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Nauman G, Danzl NM, Lee J, Borsotti C, Madley R, Fu J, Hölzl MA, Dahmani A, Dorronsoro Gonzalez A, Chavez É, Campbell SR, Yang S, Satwani P, Liu K, Sykes M. Defects in Long-Term APC Repopulation Ability of Adult Human Bone Marrow Hematopoietic Stem Cells (HSCs) Compared with Fetal Liver HSCs. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2022; 208:1652-1663. [PMID: 35315788 PMCID: PMC8976823 DOI: 10.4049/jimmunol.2100966] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Accepted: 01/25/2022] [Indexed: 04/28/2023]
Abstract
Immunodeficient mice reconstituted with immune systems from patients, or personalized immune (PI) mice, are powerful tools for understanding human disease. Compared with immunodeficient mice transplanted with human fetal thymus tissue and fetal liver-derived CD34+ cells administered i.v. (Hu/Hu mice), PI mice, which are transplanted with human fetal thymus and adult bone marrow (aBM) CD34+ cells, demonstrate reduced levels of human reconstitution. We characterized APC and APC progenitor repopulation in human immune system mice and detected significant reductions in blood, bone marrow (BM), and splenic APC populations in PI compared with Hu/Hu mice. APC progenitors and hematopoietic stem cells (HSCs) were less abundant in aBM CD34+ cells compared with fetal liver-derived CD34+ cell preparations, and this reduction in APC progenitors was reflected in the BM of PI compared with Hu/Hu mice 14-20 wk posttransplant. The number of HSCs increased in PI mice compared with the originally infused BM cells and maintained functional repopulation potential, because BM from some PI mice 28 wk posttransplant generated human myeloid and lymphoid cells in secondary recipients. Moreover, long-term PI mouse BM contained functional T cell progenitors, evidenced by thymopoiesis in thymic organ cultures. Injection of aBM cells directly into the BM cavity, transgenic expression of hematopoietic cytokines, and coinfusion of human BM-derived mesenchymal stem cells synergized to enhance long-term B cell and monocyte levels in PI mice. These improvements allow a sustained time frame of 18-22 wk where APCs and T cells are present and greater flexibility for modeling immune disease pathogenesis and immunotherapies in PI mice.
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Affiliation(s)
- Grace Nauman
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University Medical Center, Columbia University, New York, NY
- Department of Microbiology and Immunology, Columbia University Medical Center, Columbia University, New York, NY
- Columbia University Vagelos College of Physicians and Surgeons, Columbia University, New York, NY
| | - Nichole M Danzl
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University Medical Center, Columbia University, New York, NY
- Columbia University Vagelos College of Physicians and Surgeons, Columbia University, New York, NY
| | - Jaeyop Lee
- Department of Microbiology and Immunology, Columbia University Medical Center, Columbia University, New York, NY
- Columbia University Vagelos College of Physicians and Surgeons, Columbia University, New York, NY
| | - Chiara Borsotti
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University Medical Center, Columbia University, New York, NY
- Columbia University Vagelos College of Physicians and Surgeons, Columbia University, New York, NY
| | - Rachel Madley
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University Medical Center, Columbia University, New York, NY
- Department of Microbiology and Immunology, Columbia University Medical Center, Columbia University, New York, NY
- Columbia University Vagelos College of Physicians and Surgeons, Columbia University, New York, NY
| | - Jianing Fu
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University Medical Center, Columbia University, New York, NY
- Columbia University Vagelos College of Physicians and Surgeons, Columbia University, New York, NY
| | - Markus A Hölzl
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University Medical Center, Columbia University, New York, NY
- Columbia University Vagelos College of Physicians and Surgeons, Columbia University, New York, NY
| | - Alexander Dahmani
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University Medical Center, Columbia University, New York, NY
- Columbia University Vagelos College of Physicians and Surgeons, Columbia University, New York, NY
| | - Akaitz Dorronsoro Gonzalez
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University Medical Center, Columbia University, New York, NY
- Columbia University Vagelos College of Physicians and Surgeons, Columbia University, New York, NY
