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CD45 in human physiology and clinical medicine. Immunol Lett 2018; 196:22-32. [PMID: 29366662 DOI: 10.1016/j.imlet.2018.01.009] [Citation(s) in RCA: 135] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Revised: 01/18/2018] [Accepted: 01/19/2018] [Indexed: 01/20/2023]
Abstract
CD45 is an evolutionary highly conserved receptor protein tyrosine phosphatase exclusively expressed on all nucleated cells of the hematopoietic system. It is characterized by the expression of several isoforms, specific to a certain cell type and the developmental or activation status of the cell. CD45 is one of the key players in the initiation of T cell receptor signaling by controlling the activation of the Src family protein-tyrosine kinases Lck and Fyn. CD45 deficiency results in T- and B-lymphocyte dysfunction in the form of severe combined immune deficiency. It also plays a significant role in autoimmune diseases and cancer as well as in infectious diseases including fungal infections. The knowledge collected on CD45 biology is rather vast, but it remains unclear whether all findings in rodent immune cells also apply to human CD45. This review focuses on human CD45 expression and function and provides an overview on its ligands and role in human pathology.
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Mukhametshina RT, Ruhs A, Singh I, Hasan D, Contreras A, Mehta A, Nikam VS, Ahlbrecht K, Carraro G, Cabrera-Fuentes HA, Jiang D, Voswinckel R, Seeger W, Bellusci S, Scharffetter-Kochanek K, Bagaeva TV, Preissner KT, Boettger T, Braun T, Krüger M, Barreto G. Quantitative proteome analysis of alveolar type-II cells reveals a connection of integrin receptor subunits beta 2/6 and WNT signaling. J Proteome Res 2013; 12:5598-608. [PMID: 24175614 DOI: 10.1021/pr400573k] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Alveolar type-II cells (ATII cells) are lung progenitor cells responsible for regeneration of alveolar epithelium during homeostatic turnover and in response to injury. Characterization of ATII cells will have a profound impact on our understanding and treatment of lung disease. The identification of novel ATII cell-surface proteins can be used for sorting and enrichment of these cells for further characterization. Here we combined a high-resolution mass spectrometry-based membrane proteomic approach using lungs of the SILAC mice with an Affymetrix microarray-based transcriptome analysis of ATII cells. We identified 16 proteins that are enriched in the membrane fraction of ATII cells and whose genes are highly expressed in these cells. Interestingly, we confirmed our data for two of these genes, integrin beta 2 and 6 (Itgb2 and Itgb6), by qRT-PCR expression analysis and Western blot analysis of protein extracts. Moreover, flow cytometry and immunohistochemistry in adult lung revealed that ITGB2 and ITGB6 are present in subpopulations of surfactant-associated-protein-C-positive cells, suggesting the existence of different types of ATII cells. Furthermore, analysis of the Itgb2(-/-) mice showed that Itgb2 is required for proper WNT signaling regulation in the lung.
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Affiliation(s)
- Regina T Mukhametshina
- LOEWE Research Group Lung Cancer Epigenetic, ‡Division of Biomolecular Mass Spectrometry, §Department of Lung Development and Remodeling, and ∥Department of Cardiac Development and Remodeling, Max-Planck-Institute for Heart and Lung Research, member of the Universities of Giessen and Marburg Lung Center (UGMLC) and German Center of Lung Research (DZL) , Parkstraße 1, 61231 Bad Nauheim, Germany
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3
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Spinozzi F, Agea E, Fiorucci G, Gerli R, Muscat C, Belia S, Bertotto A. Ethanol-induced CD3 and CD2 hyporesponsiveness of peripheral blood T lymphocytes. Immunopharmacol Immunotoxicol 2008; 14:939-53. [PMID: 1363475 DOI: 10.3109/08923979209009243] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The functional relevance of a direct ethanol effect on the membrane structure of T lymphocytes and accessory cells (APC), as well as on signal transduction systems was studied in ten normal subjects. Ethanol incubation (80 mM for 24h) of highly purified T cells increased the number of CD4+/CD45RA+ lymphocytes. In contrast, ethanol exposure induced a drop in CD14+/LFA-3+ APC values. These changes were accompanied by faulty T-cell proliferation in response to anti-CD3 and anti-CD2 mAb and inhibition of CD3- and CD2-mediated rises in intracellular calcium and, to a lesser extent, inositol 1,4,5-triphosphate levels. These data clearly indicate that a membrane-specific ethanol interaction both modifies surface glycoproteic and/or glycolipidic structures and alters transmembrane transduction of the activation signals.
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Affiliation(s)
- F Spinozzi
- Department of Internal Medicine, University of Perugia, Italy
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4
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Jackson MD, Denu JM. Molecular reactions of protein phosphatases--insights from structure and chemistry. Chem Rev 2001; 101:2313-40. [PMID: 11749375 DOI: 10.1021/cr000247e] [Citation(s) in RCA: 168] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- M D Jackson
- Department of Biochemistry and Molecular Biology, Oregon Health Sciences University, 3181 SW Sam Jackson Park Road, Portland, Oregon 97201, USA
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5
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Tsuchida M, Manthei ER, Alam T, Knechtle SJ, Hamawy MM. Regulation of T cell receptor- and CD28-induced tyrosine phosphorylation of the focal adhesion tyrosine kinases Pyk2 and Fak by protein kinase C. A role for protein tyrosine phosphatases. J Biol Chem 2000; 275:1344-50. [PMID: 10625683 DOI: 10.1074/jbc.275.2.1344] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The T cell receptor (TCR)-CD3 complex and the costimulatory molecule CD28 are critical for T cell function. Both receptors utilize protein tyrosine kinases (PTKs) for the phosphorylation of various signaling molecules, a process that is critical for the function of both receptors. The PTKs of the focal adhesion family, Pyk2 and Fak, have been implicated in the signaling of TCR and CD28. We show here evidence for the regulation of TCR- and CD28-induced tyrosine phosphorylation of the focal adhesion PTKs by protein kinase C (PKC). Thus, treating Jurkat T cells with the PKC activator phorbol 12-myristate 13-acetate (PMA) rapidly and strongly reversed receptor-induced tyrosine phosphorylation of the focal adhesion PTKs. In contrast, PMA did not affect TCR-induced tyrosine phosphorylation of CD3zeta or the PTKs Fyn and Zap-70. However, PMA induced a strong and rapid dephosphorylation of the linker molecule for activation of T cells. PMA failed to induce the dephosphorylation of proteins in PKC-depleted cells or in cells pretreated with the PKC inhibitor Ro-31-8220, confirming the role of PKC in mediating the PMA effect on receptor-induced protein tyrosine phosphorylation. The involvement of protein tyrosine phosphatases (PTPases) in mediating the dephosphorylation of the focal adhesion PTKs was confirmed by the failure of PMA to dephosphorylate Pyk2 in cells pretreated with the PTPase inhibitor orthovanadate. These results implicate PKC in the regulation of receptor-induced tyrosine phosphorylation of the focal adhesion PTKs in T cells. The data also suggest a role for PTPases in the PKC action.
