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The prospects for targeting FcR as a novel therapeutic strategy in rheumatoid arthritis. Biochem Pharmacol 2020; 183:114360. [PMID: 33301760 DOI: 10.1016/j.bcp.2020.114360] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2020] [Revised: 12/03/2020] [Accepted: 12/03/2020] [Indexed: 01/05/2023]
Abstract
Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease characterized by synovial membrane hyperplasia, infiltration of inflammatory cells and bone tissue destruction. Although there have been many measures taken for RA therapy in recent years, they are not sufficiently safe or effective. Thus, it is very important to develop new drugs and slow down damage to other healthy organs in the case of RA. Lately, immunoglobulin Fc receptors (FcRs), such as the IgG Fc receptor (FcγR), IgA Fc receptor (FcαR), and IgD Fc receptor (FcδR), have been found to be involved in inducing or suppressing arthritis. FcRs interacting with immune complexes (ICs) are a key factor in the etiopathogenesis of RA. Therefore, an increasing number of methodsfor the targeted treatment of RA with FcRs are emerging, such as recombinant soluble FcγRs, recombinant multimeric Fc fragments and monoclonal antibodies, and have been demonstrated to significantly improve RA symptoms. Simultaneously, certain kinases involved in the downstream signaling of FcRs can also be a target for the treatment of RA, such as Syk and Btk inhibitors. An overview of these FcRs is provided in this review, including a description of FcR-related functions, signaling pathways, and potential FcR-targeting molecules for RA therapy. To date, the initial results of those developed FcR-targeting molecules have been promising. With this, FcRs might offer a better alternative to RA medication. Additionally, further pharmacological characterization and a better understanding of the unique mechanisms of FcR-targeting molecules are necessary.
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Hamdan TA, Lang PA, Lang KS. The Diverse Functions of the Ubiquitous Fcγ Receptors and Their Unique Constituent, FcRγ Subunit. Pathogens 2020; 9:pathogens9020140. [PMID: 32093173 PMCID: PMC7168688 DOI: 10.3390/pathogens9020140] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2019] [Revised: 02/15/2020] [Accepted: 02/17/2020] [Indexed: 01/03/2023] Open
Abstract
Fc gamma receptors (FcγRs) are widely expressed on a variety of immune cells and play a myriad of regulatory roles in the immune system because of their structural diversity. Apart from their indispensable role in specific binding to the Fc portion of antibody subsets, FcγRs manifest diverse biological functions upon binding to their putative ligands. Examples of such manifestation include phagocytosis, presentation of antigens, mediation of antibody-dependent cellular cytotoxicity, anaphylactic reactions, and the promotion of apoptosis of T cells and natural killer cells. Functionally, the equilibrium between activating and inhibiting FcγR maintains the balance between afferent and efferent immunity. The γ subunit of the immunoglobulin Fc receptor (FcRγ) is a key component of discrete immune receptors and Fc receptors including the FcγR family. Furthermore, FcγRs exert a key role in terms of crosslinking the innate and adaptive workhorses of immunity. Ablation of one of these receptors might positively or negatively influence the immune response. Very recently, we discovered that FcRγ derived from natural cytotoxicity triggering receptor 1 (NCR1) curtails CD8+ T cell expansion and thereby turns an acute viral infection into a chronic one. Such a finding opens a new avenue for targeting the FcγRs as one of the therapeutic regimens to boost the immune response. This review highlights the structural heterogeneity and functional diversity of the ubiquitous FcγRs along with their featured subunit, FcRγ.
