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Zhao W, Li M, Song S, Zhi Y, Huan C, Lv G. The role of natural killer T cells in liver transplantation. Front Cell Dev Biol 2024; 11:1274361. [PMID: 38250325 PMCID: PMC10796773 DOI: 10.3389/fcell.2023.1274361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Accepted: 12/15/2023] [Indexed: 01/23/2024] Open
Abstract
Natural killer T cells (NKTs) are innate-like lymphocytes that are abundant in the liver and participate in liver immunity. NKT cells express both NK cell and T cell markers, modulate innate and adaptive immune responses. Type I and Type II NKT cells are classified according to the TCR usage, while they recognize lipid antigen in a non-classical major histocompatibility (MHC) molecule CD1d-restricted manner. Once activated, NKT cells can quickly produce cytokines and chemokines to negatively or positively regulate the immune responses, depending on the different NKT subsets. In liver transplantation (LTx), the immune reactions in a series of processes determine the recipients' long-term survival, including ischemia-reperfusion injury, alloresponse, and post-transplant infection. This review provides insight into the research on NKT cells subpopulations in LTx immunity during different processes, and discusses the shortcomings of the current research on NKT cells. Additionally, the CD56-expressing T cells are recognized as a NK-like T cell population, they were also discussed during these processes.
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Affiliation(s)
- Wenchao Zhao
- Department of Hepatobiliary and Pancreatic Surgery, General Surgery Center, The First Hospital of Jilin University, Changchun, Jilin, China
| | - Mingqian Li
- Department of Hepatobiliary and Pancreatic Surgery, General Surgery Center, The First Hospital of Jilin University, Changchun, Jilin, China
| | - Shifei Song
- Department of Hepatobiliary and Pancreatic Surgery, General Surgery Center, The First Hospital of Jilin University, Changchun, Jilin, China
| | - Yao Zhi
- Department of Hepatobiliary and Pancreatic Surgery, General Surgery Center, The First Hospital of Jilin University, Changchun, Jilin, China
| | - Chen Huan
- Center of Infectious Diseases and Pathogen Biology, Institute of Virology and AIDS Research, Key Laboratory of Organ Regeneration and Transplantation of The Ministry of Education, The First Hospital of Jilin University, Changchun, Jilin, China
| | - Guoyue Lv
- Department of Hepatobiliary and Pancreatic Surgery, General Surgery Center, The First Hospital of Jilin University, Changchun, Jilin, China
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Farshbafnadi M, Razi S, Rezaei N. Transplantation. Clin Immunol 2023. [DOI: 10.1016/b978-0-12-818006-8.00008-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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Sirajuddin N, Yin XT, Stuart PM. Role of NK T cells in transplantation with particular emphasis on corneal transplantation. Transpl Immunol 2022; 75:101727. [PMID: 36183944 DOI: 10.1016/j.trim.2022.101727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 09/15/2022] [Accepted: 09/25/2022] [Indexed: 11/18/2022]
Abstract
Natural killer T cells (NKT cells) are a unique subset of the immune system that possess characteristics of both an innate and adaptive immune response. This study reviews the reported roles of NKT cells in different solid transplantations such as cardiac, skin, liver, and corneal grafts as well as investigates a novel role of NKT cells in steroid-resistant corneal rejections. It is unknown why there is late corneal graft rejection despite being treated with immunosuppression. Our experimental data suggests NKT cells are playing a crucial part in steroid-resistant late graft rejections. While the pathophysiology of acute rejection is better understood, the process of chronic graft rejection is much less clear. Our data suggests NKT cells as a potential therapeutic target to prevent chronic transplant rejection which needs further investigation.
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Affiliation(s)
- Nadia Sirajuddin
- Department of Ophthalmology, Saint Louis University School of Medicine, St. Louis, MO, USA
| | - Xiao-Tang Yin
- Department of Ophthalmology, Saint Louis University School of Medicine, St. Louis, MO, USA
| | - Patrick M Stuart
- Department of Ophthalmology, Saint Louis University School of Medicine, St. Louis, MO, USA.
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Abstract
In this chapter, we describe the history of transplantation, the multiple cell types, and mechanisms that are involved in rejection and tolerance of a transplanted organ, as well as summarize the common and promising new therapeutics used in transplant patients.