| | - Éstefania Chavez
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University Medical Center, Columbia University, New York, NY
- Columbia University Vagelos College of Physicians and Surgeons, Columbia University, New York, NY
| | - Sean R Campbell
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University Medical Center, Columbia University, New York, NY
- Columbia University Vagelos College of Physicians and Surgeons, Columbia University, New York, NY
| | - Suxiao Yang
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University Medical Center, Columbia University, New York, NY
- Columbia University Vagelos College of Physicians and Surgeons, Columbia University, New York, NY
| | - Prakash Satwani
- Columbia University Vagelos College of Physicians and Surgeons, Columbia University, New York, NY
- Department of Pediatrics, Columbia University Medical Center, Columbia University, New York, NY
| | - Kang Liu
- Department of Microbiology and Immunology, Columbia University Medical Center, Columbia University, New York, NY
- Columbia University Vagelos College of Physicians and Surgeons, Columbia University, New York, NY
- Department of Cancer Immunology and Immune Modulation, Boehringer Ingelheim Pharmaceuticals, Inc., Ridgefield, CT; and
| | - Megan Sykes
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University Medical Center, Columbia University, New York, NY;
- Department of Microbiology and Immunology, Columbia University Medical Center, Columbia University, New York, NY
- Columbia University Vagelos College of Physicians and Surgeons, Columbia University, New York, NY
- Department of Surgery, Columbia University Medical Center, Columbia University, New York, NY
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Binder C, Sellberg F, Cvetkovski F, Berg S, Berglund E, Berglund D. Siplizumab Induces NK Cell Fratricide Through Antibody-Dependent Cell-Mediated Cytotoxicity. Front Immunol 2021; 12:599526. [PMID: 33643309 PMCID: PMC7904868 DOI: 10.3389/fimmu.2021.599526] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Accepted: 01/05/2021] [Indexed: 12/17/2022] Open
Abstract
The glycoprotein CD2 is expressed on T and NK cells and contributes to cell-cell conjugation, agonistic signaling and actin cytoskeleton rearrangement. CD2 has previously been shown to have an important function in natural NK cell cytotoxicity but to be expendable in antibody-mediated cytotoxicity. Siplizumab is a monoclonal anti-CD2 IgG1 antibody that is currently undergoing clinical trials in the field of transplantation. This study investigated the effect of CD2 binding and Fc γ receptor binding by siplizumab (Fc-active) and Fc-silent anti-CD2 monoclonal antibodies in allogeneic mixed lymphocyte reaction and autologous lymphocyte culture. Further, induction of NK cell fratricide and inhibition of natural cytotoxicity as well as antibody-dependent cytotoxicity by these agents were assessed. Blockade of CD2 via monoclonal antibodies in the absence of Fc γ receptor binding inhibited NK cell activation in allogeneic mixed lymphocyte reaction. In contrast, siplizumab increased NK cell activation in both mixed lymphocyte reaction and autologous lymphocyte culture due to FcγRIIIA binding. However, experiments using purified NK cells did not show an inhibitory effect of CD2 blockade on natural cytotoxicity or antibody-dependent cytotoxicity. Lastly, it was shown that siplizumab induces NK cell fratricide. Concluding, siplizumab is a promising biopharmaceutical drug candidate for depletion of T and NK cells with minimal off-target effects.
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Affiliation(s)
- Christian Binder
- Department of Immunology, Genetics and Pathology, Section of Clinical Immunology, Uppsala University, Uppsala, Sweden
- Research and Development, ITB-Med AB, Stockholm, Sweden
| | - Felix Sellberg
- Department of Immunology, Genetics and Pathology, Section of Clinical Immunology, Uppsala University, Uppsala, Sweden
- Research and Development, ITB-Med AB, Stockholm, Sweden
| | | | - Stefan Berg
- Research and Development, ITB-Med AB, Stockholm, Sweden
| | - Erik Berglund
- Research and Development, ITB-Med AB, Stockholm, Sweden
- Division of Transplantation Surgery, Department of Clinical Science, Intervention and Technology (CLINTEC), Karolinska Institute and Karolinska University Hospital, Stockholm, Sweden
| | - David Berglund
- Department of Immunology, Genetics and Pathology, Section of Clinical Immunology, Uppsala University, Uppsala, Sweden
- Research and Development, ITB-Med AB, Stockholm, Sweden
