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Koutsogiannaki S, Kim S, Yuki K. Age-dependent transcriptomic profiles of leukocytes in pediatric population. Clin Immunol 2023; 255:109728. [PMID: 37562722 PMCID: PMC10543464 DOI: 10.1016/j.clim.2023.109728] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 07/24/2023] [Accepted: 07/30/2023] [Indexed: 08/12/2023]
Abstract
Immunity at birth is considered immature. Following birth, our immune function is considered to grow and reach maturation over time. To obtain granular information of leukocyte functions and transcriptomic profiles in pediatric cohort, we examined leukocyte profiles in infants, preschool and school children using single cell RNA sequencing of their peripheral blood mononuclear cells (PBMCs). Monocytes and natural killer (NK) cells showed immaturity in infants. Their innate and adaptive immunity was developed by preschool age. Adaptive immune cells showed different maturation patterns. CD4, CD8 naïve T cells and plasma cells continued to mature untill school age. In CD8 naïve T cells, innate immunity was upregulated in infants, in support of our knowledge that they manifests more innate cell-like phenotype soon after birth. Many signaling pathways have been differentially up- and/or down-regulated in infants, preschool and school children. Their contribution to the development of the immune system needs to be delineated.
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Affiliation(s)
- Sophia Koutsogiannaki
- Department of Anesthesiology, Critical Care and Pain Medicine, Cardiac Anesthesia Division, Boston Children's Hospital, Boston, MA, 02115, United States; Department of Anaesthesia and Immunology, Harvard Medical School, Boston, MA, 02115, United States; Broad Institute of MIT and Harvard, Cambridge, MA, 02141, United States
| | - Samuel Kim
- Department of Anesthesiology, Critical Care and Pain Medicine, Cardiac Anesthesia Division, Boston Children's Hospital, Boston, MA, 02115, United States
| | - Koichi Yuki
- Department of Anesthesiology, Critical Care and Pain Medicine, Cardiac Anesthesia Division, Boston Children's Hospital, Boston, MA, 02115, United States; Department of Anaesthesia and Immunology, Harvard Medical School, Boston, MA, 02115, United States; Broad Institute of MIT and Harvard, Cambridge, MA, 02141, United States.
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2
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Mansoor A, Kamran H, Akhter A, Seno R, Torlakovic EE, Roshan TM, Shabani-Rad MT, Elyamany G, Minoo P, Stewart D. Identification of Potential Therapeutic Targets for Plasmablastic Lymphoma Through Gene Expression Analysis: Insights into RAS and Wnt Signaling Pathways. Mod Pathol 2023; 36:100198. [PMID: 37105495 DOI: 10.1016/j.modpat.2023.100198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 03/20/2023] [Accepted: 04/17/2023] [Indexed: 04/29/2023]
Abstract
Plasmablastic lymphoma (PBL) is a rare and aggressive B-cell lymphoma with overlapping characteristics with diffuse large B-cell lymphoma (DLBCL) and multiple myeloma. Hyperactive Wnt signaling derails homeostasis and promotes oncogenesis and chemoresistance in DLBCL and multiple myeloma. Evidence suggests active cross-talk between the Wnt and RAS pathways impacting metastasis in solid cancers in which combined targeted therapies show effective results. Recent genomic studies in PBL demonstrated a high frequency of mutations linked with the RAS signaling pathway. However, the role of RAS and Wnt signaling pathway molecule expression in PBL remained unknown. We examined the expression of Wnt and RAS pathway-related genes in a well-curated cohort of PBL. Because activated B cells are considered immediate precursors of plasmablasts in B cell development, we compared this data with activated B-cell type DLBCL (ABC-DLBCL) patients, employing NanoString transcriptome analysis (770 genes). Hierarchical clustering revealed distinctive differential gene expression between PBL and ABC-DLBCL. Gene set enrichment analysis labeled the RAS signaling pathway as the most enriched (37 genes) in PBL, including upregulating critical genes, such as NRAS, RAF1, SHC1, and SOS1. Wnt pathway genes were also enriched (n = 22) by gene set enrichment analysis. Molecules linked with Wnt signaling activation, such as ligands or targets (FZD3, FZD7, c-MYC, WNT5A, WNT5B, and WNT10B), were elevated in PBL. Our data also showed that, unlike ABC-DLBCL, the deranged Wnt signaling activity in PBL was not linked with hyperactive nuclear factor κB and B-cell receptor signaling. In divergence, Wnt signaling inhibitors (CXXC4, SFRP2, and DKK1) also showed overexpression in PBL. The high expression of RAS signaling molecules reported may indicate linkage with gain-in-function RAS mutations. In addition, high expression of Wnt and RAS signaling molecules may pave pathways to explore benefiting from combined targeted therapies, as reported in solid cancer, to improve prognosis in PBL patients.
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Affiliation(s)
- Adnan Mansoor
- Department of Pathology & Laboratory Medicine, University of Calgary, and Alberta Precision Laboratories (APL), Calgary, Alberta, Canada.
