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Chuang HC, Tan TH. MAP4K Family Kinases and DUSP Family Phosphatases in T-Cell Signaling and Systemic Lupus Erythematosus. Cells 2019; 8:cells8111433. [PMID: 31766293 PMCID: PMC6912701 DOI: 10.3390/cells8111433] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 11/08/2019] [Accepted: 11/11/2019] [Indexed: 12/21/2022] Open
Abstract
T cells play a critical role in the pathogenesis of systemic lupus erythematosus (SLE), which is a severe autoimmune disease. In the past 60 years, only one new therapeutic agent with limited efficacy has been approved for SLE treatment; therefore, the development of early diagnostic biomarkers and therapeutic targets for SLE is desirable. Mitogen-activated protein kinase kinase kinase kinases (MAP4Ks) and dual-specificity phosphatases (DUSPs) are regulators of MAP kinases. Several MAP4Ks and DUSPs are involved in T-cell signaling and autoimmune responses. HPK1 (MAP4K1), DUSP22 (JKAP), and DUSP14 are negative regulators of T-cell activation. Consistently, HPK1 and DUSP22 are downregulated in the T cells of human SLE patients. In contrast, MAP4K3 (GLK) is a positive regulator of T-cell signaling and T-cell-mediated immune responses. MAP4K3 overexpression-induced RORγt–AhR complex specifically controls interleukin 17A (IL-17A) production in T cells, leading to autoimmune responses. Consistently, MAP4K3 and the RORγt–AhR complex are overexpressed in the T cells of human SLE patients, as are DUSP4 and DUSP23. In addition, DUSPs are also involved in either human autoimmune diseases (DUSP2, DUSP7, DUSP10, and DUSP12) or T-cell activation (DUSP1, DUSP5, and DUSP14). In this review, we summarize the MAP4Ks and DUSPs that are potential biomarkers and/or therapeutic targets for SLE.
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Katsuyama T, Tsokos GC, Moulton VR. Aberrant T Cell Signaling and Subsets in Systemic Lupus Erythematosus. Front Immunol 2018; 9:1088. [PMID: 29868033 PMCID: PMC5967272 DOI: 10.3389/fimmu.2018.01088] [Citation(s) in RCA: 142] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 05/01/2018] [Indexed: 12/20/2022] Open
Abstract
Systemic lupus erythematosus (SLE) is a chronic multi-organ debilitating autoimmune disease, which mainly afflicts women in the reproductive years. A complex interaction of genetics, environmental factors and hormones result in the breakdown of immune tolerance to "self" leading to damage and destruction of multiple organs, such as the skin, joints, kidneys, heart and brain. Both innate and adaptive immune systems are critically involved in the misguided immune response against self-antigens. Dendritic cells, neutrophils, and innate lymphoid cells are important in initiating antigen presentation and propagating inflammation at lymphoid and peripheral tissue sites. Autoantibodies produced by B lymphocytes and immune complex deposition in vital organs contribute to tissue damage. T lymphocytes are increasingly being recognized as key contributors to disease pathogenesis. CD4 T follicular helper cells enable autoantibody production, inflammatory Th17 subsets promote inflammation, while defects in regulatory T cells lead to unchecked immune responses. A better understanding of the molecular defects including signaling events and gene regulation underlying the dysfunctional T cells in SLE is necessary to pave the path for better management, therapy, and perhaps prevention of this complex disease. In this review, we focus on the aberrations in T cell signaling in SLE and highlight therapeutic advances in this field.
