title: Indoleamine 2,3-dioxygenase is involved in defense against Neospora caninum in human and bovine cells.
abstract: Neospora caninum is an apicomplexan parasite closely related to Toxoplasma gondii. In nature this parasite is found especially in dogs and cattle, but it may also infect other livestock. The growth of N. caninum, which is an obligate intracellular parasite, is controlled mainly by the cell-mediated immune response. During infection the cytokine gamma interferon (IFN-gamma) plays a prominent role in regulating the growth of N. caninum in natural and experimental disease. The present study showed that induction of the tryptophan-degrading enzyme indoleamine 2,3-dioxygenase (IDO) is responsible for the inhibition of parasite growth that is mediated by IFN-gamma-activated bovine fibroblasts and endothelial cells. This antiparasite effect could be abrogated by addition of tryptophan, as well as by the IDO-specific inhibitor 1-L-methyltryptophan. In conclusion, our data show that human and bovine cells use the same effector mechanism to control the growth of N. caninum.
authors.affiliation: Institute of Medical Microbiology and Hospital Hygiene, Heinrich Heine University, Düsseldorf, Germany.
authors.forename: Katrin
authors.initials: K
authors.lastname: Spekker
authors.forename: Markus
authors.initials: M
authors.lastname: Czesla
authors.forename: Vanessa
authors.initials: V
authors.lastname: Ince
authors.forename: Kathrin
authors.initials: K
authors.lastname: Heseler
authors.forename: Silvia K
authors.initials: SK
authors.lastname: Schmidt
authors.forename: Gereon
authors.initials: G
authors.lastname: Schares
authors.forename: Walter
authors.initials: W
authors.lastname: Däubener
mesh_terms: D000818:Animals; D002417:Cattle; D002460:Cell Line; D042783:Endothelial Cells / Q000276:immunology / Q000469:parasitology*; D004847:Epithelial Cells / Q000276:immunology / Q000469:parasitology*; D005347:Fibroblasts / Q000276:immunology / Q000469:parasitology*; D006801:Humans; D050503:Indoleamine-Pyrrole 2,3,-Dioxygenase / Q000096:biosynthesis* / Q000276:immunology*; D018688:Neospora / Q000254:growth & development* / Q000276:immunology*
chemical_list: D050503:Indoleamine-Pyrrole 2,3,-Dioxygenase