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Affiliation(s)
- M Tsuchida
- Department of Surgery, University of Wisconsin, Madison, Wisconsin 53792, USA
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6
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Wang Y, Guo W, Liang L, Esselman WJ. Phosphorylation of CD45 by casein kinase 2. Modulation of activity and mutational analysis. J Biol Chem 1999; 274:7454-61. [PMID: 10066810 DOI: 10.1074/jbc.274.11.7454] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
CD45 is a receptor-type protein-tyrosine phosphatase (PTP) that is required for antigen-specific stimulation and proliferation in lymphocytes. This study was designed to determine the nature of specific kinases in lymphocytes that phosphorylate CD45 and to determine the effect of phosphorylation on CD45 PTP activity. A major cytoplasmic lymphocyte kinase that phosphorylated CD45 was identified as casein kinase 2 (CK2) by use of an in-gel kinase assay in combination with immunoprecipitation, immunodepletion, and specific inhibition. Mutational analysis of CK2 consensus sites showed that the target for CK2 was in an acidic insert of 19 amino acids in the D2 domain, and Ser to Ala mutations at amino acids 965, 968, 969, and 973 abrogated CK2 phosphorylation of CD45. CK2 phosphorylation increased CD45 activity 3-fold toward phosphorylated myelin basic protein, and this increase was reversible by PP2A treatment. Mutation of Ser to Glu at the CK2 sites had the same effect as phosphorylation and also tripled the Vmax of CD45. CD45 isolated in vivo was highly phosphorylated and could not be phosphorylated by CK2 without prior dephosphorylation with phosphatase PP2A. We conclude that CK2 is a major lymphocyte kinase that is responsible for in vivo phosphorylation of CD45, and phosphorylation at specific CK2 sites regulates CD45 PTP activity.
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Affiliation(s)
- Y Wang
- Department of Microbiology, Michigan State University, East Lansing, Michigan 48824-1101, USA
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Affiliation(s)
- L B Justement
- Department of Microbiology, University of Alabama at Birmingham 35294, USA
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Altin JG, Sloan EK. The role of CD45 and CD45-associated molecules in T cell activation. Immunol Cell Biol 1997; 75:430-45. [PMID: 9429890 DOI: 10.1038/icb.1997.68] [Citation(s) in RCA: 135] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
CD45 (lymphocyte common antigen) is a receptor-linked protein tyrosine phosphatase that is expressed on all leucocytes, and which plays a crucial role in the function of these cells. On T cells the extracellular domain of CD45 is expressed in several different isoforms, and the particular isoform(s) expressed depends on the particular subpopulation of cell, their state of maturation, and whether or not they have previously been exposed to antigen. It has been established that the expression of CD45 is essential for the activation of T cells via the TCR, and that different CD45 isoforms display a different ability to support T cell activation. Although the tyrosine phosphatase activity of the intracellular region of CD45 has been shown to be crucial for supporting signal transduction from the TCR, the nature of the ligands for the different isoforms of CD45 have been elusive. Moreover, the precise mechanism by which potential ligands may regulate CD45 function is unclear. Interestingly, in T cells CD45 has been shown to associate with numerous molecules, both membrane associated and intracellular; these include components of the TCR-CD3 complex and CD4/CD8. In addition, CD45 is reported to associate with several intracellular protein tyrosine kinases including p56lck and p59fyn of the src family, and ZAP-70 of the Syk family, and with numerous proteins of 29-34 kDa. These CD45-associated molecules may play an important role in regulating CD45 tyrosine phosphatase activity and function. However, although the role of some of the CD45-associated molecules (e.g. CD45-AP and LPAP) has become better understood in recent years, the role of others still remains obscure. This review aims to summarize recent findings on the role of CD45 and CD45-associated molecules in T cell activation, and to highlight issues that seem relevant to ongoing research in this area.
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Affiliation(s)
- J G Altin
- Division of Biochemistry and Molecular Biology, School of Life Sciences, Faculty of Science, Australian National University, Canberra, Australia.
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9
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Kang S, Liao PC, Gage DA, Esselman WJ. Identification of in vivo phosphorylation sites of CD45 protein-tyrosine phosphatase in 70Z/3.12 cells. J Biol Chem 1997; 272:11588-96. [PMID: 9111075 DOI: 10.1074/jbc.272.17.11588] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Phosphorylation of CD45, a transmembrane protein-tyrosine phosphatase (PTPase), has been proposed to mediate docking of signaling proteins and to modulate PTPase activity. To study the role of phosphorylation in CD45, in vivo phosphorylation sites of CD45 from 70Z/3.12 cells were identified using 32P labeling, trypsin digestion, two-dimensional peptide mapping, high performance liquid chromatography, phosphoamino acid analysis, matrix-assisted laser desorption/ionization mass spectrometry, and specific enzymatic degradation. Eight phosphopeptides, a through h, were isolated and four phosphorylation sites were identified. All four phosphorylation sites were in the membrane-distal PTPase domain (D2) and the C-terminal tail and none were in the membrane-proximal PTPase domain (D1). One site, Ser(P)939 peptide h, was in the D2 domain and, by comparison to the three-dimensional structure of PTP1B, is predicted to lie at the apex of the substrate binding loop. Ser939 was the only in vitro phosphorylation site for protein kinase C among the phosphorylation sites identified. Four of the C-terminal peptides identified (d, e, f, and g) spanned the same sequence and were derived from the same phosphorylation site in the C-terminal tail, Ser1204. Peptide a was derived from the intact C terminus and comprised a mixture of monophosphorylated peptides containing either Ser(P)1248 or Thr(P)1246. Knowledge of the precise phosphorylation sites of CD45 will lead to the design of experiments to define the role of phosphorylation in PTPase activity and in signaling.
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Affiliation(s)
- S Kang
- Department of Microbiology, Michigan State University, East Lansing, Michigan 48824-1101, USA
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Kuo ML, Huang TS, Lin JK. Preferential requirement for protein tyrosine phosphatase activity in the 12-O-tetradecanoylphorbol-13-acetate-induced differentiation of human colon cancer cells. Biochem Pharmacol 1995; 50:1217-22. [PMID: 7488237 DOI: 10.1016/0006-2952(95)00261-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Some lines of colon cancer cells are forced to undergo differentiation by 12-O-tetradecanoylphorbol-13-acetate (TPA). The increases in activities of both protein tyrosine phosphatase (PTP) and protein tyrosine kinase (PTK) have been reported to be associated with the TPA-induced differentiation of HL-60 leukemia cells. In the present study, a 2-fold increase in PTP activity was observed in SW620 human colon cancer cells after 30 min of TPA treatment; a maximal level (4- to 5-fold) was reached at 60 min and continued for more than 6 hr. In addition, two TPA-induced differentiated characteristics, morphological alteration and release of cellular surface proteoglycan, were effectively blocked by PTP inhibitors, such as sodium orthovanadate (50 microM), zinc chloride (100 microM), and iodoacetate (250 microM), but not by the protein serine/threonine phosphatase inhibitor okadaic acid (20 nM). On the other hand, although TPA induced a transient slight increase in PTK activity (1.4-fold) at 60 min, four PTK inhibitors (genistein, herbimycin A, tyrphostin-23 and quercetin) had different effects on the TPA-induced release of cell surface proteoglycan. Genistein (60 microM) potentiated this process, but in contrast, quercetin (45 microM) could partially inhibit the TPA effect. Taken together, these observations suggest that both PTP and PTK activities were increased in SW620 cells in response to TPA; however, the activation of PTP seems to be preferentially required for the TPA-induced differentiation of SW620 human colon cancer cells.
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Affiliation(s)
- M L Kuo
- Institute of Toxicology, College of Medicine, National Taiwan University, Taipei
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Dubois T, Oudinet JP, Russo-Marie F, Rothhut B. In vivo and in vitro phosphorylation of annexin II in T cells: potential regulation by annexin V. Biochem J 1995; 310 ( Pt 1):243-8. [PMID: 7646452 PMCID: PMC1135879 DOI: 10.1042/bj3100243] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
In order to understand how signal transduction occurs during T cell activation, it is necessary to identify the key regulatory molecules whose function is influenced by phosphorylation. Annexins II (A-II) and V (A-V) belong to a large family of Ca(2+)-dependent phospholipid-binding proteins. Among many putative functions, annexins may be involved in signal transduction during cellular proliferation and differentiation. In the present study we show that A-II is phosphorylated in vivo in the Jurkat human T cell line. Indeed, A-II is phosphorylated after stimulation by phorbol myristate acetate and on serine residues after T cell antigen receptor (TcR) stimulation. In cytosol from Jurkat cells, A-II is phosphorylated only by Ca2+/phospholipid-stimulated kinases such as Ca(2+)-dependent protein kinases C (cPKCs). A-V inhibits the phosphorylation of A-II and other substrates of cPKCs and has no effect on kinases activated only by phospholipids. In conclusion, A-II is phosphorylated both in vitro and in vivo in Jurkat cells, and may play a role as a substrate during signal transduction in lymphocytes via the TcR through the PKC pathway. On the other hand, A-V could act as a potent modulator of cPKCs in Jurkat cells.
