title: Indoleamine 2,3-Dioxygenase Is Involved in the Inflammation Response of Corneal Epithelial Cells to Aspergillus fumigatus Infections.
abstract: Indoleamine 2,3-dioxygenase (IDO), which is mainly expressed in activated dendritic cells, is known as a regulator of immune responses. However, the role of IDO in immune responses against fungal corneal infection has not been investigated. To evaluate the regulatory mechanisms of IDO in fungal inflammation, we resorted to human corneal epithelial cells (HCECs), known as the first barrier of cornea against pathogenic microorganisms. We found that IDO was significantly up-regulated in corneal epithelium infected with Aspergillus fumigatus (A. fumigatus) and HCECs incubated with spores of A. fumigatus. Furthermore, IDO inhibitor (1-methyltryptophan, 1-MT) enhanced inflammatory cytokines IL-1β and IL-6 expression which were up-regulated by A. fumigatus spores infection. Dectin-1, as one of the important C-type lectin receptors, can identify β-glucan, and mediate fungal innate immune responses. In the present study, pre-treatment with curdlan, a Dectin-1 agonist, further enhanced IDO expression compared with A. fumigatus stimulation. While laminarin, the Dectin-1 specific inhibitor, partially inhibited IDO expression stimulated by A. fumigatus. Further studies demonstrated inhibition of IDO activity amplified the expressions of inflammatory cytokines IL-1β and IL-6 induced by activation of Dectin-1. These results suggested that IDO was involved in the immune responses of fungal keratitis. The activation of Dectin-1 may contribute to A. fumigatus spores-induced up-regulation of IDO.
authors.affiliation: Department of Ophthalmology, the Affiliated Hospital of Qingdao University, Qingdao, 266003, Shandong Province, China.
authors.forename: Nan
authors.initials: N
authors.lastname: Jiang
authors.affiliation: Department of Ophthalmology, the Affiliated Hospital of Qingdao University, Qingdao, 266003, Shandong Province, China.
authors.forename: Guiqiu
authors.initials: G
authors.lastname: Zhao
authors.affiliation: Department of Ophthalmology, the Affiliated Hospital of Qingdao University, Qingdao, 266003, Shandong Province, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Lin
authors.affiliation: Department of Ophthalmology, the Affiliated Hospital of Qingdao University, Qingdao, 266003, Shandong Province, China.
authors.forename: Liting
authors.initials: L
authors.lastname: Hu
authors.affiliation: Department of Ophthalmology, the Affiliated Hospital of Qingdao University, Qingdao, 266003, Shandong Province, China.
authors.forename: Chengye
authors.initials: C
authors.lastname: Che
authors.affiliation: Department of Ophthalmology, the Affiliated Hospital of Qingdao University, Qingdao, 266003, Shandong Province, China.
authors.forename: Cui
authors.initials: C
authors.lastname: Li
authors.affiliation: Department of Ophthalmology, the Affiliated Hospital of Qingdao University, Qingdao, 266003, Shandong Province, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Department of Ophthalmology, the Affiliated Hospital of Qingdao University, Qingdao, 266003, Shandong Province, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Xu
authors.affiliation: Department of Ophthalmology, the Affiliated Hospital of Qingdao University, Qingdao, 266003, Shandong Province, China.
authors.forename: Xudong
authors.initials: X
authors.lastname: Peng
mesh_terms: D000818:Animals; D001232:Aspergillus fumigatus / Q000235:genetics*; D016207:Cytokines / Q000378:metabolism; D004195:Disease Models, Animal; D019573:Epithelium, Corneal / Q000378:metabolism / Q000382:microbiology / Q000473:pathology; D005260:Female; D015870:Gene Expression; D006801:Humans; D050503:Indoleamine-Pyrrole 2,3,-Dioxygenase / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D018836:Inflammation Mediators / Q000378:metabolism; D007634:Keratitis / Q000175:diagnosis / Q000378:metabolism* / Q000382:microbiology*; D037181:Lectins, C-Type / Q000378:metabolism; D051379:Mice; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D047071:beta-Glucans / Q000494:pharmacology; D000099181:Dectin-1
chemical_list: D016207:Cytokines; D050503:Indoleamine-Pyrrole 2,3,-Dioxygenase; D018836:Inflammation Mediators; D037181:Lectins, C-Type; D012333:RNA, Messenger; D047071:beta-Glucans; D000099181:Dectin-1; C038459:curdlan