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Affiliation(s)
- Jessica Stolp
- Transplantation Research Immunology Group, Nuffield Department of Surgical Sciences, John Radcliffe Hospital, University of Oxford, Oxford, UK
| | - Masaaki Zaitsu
- Transplantation Research Immunology Group, Nuffield Department of Surgical Sciences, John Radcliffe Hospital, University of Oxford, Oxford, UK
| | - Kathryn J Wood
- Transplantation Research Immunology Group, Nuffield Department of Surgical Sciences, John Radcliffe Hospital, University of Oxford, Oxford, UK.
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Rodriguez-Barbosa JI, Ferreras MC, Buhler L, Jones ND, Schneider P, Perez-Simon JA, Del Rio ML. Therapeutic implications of NK cell regulation of allogeneic CD8 T cell-mediated immune responses stimulated through the direct pathway of antigen presentation in transplantation. MAbs 2018; 10:1030-1044. [PMID: 30036156 PMCID: PMC6204794 DOI: 10.1080/19420862.2018.1502127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Natural killer (NK) cells are a population of innate type I lymphoid cells essential for early anti-viral responses and are known to modulate the course of humoral and cellular-mediated T cell responses. We assessed the role of NK cells in allogeneic CD8 T cell-mediated responses in an immunocompetent mouse model across an MHC class I histocompatibility barrier to determine its impact in therapeutic clinical interventions with polyclonal or monoclonal antibodies (mAbs) targeting lymphoid cells in transplantation. The administration of an NK cell depleting antibody to either CD8 T cell replete or CD8 T cell-depleted naïve C57BL/6 immunocompetent mice accelerated graft rejection. This accelerated rejection response was associated with an in vivo increased cytotoxic activity of CD8 T cells against bm1 allogeneic hematopoietic cells and bm1 skin allografts. These findings show that NK cells were implicated in the control host anti-donor cytotoxic responses, likely by competing for common cell growth factors in both CD8 T cell replete and CD8 T cell-depleted mice, the latter reconstituting in response to lymphopenia. Our data calls for precaution in solid organ transplantation under tolerogenic protocols involving extensive depletion of lymphocytes. These pharmacological biologics with depleting properties over NK cells may accelerate graft rejection and promote aggressive CD8 T cell cytotoxic alloresponses refractory to current immunosuppression.
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Affiliation(s)
- J I Rodriguez-Barbosa
- a Transplantation Immunobiology Section , University of León , Leon , Spain.,h Acción Estratégica en Salud , Consorcio CIBER-ONC, Seville, Spain
| | - M C Ferreras
- b Department of Animal Health, Mountain Livestock Institute (CSIC), School of Veterinary Sciences , University of Leon , Leon , Spain
| | - L Buhler
- c Visceral and Transplantation Surgery, Department of Surgery , University Hospitals of Geneva and Faculty of Medicine , Geneva , Switzerland
| | - N D Jones
- d MRC Centre of Immune Regulation, School of Immunity and Infection, Medical School , University of Birmingham , Birmingham , United Kingdom
| | - P Schneider
- e Department of Biochemistry , University of Lausanne , Epalinges , Switzerland
| | - J A Perez-Simon
- f Department of Hematology , University Hospital Virgen del Rocio/Institute of Biomedicine (IBIS/CSIC) , Sevilla , Spain.,h Acción Estratégica en Salud , Consorcio CIBER-ONC, Seville, Spain
| | - M L Del Rio
- a Transplantation Immunobiology Section , University of León , Leon , Spain.,g Leon Regional Transplantation Coordination Center , Leon University Hospital , Leon , Spain.,h Acción Estratégica en Salud , Consorcio CIBER-ONC, Seville, Spain
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Yang JH, Eun SC. Therapeutic application of T regulatory cells in composite tissue allotransplantation. J Transl Med 2017; 15:218. [PMID: 29073905 PMCID: PMC5658973 DOI: 10.1186/s12967-017-1322-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2017] [Accepted: 10/20/2017] [Indexed: 12/21/2022] Open
Abstract