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Affiliation(s)
| | | | - Vaishali R. Moulton
- Division of Rheumatology, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States
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Barrera-Vargas A, Gómez-Martín D, Alcocer-Varela J. T cell receptor-associated protein tyrosine kinases: the dynamics of tolerance regulation by phosphorylation and its role in systemic lupus erythematosus. Hum Immunol 2014; 75:945-52. [PMID: 25173412 DOI: 10.1016/j.humimm.2014.08.207] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Revised: 06/10/2014] [Accepted: 08/21/2014] [Indexed: 01/27/2023]
Abstract
There are different abnormalities that lead to the autoreactive phenotype in T cells from systemic lupus erythematosus (SLE) patients. Proximal signaling, involving the T-cell receptor (TCR) and its associated protein tyrosine kinases (PTKs), is significantly affected in SLE. This ultimately leads to aberrant responses, which include enhanced tyrosine phosphorylation and calcium release, as well as decreased IL-2 secretion. Lck, ZAP70 and Syk, which are PTKs with a major role in proximal signaling, all present abnormal functioning that contributes to an altered T cell response in these patients. A number of other molecules, especially regulatory proteins, are also involved. This review will focus on the PTKs that participate in proximal signaling, with specific emphasis on their relevance in maintaining peripheral tolerance, their abnormalities in SLE and how these contribute to an altered T cell response.
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Affiliation(s)
- Ana Barrera-Vargas
- Department of Immunology and Rheumatology, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Vasco de Quiroga 15, Tlalpan, 14000 Mexico City, Mexico.
| | - Diana Gómez-Martín
- Department of Immunology and Rheumatology, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Vasco de Quiroga 15, Tlalpan, 14000 Mexico City, Mexico.
| | - Jorge Alcocer-Varela
- Department of Immunology and Rheumatology, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Vasco de Quiroga 15, Tlalpan, 14000 Mexico City, Mexico.
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Mak A, Kow NY. The pathology of T cells in systemic lupus erythematosus. J Immunol Res 2014; 2014:419029. [PMID: 24864268 PMCID: PMC4017881 DOI: 10.1155/2014/419029] [Citation(s) in RCA: 111] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Revised: 03/12/2014] [Accepted: 03/12/2014] [Indexed: 12/02/2022] Open
Abstract
Systemic lupus erythematosus (SLE) is characterized by the production of a wide array of autoantibodies. Thus, the condition was traditionally classified as a "B-cell disease". Compelling evidence has however shown that without the assistance of the helper T lymphocytes, it is indeed difficult for the "helpless" B cells to become functional enough to trigger SLE-related inflammation. T cells have been recognized to be crucial in the pathogenicity of SLE through their capabilities to communicate with and offer enormous help to B cells for driving autoantibody production. Recently, a number of phenotypic and functional alterations which increase the propensity to trigger lupus-related inflammation have been identified in lupus T cells. Here, potential mechanisms involving alterations in T-cell receptor expressions, postreceptor downstream signalling, epigenetics, and oxidative stress which favour activation of lupus T cells will be discussed. Additionally, how regulatory CD4+, CD8+, and γδ T cells tune down lupus-related inflammation will be highlighted. Lastly, while currently available outcomes of clinical trials evaluating therapeutic agents which manipulate the T cells such as calcineurin inhibitors indicate that they are at least as efficacious and safe as conventional immunosuppressants in treating lupus glomerulonephritis, larger clinical trials are undoubtedly required to validate these as-yet favourable findings.
