51
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Kumar A, Humphreys TD, Kremer KN, Bramati PS, Bradfield L, Edgar CE, Hedin KE. CXCR4 physically associates with the T cell receptor to signal in T cells. Immunity 2006; 25:213-24. [PMID: 16919488 DOI: 10.1016/j.immuni.2006.06.015] [Citation(s) in RCA: 187] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2005] [Revised: 04/26/2006] [Accepted: 06/06/2006] [Indexed: 11/17/2022]
Abstract
SDF-1alpha (CXCL12) signaling via its receptor, CXCR4, stimulates T cell chemotaxis and gene expression. The ZAP-70 tyrosine kinase critically mediates SDF-1alpha-dependent migration and prolonged ERK mitogen-activated protein (MAP) kinase activation in T cells. However, the molecular mechanism by which CXCR4 or other G protein-coupled receptors activate ZAP-70 has not been characterized. Here we show that SDF-1alpha stimulates the physical association of CXCR4 and the T cell receptor (TCR) and utilizes the ZAP-70 binding ITAM domains of the TCR for signal transduction. This pathway is responsible for several of the effects of SDF-1alpha on T cells, including prolonged ERK MAP kinase activity, increased intracellular calcium ion concentrations, robust AP-1 transcriptional activity, and SDF-1alpha costimulation of cytokine secretion. These results suggest new paradigms for understanding the effects of SDF-1alpha and other chemokines on immunity.
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MESH Headings
- Antigens, CD/metabolism
- Antigens, Differentiation, T-Lymphocyte/metabolism
- Calcium/metabolism
- Cells, Cultured
- Chemokine CXCL12
- Chemokines, CXC/pharmacology
- Enzyme Activation/drug effects
- Humans
- Interleukin-10/metabolism
- Interleukin-2/metabolism
- Lectins, C-Type
- Models, Immunological
- Phosphotyrosine/metabolism
- Protein Binding
- Receptors, Antigen, T-Cell/immunology
- Receptors, Antigen, T-Cell/metabolism
- Receptors, CXCR4/immunology
- Signal Transduction/immunology
- T-Lymphocytes/drug effects
- T-Lymphocytes/immunology
- T-Lymphocytes/metabolism
- Transcription Factor AP-1/metabolism
- Transcriptional Activation/genetics
- ZAP-70 Protein-Tyrosine Kinase/metabolism
- ras Proteins/metabolism
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Affiliation(s)
- Ashok Kumar
- Department of Immunology, Mayo Clinic College of Medicine, Mayo Clinic, Rochester, Minnesota 55905, USA
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52
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Tangye SG, Bryant VL, Cuss AK, Good KL. BAFF, APRIL and human B cell disorders. Semin Immunol 2006; 18:305-17. [PMID: 16916610 DOI: 10.1016/j.smim.2006.04.004] [Citation(s) in RCA: 149] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2006] [Accepted: 04/03/2006] [Indexed: 12/19/2022]
Abstract
B cells require signals from multiple sources for their development from precursor cells, and differentiation into effector cells. BAFF has been identified as a critical regulator of B cell development and differentiation. Defects in the production of BAFF and/or expression of its receptors have been associated with a diverse array of human immunopathologies characterised by perturbed B cell function and behaviour, including autoimmunity, malignancy, and immunodeficiency. This review will discuss the role of BAFF in the pathogenesis of these human immune disorders. It will also highlight relevant differences between the function of BAFF in humans and mice and the impact of this on the therapeutic utility of BAFF antagonists in the treatment of different human diseases.
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Affiliation(s)
- Stuart G Tangye
- Centenary Institute of Cancer Medicine and Cell Biology, Newtown, NSW, Australia.
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53
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Junt T, Tumanov AV, Harris N, Heikenwalder M, Zeller N, Kuprash DV, Aguzzi A, Ludewig B, Nedospasov SA, Zinkernagel RM. Expression of lymphotoxin beta governs immunity at two distinct levels. Eur J Immunol 2006; 36:2061-75. [PMID: 16841297 DOI: 10.1002/eji.200626255] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Interaction of lymphotoxin alpha(1)beta(2) (LTalpha(1)beta(2)) with its receptor is key for the generation and maintenance of secondary lymphoid organ microstructure. We used mice conditionally deficient for LTbeta on different lymphocyte subsets to determine how the LTbeta-dependent lymphoid structure influences immune reactivity. All conditionally LTbeta-deficient mice mounted normal immune responses against vesicular stomatitis virus (VSV), and were protected against lymphocytic choriomeningitis virus (LCMV). In contrast, they exhibited reduced immune responses against non-replicating antigens. Completely LTbeta-deficient mice failed to retain VSV in the marginal zone and died from VSV infections, and they became virus carriers following infection with the non-cytopathic LCMV, which was correlated with defective virus replication in dendritic cells. It was ruled out that LTbeta expression on lymphocytes influenced their activation, homing capacity, or maturation. We therefore conclude that LTbeta expression influences immune reactivity at two distinct levels: (i) Expression of LTbeta on lymphocytes enhances the induction of immune responses against limiting amounts of antigen. (ii) Expression of LTbeta on non-lymphocytes governs antiviral immunity by enhancing antigen presentation on antigen-presenting cells. This prevents cytotoxic T lymphocytes exhaustion or death of the host by uncontrolled virus spread.
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Affiliation(s)
- Tobias Junt
- Institute of Experimental Immunology, Zürich, Switzerland.
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54
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Columba-Cabezas S, Griguoli M, Rosicarelli B, Magliozzi R, Ria F, Serafini B, Aloisi F. Suppression of established experimental autoimmune encephalomyelitis and formation of meningeal lymphoid follicles by lymphotoxin beta receptor-Ig fusion protein. J Neuroimmunol 2006; 179:76-86. [PMID: 16870269 DOI: 10.1016/j.jneuroim.2006.06.015] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2006] [Revised: 05/16/2006] [Accepted: 06/09/2006] [Indexed: 12/30/2022]
Abstract
We have recently shown that de novo formation of lymphoid structures resembling B-cell follicles occurs in the inflamed central nervous system (CNS) meninges in a subset of patients with secondary progressive multiple sclerosis and in SJL mice with relapsing-remitting experimental autoimmune encephalomyelitis (EAE). Because lymphotoxin (LT) alpha(1)beta(2) is essential for lymphoid tissue organization, we used real-time PCR to examine LTbeta and LTbeta receptor (LTbetaR) gene expression in the CNS of SJL mice immunized with PLP 139-151 peptide. Moreover, we used the decoy receptor LTbetaR-immunoglobulin fusion protein to block the interaction of lymphotoxin (LT) alpha(1)beta(2) with the LTbeta receptor (LTbetaR) in mice with established EAE and evaluate the effect of systemic and local treatments with the fusion protein on disease progression, CNS lymphocytic infiltration and formation of meningeal B-cell follicles. The present findings indicate that both LTbeta and LTbetaR are upregulated at EAE onset and during subsequent relapses and that systemic and local blockade of the LT pathway with LTbetaR-Ig results in protracted and transient inhibition of EAE clinical signs, respectively. LTbetaR-Ig treatment also reduces T- and B-cell infiltration and prevents the induction of the chemokines CXCL10 and CXCL13 and the formation of organized ectopic follicles in the EAE-affected CNS. Targeting of molecules involved in lymphoid organogenesis could represent a valid strategy to inhibit CNS inflammation and formation of ectopic follicles, which may play a role in maintaining an abnormal, intrathecal humoral immune response in CNS autoimmune disease.
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MESH Headings
- Animals
- B-Lymphocytes/immunology
- Central Nervous System/immunology
- Central Nervous System/metabolism
- Central Nervous System/pathology
- Chemokine CXCL10
- Chemokine CXCL13
- Chemokines, CXC/biosynthesis
- Chemokines, CXC/immunology
- Encephalomyelitis, Autoimmune, Experimental/immunology
- Encephalomyelitis, Autoimmune, Experimental/pathology
- Encephalomyelitis, Autoimmune, Experimental/prevention & control
- Female
- Gene Expression
- Gene Expression Profiling
- Humans
- Immunoglobulin G/administration & dosage
- Immunoglobulin G/immunology
- Immunohistochemistry
- Inflammation/immunology
- Inflammation/pathology
- Injections, Intraventricular
- Lymphotoxin beta Receptor/genetics
- Lymphotoxin beta Receptor/metabolism
- Lymphotoxin-beta/antagonists & inhibitors
- Lymphotoxin-beta/genetics
- Meninges/immunology
- Mice
- Microscopy, Confocal
- Myelin Proteolipid Protein/immunology
- Peptide Fragments/immunology
- RNA, Messenger/analysis
- Recombinant Fusion Proteins/administration & dosage
- Recombinant Fusion Proteins/immunology
- Reverse Transcriptase Polymerase Chain Reaction
- T-Lymphocytes/immunology
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Affiliation(s)
- Sandra Columba-Cabezas
- Department of Cell Biology and Neuroscience, Istituto Superiore di Sanità, Viale Regina Elena 299, Rome, Italy
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55
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Ortolano S, Hwang IY, Han SB, Kehrl JH. Roles for phosphoinositide 3-kinases, Bruton's tyrosine kinase, and Jun kinases in B lymphocyte chemotaxis and homing. Eur J Immunol 2006; 36:1285-95. [PMID: 16619289 DOI: 10.1002/eji.200535799] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
B lymphocyte chemokine receptors signal to downstream effectors by activating heterotrimeric G proteins. However, many of these effectors remain unknown and the known ones often have ill-defined roles in B cell trafficking. Here we report that pharmacological inhibitors of phosphoinositide 3-kinases (wortmannin, WMN), Bruton's tyrosine kinase (LFM-A13), and Jun kinases (SP600125) all significantly impair CXCL12-induced mouse B cell chemotaxis and that of a human B lymphoma cell line. Examination of two CXCR4-induced signaling pathways revealed that LFM-A13 and WMN blocked Akt activation, while SP600125 and WMN blocked JNK activation. Each of the inhibitors impaired the homing of transferred B cells to peripheral lymph nodes. Intravital imaging of control and inhibitor-treated mouse B cells in the inguinal lymph node high endothelial venules (HEV) demonstrated a 17%, 35%, and 60% reduction in the number of firmly adherent B cells with LFM-A13, SP600125, and WMN, respectively. These results implicate chemokine receptor mediated activation of phosphoinositide 3-kinases in the firm adhesion of mouse B cells within peripheral lymph node HEV, while Bruton's tyrosine kinase and JNK activation are less important and more likely needed during B cell transmigration through the endothelium and/or trafficking into the lymph node parenchyma.
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Affiliation(s)
- Saida Ortolano
- B Cell Molecular Immunology Section, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
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56
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Abstract
The pathogenic roles of B cells in autoimmune diseases occur through several mechanistic pathways that include autoantibodies, immune complexes, dendritic and T cell activation, cytokine synthesis, chemokine-mediated functions, and ectopic neolymphogenesis. Each of these pathways participate to different degrees in autoimmune diseases. The use of B cell-targeted and B cell subset-targeted therapies in humans is illuminating the mechanisms at work in a variety of human autoimmune diseases. In this review, we highlight some of these recent findings that provide insights into both murine models of autoimmunity and human autoimmune diseases.
