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Del Bello A, Treiner E. Immune Checkpoints in Solid Organ Transplantation. BIOLOGY 2023; 12:1358. [PMID: 37887068 PMCID: PMC10604300 DOI: 10.3390/biology12101358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 10/17/2023] [Accepted: 10/19/2023] [Indexed: 10/28/2023]
Abstract
Allogenic graft acceptance is only achieved by life-long immunosuppression, which comes at the cost of significant toxicity. Clinicians face the challenge of adapting the patients' treatments over long periods to lower the risks associated with these toxicities, permanently leveraging the risk of excessive versus insufficient immunosuppression. A major goal and challenge in the field of solid organ transplantation (SOT) is to attain a state of stable immune tolerance specifically towards the grafted organ. The immune system is equipped with a set of inhibitory co-receptors known as immune checkpoints (ICs), which physiologically regulate numerous effector functions. Insufficient regulation through these ICs can lead to autoimmunity and/or immune-mediated toxicity, while excessive expression of ICs induces stable hypo-responsiveness, especially in T cells, a state sometimes referred to as exhaustion. IC blockade has emerged in the last decade as a powerful therapeutic tool against cancer. The opposite action, i.e., subverting IC for the benefit of establishing a state of specific hypo-responsiveness against auto- or allo-antigens, is still in its infancy. In this review, we will summarize the available literature on the role of ICs in SOT and the relevance of ICs with graft acceptance. We will also discuss the possible influence of current immunosuppressive medications on IC functions.
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Affiliation(s)
- Arnaud Del Bello
- Department of Nephrology, University Hospital of Toulouse, 31400 Toulouse, France
- Metabolic and Cardiovascular Research Institute (I2MC), Inserm UMR1297, CEDEX 4, 31432 Toulouse, France
- Faculty of Medicine, University Toulouse III Paul Sabatier, 31062 Toulouse, France
| | - Emmanuel Treiner
- Faculty of Medicine, University Toulouse III Paul Sabatier, 31062 Toulouse, France
- Laboratory of Immunology, University Hospital of Toulouse, 31300 Toulouse, France
- Toulouse Institute for Infectious and Inflammatory Diseases (Infinity), Inserm UMR1291, 31024 Toulouse, France
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2
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Yeung MY, Grimmig T, Sayegh MH. Costimulation Blockade in Transplantation. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1189:267-312. [PMID: 31758538 DOI: 10.1007/978-981-32-9717-3_10] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
T cells play a pivotal role in orchestrating immune responses directed against a foreign (allogeneic) graft. For T cells to become fully activated, the T-cell receptor (TCR) must interact with the major histocompatibility complex (MHC) plus peptide complex on antigen-presenting cells (APCs), followed by a second "positive" costimulatory signal. In the absence of this second signal, T cells become anergic or undergo deletion. By blocking positive costimulatory signaling, T-cell allo-responses can be aborted, thus preventing graft rejection and promoting long-term allograft survival and possibly tolerance (Alegre ML, Najafian N, Curr Mol Med 6:843-857, 2006; Li XC, Rothstein DM, Sayegh MH, Immunol Rev 229:271-293, 2009). In addition, costimulatory molecules can provide negative "coinhibitory" signals that inhibit T-cell activation and terminate immune responses; strategies to promote these pathways can also lead to graft tolerance (Boenisch O, Sayegh MH, Najafian N, Curr Opin Organ Transplant 13:373-378, 2008). However, T-cell costimulation involves an incredibly complex array of interactions that may act simultaneously or at different times in the immune response and whose relative importance varies depending on the different T-cell subsets and activation status. In transplantation, the presence of foreign alloantigen incites not only destructive T effector cells but also protective regulatory T cells, the balance of which ultimately determines the fate of the allograft (Lechler RI, Garden OA, Turka LA, Nat Rev Immunol 3:147-158, 2003). Since the processes of alloantigen-specific rejection and regulation both require activation of T cells, costimulatory interactions may have opposing or synergistic roles depending on the cell being targeted. Such complexities present both challenges and opportunities in targeting T-cell costimulatory pathways for therapeutic purposes. In this chapter, we summarize our current knowledge of the various costimulatory pathways in transplantation and review the current state and challenges of harnessing these pathways to promote graft tolerance (summarized in Table 10.1).
