TY - JOUR
T1 - Endogenous Cortisol and TGF- in Human Aqueous Humor Contribute to Ocular Immune Privilege by Regulating Dendritic Cell Function
AU - Denniston, Alastair
AU - Kottoor, Sherine
AU - Khan, I
AU - Oswal, Kadambari
AU - Williams, Geraint
AU - Abbott, J
AU - Salmon, M
AU - Rauz, Saaeha
AU - Murray, Philip
AU - Curnow, Stephen
PY - 2010/11/24
Y1 - 2010/11/24
N2 - Aqueous humor (AqH) has been shown to have significant immunosuppressive effects on APCs in animal models. We wanted to establish whether, in humans, AqH can regulate dendritic cell (DC) function and to identify the dominant mechanism involved. Human AqH inhibited the capacity of human peripheral blood monocyte-derived DC to induce naive CD4(+) T cell proliferation and cytokine production in vitro, associated with a reduction in DC expression of the costimulatory molecule CD86. This was seen both for DC cultured under noninflammatory conditions (immature DC) and for DC stimulated by proinflammatory cytokines (mature DC). DC expression of MHC classes I/II and CD83 was reduced (mature DC only). Myeloid DC from peripheral blood were similarly sensitive to the effects of human AqH, but only under inflammatory conditions. The addition of α-melanocyte stimulating hormone and vasoactive intestinal peptide did not cause significant inhibition at physiological levels. However, the addition of exogenous cortisol at physiological levels recapitulated the AqH-induced reduction in CD86 and inhibition of DC-induced T cell proliferation, and blockade of cortisol in AqH partially reversed its suppressive effects. TGF-β2 had an additional effect with cortisol, and although simultaneous blockade of cortisol and TGF-β2 in AqH reduced its effectiveness, there was still a cortisol- and TGF-β-independent component. In humans, AqH regulates DC maturation and function by the combined actions of cortisol and TGF-β2, a pathway that is likely to contribute to the maintenance of immune privilege in the eye.
AB - Aqueous humor (AqH) has been shown to have significant immunosuppressive effects on APCs in animal models. We wanted to establish whether, in humans, AqH can regulate dendritic cell (DC) function and to identify the dominant mechanism involved. Human AqH inhibited the capacity of human peripheral blood monocyte-derived DC to induce naive CD4(+) T cell proliferation and cytokine production in vitro, associated with a reduction in DC expression of the costimulatory molecule CD86. This was seen both for DC cultured under noninflammatory conditions (immature DC) and for DC stimulated by proinflammatory cytokines (mature DC). DC expression of MHC classes I/II and CD83 was reduced (mature DC only). Myeloid DC from peripheral blood were similarly sensitive to the effects of human AqH, but only under inflammatory conditions. The addition of α-melanocyte stimulating hormone and vasoactive intestinal peptide did not cause significant inhibition at physiological levels. However, the addition of exogenous cortisol at physiological levels recapitulated the AqH-induced reduction in CD86 and inhibition of DC-induced T cell proliferation, and blockade of cortisol in AqH partially reversed its suppressive effects. TGF-β2 had an additional effect with cortisol, and although simultaneous blockade of cortisol and TGF-β2 in AqH reduced its effectiveness, there was still a cortisol- and TGF-β-independent component. In humans, AqH regulates DC maturation and function by the combined actions of cortisol and TGF-β2, a pathway that is likely to contribute to the maintenance of immune privilege in the eye.
U2 - 10.4049/jimmunol.1001450
DO - 10.4049/jimmunol.1001450
M3 - Article
C2 - 21106846
SN - 1550-6606
JO - Journal of Immunology
JF - Journal of Immunology
ER -