Article
Indoleamine-2,3-Dioxygenase activity in the cornea
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Authors
Published: | September 22, 2004 |
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Outline
Text
Objective
Indoleamine-2,3-dioxygenase (IDO), an IFNγ-controlled intracellular enzyme present in dendritic cells and macrophages, is a modulator of T-cell response. By reducing local concentrations of tryptophan and producing L-Kynurenine it can render activated T-cells apoptotic. There is no information on IDO activity in the corneal immune and its possible involvement in corneal inflammation.
Methods
We examined for IDO mRNA and protein in (a) a murine corneal endothelial cell line (MCE), (b) primary corneal endothelial cells and (c) full-thickness cornea. The function of IDO was assessed by detecting its metabolites and in a T-cell proliferation assay.
Results
IDO was detected in (a-c) and was found to be competent to reduce tryptophan in vitro. Competitive inhibition of IDO significantly increased T-cell proliferation in vitro.
Conclusions
IDO is a possible modulator of T-cell response in the cornea and anterior chamber in vivo. This may have implications in intervention strategies to prevent of corneal inflammatory disorders including allograft rejection.