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Khan N, Hu Y, Lowell CA, Rothstein TL. TLR Engagement Induces an Alternate Pathway for BCR Signaling that Results in PKCδ Phosphorylation. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2024; 212:1639-1646. [PMID: 38629913 DOI: 10.4049/jimmunol.2300784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Accepted: 03/19/2024] [Indexed: 05/22/2024]
Abstract
Recently, we reported that preexposure of B cells to IL-4 induced an alternate, signalosome-independent BCR signaling pathway leading to protein kinase C (PKC)δ phosphorylation (pTyr311), which occurs in the membrane compartment. This is considered to represent a form of receptor crosstalk and signal integration. Unlike the classical BCR signaling pathway, Lyn kinase is indispensable for BCR-induced downstream events in the alternate pathway. Our previous report that alternate BCR signaling leading to ERK phosphorylation is triggered by LPS and PAM3CSK4 (much like IL-4) raises the possibility that other signaling outcomes such as PKCδ phosphorylation might be similarly affected. To explore the range of mediators capable of producing an alternate pathway for BCR signaling, we examined PKCδ translocation and phosphorylation in LPS- and PAM3CSK4-treated B cells stimulated by anti-Ig. We found that LPS and PAM3CSK4 alter the signaling pathway used by the BCR to produce PKCδ phosphorylation. As with IL-4, elements of the signalosome are not needed for PKCδ phosphorylation when BCR triggering occurs after LPS and PAM3CSK4. However, with LPS and PAM3CSK4, anti-Ig-induced phosphorylation of PKCδ takes place in the cytosol, in contrast to the IL-4-induced alternate pathway, wherein PKCδ phosphorylation occurs in the membrane. Furthermore, the BCR signaling pathway induced by LPS and PAM3CSK4 differs from that induced by IL-4 by not requiring Lyn. Thus, an alternate, signalosome-independent BCR signaling pathway for PKCδ phosphorylation is induced by TLR agonists but differs in important ways from the alternate pathway induced by IL-4.
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Affiliation(s)
- Naeem Khan
- Center for Immunobiology, Western Michigan University Homer Stryker M.D. School of Medicine, Kalamazoo, MI
| | - Yongmei Hu
- Department of Laboratory Medicine, University of California, San Francisco School of Medicine, San Francisco, CA
| | - Clifford A Lowell
- Department of Laboratory Medicine, University of California, San Francisco School of Medicine, San Francisco, CA
| | - Thomas L Rothstein
- Center for Immunobiology, Western Michigan University Homer Stryker M.D. School of Medicine, Kalamazoo, MI
- Department of Investigative Medicine, Western Michigan University Homer Stryker M.D. School of Medicine, Kalamazoo, MI
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2
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Borbet TC, Hines MJ, Koralov SB. MicroRNA regulation of B cell receptor signaling. Immunol Rev 2021; 304:111-125. [PMID: 34523719 PMCID: PMC8616848 DOI: 10.1111/imr.13024] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2021] [Revised: 08/29/2021] [Accepted: 08/31/2021] [Indexed: 12/19/2022]
Abstract
B lymphocytes play a central role in host immune defense. B cell receptor (BCR) signaling regulates survival, proliferation, and differentiation of B lymphocytes. Signaling through the BCR signalosome is a multi-component cascade that is tightly regulated and is important in the coordination of B cell differentiation and function. At different stages of development, B cells that have BCRs recognizing self are eliminated to prevent autoimmunity. microRNAs (miRNAs) are small single-stranded non-coding RNAs that contribute to post-transcriptional regulation of gene expression and have been shown to orchestrate cell fate decisions through the regulation of lineage-specific transcriptional profiles. Studies have identified miRNAs to be crucial for B cell development in the bone marrow and their subsequent population of the peripheral immune system. In this review, we focus on the role of miRNAs in the regulation of BCR signaling as it pertains to B lymphocyte development and function. In particular, we discuss the most recent studies describing the role of miRNAs in the regulation of both early B cell development and peripheral B cell responses and examine the ways by which miRNAs regulate signal downstream of B cell antigen receptor to prevent aberrant activation and autoimmunity.