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MESH Headings
- Animals
- Autoantibodies/biosynthesis
- B-Lymphocytes/immunology
- B-Lymphocytes/pathology
- Calcineurin Inhibitors/therapeutic use
- Cell Communication
- Clinical Trials as Topic
- Gene Expression Regulation
- Humans
- Immunologic Factors/therapeutic use
- Lupus Erythematosus, Systemic/drug therapy
- Lupus Erythematosus, Systemic/genetics
- Lupus Erythematosus, Systemic/immunology
- Lupus Erythematosus, Systemic/pathology
- Mice
- Receptors, Antigen, T-Cell/genetics
- Receptors, Antigen, T-Cell/immunology
- Signal Transduction
- T-Lymphocytes, Helper-Inducer/immunology
- T-Lymphocytes, Helper-Inducer/pathology
- T-Lymphocytes, Regulatory/immunology
- T-Lymphocytes, Regulatory/pathology
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Affiliation(s)
- Anselm Mak
- Division of Rheumatology, Department of Medicine, University Medicine Cluster, 1E Kent Ridge Road, Level 10, NUHS Tower Block, Singapore 119228
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228
| | - Nien Yee Kow
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228
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5
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Abstract
Tyrosine phosphorylation is one of the key covalent modifications that occur in multicellular organisms. Since its discovery more than 30 years ago, tyrosine phosphorylation has come to be understood as a fundamentally important mechanism of signal transduction and regulation in all eukaryotic cells. The tyrosine kinase Lck (lymphocyte-specific protein tyrosine kinase) plays a crucial role in the T-cell response by transducing early activation signals triggered by TCR (T-cell receptor) engagement. These signals result in the phosphorylation of immunoreceptor tyrosine-based activation motifs present within the cytosolic tails of the TCR-associated CD3 subunits that, once phosphorylated, serve as scaffolds for the assembly of a large supramolecular signalling complex responsible for T-cell activation. The existence of membrane nano- or micro-domains or rafts as specialized platforms for protein transport and cell signalling has been proposed. The present review discusses the signals that target Lck to membrane rafts and the importance of these specialized membranes in the transport of Lck to the plasma membrane, the regulation of Lck activity and the phosphorylation of the TCR.
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Llanes-Fernández L, del Carmen Arango-Prado M, Alcocer-González JM, Guerra-Yi ME, Franco-Odio S, Camacho-Rodríguez R, Madrid-Marina V, Tamez-Guerra R, Rodríguez-Padilla C. Association between the expression of IL-10 and T cell activation proteins loss in early breast cancer patients. J Cancer Res Clin Oncol 2008; 135:255-64. [DOI: 10.1007/s00432-008-0446-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2007] [Accepted: 06/26/2008] [Indexed: 11/28/2022]
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Pistol G, Matache C, Calugaru A, Stavaru C, Tanaseanu S, Ionescu R, Dumitrache S, Stefanescu M. Roles of CD147 on T lymphocytes activation and MMP-9 secretion in systemic lupus erythematosus. J Cell Mol Med 2007; 11:339-48. [PMID: 17488482 PMCID: PMC3822832 DOI: 10.1111/j.1582-4934.2007.00022.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The cellular and molecular mechanisms involved in many abnormalities described in Systemic Lupus Erythematosus (SLE) are still unclear. Some of these abnormalities referred to the hyperactivation of T lymphocytes and the enhanced secretion of MMP-9 by peripheral blood mononuclear cells (PBMCs). Therefore, in this paper we investigated the potential role of CD147 molecule in these abnormalities. Our results demonstrated that CD147 molecule is overexpressed on CD3+T lymphocytes from SLE patients when compared with CD3+T lymphocytes from healthy donors. Monoclonal anti-CD147 antibodies, MEM-M6/1 clone, were able to inhibit protein tyrosine phosphorylation only in CD3 x CD28 costimulated T lymphocytes from SLE patients. However, this monoclonal antibody was unable to inhibit the enhanced activity of MMP-9 secreted by SLE PBMCs.
