epub 2010 Mar 22.

Abstract

Immune dysfunction is well documented during tumor progression and likely contributes to tumor immune evasion. CD8(+) cytotoxic T lymphocytes (CTLs) are involved in antigen-specific tumor destruction and CD4(+) T cells are essential for helping this CD8(+) T cell-dependent tumor eradication. Tumors often target and inhibit T-cell function to escape from immune surveillance. This dysfunction includes loss of effector and memory T cells, bias towards type 2 cytokines and expansion of T regulatory (Treg) cells. Curcumin has previously been shown to have antitumor activity and some research has addressed the immunoprotective potential of this plant-derived polyphenol in tumor-bearing hosts. Here we examined the role of curcumin in the prevention of tumor-induced dysfunction of T cell-based immune responses. We observed severe loss of both effector and memory T-cell populations, downregulation of type 1 and upregulation of type 2 immune responses and decreased proliferation of effector T cells in the presence of tumors. Curcumin, in turn, prevented this loss of T cells, expanded central memory T cell (T(CM))/effector memory T cell (T(EM)) populations, reversed the type 2 immune bias and attenuated the tumor-induced inhibition of T-cell proliferation in tumor-bearing hosts. Further investigation revealed that tumor burden upregulated Treg cell populations and stimulated the production of the immunosuppressive cytokines transforming growth factor (TGF)-beta and IL-10 in these cells. Curcumin, however, inhibited the suppressive activity of Treg cells by downregulating the production of TGF-beta and IL-10 in these cells. More importantly, curcumin treatment enhanced the ability of effector T cells to kill cancer cells. Overall, our observations suggest that the unique properties of curcumin may be exploited for successful attenuation of tumor-induced suppression of cell-mediated immune responses.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptive Immunity / drug effects*
  • Animals
  • Antineoplastic Agents / pharmacology*
  • CD4 Antigens / metabolism
  • Cell Proliferation / drug effects
  • Curcumin / pharmacology*
  • Cytotoxicity, Immunologic / drug effects
  • Down-Regulation / drug effects
  • Drug Screening Assays, Antitumor
  • Forkhead Transcription Factors / metabolism
  • Immunologic Memory / drug effects
  • Interleukin-10 / metabolism
  • Interleukin-2 Receptor alpha Subunit / metabolism
  • Lymphocyte Depletion
  • Mice
  • Neoplasms / immunology*
  • Neoplasms / pathology
  • Survival Analysis
  • T-Lymphocytes / drug effects*
  • T-Lymphocytes / immunology*
  • T-Lymphocytes, Helper-Inducer / drug effects
  • T-Lymphocytes, Helper-Inducer / immunology
  • T-Lymphocytes, Helper-Inducer / pathology
  • T-Lymphocytes, Regulatory / cytology
  • T-Lymphocytes, Regulatory / drug effects
  • T-Lymphocytes, Regulatory / immunology
  • Transforming Growth Factor beta / metabolism

Substances

  • Antineoplastic Agents
  • CD4 Antigens
  • Forkhead Transcription Factors
  • Foxp3 protein, mouse
  • Interleukin-2 Receptor alpha Subunit
  • Transforming Growth Factor beta
  • Interleukin-10
  • Curcumin