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Affiliation(s)
- Flavius Martin
- Department of Immunology, Genentech, Inc., South San Francisco, California 94080, USA.
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57
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Abstract
The frequent observation of organized lymphoid structures that resemble secondary lymphoid organs in tissues that are targeted by chronic inflammatory processes, such as autoimmunity and infection, has indicated that lymphoid neogenesis might have a role in maintaining immune responses against persistent antigens. In this Review, we discuss recent progress in several aspects of lymphoid neogenesis, focusing on the similarities with lymphoid tissue development, the mechanisms of induction, functional competence and pathophysiological significance. As more information on these issues becomes available, a better understanding of the role of lymphoid neogenesis in promoting chronic inflammation might eventually lead to new strategies to target immunopathological processes.
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Affiliation(s)
- Francesca Aloisi
- Department of Cell Biology and Neuroscience, Istituto Superiore di Sanità, Rome, Italy.
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58
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Dai X, Chen Y, Schuman J, Hua Z, Adamson JW, Wen R, Wang D. Distinct roles of phosphoinositide-3 kinase and phospholipase Cgamma2 in B-cell receptor-mediated signal transduction. Mol Cell Biol 2006; 26:88-99. [PMID: 16354682 PMCID: PMC1317611 DOI: 10.1128/mcb.26.1.88-99.2006] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
During B-cell receptor (BCR) signaling, phosphoinositide-3 kinase (PI3K) is thought to function upstream of phospholipase Cgamma2 (PLCgamma2). PLCgamma2 deficiency specifically impedes transitional type 2 (T2) to follicular (FO) mature B-cell transition. Here, we demonstrate that PI3K deficiency specifically impaired T2-to-FO mature B-cell transition and marginal zone B-cell development. Furthermore, we investigated the functional relationship between PI3K and PLCgamma2 using PI3K-/-, PLCgamma2-/-, and PI3K-/- PLCgamma2-/- B cells. Interestingly, PLCgamma2 deficiency had no effect on BCR-mediated PI3K activation, whereas PI3K deficiency only partially blocked activation of PLCgamma2. Moreover, whereas PI3K-/- PLCgamma2-/- double deficiency did not affect hematopoiesis, it resulted in embryonic lethality. PI3K-/- PLCgamma2-/- fetal liver cells transplanted into B-cell null JAK3-/- mice failed to restore development of peripheral B cells and failed to progress through early B-cell development at the pro-B- to pre-B-cell transition, a more severe phenotype than was observed with either PI3K or PLCgamma2 single-deficiency B cells. Consistent with this finding, BCR signaling was more severely impaired in the absence of both PI3K and PLCgamma2 genes than in the absence of either one alone. Taken together, these results demonstrate that whereas PI3K functions upstream of PLCgamma2, activation of PLCgamma2 can occur independently of PI3K and that PI3K and PLCgamma2 also have distinct functions in BCR signal transduction.
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Affiliation(s)
- Xuezhi Dai
- Blood Research Institute, 8727 Watertown Plank Rd., Milwaukee, WI 53226, USA
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59
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Pabst R, Rothkötter HJ. Structure and Function of the Gut Mucosal Immune System. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2006; 579:1-14. [PMID: 16620008 DOI: 10.1007/0-387-33778-4_1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Reinhard Pabst
- Center of Anatomy, Medical of School of Hannover, Hannover, Germany
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60
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Brandtzaeg P, Carlsen HS, Halstensen TS. The B-cell system in inflammatory bowel disease. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2006; 579:149-67. [PMID: 16620017 DOI: 10.1007/0-387-33778-4_10] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Secretory immunity is the best-defined part ot the mucosal immune system. This adaptive humoral defense mechanism depends on a fine-tuned cooperation between secretory epithelia and local plasma cells. Such mucosal immunocytes produce preferentially dimers and larger polymers of immunoglobulin A (collectively called pIgA), which contain J chain and therefore can bind to the epithelial secretory component (SC). This transmembrane glycoprotein functions as pIg receptor (pIgR) that also translocates pentameric IgM to the epithelial surface. B cells with a high level of J-chain expression and pIg-pIgR interactions at mucosal effector sites are thus necessary for the generation of secretory antibodies (SIgA and SIgM). Secretory antibodies perform immune exclusion in a first-line defense, thereby counteracting microbial colonization and mucosal penetration of soluble antigens. However, local production of pIgA is significantly down-regulated in inflammatory bowel disease (IBD), as revealed by strikingly decreased J-chain expression. Although the total increase of the immunocyte population in IBD lesions probably compensates for the relatively reduced pIgA production, decreased pIgR/SC expression in regenerating and dysplastic epithelium signifies that the SIgA system is topically deficient. There is, moreover, a significant shift from IgA2 to IgA1 production, the latter subclass being less resistant to proteolytic degradation. These changes--together with activation of mucosal macrophages and a dramatic increase of IgG-producing cells--may reflect local establishment of a second defense line which, however, is unsuccessful in its attempt to eliminate antigens derived from the indigenous microbial flora. Such a 'frustrated' local humoral immune system results in altered immunological homeostasis and jeopardized mucosal integrity. Complement activation observed in relation to epithelium-bound IgG1 in ulcerative colitis indicates, moreover, that the surface epithelium is subjected to immunological attack by an autoimmune reaction. These luminal deposits regularly contain terminal cytotoxic complement, and often also C3b as a sign of persistent activation. Comparison of identical twins, discordant with regard to ulcerative colitis, suggests that the markedly skewed local IgG1 response seen in this IBD entity may be genetically determined. The initial event(s) eliciting B-cell driven immunopathology in IBD remains unknown. Abrogation of oral tolerance to certain antigens from commensal bacteria has been suggested as a putative early mechanism, and lymphoid neogenesis and hyperplasia in the lesions most likely signify massive microbial overstimulation of the local B-cell system. Such ectopic lymphoid microcompartments may contribute substantially to the proinflammatory systemic-type of B-cell responses occurring in established IBD lesions.
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Affiliation(s)
- Per Brandtzaeg
- Laboratory for Immunohistochemistry and Immunopathology (LIIPAT), Institute of Pathology, University of Oslo, Norway
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61
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Tarzi MD, Jenner M, Hattotuwa K, Faruqi AZ, Diaz GA, Longhurst HJ. Sporadic case of warts, hypogammaglobulinemia, immunodeficiency, and myelokathexis syndrome. J Allergy Clin Immunol 2005; 116:1101-5. [PMID: 16275383 DOI: 10.1016/j.jaci.2005.08.040] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2005] [Revised: 08/02/2005] [Accepted: 08/23/2005] [Indexed: 10/25/2022]
Abstract
The term WHIM syndrome (WHIMS) is an acronym describing a rare primary immunodeficiency disorder characterized by warts, hypogammaglobulinemia, immunodeficiency, and myelokathexis, the unusual association of neutropenia with bone marrow myeloid hypercellularity. WHIMS was recently associated with mutations in the gene encoding the chemokine receptor CXCR4 and as such is the first disease ascribed to abnormalities of chemokine signaling. We report a sporadic case of WHIMS in a woman presenting with recurrent infections and human papilloma virus-related genital dysplasia.
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Affiliation(s)
- Michael D Tarzi
- Department of Immunology, St Bartholomew's Hospital, West Smithfield, London, EC1A 7BE, United Kingdom.
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62
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Peeva E, Zouali M. Spotlight on the role of hormonal factors in the emergence of autoreactive B-lymphocytes. Immunol Lett 2005; 101:123-43. [PMID: 16061292 DOI: 10.1016/j.imlet.2005.05.014] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2005] [Revised: 05/27/2005] [Accepted: 05/27/2005] [Indexed: 12/16/2022]
Abstract
Pathogenic autoimmunity requires a combination of inherited and acquired factors. In as much as hormones influence the sexual dimorphism of the immune system, it is possible that they can initiate or accelerate an autoimmune process, and contribute to gender-biased autoimmune disorders. Not only natural hormones, but also endocrine disruptors, such as environmental estrogens, may act in conjunction with other factors to override immune tolerance to self-antigens. In lupus, murine and human studies demonstrate that female sex hormones are implicated in disease pathogenesis. In the B cell compartment, both prolactin and estrogen are immunomodulators that affect maturation, selection and antibody secretion. Their impact may be based on their capacity to allow autoreactive B cells to escape the normal mechanisms of tolerance and to accumulate in sufficient numbers to cause clinically apparent disease. Both hormones lead to the survival and activation of autoreactive B cells, but they skew B cell maturation towards different directions, with prolactin inducing T cell-dependent autoreactive follicular B cells and estrogen eliciting T cell-independent autoreactive marginal zone B cells. Differential modulation of the cytokine milieu by hormones may also affect the development and activation of specific mature B cell subsets. This novel insight suggests that targeted manipulation of these pathways may represent a promising avenue in the treatment of lupus and other gender-biased autoimmune diseases.
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Affiliation(s)
- Elena Peeva
- Albert Einstein College of Medicine, Department of Medicine, Microbiology and Immunology, 1300 Morris Park Avenue, F717, Bronx, NY 10461, USA
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63
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Honczarenko M, Le Y, Swierkowski M, Ghiran I, Glodek AM, Silberstein LE. Human bone marrow stromal cells express a distinct set of biologically functional chemokine receptors. Stem Cells 2005; 24:1030-41. [PMID: 16253981 DOI: 10.1634/stemcells.2005-0319] [Citation(s) in RCA: 498] [Impact Index Per Article: 26.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Stromal cells isolated from bone marrow (BMSCs), often referred to as mesenchymal stem cells, are currently under investigation for a variety of therapeutic applications. However, limited data are available regarding receptors that can influence their homing to and positioning within the bone marrow. In the present study, we found that second passage BMSCs express a unique set of chemokine receptors: three CC chemokine receptors (CCR1, CCR7, and CCR9) and three CXC chemokine receptors (CXCR4, CXCR5, and CXCR6). BMSCs cultured in serum-free medium secrete several chemokine ligands (CCL2, CCL4, CCL5, CCL20, CXCL12, CXCL8, and CX3CL1). The surface-expressed chemokine receptors were functional by several criteria. Stimulation of BMSCs with chemokine ligands triggers phosphorylation of the mitogen-activated protein kinase (e.g., extracellular signal-related kinase [ERK]-1 and ERK-2) and focal adhesion kinase signaling pathways. In addition, CXCL12 selectively activates signal transducer and activator of transcription (STAT)-5 whereas CCL5 activates STAT-1. In cell biologic assays, all of the chemokines tested stimulate chemotaxis of BMSCs, and CXCL12 induces cytoskeleton F-actin polymerization. Studies of culture-expanded BMSCs, for example, 12-16 passages, indicate loss of surface expression of all chemokine receptors and lack of chemotactic response to chemokines. The loss in chemokine receptor expression is accompanied by a decrease in expression of adhesion molecules (ICAM-1, ICAM-2, and vascular cell adhesion molecule 1) and CD157, while expression of CD90 and CD105 is maintained. The change in BMSC phenotype is associated with slowing of cell growth and increased spontaneous apoptosis. These findings suggest that several chemokine axes may operate in BMSC biology and may be important parameters in the validation of cultured BMSCs intended for cell therapy.
