51
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Ibáñez A, Sarrias MR, Farnós M, Gimferrer I, Serra-Pagès C, Vives J, Lozano F. Mitogen-Activated Protein Kinase Pathway Activation by the CD6 Lymphocyte Surface Receptor. THE JOURNAL OF IMMUNOLOGY 2006; 177:1152-9. [PMID: 16818773 DOI: 10.4049/jimmunol.177.2.1152] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
CD6 is a cell surface receptor primarily expressed on immature thymocytes and mature T and B1a lymphocytes. Through its binding to activated leukocyte cell adhesion molecule (ALCAM/CD166), CD6 is considered to play an important role in lymphocyte development and activation. Accordingly, CD6 associates with the TCR/CD3 complex and colocalizes with it at the center of the mature immunological synapse on T lymphocytes. Moreover, the CD6-ALCAM interaction has been shown to be critical for proper immunological synapse maturation and T cell proliferative responses. However, the precise biological effects of CD6 ligation and its signaling pathway are still not well understood. The present study shows that CD6 ligation with three different specific mAbs (161.8, SPV-L14.2, and MAE1-C10) induces time- and dose-dependent activation of ERK1/2 on normal and leukemic human T cells. This effect was also observed upon CD6 ligation with a chimerical ALCAM protein (ALCAM-Fc). The C-terminal cytoplasmic region of CD6, as well as Src tyrosine kinases, was critical for CD6-induced ERK1/2 activation. Synergistic effects were observed upon coligation of the TCR/CD3 complex with CD6. The ligation of CD6 induced the transcriptional activation of reporter genes under the control of the c-Fos serum responsive element and AP-1. Accordingly, CD6-mediated activation of p38 and JNK was also observed. These findings indicate that the CD6-ALCAM interaction results in activation of the three MAPK cascades, likely influencing the dynamic balance that determines whether resting or activated lymphocytes survive or undergo apoptosis.
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MESH Headings
- Activated-Leukocyte Cell Adhesion Molecule/metabolism
- Activated-Leukocyte Cell Adhesion Molecule/physiology
- Antibodies, Monoclonal/metabolism
- Antigens, CD/immunology
- Antigens, CD/metabolism
- Antigens, CD/physiology
- Antigens, Differentiation, T-Lymphocyte/immunology
- Antigens, Differentiation, T-Lymphocyte/metabolism
- Antigens, Differentiation, T-Lymphocyte/physiology
- Apoptosis/immunology
- CD3 Complex/immunology
- CD3 Complex/metabolism
- Cell Line, Tumor
- Cell Survival/immunology
- Cytoplasm/chemistry
- Cytoplasm/immunology
- Cytoplasm/metabolism
- Enzyme Activation/immunology
- Enzyme Induction/immunology
- Humans
- Jurkat Cells
- Leukemia/enzymology
- Leukemia/immunology
- Leukemia/pathology
- Ligands
- MAP Kinase Signaling System/immunology
- Mitogen-Activated Protein Kinase 1/biosynthesis
- Mitogen-Activated Protein Kinase 1/metabolism
- Mitogen-Activated Protein Kinase 3/biosynthesis
- Mitogen-Activated Protein Kinase 3/metabolism
- Peptide Fragments/physiology
- T-Lymphocytes/cytology
- T-Lymphocytes/enzymology
- T-Lymphocytes/pathology
- Up-Regulation/immunology
- src-Family Kinases/physiology
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Affiliation(s)
- Anna Ibáñez
- Servei d'Immunologia, Hospital Clínic i Provincial de Barcelona, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Facultat de Medicina, Universitat de Barcelona, Villaroel 170, 08036 Barcelona, Spain
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52
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Masedunskas A, King JA, Tan F, Cochran R, Stevens T, Sviridov D, Ofori-Acquah SF. Activated leukocyte cell adhesion molecule is a component of the endothelial junction involved in transendothelial monocyte migration. FEBS Lett 2006; 580:2637-45. [PMID: 16650408 DOI: 10.1016/j.febslet.2006.04.013] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2006] [Revised: 03/31/2006] [Accepted: 04/07/2006] [Indexed: 12/30/2022]
Abstract
Transendothelial leukocyte migration is a major aspect of the innate immune response. It is essential in repair and regeneration of damaged tissues and is regulated by multiple cell adhesion molecules (CAMs) including members of the immunoglobulin (Ig) superfamily. Activated leukocyte cell adhesion molecule (ALCAM/CD166) is an Ig CAM expressed by activated monocytes and endothelial cells. Hitherto, the functional relevance of ALCAM expression by endothelial cells and activated monocytes remained unknown. In this report, we demonstrate soluble recombinant human ALCAM significantly inhibited the rate of transendothelial migration of monocyte cell lines. Direct involvement of ALCAM in transendothelial migration was evident from the robust inhibition of this process by ALCAM blocking antibodies. However, soluble recombinant ALCAM had no impact on monocyte migration or adhesion to endothelium. Localization of ALCAM specifically at cell-cell junctions in endothelial cells supported its role in transendothelial migration. This study is the first to localize ALCAM to endothelial cell junctions and demonstrate a functional relevance for co-expression of ALCAM by activated monocytes and endothelial cells.
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Affiliation(s)
- Andrius Masedunskas
- Department of Cell Biology and Neuroscience, MSB 2348, University of South Alabama, Mobile, 36688-0002, USA
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53
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Zimmerman AW, Joosten B, Torensma R, Parnes JR, van Leeuwen FN, Figdor CG. Long-term engagement of CD6 and ALCAM is essential for T-cell proliferation induced by dendritic cells. Blood 2006; 107:3212-20. [PMID: 16352806 DOI: 10.1182/blood-2005-09-3881] [Citation(s) in RCA: 146] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Abstract
Interactions between T cells and antigen-presenting cells (APCs) are the first step in the induction of an adaptive immune response. Here, we show that CD6 and its ligand activated leukocyte cell adhesion molecule (ALCAM) are actively recruited to the antigen-induced dendritic cell (DC)–T-cell contact zone. Moreover, ALCAM-blocking antibodies interfere with DC–T-cell conjugate formation, demonstrating that CD6-ALCAM binding is essential for stable T-cell–APC contact. We now demonstrate that besides their role in establishing initial contacts, CD6-ALCAM interactions are also required during the proliferative phase of the T-cell response; the presence of CD6-blocking antibodies or recombinant ALCAM-Fc proteins results in a strong and sustained inhibition of T-cell proliferation. Furthermore, simultaneous crosslinking of CD6 and CD3 induces enhanced proliferation and transcriptional activity to a similar level as observed after CD3 and CD28 co-crosslinking, demonstrating that CD6 is an important costimulatory molecule. The stability of ALCAM-CD6 binding, which contrasts with transient homotypic ALCAM-ALCAM interactions, further supports the long-lasting effects observed on T-cell proliferation. Taken together, we demonstrate that CD6 and ALCAM form a key adhesive receptor-ligand pair that is not only involved in early DC-T-cell binding but also in sustaining DC-induced T-cell proliferation long after the initial contact has been established.
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MESH Headings
- Antibodies, Monoclonal/genetics
- Antibodies, Monoclonal/immunology
- Antibodies, Monoclonal/pharmacology
- Antigen Presentation/drug effects
- Antigen Presentation/immunology
- Antigens, CD/genetics
- Antigens, CD/immunology
- Antigens, CD/pharmacology
- Antigens, Differentiation, T-Lymphocyte/immunology
- CD28 Antigens/immunology
- CD3 Complex/immunology
- Cell Adhesion Molecules, Neuronal/genetics
- Cell Adhesion Molecules, Neuronal/immunology
- Cell Adhesion Molecules, Neuronal/pharmacology
- Cell Communication/drug effects
- Cell Communication/immunology
- Cell Differentiation/drug effects
- Cell Differentiation/immunology
- Cells, Cultured
- Dendritic Cells/cytology
- Dendritic Cells/immunology
- Fetal Proteins/genetics
- Fetal Proteins/immunology
- Fetal Proteins/pharmacology
- Humans
- Recombinant Fusion Proteins/genetics
- Recombinant Fusion Proteins/immunology
- Recombinant Fusion Proteins/pharmacology
- T-Lymphocytes/cytology
- T-Lymphocytes/immunology
- Time Factors
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Affiliation(s)
- Aukje W Zimmerman
- Department of Tumor Immunology, Nijmegen Centre for Molecular Life Sciences, The Netherlands
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54
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Davis WC, Hamilton MJ. Use of flow cytometry to characterize immunodeficiency syndromes in camelids. Small Rumin Res 2006. [DOI: 10.1016/j.smallrumres.2005.07.008] [Citation(s) in RCA: 1] [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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55
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Jiang Y, Oliver P, Davies KE, Platt N. Identification and characterization of murine SCARA5, a novel class A scavenger receptor that is expressed by populations of epithelial cells. J Biol Chem 2006; 281:11834-45. [PMID: 16407294 DOI: 10.1074/jbc.m507599200] [Citation(s) in RCA: 117] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Epithelia are positioned at a critical interface to prevent invasion by microorganisms from the environment. Pattern recognition receptors are important components of innate immunity because of their ability to interact with specific microbe-associated structures and initiate immune responses. Several distinct groups of receptors have been recognized. One of these, the scavenger receptors, has been classified into at least eight separate classes. The class A scavenger receptors are characterized by the presence of a collagen-like domain and include macrophage scavenger receptor type A (SR-A1 I/II, SCARA1) and MARCO (SCARA2). These receptors are known to make important contributions to host defense. Here, we identify a novel murine scavenger receptor, SCARA5, which has a structure typical of this class. The cDNA encodes 491 amino acids, which predict a type II protein that contains C-terminal intracellular, transmembrane, extracellular spacer, collagenous, and N-terminal scavenger receptor cysteine rich domains. Expression in Chinese hamster ovary cells confirmed that the receptor assembles as a homotrimer and is expressed at the plasma membrane. SCARA5-transfected cells bound Escherichia coli and Staphylococcus aureus, but not zymosan, in a polyanionic-inhibitable manner. Unlike other class A scavenger receptors, the receptor was unable to endocytose acetylated or oxidized low density lipoprotein. Quantitative RT-PCR and in situ hybridization demonstrate SCARA5 has a tissue and cellular distribution unique among class A scavenger receptors. Because of the restriction of SCARA5 transcripts to populations of epithelial cells, we propose that this receptor may play important roles in the innate immune activities of these cells.