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Affiliation(s)
- Thamer A. Hamdan
- Institute of Immunology, Medical Faculty, University of Duisburg-Essen, Hufelandstraße 55, 45147 Essen, Germany
- Correspondence:
| | - Philipp A. Lang
- Department of Molecular Medicine II, Medical Faculty, Heinrich Heine University, Universitätsstrasse 1, 40225 Düsseldorf, Germany
| | - Karl S. Lang
- Institute of Immunology, Medical Faculty, University of Duisburg-Essen, Hufelandstraße 55, 45147 Essen, Germany
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Huang S, Wu S, Zhang Z, Deng W, Fan J, Feng R, Kong W, Qi J, Chen W, Tang X, Yao G, Feng X, Wang D, Chen H, Sun L. Mesenchymal stem cells induced CD4+ T cell apoptosis in treatment of lupus mice. Biochem Biophys Res Commun 2018; 507:30-35. [PMID: 30409422 DOI: 10.1016/j.bbrc.2018.10.133] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Accepted: 10/22/2018] [Indexed: 12/29/2022]
Abstract
Umbilical cord-derived mesenchymal stem cell transplantation (UCMSCT) has been used to treat human autoimmune diseases like lupus for example, but little is known about its effect on cell apoptosis. Here we evaluated the efficacy of UCMSCT for lupus treatment and explored the mechanism by which mesenchymal stem cells (MSCs) modulate T cell apoptosis in lupus mice. 1 × 106 human umbilical cord-derived mesenchymal stem cells (UC-MSCs) were injected into B6.MRL-Faslpr (B6.lpr) mice via tail vein. 6 h, 24 h or 4 weeks later, the mice were sacrificed and the apoptosis of lymphocytes in peripheral blood and spleen were detected by flow cytometry. The immune cell subpopulations in spleen were also measured at 6 h and 24 h, respectively. The therapeutic effects were assessed after 4 weeks. The frequency of peripheral blood CD4+ T cell apoptosis was reduced in lupus-prone B6.lpr mice. UCMSCT alleviated the disease phenotypes in B6.lpr mice, decreased the ratio of Th1 as well as Th2 cells, and increased percentages of apoptotic CD4+ T cells in vivo and vitro. Collectively, our findings unravel that UCMSCT alleviate lupus disease and reverse immune imbalance possibly by promoting T cell apoptosis in B6.lpr mice.
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Affiliation(s)
- Saisai Huang
- Department of Rheumatology and Immunology, Drum Tower Clinical Medical College of Nanjing Medical University, 321 Zhongshan Road, Nanjing, Jiangsu, 210008, China.
| | - Shufang Wu
- Department of Rheumatology and Immunology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, 321 Zhongshan Road, Nanjing, Jiangsu, 210008, China.
| | - Zhuoya Zhang
- Department of Rheumatology and Immunology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, 321 Zhongshan Road, Nanjing, Jiangsu, 210008, China.
| | - Wei Deng
- Department of Rheumatology and Immunology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, 321 Zhongshan Road, Nanjing, Jiangsu, 210008, China.
| | - Junyu Fan
- Department of Rheumatology and Immunology, Nanjing Drum Tower Clinical Medical College of Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, 321 Zhongshan Road, Nanjing, Jiangsu, 210008, China.
| | - Ruihai Feng
- Department of Rheumatology and Immunology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, 321 Zhongshan Road, Nanjing, Jiangsu, 210008, China.
| | - Wei Kong
- Department of Rheumatology and Immunology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, 321 Zhongshan Road, Nanjing, Jiangsu, 210008, China.
| | - Jingjing Qi
- Department of Rheumatology and Immunology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, 321 Zhongshan Road, Nanjing, Jiangsu, 210008, China.
| | - Weiwei Chen
- Department of Rheumatology and Immunology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, 321 Zhongshan Road, Nanjing, Jiangsu, 210008, China.
| | - Xiaojun Tang
- Department of Rheumatology and Immunology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, 321 Zhongshan Road, Nanjing, Jiangsu, 210008, China.
| | - Genhong Yao
- Department of Rheumatology and Immunology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, 321 Zhongshan Road, Nanjing, Jiangsu, 210008, China.
| | - Xuebing Feng
- Department of Rheumatology and Immunology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, 321 Zhongshan Road, Nanjing, Jiangsu, 210008, China.
| | - Dandan Wang
- Department of Rheumatology and Immunology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, 321 Zhongshan Road, Nanjing, Jiangsu, 210008, China.
| | - Hongwei Chen
- Department of Rheumatology and Immunology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, 321 Zhongshan Road, Nanjing, Jiangsu, 210008, China.
| | - Lingyun Sun
- Department of Rheumatology and Immunology, Drum Tower Clinical Medical College of Nanjing Medical University, 321 Zhongshan Road, Nanjing, Jiangsu, 210008, China.
