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Evaluation of Ammonia Nitrogen Exposure in Immune Defenses Present on Spleen and Head-Kidney of Wuchang Bream ( Megalobrama amblycephala). Int J Mol Sci 2022; 23:ijms23063129. [PMID: 35328551 PMCID: PMC8953400 DOI: 10.3390/ijms23063129] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 03/08/2022] [Accepted: 03/11/2022] [Indexed: 02/04/2023] Open
Abstract
Ammonia is one of the most important environmental factors in aquatic ecosystems. However, there are limited studies on the effects of chronic or long-term ammonia stress and its potential molecular mechanism in fish. This study aimed to investigate the immune response and molecular mechanisms in the spleen and head-kidney of fish following chronic ammonia exposure. Megalobrama amblycephala (9.98 ± 0.48 g) were exposed to different concentrations of total ammonia nitrogen (0-30 mg/L) for 30 days. Ammonia exposure caused significant increases in cortisol levels and decreases in lysozyme and complement 3/4 concentrations in the serum, indicating inhibitory effects of ammonia stress on innate immune responses. Ammonia exposure also induced concentration-dependent increases in ammonia concentrations in tissue, pathological damage and indexes of spleen and head-kidney. Additionally, the contents of immunoglobulin M (IgM), interleukin 1β (IL-1β) and tumor necrosis factor α (TNF-α) as well as mRNA levels of toll-like receptors (TLRs)/Myeloid differentiation factor 88 (MyD88)-independent signaling molecules in the spleen and head-kidney were significantly downregulated after ammonia exposure. Our findings suggested that chronic ammonia exposure caused the suppression of innate and adaptive immune responses through downregulating TLR/MyD88-independent signaling. Adverse influences of chronic ammonia stress were more severe in the spleen than in the head-kidney.
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Shiraz AK, Panther EJ, Reilly CM. Altered Germinal-Center Metabolism in B Cells in Autoimmunity. Metabolites 2022; 12:metabo12010040. [PMID: 35050162 PMCID: PMC8780703 DOI: 10.3390/metabo12010040] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 12/18/2021] [Accepted: 12/21/2021] [Indexed: 12/27/2022] Open
Abstract
B lymphocytes play an important role in the pathophysiology of many autoimmune disorders by producing autoantibodies, secreting cytokines, and presenting antigens. B cells undergo extreme physiological changes as they develop and differentiate. Aberrant function in tolerogenic checkpoints and the metabolic state of B cells might be the contributing factors to the dysfunctionality of autoimmune B cells. Understanding B-cell metabolism in autoimmunity is important as it can give rise to new treatments. Recent investigations have revealed that alterations in metabolism occur in the activation of B cells. Several reports have suggested that germinal center (GC) B cells of individuals with systemic lupus erythematosus (SLE) have altered metabolic function. GCs are unique microenvironments in which the delicate and complex process of B-cell affinity maturation occurs through somatic hypermutation (SHM) and class switching recombination (CSR) and where Bcl6 tightly regulates B-cell differentiation into memory B-cells or plasma cells. GC B cells rely heavily on glucose, fatty acids, and oxidative phosphorylation (OXPHOS) for their energy requirements. However, the complicated association between GC B cells and their metabolism is still not clearly understood. Here, we review several studies of B-cell metabolism, highlighting the significant transformations that occur in GC progression, and suggest possible approaches that may be investigated to more precisely target aberrant B-cell metabolism in SLE.
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Affiliation(s)
- Ashton K. Shiraz
- Department of Biomedical Sciences & Pathobiology, Virginia-Maryland Regional College of Veterinary Medicine, Virginia Polytechnic Institute and State University, 205 Duck Pond Drive, Blacksburg, VA 24061, USA;
- Correspondence: (A.K.S.); (C.M.R.); Tel.: +1-540-231-9365 (C.M.R.)
| | - Eric J. Panther
- Department of Biomedical Sciences & Pathobiology, Virginia-Maryland Regional College of Veterinary Medicine, Virginia Polytechnic Institute and State University, 205 Duck Pond Drive, Blacksburg, VA 24061, USA;
| | - Christopher M. Reilly
- Department of Biomedical Sciences & Pathobiology, Virginia-Maryland Regional College of Veterinary Medicine, Virginia Polytechnic Institute and State University, 205 Duck Pond Drive, Blacksburg, VA 24061, USA;
- Via College of Osteopathic Medicine, Blacksburg, VA 24060, USA
- Correspondence: (A.K.S.); (C.M.R.); Tel.: +1-540-231-9365 (C.M.R.)