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Affiliation(s)
- Gina Pistol
- Centre for Advanced Studies, Cellular Receptors Laboratory, Cantacuzino National Institute of Research and Development for Microbiology and Immunology, Bucharest, Romania
- *Correspondence to: Dr Maria STEFANESCU Centre for Advanced Studies, Cellular Receptors Laboratory, Cantacuzino National Institute of Research and Development for Microbiology and Immunology, Splaiul Independentei 103, Bucharest 050096, Romania. Tel.: ++40(21)3184410 (252) Fax: ++40(21)3184414 E-mail:
| | - Cristiana Matache
- Centre for Advanced Studies, Cellular Receptors Laboratory, Cantacuzino National Institute of Research and Development for Microbiology and Immunology, Bucharest, Romania
| | - Ana Calugaru
- Centre for Advanced Studies, Cellular Receptors Laboratory, Cantacuzino National Institute of Research and Development for Microbiology and Immunology, Bucharest, Romania
| | - Crina Stavaru
- Centre for Advanced Studies, Cellular Receptors Laboratory, Cantacuzino National Institute of Research and Development for Microbiology and Immunology, Bucharest, Romania
| | | | | | | | - Maria Stefanescu
- Centre for Advanced Studies, Cellular Receptors Laboratory, Cantacuzino National Institute of Research and Development for Microbiology and Immunology, Bucharest, Romania
- *Correspondence to: Dr Maria STEFANESCU Centre for Advanced Studies, Cellular Receptors Laboratory, Cantacuzino National Institute of Research and Development for Microbiology and Immunology, Splaiul Independentei 103, Bucharest 050096, Romania. Tel.: ++40(21)3184410 (252) Fax: ++40(21)3184414 E-mail:
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Nagy G, Perl A. The role of nitric oxide in abnormal T cell signal transduction in systemic lupus erythematosus. Clin Immunol 2006; 118:145-51. [PMID: 16406340 PMCID: PMC3142588 DOI: 10.1016/j.clim.2005.10.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2005] [Accepted: 10/28/2005] [Indexed: 12/17/2022]
Abstract
Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by production of antinuclear autoantibodies and diverse array of clinical manifestations. T cells from patients with SLE have been shown to be activated in vivo and provide help to autoreactive B cells. Lupus T cells exhibit enhanced spontaneous and diminished activation-induced apoptosis and predisposition to necrosis. Persistent mitochondrial hyperpolarization and ATP depletion - associated with significantly increased mitochondrial mass - characterize T lymphocyte dysfunction in SLE. In addition to cell death abnormalities, mitochondrial dysfunction is associated with altered signal transduction through the T cell receptor and Ca2+ fluxing. Exposure of normal T cell to nitric oxide induces mitochondrial hyperpolarization and biogenesis and regenerates the Ca2+ signaling profile of lupus T cells. This article reviews a novel understanding of the role of nitric oxide in signal transduction and cell death abnormalities in SLE.
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Kammer GM. Altered regulation of IL-2 production in systemic lupus erythematosus: an evolving paradigm. J Clin Invest 2005; 115:836-40. [PMID: 15841173 PMCID: PMC1070433 DOI: 10.1172/jci24791] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
In systemic lupus erythematosus (SLE), IL-2 production by T lymphocytes in vitro is impaired. Deficient IL-2 production may be an outcome of a primary SLE T cell disorder that is due to impaired signal transduction. In this issue of the JCI, evidence is presented that an anti-TCR/CD3 complex autoantibody present in SLE sera can bind to T cells and activate the Ca(2+)-calmodulin kinase IV (CaMKIV) signaling cascade, resulting in downregulation of IL-2 transcription and IL-2 production. Because IL-2 may contribute to the maintenance of T cell tolerance, deficient IL-2 production could promote a breach of T cell tolerance that results in autoantibody production in SLE.
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Affiliation(s)
- Gary M Kammer
- Arthritis Associates Inc., Willoughby, Ohio 44094, USA.
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Takeuchi T, Tsuzaka K, Abe T. Altered expression of the T cell receptor-CD3 complex in systemic lupus erythematosus. Int Rev Immunol 2005; 23:273-91. [PMID: 15204089 DOI: 10.1080/08830180490452594] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
SLE T cells may play a key role in autoantibody production in SLE B cells. In addition, accumulating evidence has shown that SLE T cells participate in the attack on target cells or tissues through the overproduction of pro-inflammatory cytokines or an increase in cell-to-cell adhesion. Thus, the functional abnormality of SLE T cells appears to be pivotal to an understanding of SLE pathogenesis. Accumulating evidence suggests that potential defects may reside in the proximal signal transduction around the TCR-CD3 complex. We have demonstrated that the expression of TCR zeta chain is significantly decreased in peripheral blood T cells from SLE patients. To explore the mechanism of defective expression of TCR zeta chain, we examined mRNA of TCR zeta, and found that two alternatively spliced variants such as exon 7 (-) and short 3'-UTR are detected in SLE. We review the possible role of the TCR zeta defects in autoimmunity and discuss how the splicing variants lead to downregulated protein expression of TCR zeta chain.