| | - Hamza Kamran
- Department of Pathology & Laboratory Medicine, University of Calgary, and Alberta Precision Laboratories (APL), Calgary, Alberta, Canada
| | - Ariz Akhter
- Department of Pathology & Laboratory Medicine, University of Calgary, and Alberta Precision Laboratories (APL), Calgary, Alberta, Canada
| | - Rommel Seno
- Department of Pathology & Laboratory Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Emina E Torlakovic
- Department of Pathology & Laboratory Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Tariq Mahmood Roshan
- Department of Pathology & Laboratory Medicine, University of Calgary, and Alberta Precision Laboratories (APL), Calgary, Alberta, Canada
| | - Meer-Taher Shabani-Rad
- Department of Pathology & Laboratory Medicine, University of Calgary, and Alberta Precision Laboratories (APL), Calgary, Alberta, Canada
| | - Ghaleb Elyamany
- Department of Pathology & Laboratory Medicine, University of Calgary, and Alberta Precision Laboratories (APL), Calgary, Alberta, Canada
| | - Parham Minoo
- Department of Pathology & Laboratory Medicine, University of Calgary, and Alberta Precision Laboratories (APL), Calgary, Alberta, Canada
| | - Douglas Stewart
- Department of Oncology, University of Calgary, Tom Baker Cancer Centre, Calgary, Alberta, Canada
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3
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van Os BW, Kusters PJH, den Toom M, Beckers L, van Tiel CM, Vos WG, de Jong E, Kieser A, van Roomen C, Binder CJ, Reiche ME, de Winther MP, Bosmans LA, Lutgens E. Deficiency of germinal center kinase TRAF2 and NCK-interacting kinase (TNIK) in B cells does not affect atherosclerosis. Front Cardiovasc Med 2023; 10:1171764. [PMID: 37215541 PMCID: PMC10196212 DOI: 10.3389/fcvm.2023.1171764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 04/06/2023] [Indexed: 05/24/2023] Open
Abstract
Background Atherosclerosis is the underlying cause of many cardiovascular diseases, such as myocardial infarction or stroke. B cells, and their production of pro- and anti-atherogenic antibodies, play an important role in atherosclerosis. In B cells, TRAF2 and NCK-interacting Kinase (TNIK), a germinal center kinase, was shown to bind to TNF-receptor associated factor 6 (TRAF6), and to be involved in JNK and NF-κB signaling in human B cells, a pathway associated with antibody production. Objective We here investigate the role of TNIK-deficient B cells in atherosclerosis. Results ApoE-/-TNIKfl/fl (TNIKBWT) and ApoE-/-TNIKfl/flCD19-cre (TNIKBKO) mice received a high cholesterol diet for 10 weeks. Atherosclerotic plaque area did not differ between TNIKBKO and TNIKBWT mice, nor was there any difference in plaque necrotic core, macrophage, T cell, α-SMA and collagen content. B1 and B2 cell numbers did not change in TNIKBKO mice, and marginal zone, follicular or germinal center B cells were unaffected. Total IgM and IgG levels, as well as oxidation specific epitope (OSE) IgM and IgG levels, did not change in absence of B cell TNIK. In contrast, plasma IgA levels were decreased in TNIKBKO mice, whereas the number of IgA+ B cells in intestinal Peyer's patches increased. No effects could be detected on T cell or myeloid cell numbers or subsets. Conclusion We here conclude that in hyperlipidemic ApoE-/- mice, B cell specific TNIK deficiency does not affect atherosclerosis.
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Affiliation(s)
- Bram W. van Os
- Department of Medical Biochemistry, Amsterdam UMC Location University of Amsterdam, Amsterdam, Netherlands
- Amsterdam Cardiovascular Sciences, Atherosclerosis & Ischemic Syndromes, Amsterdam, Netherlands
- Amsterdam Immunity and Infection, Amsterdam UMC, Amsterdam, Netherlands
| | - Pascal J. H. Kusters
- Department of Medical Biochemistry, Amsterdam UMC Location University of Amsterdam, Amsterdam, Netherlands
- Amsterdam Cardiovascular Sciences, Atherosclerosis & Ischemic Syndromes, Amsterdam, Netherlands
- Amsterdam Immunity and Infection, Amsterdam UMC, Amsterdam, Netherlands
| | - Myrthe den Toom
- Department of Medical Biochemistry, Amsterdam UMC Location University of Amsterdam, Amsterdam, Netherlands
- Amsterdam Cardiovascular Sciences, Atherosclerosis & Ischemic Syndromes, Amsterdam, Netherlands
- Amsterdam Immunity and Infection, Amsterdam UMC, Amsterdam, Netherlands
| | - Linda Beckers
- Department of Medical Biochemistry, Amsterdam UMC Location University of Amsterdam, Amsterdam, Netherlands
- Amsterdam Cardiovascular Sciences, Atherosclerosis & Ischemic Syndromes, Amsterdam, Netherlands
- Amsterdam Immunity and Infection, Amsterdam UMC, Amsterdam, Netherlands
| | - Claudia M. van Tiel
- Department of Medical Biochemistry, Amsterdam UMC Location University of Amsterdam, Amsterdam, Netherlands
- Amsterdam Cardiovascular Sciences, Atherosclerosis & Ischemic Syndromes, Amsterdam, Netherlands
- Amsterdam Immunity and Infection, Amsterdam UMC, Amsterdam, Netherlands
| | - Winnie G. Vos
- Department of Medical Biochemistry, Amsterdam UMC Location University of Amsterdam, Amsterdam, Netherlands
- Amsterdam Cardiovascular Sciences, Atherosclerosis & Ischemic Syndromes, Amsterdam, Netherlands
- Amsterdam Immunity and Infection, Amsterdam UMC, Amsterdam, Netherlands
| | - Elize de Jong
- Department of Medical Biochemistry, Amsterdam UMC Location University of Amsterdam, Amsterdam, Netherlands
| | - Arnd Kieser
- Research Unit Signaling and Translation, Helmholtz Zentrum München-German Research Center for Environmental Health, Neuherberg, Germany
| | - Cindy van Roomen
- Department of Medical Biochemistry, Amsterdam UMC Location University of Amsterdam, Amsterdam, Netherlands
- Amsterdam Cardiovascular Sciences, Atherosclerosis & Ischemic Syndromes, Amsterdam, Netherlands
- Amsterdam Immunity and Infection, Amsterdam UMC, Amsterdam, Netherlands
| | - Christoph J. Binder
- Department of Laboratory Medicine, Medical University of Vienna, Vienna, Austria
| | - Myrthe E. Reiche
- Department of Medical Biochemistry, Amsterdam UMC Location University of Amsterdam, Amsterdam, Netherlands
- Amsterdam Cardiovascular Sciences, Atherosclerosis & Ischemic Syndromes, Amsterdam, Netherlands
- Amsterdam Immunity and Infection, Amsterdam UMC, Amsterdam, Netherlands
| | - Menno P. de Winther
- Department of Medical Biochemistry, Amsterdam UMC Location University of Amsterdam, Amsterdam, Netherlands
