TY - JOUR
T1 - Functional expression of indoleamine 2,3-dioxygenase by murine CD8α+ dendritic cells
AU - Fallarino, Francesca
AU - Vacca, Carmine
AU - Orabona, Ciriana
AU - Belladonna, Maria L.
AU - Bianchi, Roberta
AU - Marshall, Brendan
AU - Keskin, Derin B.
AU - Mellor, Andrew L.
AU - Fioretti, Maria C.
AU - Grohmann, Ursula
AU - Puccetti, Paolo
PY - 2002
Y1 - 2002
N2 - Immunoregulatory antigen-presenting cells (APC) play an important role in maintaining T cell homeostasis and self-tolerance. In particular, recent evidence demonstrates a role for inhibition of T cell proliferation by macrophage tryptophan catabolism involving the activity of the enzyme indoleamine 2,3-dioxygenase (IDO). Dendritic cells (DC) have also been shown to exert immunoregulatory effects mediated by tryptophan catabolism and to cause T cell apoptosis. In the present study, we have comparatively analyzed the expression of IDO activity by murine macrophages and splenic DC. By means of PCR, Western blotting and measurements of enzyme functional activity, we obtained evidence that, different from macrophages, DC constitutively express IDO. Following activation by IFN-γ, the latter cells, in particular the CD8α+ subset, exhibit high functional activity and, unlike macrophages, mediate apoptosis of Th cells in vitro. Therefore, in the mouse, CD8α+ DC may be unique APC capable of fully expressing the IDO mechanism functionally.
AB - Immunoregulatory antigen-presenting cells (APC) play an important role in maintaining T cell homeostasis and self-tolerance. In particular, recent evidence demonstrates a role for inhibition of T cell proliferation by macrophage tryptophan catabolism involving the activity of the enzyme indoleamine 2,3-dioxygenase (IDO). Dendritic cells (DC) have also been shown to exert immunoregulatory effects mediated by tryptophan catabolism and to cause T cell apoptosis. In the present study, we have comparatively analyzed the expression of IDO activity by murine macrophages and splenic DC. By means of PCR, Western blotting and measurements of enzyme functional activity, we obtained evidence that, different from macrophages, DC constitutively express IDO. Following activation by IFN-γ, the latter cells, in particular the CD8α+ subset, exhibit high functional activity and, unlike macrophages, mediate apoptosis of Th cells in vitro. Therefore, in the mouse, CD8α+ DC may be unique APC capable of fully expressing the IDO mechanism functionally.
KW - Antigen-presenting cells
KW - Indoleamie 2,3-dioxygenase
KW - T cell apoptosis
KW - Tryptophan metabolism
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U2 - 10.1093/intimm/14.1.65
DO - 10.1093/intimm/14.1.65
M3 - Article
C2 - 11751753
AN - SCOPUS:0036155562
SN - 0953-8178
VL - 14
SP - 65
EP - 68
JO - International Immunology
JF - International Immunology
IS - 1
ER -