[Principles of specific immunotherapy of IgE-induced allergic reactions]

Allergen-specific immunotherapy (SIT) aims to selectively skew an allergic immune response into a normal immunity. It appeared that the induction of specific anergy in peripheral T cells and reactivation of anergized T cells by microenvironmental cytokines represent two key steps in the mechanism of SIT. In SIT of bee venom allergy the proliferative and cytokine responses were significantly suppressed within seven days, simultaneously with an increase in IL-10 production. IL-10 induces total anergy in T cells by autokrine interaction. In addition, it can counter-regulate IgE and IgG4 synthesis. The addition of blocking anti-IL-10 to stimulated PBMC fully reconstituted the proliferative and cytokine responses in anergized T-cells. Again, particular cytokines are able to reactivate anergic T cells to produce distinct IFN-gamma/IL-2 or IL-4/IL-13 dominated T cell cytokine patterns and direct by this way SIT towards successful or unsuccessful treatment. The suppression of T cells by IL-10 is an active biochemical process, which depends on the interaction of the ligated IL-10 receptor with the CD28 costimulatory signaling pathway in T cells.