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MESH Headings
- Arthritis, Rheumatoid/immunology
- Arthritis, Rheumatoid/pathology
- Autoimmunity
- Collagen Diseases/immunology
- Collagen Diseases/metabolism
- Humans
- Lupus Erythematosus, Systemic/immunology
- Membrane Proteins/genetics
- Membrane Proteins/immunology
- Membrane Proteins/metabolism
- Receptor-CD3 Complex, Antigen, T-Cell/chemistry
- Receptor-CD3 Complex, Antigen, T-Cell/immunology
- Receptor-CD3 Complex, Antigen, T-Cell/metabolism
- Receptors, Antigen, T-Cell/genetics
- Receptors, Antigen, T-Cell/immunology
- Receptors, Antigen, T-Cell/metabolism
- Signal Transduction
- T-Lymphocytes/immunology
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Affiliation(s)
- Tsutomu Takeuchi
- Second Department of Internal Medicine, Saitama Medical Center, Saitama Medical School, Kawagoe, Saitama, Japan.
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Kyttaris V, Tsokos G. Uncovering the genetics of systemic lupus erythematosus: implications for therapy. AMERICAN JOURNAL OF PHARMACOGENOMICS : GENOMICS-RELATED RESEARCH IN DRUG DEVELOPMENT AND CLINICAL PRACTICE 2004; 3:193-202. [PMID: 12814327 DOI: 10.2165/00129785-200303030-00005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Although it is well known that genetic factors contribute significantly to the expression of systemic lupus erythematosus (SLE) it was only recently realized, through genome-wide searches, that the number of involved genes is rather large. The published information hints at two facts: first, the number of genomic loci identified in various diverse cohorts is large and not necessarily overlapping; and second, certain loci may be preferentially linked with specific clinical manifestations. The latter may ultimately lead to a better understanding of the nature of the clinical entity that we know as SLE, and identification of groups of patients prone to respond better to treatment or to develop significant adverse effects. Advances attained regarding the nature of the biochemical and molecular defects that underwrite the aberrant function of immune cells parallel the progress made on the genetic origin of the disease. The genetic links need to be connected with aberrant function of their products to validate their significance. It is expected that correction of molecular aberrations either medicinally or by gene therapy will provide the needed specific treatment for patients with SLE.
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Affiliation(s)
- Vasileios Kyttaris
- Division of Rheumatology, Washington Hospital Center, Washington, DC, USA
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12
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Abstract
In the last few years it has become clear that in cells of the immune system, specialized microdomains present in the plasma membrane, called lipid rafts, have been found to play a central role in regulating signalling by immune receptors. Recent studies have looked at whether lipid rafts may be connected to the abnormalities in signalling seen in T lymphocytes isolated from patients with systemic lupus erythematosus (SLE). These early findings show that in SLE T cells, the expression and protein composition of lipid rafts is different when compared with normal T cells. These results also demonstrate changes in the function and localization of critical signalling molecules such as the LCK tyrosine kinase and the CD45 tyrosine phosphatase.
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Affiliation(s)
- E C Jury
- Centre for Rheumatology, Royal Free and University College Medical School, London, UK.