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Affiliation(s)
- Marek Honczarenko
- Joint Program in Transfusion Medicine, Children's Hospital Boston, Harvard Medical School, Karp Family Research Bldg, RB10217, 1 Blackfan Circle, Boston, Massachusetts 02115, USA
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64
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Moon EY, Noh YW, Han YH, Kim SU, Kim JM, Yu DY, Lim JS. T lymphocytes and dendritic cells are activated by the deletion of peroxiredoxin II (Prx II) gene. Immunol Lett 2005; 102:184-90. [PMID: 16290204 DOI: 10.1016/j.imlet.2005.09.003] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2005] [Revised: 09/13/2005] [Accepted: 09/13/2005] [Indexed: 10/25/2022]
Abstract
Peroxiredoxin II (Prx II) is a member of antioxidant enzyme family and it plays a protective role against oxidative damage. Constitutive production of endogenous reactive oxygen species was detected in spleen and bone marrow cells lacking Prx II. Here, we investigated the role of Prx II in immune responses. The total number of splenocytes (especially, the population of S-phase cells and CD3(+) T cells) was significantly higher in Prx II(-/-) mice than in wild type. Number of peripheral blood mononuclear cells (PBMCs) in Prx II(-/-) mice was also higher than wild type. Differentiation of Prx II(-/-) mouse bone marrow cells into CD11c-positive dendritic cells was greater than that of wild type. Transplantation of Prx II(-/-) bone marrow cells into wild type mice increased PBMCs in blood and bone marrow-derived dendritic cells. Prx II deletion enhances concanavalin A (ConA)-induced splenocyte proliferation and mixed lymphocyte reaction (MLR) activity of bone marrow-derived CD11c-positive dendritic cells to stimulate recipient splenocytes. Collectively, these data suggest that Prx II inhibits the immune cell responsiveness, which may be regulated by scavenging the low amount of reactive oxygen species (ROS).
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Affiliation(s)
- Eun-Yi Moon
- Laboratory of Human Genomics, Korea Research Institute of Bioscience and Biotechnology, Taejeon 305-806, Republic of Korea.
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65
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Hrecka K, Swigut T, Schindler M, Kirchhoff F, Skowronski J. Nef proteins from diverse groups of primate lentiviruses downmodulate CXCR4 to inhibit migration to the chemokine stromal derived factor 1. J Virol 2005; 79:10650-9. [PMID: 16051857 PMCID: PMC1182621 DOI: 10.1128/jvi.79.16.10650-10659.2005] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2005] [Accepted: 05/20/2005] [Indexed: 11/20/2022] Open
Abstract
Nef proteins of primate lentiviruses promote viral replication, virion infectivity, and evasion of antiviral immune responses by modulating signal transduction pathways and downregulating expression of receptors at the cell surface that are important for efficient antigen-specific responses, such as CD4, CD28, T-cell antigen receptor, and class I and class II major histocompatibility complex. Here we show that Nef proteins from diverse groups of primate lentiviruses which do not require the chemokine receptor CXCR4 for entry into target cells strongly downmodulate the cell surface expression of CXCR4. In contrast, all human immunodeficiency virus type 1 (HIV-1) and the majority of HIV-2 Nef proteins tested did not have such strong effects. SIVmac239 Nef strongly inhibited lymphocyte migration to CXCR4 ligand, the chemokine stromal derived factor 1 (SDF-1). SIVmac239 Nef downregulated CXCR4 by accelerating the rate of its endocytosis. Downmodulation of CXCR4 was abolished by mutations that disrupt the constitutively strong AP-2 clathrin adaptor binding element located in the N-terminal region of the Nef molecule, suggesting that Nef accelerates CXCR4 endocytosis via an AP-2-dependent pathway. Together, these results point to CXCR4 as playing an important role in simian immunodeficiency virus and possibly also HIV-2 persistence in vivo that is unrelated to viral entry into target cells. We speculate that Nef targets CXCR4 to disrupt ordered trafficking of infected leukocytes between local microenvironments in order to facilitate their dissemination and/or impair the antiviral immune response.
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Affiliation(s)
- Kasia Hrecka
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
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66
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Smaniotto S, de Mello-Coelho V, Villa-Verde DMS, Pléau JM, Postel-Vinay MC, Dardenne M, Savino W. Growth hormone modulates thymocyte development in vivo through a combined action of laminin and CXC chemokine ligand 12. Endocrinology 2005; 146:3005-17. [PMID: 15802502 DOI: 10.1210/en.2004-0709] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Previous evidence indicates that GH modulates thymic cell migration. In this study we approached this issue in vivo, studying thymocyte migration in GH transgenic animals and in normal mice treated intrathymically with GH. Extracellular matrix and chemokines are involved in thymocyte migration. In this respect, thymocyte adhesion to laminin was higher in GH-treated animals than controls, and the numbers of migrating cells in laminin-coated Transwells was higher in GH-transgenic and GH-injected mice. Additionally, CXC chemokine ligand 12 (CXCL12)-driven migration was higher in GH-Tg and GH-treated animals compared with controls. Interestingly, although CXCR4 expression on thymocytes did not change in GH-Tg mice, the CXCL12 intrathymic contents were higher. We found that CXCL12, in conjunction with laminin, would additionally enhance the migration of thymocytes previously exposed to high concentrations of GH in vivo. Lastly, there was an augmentation of recent thymic emigrants in lymph nodes from GH-Tg and GH-injected animals. In conclusion, enhanced thymocyte migration in GH transgenic mice as well as GH-injected mice results at least partially from a combined action of laminin and CXCL12. Considering that GH is presently being used as an adjuvant therapeutic agent in immunodeficiencies, including AIDS, the concepts defined herein provide important background knowledge for future GH-based immune interventions.
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Affiliation(s)
- Salete Smaniotto
- Institut National de la Santé et de la Recherche Médicale/Fiocruz Associate Laboratory of Immunology, Laboratory on Thymus Research, Oswaldo Cruz Institute, 21045-900 Rio de Janeiro, Brazil
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67
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Abstract
Secondary lymphoid organs serve as hubs for the adaptive immune system, bringing together antigen, antigen-presenting cells, and lymphocytes. Two families of G protein-coupled receptors play essential roles in lymphocyte migration through these organs: chemokine receptors and sphingosine-1-phosphate (S1P) receptors. Chemokines expressed by lymphoid stromal cells guide lymphocyte and dendritic cell movements during antigen surveillance and the initiation of adaptive immune responses. S1P receptor-1 is required for lymphocyte egress from thymus and secondary lymphoid organs and is downregulated by the immunosuppressive drug FTY720. Here, we review the steps associated with the initiation of adaptive immune responses in secondary lymphoid organs, highlighting the roles of chemokines and S1P.
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Affiliation(s)
- Jason G Cyster
- Howard Hughes Medical Institute and Department of Microbiology and Immunology, University of California, San Francisco, California 94143-0414, USA.
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68
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Subrata LS, Lowes KN, Olynyk JK, Yeoh GCT, Quail EA, Abraham LJ. Hepatic expression of the tumor necrosis factor family member lymphotoxin-beta is regulated by interleukin (IL)-6 and IL-1beta: transcriptional control mechanisms in oval cells and hepatoma cell lines. Liver Int 2005; 25:633-46. [PMID: 15910501 DOI: 10.1111/j.1478-3231.2005.01080.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
BACKGROUND Lymphotoxin-beta (LT-beta) plays an important role in inflammation and its promoter contains a functional nuclear factor-kappaB (NF-kappaB) element, rendering it a likely target of pro-inflammatory cytokines. Inflammatory cytokines play a central role in liver regeneration resulting from acute or chronic liver injury, with interleukin (IL)-6 signaling essential for liver regeneration induced by partial hepatectomy. In hepatic oval cells observed following chronic liver injury, LT-beta levels are upregulated, suggesting a link between LT-beta and liver regeneration. RESULTS The expression of LT-beta in hepatic oval cell and hepatocellular carcinoma cell lines was further investigated, along with its responsiveness to IL-6 and IL-1beta. Key regulatory cis-acting elements of the LT-beta promoter that mediate IL-6 responsiveness (Sp/BKLF, Ets, NF-kappaB and Egr-1/Sp1) and IL-1beta responsiveness (NF-kappaB and Ets) of hepatic LT-beta expression were identified. The novel binding of basic Kruppel-like factor (BKLF) proteins to an apparent composite Sp/BKLF site of the LT-beta promoter was shown to mediate IL-6 responsiveness. Binding of NF-kappaB p65/p50 heterodimers and Ets-related transcription factors to their respective sites mediates responsiveness to IL-1beta. CONCLUSION The identification of IL-6 and IL-1beta as activators of LT-beta supports their involvement in LT-beta signaling in liver regeneration associated with chronic liver damage.
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Affiliation(s)
- Lily S Subrata
- Biochemistry and Molecular Biology, School of Biomedical and Chemical Sciences, The University of Western Australia, Crawley, Western Australia, Australia
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69
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Witt CM, Raychaudhuri S, Schaefer B, Chakraborty AK, Robey EA. Directed migration of positively selected thymocytes visualized in real time. PLoS Biol 2005; 3:e160. [PMID: 15869324 PMCID: PMC1088277 DOI: 10.1371/journal.pbio.0030160] [Citation(s) in RCA: 123] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2004] [Accepted: 03/04/2005] [Indexed: 12/02/2022] Open
Abstract
Development of many vertebrate tissues involves long-range cell migrations. In most cases, these migrations have been inferred from analysis of single time points and the migration process has not been directly observed and quantitated in real time. In the mammalian adult thymus, immature CD4+CD8+ double-positive (DP) thymocytes are found in the outer cortex, whereas after T cell antigen receptor (TCR) repertoire selection, CD4+CD8– and CD4–CD8+ single-positive (SP) thymocytes are found in the central medulla. Here we have used two-photon laser-scanning microscopy and quantitative analysis of four-dimensional cell migration data to investigate the movement of thymocytes through the cortex in real time within intact thymic lobes. We show that prior to positive selection, cortical thymocytes exhibit random walk migration. In contrast, positive selection is correlated with the appearance of a thymocyte population displaying rapid, directed migration toward the medulla. These studies provide our first glimpse into the dynamics of developmentally programmed, long-range cell migration in the mammalian thymus. Two-photon laser-scanning microscopy reveals the change from random motion to directed migration that occurs when thymocytes undergo positive selection.
