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Kruglova NA, Kopylov AT, Filatov AV. Identification of the Molecular Partners of Lymphocyte Phosphatase-Associated Phosphoprotein (LPAP) That Are Involved in Human Lymphocyte Activation. Mol Biol 2019. [DOI: 10.1134/s002689331905011x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Kruglova NA, Meshkova TD, Kopylov AT, Mazurov DV, Filatov AV. Constitutive and activation-dependent phosphorylation of lymphocyte phosphatase-associated phosphoprotein (LPAP). PLoS One 2017; 12:e0182468. [PMID: 28827793 PMCID: PMC5565103 DOI: 10.1371/journal.pone.0182468] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2017] [Accepted: 07/19/2017] [Indexed: 12/15/2022] Open
Abstract
Lymphocyte phosphatase-associated phosphoprotein (LPAP) is a small transmembrane protein expressed exclusively in lymphocytes. LPAP is a component of a supramolecular complex composed of the phosphatase CD45, the co-receptor CD4, and the kinase Lck. In contrast to its immunologically important partners, the function of LPAP is unknown. We hypothesized that the biological role of LPAP may be determined by analyzing LPAP phosphorylation. In the present study, we identified LPAP phosphorylation sites by site-directed mutagenesis, phospho-specific antibodies, and protein immunoprecipitation coupled to mass spectrometry analysis. Our results confirmed previous reports that Ser-99, Ser-153, and Ser-163 are phosphorylated, as well as provided evidence for the phosphorylation of Ser-172. Using various SDS-PAGE techniques, we detected and quantified a set of LPAP phosphoforms that were assigned to a combination of particular phosphorylation events. The phosphorylation of LPAP appears to be a tightly regulated process. Our results support the model: following phorbol 12-myristate 13-acetate (PMA) or TCR/CD3 activation of T cells, LPAP is rapidly dephosphorylated at Ser-99 and Ser-172 and slowly phosphorylated at Ser-163. Ser-153 exhibited a high basal level of phosphorylation in both resting and activated cells. Therefore, we suggest that LPAP may function as a co-regulator of T-cell signaling.
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Landskron J, Kraggerud SM, Wik E, Dørum A, Bjørnslett M, Melum E, Helland Ø, Bjørge L, Lothe RA, Salvesen HB, Taskén K. C77G in PTPRC (CD45) is no risk allele for ovarian cancer, but associated with less aggressive disease. PLoS One 2017; 12:e0182030. [PMID: 28759630 PMCID: PMC5536273 DOI: 10.1371/journal.pone.0182030] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Accepted: 07/11/2017] [Indexed: 12/12/2022] Open
Abstract
The pan lymphocyte marker CD45 exists in various isoforms arising from alternative splicing of the exons 4, 5 and 6. While naïve T cells express CD45RA translated from an mRNA containing exon 4, exons 4–6 are spliced out to encode the shorter CD45R0 in antigen-experienced effector/memory T cells. The SNP C77G (rs17612648) is located in exon 4 and blocks the exon’s differential splicing from the pre-mRNA, enforcing expression of CD45RA. Several studies have linked C77G to autoimmune diseases but lack of validation in other cohorts has left its role elusive. An incidental finding in an ovarian cancer patient cohort from West Norway (Bergen region, n = 312), suggested that the frequency of C77G was higher among ovarian cancer patients than in healthy Norwegians (n = 1,357) (3.0% vs. 1.8% allele frequency). However, this finding could not be validated in a larger patient cohort from South-East Norway (Oslo region, n = 1,198) with 1.2% allele frequency. Hence, C77G is not associated with ovarian cancer in the Norwegian population. However, its frequency was increased in patients with FIGO stage II, endometrioid histology or an age at diagnosis of 60 years or older indicating a possible association with a less aggressive cancer type.
