| 1. |
- Chen, Jibing, et al.
(författare)
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An N-(alkylcarbonyl)anthranilic acid derivative prolongs cardiac allograft survival synergistically with cyclosporine A in a high-responder rat model
- 2010
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Ingår i: Transplant Immunology. - : Elsevier BV. - 1878-5492 .- 0966-3274. ; 23:4, s. 180-184
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Tidskriftsartikel (refereegranskat)abstract
- We investigated the immunosuppressive effects of the dihydroortate dehydrogenase (DHODH) inhibitor compounds ABR-222417 and ABR-224050 from Active Biotech (Sweden). We verified the inhibitory effects of these compounds on the proliferation of CD4(+) and CD8(+) T-cells in vivo by using superantigen staphylococcus enterotoxin A (SEA)-mediated proliferation test. To evaluate their efficacy, the compounds were screened in a low-responder heart allograft transplantation model in rats [heart from Piebald Virol Glaxo (PVG) transplanted to Dark Agouti (DA)]. The immunosuppressive effects of the compounds were then investigated in a high-responder model (DA to PVG). Treatment with ABR-222417 (30 mg/kg) was more efficient than that with ABR-224050 (10 mg/kg), and the former provided a longer graft median survival time (MST, 29.5 days) than the latter (MST, 18.5 days). Furthermore, there was a marked increase in graft survival time (53 days) when low doses of ABR-222417 and cyclosporine A (CsA) were used in combination. No sign of tolerability problems was detected using this combination or when ABR-222417 was used singly at a higher dose. Furthermore, T-cell proliferation studies in vitro support that the anti proliferative effect of ABR-222417 is caused by inhibition of de novo pyrimidine synthesis, which is the consequence of DHODH inhibition. These results show that ABR-222417 had marked immunosuppressive effects on the heart allograft transplantation and that it exerts an even more powerful inhibitory effect on graft rejection when used in combination with CsA, with good tolerability. (C) 2010 Elsevier B.V. All rights reserved.
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| 2. |
- Dai, Helong, et al.
(författare)
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Blockade of CD27/CD70 pathway to reduce the generation of memory T cells and markedly prolong the survival of heart allografts in presensitized mice
- 2011
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Ingår i: Transplant Immunology. - : Elsevier BV. - 1878-5492 .- 0966-3274. ; 24:4, s. 195-202
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Tidskriftsartikel (refereegranskat)abstract
- Background: Alloreactive memory T cells are a major obstacle to transplantation acceptance due to their capacity for accelerated rejection. Methods: C57BL/6 mice that had rejected BALB/c skin grafts 4 weeks earlier were used as recipients. The recipient mice were treated with anti-CD154/LFA-1 with or without anti-CD70 during the primary skin transplantation and anti-CD154/LFA-1 or not during the secondary transplantation of BALB/c heart. We evaluated the impact of combinations of antibody-mediated blockade on the generation of memory T cells and graft survival after fully MHC-mismatched transplantations. Results: One month after the primary skin transplantation, the proportions of CD4(+) memory T cells/CD4(+) T cells and CD8(+)memory T cells/CD8(+) T cells in the anti-CD154/LFA-1 combination group were 47.32 +/- 428% and 23.18 +/- 2.77%, respectively. In the group that included anti-CD70 treatment, the proportions were reduced to 34.10 +/- 2.71% and 12.19 +/- 3.52% (P<0.05 when comparing the proportion of memory T cells between the two groups). The addition of anti-CD70 to the treatment regimen prolonged the mean survival time following secondary heart transplantation from 10 days to more than 90 days (P<0.001). Furthermore, allogenic proliferation of recipient splenic T cells and graft-infiltrating lymphocytes were significantly decreased. Meanwhile, the proportion of regulatory T cells was increased to 9.46 +/- 1.48% on day 100 post-transplantation (P<0.05). Conclusions: The addition of anti-CD70 to the anti-CD154/LFA-1 combination given during the primary transplantation reduced the generation of memory T cells. This therapy regimen provided a potential means to alleviate the accelerated rejection mediated by memory T cells during secondary heart transplantation and markedly prolong the survival of heart allografts. (C) 2011 Elsevier B.V. All rights reserved.
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| 3. |
- Kang, Xiangpeng, et al.
