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* Department of Laboratory Medicine and Pathobiology, Multi Organ Transplantation Program, Toronto General Research Institute, University Health Network, and
Department of Immunology, University of Toronto, Toronto, Canada
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Abstract |
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 Top Abstract IntroductionMaterials and MethodsResultsDiscussionReferences |
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Introduction |
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TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
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We and others have demonstrated that the infusion of single MHC class I locus-mismatched donor lymphocytes may lead to permanent acceptance of donor-specific skin and heart allografts without the need for nonspecific immunosuppression in H-2Kbm1 (7, 8)-, H-2Kb (9, 10)-, and H-2Ld (11, 12, 13, 14)-mismatched mouse models. Likewise, it has been shown that the infusion of recipient cells that have been genetically engineered to express a donor MHC class I molecule can also induce transplantation tolerance (10, 15, 16). BMT using single HLA locus-mismatched donors is considered, in general, to have a higher incidence of GVHD than using completely HLA-matched donors. However, multivariant analysis at multiple centers has revealed that the risk of acute GVHD is not increased in recipients that received single Ag-mismatched BMT compared with patients that received grafts from HLA-identical siblings (3, 17). Collectively, these findings suggest that single class I locus-mismatched BMT may be a viable alternative to completely HLA-matched allogeneic BMT.
The mechanism by which infusion of single class I-mismatched cells leads to transplantation tolerance rather than rejection remains unclear. Accumulating evidence indicates that regulatory T (Treg) lymphocytes play an important role in the down-regulation of immune responses to self or allogeneic Ags (13, 18, 19, 20, 21, 22, 23, 24, 25, 26). Recently, several groups have shown that CD4+CD25+ Treg cells are involved in suppressing GVHD after semi- and fully allogeneic BMT (7, 27, 28). We have demonstrated in three different models that CD3+CD4-CD8- double-negative (DN) Treg cells play an important role in induction of allogeneic skin (13, 14) and xenogeneic heart (29) transplantation tolerance. This population of DN Treg cells differs from other Treg cells in its surface marker expression, cytokine profile, and mechanism of suppression (13), and can specifically suppress CD8+ and CD4+ T cells that are primed against the same alloantigen (7, 13, 29, 30). Whether this population of DN Treg cells is involved in preventing the development of GVHD has not been studied.
In this study, we investigated the effect of the infusion of single class I locus-mismatched lymphocytes on the development of GVHD in immunodeficient mice and the underlying mechanisms. We demonstrate that recipient mice did not develop GVHD following infusion of Ld-mismatched allogeneic lymphocytes. The number of donor-derived DN Treg cells in the periphery of recipient mice was significantly increased after the infusion of Ld-mismatched lymphocytes. These DN Treg cells could specifically suppress the proliferation of antihost CD8+ T cells, and attenuate GVHD when coinfused with allogeneic CD8+ T cells. These findings indicate that DN Treg cells play an important role in the induction of donor-specific transplantation tolerance in single class I locus-mismatched models, and indicate the potential to use single class I locus-mismatched allogeneic cells as a novel cellular therapy.
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Materials and Methods |
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TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
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C57BL/6 (B6, H-2b), C3H (H-2k), (B6 x BALB/c)F1 (H-2b/d), and BALB/c H-2-dm2 (dm2) mice were purchased from The Jackson Laboratory (Bar Harbor, ME). Breeding stocks of 2C and HY transgenic mice were kindly provided by D. Y. Loh (Hoffman-LaRoche, Nutley, NJ) (31) and H.-S. Teh (University of British Columbia, Vancouver, Canada), respectively. The 2C transgenic mice (on B6 background) carry functionally rearranged TCR 
- and 
-chain transgenes that are specific for class I MHC Ld (31), and are recognized by the mAb 1B2 (32). The 2C transgenic mice were bred with dm2 mice (a BALB/c Ld loss mutant). The offspring, either (2C x dm2)F1 mice (H-2b/d, Ld-, 1B2+) or (B6 x dm2)F1 mice (H-2b/d, Ld-, 1B2-), were used as lymphocyte donors. C.B-17 SCID mice (effectively BALB/c congenic to B6 at the IgH locus, H-2d/d) were bred with B6 SCID mice. The resulting SCID F1 mice (Db/d, Kb/d, Ld+) were sublethally irradiated (2.5 Gy) and used as recipients. Lethally irradiated (8.5 Gy) (B6 x BALB/c)F1 mice (H-2b/d, Ld+) were also used as recipients.