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Affiliation(s)
- Timothy C. Borbet
- New York University School of Medicine, Department of Pathology, New York, NY 10016
| | - Marcus J. Hines
- New York University School of Medicine, Department of Pathology, New York, NY 10016
| | - Sergei B. Koralov
- New York University School of Medicine, Department of Pathology, New York, NY 10016
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3
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Abstract
The immune (innate and adaptive) system has evolved to protect the host from any danger present in the surrounding outer environment (microbes and associated MAMPs or PAMPs, xenobiotics, and allergens) and dangers originated within the host called danger or damage-associated molecular patterns (DAMPs) and recognizing and clearing the cells dying due to apoptosis. It also helps to lower the tissue damage during trauma and initiates the healing process. The pattern recognition receptors (PRRs) play a crucial role in recognizing different PAMPs or MAMPs and DAMPs to initiate the pro-inflammatory immune response to clear them. Toll-like receptors (TLRs) are first recognized PRRs and their discovery proved milestone in the field of immunology as it filled the gap between the first recognition of the pathogen by the immune system and the initiation of the appropriate immune response required to clear the infection by innate immune cells (macrophages, neutrophils, dendritic cells or DCs, and mast cells). However, in addition to their expression by innate immune cells and controlling their function, TLRs are also expressed by adaptive immune cells. We have identified 10 TLRs (TLR1-TLR10) in humans and 12 TLRs (TLR1-TLR13) in laboratory mice till date as TLR10 in mice is present only as a defective pseudogene. The present chapter starts with the introduction of innate immunity, timing of TLR evolution, and the evolution of adaptive immune system and its receptors (T cell receptors or TCRs and B cell receptors or BCRs). The next section describes the role of TLRs in the innate immune function and signaling involved in the generation of inflammation. The subsequent sections describe the expression and function of different TLRs in murine and human adaptive immune cells (B cells and different types of T cells, including CD4+T cells, CD8+T cells, CD4+CD25+Tregs, and CD8+CD25+Tregs, etc.). The modulation of TLRs expressed on T and B cells has a great potential to develop different vaccine candidates, adjuvants, immunotherapies to target various microbial infections, including current COVID-19 pandemic, cancers, and autoimmune and autoinflammatory diseases.
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Affiliation(s)
- Vijay Kumar
- Children's Health Queensland Clinical Unit, School of Clinical Medicine, Faculty of Medicine, Mater Research, University of Queensland, Brisbane, QLD, Australia.
- School of Biomedical Sciences, Faculty of Medicine, University of Queensland, Brisbane, QLD, Australia.
- Department of Pharmaceutical Sciences, College of Pharmacy, The University of Tennessee Health Science Center (UTHSC), Memphis, TN, USA.
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Jackson JT, Mulazzani E, Nutt SL, Masters SL. The role of PLCγ2 in immunological disorders, cancer, and neurodegeneration. J Biol Chem 2021; 297:100905. [PMID: 34157287 PMCID: PMC8318911 DOI: 10.1016/j.jbc.2021.100905] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 06/15/2021] [Accepted: 06/18/2021] [Indexed: 02/06/2023] Open
Abstract
Phosphatidylinositol-specific phospholipase Cγ2 (PLCγ2) is a critical signaling molecule activated downstream from a variety of cell surface receptors that contain an intracellular immunoreceptor tyrosine-based activation motif. These receptors recruit kinases such as Syk, BTK, and BLNK to phosphorylate and activate PLCγ2, which then generates 1D-myo-inositol 1,4,5-trisphosphate and diacylglycerol. These well-known second messengers are required for diverse membrane functionality including cellular proliferation, endocytosis, and calcium flux. As a result, PLCγ2 dysfunction is associated with a variety of diseases including cancer, neurodegeneration, and immune disorders. The diverse pathologies associated with PLCγ2 are exemplified by distinct genetic variants. Inherited mutations at this locus cause PLCγ2-associated antibody deficiency and immune dysregulation, in some cases with autoinflammation. Acquired mutations at this locus, which often arise as a result of BTK inhibition to treat chronic lymphocytic leukemia, result in constitutive downstream signaling and lymphocyte proliferation. Finally, a third group of PLCγ2 variants actually has a protective effect in a variety of neurodegenerative disorders, presumably by increased uptake and degradation of deleterious neurological aggregates. Therefore, manipulating PLCγ2 activity either up or down could have therapeutic benefit; however, we require a better understanding of the signaling pathways propagated by these variants before such clinical utility can be realized. Here, we review the signaling roles of PLCγ2 in hematopoietic cells to help understand the effect of mutations driving immune disorders and cancer and extrapolate from this to roles which may relate to protection against neurodegeneration.
