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Cheung J, Zahorowska B, Suranyi M, Wong JKW, Diep J, Spicer ST, Verma ND, Hodgkinson SJ, Hall BM. CD4 +CD25 + T regulatory cells in renal transplantation. Front Immunol 2022; 13:1017683. [PMID: 36426347 PMCID: PMC9681496 DOI: 10.3389/fimmu.2022.1017683] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Accepted: 10/13/2022] [Indexed: 09/14/2023] Open
Abstract
The immune response to an allograft activates lymphocytes with the capacity to cause rejection. Activation of CD4+CD25+Foxp3+T regulatory cells (Treg) can down-regulate allograft rejection and can induce immune tolerance to the allograft. Treg represent <10% of peripheral CD4+T cells and do not markedly increase in tolerant hosts. CD4+CD25+Foxp3+T cells include both resting and activated Treg that can be distinguished by several markers, many of which are also expressed by effector T cells. More detailed characterization of Treg to identify increased activated antigen-specific Treg may allow reduction of non-specific immunosuppression. Natural thymus derived resting Treg (tTreg) are CD4+CD25+Foxp3+T cells and only partially inhibit alloantigen presenting cell activation of effector cells. Cytokines produced by activated effector cells activate these tTreg to more potent alloantigen-activated Treg that may promote a state of operational tolerance. Activated Treg can be distinguished by several molecules they are induced to express, or whose expression they have suppressed. These include CD45RA/RO, cytokine receptors, chemokine receptors that alter pathways of migration and transcription factors, cytokines and suppression mediating molecules. As the total Treg population does not increase in operational tolerance, it is the activated Treg which may be the most informative to monitor. Here we review the methods used to monitor peripheral Treg, the effect of immunosuppressive regimens on Treg, and correlations with clinical outcomes such as graft survival and rejection. Experimental therapies involving ex vivo Treg expansion and administration in renal transplantation are not reviewed.
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Affiliation(s)
- Jason Cheung
- Renal Unit, Liverpool Hospital, Sydney, NSW, Australia
| | | | - Michael Suranyi
- Renal Unit, Liverpool Hospital, Sydney, NSW, Australia
- South Western Sydney Clinical School, University of New South Wales (UNSW), Sydney, NSW, Australia
| | | | - Jason Diep
- Renal Unit, Liverpool Hospital, Sydney, NSW, Australia
- South Western Sydney Clinical School, University of New South Wales (UNSW), Sydney, NSW, Australia
| | - Stephen T. Spicer
- Renal Unit, Liverpool Hospital, Sydney, NSW, Australia
- South Western Sydney Clinical School, University of New South Wales (UNSW), Sydney, NSW, Australia
| | - Nirupama D. Verma
- South Western Sydney Clinical School, University of New South Wales (UNSW), Sydney, NSW, Australia
- Immune Tolerance Laboratory, Ingham Institute for Applied Medical Research, University of New South Wales (UNSW), Sydney, NSW, Australia
| | - Suzanne J. Hodgkinson
- South Western Sydney Clinical School, University of New South Wales (UNSW), Sydney, NSW, Australia
- Immune Tolerance Laboratory, Ingham Institute for Applied Medical Research, University of New South Wales (UNSW), Sydney, NSW, Australia
| | - Bruce M. Hall
- Renal Unit, Liverpool Hospital, Sydney, NSW, Australia
- South Western Sydney Clinical School, University of New South Wales (UNSW), Sydney, NSW, Australia
- Immune Tolerance Laboratory, Ingham Institute for Applied Medical Research, University of New South Wales (UNSW), Sydney, NSW, Australia
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Tran GT, Verma ND, Smyth LM, Hall BM. Editorial: Characterisation, functions and roles of antigen-specific regulatory T cells in health and disease. Front Immunol 2022; 13:1022813. [PMID: 36238272 PMCID: PMC9553274 DOI: 10.3389/fimmu.2022.1022813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Accepted: 08/30/2022] [Indexed: 11/13/2022] Open
Affiliation(s)
- Giang T. Tran
- Immune Tolerance Laboratory, Ingham Institute for Applied Medical Research, University of New South Wales (UNSW), Sydney, NSW, Australia
- South Western Sydney Clinical School, University of New South Wales (UNSW), Sydney, NSW, Australia
| | - Nirupama D. Verma
- Immune Tolerance Laboratory, Ingham Institute for Applied Medical Research, University of New South Wales (UNSW), Sydney, NSW, Australia
| | - Lesley M. Smyth
- Department of Bioscience, School of Health, Sport and Bioscience, University of East London, London, United Kingdom
| | - Bruce M. Hall
- Immune Tolerance Laboratory, Ingham Institute for Applied Medical Research, University of New South Wales (UNSW), Sydney, NSW, Australia
- *Correspondence: Bruce M. Hall,
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Hall BM, Verma ND, Tran GT, Hodgkinson SJ. Transplant Tolerance, Not Only Clonal Deletion. Front Immunol 2022; 13:810798. [PMID: 35529847 PMCID: PMC9069565 DOI: 10.3389/fimmu.2022.810798] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2021] [Accepted: 02/23/2022] [Indexed: 11/13/2022] Open
Abstract
The quest to understand how allogeneic transplanted tissue is not rejected and how tolerance is induced led to fundamental concepts in immunology. First, we review the research that led to the Clonal Deletion theory in the late 1950s that has since dominated the field of immunology and transplantation. At that time many basic mechanisms of immune response were unknown, including the role of lymphocytes and T cells in rejection. These original observations are reassessed by considering T regulatory cells that are produced by thymus of neonates to prevent autoimmunity. Second, we review "operational tolerance" induced in adult rodents and larger animals such as pigs. This can occur spontaneously especially with liver allografts, but also can develop after short courses of a variety of rejection inhibiting therapies. Over time these animals develop alloantigen specific tolerance to the graft but retain the capacity to reject third-party grafts. These animals have a "split tolerance" as peripheral lymphocytes from these animals respond to donor alloantigen in graft versus host assays and in mixed lymphocyte cultures, indicating there is no clonal deletion. Investigation of this phenomenon excludes many mechanisms, including anti-donor antibody blocking rejection as well as anti-idiotypic responses mediated by antibody or T cells. This split tolerance is transferred to a second immune-depleted host by T cells that retain the capacity to effect rejection of third-party grafts by the same host. Third, we review research on alloantigen specific inhibitory T cells that led to the first identification of the CD4+CD25+T regulatory cell. The key role of T cell derived cytokines, other than IL-2, in promoting survival and expansion of antigen specific T regulatory cells that mediate transplant tolerance is reviewed. The precise methods for inducing and diagnosing operational tolerance remain to be defined, but antigen specific T regulatory cells are key mediators.
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Affiliation(s)
- Bruce M. Hall
- Immune Tolerance Laboratory, School of Medicine, University of New South Wales (UNSW) Sydney, Ingham Institute, and Renal Service and Multiple Sclerosis Clinic, Liverpool Hospital, Liverpool, NSW, Australia
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Verma ND, Robinson CM, Carter N, Wilcox P, Tran GT, Wang C, Sharland A, Nomura M, Plain KM, Bishop GA, Hodgkinson SJ, Hall BM. Alloactivation of Naïve CD4 +CD8 -CD25 +T Regulatory Cells: Expression of CD8α Identifies Potent Suppressor Cells That Can Promote Transplant Tolerance Induction. Front Immunol 2019; 10:2397. [PMID: 31681288 PMCID: PMC6802415 DOI: 10.3389/fimmu.2019.02397] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 09/24/2019] [Indexed: 01/08/2023] Open
Abstract
Therapy with alloantigen-specific CD4+CD25+ T regulatory cells (Treg) for induction of transplant tolerance is desirable, as naïve thymic Treg (tTreg) are not alloantigen-specific and are weak suppressor cells. Naïve tTreg from DA rats cultured with fully allogeneic PVG stimulator cells in the presence of rIL-2 express IFN-gamma receptor (IFNGR) and IL-12 receptor beta2 (IL-12Rβ2) and are more potent alloantigen-specific regulators that we call Ts1 cells. This study examined additional markers that could identify the activated alloantigen-specific Treg as a subpopulation within the CD4+CD25+Foxp3+Treg. After culture of naïve DA CD4+CD8−CD25+T cells with rIL-2 and PVG alloantigen, or rIL-2 without alloantigen, CD8α was expressed on 10–20% and CD8β on <5% of these cells. These cells expressed ifngr and Il12rb2. CD8α+ cells had increased Ifngr that characterizes Ts1 cells as well was Irf4, a transcription factor induced by TCR activation. Proliferation induced by re-culture with rIL-12 and alloantigen was greater with CD4+CD8α+CD25+Treg consistent with the CD8α+ cells expressing IL-12R. In MLC, the CD8α+ fraction suppressed responses against allogeneic stimulators more than the mixed Ts1 population, whereas the CD4+CD8−CD25+T cells were less potent. In an adoptive transfer assay, rIL-2 and alloantigen activated Treg suppress rejection at a ratio of 1:10 with naïve effector cells, whereas alloantigen and rIL-2 activated tTreg depleted of the CD8α+ cells were much less effective. This study demonstrated that expression of CD8α by rIL-2 and alloantigen activation of CD4+CD8−CD25+Foxp3+T cells was a marker of activated and potent Treg that included alloantigen-specific Treg.