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Affiliation(s)
- Yanyan Jiang
- Department of Human Anatomy and Genetics, University of Oxford, Oxford OX1 3QX
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56
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Abstract
Mature tissue macrophages form a first line of defense to recognize and eliminate potential pathogens; these specialized cells are capable of phagocytosis, degradation of self and foreign materials, establishment of cell-cell interactions, and the production of inflammatory mediators. Mature tissue macrophages express a variety of receptors, including the scavenger receptor cystein-rich (SRCR) superfamily members. CD163 is a member of the SRCR family class B and is expressed on most subpopulations of mature tissue macrophages. The best characterized function of CD163, which is essentially a homeostatic one, is related to the binding of Hemoglobin:Haptoglobin complexes. Furthermore, it has been suggested that CD163 positive macrophages or the soluble form of CD163 plays a role in the resolution of inflammation, as they are found in high numbers in inflamed tissue.
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MESH Headings
- Animals
- Antigens, CD/chemistry
- Antigens, CD/immunology
- Antigens, CD/metabolism
- Antigens, Differentiation, Myelomonocytic/chemistry
- Antigens, Differentiation, Myelomonocytic/immunology
- Antigens, Differentiation, Myelomonocytic/metabolism
- Humans
- Macrophages/immunology
- Macrophages/metabolism
- Receptors, Cell Surface/chemistry
- Receptors, Cell Surface/immunology
- Receptors, Cell Surface/metabolism
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Affiliation(s)
- Babs O Fabriek
- Department of Molecular Cell Biology and Immunology, VU Medical Center, P.O. Box 7057, 1007MB Amsterdam, The Netherlands.
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57
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Sarrias MR, Roselló S, Sánchez-Barbero F, Sierra JM, Vila J, Yélamos J, Vives J, Casals C, Lozano F. A role for human Sp alpha as a pattern recognition receptor. J Biol Chem 2005; 280:35391-8. [PMID: 16030018 DOI: 10.1074/jbc.m505042200] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Human Sp alpha is a soluble protein belonging to group B of the scavenger receptor cysteine-rich (SRCR) superfamily for which little functional information is available. It is expressed by macrophages present in lymphoid tissues (spleen, lymph node, thymus, and bone marrow), and it binds to myelomonocytic and lymphoid cells, which suggests that it may play an important role in the regulation of the innate and adaptive immune systems. In the present study we show that recombinant human Sp alpha (rSp alpha) binds to the surface of several gram-positive and gram-negative bacterial strains. Competition studies indicated that such binding is mediated by the recognition of lipoteichoic acid (LTA) and lipopolysaccharide (LPS), respectively, through nonoverlapping sites on the Sp alpha molecule. The most conserved part of LPS (2-keto-3-deoxyoctulosonic acid and lipid A) was shown to be involved in the recognition by Sp alpha. Bacterial binding studies using the SRCR domain 1 of Sp alpha showed that this domain retains both the LPS and LTA binding activities, indicating that both bacterial interacting sites are retained in a single SRCR domain. Furthermore, rSp alpha induced aggregation of gram-positive and gram-negative bacteria strains. On the other hand, rSp alpha inhibited tumor necrosis factor-alpha secretion by human monocytes stimulated with LPS or LTA. Binding of Sp alpha to conserved components of bacterial surfaces and modulation of the monocyte response indicate that this molecule is an active constituent of the innate immune response of the host.
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MESH Headings
- Amino Acid Sequence
- Animals
- Apoptosis Regulatory Proteins
- Bacteria/metabolism
- Binding Sites
- Dose-Response Relationship, Drug
- Electrophoresis, Polyacrylamide Gel
- Enzyme-Linked Immunosorbent Assay
- Escherichia coli/metabolism
- Humans
- Immunity, Innate
- Lipopolysaccharides/chemistry
- Lipopolysaccharides/pharmacology
- Listeria/metabolism
- Macrophages/metabolism
- Mice
- Molecular Sequence Data
- Monocytes/metabolism
- Protein Binding
- Protein Structure, Tertiary
- Receptors, Immunologic/chemistry
- Receptors, Immunologic/physiology
- Receptors, Scavenger/chemistry
- Recombinant Proteins/chemistry
- Scavenger Receptors, Class B
- Sequence Homology, Amino Acid
- Spectrometry, Fluorescence
- Teichoic Acids/chemistry
- Temperature
- Tissue Distribution
- Tumor Necrosis Factor-alpha/metabolism
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Affiliation(s)
- Maria-Rosa Sarrias
- Servei d'Immunologia, Hospital Clínic i Provincial de Barcelona, Institut de Investigacions Biomèdiques August Pi i Sunyer, Barcelona 08036, Spain
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58
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Ace CI, Okulicz WC. The 5' Flanking Region of the Rhesus Monkey H3 (DMBT1) Gene Contains Putative Progesterone Response Elements. DNA Cell Biol 2005; 24:345-9. [PMID: 15941386 DOI: 10.1089/dna.2005.24.345] [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] Open
Abstract
DMBT1 (deleted in malignant brain tumors) encodes a large scavenger receptor cysteine rich (SRCR) protein with proposed tumor suppressor properties due to its frequent deletion or lack of expression in a variety of different tumors including endometrial cancers. The gene is alternatively spliced to produce a number of related proteins with suspected functions in mucosal inflammation and epithelial regeneration. Expression of DMBT1 has been demonstrated in a wide variety of cell types, mostly of epithelial origin, including tissues of the respiratory system, the alimentary system, brain, and reproductive system. We have previously identified a Rhesus monkey cDNA clone H3 (homologous to human DMBT1) as a progesterone-induced gene in Rhesus monkey endometrium during the secretory phase of the menstrual cycle. As an initial step in understanding the molecular mechanisms of H3 (DMBT1) regulation we have cloned and sequenced 1.5 kb of the 5'-flanking region expected to contain promoter sequences of the Rhesus monkey gene and identified six putative progesterone receptor binding sites in the 5'-upstream region.
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Affiliation(s)
- Christopher I Ace
- Department of Physiology, University of Massachusetts Medical School, Worcester, Massachusetts, USA
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59
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Sarrias MR, Padilla O, Monreal Y, Carrascal M, Abian J, Vives J, Yélamos J, Lozano F. Biochemical characterization of recombinant and circulating human Spalpha. ACTA ACUST UNITED AC 2004; 63:335-44. [PMID: 15009805 DOI: 10.1111/j.0001-2815.2004.00193.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Human Spalpha is a soluble protein expressed by macrophages present in lymphoid tissues (spleen, lymph node, thymus, and bone marrow), for which little functional and structural information is available. It belongs to the group B of the scavenger receptor cysteine-rich superfamily (SRCR-SF) that includes the lymphocyte surface receptors CD5 and CD6 among others. Spalpha is able to bind to different cells of the immune system (monocytes and lymphocytes), which suggests that it may play an important role in the regulation of this system. To study Spalpha, an episomal mammalian expression system (pCEP-Pu/HEK 293-EBNA) was used to produce a recombinant form (rSpalpha) that was utilized for biochemical studies and for the generation of specific hybridomas. Four monoclonal antibodies were selected for their reactivity against rSpalpha by Western blot, immunoprecipitation, and enzyme-linked immunosorbent assays. The monoclonal antibodies recognized three different epitopes on Spalpha. The monoclonal antibodies revealed the existence of two Spalpha isoforms of 38 and 40 kDa, resulting from different sialic acid content. They also showed that Spalpha is a relatively abundant serum protein (60 micro g/ml) that mostly circulates in association with other serum proteins. Accordingly, rSpalpha allowed affinity chromatography isolation of polyclonal and monoclonal immunoglobulin M (IgM). These data indicate that Spalpha is a circulating protein that may play a role in the homeostasis of IgM antibodies.
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MESH Headings
- Antibodies, Monoclonal/immunology
- Antigens, CD/immunology
- Antigens, Differentiation, T-Lymphocyte/immunology
- Apoptosis Regulatory Proteins
- CD5 Antigens/immunology
- Chromatography, Affinity
- Epitopes/immunology
- Gene Expression
- Genetic Vectors
- Humans
- Immunoglobulin M/blood
- Immunoglobulin M/immunology
- Receptors, Immunologic/blood
- Receptors, Immunologic/genetics
- Receptors, Immunologic/immunology
- Receptors, Immunologic/metabolism
- Receptors, Scavenger
- Recombinant Proteins/blood
- Recombinant Proteins/chemistry
- Recombinant Proteins/immunology
- Scavenger Receptors, Class B
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Affiliation(s)
- M R Sarrias
- Servei d'Immunologia, Institut Clínic d'Infeccions i Immunologia, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Hospital Clínic, Villaroel 170, 08036 Barcelona, Spain
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60
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Bikker FJ, Ligtenberg AJM, End C, Renner M, Blaich S, Lyer S, Wittig R, van't Hof W, Veerman ECI, Nazmi K, de Blieck-Hogervorst JMA, Kioschis P, Nieuw Amerongen AV, Poustka A, Mollenhauer J. Bacteria Binding by DMBT1/SAG/gp-340 Is Confined to the VEVLXXXXW Motif in Its Scavenger Receptor Cysteine-rich Domains. J Biol Chem 2004; 279:47699-703. [PMID: 15355985 DOI: 10.1074/jbc.m406095200] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The scavenger receptor cysteine-rich (SRCR) proteins form an archaic group of metazoan proteins characterized by the presence of SRCR domains. These proteins are classified in group A and B based on the number of conserved cysteine residues in their SRCR domains, i.e. six for group A and eight for group B. The protein DMBT1 (deleted in malignant brain tumors 1), which is identical to salivary agglutinin and lung gp-340, belongs to the group B SRCR proteins and is considered to be involved in tumor suppression and host defense by pathogen binding. In a previous study we used nonoverlapping synthetic peptides covering the SRCR consensus sequence to identify a 16-amino acid bacteria-binding protein loop (peptide SRCRP2; QGRVEVLYRGSWGTVC) within the SRCR domains. In this study, using overlapping peptides, we pinpointed the minimal bacteria-binding site on SRCRP2, and thus DMBT1, to an 11-amino acid motif (DMBT1 pathogen-binding site 1 or DMBT1pbs1; GRVEVLYRGSW). An alanine substitution scan revealed that VEVL and Trp are critical residues in this motif. Bacteria binding by DMBT1pbs1 was different from the bacteria binding by the macrophage receptor MARCO in which an RXR motif was critical. In addition, the homologous consensus sequences of a number of SRCR proteins were synthesized and tested for bacteria binding. Only consensus sequences of DMBT1 orthologues bound bacteria by this motif.