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Affiliation(s)
- T Dubois
- Laboratoire de Signalisation, Inflammation et Transformation Cellulaire, INSERM U.332, Institut Cochin de Génétique Moléculaire (ICGM), Université René Descartes, Paris, France
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Heimerl P, Stader C, Willmann R, Hofer HW. Phorbol ester-dependent regulation of nuclear protein tyrosine phosphatase in situ. Cell Signal 1995; 7:341-50. [PMID: 8527303 DOI: 10.1016/0898-6568(95)00012-e] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Incubation of splenal lymphocytes with phorbol ester (50 nM PMA) influenced nuclear protein tyrosine phosphatase activity in a time-dependent manner. The activity was elevated after a short incubation (90 s) but was decreased in comparison to untreated cells after 30 and 120 min of incubation. The presence of H7 suppressed the changes. Okadaic acid, an inhibitor of protein phosphatases 2A and 1, led to a similar increase in the activity of nuclear protein tyrosine phosphatase during short-term incubations as phorbol ester but eliminated the subsequent activity decrease. Immunoblots revealed that the same amounts of two forms (49,000 and 60,000 M(r)) of protein tyrosine phosphatases were present in the nuclei from phorbol ester-stimulated and non-stimulated cells. The 60,000 M(r) form co-migrated with a phosphotyrosine-containing protein. The amount of phosphotyrosine was increased in comparison to control cells after 30 min of phorbol ester treatment.
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Affiliation(s)
- P Heimerl
- Faculty of Biology, University of Konstanz, Germany
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13
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Protein-tyrosine phosphatase activity of CD45 is activated by sequential phosphorylation by two kinases. Mol Cell Biol 1994. [PMID: 7518565 DOI: 10.1128/mcb.14.8.5523] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We describe a potential regulatory mechanism for the transmembrane protein-tyrosine phosphatase CD45. Phosphorylation on both tyrosine and serine residues in vitro results in an activation of CD45 specifically toward one artificial substrate but not another. The activation of these kinases appears to be order dependent, as it is enhanced when phosphorylation of tyrosine precedes that of serine but phosphorylation in the reverse order yields no activation. Any of four protein-tyrosine kinases tested, in combination with the protein-serine/threonine kinase, casein kinase II, was capable of mediating this activation in vitro. The time course of phosphorylation of CD45 in response to T-cell activation is consistent with the possibility that this regulatory mechanism is utilized in vivo.
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Stover DR, Walsh KA. Protein-tyrosine phosphatase activity of CD45 is activated by sequential phosphorylation by two kinases. Mol Cell Biol 1994; 14:5523-32. [PMID: 7518565 PMCID: PMC359072 DOI: 10.1128/mcb.14.8.5523-5532.1994] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
We describe a potential regulatory mechanism for the transmembrane protein-tyrosine phosphatase CD45. Phosphorylation on both tyrosine and serine residues in vitro results in an activation of CD45 specifically toward one artificial substrate but not another. The activation of these kinases appears to be order dependent, as it is enhanced when phosphorylation of tyrosine precedes that of serine but phosphorylation in the reverse order yields no activation. Any of four protein-tyrosine kinases tested, in combination with the protein-serine/threonine kinase, casein kinase II, was capable of mediating this activation in vitro. The time course of phosphorylation of CD45 in response to T-cell activation is consistent with the possibility that this regulatory mechanism is utilized in vivo.
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Affiliation(s)
- D R Stover
- Department of Biochemistry, University of Washington, Seattle 98195
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Tyrosine phosphorylation of CD45 phosphotyrosine phosphatase by p50csk kinase creates a binding site for p56lck tyrosine kinase and activates the phosphatase. Mol Cell Biol 1994. [PMID: 7507203 DOI: 10.1128/mcb.14.2.1308] [Citation(s) in RCA: 99] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Src family protein tyrosine kinases (PTKs) play an essential role in antigen receptor-initiated lymphocyte activation. Their activity is largely regulated by a negative regulatory tyrosine which is a substrate for the activating action of the CD45 phosphotyrosine phosphatase (PTPase) or, conversely, the suppressing action of the cytosolic p50csk PTK. Here we report that CD45 was phosphorylated by p50csk on two tyrosine residues, one of them identified as Tyr-1193. This residue was not phosphorylated by T-cell PTKs p56lck and p59fyn. Tyr-1193 was phosphorylated in intact T cells, and phosphorylation increased upon treatment with PTPase inhibitors, indicating that this tyrosine is a target for a constitutively active PTK. Cotransfection of CD45 and csk into COS-1 cells caused tyrosine phosphorylation of CD45 in the intact cells. Tyrosine-phosphorylated CD45 bound p56lck through the SH2 domain of the kinase. Finally, p50csk-mediated phosphorylation of CD45 caused a severalfold increase in its PTPase activity. Our results show that direct tyrosine phosphorylation of CD45 can affect its activity and association with Src family PTKs and that this phosphorylation could be mediated by p50csk. If this is also true in the intact cells, it adds a new dimension to the physiological function of p50csk in T lymphocytes.
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Autero M, Saharinen J, Pessa-Morikawa T, Soula-Rothhut M, Oetken C, Gassmann M, Bergman M, Alitalo K, Burn P, Gahmberg CG. Tyrosine phosphorylation of CD45 phosphotyrosine phosphatase by p50csk kinase creates a binding site for p56lck tyrosine kinase and activates the phosphatase. Mol Cell Biol 1994; 14:1308-21. [PMID: 7507203 PMCID: PMC358486 DOI: 10.1128/mcb.14.2.1308-1321.1994] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Src family protein tyrosine kinases (PTKs) play an essential role in antigen receptor-initiated lymphocyte activation. Their activity is largely regulated by a negative regulatory tyrosine which is a substrate for the activating action of the CD45 phosphotyrosine phosphatase (PTPase) or, conversely, the suppressing action of the cytosolic p50csk PTK. Here we report that CD45 was phosphorylated by p50csk on two tyrosine residues, one of them identified as Tyr-1193. This residue was not phosphorylated by T-cell PTKs p56lck and p59fyn. Tyr-1193 was phosphorylated in intact T cells, and phosphorylation increased upon treatment with PTPase inhibitors, indicating that this tyrosine is a target for a constitutively active PTK. Cotransfection of CD45 and csk into COS-1 cells caused tyrosine phosphorylation of CD45 in the intact cells. Tyrosine-phosphorylated CD45 bound p56lck through the SH2 domain of the kinase. Finally, p50csk-mediated phosphorylation of CD45 caused a severalfold increase in its PTPase activity. Our results show that direct tyrosine phosphorylation of CD45 can affect its activity and association with Src family PTKs and that this phosphorylation could be mediated by p50csk. If this is also true in the intact cells, it adds a new dimension to the physiological function of p50csk in T lymphocytes.
