CD4 +CD25 + regulatory T cells decreased the antitumor activity of cytokine-induced killer (CIK) cells of lung cancer patients.

Li H1, Yu JP, Cao S, Wei F, Zhang P, An XM, Huang ZT, Ren XB.
Source: J Clin Immunol
Publication Date: (2007)
Issue: 27 (3): 317-26
Research Area:
Cancer Research/Cell Biology
Immunotherapy / Hematology
Cells used in publication:
Cytokine induced killer, human (CIK)
Species: human
Tissue Origin: blood
Culture Media:

CIK and CIK-Tregdel cells were generated from PBMCs and PBMCs depleted of CD4 +CD25+ regulatory T cells, respectively.

Ficoll-separated cells were cultured in XVIVO 20 serum-free medium (Cambrex, USA), consisting of 100 U/ml of recombinant human IL-1a, 50 ng/ml of anti-CD3 antibody (e-Bioscience, USA), and 1000 U/ml of recombinant human IFN-? (PEPROTECH, USA) at 37? in a humidified atmosphere of 5% CO2 for 24 h before 300 U/ml of recombinant human Interleukin (IL)-2 (PEPROTECH, USA) was added to media.

Cells were subcultured every 3 days in IL-2 and IFN-? containing medium. On day 14, the phenotype and cytotoxicity of CIK cells were assayed.


CD(4) (+)CD(25) (+) regulatory T cells (Tregs) have been shown to inhibit cytotoxic lymphocytes-mediated immune responses. Cytokine-induced killer (CIK) cells exert high impact on adoptive immunotherapeutic approaches. Therefore, the purpose of this report was to determine the effect of Tregs on CIK cell growth and CIK-induced cytotoxicity for inhibition of tumor growth in vivo as well as in vitro. After depletion of CD(4) (+)CD(25) (+) cells before culture, the proliferation and cytotoxicity of CIK cells, which indicated in bromodeoxyuridine (BrdU) and lactic dehydrogenase (LDH) assays, were significantly increased. Depletion of CD(4) (+)CD(25) (+) cells preculture also enhanced the suppression effect on the lung cancer cells inoculated in experimental animals. Blockage of glucocorticoid-induced tumor necrosis factor receptor (GITR) and transforming growth factor beta1 (TGF-beta1) by antibodies partially abrogated the suppressive effect of CD(4) (+)CD(25) (+) cells on CIK. These results indicated that Tregs could inhibit the antitumor activity of CIK cells. The molecules TGF-beta and GITR may contribute to the suppressive function of CD(4) (+)CD(25) (+) cells.