(författare)
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Isatis tinctoria L. combined with co-stimulatory molecules blockade prolongs survival of cardiac allografts in alloantigen-primed mice
- 2010
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Ingår i: Transplant Immunology. - : Elsevier BV. - 1878-5492 .- 0966-3274. ; 23:1-2, s. 34-39
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Tidskriftsartikel (refereegranskat)abstract
- Memory T cells present a unique challenge in transplantation. Although memory T cells express robust immune responses to invading pathogens. they may be resistant to the effects of immunosuppressive therapies used to prolong graft survival. In previous studies, we found that compound K. the synthesized analogue of highly unsaturated fatty acids from Isatis tinctoria L., reduced acute cardiac allograft rejection in mice (Wang et al., 2009 [1]). Here, we further investigated the effect of compound K on cardiac allograft rejection in alloantigen-primed mice. We found that compound K significantly inhibited CD4(+) and CD8(+) memory T cells proliferation in a mixed lymphocyte reaction (MLR). In vivo, compound K combined with anti-CD154 and anti-LFA-1 monoclonal antibodies (mAbs) significantly extended the survival time of heart grafts in alloantigen-primed mice with no obvious toxic side effects. Furthermore, our data suggests that compound K works by reducing the expression of both IL-2 and IFN-gamma within the graft rather than enhancing expression of regulatory T cells (Tregs). Compound K can also inhibit the alloresponses of memory T cells, while increasing the proportion of CD4(+) memory T cells in the spleen of the recipients and significantly reducing the level of alloantibodies in the serum. Our study highlights the unique immune effects of compound K that may be further explored for clinical use in extending the survival of transplant grafts. (C) 2010 Elsevier B.V. All rights reserved.
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| 4. |
- Lin, Yingying, et al.
(författare)
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Arsenic trioxide is a novel agent for combination therapy to prolong heart allograft survival in allo-primed T cells transferred mice
- 2011
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Ingår i: Transplant Immunology. - : Elsevier BV. - 1878-5492 .- 0966-3274. ; 25:4, s. 194-201
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Tidskriftsartikel (refereegranskat)abstract
- Alloreactive memory T cells are major barriers to transplantation acceptance due to their capacity to accelerate rejection. Here, we investigated the effects of combined treatment with arsenic trioxide (As(2)O(3)) and blocking monoclonal antibodies (mAb) against CD154 and LFA-1 (anti-CD154/LFA-1) on graft survival as well as changes in pathology and immunological responses in mice with adoptively transferred allo-primed T cells. The mean survival time (MST) for the cardiac allografts in recipient mice receiving the combination of As(2)O(3) and anti-CD154/LFA-1 was significantly longer (>113.7 days) compared to those receiving anti-CD154/LFA-1 (232 days), As(2)O(3) (12.5 days) alone or no treatment (5.5 days). This combined strategy distinctly inhibited lymphocyte infiltration in grafts, proliferation of splenic T cells and the generation of memory T cells in spleens. Moreover, the combined treatment caused the significant down-regulation of IL-2 and IFN-gamma accompanied by increased expression of TGF-beta and regulatory T cells (Tregs) in spleens, which led to long-term cardiac allograft survival in recipient mice. These results highlight the potential application of As(2)O(3) and its contribution in combination therapy with antibody blockade to delay rejection by memory T cells. (C) 2011 Elsevier B.V. All rights reserved.
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| 5. |
- Shao, Wei, et al.
(författare)
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CD44/CD70 blockade and anti-CD154/LFA-1 treatment synergistically suppress accelerated rejection and prolong cardiac allograft survival in mice.
- 2011
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Ingår i: Scandinavian Journal of Immunology. - : Wiley. - 1365-3083 .- 0300-9475. ; 74, s. 430-437
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Tidskriftsartikel (refereegranskat)abstract
- Current treatments that are efficient in controlling effector T cells responses to allografts have limited efficacy on the accelerated rejection mediated by memory T cells. Effective targeting of alloreactive memory T cells may therefore be explored to improve therapeutic approaches towards solving this problem. In this study, we investigated the synergistic effect of CD44/CD70 blockade and anti-CD154/LFA-1 treatment on the accelerated rejection mediated by memory T cells. While CD44/CD70 blockade had limited effects on the alloresponses of effector T cells in vivo, it diminished the expansion of both CD4(+) and CD8(+) memory T cells in recipients adoptively transferred with donor-sensitized T cells. In combination with anti-CD154/LFA-1 treatment, CD44/CD70 blockade significantly prolonged cardiac allograft survival in adoptive transfer recipients. We demonstrated that treatment with the combination of all four antibodies (anti-CD154/LFA-1/CD44/CD70) inhibited accelerated rejection by markedly suppressing the alloresponses of effector and memory T cells and reducing the number of graft-infiltration lymphocytes in adoptive transfer recipients. Meanwhile, CD44/CD70 blockade and anti-CD154/LFA-1 treatment synergically enhanced regulatory T cells (Tregs) by increasing the proportion of splenic Tregs and the expression of IL-10 in these recipients. Our findings contribute to the potential design of therapies for accelerated allograft rejection.