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Affiliation(s)
- M Autero
- Department of Biochemistry, University of Helsinki, Finland
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Zor U, Ferber E, Gergely P, Szücs K, Dombrádi V, Goldman R. Reactive oxygen species mediate phorbol ester-regulated tyrosine phosphorylation and phospholipase A2 activation: potentiation by vanadate. Biochem J 1993; 295 ( Pt 3):879-88. [PMID: 7694572 PMCID: PMC1134643 DOI: 10.1042/bj2950879] [Citation(s) in RCA: 101] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
We have previously shown that vanadate potentiates the activating effect of phorbol ester (TPA) on cellular phospholipase A2 (PLA2) in a pathway dependent on the formation of reactive oxygen species (ROS). Here we evaluate the chain of enzymes (protein kinases and phosphatases) that participate in this process. Treatment of macrophages with vanadate plus TPA led to activation of protein kinase C (PKC) and NADPH oxidase (O2- generation in intact cells), massive cellular protein tyrosine phosphorylation, suppression of protein tyrosine phosphatase (PTP) activity and a sustained activation of protein tyrosine kinase (PTK) and myelin basic protein kinase activity (the latter three enzyme activities were assessed in cell lysates). Inhibition of ROS formation by diphenyleneiodonium (DPI) prevented PTP inhibition, PTK activation and protein tyrosine phosphorylation by vanadate plus TPA. Vanadate plus H2O2 mimicked the effect of vanadate plus TPA on PKC activation, cellular protein tyrosine phosphorylation, PTP and PTK, but their effects were resistant to DPI. Suppression of PKC activity (down-regulation; selective inhibitors) prevented the above-mentioned effects of vanadate plus TPA, but not of vanadate plus H2O2. Collectively, the results show that ROS formation induced by TPA in association with vanadate is essential in the modulation of protein tyrosine phosphorylation and PLA2 activity.
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Affiliation(s)
- U Zor
- Department of Hormone Research, Weizmann Institute of Science, Rehovot, Israel
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Spinozzi F, Agea E, Bassotti G, Belia S, Rondoni F, Broccucci L, Solinas A, Gerli R, Bertotto A. Ethanol-specific impairment of T-lymphocyte activation is caused by a transitory block in signal-transduction pathways. Gastroenterology 1993; 105:1490-501. [PMID: 8224653 DOI: 10.1016/0016-5085(93)90156-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
BACKGROUND Immune system derangement is characteristic of alcoholic liver cirrhosis. However, in vitro studies have never clarified the alcohol-induced T-lymphocyte dysfunction. The aim of this study was to examine any discrete phenotypical and functional abnormalities and possible impairment in transmembrane signal-transduction pathways that, if present on lymphocytes of patients with alcoholic cirrhosis, would also be reproducible after in vitro ethanol exposure of normal T cells. METHODS Lymphocytes from 25 patients were analyzed for their in vitro proliferative functions, intracellular Ca2+ fluxes, and inositol 1,4,5-triphosphate (IP3) generation. The same procedures were applied to normal T cells exposed in vitro to ethanol. RESULTS Lymphocytes failed to respond to anti-CD3 and anti-CD2 after in vitro stimulation, with decreased intracellular Ca2+ mobilization and IP3 generation but showed normal proliferative response to phytohemagglutinin. In vitro ethanol incubation of normal T lymphocytes resulted in rearrangement of the membrane CD45 antigen, favoring the expression of high-molecular-weight isoforms, and showed a poor blastogenic response to anti-CD3 and anti-CD2 with a decrease in intracellular Ca2+ mobilization and IP3 production. After a 6-month period of ethanol withdrawal, some patients had normalization of phenotypic and functional alterations. CONCLUSIONS The T-lymphocyte response to specific polyclonal activators may be severely impaired in alcohol abusers. However, it seems reversible after a period of controlled ethanol withdrawal.
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Affiliation(s)
- F Spinozzi
- Department of Internal Medicine, School of Medicine, University of Perugia, Italy
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19
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Tyrosine phosphatase activity of lymphoma CD45 (GP180) is regulated by a direct interaction with the cytoskeleton. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(19)36645-1] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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20
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Brautigan DL. Great expectations: protein tyrosine phosphatases in cell regulation. BIOCHIMICA ET BIOPHYSICA ACTA 1992; 1114:63-77. [PMID: 1390871 DOI: 10.1016/0304-419x(92)90007-l] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- D L Brautigan
- Brown University, J.W. Wilson Laboratory, Providence, RI 02912
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21
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Yamada A, Kaneyuki T, Hara A, Rothstein DM, Yokoyama MM. CD45 isoform expression on human neonatal T cells: expression and turnover of CD45 isoforms on neonatal versus adult T cells after activation. Cell Immunol 1992; 142:114-24. [PMID: 1534035 DOI: 10.1016/0008-8749(92)90273-r] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Neonatal T cells are phenotypically similar to "naive" T cells from adult donors in the CD45 isoform expression. Despite the phenotypic similarity, large differences were found between neonatal and adult T cells when T cells were activated. After activation with PHA, adult CD45RA+ T cells began to express CD45RO and no loss of CD45RA expression had yet occurred at Day 3 post-stimulation. Three days after activation, CD45RA+ neonatal T cells also coexpressed CD45RO; however, in contrast to adult T cells, a marked loss of CD45RA was observed. We analyzed the rapid loss of CD45RA found in neonatal T cells. The de novo synthesis of CD45 isoforms in neonatal T cells was essentially the same as that in the adult T cells. Turnover of the CD45RA was very rapid in both resting adult and neonatal T cells. After activation with PHA, the turnover of CD45RA on adult T cells was decreased significantly, while the turnover of CD45RA on neonatal T cells was not changed after activation. Therefore, the regulation of CD45 isoform expression not only involves switches in alternative splicing, but also involves different regulation of turnover of these isoforms from the cell membrane.
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Affiliation(s)
- A Yamada
- Department of Immunology, Kurume University School of Medicine, Japan
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22
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Lozano F, Alberola-Ila J, Places L, Vives J. Effect of protein kinase C activators on the phosphorylation and the surface expression of the CDw50 leukocyte antigen. EUROPEAN JOURNAL OF BIOCHEMISTRY 1992; 203:321-6. [PMID: 1730238 DOI: 10.1111/j.1432-1033.1992.tb19862.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The CDw50 antigen is a constitutively non-phosphorylated leukocyte surface molecule which becomes highly phosphorylated in all the normal and lymphoblastoid cells analyzed (peripheral blood mononuclear cells, Molt 4, CEM, 8402, Namalwa), after stimulation with tumor promoter agents (phorbol 12-myristate 13-acetate, phorbol 12,13-dibutyrate, mezerein). This phosphorylation is rapid (within 1-5 min), dose-dependent and results in the incorporation of PO(3-)4 groups on serine residues. Furthermore, the level of CDw50 phosphorylation induced by tumor promoter agents is decreased by the protein kinase C inhibitors staurosporine and 1-(5-isoquinolinylsulfonyl)-2-methylpiperazine. Activation of peripheral lymphocytes with concanavalin A, phytohemagglutinin and cross-linking of CD3 molecules also induces CDw50 phosphorylation, but the response is delayed and less intense than when tumor promoting agents are used. Treatment with any of the aforementioned agents is not accompanied by quantitative changes in the CDw50 surface expression. We therefore conclude that protein-kinase-C-mediated mechanisms are involved in phosphorylation, but not in regulation of the surface expression of the CDw50 leukocyte antigen.