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Binder C, Sellberg F, Cvetkovski F, Berglund E, Berglund D. Siplizumab, an Anti-CD2 Monoclonal Antibody, Induces a Unique Set of Immune Modulatory Effects Compared to Alemtuzumab and Rabbit Anti-Thymocyte Globulin In Vitro. Front Immunol 2020; 11:592553. [PMID: 33262770 PMCID: PMC7686512 DOI: 10.3389/fimmu.2020.592553] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 10/14/2020] [Indexed: 01/09/2023] Open
Abstract
Antibodies are commonly used in organ transplant induction therapy and to treat autoimmune disorders. The effects of some biologics on the human immune system remain incompletely characterized and a deeper understanding of their mechanisms of action may provide useful insights for their clinical application. The goal of this study was to contrast the mechanistic properties of siplizumab with Alemtuzumab and rabbit Anti-Thymocyte Globulin (rATG). Mechanistic assay systems investigating antibody-dependent cell-mediated cytotoxicity, antibody-dependent cell phagocytosis and complement-dependent cytotoxicity were used to characterize siplizumab. Further, functional effects of siplizumab, Alemtuzumab, and rATG were investigated in allogeneic mixed lymphocyte reaction. Changes in T cell activation, T cell proliferation and frequency of naïve T cells, memory T cells and regulatory T cells induced by siplizumab, Alemtuzumab and rATG in allogeneic mixed lymphocyte reaction were assessed via flow cytometry. Siplizumab depleted T cells, decreased T cell activation, inhibited T cell proliferation and enriched naïve and bona fide regulatory T cells. Neither Alemtuzumab nor rATG induced the same combination of functional effects. The results presented in this study should be used for further in vitro and in vivo investigations that guide the clinical use of immune modulatory biologics.
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Affiliation(s)
- Christian Binder
- Section of Clinical Immunology, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden.,Research and Development, ITB-Med AB, Stockholm, Sweden
| | - Felix Sellberg
- Section of Clinical Immunology, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden.,Research and Development, ITB-Med AB, Stockholm, Sweden
| | | | - Erik Berglund
- Research and Development, ITB-Med AB, Stockholm, Sweden.,Department of Clinical Science, Intervention and Technology (CLINTEC), Division of Transplantation Surgery, Karolinska Institute and Karolinska University Hospital, Stockholm, Sweden
| | - David Berglund
- Section of Clinical Immunology, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden.,Research and Development, ITB-Med AB, Stockholm, Sweden
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Madley R, Nauman G, Danzl N, Borsotti C, Khosravi Maharlooei M, Li HW, Chavez E, Creusot RJ, Nakayama M, Roep B, Sykes M. Negative selection of human T cells recognizing a naturally-expressed tissue-restricted antigen in the human thymus. J Transl Autoimmun 2020; 3:100061. [PMID: 32875283 PMCID: PMC7451786 DOI: 10.1016/j.jtauto.2020.100061] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 08/02/2020] [Indexed: 12/15/2022] Open
Abstract
During T cell development in mice, thymic negative selection deletes cells with the potential to recognize and react to self-antigens. In human T cell-dependent autoimmune diseases such as Type 1 diabetes, multiple sclerosis, and rheumatoid arthritis, T cells reactive to autoantigens are thought to escape negative selection, traffic to the periphery and attack self-tissues. However, physiological thymic negative selection of autoreactive human T cells has not been previously studied. We now describe a human T-cell receptor-transgenic humanized mouse model that permits the study of autoreactive T-cell development in a human thymus. Our studies demonstrate that thymocytes expressing the autoreactive Clone 5 TCR, which recognizes insulin B:9-23 presented by HLA-DQ8, are efficiently negatively selected at the double and single positive stage in human immune systems derived from HLA-DQ8+ HSCs. In the absence of hematopoietic expression of the HLA restriction element, negative selection of Clone 5 is less efficient and restricted to the single positive stage. To our knowledge, these data provide the first demonstration of negative selection of human T cells recognizing a naturally-expressed tissue-restricted antigen. Intrathymic antigen presenting cells are required to delete less mature thymocytes, while presentation by medullary thymic epithelial cells may be sufficient to delete more mature single positive cells. These observations set the stage for investigation of putative defects in negative selection in human autoimmune diseases.