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Affiliation(s)
- Colleen M Witt
- 1Division of Immunology, Department of Molecular and Cell Biology, University of CaliforniaBerkeley, CaliforniaUnited States of America
| | - Subhadip Raychaudhuri
- 2Department of Chemical Engineering, University of CaliforniaBerkeley, CaliforniaUnited States of America
| | - Brian Schaefer
- 3Department of Microbiology and Immunology, Uniformed Services University of the Health SciencesBethesda, MarylandUnited States of America
| | - Arup K Chakraborty
- 2Department of Chemical Engineering, University of CaliforniaBerkeley, CaliforniaUnited States of America
| | - Ellen A Robey
- 1Division of Immunology, Department of Molecular and Cell Biology, University of CaliforniaBerkeley, CaliforniaUnited States of America
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70
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Hehlgans T, Pfeffer K. The intriguing biology of the tumour necrosis factor/tumour necrosis factor receptor superfamily: players, rules and the games. Immunology 2005; 115:1-20. [PMID: 15819693 PMCID: PMC1782125 DOI: 10.1111/j.1365-2567.2005.02143.x] [Citation(s) in RCA: 567] [Impact Index Per Article: 29.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2004] [Revised: 01/17/2004] [Accepted: 01/25/2005] [Indexed: 11/28/2022] Open
Abstract
The members of the tumour necrosis factor (TNF)/tumour necrosis factor receptor (TNFR) superfamily are critically involved in the maintenance of homeostasis of the immune system. The biological functions of this system encompass beneficial and protective effects in inflammation and host defence as well as a crucial role in organogenesis. At the same time, members of this superfamily are responsible for host damaging effects in sepsis, cachexia, and autoimmune diseases. This review summarizes recent progress in the immunobiology of the TNF/TNFR superfamily focusing on results obtained from animal studies using gene targeted mice. The different modes of signalling pathways affecting cell proliferation, survival, differentiation, apoptosis, and immune organ development as well as host defence are reviewed. Molecular and cellular mechanisms that demonstrate a therapeutic potential by targeting individual receptors or ligands for the treatment of chronic inflammatory or autoimmune diseases are discussed.
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Affiliation(s)
- Thomas Hehlgans
- Institute of Medical Microbiology, University of Düsseldorf, Germany.
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71
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Geissmann F, Cameron TO, Sidobre S, Manlongat N, Kronenberg M, Briskin MJ, Dustin ML, Littman DR. Intravascular immune surveillance by CXCR6+ NKT cells patrolling liver sinusoids. PLoS Biol 2005; 3:e113. [PMID: 15799695 PMCID: PMC1073691 DOI: 10.1371/journal.pbio.0030113] [Citation(s) in RCA: 504] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2004] [Accepted: 01/28/2005] [Indexed: 12/28/2022] Open
Abstract
We examined the in vivo behavior of liver natural killer T cells (NKT cells) by intravital fluorescence microscopic imaging of mice in which a green fluorescent protein cDNA was used to replace the gene encoding the chemokine receptor CXCR6. NKT cells, which account for most CXCR6(+) cells in liver, were found to crawl within hepatic sinusoids at 10-20 microm/min and to stop upon T cell antigen receptor activation. CXCR6-deficient mice exhibited a selective and severe reduction of CD1d-reactive NKT cells in the liver and decreased susceptibility to T-cell-dependent hepatitis. CXCL16, the cell surface ligand for CXCR6, is expressed on sinusoidal endothelial cells, and CXCR6 deficiency resulted in reduced survival, but not in altered speed or pattern of patrolling of NKT cells. Thus, NKT cells patrol liver sinusoids to provide intravascular immune surveillance, and CXCR6 contributes to liver-based immune responses by regulating their abundance.
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Affiliation(s)
- Frederic Geissmann
- 1Molecular Pathogenesis Program, Skirball Institute of Biomolecular MedicineNew York University School of Medicine, New York, New YorkUnited States of America
| | - Thomas O Cameron
- 1Molecular Pathogenesis Program, Skirball Institute of Biomolecular MedicineNew York University School of Medicine, New York, New YorkUnited States of America
| | - Stephane Sidobre
- 2La Jolla Institute for Allergy and Immunology, San DiegoCaliforniaUnited States of America
| | - Natasha Manlongat
- 3Millenium Pharmaceuticals, CambridgeMassachusettsUnited States of America
| | - Mitchell Kronenberg
- 2La Jolla Institute for Allergy and Immunology, San DiegoCaliforniaUnited States of America
| | - Michael J Briskin
- 3Millenium Pharmaceuticals, CambridgeMassachusettsUnited States of America
| | - Michael L Dustin
- 1Molecular Pathogenesis Program, Skirball Institute of Biomolecular MedicineNew York University School of Medicine, New York, New YorkUnited States of America
| | - Dan R Littman
- 1Molecular Pathogenesis Program, Skirball Institute of Biomolecular MedicineNew York University School of Medicine, New York, New YorkUnited States of America
- 4Howard Hughes Medical Institute, Skirball Institute of Biomolecular MedicineNew York University School of Medicine, New York, New YorkUnited States of America
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72
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Moriguchi M, Hissong BD, Gadina M, Yamaoka K, Tiffany HL, Murphy PM, Candotti F, O'Shea JJ. CXCL12 Signaling Is Independent of Jak2 and Jak3. J Biol Chem 2005; 280:17408-14. [PMID: 15611059 DOI: 10.1074/jbc.m414219200] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Janus kinases (Jaks) are a small family of cytoplasmic tyrosine kinases, critical for signaling by Type I and II cytokine receptors. The importance of Jaks in signaling by these receptors has been firmly established by analysis of mutant cell lines, the generation of Jak knock-out mice, and the identification of patients with Jak3 mutations. While a number of other ligands that do not bind Type I and II cytokine receptors have also been reported to activate Jaks, the requirement for Jaks in signaling by these receptors is less clear. Chemokines for example, which bind seven transmembrane receptors, have been reported to activate Jaks, and principally through the use of pharmacological inhibitors, it has been argued that Jaks are essential for chemokine signaling. In the present study, we focused on CXCR4, which binds the chemokine CXCL12 or stromal cell-derived factor-1, a chemokine that has been reported to activate Jak2 and Jak3. We found that the lack of Jak3 had no effect on CXCL12 signaling or chemotaxis nor did overexpression of wild-type versions of the kinase. Similarly, overexpression of wild-type or catalytically inactive Jak2 or "knocking-down" Jak2 expression using siRNA also had no effect. We also found that in primary lymphocytes, CXCL12 did not induce appreciable phosphorylation of any of the Jaks compared with cytokines for which these kinases are required. Additionally, little or no Stat (signal transducer and activator of transcription) phosphorylation was detected. Thus, we conclude that in contrast to previous reports, Jaks, especially Jak3, are unlikely to play an essential role in chemokine signaling.
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MESH Headings
- Blotting, Western
- Calcium/metabolism
- Catalysis
- Cell Line
- Cell Line, Transformed
- Chemokine CXCL12
- Chemokines/metabolism
- Chemokines, CXC/metabolism
- Cytokines/metabolism
- DNA, Complementary/metabolism
- Dose-Response Relationship, Drug
- Electrophoresis, Polyacrylamide Gel
- Humans
- Immunoprecipitation
- Interleukin-2/metabolism
- Janus Kinase 2
- Janus Kinase 3
- Jurkat Cells
- Leukocytes, Mononuclear/cytology
- Leukocytes, Mononuclear/metabolism
- Ligands
- Lymphocytes/metabolism
- Mutation
- Mutation, Missense
- Phosphorylation
- Plasmids/metabolism
- Protein-Tyrosine Kinases/metabolism
- Proto-Oncogene Proteins/metabolism
- RNA, Small Interfering/metabolism
- Signal Transduction
- Time Factors
- Transfection
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Affiliation(s)
- Masato Moriguchi
- Molecular Immunology and Inflammation Branch, NIAMS, Laboratory of Host Defenses, NIAID, and Genetics and Molecular Biology Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
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73
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Howard OMZ, Dong HF, Su SB, Caspi RR, Chen X, Plotz P, Oppenheim JJ. Autoantigens signal through chemokine receptors: uveitis antigens induce CXCR3- and CXCR5-expressing lymphocytes and immature dendritic cells to migrate. Blood 2005; 105:4207-14. [PMID: 15713799 PMCID: PMC1895027 DOI: 10.1182/blood-2004-07-2697] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
We tested the hypothesis that interaction between autoantigens and chemoattractant receptors may be an important step in the development of autoimmunity. The retinal autoantigens S-antigen (S-Ag) and interphotoreceptor retinoid binding protein (IRBP) can induce autoimmune uveitis in rodent models. We evaluated the chemotactic activity of S-Ag and IRBP and found that both induced migration of human and mouse immature dendritic cells (iDCs) and lymphocytes, but not neutrophils, monocytes, or mature DCs. Cross-desensitization studies and single-receptor transfected cells revealed that subfamily of alpha chemokine receptors CXCR5 and CXCR3 mediated the chemotactic effect of IRBP, while only CXCR3 was required for the chemotactic response to S-Ag. Examination of the relationships between chemoattraction and the ability to elicit pathology at the protein or peptide levels in the mouse uveitis model revealed dissociation of the capacity to induce uveitis, lymphocyte proliferation, and chemoattraction. These studies suggest that IRBP and S-Ag can initiate innate and, in sensitive individuals, adaptive immune response by attracting iDCs and T and B cells expressing CXCR3 and CXCR5.
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Affiliation(s)
- O M Zack Howard
- National Cancer Institute-Center for Cancer Research, Laboratory of Molecular Immunoregulation, Basic Research Program, Science Applications International Corporation, Frederick, MD, USA.
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74
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Savino W, Smaniotto S, Dardenne M. Hematopoiesis. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2005; 567:167-85. [PMID: 16370140 DOI: 10.1007/0-387-26274-1_7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Wilson Savino
- Laboratory on Thymus Research, Department of Immunology, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
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75
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Hansen A, Reiter K, Ziprian T, Jacobi A, Hoffmann A, Gosemann M, Scholze J, Lipsky PE, Dörner T. Dysregulation of chemokine receptor expression and function by B cells of patients with primary Sjögren's syndrome. ACTA ACUST UNITED AC 2005; 52:2109-19. [PMID: 15986367 DOI: 10.1002/art.21129] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE To assess whether abnormal chemokine receptor expression and/or abnormal responsiveness to the cognate ligands might underlie some of the disturbances in B cell homeostasis characteristic of primary Sjögren's syndrome (SS). METHODS Chemokine receptor expression by CD27- naive and CD27+ memory B cells from patients with primary SS and healthy control subjects was analyzed using flow cytometry, single-cell reverse transcriptase-polymerase chain reaction (RT-PCR), and migration assays. RESULTS In contrast to healthy subjects, significantly higher expression of both surface CXCR4 and CXCR4 messenger RNA (mRNA) was seen in peripheral blood B cells from patients with primary SS. These differences were most prominent in CD27- naive B cells (P < or = 0.0006). In addition, significantly higher frequencies of CD27- naive B cells from patients with primary SS expressed mRNA for the inhibitory regulator of G protein signaling 13 (P = 0.001). Expression of CXCR5 by peripheral CD27+ memory B cells was moderately diminished in patients with primary SS compared with healthy controls (P = 0.038). No significant differences were noted in the expression of CXCR3, CCR6, CCR7, and CCR9 between B cells from healthy controls and those from patients with primary SS. Transmigration assays of blood B cells from patients with primary SS and healthy controls showed comparable responses of CD27- naive B cells but significantly diminished responses of activated primary SS CD27+ memory B cells to the ligands of CXCR4 and CXCR5, CXCL12 (P = 0.032), and CXCL13 (B lymphocyte chemoattractant; B cell-attracting chemokine 1; P = 0.018), respectively, when compared with those from healthy controls. Finally, compared with controls, peripheral reduction but glandular accumulation of CXCR4+,CXCR5+,CD27+ memory B cells was identified in patients with primary SS. CONCLUSION In primary SS, overexpression of CXCR4 by circulating blood B cells does not translate into enhanced migratory response to the cognate ligand, CXCL12. This migratory response may be modulated by intracellular regulators. Retention of CXCR4+,CXCR5+, CD27+ memory B cells in the inflamed glands seems to contribute to diminished peripheral CD27+ memory B cells in primary SS.
