title: Immunotolerant indoleamine-2,3-dioxygenase is increased in condyloma acuminata.
abstract: BACKGROUND
  The tryptophan-depleting enzyme indoleamine-2,3-dioxygenase (IDO) is critical for the regulation of immunotolerance and plays an important role in immune-associated skin diseases.
  
  
  OBJECTIVE
  To analyse the level of IDO in condyloma acuminata (CA) and its role in this condition.
  
  
  METHODS
  IDO expression was assessed in the skin and peripheral blood of healthy controls and patients with CA. To assess the role of skin IDO in immunity, the ability of isolated epidermal cells to metabolize tryptophan and the influence on polyclonal T-cell mitogen (PHA)-stimulated T-cell proliferation were explored.
  
  
  RESULTS
  IDO median fluorescence intensities in peripheral blood mononuclear cells from patients with CA were similar to those from healthy controls. Immunohistochemistry showed that IDO+cells were rare in normal skin and the control skin of patients with CA, but were greatly accumulated in wart tissue. Most fluorescence signals of IDO+cells did not overlap with those of CD1a+Langerhans cells. Human papillomavirus (HPV) DNA probe in situ hybridization showed a large number of IDO+cells in the HPV-site. Keratinocytes in the skin of healthy controls and the circumcised skin of patients with CA could minimally transform tryptophan into kynurenine, but IDO-competent epidermal cells from warts could transform tryptophan. In addition, these IDO-competent epidermal cells could inhibit PHA-stimulated T-cell proliferation. The addition of an IDO inhibitor, 1-methyl-d-tryptophan, restored the inhibited T-cell proliferation.
  
  
  CONCLUSIONS
  Abnormally localized high IDO expression might be involved in the formation of a local immunotolerant microenvironment.
authors.affiliation: Department of Dermatology, Sichuan Academy of Medical Science & Sichuan Provincial People's Hospital, Chengdu, China.
authors.forename: Z
authors.initials: Z
authors.lastname: Xie
authors.affiliation: Department of Gastroenterology, the Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.
authors.forename: M
authors.initials: M
authors.lastname: Zhang
authors.affiliation: Division of Urology and Transplantation, Department of Surgery, Sichuan Academy of Medical Science & Sichuan Provincial People's Hospital, Chengdu, China.
authors.forename: W
authors.initials: W
authors.lastname: Xiong
authors.affiliation: Department of Dermatology, Sichuan Academy of Medical Science & Sichuan Provincial People's Hospital, Chengdu, China.
authors.forename: H Y
authors.initials: HY
authors.lastname: Wan
authors.affiliation: Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China.|Nanfang Medical University, Guangzhou, China.
authors.forename: X C
authors.initials: XC
authors.lastname: Zhao
authors.affiliation: Department of Dermatology, Guangdong Provincial Hospital of Chinese Hospital, Guangzhou, China.
authors.forename: T
authors.initials: T
authors.lastname: Xie
authors.affiliation: Department of Dermatology, Sichuan Academy of Medical Science & Sichuan Provincial People's Hospital, Chengdu, China.
authors.forename: H
authors.initials: H
authors.lastname: Lei
authors.affiliation: Department of Dermatology, Sichuan Academy of Medical Science & Sichuan Provincial People's Hospital, Chengdu, China.
authors.forename: Z C
authors.initials: ZC
authors.lastname: Lin
authors.affiliation: Department of Dermatology, Sichuan Academy of Medical Science & Sichuan Provincial People's Hospital, Chengdu, China.
authors.forename: D S
authors.initials: DS
authors.lastname: Luo
authors.affiliation: Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China.
authors.forename: X L
authors.initials: XL
authors.lastname: Liang
authors.affiliation: Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China.
authors.forename: Y H
authors.initials: YH
authors.lastname: Chen
mesh_terms: D000328:Adult; D001004:Anus Diseases / Q000201:enzymology* / Q000276:immunology; D016022:Case-Control Studies; D049109:Cell Proliferation / Q000502:physiology; D002478:Cells, Cultured; D003218:Condylomata Acuminata / Q000201:enzymology* / Q000276:immunology; D005260:Female; D052776:Female Urogenital Diseases / Q000201:enzymology* / Q000276:immunology; D006801:Humans; D007108:Immune Tolerance / Q000502:physiology; D050503:Indoleamine-Pyrrole 2,3,-Dioxygenase / Q000276:immunology / Q000378:metabolism*; D007963:Leukocytes, Mononuclear / Q000201:enzymology; D008297:Male; D052801:Male Urogenital Diseases / Q000201:enzymology*; D010502:Perineum; D013601:T-Lymphocytes / Q000821:virology; D014364:Tryptophan / Q000378:metabolism
chemical_list: D050503:Indoleamine-Pyrrole 2,3,-Dioxygenase; D014364:Tryptophan