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Dieker J, Hilbrands L, Thielen A, Dijkman H, Berden JH, van der Vlag J. Enhanced activation of dendritic cells by autologous apoptotic microvesicles in MRL/lpr mice. Arthritis Res Ther 2015; 17:103. [PMID: 25886192 PMCID: PMC4422546 DOI: 10.1186/s13075-015-0617-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Accepted: 04/07/2015] [Indexed: 11/17/2022] Open
Abstract
Introduction Systemic lupus erythematosus is associated with a persistent circulation of modified autoantigen-containing apoptotic debris that might be capable of breaking tolerance. We aimed to evaluate apoptotic microvesicles obtained from lupus or control mice for the presence of apoptosis-associated chromatin modifications and for their capacity to stimulate dendritic cells (DC) from lupus and control mice. Method Apoptotic microvesicles were in vitro generated from splenocytes, and ex vivo isolated from plasma of both MRL/lpr lupus mice and normal BALB/c mice. Microvesicles were analyzed using flow cytometry. Bone marrow-derived (BM)-DC cultured from MRL/lpr or BALB/c mice were incubated with microvesicles and CD40 expression and cytokine production were determined as measure of activation. Results Microvesicles derived from apoptotic splenocytes or plasma of MRL/lpr mice contained more modified chromatin compared to microvesicles of BALB/c mice, and showed enhanced activation of DC, either from MRL/lpr or BALB/c mice, and consecutively an enhanced DC-mediated activation of splenocytes. The content of apoptosis-modified chromatin in microvesicles of apoptotic splenocytes correlated with their potency to induce interleukin-6 (IL-6) production by DC. Microvesicle-activated MRL/lpr DC showed a significant higher production of IL-6 and tumor growth factor-β (TGF-β) compared to BALB/c DC, and were more potent in the activation of splenocytes. Conclusion Apoptotic microvesicles from MRL/lpr mice are more potent activators of DC, and DC from MRL/lpr mice appear relatively more sensitive to activation by apoptotic microvesicles. Our findings indicate that aberrations at the level of apoptotic microvesicles and possibly DC contribute to the autoimmune response against chromatin in MRL/lpr mice.
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Affiliation(s)
- Jürgen Dieker
- Department of Nephrology, Radboud University Medical Centre, Nijmegen, The Netherlands.
| | - Luuk Hilbrands
- Department of Nephrology, Radboud University Medical Centre, Nijmegen, The Netherlands.
| | - Astrid Thielen
- Department of Nephrology, Radboud University Medical Centre, Nijmegen, The Netherlands.
| | - Henry Dijkman
- Department of Pathology, Radboud University Medical Centre, Nijmegen, The Netherlands.
| | - Jo H Berden
- Department of Nephrology, Radboud University Medical Centre, Nijmegen, The Netherlands.
| | - Johan van der Vlag
- Department of Nephrology, Radboud University Medical Centre, Nijmegen, The Netherlands. .,Department of Nephrology, Radboud Institute of Molecular Life Sciences, Radboud University Medical Centre, Geert Grooteplein 10, Nijmegen, 6525, GA, The Netherlands.