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Affiliation(s)
- Melissa Y Yeung
- Department of Medicine, Renal Division, Brigham and Women's Hospital, Boston, MA, USA. .,Harvard Medical School, Boston, MA, USA.
| | - Tanja Grimmig
- Department of Surgery, Molecular Oncology and Immunology, University of Wuerzburg, Wuerzburg, Germany
| | - Mohamed H Sayegh
- Department of Medicine, Renal Division, Brigham and Women's Hospital, Boston, MA, USA.,Harvard Medical School, Boston, MA, USA.,Department of Medicine and Immunology, American University of Beirut, Beirut, Lebanon
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3
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Leibler C, Thiolat A, Elsner RA, El Karoui K, Samson C, Grimbert P. Costimulatory blockade molecules and B-cell-mediated immune response: current knowledge and perspectives. Kidney Int 2019; 95:774-786. [PMID: 30711200 DOI: 10.1016/j.kint.2018.10.028] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 09/17/2018] [Accepted: 10/18/2018] [Indexed: 12/12/2022]
Abstract
There is an urgent need for therapeutic agents that target humoral alloimmunity in solid organ transplantation. This includes sensitized patients with preformed donor-specific human leukocyte antigen antibodies and patients who develop de novo donor-specific antibodies, both of which are associated with acute and chronic antibody-mediated rejection and allograft loss. In the last decade, both experimental and clinical studies highlighted the major impact of costimulation molecules in the control of immune responses both in the field of transplantation and autoimmune disease. Although these molecules have been initially developed to control the early steps of T-cell activation, recent evidence also supports their influence at several steps of the humoral response. In this review, we aim to provide an overview of the current knowledge of the effects of costimulatory blockade agents on humoral responses in both autoimmune and allogeneic contexts. We first present the effects of costimulatory molecules on the different steps of alloantibody production. We then summarize mechanisms and clinical results observed using cytotoxic T lymphocyte antigen-4 (CTLA4)-Ig molecules both in transplantation and autoimmunity. Finally, we present the potential interest and implications of other costimulatory family members as therapeutic targets, with emphasis on combinatorial approaches, for the optimal control of the alloantigen-specific humoral response.
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Affiliation(s)
- Claire Leibler
- Service de Néphrologie et Transplantation, Pôle Cancérologie-Immunité-Transplantation-Infectiologie, Paris-Est Creteil, France; Institut National de la Santé et de la Recherch Médicale, U955, Equipe 21 and Université Paris-Est, Créteil, France; Department of Immunology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Allan Thiolat
- Institut National de la Santé et de la Recherch Médicale, U955, Equipe 21 and Université Paris-Est, Créteil, France
| | - Rebecca A Elsner
- Department of Immunology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Khalil El Karoui
- Service de Néphrologie et Transplantation, Pôle Cancérologie-Immunité-Transplantation-Infectiologie, Paris-Est Creteil, France; Institut National de la Santé et de la Recherch Médicale, U955, Equipe 21 and Université Paris-Est, Créteil, France
| | - Chloe Samson
- Institut National de la Santé et de la Recherch Médicale, U955, Equipe 21 and Université Paris-Est, Créteil, France
| | - Philippe Grimbert
- Service de Néphrologie et Transplantation, Pôle Cancérologie-Immunité-Transplantation-Infectiologie, Paris-Est Creteil, France; Institut National de la Santé et de la Recherch Médicale, U955, Equipe 21 and Université Paris-Est, Créteil, France.