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Affiliation(s)
- Arne Hansen
- Department of Medicine, Outpatient Department, Charité University Hospital, Berlin, Germany.
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76
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Chong Y, Nabeshima S, Furusyo N, Murata M, Yamaji K, Hayashi J. Downregulation of CXCR5 in CD27- B cells of HIV-1 infected patients. J Med Virol 2004; 73:362-7. [PMID: 15170629 DOI: 10.1002/jmv.20099] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The CD27(-) (naive) B cells of HIV-1 infected patients have been shown to be increased in frequency and to be activated, as indicated by high CD38 expression on the cell surface. CXCR5, a B cell chemokine receptor, is expressed on circulating CD27(-) (naive) B cells and plays a pivotal role in peripheral B cell development. To investigate the effect of HIV-1 infection on the expression of this chemokine receptor on naive B cells, the expression level of CXCR5 on CD27(-) B cells was examined in 19 drug-naive HIV-1 infected patients, 27 HAART-treated patients, and 20 controls. CXCR5 expression on CD27(-) B cells was significantly lower in drug-naive patients than in HAART-treated patients and controls (P < 0.01). CD27(-) B cells with high CD38 expression exhibited low CXCR5 expression. The CXCR5 expression level on CD27(-) B cells recovered to within the normal range after effective antiretroviral therapy. These findings suggested that HIV-1 infection induces a remarkable phenotypic alteration of naive B cells and that the activated naive B cells found in HIV-1 infection downregulate CXCR5 on their surface. Impaired homing of naive B cells may contribute to HIV-1 induced immunological deficiencies.
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Affiliation(s)
- Yong Chong
- Department of General Medicine, Kyushu University Hospital, Higashiku, Fukuoka, Japan.
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77
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Clay CC, Rodrigues DSS, Brignolo LL, Spinner A, Tarara RP, Plopper CG, Leutenegger CM, Esser U. Chemokine networks and in vivo T-lymphocyte trafficking in nonhuman primates. J Immunol Methods 2004; 293:23-42. [PMID: 15541274 DOI: 10.1016/j.jim.2004.06.019] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2004] [Revised: 06/15/2004] [Accepted: 06/15/2004] [Indexed: 11/30/2022]
Abstract
T-lymphocyte migratory circuits in human and nonhuman primates remain largely unexplored due to the difficulty of defining cell trafficking in vivo. However, this knowledge may reveal critical aspects of immunity and T-lymphocyte homeostasis in both health and disease. Furthermore, in vivo T-lymphocyte trafficking studies may facilitate defining mechanism(s) of immune dysfunction in the nonhuman primate model for acquired immunodeficiency syndrome (AIDS). Here, we developed a model for in vivo T-lymphocyte trafficking in nonhuman primates, and delineated homing characteristics of unstimulated peripheral blood mononuclear cells (PBMCs) to lymphoid and nonlymphoid compartments in healthy rhesus macaques. T-lymphocyte homing of autologous, carboxyfluorescein diacetate succinimidyl ester (CFSE)-labeled PBMCs was defined within 48 h of intravenous transfer. The highest relative frequency of CFSE+ T lymphocytes was observed in peripheral blood and spleen. Expression of chemokine receptor CCR7 and its ligands correlated with recirculation of T lymphocytes through the periphery and homing to paracortical regions of lymph node, where cells remained largely excluded from B-cell follicles. T-lymphocyte trafficking was also detected to the liver and bone marrow, and at low levels to the thymus and small intestine. The liver contained the highest proportion of CD45RA- T lymphocytes, consistent with homing of activated/memory T lymphocytes to this nonlymphoid site. Our data suggest that lymphoid and nonlymphoid organs are under continuous immunosurveillance in healthy macaques, and that this model may serve to investigate aberrant patterns in disease.
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Affiliation(s)
- Candice C Clay
- Immunology Graduate Program, University of California at Davis, CA 95616, USA
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78
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Suematsu S, Watanabe T. Generation of a synthetic lymphoid tissue-like organoid in mice. Nat Biotechnol 2004; 22:1539-45. [PMID: 15568019 DOI: 10.1038/nbt1039] [Citation(s) in RCA: 113] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2004] [Accepted: 10/19/2004] [Indexed: 01/10/2023]
Abstract
Stromal cells play an important role in the formation of the normal organized microarchitecture of secondary lymphoid organs. Here we demonstrate that a tissue-engineered, lymphoid tissue-like organoid, which was constructed by transplantation of stromal cells embedded in biocompatible scaffolds into the renal subcapsular space in mice, had an organized tissue structure similar to secondary lymphoid organs. This organoid contained compartmentalized B-cell and T-cell clusters, high endothelial venule-like vessels, germinal centers and follicular dendritic cell networks. Furthermore, the organoid was transplantable to naive normal or severe combined immunodeficiency (SCID) mice, and antigen-specific, IgG-isotype antibody formation could be induced soon after intravenous administration of the antigen. This simplified system of lymphoid tissue-like organoid construction will facilitate analyses of cell-cell interactions required for development of secondary lymphoid organs and efficient induction of adaptive immune responses, and may have possible applications in the treatment of immune deficiency.
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Affiliation(s)
- Sachiko Suematsu
- Research Unit for Immune Surveillance, RIKEN Research Center for Allergy and Immunology, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama City, Kanagawa, 230-0045, Japan.
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79
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Chemokine-mediated control of T cell traffic in lymphoid and peripheral tissues. Mol Immunol 2004; 42:799-809. [PMID: 15829268 DOI: 10.1016/j.molimm.2004.06.040] [Citation(s) in RCA: 213] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2004] [Accepted: 06/10/2004] [Indexed: 02/02/2023]
Abstract
Antigen-driven T cell education and subsequent pathogen elimination present particular challenges for the immune system. Pathogens generally enter the body at peripheral sites such as the skin, gastrointestinal tract or lung, areas from which naïve T cells are largely excluded. Instead, naïve T cells constantly recirculate through secondary lymphoid organs, such as lymph nodes and Peyer's patches, in search for antigen brought to these locations by means of afferent lymphatic channels. Here, antigen-loaded dendritic cells present antigen-peptide-MHC complexes to clonotypic T cells and provide appropriate co-stimulatory signals for immune response initiation. As a result, short-lived effector T cells and long-lived memory T cells are generated that reach the peripheral tissue for participation in immune responses and immune surveillance. Effector and memory T cell relocation is non-random, due to tissue-specific "address codes" that allow proper tissue homing. This process involves adhesion molecules, including selectins, integrins, and corresponding vascular ligands as well as the large family of chemokines and their receptors. Here, we discuss the changes in chemokine receptor expression that occur during T cell activation and differentiation, and the ways in which these changes impact on the migration potential of naïve, effector, and memory T cells. We summarize our current understanding of T cell homing to the T zone and B cell follicles within secondary lymphoid tissues and highlight the two chemokine receptors CCR7 and CXCR5 that recognize chemokines constitutively present either in the T zone (CCR7 ligands CCL19/ELC and CCL21/SLC) or follicular compartment (CXCR5 ligand CXCL13/BCA-1). CCR7 is characteristic for naive and central memory T (T(CM)) cells whereas CXCR5 distinguishes follicular B helper T (T(FH)) cells. In addition, we further subdivide long-lived memory T cells into CCR7-negative effector memory T (T(EM)) cells and peripheral immune surveillance T (T(PS)) cells. The latter term designates the extraordinarily large subset of memory T cells with primary residence in normal (healthy) peripheral tissues. Our current understanding of T(PS) cell migration and function is highly fragmentary, but these cells are thought to provide immediate protection locally at the site of pathogen entry. Here, we propose that the tissue distribution of T(PS) cells is determined by a distinct set of chemokines and corresponding receptors that differs from those operating in secondary lymphoid tissues and inflammatory sites.
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80
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Fahy OL, Townley SL, Coates NJ, Clark-Lewis I, McColl SR. Control of Salmonella dissemination in vivo by macrophage inflammatory protein (MIP)-3alpha/CCL20. J Transl Med 2004; 84:1501-11. [PMID: 15448707 DOI: 10.1038/labinvest.3700176] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
While chemokines are clearly important in the generation of protective immunity, the role of individual chemokines in the control of bacterial infection is still poorly understood. In this study, we investigated the role of macrophage inflammatory protein (MIP)-3alpha/CCL20, a chemokine that attracts activated T and B lymphocytes and immature dendritic cells, in host responses to bacterial infection. CCL20 production was induced in subcutaneous tissue in the BALB/c mouse in response to Salmonella enteritidis, Staphylococcus aureus and zymosan, with S. enteritidis being the most potent. S. enteritidis induced CCL20 production in the spleen following either oral administration or injection into the peritoneal cavity. In contrast, no increase was observed in the Peyer's patches. In this model, following intraperitoneal injection, dose-dependent colonization of the spleen and Peyer's patches by S. enteritidis, expression of IFNgamma and IL-4, and production of antibodies against the S. enteritidis surface antigen SefA were observed. Prior treatment with neutralizing antibodies against CCL20 enhanced bacterial dissemination to the spleen and Peyer's patches and strongly biased the IFNgamma/IL-4 ratio towards a type 2 profile in the spleen, while the humoral response was unaffected. In contrast, treatment with neutralizing anti-MIP-1alpha/CCL3 antibodies enhanced the bacterial burden in the Peyer's patches but not in the spleen, had no significant effect on the cytokine ratio, but significantly inhibited anti-SefA production. Together, these results demonstrate an important role for CCL20 in the control of bacterial infection and more specifically in the regulation of cell-mediated immunity against intracellular bacteria such as S. enteritidis.
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Affiliation(s)
- Olivier L Fahy
- School of Molecular and Biomedical Science, University of Adelaide, Adelaide, South Australia, Australia.
