IDO production, adaptive immunity, and CTL killing

Comment on Braun et al, page [2375][1], and comment on Potula et al, page [2382][2] Indoleamine 2,3-dioxygenase, an enzyme induced in antigen-presenting cells by specific proinflammatory mediators such as prostaglandin E2 (PGE2) or viral infection, can inactivate specific T-cell functions.