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Mendoza P, Martínez-Martín N, Bovolenta ER, Reyes-Garau D, Hernansanz-Agustín P, Delgado P, Diaz-Muñoz MD, Oeste CL, Fernández-Pisonero I, Castellano E, Martínez-Ruiz A, Alonso-Lopez D, Santos E, Bustelo XR, Kurosaki T, Alarcón B. R-Ras2 is required for germinal center formation to aid B cells during energetically demanding processes. Sci Signal 2018; 11:11/532/eaal1506. [DOI: 10.1126/scisignal.aal1506] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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Veselits M, Tanaka A, Chen Y, Hamel K, Mandal M, Kandasamy M, Manicassamy B, O'Neill SK, Wilson P, Sciammas R, Clark MR. Igβ ubiquitination activates PI3K signals required for endosomal sorting. J Exp Med 2017; 214:3775-3790. [PMID: 29141870 PMCID: PMC5716028 DOI: 10.1084/jem.20161868] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Revised: 07/20/2017] [Accepted: 09/12/2017] [Indexed: 12/26/2022] Open
Abstract
Veselits et al. show that Igβ ubiquitination activates PI3K and the accumulation of PIP3 on BCR-associated endosomal membranes, which is necessary and sufficient for sorting into classical antigen-processing compartments. Surprisingly, proper BCR sorting is critical for endosomal TLR activation yet dispensable for T-dependent humoral immunity. A wealth of in vitro data has demonstrated a central role for receptor ubiquitination in endocytic sorting. However, how receptor ubiquitination functions in vivo is poorly understood. Herein, we report that ablation of B cell antigen receptor ubiquitination in vivo uncouples the receptor from CD19 phosphorylation and phosphatidylinositol 3-kinase (PI3K) signals. These signals are necessary and sufficient for accumulating phosphatidylinositol (3,4,5)-trisphosphate (PIP3) on B cell receptor–containing early endosomes and proper sorting into the MHC class II antigen-presenting compartment (MIIC). Surprisingly, MIIC targeting is dispensable for T cell–dependent immunity. Rather, it is critical for activating endosomal toll-like receptors and antiviral humoral immunity. These findings demonstrate a novel mechanism of receptor endosomal signaling required for specific peripheral immune responses.
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Affiliation(s)
- Margaret Veselits
- Section of Rheumatology and Gwen Knapp Center for Lupus and Immunology Research, Departments of Medicine and Pathology, University of Chicago, Chicago, IL
| | - Azusa Tanaka
- Section of Rheumatology and Gwen Knapp Center for Lupus and Immunology Research, Departments of Medicine and Pathology, University of Chicago, Chicago, IL
| | - Yaoqing Chen
- Section of Rheumatology and Gwen Knapp Center for Lupus and Immunology Research, Departments of Medicine and Pathology, University of Chicago, Chicago, IL
| | - Keith Hamel
- Section of Rheumatology and Gwen Knapp Center for Lupus and Immunology Research, Departments of Medicine and Pathology, University of Chicago, Chicago, IL
| | - Malay Mandal
- Section of Rheumatology and Gwen Knapp Center for Lupus and Immunology Research, Departments of Medicine and Pathology, University of Chicago, Chicago, IL
| | | | | | | | - Patrick Wilson
- Section of Rheumatology and Gwen Knapp Center for Lupus and Immunology Research, Departments of Medicine and Pathology, University of Chicago, Chicago, IL
| | - Roger Sciammas
- Center for Comparative Medicine, University of California, Davis, Davis, CA
| | - Marcus R Clark
- Section of Rheumatology and Gwen Knapp Center for Lupus and Immunology Research, Departments of Medicine and Pathology, University of Chicago, Chicago, IL
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Taher TE, Bystrom J, Ong VH, Isenberg DA, Renaudineau Y, Abraham DJ, Mageed RA. Intracellular B Lymphocyte Signalling and the Regulation of Humoral Immunity and Autoimmunity. Clin Rev Allergy Immunol 2017; 53:237-264. [PMID: 28456914 PMCID: PMC5597704 DOI: 10.1007/s12016-017-8609-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