Generation and maintenance of DN Treg cell clones
Spleen cells were collected from naive (2C x dm2)F1 mice and used to generate T cell clones using standard cloning and subcloning procedures, as described elsewhere (13). To maintain the T cell clones, 5 x 104 cells were cultured in a 24-well plate containing 5 x 105 irradiated Ld+ cells in -MEM supplemented with 10% FCS, 30 IU/ml rIL-2, and 30 IU/ml rIL-4. The cells were incubated at 37°C with 5% CO2. The T cell clones were stimulated in the above manner every 3–4 days. The 1B2+DN Treg clone TN12.2 was used for studies.
Infusion of allogeneic lymphocytes and evaluation of GVHD
SCID F1 or C.B-17 SCID mice were sublethally irradiated (2 Gy) or (B6 x BALB/c)F1 mice were lethally irradiated (8.5 Gy) and used as recipients. Single viable cell suspensions were prepared from the spleen and lymph nodes of donor mice or DN T cell clones and injected into sex-matched recipient mice via the tail vein (4 x 107 cells/mouse for spleen and lymph node cells; 5 x 106 cells/mouse for DN T cell clones). Clinical signs of GVHD (33), such as weight loss, diarrhea, ruffled fur, hunched posture, and scaled ears, were monitored three times per week. In addition, tissue samples from major GVHD lesion sites (liver, skin, and intestine) were harvested, stained with H&E, and evaluated by light microscopy for GVHD, according to standard methods (33).
Cell surface marker staining
Splenocytes were collected at various time points following reconstitution and triple stained with fluorescence-conjugated mAbs specifically recognizing the -TCR (1B2, hybridoma from H. Eison; MRT, Boston, MA), CD4, and CD8. In some mice, staining was also performed using anti-CD3, anti-NK1.1, and T3.70 (hybridoma from J. Penninger; University Health Network, Toronto, Canada) mAbs. All mAbs, except 1B2 and T3.70, were purchased from BD PharMingen (San Diego, CA). Data were acquired and analyzed on an EPICS XL-MCL flow cytometer.
Suppression assays
DN Treg cells were purified from the spleens of reconstituted mice by FACS, as described previously (13). Varying numbers of DN Treg cells or DN T cell clones were cocultured with Ld-specific CD8+ responder cells (1000/well) in the presence of 105 irradiated (20 Gy) (B6 x BALB/c)F1 splenocytes, 50 IU/ml rIL-2, and 30 IU/ml rIL-4. After 3.5 days of culture, 1 µCi of [3H]TdR was added. Proliferation was measured 18 h later using a Top Count (Packard, Boston, MA) scintillation counter.
Cytotoxicity assays
Target cell death resulting from coculture with DN T cells was measured, as previously reported (13). Briefly, DN T cell clones were stimulated by irradiated allogeneic splenocytes for 3 days in the presence of rIL-2/rIL-4. Viable cells were harvested and seeded into 96-well microtiter plates as effector cells. The 1B2+CD8+ target cells were activated with Ld+ (B6 x BALB/c)F1 splenocytes and rIL-2 for 2–3 days. Activated CD8+ T cells were collected, labeled with 10 µCi/ml of [3H]TdR at 37°C overnight, and used as targets. After coculture with the effector cells at 37°C for 18 h (in the presence of fresh irradiated allogeneic splenocytes), the cells were harvested and counted in a beta counter. The JAM assay (34) was used to determine Fas-dependent cytotoxicity. Specific cell lysis was calculated using the equation: percentage of specific killing = (S - E)/S x 100, in which E (experimental) is cpm of retained DNA in the presence of effector cells, and S (spontaneous) is cpm of retained DNA in the absence of effector cells.
Statistical analyses
All statistical analyses were performed using the Student’s t test, and were calculated using Microsoft Excel XP. Error bars represent SD.