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Affiliation(s)
- Rachel Madley
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University College of Physicians and Surgeons, New York, NY, 10032, USA,Columbia University Department of Microbiology and Immunology, New York, NY, 10032, USA
| | - Grace Nauman
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University College of Physicians and Surgeons, New York, NY, 10032, USA,Columbia University Department of Microbiology and Immunology, New York, NY, 10032, USA
| | - Nichole Danzl
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University College of Physicians and Surgeons, New York, NY, 10032, USA
| | - Chiara Borsotti
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University College of Physicians and Surgeons, New York, NY, 10032, USA
| | - Mohsen Khosravi Maharlooei
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University College of Physicians and Surgeons, New York, NY, 10032, USA
| | - Hao Wei Li
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University College of Physicians and Surgeons, New York, NY, 10032, USA
| | - Estefania Chavez
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University College of Physicians and Surgeons, New York, NY, 10032, USA
| | - Remi J. Creusot
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University College of Physicians and Surgeons, New York, NY, 10032, USA
| | - Maki Nakayama
- Barbara Davis Center for Childhood Diabetes, University of Colorado School of Medicine, Aurora, CO, 80045, USA
| | - Bart Roep
- Department of Immunohaematology & Blood Transfusion, Leiden University Medical Center, 2300 RC, Leiden, the Netherlands,Department of Diabetes Immunology, Diabetes & Metabolism Research Institute at the Beckman Research Institute, City of Hope, Duarte, CA, 91010, USA
| | - Megan Sykes
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University College of Physicians and Surgeons, New York, NY, 10032, USA,Columbia University Department of Microbiology and Immunology, New York, NY, 10032, USA,Columbia University Department of Surgery, New York, NY, 10032, USA,Corresponding author. Columbia Center for Translational Immunology, Department of Medicine, Columbia University College of Physicians and Surgeons, New York, NY, 10032, USA.
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5
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Nauman G, Borsotti C, Danzl N, Khosravi-Maharlooei M, Li HW, Chavez E, Stone S, Sykes M. Reduced positive selection of a human TCR in a swine thymus using a humanized mouse model for xenotolerance induction. Xenotransplantation 2020; 27:e12558. [PMID: 31565822 PMCID: PMC7007369 DOI: 10.1111/xen.12558] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 08/27/2019] [Accepted: 09/13/2019] [Indexed: 12/17/2022]
Abstract
BACKGROUND Tolerance-inducing approaches to xenotransplantation would be optimal and may be necessary for long-term survival of transplanted pig organs in human patients. The ideal approach would generate donor-specific unresponsiveness to the pig organ without suppressing the patient's normal immune function. Porcine thymus transplantation has shown efficacy in promoting xenotolerance in humanized mice and large animal models. However, murine studies demonstrate that T cells selected in a swine thymus are positively selected only by swine thymic epithelial cells, and therefore, cells expressing human HLA-restricted TCRs may not be selected efficiently in a transplanted pig thymus. This may lead to suboptimal patient immune function. METHODS To assess human thymocyte selection in a pig thymus, we used a TCR transgenic humanized mouse model to study positive selection of cells expressing the MART1 TCR, a well-characterized human HLA-A2-restricted TCR, in a grafted pig thymus. RESULTS Positive selection of T cells expressing the MART1 TCR was inefficient in both a non-selecting human HLA-A2- or swine thymus compared with an HLA-A2+ thymus. Additionally, CD8 MART1 TCRbright T cells were detected in the spleens of mice transplanted with HLA-A2+ thymi but were significantly reduced in the spleens of mice transplanted with swine or HLA-A2- thymi. [Correction added on October 15, 2019, after first online publication: The missing superscript values +, -, and bright have been included in the Results section.] CONCLUSIONS: Positive selection of cells expressing a human-restricted TCR in a transplanted pig thymus is inefficient, suggesting that modifications to improve positive selection of cells expressing human-restricted TCRs in a pig thymus may be necessary to support development of a protective human T-cell pool in future patients.