B lymphocytes are critical for effective immunity; they produce antibodies and cytokines, present antigens to T lymphocytes and regulate immune responses. However, because of the inherent randomness in the process of generating their vast repertoire of antigen-specific receptors, B cells can also cause diseases through recognizing and reacting to self. Therefore, B lymphocyte selection and responses require tight regulation at multiple levels and at all stages of their development and activation to avoid diseases. Indeed, newly generated B lymphocytes undergo rigorous tolerance mechanisms in the bone marrow and, subsequently, in the periphery after their migration. Furthermore, activation of mature B cells is regulated through controlled expression of co-stimulatory receptors and intracellular signalling thresholds. All these regulatory events determine whether and how B lymphocytes respond to antigens, by undergoing apoptosis or proliferation. However, defects that alter regulated co-stimulatory receptor expression or intracellular signalling thresholds can lead to diseases. For example, autoimmune diseases can result from altered regulation of B cell responses leading to the emergence of high-affinity autoreactive B cells, autoantibody production and tissue damage. The exact cause(s) of defective B cell responses in autoimmune diseases remains unknown. However, there is evidence that defects or mutations in genes that encode individual intracellular signalling proteins lead to autoimmune diseases, thus confirming that defects in intracellular pathways mediate autoimmune diseases. This review provides a synopsis of current knowledge of signalling proteins and pathways that regulate B lymphocyte responses and how defects in these could promote autoimmune diseases. Most of the evidence comes from studies of mouse models of disease and from genetically engineered mice. Some, however, also come from studying B lymphocytes from patients and from genome-wide association studies. Defining proteins and signalling pathways that underpin atypical B cell response in diseases will help in understanding disease mechanisms and provide new therapeutic avenues for precision therapy.
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Affiliation(s)
- Taher E Taher
- Centre for Experimental Medicine and Rheumatology, William Harvey Research Institute, Queen Mary University of London, Charterhouse Square, London, EC1M 6BQ, UK
| | - Jonas Bystrom
- Centre for Experimental Medicine and Rheumatology, William Harvey Research Institute, Queen Mary University of London, Charterhouse Square, London, EC1M 6BQ, UK
| | - Voon H Ong
- Centre for Rheumatology and Connective Tissue Diseases, Royal Free Hospital, University College London, London, UK
| | | | - Yves Renaudineau
- Immunology Laboratory, University of Brest Medical School, Brest, France
| | - David J Abraham
- Centre for Rheumatology and Connective Tissue Diseases, Royal Free Hospital, University College London, London, UK
| | - Rizgar A Mageed
- Centre for Experimental Medicine and Rheumatology, William Harvey Research Institute, Queen Mary University of London, Charterhouse Square, London, EC1M 6BQ, UK.
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Ushmorov A, Wirth T. FOXO in B-cell lymphopoiesis and B cell neoplasia. Semin Cancer Biol 2017; 50:132-141. [PMID: 28774833 DOI: 10.1016/j.semcancer.2017.07.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Revised: 07/17/2017] [Accepted: 07/30/2017] [Indexed: 12/31/2022]
Abstract
FOX O family transcription factors are important for differentiation and function of multiple cell types. In B lymphocytes they play a critical role. The activity of FOXOs is directly regulated both by signaling from B cell receptor (BCR) and cytokine receptors. FOXO1 action controls the transition between differentiation stages of B cell development. In comparison to other FOXO family members, FOXO1 plays a superior role in the regulation of early stages of B-cell differentiation. Although being known as a negative regulator of cell proliferation and therefore potential tumor suppressor, FOXO1 is downregulated only in Hodgkin lymphoma (HL) subtypes. In non-Hodgkin lymphoma (NHL) entities its expression is maintained at significant levels, raising the question on the role of FOXO-transcription factors in the proliferation and survival programs in the process of B cell differentiation as well as their contribution to the oncogenic programs of B-cell lymphomas. In particular, we discuss molecular mechanisms that might determine the switch between pro-apoptotic and pro-survival effects of FOXO1 and their interplay with specific differentiation programs.
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Affiliation(s)
- Alexey Ushmorov
- Institute of Physiological Chemistry, University of Ulm, Ulm, Germany
| | - Thomas Wirth
- Institute of Physiological Chemistry, University of Ulm, Ulm, Germany.