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Affiliation(s)
- F Lozano
- Servei d'Immunología, Hospital Clínic i Provincial de Barcelona, Spain
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23
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Trowbridge IS, Ostergaard HL, Johnson P. CD45: a leukocyte-specific member of the protein tyrosine phosphatase family. BIOCHIMICA ET BIOPHYSICA ACTA 1991; 1095:46-56. [PMID: 1834176 DOI: 10.1016/0167-4889(91)90043-w] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- I S Trowbridge
- Department of Cancer Biology, Salk Institute, San Diego, CA 92186-5800
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24
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Schraven B, Kirchgessner H, Gaber B, Samstag Y, Meuer S. A functional complex is formed in human T lymphocytes between the protein tyrosine phosphatase CD45, the protein tyrosine kinase p56lck and pp32, a possible common substrate. Eur J Immunol 1991; 21:2469-77. [PMID: 1655467 DOI: 10.1002/eji.1830211025] [Citation(s) in RCA: 87] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
In vitro protein kinase assays of CD45 immunoprecipitates prepared from digitonin lysates of resting human T lymphocytes resulted in exclusive tyrosine phosphorylation of a 32-kDa protein (pp32). Reprecipitation of the in vitro phosphorylated proteins and Western blot analysis of whole CD45 immunoprecipitates employing antisera specifically directed at different protein tyrosine kinases demonstrated that the p56lck protein tyrosine kinase was responsible for in vitro phosphorylation of pp32. Since in vitro kinase assays of p56lck immunoprecipitates also resulted in phosphorylation of pp32, the present data strongly suggest that a functional complex is formed between CD45, p56lck and pp32. Such a notion is supported by the findings that phosphorylation of pp32 by p56lck correlated with expression of the CD45 molecules and that in vitro phosphorylated pp32 was completely dephosphorylated by purified CD45.
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Affiliation(s)
- B Schraven
- Abteilung Angewandte Immunologie, Deutsches Krebsforschungszentrum, Heidelberg, FRG
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25
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Ostergaard HL, Trowbridge IS. Negative regulation of CD45 protein tyrosine phosphatase activity by ionomycin in T cells. Science 1991; 253:1423-5. [PMID: 1654595 DOI: 10.1126/science.1654595] [Citation(s) in RCA: 81] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
CD45 is a leukocyte-specific, transmembrane protein tyrosine phosphatase (PTPase) required for T cell responsiveness. How the activity of PTPases is regulated in vivo is unclear. Treatment of murine thymocytes and a variety of murine T cell lines with the calcium ionophore ionomycin decreased CD45 PTPase activity. Ionomycin treatment also led to a decreased phosphorylation of serine residues in CD45. These results indicate that increased intracellular calcium modulates CD45 PTPase activity, demonstrating regulation of CD45 PTPase activity in vivo, and also implicate serine dephosphorylation as a possible mechanism.
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Affiliation(s)
- H L Ostergaard
- Department of Cancer Biology, Salk Institute, San Diego, CA 92186
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26
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Ingles-Esteve J, Lozano F, Plana M, Alberola-Ila J, Places L, Vives J. The protein kinase C-independent human B cell proliferation induced via surface immunoglobulins is unaffected by CD45 monoclonal antibodies. Immunobiology 1991; 182:152-60. [PMID: 1832138 DOI: 10.1016/s0171-2985(11)80199-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
In the present study the effect of 72-5D3 monoclonal antibody (CD45) on the proliferation induced by cross-linking of surface immunoglobulins on untreated and 4 beta-phorbol 12-myristate 13-acetate-treated human dense B cells was studied. The 72-5D3 mAb inhibited the proliferation induced via surface immunoglobulins alone or plus soluble T cell factors without affecting the release of inositol phosphate metabolites. However, after prolonged incubation (24 h) with high doses (100 ng/ml) of 4 beta-phorbol 12-myristate 13-acetate or mezerein, but not with 4 beta-phorbol, the same inhibitory effect did not take place. Therefore, our data support the hypothesis that protein kinase C is necessary for the antiproliferative effect of the 72-5D3 monoclonal antibodies.
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Affiliation(s)
- J Ingles-Esteve
- Servei d'Immunologia, Hospital Clínic i Provincial, Villarroel, Barcelona, Spain
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27
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Caldwell CW, Marty LM, Feldbush TL. Expression of the low Mr isoform of CD45 (CD45RO) in B-cell non-Hodgkin's lymphomas. CLINICAL IMMUNOLOGY AND IMMUNOPATHOLOGY 1991; 58:377-84. [PMID: 1825807 DOI: 10.1016/0090-1229(91)90128-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The CD45 antigen family consists of multiple molecular isoforms ranging from 180 to 220 relative molecular mass (Mr). The highest Mr isoforms are recognized by monoclonal antibodies (MoAbs) designated CD45RA, while those recognizing the low Mr isoform are designated CD45RO. About half of the T-cells in peripheral blood express CD45RA while the remainder express CD45RO. A switch from the high to the low Mr isoform of CD45 has been found in association with the process of T-cell stimulation and acquisition of "memory." B-cells normally express CD45RA, but not CD45RO. However, under stimulatory conditions, B-cells may be capable of undergoing an isoform switch and expressing CD45RO. The expression of this low Mr isoform of CD45 was investigated in lymphomas composed of monoclonal B-cells to determine if such a switch occurs in malignant B-cell populations. The vast majority (110/117 cases) of B-cell lymphomas expressed only CD45RA, while a very small number (7/117 cases) expressed CD45RO, but not CD45RA. There was no relationship between the CD45RO expression and the histologic subtype. The physiological significance of this unusual expression of CD45RO in a subpopulation of B-cell lymphomas is not clear. In that CD45RO, as defined by the MoAb UCHL 1, is typically used as a marker of T-cells in tissue sections, caution must be exercised in interpretation, since not all T-cells are reactive and some B-cell lymphomas are reactive.
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MESH Headings
- Antigens, Differentiation/biosynthesis
- Flow Cytometry
- Histocompatibility Antigens/biosynthesis
- Humans
- Immunophenotyping
- Isoantigens
- Leukemia, Lymphocytic, Chronic, B-Cell/immunology
- Leukocyte Common Antigens
- Lymph Nodes/cytology
- Lymph Nodes/metabolism
- Lymphoma, B-Cell/immunology
- Lymphoma, B-Cell/metabolism
- Lymphoma, Follicular/immunology
- Lymphoma, Large B-Cell, Diffuse/immunology
- Lymphoma, Large-Cell, Immunoblastic/immunology
- Lymphoma, Non-Hodgkin/immunology
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Affiliation(s)
- C W Caldwell
- Department of Pathology, University of Missouri School of Medicine, Columbia 65212
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28
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Caldwell CW. Expression of CD45 isoforms in lymph node reactive hyperplasia. CLINICAL IMMUNOLOGY AND IMMUNOPATHOLOGY 1990; 57:411-9. [PMID: 2147134 DOI: 10.1016/0090-1229(90)90115-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The CD45 antigen family consists of multiple molecular isoforms ranging from 180 to 220 kDa. The highest Mr isoforms are recognized by monoclonal antibodies (MoAbs) designated CD45RA, while those recognizing the low Mr isoforms are designated CD45RO. T cells expressing CD45RA are "naive" or unprimed, while those expressing CD45RO have "memory." Further, stimulation of CD45RA+ T cells induces an isoform switch to the CD45RA-/CD45RO+ phenotype. The present study examined this in vitro process by determining the in vivo CD45 isoform expression of T cells from human hyperplastic lymph nodes. Hyperplastic, as opposed to nonhyperplastic, lymph nodes exhibited the expected CD45 isoform switch from CD45RA+ to CD45RO+ T cells that has been described in vitro. The percentage of CD45RO+ T cells did not correlate with other parameters of lymphoid activation. Thus, CD45RO expression probably represents a marker of differentiation and acquisition of "memory" or late cellular activation.