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Affiliation(s)
- Grace Nauman
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University Medical Center, Columbia University, New York, NY, USA
- Department of Microbiology and Immunology, Columbia University Medical Center, Columbia University, New York, NY, USA
| | - Chiara Borsotti
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University Medical Center, Columbia University, New York, NY, USA
| | - Nichole Danzl
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University Medical Center, Columbia University, New York, NY, USA
| | - Mohsen Khosravi-Maharlooei
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University Medical Center, Columbia University, New York, NY, USA
| | - Hao-Wei Li
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University Medical Center, Columbia University, New York, NY, USA
| | - Estefania Chavez
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University Medical Center, Columbia University, New York, NY, USA
| | - Samantha Stone
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University Medical Center, Columbia University, New York, NY, USA
| | - Megan Sykes
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University Medical Center, Columbia University, New York, NY, USA
- Department of Microbiology and Immunology, Columbia University Medical Center, Columbia University, New York, NY, USA
- Department of Surgery, Columbia University Medical Center, Columbia University, New York, NY, USA
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Erben U, Pawlowski NN, Doerfel K, Loddenkemper C, Hoffmann JC, Siegmund B, Kühl AA. Targeting human CD2 by the monoclonal antibody CB.219 reduces intestinal inflammation in a humanized transfer colitis model. Clin Immunol 2015; 157:16-25. [DOI: 10.1016/j.clim.2015.01.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Revised: 12/18/2014] [Accepted: 01/02/2015] [Indexed: 01/12/2023]
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Abstract
Large animal models have long served as the proving grounds for advances in transplantation, bridging the gap between inbred mouse experimentation and human clinical trials. Although a variety of species have been and continue to be used, the emergence of highly targeted biologic- and antibody-based therapies has required models to have a high degree of homology with humans. Thus, the nonhuman primate has become the model of choice in many settings. This article will provide an overview of nonhuman primate models of transplantation. Issues of primate genetics and care will be introduced, and a brief overview of technical aspects for various transplant models will be discussed. Finally, several prominent immunosuppressive and tolerance strategies used in primates will be reviewed.
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Affiliation(s)
- Douglas J Anderson
- Emory Transplant Center, Emory University School of Medicine, Atlanta, Georgia 30322
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8
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Monoclonal antibodies generated by DNA immunization recognize CD2 from a broad range of primates. Immunol Cell Biol 2009; 87:413-8. [PMID: 19204736 DOI: 10.1038/icb.2009.4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Using heterologous prime-boost (DNA immunization followed by immunization with transfected cells), we have generated depleting mouse anti-baboon CD2 monoclonal antibodies (mAb). These anti-CD2 mAb recognized a diverse range of primate CD2 from New World monkeys and Old World monkeys to humans and have potent immunosuppressive activity for human allo-MLR responses and anti-tetanus-toxoid recall responses. There was no upregulation of activation markers or release of cytokines when the mAb were incubated with human peripheral blood mononuclear cells. Using chimeric NOD-SCID IL2rgamma(null) mice, the mAb were shown to deplete human and cynomolgus monkey T cells in vivo. These anti-CD2 mAb may therefore be important immunological tools in allo- and xenotransplantation.
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Abstract
T-cell depletion strategies are an efficient therapy for the treatment of acute rejection after organ transplantation and have been successfully used as induction regimens. Although eliminating whole T cells blocks alloreactivity, this therapy challenges the development of regulatory mechanisms because it depletes regulatory cells and modifies the profile of T cells after homeostatic repopulation. Targeting T-cell subpopulations or selectively activated T cells, without modifying Treg cells, could constitute a pro-tolerogenic approach. However, the perfect molecular target that would be totally specific probably still needs to be identified. In this study, we have reviewed the biological activities of broad or specific T-cell depletion strategies as these contribute to the induction of regulatory cells and tolerance in organ transplantation.
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Affiliation(s)
- Thomas Haudebourg
- INSERM, U643, CHU Nantes, Institut de Transplantation et de Recherche en Transplantation, ITERT, Université de Nantes, Faculté de Médecine, Nantes, France
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10
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Dehoux JP, Nizet Y, de la Parra B, Lecuivre C, Vergauwen M, Bazin H, Latinne D, Gianello P. Cell-mediated cytotoxicity to porcine aortic endothelial cells is not dependent on galactosyl residues when baboon peripheral blood lymphocytes are previously primed with pig xenoantigens. Transplantation 2003; 76:1675-80. [PMID: 14688514 DOI: 10.1097/01.tp.0000093833.02551.0b] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND In the pig-to-baboon model, acute vascular rejection remains the main hurdle for successful long-term xenograft survival. The production of galactosyl knockout pigs could solve concomitantly the problem of hyperacute and acute vascular rejection. This work studies in vitro the cell-mediated cytotoxicity of natural killer (NK) and T cells after priming of baboon peripheral blood lymphocytes (PBLs) with pig antigens to evaluate whether cytotoxicity is galactosyl-dependent. MATERIAL AND METHODS PBLs from naive and primed baboons were used as effectors on primary porcine aortic endothelial cells (PAECs) to assess cytotoxicity. Untreated or galactosidase-digested PAECs were used to evidence the role of galactosyl residues on cell-mediated cytotoxicity. Two rat-anti baboon monoclonal antibodies were tested to inhibit either T+NK cells (LO-CD2b) or NK cells alone (LO-CD94). RESULTS When using PBLs from naive animals, spontaneous lysis occurred and was inhibited by both LOCD-2b and LO-CD94. In comparison, lysis of PAECs was significantly higher when baboon PBLs were first primed in vivo with pig xenoantigens. In this case, cytotoxicity was completely inhibited by LO-CD2b but only partially by LO-CD94. Reduction of galactosyl residues by galactosidase digestion showed that PAEC lysis almost completely disappeared with naive baboon PBLs but not with primed baboon PBLs, thereby indicating that anti-pig T-cell response is not dependent on galactosyl residues. CONCLUSION Galactosyl knockout pigs could solve hyperacute rejection and also prevent the activation of NK cells even after xenogeneic priming. T cells will then be the next hurdle for the success of xenografting.
