A study of cytokine in palatine tonsil--flow cytometric analysis of cytokine production in tonsillar mononuclear cells

Abstract

Using two-color flow cytometry, we measured intracellular expression of interleukin-1 alpha (IL-1 alpha), IL-2, IL-4, IL-6, IL-8, interferon gamma (IFN-gamma) and tumor necrosis factor-alpha (TNF-alpha) in tonsillar mononuclear cells freshly isolated and stimulated by phorbol myristate acetate (PMA) and ionomycin. In freshly isolated tonsillar mononuclear cells, IL-1 alpha was produced in 0.39% of CD3 cells, 0.48% of CD4 cells, 0.66% of CD19 and 11.2% of CD14 cells; TNF-alpha was found in 5.4% of CD14 cells. After 8-hour culture without any mitogens, IL-4, IL-8, TNF-alpha and IL-1 alpha were detected in 2.1%, 0.8%, 0.55%, and 0.42% of tonsillar mononuclear cells, respectively. Flow cytometric detection of intracellular cytokines in tonsillar mononuclear cells stimulated with PMA and ionomycin revealed that CD3 cells produced IL-1 alpha, IL-2, IL-4, IL-8, IFN-gamma and TNF-alpha, and CD19 cells produced IL-1 alpha, IL-6, IL-8 and TFN-alpha. In CD3 cells, the number of cells producing IL-2 and TNF-alpha were significantly higher than those expressing other cytokines; and the number of cells producing IFN-gamma and IL-8 were significantly higher than those expressing IL-4 and IL-1 alpha. In CD19 cells, the number of cells producing IL-6 and TNF-alpha were significantly higher than those of IL-8 and IL-1 alpha; and the number of cells producing IL-8 was significantly higher than that of IL-1 alpha. There was no difference in the number of CD3 and CD19 cells producing any cytokine between the adult recurrent tonsillitis group and adult obstructive sleep apnea syndrome group. However, the number of CD3 cells producing IL-2 or TNF-alpha and CD19 cells producing IL-1 alpha, IL-6 or TNF-alpha were significantly lower in children than that of adults (p < 0.05). These findings indicate that the cytokine production in tonsillar mononuclear cells is heterogenous according to the subset and activation and that flow cytometric analysis of intracellular cytokines is a useful means to investigate the pathophysiological role of cytokines in the tonsils.