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Proc Natl Acad Sci U S A. 2012 Mar 6;109(10):3909-14. doi: 10.1073/pnas.1117736109. Epub 2012 Feb 21.

Tolerance to apoptotic cells is regulated by indoleamine 2,3-dioxygenase.

Author information

1
Department of Medicine, and Immunotherapy Center, Georgia Health Sciences University, Augusta, GA 30912, USA.

Abstract

Tolerance to self-antigens present in apoptotic cells is critical to maintain immune-homeostasis and prevent systemic autoimmunity. However, mechanisms that sustain self-tolerance are poorly understood. Here we show that systemic administration of apoptotic cells to mice induced splenic expression of the tryptophan catabolizing enzyme indoleamine 2,3-dioxygenase (IDO). IDO expression was confined to the splenic marginal zone and was abrogated by depletion of CD169(+) cells. Pharmacologic inhibition of IDO skewed the immune response to apoptotic cells, resulting in increased proinflammatory cytokine production and increased effector T-cell responses toward apoptotic cell-associated antigens. Presymptomatic lupus-prone MRL(lpr/lpr) mice exhibited abnormal elevated IDO expression in the marginal zone and red pulp and inhibition of IDO markedly accelerated disease progression. Moreover, chronic exposure of IDO-deficient mice to apoptotic cells induced a lupus-like disease with serum autoreactivity to double-stranded DNA associated with renal pathology and increased mortality. Thus, IDO limits innate and adaptive immunity to apoptotic self-antigens and IDO-mediated regulation inhibits inflammatory pathology caused by systemic autoimmune disease.

PMID:
22355111
PMCID:
PMC3309765
DOI:
10.1073/pnas.1117736109
[Indexed for MEDLINE]
Free PMC Article

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