Hepatitis Research Today is a free monthly online journal that collates and summarizes the latest research about Hepatitis, including details on hepatitis a, b, c, causes, symptoms.

Upregulation of indoleamine 2,3-dioxygenase in hepatitis C virus infection.

Larrea E, Riezu-Boj JI, Gil-Guerrero L, Casares N, Aldabe R, Sarobe P, Civeira MP, Heeney JL, Rollier C, Verstrepen B, Wakita T, Borrás-Cuesta F, Lasarte JJ, Prieto J

Division of Gene Therapy and Hepatology, Center for Applied Medical Research, CIMA, Avenida Pío XII 55, 31008 Pamplona, Spain.

Indoleamine 2,3-dioxygenase (IDO) is induced by proinflammatory cytokines and by CTLA-4-expressing T cells and constitutes an important mediator of peripheral immune tolerance. In chronic hepatitis C, we found upregulation of IDO expression in the liver and an increased serum kynurenine/tryptophan ratio (a reflection of IDO activity). Huh7 cells supporting hepatitis C virus (HCV) replication expressed higher levels of IDO mRNA than noninfected cells when stimulated with gamma interferon or when cocultured with activated T cells. In infected chimpanzees, hepatic IDO expression decreased in animals that cured the infection, while it remained high in those that progressed to chronicity. For both patients and chimpanzees, hepatic expression of IDO and CTLA-4 correlated directly. Induction of IDO may dampen T-cell reactivity to viral antigens in chronic HCV infection.

Published 14 March 2007 in J Virol, 81(7): 3662-6.
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