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Affiliation(s)
- Jacob T Jackson
- Immunology Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia; Inflammation Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
| | - Elisabeth Mulazzani
- Inflammation Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia; Department of Medical Biology, University of Melbourne, Parkville, Victoria, Australia
| | - Stephen L Nutt
- Immunology Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia; Department of Medical Biology, University of Melbourne, Parkville, Victoria, Australia
| | - Seth L Masters
- Inflammation Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia; Department of Medical Biology, University of Melbourne, Parkville, Victoria, Australia; Immunology Laboratory, Guangzhou Institute of Paediatrics, Guangzhou Women and Children's Medical Centre, Guangzhou, Guangdong, China.
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Expression of the prosurvival kinase HCK requires PAX5 and mutated MYD88 signaling in MYD88-driven B-cell lymphomas. Blood Adv 2021; 4:141-153. [PMID: 31935288 DOI: 10.1182/bloodadvances.2019000947] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Accepted: 11/12/2019] [Indexed: 11/20/2022] Open
Abstract
Hematopoietic cell kinase (HCK) is an SRC family member that is aberrantly upregulated in B-cell neoplasms dependent on MYD88-activating mutations and supports their growth and survival. We showed herein that activation of Toll-like receptor (TLR) signaling in MYD88 wild-type B cells also triggered HCK expression, denoting on path regulatory function for HCK by MYD88. To clarify the signaling cascades responsible for aberrant HCK expression in MYD88-mutated B-cell lymphomas, we performed promoter-binding transcription factor (TF) profiling, PROMO weighted TF consensus binding motif analysis, and chromatin immunoprecipitation studies. We identified PAX5, and the mutated MYD88 downstream signaling mediators STAT3, NF-κB, and AP-1, as important drivers of HCK transcription. Knockdown of PAX5, a crucial regulatory factor required for B-cell commitment and identity, abrogated HCK transcription in MYD88-mutated lymphoma cells. Among AP-1 complex components, JunB showed greatest relevance to TLR/MYD88 signaling and HCK transcription regulation. In MYD88-mutated Waldenström macroglobulinemia and activated B-cell-diffuse large B-cell lymphoma cells, knockdown of MYD88 reduced phosphorylation of JunB but not c-Jun, and knockdown of JunB reduced HCK protein levels. Deletion of STAT3, NF-κB, and AP-1 binding sites reduced corresponding TFs binding and HCK promoter activity. Moreover, inhibitors to STAT3, NF-κB, and AP-1 reduced HCK promoter activity and messenger RNA levels, particularly in combination, in MYD88-mutated lymphoma cells. The findings provide new insights into the transcriptional regulation of HCK prosurvival signaling by mutated MYD88, and the importance of JunB as a downstream mediator of the MYD88-directed signaling apparatus.
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Sarapulov AV, Petrov P, Hernández-Pérez S, Šuštar V, Kuokkanen E, Cords L, Samuel RVM, Vainio M, Fritzsche M, Carrasco YR, Mattila PK. Missing-in-Metastasis/Metastasis Suppressor 1 Regulates B Cell Receptor Signaling, B Cell Metabolic Potential, and T Cell-Independent Immune Responses. Front Immunol 2020; 11:599. [PMID: 32373113 PMCID: PMC7176992 DOI: 10.3389/fimmu.2020.00599] [Citation(s) in RCA: 3] [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: 11/18/2019] [Accepted: 03/16/2020] [Indexed: 11/13/2022] Open
Abstract
Efficient generation of antibodies by B cells is one of the prerequisites of protective immunity. B cell activation by cognate antigens via B cell receptors (BCRs), or pathogen-associated molecules through pattern-recognition receptors, such as Toll-like receptors (TLRs), leads to transcriptional and metabolic changes that ultimately transform B cells into antibody-producing plasma cells or memory cells. BCR signaling and a number of steps downstream of it rely on coordinated action of cellular membranes and the actin cytoskeleton, tightly controlled by concerted action of multiple regulatory proteins, some of them exclusive to B cells. Here, we dissect the role of Missing-In-Metastasis (MIM), or Metastasis suppressor 1 (MTSS1), a cancer-associated membrane and actin cytoskeleton regulating protein, in B cell-mediated immunity by taking advantage of MIM knockout mouse strain. We show undisturbed B cell development and largely normal composition of B cell compartments in the periphery. Interestingly, we found that MIM-/- B cells are defected in BCR signaling in response to surface-bound antigens but, on the other hand, show increased metabolic activity after stimulation with LPS or CpG. In vivo, MIM knockout animals exhibit impaired IgM antibody responses to immunization with T cell-independent antigen. This study provides the first comprehensive characterization of MIM in B cells, demonstrates its regulatory role for B cell-mediated immunity, as well as proposes new functions for MIM in tuning receptor signaling and cellular metabolism, processes, which may also contribute to the poorly understood functions of MIM in cancer.
