scholarly journals Cyclosporin A-Induced Autoimmunity in the Rat: Central versus Peripheral Tolerance

2002 ◽  
Vol 15 (2) ◽  
pp. 81-87 ◽  
Author(s):  
J.G.M.C. Damoiseaux

Cyclosporin A-induced autoimmunity (CsA-AI) is a thymus dependent and T cell-mediated autoimmune disease that is readily induced in rodents (1, 2) and also occurs in humans (3). Induction of CsA-AI requires total body X-irradiation, rescue with syngeneic or autologous bone marrow, and subsequent cyclosporin A (CsA) administration for about 4 weeks (4). Because the induction protocol involves bone marrow transplantation (BMT), CsA-AI is also referred to as syngeneic or autoimmune graft-versus-host disease (GvHD) (5). The CsA-AI model is being studied for three reasons. Firstly, the animal model, and in particular the chronic phase of the disease, has been reported to have several macroscopic and histopathologic similarities with human scleroderma (6,7). Secondly, CsA-AI is clinically and experimentally examined for its graft- versus-tumour potential against lympho-hematopoietic malignancies as well as metastatic breast cancer (8). And thirdly, CsA-AI has been very informative in terms of T cell development and tolerance induction, including central as well as peripheral control of autoreactivity (9, 10). In the present review, a summary of the characteristics of CsA-AI will be given. Next, the supposed mechanism of CsA for interference with central tolerance induction will be presented. Finally, the role of peripheral tolerance, and in particular dominant T cell tolerance as mediated by regulatory T cells, will be discussed in relation to induction of CsA-AI as well as to strain-related resistance to CsA-AI.

2002 ◽  
Vol 197 (1) ◽  
pp. 19-26 ◽  
Author(s):  
Melanie S. Vacchio ◽  
Richard J. Hodes

Whereas ligation of CD28 is known to provide a critical costimulatory signal for activation of CD4 T cells, the requirement for CD28 as a costimulatory signal during activation of CD8 cells is less well defined. Even less is known about the involvement of CD28 signals during peripheral tolerance induction in CD8 T cells. In this study, comparison of T cell responses from CD28-deficient and CD28 wild-type H-Y–specific T cell receptor transgenic mice reveals that CD8 cells can proliferate, secrete cytokines, and generate cytotoxic T lymphocytes efficiently in the absence of CD28 costimulation in vitro. Surprisingly, using pregnancy as a model to study the H-Y–specific response of maternal T cells in the presence or absence of CD28 costimulation in vivo, it was found that peripheral tolerance does not occur in CD28KO pregnants in contrast to the partial clonal deletion and hyporesponsiveness of remaining T cells observed in CD28WT pregnants. These data demonstrate for the first time that CD28 is critical for tolerance induction of CD8 T cells, contrasting markedly with CD28 independence of in vitro activation, and suggest that the role of CD28/B7 interactions in peripheral tolerance of CD8 T cells may differ significantly from that of CD4 T cells.


Blood ◽  
1987 ◽  
Vol 69 (2) ◽  
pp. 597-604
Author(s):  
KC Anderson ◽  
J Ritz ◽  
T Takvorian ◽  
F Coral ◽  
H Daley ◽  
...  

Hematologic engraftment and immune reconstitution were examined in patients who received cyclophosphamide and total body irradiation therapy followed by infusion of autologous bone marrow purged with anti- B1 monoclonal antibody (MoAb) and complement as therapy for non- Hodgkin's lymphoma. Hematologic engraftment was prompt with return of greater than or equal to 0.5 X 10(3)/microL granulocytes and greater than or equal to 2 X 10(4)/microL platelets at a median of 26 and 29 days posttransplant, respectively. Immunologic reconstitution, in contrast, was prolonged. Normal numbers of circulating B cells were consistently noted by five months posttransplant, whereas return of normal immunoglobulin levels in some patients did not occur for one year. Normal numbers of T cells were evident within the first month posttransplant, but a reversed T4:T8 ratio persisted in some patients up to three years. In vitro responses of either B cells to triggers of activation or of T cells to mitogens and antigens were not normal for at least three months posttransplant. Natural killer (NK) cells predominated early after transplant and may demonstrate cytotoxicity against tumor cells. Our studies demonstrate that transplantation with anti-B1 purged autologous bone marrow results in complete hematologic and delayed immunologic engraftment. No significant acute or chronic clinical toxicities have been observed.


Blood ◽  
1995 ◽  
Vol 85 (8) ◽  
pp. 2263-2268 ◽  
Author(s):  
A Devergie ◽  
D Blaise ◽  
M Attal ◽  
JD Tigaud ◽  
JP Jouet ◽  
...  

From March 1988 to March 1991, 19 French bone marrow transplant (BMT) centers participated in a prospective randomized trial comparing two conditioning regimens for patients with chronic myeloid leukemia transplanted in first chronic phase with an HLA identical sibling donor. A total of 120 consecutive patients were randomized to receive either 120 mg/kg of cyclophosphamide followed by total body irradiation (CY-TBI; n = 55) or 16 mg/kg of busulfan followed by 120 mg/kg of CY (BU-CY; n = 65). Two different TBI regimens were used. Thirteen patients received a 10-Gy single-dose TBI (SDTBI), and 42 received a fractionated TBI (FTBI). Median time between diagnosis and BMT was 315 days. Overall 5-year actuarial survival was 62.9% (65.8% +/- 12.5% for CY-TBI and 60.6 +/- 11.7% for BU-CY; P = .5), and overall disease-free survival was 55% (51% +/- 14% for CY-TBI and 59.1% +/- 11.8% for BU-CY; P = .75). All patients conditioned with CY-TBI experienced sustained engraftment; in contrast, 4 of 65 patients conditioned with BU-CY rejected the graft (P = .18). There was no significant statistical difference between the two groups regarding transplant-related mortality (29% for CY-TBI and 38% for BU-CY; P = .44). So far, with a median follow up of 42 months, 11 patients have relapsed; 9 relapses occurred after CY-TBI, mostly after FTBI (8 of 9) and 2 after BU-CY (P = .02). The actuarial risk of relapse was 4.4% +/- 6.7% after BU-CY, 11.1% +/- 20.8% after SDTBI, and 31.3% +/- 18.1% after FTBI (P = .039). In addition, independently of the conditioning regimen, the increase of posttransplant immunosuppression in 16 patients with an anti- interleukin-2 receptor monoclonal antibody (MoAb) in addition to a short course of methotrexate and cyclosporine was shown to increase the actuarial risk of relapse (57% +/- 30% with MoAb v 9% +/- 7.3% without MoAb; P = .001). We conclude that BU is an acceptable alternative to TBI for patients with chronic myeloid leukemia in first chronic phase receiving BMT from HLA identical sibling donors. Both BU-CY and CY-TBI regimens gave similar transplant-related mortality, and the antileukemic efficiency of BU-CY regimen was either similar or even higher than that of CY-TBI.


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