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| 6. |
- Shao, Wei, et al.
(författare)
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Combination of monoclonal antibodies with DST inhibits accelerated rejection mediated by memory T cells to induce long-lived heart allograft acceptance in mice
- 2011
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Ingår i: Immunology Letters. - : Elsevier BV. - 0165-2478. ; 138:2, s. 122-128
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Tidskriftsartikel (refereegranskat)abstract
- Donor-reactive memory T cells mediated accelerated rejection is known as a barrier to the survival of transplanted organs. We investigated the combination of different monoclonal antibodies (mAbs) and donor-specific transfusion (DST) in memory T cells-based adoptive mice model. In the presence of donor reactive memory T cells, the mean survival time (MST) of grafts in the anti-CD40L/LFA-1/DST group was 49.8 d. Adding anti-CD44/CD70 mAbs to anti-CD40L/LFA-1/DST treatment. The MST was more than 100 d (MST > 100 d). Compared with anti-CD40L/LFA-1/DST group, anti-CD40L/LFA-1/CD44/CD70/DST group notably reduced the expansion of memory T cells, enhanced the proportion of CD4(+)Foxp3(+) regulatory T cells (Tregs) and suppressed donor-specific responses. Our data suggest that anti-CD40L/LFA--1/CD44/CD70 mAbs and DST can synergistically inhibit accelerated rejection mediated by memory T cells to induce long-lived heart allograft acceptance in mice. (C) 2011 Elsevier B.V. All rights reserved.
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| 7. |
- Wang, Feng, et al.
(författare)
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Anti-CD44 Monoclonal Antibody Inhibits Heart Transplant Rejection Mediated by Alloantigen-primed CD4(+) Memory T Cells in Nude Mice
- 2010
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Ingår i: Immunological Investigations. - : Informa UK Limited. - 0882-0139 .- 1532-4311. ; 39:8, s. 807-819
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Tidskriftsartikel (refereegranskat)abstract
- Donor-reactive CD4(+) memory T cells threaten the survival of transplanted organs. In this study, we used anti-CD44 monoclonal antibody (mAb) to inhibit adoptively transferred B6-reactive CD4(+) memory T cells (BALB/c origin) and to induce tolerance of B6 hearts in nude mice. The median survival time (MST) of the grafts was 6 days in the isotype group, and more than 100 days in the group treated with 8 doses of anti-CD44 at four-day intervals. Histological analysis revealed that the mean rejection level was Grade 3 in the isotype group, and Grade 0 or 1 in the multi-dose anti-CD44 treatment group. Compared with the isotype group, the multiply treated anti-CD44 group had significantly decreased IL-2 and IFN-gamma expressions, while IL-10 and TGF-beta were increased in the serum and the graft. Foxp3 in the graft was also increased. These data demonstrate that alloreactive CD4(+) memory T cells mediate the destruction of allografts, and the adhesion molecule CD44 plays an important role in this course. Anti-CD44 mAb may promote the reduction of CD4(+) memory T cells and the production of regulatory T cells (Tregs). Furthermore, Tregs are maintained at a certain level while suppressing cellular immunity and inducing the grafts long-term survival in transplant recipients.
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| 8. |
- Wang, Feiyu, et al.
(författare)
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Combination of antibodies inhibits accelerated rejection mediated by memory T cells in xenoantigen-primed mice.