With growing number of cases in recent years, composite tissue allotransplantation (CTA) has been improving the quality of life of patient who seeks reconstruction and repair of damaged tissues. Composite tissue allografts are heterogeneous. They are composed of a variety of tissue types, including skin, muscle, vessel, bone, bone marrow, lymph nodes, nerve, and tendon. As a primary target of CTA, skin has high antigenicity with a rich repertoire of resident cells that play pivotal roles in immune surveillance. In this regard, understanding the molecular mechanisms involved in immune rejection in the skin would be essential to achieve successful CTA. Although scientific evidence has proved the necessity of immunosuppressive drugs to prevent rejection of allotransplanted tissues, there remains a lingering dilemma due to the lack of specificity of targeted immunosuppression and risks of side effects. A cumulative body of evidence has demonstrated T regulatory (Treg) cells have critical roles in induction of immune tolerance and immune homeostasis in preclinical and clinical studies. Presently, controlling immune susceptible characteristics of CTA with adoptive transfer of Treg cells is being considered promising and it has drawn great interests. This updated review will focus on a dominant form of Treg cells expressing CD4+CD25+ surface molecules and a forkhead box P3 transcription factor with immune tolerant and immune homeostasis activities. For future application of Treg cells as therapeutics in CTA, molecular and cellular characteristics of CTA and immune rejection, Treg cell development and phenotypes, Treg cell plasticity and stability, immune tolerant functions of Treg cells in CTA in preclinical studies, and protocols for therapeutic application of Treg cells in clinical settings are addressed in this review. Collectively, Treg cell therapy in CTA seems feasible with promising perspectives. However, the extreme high immunogenicity of CTA warrants caution.
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Affiliation(s)
- Jeong-Hee Yang
- Department of Plastic and Reconstructive Surgery, Composite Tissue Allotransplantation Immunology Laboratory, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam, South Korea
| | - Seok-Chan Eun
- Department of Plastic and Reconstructive Surgery, Composite Tissue Allotransplantation Immunology Laboratory, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam, South Korea
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From Donor to Recipient: Current Questions Relating to Humoral Alloimmunization. Antibodies (Basel) 2014. [DOI: 10.3390/antib3010130] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
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Wood KJ, Bushell A, Hester J. Regulatory immune cells in transplantation. Nat Rev Immunol 2012; 12:417-30. [DOI: 10.1038/nri3227] [Citation(s) in RCA: 340] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Cellular immunotolerance in the transplant. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012. [PMID: 22457102 DOI: 10.1007/978-1-4614-2098-9_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/30/2023]
Abstract
In humans, a state of operational tolerance has been observed in some recipients who anecdotally or experimentally abandoned their immunosuppressive treatment. Besides, advances in the understanding of the immune response and the continuous appearance of new biological molecules have boosted the growing interest in transferring the knowledge concerning immune tolerance from experimental models to clinical transplantation. Most of the strategies for inducing tolerance target the T-lymphocytes, especially T CD4(+) since they play a central role in the regulation of the immune response. However, an effective tolerogenic treatment must also take into account the role of alloantibody producing B-lymphocytes, which have been shown to play a fundamental role in chronic rejection phenomena. There are multiple regulation and silencing mechanisms that operate both during lymphocyte ontogeny in the bone marrow and thymus (central tolerance) and in the periphery (peripheral tolerance). These regulatory mechanisms include the destruction of APCs by cytotoxic lymphocytes, suppressive cytokines, and activation-induced cell death, among others. However, the mechanism that in recent years has come to be attributed the greatest role has been the active suppression of the response by T-lymphocytes themselves. These lymphocytes are named as regulatory T cells that include Tregs CD4(+)CD25(+), Tr1 cells and Th3. The great therapeutic potential of regulatory lymphocyte populations for the control of allogeneic rejection is evident and several clinical trials in humans have been started to be implemented using populations of both Tregs and Tr1 cells for the prevention of allogeneic reactions.