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Wentink M, Dalm V, Lankester AC, van Schouwenburg PA, Schölvinck L, Kalina T, Zachova R, Sediva A, Lambeck A, Pico-Knijnenburg I, van Dongen JJM, Pac M, Bernatowska E, van Hagen M, Driessen G, van der Burg M. Genetic defects in PI3Kδ affect B-cell differentiation and maturation leading to hypogammaglobulineamia and recurrent infections. Clin Immunol 2017; 176:77-86. [PMID: 28104464 DOI: 10.1016/j.clim.2017.01.004] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Revised: 01/05/2017] [Accepted: 01/06/2017] [Indexed: 12/18/2022]
Abstract
BACKGROUND Mutations in PIK3CD and PIK3R1 cause activated PI3K-δ syndrome (APDS) by dysregulation of the PI3K-AKT pathway. METHODS We studied precursor and peripheral B-cell differentiation and apoptosis via flowcytometry. Furthermore, we performed AKT-phosphorylation assays and somatic hypermutations (SHM) and class switch recombination (CSR) analysis. RESULTS We identified 13 patients of whom 3 had new mutations in PIK3CD or PIK3R1. Patients had low total B-cell numbers with increased frequencies of transitional B cells and plasmablasts, while the precursor B-cell compartment in bone marrow was relatively normal. Basal AKT phosphorylation was increased in lymphocytes from APDS patients and natural effector B cells where most affected. PI3K mutations resulted in altered SHM and CSR and increased apoptosis. CONCLUSIONS The B-cell compartment in APDS patients is affected by the mutations in PI3K. There is reduced differentiation beyond the transitional stage, increased AKT phosphorylation and increased apoptosis. This B-cell phenotype contributes to the clinical phenotype.
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Affiliation(s)
- Marjolein Wentink
- Dept. of Immunology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Virgil Dalm
- Dept. of Immunology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands; Dept. of Internal Medicine, Division of Clinical Immunology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Arjan C Lankester
- Dept. of Pediatric Hematology, Leiden University Medical Centre, Leiden, The Netherlands
| | | | - Liesbeth Schölvinck
- University of Groningen, University Medical Centre Groningen, Beatrix Children's Hospital, Department of Paediatrics, Infectious Diseases and Immunology Section, Groningen, The Netherlands
| | - Tomas Kalina
- Dept. of Pediatric Hematology and Oncology, Charles University, 2nd Faculty of Medicine, Prague, Czech Republic
| | - Radana Zachova
- Dept. of Immunology, Charles University, 2nd Faculty of Medicine and Motol Hospital, Prague, Czech Republic
| | - Anna Sediva
- Dept. of Immunology, Charles University, 2nd Faculty of Medicine and Motol Hospital, Prague, Czech Republic
| | - Annechien Lambeck
- University of Groningen, University Medical Centre Groningen, Beatrix Children's Hospital, Department of Paediatrics, Infectious Diseases and Immunology Section, Groningen, The Netherlands
| | - Ingrid Pico-Knijnenburg
- Dept. of Immunology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Jacques J M van Dongen
- Dept. of Immunology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands; Dept. of Immunohematology and Blood Bank, Leiden University Medical Center, Leiden, The Netherlands
| | - Malgorzata Pac
- Dept. of Immunology, The Children's Memorial Health Institute, Warsaw, Poland
| | - Ewa Bernatowska
- Dept. of Immunology, The Children's Memorial Health Institute, Warsaw, Poland
| | - Martin van Hagen
- Dept. of Immunology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands; Dept. of Internal Medicine, Division of Clinical Immunology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Gertjan Driessen
- Dept. of Pediatric Immunology and Infectious Diseases, Sophia Children's Hospital, Erasmus MC, Rotterdam, The Netherlands.
| | - Mirjam van der Burg
- Dept. of Immunology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands.
