Differential chemokine expression patterns in tonsillar disease

Mandapathil, M.; H.Beier, U.; Graefe, H.; Kröger, B.; Hedderich, J.; Maune, S.; Meyer, J. E

role in host immune defence by conveying chemotaxis and activation of neutrophils, similar to IL-8. However, in our data, mRNA expression levels of GROalpha were not significantly elevated in acute nor chronic tonsillitis compared to tonsillar hyperplasia. MCP 1-4, RANTES, eotaxin, eotaxin-2 und eotaxin-3 are CC-chemokines. RANTES is a selective attractant for T-cell and monocytes migration 35 . Proinflammatory cytokines, such as TNF-a or IL-1ß, have been described to be some of the most potent stimulators of RANTES expression. Furthermore, a combination of TNF-a and INFc strongly stimulate production of RANTES 36 . Another important function of RANTES is its ability to enhance the mucosal as well as systemic humoral production of antibodies, via an elevation of the production of IFN-c-, IL-2-, IL-5-and IL-6, and further an induction of co-stimulatory molecules as well as expression of cytokine receptors for CD 4 + T cells 37 . In our data, RANTES expression was evident in all subgroups analysed with no significant differences in relative mRNA expression levels within these groups. Eotaxin-2 is also described to be a potent chemoattractor for eosinophils in vitro and in vivo 38 39 . In eosinophils, eotaxin-2 causes a dose-dependent increase of the production of free radicals, mobilisation of intracellular calcium and upregulation of CD11b 40 . Eotaxin-2 expression was evident in all analysed subgroups with a significant upregulation in adenoids, suggesting an involvement of Th2-immune responses as eotaxin-2 which is known to play a crucial role in the pathogenesis of atopic diseases involving Th 2-cell activation 41 . Significant upregulation of eotaxin-2 has been observed in bronchial asthma 42 and allergic rhinitis 43 . However, the significance of eotaxin-2 expression in lymphatic tissue of the Waldeyer's tonsillar ring still largely remains uncertain, like their role in the maturation of the adaptive immune system in the mucosa of the upper aerodigestive tract. However, it is remarkable that eotaxin-2 as well as RANTES are constitutively expressed in the mucosa of the gastrointestinal tract, an organ with distinctive antigen contact, such as Waldeyer`s tonsilar ring 44 45 .