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Chen C, Zhu WD, Xie F, Huang JA. Nuclear localization of B7-H4 in pulmonary adenocarcinomas presenting as a solitary pulmonary nodule. Oncotarget 2018; 7:58563-58568. [PMID: 27438152 PMCID: PMC5295452 DOI: 10.18632/oncotarget.10542] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Accepted: 06/25/2016] [Indexed: 12/16/2022] Open
Abstract
PURPOSE Although the pathogenicity of B7-H4 in cancer is well established, its role in pulmonary adenocarcinoma, especially lesions presenting as solitary pulmonary nodules (SPNs), remains unclear. METHODS 40 cases of pulmonary adenocarcinoma presenting with SPN were enrolled during year 2012-2015. The B7-H4 expression and its subcellular distribution in pulmonary adenocarcinoma presenting with SPN were analyzed by immunohistochemistry, further its correlation with Ki-67 expression and CT feature. In vitro, the B7-H4 expression in the cytoplasmic and nucleus fractions of lung cancer cell lines was determinate by western blotting. RESULTS Immunostaining revealed B7-H4 in the cytoplasm of cells from all 40 SPN samples studied. No surface localization of B7-H4 was detected, but in 18 samples the nuclear membranes were B7-H4-positive. Moreover, patients with more poorly differentiated and invasive adenocarcinomas showed greater localization of B7-H4 to the nuclear membrane. The percentage of lesions with ground-glass opacity was significantly greater among samples negative for nuclear membrane B7-H4. Most importantly, there was a statistically significant relationships between the Ki-67 index and B7-H4 positivity of the nuclear membrane. This suggests tumors exhibiting higher nuclear membrane B7-H4 have greater proliferative potential. Western blotting confirmed both cytoplasmic and nuclear B7-H4 localization in lung adenocarcinoma cell lines. CONCLUSIONS Taken together, our study provides a new insight into the tumorigenicity of B7-H4 in lung adenocarcinoma. We suggest that in pulmonary adenocarcinoma presenting with SPN, nuclear membrane localization of B7-H4 within the tumor cells is associated with increased malignancy.
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Affiliation(s)
- Cheng Chen
- Respiratory Department, The First Affiliated Hospital of Soochow University, Suzhou, 215006, China
| | - Wei-Dong Zhu
- Pathology Department, The First Affiliated Hospital of Soochow University, Suzhou, 215006, China
| | - Fang Xie
- Pathology Department, Soochow University, Suzhou, 215006, China
| | - Jian-An Huang
- Respiratory Department, The First Affiliated Hospital of Soochow University, Suzhou, 215006, China
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Kean LS, Turka LA, Blazar BR. Advances in targeting co-inhibitory and co-stimulatory pathways in transplantation settings: the Yin to the Yang of cancer immunotherapy. Immunol Rev 2017; 276:192-212. [PMID: 28258702 PMCID: PMC5338458 DOI: 10.1111/imr.12523] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
In the past decade, the power of harnessing T-cell co-signaling pathways has become increasingly understood to have significant clinical importance. In cancer immunotherapy, the field has concentrated on two related modalities: First, targeting cancer antigens through highly activated chimeric antigen T cells (CAR-Ts) and second, re-animating endogenous quiescent T cells through checkpoint blockade. In each of these strategies, the therapeutic goal is to re-ignite T-cell immunity, in order to eradicate tumors. In transplantation, there is also great interest in targeting T-cell co-signaling, but with the opposite goal: in this field, we seek the Yin to cancer immunotherapy's Yang, and focus on manipulating T-cell co-signaling to induce tolerance rather than activation. In this review, we discuss the major T-cell signaling pathways that are being investigated for tolerance induction, detailing preclinical studies and the path to the clinic for many of these molecules. These include blockade of co-stimulation pathways and agonism of coinhibitory pathways, in order to achieve the delicate state of balance that is transplant tolerance: a state which guarantees lifelong transplant acceptance without ongoing immunosuppression, and with preservation of protective immune responses. In the context of the clinical translation of immune tolerance strategies, we discuss the significant challenge that is embodied by the fact that targeted pathway modulators may have opposing effects on tolerance based on their impact on effector vs regulatory T-cell biology. Achieving this delicate balance holds the key to the major challenge of transplantation: lifelong control of alloreactivity while maintaining an otherwise intact immune system.