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8
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Driessen GJ, IJspeert H, Wentink M, Yntema HG, van Hagen PM, van Strien A, Bucciol G, Cogulu O, Trip M, Nillesen W, Peeters EA, Pico-Knijnenburg I, Barendregt BH, Rizzi M, van Dongen JJ, Kutukculer N, van der Burg M. Increased PI3K/Akt activity and deregulated humoral immune response in human PTEN deficiency. J Allergy Clin Immunol 2016; 138:1744-1747.e5. [DOI: 10.1016/j.jaci.2016.07.010] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Revised: 05/18/2016] [Accepted: 07/04/2016] [Indexed: 02/03/2023]
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9
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Aryan Z, Aghamohammadi A, Rezaei N. Toward the stratification and personalization of common variable immunodeficiency treatment. Expert Opin Orphan Drugs 2016. [DOI: 10.1080/21678707.2016.1205480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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10
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B cells biology in systemic lupus erythematosus—from bench to bedside. SCIENCE CHINA-LIFE SCIENCES 2015; 58:1111-25. [DOI: 10.1007/s11427-015-4953-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Accepted: 10/09/2015] [Indexed: 12/20/2022]
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Chen Z, Getahun A, Chen X, Dollin Y, Cambier JC, Wang JH. Imbalanced PTEN and PI3K Signaling Impairs Class Switch Recombination. THE JOURNAL OF IMMUNOLOGY 2015; 195:5461-5471. [PMID: 26500350 DOI: 10.4049/jimmunol.1501375] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Accepted: 09/24/2015] [Indexed: 02/05/2023]
Abstract
Class switch recombination (CSR) generates isotype-switched Abs with distinct effector functions. B cells express phosphatase and tensin homolog (PTEN) and multiple isoforms of class IA PI3K catalytic subunits, including p110α and p110δ, whose roles in CSR remain unknown or controversial. In this article, we demonstrate a direct effect of PTEN on CSR signaling by acute deletion of Pten specifically in mature B cells, thereby excluding the developmental impact of Pten deletion. We show that mature B cell-specific PTEN overexpression enhances CSR. More importantly, we establish a critical role for p110α in CSR. Furthermore, we identify a cooperative role for p110α and p110δ in suppressing CSR. Mechanistically, dysregulation of p110α or PTEN inversely affects activation-induced deaminase expression via modulating AKT activity. Thus, our study reveals that a signaling balance between PTEN and PI3K isoforms is essential to maintain normal CSR.
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Affiliation(s)
- Zhangguo Chen
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, School of Medicine, Aurora, CO 80045.,Department of Biomedical Research, National Jewish Health, Denver, CO 80206
| | - Andrew Getahun
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, School of Medicine, Aurora, CO 80045.,Department of Biomedical Research, National Jewish Health, Denver, CO 80206
| | - Xiaomi Chen
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, School of Medicine, Aurora, CO 80045
| | - Yonatan Dollin
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, School of Medicine, Aurora, CO 80045
| | - John C Cambier
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, School of Medicine, Aurora, CO 80045.,Department of Biomedical Research, National Jewish Health, Denver, CO 80206
| | - Jing H Wang
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, School of Medicine, Aurora, CO 80045.,Department of Biomedical Research, National Jewish Health, Denver, CO 80206
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12
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Clinical impact of molecular features in diffuse large B-cell lymphoma and follicular lymphoma. Blood 2015; 127:181-6. [PMID: 26447189 DOI: 10.1182/blood-2015-07-658401] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Accepted: 10/03/2015] [Indexed: 02/08/2023] Open
Abstract
Our understanding of the pathogenesis and heterogeneity of diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL) has been dramatically enhanced by recent attempts to profile molecular features of these lymphomas. In this article, we discuss ways in which testing for molecular features may impact DLBCL and FL management if clinical trials are designed to incorporate such tests. Specifically, we discuss how distinguishing lymphomas on the basis of cell-of-origin subtypes or the presence of other molecular features is prognostically and therapeutically significant. Conversely, we discuss how the molecular similarities of DLBCL and FL have provided insight into the potential of both DLBCL and FL cases to respond to agents targeting alterations they have in common. Through these examples, we demonstrate how the translation of our understanding of cancer biology into improvements in patient outcomes depends on analyzing the molecular correlates of treatment outcomes in clinical trials and in routinely treated patients.
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Taher TE, Muhammad HA, Rahim A, Flores-Borja F, Renaudineau Y, Isenberg DA, Mageed RA. Aberrant B-lymphocyte responses in lupus: inherent or induced and potential therapeutic targets. Eur J Clin Invest 2013; 43:866-80. [PMID: 23701475 DOI: 10.1111/eci.12111] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2013] [Accepted: 04/29/2013] [Indexed: 12/11/2022]
Abstract
BACKGROUND Lupus is a prototype autoimmune disease of unknown aetiology. The disease is complex; manifest diverse clinical symptoms and disease mechanisms. This complexity has provided many leads to explore: from disease mechanisms to approaches for therapy. B-lymphocytes play a central role in the pathogenesis of the disease. However, the cause of aberrant B-lymphocyte responses in patients and, indeed, its causal relationship with the disease remain unclear. DESIGN This article provides a synopsis of current knowledge of immunological abnormalities in lupus with an emphasis on abnormalities in the B-lymphocyte compartment. RESULTS There is evidence for abnormalities in most compartments of the immune system in animal models and patients with lupus including an ever expanding list of abnormalities within the B-lymphocyte compartment. In addition, recent genome-wide linkage analyses in large cohorts of patients have identified new sets of genetic association factors some with potential links with defective B-lymphocyte responses although their full pathophysiological effects remain to be determined. The accumulating knowledge may help in the identification and application of new targeted therapies for treating lupus disease. CONCLUSIONS Cellular, molecular and genetic studies have provided significant insights into potential causes of immunological defects associated with lupus. Most of this insight relate to defects in B- and T-lymphocyte tolerance, signalling and responses. For B-lymphocytes, there is evidence for altered regulation of inter and intracellular signalling pathways at multiple levels. Some of these abnormalities will be discussed within the context of potential implications for disease pathogenesis and targeted therapies.