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13
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Jury EC, Kabouridis PS, Abba A, Mageed RA, Isenberg DA. Increased ubiquitination and reduced expression of LCK in T lymphocytes from patients with systemic lupus erythematosus. ARTHRITIS AND RHEUMATISM 2003; 48:1343-54. [PMID: 12746907 DOI: 10.1002/art.10978] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
OBJECTIVE To explore regulation of proximal signaling and composition of lipid rafts in T lymphocytes from patients with systemic lupus erythematosus (SLE). METHODS The expression, phosphorylation, and degradation of lipid raft-associated signaling molecules in T lymphocytes from 50 patients with SLE compared with 28 healthy controls and 22 rheumatoid arthritis patients were investigated. Lipid raft and nonraft fractions from T cells were isolated by ultracentrifugation. Proteins in the lipid raft and nonraft fractions were analyzed by Western blotting and probed for phosphotyrosine activity and for LCK, LAT, and CD3 epsilon. Immunoprecipitation experiments were performed to assess protein ubiquitination in T cell lysates. T cell phenotype and levels of intracellular LCK were determined by flow cytometry. RESULTS LCK, an essential signaling molecule for T cell activation, was significantly reduced in both lipid raft and nonraft fractions of T lymphocytes from patients with active SLE compared with controls, and the reduction was independent of treatment. To identify the likely causes of reduced LCK, we explored the possibility that chronic activation of T lymphocytes underlies LCK degradation. The results revealed an increase in protein ubiquitination, and specifically LCK ubiquitination, in T cells from SLE patients. However, our findings suggest that the increase in ubiquitination is independent of T cell activation. CONCLUSION LCK is reduced in T cell lipid rafts from patients with SLE. This reduction appears to be independent of activation and may be associated with abnormal ubiquitin-mediated regulation mechanisms.
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Affiliation(s)
- Elizabeth C Jury
- Royal Free and University College Medical School, University College, London, UK.
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14
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Kammer GM, Perl A, Richardson BC, Tsokos GC. Abnormal T cell signal transduction in systemic lupus erythematosus. ARTHRITIS AND RHEUMATISM 2002; 46:1139-54. [PMID: 12115215 DOI: 10.1002/art.10192] [Citation(s) in RCA: 117] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Gary M Kammer
- Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157, USA.
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Matache C, Onu A, Stefanescu M, Tanaseanu S, Dragomir C, Dolganiuc A, Szegli G. Dysregulation of p56lck kinase in patients with systemic lupus erythematosus. Autoimmunity 2002; 34:27-38. [PMID: 11681490 DOI: 10.3109/08916930108994123] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
In this study we investigated one of the possible mechanisms of p56lck down-regulation in peripheral blood lymphocytes (PBLs) from Systemic Lupus Erythematosus (SLE) patients and we correlated p56lck dysregulation with accelerated apoptosis in SLE PBLs. PBLs from SLE patients and healthy donors were isolated. p56lck protein expression and lck mRNA level were estimated by immunoblotting and RT-PCR, respectively. FACS analysis was used to evaluate the apoptosis and p56lck levels in apoptotic and non-apoptotic PBLs. A non-radioactive Tyrosine Kinase Assay Kit was used to measure p56lck activity. Our results demonstrated that PBLs from SLE patients displayed lower levels of lck mRNA and p56lck protein as compared to healthy donors. The apoptosis of fresh or cultured PBLs was enhanced in SLE patients, especially in anti-DNA negative group. The expression of p56lck was inverse correlated with apoptosis of fresh and cultured SLE PBLs, especially in anti-DNA negative patients. Double staining FACS analysis showed that p56lck expression was lower in apoptotic than in non-apoptotic PBLs. p56lck specific activity was directly correlated to apoptosis in SLE PBLs. While the low expression of p56lck may be the result of lower degree of synthesis, the increased specific activity could directly correlated to the extent of apoptosis in SLE PBLs. Based on our observations, we assume that the p56lck dysregulation could play a role in SLE pathogenesis.