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Affiliation(s)
- Johannes Landskron
- Centre for Molecular Medicine Norway, Nordic EMBL Partnership, University of Oslo and Oslo University Hospital, Oslo, Norway
- K.G. Jebsen Centre for Cancer Immunotherapy, University of Oslo, Oslo, Norway
| | - Sigrid M. Kraggerud
- Department of Molecular Oncology, Institute for Cancer Research, Oslo University Hospital, The Norwegian Radium Hospital, Oslo, Norway
- Center for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Oslo, Norway
- K.G. Jebsen Colorectal Cancer Research Centre, Oslo University Hospital, Oslo, Norway
| | - Elisabeth Wik
- Department of Pathology, Haukeland University Hospital, Bergen, Norway
- Centre for Cancer Biomarkers CCBIO, Department of Clinical Medicine, Section for Pathology, University of Bergen, Bergen, Norway
| | - Anne Dørum
- Department of Gynaecologic Oncology, Oslo University Hospital, The Norwegian Radium Hospital, Oslo, Norway
| | - Merete Bjørnslett
- Department of Molecular Oncology, Institute for Cancer Research, Oslo University Hospital, The Norwegian Radium Hospital, Oslo, Norway
- Center for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Oslo, Norway
- K.G. Jebsen Colorectal Cancer Research Centre, Oslo University Hospital, Oslo, Norway
| | - Espen Melum
- Norwegian PSC Research Centre, Department of Transplantation Medicine, Division of Surgery, Inflammatory Medicine and Transplantation, Oslo University Hospital, The National Hospital, Oslo, Norway
- K.G. Jebsen Inflammation Research Centre, University of Oslo, Oslo, Norway
| | - Øystein Helland
- Department of Obstetrics and Gynaecology, Haukeland University Hospital, Bergen, Norway
- Department of Clinical Science, Centre for Cancer Biomarkers, University of Bergen, Bergen, Norway
| | - Line Bjørge
- Department of Obstetrics and Gynaecology, Haukeland University Hospital, Bergen, Norway
- Department of Clinical Science, Centre for Cancer Biomarkers, University of Bergen, Bergen, Norway
| | - Ragnhild A. Lothe
- Department of Molecular Oncology, Institute for Cancer Research, Oslo University Hospital, The Norwegian Radium Hospital, Oslo, Norway
- Center for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Oslo, Norway
- K.G. Jebsen Colorectal Cancer Research Centre, Oslo University Hospital, Oslo, Norway
| | - Helga B. Salvesen
- Department of Obstetrics and Gynaecology, Haukeland University Hospital, Bergen, Norway
- Department of Clinical Science, Centre for Cancer Biomarkers, University of Bergen, Bergen, Norway
| | - Kjetil Taskén
- Centre for Molecular Medicine Norway, Nordic EMBL Partnership, University of Oslo and Oslo University Hospital, Oslo, Norway
- K.G. Jebsen Centre for Cancer Immunotherapy, University of Oslo, Oslo, Norway
- K.G. Jebsen Inflammation Research Centre, University of Oslo, Oslo, Norway
- * E-mail:
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Wang J, Wang T, Xu J, Chen W, Shi W, Cheng J, Liu P, Zhou X. Prognostic significance of X-ray cross-complementing gene 1 expression in gastric cancer. Chin J Cancer Res 2016; 28:355-61. [PMID: 27478321 PMCID: PMC4949281 DOI: 10.21147/j.issn.1000-9604.2016.03.10] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Objective The aim of this study is to identify the prognostic significance of X-ray cross-complementing gene 1 (XRCC1) in patients with gastric cancer undergoing surgery and platinum-based adjuvant chemotherapy.
Methods Immunohistochemistry (IHC) was used to evaluate XRCC1 protein expression profiles on surgical specimens of 612 gastric cancer patients. The relationship between XRCC1 expression and existing prognostic factors, platinum-based adjuvant chemotherapy, disease-free survival (DFS) and overall survival (OS) were analyzed. Results Among 612 patients staged Ⅱ/Ⅲ in our study, 182 (29.74%) were evaluated as XRCC1 IHC positive. XRCC1 expression was not significantly related to OS (P = 0.347) or DFS (P = 0.297). Compared with surgery only, platinum-based adjuvant chemotherapy significantly improved the OS (P = 0.031). And the patients with negative XRCC1 expression benefited more from platinum-based adjuvant chemotherapy (P = 0.049). Multivariate analysis demonstrated that tumor size, T category, N category, vascular or nerve invasion and platinum-based chemotherapy were good prognostic factors for OS (P < 0.05). Though XRCC1 plays an important role in DNA repair pathways, no significant relationship is found in XRCC1 expression and OS among gastric cancer in our study.
Conclusions XRCC1 might be an alternative prognostic marker for the patients of gastric cancer after radical resection. The patients with negative XRCC1 expression can benefit more from platinum-based adjuvant chemotherapy.