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Affiliation(s)
- Taher E Taher
- Bone & Joint Research Unit, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK
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Taher TE, Muhammad HA, Bariller E, Flores-Borja F, Renaudineau Y, Isenberg DA, Mageed RA. B-lymphocyte signalling abnormalities and lupus immunopathology. Int Rev Immunol 2013; 32:428-44. [PMID: 23768155 DOI: 10.3109/08830185.2013.788648] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Lupus is a complex autoimmune rheumatic disease of unknown aetiology. The disease is associated with diverse features of immunological abnormality in which B-lymphocytes play a central role. However, the cause of atypical B-lymphocyte responses remains unclear. In this article, we provide a synopsis of current knowledge on intracellular signalling abnormalities in B-lymphocytes in lupus and their potential effects on the response of these cells in mouse models and in patients. There are numerous reported defects in the regulation of intracellular signalling proteins and pathways in B-lymphocytes in lupus that, potentially, affect critical biological responses. Most of the evidence for these defects comes from studies of disease models and genetically engineered mice. However, there is also increasing evidence from studying B-lymphocytes from patients and from genome-wide linkage analyses for parallel defects to those observed in mice. These studies provide molecular and genetic explanations for the key immunological abnormalities associated with lupus. Most of the new information appears to relate to defects in intracellular signalling that impact B-lymphocyte tolerance, cytokine production and responses to infections. Some of these abnormalities will be discussed within the context of disease pathogenesis.
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Affiliation(s)
- Taher E Taher
- Bone & Joint Research Unit, William Harvey Research Institute, Barts
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15
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Chapman CM, Sun X, Roschewski M, Aue G, Farooqui M, Stennett L, Gibellini F, Arthur D, Pérez-Galán P, Wiestner A. ON 01910.Na is selectively cytotoxic for chronic lymphocytic leukemia cells through a dual mechanism of action involving PI3K/AKT inhibition and induction of oxidative stress. Clin Cancer Res 2012; 18:1979-91. [PMID: 22351695 DOI: 10.1158/1078-0432.ccr-11-2113] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
PURPOSE Chronic lymphocytic leukemia (CLL), a malignancy of mature B cells, is incurable with chemotherapy. Signals from the microenvironment support leukemic cell survival and proliferation and may confer chemotherapy resistance. ON 01910.Na (Rigosertib), a multikinase phosphoinositide 3-kinase (PI3K) inhibitor, is entering phase III trials for myelodysplastic syndrome. Our aim was to analyze the efficacy of ON 01910.Na against CLL cells in vitro and investigate the molecular effects of this drug on tumor biology. EXPERIMENTAL DESIGN Cytotoxicity of ON 01910.Na against CLL cells from 34 patients was determined in vitro with flow cytometry of cells stained with Annexin V and CD19. Global gene expression profiling on Affymetrix microarrays, flow cytometry, Western blotting, and cocultures with stroma cells were used to delineate ON 01910.Na mechanism of action. RESULTS ON 01910.Na induced apoptosis in CLL B cells without significant toxicity against T cells or normal B cells. ON 01910.Na was equally active against leukemic cells associated with a more aggressive disease course [immunoglobulin heavy-chain variable region unmutated, adverse cytogenetics] than against cells without these features. Gene expression profiling revealed two main mechanisms of action: PI3K/AKT inhibition and induction of ROS that resulted in an oxidative stress response through activating protein 1 (AP-1), c-jun-NH(2)-terminal kinase, and ATF3 culminating in the upregulation of NOXA. ROS scavengers and shRNA mediated knockdown of ATF3- and NOXA-protected cells from drug-induced apoptosis. ON 01910.Na also abrogated the prosurvival effect of follicular dendritic cells on CLL cells and reduced SDF-1-induced migration of leukemic cells. CONCLUSIONS These data support the clinical development of ON 01910.Na in CLL.