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Results |
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To study whether the infusion of single class I locus-mismatched lymphocytes causes GVHD in mice, we developed a model using both immunodeficient SCID F1 mice and wild-type (B6 x BALB/c)F1 mice, which are on the same background (H-2b/d). SCID F1 mice were sublethally irradiated and (B6 x BALB/c)F1 mice were lethally irradiated, followed by infusion of Ld-mismatched lymphocytes from (2C x dm2)F1 mice, which have a transgenic anti-Ld TCR. As a positive control for GVHD, SCID F1 and (B6 x BALB/c)F1 mice were infused with splenocytes from one haplotype-mismatched B6 mice. All of the SCID F1 and (B6 x BALB/c)F1 mice that received Ld-mismatched allogeneic lymphocytes survived longer than 150 days (Table I), and none of the animals lost weight (Fig. 1a) or showed other pathohistologic signs of GVHD (Fig. 1b, top). In contrast, mice infused with semiallogeneic B6 lymphocytes rapidly lost weight (Fig. 1a) and developed lesions in the liver that are typical of GVHD (Fig. 1b, middle).
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Recipient mice develop Ag-specific transplantation tolerance following the infusion of Ld-mismatched lymphocytes
Next, we studied whether mice given Ld-mismatched lymphocytes could generate immune responses against allogeneic Ags. Three weeks after the infusion of Ld-mismatched allogeneic spleen cells,recipient SCID F1 mice were given skin allografts from both (B6 x BALB/c)F1 (donor-specific) and C3H (third-party) mice. As a control, a group of naive SCID F1 mice was also given both skin allografts. As shown in Fig. 2a, naive SCID F1 mice were unable to reject either of the skin allografts up to 150 days after transplantation. In contrast, SCID F1 mice that were given Ld-mismatched lymphocytes were able to reject third-party C3H skin allografts within 1 wk (Fig. 2a). Interestingly, the Ld-mismatched (B6 x BALB/c)F1 skin allografts were not rejected in these mice. These findings indicate that the immunodeficient recipients that were infused with Ld-mismatched lymphocytes established immunity to third-party Ags, but remained unresponsive to Ld.
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Because SCID F1 and (B6 x BALB/c)F1 mice did not develop GVHD (Table I and Fig. 1) and did not reject Ld+ skin grafts following the infusion of allogeneic lymphocytes (Fig. 2a), it is possible that donor-derived anti-Ld CD8+ T cells were suppressed following their infusion into recipient mice. To study this possibility, Ld-specific 1B2+CD8+ T cells were purified from naive female (2C x dm2)F1 mice and infused into Ld+ male (B6 x BALB/c)F1 mice 60 days after reconstitution with (B6 x dm2)F1 splenocytes. As a control, all mice were also infused with the same number of purified anti-male HY T3.70+CD8+ T cells purified from female B6 anti-male TCR transgenic mice. In this setting, the recipient mice express both Ld and male HY Ags, which can be recognized by 1B2+CD8+ and T3.70+CD8+ T cells, respectively. As expected, the number of anti-male HY T3.70+CD8+ T cells in the spleen expanded significantly between days 1 and 4 after infusion into reconstituted mice (Fig. 2b). Previously, we have demonstrated that naive 1B2+CD8+ T cells expand when infused into naive Ld+ mice (35, 36). Interestingly, no expansion of newly injected naive 1B2+CD8+ T cells was observed in reconstituted mice (Fig. 2b), indicating that the proliferation of the anti-Ld CD8+ T cells was selectively inhibited. These results provide direct in vivo evidence that donor-derived lymphocytes from reconstituted mice can specifically suppress the proliferation of newly injected anti-Ld, but not third-party CD8+ T cells.
DN Treg cells increase in recipient mice following infusion of Ld-mismatched lymphocytes
The above results indicate that specific tolerance to Ld alloantigen was established in recipients after infusion of Ld-mismatched lymphocytes. This suggests that the anti-Ld immune response was suppressed in vivo by donor-derived lymphocytes. To gain further insight into the mechanism by which anti-Ld immune responses were inhibited, the fate of donor-derived Ld-specific T lymphocytes was monitored in vivo using 1B2 mAb, which binds T cells with a transgenic anti-Ld TCR. We observed a vigorous expansion, followed by a massive depletion of the number of antihost 1B2+CD8+ T cells in the spleen of recipients (Fig. 3). However, the depletion of 1B2+CD8+ T cells was not complete. A significant number of antihost 1B2+CD8+ T cells persisted in the spleen of the recipients even at 125 days after infusion. Because the recipients did not develop GVHD, it suggests that the function of these residual anti-Ld CD8+ T cells was inhibited in vivo. Interestingly, as shown in Fig. 3, we found a steady increase in the number of donor-derived 1B2+DN T cells in these recipient mice. These 1B2+DN T cells express the same set of cell surface markers as found on DN Treg cells, e.g., -TCR+CD3+CD4-CD8-NK1.1- (13), and became the dominant population of T cells in the spleen of recipients over time. The 1B2+CD4+ T cells also increased in the first 21 days after infusion of donor lymphocytes, but remained relatively unchanged thereafter (Fig. 3).