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81
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Sumen C, Mempel TR, Mazo IB, von Andrian UH. Intravital microscopy: visualizing immunity in context. Immunity 2004; 21:315-29. [PMID: 15357943 DOI: 10.1016/j.immuni.2004.08.006] [Citation(s) in RCA: 149] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2004] [Revised: 08/08/2004] [Accepted: 08/10/2004] [Indexed: 11/18/2022]
Abstract
Recent advances in photonics, particularly multi-photon microscopy (MPM) and new molecular and genetic tools are empowering immunologists to answer longstanding unresolved questions in living animals. Using intravital microscopy (IVM) investigators are dissecting the cellular and molecular underpinnings controlling immune cell motility and interactions in tissues. Recent IVM work showed that T cell responses to antigen in lymph nodes are different from those observed in vitro and appear dictated by factors uniquely relevant to intact organs. Other IVM models, particularly in the bone marrow, reveal how different anatomic contexts regulate leukocyte development, immunity, and inflammation. This article will discuss the current state of the field and outline how IVM can generate new discoveries and serve as a "reality check" for areas of research that were formerly the exclusive domain of in vitro experimentation.
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Affiliation(s)
- Cenk Sumen
- The CBR Institute for Biomedical Research, Boston, MA 02115, USA
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82
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Odendahl M, Mei H, Hoyer BF, Jacobi AM, Hansen A, Muehlinghaus G, Berek C, Hiepe F, Manz R, Radbruch A, Dörner T. Generation of migratory antigen-specific plasma blasts and mobilization of resident plasma cells in a secondary immune response. Blood 2004; 105:1614-21. [PMID: 15507523 DOI: 10.1182/blood-2004-07-2507] [Citation(s) in RCA: 334] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Maintenance of protective humoral immunity depends on the generation and survival of antibody-secreting cells. The bone marrow provides niches for long-term survival of plasma cells generated in the course of systemic immune responses in secondary lymphoid organs. Here, we have analyzed migratory human plasma blasts and plasma cells after secondary vaccination with tetanus toxin. On days 6 and 7 after immunization, CD19(+)/CD27(high)/intracellular immunoglobulin G(high) (IgG(high))/HLA-DR(high)/CD38(high)/CD20(-)/CD95(+) tetanus toxin-specific antibody-secreting plasma blasts were released in large numbers from the secondary lymphoid organs into the blood. These cells show chemotactic responsiveness toward ligands for CXCR3 and CXCR4, probably guiding them to the bone marrow or inflamed tissue. At the same time, a population of CD19(+)/CD27(high)/intracellular IgG(high)/HLA-DR(low)/CD38(+)/CD20(-)/CD95(+) cells appeared in the blood in large numbers. These cells, with the phenotype of long-lived plasma cells, secreted antibodies of unknown specificity, not tetanus toxoid. The appearance of these plasma cells in the blood indicates successful competition for survival niches in the bone marrow between newly generated plasma blasts and resident plasma cells as a fundamental mechanism for the establishment of humoral memory and its plasticity.
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MESH Headings
- Adult
- Antibodies, Bacterial/biosynthesis
- Antibody Specificity
- Antibody-Producing Cells/immunology
- Antigens, CD19/biosynthesis
- B-Lymphocyte Subsets/cytology
- B-Lymphocyte Subsets/immunology
- Chemokine CXCL12
- Chemokine CXCL9
- Chemokines, CXC/metabolism
- Chemotaxis, Leukocyte/immunology
- Epitopes, B-Lymphocyte/immunology
- Female
- HLA-DR Antigens/biosynthesis
- Humans
- Immunization, Secondary
- Immunologic Memory
- Immunophenotyping
- Intercellular Signaling Peptides and Proteins/metabolism
- Kinetics
- Lymphocyte Activation
- Lymphocyte Count
- Male
- Plasma Cells/cytology
- Plasma Cells/immunology
- Plasma Cells/metabolism
- Receptors, CXCR3
- Receptors, CXCR4/biosynthesis
- Receptors, Chemokine/biosynthesis
- Tetanus Toxoid/administration & dosage
- Tetanus Toxoid/immunology
- Tumor Necrosis Factor Receptor Superfamily, Member 7/biosynthesis
- Vaccines, Synthetic/immunology
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Affiliation(s)
- Marcus Odendahl
- Department of Medicine, Charité, Humbold University, D-10117 Berlin, Germany
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83
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Abstract
Although it is widely supposed that chemokines play a role in the thymus, most existing evidence is circumstantial. In this issue, two groups provide direct evidence that the chemokine receptor CCR7 is required for normal thymocyte migration (Ueno, T., F. Saito, D. Gray, S. Kuse, K. Hieshima, H. Nakano, T. Kakiuchi, M. Lipp, R. Boyd, and Y. Takahama. 2004. J. Exp. Med. 200:493-505; Misslitz, A., O. Pabst, G. Hintzen, L. Ohl, E. Kremmer, H. T. Petrie, and R. Forster. 2004. J. Exp. Med. 200:481-491). The two papers focus on distinct and opposite migration events, an early outward migration and a later inward migration. Together these papers provide a fascinating picture of the complex role of CCR7 in orchestrating thymocyte migration.
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Affiliation(s)
- Colleen M Witt
- Department of Molecular and Cell Biology, 471 Life Sciences Addition, University of California, Berkeley 94720, USA.
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84
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Bonizzi G, Bebien M, Otero DC, Johnson-Vroom KE, Cao Y, Vu D, Jegga AG, Aronow BJ, Ghosh G, Rickert RC, Karin M. Activation of IKKalpha target genes depends on recognition of specific kappaB binding sites by RelB:p52 dimers. EMBO J 2004; 23:4202-10. [PMID: 15470505 PMCID: PMC524385 DOI: 10.1038/sj.emboj.7600391] [Citation(s) in RCA: 260] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2004] [Accepted: 08/10/2004] [Indexed: 12/18/2022] Open
Abstract
IkappaB Kinase (IKK)alpha is required for activation of an alternative NF-kappaB signaling pathway based on processing of the NF-kappaB2/p100 precursor protein, which associates with RelB in the cytoplasm. This pathway, which activates RelB:p52 dimers, is required for induction of several chemokine genes needed for organization of secondary lymphoid organs. We investigated the basis for the IKKalpha dependence of the induction of these genes in response to engagement of the lymphotoxin beta receptor (LTbetaR). Using chromatin immunoprecipitation, we found that the promoters of organogenic chemokine genes are recognized by RelB:p52 dimers and not by RelA:p50 dimers, the ubiquitous target for the classical NF-kappaB signaling pathway. We identified in the IKKalpha-dependent promoters a novel type of NF-kappaB-binding site that is preferentially recognized by RelB:p52 dimers. This site links induction of organogenic chemokines and other important regulatory molecules to activation of the alternative pathway.
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Affiliation(s)
- Giuseppina Bonizzi
- Laboratory of Gene Regulation and Signal Transduction, Department of Pharmacology, School of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Magali Bebien
- Laboratory of Gene Regulation and Signal Transduction, Department of Pharmacology, School of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Dennis C Otero
- Division of Biological Sciences and UCSD Cancer Center, University of California, San Diego, La Jolla, CA, USA
| | - Kirsten E Johnson-Vroom
- Division of Biological Sciences and UCSD Cancer Center, University of California, San Diego, La Jolla, CA, USA
| | - Yixue Cao
- Laboratory of Gene Regulation and Signal Transduction, Department of Pharmacology, School of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Don Vu
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA, USA
| | - Anil G Jegga
- Department of Biomedical Informatics, Children's Hospital Research, Foundation and University of Cincinnati, Cincinnati, OH, USA
| | - Bruce J Aronow
- Department of Biomedical Informatics, Children's Hospital Research, Foundation and University of Cincinnati, Cincinnati, OH, USA
| | - Gourisankar Ghosh
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA, USA
| | - Robert C Rickert
- Division of Biological Sciences and UCSD Cancer Center, University of California, San Diego, La Jolla, CA, USA
| | - Michael Karin
- Laboratory of Gene Regulation and Signal Transduction, Department of Pharmacology, School of Medicine, University of California, San Diego, La Jolla, CA, USA
- Laboratory of Gene Regulation and Signal Transduction, Department of Pharmacology, School of Medicine, University of California, San Diego, 9500 Gilman Drive, La, Jolla, CA 92093-0636, USA. Tel.: +1 858 534 1361; Fax: +1 858 534 8158; E-mail:
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85
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Curnow SJ, Wloka K, Faint JM, Amft N, Cheung CMG, Savant V, Lord J, Akbar AN, Buckley CD, Murray PI, Salmon M. Topical glucocorticoid therapy directly induces up-regulation of functional CXCR4 on primed T lymphocytes in the aqueous humor of patients with uveitis. THE JOURNAL OF IMMUNOLOGY 2004; 172:7154-61. [PMID: 15153539 DOI: 10.4049/jimmunol.172.11.7154] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Overexpression of the constitutive chemokine receptor CXCR4 has been shown to contribute to the accumulation of leukocytes at sites of chronic inflammation. Glucocorticoids are widely used to treat inflammatory disorders such as uveitis to considerable effect, yet paradoxically have been reported to increase CXCR4 expression in vitro. We show here that ocular lymphocytes isolated from patients with uveitis who had been treated with topical glucocorticoids expressed highly elevated levels of CXCR4. The up-regulation of CXCR4 could be reproduced in vitro by culture of CD4(+) T cells with aqueous humor (AqH), indicating a role for the ocular microenvironment rather than preferential recruitment of CXCR4(+) cells. Untreated uveitis and noninflammatory AqH up-regulated CXCR4 to a limited extent; this was dependent on TGF-beta2. However, the highest levels of CXCR4 both in vivo and in vitro were found in the glucocorticoid-treated patients. Glucocorticoids appeared to be directly responsible for the induction of CXCR4 in treated patients, as the glucocorticoid receptor antagonist RU38486 inhibited the in vitro up-regulation by AqH from these patients. Dexamethasone selectively up-regulated CXCR4 in vitro, but not any of a wide range of other chemokine receptors. CXCL12, the ligand for CXCR4, was present in AqH under noninflammatory conditions, but the levels were low in untreated uveitis and undetectable in treated uveitis AqH. The importance of these results for the treatment of HIV patients with glucocorticoids is discussed as well as a role for glucocorticoid-induced CXCR4 up-regulation and CXCL12 down-regulation in controlling the migration of lymphocyte populations, resulting in resolution of inflammation.
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Affiliation(s)
- S John Curnow
- Department of Rheumatology, Medical Research Council Centre for Immune Regulation, Division of Immunity and Infection, Medical School, University of Birmingham, Birmingham, United Kingdom
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86
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Moratz C, Hayman JR, Gu H, Kehrl JH. Abnormal B-cell responses to chemokines, disturbed plasma cell localization, and distorted immune tissue architecture in Rgs1-/- mice. Mol Cell Biol 2004; 24:5767-75. [PMID: 15199133 PMCID: PMC480912 DOI: 10.1128/mcb.24.13.5767-5775.2004] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Normal lymphoid tissue development and function depend upon chemokine-directed cell migration. Since chemokines signal through heterotrimeric G-protein-coupled receptors, RGS proteins, which act as GTPase-activating proteins for Galpha subunits, likely fine tune the cellular responses to chemokines. Here we show that Rgs1(-/-) mice possess B cells that respond excessively and desensitize improperly to the chemokines CXCL12 and CXCL13. Many of the B-cell follicles in the spleens of Rgs1(-/-) mice have germinal centers even in the absence of immune stimulation. Furthermore, immunization of these mice leads to exaggerated germinal center formation; partial disruption of the normal architecture of the spleen and Peyer's patches; and abnormal trafficking of immunoglobulin-secreting cells. These results reveal the importance of a regulatory mechanism that limits and desensitizes chemokine receptor signaling.