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Affiliation(s)
- Leslie S. Kean
- Ben Towne Center for Childhood Cancer Research, Seattle Children’s Research Institute, The Fred Hutchinson Cancer Research Center and the Department of Pediatrics, University of Washington, Seattle Washington
| | - Laurence A. Turka
- Center for Transplantation Sciences, Department of Surgery, and Immune Tolerance Network, Massachusetts General Hospital and Harvard Medical School, Boston, MA
| | - Bruce R. Blazar
- Division of Blood and Marrow Transplantation, Department of Pediatrics and the Masonic Cancer Center, University of Minnesota, Minneapolis, MN
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Abomaray FM, Al Jumah MA, Kalionis B, AlAskar AS, Al Harthy S, Jawdat D, Al Khaldi A, Alkushi A, Knawy BA, Abumaree MH. Human Chorionic Villous Mesenchymal Stem Cells Modify the Functions of Human Dendritic Cells, and Induce an Anti-Inflammatory Phenotype in CD1+ Dendritic Cells. Stem Cell Rev Rep 2016; 11:423-41. [PMID: 25287760 DOI: 10.1007/s12015-014-9562-8] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND Mesenchymal stem cells derived from the chorionic villi of human term placenta (pMSCs) have drawn considerable interest because of their multipotent differentiation potential and their immunomodulatory capacity. These properties are the foundation for their clinical application in the fields of stem cell transplantation and regenerative medicine. Previously, we showed that pMSCs induce an anti-inflammatory phenotype in human macrophages. In this study, we determined whether pMSCs modify the differentiation and maturation of human monocytes into dendritic cells (DCs). The consequences on dendritic function and on T cell proliferation were also investigated. METHODS Interleukin-4 (IL-4) and granulocyte-macrophage colony stimulating factor (GM-CSF) were used to stimulate the differentiation of monocytes into immature dendritic cells (iDCs), which were subsequently co-cultured with pMSCs. Lipopolysaccharide (LPS) was used to induce maturation of iDCs into mature dendritic cells (mDCs). Flow cytometry and enzyme-linked immunosorbent assays (ELISA) were used to quantify the effect pMSC co-culturing on DC differentiation using CD1a, a distinctive marker of DCs, as well as other molecules important in the immune functions of DCs. The phagocytic activity of iDCs co-cultured with pMSCs, and the effects of iDCs and mDC stimulation on T cell proliferation, were also investigated. RESULTS Monocyte differentiation into iDCs was inhibited when co-cultured with pMSCs and maturation of iDCs by LPS treatment was also prevented in the presence of pMSCs as demonstrated by reduced expression of CD1a and CD83, respectively. The inhibitory effect of pMSCs on iDC differentiation was dose dependent. In addition, pMSC co-culture with iDCs and mDCs resulted in both phenotypic and functional changes as shown by reduced expression of costimulatory molecules (CD40, CD80, CD83 and CD86) and reduced capacity to stimulate CD4(+) T cell proliferation. In addition, pMSC co-culture increased the surface expression of major histocompatibility complex (MHC-II) molecules on iDCs but decreased MHC-II expression on mDCs. Moreover, pMSC co-culture with iDCs or mDCs increased the expression of immunosuppressive molecules [B7H3, B7H4, CD273, CD274 and indoleamine-pyrrole 2,3-dioxygenase (IDO). Additionally, the secretion of IL-12 and IL-23 by iDCs and mDCs co-cultured with pMSCs was decreased. Furthermore, pMSC co-culture with mDCs decreased the secretion of IL-12 and INF-γ whilst increasing the secretion of IL-10 in a T cell proliferation experiment. Finally, pMSC co-culture with iDCs induced the phagocytic activity of iDCs. CONCLUSIONS We have shown that pMSCs have an inhibitory effect on the differentiation, maturation and function of DCs, as well as on the proliferation of T cells, suggesting that pMSCs can control the immune responses at multiple levels.