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Affiliation(s)
- Colby M Chapman
- Hematology Branch, NHLBI, NIH, Bld 10, CRC 3-5140, 10 Center Drive, 20892-1202 Bethesda, MD, USA
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16
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Abstract
Engagement of the B-cell antigen receptor (BCR) or its precursor, the pre-BCR, induces a cascade of biochemical reactions that regulate the differentiation, selection, survival, and activation of B cells. This cascade is initiated by receptor-associated tyrosine kinases that activate multiple downstream signaling pathways. Since it is required for metabolism, cell growth, development, and survival, the activation of phosphoinositide 3-kinase (PI3K)-dependent pathways represents a crucial event of BCR/pre-BCR signaling. The phosphorylated substrates of the PI3K promote specific recruitment of selected signaling proteins to the plasma membrane, where important signaling complexes are formed to mediate the above-mentioned biological processes. Here, we review the principles of PI3K signaling and highlight the role of an important PI3K-driven module in VDJ recombination of immunoglobulin (Ig) genes during early B-cell development as compared with class switch recombination of Ig genes in mature B cells after activation by specific antigens. Furthermore, we discuss the role of PI3K in the survival of mature B cells, which is strictly dependent on BCR expression and basal BCR signaling.
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Affiliation(s)
- Markus Werner
- Faculty of Biology, Department of Molecular Immunology, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
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Taher TE, Parikh K, Flores-Borja F, Mletzko S, Isenberg DA, Peppelenbosch MP, Mageed RA. Protein phosphorylation and kinome profiling reveal altered regulation of multiple signaling pathways in B lymphocytes from patients with systemic lupus erythematosus. ACTA ACUST UNITED AC 2010; 62:2412-23. [PMID: 20506108 DOI: 10.1002/art.27505] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE The cause of B lymphocyte hyperactivity and autoantibody production in systemic lupus erythematosus (SLE) remains unclear. Previously, we identified abnormalities in the level and translocation of signaling molecules in B cells in SLE patients. The present study was undertaken to examine the extent of signaling abnormalities that relate to altered B cell responses in SLE. METHODS B lymphocytes from 88 SLE patients and 72 healthy controls were isolated from blood by negative selection. Protein tyrosine phosphorylation and cellular kinase levels were analyzed by Western blotting, flow cytometry, and a kinome array protocol. Changes in protein phosphorylation were determined in ex vivo B cells and following B cell receptor engagement. RESULTS Differences in tyrosine phosphorylation in B cells from patients with SLE, compared with matched controls, were demonstrated. Further, the kinome array analysis identified changes in the activation of key kinases, i.e., the activity of phosphatidylinositol 3-kinase, which regulates survival and differentiation, was up-regulated and the activity of Rac and Rho kinases, which regulate the cytoskeleton and migration, was increased. In contrast, the activity of ATR, which regulates the cell cycle, was down-regulated in SLE patients compared with controls. Differences in signaling pathways were seen in all SLE B lymphocyte subsets that manifested phenotypic features of immature, mature, and memory cells. CONCLUSION This study revealed dysregulation in multiple signaling pathways that control key responses in B cells of SLE patients. Data generated in this study provide a molecular basis for further analysis of the altered B lymphocyte responses in SLE.