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Affiliation(s)
- Chantal Moratz
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
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87
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Rot A, von Andrian UH. Chemokines in innate and adaptive host defense: basic chemokinese grammar for immune cells. Annu Rev Immunol 2004; 22:891-928. [PMID: 15032599 DOI: 10.1146/annurev.immunol.22.012703.104543] [Citation(s) in RCA: 910] [Impact Index Per Article: 45.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Chemokines compose a sophisticated communication system used by all our cell types, including immune cells. Chemokine messages are decoded by specific receptors that initiate signal transduction events leading to a multitude of cellular responses, leukocyte chemotaxis and adhesion in particular. Critical determinants of the in vivo activities of chemokines in the immune system include their presentation by endothelial cells and extracellular matrix molecules, as well as their cellular uptake via "silent" chemokine receptors (interceptors) leading either to their transcytosis or to degradation. These regulatory mechanisms of chemokine histotopography, as well as the promiscuous and overlapping receptor specificities of inflammation-induced chemokines, shape innate responses to infections and tissue damage. Conversely, the specific patterns of homeostatic chemokines, where each chemokine is perceived by a single receptor, are charting lymphocyte navigation routes for immune surveillance. This review presents our current understanding of the mechanisms that regulate the cellular perception and pathophysiologic meaning of chemokines.
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Affiliation(s)
- Antal Rot
- Novartis Institute for Biomedical Research, Vienna, A-1235 Austria.
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88
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Abstract
The cellular and molecular dynamics underlying intrathymic T-cell development are still poorly understood. Dynamic imaging techniques offer new opportunities for dissecting the complex journey of developing T cells in the thymus. In particular, two-photon laser scanning microscopy has recently demonstrated great promise in tracking lymphocyte behavior in tissue environments. Resolving thymocyte behavior at the single-cell level should help to clarify the mode of trafficking in the thymus and identify the spatio-temporal aspects of thymic selection events.
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Affiliation(s)
- Philippe Bousso
- Institut National de la Sante et de la Recherche Medicale U277, Département d'Immunologie, Institut Pasteur, 25 Rue du Dr Roux, 75015 Paris, France.
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89
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Voon DC, Subrata LS, Karimi M, Ulgiati D, Abraham LJ. TNF and phorbol esters induce lymphotoxin-beta expression through distinct pathways involving Ets and NF-kappa B family members. THE JOURNAL OF IMMUNOLOGY 2004; 172:4332-41. [PMID: 15034048 DOI: 10.4049/jimmunol.172.7.4332] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Lymphotoxin-beta (LT-beta) is a transmembrane protein expressed mainly on cells of the lymphoid lineage. It associates with LT-alpha on the cell surface to form the heterotrimeric LTalpha1,beta2 complex, which binds the LT-beta receptor. Membrane lymphotoxin is a crucial signal for the appropriate development of lymph nodes and Peyer's patches, and in the formation of B and T cell compartments in the spleen. In this study we report the characterization of mechanisms governing both basal as well as PMA- and TNF-inducible regulation of the human LT-beta promoter. Using a Jurkat T cell line, induction with either PMA or TNF resulted in an increase in mRNA levels compared with uninduced values. This induction corresponded to an increase in transcriptional activity of the human LT-beta promoter. Mutational and deletion analysis demonstrated the importance of Ets and NF-kappaB motifs in the regulation of basal transcription. Furthermore, the ability of PMA to induce activity was lost in the Ets mutant constructs. Interestingly, the same mutation had little effect on the ability of TNF to induce transcription of the LT-beta promoter. TNF inducibility was localized to the NF-kappaB site positioned at -83 of the promoter sequence. Thus, it appears that the Ets site, although playing a major role in PMA induction, did not mediate TNF inducibility. Therefore, our study suggests that alternative signaling pathways may be present to induce the expression of LT-beta in response to different immunological or inflammatory stimuli.
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Affiliation(s)
- Dominic C Voon
- Biochemistry and Molecular Biology, School of Biomedical and Chemical Sciences and the Center for Medical Research, University of Western Australia, Crawley, Western Australia, Australia
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90
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Kwan J, Killeen N. CCR7 directs the migration of thymocytes into the thymic medulla. THE JOURNAL OF IMMUNOLOGY 2004; 172:3999-4007. [PMID: 15034011 DOI: 10.4049/jimmunol.172.7.3999] [Citation(s) in RCA: 130] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Developing thymocytes migrate from the cortex to the medulla of the thymus as a consequence of positive selection. This migration is likely to be essential for tolerance because it allows the developing cells to move into an environment that is optimal for negative selection. Guidance mechanisms that draw positively selected thymocytes into the medulla have not been clarified, but several studies have implicated chemokines in the process. CCR7, the receptor for the medullary chemokines CCL19 and CCL21, is induced on thymocytes during their positive selection. In this study we show that premature expression of CCR7 repositions CD4(+)CD8(+) double-positive cells into the medulla of transgenic mice. This repositioning of the thymocytes is accompanied by impairment of their development. The data show the involvement of CCR7 in medullary migration and emphasize the importance of proper thymocyte positioning for efficient T cell development.
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MESH Headings
- Animals
- Animals, Newborn
- CD4 Antigens/biosynthesis
- CD8 Antigens/biosynthesis
- Cell Aggregation/genetics
- Cell Aggregation/immunology
- Cell Differentiation/genetics
- Cell Differentiation/immunology
- Chemokines, CC/metabolism
- Chemotaxis, Leukocyte/immunology
- Ligands
- Mice
- Mice, Inbred C57BL
- Mice, Inbred DBA
- Mice, Transgenic
- Receptors, CCR7
- Receptors, Chemokine/biosynthesis
- Receptors, Chemokine/genetics
- Receptors, Chemokine/physiology
- Spleen/cytology
- Spleen/immunology
- Spleen/metabolism
- T-Lymphocyte Subsets/cytology
- T-Lymphocyte Subsets/immunology
- T-Lymphocyte Subsets/metabolism
- T-Lymphocyte Subsets/pathology
- Thymus Gland/cytology
- Thymus Gland/immunology
- Thymus Gland/metabolism
- Thymus Gland/pathology
- Transgenes/immunology
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Affiliation(s)
- Joanne Kwan
- Department of Microbiology and Immunology, University of California, San Francisco, CA 94143, USA
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91
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Serafini B, Rosicarelli B, Magliozzi R, Stigliano E, Aloisi F. Detection of ectopic B-cell follicles with germinal centers in the meninges of patients with secondary progressive multiple sclerosis. Brain Pathol 2004; 14:164-74. [PMID: 15193029 PMCID: PMC8095922 DOI: 10.1111/j.1750-3639.2004.tb00049.x] [Citation(s) in RCA: 872] [Impact Index Per Article: 43.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Multiple sclerosis (MS) is characterized by synthesis of oligoclonal immunoglobulins and the presence of B-cell clonal expansions in the central nervous system (CNS). Because ectopic lymphoid tissue generated at sites of chronic inflammation is thought to be important in sustaining immunopathological processes, we have investigated whether structures resembling lymphoid follicles could be identified in the CNS of MS patients. Sections from post-mortem MS brains and spinal cords were screened using immunohistochemistry for the presence of CD20+ B-cells, CD3+ T-cells, CD138+ plasma cells and CD21+, CD35+ follicular dendritic cells, and for the expression of lymphoid chemokines (CXCL 13, CCL21) and peripheral node addressin (PNAd). Lymphoid follicle-like structures containing B-cells, T-cells and plasma cells, and a network of follicular dendritic cells producing CXCL13 were observed in the cerebral meninges of 2 out of 3 patients with secondary progressive MS, but not in relapsing remitting and primary progressive MS. We also show that proliferating B-cells are present in intrameningeal follicles, a finding which is suggestive of germinal center formation. No follicle-like structures were detected in parenchymal lesions. The formation of ectopic lymphoid follicies in the meninges of patients with MS could represent a critical step in maintaining humoral autoimmunity and in disease exacerbation.
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Affiliation(s)
- Barbara Serafini
- Department of Cell Biology and Neuroscience, Istituto Superiore di Sanità, Rome, Italy
| | - Barbara Rosicarelli
- Department of Cell Biology and Neuroscience, Istituto Superiore di Sanità, Rome, Italy
| | - Roberta Magliozzi
- Department of Cell Biology and Neuroscience, Istituto Superiore di Sanità, Rome, Italy
| | - Egidio Stigliano
- Institute of Pathological Anatomy, U.C.S.C. Policlinico A. Gemelli, Rome, Italy
| | - Francesca Aloisi
- Department of Cell Biology and Neuroscience, Istituto Superiore di Sanità, Rome, Italy
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92
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Abstract
The pathogenic roles of B cells in human autoimmune diseases involve a multitude of mechanistic pathways and include the well-established contributions of autoantibodies and immune complexes that induce local inflammatory reactions and tissue destruction. Recent results using several novel B cell-directed therapies have provided new insights into additional roles of B cells in human autoimmunity. In this review, we will highlight some of these studies and discuss how clinical insights parallel murine models of normal immunity and autoimmunity.
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Affiliation(s)
- Flavius Martin
- Department of Immunology, One DNA Way, MS-34, South San Francisco, CA 94080 USA.
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93
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Abstract
The surge in interest in chemokines is explained by the recognition that numerous aspects of immunity are intimately related to leukocyte traffic. Chemokines are leukocyte attractants but also contribute to immune processes that do not directly involve leukocyte migration. Recent progress is most evident in the areas of lymphocyte development, immune response initiation and immune pathology. Important observations have also been reported on chemokine-receptor interactions, signal transduction and cellular responses. New insights into the role of chemokines in leukocyte attraction and relocation will be discussed, with emphasis on the distinct levels of leukocyte migration control that ultimately determine the performance of our immune defense system.
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Affiliation(s)
- Bernhard Moser
- Theodor-Kocher Institute, University of Bern, Freiestrasse 1, CH-3012 Bern, Switzerland.