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Affiliation(s)
- Alexey V. Sarapulov
- Institute of Biomedicine and MediCity Research Laboratories, University of Turku, Turku, Finland
- Turku Bioscience, University of Turku and Åbo Akademi University, Turku, Finland
| | - Petar Petrov
- Institute of Biomedicine and MediCity Research Laboratories, University of Turku, Turku, Finland
- Turku Bioscience, University of Turku and Åbo Akademi University, Turku, Finland
| | - Sara Hernández-Pérez
- Institute of Biomedicine and MediCity Research Laboratories, University of Turku, Turku, Finland
- Turku Bioscience, University of Turku and Åbo Akademi University, Turku, Finland
| | - Vid Šuštar
- Institute of Biomedicine and MediCity Research Laboratories, University of Turku, Turku, Finland
| | - Elina Kuokkanen
- Institute of Biomedicine and MediCity Research Laboratories, University of Turku, Turku, Finland
| | - Lena Cords
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
| | - Rufus V. M. Samuel
- Institute of Biomedicine and MediCity Research Laboratories, University of Turku, Turku, Finland
| | - Marika Vainio
- Institute of Biomedicine and MediCity Research Laboratories, University of Turku, Turku, Finland
- Turku Bioscience, University of Turku and Åbo Akademi University, Turku, Finland
| | - Marco Fritzsche
- Kennedy Institute for Rheumatology, University of Oxford, Oxford, United Kingdom
- Rosalind Franklin Institute, Didcot, United Kingdom
| | - Yolanda R. Carrasco
- Department of Immunology and Oncology, Centro Nacional de Biotecnología (CNB)-CSIC, Madrid, Spain
| | - Pieta K. Mattila
- Institute of Biomedicine and MediCity Research Laboratories, University of Turku, Turku, Finland
- Turku Bioscience, University of Turku and Åbo Akademi University, Turku, Finland
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Inhibition of the IRE-1α/XBP-1 pathway prevents chronic GVHD and preserves the GVL effect in mice. Blood Adv 2019; 2:414-427. [PMID: 29483082 DOI: 10.1182/bloodadvances.2017009068] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Accepted: 02/02/2018] [Indexed: 01/07/2023] Open
Abstract
Hematopoietic stem cell transplantation (HCT) is a curative procedure for hematological malignancies, but chronic graft-versus-host disease (cGVHD) remains a major complication after allogeneic HCT. Because donor B cells are essential for cGVHD development and B cells are sensitive to endoplasmic reticulum (ER) stress, we hypothesized that the IRE-1α/XBP-1 pathway is required for B-cell activation and function and for the development of cGVHD. To test this hypothesis, we used conditional knock-out mice deficient of XBP-1 specifically in B cells. Recipients transplanted with donor grafts containing XBP-1-deficient B cells displayed reduced cGVHD compared with controls. Reduction of cGVHD correlated with impaired B-cell functions, including reduced production of anti-double-stranded DNA immunoglobulin G antibodies, CD86, Fas, and GL7 surface expression, and impaired T-cell responses, including reduced interferon-γ production and follicular helper T cells. In a bronchiolitis obliterans cGVHD model, recipients of transplants containing XBP-1-deficient B cells demonstrated improved pulmonary function correlated with reduced donor splenic follicular helper T cells and increased B cells compared with those of wild-type control donor grafts. We then tested if XBP-1 blockade via an IRE-1α inhibitor, B-I09, would attenuate cGVHD and preserve the graft-versus-leukemia (GVL) effect. In a cutaneous cGVHD model, we found that prophylactic administration of B-I09 reduced clinical features of cGVHD, which correlated with reductions in donor T-cell and dendritic cell skin infiltrates. Inhibition of the IRE-1α/XBP-1 pathway also preserved the GVL effect against chronic myelogenous leukemia mediated by allogeneic splenocytes. Collectively, the ER stress response mediated by the IRE-1α/XBP-1 axis is required for cGVHD development but dispensable for GVL activity.