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We have recently demonstrated in three different mouse models that DN T cells have a regulatory function and can suppress immune responses mediated by CD8+ or CD4+ T cells that are syngeneic to the DN T cells (7, 8, 13, 14, 29, 30). Next, we studied whether DN T cells from reconstituted recipient mice were able to suppress proliferation of syngeneic antihost CD8+ T cells. The 1B2+DN T cells and CD3+DN T cells were isolated from recipient mice 30 wk after infusion of (2C x dm2)F1 or (B6 x dm2)F1 splenocytes and used as putative suppressor cells. As shown in Fig. 4, DN T cells isolated from both transgenic and nontransgenic recipient mice that were infused with Ld-mismatched allogeneic splenocytes were able to inhibit the proliferation of syngeneic anti-Ld CD8+ T cells in a dose-dependent fashion. These data indicate that donor-derived DN Treg cells expand to become the dominant T lymphocyte population in reconstituted mice, and that these cells can suppress antihost CD8+ T cells in vitro.
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To further determine whether DN Treg cells can be generated in vitro and used for inhibition of GVHD, we first generated a panel of Ld-specific DN Treg clones and studied their ability to suppress anti-Ld T cell responses in vitro. The 1B2+DN T cells were purified from naive (2C x dm2)F1 mice by fluorescence-activated cell sorting and were cloned using standard techniques. A total of 5 x 104 1B2+DN Treg cell clones was stimulated in 24-well plates together with irradiated (B6 x BALB/c)F1 Ld+ splenocytes for 4 days, and the ability of these clones to suppress anti-Ld T cells was assessed. When coincubated with 1B2+CD8+ T cells, DN Treg clones were able to suppress the proliferation of cells up to 75% (Fig. 5a). To further determine whether DN T cells could also kill CD8+ T cells, 1B2+DN Treg clones were used as effector cells, and activated 1B2+CD8+ T cells were labeled and used as targets. Up to 28% of 1B2+CD8+ T cells were killed by 1B2+DN T cell clones after 18-h incubation (Fig. 5b). These results demonstrate that stimulating DN T cells with Ld-mismatched allogeneic lymphocytes in vitro produces activated DN Treg cells. Like the DN Treg cells purified from reconstituted mice, the in vitro activated DN Treg clones could both suppress the proliferation of and kill activated Ld-specific CD8+ T cells.
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Finally, we evaluated the anti-GVHD activity of in vitro generated DN Treg cells. To this end, purified 1B2+CD8+ T lymphocytes were infused into sublethally (2.5Gy) irradiated C.B-17 SCID (H-2d+) mice either alone or in combination with 1B2+DN Treg clone). Both clinical signs of GVHD (33) and body weight of recipient mice were monitored every second day. We found that mice infused with 1B2+CD8+ T cells alone had ruffled fur, hunched backs, and diarrhea, and lost 20–25% of body weight (Fig. 6a). Despite slowly recovering body weight, histology taken at 100 days after infusion of CD8+ cells clearly showed evidence of GVHD (Fig. 6b). This finding indicates that the infusion of purified Ld-mismatched allogeneic CD8+ T cells is sufficient to cause GVHD. Interestingly, the mice that were given 1B2+CD8+ T cells together with 1B2+DN Treg clones had ruffled fur, but no diarrhea or hunched back. Their weight loss was less severe, and these mice recovered much faster (Fig. 6a). More importantly, histology taken at 100 days after coinjection of DN Treg clones with CD8+ T cells showed normal liver (Fig. 6c), skin, and intestine (data not shown) histology with no signs of GVHD. These data demonstrate that in vitro generated DN Treg cells are able to attenuate GVHD caused by allogeneic CD8+ T cells.