- Amsterdam Cardiovascular Sciences, Atherosclerosis & Ischemic Syndromes, Amsterdam, Netherlands
- Amsterdam Immunity and Infection, Amsterdam UMC, Amsterdam, Netherlands
| | - Laura A. Bosmans
- Department of Medical Biochemistry, Amsterdam UMC Location University of Amsterdam, Amsterdam, Netherlands
- Amsterdam Cardiovascular Sciences, Atherosclerosis & Ischemic Syndromes, Amsterdam, Netherlands
- Amsterdam Immunity and Infection, Amsterdam UMC, Amsterdam, Netherlands
| | - Esther Lutgens
- Department of Medical Biochemistry, Amsterdam UMC Location University of Amsterdam, Amsterdam, Netherlands
- Institute for Cardiovascular Prevention (IPEK), Ludwig-Maximilians-Universität, Munich, Germany
- German Center for Cardiovascular Research (DZHK), Partner site Munich Heart Alliance, Ludwig-Maximilians-Universität München, Germany
- Department of Cardiovascular Medicine and Immunology, Mayo Clinic, Rochester, MN, United States
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4
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Spatial Proteomics Reveals Differences in the Cellular Architecture of Antibody-Producing CHO and Plasma Cell-Derived Cells. Mol Cell Proteomics 2022; 21:100278. [PMID: 35934186 PMCID: PMC9562429 DOI: 10.1016/j.mcpro.2022.100278] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 07/28/2022] [Accepted: 07/30/2022] [Indexed: 01/18/2023] Open
Abstract
Most of the recombinant biotherapeutics employed today to combat severe illnesses, for example, various types of cancer or autoimmune diseases, are produced by Chinese hamster ovary (CHO) cells. To meet the growing demand of these pharmaceuticals, CHO cells are under constant development in order to enhance their stability and productivity. The last decades saw a shift from empirical cell line optimization toward rational cell engineering using a growing number of large omics datasets to alter cell physiology on various levels. Especially proteomics workflows reached new levels in proteome coverage and data quality because of advances in high-resolution mass spectrometry instrumentation. One type of workflow concentrates on spatial proteomics by usage of subcellular fractionation of organelles with subsequent shotgun mass spectrometry proteomics and machine learning algorithms to determine the subcellular localization of large portions of the cellular proteome at a certain time point. Here, we present the first subcellular spatial proteome of a CHO-K1 cell line producing high titers of recombinant antibody in comparison to the spatial proteome of an antibody-producing plasma cell-derived myeloma cell line. Both cell lines show colocalization of immunoglobulin G chains with chaperones and proteins associated in protein glycosylation within the endoplasmic reticulum compartment. However, we report differences in the localization of proteins associated to vesicle-mediated transport, transcription, and translation, which may affect antibody production in both cell lines. Furthermore, pairing subcellular localization data with protein expression data revealed elevated protein masses for organelles in the secretory pathway in plasma cell-derived MPC-11 (Merwin plasma cell tumor-11) cells. Our study highlights the potential of subcellular spatial proteomics combined with protein expression as potent workflow to identify characteristics of highly efficient recombinant protein-expressing cell lines. Data are available via ProteomeXchange with identifier PXD029115.
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Goldsberry WN, Londoño A, Randall TD, Norian LA, Arend RC. A Review of the Role of Wnt in Cancer Immunomodulation. Cancers (Basel) 2019; 11:cancers11060771. [PMID: 31167446 PMCID: PMC6628296 DOI: 10.3390/cancers11060771] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 05/17/2019] [Accepted: 05/31/2019] [Indexed: 12/12/2022] Open
Abstract
Alterations in the Wnt signaling pathway are associated with the advancement of cancers; however, the exact mechanisms responsible remain largely unknown. It has recently been established that heightened intratumoral Wnt signaling correlates with tumor immunomodulation and immune suppression, which likely contribute to the decreased efficacy of multiple cancer therapeutics. Here, we review available literature pertaining to connections between Wnt pathway activation in the tumor microenvironment and local immunomodulation. We focus specifically on preclinical and clinical data supporting the hypothesis that strategies targeting Wnt signaling could act as adjuncts for cancer therapy, either in combination with chemotherapy or immunotherapy, in a variety of tumor types.
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Affiliation(s)
- Whitney N Goldsberry
- Department of Obstetrics and Gynecology, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
| | - Angelina Londoño
- Department of Obstetrics and Gynecology, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
| | - Troy D Randall
- Division of Immunology & Rheumatology, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
| | - Lyse A Norian
- Department of Nutritional Sciences, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
| | - Rebecca C Arend
- Department of Obstetrics and Gynecology, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
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6
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Galluzzi L, Spranger S, Fuchs E, López-Soto A. WNT Signaling in Cancer Immunosurveillance. Trends Cell Biol 2019; 29:44-65. [PMID: 30220580 PMCID: PMC7001864 DOI: 10.1016/j.tcb.2018.08.005] [Citation(s) in RCA: 150] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Accepted: 08/23/2018] [Indexed: 12/25/2022]
Abstract
Deregulated WNT signaling has been shown to favor malignant transformation, tumor progression, and resistance to conventional cancer therapy in a variety of preclinical and clinical settings. Accumulating evidence suggests that aberrant WNT signaling may also subvert cancer immunosurveillance, hence promoting immunoevasion and resistance to multiple immunotherapeutics, including immune checkpoint blockers. Here, we discuss the molecular and cellular mechanisms through which WNT signaling influences cancer immunosurveillance and present potential therapeutic avenues to harness currently available WNT modulators for cancer immunotherapy.