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Affiliation(s)
- C W Caldwell
- Department of Pathology, University of Missouri School of Medicine, Columbia 65212
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29
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Yamada A, Streuli M, Saito H, Rothstein DM, Schlossman SF, Morimoto C. Effect of activation of protein kinase C on CD45 isoform expression and CD45 protein tyrosine phosphatase activity in T cells. Eur J Immunol 1990; 20:1655-60. [PMID: 2170146 DOI: 10.1002/eji.1830200806] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The T200/leukocyte common antigen (CD45) is a family of at least five large-molecular weight glycoproteins, which are differentially expressed on T cell subsets. The CD45 antigen consists of a variable heavily glycosylated exterior domain, a single membrane-spanning region, and a large cytoplasmic domain that has protein tyrosine phosphatase (PTPase) activity. In this study, we examined the effects of activation of protein kinase C (PKC) on the phosphorylation and expression of CD45 isoforms and PTPase activity in human T cells. After activation of PKC by phorbol 12-myristate 13-acetate (PMA), CD45RA expression rapidly increased within the first 24 h, whereas CD45R0 expression did not change within this time. However by 48 h, expression of CD45R0 also began to increase. Metabolic labeling showed that the rapid increment in CD45RA expression observed after PMA stimulation is primarily due to increased de novo synthesis of the 205-kDa and not the 220-kDa molecule. PMA treatment resulted in the phosphorylation of each CD45 isoform to a degree corresponding to its relative surface expression. Significantly, we found that the phosphorylation of CD45 by PKC activation down-regulated CD45 PTPase activity.
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Affiliation(s)
- A Yamada
- Division of Tumor Immunology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115
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30
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Tonks NK, Diltz CD, Fischer EH. CD45, an integral membrane protein tyrosine phosphatase. Characterization of enzyme activity. J Biol Chem 1990. [DOI: 10.1016/s0021-9258(18)86999-x] [Citation(s) in RCA: 89] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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31
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Biosynthesis of truncated O-glycans in the T cell line Jurkat. Localization of O-glycan initiation. J Biol Chem 1990. [DOI: 10.1016/s0021-9258(19)38842-8] [Citation(s) in RCA: 91] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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32
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Abstract
Understanding the intracellular mechanisms by which binding of ligands, such as hormones and growth factors, to their specific receptors elicits the appropriate cellular response has long been a topic of great interest. Considerable excitement was generated when it was recognised that several receptor-ligand interactions operate via the hydrolysis of inositol phospholipids. This yields, at least, two 'second messengers', namely, inositol 1,4,5-trisphosphate [Ins(1,4,5)P3], which causes the release of Ca2+ from intracellular stores, and 1,2-diacylglycerol (ac2Gro), which activates the serine/threonine-specific enzyme, protein kinase C(PKC), reviewed in [1] and [2]. The pertinent question that follows is, how do PKC activation and elevation of the intracellular Ca2+ concentration evoke cell responses? In this review, attention has been focused on PKC, and the consequences of its activation in resting human T cells. Evidence that PKC activity is, at least partially, responsible for activation of resting human T cells will be examined, and some of the more recent research investigating how PKC activation elicits this cell response will be described.
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Affiliation(s)
- N Berry
- Department of Biochemistry, Kobe University School of Medicine, Japan
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33
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Affiliation(s)
- A Altman
- Department of Immunology, Scripps Clinic and Research Foundation, La Jolla, California 92037
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34
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Abstract
The protein tyrosine phosphatases comprise a family of enzymes that specifically dephosphorylate tyrosyl residues. Determination of the amino acid sequence of a major low molecular mass form isolated from human placenta (PTPase 1B) provided the basis for the first identification of transmembrane proteins that bear intracellular phosphatase domains. The existence of such molecules, bearing the hallmarks of receptors, raises the exciting possibility of a novel mechanism of signal transduction in which the early events involve the ligand-induced dephosphorylation of tyrosyl residues in proteins.
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35
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Phosphorylation of the major leukocyte surface sialoglycoprotein, leukosialin, is increased by phorbol 12-myristate 13-acetate. J Biol Chem 1989. [DOI: 10.1016/s0021-9258(18)51541-6] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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36
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Axelsson B, Perlmann P. Persistent superphosphorylation of leukosialin (CD43) in activated T cells and in tumour cell lines. Scand J Immunol 1989; 30:539-47. [PMID: 2531463 DOI: 10.1111/j.1365-3083.1989.tb02461.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
CD43 (leukosialin) is a highly sialylated, single-chain molecule expressed on most human leucocytes. Regulatory signals appear to be transduced through the molecule as suggested by the ability of anti-CD43 antibodies to induce aggregation and proliferation of T cells and to enhance B-cell proliferation and natural killer cell activity. Activation of protein kinases is an essential event in signal transduction. We were therefore interested to study whether CD43 may function as a substrate for protein kinases during mitogenic activation of lymphocytes. We show that CD43 was rapidly superphosphorylated (within minutes) on serine residues following addition of phorbol ester (PMA) to peripheral blood lymphocytes. PMA treatment of the cells was not followed by rapid down-regulation of CD43. Activation of the lymphocytes by concanavalin A or anti-CD3 antibodies (OKT-3) also resulted in superphosphorylation of CD43. However, the phosphorylation was delayed as compared to that induced by PMA and was detected 3-4 h after the addition of the reagents. A plateau was reached after 24-48 h of stimulation. Interestingly, the high level of phosphorylation of CD43 was maintained in long-term cultures of T cells activated by various means. Furthermore, CD43 was found to be constitutively superphosphorylated (on serine and tyrosine) in continuously growing cell lines of T, B, and non-lymphoid origin. Taken together, the results suggest that CD43 has an important role during both early and late phases of T-cell activation and that modulation of its biochemical properties by protein kinases may be associated with progression through the cell cycle and with cellular growth.
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Affiliation(s)
- B Axelsson
- Department of Immunology, University of Stockholm, Sweden
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37
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Taffs RE, Ewald SJ. Concanavalin A induces a cytoskeletal association of T200 molecules in T lymphocytes. Mol Immunol 1989; 26:925-37. [PMID: 2531840 DOI: 10.1016/0161-5890(89)90111-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
A recent report indicated that T200 molecules interact with elements of the cytoskeleton in BW5147 T lymphoma cells. We have confirmed the cytoskeletal association of T200 by examining nonionic detergent-soluble and detergent-insoluble fractions of murine T cell tumor cell lines, cloned cytotoxic T lymphocyte lines, and thymocytes. Concanavalin A (Con A)-treated and untreated cells were extracted with 0.5% Triton X-100 and the remaining insoluble material was extracted under conditions allowing actin depolymerization. In the absence of Con A treatment, little T200 could be recovered from the depolymerized insoluble fraction. However, in T cells treated with capping concentrations of Con A, a considerable amount of T200 was rendered insoluble in nonionic detergent, and T200 could be recovered from the insoluble fraction by a buffer which dissociates actin polymers. A lesser, but still significant, amount of T200 associated with the detergent-insoluble fraction of thymocytes treated with concentrations of Con A and succinyl Con A, which are mitogenic for T cells. We also found that in T cells treated with mitogenic concentrations of succinyl Con A, more T200 associated with cytoskeleton than did H-2 or LFA-1 molecules. Because T200 is such a predominant molecule on the surface of T cells, such translocations of the molecule may have a major impact on the physiology of the cell, especially if T200 functions as a protein tyrosine phosphatase as recent evidence by others suggests.