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Affiliation(s)
- Floris J Bikker
- Department of Oral Biochemistry, Academic Centre for Dentistry Amsterdam (ACTA), Vrije Universiteit en Universiteit van Amsterdam, The Netherlands
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61
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Ikeda K, Quertermous T. Molecular isolation and characterization of a soluble isoform of activated leukocyte cell adhesion molecule that modulates endothelial cell function. J Biol Chem 2004; 279:55315-23. [PMID: 15496415 DOI: 10.1074/jbc.m407776200] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Cell adhesion molecules regulate a variety of endothelial cell functions such as migration, response to inflammation, and angiogenesis. Recently, activated leukocyte cell adhesion molecule (ALCAM), a member of the Ig superfamily, has been detected in the primitive subsets of hematopoietic cells and endothelial cells during embryogenesis. ALCAM supports the development of hematopoietic cells as well as enhancing capillary tube formation in vitro. Here, we isolated a novel soluble isoform of ALCAM (sALCAM) that is produced via alternative splicing. sALCAM contains the single amino-terminal Ig-like domain of ALCAM and lacks a transmembrane domain. When expressed in cultured cells, sALCAM was properly secreted into the media. Both ALCAM and sALCAM are expressed in a variety of cultured human endothelial cells. Notably, their transcripts were differentially regulated in human microvascular endothelial cells (HMVEC) upon tumor necrosis factor-alpha stimulation. ALCAM significantly enhanced tube formation of endothelial-like yolk sac cells on Matrigel, whereas it inhibited their migration in vitro. sALCAM completely abolished these effects of ALCAM. Furthermore, sALCAM enhanced migration of mock-transfected endothelial-like yolk sac cells that do not express ALCAM, indicating that sALCAM has an independent effect on cell migration in addition to modulating ALCAM function. In addition, sALCAM significantly enhanced migration of HMVEC, whereas it inhibited tube formation of HMVEC on Matrigel. sALCAM demonstrated an ability to bind ALCAM and partially inhibited ALCAM-ALCAM homophilic interactions. Taken together, these data characterize a novel soluble isoform of ALCAM that may have ALCAM-dependent and ALCAM-independent functions, providing further insights regarding the role of this adhesion molecule in the regulation of endothelial cell function.
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Affiliation(s)
- Koji Ikeda
- Donald W. Reynolds Cardiovascular Clinical Research Center, Division of Cardiovascular Medicine, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, CA 94305, USA
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62
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Gimferrer I, Calvo M, Mittelbrunn M, Farnós M, Sarrias MR, Enrich C, Vives J, Sánchez-Madrid F, Lozano F. Relevance of CD6-Mediated Interactions in T Cell Activation and Proliferation. THE JOURNAL OF IMMUNOLOGY 2004; 173:2262-70. [PMID: 15294938 DOI: 10.4049/jimmunol.173.4.2262] [Citation(s) in RCA: 108] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CD6 is a cell surface receptor expressed on immature thymocytes and mature T and B1a lymphocytes. The ultimate function of CD6 has not been deciphered yet, but much evidence supports a role for CD6 in T cell activation and differentiation. In this study, we show that a fraction of CD6 molecules physically associates with the TCR/CD3 complex by coimmunoprecipitation, cocapping, and fluorescence resonance energy transfer experiments. Image analysis of Ag-specific T-APC conjugates demonstrated that CD6 and its ligand, activated leukocyte cell adhesion molecule (CD166), colocalize with TCR/CD3 at the center of the immunological synapse, the so-called central supramolecular activation cluster. The addition of a soluble rCD6 form significantly reduced the number of mature Ag-specific T-APC conjugates, indicating that CD6 mediates early cell-cell interactions needed for immunological synapse maturation to proceed. This was in agreement with the dose-dependent inhibition of CD3-mediated T cell proliferation induced by soluble rCD6. Taken together, our data illustrate the important role played by the intra- and intercellular molecular interactions mediated by CD6 during T cell activation and proliferation processes.
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Affiliation(s)
- Idoia Gimferrer
- Servei d'Immunologia, Hospital Clínic i Provincial de Barcelona, Institut de Investigacions Biomèdiques August Pi i Sunyer, Barcelona, Spain
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63
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Konno A, Takada K, Saegusa J, Takiguchi M. Presence of B7-2+ dendritic cells and expression of Th1 cytokines in the early development of sialodacryoadenitis in the IqI/Jic mouse model of primary Sjörgren's syndrome. Autoimmunity 2003; 36:247-54. [PMID: 14563019 DOI: 10.1080/0891693031000141077] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Subpopulations of infiltrating lymphocytes, professional antigen-presenting cells (APCs), and Th1/Th2 cytokines that could initiate an autoimmune sialodacryoadenitis were studied in the IQI/Jic mouse model of primary Sjögren's syndrome. Although lymphocytic infiltrations were first seen in submandibular glands (SMGs) of females and in lacrimal glands (LGs) of males at 8 weeks of age, clusters of MHC class II+, CD11c+, B7-2+ dendritic cells (DCs) were already localized in these tissues at 4 weeks. At 8 weeks, the infiltrating lymphocytes consisted of almost equal numbers of B cells and CD4+ T cells. In the inflammatory foci, MHC class II+, CD11c+, B7-2+ DCs formed network-like structures. Duct cells in the lesions showed immunoreactivities for MHC class II and ALCAM (a costimulatory adhesion molecule). IL-12 and IFN-gamma transcripts were detected by RT-PCR in SMGs of females and in LGs of males at 8-12 weeks. These results suggest that the clustered DCs might play an important role in the initiation of the adenitis, and further suggest that the DCs and epithelial cells may participate in the activation of CD4+ T cells. It is also likely that Th1 cytokines mediate the functional interactions between the APCs and CD4+ T cells in the early lesions.
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Affiliation(s)
- Akihiro Konno
- Department of Biomedical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan.
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64
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Ohbo K, Yoshida S, Ohmura M, Ohneda O, Ogawa T, Tsuchiya H, Kuwana T, Kehler J, Abe K, Schöler HR, Suda T. Identification and characterization of stem cells in prepubertal spermatogenesis in mice. Dev Biol 2003; 258:209-25. [PMID: 12781694 DOI: 10.1016/s0012-1606(03)00111-8] [Citation(s) in RCA: 165] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The stem cell properties of gonocytes and prospermatogonia at prepubertal stages are still largely unknown: it is not clear whether gonocytes and prospermatogonia are a special cell type or similar to adult undifferentiated spermatogonia. To characterize these cells, we have established transgenic mice carrying EGFP (enhanced green fluorescence protein) cDNA under control of an Oct4 18-kb genomic fragment containing the minimal promoter and proximal and distal enhancers; Oct4 is reported to be expressed in undifferentiated spermatogonia at prepubertal stages. Generation of transgenic mice enabled us to purify gonocytes and prospermatogonia from the somatic cells of the testis. Transplantation studies of testicular cells so far have been done with a mixture of germ cells and somatic cells. This is the first report that establishes how to purify germ cells from total testicular cells, enabling evaluation of cell-autonomous repopulating activity of a subpopulation of prospermatogonia. We show that prospermatogonia differ markedly from adult spermatogonia in both the size of the KIT-negative population and cell cycle characteristics. The GFP(+) KIT(-) fraction of prospermatogonia has much higher repopulating activity than does the GFP(+)KIT(+) population in the adult environment. Interestingly, the GFP(+)KIT(+) population still exhibits repopulating activity, unlike adult KIT-positive spermatogonia. We also show that ALCAM, activated leukocyte cell adhesion molecule, is expressed transiently in gonocytes. Sertoli cells and myoid cells also express ALCAM at the same stage, suggesting that ALCAM may contribute to gonocyte-Sertoli cell adhesion and migration of gonoyctes toward the basement membrane.
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Affiliation(s)
- Kazuyuki Ohbo
- The Sakaguchi Laboratory of Developmental Biology, School of Medicine, Keio University, Tokyo 160-8582, Japan.
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65
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Kang W, Reid KBM. DMBT1, a regulator of mucosal homeostasis through the linking of mucosal defense and regeneration? FEBS Lett 2003; 540:21-5. [PMID: 12681477 DOI: 10.1016/s0014-5793(03)00217-5] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
DMBT1 (deleted in malignant brain tumor 1), which encodes a large scavenger receptor cysteine rich (SRCR) B protein, has been proposed to be a tumor suppressor gene, due to the high frequency of its homozygous deletion and the lack of expression in a variety of cancers. However, studies on its physiological functions and its relationship with tumorigenesis are still at an initial stage. Two mucosal defense-related molecules, gp-340 and salivary agglutinin, have been identified to be alternatively spliced products of DMBT1, which suggests that DMBT1 is a pattern recognition receptor in innate immunity. Meanwhile, results from immunohistochemical staining and studies at the cellular level, began to associate DMBT1 with a proliferation to differentiation switching process in gastrointestinal epithelial cells. Together with its up-regulation in inflammation, these findings suggest that DMBT1 might be a local regulator of homeostasis, possibly through linking mucosal inflammation to the modulation of epithelial regeneration, and whose abnormality is a frequent cause of malignancy.
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Affiliation(s)
- Weiqun Kang
- MRC Immunochemistry Unit, Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
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66
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Gimferrer I, Farnós M, Calvo M, Mittelbrunn M, Enrich C, Sánchez-Madrid F, Vives J, Lozano F. The accessory molecules CD5 and CD6 associate on the membrane of lymphoid T cells. J Biol Chem 2003; 278:8564-71. [PMID: 12473675 DOI: 10.1074/jbc.m209591200] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
CD5 and CD6 are closely related lymphocyte surface receptors of the scavenger receptor cysteine-rich superfamily, which show highly homologous extracellular regions but little conserved cytoplasmic tails. Both molecules are expressed on the same lymphocyte populations (thymocytes, mature T cells, and B1a cells) and share similar co-stimulatory properties on mature T cells. Although several works have been reported on the molecular associations and the signaling pathway mediated by CD5, very limited information is available for CD6 in this regard. Here we show the physical association of CD5 and CD6 at the cell membrane of lymphocytes, as well as their localization at the immunological synapse. CD5 and CD6 co-immunoprecipitate from Brij 96 but not Nonidet P-40 cell lysates, independently of both the co-expression of other lymphocyte surface receptors and the integrity of CD5 cytoplasmic region. Fluorescence resonance energy transfer analysis, co-capping, and co-modulation experiments demonstrate the physical in vivo association of CD5 and CD6. Analysis of T cell/antigen-presenting cells conjugates shows the accumulation of both molecules at the immunological synapse. These results indicate that CD5 and CD6 are structurally and physically related receptors, which may be functionally linked to provide either similar or complementary accessory signals during T cell activation and/or differentiation.