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Jukes JP, Wood KJ, Jones ND. Bystander activation of iNKT cells occurs during conventional T-cell alloresponses. Am J Transplant 2012; 12:590-9. [PMID: 22070799 PMCID: PMC3326729 DOI: 10.1111/j.1600-6143.2011.03847.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
It is well established that iNKT cells can be activated by both exogenous and a limited number of endogenous glycolipids. However, although iNKT cells have been implicated in the immune response to transplanted organs, the mechanisms by which iNKT cells are activated in this context remain unknown. Here we demonstrate that iNKT cells are not activated by allogeneic cells per se, but expand, both in vitro and in vivo, in the presence of a concomitant conventional T-cell response to alloantigen. This form of iNKT activation was found to occur independently of TCR-glycolipid/CD1d interactions but rather was a result of sequestration of IL-2 produced by conventional alloreactive T cells. These results show for the first time that IL-2, produced by activated conventional T cells, can activate iNKT cells independently of glycolipid/CD1d recognition. Therefore, we propose that the well-documented involvement of iNKT cells in autoimmunity, the control of cancer as well as following transplantation need not involve recognition of endogenous or exogenous glycolipids but alternatively may be a consequence of specific adaptive immune responses.
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Affiliation(s)
- J-P Jukes
- Transplantation Research Immunology Group, Nuffield Department of Surgical Sciences, University of Oxford, John Radcliffe Hospital, Headington, Oxford, UK. Tel: ++44 1865 221305 Fax: ++44 1865 788876
| | - K J Wood
- Transplantation Research Immunology Group, Nuffield Department of Surgical Sciences, University of Oxford, John Radcliffe Hospital, Headington, Oxford, UK. Tel: ++44 1865 221305 Fax: ++44 1865 788876
| | - ND Jones
- Transplantation Research Immunology Group, Nuffield Department of Surgical Sciences, University of Oxford, John Radcliffe Hospital, Headington, Oxford, UK. Tel: ++44 1865 221305 Fax: ++44 1865 788876
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Jukes JP, Jones ND. Immunology in the Clinic Review Series; focus on host responses: invariant natural killer T cell activation following transplantation. Clin Exp Immunol 2012; 167:32-9. [PMID: 22132882 DOI: 10.1111/j.1365-2249.2011.04500.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Invariant natural killer T (iNKT) cells have been shown to play a key role in the regulation of immunity in health and disease. However, iNKT cell responses have also been found to influence both rejection and the induction of tolerance following transplantation of allogeneic cells or organs. Although a number of mechanisms have been identified that lead to iNKT cell activation, how iNKT cells are activated following transplantation remains unknown. This review will attempt to identify potential mechanisms of iNKT cell activation in the context of transplantation by applying knowledge garnered from other disease situations. Furthermore, we put forward a novel mechanism of iNKT cell activation which we believe may be the dominant mechanism responsible for iNKT activation in this setting, i.e. bystander activation by interleukin-2 secreted by recently activated conventional T cells.
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Affiliation(s)
- J-P Jukes
- Medical Research Council Human Immunology Unit, Nuffield Department of Medicine, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
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Islet allograft tolerance in the absence of invariant natural killer T cells. Clin Immunol 2011; 141:268-72. [PMID: 21996456 DOI: 10.1016/j.clim.2011.09.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2011] [Revised: 09/09/2011] [Accepted: 09/10/2011] [Indexed: 11/22/2022]
Abstract
The invariant NKT cells are involved in both immunity and immune tolerance. However, their roles in transplant models remain controversial. We studied the role of NKT cells in the allograft response using two different strains of NKT deficient mice (CD1d-/- and Jα18-/- mice), and found that CD1d-/- and Jα18-/- mice rejected islet allografts with a similar kinetics as wild type B6 mice. Treatment of CD1d-/- and Jα18-/- mice with donor specific transfusion and anti-CD154 induced donor specific tolerance, which was identical to similarly treated wt B6 mice. The islet allograft tolerance requires Foxp3(+) Tregs. In the periphery, Foxp3(+) Tregs in CD1d-/-, Jα18-/-, and wt B6 mice were comparable both phenotypically and functionally. In addition, CD1d-/- and Jα18-/- CD4(+) T cells (non-Tregs) could be readily converted to Foxp3(+) Tregs by TGF-β in vitro. Our data suggest that islet allograft tolerance can be successfully established without invariant NKT cells.
