| 1. |
- Gao, Xindi, et al.
(författare)
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Cryptococcal Hsf3 controls intramitochondrial ROS homeostasis by regulating the respiratory process
- 2022
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 13:1
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Tidskriftsartikel (refereegranskat)abstract
- Mitochondrial quality control prevents accumulation of intramitochondrial-derived reactive oxygen species (mtROS), thereby protecting cells against DNA damage, genome instability, and programmed cell death. However, underlying mechanisms are incompletely understood, particularly in fungal species. Here, we show that Cryptococcus neoformans heat shock factor 3 (CnHsf3) exhibits an atypical function in regulating mtROS independent of the unfolded protein response. CnHsf3 acts in nuclei and mitochondria, and nuclear- and mitochondrial-targeting signals are required for its organelle-specific functions. It represses the expression of genes involved in the tricarboxylic acid cycle while promoting expression of genes involved in electron transfer chain. In addition, CnHsf3 responds to multiple intramitochondrial stresses; this response is mediated by oxidation of the cysteine residue on its DNA binding domain, which enhances DNA binding. Our results reveal a function of HSF proteins in regulating mtROS homeostasis that is independent of the unfolded protein response.
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| 2. |
- 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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| 3. |
- 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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| 4. |
- 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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