INTERFERON-GAMMA INDUCES HIGH-AFFINITY TRANSFORMING GROWTH-FACTOR-BETA RECEPTOR EXPRESSION ON HUMAN CORNEAL FIBROBLASTS

The effect of interferon-gamma (IFN-gamma) on the expression of transf orming growth factor-beta (TGF-beta) receptors on cultured human corne al stromal fibroblasts was examined. Scatchard analysis of specific sa turable TGF-beta 1 binding data indicated that corneal fibroblasts exp ressed TGF-beta receptors with an average association constant of 6x(1 0) M(-1), before and after IFN-gamma treatment. An additional populati on of higher affinity TGF-beta receptors, with an average association constant of 4 x 10(12) M(-1), was demonstrated only on IFN-gamma-treat ed corneal fibroblasts. Interferon-gamma may alter the response of cor neal fibroblasts to transforming growth factor-betas by upregulating t heir higher affinity TGF-beta receptors. The induction of higher affin ity TGF-beta receptors by an immune cytokine and an associated autocri ne elevation of TGF-beta output by the corneal fibroblasts may be a tr ansient compensatory mechanism that maintains the homeostasis of corne al optical competency through enhancement of corneal immunoseclusion.