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Affiliation(s)
- Idoia Gimferrer
- Servei d'Immunologia, Institut Clinic d'Infeccions i Immunologia, Institut d'Investigacions Biomèdiques August Pi i Sunyer, Hospital Clinic, Barcelona 08036, Spain
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67
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Bisgaard HC, Holmskov U, Santoni-Rugiu E, Nagy P, Nielsen O, Ott P, Hage E, Dalhoff K, Rasmussen LJ, Tygstrup N. Heterogeneity of ductular reactions in adult rat and human liver revealed by novel expression of deleted in malignant brain tumor 1. THE AMERICAN JOURNAL OF PATHOLOGY 2002; 161:1187-98. [PMID: 12368192 PMCID: PMC1867299 DOI: 10.1016/s0002-9440(10)64395-7] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The regenerative capacity of mammalian adult liver reflects the ability of a number of cell populations within the hepatic lineage to take action. Limited information is available regarding factors and mechanisms that determine the specific lineage level at which liver cells contribute to liver repair as well as the fate of their progeny in the hostile environment created by liver injury. In the present study, we attempted to identify novel molecules preferentially involved in liver regeneration by recruitment of transit-amplifying, ductular (oval) cell populations. With a subtractive cDNA library screening approach, we identified 48 enriched, nonredundant gene products associated with liver injury and oval cell proliferation in the adult rat liver. Of these, only two, namely alpha-fetoprotein and a novel transcript with high homology to human DMBT1 (deleted in malignant brain tumor 1), were specifically associated with the emergence of ductular (oval) cell populations in injured liver. Subsequent cloning and characterization of the rat DMBT1 homologue revealed a highly inducible expression in ductular reactions composed of transit-amplifying ductular (oval) cells, but not in ductular reactions after ligation of the common bile duct. In human liver diseases, DMBT1 was expressed in ductular reactions after infection with hepatitis B and acetaminophen intoxication, but not in primary biliary cirrhosis, primary sclerosing cholangitis, and obstruction of the large bile duct. The expression heterogeneity in ductular reactions and multiple functions of DMBT1 homologues point to intriguing roles in regulating not only tissue repair but also fate decision and differentiation paths of specific cell populations in the hepatic lineage.
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Affiliation(s)
- Hanne Cathrine Bisgaard
- Department of Medical Biochemistry and Genetics, The Panum Institute, University of Copenhagen, Copenhagen, Denmark.
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68
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Bikker FJ, Ligtenberg AJM, Nazmi K, Veerman ECI, van't Hof W, Bolscher JGM, Poustka A, Nieuw Amerongen AV, Mollenhauer J. Identification of the bacteria-binding peptide domain on salivary agglutinin (gp-340/DMBT1), a member of the scavenger receptor cysteine-rich superfamily. J Biol Chem 2002; 277:32109-15. [PMID: 12050164 DOI: 10.1074/jbc.m203788200] [Citation(s) in RCA: 117] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Salivary agglutinin is encoded by DMBT1 and identical to gp-340, a member of the scavenger receptor cysteine-rich (SRCR) superfamily. Salivary agglutinin/DMBT1 is known for its Streptococcus mutans agglutinating properties. This 300-400 kDa glycoprotein is composed of conserved peptide motifs: 14 SRCR domains that are separated by SRCR-interspersed domains (SIDs), 2 CUB (C1r/C1s Uegf Bmp1) domains, and a zona pellucida domain. We have searched for the peptide domains of agglutinin/DMBT1 responsible for bacteria binding. Digestion with endoproteinase Lys-C resulted in a protein fragment containing exclusively SRCR and SID domains that binds to S. mutans. To define more closely the S. mutans-binding domain, consensus-based peptides of the SRCR domains and SIDs were designed and synthesized. Only one of the SRCR peptides, designated SRCRP2, and none of the SID peptides bound to S. mutans. Strikingly, this peptide was also able to induce agglutination of S. mutans and a number of other bacteria. The repeated presence of this peptide in the native molecule endows agglutinin/DMBT1 with a general bacterial binding feature with a multivalent character. Moreover, our studies demonstrate for the first time that the polymorphic SRCR domains of salivary agglutinin/DMBT1 mediate ligand interactions.
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Affiliation(s)
- Floris J Bikker
- Department of Dental Basic Sciences, Section of Oral Biochemistry, Academic Centre for Dentistry Amsterdam (ACTA), 1081 BT Amsterdam, The Netherlands.
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69
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Ahn JS, Konno A, Gebe JA, Aruffo A, Hamilton MJ, Park YH, Davis WC. Scavenger receptor cysteine‐rich domains 9 and 11 of WC1 are receptors for the WC1 counter receptor. J Leukoc Biol 2002. [DOI: 10.1189/jlb.72.2.382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Affiliation(s)
- J. S. Ahn
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman
| | - A. Konno
- Department of Biomedical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Japan
| | - J. A. Gebe
- Benoaroya Research Institute, Virginia Mason Research Center, Seattle, Washington
| | - A. Aruffo
- Bristol‐Myers Squibb Pharmaceutical Research Institute, Princeton, New Jersey; and
| | - M. J. Hamilton
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman
| | - Y. H. Park
- Department of Veterinary Microbiology, Seoul National University, Korea
| | - W. C. Davis
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman
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70
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Platt N, Haworth R, Darley L, Gordon S. The many roles of the class A macrophage scavenger receptor. INTERNATIONAL REVIEW OF CYTOLOGY 2002; 212:1-40. [PMID: 11804035 DOI: 10.1016/s0074-7696(01)12002-4] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The class A macrophage scavenger receptor (SR-A) is the prototypic example of a group of plasma membrane receptors collectively known as scavenger receptors. SR-A displays the ability to bind and endocytose large quantities of modified lipoprotein. Hence, it is thought to be one of the main receptors involved in mediating lipid influx into macrophages (Mphi), which promotes their conversion into foam cells that are abundant in the atherosclerotic lesion. However, as a result of increased interest and research effort and through the development of specific reagents and animal models, it is now appreciated to be multifunctional. These roles include Mphi growth and maintenance, adhesion to the substratum, cell-cell interactions, phagocytosis, and host defense. In this review, we attempt to summarize the evidence and argue that these kinds of activities underlie the biological versatility of Mphi.
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Affiliation(s)
- Nick Platt
- Sir William Dunn School of Pathology, University of Oxford, United Kingdom
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71
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Abstract
Whether B-1a (CD5+) cells are a distinct lineage derived from committed fetal/neonatal precursors or arise from follicular B-2 cells in response to BCR ligation and other, unknown signals remains controversial. Recent evidence indicates that B-1a cells can derive from adult precursors expressing an appropriate specificity when the (self-) antigen is present. Antibody specificity determines whether a B cell expressing immunoglobulin transgenes has a B-2, B-1a or marginal zone (MZ) phenotype. MZ cells share many phenotypic characteristics of B-1 cells and, like them, appear to develop in response to T independent type 2 antigens. Because fetal-derived B cell progenitors fail to express terminal deoxynucleotidyl transferase (TdT) and for other reasons, they are likely to express a repertoire that allows selection into the B-1a population. As it is selected by self-antigen, the B-1 repertoire tends to be autoreactive. This potentially dangerous repertoire is also useful, as B-1 cells are essential for resistance to several pathogens and they play an important role in mucosal immunity. The CD5 molecule can function as a negative regulator of BCR signaling that may help prevent inappropriate activation of autoreactive B-1a cells.
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Affiliation(s)
- Robert Berland
- Department of Pathology, Tufts University School of Medicine, Boston, Massachusetts 02111, USA.
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72
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Singer NG, Fox DA, Haqqi TM, Beretta L, Endres JS, Prohaska S, Parnes JR, Bromberg J, Sramkoski RM. CD6: expression during development, apoptosis and selection of human and mouse thymocytes. Int Immunol 2002; 14:585-97. [PMID: 12039910 DOI: 10.1093/intimm/dxf025] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
CD6, a 130-kDa surface glycoprotein, is expressed primarily on cells of T lineage. A co-stimulatory role for CD6 in mature T cells has been shown, but the function of CD6 during thymocyte development is unknown. Since CD6 ligands are expressed on thymic epithelium, their interactions with CD6 could be important in thymic selection. In this report we show that CD6 is developmentally regulated in human and mouse thymocytes, and further demonstrate that increase in the level of CD6 expression correlates with expression of the selection marker CD69. We also show that activation via CD2 induces CD6 expression on mature human thymocytes and on a subset of immature human thymocytes that are resistant to apoptosis. In human and mouse thymocytes that express heterogeneous TCR, CD6 increases occur as double-positive thymocytes are selected to a single-positive stage. In contrast, in thymocytes from TCR transgenic mice, CD6 is barely increased following selection, suggesting that as functional avidity increases, requirements for CD6-dependent co-stimulation decrease. Taken together, these results indicate that during thymic development CD6-dependent signals may contribute both to thymocyte survival, and to the overall functional avidity of selection in both man and mouse.
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MESH Headings
- Animals
- Antigens, CD/metabolism
- Antigens, Differentiation, T-Lymphocyte/metabolism
- Apoptosis/immunology
- CD2 Antigens/metabolism
- Cell Differentiation
- Cell Survival
- Humans
- In Vitro Techniques
- Infant
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Mice, Knockout
- Mice, Transgenic
- Receptors, Antigen, T-Cell/genetics
- Receptors, Antigen, T-Cell/metabolism
- Signal Transduction
- T-Lymphocyte Subsets/cytology
- T-Lymphocyte Subsets/immunology
- T-Lymphocytes/cytology
- T-Lymphocytes/immunology
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Affiliation(s)
- Nora G Singer
- Case Western Reserve University School of Medicine and Rainbow Babies and Children's Hospital/University Hospitals of Cleveland, Cleveland, OH 44106, USA.
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73
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Delrieu I, Waller CC, Mota MM, Grainger M, Langhorne J, Holder AA. PSLAP, a protein with multiple adhesive motifs, is expressed in Plasmodium falciparum gametocytes. Mol Biochem Parasitol 2002; 121:11-20. [PMID: 11985859 DOI: 10.1016/s0166-6851(02)00016-6] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A gene coding for a protein containing two Scavenger Receptor Cysteine-Rich (SRCR) motifs, four Limulus factor C, Coch-5b2 and Lgl1 (LCCL) motifs; and one Polycystin-1, Lipoxygenase and Alpha Toxin (PLAT) motif was cloned from Plasmodium chabaudi and homologues identified in the P. falciparum and P. yoelii genome data bases. At least one of these sequence motifs (SRCR) has adhesive properties in other proteins, therefore, we propose to name this protein PSLAP for Plasmodium SRCR, LCCL Adhesive-like Protein. Southern blotting and chromosome analysis showed that pslap is a single copy gene on chromosome 14 in P. falciparum 3D7. pslap mRNA is strongly expressed in P. falciparum gametocytes, but was undetectable on Northern blots of RNA from the asexual blood stages. Polyclonal antibodies raised to different parts of PSLAP detected a protein expressed in late gametocytes, but not in the early stages of gametocytogenesis or asexual blood stages of P. falciparum. We suggest that PSLAP functions in the mosquito, for example, in modulation of the invertebrate host immune response or in protection against complement factors in the blood meal.