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Affiliation(s)
- Jian Wang
- Department of Medical Oncology, the First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, China; Jiangsu Key Lab of Cancer Biomarkers, Prevention & Treatment, Cancer Center, Nanjing Medical University, Nanjing 210029, China
| | - Tongshan Wang
- Department of Medical Oncology, the First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, China; Jiangsu Key Lab of Cancer Biomarkers, Prevention & Treatment, Cancer Center, Nanjing Medical University, Nanjing 210029, China
| | - Jun Xu
- Department of Medical Oncology, the First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, China
| | - WenJiao Chen
- Department of Pathology, the First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, China
| | - Wei Shi
- Department of Medical Oncology, the First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, China
| | - Jianfeng Cheng
- Carolinas Medical Center, University of North Carolina Charlotte Campus, Charlotte, NC 28203, USA
| | - Ping Liu
- Carolinas Medical Center, University of North Carolina Charlotte Campus, Charlotte, NC 28203, USA
| | - Xiqiao Zhou
- Department of Gastroenterology, the First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, China
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Filatov A, Kruglova N, Meshkova T, Mazurov D. Lymphocyte phosphatase-associated phosphoprotein proteoforms analyzed using monoclonal antibodies. Clin Transl Immunology 2015; 4:e44. [PMID: 26682052 PMCID: PMC4673442 DOI: 10.1038/cti.2015.22] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Revised: 09/03/2015] [Accepted: 09/03/2015] [Indexed: 11/09/2022] Open
Abstract
Phosphatase CD45 regulates the activation of lymphocytes by controlling the level of receptor and signal molecule phosphorylation. However, it remains unknown which molecules mediate the phosphatase activity of CD45. A candidate for such a molecule is a small transmembrane adapter protein called lymphocyte phosphatase-associated phosphoprotein (LPAP). LPAP forms a supramolecular complex that consists of not only CD45 molecule but also CD4 and Lck kinase. The function of LPAP has not been defined clearly. In our study, we determined the pattern of LPAP expression in various cell types and characterized its proteoforms using new monoclonal antibodies generated against the intracellular portion of the protein. We show that LPAP is a pan-lymphocyte marker, and its expression in cells correlates with the expression of CD45. The majority of T, B and NK cells express high levels of LPAP, whereas monocytes, granulocytes, monocyte-derived dendritic cells, platelets and red blood cells are negative for LPAP. Using one- and two-dimensional protein gel electrophoresis, we demonstrate that LPAP has at least four sites of phosphorylation. The resting cells express at least six different LPAP phosphoforms representing mono-, di- and tri-phosphorylated LPAP. T and B cells differ in the distribution of the protein between phosphoforms. The activation of lymphocytes with PMA reduces the diversity of phosphorylated forms. Our experiments on Lck-deficient Jurkat cells show that Lck kinase is not involved in LPAP phosphorylation. Thus, LPAP is a dynamically phosphorylated protein, the function of which can be understood, when all phosphosites and kinases involved in its phosphorylation will be identified.
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Affiliation(s)
- Alexander Filatov
- Laboratory of Immunochemistry, Institute of Immunology , Moscow, Russia
| | - Natalia Kruglova
- Faculty of Biology, Lomonosov Moscow State University , Moscow, Russia
| | - Tatiana Meshkova
- Faculty of Biology, Lomonosov Moscow State University , Moscow, Russia
| | - Dmitriy Mazurov
- Laboratory of Immunochemistry, Institute of Immunology , Moscow, Russia
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Kleiman E, Salyakina D, De Heusch M, Hoek KL, Llanes JM, Castro I, Wright JA, Clark ES, Dykxhoorn DM, Capobianco E, Takeda A, Renauld JC, Khan WN. Distinct Transcriptomic Features are Associated with Transitional and Mature B-Cell Populations in the Mouse Spleen. Front Immunol 2015; 6:30. [PMID: 25717326 PMCID: PMC4324157 DOI: 10.3389/fimmu.2015.00030] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Accepted: 01/15/2015] [Indexed: 11/30/2022] Open
Abstract
Splenic transitional B-cells (T1 and T2) are selected to avoid self-reactivity and to safeguard against autoimmunity, then differentiate into mature follicular (FO-I and FO-II) and marginal zone (MZ) subsets. Transcriptomic analysis by RNA-seq of the five B-cell subsets revealed T1 cell signature genes included RAG suggesting a potential for receptor revision. T1 to T2 B-cell differentiation was marked by a switch from Myb to Myc, increased expression of the PI3K adapter DAP10 and MHC class II. FO-II may be an intermediate in FO-I differentiation and may also become MZ B-cells as suggested by principle component analysis. MZ B-cells possessed the most distinct transcriptome including down-regulation of CD45 phosphatase-associated protein (CD45-AP/PTPRC-AP), as well as upregulation of IL-9R and innate molecules TLR3, TLR7, and bactericidal Perforin-2 (MPEG1). Among the endosomal TLRs, stimulation via TLR3 further enhanced Perforin-2 expression exclusively in MZ B-cells. Using gene-deleted and overexpressing transgenic mice we show that IL-9/IL-9R interaction resulted in rapid activation of STAT1, 3, and 5, primarily in MZ B-cells. Importantly, CD45-AP mutant mice had reduced transitional and increased mature MZ and FO B-cells, suggesting that it prevents premature entry of transitional B-cells to the mature B-cell pool or their survival and proliferation. Together, these findings suggest, developmental plasticity among splenic B-cell subsets, potential for receptor revision in peripheral tolerance whereas enhanced metabolism coincides with T2 to mature B-cell differentiation. Further, unique core transcriptional signatures in MZ B-cells may control their innate features.