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Goury A, Meghraoui-Kheddar A, Belmokhtar K, Vuiblet V, Ortillon J, Jaisson S, Devy J, Le Naour R, Tabary T, Cohen JHM, Schmidt AM, Rieu P, Touré F. Deletion of receptor for advanced glycation end products exacerbates lymphoproliferative syndrome and lupus nephritis in B6-MRL Fas lpr/j mice. THE JOURNAL OF IMMUNOLOGY 2015; 194:3612-22. [PMID: 25762779 DOI: 10.4049/jimmunol.1402342] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Accepted: 02/07/2015] [Indexed: 01/10/2023]
Abstract
The receptor for advanced glycation end products (RAGE) is a pattern recognition receptor that interacts with advanced glycation end products, but also with C3a, CpG DNA oligonucleotides, and alarmin molecules such as HMGB1 to initiate a proinflammatory reaction. Systemic lupus erythematosus is an autoimmune disorder associated with the accumulation of RAGE ligands. We generated mice invalidated for RAGE in the lupus-prone B6-MRL Fas lpr/j background to determine the role of RAGE in the pathogenesis of systemic lupus erythematosus. We compared the phenotype of these mice with that of their wild-type and B6-MRL Fas lpr/j littermates. Lymphoproliferative syndrome, production of anti-dsDNA Abs, lupus nephritis, and accumulation of CD3(+)B220(+)CD4(-)CD8(-) autoreactive T cells (in the peripheral blood and the spleen) were significantly increased in B6-MRL Fas lpr/j RAGE(-/-) mice compared with B6-MRL Fas lpr/j mice (respectively p < 0.005, p < 0.05, p < 0.001, and p < 0.001). A large proportion of autoreactive T cells from B6-MRL Fas lpr/j mice expressed RAGE at their surface. Time course studies of annexin V expression revealed that autoreactive T cells in the spleen of B6-MRL Fas lpr/j-RAGE(-/-) mice exhibited a delay in apoptosis and expressed significantly less activated caspase 3 (39.5 ± 4.3%) than T cells in B6-MRL Fas lpr/j mice (65.5 ± 5.2%) or wild-type mice (75.3 ± 2.64%) (p = 0.02). We conclude that the deletion of RAGE in B6-MRL Fas lpr/j mice promotes the accumulation of autoreactive CD3(+)B220(+)CD4(-)CD8(-) T cells, therefore exacerbating lymphoproliferative syndrome, autoimmunity, and organ injury. This suggests that RAGE rescues the apoptosis of T lymphocytes when the death receptor Fas/CD95 is dysfunctional.
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Affiliation(s)
- Antoine Goury
- Faculté de Médecine, Laboratoire de Néphrologie, Université de Reims Champagne-Ardenne, Centre National de la Recherche Scientifique Unité Mixte de Recherche 7369 (Matrice Extracellulaire et Dynamique Cellulaire), 51100 Reims, France; Service de Néphrologie, Centre Hospitalier Universitaire de Reims, 51100 Reims, France
| | - Aïda Meghraoui-Kheddar
- Faculté de Pharmacie, Université de Reims Champagne-Ardenne, EA4683 (Immunité Adaptative et Fonctionnalité des Barrières Biologiques), 51100 Reims, France
| | - Karim Belmokhtar
- Faculté de Médecine, Laboratoire de Néphrologie, Université de Reims Champagne-Ardenne, Centre National de la Recherche Scientifique Unité Mixte de Recherche 7369 (Matrice Extracellulaire et Dynamique Cellulaire), 51100 Reims, France; Service de Néphrologie, Centre Hospitalier Universitaire de Reims, 51100 Reims, France
| | - Vincent Vuiblet
- Faculté de Médecine, Laboratoire de Néphrologie, Université de Reims Champagne-Ardenne, Centre National de la Recherche Scientifique Unité Mixte de Recherche 7369 (Matrice Extracellulaire et Dynamique Cellulaire), 51100 Reims, France; Service de Néphrologie, Centre Hospitalier Universitaire de Reims, 51100 Reims, France
| | - Jeremy Ortillon
- Faculté de Médecine, Laboratoire de Néphrologie, Université de Reims Champagne-Ardenne, Centre National de la Recherche Scientifique Unité Mixte de Recherche 7369 (Matrice Extracellulaire et Dynamique Cellulaire), 51100 Reims, France