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Affiliation(s)
- Lorenzo Galluzzi
- Department of Radiation Oncology, Weill Cornell Medical College, New York, NY 10065, USA; Sandra and Edward Meyer Cancer Center, New York, NY 10065, USA; Université Paris Descartes/Paris V, 75006 Paris, France.
| | - Stefani Spranger
- The Koch Institute for Integrative Cancer Research at Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Elaine Fuchs
- Robin Chemers Neustein Laboratory of Mammalian Cell Biology and Development, The Rockefeller University, New York, NY 10065, USA; Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10065, USA
| | - Alejandro López-Soto
- Departamento de Biología Funcional, Área de Inmunología, Universidad de Oviedo. Instituto Universitario de Oncología del Principado de Asturias (IUOPA), 33006 Oviedo, Spain; Instituto de Investigación Sanitaria del Principado de Asturias (IISPA), 33011 Oviedo, Asturias, Spain.
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7
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Beckert H, Meyer-Martin H, Buhl R, Taube C, Reuter S. The Canonical but Not the Noncanonical Wnt Pathway Inhibits the Development of Allergic Airway Disease. THE JOURNAL OF IMMUNOLOGY 2018; 201:1855-1864. [PMID: 30135183 DOI: 10.4049/jimmunol.1800554] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Accepted: 07/26/2018] [Indexed: 12/27/2022]
Abstract
Asthma is a syndrome with multifactorial causes, resulting in a variety of different phenotypes. Current treatment options are not curative and are sometimes ineffective in certain disease phenotypes. Therefore, novel therapeutic approaches are required. Recent findings have shown that activation of the canonical Wnt signaling pathway suppresses the development of allergic airway disease. In contrast, the effect of the noncanonical Wnt signaling pathway activation on allergic airway disease is not well described. The aim of this study was to validate the therapeutic effectiveness of Wnt-1-driven canonical Wnt signaling compared with Wnt-5a-driven noncanonical signaling in murine models. In vitro, both ligands were capable of attenuating allergen-specific T cell activation in a dendritic cell-dependent manner. In addition, the therapeutic effects of Wnt ligands were assessed in two different models of allergic airway disease. Application of Wnt-1 resulted in suppression of airway inflammation as well as airway hyperresponsiveness and mucus production. In contrast, administration of Wnt-5a was less effective in reducing airway inflammation or goblet cell metaplasia. These results suggest an immune modulating function for canonical as well as noncanonical Wnt signaling, but canonical Wnt pathway activation appears to be more effective in suppressing allergic airway disease than noncanonical Wnt activation.
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Affiliation(s)
- Hendrik Beckert
- Department of Pulmonary Medicine, University Medical Center Essen-Ruhrlandklinik, Essen, North Rhine-Westphalia 45239, Germany; and
| | - Helen Meyer-Martin
- Department of Pulmonary Medicine, III. Medical Clinic, University Medical Center of the Johannes Gutenberg University, D-55131 Mainz, Germany
| | - Roland Buhl
- Department of Pulmonary Medicine, III. Medical Clinic, University Medical Center of the Johannes Gutenberg University, D-55131 Mainz, Germany
| | - Christian Taube
- Department of Pulmonary Medicine, University Medical Center Essen-Ruhrlandklinik, Essen, North Rhine-Westphalia 45239, Germany; and
| | - Sebastian Reuter
- Department of Pulmonary Medicine, University Medical Center Essen-Ruhrlandklinik, Essen, North Rhine-Westphalia 45239, Germany; and
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8
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Osugui L, de Roo JJ, de Oliveira VC, Sodré ACP, Staal FJT, Popi AF. B-1 cells and B-1 cell precursors prompt different responses to Wnt signaling. PLoS One 2018; 13:e0199332. [PMID: 29928002 PMCID: PMC6013157 DOI: 10.1371/journal.pone.0199332] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 06/05/2018] [Indexed: 11/17/2022] Open
Abstract
Recently several studies demonstrated a role for the Wnt pathway in lymphocyte development and self-renewal of hematopoietic stem cells (HSCs). B-1 cells constitute a separate lineage of B lymphocytes, originating during fetal hematopoiesis, expressing lymphoid and myeloid markers and possessing self-renewal ability, similar to early hematopoietic progenitors and HSCs. A plethora of studies have shown an important role for the evolutionary conserved Wnt pathway in the biology of HSCs and T lymphocyte development. Our previous data demonstrated abundant expression of Wnt pathway components by B-1 cells, including Wnt ligands and receptors. Here we report that the canonical Wnt pathway is activated in B-1 cell precursors, but not in mature B-1 cells. However, both B-1 precursors and B-1 cells are able to respond to Wnt ligands in vitro. Canonical Wnt activity promotes proliferation of B-1 cells, while non-canonical Wnt signals induce the expansion of B-1 precursors. Interestingly, using a co-culture system with OP9 cells, Wnt3a stimulus supported the generation of B-1a cells. Taking together, these results indicate that B-1 cells and their progenitors are differentially responsive to Wnt ligands, and that the balance of activation of canonical and non-canonical Wnt signaling may regulate the maintenance and differentiation of different B-1 cell subsets.
