Expression of indoleamine 2,3-dioxygenase in nasopharyngeal carcinoma impairs the cytolytic function of peripheral blood lymphocytes

<p>Abstract</p> <p>Background</p> <p>Tumor-specific cytotoxic T cells and infiltrating lymphocytes are frequently found in tumor tissues in patients with nasopharyngeal carcinoma (NPC). Most patients with NPC, however, especially those with advanced stages, have a poor...

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Main Authors: Yi Yan-Mei, Zhang Ge, He Yun-Wen, Cai Shao-Hui, Xie Bai-Lu, Liu Peng, Du Jun
Format: Article
Language:English
Published: BMC 2009-11-01
Series:BMC Cancer
Online Access:http://www.biomedcentral.com/1471-2407/9/416
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author Yi Yan-Mei
Zhang Ge
He Yun-Wen
Cai Shao-Hui
Xie Bai-Lu
Liu Peng
Du Jun
author_facet Yi Yan-Mei
Zhang Ge
He Yun-Wen
Cai Shao-Hui
Xie Bai-Lu
Liu Peng
Du Jun
author_sort Yi Yan-Mei
collection DOAJ
description <p>Abstract</p> <p>Background</p> <p>Tumor-specific cytotoxic T cells and infiltrating lymphocytes are frequently found in tumor tissues in patients with nasopharyngeal carcinoma (NPC). Most patients with NPC, however, especially those with advanced stages, have a poor clinical prognosis despite conventional immunotherapy. The aim of this work was to examine the effect of indoleamine 2,3-dioxygenase (IDO), an immunosuppressive enzyme, on the lymphocyte function in NPC.</p> <p>Methods</p> <p>The NPC cell line CNE2 was treated by interferon-γ (IFNγ) and the levels of IDO expression was analyzed by Western blotting and reverse phase high-performance liquid chromatography (HPLC). Lymphocytes from health human exposed to the milieu created by IDO-positive CNE2 cells and the lymphocyte cytotoxicity to target tumor cells was analyzed by standard lactate dehydrogenase (LDH) release assay. Additionally, expression of IDO was determined by Immunohistochemical assay in the tumor tissues form clinically evaluated NPC.</p> <p>Results</p> <p>IDO expression was acutely induced in the NPC cell line CNE2 by low dose interferon-γ (IFNγ) or by co-incubation with activated lymphocytes. Exposure to the milieu created by IDO-positive CNE2 cells did not promote lymphocyte death, but lymphocyte cytotoxicity against target tumor cells was impaired. The suppression of lymphocyte cytotoxic function was fully restored when the conditioned medium was replaced by fresh medium for 24 h. In additionally, the IDO-positive cells were found scattered in the tumor tissues from patients with NPC.</p> <p>Conclusion</p> <p>Altogether, these findings suggest that IDO-mediated immunosuppression may be involved in the tumor immune evasion, and that blocking IDO activity in tumor cells may help to re-establish an effective anti-tumor T cell response in NPC.</p>
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spelling doaj.art-934c997b17054513884a055d41e314262022-12-21T19:11:26ZengBMCBMC Cancer1471-24072009-11-019141610.1186/1471-2407-9-416Expression of indoleamine 2,3-dioxygenase in nasopharyngeal carcinoma impairs the cytolytic function of peripheral blood lymphocytesYi Yan-MeiZhang GeHe Yun-WenCai Shao-HuiXie Bai-LuLiu PengDu Jun<p>Abstract</p> <p>Background</p> <p>Tumor-specific cytotoxic T cells and infiltrating lymphocytes are frequently found in tumor tissues in patients with nasopharyngeal carcinoma (NPC). Most patients with NPC, however, especially those with advanced stages, have a poor clinical prognosis despite conventional immunotherapy. The aim of this work was to examine the effect of indoleamine 2,3-dioxygenase (IDO), an immunosuppressive enzyme, on the lymphocyte function in NPC.</p> <p>Methods</p> <p>The NPC cell line CNE2 was treated by interferon-γ (IFNγ) and the levels of IDO expression was analyzed by Western blotting and reverse phase high-performance liquid chromatography (HPLC). Lymphocytes from health human exposed to the milieu created by IDO-positive CNE2 cells and the lymphocyte cytotoxicity to target tumor cells was analyzed by standard lactate dehydrogenase (LDH) release assay. Additionally, expression of IDO was determined by Immunohistochemical assay in the tumor tissues form clinically evaluated NPC.</p> <p>Results</p> <p>IDO expression was acutely induced in the NPC cell line CNE2 by low dose interferon-γ (IFNγ) or by co-incubation with activated lymphocytes. Exposure to the milieu created by IDO-positive CNE2 cells did not promote lymphocyte death, but lymphocyte cytotoxicity against target tumor cells was impaired. The suppression of lymphocyte cytotoxic function was fully restored when the conditioned medium was replaced by fresh medium for 24 h. In additionally, the IDO-positive cells were found scattered in the tumor tissues from patients with NPC.</p> <p>Conclusion</p> <p>Altogether, these findings suggest that IDO-mediated immunosuppression may be involved in the tumor immune evasion, and that blocking IDO activity in tumor cells may help to re-establish an effective anti-tumor T cell response in NPC.</p>http://www.biomedcentral.com/1471-2407/9/416
spellingShingle Yi Yan-Mei
Zhang Ge
He Yun-Wen
Cai Shao-Hui
Xie Bai-Lu
Liu Peng
Du Jun
Expression of indoleamine 2,3-dioxygenase in nasopharyngeal carcinoma impairs the cytolytic function of peripheral blood lymphocytes
BMC Cancer
title Expression of indoleamine 2,3-dioxygenase in nasopharyngeal carcinoma impairs the cytolytic function of peripheral blood lymphocytes
title_full Expression of indoleamine 2,3-dioxygenase in nasopharyngeal carcinoma impairs the cytolytic function of peripheral blood lymphocytes
title_fullStr Expression of indoleamine 2,3-dioxygenase in nasopharyngeal carcinoma impairs the cytolytic function of peripheral blood lymphocytes
title_full_unstemmed Expression of indoleamine 2,3-dioxygenase in nasopharyngeal carcinoma impairs the cytolytic function of peripheral blood lymphocytes
title_short Expression of indoleamine 2,3-dioxygenase in nasopharyngeal carcinoma impairs the cytolytic function of peripheral blood lymphocytes
title_sort expression of indoleamine 2 3 dioxygenase in nasopharyngeal carcinoma impairs the cytolytic function of peripheral blood lymphocytes
url http://www.biomedcentral.com/1471-2407/9/416
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