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Affiliation(s)
- Isabelle Delrieu
- Division of Parasitology, National Institute for Medical Research, The Ridgeway, London, UK
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74
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Joliat MJ, Lang PA, Lyons BL, Burzenski L, Lynes MA, Yi T, Sundberg JP, Shultz LD. Absence of CD5 dramatically reduces progression of pulmonary inflammatory lesions in SHP-1 protein-tyrosine phosphatase-deficient 'viable motheaten' mice. J Autoimmun 2002; 18:105-17. [PMID: 11908943 DOI: 10.1006/jaut.2001.0570] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Mice homozygous for the viable motheaten (Hcph(me-v)) mutation are deficient in SHP-1 protein-tyrosine phosphatase, resulting in severe systemic autoimmunity and immune dysfunction. A high percentage of B-cells in viable motheaten mice express the cell surface glycoprotein CD5, in contrast to wild type mice that express CD5 on only a small percentage of B-cells. CD5(+) B-cells have been associated with autoantibody production. To determine the role of CD5 in the development of the inflammatory disease in me(v)/ me(v) mice, we created a stock of CD5(null)me(v)/ me(v) mice. The longevity of CD5(null)me(v)/ me(v) mice was increased 69% in comparison to me(v)/ me(v) mice on a similar (B6;129) background. The increased lifespan was associated with a marked reduction in pulmonary inflammation. Flow cytometry analysis of spleen cells from CD5(null)me(v)/ me(v) mice at 9-12 weeks of age revealed significant decreases in percentages of IgM/B220 double positive B-cells, Mac-1/Gr-1 double positive cells and CD4(+) T-cells compared with me(v)/ me(v) mice. CD5(null)me(v)/ me(v) mice also had significantly lower serum IgM levels in comparison to me(v)/ me(v) mice. Study of CD5(null)me(v)/ me(v) mice may provide further insight into the role of CD5 in cell signaling and may help explain the observed association of CD5(+) B-cells with autoimmune disease.
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75
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Pancer Z. Individual-specific repertoires of immune cells SRCR receptors in the purple sea urchin (S. Purpuratus). ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2002; 484:31-40. [PMID: 11418998 DOI: 10.1007/978-1-4615-1291-2_3] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Z Pancer
- Department of Biology, California Institute of Technology, Pasadena, CA 98765, USA
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76
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Brown WC. Molecular approaches to elucidating innate and acquired immune responses to Babesia bovis, a protozoan parasite that causes persistent infection. Vet Parasitol 2001; 101:233-48. [PMID: 11707299 DOI: 10.1016/s0304-4017(01)00569-6] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
For many vector-transmitted protozoal parasites, immunological control of acute infection leads to a state of persistent infection during which parasitemias may cycle unnoticed in infected but otherwise clinically healthy animals. Achieving persistent infection is a strategy that favors parasitism, since both host and, therefore, parasite survive, and endemically infected animal populations provide a reservoir of parasites continually available for subsequent transmission. Examples of the major economically important protozoan pathogens that cause persistent infection in mammals include the related Theileria and Babesia parasites as well as Trypanosoma species. Control of acute infection and maintenance of clinical immunity against subsequent infection are determined by the interplay of innate and acquired immune responses. This review will focus on approaches taken to gain an understanding of the molecular basis for innate and acquired immunity against the hemoprotozoan parasite of cattle, Babesia bovis. Knowledge of mechanisms used by the parasite to survive within infected cattle from acute to persistent infection combined with definition of the correlates of protective immunity in cattle should be applicable to designing effective vaccines.
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Affiliation(s)
- W C Brown
- Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, WA 99164-7040, USA.
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77
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Högger P, Sorg C. Soluble CD163 inhibits phorbol ester-induced lymphocyte proliferation. Biochem Biophys Res Commun 2001; 288:841-3. [PMID: 11688984 DOI: 10.1006/bbrc.2001.5845] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
CD163 is a member of the scavenger receptor cysteine-rich family which is expressed exclusively on human monocytes and macrophages. Upon an inflammatory stimulus the protein is shed rapidly from the membranes' surface. CD163 expression is significantly upregulated by glucocorticoids and IL-10. While the membrane-bound form of CD163 was recently identified as scavenger receptor for hemoglobin-haptoglobin complexes, there is no information about a possible role of the shed soluble CD163. It has been suggested earlier that CD163 plays a pivotal role in the downregulatory phase of inflammation. However, it has remained elusive so far as to how this protein might influence the inflammatory process. We have now identified a potential direct anti-inflammatory effect mediated by soluble CD163. The highly purified protein statistically significantly inhibits phorbol ester-induced human T-lymphocyte activation, thus attenuating the immune response to the inflammatory mediator.
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MESH Headings
- Analysis of Variance
- Antigens, CD
- Antigens, Differentiation, Myelomonocytic/isolation & purification
- Antigens, Differentiation, Myelomonocytic/metabolism
- Antigens, Differentiation, Myelomonocytic/pharmacology
- Cell Division/drug effects
- Cells, Cultured
- Glucocorticoids/pharmacology
- Humans
- Lymphocyte Activation/drug effects
- Monocytes/chemistry
- Monocytes/metabolism
- Receptors, Cell Surface/isolation & purification
- Receptors, Cell Surface/metabolism
- Solubility
- T-Lymphocytes/cytology
- T-Lymphocytes/drug effects
- Tetradecanoylphorbol Acetate/antagonists & inhibitors
- Tetradecanoylphorbol Acetate/pharmacology
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Affiliation(s)
- P Högger
- Institute of Pharmaceutical Chemistry, Westfälische Wilhelms-Universität, Münster, Germany.
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78
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van Kempen LC, Nelissen JM, Degen WG, Torensma R, Weidle UH, Bloemers HP, Figdor CG, Swart GW. Molecular basis for the homophilic activated leukocyte cell adhesion molecule (ALCAM)-ALCAM interaction. J Biol Chem 2001; 276:25783-90. [PMID: 11306570 DOI: 10.1074/jbc.m011272200] [Citation(s) in RCA: 122] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Activated leukocyte cell adhesion molecule (ALCAM/CD166), a member of the immunoglobulin superfamily with five extracellular immunoglobulin-like domains, facilitates heterophilic (ALCAM-CD6) and homophilic (ALCAM-ALCAM) cell-cell interactions. While expressed in a wide variety of tissues and cells, ALCAM is restricted to subsets of cells usually involved in dynamic growth and/or migration processes. A structure-function analysis, using two monoclonal anti-ALCAM antibodies and a series of amino-terminally deleted ALCAM constructs, revealed that homophilic cell adhesion depended on ligand binding mediated by the membrane-distal amino-terminal immunoglobulin domain and on avidity controlled by ALCAM clustering at the cell surface involving membrane-proximal immunoglobulin domains. Co-expression of a transmembrane ALCAM deletion mutant, which lacks the ligand binding domain, and endogenous wild-type ALCAM inhibited homophilic cell-cell interactions by interference with ALCAM avidity, while homophilic, soluble ligand binding remained unaltered. The extracellular structures of ALCAM thus provide two structurally and functionally distinguishable modules, one involved in ligand binding and the other in avidity. Functionality of both modules is required for stable homophilic ALCAM-ALCAM cell-cell adhesion.
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Affiliation(s)
- L C van Kempen
- Department of Biochemistry, University of Nijmegen, P. O. Box 9101, NL-6500 HB Nijmegen, The Netherlands
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79
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Koskinen R, Salomonsen J, Goodchild M, Bumstead N, Boyd Y, Vainio O. Structure and chromosomal localization of chicken CD5. Scand J Immunol 2001; 54:141-5. [PMID: 11439160 DOI: 10.1046/j.1365-3083.2001.00961.x] [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: 11/20/2022]
Abstract
CD5 is a transmembrane glycoprotein on all T cells and on a subpopulation of B cells. Based on the analysis of chicken CD5-cDNA we have previously shown that the structure of the CD5 protein is conserved between species. Here we report the isolation and chromosomal mapping of the chicken CD5 gene. The gene spans 3.4 kb and is extremely compact with a high GC-nucleotide content. There are 10 exons and the introns are spliced out similarly to those in the human CD5 gene. Each of the three extracellular scavenger receptor cysteine-rich (SRCR) domains is encoded as an exon of its own, as is the proline-rich hinge region that separates the first two membrane-distal SRCR domains. The fluorescence in situ hybridization (FISH) technique was used to map the gene to chromosome five. This is the first report describing the organization of the CD5 gene from a nonmammalian species.
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Affiliation(s)
- R Koskinen
- Turku Immunology Centre and Department of Medical Microbiology, Turku University, Turku, Finland
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80
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Vilà J, Gimferrer I, Padilla O, Arman M, Places L, Simarro M, Vives J, Lozano F. Residues Y429 and Y463 of the human CD5 are targeted by protein tyrosine kinases. Eur J Immunol 2001. [DOI: 10.1002/1521-4141(200104)31:4<1191::aid-immu1191>3.0.co;2-h] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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81
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Ritter M, Buechler C, Kapinsky M, Schmitz G. Interaction of CD163 with the regulatory subunit of casein kinase II (CKII) and dependence of CD163 signaling on CKII and protein kinase C. Eur J Immunol 2001; 31:999-1009. [PMID: 11298324 DOI: 10.1002/1521-4141(200104)31:4<999::aid-immu999>3.0.co;2-r] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
CD163 is a recently identified member of the scavenger receptor cysteine-rich superfamily, which is expressed on peripheral blood monocytes and most tissue macrophages and is thought to play an important role in the regulation of the inflammatory response of these cells. Cross-linking of CD163 on glucocorticoid-stimulated macrophages results in the secretion of several proinflammatory cytokines, but the precise mechanism of CD163 mediated signal transduction is not understood. The existence of several CD163 isoforms, which differ in the structure of their cytoplasmic domains and putative phosphorylation sites, suggests that these isoforms also differ in their signaling mechanism. Using the Yeast Two-Hybrid system and further in vitro and in vivo studies, we identified the regulatory beta-subunit of casein kinase II (CKII), which specifically binds to the cytoplasmic domain of CD163 and its isoforms. We also found, that in vitro the CD163 isoforms differ in their association with the CKII holoenzyme and in the phosphorylation by CKII. Furthermore, we demonstrated that the cytoplasmic domains of CD163 variants are phosphorylated by PKC-alpha in vitro. Inhibition studies using specific kinase inhibitors reveal that both CKII and PKC are involved in the CD163 signaling mechanism resulting in the secretion of proinflammatory cytokines.