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Affiliation(s)
- Eden Kleiman
- Department of Microbiology and Immunology, Miller School of Medicine, University of Miami , Miami, FL , USA
| | - Daria Salyakina
- Center for Computational Science, University of Miami , Miami, FL , USA
| | - Magali De Heusch
- Ludwig Institute for Cancer Research, Brussels Branch , Brussels , Belgium ; de Duve Institute, Université Catholique de Louvain , Brussels , Belgium
| | - Kristen L Hoek
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine , Nashville, TN , USA
| | - Joan M Llanes
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine , Nashville, TN , USA
| | - Iris Castro
- Department of Microbiology and Immunology, Miller School of Medicine, University of Miami , Miami, FL , USA
| | - Jacqueline A Wright
- Department of Microbiology and Immunology, Miller School of Medicine, University of Miami , Miami, FL , USA
| | - Emily S Clark
- Department of Microbiology and Immunology, Miller School of Medicine, University of Miami , Miami, FL , USA
| | - Derek M Dykxhoorn
- Hussman Institute for Human Genomics, University of Miami , Miami, FL , USA
| | - Enrico Capobianco
- Center for Computational Science, University of Miami , Miami, FL , USA
| | - Akiko Takeda
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis , St. Louis, MO , USA
| | - Jean-Christophe Renauld
- Ludwig Institute for Cancer Research, Brussels Branch , Brussels , Belgium ; de Duve Institute, Université Catholique de Louvain , Brussels , Belgium
| | - Wasif N Khan
- Department of Microbiology and Immunology, Miller School of Medicine, University of Miami , Miami, FL , USA
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Dulmage BO, Geskin LJ. Lessons learned from gene expression profiling of cutaneous T-cell lymphoma. Br J Dermatol 2014; 169:1188-97. [PMID: 23937674 DOI: 10.1111/bjd.12578] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/01/2013] [Indexed: 12/14/2022]
Abstract
Gene expression studies of cutaneous T-cell lymphoma (CTCL) span a decade, yet the pathogenesis is poorly understood and diagnosis remains a challenge. This review examines the varied approaches to gene expression analysis of CTCL, with emphasis on cell populations, control selection and expression data collection. Despite discordant results, several dysregulated genes have been identified across multiple studies, including PLS3, KIR3DL2, TWIST1 and STAT4. Here, we provide an overview of the most consistently expressed genes across different studies and bring them together through common pathways biologically relevant to CTCL. Four pathways - evasion of activation-induced cell death, T helper 2 lymphocyte differentiation, transforming growth factor-β receptor expression, and tumour necrosis factor receptor ligands - appear to encompass the most frequently affected genes, hypothetically providing insight into the disease pathogenesis.
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Affiliation(s)
- B O Dulmage
- Department of Dermatology, University of Pittsburgh, 200 Lothrop St, Pittsburgh, PA, 15213, U.S.A
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Abstract
Gastric cancer (GC) is an important cause of morbidity and mortality worldwide. In addition to environmental factors, genetic factors also play an important role in GC etiology, as demonstrated by the fact that only a small proportion of individuals exposed to the known environmental risk factors develop GC. Molecular studies have provided evidence that GC arises not only from the combined effects of environmental factors and susceptible genetic variants but also from the accumulation of genetic and epigenetic alterations that play crucial roles in the process of cellular immortalization and tumorigenesis. This review is intended to focus on the recently described basic aspects that play key roles in the process of gastric carcinogenesis. Genetic variation in the genes DNMT3A, PSCA, VEGF, and XRCC1 has been reported to modify the risk of developing gastric carcinoma. Several genes have been newly associated with gastric carcinogenesis, both through oncogenic activation (MYC, SEMA5A, BCL2L12, RBP2 and BUBR1) and tumor suppressor gene inactivation mechanisms (KLF6, RELN, PTCH1A, CLDN11, and SFRP5). At the level of gastric carcinoma treatment, the HER-2 tyrosine kinase receptor has been demonstrated to be a molecular target of therapy.