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Discussion |
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Although tolerance resulting from the infusion of single class I locus-mismatched donor lymphocytes has been observed for many years, the mechanism by which tolerance is induced has not been clearly identified. In this study, we show that the number of 1B2+CD8+ antihost CD8+ T cells increased following infusion of donor lymphocytes, but rapidly decreased by day 21. We and others have shown that 1B2+CD8+ T cells can die by activation-induced cell death (AICD) following infusion into Ld+ mice (35, 37, 38). These findings suggest that the initial decrease in the number of antihost CD8+ T cells may be due to AICD. Nonetheless, AICD was not complete, as the recipients still had a significant number of antihost CD8+ T cells throughout the experimental period (Fig. 3). Because none of the recipient mice developed GVHD in the presence of these antihost T cells, it indicates that AICD alone is not sufficient to explain the maintenance of tolerance.
As postulated by Turka’s group (39), the initial decline in CD8+ T cells may be necessary to decrease the size of the pool of lymphocytes, but the prevention of GVHD may also depend on other mechanisms of tolerance, such as anergy or suppression. There are several indications that antihost CD8+ T cells are specifically suppressed: 1) the survival of Ld+, but not third-party skin grafts was prolonged following a lymphocyte infusion into immunodeficient mice (Fig. 2a); 2) recipient mice did not develop GVHD even after a second infusion of naive anti-Ld lymphocytes (data not shown); 3) naive anti-HY CD8+ T cells proliferated well, but naive anti-Ld T cells did not proliferate when these cells were infused into recipient mice that had been reconstituted with Ld-mismatched lymphocytes (Fig. 2b); 4) DN Treg cells purified from tolerant recipient mice were able to suppress the proliferation of 1B2+CD8+ T cells in vitro (Fig. 4); 5) DN Treg cells prevented GVHD caused by the infusion of 1B2+CD8+ T cells in mice (Fig. 6). Together, these findings strongly suggest that the remaining antihost CD8+ T cells are suppressed by DN Treg cells in an Ag-specific manner in mice following the initial decline in the number of antihost CD8+ T cells.
We have demonstrated the mechanism for DN Treg cell-mediated suppression of anti-Ld T cells in a skin-grafting model (13, 30). Briefly, DN T cells are able to acquire Ld from APC and express the acquired Ld on their surface. The acquired Ag on DN Treg cells is recognized by anti-Ld CD8+ T cells, and when these cells come into contact the CD8+ T cell is killed through a Fas/Fas ligand-dependent pathway (13). The 1B2+DN Treg cells cannot acquire Ag from Ld- APCs (Young et al., manuscript in preparation), and are therefore unable to trap and kill anti-third-party T cells. This model can explain how Ag-specific tolerance is maintained in mice following the infusion of single class I locus-mismatched splenocytes.
Different subsets of Treg cells, including CD4+ (18, 19, 20, 21, 22), CD8+ (23), 
TCR+ (24), DN (7, 13, 14, 29, 30), and NKT (25, 26) cells, have been demonstrated to play an important role in the down-regulation of immune responses against self and allogeneic Ags. Tutschka et al. (40) were one of the earliest to describe the involvement of suppressor T cells after allogeneic BMT. They reported that rats that were given an allogeneic BMT and survived acute GVHD were resistant to GVHD caused by the infusion of allogeneic donor lymphocytes at day 250. Furthermore, T lymphocytes from the rats that survived acute GVHD could suppress both in vitro antihost immune responses and GVHD when adoptively transferred into naive animals. However, the phenotype of the T cells that were able to suppress GVHD in this model was not known. Zeng et al. (41) show that -TCR+DN NKT cells were able to suppress GVHD in BALB/c mice challenged with purified CD4+ or CD8+ T cells from B6 mice. Johnson et al. (42) reported that AKR (H-2k) mice that were given an allogeneic BMT from either fully MHC-mismatched B6 (H-2b) or MHC-matched B.10.BR mice, followed by a donor lymphocyte infusion from the same mice on day 21, only develop mild GVHD due to suppression by Thy-1+ CD4+ and DN T cells. Similarly, an increase in CD3+DN T cells has been identified in mice that were given a high dose injection of IL-2 at the time of BMT and were protected from GVHD (43, 44), although the function of these cells was not directly assessed.