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Akhter A, Street L, Ghosh S, Burns BF, Elyamany G, Shabani-Rad MT, Stewart DA, Mansoor A. Concomitant high expression of Toll-like receptor (TLR) and B-cell receptor (BCR) signalling molecules has clinical implications in mantle cell lymphoma. Hematol Oncol 2015; 35:79-86. [PMID: 26354285 DOI: 10.1002/hon.2251] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2015] [Revised: 07/21/2015] [Accepted: 07/22/2015] [Indexed: 11/07/2022]
Abstract
Mantle cell lymphoma (MCL) is an aggressive disease with frequent relapse. Targeted therapies against B-cell receptor (BCR) molecules have demonstrated improved outcomes in relapsed cases. However, clinical responses are slow and selective, with failure to attain complete remission in a significant subset of patients. Complex interaction of BCR signal transduction with toll-like receptor (TLR) and other pathways in MCL remains unknown, thus averting progress in development of targeted therapies. We have performed detailed digital quantification of BCR/TLR signalling molecules and their effector pathways in a cohort (n = 81) of MCL patients and correlated these data with overall survival. Hierarchical clustering model based on BCR/TLR genes revealed two distinct (BCRhigh and BCRlow ) subsets of patients (n = 32; 40%) with significant differences in expression (>1.5-fold change; p < 0.05). Higher levels of BTK/SYK/BLNK/CARD11/PLCG signalosome and lower expression of MALT1/BCL10 genes suggested tonic pattern of BCR activation. Amplified expression of TLR6/TLR7/TLR9 was noted in concert with hyper-responsiveness of BCR machinery. MYD88, a key TLR adaptor molecule, was not upregulated in any of these clusters, which may suggest a 'cross-talk' between BCR and TLR pathways. In sync with BCR/TLR signalling, we recorded significantly enhanced expression of genes associated with NF-kB pathway in BCRhigh subset of MCL patients. On univariate analysis, the BCRhigh patients showed a trend towards inferior clinical response to a standardized treatment protocol, compared with the BCRlow group (log rank, p = 0.043). In conclusion, we have identified hyperactive BCR/TLR signalling pathways and their effector downstream targets in a subset of MCL patients and associated it with poor clinical outcomes. Our study provides quantitative evidence at RNA expression level of possible concomitant collaboration between TLR and BCR signalling molecules in MCL. These data will provide further insights for future functional studies and, hence, development of targeted therapies for MCL patients. Copyright © 2015 John Wiley & Sons, Ltd.
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Affiliation(s)
- Ariz Akhter
- Division of Hematology and Transfusion Medicine, Department of Pathology and Laboratory Medicine, University of Calgary/Calgary Laboratory Services (CLS), Calgary, Alberta, Canada
| | - Lesley Street
- Division of Hematology and Hematologic Malignancies, Tom Baker Cancer Center, University of Calgary, Calgary, Alberta, Canada
| | - Sunita Ghosh
- Department of Biostatistics, Cross Cancer Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Bruce F Burns
- Department of Pathology and Laboratory Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Ghaleb Elyamany
- Department of Pathology and Laboratory Medicine, Prince Sultan Military Medical City, Riyadh, Saudi Arabia
| | - Meer-Taher Shabani-Rad
- Division of Hematology and Transfusion Medicine, Department of Pathology and Laboratory Medicine, University of Calgary/Calgary Laboratory Services (CLS), Calgary, Alberta, Canada
| | - Douglas A Stewart
- Division of Hematology and Hematologic Malignancies, Tom Baker Cancer Center, University of Calgary, Calgary, Alberta, Canada
| | - Adnan Mansoor
- Division of Hematology and Transfusion Medicine, Department of Pathology and Laboratory Medicine, University of Calgary/Calgary Laboratory Services (CLS), Calgary, Alberta, Canada
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Williams JM, Bonami RH, Hulbert C, Thomas JW. Reversing Tolerance in Isotype Switch-Competent Anti-Insulin B Lymphocytes. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2015; 195:853-64. [PMID: 26109644 PMCID: PMC4506889 DOI: 10.4049/jimmunol.1403114] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 05/30/2015] [Indexed: 12/22/2022]
Abstract