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Affiliation(s)
- F M Abomaray
- King Abdullah International Medical Research Center, P.O. Box 22490, Riyadh, 11426, Mail Code 1515, Kingdom of Saudi Arabia
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Radichev IA, Maneva-Radicheva LV, Amatya C, Parker C, Ellefson J, Wasserfall C, Atkinson M, Burn P, Savinov AY. Nardilysin-dependent proteolysis of cell-associated VTCN1 (B7-H4) marks type 1 diabetes development. Diabetes 2014; 63:3470-82. [PMID: 24848066 PMCID: PMC4171653 DOI: 10.2337/db14-0213] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
T-cell responses directed against insulin-secreting pancreatic β-cells are the key events highlighting type 1 diabetes (T1D). Therefore, a defective control of T-cell activation is thought to underlie T1D development. Recent studies implicated a B7-like negative costimulatory protein, V-set domain-containing T-cell activation inhibitor-1 (VTCN1), as a molecule capable of inhibiting T-cell activation and, potentially, an important constituent in experimental models of T1D. Here, we unravel a general deficiency within the VTCN1 pathway that is shared between diabetes-prone mice and a subset of T1D patients. Gradual loss of membrane-tethered VTCN1 from antigen-presenting cells combined with an increased release of soluble VTCN1 (sVTCN1) occurs in parallel to natural T1D development, potentiating hyperproliferation of diabetogenic T cells. Mechanistically, we demonstrate that the loss of membrane-tethered VTCN1 is linked to proteolytic cleavage mediated by the metalloproteinase nardilysin. The cleaved sVTCN1 fragment was detected at high levels in the peripheral blood of 53% T1D patients compared with only 9% of the healthy subjects. Elevated blood sVTCN1 levels appeared early in the disease progression and correlated with the aggressive pace of disease, highlighting the potential use of sVTCN1 as a new T1D biomarker, and identifying nardilysin as a potential therapeutic target.
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Affiliation(s)
- Ilian A Radichev
- Sanford Project/Children's Health Research Center at Sanford Research, Sioux Falls, SD Department of Pediatrics, University of South Dakota School of Medicine, Sioux Falls, SD
| | - Lilia V Maneva-Radicheva
- Sanford Project/Children's Health Research Center at Sanford Research, Sioux Falls, SD Department of Pediatrics, University of South Dakota School of Medicine, Sioux Falls, SD
| | - Christina Amatya
- Sanford Project/Children's Health Research Center at Sanford Research, Sioux Falls, SD Department of Pediatrics, University of South Dakota School of Medicine, Sioux Falls, SD
| | - Camille Parker
- Sanford Project/Children's Health Research Center at Sanford Research, Sioux Falls, SD Department of Pediatrics, University of South Dakota School of Medicine, Sioux Falls, SD
| | - Jacob Ellefson
- Sanford Project/Children's Health Research Center at Sanford Research, Sioux Falls, SD Department of Pediatrics, University of South Dakota School of Medicine, Sioux Falls, SD
| | - Clive Wasserfall
- Department of Pathology, College of Medicine, University of Florida, Gainesville, FL
| | - Mark Atkinson
- Department of Pathology, College of Medicine, University of Florida, Gainesville, FL
| | - Paul Burn
- Sanford Project/Children's Health Research Center at Sanford Research, Sioux Falls, SD Department of Pediatrics, University of South Dakota School of Medicine, Sioux Falls, SD
| | - Alexei Y Savinov
- Sanford Project/Children's Health Research Center at Sanford Research, Sioux Falls, SD Department of Pediatrics, University of South Dakota School of Medicine, Sioux Falls, SD
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Abstract
B7-H4 is a ligand in the B7 costimulatory family, executing suppressive function on the immune system in many diseases, such as cancer, allograft rejection, and autoimmune diseases. The receptor for this molecule has yet to be clarified. The engagement of B7-H4 inhibits proliferation of immune cells by stopping the cell cycle at the G0/G1 phase and leads to apoptosis via the Fas/FasL pathway consequently accelerating tumor progression and alleviating allograft rejection. The pathogenic role of B7-H4 in tumors has been widely established, but few studies have focused on its function in other disorders. Here, we review recent advances in our understanding of B7-H4 biology in disease settings other than tumors and document the beneficial values to treat those diseases by targeting this molecule and related signaling pathways.