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Affiliation(s)
- Lika Osugui
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Jolanda J de Roo
- Department of Immunohematology and Blood Transfusion, Leiden University Medical Center, Leiden, The Netherlands
| | - Vivian Cristina de Oliveira
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Ana Clara Pires Sodré
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Frank J T Staal
- Department of Immunohematology and Blood Transfusion, Leiden University Medical Center, Leiden, The Netherlands
| | - Ana Flavia Popi
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
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9
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Spaan I, Raymakers RA, van de Stolpe A, Peperzak V. Wnt signaling in multiple myeloma: a central player in disease with therapeutic potential. J Hematol Oncol 2018; 11:67. [PMID: 29776381 PMCID: PMC5960217 DOI: 10.1186/s13045-018-0615-3] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 05/06/2018] [Indexed: 12/18/2022] Open
Abstract
Multiple myeloma is the second most frequent hematological malignancy in the western world and remains incurable, predominantly due to acquired drug resistance and disease relapse. The highly conserved Wnt signal transduction pathway, which plays a key role in regulating cellular processes of proliferation, differentiation, migration, and stem cell self-renewal, is associated with multiple aspects of disease. Bone homeostasis is severely disturbed by Wnt antagonists that are secreted by the malignant plasma cells in the bone marrow. In the vast majority of patients, this results in osteolytic bone disease, which is associated with bone pain and pathological fractures and was reported to facilitate disease progression. More recently, cumulative evidence also indicates the importance of intrinsic Wnt signaling in the survival of multiple myeloma cells. However, Wnt pathway-activating gene mutations could not be identified. The search for factors or processes responsible for Wnt pathway activation currently focuses on aberrant ligand levels in the bone marrow microenvironment, increased expression of Wnt transcriptional co-factors and associated micro-RNAs, and disturbed epigenetics and post-translational modification processes. Furthermore, Wnt pathway activation is associated with acquired cell adhesion-mediated resistance of multiple myeloma cells to conventional drug therapies, including doxorubicin and lenalidomide. In this review, we present an overview of the relevance of Wnt signaling in multiple myeloma and highlight the Wnt pathway as a potential therapeutic target for this disease.
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Affiliation(s)
- Ingrid Spaan
- Laboratory of Translational Immunology, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX, Utrecht, the Netherlands
| | - Reinier A Raymakers
- Department of Hematology, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX, Utrecht, the Netherlands
| | - Anja van de Stolpe
- Molecular Diagnostics, Philips Research, High Tech Campus 11, 5656 AE, Eindhoven, the Netherlands
| | - Victor Peperzak
- Laboratory of Translational Immunology, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX, Utrecht, the Netherlands.
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10
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Cuvertino S, Lacaud G, Kouskoff V. SOX7-enforced expression promotes the expansion of adult blood progenitors and blocks B-cell development. Open Biol 2016; 6:160070. [PMID: 27411892 PMCID: PMC4967825 DOI: 10.1098/rsob.160070] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Accepted: 06/22/2016] [Indexed: 12/29/2022] Open
Abstract
During embryogenesis, the three SOXF transcription factors, SOX7, SOX17 and SOX18, regulate the specification of the cardiovascular system and are also involved in the development of haematopoiesis. The ectopic expression of SOX17 in both embryonic and adult blood cells enhances self-renewal. Likewise, the enforced expression of SOX7 during embryonic development promotes the proliferation of early blood progenitors and blocks lineage commitment. However, whether SOX7 expression can also affect the self-renewal of adult blood progenitors has never been explored. In this study, we demonstrate using an inducible transgenic mouse model that the enforced expression of Sox7 ex vivo in bone marrow/stroma cell co-culture promotes the proliferation of blood progenitors which retain multi-lineage short-term engrafting capacity. Furthermore, SOX7 expression induces a profound block in the generation of B lymphocytes. Correspondingly, the ectopic expression of SOX7 in vivo results in dramatic alterations of the haematopoietic system, inducing the proliferation of blood progenitors in the bone marrow while blocking B lymphopoiesis. In addition, SOX7 expression induces extra-medullary haematopoiesis in the spleen and liver. Together, these data demonstrate that the uncontrolled expression of the transcription factor SOX7 in adult haematopoietic cells has dramatic consequences on blood homeostasis.
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Affiliation(s)
- Sara Cuvertino
- Stem Cell Hematopoiesis Group, Cancer Research UK Manchester Institute, University of Manchester, Wilmslow Road, Manchester M20 4BX, UK
| | - Georges Lacaud
- Stem Cell Biology Group, Cancer Research UK Manchester Institute, University of Manchester, Wilmslow Road, Manchester M20 4BX, UK
| | - Valerie Kouskoff
- Stem Cell Hematopoiesis Group, Cancer Research UK Manchester Institute, University of Manchester, Wilmslow Road, Manchester M20 4BX, UK
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11
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Sertorio M, Amarachintha S, Wilson A, Pang Q. Loss of Fancc Impairs Antibody-Secreting Cell Differentiation in Mice through Deregulating the Wnt Signaling Pathway. THE JOURNAL OF IMMUNOLOGY 2016; 196:2986-94. [PMID: 26895835 DOI: 10.4049/jimmunol.1501056] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Accepted: 01/20/2016] [Indexed: 11/19/2022]
Abstract
Fanconi anemia (FA) is characterized by a progressive bone marrow failure and an increased incidence of cancer. FA patients have high susceptibility to immune-related complications such as infection and posttransplant graft-versus-host disease. In this study, we investigated the effect of FA deficiency in B cell function using the Fancc mouse model. Fancc(-/-) B cells show a specific defect in IgG2a switch and impaired Ab-secreting cell (ASC) differentiation. Global transcriptome analysis of naive B cells by mRNA sequencing demonstrates that FA deficiency deregulates a network of genes involved in immune function. Significantly, many genes implicated in Wnt signaling were aberrantly expressed in Fancc(-/-) B cells. Consistently, Fancc(-/-) B cells accumulate high levels of β-catenin under both resting and stimulated conditions, suggesting hyperactive Wnt signaling. Using an in vivo Wnt GFP reporter assay, we verified the upregulation of Wnt signaling as a potential mechanism responsible for the impaired Fancc(-/-) B cell differentiation. Furthermore, we showed that Wnt signaling inhibits ASC differentiation possibly through repression of Blimp1 and that Fancc(-/-) B cells are hypersensitive to Wnt activation during ASC differentiation. Our findings identify Wnt signaling as a physiological regulator of ASC differentiation and establish a role for the Wnt pathway in normal B cell function and FA immune deficiency.