Autoreactive B lymphocytes that escape central tolerance and mature in the periphery are a liability for developing autoimmunity. IgG insulin autoantibodies that predict type 1 diabetes and complicate insulin therapies indicate that mechanisms for tolerance to insulin are flawed. To examine peripheral tolerance in anti-insulin B cells, we generated C57BL/6 mice that harbor anti-insulin VDJH-125 site directed to the native IgH locus (VH125(SD)). Class switch-competent anti-insulin B cells fail to produce IgG Abs following T cell-dependent immunization of VH125(SD) mice with heterologous insulin, and they exhibit markedly impaired proliferation to anti-CD40 plus insulin in vitro. In contrast, costimulation with LPS plus insulin drives robust anti-insulin B cell proliferation. Furthermore, VH125(SD) mice produce both IgM and IgG2a anti-insulin Abs following immunization with insulin conjugated to type 1 T cell-independent Brucella abortus ring test Ag (BRT). Anti-insulin B cells undergo clonal expansion in vivo and emerge as IgM(+) and IgM(-) GL7(+)Fas(+) germinal center (GC) B cells following immunization with insulin-BRT, but not BRT alone. Analysis of Igκ genes in VH125(SD) mice immunized with insulin-BRT reveals that anti-insulin Vκ from the preimmune repertoire is selected into GCs. These data demonstrate that class switch-competent anti-insulin B cells remain functionally silent in T cell-dependent immune responses, yet these B cells are vulnerable to reversal of anergy following combined BCR/TLR engagement that promotes Ag-specific GC responses and Ab production. Environmental factors that lead to infection and inflammation could play a critical yet underappreciated role in driving loss of tolerance and promoting autoimmune disease.
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Affiliation(s)
- Jonathan M Williams
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University, Nashville, TN 37232; and Division of Rheumatology and Immunology, Department of Medicine, Vanderbilt University, Nashville, TN 37232
| | - Rachel H Bonami
- Division of Rheumatology and Immunology, Department of Medicine, Vanderbilt University, Nashville, TN 37232
| | - Chrys Hulbert
- Division of Rheumatology and Immunology, Department of Medicine, Vanderbilt University, Nashville, TN 37232
| | - James W Thomas
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University, Nashville, TN 37232; and Division of Rheumatology and Immunology, Department of Medicine, Vanderbilt University, Nashville, TN 37232
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Zhang J, Li H, Huo R, Zhai T, Li H, Sun Y, Shen B, Li N. Paeoniflorin selectively inhibits LPS-provoked B-cell function. J Pharmacol Sci 2015; 128:8-16. [DOI: 10.1016/j.jphs.2015.02.011] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Revised: 02/16/2015] [Accepted: 02/19/2015] [Indexed: 10/23/2022] Open
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12
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Ko HM, Lee SH, Kim KC, Joo SH, Choi WS, Shin CY. The Role of TLR4 and Fyn Interaction on Lipopolysaccharide-Stimulated PAI-1 Expression in Astrocytes. Mol Neurobiol 2014; 52:8-25. [DOI: 10.1007/s12035-014-8837-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Accepted: 07/28/2014] [Indexed: 01/05/2023]
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13
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Activation of Ras overcomes B-cell tolerance to promote differentiation of autoreactive B cells and production of autoantibodies. Proc Natl Acad Sci U S A 2014; 111:E2797-806. [PMID: 24958853 DOI: 10.1073/pnas.1402159111] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Newly generated immature B cells are selected to enter the peripheral mature B-cell pool only if they do not bind (or bind limited amount of) self-antigen. We previously suggested that this selection relies on basal extracellular signal-regulated kinase (Erk) activation mediated by tonic B-cell antigen receptor (BCR) signaling and that this signal can be replaced by an active rat sarcoma (Ras), which are small GTPase proteins. In this study we compared the activity of Ras and Erk in nonautoreactive and autoreactive immature B cells and investigated whether activation of Ras can break tolerance. Our results demonstrate lower levels of active Erk and Ras in autoreactive immature B cells, although this is evident only when these cells display medium/high avidity for self-antigen. Basal activation of Erk in immature B cells is proportional to surface IgM and dependent on sarcoma family kinases, whereas it is independent of B-cell activating factor, IFN, and Toll-like receptor signaling. Ectopic expression of the constitutively active mutant Ras form N-RasD12 in autoreactive cells raises active Erk, halts receptor editing via PI3 kinase, and promotes differentiation via Erk, breaking central tolerance. Moreover, when B cells coexpress autoreactive and nonautoreactive BCRs, N-RasD12 leads also to a break in peripheral tolerance with the production of autoantibodies. Our findings indicate that in immature B cells, basal activation of Ras and Erk are controlled by tonic BCR signaling, and that positive changes in Ras activity can lead to a break in both central and peripheral B-cell tolerance.
