The Role of Indoleamine 2,3-Dioxygenase in Retinal Pigment Epithelial Cell-mediated Immune Modulation
Source: Ocular Immunology and Inflammation, Volume 18, Number 1, January 2010 , pp. 24-31(8)
Publisher: Informa Healthcare
Abstract:Purpose: To evaluate the role of indoleamine dioxygenase (IDO) in human retinal pigment epithelial cell (RPE)-mediated immune modulation.
Methods: The immunosuppression of cultured human RPEs (ARPE-19 cells) was assayed using the mixed lymphocyte reaction (MLR) harvested from CBA/J and BALB/c mice. The expression of critical immune modulatory molecules, such as class II major histocompatibility complex (MHC) molecules, co-stimulatory molecules (B7-1 and B7-2), and indoleamine dioxygenase (IDO), was examined by reverse transcriptase polymerase chain reaction, flow cytometry, and immunofluorescence staining with and without IFN- stimulation.
Results: RPEs expressed IDO and class II MHC molecules under IFN- stimulation. However, B7-1 and B7-2 were not expressed. RPE significantly suppressed MLR in the absence of IFN- prestimulation. This phenomenon was enhanced by IFN- stimulation. The addition of 1-methyl tryptophan (1-MT) into the culture medium successfully reversed RPE immunosuppression.
Conclusions: The expression of IDO may in part explain RPE-mediated immune suppression effects.
Document Type: Original Article
Affiliations: 1: 1Department of Ophthalmology, Dongguk University, School of Medicine, Koyang, South Korea 2: 2Department of Microbiology and Immunology, Cancer Research Institute, TIMRC, Transplantation Research Institute, XRC, Seoul National University, College of Medicine, Seoul, South Korea 3: 3Department of Ophthalmology, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, New York, USA 4: 4Department of Ophthalmology, Johns Hopkins University, School of Medicine, Baltimore, Maryland, USA
Publication date: January 1, 2010