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Affiliation(s)
- Carlos Resende
- Institute of Molecular Pathology and Immunology of the University of Porto, Rua Dr. Roberto Frias s ⁄ n, Porto, Portugal
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A regulatory polymorphism at position -309 in PTPRCAP is associated with susceptibility to diffuse-type gastric cancer and gene expression. Neoplasia 2010; 11:1340-7. [PMID: 20019842 DOI: 10.1593/neo.91132] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2009] [Revised: 08/25/2009] [Accepted: 09/01/2009] [Indexed: 01/06/2023] Open
Abstract
PTPRCAP (CD45-AP) is a positive regulator of protein tyrosine phosphatase PTPRC (CD45), which activates Src family kinases implicated in tumorigenesis. Single-nucleotide polymorphism (SNP) rs869736 located at position -309 of the PTPRCAP promoter was associated with susceptibility to diffuse-type gastric cancer in the current case-control study. The minor-allele homozygote was significantly associated with a 2.5-fold increased susceptibility to diffuse-type gastric cancer (P = .0021, n = 252), but not to intestinal-type (P = .30, n = 178), versus the major-allele homozygote, when comparing unrelated Korean patients with healthy controls (n = 406). Nine other SNPs were in nearly perfect linkage disequilibrium (r(2) >or= 0.97) with this SNP, exhibiting the same association, and spread out for 26 kb on chromosome 11q13.1 covering RPS6KB2, PTPRCAP, CORO1B, and GPR152. Among the four genes, however, only PTPRCAP expression was affected by haplotypes of the 10 SNPs. Endogenous transcript levels of PTPRCAP were linearly correlated with copy numbers (0, 1, and 2) of the risk-haplotype (P = .0060) in 12 lymphoblastoid cells derived from blood samples, but those of the other three genes were not. Furthermore, the cancer-risk, minor-allele T of rs869736 increased both promoter activity and specific nuclear protein-binding affinity than the nonrisk, major-allele G in luciferase reporter and electrophoretic mobility shift assays, respectively. Accordingly, the minor allele of rs869736 in the PTPRCAP promoter is associated with increased susceptibility to diffuse-type gastric cancer by increasing PTPRCAP expression, possibly leading to activation of the oncogenic Src family kinases.
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10
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Dupéré-Minier G, Desharnais P, Bernier J. Involvement of tyrosine phosphatase CD45 in apoptosis. Apoptosis 2010; 15:1-13. [PMID: 19856105 DOI: 10.1007/s10495-009-0413-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
CD45 is a transmembrane molecule with phosphatase activity expressed in all nucleated haematopoietic cells and plays a major role in immune cells. It is a protein tyrosine phosphatase that is essential for antigen-receptor-mediated signal transduction by regulating Src family members that initiate TCR signaling. CD45 is being attributed a new emerging role as an apoptosis regulator. Cross-linking of the extracellular portion of the CD45 by monoclonal antibodies and by galectin-1, can induce apoptosis in T and B cells. Interestingly, this phosphatase has also been involved in nuclear apoptosis induced by mitochondrial perturbing agents. Furthermore, it is involved in apoptosis induced by HIV-1. CD45 defect is implicated in various diseases such as severe-combined immunodeficiency disease (SCID), acquired immunodeficiency syndrome (AIDS), lymphoma and multiple myelomas. The understanding of the mechanisms by which CD45 regulates apoptosis would be very useful in disease treatment.
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Saunders AE, Johnson P. Modulation of immune cell signalling by the leukocyte common tyrosine phosphatase, CD45. Cell Signal 2010; 22:339-48. [PMID: 19861160 DOI: 10.1016/j.cellsig.2009.10.003] [Citation(s) in RCA: 112] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2009] [Accepted: 10/18/2009] [Indexed: 01/01/2023]
Abstract
CD45 is a leukocyte specific transmembrane glycoprotein and a receptor-like protein tyrosine phosphatase (PTP). CD45 can be expressed as several alternatively spliced isoforms that differ in the extracellular domain. The isoforms are regulated in a cell type and activation state-dependent manner, yet their function has remained elusive. The Src family kinase members Lck and Lyn are key substrates for CD45 in T and B lymphocytes, respectively. CD45 lowers the threshold of antigen receptor signalling, which impacts T and B cell activation and development. CD45 also regulates antigen triggered Fc receptor signalling in mast cells and Toll-like receptor (TLR) signalling in dendritic cells, thus broadening the role of CD45 to other recognition receptors involved in adaptive and innate immunity. In addition, CD45 can affect immune cell adhesion and migration and can modulate cytokine production and signalling. Here we review what is known about the substrate specificity and regulation of CD45 and summarise its effect on immune cell signalling pathways, from its established role in T and B antigen receptor signalling to its emerging role regulating innate immune cell recognition and cytokine production.