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Affiliation(s)
- R E Taffs
- Department of Microbiology, Montana State University, Bozeman 59717
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38
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Yamashita Y, Imai Y, Osawa T. Poly[N-acetyl-lactosamine]-type sugar chains in CD45 antigens of abnormal T cells of lpr mice are different from those of normal T cells and B cells. Mol Immunol 1989; 26:905-13. [PMID: 2532304 DOI: 10.1016/0161-5890(89)90147-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The lymph node (LN) T cells from autoimmune MRL/MpJ-lpr/lpr (lpr) mice and control MRL/MpJ-+/+ (+/+) mice were compared as to their cell surface lectin binding sites and the glycoproteins responsible for the lectin binding. T cells from enlarged lymph nodes of lpr mice were found to express more binding sites for lectins which are reactive to poly[N-acetyl-lactosamine]-type sugar chains than normal +/+ mouse lymph node T cells. Furthermore, we found that high mol. wt (180,000-220,000) glycoproteins on lpr T cells were strongly stained with these poly [N-acetyl-lactosamine]-binding lectins on Western-blotting. These glycoproteins were found to belong to the CD45 family on immunoprecipitation and absorption with monoclonal anti-CD45 antibody. Thus, aberrant expression of high mol. wt CD45 (CD45R) antigens on lpr T cells may contribute greatly to the strong reaction of these cells with poly[N-acetyl-lactosamine]-binding lectins. We also found that poly[N-acetyl-lactosamine]-type sugar chains are more abundant on B cells than on lpr T cells, and that the molecular weights and the carbohydrate moieties of CD45R antigens on lpr T cells are different from those of CD45R antigens on +/+ spleen B cells.
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Affiliation(s)
- Y Yamashita
- Division of Chemical Toxicology and Immunochemistry, Faculty of Pharmaceutical Sciences, University of Tokyo, Japan
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39
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Clark EA, Ledbetter JA. Leukocyte cell surface enzymology: CD45 (LCA, T200) is a protein tyrosine phosphatase. IMMUNOLOGY TODAY 1989; 10:225-8. [PMID: 2553046 DOI: 10.1016/0167-5699(89)90257-0] [Citation(s) in RCA: 85] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
During 1987, striking advances were made in defining the receptors and ligands for cell-to-cell adhesion interactions involving leukocytes. In 1988, two major leukocyte differentiation antigens, CD10 (cALLA) and CD45 (LCA, T200), were shown to be enzymes while two other markers, CD4 and CD8, were found to be associated with an enzyme. In this article, Ed Clark and Jeff Ledbetter discuss recent findings in the emerging area of leukocyte cell surface enzymology with emphasis on CD45, a membrane-associated protein tyrosine phosphatase (PTPase)2,3.
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40
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Pilarski LM, Deans JP. Selective expression of CD45 isoforms and of maturation antigens during human thymocyte differentiation: observations and hypothesis. Immunol Lett 1989; 21:187-98. [PMID: 2527812 DOI: 10.1016/0165-2478(89)90103-x] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Selective expression of high and low molecular weight isoforms of CD45 (T200) occurs coincident with activation of mature T lymphocytes. Expression of CD45 p180 and CDw29 defines antigen-experienced memory T cells in the periphery, and expression of CD45R (CD45 p205/220) defines naive T cells. Upon activation, CD45R+ T cells lose CD45R and acquire CD45 p180 and high density CDw29. In this review we discuss the expression of CD45 isoforms, CDw29, pgp-1 and CD1 on human thymocytes and develop the hypothesis that expression of CD45R marks the generative thymic lineage while expression of CD45 p180 marks those cells destined for intrathymic death. This hypothesis is supported by evidence from phenotypic, molecular and functional analysis of thymocyte subsets. We propose that expression of high molecular weight isoforms of CD45 is essential for growth and differentiation of immature T cells and that inappropriate rearrangement or specificity of TCR activates a transition from expression of CD45R to that of CD45 p180 and intrathymic death.
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Affiliation(s)
- L M Pilarski
- Department of Immunology, University of Alberta, Edmonton, Canada
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41
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Cebrián M, Redondo JM, López-Rivas A, Rodríguez-Tarduchy G, De Landázuri MO, Sánchez-Madrid F. Expression and function of AIM, an activation inducer molecule of human lymphocytes, is dependent on the activation of protein kinase C. Eur J Immunol 1989; 19:809-15. [PMID: 2786811 DOI: 10.1002/eji.1830190505] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
AIM is an activation inducer molecule selectively expressed by activated lymphocytes through which agonistic proliferative signals can be triggered. The relationship between the expression of AIM with the activation of protein kinase C (PKC) has been studied. Different activators of PKC such as the active phorbol esters, phorbol myristate acetate and phorbol dibutyrate, or the phorbol-related ester mezerein were able to induce AIM expression on peripheral blood lymphocytes as assessed by immunofluorescence flow cytometry. Moreover, the expression of this activation antigen was also induced by treatment of peripheral blood lymphocytes either with dioctanoyl-rac-glycerol, a synthetic analogue of diacylglycerol, the physiological mediator of PKC activation. Further indirect evidence that AIM expression was dependent on the activation of PKC was obtained by blockade of the induction of its expression in cells treated with H7, an inhibitor of PKC. The AIM expression can be detected as early as 3 h after addition of phorbol esters and it requires active RNA and protein synthesis. The activation of PKC appears to be also required in the proliferative response induced by anti-AIM monoclonal antibody (mAb) in conjunction with phorbol esters. Agents such as phorbol myristate acetate, phorbol dibutyrate or mezerein but not the inactive phorbol ester methyl-phorbol myristate acetate induced a high proliferation of peripheral blood lymphocytes in the presence of anti-AIM mAb. In addition, we have demonstrated that the anti-AIM mAb is not sufficient by itself to induce cellular proliferation once the AIM antigen is expressed at the cell surface, requiring the simultaneous stimulation of the PKC to trigger high proliferative responses. Furthermore, the anti-AIM mAb did not appear to exert its effect on proliferation by rapidly increasing the intracytoplasmic Ca2+ levels. Taken together all these results indicate that the expression and function of AIM antigen is dependent on the activation of PKC.
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Affiliation(s)
- M Cebrián
- Servicio de Immunología, Hospital de la Princesa, Madrid, Spain
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42
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Johnson NA, Meyer CM, Pingel JT, Thomas ML. Sequence Conservation in Potential Regulatory Regions of the Mouse and Human Leukocyte Common Antigen Gene. J Biol Chem 1989. [DOI: 10.1016/s0021-9258(18)83337-3] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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43
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Pilarski LM, Gillitzer R, Zola H, Shortman K, Scollay R. Definition of the thymic generative lineage by selective expression of high molecular weight isoforms of CD45 (T200). Eur J Immunol 1989; 19:589-97. [PMID: 2525097 DOI: 10.1002/eji.1830190403] [Citation(s) in RCA: 88] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Selective expression of CD45 isoforms distinguishes naive and memory T cells in peripheral blood. Paradoxically, although the most recent thymic emigrants are CD45R+ CD45 p180-, the majority of thymocytes are CD45 p180+. Speculating that the small subset of thymocytes selectively expressing only the high molecular weight isoforms of CD45 constitute the thymic generative lineage giving rise to peripheral T cells, we characterized the phenotypic and functional properties of CD45 p180- thymocytes. All cells bearing CD45 p180 were removed by rigorous depletion or all CD45R+ thymocytes were removed in a parallel depletion. CD45R- thymocytes were essentially the same in phenotype and CD4/CD8 subset distribution as unfractionated thymus, and dissimilar to naive peripheral blood lymphocyte (PBL) T cells. In contrast, CD45 p180- thymocytes, mainly CD45R+, were CD1- CD38- pgp 1+, corresponding closely to the phenotype of naive CD45R+ PBL T cells. This subset is enriched in CD4+ or CD8+ single positives, includes a high proportion of CD4-8- thymocytes which are predominantly CD3-, and appears to have a medullary location. Approximately 40%-50% of CD45 p180- thymocytes expressed a high density of CDw29 (4B4), which in the periphery is expressed at high density only on CD45 p180+ memory T cells and at low density on CD45R+ naive T cells. However, the expression of high density CDw29 in the absence of CD45 p180 indicates a close resemblance to fetal lymphocytes and suggests an essential role for CDw29 in both the least and the most mature of T cells. If CD45 p180- thymocytes constitute the generative lineage and CD45 p180+ cells are commited to intrathymic death, then the CD45 p180- subset should have enhanced proliferative potential. By combining depletion methods with a limiting dilution assay for clonogenic potential, we found that 100% of the clonogenic precursors present in unfractionated thymus were CD45R+ CD45 p180- cells. This indicates that the CD45 p180+ majority of thymocytes has a very limited capability for proliferation consistent with a commitment to intrathymic death. The clonogenic potential of CD45 p180- thymocytes indicates a greater functional resemblance to PBL T cells than to CD45 p180+ thymocytes. In so far as clonogenic potential in vitro reflects generative potential in vivo, expression of high molecular weight CD45 isoforms appears to define the generative thymic lineage. Our working hypothesis proposes that expression of CD45 p180 implements the mechanism for eliminating thymocytes with self-reactive receptor specificities.