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A potential role for CD25+ regulatory T-cells in the protection against casein allergy by dietary non-digestible carbohydrates. Br J Nutr 2011; 107:96-105. [DOI: 10.1017/s0007114511002637] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Dietary non-digestible carbohydrates reduce the development of cows' milk allergy in mice. In the present study, the contribution of CD25+ regulatory T-cells (Treg) was investigated using in vivo Treg depletion and adoptive transfer studies. Mice were orally sensitised with casein and fed a diet containing 2 % short-chain galacto-, long-chain fructo- and acidic oligosaccharides (GFA) or a control diet. Donor splenocytes of mice sensitised with casein and fed the GFA or control diet were adoptively transferred to naive recipient mice, which were casein- or sham-sensitised and fed the control diet. In addition, in vivo or ex vivo CD25+ Treg depletion was performed using anti-CD25 (PC61). The acute allergic skin response upon intradermal casein challenge and casein-specific Ig were determined. Furthermore, T-helper (TH) 1 and TH2 cell numbers were analysed in the mesenteric lymph nodes. The oligosaccharide diet strongly reduced the development of the acute allergic skin response, which was abrogated by the in vivo anti-CD25 treatment. The diet enhanced the percentage of TH1 cells and tended to reduce the percentage of TH2 cells in casein-sensitised mice. Recipient mice were protected against the development of an acute allergic skin response when transferred with splenocytes from casein-sensitised GFA-fed donor mice before sensitisation. Ex vivo depletion of CD25+ Treg abrogated this transfer of tolerance. Splenocytes from sham-sensitised GFA-fed donor mice did not suppress the allergic response in recipient mice. In conclusion, CD25+ Treg contribute to the suppression of the allergic effector response in casein-sensitised mice induced by dietary intervention with non-digestible carbohydrates.
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Nierlich PN, Klaus C, Bigenzahn S, Pilat N, Koporc Z, Pree I, Baranyi U, Taniguchi M, Muehlbacher F, Wekerle T. The role of natural killer T cells in costimulation blockade-based mixed chimerism. Transpl Int 2011; 23:1179-89. [PMID: 20536788 DOI: 10.1111/j.1432-2277.2010.01120.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Distinct lymphocyte populations have been identified that either promote or impede the establishment of chimerism and tolerance through allogeneic bone marrow transplantation (BMT). Natural killer T (NKT) cells have pleiotropic regulatory properties capable of either augmenting or downmodulating various immune responses. We investigated in this study whether NKT cells affect outcome in mixed chimerism models employing fully mismatched nonmyeloablative BMT with costimulation blockade (CB). The absence of NKT cells had no detectable effect on chimerism or skin graft tolerance after conditioning with 3Gy total body irradiation (TBI), and a limited positive effect with 1Gy TBI. Stimulation of NKT cells with alpha-galactosylceramide (alpha-gal) at the time of BMT prevented chimerism and tolerance. Activation of recipient (as opposed to donor) NKT cells was necessary and sufficient for the alpha-gal effect. The detrimental effect of NKT activation was also observed in the absence of T cells after conditioning with in vivo T-cell depletion (TCD). NKT cells triggered rejection of BM via NK cells as chimerism and tolerance were not abrogated when NKT cells were stimulated in the absence of both NK cells and T cells. Thus, activation of NKT cells at the time of BMT overcomes the effects of CB, inhibiting the establishment of chimerism and tolerance.