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Affiliation(s)
- A E Saunders
- Department of Microbiology and Immunology, Life Sciences Institute, 2350 Health Sciences Mall, University of British Columbia, Vancouver, BC, Canada V6T 1Z3
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12
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Leitenberg D, Falahati R, Lu DD, Takeda A. CD45-associated protein promotes the response of primary CD4 T cells to low-potency T-cell receptor (TCR) stimulation and facilitates CD45 association with CD3/TCR and lck. Immunology 2007; 121:545-54. [PMID: 17428310 PMCID: PMC2265975 DOI: 10.1111/j.1365-2567.2007.02602.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Although it is clear that the CD45 tyrosine phosphatase is required for efficient T-cell activation and T-cell development, the factors that regulate CD45 function remain uncertain. Previous data have indicated that there is an association of CD45 with CD4 and the T-cell receptor (TCR) complex controlled by the variable ectodomain of CD45 and, following activation, by high- and low-potency peptides. This suggests that controlling substrate access to CD45 may be an important regulatory mechanism during T-cell activation. In the present study we have examined the role of the transmembrane adapter-like molecule CD45-associated protein (CD45-AP) in regulating the association of CD45 with CD3/TCR and lck, and in regulating primary CD4(+) T-lymphocyte activation. In CD4(+) T cells from CD45-AP-deficient mice, coimmunoprecipitation of CD45 with the CD3/TCR complex, in addition to lck, is significantly reduced compared with wild-type T cells. Functionally, this correlates with a decreased proliferative response, a decrease in interleukin (IL)-2 production, and a decrease in calcium flux upon stimulation with a low-potency altered peptide ligand. However, the response of CD45-AP-deficient T cells to stimulation with a high-avidity agonist peptide was largely intact, except for a modest decrease in IL-2 production. These data suggest that CD45-AP promotes or stabilizes the association of CD45 with substrates and regulates the threshold of T-cell activation.
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Affiliation(s)
- David Leitenberg
- Department of Microbiology, Immunology and Tropical Medicine, George Washington University Medical Center, Washington, DC 20037, USA.
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13
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Takeda A, Matsuda A, Paul RMJ, Yaseen NR. CD45-associated protein inhibits CD45 dimerization and up-regulates its protein tyrosine phosphatase activity. Blood 2004; 103:3440-7. [PMID: 14715639 DOI: 10.1182/blood-2003-06-2083] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
AbstractCD45, a receptor-like protein tyrosine phosphatase (PTP), plays an essential role in lymphocyte development and immune responses. Recent evidence suggests that dimerization of CD45 down-regulates its function. However, the mechanisms by which CD45 dimerization is regulated remain unclear, and there is no direct evidence that the PTP activity of CD45 dimers is less than that of monomers. CD45 in lymphocytes associates with CD45-AP (CD45-associated protein). Here we show that T cells from CD45-AP-null mice have a much higher level of CD45 dimers than those of wild-type mice, suggesting that CD45-AP inhibits CD45 dimer formation. This was confirmed with the use of a novel CD45-AP-null T-cell line, ALST-1, that we established from a spontaneous thymic tumor found in a CD45-AP-null mouse. Transfected CD45-AP inhibited CD45 dimer formation in ALST-1 cells in proportion to the amount of CD45-AP expressed. Finally, with the use of microsomal fractions from both mouse thymocytes and ALST-1 transfectants, the PTP activity of CD45 was found to be significantly lower in CD45-AP-negative cells than in CD45-AP-positive cells. Therefore, our results support a model in which binding of CD45-AP to inactive CD45 dimers converts them to active monomers. (Blood. 2004;103:3440-3447)
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Affiliation(s)
- Akiko Takeda
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Ward 6-011, 303 E Chicago Ave, Chicago, IL 60611, USA.
