Expression of various cytokines in the tonsillar compartments, and in
vitro cytokine production and cytokine mRNA expression by tonsillar ly
mphocytes (TL), were investigated. In immunohistological analysis, a w
ide variety of cytokines such as interleukin (IL)-1 beta, IL-2, IL-4,
IL-5, IL-10 was expressed intensively in the lyumphoepithelial symbios
is (LES). A certain number of cells producing IL-6, interferon (IFN)-g
amma, and tumor necrosis factor (TNF)-alpha was distributed not only i
n the LES but also in the extrafollicular area. A significant amount o
f IL-6, IFN-gamma, and TNF-alpha was detected by enzyme-linked immunos
orbent assay in the culture supernatants of TL cultured with streptoco
ccal antigen, even without any mitogens. Furthermore, mRNA of IL-6, IF
N-gamma, and TNF-alpha was determined by reverse transcription polymer
ase chain reaction on the TL freshly isolated and with streptococcal s
timulated antigen, whereas, production of IL-1 alpha, IL-4, and IL-5,
and expression of their mRNA were not found on TL with or without stre
ptococcal stimulation. These data indicate that tonsils are highly act
ive immunological organs containing a wide variety of cytokine-produci
ng cells, and suggest that IFN-gamma, TNF-alpha, and IL-6 may play an
important role on the immune response to bacteria in the tonsil.