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Affiliation(s)
- L M Pilarski
- Department of Immunology, University of Alberta, Edmonton, Canada
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44
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Schraven B, Roux M, Hutmacher B, Meuer SC. Triggering of the alternative pathway of human T cell activation involves members of the T 200 family of glycoproteins. Eur J Immunol 1989; 19:397-403. [PMID: 2467820 DOI: 10.1002/eji.1830190226] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The present report describes functional characteristics of a monoclonal antibody (mAb), TA/211, which is reactive with a common determinant of the human CD45 molecules. When added to purified testing human T cells, TA/211, which is itself not mitogenic, leads to a strong proliferative response in combination with submitogenic concentrations of anti-T11(2) plus anti-T11(3) mAb. Interestingly, while amplifying anti-CD2-mediated immune responses, T cell activation induced through triggering of the CD3 molecule is not enhanced by TA/211, indicating that the triggering signal provided through CD45 is restricted to alternative pathway activation. Employing T cell subsets negatively selected for the expression of CD45R molecules defined by the mAb anti-2H4 or UCHL1, respectively, it is demonstrated that resting T cells expressing the 2H4 molecules proliferate much stronger to TA/211 than the UCHL1+ T cell subset. Together with the finding that the 2H4+ T cell subset can be activated by the concomitant binding of anti-CD2 antibodies plus anti-2H4, these data strongly suggest that the high molecular weight species of CD45 expressed by unprimed T cells are themselves involved in T cell activation via the alternative pathway.
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Affiliation(s)
- B Schraven
- Abteilung für Angewandte Immunologie, Deutsches Krebsforschungszentrum, Heidelberg, FRG
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45
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Tonks NK, Charbonneau H, Diltz CD, Fischer EH, Walsh KA. Demonstration that the leukocyte common antigen CD45 is a protein tyrosine phosphatase. Biochemistry 1988; 27:8695-701. [PMID: 2853967 DOI: 10.1021/bi00424a001] [Citation(s) in RCA: 352] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
It has been proposed on the basis of amino acid sequence homology that the leukocyte common antigen CD45 represents a family of catalytically active, receptor-linked protein tyrosine phosphatases [Charbonneau, H., Tonks, N. K., Walsh, K. A., & Fischer, E. H. (1988) Proc. Natl. Acad. Sci. U.S.A. 85, 7182-7186]. The present study confirms that CD45 possesses intrinsic protein tyrosine phosphatase (PTPase) activity. First, a mouse monoclonal antibody to CD45 (mAb 9.4) specifically eliminated, by precipitation, PTPase activity from a high Mr fraction containing CD45, prepared by gel filtration (Sephacryl S200) of a Triton X-100 extract of human spleen. Second, PTPase activity was demonstrated in a highly purified preparation of CD45 that was eluted with a high pH buffer from an affinity column, constructed from the same antibody. Third, on sucrose density gradient centrifugation, PTPase activity was only found in those fractions that contained CD45 as determined by Western analysis. When CD45 was caused to aggregate, first by reacting it with mAb 9.4 and then adding a secondary, cross-linking anti-mouse mAb, the PTPase activity shifted to the same higher Mr fractions that contained CD45. No shift in CD45 or PTPase was observed following addition of a control IgG2a. On this basis, it is concluded that CD45 is a protein tyrosine phosphatase.
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Affiliation(s)
- N K Tonks
- Department of Biochemistry, University of Washington, Seattle 98195
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46
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CD45 regulates signal transduction and lymphocyte activation by specific association with receptor molecules on T or B cells. Proc Natl Acad Sci U S A 1988; 85:8628-32. [PMID: 2973067 PMCID: PMC282512 DOI: 10.1073/pnas.85.22.8628] [Citation(s) in RCA: 181] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Evidence is presented that the leukocyte common antigen CD45 can regulate both signal transduction by lymphocyte receptor molecules and T- and B-cell proliferation in a manner dependent on specific interactions between these receptors on the cell surface. Formation of homoaggregates of CD3, CD2, or CD28 on the surface of T cells induced by crosslinking with monoclonal antibodies (mAbs) results in an increase in cytoplasmic free calcium concentration ([Ca2+]i). This increase in [Ca2+]i was abolished when these receptors were crosslinked to CD45 on the cell surface. In contrast, the increase in [Ca2+]i induced by formation of homoaggregates of CD4 was strongly amplified when CD4 was coupled to CD45. T-cell proliferation initiated by immobilized anti-CD3 was inhibited by anti-CD45 or anti-CD45R when immobilized on the same surface, but not when in solution. Similarly, proliferation after stimulation of the CD2 and CD28 receptors was inhibited when a CD45 mAb was crosslinked to either CD2 or CD28 mAbs, but not when a CD45-specific mAb was bound to the cell surface separately. In B cells, the increase in [Ca2+]i and resulting proliferation induced by crosslinking either the CD19 or Bgp95 receptors was inhibited by coupling these molecules to CD45. Thus, CD45 appears to modify other cellular receptors functionally when brought into close physical association with them. The homology of the CD45 conserved cytoplasmic domains with a major human placental protein tyrosine phosphatase suggests that the effects of CD45 described here result from alterations in the phosphorylation state of tyrosyl residues in membrane-associated proteins.
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47
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Charbonneau H, Tonks NK, Walsh KA, Fischer EH. The leukocyte common antigen (CD45): a putative receptor-linked protein tyrosine phosphatase. Proc Natl Acad Sci U S A 1988; 85:7182-6. [PMID: 2845400 PMCID: PMC282148 DOI: 10.1073/pnas.85.19.7182] [Citation(s) in RCA: 332] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
A major protein tyrosine phosphatase (PTPase 1B) has been isolated in essentially homogeneous form from the soluble and particulate fractions of human placenta. Unexpectedly, partial amino acid sequences displayed no homology with the primary structures of the protein Ser/Thr phosphatases deduced from cDNA clones. However, the sequence is strikingly similar to the tandem C-terminal homologous domains of the leukocyte common antigen (CD45). A 157-residue segment of PTPase 1B displayed 40% and 33% sequence identity with corresponding regions from cytoplasmic domains I and II of human CD45. Similar degrees of identity have been observed among the catalytic domains of families of regulatory proteins such as protein kinases and cyclic nucleotide phosphodiesterases. On this basis, it is proposed that the CD45 family has protein tyrosine phosphatase activity and may represent a set of cell-surface receptors involved in signal transduction. This suggests that the repertoire of signal transduction mechanisms may include the direct control of an intracellular protein tyrosine phosphatase, offering the possibility of a regulatory balance with those protein tyrosine kinases that act at the internal surface of the membrane.
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Affiliation(s)
- H Charbonneau
- Department of Biochemistry, University of Washington, Seattle 98195
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48
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Thomas ML, Lefrançois L. Differential expression of the leucocyte-common antigen family. IMMUNOLOGY TODAY 1988; 9:320-6. [PMID: 2978372 DOI: 10.1016/0167-5699(88)91326-6] [Citation(s) in RCA: 128] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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