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Rachmilewitz J, Borovsky Z, Riely GJ, Miller R, Tykocinski ML. Negative regulation of T cell activation by placental protein 14 is mediated by the tyrosine phosphatase receptor CD45. J Biol Chem 2003; 278:14059-65. [PMID: 12556471 DOI: 10.1074/jbc.m211716200] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
CD45 is the major protein tyrosine phosphatase receptor on T cell surfaces that functions as both a positive and a negative regulator of T cell receptor (TCR) signaling. Although CD45 is required for the activation of TCR-associated Src family kinases, it also dephosphorylates phosphoproteins involved in the TCR-signaling cascade. This study links CD45 to the inhibitory activity of placental protein 14 (PP14), a major soluble protein of pregnancy that is now known to be a direct modulator of T cells and to function by desensitizing TCR signaling. PP14 and CD45 co-capped with each other, pointing to a physical linkage between the two. Interestingly, however, the binding of PP14 to T cell surfaces was not restricted to CD45 alone, with evidence showing that PP14 binds to other surface molecules in a carbohydrate-dependent fashion. Notwithstanding the broader molecular binding potential of PP14, its interaction with CD45 appeared to have special functional significance. Using transfected derivatives of the HPB. ALL mutant T cell line that differ in CD45 expression, we established that the inhibitory effects of PP14 are dependent upon the expression of intact CD45 on T cell surfaces. Based upon these findings, we propose a new immunoregulatory model for PP14, wherein one of its surface molecular targets, CD45, mediates its T cell inhibitory activity, accounting for the intriguing capacity of PP14 to elevate TCR activation thresholds and thereby down-regulate T cell activation.
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Affiliation(s)
- Jacob Rachmilewitz
- Goldyne Savad Institute of Gene Therapy, Hadassah University Hospital, Jerusalem 91120, Israel.
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Qin S, Chock PB. Tyrosine phosphatase CD45 regulates hydrogen peroxide-induced calcium mobilization in B cells. Antioxid Redox Signal 2002; 4:481-90. [PMID: 12215216 DOI: 10.1089/15230860260196281] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
By taking advantage of established CD45-deficient DT40 cells, the roles of CD45 in oxidative stress signaling were investigated. Using p-nitrophenyl phosphate as substrate, it was found that CD45 constituted nearly 40% of the total protein-tyrosine phosphatase activity. Almost 90% of the phosphatase activity was rapidly inactivated upon hydrogen peroxide treatment. Hydrogen peroxide-induced tyrosine phosphorylation of cellular proteins and c-Jun N-terminal kinase activation were markedly enhanced in CD45-deficient cells relative to that in its parental cells. In comparison, hydrogen peroxide-induced inositol 1,4,5-trisphosphate production and Ca(2+) mobilization were impaired in CD45-deficient DT40 cells. However, hydrogen peroxide-induced tyrosine phosphorylation of phospholipase Cgamma2 (PLCgamma2), phosphatidylinositol 3-kinase activity precipitated by anti-phosphotyrosine antibody, and activation of Bruton's tyrosine kinase appeared intact in CD45-deficient DT40 cells. This suggests that CD45 mediates the ability of hydrogen peroxide-activated PLCgamma2 to hydrolyze its substrate via a mechanism independent of both tyrosine phosphorylation of PLCgamma2 and phosphatidylinositol 3-kinase, as well as activation of Bruton's tyrosine kinase. Taken together, our observations demonstrated that, in addition to its negative regulatory or phosphatase activity, CD45 has a positive role in oxidative stress signaling.
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Affiliation(s)
- Suofu Qin
- Laboratory of Biochemistry, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892-8012, USA
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16
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Leitenberg D, Balamuth F, Bottomly K. Changes in the T cell receptor macromolecular signaling complex and membrane microdomains during T cell development and activation. Semin Immunol 2001; 13:129-38. [PMID: 11308296 DOI: 10.1006/smim.2000.0304] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Initiation and propagation of T cell receptor signaling pathways involves the mobilization and aggregation of a variety of signaling intermediates with the T cell receptor and associated molecules into specialized signaling complexes. Accumulating evidence suggests that differential regulation of the formation and composition of the T cell receptor macromolecular signaling complex may affect the different biological consequences of T cell activation. The regulatory mechanisms involved in the assembly of these complexes remains poorly understood, but in part is affected by the avidity of the T cell receptor ligand, co-stimulatory signals, and by the differentiation state of the T cell.
