Characterization of Intracellular Cytokine Profile of CD4(+) T Cells in Peripheral Blood and Tumor-draining Lymph Nodes of Patients with Gastrointestinal Cancer

Abstract

Analysis of serum cytokine levels has shown that cancer-bearing hosts have lower levels of IL-2 and IFN-gamma, suggesting that Th1-type immunity is impaired by cancer. However, the mechanisms of the Th1 dysfunction are not clearly understood. The frequencies of Th1 cells in CD4(+) helper T cells were evaluated with an intracytoplasmic cytokine staining method in peripheral blood lymphocytes (PBL) and lymph node lymphocytes (LNL) of patients with gastrointestinal cancer. Activation of lymphocytes with PMA + Ionomycin induced the expression of IL-2 and IFN-gamma in each lymphocyte population. Compared with PBL of non-malignant donors, PBL in cancer patients contained significantly lower frequencies of CD4(+) T cells that produced IL-2 and IFN-gamma. LNL in cancer patients also contained lower levels of IL-2- and IFN-gamma-producing CD4(+) T cells, although the percentages did not show significant differences from those of PBL in the same patients. Our data suggest that suppression of Th1 cytokine in cancer patients is, at least in part, due to the decreased frequency of Th1 cells with CD4(+) phenotype.