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Affiliation(s)
- Nirupama D Verma
- Immune Tolerance Laboratory, South Western Clinical School of Medicine, UNSW Sydney and Ingham Institute, Liverpool Hospital, Liverpool, NSW, Australia
| | - Catherine M Robinson
- Immune Tolerance Laboratory, South Western Clinical School of Medicine, UNSW Sydney and Ingham Institute, Liverpool Hospital, Liverpool, NSW, Australia
| | - Nicole Carter
- Immune Tolerance Laboratory, South Western Clinical School of Medicine, UNSW Sydney and Ingham Institute, Liverpool Hospital, Liverpool, NSW, Australia
| | - Paul Wilcox
- Immune Tolerance Laboratory, South Western Clinical School of Medicine, UNSW Sydney and Ingham Institute, Liverpool Hospital, Liverpool, NSW, Australia
| | - Giang T Tran
- Immune Tolerance Laboratory, South Western Clinical School of Medicine, UNSW Sydney and Ingham Institute, Liverpool Hospital, Liverpool, NSW, Australia
| | - Chaunmin Wang
- Transplantation Immunobiology Research Group, Faculty of Medicine and Health, Charles Perkins Centre, Central Clinical School, University of Sydney, Sydney, NSW, Australia
| | - Alexandra Sharland
- Transplantation Immunobiology Research Group, Faculty of Medicine and Health, Charles Perkins Centre, Central Clinical School, University of Sydney, Sydney, NSW, Australia
| | - Masaru Nomura
- Department of Surgery, Keiwakai Ebetsu Hospital, Ebetsu, Japan
| | - Karren M Plain
- Immune Tolerance Laboratory, South Western Clinical School of Medicine, UNSW Sydney and Ingham Institute, Liverpool Hospital, Liverpool, NSW, Australia
| | - G Alexander Bishop
- Transplantation Immunobiology Research Group, Faculty of Medicine and Health, Charles Perkins Centre, Central Clinical School, University of Sydney, Sydney, NSW, Australia
| | - Suzanne J Hodgkinson
- Transplantation Immunobiology Research Group, Faculty of Medicine and Health, Charles Perkins Centre, Central Clinical School, University of Sydney, Sydney, NSW, Australia
| | - Bruce M Hall
- Immune Tolerance Laboratory, South Western Clinical School of Medicine, UNSW Sydney and Ingham Institute, Liverpool Hospital, Liverpool, NSW, Australia
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Shaban E, Bayliss G, Malhotra DK, Shemin D, Wang LJ, Gohh R, Dworkin LD, Gong R. Targeting Regulatory T Cells for Transplant Tolerance: New Insights and Future Perspectives. KIDNEY DISEASES 2018; 4:205-213. [PMID: 30574497 DOI: 10.1159/000490703] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Accepted: 06/07/2018] [Indexed: 01/15/2023]
Abstract
Background Organ transplantation is considered the ultimate therapy for end-stage organ disease. While pharmacologic immunosuppression is the mainstay of therapeutic strategies to prolong the survival of the graft, long-term use of immunosuppressive medications carries the risk of organ toxicity, malignancies, serious opportunistic infections, and diabetes. Therapies that promote recipient tolerance in solid organ transplantation are able to improve patient outcomes by eliminating the need for long-term immunosuppression. Summary Establishing tolerance to an allograft has become an area of intense study and would be the ideal therapy in clinical practice. The discovery of a subset of T cells naturally committed to perform immunoregulation has led to further investigation into their role in the immunopathogenesis of transplantation. Evidence suggests that regulatory T cells (Tregs) are fundamentally involved in promoting allograft tolerance. Efforts to characterize specific markers for Tregs, while challenging, have identified Foxp3 gene expression as a crucial step in promoting the tolerance-inducing features of Tregs. A number of approaches, including those based on targeting the glycogen synthase kinase 3β signaling pathway or activating the melanocortinergic pathway, have been tested as a way to promote Treg lineage commitment and maintenance as well as to facilitate immune tolerance. In order to be effective in clinical practice, Tregs must be allospecific and possess a specific phenotype to avoid suppression of other aspects of the immune system or increasing the risk of malignancy or infections. Multiple experimental and clinical studies have demonstrated the impact of currently used immunosuppressants on the immunoregulatory activities of Tregs and their Foxp3 expression status. Pharmacological induction of tolerogenic Tregs for inducing transplant tolerance, including epigenetic therapies, is in the ascendant. Key Messages Therapies that promote Treg function and survival may represent a novel strategy for achieving immune tolerance in transplant patients.
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Affiliation(s)
- Eman Shaban
- Division of Kidney Disease and Hypertension, Department of Medicine, Rhode Island Hospital, Alpert Medical School, Brown University, Providence, Rhode Island, USA.,Transplant Center, University of Michigan, Ann Arbor, Michigan, USA
| | - George Bayliss
- Division of Kidney Disease and Hypertension, Department of Medicine, Rhode Island Hospital, Alpert Medical School, Brown University, Providence, Rhode Island, USA.,Department of Pathology, Rhode Island Hospital, Alpert Medical School, Brown University, Providence, Rhode Island, USA
| | - Deepak K Malhotra
- Division of Nephrology, Department of Medicine, The University of Toledo College of Medicine, Toledo, Ohio, USA
| | - Douglas Shemin
- Division of Kidney Disease and Hypertension, Department of Medicine, Rhode Island Hospital, Alpert Medical School, Brown University, Providence, Rhode Island, USA
| | - Li Juan Wang
- Department of Pathology, Rhode Island Hospital, Alpert Medical School, Brown University, Providence, Rhode Island, USA
| | - Reginald Gohh
- Division of Kidney Disease and Hypertension, Department of Medicine, Rhode Island Hospital, Alpert Medical School, Brown University, Providence, Rhode Island, USA
| | - Lance D Dworkin
- Division of Nephrology, Department of Medicine, The University of Toledo College of Medicine, Toledo, Ohio, USA
| | - Rujun Gong
- Division of Kidney Disease and Hypertension, Department of Medicine, Rhode Island Hospital, Alpert Medical School, Brown University, Providence, Rhode Island, USA.,Division of Nephrology, Department of Medicine, The University of Toledo College of Medicine, Toledo, Ohio, USA
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Hall BM, Robinson CM, Plain KM, Verma ND, Tran GT, Nomura M, Carter N, Boyd R, Hodgkinson SJ. Changes in Reactivity In Vitro of CD4 +CD25 + and CD4 +CD25 - T Cell Subsets in Transplant Tolerance. Front Immunol 2017; 8:994. [PMID: 28878770 PMCID: PMC5572370 DOI: 10.3389/fimmu.2017.00994] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Accepted: 08/03/2017] [Indexed: 01/03/2023] Open
Abstract
Transplant tolerance induced in adult animals is mediated by alloantigen-specific CD4+CD25+ T cells, yet in many models, proliferation of CD4+ T cells from hosts tolerant to specific-alloantigen in vitro is not impaired. To identify changes that may diagnose tolerance, changes in the patterns of proliferation of CD4+, CD4+CD25+, and CD4+CD25− T cells from DA rats tolerant to Piebald Virol Glaxo rat strain (PVG) cardiac allografts and from naïve DA rats were examined. Proliferation of CD4+ T cells from both naïve and tolerant hosts was similar to both PVG and Lewis stimulator cells. In mixed lymphocyte culture to PVG, proliferation of naïve CD4+CD25− T cells was greater than naïve CD4+ T cells. In contrast, proliferation of CD4+CD25− T cells from tolerant hosts to specific-donor PVG was not greater than CD4+ T cells, whereas their response to Lewis and self-DA was greater than CD4+ T cells. Paradoxically, CD4+CD25+ T cells from tolerant hosts did not proliferate to PVG, but did to Lewis, whereas naïve CD4+CD25+ T cells proliferate to both PVG and Lewis but not to self-DA. CD4+CD25+ T cells from tolerant, but not naïve hosts, expressed receptors for interferon (IFN)-γ and IL-5 and these cytokines promoted their proliferation to specific-alloantigen PVG but not to Lewis or self-DA. We identified several differences in the patterns of proliferation to specific-donor alloantigen between cells from tolerant and naïve hosts. Most relevant is that CD4+CD25+ T cells from tolerant hosts failed to proliferate or suppress to specific donor in the absence of either IFN-γ or IL-5. The proliferation to third-party and self of each cell population from tolerant and naïve hosts was similar and not affected by IFN-γ or IL-5. Our findings suggest CD4+CD25+ T cells that mediate transplant tolerance depend on IFN−γ or IL-5 from alloactivated Th1 and Th2 cells.
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Affiliation(s)
- Bruce M Hall
- Immune Tolerance Laboratory, Department of Medicine, Ingham Institute, University of New South Wales, Liverpool Hospital, Liverpool, NSW, Australia
| | - Catherine M Robinson
- Immune Tolerance Laboratory, Department of Medicine, Ingham Institute, University of New South Wales, Liverpool Hospital, Liverpool, NSW, Australia
| | - Karren M Plain
- Immune Tolerance Laboratory, Department of Medicine, Ingham Institute, University of New South Wales, Liverpool Hospital, Liverpool, NSW, Australia.,Faculty of Veterinary Sciences, University of Sydney, Cobbity, NSW, Australia
| | - Nirupama D Verma
- Immune Tolerance Laboratory, Department of Medicine, Ingham Institute, University of New South Wales, Liverpool Hospital, Liverpool, NSW, Australia
| | - Giang T Tran
- Immune Tolerance Laboratory, Department of Medicine, Ingham Institute, University of New South Wales, Liverpool Hospital, Liverpool, NSW, Australia
| | - Masaru Nomura
- Immune Tolerance Laboratory, Department of Medicine, Ingham Institute, University of New South Wales, Liverpool Hospital, Liverpool, NSW, Australia.,Department of Surgery, Nakashibetsu Hospital Shibetu-gun Nakashibetsu-cho, Hokkaido, Japan
| | - Nicole Carter
- Immune Tolerance Laboratory, Department of Medicine, Ingham Institute, University of New South Wales, Liverpool Hospital, Liverpool, NSW, Australia.,Faculty of Veterinary Sciences, University of Sydney, Cobbity, NSW, Australia
| | - Rochelle Boyd
- Immune Tolerance Laboratory, Department of Medicine, Ingham Institute, University of New South Wales, Liverpool Hospital, Liverpool, NSW, Australia.,Faculty of Medicine and Health Sciences, Macquarie University, Macquarie Park, NSW, Australia
| | - Suzanne J Hodgkinson
- Immune Tolerance Laboratory, Department of Medicine, Ingham Institute, University of New South Wales, Liverpool Hospital, Liverpool, NSW, Australia
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Cytokines affecting CD4 +T regulatory cells in transplant tolerance. III. Interleukin-5 (IL-5) promotes survival of alloantigen-specific CD4 + T regulatory cells. Transpl Immunol 2017; 43-44:33-41. [PMID: 28652007 DOI: 10.1016/j.trim.2017.06.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 06/22/2017] [Accepted: 06/22/2017] [Indexed: 12/31/2022]
Abstract
CD4+T cells mediate antigen-specific allograft tolerance, but die in culture without activated lymphocyte derived cytokines. Supplementation of the media with cytokine rich supernatant, from ConA activated spleen cells, preserves the capacity of tolerant cells to transfer tolerance and suppress rejection. rIL-2 or rIL-4 alone are insufficient to maintain these cells, however. We observed that activation of naïve CD4+CD25+FOXP3+Treg with alloantigen and the Th2 cytokine rIL-4 induces them to express interleukin-5 specific receptor alpha (IL-5Rα) suggesting that IL-5, a Th2 cytokine that is produced later in the immune response may promote tolerance mediating Treg. This study examined if recombinant IL-5(rIL-5) promoted survival of tolerant CD4+, especially CD4+CD25+T cells. CD4+T cells, from DA rats tolerant to fully allogeneic PVG heart allografts surviving over 100days without on-going immunosuppression, were cultured with PVG alloantigen and rIL-5. The ability of these cells to adoptively transfer tolerance to specific-donor allograft and suppress normal CD4+T cell mediated rejection in adoptive DA hosts was examined. Tolerant CD4+CD25+T cells' response to rIL-5 and expression of IL-5Rα was also assessed. rIL-5 was sufficient to promote transplant tolerance mediating CD4+T cells' survival in culture with specific-donor alloantigen. Tolerant CD4+T cells cultured with rIL-5 retained the capacity to transfer alloantigen-specific tolerance and inhibited naïve CD4+T cells' capacity to effect specific-donor graft rejection. rIL-5 promoted tolerant CD4+CD25+T cells' proliferation in vitro when stimulated with specific-donor but not third-party stimulator cells. Tolerant CD4+CD25+T cells expressed IL-5Rα. This study demonstrated that IL-5 promoted the survival of alloantigen-specific CD4+CD25+T cells that mediate transplant tolerance.