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Affiliation(s)
- Jean-Paul Dehoux
- Laboratory of Experimental Surgery, Faculty of Medicine, Université Catholique de Louvain, CHEX/5570, 55 Avenue Hippocrate, B-1200 Brussels, Belgium
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11
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Matthews JB, Ramos E, Bluestone JA. Clinical trials of transplant tolerance: slow but steady progress. Am J Transplant 2003; 3:794-803. [PMID: 12814471 DOI: 10.1046/j.1600-6135.2003.0154.x] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The search for tolerance therapies that would thwart the alloimmune response following organ transplantation while preserving a patient's protective immune response has been a formidable goal for clinical immunologists. Over the past few decades, a more detailed understanding of the molecular events associated with T-cell recognition and activation has demonstrated the feasibility of various tolerance approaches, such as costimulation blockade, in numerous animal models of both autoimmunity and transplantation. Yet, only a few promising new therapies have reached the early stages of human clinical development. In contrast, the use of T-cell depleting induction therapy has become widespread, and new trials have been designed with immunosuppressive drug withdrawal in mind. Furthermore, nonmyeloablative mixed chimeric approaches have allowed complete immunosuppressive withdrawal in some limited cases. In the course of these investigations, however, what has become increasingly clear is that the distinctions between immunosuppression and tolerance have been blurred as the success and durability of the therapies rely as much on the state of the organ and organism as they do the mechanism of action of the drug. In this review, we provide a summary of the progress and lessons in promoting clinical transplant tolerance and an overview of promising agents.
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Affiliation(s)
- Jeffrey B Matthews
- Immune Tolerance Network, University of California, San Francisco, CA, USA
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12
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Dehoux JP, de la Parra B, Latinne D, Bazin H, Gianello P. Effect in vitro and in vivo of a rat anti-CD2 monoclonal antibody (LO-CD2b) on pig-to-baboon xenogeneic cellular (T and natural killer cells) immune response. Xenotransplantation 2001; 8:193-201. [PMID: 11472627 DOI: 10.1034/j.1399-3089.2001.0o092.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Although hyperacute rejection of discordant xenogeneic grafts can be prevented, baboon or human anti-pig cellular response may lead to acute xenograft rejection. Among the immune cellular actors participating in such a xenograft rejection are both T and natural killer (NK) cells. In the pre-clinical model of pig-to-baboon discordant xenograft, there is however, a lack of specific immunological therapeutic agent, in particular antibaboon T-cell monoclonal antibodies do not exist. We therefore developed a rat anti-CD2 monoclonal antibody (LO-CD2b) that recognizes both baboon and human CD2 + cells. In this study, we show that in vitro LO-CD2b inhibits a pig-to-baboon mixed lymphocyte reaction, the direct cytotoxicity of baboon peripheral blood lymphocytes to pig aortic endothelial cells, as well as the baboon NK activity against K562 cell line. In vivo, LO-CD2b produces a strong depletion of all peripheral CD2+ cells including NK CD2+ cells. In summary, LO-CD2b represents an important immunological tool that can be used in the preclinical model of discordant pig-to-baboon vascularized xenograft.
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Affiliation(s)
- J P Dehoux
- Laboratory of Experimental Surgery, Faculty of Medicine, Université Catholique de Louvain, Avenue Hippocrate, 55, B-1200 Brussels, Belgium
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