| | - Stéphane Jaisson
- Faculté de Médecine, Laboratoire de Néphrologie, Université de Reims Champagne-Ardenne, Centre National de la Recherche Scientifique Unité Mixte de Recherche 7369 (Matrice Extracellulaire et Dynamique Cellulaire), 51100 Reims, France
| | - Jerôme Devy
- Faculté des Sciences, Laboratoire Signalisation et Récepteurs Matriciels, Université de Reims Champagne-Ardenne, Centre National de la Recherche Scientifique Unité Mixte de Recherche 7369 (Matrice Extracellulaire et Dynamique Cellulaire), 51100 Reims, France
| | - Richard Le Naour
- Faculté de Pharmacie, Université de Reims Champagne-Ardenne, EA4683 (Immunité Adaptative et Fonctionnalité des Barrières Biologiques), 51100 Reims, France
| | - Thierry Tabary
- Laboratoire d'Immunologie, Université de Reims Champagne-Ardenne, Laboratoire de Recherche en Nanosciences EA4682 et Centre Hospitalier Universitaire de Reims, Reims 51100, France; and
| | - Jacques H M Cohen
- Laboratoire d'Immunologie, Université de Reims Champagne-Ardenne, Laboratoire de Recherche en Nanosciences EA4682 et Centre Hospitalier Universitaire de Reims, Reims 51100, France; and
| | | | - Philippe Rieu
- Faculté de Médecine, Laboratoire de Néphrologie, Université de Reims Champagne-Ardenne, Centre National de la Recherche Scientifique Unité Mixte de Recherche 7369 (Matrice Extracellulaire et Dynamique Cellulaire), 51100 Reims, France; Service de Néphrologie, Centre Hospitalier Universitaire de Reims, 51100 Reims, France
| | - Fatouma Touré
- Faculté de Médecine, Laboratoire de Néphrologie, Université de Reims Champagne-Ardenne, Centre National de la Recherche Scientifique Unité Mixte de Recherche 7369 (Matrice Extracellulaire et Dynamique Cellulaire), 51100 Reims, France; Service de Néphrologie, Centre Hospitalier Universitaire de Reims, 51100 Reims, France;
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Martina MN, Bandapalle S, Rabb H, Hamad AR. Isolation of double negative αβ T cells from the kidney. J Vis Exp 2014. [PMID: 24893925 DOI: 10.3791/51192] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
There is currently no standard protocol for the isolation of DN T cells from the non-lymphoid tissues despite their increasingly reported involvement in various immune responses. DN T cells are a unique immune cell type that has been implicated in regulating immune and autoimmune responses and tolerance to allotransplants(1-6). DN T cells are, however, rare in peripheral blood and secondary lymphoid organs (spleen and lymph nodes), but are major residents of the normal kidney. Very little is known about their pathophysiologic function(7) due to their paucity in the periphery. We recently described a comprehensive phenotypic and functional analysis of this population in the kidney(8) in steady state and during ischemia reperfusion injury. Analysis of DN T cell function will be greatly enhanced by developing a protocol for their isolation from the kidney. Here, we describe a novel protocol that allows isolation of highly pure ab CD4+ CD8+ T cells and DN T cells from the murine kidney. Briefly, we digest kidney tissue using collagenase and isolate kidney mononuclear cells (KMNC) by density gradient. This is followed by two steps to enrich hematopoietic T cells from 3% to 70% from KMNC. The first step consists of a positive selection of hematopoietic cells using a CD45+ isolation kit. In the second step, DN T cells are negatively isolated by removal of non-desired cells using CD4, CD8, and MHC class II monoclonal antibodies and CD1d α-galcer tetramer. This strategy leads to a population of more than 90% pure DN T cells. Surface staining with the above mentioned antibodies followed by FACs analysis is used to confirm purity.