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Nomura M, Hodgkinson SJ, Tran GT, Verma ND, Robinson C, Plain KM, Boyd R, Hall BM. Cytokines affecting CD4 +T regulatory cells in transplant tolerance. II. Interferon gamma (IFN-γ) promotes survival of alloantigen-specific CD4 +T regulatory cells. Transpl Immunol 2017; 42:24-33. [PMID: 28487237 DOI: 10.1016/j.trim.2017.05.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 04/21/2017] [Accepted: 05/05/2017] [Indexed: 10/19/2022]
Abstract
CD4+T cells that transfer alloantigen-specific transplant tolerance are short lived in culture unless stimulated with specific-donor alloantigen and lymphocyte derived cytokines. Here, we examined if IFN-γ maintained survival of tolerance transferring CD4+T cells. Alloantigen-specific transplant tolerance was induced in DA rats with heterotopic adult PVG heart allografts by a short course of immunosuppression and these grafts functioned for >100days with no further immunosuppression. In previous studies, we found the CD4+T cells from tolerant rats that transfer tolerance to an irradiated DA host grafted with a PVG heart, lose their tolerance transferring ability after 3days of culture, either with or without donor alloantigen, and effect rejection of specific-donor grafts. If cultures with specific-donor alloantigen are supplemented by supernatant from ConA activated lymphocytes the tolerance transferring cells survive, suggesting these cells depend on cytokines for their survival. In this study, we found addition of rIFN-γ to MLC with specific-donor alloantigen maintained the capacity of tolerant CD4+T cells to transfer alloantigen-specific tolerance and their ability to suppress PVG allograft rejection mediated by co-administered naïve CD4+T cells. IFN-γ suppressed the in vitro proliferation of tolerant CD4+T cells. Tolerant CD4+CD25+T cells did not proliferate in MLC to PVG stimulator cells with no cytokine added, but did when IFN-γ was present. IFN-γ did not alter proliferation of tolerant CD4+CD25+T cells to third-party Lewis. Tolerant CD4+CD25+T cells' expression of IFN-γ receptor (IFNGR) was maintained in culture when IFN-γ was present. This study suggested that IFN-γ maintained tolerance mediating alloantigen-specific CD4+CD25+T cells.
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Affiliation(s)
- Masaru Nomura
- Immune Tolerance Group, Faculty of Medicine, UNSW Australia, Sydney and Ingham Institute Liverpool Hospital, NSW, Australia
| | - Suzanne J Hodgkinson
- Immune Tolerance Group, Faculty of Medicine, UNSW Australia, Sydney and Ingham Institute Liverpool Hospital, NSW, Australia
| | - Giang T Tran
- Immune Tolerance Group, Faculty of Medicine, UNSW Australia, Sydney and Ingham Institute Liverpool Hospital, NSW, Australia
| | - Nirupama D Verma
- Immune Tolerance Group, Faculty of Medicine, UNSW Australia, Sydney and Ingham Institute Liverpool Hospital, NSW, Australia
| | - Catherine Robinson
- Immune Tolerance Group, Faculty of Medicine, UNSW Australia, Sydney and Ingham Institute Liverpool Hospital, NSW, Australia
| | - Karren M Plain
- Immune Tolerance Group, Faculty of Medicine, UNSW Australia, Sydney and Ingham Institute Liverpool Hospital, NSW, Australia
| | - Rochelle Boyd
- Immune Tolerance Group, Faculty of Medicine, UNSW Australia, Sydney and Ingham Institute Liverpool Hospital, NSW, Australia
| | - Bruce M Hall
- Immune Tolerance Group, Faculty of Medicine, UNSW Australia, Sydney and Ingham Institute Liverpool Hospital, NSW, Australia.
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10
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Hall BM, Tran GT, Robinson CM, Hodgkinson SJ. Induction of antigen specific CD4+CD25+Foxp3+T regulatory cells from naïve natural thymic derived T regulatory cells. Int Immunopharmacol 2015; 28:875-86. [DOI: 10.1016/j.intimp.2015.03.049] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2015] [Accepted: 03/28/2015] [Indexed: 12/14/2022]
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Abstract
Induction of specific immune tolerance to grafts remains the sought-after standard following transplantation. Defined by expression of the Foxp3 (forkhead box protein 3) transcription factor, the regulatory T-cell (Treg) lineage has been noted to exert potent immunoregulatory functions that contribute to specific graft tolerance. In this review, we discuss the known signals and pathways which govern Treg development, both in the thymus and in peripheral sites, as well as lineage maintenance and homeostasis. In particular, we highlight the roles of T-cell receptor signaling, CD28 costimulation, and signals through phosphatidyl inositol 3-kinase (PI3K) and related metabolic pathways in multiple aspects of Treg biology.
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Affiliation(s)
- Alexandria Huynh
- Division of Medical Sciences, Harvard Medical School, Boston, MA, USA; Transplantation Biology Research Center, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
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12
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Chong AS, Alegre ML. Transplantation tolerance and its outcome during infections and inflammation. Immunol Rev 2015; 258:80-101. [PMID: 24517427 DOI: 10.1111/imr.12147] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Much progress has been made toward understanding the mechanistic basis of transplantation tolerance in experimental models, which implicates clonal deletion of alloreactive T and B cells, induction of cell-intrinsic hyporesponsiveness, and dominant regulatory cells mediating infectious tolerance and linked suppression. Despite encouraging success in the laboratory, achieving tolerance in the clinic remains challenging, although the basis for these challenges is beginning to be understood. Heterologous memory alloreactive T cells generated by infections prior to transplantation have been shown to be a critical barrier to tolerance induction. Furthermore, infections at the time of transplantation and tolerance induction provide a pro-inflammatory milieu that alters the stability and function of regulatory T cells as well as the activation requirements and differentiation of effector T cells. Thus, infections can result in enhanced alloreactivity, resistance to tolerance induction, and destabilization of the established tolerance state. We speculate that these experimental findings have relevance to the clinic, where infections have been associated with allograft rejection and may be a causal event precipitating the loss of grafts after long periods of stable operational tolerance. Understanding the mechanisms by which infections prevent and destabilize tolerance can lead to therapies that promote stable life-long tolerance in transplant recipients.
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Affiliation(s)
- Anita S Chong
- Section of Transplantation, Department of Surgery, The University of Chicago, Chicago, IL, USA
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13
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Verma ND, Hall BM, Plain KM, Robinson CM, Boyd R, Tran GT, Wang C, Bishop GA, Hodgkinson SJ. Interleukin-12 (IL-12p70) Promotes Induction of Highly Potent Th1-Like CD4(+)CD25(+) T Regulatory Cells That Inhibit Allograft Rejection in Unmodified Recipients. Front Immunol 2014; 5:190. [PMID: 24847323 PMCID: PMC4023029 DOI: 10.3389/fimmu.2014.00190] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2014] [Accepted: 04/14/2014] [Indexed: 11/13/2022] Open
Abstract
In rat models, CD4(+)CD25(+) T regulatory cells (Treg) play a key role in the induction and maintenance of antigen-specific transplant tolerance, especially in DA rats with PVG cardiac allografts (1, 2). We have previously described generation of alloantigen-specific Treg (Ts1), by culture of naïve natural CD4(+)CD25(+) Treg (nTreg) with specific alloantigen and IL-2 for 4 days. These cells express mRNA for IFN-γ receptor (ifngr) and suppress donor but not third party cardiac allograft rejection mediated by alloreactive CD4(+) T cells at ratios of <1:10. Here, we show that Ts1 also expressed the IL-12p70 specific receptor (il-12rβ2) and that rIL-12p70 can induce their proliferation. Ts1 cells re-cultured with rIL-12p70 alone or rIL-12p70 and recombinant interleukin-2 (rIL-2), suppressed proliferation of CD4(+) T cells in mixed lymphocyte culture at <1:1024, whereas Ts1 cells re-cultured with rIL-2 and alloantigen only suppressed at 1:32-64. The rIL-12p70 alloactivated Ts1 cells markedly delayed PVG, but not third party Lewis, cardiac allograft rejection in normal DA recipients. Ts1 cells re-cultured for 4 days with rIL-12p70 alone, but not those re-cultured with rIL-12p70 and rIL-2, expressed more il-12rβ2, t-bet, and ifn-γ, and continued to express the markers of Ts1 cells, foxp3, ifngr, and il-5 indicating Th1-like Treg were induced. Ts1 cells re-cultured with rIL-2 and alloantigen remained of the Ts1 phenotype and did not suppress cardiac graft rejection in normal DA rats. We induced highly suppressive Th1-like Treg from naïve nTreg in 7 days by culture with alloantigen, first with rIL-2 then with rIL-12p70. These Th1-like Treg delayed specific donor allograft rejection demonstrating therapeutic potential.