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Affiliation(s)
- Patrick-Nikolaus Nierlich
- Division of Transplantation, Department of Surgery, Medical University of Vienna, Vienna General Hospital, Vienna, Austria
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Cao Z, Dhupar R, Cai C, Li P, Billiar TR, Geller DA. A critical role for IFN regulatory factor 1 in NKT cell-mediated liver injury induced by alpha-galactosylceramide. THE JOURNAL OF IMMUNOLOGY 2010; 185:2536-43. [PMID: 20624945 DOI: 10.4049/jimmunol.1000092] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
NKT cells are remarkably abundant in mouse liver. Compelling experimental evidence has suggested that NKT cells are involved in the pathogenesis of many liver diseases. Activation of NKT cells with alpha-galactosylceramide (alpha-GalCer) causes liver injury through mechanisms that are not well understood. We undertook studies to characterize the key pathways involved in alpha-GalCer-induced liver injury. We found that expression of the transcription factor IFN regulatory factor 1 (IRF-1) in mouse liver was dramatically upregulated by alpha-GalCer treatment. Neutralization of either TNF-alpha or IFN-gamma inhibited alpha-GalCer-mediated IRF-1 upregulation. alpha-GalCer-induced liver injury was significantly suppressed in IRF-1 knockout mice or in wild-type C56BL/6 mice that received a microRNA specifically targeting IRF-1. In contrast, overexpression of IRF-1 greatly potentiated alpha-GalCer-induced liver injury. alpha-GalCer injection also induced a marked increase in hepatic inducible NO synthase expression in C56BL/6 mice, but not in IRF-1 knockout mice. Inducible NO synthase knockout mice exhibited significantly reduced liver injury following alpha-GalCer treatment. Finally, we demonstrated that both NKT cells and hepatocytes expressed IRF-1 in response to alpha-GalCer. However, it appeared that the hepatocyte-derived IRF-1 was mainly responsible for alpha-GalCer-induced liver injury, based on the observation that inhibition of IRF-1 by RNA interference did not affect alpha-GalCer-induced NKT cell activation. Our findings revealed a novel mechanism of NKT cell-mediated liver injury in mice, which has implications in the development of human liver diseases.
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Affiliation(s)
- Zongxian Cao
- Department of Surgery, University of Pittsburgh, Pittsburgh, PA 15213, USA
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Cheng X, Dai H, Wan N, Moore Y, Vankayalapati R, Dai Z. Interaction of programmed death-1 and programmed death-1 ligand-1 contributes to testicular immune privilege. Transplantation 2009; 87:1778-86. [PMID: 19543053 DOI: 10.1097/tp.0b013e3181a75633] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND Immune responses are tempered in immunologically privileged sites including the testis. Previous studies have shown that islet transplantation in the testis significantly prolongs islet allograft survival. However, mechanisms underlying testicular immune privilege and intratesticular allograft survival remain unclear. METHODS Allogeneic murine islets were transplanted in the testis. Programmed death-1 ligand-1 (PD-L1) expression was detected by immunohistochemstry and real-time polymerase chain reaction. Infiltrating T-cell proliferation was measured by bromodeoxyuridine uptakes, whereas their apoptosis was quantified by terminal deoxynucleotide transferase-mediated dUTP nick-end labeling methods. Transgenic T cells were used to track allospecific memory T-cell generation. RESULTS We found that programmed death-1 (PD-1):PD-L1 negative costimulation is essential for prolonged survival of intratesticular islet allografts, as blocking PD-L1 or PD-1, but not PD-L2 and cytotoxic T-lymphocyte antigen 4, abrogated long-term survival of intratesticular islet allografts. As controls, blocking PD-1 or PD-L1 did not significantly accelerate the acute rejection of islet allografts transplanted under the renal capsule, a conventional islet-grafting site. We also found for the first time that PD-L1 is constitutively expressed mainly by spermatocytes and spermatids in seminiferous tubules of the testis. Moreover, infiltrating T cells underwent less vigorous proliferation but faster apoptosis in the testis than in the kidney. Blocking PD-1:PD-L1 costimulation largely abolished the suppression of T-cell proliferation and acceleration of T-cell apoptosis. Importantly, testicular immune privilege significantly suppressed the generation and proliferation of donor-specific memory CD8 T cells. CONCLUSIONS The constitutive expression of PD-L1 in the testis is an important mechanism underlying testicular immune privilege and long-term survival of intratesticular islet allografts.
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Affiliation(s)
- Xuyang Cheng
- Center for Biomedical Research, University of Texas Health Science Center, Tyler, TX 75708, USA
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Balato A, Unutmaz D, Gaspari AA. Natural killer T cells: an unconventional T-cell subset with diverse effector and regulatory functions. J Invest Dermatol 2009; 129:1628-42. [PMID: 19262602 DOI: 10.1038/jid.2009.30] [Citation(s) in RCA: 107] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Natural killer T (NKT) cells are a unique subset of lymphocytes that express NK cell markers such as CD161 and CD94, as well as a T-cell receptor (TCR) alpha/beta, with a restricted repertoire, which distinguishes them from NK cells, which lack a TCR. In contrast to conventional T-lymphocytes, the TCR of NKT cells does not interact with that of peptide antigens presented by classical major histocompatibility complex-encoded class I or II molecules. Instead, this TCR recognizes glycolipids presented by CD1d, a non-classical antigen-presenting molecule. The rapid response of NKT cells to their cognate antigens is characteristic of an innate immune response, and allows the polarizing cytokines (IFN-gamma and/or IL-4) to regulate adaptive immunity. NKT cells have been found to be critical in the immune response against viral infections and malaria, as well as in tumor immunity, and certain autoimmune diseases. NKT cells have been assessed to represent the "trait d'union" between innate and adaptive immunity. They play an active role in skin diseases, such as contact sensitivity, which have been implicated in UV-induced immunosuppression and psoriasis. Thus, NKT-cells are emerging as an important subset of lymphocytes, with a protective role in host defense and a pathogenic role in certain immune-mediated disease states.
