Immunotolerant indoleamine-2,3-dioxygenase is increased in condyloma acuminata.

The tryptophan-depleting enzyme indoleamine-2,3-dioxygenase (IDO) is critical for the regulation of immunotolerance and plays an important role in immune-associated skin diseases. To analyse the level of IDO in condyloma acuminata (CA) and its role in this condition. IDO expression was assessed in the skin and peripheral blood of healthy controls and patients with CA. To assess the role of skin IDO in immunity, the ability of isolated epidermal cells to metabolize tryptophan and the influence on polyclonal T-cell mitogen (PHA)-stimulated T-cell proliferation were explored. IDO median fluorescence intensities in peripheral blood mononuclear cells from patients with CA were similar to those from healthy controls. Immunohistochemistry showed that IDO Abnormally localized high IDO expression might be involved in the formation of a local immunotolerant microenvironment.