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MESH Headings
- 2,3-Diphosphoglycerate/pharmacology
- Amino Acid Sequence
- Antibodies, Monoclonal
- Antigens, CD
- Antigens, Differentiation, Myelomonocytic/chemistry
- Antigens, Differentiation, Myelomonocytic/genetics
- Antigens, Differentiation, Myelomonocytic/metabolism
- Casein Kinase II
- Cells, Cultured
- Dexamethasone/pharmacology
- Dichlororibofuranosylbenzimidazole/pharmacology
- Genistein/pharmacology
- Holoenzymes/chemistry
- Holoenzymes/metabolism
- Humans
- Indoles/pharmacology
- Interleukin-1/biosynthesis
- Interleukin-6/biosynthesis
- Isoenzymes/antagonists & inhibitors
- Isoenzymes/metabolism
- Macrophages/drug effects
- Macrophages/enzymology
- Macrophages/metabolism
- Maleimides/pharmacology
- Molecular Sequence Data
- Phosphorylation/drug effects
- Protein Binding
- Protein Isoforms/antagonists & inhibitors
- Protein Isoforms/chemistry
- Protein Isoforms/genetics
- Protein Isoforms/metabolism
- Protein Kinase C/antagonists & inhibitors
- Protein Kinase C/metabolism
- Protein Kinase C-alpha
- Protein Serine-Threonine Kinases/antagonists & inhibitors
- Protein Serine-Threonine Kinases/chemistry
- Protein Serine-Threonine Kinases/genetics
- Protein Serine-Threonine Kinases/metabolism
- Protein Structure, Tertiary
- Protein Subunits
- Receptors, Cell Surface/chemistry
- Receptors, Cell Surface/genetics
- Receptors, Cell Surface/metabolism
- Signal Transduction/drug effects
- Substrate Specificity
- Two-Hybrid System Techniques
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Affiliation(s)
- M Ritter
- Institute for Clinical Chemistry and Laboratory Medicine, University of Regensburg, Regensburg, Germany
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82
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Iwasaki K, Morimatsu M, Inanami O, Uchida E, Syuto B, Kuwabara M, Niiyama M. Isolation, characterization, and cDNA cloning of chicken turpentine-induced protein, a new member of the scavenger receptor cysteine-rich (SRCR) family of proteins. J Biol Chem 2001; 276:9400-5. [PMID: 11136738 DOI: 10.1074/jbc.m011713200] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Acute-phase serum proteins were induced by administrating a chicken with turpentine oil. One of these proteins was a new protein that appeared in front of albumin in polyacrylamide disc gel electrophoresis using a 4.5-16% gel. To purify this protein, turpentine-administrated chicken serum was fractionated by ammonium sulfate precipitation at 50% saturation, and the supernatant fraction was chromatographed on a DEAE-Toyopearl 650S column. The purified protein is a mannose-glycoprotein, and its N-terminal sequence, determined by the Edoman method, is not homologous from that of other reported acute-phase proteins. An analysis of physiological function with two different test systems, chemiluminescence measurement and electron spin resonance spectroscopy, showed that the purified protein has antioxidant activity and inhibits superoxide (O(2)) mediated by activation of the receptor. In support of these results, the complete amino acid sequence of 18-B is homologous to the scavenger receptor cysteine-rich (SRCR) family of proteins that participate in the regulation of leukocyte function. 18-B is composed of four SRCR domains, which is different from the previously characterized SRCR family of proteins such as Spalpha, CD6, and CD163. These findings indicate that turpentine-induced 18-B, a new member of scavenger receptor cysteine-rich family, may be implicated in regulation of cell function in a manner of inhibition of the overproduction of the reactive oxygen species.
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Affiliation(s)
- K Iwasaki
- Department of Veterinary Internal Medicine II, School of Veterinary Medicine, Rakuno Gakuen University, Hokkaido 069-8501, Japan
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83
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Choi S, Kobayashi M, Wang J, Habelhah H, Okada F, Hamada J, Moriuchi T, Totsuka Y, Hosokawa M. Activated leukocyte cell adhesion molecule (ALCAM) and annexin II are involved in the metastatic progression of tumor cells after chemotherapy with Adriamycin. Clin Exp Metastasis 2001; 18:45-50. [PMID: 11206837 DOI: 10.1023/a:1026507713080] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Metastasis frequently occurs during and/or after chemotherapy resulting in failure. This suggests that inadequate chemotherapy promotes the emergence of more malignant tumor cells with metastatic potential. However, it is not determined how chemotherapy could promote the metastatic progression of tumor cells. In this study, we isolated highly metastatic clones from the tumors treated with ADR using an in vivo experimental model, in which non-metastatic tumor cells were inoculated s.c. in mice, treated with or without Adriamycin and then culture lines were re-established from the tumors. Then we isolated cDNAs for activated leukocyte cell adhesion molecule (ALCAM), osteopontin, and annexin II as candidates for metastasis-promoting genes with the use of a PCR-based subtraction method. Further we examined the metastatic potential of transfectants over-expressing ALCAM, osteopontin, or annexin II and combinations of them. Metastasis to the lung was observed in the mice where transfectants over-expressing ALCAM plus annexin II had been inoculated via tail vein. These results suggest that the over-expression of ALCAM and annexin II play a role in the metastatic progression after chemotherapy with ADR.
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Affiliation(s)
- S Choi
- Division of Cancer Pathobiology, Institute for Genetic Medicine, Hokkaido University, Sapporo, Japan
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84
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Shakhov AN, Nedospasov SA. Expression profiling in knockout mice: lymphotoxin versus tumor necrosis factor in the maintenance of splenic microarchitecture. Cytokine Growth Factor Rev 2001; 12:107-19. [PMID: 11312122 DOI: 10.1016/s1359-6101(01)00004-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Expression profiling provides a powerful approach to define the underlying molecular mechanisms in disease. Several techniques referred collectively to as gene profiling may be also helpful in the analysis of the phenotype of mice with targeted mutations, especially if applied to distinct histological compartments, to specific cell types or to evaluate the effect of specific challenges, such as infection. Here we review several of the existing techniques applicable to genetic knockout studies, and share our experience from the study of mice with tumor necrosis factor (TNF) and lymphotoxin (LT) deficiencies, with specific emphasis on the distinction between TNF- and LT-mediated signalling pathways in vivo. Gene expression profiling analysis of TNF/LT-deficient mice supports the notion that TNF and LT, originally discovered as distinct biological activities, manifest both distinct and redundant functions in vivo.
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Affiliation(s)
- A N Shakhov
- Intramural Research Support Program, SAIC Frederick, Division of Basic Sciences, Building 560, Room 31-33, NCI-FCRDC, PO Box B, Frederick, MD 21702, USA.
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85
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Vilà JM, Calvo J, Places L, Padilla O, Arman M, Gimferrer I, Aussel C, Vives J, Lozano F. Role of two conserved cytoplasmic threonine residues (T410 and T412) in CD5 signaling. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 166:396-402. [PMID: 11123317 DOI: 10.4049/jimmunol.166.1.396] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CD5 is a transmembrane coreceptor that modulates activation and differentiation signals mediated by the Ag-specific receptor present on both T and B1a lymphocytes. CD5 lacks intrinsic catalytic activity, and its immunomodulatory properties result from intracellular interactions mediated by the CD5 cytoplasmic tail. The nature of these interactions is currently a matter of investigation. Here, we present a selective mutagenesis analysis of two conserved threonine residues (T410 and T412) located at the membrane-proximal cytoplasmic region of CD5. These residues are contained within consensus phosphorylation motifs for protein kinase C and are shown here to be critical for in vivo protein kinase C-mediated phosphorylation of CD5. Functional studies revealed that the integrity of T410 and T412 is also critical for CD5-mediated phosphatidylcholine-specific phospholipase C (PC-PLC) activation and phorbol ester-mediated inhibition of Ab-induced internalization of CD5. These results strongly argue in favor of a role for T410 and T412 in the signaling mediated by CD5.
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Affiliation(s)
- J M Vilà
- Servei d'Immunologia, Institut d'Investigacions Biomèdiques August Pi i Sunyer, Hospital Clínic, Barcelona, Spain
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86
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Pancer Z. Dynamic expression of multiple scavenger receptor cysteine-rich genes in coelomocytes of the purple sea urchin. Proc Natl Acad Sci U S A 2000; 97:13156-61. [PMID: 11069281 PMCID: PMC27194 DOI: 10.1073/pnas.230096397] [Citation(s) in RCA: 115] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Coelomocytes, the heterogeneous population of sea urchin putative immune cells, were found to express a complex set of transcripts featuring scavenger receptor cysteine-rich (SRCR) repeats. SRCR domains define a metazoan superfamily of proteins, many of which are implicated in development and regulation of the immune system of vertebrates. Coelomocytes transcribe multiple SRCR genes from among a multigene family encoding an estimated number of 1,200 SRCR domains in specific patterns particular to each individual. Transcription levels for given SRCR genes may range from pronounced to undetectable, yet all tested animals harbor the genomic loci encoding these genes. Analysis of several SRCR genes revealed multiple loci corresponding to each type. In the case of one SRCR type, a cluster of at least three genes was detected within a 133-kb bacterial artificial chromosome insert, and conserved as well as unique regions were identified in sequences of three genomic clones derived from a single animal. Array hybridizations with repeated samples of coelomocyte messages revealed substantial alterations in levels of expression of many SRCR genes, with fluctuations of up to 10-fold in 1 week and up to 30-fold over a period of 3 months. This report is the first demonstration of genomic and transcriptional complexity in molecules expressed by invertebrate coelomocytes. The mechanisms controlling SRCR gene expression and the functional significance of this dynamic system await elucidation.
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Affiliation(s)
- Z Pancer
- Division of Biology 156-29, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125, USA.
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87
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Underwood LJ, Shigemasa K, Tanimoto H, Beard JB, Schneider EN, Wang Y, Parmley TH, O'Brien TJ. Ovarian tumor cells express a novel multi-domain cell surface serine protease. BIOCHIMICA ET BIOPHYSICA ACTA 2000; 1502:337-50. [PMID: 11068177 DOI: 10.1016/s0925-4439(00)00058-2] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Serine proteases serve many functions in normal biological processes. These functions are often usurped by cancer cells to allow progression of tumors by increasing the growth and metastatic potential of the neoplasia. Here, we have used a polymerase chain reaction (PCR)-based strategy to clone Tumor Associated Differentially-expressed Gene-12 (TADG-12), a new serine protease from ovarian carcinoma. This technique also revealed a variant splicing form of TADG-12 that could lead to a truncated protein product. Semi-quantitative PCR showed that TADG-12 is overexpressed in 41 of 55 ovarian cancer specimens relative to normal expression, and the variant form, TADG-12V is found at increased levels in 8 of 22 carcinomas examined. Northern blot revealed three transcripts, the largest of which is approximately 2.4 kb. An ovarian tumor cDNA library was screened, and the entire cDNA of TADG-12 has been identified. This sequence encodes a putative protein of 454 amino acids which includes a potential transmembrane domain, an LDL receptor-like domain, a scavenger receptor cysteine-rich domain, and a serine protease domain. These features imply that TADG-12 will be at the cell surface, and it may be useful as a molecular target for therapy or a diagnostic marker.