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Affiliation(s)
- Anna Balato
- Department of Dermatology, University of Naples Federico II, Naples, Italy
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Li Z, Benghiat FS, Charbonnier LM, Kubjak C, Rivas MN, Cobbold SP, Waldmann H, De Wilde V, Petein M, Schuind F, Goldman M, Le Moine A. CD8+ T-Cell depletion and rapamycin synergize with combined coreceptor/stimulation blockade to induce robust limb allograft tolerance in mice. Am J Transplant 2008; 8:2527-36. [PMID: 18853957 DOI: 10.1111/j.1600-6143.2008.02419.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The growing development of composite tissue allografts (CTA) highlights the need for tolerance induction protocols. Herein, we developed a mouse model of heterotopic limb allograft in a stringent strain combination in which potentially tolerogenic strategies were tested taking advantage of donor stem cells in the grafted limb. BALB/c allografts were transplanted into C57BL/6 mice treated with anti-CD154 mAb, nondepleting anti-CD4 combined to either depleting or nondepleting anti-CD8 mAbs. Some groups received additional rapamycin. Both depleting and nondepleting mAb combinations without rapamycin only delayed limb allograft rejection, whereas the addition of rapamycin induced long-term allograft survival in both combinations. Nevertheless, robust donor-specific tolerance, defined by the acceptance of a fresh donor-type skin allograft and simultaneous rejection of third-party grafts, required initial CD8(+) T-cell depletion. Mixed donor-recipient chimerism was observed in lymphoid organs and recipient bone marrow of tolerant but not rejecting animals. Tolerance specificity was confirmed by the inability to produce IL-2, IFN-gamma and TNF-alpha in MLC with donor antigen while significant alloreactivity persisted against third- party alloantigens. Collectively, these results show that robust CTA tolerance and mixed donor-recipient chimerism can be achieved in response to the synergizing combination of rapamycin, transient CD8(+) T-cell depletion and costimulation/coreceptor blockade.
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Affiliation(s)
- Z Li
- Institute for Medical Immunology, Université Libre de Bruxelles, Bruxelles, Belgium
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Abstract
Mesenchymal stromal cells (MSCs) originally isolated from bone marrow have been derived from almost every tissue in the body. These multipotent cells can be differentiated in vitro and in vivo into various cell types of mesenchymal origin, such as bone, fat, and cartilage. Furthermore, under some experimental conditions, these cells can differentiate into a wider variety of cell types. Upon systemic administration, ex vivo expanded MSCs preferentially home to damaged tissues and participate in regeneration processes through their diverse biological properties. In vitro and in vivo data suggest that MSCs have low inherent immunogenicity and modulate/suppress immunologic responses through interactions with different immune cells. Ease of isolation and ex vivo expansion of MSCs, combined with their intriguing differentiation and immunomodulatory potential, and their impressive record of safety in clinical trials make these cells prime candidates for cellular therapy. Mesenchymal stromal cells derived from bone marrow are currently being evaluated for a wide range of clinical applications including for treatment of immune dysregulation disorders such as acute graft-versus-host disease after allogeneic hematopoietic stem cell transplantation. In the future, MSCs might potentially provide novel therapeutic options for treatment/prevention of rejection and/or repair of organ allografts through their multifaceted properties.
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Affiliation(s)
- Peiman Hematti
- Department of Medicine, University of Wisconsin-Madison, School of Medicine and Public Health, Madison, WI 53792, USA.
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