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Affiliation(s)
- Mathieu Sertorio
- Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229
| | - Surya Amarachintha
- Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229
| | - Andrew Wilson
- Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229
| | - Qishen Pang
- Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229
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12
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Cao J, Zhang L, Wan Y, Li H, Zhou R, Ding H, Liu Y, Yao Z, Guo X. Ablation of Wntless in endosteal niches impairs lymphopoiesis rather than HSCs maintenance. Eur J Immunol 2015; 45:2650-60. [PMID: 26173091 DOI: 10.1002/eji.201445405] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Revised: 04/29/2015] [Accepted: 07/07/2015] [Indexed: 01/06/2023]
Abstract
Osteoblasts and perivascular stromal cells constitute essential niches for HSC self-renewal and maintenance in the bone marrow. Wnt signaling is important to maintain HSC integrity. However, the paracrine role of Wnt proteins in osteoblasts-supported HSC maintenance and differentiation remains unclear. Here, we investigated hematopoiesis in mice with Wntless (Wls) deficiency in osteoblasts or Nestin-positive mesenchymal progenitor cells, which presumptively block Wnt secretion in osteoblasts. We detected defective B-cell lymphopoiesis and abnormal T-cell infiltration in the bone marrow of Wls mutant mice. Notably, no impact on HSC frequency and repopulation in the bone marrow was observed with the loss of osteoblastic Wls. Our findings revealed a supportive role of Wnts in osteoblasts-regulated B-cell lymphopoiesis. They also suggest a preferential niche role of osteoblastic Wnts for lymphoid cells rather than HSCs, providing new clues for the molecular nature of distinct niches occupied by different hematopoietic cells.
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Affiliation(s)
- Jingjing Cao
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai, China
| | - Lingling Zhang
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai, China
| | - Yong Wan
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai, China
| | - Hanjun Li
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai, China
| | - Rujiang Zhou
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai, China
| | - Heyuan Ding
- The Fifth People's Hospital of Shanghai, Fudan University, China
| | | | - Zhengju Yao
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai, China
| | - Xizhi Guo
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai, China
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13
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Tiemessen MM, Staal FJT. Wnt signaling in leukemias and myeloma: T-cell factors are in control. Future Oncol 2014; 9:1757-72. [PMID: 24156335 DOI: 10.2217/fon.13.122] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Aberrant activation of the Wnt pathway has been implicated in the pathogenesis of many malignancies, especially solid tumors. During the past decade it also became clear that in hematological malignancies abnormal regulation of the Wnt pathway can either be causative or enhance disease progression, which will be discussed in detail in this review.
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Affiliation(s)
- Machteld M Tiemessen
- Department of Immunohematology & Blood Transfusion, Leiden University Medical Center, Leiden, The Netherlands
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14
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Integrated genetic approaches identify the molecular mechanisms of Sox4 in early B-cell development: intricate roles for RAG1/2 and CK1ε. Blood 2014; 123:4064-76. [PMID: 24786772 DOI: 10.1182/blood-2013-12-543801] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Commitment of hematopoietic stem cells to B lineage precursors and subsequent development of B lineage precursors into mature B cells is stringently controlled by stage-specific transcription factors. In this study, we used integrated genetic approaches and systematically determined the role of Sry-related high mobility group box (Sox) 4 and the underlying molecular mechanisms in early B-cell development. We found that Sox4 coordinates multilevel controls in the differentiation of early stage B cells. At the molecular level, Sox4 orchestrates a unique gene regulatory program, and its function was predominantly mediated through a conventional Sox4-binding motif as well as an unconventional GA-binding protein α chain binding motif. Our integrated gene network and functional analysis indicated that Sox4 functions as a bimodular transcription factor and ensures B lineage precursor differentiation through 2 distinct mechanisms. It positively induces gene rearrangements at immunoglobulin heavy chain gene loci by transcriptionally activating the Rag1 and Rag2 genes and negatively regulates Wnt signaling, which is critical for self-renewal, by inducing the expression of casein kinase 1 ε. Our findings illustrate that Sox4 mediates critical fine-tuning of the 2 opposing forces in early B-cell development and also set forth a model for characterization of critical genes whose deficiency, like Sox4 deficiency, is detrimental to this process.
