Natural indoleamine-2,3-dioxygenase (IDO)-reactive CD4(+) T cells have been shown to release interferonγ (IFNγ), tumor necrosis factor α (TNFα), as well as interleukin 17 (IL-17). In some individuals, these cells also demonstrated the ability to suppress IL-10 production. IDO-specific CD4(+) helper T cells among peripheral blood lymphocytes may participate in immunoregulatory networks by delaying the immune suppressive actions of IDO. However, IDO-specific CD4(+) T cells may also have a regulatory phenotype, de facto exerting immunosuppressive functions.
Oncoimmunology, 2012, Vol 1, Issue 7, p. 1211-1212