- 2010
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Ingår i: Xenotransplantation. - : Wiley. - 0908-665X. ; 17:6, s. 460-468
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Tidskriftsartikel (refereegranskat)abstract
- Wang F, Xia J, Chen J, Peng Y, Cheng P, Ekberg H, Wang X, Qi Z. Combination of antibodies inhibits accelerated rejection mediated by memory T cells in xenoantigen-primed mice. Xenotransplantation 2010; 17: 460-468. © 2010 John Wiley & Sons A/S. Abstract: Background: Donor-reactive memory T cells are known to accelerate allograft rejection; in our previous study, we reported that combined monoclonal antibodies (mAbs) could prolong islet allograft survival in alloantigen-primed mice. In this study, we examine the effects of donor-reactive memory T cells on the xenograft survival and methods to prolong the islet graft survival. Methods: To collect donor-reactive T cells, we performed full-thickness rat skin xenografting on BALB/c mice and isolated the T cells from the mice after 6-8 weeks. These cells were then adoptively transferred to syngenic mice 1 day before rat-to-mouse islet transplantation. Three experimental groups were established in the adoptive transfer model: recipient mice treated with isotype mAbs (isotype group); mice treated with anti-CD40L mAb (anti-CD40L group); and mice treated with anti-CD40L, anti-OX40L, and anti-CD122 mAbs (3-combined group). Results: Lewis rat islet xenografts transplanted in naïve mice showed a mean survival time (MST) of 12.8 days, while the graft rejection was accelerated if the recipient mice were treated with adoptively transferred donor-reactive T cells (MST, 8.67 days). Treatment with anti-CD40L mb could not reverse the accelerated rejection (MST, 9.3 days). However, when anti-CD40L mb was combined with anti-OX40L and anti-CD122 mAbs, there was a considerable increase in the MST, which was 72.2 days. Compared to the isotype group, the 3-combined group had significantly lesser proportion of memory T cells and greater proportion of regulatory T cells (Tregs) in the spleen. Meanwhile, in the 3-combined group, the production of anti-rat antibodies was markedly inhibited. Conclusion: Treatment with a combination of antibodies could significantly reverse the accelerated rejection mediated by donor-reactive memory T cells by inhibiting cellular and humoral immune responses.
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| 9. |
- Wang, Feng, et al.
(författare)
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The major histocompatibility complex (MHC) of the secondary transplant tissue donor influences the cross-reactivity of alloreactive memory cells.
- 2011
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Ingår i: Scandinavian Journal of Immunology. - : Wiley. - 1365-3083 .- 0300-9475. ; 73, s. 190-197
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Tidskriftsartikel (refereegranskat)abstract
- Memory cells are currently thought to be a major barrier to tolerance induction in transplantation. However, whether alloreactive memory cells resulting from a primary transplant have cross-reactivity in a second transplant is unclear. Here, we used skin transplantation from BALB/c mice donors to pre-sensitize C(57) BL/6 (B6) mice. One month later, several strains of mice (including BALB/c, DBA/2, NOD, C3H and B6 mice) were chosen as donors to construct a memory model of heterotopic cardiac transplantation. The higher degree of MHC mismatch to sensitizing MHC resulted in longer Median survival times (MSTs, BALB/c 3.63 days VS C3H 6.08 days). 3.5 days after cardiac transplantation, compared with the BALB/c and DBA/2 groups, in the groups of NOD and C3H, the infiltration of inflammatory cells in the grafts, the proportion and proliferation of memory cells in spleens, and the function of allogeneic antibodies decreased significantly. The varying degrees of MHC mismatch between the primary and secondary donors influenced the intensity of alloreactive memory cell function, the higher degree of MHC mismatch resulted in better tolerance during secondary transplantation, and these may be related to the changed activation, proliferation and function of the alloreactive memory cells.
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| 10. |
- Xia, Junjie, et al.
(författare)
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Suppressing memory T cell activation induces islet allograft tolerance in alloantigen-primed mice
- 2010
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Ingår i: Transplant International. - : Frontiers Media SA. - 1432-2277 .- 0934-0874. ; 23:11, s. 1154-1163
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Tidskriftsartikel (refereegranskat)abstract
- P>Memory T cells are known to play a key role in prevention of allograft tolerance in alloantigen-primed mice. Here, we used an adoptively transferred memory T cell model and an alloantigen-primed model to evaluate the abilities of different combinations of monoclonal antibodies (mAb) to block key signaling pathways involved in activation of effector and memory T cells. In the adoptively transferred model, the use of anti-CD134L mAb effectively prevented activation of CD4+ memory T cells and significantly prolonged islet survival, similar to the action of anti-CD122 mAb to CD8+ memory T cells. In the alloantigen-primed model, use of anti-CD134L and anti-CD122 mAbs in addition to co-stimulatory blockade with anti-CD154 and anti-LFA-1 prolonged secondary allograft survival and significantly reduced the proportion of memory T cells; meanwhile, this combination therapy increased the proportion of regulatory T cells (Tregs) in the spleen, inhibited lymphocyte infiltration in the graft, and suppressed alloresponse of recipient splenic T cells. However, we also detected high levels of alloantibodies in the serum which caused high levels of damage to the allogeneic spleen cells. Our results suggest that combination of four mAbs can significantly suppress the function of memory T cells and prolong allograft survival in alloantigen primed animals.
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