Effect of 17β-oestradiol on expression of IL-2, IL-6 and IFN-γ mRNA in human tonsillar cells.

Oestradiol (E(2)) alters lymphocyte functionin vitro including T cell DNA synthesis and B cell immunoglobulin production in human tonsillar, splenic and peripheral blood cells. We have investigated whether one mechanism for this effect is that E(2) modifies the expression of IL-2, IL-6 and IFN-γ mRNA in human tonsillar mononuclear cells. Without E(2), addition of PHA (1 μg ml(-1)) for 10 h increased the expression of IL-2 and IL-6 mRNA but had no significant effect on IFN-γ mRNA. In separated T cells after 24 h incubation, E(2) (7×10(-8) M: ) increased only the IFN-γ mRNA levels. However, when E(2) was present in PHA-stimulated T cell cultures, mRNA levels from all cytokines were suppressed. E(2) decreased IL-2 mRNA levels in the T cell preparation after 24 h culture. For IL-6, E(2) decreased mRNA both in mononuclear cells and T cells after 10 h incubation. For IFN-γ, E(2) decreased mRNA levels in the mononuclear cell preparation after 24 h culture. Stimulation of the T cell preparation with PHA after 24 h incubation with E(2) decreased the IFN-γ mRNA levels compared to the cultures incubated with E(2) only. One part of the action of E(2) may be through a block in the up-regulation of the mRNA of IL-2, IL-6 and IFN-γ in activated cells.