In this study, we demonstrate that donor-derived DN Treg cells expand in the periphery of immunodeficient mice following an infusion of Ld-mismatched lymphocytes (Fig. 3). These DN Treg cells are able to specifically suppress proliferation of anti-Ld CD8+ T cells in vitro (Fig. 4). Ideally, we should study the anti-GVHD ability of DN Treg cells by either in vivo depletion of DN Treg cells from tolerant mice or adoptively transferring these cells into naive mice. However, due to the lack of specific markers on DN Treg cells, it is currently not possible to selectively deplete DN Treg cells in vivo without affecting other T cell subsets. Likewise, the purification of a sufficient number of DN T cells from the spleens of reconstituted mice was not practical due to extremely long sorting times that would be required. As an alternative approach, we generated DN Treg cells in vitro and demonstrated that these in vitro produced DN Treg cells could specifically suppress the proliferation of 1B2+CD8+ T cells. Moreover, the infusion of in vitro generated DN Treg cells attenuated GVHD caused by the infusion of anti-Ld CD8+ T cells (Fig. 6). Collectively, these data provide direct evidence that DN Treg cells are able to suppress antihost CD8+ T cells and attenuate GVHD. It has been demonstrated in skin and cardiac transplant models that tolerance to single MHC class I molecules can spread to other miHA and MHC molecules (9, 12). Whether DN Treg cells can similarly prevent GVHD in multiple miHA- and MHC-mismatched models needs to be determined.
Recently, it has been shown that the depletion of CD4+CD25+ Treg cells from lymphocyte populations that were subsequently transferred into semi or fully MHC-mismatched mice leads to an accelerated GVHD (27). Furthermore, the infusion of B6 CD4+CD25+ Treg cells together with B6 CD4+ T cells into BALB/c or BALB/c SCID mice markedly suppressed acute GVHD compared with controls infused with CD4+ T cells alone or together with CD4+CD25- T cells (27, 28). These findings define a role for CD4+CD25+ Treg cells in suppressing GHVD in semi or fully MHC-mismatched models. It is unclear what role CD4+CD25+ Treg cells might have in a single class I-mismatched model. We found that there are a smaller, but significant number of CD4+ T cells in mice that that were given single MHC locus-mismatched lymphocyte infusions (Fig. 3). It is possible that CD4+ T cells might also have a suppressive capability or may produce cytokines, including IL-2 and IL-4, which are required for DN T cell survival and function (11, 45). These possibilities are currently under study.
Taken together, the results presented in this work demonstrate that infusion of MHC class I Ld-mismatched allogeneic lymphocytes results in Ag-specific transplantation tolerance. The mechanism involves both the deletion of the majority of antihost CD8+ T cells and the activation of donor-derived DN Treg cells. DN Treg cells either purified from tolerant recipient mice or generated in vitro can suppress antihost CD8+ T cell responses in vitro. Significantly, in vitro generated DN Treg cells are also able to prevent GVHD caused by the infusion of Ld-specific CD8+ T cells. Collectively, these findings suggest that single MHC class I locus-mismatched transplants may be a viable alternative to using fully matched grafts, and that DN Treg cells may be useful as a novel cellular therapy to prevent GVHD.
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Acknowledgments |
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Footnotes |
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2 Address correspondence and reprint requests to Dr. Li Zhang, Toronto General Hospital, University Health Network, NU-G-001, 621 University Avenue, Toronto, Ontario, M5G 2C4, Canada. E-mail address: lzhang{at}transplantunit.org
3 Abbreviations used in this paper: miHA, minor histocompatibility Ag; AICD, activation-induced cell death; BMT, bone marrow transplantation; DN, double negative; GVHD, graft-vs-host disease; Treg, regulatory T.
Received for publication February 13, 2003. Accepted for publication April 28, 2003.