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B7-H4 as a potential target for immunotherapy for gynecologic cancers: a closer look. Gynecol Oncol 2014; 134:181-189. [PMID: 24657487 DOI: 10.1016/j.ygyno.2014.03.553] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Revised: 03/14/2014] [Accepted: 03/16/2014] [Indexed: 12/16/2022]
Abstract
B7-H4 is a transmembrane protein that binds an unknown receptor on activated T cells resulting in inhibition of T-cell effector function via cell cycle arrest, decreased proliferation, and reduced IL-2 production. B7-H4 is up-regulated on the surface of cancer cells and immunosuppressive tumor-associated macrophages (TAMs) in a variety of human cancers. Notably, B7-H4 expression levels inversely correlate with patient survival in ovarian cancer, making B7-H4 an attractive candidate for therapeutic intervention. Here, we summarize the experimental data and methodologies that have revealed B7-H4's mRNA and protein expression and function in both mice and humans since its discovery in 2003, with a specific focus on B7-H4's role in ovarian cancer. We also underscore the discrepancies in published data due to high variability in methodology and use of different antibodies, most of which are not commercially available. Finally, since B7-H4 is expressed on tumor cells and TAMs in various cancer types, directing therapeutics against B7-H4 could have tremendous synergistic outcomes in favorably altering the tumor micro-environment and eliminating cancer cells. We highlight the therapeutic potential of targeting B7-H4, both by comparing other negative immune modulators such as PD-1 and CTLA-4 and by identifying novel methods to target B7-H4 directly or indirectly to overcome B7-H4-mediated T-cell inhibition.
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10
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Abstract
BACKGROUND Allograft rejection is one of the main obstacles for islet transplantation. B7-H4 plays a key role in maintaining T-cell homeostasis by reducing T-cell proliferation and cytokine production. In this study, we investigated whether the endogenous expression of B7-H4 in β cells from B7-H4 transgenic mice enhances islet allograft survival. METHODS B7-H4 transgenic C57BL/6 (B6) mice (RIP.B7-H4) were developed by inserting the entire B7-H4 open reading frame under the rat insulin promoter (RIP). B7-H4 protein expression was examined by flow cytometric analysis and immunohistochemical staining. Islet allograft survival was investigated in streptozotocin-induced diabetic recipient BALB/c (H-2d) mice transplanted with 400 islets from RIP.B7-H4 (H-2b) mice under the kidney capsule. The recipient control group received islets from wild-type B6 donors. RESULTS B7-H4 protein was significantly up-regulated in isolated islets from RIP.B7-H4 compared with wild-type B6 mice (56%±23% vs. 3%±1.2%). B7-H4 was coexpressed with insulin, but not glucagon, suggesting that B7-H4 is expressed in a β-cell-specific manner. Recipient BALB/c mice transplanted with RIP.B7-H4 islets established euglycemia for 42.3±18.4 days (mean±SD; n=9) compared with controls at 23.1±7.8 days (mean±SD; n=12; P<0.004, log-rank test). CONCLUSIONS The endogenous expression of B7-H4 in donor β cells from transgenic mice prolongs islet allograft survival, confirming the negative role of B7-H4 in regulating alloreactive T-cell responses.
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Wang X, Hao J, Metzger DL, Mui A, Lee IF, Akhoundsadegh N, Chen CL, Ou D, Ao Z, Verchere CB, Warnock GL. Blockade of both B7-H4 and CTLA-4 co-signaling pathways enhances mouse islet allograft survival. Islets 2012; 4:284-95. [PMID: 22878670 PMCID: PMC3496653 DOI: 10.4161/isl.21239] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Costimulation blockade is an effective way to prevent allograft rejection. In this study, we tested the efficacy of two negative co-signaling molecules in protecting islet allograft function. We used local expression of B7-H4 by adenoviral transduction of islets (Ad-B7-H4) and systemic administration of CTLA-4.Ig to investigate the outcomes of allograft survival. Five groups of streptozotocin-induced diabetic C57BL/6 mice received 400 islets each from BALB/c donors. The groups consisted of control (G1); CTLA-4.Ig (G2); Ad-LacZ (G3); Ad-B7-H4 (G4); and Ad-B7-H4 and CTLA-4.Ig combined (G5). G1 and G3 developed graft failure on average of two weeks. G2, G4 and G5 survived for 43.8 ± 34.8, 54.7 ± 31.2 and 77.8 ± 21.5 d, respectively. Activated T and B cells in the lymph nodes were significantly controlled by CTLA-4.Ig treatment. Significantly reduced infiltrates were also detected in the allografts of G2 compared with G1. By contrast, B7-H4 significantly inhibited Th1-associated IFN-gamma secretion in the early stage and increased Foxp3 (+) T cells in the long-term surviving allografts. Our study suggests that CTLA-4 and B7-H4 inhibit alloimmune responses through distinct mechanisms, and that combination therapy which activates two negative co-signaling pathways can further enhance islet allograft survival.
