Induction of a polarized micro-environment by human T cells and interferon-gamma in three-dimensional spheroid cultures of human endometrial epithelial cells

Expression of human leukocyte antigen (HLA)-DR molecules andproliferation of epithelium in human endometrium are polarized.We have suggested that the induction of such a polarized micro-environmentis T cell and interferon (IFN)-gamma dependent. The presentstudy was designed to demonstrate the induction of such a micro-environmentaround T cells and around the source of IFN-gamma. Spheroidsreminiscent of endometrial glands were formed by allowing three-dimensionalaggregation of endometrial epithelial cells of a cloned HLA-DRnegative endometrial carcinoma cell line (ECC1) over agarose.Both HLA-DR expression and inhibition of proliferation werefound to be directly dependent on the dose of IFN-gamma thatwas allowed to diffuse in the agarose beneath the spheroids.To show that the interaction of the epithelial cells with activatedT cells also induces HLA-DR molecules in a paracrine fashionin the epithelial cells, ECC1 spheroids were co-cultured withincreasing numbers of allogeneic peripheral blood T cells forvarious time-intervals. T cells bound to the ECC1 cells, andbecame activated as indicated by the expression of interleukin(IL)-2 receptor and HLA-DR molecules. A focal HLA-DR expressionbecame apparent in the ECC1 cells adjacent to the T cells. Asthe number of T cells added to spheroid cultures was increased,a concomitant increase in the number of HLA-DR positive ECC1cells occurred and HLA-DR immunoreactivity was enhanced in eachcell. There was a corresponding decrease in the proliferationof the ECC1 cells in T cell-ECC1 spheroid co-cultures. Basedon these data, we suggest that activation of T cells is associatedwith the induction of HLA-DR expression and inhibition of proliferationin a paracrine fashion in the epithelial cells and may be responsiblefor the creation of a polarized micro-environment in vivo.