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Affiliation(s)
- L J Underwood
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, AR 72205-7199, USA
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88
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Nelissen JM, Peters IM, de Grooth BG, van Kooyk Y, Figdor CG. Dynamic regulation of activated leukocyte cell adhesion molecule-mediated homotypic cell adhesion through the actin cytoskeleton. Mol Biol Cell 2000; 11:2057-68. [PMID: 10848629 PMCID: PMC14903 DOI: 10.1091/mbc.11.6.2057] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Restricted expression of activated leukocyte cell adhesion molecule (ALCAM) by hematopoietic cells suggests an important role in the immune system and hematopoiesis. To get insight into the mechanisms that control ALCAM-mediated adhesion we have investigated homotypic ALCAM-ALCAM interactions. Here, we demonstrate that the cytoskeleton regulates ALCAM-mediated cell adhesion because inhibition of actin polymerization by cytochalasin D (CytD) strongly induces homotypic ALCAM-ALCAM interactions. This induction of cell adhesion is likely due to clustering of ALCAM at the cell surface, which is observed after CytD treatment. Single-particle tracking demonstrated that the lateral mobility of ALCAM in the cell membrane is increased 30-fold after CytD treatment. In contrast, both surface distribution and adhesion of a glycosylphosphatidylinositol (GPI)-anchored ALCAM mutant are insensitive to CytD, despite the increase in lateral mobility of GPI-ALCAM upon CytD treatment. This demonstrates that clustering of ALCAM is essential for cell adhesion, whereas enhanced diffusion of ALCAM alone is not sufficient for cluster formation. In addition, upon ligand binding, both free diffusion and the freely dragged distance of wild-type ALCAM, but not of GPI-ALCAM, are reduced over time, suggesting strengthening of the cytoskeleton linkage. From these findings we conclude that activation of ALCAM-mediated adhesion is dynamically regulated through actin cytoskeleton-dependent clustering.
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Affiliation(s)
- J M Nelissen
- Department of Tumor Immunology, University Medical Center, NL-6525 EX Nijmegen, The Netherlands
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89
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Davis WC, Heirman LR, Hamilton MJ, Parish SM, Barrington GM, Loftis A, Rogers M. Flow cytometric analysis of an immunodeficiency disorder affecting juvenile llamas. Vet Immunol Immunopathol 2000; 74:103-20. [PMID: 10760393 DOI: 10.1016/s0165-2427(00)00167-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The present study was undertaken to characterize the immune system of llamas and alpacas and establish the basis for an immunodeficiency disorder affecting juvenile llamas. Flow cytometric (FC) analysis of the immune system with a panel of monoclonal antibodies (mAbs) revealed the immune system of llamas and alpacas is similar in leukocyte subset composition to that in ruminants. Peripheral blood mononuclear cells in adults are comprised of surface immunoglobulin (sIg(+)) B-cells (31%+/-8 S.D.), alphabeta T-cells (27%+/-12 S.D.), WC1(+) gammadelta T-cells (16%+/-11 S.D.), and 5-16% monocytes. In contrast to cattle, goats, and sheep, however, the frequency of WC1(+) gammadelta T-cells is not high in juveniles but similar to the frequency in adults. Also, sIg(+) B-cells are present in high concentration in juveniles (43%+/-11 S.D. ). Expression of major histocompatibility class II molecules on resting T-cells was low or absent. Comparative analysis of peripheral blood lymphocyte composition in normal juvenile llamas and llamas presenting with the signs of the juvenile llama immunodeficiency syndrome (JLIDS) revealed the concentration of B-cells is extremely low (1-5%) in affected animals. The findings suggest JLIDS is attributable to an autosomal recessive genetic defect in the development of B-cells.
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Affiliation(s)
- W C Davis
- Departments of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, WA 99164-7040, USA.
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90
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Abstract
MARCO (macrophage receptor with collagenous structure) belongs to the class A scavenger receptor molecules. The structure and function of the molecule is described. Although it is expressed on subsets of macrophages, it can be upregulated on other macrophages after bacterial infection. The strategic position of MARCO-expressing cells in lymphoid organs suggests an important role for this bacteria-binding molecule in removal of pathogens.
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Affiliation(s)
- G Kraal
- Department of Cell Biology and Immunology, Vrije Universiteit Amsterdam, van der Boechorststraat 7, 1081 BT, Amsterdam, the Netherlands
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91
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van Kempen LC, van den Oord JJ, van Muijen GN, Weidle UH, Bloemers HP, Swart GW. Activated leukocyte cell adhesion molecule/CD166, a marker of tumor progression in primary malignant melanoma of the skin. THE AMERICAN JOURNAL OF PATHOLOGY 2000; 156:769-74. [PMID: 10702391 PMCID: PMC1876839 DOI: 10.1016/s0002-9440(10)64943-7] [Citation(s) in RCA: 177] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Expression of activated leukocyte cell adhesion molecule (ALCAM)/CD166 correlates with the aggregation and metastatic capacity of human melanoma cell lines (Am J Pathol 1998, 152:805-813). Immunohistochemistry on a series of human melanocytic lesions reveals that ALCAM expression correlates with melanoma progression. Most nevi (34/38) and all thin melanomas studied (Clark levels I and II) did not express ALCAM. In contrast, immunoreactivity was detected in the invasive, vertical growth phase of 2 of the 13 Clark level III lesions tested. The fraction of positive lesions further increased in Clark level IV (13/19) and in Clark level V (4/4) lesions. ALCAM expression was exclusively detectable in the vertical growth phase of the primary tumor. In melanoma metastases, approximately half of the lesions tested (13/28) were ALCAM positive. According to the Breslow-thickness, ALCAM expression was observed in less than 10% of the lesions that were thinner than 1.5 mm and in over 70% of the lesions that were thicker than 1.5 mm. Our results strongly suggest that ALCAM plays an important role in melanocytic tumor progression and depict it as a new molecular marker for neoplastic progression of primary human melanoma.
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Affiliation(s)
- L C van Kempen
- Department of Biochemistry, University of Nijmegen, Nijmegen, The Netherlands
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92
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Matsushita F, Miyawaki A, Mikoshiba K. Vomeroglandin/CRP-Ductin is strongly expressed in the glands associated with the mouse vomeronasal organ: identification and characterization of mouse vomeroglandin. Biochem Biophys Res Commun 2000; 268:275-81. [PMID: 10679193 DOI: 10.1006/bbrc.2000.2104] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Vomeroglandin, a subform of mouse CRP-ductin, is a protein strongly expressed in the glands of mouse vomeronasal system. Both the proteins contain several of scavenger receptor cysteine-rich and CUB domains and one ZP domain. This domain arrangement is similar to those of rat Ebnerin, human DMBT1, and rabbit hensin. In situ hybridization analysis shows strong expression of vomeroglandin mRNA in the glands of vomeronasal system. Immunological analyses detect both membrane-bound and secreted forms of vomeroglandin. The secreted protein seems to be localized in the lumen of the vomeronasal organ, playing a certain role in the pheromone perception.
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Affiliation(s)
- F Matsushita
- Department of Molecular Neurobiology, Institute of Medical Science, University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo, 108-0071, Japan.
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93
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94
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Pospisil R, Silverman GJ, Marti GE, Aruffo A, Bowen MA, Mage RG. CD5 is A potential selecting ligand for B-cell surface immunoglobulin: a possible role in maintenance and selective expansion of normal and malignant B cells. Leuk Lymphoma 2000; 36:353-65. [PMID: 10674908 DOI: 10.3109/10428190009148857] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Although the function of CD5 on B cells is unknown, previous studies suggested that CD5 interaction with V(H) framework regions of surface immunoglobulins (Igs) may contribute to survival and expansion of B cells. Here we used B-chronic lymphocytic leukemia (B-CLL) cells and transformed B-cell lines from normal and B-CLL patients to study CD5-Ig interactions. Immobilized Ig binds and permits isolation of CD5 from lysates of CD5-expressing cell lines. Immunoglobulins or Fab fragments of different V(H) families varied in their effectiveness as inhibitors of anti-CD5 staining of CLL cells, appendix and tonsil tissue sections. Human Ig also binds to purified recombinant CD5. We show here for the first time that the unconventional Ig-CD5 interaction maps to the extracellular CD5-D2 domain whereas conventional epitopes recognized by anti-CD5 antibodies are localized in the D1 domain of CD5. We propose that interactions of VH framework regions with CD5 as a ligand may maintain, select or expand normal, autoimmune or transformed B cells and also contribute to skewing of the normal V(H) repertoire.
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Affiliation(s)
- R Pospisil
- Laboratory of Immunology, NIAID, NIH, Bethesda, MD 20892, USA
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95
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Gebe JA, Llewellyn M, Hoggatt H, Aruffo A. Molecular cloning, genomic organization and cell-binding characteristics of mouse Spalpha. Immunology 2000; 99:78-86. [PMID: 10651944 PMCID: PMC2327131 DOI: 10.1046/j.1365-2567.2000.00903.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Several group B scavenger receptor cysteine-rich (SRCR) proteins have been shown to function as modulators in the immune response. Recently, we reported the cloning of a new member of this family, human Spalpha (hSpalpha). Herein we report the cloning and characterization of the mouse homologue of hSpalpha. Like its human counterpart, mouse Spalpha (mSpalpha), is a secreted protein containing three SRCR domains. Most lymphoid tissues express RNA transcripts encoding mSpalpha. Characterization of a genomic clone encoding the mature mSpalpha protein showed that each of the SRCR domains of mSpalpha is encoded by a single exon. Comparison of the sequence of mSPalpha with those of other published proteins indicates that it is the same as the recently reported protein named AIM (apoptosis inhibitor expressed by macrophages). Cell-binding studies with a mSpalpha immunoglobulin (mSpalpha-Rgamma) fusion protein indicated that mSpalpha is capable of binding to spleen-derived CD19+ B cells and minimally to peritoneal cavity-derived CD19+ B cells but not to peripheral blood-derived B cells. Spleen-derived CD3+ T cells also bound mSpalpha-Rgamma; however, no binding was observed to either peripheral blood mononuclear cells or peritoneal cavity-derived CD3+ T cells. The mSpalpha-Rgamma fusion protein was also shown to bind to the mouse cell lines WEHI3 (monocytic) and EL-4 (thymoma, T cell). The cloning of cDNA and genomic clones encoding mSpalpha and the identification of cells expressing a putative mSpalpha receptor(s) should facilitate in vivo studies designed to investigate the function of Spalpha in the immune compartment.
