Effects of interleukin-4 on the in-vitro production of cytokines by human endometrial stromal cells

A T helper (Th)1/Th2 model has been applied to as a system regulating the cytokine network during pregnancy. To evaluate the effects of interleukin (IL)-4, a Th2 cytokine, on the cytokine production by endometrial stromal cells (ESC), an enzyme-linked immunosorbent assay was used to measure the concentrations of IL-6, IL-8, monocyte chemoattractant protein-1 (MCP-1), and macrophage colony-stimulating factor (M-CSF) in the culture media of ESC and of an endometrial stromal sarcoma cell line, MaMi, following the addition of recombinant human IL-4. The expression of mRNAs for IL-6 and IL-8 in ESC after stimulation with IL-4 was also evaluated by Northern blot analysis. Increases in the concentrations of IL-6, IL-8, MCP-1, and M-CSF in the culture media of ESC and MaMi cells were observed on the addition of increasing amounts of IL-4. This cytokine also stimulated the transcription of IL-6 and IL-8 in ESC in a dose-dependent manner. It is suggested that IL-4 secreted by the maternal decidual tissue as well as by the developing embryo may stimulate the production of IL-6, IL-8, MCP-1, and M-CSF by ESC. The increased concentration of these cytokines in the local environment may contribute to the maintenance of early pregnancy by modulating the immune reaction at the feto-maternal interface.