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Uslu K, Coleman AS, Allman WR, Katsenelson N, Bram RJ, Alugupalli KR, Akkoyunlu M. Impaired B Cell Receptor Signaling Is Responsible for Reduced TACI Expression and Function in X-Linked Immunodeficient Mice. THE JOURNAL OF IMMUNOLOGY 2014; 192:3582-95. [DOI: 10.4049/jimmunol.1203468] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Chandra R, Federici S, Németh ZH, Csóka B, Thomas JA, Donnelly R, Spolarics Z. Cellular mosaicism for X-linked polymorphisms and IRAK1 expression presents a distinct phenotype and improves survival following sepsis. J Leukoc Biol 2013; 95:497-507. [PMID: 24193737 DOI: 10.1189/jlb.0713397] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
ChrX cellular mosaicism for X-linked genetic polymorphisms in females versus the single ChrX representation in males denotes a genetic difference, which may contribute to gender bias in the inflammatory response. This hypothesis was tested in female F1 offspring of consomic mice (BL6J-ChrX(A/J)/NaJ) that were homokaryotic or mosaic for the active BL6 and AJ ChrXs or for IRAK1 deficiency linked to the BL6 ChrX. Sepsis was initiated by CLP. IRAK1-deficient and IRAK1-mosaic mice showed similar protection from sepsis-induced mortality and reduced IL-6 and IL-10 release compared with WT. BM cellularity and blood B cell counts were increased in naive IRAK1-mosaic mice compared with WT-mosaic or IRAK1-deficient animals. Sepsis-induced BM cell depletion was greater in IRAK1-mosaic mice compared with WT-mosaic or IRAK1-deficient subjects, whereas splenic B and T cell depletion was less in IRAK1-mosaic and IRAK1-deficient than WT-mosaic mice. Skewing toward AJ or BL6-ChrX-expressing cells was assessed by testing allele-specific expression of strain-variant Xkrx and BTK genes. In naive IRAK1-mosaic mice, BM and blood cells with the active BL6-ChrX, were greater than cells expressing the AJ-ChrX (cell ratio 2.5 in IRAK1-mosaic; 1.5 in WT-mosaic mice). Sepsis decreased cell ratios more in IRAK1-mosaic than in WT-mosaic mice. The study reveals functional variability in cellular mosaicism for IRAK1 expression and natural X-linked polymorphisms during sepsis. Mosaicism for IRAK1 expression is accompanied by skewing toward deficient immune cell populations, producing a phenotype that is preconditioned for improved sepsis outcome similar to that observed in IRAK1 deficiency.
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Affiliation(s)
- Rachna Chandra
- 1.Rutgers New Jersey Medical School, 185 South Orange Ave., MSB G-578, Newark, NJ 07103, USA.
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Differential role of Dok1 and Dok2 in TLR2-induced inflammatory signaling in glia. Mol Cell Neurosci 2013; 56:148-58. [DOI: 10.1016/j.mcn.2013.04.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Revised: 04/08/2013] [Accepted: 04/26/2013] [Indexed: 02/07/2023] Open
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17
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Wu TT, Tai YT, Cherng YG, Chen TG, Lin CJ, Chen TL, Chang HC, Chen RM. GATA-2 transduces LPS-induced il-1β gene expression in macrophages via a toll-like receptor 4/MD88/MAPK-dependent mechanism. PLoS One 2013; 8:e72404. [PMID: 23940812 PMCID: PMC3735524 DOI: 10.1371/journal.pone.0072404] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Accepted: 07/10/2013] [Indexed: 12/15/2022] Open
Abstract
Lipopolysaccharide (LPS) is a critical factor for inducing acute lung injury. GATA-2, a transcription factor, contributes to the control of cell activity and function. Exposure of RAW 264.7 cells to LPS induced interleukin (IL)-1β mRNA and protein expression and GATA-2 translocation from the cytoplasm to nuclei in concentration- and time-dependent manners. A bioinformatic search revealed that GATA-2-specific binding elements exist in the 5'-promoter region of the il-1β gene. LPS could enhance the transactivation activity of GATA-2 in macrophages. Knocking-down translation of GATA-2 mRNA using RNA interference significantly alleviated LPS-induced IL-1β mRNA and protein expression. As to the mechanism, transfection of toll-like receptor (TLR) 4 small interfering (si)RNA into macrophages concurrently decreased LPS-caused increases in nuclear GATA-2 levels. Sequentially, treatment with myeloid differentiation factor 88 (MyD88) siRNA decreased LPS-induced phosphorylation of mitogen-activated protein kinases (MAPKs) kinase 1/2 and subsequent translocation of GATA-2. Reducing MAPK activities using specific inhibitors simultaneously decreased GATA-2 activation. Furthermore, exposure of primary macrophages to LPS significantly increased the transactivation activities of GATA-2 and IL-1β mRNA and protein expression. Transfection of GATA-2 siRNA inhibited LPS-induced IL-1β mRNA expression. Results of this study show that LPS induction of il-1β gene expression in macrophages is mediated by GATA-2 via activation of TLR4, MyD88, and MAPKs.
