Cytokines Induce Indoleamine 2,3-Dioxygenase Expression in Human Atheroma-Associated Cells: Implications for Persistent Chlamydophila pneumoniae Infection

This study shows that vascular smooth muscle cells express significantly higher levels of gamma interferon-inducible indoleamine 2,3-dioxygenase (IDO) activity than endothelium or mononuclear cells. Since IDO activity is linked to persistent Chlamydophila pneumoniae infection, our results suggest that smooth muscle cells may be an important reservoir of that organism in atherosclerosis.