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Affiliation(s)
- Nirupama Darshan Verma
- Immune Tolerance Laboratory, Department of Medicine, Liverpool Hospital, University of New South Wales , Kensington, NSW , Australia
| | - Bruce Milne Hall
- Immune Tolerance Laboratory, Department of Medicine, Liverpool Hospital, University of New South Wales , Kensington, NSW , Australia
| | - Karren Michelle Plain
- Immune Tolerance Laboratory, Department of Medicine, Liverpool Hospital, University of New South Wales , Kensington, NSW , Australia
| | - Catherine M Robinson
- Immune Tolerance Laboratory, Department of Medicine, Liverpool Hospital, University of New South Wales , Kensington, NSW , Australia
| | - Rochelle Boyd
- Immune Tolerance Laboratory, Department of Medicine, Liverpool Hospital, University of New South Wales , Kensington, NSW , Australia
| | - Giang T Tran
- Immune Tolerance Laboratory, Department of Medicine, Liverpool Hospital, University of New South Wales , Kensington, NSW , Australia
| | - Chuanmin Wang
- Collaborative Transplant Research Laboratory, Royal Prince Alfred Hospital, The University of Sydney , Camperdown, NSW , Australia
| | - G Alex Bishop
- Collaborative Transplant Research Laboratory, Royal Prince Alfred Hospital, The University of Sydney , Camperdown, NSW , Australia
| | - Suzanne J Hodgkinson
- Immune Tolerance Laboratory, Department of Medicine, Liverpool Hospital, University of New South Wales , Kensington, NSW , Australia
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14
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Hall BM, Tran GT, Verma ND, Plain KM, Robinson CM, Nomura M, Hodgkinson SJ. Do Natural T Regulatory Cells become Activated to Antigen Specific T Regulatory Cells in Transplantation and in Autoimmunity? Front Immunol 2013; 4:208. [PMID: 23935597 PMCID: PMC3731939 DOI: 10.3389/fimmu.2013.00208] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Accepted: 07/08/2013] [Indexed: 12/20/2022] Open
Abstract
Antigen specific T regulatory cells (Treg) are often CD4+CD25+FoxP3+ T cells, with a phenotype similar to natural Treg (nTreg). It is assumed that nTreg cannot develop into an antigen specific Treg as repeated culture with IL-2 and a specific antigen does not increase the capacity or potency of nTreg to promote immune tolerance or suppress in vitro. This has led to an assumption that antigen specific Treg mainly develop from CD4+CD25−FoxP3− T cells, by activation with antigen and TGF-β in the absence of inflammatory cytokines such as IL-6 and IL-1β. Our studies on antigen specific CD4+CD25+ T cells from animals with tolerance to an allograft, identified that the antigen specific and Treg are dividing, and need continuous stimulation with specific antigen T cell derived cytokines. We identified that a variety of cytokines, especially IL-5 and IFN-γ but not IL-2 or IL-4 promoted survival of antigen specific CD4+CD25+FoxP3+ Treg. To examine if nTreg could be activated to antigen specific Treg, we activated nTreg in culture with either IL-2 or IL-4. Within 3 days, antigen specific Treg are activated and there is induction of new cytokine receptors on these cells. Specifically nTreg activated by IL-2 and antigen express the interferon-γ receptor (IFNGR) and IL-12p70 (IL-12Rβ2) receptor but not the IL-5 receptor (IL-5Rα). These cells were responsive to IFN-γ or IL-12p70. nTreg activated by IL-4 and alloantigen express IL-5Rα not IFNGR or IL-12p70Rβ2 and become responsive to IL-5. These early activated antigen specific Treg, were respectively named Ts1 and Ts2 cells, as they depend on Th1 or Th2 responses. Further culture of Ts1 cells with IL-12p70 induced Th1-like Treg, expressing IFN-γ, and T-bet as well as FoxP3. Our studies suggest that activation of nTreg with Th1 or Th2 responses induced separate lineages of antigen specific Treg, that are dependent on late Th1 and Th2 cytokines, not the early cytokines IL-2 and IL-4.
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Affiliation(s)
- Bruce M Hall
- Immune Tolerance Laboratory, Medicine, University of New South Wales , Sydney, NSW , Australia
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15
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Cobbold SP, Waldmann H. Regulatory cells and transplantation tolerance. Cold Spring Harb Perspect Med 2013; 3:3/6/a015545. [PMID: 23732858 DOI: 10.1101/cshperspect.a015545] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Transplantation tolerance is a continuing therapeutic goal, and it is now clear that a subpopulation of T cells with regulatory activity (Treg) that express the transcription factor foxp3 are crucial to this aspiration. Although reprogramming of the immune system to donor-specific transplantation tolerance can be readily achieved in adult mouse models, it has yet to be successfully translated in human clinical practice. This requires that we understand the fundamental mechanisms by which donor antigen-specific Treg are induced and function to maintain tolerance, so that we can target therapies to enhance rather than impede these regulatory processes. Our current understanding is that Treg act via numerous molecular mechanisms, and critical underlying components such as mTOR inhibition, are only now emerging.
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Affiliation(s)
- Stephen P Cobbold
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, United Kingdom.
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16
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Shalev I, Selzner N, Shyu W, Grant D, Levy G. Role of regulatory T cells in the promotion of transplant tolerance. Liver Transpl 2012; 18:761-70. [PMID: 22523007 DOI: 10.1002/lt.23458] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Liver transplantation is now recognized as the most effective therapy for patients with end-stage acute and chronic liver failure. Despite outstanding short-term graft and patient survival, liver transplantation continues to face several major challenges, including poor long-term graft survival due to chronic rejection and major side effects of long-term immunosuppressive therapy (which is required for the prevention of rejection). The ability to produce a state of tolerance after transplantation would potentially obviate long-term immunosuppression. Self-tolerance and immune homeostasis involve both central and peripheral immunoregulatory mechanisms. To date, studies have shown that many subsets of regulatory T cells (Tregs) control immune responses to foreign and alloantigens. The identification of Tregs that are positive for CD4, CD25, and the transcription factor forkhead box (Foxp3) has resulted in major advances in our understanding of the immunology of rejection and the development of transplant tolerance. In this article, we focus on the importance of Tregs in tolerance induction in experimental models of liver transplantation. Furthermore, we discuss the therapeutic potential of Tregs for the promotion of tolerance in transplant patients and highlight recent clinical trials of Treg-based therapies.
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Affiliation(s)
- Itay Shalev
- University of Toronto Transplantation Institute, Toronto, Ontario, Canada
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17
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Hall BM, Tran G, Hodgkinson SJ. Alloantigen specific T regulatory cells in transplant tolerance. Int Immunopharmacol 2009; 9:570-4. [PMID: 19539571 DOI: 10.1016/j.intimp.2009.01.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2009] [Accepted: 01/22/2009] [Indexed: 01/08/2023]
Abstract
CD4(+)CD25(+)Foxp3(+)T cells are regulatory/suppressor cells (Treg) that include non-antigen(Ag)-specific as well as Ag-specific Tregs. How non-Ag-specific naïve CD4(+)CD25(+)Treg develop into specific Tregs is unknown. We have studied DA rats tolerant to fully allogeneic PVG cardiac grafts that survived with out immunosuppression for over 100 days and identified the cellular basis of alloantigen specific tolerance. Key observations from our studies will be reviewed including how CD4(+)CD25(+)Tregs were first identified and the cytokine dependence of CD4(+)T cells that transfer alloantigen specific transplant tolerance which died in culture unless stimulated with both cytokine rich ConA supernatant and specific donor alloantigen. Both the tolerant CD4(+)CD25(+) and CD4(+)CD25(-) T cell populations are required to transfer tolerance, yet alone the CD4(+)CD25(-) T cell effect rejection. Tolerance transfer occurs with a low ratio of CD4(+)CD25(+)T cells (<1:10), whereas to induce tolerance with naive CD4(+)CD25(+)T cells requires both a ratio of >1:1 and is not alloantigen specific. Recent findings on how naïve CD4(+)CD25(+)T cells developed into two separated pathways of alloantigen specific Tregs, by culturing them with alloAg with either IL-2 or IL-4 and donor alloantigen are described. IL-2 enhances IFN-gammaR and IL-5 mRNA while IL-4 induced a reciprocal profile with de novo IL-5Ralpha and increased IFN-gamma mRNA expression. Both IL-2 and IL-4 alloactivated CD4(+)CD25(+)Tregs within 3-4 days of culture can induce alloantigen specific tolerance at ratios of 1:10. Long term, CD4(+)CD25(+)T cells from tolerant hosts given IL-2 cultured cells have increased IL-5 and IFN-gammaR mRNA; whereas hosts given IL-4 cultured cells had enhanced IL-5Ralpha mRNA expression and IL-5 enhanced their proliferation to donor but not third party alloAg. These findings suggest that Th1 and Th2 responses activate two pathways of alloantigen specific Tregs that can mediate transplant tolerance but are dependent upon cytokines produced by ongoing Th1 and/or Th2 immune responses.
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Affiliation(s)
- Bruce M Hall
- Department of Medicine, The University of New South Wales, Liverpool Hospital, Liverpool, NSW, Australia.
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18
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19
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Wang S, Jiang J, Guan Q, Lan Z, Wang H, Nguan CY, Jevnikar AM, Du C. Reduction of Foxp3-expressing regulatory T cell infiltrates during the progression of renal allograft rejection in a mouse model. Transpl Immunol 2008; 19:93-102. [DOI: 10.1016/j.trim.2008.03.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2007] [Revised: 03/26/2008] [Accepted: 03/26/2008] [Indexed: 11/15/2022]
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20
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Hall BM, Robinson CM, Plain KM, Verma ND, Carter N, Boyd RA, Tran GT, Hodgkinson SJ. Studies on naïve CD4+CD25+T cells inhibition of naïve CD4+CD25−T cells in mixed lymphocyte cultures. Transpl Immunol 2008; 18:291-301. [DOI: 10.1016/j.trim.2007.09.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2007] [Revised: 08/24/2007] [Accepted: 09/12/2007] [Indexed: 11/28/2022]
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Hall BM, Plain KM, Verma ND, Tran GT, Boyd R, Robinson CM, Nicolls MR, Berger ME, Nomura M, Hodgkinson SJ. Transfer of Allograft Specific Tolerance Requires CD4+CD25+T Cells but Not Interleukin-4 or Transforming Growth Factor–β and Cannot Induce Tolerance to Linked Antigens. Transplantation 2007; 83:1075-84. [PMID: 17452898 DOI: 10.1097/01.tp.0000259553.66185.2f] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND The mechanisms by which CD4+T cells, especially CD4+ CD25+T cells, transfer allograft specific tolerance are poorly defined. The role of cytokines and the effect on antigen-presenting cells is not resolved. METHODS Anti-CD3 monoclonal antibody (mAb) therapy induced tolerance to PVG heterotopic cardiac transplantation in DA rats. Peripheral CD4+T cells or CD4+ CD25+ and CD4+ CD25-T cell subsets were adoptively transferred to irradiated DA hosts grafted with PVG heart grafts. For specificity studies, tolerant CD4+T cells were transferred to hosts with Lewis or (PVGxLewis)F1 heart grafts. Cytokine mRNA induction and the requirement for interleukin (IL)-4 and transforming growth factor (TGF)-beta in the transfer of tolerance was assessed. RESULTS CD4+T cells transferred specific tolerance and suppressed naïve CD4+T cells capacity to effect rejection of PVG but not Lewis grafts. (PVGxLewis)F1 grafts had a major rejection episode but recovered. Later these hosts accepted PVG but not Lewis skin grafts. Adoptive hosts restored with tolerant or naïve cells had similar levels of mRNA expression for all Th1 and Th2 cytokines and effector molecules assayed. Transfer of tolerance by CD4+T cells was not blocked by mAb to IL-4 or TGF-beta. CD4+ CD25-T cells from either naïve or tolerant hosts effected rejection. In contrast neither tolerant nor naïve CD4+ CD25+T cells restored rejection. CONCLUSIONS Specific tolerance transfer required CD4+ containing CD4+ CD25+T cells. An inflammatory response with induction of mRNA for Th1 and Th2 cytokines plus cytotoxic effector molecules occurred, but IL-4 and TGF-beta were not essential. Inhibition of antigen presenting cells was not the sole mechanism as there was no linked tolerance.
