Cutting edge: Induced indoleamine 2,3 dioxygenase expression in dendritic cell subsets suppresses T cell clonal expansion

Andrew L. Mellor, Babak Baban, Phillip Chandler, Brendan Marshall, Kanchan Jhaver, Anna Hansen, Pandelakis A. Koni, Makio Iwashima, David H. Munn

Research output: Contribution to journalArticle

368 Scopus citations


In mice, immunoregulatory APCs express the dendritic cell (DC) marker CD11c, and one or more distinctive markers (CD8α, B220, DX5). In this study, we show that expression of the tryptophan-degrading enzyme indoleamine 2,3 dioxygenase (IDO) is selectively induced in specific splenic DC subsets when mice were exposed to the synthetic immunomodulatory reagent CTLA4-Ig. CTLA4-Ig did not induce IDO expression in macrophages or lymphoid cells. Induction of IDO completely blocked clonal expansion of T cells from TCR transgenic mice following adoptive transfer, whereas CTLA4-Ig treatment did not block T cell clonal expansion in IDO-deficient recipients. Thus, IDO expression is an inducible feature of specific subsets of DCs, and provides a potential mechanistic explanation for their T cell regulatory properties.

Original languageEnglish (US)
Pages (from-to)1652-1655
Number of pages4
JournalJournal of Immunology
Issue number4
Publication statusPublished - Aug 15 2003


ASJC Scopus subject areas

  • Immunology and Allergy
  • Immunology

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