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Affiliation(s)
- Tsu-Tuan Wu
- Graduate Institute of Medical Sciences and Center of Excellent Cancer Research, Taipei Medical University, Taipei, Taiwan
- Section of Respiratory and Critical Care Medicine, Department of Internal Medicine, Taipei County Hospital, Taipei, Taiwan
| | - Yu-Ting Tai
- Department of Anesthesiology, Wan-Fang Hospital, Taipei Medical University, Taipei, Taiwan
| | - Yih-Giun Cherng
- Department of Anesthesiology, Shuang-Ho Hospital, Taipei Medical University, Taipei, Taiwan
| | - Tyng-Guey Chen
- Department of Anesthesiology, Wan-Fang Hospital, Taipei Medical University, Taipei, Taiwan
| | - Chien-Ju Lin
- Graduate Institute of Medical Sciences and Center of Excellent Cancer Research, Taipei Medical University, Taipei, Taiwan
| | - Ta-Liang Chen
- Anesthetics and Toxicology Research Center, Department of Anesthesiology, Taipei Medical University Hospital, Taipei, Taiwan
| | - Huai-Chia Chang
- Anesthetics and Toxicology Research Center, Department of Anesthesiology, Taipei Medical University Hospital, Taipei, Taiwan
| | - Ruei-Ming Chen
- Graduate Institute of Medical Sciences and Center of Excellent Cancer Research, Taipei Medical University, Taipei, Taiwan
- Anesthetics and Toxicology Research Center, Department of Anesthesiology, Taipei Medical University Hospital, Taipei, Taiwan
- Cell Physiology and Molecular Image Research Center, Wan-Fang Hospital, Taipei Medical University, Taipei, Taiwan
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New insights into pre-BCR and BCR signalling with relevance to B cell malignancies. Nat Rev Immunol 2013; 13:578-91. [DOI: 10.1038/nri3487] [Citation(s) in RCA: 208] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Nündel K, Busto P, Debatis M, Marshak-Rothstein A. The role of Bruton's tyrosine kinase in the development and BCR/TLR-dependent activation of AM14 rheumatoid factor B cells. J Leukoc Biol 2013; 94:865-75. [PMID: 23804807 DOI: 10.1189/jlb.0313126] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The protein kinase Btk has been implicated in the development, differentiation, and activation of B cells through its role in the BCR and TLR signaling cascades. These receptors and in particular, the BCR and either TLR7 or TLR9 also play a critical role in the activation of autoreactive B cells by RNA- or DNA-associated autoantigens. To explore the role of Btk in the development of autoreactive B cells, as well as their responses to nucleic acid-associated autoantigens, we have now compared Btk-sufficient and Btk-deficient mice that express a prototypic RF BCR encoded by H- and L-chain sdTgs. These B cells bind autologous IgG2a with low affinity and only proliferate in response to IgG2a ICs that incorporate DNA or RNA. We found that Btk-sufficient RF(+) B cells mature into naïve FO B cells, all of which express the Tg BCR, despite circulating levels of IgG2a. By contrast, a significant proportion of Btk-deficient RF(+) B cells acquires a MZ or MZ precursor phenotype. Remarkably, despite the complete inability of RF(+) Xid/y B cells to respond to F(ab')2 anti-IgM, RF(+) Xid/y B cells could respond well to autoantigen-associated ICs. These data reveal unique features of the signaling cascades responsible for the activation of autoreactive B cells.
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Affiliation(s)
- Kerstin Nündel
- 2.Division of Rheumatology, University of Massachusetts Medical School, 364 Plantation St., