In vitro induction of CD25+ CD4+ regulatory T cells by the neuropeptide alpha‐melanocyte stimulating hormone (α‐MSH)

Immunology and Cell Biology - Tập 79 Số 4 - Trang 358-367 - 2001
AW Taylor1, Kenichi Namba1
1Schepens Eye Research Institute and Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, USA

Tóm tắt

Recently, we have found that the neuropeptide alpha‐melanocyte stimulating hormone (α‐MSH) not only suppresses IFN‐γ production, but also induces TGF‐β1 production by activated effector T cells. These α‐MSH‐ treated effector T cells function as regulatory T cells in that they suppress IFN‐γ production and hypersensitivity mediated by other effector T cells. Experimental autoimmune uveoretinitis (EAU) was suppressed in its severity and incidence in mice that were injected with primed T cells activated in vitro by APC and antigen in the presence of α‐MSH. Moreover, it appeared that α‐MSH had converted a population of effector T cells polarized to mediate hypersensitivity into a population of T cells that now mediated immunoregulation. To characterize these α‐MSH‐ treated T cells, primed T cells were TCR‐stimulated in the presence of α‐MSH in vitro and their lymphokine profile was examined. Such effector T cells displayed enhanced levels of TGF‐β1 production and no IFN‐γ or IL‐10, with IL‐4 levels remaining unchanged in comparison with inactivated T cells. In addition, if soluble TGF‐β receptor II was added to cocultures of α‐MSH‐treated T cells and activated Th1 cells, the α‐MSH‐treated T cells could not suppress IFN‐γ production by the Th1 cells. These results suggest that α‐MSH induces T cells with a regulatory lymphokine pattern, and that through their production of TGF‐β1 these cells suppress other effector T cells. Examination of the α‐MSH‐treated T cells showed that α‐MSH did not alter the phosphorylation of CD3 molecules following TCR engagement. Primed T cells express the melanocortin 5 receptor (MC5r), a receptor that is linked to an intracellular signalling pathway shared by other cytokine receptors. Blocking the receptor with antibody prevented α‐MSH from suppressing IFN‐γ production by the activated regulatory T cells, suggesting that α‐MSH immunoregulation is through the MC5r on primed T cells. Surface staining and cell sorting of the α‐MSH‐ treated primed T cells showed that the regulatory T cells are CD25+ CD4+ T cells. From these results we find that α‐MSH can mediate the induction of CD25+ CD4+ regulatory T cells. These regulatory T cells require specific antigen for activation, but through non‐specific TGF‐β1‐mediated mechanisms they can suppress other effector T cells.

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Tài liệu tham khảo

Star RA, 1995, Evidence of autocrine modulation of macrophage nitric oxide synthase by α‐MSH, Proc. Natl Acad. Sci. USA, 90, 8856

10.1016/S0021-9258(18)64183-3

10.1016/0167-4889(96)00063-8

Rajora N, 1996, α‐MSH production, receptors, and influence on neopterin in a human monocyte/ macrophage cell line, JAMA, 59, 248

10.1016/S0167-5699(97)01009-8

10.1111/1523-1747.ep12326950

10.1002/9780470110249.ch7

Manna SK, 1998, α‐Melanocyte stimulating hormone inhibits the nuclear transcription factor NF‐κB activation induced by various inflammatory agents, J. Immunol., 161, 2873, 10.4049/jimmunol.161.6.2873

10.1016/S0006-8993(99)01584-X

Mason MJ, 1989, Modulation of IL‐1, tumor necrosis factor, and C5A‐mediated murine neutrophil migration by α‐melanocyte‐stimulating hormone, J. Immunol., 142, 1646, 10.4049/jimmunol.142.5.1646

Cannon JG, 1986, α‐Melanocyte stimulating hormone inhibits immunostimulatory and inflammatory actions of interleukin 1, J. Immunol., 137, 2232, 10.4049/jimmunol.137.7.2232

10.1016/0196-9781(96)00037-X

Martin LW, 1990, Acute phase response to endotoxin: rise in plasma α‐MSH and effects of α‐MSH injection, Am. J. Pysiol., 259, R768

Holdeman M, 1985, Fever‐specific changes in central MSH and CRF concentrations, Am. J. Pysiol., 248, R125

10.1016/0361-9230(93)90192-E

10.1016/1043-4666(92)90073-Z

Shih ST, 1986, Central administration of α‐MSH antiserum augments fever in the rabbit, Am. J. Physiol., 250, R803

10.1172/JCI118639

10.1016/0196-9781(91)90015-H

Lipton JM, 1990, Modulation of host defense by the neuropeptide α‐MSH, Yale J. Biol. Med., 63, 173

Grabbe S, 1996, α‐Melanocyte stimulating hormone induces hapten‐specific tolerance in mice, J. Immunol., 156, 473, 10.4049/jimmunol.156.2.473

Bhardwaj RS, 1996, Pro‐opiomelanocortin‐derived peptides induce IL‐10 production in human monocytes, J. Immunol., 156, 2517, 10.4049/jimmunol.156.7.2517

10.3109/02713689208999545

10.1159/000097167

10.1159/000058738

10.1076/ceyr.16.9.900.5043

Caspi R, 1988, A new model of autoimmune disease, experimental autoimmune uveoretinitis induced in mice with two different retinal antigens, J. Immunol., 140, 1490, 10.4049/jimmunol.140.5.1490

10.1111/j.1749-6632.2000.tb05389.x

Nishida T, 1999, Specific aqueous humor factors induce activation of regulatory T cells, Invest. Ophthalmol. Vis. Sci., 40, 2268

Silver P, 1995, Identification of a major pathogenic epitope in the human IRBP molecule recognized by mice of the H‐2r haplotype, Invest. Ophthalmol. Vis. Sci., 36, 946

10.1016/S0167-5699(97)01053-0

10.1126/science.1325670

10.1042/bj3310211

10.1006/bbrc.1999.1848

10.1002/9780470515525.ch15

10.1084/jem.188.2.287

Suri‐Payer E, 1998, CD4+ CD25+ T cells inhibit both the induction and effector function of autoreactive T cells and represent a unique linage of immunoregulatory cells, J. Immunol., 160, 1212, 10.4049/jimmunol.160.3.1212

10.1084/jem.192.2.303

10.1084/jem.192.2.295

10.1016/S1074-7613(00)80195-8

10.1002/(SICI)1521-4141(199811)28:11<3435::AID-IMMU3435>3.0.CO;2-P

10.1084/jem.189.5.877

10.1126/science.7520605

10.1111/j.1749-6632.1996.tb21139.x

Maggi E, 1992, Reciprocal regulatory effects of INF‐γ and IL‐4 on the in vitro development of human Th1 and Th2 clones, J. Immunol., 148, 2142, 10.4049/jimmunol.148.7.2142

10.1210/me.8.10.1298

10.1016/S0092-8674(00)81865-6

10.1016/S0014-2999(98)00212-X