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Affiliation(s)
- Taher E Taher
- Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK
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North CM, Crawford RB, Lu H, Kaminski NE. 2,3,7,8-tetrachlorodibenzo-p-dioxin-mediated suppression of toll-like receptor stimulated B-lymphocyte activation and initiation of plasmacytic differentiation. Toxicol Sci 2010; 116:99-112. [PMID: 20348231 DOI: 10.1093/toxsci/kfq095] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
2,3,7,8-Tetrachlordibenzo-p-dioxin (TCDD) is a potent suppressor of humoral immunity, disrupting antibody production in response to both T cell-dependent and T cell-independent antigens. Among the cell types required for humoral responses, the B cell is highly, and directly, sensitive to TCDD. B cells become antibody-secreting cells via plasmacytic differentiation, a process regulated by several transcription factors, including activator protein-1, B-cell CLL/lymphoma 6 (BCL-6), and B lymphocyte-induced maturation protein 1 (Blimp-1). The overarching conceptual framework guiding experimentation is that TCDD disrupts plasmacytic differentiation by altering the expression or activity for upstream regulators of Blimp-1. Multiparametric flow cytometry was used to investigate TCDD-induced alterations in both activation marker and transcription factor expression following lipopolysaccharide (LPS) activation of purified B cells. TCDD significantly impaired LPS-activated expression of major histocompatibility complex class II, cluster of differentiation (CD)69, CD80, and CD86. Immunosuppressive concentrations of TCDD also suppressed LPS-activated Blimp-1 and phosphorylated c-Jun expression, whereas elevating BCL-6 expression. Because BCL-6 and c-Jun are directly and indirectly regulated by the kinases AKT, extracellular signal-regulated kinase (ERK), and Jun N-terminal kinase (JNK), it was hypothesized that TCDD alters toll-like receptor-activated kinase phosphorylation. TCDD at 0.03 and 0.3 nM significantly impaired phosphorylation of AKT, ERK, and JNK in CH12.LX B cells activated with LPS, CpG oligonucleotides, or resiquimod (R848). In primary B cells, R848-activated phosphorylation of AKT, ERK, and JNK was also impaired by TCDD at 30 nM. These results suggest that impairment of plasmacytic differentiation by TCDD involves altered transcription factor expression, in part, by suppressed kinase phosphorylation.
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Affiliation(s)
- Colin M North
- Center for Integrative Toxicology, Department of Pharmacology & Toxicology, Michigan State University, East Lansing, Michigan 48824, USA
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Rommel C. Taking PI3Kδ and PI3Kγ One Step Ahead: Dual Active PI3Kδ/γ Inhibitors for the Treatment of Immune-Mediated Inflammatory Diseases. Curr Top Microbiol Immunol 2010; 346:279-99. [DOI: 10.1007/82_2010_79] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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The role of PI3K signalling in the B cell response to antigen. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2009; 633:43-53. [PMID: 19209680 DOI: 10.1007/978-0-387-79311-5_5] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The PI3K signalling pathway is crucial to normal B cell development and response to antigen. The p1108 catalytic subunit plays an important and non-redundant role within this pathway although other catalytic isoforms may also contribute. Although CD40, TLR and cytokines all activate PI3K the BCR seems especially dependent upon PI3K signalling. The downstream effects of PI3K may be mediated to a large extent by activation of PKB. In B cell development PI3K promotes development of MZ and Bl cells. In the response to antigen PI3K is crucial to BCR-mediated proliferation. PI3K activity has been shown to be inhibitory to CSR. The effects on immunoglobulin production and ASC differentiation are harder to disentangle from the developmental effects on cell populations and at present remain uncertain.
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Douglas RS, Naik V, Hwang CJ, Afifiyan NF, Gianoukakis AG, Sand D, Kamat S, Smith TJ. B cells from patients with Graves' disease aberrantly express the IGF-1 receptor: implications for disease pathogenesis. THE JOURNAL OF IMMUNOLOGY 2008; 181:5768-74. [PMID: 18832736 DOI: 10.4049/jimmunol.181.8.5768] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Graves' disease (GD) is an autoimmune process involving the thyroid and connective tissues in the orbit and pretibial skin. Activating anti-thyrotropin receptor Abs are responsible for hyperthyroidism in GD. However, neither these autoAbs nor the receptor they are directed against have been convincingly implicated in the connective tissue manifestations. Insulin-like growth factor-1 receptor (IGF-1R)-bearing fibroblasts overpopulate connective tissues in GD and when ligated with IgGs from these patients, express the T cell chemoattractants, IL-16, and RANTES. Disproportionately large fractions of peripheral blood T cells also express IGF-1R in patients with GD and may account, at least in part, for expansion of IGF-1R(+) memory T cells. We now report a similarly skewed B cell population exhibiting the IGF-1R(+) phenotype from the blood, orbit, and bone marrow of patients with GD. This expression profile exhibits durability in culture and is maintained or increased with CpG activation. Moreover, IGF-1R(+) B cells produce pathogenic Abs against the thyrotropin receptor. In lymphocytes from patients with GD, IGF-1 enhanced IgG production (p < 0.05) and increased B cell expansion (p < 0.02) in vitro while those from control donors failed to respond. These findings suggest a potentially important role for IGF-1R display by B lymphocytes in patients with GD in supporting their expansion and abnormal Ig production.
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Affiliation(s)
- Raymond S Douglas
- Division of Molecular Medicine, Department of Medicine, Harbor-UCLA Medical Center, Torrance, CA 90502, USA
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