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Affiliation(s)
- Xiaojie Wang
- Department of Surgery; University of British Columbia; Vancouver, BC Canada
- These authors contributed equally to this work
| | - Jianqiang Hao
- Department of Surgery; University of British Columbia; Vancouver, BC Canada
- These authors contributed equally to this work
| | - Daniel L. Metzger
- Department of Pediatrics; University of British Columbia; Vancouver, BC Canada
| | - Alice Mui
- Department of Surgery; University of British Columbia; Vancouver, BC Canada
| | - I-Fang Lee
- Department of Surgery; University of British Columbia; Vancouver, BC Canada
| | | | - C. Lieping Chen
- Department of Immunobiology; Yale University School of Medicine; New Haven, CT USA
| | - Dawei Ou
- Department of Surgery; University of British Columbia; Vancouver, BC Canada
| | - Ziliang Ao
- Department of Surgery; University of British Columbia; Vancouver, BC Canada
| | - C. Bruce Verchere
- 4Department of Pathology and Laboratory Medicine; University of British Columbia; Vancouver, BC Canada
| | - Garth L. Warnock
- Department of Surgery; University of British Columbia; Vancouver, BC Canada
- Correspondence to: Garth L. Warnock,
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McGrath MM, Najafian N. The role of coinhibitory signaling pathways in transplantation and tolerance. Front Immunol 2012; 3:47. [PMID: 22566929 PMCID: PMC3342378 DOI: 10.3389/fimmu.2012.00047] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2011] [Accepted: 02/28/2012] [Indexed: 12/25/2022] Open
Abstract
Negative costimulatory molecules, acting through so-called inhibitory pathways, play a crucial role in the control of T cell responses. This negative “second signal” opposes T cell receptor activation and leads to downregulation of T cell proliferation and promotes antigen specific tolerance. Much interest has focused upon these pathways in recent years as a method to control detrimental alloresponses and promote allograft tolerance. However, recent experimental data highlights the complexity of negative costimulatory pathways in alloimmunity. Varying effects are observed from molecules expressed on donor and recipient tissues and also depending upon the activation status of immune cells involved. There appears to be significant overlap and redundancy within these systems, rendering this a challenging area to understand and exploit therapeutically. In this article, we will review the literature at the current time regarding the major negative costimulation pathways including CTLA-4:B7, PD-1:PD-L1/PD-L2 and PD-L1:B7-1, B7-H3, B7-H4, HVEM:BTLA/CD160, and TIM-3:Galectin-9. We aim to outline the role of these pathways in alloimmunity and discuss their potential applications for tolerance induction in transplantation.
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Affiliation(s)
- Martina M McGrath
- Transplantation Research Center, Brigham and Women's Hospital and Children's Hospital, Harvard Medical School Boston, MA, USA
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13
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B7-H4 Pathway in Islet Transplantation and β-Cell Replacement Therapies. J Transplant 2011; 2011:418902. [PMID: 22028949 PMCID: PMC3196026 DOI: 10.1155/2011/418902] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2011] [Accepted: 08/03/2011] [Indexed: 12/18/2022] Open
Abstract
Type 1 diabetes (T1D) is a chronic autoimmune disease and characterized by absolute insulin deficiency. β-cell replacement by islet cell transplantation has been established as a feasible treatment option for T1D. The two main obstacles after islet transplantation are alloreactive T-cell-mediated graft rejection and recurrence of autoimmune diabetes mellitus in recipients. T cells play a central role in determining the outcome of both autoimmune responses and allograft survival. B7-H4, a newly identified B7 homolog, plays a key role in maintaining T-cell homeostasis by reducing T-cell proliferation and cytokine production. The relationship between B7-H4 and allograft survival/autoimmunity has been investigated recently in both islet transplantation and the nonobese diabetic (NOD) mouse models. B7-H4 protects allograft survival and generates donor-specific tolerance. It also prevents the development of autoimmune diabetes. More importantly, B7-H4 plays an indispensable role in alloimmunity in the absence of the classic CD28/CTLA-4 : B7 pathway, suggesting a synergistic/additive effect with other agents such as CTLA-4 on inhibition of unwanted immune responses.
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