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15
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Cain CJ, Manilay JO. Hematopoietic stem cell fate decisions are regulated by Wnt antagonists: Comparisons and current controversies. Exp Hematol 2013; 41:3-16. [DOI: 10.1016/j.exphem.2012.09.006] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2012] [Revised: 08/31/2012] [Accepted: 09/05/2012] [Indexed: 12/19/2022]
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16
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Tian X, Zhang J, Tan TK, Lyons JG, Zhao H, Niu B, Lee SR, Tsatralis T, Zhao Y, Wang Y, Cao Q, Wang C, Wang Y, Lee VWS, Kahn M, Zheng G, Harris DCH. Association of β-catenin with P-Smad3 but not LEF-1 dissociates in vitro profibrotic from anti-inflammatory effects of TGF-β1. J Cell Sci 2012. [PMID: 23203799 DOI: 10.1242/jcs.103036] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Transforming growth factor β1 (TGF-β1) is known to be both anti-inflammatory and profibrotic. Cross-talk between TGF-β/Smad and Wnt/β-catenin pathways in epithelial-mesenchymal transition (EMT) suggests a specific role for β-catenin in profibrotic effects of TGF-β1. However, no such mechanistic role has been demonstrated for β-catenin in the anti-inflammatory effects of TGF-β1. In the present study, we explored the role of β-catenin in the profibrotic and anti-inflammatory effects of TGF-β1 by using a cytosolic, but not membrane, β-catenin knockdown chimera (F-TrCP-Ecad) and the β-catenin/CBP inhibitor ICG-001. TGF-β1 induced nuclear Smad3/β-catenin complex, but not β-catenin/LEF-1 complex or TOP-flash activity, during EMT of C1.1 (renal tubular epithelial) cells. F-TrCP-Ecad selectively degraded TGF-β1-induced cytoplasmic β-catenin and blocked EMT of C1.1 cells. Both F-TrCP-Ecad and ICG-001 blocked TGF-β1-induced Smad3/β-catenin and Smad reporter activity in C1.1 cells, suggesting that TGF-β1-induced EMT depends on β-catenin binding to Smad3, but not LEF-1 downstream of Smad3, through canonical Wnt. In contrast, in J774 macrophages, the β-catenin level was low and was not changed by interferon-γ (IFN-γ) or lipopolysaccharide (LPS) with or without TGF-β1. TGF-β1 inhibition of LPS-induced TNF-α and IFN-γ-stimulated inducible NO synthase (iNOS) expression was not affected by F-TrCP-Ecad, ICG-001 or by overexpression of wild-type β-catenin in J774 cells. Inhibition of β-catenin by either F-TrCP-Ecad or ICG-001 abolished LiCl-induced TOP-flash, but not TGF-β1-induced Smad reporter, activity in J774 cells. These results demonstrate for the first time that β-catenin is required as a co-factor of Smad in TGF-β1-induced EMT of C1.1 epithelial cells, but not in TGF-β1 inhibition of macrophage activation. Targeting β-catenin may dissociate the TGF-β1 profibrotic and anti-inflammatory effects.
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Affiliation(s)
- Xinrui Tian
- Centre for Transplantation and Renal Research, the University of Sydney at Westmead Millennium Institute, Sydney, NSW 2145, Australia
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17
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Abstract
BCL6 is a transcriptional repressor required in mature B cells during the germinal center (GC) reaction. Multiple mechanisms act coordinately to timely modulate BCL6 expression at transcriptional and post-transcriptional levels. BCL6 prevents premature activation and differentiation of GC B cells and provides an environment tolerant of the DNA breaks associated with immunoglobulin gene remodeling mechanisms involved in the production of high-affinity antibodies of different isotypes. The critical functions exerted by BCL6 during normal B-cell development can be hijacked by the malignant transformation process. Indeed, BCL6 is targeted by genetic aberrations and acts as an oncogene in GC-derived lymphomas. The aberrations affecting BCL6 interfere with the multiple levels of regulation that grant a fine tuning of BCL6 expression and activity in physiologic conditions. This review summarizes the current knowledge on BCL6 function and its role in lymphomagenesis.
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Affiliation(s)
- Katia Basso
- Department of Pathology and Cell Biology, Institute for Cancer Genetics, the Herbert Irving Comprehensive Cancer Center, Columbia University, New York, NY 10032, USA
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18
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Cain CJ, Rueda R, McLelland B, Collette NM, Loots GG, Manilay JO. Absence of sclerostin adversely affects B-cell survival. J Bone Miner Res 2012; 27:1451-61. [PMID: 22434688 PMCID: PMC3377789 DOI: 10.1002/jbmr.1608] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Increased osteoblast activity in sclerostin-knockout (Sost(-/-)) mice results in generalized hyperostosis and bones with small bone marrow cavities resulting from hyperactive mineralizing osteoblast populations. Hematopoietic cell fate decisions are dependent on their local microenvironment, which contains osteoblast and stromal cell populations that support both hematopoietic stem cell quiescence and facilitate B-cell development. In this study, we investigated whether high bone mass environments affect B-cell development via the utilization of Sost(-/-) mice, a model of sclerosteosis. We found the bone marrow of Sost(-/-) mice to be specifically depleted of B cells because of elevated apoptosis at all B-cell developmental stages. In contrast, B-cell function in the spleen was normal. Sost expression analysis confirmed that Sost is primarily expressed in osteocytes and is not expressed in any hematopoietic lineage, which indicated that the B-cell defects in Sost(-/-) mice are non-cell autonomous, and this was confirmed by transplantation of wild-type (WT) bone marrow into lethally irradiated Sost(-/-) recipients. WT→Sost(-/-) chimeras displayed a reduction in B cells, whereas reciprocal Sost(-/-) →WT chimeras did not, supporting the idea that the Sost(-/-) bone environment cannot fully support normal B-cell development. Expression of the pre-B-cell growth stimulating factor, Cxcl12, was significantly lower in bone marrow stromal cells of Sost(-/-) mice, whereas the Wnt target genes Lef-1 and Ccnd1 remained unchanged in B cells. Taken together, these results demonstrate a novel role for Sost in the regulation of bone marrow environments that support B cells.