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References |
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TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
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cells: a right time and a right place for a conserved third way of protection. Annu. Rev. Immunol. 18:975.[Medline]
+ or DX5+TCR+ T cells in mice conditioned with fractionated lymphoid irradiation protects against graft-versus-host disease: "natural suppressor" cells. J. Immunol. 167:2087.+ CD4-CD8- antigen-specific suppressor T-cell clones. J. Immunol. 162:5860.This article has been cited by other articles:
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  R. Chakraverty, B. Flutter, F. Fallah-Arani, H.-S. Eom, T. Means, G. Andreola, S. Schwarte, J. Buchli, P. Cotter, G. Zhao, et al. The Host Environment Regulates the Function of CD8+ Graft-versus-Host-Reactive Effector Cells J. Immunol., November 15, 2008; 181(10): 6820 - 6828. [Abstract] [Full Text] [PDF]
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M. S. Ford McIntyre, K. J. Young, J. Gao, B. Joe, and L. Zhang Cutting Edge: In Vivo Trogocytosis as a Mechanism of Double Negative Regulatory T Cell-Mediated Antigen-Specific Suppression J. Immunol., August 15, 2008; 181(4): 2271 - 2275. [Abstract] [Full Text] [PDF]
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W. Chen, J. Diao, S. M. Stepkowski, and L. Zhang Both Infiltrating Regulatory T Cells and Insufficient Antigen Presentation Are Involved in Long-Term Cardiac Xenograft Survival J. Immunol., August 1, 2007; 179(3): 1542 - 1548. [Abstract] [Full Text] [PDF]
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L. Niu, S. Strahotin, B. Hewes, B. Zhang, Y. Zhang, D. Archer, T. Spencer, D. Dillehay, B. Kwon, L. Chen, et al. Cytokine-Mediated Disruption of Lymphocyte Trafficking, Hemopoiesis, and Induction of Lymphopenia, Anemia, and Thrombocytopenia in Anti-CD137-Treated Mice J. Immunol., April 1, 2007; 178(7): 4194 - 4213. [Abstract] [Full Text] [PDF]
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G. Chamberlain, M. Wallberg, D. Rainbow, K. Hunter, L. S. Wicker, and E. A. Green A 20-Mb Region of Chromosome 4 Controls TNF-{alpha}-Mediated CD8+ T Cell Aggression Toward beta Cells in Type 1 Diabetes J. Immunol., October 15, 2006; 177(8): 5105 - 5114. [Abstract] [Full Text] [PDF]
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M. S. Ford, Z.-X. Zhang, W. Chen, and L. Zhang Double-Negative T Regulatory Cells Can Develop Outside the Thymus and Do Not Mature from CD8+ T Cell Precursors. J. Immunol., September 1, 2006; 177(5): 2803 - 2809. [Abstract] [Full Text] [PDF]
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B. P.-L. Lee, W. Chen, H. Shi, S. D. Der, R. Forster, and L. Zhang CXCR5/CXCL13 Interaction Is Important for Double-Negative Regulatory T Cell Homing to Cardiac Allografts J. Immunol., May 1, 2006; 176(9): 5276 - 5283. [Abstract] [Full Text] [PDF]
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B. P.-L. Lee, E. Mansfield, S.-C. Hsieh, T. Hernandez-Boussard, W. Chen, C. W. Thomson, M. S. Ford, S. E. Bosinger, S. Der, Z.-x. Zhang, et al. Expression Profiling of Murine Double-Negative Regulatory T Cells Suggest Mechanisms for Prolonged Cardiac Allograft Survival J. Immunol., April 15, 2005; 174(8): 4535 - 4544. [Abstract] [Full Text] [PDF]
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 K. Fischer, S. Voelkl, J. Heymann, G. K. Przybylski, K. Mondal, M. Laumer, L. Kunz-Schughart, C. A. Schmidt, R. Andreesen, and A. Mackensen Isolation and characterization of human antigen-specific TCR{alpha}{beta}+ CD4-CD8- double-negative regulatory T cells Blood, April 1, 2005; 105(7): 2828 - 2835. [Abstract] [Full Text] [PDF]
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L. E. Marra, Z. X. Zhang, B. Joe, J. Campbell, G. A. Levy, J. Penninger, and L. Zhang IL-10 Induces Regulatory T Cell Apoptosis by Up-Regulation of the Membrane Form of TNF-{alpha} J. Immunol., January 15, 2004; 172(2): 1028 - 1035. [Abstract] [Full Text] [PDF]
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 K. J. Young, L. S. Kay, M. J. Phillips, and L. Zhang Antitumor Activity Mediated by Double-Negative T Cells Cancer Res., November 15, 2003; 63(22): 8014 - 8021. [Abstract] [Full Text] [PDF]
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), (B6 x dm2)F1 lymphocytes (
), or B6 (
) mice. Body weights were monitored at the indicated time points. b, Lethally irradiated (B6 x BALB/c)F1 mice were reconstituted with splenocytes either from (2C x dm2)F1 (top panel), B6 (middle panel), or (B6 x dm2)F1 (bottom panel) mice. H&E staining of liver is shown (x300) at 100 days after infusion of allogeneic cells. Top and bottom panels, Show that the hepatocytes, liver cell cords, and portal and venous structures are normal, with no evidence of GVHD. Middle panel, Shows infiltrating mononuclear cells, proliferation in bile ducts, and abnormal portal and venous structure, a typical lesion of chronic GVHD in the liver.
) mice, as previously reported (