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Affiliation(s)
- Maria N Martina
- Department of Pathology, Johns Hopkins University School of Medicine
| | | | - Hamid Rabb
- Department of Medicine, Johns Hopkins University School of Medicine
| | - Abdel R Hamad
- Department of Pathology, Johns Hopkins University School of Medicine;
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Berhanu TK, Holley-Cuthrell J, Roberts NW, Mull AJ, Heydemann A. Increased AMP-activated protein kinase in skeletal muscles of Murphy Roth Large mice and its potential role in altered metabolism. Physiol Rep 2014; 2:e00252. [PMID: 24760507 PMCID: PMC4002233 DOI: 10.1002/phy2.252] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Wild‐type Murphy Roth Large (MRL) mice have long been investigated for their superior healing ability when subjected to various wound and disease models. Despite this long history, the mechanisms causing their extraordinary healing ability remain undefined. As we have recently demonstrated that MRL mice with muscular dystrophy are resistant to the associated fibrosis and the Heber‐Katz group has demonstrated MRL mitochondrial mutations, we decided to investigate the skeletal muscle metabolic characteristics of the MRL mouse strain compared to the commonly utilized C57BL/6J control mouse strain. We now have evidence demonstrating an altered metabolism in the MRL quadriceps, triceps brachii, and diaphragm of 8‐week‐old animals compared to tissues from control animals. The MRL skeletal muscles have increased activated phosphorylated AMP‐activated protein kinase (pAMPK). The increased pAMPK signaling coincides with increased skeletal muscle mitochondrial content. These metabolic changes may compensate for insufficient oxidative phosphorylation which is demonstrated by altered quantities of proteins involved in oxidative phosphorylation and ex vivo metabolic investigations. We also demonstrate that the MRL muscle cells have increased metabolic physiologic reserve. These data further the investigations into this important and unique mouse strain. Why the MRL mice have increased pAMPK and how increased pAMPK and the resultant metabolic alterations affect the healing ability in the MRL mouse strain is discussed. Understanding the molecular mechanisms surrounding the super healing characteristics of these mice will lead to relevant clinical intervention points. In conclusion, we present novel data of increased mitochondrial content, pAMPK, and glycolytic indicators in MRL skeletal muscles.
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Affiliation(s)
- Tirsit K Berhanu
- Department of Physiology and Biophysics, The University of Illinois at Chicago, Chicago, Illinois
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Juvet SC, Thomson CW, Kim EY, Han M, Zhang L. FcRγ controls the fas-dependent regulatory function of lymphoproliferative double negative T cells. PLoS One 2013; 8:e65253. [PMID: 23762329 PMCID: PMC3675138 DOI: 10.1371/journal.pone.0065253] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2013] [Accepted: 04/24/2013] [Indexed: 12/21/2022] Open
Abstract
Patients with autoimmune lymphoproliferative syndrome (ALPS) and lymphoproliferation (LPR) mice are deficient in Fas, and accumulate large numbers of αβ-TCR+, CD4−, CD8− double negative (DN) T cells. The function of these DN T cells remains largely unknown. The common γ subunit of the activating Fc receptors, FcRγ, plays an important role in mediating innate immune responses. We have shown previously that a significant proportion of DN T cells express FcRγ, and that this molecule is required for TCR transgenic DN T cells to suppress allogeneic immune responses. Whether FcRγ plays a critical role in LPR DN T cell-mediated suppression of immune responses to auto and allo-antigens is not known. Here, we demonstrated that FcRγ+, but not FcRγ− LPR DN T cells could suppress Fas+ CD4+ and CD8+ T cell proliferation in vitro and attenuated CD4+ T cell-mediated graft-versus host disease. Although FcRγ expression did not allow LPR DN T cells to inhibit the expansion of Fas-deficient cells within the LPR context, adoptive transfer of FcRγ+, but not FcRγ−, DN T cells inhibited lymphoproliferation in generalized lymphoproliferative disease (GLD) mice. Furthermore, FcRγ acted in a cell-intrinsic fashion to limit DN T cell accumulation by increasing the rate of apoptosis in proliferated cells. These results indicate that FcRγ can confer Fas-dependent regulatory properties on LPR DN T cells, and suggest that FcRγ may be a novel marker for functional DN Tregs.
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Affiliation(s)
- Stephen C. Juvet
- Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
- Division of Respirology and Toronto Lung Transplant Program, Department of Medicine, University Health Network, University of Toronto, Toronto, Ontario, Canada
- Clinician-Scientist Training Program, Department of Medicine, University of Toronto, Toronto, Ontario, Canada
- Toronto General Research Institute, University Health Network, Toronto, Ontario, Canada
| | - Christopher W. Thomson
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
- Toronto General Research Institute, University Health Network, Toronto, Ontario, Canada
| | - Edward Y. Kim
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
- Toronto General Research Institute, University Health Network, Toronto, Ontario, Canada
| | - Mei Han
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
- Toronto General Research Institute, University Health Network, Toronto, Ontario, Canada
| | - Li Zhang
- Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
- Department of Immunology, University of Toronto, Toronto, Ontario, Canada
- Toronto General Research Institute, University Health Network, Toronto, Ontario, Canada
- * E-mail:
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