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Affiliation(s)
- D Leitenberg
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT 06520-8011, USA
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Lee W, Lu L, Chiang Y, Jeng L, Wang H, Lia C, Huang C, Chen M, Qian S. Immaturity of donor dendritic cells regulates recipient T-cells toward Th2 deviation. Transplant Proc 2001; 33:230. [PMID: 11266793 DOI: 10.1016/s0041-1345(00)01988-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Affiliation(s)
- W Lee
- Department of General Surgery II, Chang-Gung Memorial Hospital at LinKou, Chang-Gung University, Taipei, Taiwan, People's Republic of China
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18
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Avraham H, Avraham S, Taniguchi Y. Receptor protein tyrosine phosphatases in hematopoietic cells. JOURNAL OF HEMATOTHERAPY & STEM CELL RESEARCH 2000; 9:425-32. [PMID: 10982240 DOI: 10.1089/152581600419080] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
PTPs and PTKs control the level of tyrosine phosphorylation of cellular proteins. Although many substrates for PTKs have been identified, the specific targets of individual PTP family members, along with the consequences of protein dephosphorylation for cellular physiology, remain largely unknown. Fine regulation of tyrosine phosphorylation events is required for the proper progression of hematopoiesis. In this review, we have summarized the characterization of tyrosine phosphatases in hematopoietic cells and delineated their potential role in the process of hematopoiesis and the development of hematopoietic disorders.
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Affiliation(s)
- H Avraham
- Division of Experimental Medicine, Beth Israel Deaconess Medical Center, Harvard Institutes of Medicine, Boston, MA 02115, USA.
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Sharie N, Arpaia E, Roifman CM. CD8 LYMPHOCYTOPENIA CAUSED BY ZAP-70 DEFICIENCY. Radiol Clin North Am 2000. [DOI: 10.1016/s0033-8389(22)00180-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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20
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Sharfe N, Arpaia E, Roifman CM. CD8 LYMPHOCYTOPENIA CAUSED BY ZAP-70 DEFICIENCY. Immunol Allergy Clin North Am 2000. [DOI: 10.1016/s0889-8561(05)70135-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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21
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Anton van der Merwe P, Davis SJ, Shaw AS, Dustin ML. Cytoskeletal polarization and redistribution of cell-surface molecules during T cell antigen recognition. Semin Immunol 2000; 12:5-21. [PMID: 10723794 DOI: 10.1006/smim.2000.0203] [Citation(s) in RCA: 234] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
T cell antigen recognition is accompanied by cytoskeletal polarization towards the APC and large-scale redistribution of cell surface molecules into 'supramolecular activation clusters' (SMACs), forming an organized contact interface termed the 'immunological synapse' (IS). Molecules are arranged in the IS in a micrometer scale bull's eye pattern with a central accumulation of TCR/peptide-MHC (the cSMAC) surrounded by a peripheral ring of adhesion molecules (the pSMAC). We propose that segregation of cell surface molecules on a much smaller scale initiates TCR triggering, which drives the formation of the IS by active transport processes. IS formation may function as a checkpoint for full T cell activation, integrating information on the presence and quality of TCR ligands and the nature and activation state of the APC.
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Kung C, Okumura M, Seavitt JR, Noll ME, White LS, Pingel JT, Thomas ML. CD45-associated protein is not essential for the regulation of antigen receptor-mediated signal transduction. Eur J Immunol 1999; 29:3951-5. [PMID: 10602003 DOI: 10.1002/(sici)1521-4141(199912)29:12<3951::aid-immu3951>3.0.co;2-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
CD45 is a transmembrane protein tyrosine phosphatase required for signaling through the T-and B-cell antigen receptors. In lymphocytes, CD45 interacts with CD45-associated protein (CD45AP), a 32 000 Mr phosphoprotein, through their respective transmembrane domains. To determine whether CD45AP affects the ability of CD45 to regulate antigen receptor signaling, CD45AP-deficient mice were generated. Thymocyte development was grossly normal. Moreover, the cellularity of the thymus and spleens were normal. CD45 expression on thymocytes and splenocytes, ascertained by flow cytometry, was comparable between CD45AP-deficient mice and littermate controls. In contrast to a previous report (Matsuda et al., J. Exp. Med. 1998 187: 1863 - 1870). CD45AP-deficient and normal thymocytes and splenocytes proliferated similarly in response to various mitogens or antigen receptor cross-linking. Furthermore, thymocyte CD45-associated p56(lck) kinase activity was similar between CD45AP-deficient and normal cells. We conclude that CD45AP is not essential for the regulation of Src-family kinase activity by CD45.
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Affiliation(s)
- C Kung
- Howard Hughes Medical Institute, Department of Pathology and Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63110, USA
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