Role of Regulatory T Cells in the Pathogenesis of Autoimmune Diabetes

2001 ◽  
pp. 308-332 ◽  
Author(s):  
G.A. Arreaza ◽  
S. Sharif ◽  
M.J. Cameron ◽  
W. Chen ◽  
T.L. Delovitch
Keyword(s):  
T Cells ◽  
Regulatory T Cells ◽  
Autoimmune Diabetes

scholarly journals Unique role of CD4+CD62L+ regulatory T cells in the control of autoimmune diabetes in T cell receptor transgenic mice

2004 ◽  
Vol 101 (Supplement 2) ◽  
pp. 14580-14585 ◽  
Author(s):  
S. You ◽  
G. Slehoffer ◽  
S. Barriot ◽  
J.-F. Bach ◽  
L. Chatenoud
Keyword(s):  
T Cells ◽  
T Cell ◽  
Regulatory T Cells ◽  
Transgenic Mice ◽  
T Cell Receptor ◽  
Autoimmune Diabetes ◽  
Cell Receptor ◽  
Unique Role

scholarly journals Regulatory T Cells in the Control of Autoimmunity: the Essential Role of  Transforming Growth Factor β and Interleukin 4 in the Prevention of Autoimmune Thyroiditis in Rats by Peripheral CD4+CD45RC− Cells and CD4+CD8− Thymocytes

1999 ◽  
Vol 189 (2) ◽  
pp. 279-288 ◽  
Author(s):  
Benedict Seddon ◽  
Don Mason
Keyword(s):  
T Cells ◽  
Growth Factor ◽  
Regulatory T Cells ◽  
Autoimmune Thyroiditis ◽  
Transforming Growth Factor ◽  
Autoimmune Diabetes ◽  
Interleukin 4 ◽  
Protective Mechanism ◽  
Peripheral Cells

Previous studies have shown that induction of autoimmune diabetes by adult thymectomy and split dose irradiation of PVG.RT1u rats can be prevented by their reconstitution with peripheral CD4+CD45RC−TCR-α/β+RT6+ cells and CD4+CD8− thymocytes from normal syngeneic donors. These data provide evidence for the role of regulatory T cells in the prevention of a tissue-specific autoimmune disease but the mode of action of these cells has not been reported previously. In this study, autoimmune thyroiditis was induced in PVG.RT1c rats using a similar protocol of thymectomy and irradiation. Although a cell-mediated mechanism has been implicated in the pathogenesis of diabetes in PVG.RT1u rats, development of thyroiditis is independent of CD8+ T cells and is characterized by high titers of immunoglobulin (Ig)G1 antithyroglobulin antibodies, indicating a major humoral component in the pathogenesis of disease. As with autoimmune diabetes in PVG.RT1u rats, development of thyroiditis was prevented by the transfer of CD4+CD45RC− and CD4+CD8− thymocytes from normal donors but not by CD4+CD45RC+ peripheral T cells. We now show that transforming growth factor (TGF)-β and interleukin (IL)-4 both play essential roles in the mechanism of this protection since administration of monoclonal antibodies that block the biological activity of either of these cytokines abrogates the protective effect of the donor cells in the recipient rats. The prevention of both diabetes and thyroiditis by CD4+CD45RC− peripheral cells and CD4+CD8− thymocytes therefore does not support the view that the mechanism of regulation involves a switch from a T helper cell type 1 (Th1) to a Th2-like response, but rather relies upon a specific suppression of the autoimmune responses involving TGF-β and IL-4. The observation that the same two cytokines were implicated in the protective mechanism, whether thymocytes or peripheral cells were used to prevent autoimmunity, strongly suggests that the regulatory cells from both sources act in the same way and that the thymocytes are programmed in the periphery for their protective role. The implications of this result with respect to immunological homeostasis are discussed.

scholarly journals The role of FoxP3+ regulatory T cells and IDO+ immune and tumor cells in malignant melanoma – an immunohistochemical study

BMC Cancer ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Satu Salmi ◽  
Anton Lin ◽  
Benjamin Hirschovits-Gerz ◽  
Mari Valkonen ◽  
Niina Aaltonen ◽  
...  
Keyword(s):  
T Cells ◽  
Prognostic Factors ◽  
Regulatory T Cells ◽  
Tumor Cells ◽  
Immune Cells ◽  
Positive Association ◽  
Tumor Stage ◽  
Melanoma Cells ◽  
Melanoma Progression

Abstract Background FoxP3+ Regulatory T cells (Tregs) and indoleamine-2,3-dioxygenase (IDO) participate in the formation of an immunosuppressive tumor microenvironment (TME) in malignant cutaneous melanoma (CM). Recent studies have reported that IDO expression correlates with poor prognosis and greater Breslow’s depth, but results concerning the role of FoxP3+ Tregs in CM have been controversial. Furthermore, the correlation between IDO and Tregs has not been substantially studied in CM, although IDO is known to be an important regulator of Tregs activity. Methods We investigated the associations of FoxP3+ Tregs, IDO+ tumor cells and IDO+ stromal immune cells with tumor stage, prognostic factors and survival in CM. FoxP3 and IDO were immunohistochemically stained from 29 benign and 29 dysplastic nevi, 18 in situ -melanomas, 48 superficial and 62 deep melanomas and 67 lymph node metastases (LNMs) of CM. The number of FoxP3+ Tregs and IDO+ stromal immune cells, and the coverage and intensity of IDO+ tumor cells were analysed. Results The number of FoxP3+ Tregs and IDO+ stromal immune cells were significantly higher in malignant melanomas compared with benign lesions. The increased expression of IDO in melanoma cells was associated with poor prognostic factors, such as recurrence, nodular growth pattern and increased mitotic count. Furthermore, the expression of IDO in melanoma cells was associated with reduced recurrence˗free survival. We further showed that there was a positive correlation between IDO+ tumor cells and FoxP3+ Tregs. Conclusions These results indicate that IDO is strongly involved in melanoma progression. FoxP3+ Tregs also seems to contribute to the immunosuppressive TME in CM, but their significance in melanoma progression remains unclear. The positive association of FoxP3+ Tregs with IDO+ melanoma cells, but not with IDO+ stromal immune cells, indicates a complex interaction between IDO and Tregs in CM, which demands further studies.

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