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 transforming growth factor-beta (TGF-beta) receptors on cultured human corneal stromal fibroblasts was examined. Scatchard analysis of specific saturable TGF-beta 1 binding data indicated that corneal fibroblasts expressed TGF-beta receptors with an average association constant of 6x(10) M(-1), before and after IFN-gamma treatment. An additional population of higher affinity TGF-beta receptors, with an average association constant of 4 x 10(12) M(-1), was demonstrated only on IFN-gamma-treated corneal fibroblasts. Interferon-gamma may alter the response of corneal fibroblasts to transforming growth factor-betas by upregulating their higher affinity TGF-beta receptors. The induction of higher affinity TGF-beta receptors by an immune cytokine and an associated autocrine elevation of TGF-beta output by the corneal fibroblasts may be a transient compensatory mechanism that maintains the homeostasis of corneal optical competency through enhancement of corneal immunoseclusion.