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94
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Mizushima T, Ito T, Kishi D, Kai Y, Tamagawa H, Nezu R, Kiyono H, Matsuda H. Therapeutic effects of a new lymphocyte homing reagent FTY720 in interleukin-10 gene-deficient mice with colitis. Inflamm Bowel Dis 2004; 10:182-92. [PMID: 15290910 DOI: 10.1097/00054725-200405000-00002] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BACKGROUND FTY720 is a novel reagent that possesses potent immunosuppressive activity. The immunosuppression induced by FTY720 is mediated by completely different mechanisms from those of conventional immunosuppressants, that is, by altering the tissue distribution of lymphocytes rather than inhibiting activation. In this study, we examined the efficacy of FTY720 in the treatment of chronic colitis in an interleukin-10 gene-deficient (IL-0-/-) mouse model. METHODS FTY720 was administered orally for 4 weeks to IL-10-/- mice with clinical signs of colitis. The gross and histologic appearance of the colon and the numbers, phenotype, cytokine production, and apoptosis of lymphocytes were compared with those characteristics in a control group. RESULTS Single-dose administration of FTY720 resulted in the sequestration of circulating lymphocytes within the secondary lymphoid tissues. Four-week administration resulted in a significant reduction of the CD4+ T lymphocytes subpopulation in the colonic lamina propria and IFN-gamma production of the colonic lymphocytes, accompanied by a significant decrease in the severity of colitis. CONCLUSIONS Treatment of established colitis in IL-10-/- mice with FTY720 ameliorated the colitis, probably as a result of decreasing the number of lymphocytes in the colonic mucosa and an associated reduction in IFN-gamma production.
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Affiliation(s)
- Tsunekazu Mizushima
- Department of Surgery (E1), Osaka University Graduate School of Medicine, Japan
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95
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Magliozzi R, Columba-Cabezas S, Serafini B, Aloisi F. Intracerebral expression of CXCL13 and BAFF is accompanied by formation of lymphoid follicle-like structures in the meninges of mice with relapsing experimental autoimmune encephalomyelitis. J Neuroimmunol 2004; 148:11-23. [PMID: 14975582 DOI: 10.1016/j.jneuroim.2003.10.056] [Citation(s) in RCA: 239] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2003] [Revised: 10/06/2003] [Accepted: 10/22/2003] [Indexed: 10/26/2022]
Abstract
Given the abnormalities in B-cell activity occurring in the central nervous system (CNS) of patients with multiple sclerosis (MS), we have explored the possibility that CNS inflammation induced in mouse models of experimental autoimmune encephalomyelitis (EAE) triggers expression of molecules that control the development and functional organization of lymphoid follicles, the sites where B-cell responses are initiated. By reverse transcription-polymerase chain reaction (RT-PCR), we find that gene expression of CXCL13, a chemokine involved in B-cell recruitment into lymphoid follicles, and BAFF, a key regulator of B-cell survival, is markedly and persistently upregulated in the CNS of mice with relapsing-remitting and chronic-relapsing EAE. Using immunohistochemical techniques, we also show the presence of lymphoid follicle-like structures containing B cells and a reticulum of CXCL13+ and FDC-M1+ follicular dendritic cells within the meninges of several mice undergoing progressive relapsing EAE. These observations indicate that, under chronic inflammatory conditions, the less immunoprivileged meningeal compartment is the site where ectopic lymphoid follicles preferentially develop and where pathogenic B-cell responses could be sustained in autoimmune disorders of the CNS.
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Affiliation(s)
- Roberta Magliozzi
- Neurophysiology Unit, Laboratory Organ, System Pathophysiology, Department of Cell Biology and Neuroscience, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Roma, Italy
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96
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Katakai T, Hara T, Sugai M, Gonda H, Shimizu A. Th1-biased tertiary lymphoid tissue supported by CXC chemokine ligand 13-producing stromal network in chronic lesions of autoimmune gastritis. THE JOURNAL OF IMMUNOLOGY 2004; 171:4359-68. [PMID: 14530361 DOI: 10.4049/jimmunol.171.8.4359] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Secondary lymphoid tissue is developmentally programmed and characterized by well-ordered compartmentalization of lymphocyte subsets and specialized stromal cells supporting the tissue architecture. By contrast, tertiary lymphoid tissue is defined as that induced in ectopic sites by inflammation, although its immunological role is largely unknown. In this study, we characterize the lymphoid tissue induced in the chronic lesion of murine autoimmune gastritis (AIG). Within the lymphoid cluster in the gastric mucosa, there is a clear segregation of T and B cells. Follicle-like B cell areas are always located on the luminal side of the mucosa, while T cells are located in the basal part. A typical lymphoid reticular network and follicular dendritic cells support the structure. Importantly, complement receptor 1(+) follicular dendritic cells within the follicle express a B cell homing chemokine, CXC chemokine ligand 13. The number and size of the clusters correlate with the age of the mice and the serum autoantibody titer, suggesting the functional importance of the clusters in local Ab production, although involvement of the autoantibody in the disease progression is still unclear. AIG gastric lesions are known to constitute a Th1-biased, memory T cell-dependent immunomicroenvironment. The expression pattern of cytokines, including lymphotoxin-beta, and chemokines in the AIG stomach is consistent with this observation. Taken together, these facts suggest that, during the chronic phase of autoimmunity, long-lasting lymphocyte infiltration probably induces a unique tertiary lymphoid tissue that has a function distinct from that of regional lymph nodes. These neolymphoid tissues may maintain the local self reactivity supporting the vicious cycle of Th1-type reaction as well as autoantibody production.
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Affiliation(s)
- Tomoya Katakai
- Center for Molecular Biology and Genetics, Kyoto University, Japan
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97
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Moratz C, Harrison K, Kehrl JH. Regulation of chemokine-induced lymphocyte migration by RGS proteins. Methods Enzymol 2004; 389:15-32. [PMID: 15313557 DOI: 10.1016/s0076-6879(04)89002-5] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
G-protein-coupled receptors (GPCRs) activate heterotrimeric G proteins by inducing the G-protein alpha (Galpha) subunit to exchange guanosine diphosphate for guanosine triphosphate. Regulators of G-protein signaling (RGS) proteins enhance the deactivation of Galpha subunits, thereby reducing the activation of downstream effectors. Several members of the RGS family are expressed in lymphocytes. Among RGS proteins with the highest levels of expression are RGS1, RGS2, RGS10, RGS13, RGS14, RGS16, and RGS19. Perhaps the most important G-protein-coupled receptors in lymphocytes potentially subject to regulation by RGS proteins are the chemokine receptors. By signaling through these receptors, chemokines help orchestrate immune cell trafficking both during the development of the immune system and during responses to exogenous or infectious agents. Thus, the level and regulation of RGS proteins in lymphocytes likely significantly impact lymphocyte migration and function. This article provides some tools for the analysis of RGS protein expression in lymphocytes and outlines a number of methods for the analysis of the effects of RGS proteins on lymphocyte migration and chemokine receptor signaling.
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Affiliation(s)
- Chantal Moratz
- B Cell Molecular Immunology Section, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
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Salomonsson S, Jonsson MV, Skarstein K, Brokstad KA, Hjelmström P, Wahren-Herlenius M, Jonsson R. Cellular basis of ectopic germinal center formation and autoantibody production in the target organ of patients with Sjögren's syndrome. ACTA ACUST UNITED AC 2003; 48:3187-201. [PMID: 14613282 DOI: 10.1002/art.11311] [Citation(s) in RCA: 329] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
OBJECTIVE To investigate functional properties of the germinal center (GC)-like structures observed in salivary glands of patients with Sjögren's syndrome (SS) and to determine the frequency with which such structures develop. METHODS Hematoxylin and eosin-stained sections from 165 minor salivary gland biopsy samples were screened for GC-like structures. Expression of markers for GCs (CD3, CD20, Ki-67, CD35, CD31), adhesion molecules (intercellular adhesion molecule 1, lymphocyte function-associated antigen 1, vascular cell adhesion molecule 1, very late activation antigen 4), chemokines (CXCL13, CCL21, CXCL12), and production of autoantibodies (anti-Ro/SSA and anti-La/SSB) was investigated by immunohistochemistry. Apoptosis was investigated by TUNEL staining. RESULTS GC-like structures were observed in 28 of 165 patients (17%). When GCs were defined as T and B cell aggregates with proliferating cells with a network of follicular dendritic cells and activated endothelial cells, such microenvironments were found in all patients in whom structures with GC-like morphology were observed. The defined microenvironments were not found in patients without apparent GC-like structures. The GCs formed within the target tissue showed functional features with production of autoantibodies (anti-Ro/SSA and anti-La/SSB) and apoptotic events (by TUNEL staining), and the local production of anti-Ro/SSA and anti-La/SSB autoantibodies was significantly increased (P = 0.04) in patients with GC development. CONCLUSION Lymphoid neogenesis and functional ectopic GC formation take place in salivary glands of a subset of patients with SS. Our data suggest that the ectopic secondary lymphoid follicles contain all elements needed for driving the autoimmune response. Our findings underscore a key role for the target organ in recruitment of inflammatory cells and propagation of the disease process.
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Abstract
PURPOSE OF REVIEW WHIM syndrome (the association of warts, hypogammaglobulinemia, recurrent bacterial infections, and 'myelokathexis') is a rare congenital form of neutropenia associated with an unusual immune disorder involving hypogammaglonulinemia and abnormal susceptibility to warts. In this review, we describe the clinical, laboratory and genetic features of WHIM syndrome. RECENT FINDINGS The identification of chemokine receptor CXCR4 as the causative gene of WHIM syndrome yields new interest in the study of this disease as a model for the comprehension of CXCR4 biology in humans and highlights the importance of the chemokine network for inducing effective immune responses and governing leukocyte trafficking. SUMMARY CXCR4 participates in several biological processes (bone marrow hematopoiesis, cardiogenesis, angiogenesis, neurogenesis) and is implicated in different clinical pathologic conditions (WHIM, HIV infection, tumor metastatization, autoimmunity). Pharmacologic agents that modulate CXCR4 expression/function are already available and promise a wide range of future clinical applications.
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Affiliation(s)
- A Virginia Gulino
- Metabolism Branch, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA.
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Abstract
Blood lymphocyte numbers, which are maintained by recirculation through secondary lymphoid organs, are essential for the efficient development of immune responses. Recirculating populations of B and T lymphocytes are regulated by the sphingosine-1-phosphate (S1P) receptor-dependent control of lymphocyte egress. T-cell egress from thymus into blood, egress from lymph node and Peyer's patch into lymph, and B-cell egress into lymph are rapidly and completely inhibited by agonism of S1P receptors. Mesenteric lymph nodes show log-jamming of lymphocytes subjacent to sinus-lining endothelium. Agonism of S1P receptors produces rapid peripheral blood lymphopenia, which is maintained in the presence of receptor agonist. Effector CD4+ and CD8+ T cells, produced by clonal expansion in draining lymph node in response to antigen, are sequestered in lymph node and fail to reach the peripheral blood. The S1P receptor system may represent an early physiological link between the non-specific inflammatory response and the alteration of lymphocyte traffic through draining lymph nodes. Pharmacological subversion of the S1P receptor system, through systemic S1P agonist-induced inhibition of lymphocyte egress, suppresses antigenic responses to peripheral, but not to systemically, delivered antigen. This inhibition induces significant immunosuppression in models of transplantation and autoimmune tissue damage that may prove to be of clinical benefit.
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Affiliation(s)
- Hugh Rosen
- Department of Immunology, The Scripps Research Institute, La Jolla, CA 92037, USA.
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