A study of cytokine in palatine tonsil--cytokine mRNA expression determined by RT-PCR

Abstract

To clarify the cytokine profile of tonsils, cytokine mRNA was determined by reverse transcription-polymerase chain reaction (RT-PCR). The mRNA of interleukin-1 beta (IL 1 beta), IL-2, IL-4, IL-6, IL-8, interferon-gamma (IFN-gamma) and tumor necrosis factor-alpha (TNF-alpha) were expressed on the whole tonsillar tissue of all 5 subjects with recurrent tonsillitis, obstructive sleep apnea syndrome caused by tonsillar hypertrophy or tonsillar focal infection. These cytokine mRNAs were detected in tonsillar mononuclear cells freshly isolated from all or 14 of 15 subjects. The CD4, CD8 and CD19-positive cells were purified using immunomagnetic beads. The CD4-positive cells expressed mRNA of IL-1 beta, IL-2, IL-4, IL-8, IFN-gamma and TNF-alpha. The CD8-positive cells expressed mRNA of IFN-gamma and TNF-alpha. The CD19-positive cells expressed mRNA of IL-1 beta, IL-6, IL-8 and TNF-alpha. Quantitative measurement of PCR products in tonsillar mononuclear cells revealed that the IL-8 mRNA was expressed at a higher level than any other cytokine. A comparison among tonsillar diseases mentioned above revealed that the IL-1 beta and TNF-alpha mRNA were expressed at significantly higher levels in tonsillar mononuclear cells from patients with recurrent tonsillitis than in patients with obstructive sleep apnea syndrome caused by tonsillar hypertrophy. These data indicate that tonsils are active immunologic organs containing a wide variety of cytokines.