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Affiliation(s)
- J A Gebe
- The Bristol-Myers Squibb, Pharmaceutical Research Institute, Princeton, NJ 08543-4000, USA
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96
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Peña-Rossi C, Zuckerman LA, Strong J, Kwan J, Ferris W, Chan S, Tarakhovsky A, Beyers AD, Killeen N. Negative Regulation of CD4 Lineage Development and Responses by CD5. THE JOURNAL OF IMMUNOLOGY 1999. [DOI: 10.4049/jimmunol.163.12.6494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
CD5 deficiency results in a hyper-responsive phenotype to Ag receptor stimulation. Here we show that the development and responses of CD4 lineage T cells are regulated by the function of CD5. Thymocytes expressing the I-Ad-restricted DO11.10 TCR undergo abnormal selection without CD5. In H-2d mice, the absence of CD5 causes deletion of double-positive thymocytes, but allows for efficient selection of cells expressing high levels of the DO11.10 clonotype. By contrast, there is enhanced negative selection against the DO11.10 clonotype in the presence of I-Ab. T cell hybridomas and DO11.10 T cells are more responsive to TCR stimulation in the absence of CD5. Such hypersensitivity can be eliminated by expression of wild-type CD5, but not by a form of CD5 that lacks the cytoplasmic tail. Finally, CD5 deficiency partially suppresses the block of CD4 lineage development in CD4-deficient mice. Taken together, the data support a general role for CD5 as a negative regulator of Ag receptor signaling in the development and immune responses of CD4 lineage T cells.
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Affiliation(s)
- Claudia Peña-Rossi
- *Department of Microbiology and Immunology, University of California, San Francisco, CA 94143
| | - Linda A. Zuckerman
- *Department of Microbiology and Immunology, University of California, San Francisco, CA 94143
| | - Julie Strong
- *Department of Microbiology and Immunology, University of California, San Francisco, CA 94143
| | - Joanne Kwan
- *Department of Microbiology and Immunology, University of California, San Francisco, CA 94143
| | - William Ferris
- †Department of Medical Biochemistry and Medical Research Council Center for Molecular and Cellular Biology, University of Stellenbosch, Tygerberg, South Africa
| | - Susan Chan
- ‡Institut de Génétique et de Biologie Moléculaire et Cellulaire, Strasbourg, Illkirch, France; and
| | | | - Albert D. Beyers
- †Department of Medical Biochemistry and Medical Research Council Center for Molecular and Cellular Biology, University of Stellenbosch, Tygerberg, South Africa
| | - Nigel Killeen
- *Department of Microbiology and Immunology, University of California, San Francisco, CA 94143
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97
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Calvo J, Places L, Espinosa G, Padilla O, Vilà JM, Villamor N, Ingelmo M, Gallart T, Vives J, Font J, Lozano F. Identification of a natural soluble form of human CD5. TISSUE ANTIGENS 1999; 54:128-37. [PMID: 10488739 DOI: 10.1034/j.1399-0039.1999.540203.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
CD5 is a 67 kDa type I glycoprotein which belongs to the Scavenger Receptor Cysteine-Rich (SRCR) family of receptors. This family includes either cell-surface (e.g. CD6) or secreted (e.g. Spalpha) proteins implicated in the development of the immune system and the regulation of immune responses. In this study, we purified and characterised a circulating natural soluble CD5 form (nsCD5) which is indistinguishable (in apparent molecular mass, glycosylation pattern, and antibody reactivity) from a recombinant soluble CD5 form (rsCD5) composed of the three extracellular SCRC domains. The nsCD5 is a N-glycosylated 52 kDa molecule present in normal human serum and in supernatants of in vitro phorbol ester- and CD3-stimulated peripheral blood mononuclear cells. The nsCD5 concentration in sera from healthy donors is relatively low (median 1.75 ng/ml, rn=166) and is similar to that found in sera from patients suffering of various autoimmune (systemic lupus erythematosus, primary Sjogren syndrome, rheumatoid arthritis) and non-autoimmune (chronic renal failure, B-cell chronic lymphocytic leukemia) disorders. In vitro experiments indicate that nsCD5 is released by proteolytic cleavage of the membrane form. These results represent the first evidence of proteolytic release of a transmembrane SRCR family member following cell activation.
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Affiliation(s)
- J Calvo
- Servel d'Immunologia, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Hospital Clínic, Barcelona, Spain
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98
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Takito J, Yan L, Ma J, Hikita C, Vijayakumar S, Warburton D, Al-Awqati Q. Hensin, the polarity reversal protein, is encoded by DMBT1, a gene frequently deleted in malignant gliomas. THE AMERICAN JOURNAL OF PHYSIOLOGY 1999; 277:F277-89. [PMID: 10444583 DOI: 10.1152/ajprenal.1999.277.2.f277] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The band 3 anion exchanger is located in the apical membrane of a beta-intercalated clonal cell line, whereas the vacuolar H(+)-ATPase is present in the basolateral membrane. When these cells were seeded at confluent density, they converted to an alpha-phenotype, localizing each of these proteins to the opposite cell membrane domain. The reversal of polarity is induced by hensin, a 230-kDa extracellular matrix protein. Rabbit kidney hensin is a multidomain protein composed of eight SRCR ("scavenger receptor, cysteine rich"), two CUB ("C1r/C1s Uegf Bmp1"), and one ZP ("zona pellucida") domain. Other proteins known to have these domains include CRP-ductin, a cDNA expressed at high levels in mouse intestine (8 SRCR, 5 CUB, 1 ZP), ebnerin, a protein cloned from a rat taste bud library (4 SRCR, 3 CUB, 1 ZP), and DMBT1, a sequence in human chromosome 10q25-26 frequently deleted in malignant gliomas (9 SRCR, 2 CUB, 1 ZP). Rabbit and mouse hensin genomic clones contained a new SRCR that was not found in hensin cDNA but was homologous to the first SRCR domain in DMBT1. Furthermore, the 3'-untranslated regions and the signal peptide of hensin were homologous to those of DMBT1. Mouse genomic hensin was localized to chromosome 7 band F4, which is syntenic to human 10q25-26. These data suggest that hensin and DMBT1 are alternatively spliced forms of the same gene. The analysis of mouse hensin bacterial artificial chromosome (BAC) genomic clone by sequencing and Southern hybridization revealed that the gene also likely encodes CRP-ductin. A new antibody against the mouse SRCR1 domain recognized a protein in the mouse and rabbit brain but not in the immortalized cell line or kidney, whereas an antibody to SRCR6 and SRCR7 domains which are present in all the transcripts, recognized proteins in intestine, kidney, and brain from several species. The most likely interpretation of these data is that one gene produces at least three transcripts, namely, hensin, DMBT1, and CRP-ductin. Hensin may participate in determining the polarized phenotype of other epithelia and brain cells.
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Affiliation(s)
- J Takito
- Departments of Medicine and Physiology, College of Physicians and Surgeons of Columbia University, New York, New York 10032, USA
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Calvo J, Places L, Padilla O, Vilà JM, Vives J, Bowen MA, Lozano F. Interaction of recombinant and natural soluble CD5 forms with an alternative cell surface ligand. Eur J Immunol 1999; 29:2119-29. [PMID: 10427974 DOI: 10.1002/(sici)1521-4141(199907)29:07<2119::aid-immu2119>3.0.co;2-f] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
CD5, a member of the scavenger receptor cysteine-rich (SRCR) receptor family, plays a role in the thymocyte maturation, T cell activation and T cell-antigen-presenting cell interactions. To date only CD5 ligands (CD5L) compatible with a T-B co-stimulatory role have been described (CD72, gp40-80 and IgV(H) framework region) so the existence of alternative CD5L involved in other aspects of T cell biology warrants further exploration. Here we characterize the cell binding properties of a recombinant soluble human CD5 extracellular domain glycoprotein (rsCD5). In contrast to previously characterized ligands, this molecule binds to a broadly distributed cell surface receptor expressed on monocytes, lymphocytes and various cell lines of lymphoid, myelomonocytic and epithelial origin. The cell binding of rsCD5 is divalent cation independent and inhibited by high molar concentrations of certain monosaccharides. Both human CD5 Ig fusion proteins and a natural soluble CD5 form (present in human serum and resulting from proteolytic cleavage following lymphocyte activation) reproduce the cell binding pattern of rsCD5 and block its binding in a competitive form. The involvement of the most N-terminal CD5 SRCR domains (D1 and D2) in binding is deduced from competition cell binding assays with CD5 Ig fusion proteins. These results imply a novel CD5/CD5L interaction model recalling some aspects of the interaction of CD6 with activated leukocyte cell adhesion molecule (ALCAM).
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Affiliation(s)
- J Calvo
- Servei d'Immunologia, Institut D'Investigacions Biomèdiques August Pi i Sunyer, Hospital Clínic, Barcelona, Spain
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100
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Perez-Villar JJ, Whitney GS, Bowen MA, Hewgill DH, Aruffo AA, Kanner SB. CD5 negatively regulates the T-cell antigen receptor signal transduction pathway: involvement of SH2-containing phosphotyrosine phosphatase SHP-1. Mol Cell Biol 1999; 19:2903-12. [PMID: 10082557 PMCID: PMC84084 DOI: 10.1128/mcb.19.4.2903] [Citation(s) in RCA: 145] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The negative regulation of T- or B-cell antigen receptor signaling by CD5 was proposed based on studies of thymocytes and peritoneal B-1a cells from CD5-deficient mice. Here, we show that CD5 is constitutively associated with phosphotyrosine phosphatase activity in Jurkat T cells. CD5 was found associated with the Src homology 2 (SH2) domain containing hematopoietic phosphotyrosine phosphatase SHP-1 in both Jurkat cells and normal phytohemagglutinin-expanded T lymphoblasts. This interaction was increased upon T-cell receptor (TCR)-CD3 cell stimulation. CD5 co-cross-linking with the TCR-CD3 complex down-regulated the TCR-CD3-increased Ca2+ mobilization in Jurkat cells. In addition, stimulation of Jurkat cells or normal phytohemagglutinin-expanded T lymphoblasts through TCR-CD3 induced rapid tyrosine phosphorylation of several protein substrates, which was substantially diminished after CD5 cross-linking. The CD5-regulated substrates included CD3zeta, ZAP-70, Syk, and phospholipase Cgammal but not the Src family tyrosine kinase p56(lck). By mutation of all four CD5 intracellular tyrosine residues to phenylalanine, we found the membrane-proximal tyrosine at position 378, which is located in an immunoreceptor tyrosine-based inhibitory (ITIM)-like motif, crucial for SHP-1 association. The F378 point mutation ablated both SHP-1 binding and the down-regulating activity of CD5 during TCR-CD3 stimulation. These results suggest a critical role of the CD5 ITIM-like motif, which by binding to SHP-1 mediates the down-regulatory activity of this receptor.
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Affiliation(s)
- J J Perez-Villar
- Immunology and Inflammation Drug Discovery, Bristol-Myers Squibb Pharmaceutical Research Institute, Princeton, New Jersey 08543, USA.
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