Differential regulation of IL-2 and IL-4 in patients with tobacco-related oral squamous cell carcinoma

AIM: The aim of the study was to investigate the systemic immunity in terms of major lymphocyte subsets and the expression of IL-2 and IL-4 in T-cell subsets from peripheral blood of patients with tobacco-related intraoral squamous cell carcinoma. METHODS: CD3+, CD4+ and CD8+ T-cell subsets and CD16+ CD56+ natural killer cells, and intracellular cytokines in T-cell subsets were determined by two-colour flow cytometry and confocal microscopy. RESULTS: Oral cancer patients showed a significantly reduced (P < 0.001) CD3+ and CD4+ T-cell subsets with a lower CD4/CD8 ratio when compared with the normal controls. The frequency of CD3+ IL-4+ and CD8+ IL-4+ T cells were significantly higher (P < 0.001) while CD4+ IL-2+ were significantly lower (P < 0.02) in patients when compared with the normal controls. Late stage of the tumour was associated with reduced expression of IL-2 in both CD4+ (P < 0.05) and CD8+ (P < 0.03) subsets. CONCLUSIONS: The tobacco-related intraoral squamous cell carcinoma seems to be associated with multiple systemic immune defects particularly, an impaired CD3+ and CD4+ T cells in the peripheral blood as well as a differential regulation of IL-2 and IL-4 in CD4+ and CD8+ T-cell subsets. The cytokine response in these patients seems to be skewed from protective Th1 to immunosuppressive Th2 type. Thus these patients could be ideal candidate for immunomodulation therapy.