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Affiliation(s)
- C Matache
- Department of Immunology, Cantacuzino Institute, Bucharest, Romania
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16
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Stefanescu M, Matache C, Onu A, Tanaseanu S, Dragomir C, Constantinescu I, Schönlau F, Rohdewald P, Szegli G. Pycnogenol efficacy in the treatment of systemic lupus erythematosus patients. Phytother Res 2001; 15:698-704. [PMID: 11746863 DOI: 10.1002/ptr.915] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
A pilot study was performed to evaluate the efficacy of Pycnogenol treatment in systemic lupus erythematosus (SLE) patients. Eleven SLE patients were treated with first line medication according to disease activity and in addition, six of them received Pycnogenol and five a placebo. The SLE disease activity index (SLEDAI), serum anti-dsDNA antibodies, fibrinogen, C-reactive protein levels, erythrocyte sedimentation rate, production of reactive oxygen species (ROS) by neutrophils, spontaneous apoptosis and p56(lck) specific activity in peripheral blood lymphocytes were evaluated. Pycnogenol treatment determined a significant reduction of ROS production, apoptosis, p56(lck) specific activity and erythrocyte sedimentation rate. In addition, the decrease of SLEDAI was significant in the Pycnogenol treated group compared with the placebo group (p = 0.018). The results obtained suggest that Pycnogenol could be useful for second line therapy to reduce the inflammatory feature of SLE.
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Affiliation(s)
- M Stefanescu
- Department of Immunology, Cantacuzino Institute, Splaiul Independentei 103, Bucharest, Romania
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17
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Abstract
The immune receptors of lymphocytes are able to sense the nature of bound ligands. Through coupled signaling pathways the generated signals are appropriately delivered to the intracellular machinery, allowing specific functional responses. A central issue in contemporary immunology is how the fate of B lymphocytes is determined at the successive developmental stages and how the B cell receptor distinguishes between signals that induce immune response or tolerance. Experiments with mice expressing transgenes or lacking signal transduction molecules that lead to abnormal lymphocyte development and/or response are providing important clues to the mechanisms that regulate signaling thresholds at different developmental stages. The studies are also revealing novel potential mechanisms of induction of autoimmunity, which may have a bearing on the understanding of human diseases.
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Affiliation(s)
- P Hasler
- Rheumatologische Universitätsklinik Basel, Felix Platter-Spital, CH-4055 Basel, Switzerland
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18
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Nervi S, Atlan-Gepner C, Kahn-Perles B, Lecine P, Vialettes B, Imbert J, Naquet P. Specific deficiency of p56lck expression in T lymphocytes from type 1 diabetic patients. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2000; 165:5874-83. [PMID: 11067948 DOI: 10.4049/jimmunol.165.10.5874] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Peripheral T lymphocyte activation in response to TCR/CD3 stimulation is reduced in type 1 diabetic patients. To explore the basis of this deficiency, a comprehensive analysis of the signal transduction pathway downstream of the TCR/CD3 complex was performed for a cohort of patients (n = 38). The main result of the study shows that T cell hyporesponsiveness is positively correlated with a reduced amount of p56(lck) in resting T lymphocytes. Upon CD3-mediated activation, this defect leads to a hypophosphorylation of the CD3zeta-chain and few other polypeptides without affecting the recruitment of ZAP70. Other downstream effectors of the TCR/CD3 transduction machinery, such as phosphatidylinositol 3-kinase p85alpha, p59(fyn), linker for activation of T cells (LAT), and phospholipase C-gamma1, are not affected. In some patients, the severity of this phenotypic deficit could be linked to low levels of p56(lck) mRNA and resulted in the failure to efficiently induce the expression of the CD69 early activation marker. We propose that a primary deficiency in human type 1 diabetes is a defect in TCR/CD3-mediated T cell activation due to the abnormal expression of the p56(lck) tyrosine kinase.
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Affiliation(s)
- S Nervi
- UPRES-EA2193, Institut Fédiratif de Recherche 35, Physiopathologie Métabolique et Nutritionnelle, Université de la Méditerranée, Centre Hospitalier Universitaire Timone, Marseille, France
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