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Affiliation(s)
- Corey J Cain
- Quantitative and Systems Biology Graduate Program, School of Natural Sciences, University of California, Merced, Merced, CA, USA
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19
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Kim J, Kim DW, Chang W, Choe J, Kim J, Park CS, Song K, Lee I. Wnt5a is secreted by follicular dendritic cells to protect germinal center B cells via Wnt/Ca2+/NFAT/NF-κB-B cell lymphoma 6 signaling. THE JOURNAL OF IMMUNOLOGY 2011; 188:182-9. [PMID: 22124122 DOI: 10.4049/jimmunol.1102297] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Follicular dendritic cells (FDCs) protect germinal center (GC) B cells from rapid apoptosis to allow their survival and maturation. In this article, we show that FDCs normally produce and secrete Wnt5a to protect GC B cells. Wnt5a production is upregulated by polyI:C. Purified Wnt5a protects GC B cells from apoptosis in a dose-dependent manner. GC B cells are protected by FDC coculture or conditioned medium, and the protection is inhibited significantly by anti-Wnt5a Ab, suggesting a major role of Wnt5a in the FDC-mediated GC B cell protection. A calcium chelator BAPTA-AM blocks the Wnt5a-mediated GC B cell protection, implying a role of Wnt/Ca(2+) signaling in the GC B cell survival. Wnt5a and calcium ionophore activate NFATc1, NFATc2, NF-κB, and B cell lymphoma 6 (BCL-6) promptly and upregulate CD40 expression in GC B and Ramos cells, whereas p53 and JNK are not upregulated or activated. Cyclosporine A inhibits the Wnt5a and calcium-induced activation of NF-κB and BCL-6 in Ramos cells, supporting a role of β-catenin-independent Wnt/Ca(2+)/NFAT/NF-κB-BCL-6 signaling. Our data support that Wnt5a is a novel survival factor for GC B cells and might be a potential target for the regulation of B cell immunity.
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Affiliation(s)
- Jungtae Kim
- Asan Institute for Life Sciences, University of Ulsan College of Medicine, Seoul, Korea
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20
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Basso K, Dalla-Favera R. BCL6: master regulator of the germinal center reaction and key oncogene in B cell lymphomagenesis. Adv Immunol 2010; 105:193-210. [PMID: 20510734 DOI: 10.1016/s0065-2776(10)05007-8] [Citation(s) in RCA: 228] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BCL6 is a transcriptional repressor which has emerged as a critical regulator of germinal centers (GC), the sites where B cells are selected based on the production of antibodies with high affinity for the antigen. BCL6 is also a frequently activated oncogene in the pathogenesis of human B cell lymphomas, most of which derive from the GC B cells. A thorough understanding of the biological role of BCL6 in normal B cell development and lymphomagenesis depends upon the identification of the full set of genes that are targets of its transcriptional regulatory function. Recently, the identification of BCL6 targets has been implemented with the use of genome-wide chromatin immunoprecipitation and gene expression profiling approaches. A large set of promoters have been shown to be physically bound by BCL6, but only a fraction of them appears to be subjected to transcriptional repression in GC B cells. This set of BCL6 targets points to a number of cellular functions which are likely to be directly controlled by BCL6 during GC development, including activation, survival, DNA-damage response, cell cycle arrest, cytokine-, toll-like receptor-, TGFbeta-, WNT-signaling, and differentiation. Overall, BCL6 is revealing its dual role of "safe-keeper" in preventing centroblasts from responding to signals leading to a premature exit from the GC and of contributor to lymphomagenesis by allowing the instauration of conditions favorable to malignant transformation.
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Affiliation(s)
- Katia Basso
- Institute for Cancer Genetics, Columbia University, New York, NY, USA
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21
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Integrated biochemical and computational approach identifies BCL6 direct target genes controlling multiple pathways in normal germinal center B cells. Blood 2009; 115:975-84. [PMID: 19965633 DOI: 10.1182/blood-2009-06-227017] [Citation(s) in RCA: 168] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
BCL6 is a transcriptional repressor required for mature B-cell germinal center (GC) formation and implicated in lymphomagenesis. BCL6's physiologic function is only partially known because the complete set of its targets in GC B cells has not been identified. To address this issue, we used an integrated biochemical-computational-functional approach to identify BCL6 direct targets in normal GC B cells. This approach includes (1) identification of BCL6-bound promoters by genome-wide chromatin immunoprecipitation, (2) inference of transcriptional relationships by the use of a regulatory network reverse engineering approach (ARACNe), and (3) validation of physiologic relevance of the candidate targets down-regulated in GC B cells. Our approach demonstrated that a large set of promoters (> 4000) is physically bound by BCL6 but that only a fraction of them is repressed in GC B cells. This set of 1207 targets identifies several cellular functions directly controlled by BCL6 during GC development, including activation, survival, DNA-damage response, cell cycle arrest, cytokine signaling, Toll-like receptor signaling, and differentiation. These results define a broad role of BCL6 in preventing centroblasts from responding to signals leading to exit from the GC before they complete the phase of proliferative expansion and of antibody affinity maturation.
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22
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Malhotra S, Kincade PW. Wnt-related molecules and signaling pathway equilibrium in hematopoiesis. Cell Stem Cell 2009; 4:27-36. [PMID: 19128790 DOI: 10.1016/j.stem.2008.12.004] [Citation(s) in RCA: 122] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
There is near consensus that Wnt family molecules establish important gradients within niches where hematopoietic stem cells (HSC) reside. We review recent papers suggesting that a delicate balance is required between competing Wnt ligands and corresponding signaling pathways to maintain HSC integrity. Some steps in the transitions from HSC to lymphoid progenitor seem to be partially reversible and under the influence of Wnts. In addition, it has been recently suggested that HSC can oscillate between dormant versus active or lineage-biased states. We speculate that Wnts control a reflux process that may sustain stem cell self-renewal and differentiation potential.
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Affiliation(s)
- Sachin Malhotra
- Immunobiology and Cancer Program, Oklahoma Medical Research Foundation, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
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