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Affiliation(s)
- Bruce M Hall
- Immune Tolerance Laboratory, University of New South Wales, Australian Technology Park, New South Wales, Australia.
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22
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Plain KM, Boyd R, Verma ND, Robinson CM, Tran GT, Hodgkinson SJ, Hall BM. Transplant Tolerance Associated With a Th1 Response and Not Broken by IL-4, IL-5, and TGF-β Blockade or Th1 Cytokine Administration. Transplantation 2007; 83:764-73. [PMID: 17414711 DOI: 10.1097/01.tp.0000256326.11647.2e] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Specific transplant tolerance is mediated by CD4 T cells that die unless supported by T-cell derived cytokines and donor antigen. This study examined the role of Th1 and Th2 cytokines in the maintenance of tolerance. METHODS Tolerance to fully allogeneic PVG cardiac allografts in DA rats was induced by short-term anti-CD3 monoclonal antibody therapy. Responses of tolerant cells to donor and third party antigen were assessed in vivo by examination of the infiltrate in the heart and application of skin grafts, and in vitro in mixed lymphocyte culture. Cell subsets were stained, induction of cytokine mRNA assayed by reverse-transcriptase polymerase chain reaction and the role of cytokines determined by treating with blocking monoclonal antibody to cytokines or cytokine administration. RESULTS Tolerated grafts had a T cell and macrophage infiltrate with increased mRNA for Th1 cytokines, interleukin (IL)-2, and interferon (IFN)-gamma but not Th2 cytokines. Peripheral lymphocytes proliferated in mixed lymphocyte culture and expressed Th1 cytokine mRNA. Tolerant hosts accepted PVG and rejected Lewis skin allografts and the lymph nodes draining both these grafts had similar induction of Th1 and Th2 cytokine mRNA. Treatment of tolerant rats with Th1 cytokines IL-2, IFN-gamma, and IL-12p70 or monoclonal antibody that blocked IL-4, IL-5, and transforming growth factor-beta did not prevent acceptance of PVG skin grafts. CONCLUSIONS These studies in a model of tolerance regulated by CD4CD25 T cells demonstrated there was no defect in Th1 responses. Tolerance was due to regulation that was not solely dependent on IL-4, IL-5, or transforming growth factor-beta and was not inactivated or overwhelmed by administration of Th1 cytokines, IL-2, IFN-gamma or IL-12p70.
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Affiliation(s)
- Karren M Plain
- Immune Tolerance Laboratory, Faculty of Medicine, University of New South Wales, Sydney, Australia.
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23
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Abstract
To test the hypothesis that chronic stimulation of T cells with a weak agonistic antigen will generate regulatory T cells and immune tolerance, a study reported in this issue employed the redesign of a minor histocompatibility antigen. Using knowledge of residues at which the antigen contacts the T cell receptor, a weak agonist was produced. Pretreatment with this altered antigen produced transplant tolerance, generation of regulatory T cells, and a loss of many antigen-reactive T cells.
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Affiliation(s)
- Terry B Strom
- Division of Immunology and Transplant Research Center, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts 02115, USA.
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24
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Garin MI, Lechler RI. Regulatory T cells. Curr Opin Organ Transplant 2003. [DOI: 10.1097/00075200-200303000-00003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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25
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Lechler RI, Garden OA, Turka LA. The complementary roles of deletion and regulation in transplantation tolerance. Nat Rev Immunol 2003; 3:147-58. [PMID: 12563298 DOI: 10.1038/nri1002] [Citation(s) in RCA: 192] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Neonatal tolerance of alloantigens was described in mice nearly half a century ago, but unfortunately, the translation of these early findings into the clinical arena proved to be much more challenging than was first anticipated. However, the past decade has seen considerable progress in our understanding of the mechanisms that contribute to transplantation tolerance in experimental models. This review outlines our current understanding of the mechanisms of allograft tolerance, emphasizing the complementary roles of deletion and regulation of alloreactive T cells.
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Affiliation(s)
- Robert I Lechler
- Department of Immunology, Division of Medicine, Imperial College of Science, Technology and Medicine, Hammersmith Campus, Commonwealth Building, Du Cane Road, London W12 0NN, UK.
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26
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Nicolls MR, Coulombe M, Beilke J, Gelhaus HC, Gill RG. CD4-dependent generation of dominant transplantation tolerance induced by simultaneous perturbation of CD154 and LFA-1 pathways. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2002; 169:4831-9. [PMID: 12391193 DOI: 10.4049/jimmunol.169.9.4831] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CD154 and LFA-1 (CD11a) represent conceptually distinct pathways of receptor/ligand interactions (costimulation and adhesion/homing, respectively) that have been effectively targeted to induce long-term allograft acceptance and tolerance. In the current study, we determined the relative efficacy and nature of tolerance induced by mAbs specific for these pathways. In vitro analysis indicated that simultaneous targeting of CD154 and LFA-1 resulted in profound inhibition of alloreactivity, suggesting that combined anti-CD154/anti-LFA-1 therapy could be highly effective in vivo. Thus, we evaluated combining mAb therapies targeting CD154 and LFA-1 for inducing transplantation tolerance to pancreatic islet allografts. Monotherapy with either anti-CD154 or anti-LFA-1 was partially effective for inducing long-term allograft survival, whereas the combination resulted in uniform allograft acceptance in high-responder C57BL/6 recipients. This combined therapy was not lymphocyte depleting and did not require the long-term deletion of donor-reactive T lymphocytes to maintain allograft survival. Importantly, combined anti-CD154/anti-LFA therapy uniquely resulted in "dominant" transplantation tolerance. Therefore, simultaneous perturbation of CD154 and LFA-1 molecules can result in profound tolerance induction not accomplished through individual monotherapy approaches. Furthermore, results show that such regulatory tolerance can coexist with the presence of robust anti-donor reactivity, suggesting that active tolerance does not require a corresponding deletion of donor-reactive T cells. Interestingly, although the induction of this regulatory state was highly CD4 dependent, the adoptive transfer of tolerance was less CD4 dependent in vivo.
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MESH Headings
- Adoptive Transfer
- Animals
- Antibodies, Monoclonal/administration & dosage
- Antibodies, Monoclonal/therapeutic use
- CD4-Positive T-Lymphocytes/immunology
- CD40 Ligand/immunology
- CD40 Ligand/physiology
- Clonal Deletion/genetics
- Drug Therapy, Combination
- Immunodominant Epitopes/immunology
- Injections, Intraperitoneal
- Islets of Langerhans Transplantation/immunology
- Lymphocyte Activation/genetics
- Lymphocyte Culture Test, Mixed
- Lymphocyte Function-Associated Antigen-1/immunology
- Lymphocyte Function-Associated Antigen-1/physiology
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C3H
- Mice, Inbred C57BL
- Mice, Knockout
- Mice, Transgenic
- Signal Transduction/genetics
- Signal Transduction/immunology
- Transplantation Tolerance/genetics
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Affiliation(s)
- Mark R Nicolls
- Division of Pulmonary Sciences and Critical Care Medicine, Department of Medicine, Barbara Davis Center for Childhood Diabetes, University of Colorado Health Sciences Center, Denver 80262, USA.
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27
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Sánchez-Fueyo A, Weber M, Domenig C, Strom TB, Zheng XX. Tracking the immunoregulatory mechanisms active during allograft tolerance. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2002; 168:2274-81. [PMID: 11859115 DOI: 10.4049/jimmunol.168.5.2274] [Citation(s) in RCA: 147] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Immunoregulatory mechanisms dependent on regulatory CD4+ T cells are believed to be critical in the maintenance of peripheral tolerance to allografts. However, a detailed characterization of the effects of these regulatory T cells has been hampered by the absence of a simple means to track and study them. In this work we provide evidence that in a murine model of islet transplantation the interactions between alloaggressive and regulatory T cells can be studied in vitro and in vivo at the single-cell level. The observations made in both an in vitro coculture system and an in vivo CFSE-based adoptive transfer model indicate that lymphocytes from tolerant allograft recipients 1) proliferate weakly to donor strain allogeneic cells but vigorously to third-party strain cells; and 2) suppress the proliferation of naive syngeneic CD4+ and CD8+ T cells to donor tissue in a cell dose- and Ag-specific manner. These effects depend on the presence of CD4+CD25+ T cells and are neutralized by anti-CTLA4 mAb or rIL-2. The principal effect of anti-CTLA4 is directed against the naive, not regulatory, T cell population. These results can be replicated in vivo by transferring lymphocyte populations into transplant recipients, proving that the graft-protecting actions of regulatory T cells are blunted by a rise in the number of allodestructive T cells (pool size model) and depend on the presence of CD4+CD25+ T cells and the integrity of the CTLA4/B7 pathway.
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Affiliation(s)
- Alberto Sánchez-Fueyo
- Department of Medicine, Division of Immunology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
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28
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Coulombe M, Yang H, Wolf LA, Gill RG. Tolerance to Antigen-Presenting Cell-Depleted Islet Allografts Is CD4 T Cell Dependent. THE JOURNAL OF IMMUNOLOGY 1999. [DOI: 10.4049/jimmunol.162.5.2503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
Pretreatment of pancreatic islets in 95% oxygen culture depletes graft-associated APCs and leads to indefinite allograft acceptance in immunocompetent recipients. As such, the APC-depleted allograft represents a model of peripheral alloantigen presentation in the absence of donor-derived costimulation. Over time, a state of donor-specific tolerance develops in which recipients are resistant to donor APC-induced graft rejection. Thus, persistence of the graft is sufficient to induce tolerance independent of other immune interventions. Donor-specific tolerance could be adoptively transferred to immune-deficient SCID recipient mice transplanted with fresh immunogenic islet allografts, indicating that the original recipient was not simply “ignorant” of donor antigens. Interestingly, despite the fact that the original islet allograft presented only MHC class I alloantigens, CD8+ T cells obtained from tolerant animals readily collaborated with naive CD4+ T cells to reject donor-type islet grafts. Conversely, tolerant CD4+ T cells failed to collaborate effectively with naive CD8+ T cells for the rejection of donor-type grafts. In conclusion, the MHC class I+, II− islet allograft paradoxically leads to a change in the donor-reactive CD4 T cell subset and not in the CD8 subset. We hypothesize that the tolerant state is not due to direct class I alloantigen presentation to CD8 T cells but, rather, occurs via the indirect pathway of donor Ag presentation to CD4 T cells in the context of host MHC class II molecules.
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Affiliation(s)
- Marilyne Coulombe
- *Barbara Davis Center for Childhood Diabetes/University of Colorado Health Sciences Center, Denver, CO 80262; and
| | - Huan Yang
- *Barbara Davis Center for Childhood Diabetes/University of Colorado Health Sciences Center, Denver, CO 80262; and
| | - Leslie A. Wolf
- †Laboratory of Public Health, Virology/Serology Branch, North Carolina State, Raleigh, NC 27611
| | - Ronald G. Gill
- *Barbara Davis Center for Childhood Diabetes/University of Colorado Health Sciences Center, Denver, CO 80262; and
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Mysliwietz J, Thierfelder S. Analysis of peripheral immune tolerance uncovers a mouse strain-dependent in situ type of graft tolerance. Eur J Immunol 1999; 29:150-5. [PMID: 9933096 DOI: 10.1002/(sici)1521-4141(199901)29:01<150::aid-immu150>3.0.co;2-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
We screened various mouse strains [C57BL/6, BALB/c, DBA/2, CBA/Ca, (CBAxC57L/6)F1, SJL, C3H] for induction of peripheral immune tolerance. Only CBA/Ca mice treated with anti-CD4 + CD8 monoclonal antibodies and grafted with allogeneic skin showed long-term graft survival (150 to >200 days). Interestingly, T cells from the tolerant CBA/Ca mice rejected bone marrow/spleen cells of the skin graft donor strain and caused lethal graft-versus-host disease when transplanted to the donor strain. Furthermore, peripheral tolerance was easily broken: CBA/Ca mice could be reactivated to reject their tolerated grafts via immunization with (graft donor x recipient strain)F1 bone marrow cells. Thus, in contrast to the generalized nature of central tolerance, our experiments show that peripheral immune tolerance is strain dependent and locally restricted to graft tissue.
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Affiliation(s)
- J Mysliwietz
- CSF-National Research Center for Environment and Health, Institute of Immunology, Munich, Germany
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30
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Hall BM, Fava L, Chen J, Plain KM, Boyd RA, Spicer ST, Berger MF. Anti-CD4 Monoclonal Antibody-Induced Tolerance to MHC-Incompatible Cardiac Allografts Maintained by CD4+ Suppressor T Cells That Are Not Dependent upon IL-4. THE JOURNAL OF IMMUNOLOGY 1998. [DOI: 10.4049/jimmunol.161.10.5147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
Anti-CD4 mAb-induced tolerance to transplanted tissues has been proposed as due to down-regulation of Th1 cells by preferential induction of Th2 cytokines, especially IL-4. This study examined the role of CD4+ cells and cytokines in tolerance to fully allogeneic PVG strain heterotopic cardiac allografts induced in naive DA rats by treatment with MRC Ox38, a nondepleting anti-CD4 mAb. All grafts survived >100 days but had a minor mononuclear cell infiltrate that increased mRNA for the Th1 cytokines IL-2, IFN-γ, and TNF-β, but not for Th2 cytokines IL-4 and IL-6 or the cytolytic molecules perforin and granzyme A. These hosts accepted PVG skin grafts but rejected third-party grafts, which were not blocked by anti-IL-4 mAb. Cells from these tolerant hosts proliferated in MLC and produced IL-2, IFN-γ, and IL-4 at levels equivalent to naive cells. Unfractionated and CD4+ T cells, but not CD8+ T cells, transferred specific tolerance to irradiated heart grafted hosts and inhibited reconstitution of rejection by cotransferred naive cells. This transfer of tolerance was associated with normal induction of IL-2 and delayed induction of IFN-γ, but not with increased IL-4 or IL-10 mRNA. Transfer of tolerance was also not inhibited by anti-IL-4 mAb. This study demonstrated that tolerance induced by a nondepleting anti-CD4 mAb is maintained by a CD4+ suppressor T cell that is not associated with preferential induction of Th2 cytokines or the need for IL-4; nor is it associated with an inability to induce Th1 cytokines or anergy.
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Affiliation(s)
- Bruce M. Hall
- Department of Medicine, University of New South Wales, Liverpool Hospital, Liverpool, New South Wales, Australia
| | - Lisa Fava
- Department of Medicine, University of New South Wales, Liverpool Hospital, Liverpool, New South Wales, Australia
| | - Juchuan Chen
- Department of Medicine, University of New South Wales, Liverpool Hospital, Liverpool, New South Wales, Australia
| | - Karren M. Plain
- Department of Medicine, University of New South Wales, Liverpool Hospital, Liverpool, New South Wales, Australia
| | - Rochelle A. Boyd
- Department of Medicine, University of New South Wales, Liverpool Hospital, Liverpool, New South Wales, Australia
| | - S. Timothy Spicer
- Department of Medicine, University of New South Wales, Liverpool Hospital, Liverpool, New South Wales, Australia
| | - Manuela F. Berger
- Department of Medicine, University of New South Wales, Liverpool Hospital, Liverpool, New South Wales, Australia
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He XY, Chen J, Verma N, Plain K, Tran G, Hall BM. Treatment with interleukin-4 prolongs allogeneic neonatal heart graft survival by inducing T helper 2 responses. Transplantation 1998; 65:1145-52. [PMID: 9603159 DOI: 10.1097/00007890-199805150-00001] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND The T helper (Th) 2 cytokine interleukin (IL)-4 has been implicated as a major regulatory cytokine for the induction of transplant tolerance, but few studies have examined the capacity of IL-4 to induce tolerance. The effect of IL-4 therapy alone or with low doses of anti-CD4 monoclonal antibody (mAb) therapy on survival of fully allogeneic PVG neonatal heart graft in adult DA rats was examined. METHODS Rat recombinant (r) IL-4 was given at 30 microg (10(4) U)/kg daily intraperitoneally for 10 days and MRC OX35 (anti-CD4, nondepleting) or MRC OX81 (anti-IL-4) was given intraperitoneally on days 0, 3, 7, and 10. Semiquantitative reverse transcriptase-polymerase chain reaction was used to assay mRNA for cytokine in the graft, regional node and spleen and fluorescence-activated cell sorting was used to assay alloantibody Ig isotypes. RESULTS Grafts in rIL-4-treated rats survived a median period of 39 days (range, 28-52 days), significantly longer than in both untreated and nontransfected Chinese hamster ovary-K1 supernatant-treated controls (median, 14 days; range, 10-16 days, P=0.009). rIL-4 treatment with a suboptimal dose of anti-CD4 mAb prolonged median survival to 70 days (range, 63-80 days), which was longer than rIL-4 treatment alone or anti-CD4 mAb alone (median, 36 days; range, 30-55 days; P<0.0045). Combining MRC OX81 with MRC OX35 therapy led to earlier rejection at a median period of 26 days (range, 20-28 days); MRC OX81 alone had no effect on graft survival. Alloantibody titers, especially IgG1, were higher in rIL-4-treated animals and lower in anti-CD4 mAb-treated animals than in animals with normal rejection (P<0.05). IL-4 mRNA was increased in regional lymph nodes and spleen of the rIL-4-treated groups compared with all other groups, but there were no differences for IL-2, interferon-gamma, or IL-10. CONCLUSIONS rIL-4 therapy markedly prolonged neonatal cardiac allograft survival, and, with anti-CD4 therapy, it further prolonged survival. It induced IL-4 mRNA in lymphoid tissues and enhanced alloantibody production, especially IgG1, which demonstrated enhanced Th2 responses, but did not affect Th1 cytokines.
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Affiliation(s)
- X Y He
- Department of Medicine, University of New South Wales, Liverpool Hospital, Australia
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Merten S, Chen JC, Ha H, Plain K, Boyd RA, Penny MJ, Leenaerts P, Hall BM. The cellular basis of cardiac allograft rejection: VIII. Mechanisms underlying delayed allograft rejection in PVG C6-deficient rats. Transplantation 1998; 65:1152-8. [PMID: 9603160 DOI: 10.1097/00007890-199805150-00002] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND The delayed allograft rejection in C6-deficient PVG C6- rats compared with normal PVG rats has been attributed to the lack of alloantibody activation of the membrane attack complex of complement. As T cells alone have been shown to effect graft rejection, we examined T-cell responses in PVG C6- rats. METHODS The cellular infiltrate and its mRNA for cytokines and effector molecules in DA heart allografts to PVG and PVG C6- rats was compared by immunoperoxidase staining and semiquantitative reverse transcriptase polymerase chain reaction. The ability of pure populations of T cells or alloantibody to mediate DA heart graft rejection in irradiated (750 rads) PVG and PVG C6- rats was also compared. RESULTS The median rejection time of DA heart allografts was 8 days in PVG rats and 17.5 days in PVG C6-. PVG C6- rats sensitized to DA by two skin grafts rejected DA heart grafts in 5-6 days. CD3+, CD4+, CD8+, interleukin-2 receptor-positive T cell, macrophage, and natural killer cell infiltration, as well as class II major histocompatibility complex and intercellular adhesion molecule-1 up-regulation, in grafts was similar in naive PVG and PVG C6- rats. mRNA for T helper 1 cytokine interleukin-2, interferon-gamma, tumor necrosis factor-beta, macrophage molecules tumor necrosis factor-alpha, and inducible nitric oxide synthase, as well as cytotoxic T-cell effector molecules perforin and granzyme A and B, were found to be the same in the grafts from both naive PVG and naive PVG C6- rats. Thus, there appeared to be no difference in the T-cell effector response between the PVG and PVG C6- groups. There were higher alloantibody titers in PVG C6- rats than in PVG hosts. Irradiation ablated rejection and alloantibody responses and reconstitution with naive T cells alone restored rejection in both PVG and PVG C6- rats. Irradiated rats given serum from PVG rats that had rejected DA grafts did not effect rejection of DA grafts even if given naive T cells. Sensitized T cells restored second set. CONCLUSIONS PVG C6- rats have normal T-cell responses and can mediate allograft rejection in the absence of alloantibody. The failure of PVG C6- to reject allografts rapidly may be a result of the poor clearance of alloantisera leading to enhancement of graft survival rather than a critical role for complement and membrane attack complex in acute rejection.
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Affiliation(s)
- S Merten
- Department of Medicine, University of New South Wales, Liverpool Hospital, Australia
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Plain KM, Fava L, Spinelli A, He XY, Chen J, Boyd R, Davidson CL, Hall BM. Induction of tolerance with nondepleting anti-CD4 monoclonal antibodies is associated with down-regulation of TH2 cytokines. Transplantation 1997; 64:1559-67. [PMID: 9415556 DOI: 10.1097/00007890-199712150-00009] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND Induction of tolerance with anti-CD4 has mainly focused on monoclonal antibodies (mAbs) that deplete CD4+ T cells. In this study, the mechanisms by which nondepleting anti-CD4 mAbs induce tolerance in the Dark Agouti to PVG rat heart graft model were examined. METHODS Five anti-CD4 mAbs were tested. Immunohistology and cytokine mRNA profiles were analyzed within grafts. Effects of combining anti-CD4 therapy with alloantibody (alloAb), interleukin (IL)-4, and anti-IL-4 mAb were also examined. RESULTS All mAbs tested induced indefinite graft survival (>150 days), with blocking of alloAb production. Exogenous alloAb did not restore rejection. Similar T cell receptor alphabeta+, CD8+, IL-2 receptor+ T cell, macrophage, and natural killer cell infiltration and comparable MHC II and intercellular adhesion molecule-1 levels were seen in rejecting and tolerant grafts. mRNA for IL-2, interferon-gamma, lymphotoxin, tumor necrosis factor-alpha, transforming growth factor-beta, cytolysin, and granzyme-A/B was comparable, although inducible nitric oxide synthase was slightly reduced in tolerant grafts. IL-4 and IL-5 were significantly reduced in tolerant grafts, although IL-6, IL-10, and IL-13 levels were similar; this was consistent with partial T helper (Th)2 response inhibition, which was also manifested by inhibited alloAb. The combination of alloAb, IL-4, or anti-IL-4 mAb with anti-CD4 did not prevent tolerance induction. CONCLUSIONS This study demonstrated that anti-CD4 mAb therapy did not inhibit activation and infiltration of Th1 and CD8+ effector T cells. Preferential induction of Th2 responses, especially IL-4, was not essential for the induction of tolerance. Our studies also found no evidence to support induction of anergy or transforming growth factor-beta as mechanisms of tolerance induction. These results question whether IL-4 is required for induction of transplantation tolerance.
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Affiliation(s)
- K M Plain
- University of New South Wales, Department of Medicine, Liverpool Hospital, Australia
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Gill RG, Coulombe M, Lafferty KJ. Pancreatic islet allograft immunity and tolerance: the two-signal hypothesis revisited. Immunol Rev 1996; 149:75-96. [PMID: 9005221 DOI: 10.1111/j.1600-065x.1996.tb00900.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The principle assumption of this discussion is that costimulation (CoS) forms the primary stimulus that compels T cells to mount a response to their specific antigen. However, this response can be either positive or negative, depending on the developmental stage of the T cell and the microenvironment in which the antigen and CoS are received. Thus, both immunity and tolerance may represent different outcomes of a two-signal process. We would emphasize that CoS is a functional term and not a strict molecular definition. While many molecular interactions have been described as providing CoS activity, notably those involving the B-7 family of cell surface molecules, it is not yet clear what combination(s) of non-antigen-specific signals may fulfil this function. This point is important because many studies have achieved tolerance through strategies designed to inhibit specific CoS molecules. However, it may be that differential signaling through distinct CoS molecules, rather than a global inhibition of CoS per se, plays a role in the generation of active tolerance in such studies (Bluestone 1995). A corollary of this notion is that antigen (signal 1) delivery to T cells is a null event and so is not an inherently paralysing signal. Of course, if signal 1 is not itself a tolerogenic signal, then other mechanisms are necessary to explain many empirical observations of tolerance to allogeneic or self antigens. This is best illustrated by those forms of functional tolerance to either alloantigens or self antigens that do not appear to be the result of clonal deletion/inactivation. It would be relatively simple to invoke a model of tolerance whereby the relevant tissue-destructive cell is eliminated or inactivated; such a model would preclude the necessity to suggest active regulatory mechanisms of tolerance. However, in several model systems, including our own observations concerning tolerance induction to APC-depleted islet allografts, tissue-destructive T cells can persist in recipients tolerant to allogeneic or self antigens. Furthermore, there are key examples in which tolerance demonstrates a dominant phenotype; that is, tolerant cells can regulate the activity of naive, non-tolerant cells. This latter observation points to the function of an active, regulatory form of tolerance. As such, we would emphasize that tolerance should not be defined as unresponsiveness since the tolerant state is the consequence of very active immune reactions.
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Affiliation(s)
- R G Gill
- Barbara Davis Center for Childhood Diabetes, University of Colorado Health Sciences Center, Denver 80262, USA
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Brondz BD, Kazansky DB, Chernyshova AD, Ivanov VS. Peptides of a major histocompatibility complex class I (Kb) molecule cause prolongation of skin graft survival and induce specific down-regulatory T cells demonstrable in the mixed lymphocyte reaction. Immunol Suppl 1995; 86:219-23. [PMID: 7490121 PMCID: PMC1383998] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Six individual peptides of the major histocompatibility complex (MHC) class I molecule H-2Kb were synthesized. Intravenous injection of peptide 6 into mice prolonged the survival of Kb (BL/6 or B10.MBR) skin grafts on allogeneic R101 and B10.AKM mice, respectively. This was specific, as control skin grafts from Kk (B10.BR) or Kd (DBA/2) donors, respectively, were rejected at the same time in both control and peptide-treated mice. The optimal doses for peptide 6, which is from the alpha 2 domain, were defined. The test system was the inhibition of proliferation in vitro of naive lymph node cells by syngeneic mitomycin c-treated spleen cells from R101 mice preimmunized with irradiated stimulator splenocytes of Kb (BL/6) origin. Down-regulation was specific, as proliferation in response to third-party allogeneic stimulator Kk (B10.BR) splenocytes was not inhibited. Of the six peptides of H-2Kb tested, potent down-regulatory cells were induced by peptides 2 (alpha 1 domain) and 5 and 6 (alpha 2 domain). The greatest down-regulatory activity was obtained by giving peptide 2 to mice that had already been immunized against H-2Kb by injecting EL4 cells. Under the same conditions, injecting peptide 2 did not induce any cytotoxic T cells. In contrast, specific cytotoxic lymphocytes (CTL) were induced when cells from primed mice were incubated for 4 days with heated stimulator cells from BL/6 mice. The data suggest that peptides from MHC class I molecules activate precursors of down-regulatory T cells, but not of CTL, and this may explain their ability to prolong skin allograft survival.
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Affiliation(s)
- B D Brondz
- Laboratory of Regulatory Mechanisms in Immunity, Carcinogenesis Institute, Cancer Research Centre, Moscow, Russia
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Pawelec G. Suppressor cells in transplantation immunology: do recent advances in T cell immunobiology and cytokine networking contribute to the solution of an old conundrum? Transpl Immunol 1993; 1:172-81. [PMID: 8081775 DOI: 10.1016/0966-3274(93)90044-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- G Pawelec
- Section for Transplantation Immunology, University of Tübingen Medical School, Germany
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Brondz BD, Anfalova TV, Pavlova LS, Pankratova EV, Kojich AG, Moshnikov SA. Utilization of the MHC class I (H-2Kb) purified molecule and its synthetic peptides for inhibition of Kb-specific suppressor T cells and their induction in vivo by the MHC peptides. Scand J Immunol 1993; 37:627-33. [PMID: 8316760 DOI: 10.1111/j.1365-3083.1993.tb01674.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Six synthetic peptides of the MHC class I molecule corresponding to individual H-2Kb participants in amino acid sequences of domains alpha 1 (peptide 1 and 2) and alpha 2 (peptides 3, 4, 5, 6) were selected. Kb-specific suppressor T cells (Ts) were induced in vivo in mice, then pretreated with a set of peptides and assayed by proliferation decrease in a three-cell lymphocyte culture (MLC). The effector function of Ts was abolished by the complex of the alpha 2-domain peptides (but not by the alpha 1-domain peptides) and decreased by particular peptides separately (4, 5, 6) of the alpha 2-domain. Both alpha 1- and alpha 2-domain peptides, added in high concentration, decreased otherwise efficient enrichment of Ts during the absorption-elution procedure on the syngeneic macrophage (M psi) monolayers. A similar significant effect was observed using the purified Kb molecule (100 micrograms/ml) in the allogeneic M psi monolayer. Interaction between Ts receptors and some MHC peptides indicates in effector Ts activation in vivo by induction with peptides 5 and 6 of the alpha 2-domain. The fine mechanisms of interaction between MHC class I molecule epitopes and T-cell receptors of each of the T-cell subsets separately are presently being studied.
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Affiliation(s)
- B D Brondz
- Laboratory of Regulatory Mechanisms of Immunity, Cancer Research Center, Moscow, Russia
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Rodey GE. Anti-idiotypic like Antibodies Detected Following Alloimmunization: Their Characterization and Relevance to Allograft Acceptance. Clin Lab Med 1991. [DOI: 10.1016/s0272-2712(18)30545-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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40
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Yoshimura S, Gotoh S, Kamada N. Immunological tolerance induced by liver grafting in the rat: splenic macrophages and T cells mediate distinct phases of immunosuppressive activity. Clin Exp Immunol 1991; 85:121-7. [PMID: 1829989 PMCID: PMC1535718 DOI: 10.1111/j.1365-2249.1991.tb05692.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
In the rat combination DA into PVG, liver grafts are not rejected but induce donor-specific transplantation tolerance. We have examined the immunosuppressive properties of spleen cells from PVG recipients of DA liver grafts at various times post-grafting. The results indicate the development of two phases of cell-mediated suppressor activity, which appear to be mediated by separate spleen cell populations. Mitomycin-C-treated spleen cells taken from animals between 5 and 28 days post-grafting were able to suppress rat mixed lymphocyte reactions (MLRs). These 'early' suppressor cells were glass adherent and absent from populations purified by passage through nylon wool or G10 Sephadex columns. Suppression of MLR by purified glass adherent cells was not specific for either stimulator or responder haplotypes and was blocked by indomethacin. Nylon wool purified T cells were not suppressive at this time. Spleen cell suppressor activity declined to background levels after 35 days post-grafting. However, spleen cells from long-term surviving liver graft recipients (20 weeks or more) were again able to suppress MLR; the 'late' suppressor cells were nylon wool non-adherent and suppression was specific for the donor (DA) MHC type. We conclude that liver grafting in this combination generates early and late phases of suppression among spleen cells, that the early phase is produced by macrophages and mediated by prostaglandins and that the late phase is dependent on allospecific suppressor T cells.
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Affiliation(s)
- S Yoshimura
- Department of Experimental Surgery, National Children's Medical Research Centre, Tokyo, Japan
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41
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Yamaguchi A, Kamada N. Mechanisms in passive enhancement of cardiac and renal allografts by serum from liver-grafted rats. Immunology 1991; 72:79-84. [PMID: 1825483 PMCID: PMC1384339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The ability of serum from PVG (haplotype RT1c) rats carrying long-term surviving orthotopic DA (RT1a) liver grafts (OLT serum) to enhance cardiac allografts has been confirmed and extended to renal allografts. One millilitre of OLT serum given at the time of allografting was sufficient to cause permanent acceptance of PVG.RT1a heart or kidney grafts in PVG recipients ('enhanced recipients'); the PVG.RT1a being congenic with respect to PVG, and sharing the RT1a haplotype with DA. Adoptive transfer of thoracic duct lymphocytes (TDL) from rats carrying enhanced liver grafts into irradiated recipients indicated that specific alloreactive clones had been functionally inactivated or deleted; this was accompanied by active suppression in which specific alloreactivity of normal TDL was partially inhibited. In vitro, splenic T cells from rats with enhanced grafts mediated allospecific suppression in mixed lymphocyte reaction (MLR). The serum of rats carrying enhanced grafts was able to specifically suppress MLR of the same donor/recipient combination. Thus enhancement by orthotopic liver transplantation (OLT) serum leads to cellular and serological changes in the recipient associated with maintenance of unresponsiveness. Such changes are similar to those seen in liver graft recipients themselves.
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Affiliation(s)
- A Yamaguchi
- Department of Experimental Surgery, National Children's Medical Research Center, Tokyo, Japan
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42
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Monoclonal antibodies against interleukin-2 receptors in the immunosuppressive management of kidney graft recipients. Transplant Rev (Orlando) 1990. [DOI: 10.1016/s0955-470x(11)80007-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Hall BM, Pearce NW, Gurley KE, Dorsch SE. Specific unresponsiveness in rats with prolonged cardiac allograft survival after treatment with cyclosporine. III. Further characterization of the CD4+ suppressor cell and its mechanisms of action. J Exp Med 1990; 171:141-57. [PMID: 2136906 PMCID: PMC2187663 DOI: 10.1084/jem.171.1.141] [Citation(s) in RCA: 241] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The cellular basis of the specific unresponsiveness that develops in DA rats treated with cyclosporine (CSA) for 10 d after grafting a PVG heart was examined using an adoptive transfer assay. CD4+ cells from rats with long survival grafts specifically lack the capacity to restore PVG heart graft rejection, and can also inhibit the capacity of naive T cells to restore rejection, while in the first few weeks post-transplant, both CD4+ and CD8+ T cells from CSA-treated hosts have the capacity to effect PVG graft rejection. In this study, we demonstrated the CD4+ suppressor cells also had the capacity to inhibit restoration of rejection by CD4+ cells from CSA-treated DA rats recently transplanted with PVG hearts, and from rats sensitized to third party, but not from those specifically sensitized to PVG. They also inhibited the capacity of both naive CD8+ and sensitized CD8+ cells to effect rejection. These results showed that the CD4+ suppressor cell was capable of overriding the capacity to effect rejection of the CD4+ cell and activated CD8+ cells that were present in the CSA-treated host shortly after transplantation. The failure of naive CD8+ cells to augment suppression and the capacity of CD4+ suppressor cells to transfer unresponsiveness to irradiated hosts in which regeneration of CD8+ cells was abolished by thymectomy suggested that it was the CD4+ cell alone that mediated suppression. However, the failure of CD4+ suppressor cells to reinduce unresponsiveness in irradiated hosts whose CD8+ cells had been depleted by therapy with the mAb MRC Ox8 showed that a radioresistant CD8+ cell was required to reestablish the state of specific unresponsiveness. The induction of CD4+ suppressor cells in thymectomized hosts suggested that these cells were derived from long-lived CD4+ lymphocytes. However, their sensitivity to cyclophosphamide and their loss of suppressor function both after removal of the graft and after 3 d in culture demonstrated that the suppressor cell itself had a short lifespan. The CD4+ suppressor was shown to be MRC Ox22+ (CD45R+), MRC Ox17+ (MHC class II), and MRC Ox39+ (CD25, IL-2-R). These studies demonstrated the CD4+ suppressive cell identified in rats with specific unresponsiveness induced by CSA therapy had many features of the suppressor inducer cell identified in in vitro studies of the alloimmune response.(ABSTRACT TRUNCATED AT 400 WORDS)
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Affiliation(s)
- B M Hall
- Department of Renal Medicine, Royal Prince Alfred Hospital, Camperdown, New South Wales, Australia
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44
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Tolerance and Specific Unresponsiveness in Organ Transplantation. Immunol Allergy Clin North Am 1989. [DOI: 10.1016/s0889-8561(22)00588-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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45
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Lai H, Hasegawa Y, Mizoguchi K, Yoshida T, Isobe K, Shimokata K, Kawashima K, Nakashima I. Mode of alloantibody-mediated blockade of allo-sensitization for tumor allograft rejection. Immunobiology 1989; 179:33-43. [PMID: 2786494 DOI: 10.1016/s0171-2985(89)80005-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The mode of alloantibody-mediated inhibition of allo-sensitization for tumor allograft rejection was studied. Relatively small amounts of anti-H-2d alloantiserum administered shortly before or after injection of allogeneic spleen cells blocked the allo-sensitization for second-set tumor allograft rejection. In contrast, the alloantiserum injected shortly before inoculation of tumor barely enhanced the tumor growth. The passively administered alloantiserum inhibited the sensitization for allospecific cytotoxic T lymphocyte responses in vitro. Further study revealed that the allo-sensitization could be blocked with antiserum specific against only one of the expressed H-2 antigens on stimulator cells. Correspondingly, H-2Dd-monospecific monoclonal antibody (IgG2a) was effective in inhibiting the sensitization with cells expressing multiple H-2 alloantigens. These results suggest that antibody-mediated inactivation of stimulator cells as a whole is an important mechanism of the allograft enhancement.
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Affiliation(s)
- H Lai
- Department of Immunology, Nagoya University School of Medicine, Japan
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46
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47
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Sundt TM, Sachs DH. Applications of molecular biology to transplantation tolerance. IMMUNOLOGY TODAY 1988; 9:342-4. [PMID: 3076404 DOI: 10.1016/0167-5699(88)91334-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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48
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Selawry HP, Whittington KB, Forster HG. Intratesticular islet xenograft survival in relation to tissue cyclosporine levels. Am J Med Sci 1988; 295:497-502. [PMID: 3133946 DOI: 10.1097/00000441-198806000-00001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
A study of the comparative survival of islet xenografts using a combination of treatment modalities was carried out in the spontaneously diabetic BB/Wor rat. Islets were isolated from hamster donors, and after 4 to 6 days of incubation the cells were injected either into the immunologically privileged abdominal testis or into the nonimmunologically favored renal subcapsular space. Postoperatively the rats were given cyclosporine at two different dose schedules. The results showed that islets injected into the abdominal testis of nonimmunosuppressed rats caused the induction of normoglycemia with a mean duration of 8.3 +/- 1.3 days. A significant prolongation of normoglycemia to a mean of 36.1 +/- 4.5 days occurred in rats that were given abdominal, intratesticular islet xenografts and cyclosporine for 30 days. The longest average survival in excess of a mean of 90.1 +/- 6.5 days was achieved in rats that were given abdominal, intratesticular islet xenografts and cyclosporine continuously, every other day. All of the grafted rats reverted to diabetes upon the cessation of cyclosporine. A similar cyclosporine regimen failed to prolong islet xenograft survival for longer than a mean of 9.0 +/- 2.2 days in rats that were given islet xenografts injected into the renal subcapsular space. Extended survival of abdominal, intratesticular islet xenografts corresponded with trough plasma and testis cyclosporine levels of 457 +/- 46 ng/mL and 643 +/- 45 ng/g, of wet weight, respectively. It is concluded that islet xenografts are protected against immune destruction in the BB/Wor rat with type 1 diabetes only as long as the cells are injected into an immunologically privileged site and the host is continuously immunosuppressed with cyclosporine.
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Affiliation(s)
- H P Selawry
- Department of Medicine, Veterans Administration Medical Center, Miami, FL 33125
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49
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Halperin EC, Knechtle S, Abernethy K, Saad T, Miller D, Vernon WB, Bollinger RR. The influence of dose and dose rate of total lymphoid irradiation in the rat cardiac allograft model. Radiother Oncol 1987; 9:311-8. [PMID: 3317525 DOI: 10.1016/s0167-8140(87)80152-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Immunosuppression generated by total lymphoid irradiation (TLI) may be of use in solid organ transplantation. We have investigated the use of TLI in the rat cardiac allograft model. Lewis rats received TLI from a cobalt-60 machine. The daily dose was 1.25 Gy and treatments were administered 4 days per week. We performed experiments to assess the effect of dose rate upon graft survival. The dose rate was varied by changing the source to animal distance and by using a lead attenuator. Cardiac allografts from each ACI donor rat were transplanted to the recipient Lewis rat's abdomen utilizing microvascular surgical technique. Heart graft survival times (GST) were monitored by direct palpation of the cardiac impulse. Immune function was measured by an activity index of the mixed lymphocyte reaction. In the absence of any immunosuppression there was a mean GST of 6.9 +/- 0.3 days. When a graft was placed the day following completion of TLI, there was an increase in GST as the total TLI dose was increased. Mean GST (+/- S.E.) following 5, 10, and 15 Gy were 12.3 +/- 1.3, 14.5 +/- 1.3, and 25.5 +/- 1.1 days, respectively. Following 20 Gy, GST decreased because of irradiation induced pulmonary toxicity and host death. When 3.5 weeks were allowed to elapse between the completion of TLI and transplantation, GST were less than those seen with equivalent doses of TLI and early transplantation. Mean GST following 5, 10, and 15 Gy and a delayed transplant were 7.2 +/- 0.1, 10.7 +/- 1.2, and 19.0 +/- 3.5 days, respectively. We tested the effect of dose rate upon GST.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- E C Halperin
- Department of Radiology, Duke University Medical Center, Durham, NC 27710
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Armstrong HE, Bolton EM, McMillan I, Spencer SC, Bradley JA. Prolonged survival of actively enhanced rat renal allografts despite accelerated cellular infiltration and rapid induction of both class I and class II MHC antigens. J Exp Med 1987; 165:891-907. [PMID: 3546583 PMCID: PMC2188274 DOI: 10.1084/jem.165.3.891] [Citation(s) in RCA: 72] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Administration of 1 ml of donor whole blood 7 d before renal transplantation produces long-term (greater than 100 d) graft survival in the DA (RT1a) into PVG (RT1c) rat strain combination. Using this model, the pattern and phenotype of infiltrating leukocytes were examined in rejecting and enhanced renal allografts, at days 1, 3, 5, and 7 after transplantation, by immunohistologic techniques. Paradoxically, enhanced grafts showed a more rapid and substantial leukocyte infiltrate, the phenotype of which was similar to that in rejecting grafts except for a reduced number of MRC OX-8+ cells and MRC OX-39+ cells. Graft infiltrating cells and splenocytes from transfused animals showed similar, although modest, levels of both nonspecific cytotoxicity and alloantigen-specific cytotoxicity. Immunohistologic analysis of MHC antigen distribution within the allograft revealed, unexpectedly, that enhanced grafts underwent an accelerated and extensive induction of both donor class I and class II MHC antigens. These findings were confirmed by allospecific quantitative absorption analysis, which showed severalfold increases in class I and class II MHC antigens by day 3 in enhanced grafts but not until day 5 in rejecting grafts. An additional observation was the more rapid disappearance of donor interstitial cells from enhanced grafts. These findings emphasize the overwhelming suppressive effect induced by an organ allograft after preoperative blood transfusion despite the associated induction of large numbers of potential effector cells and increased target antigen density within the graft.
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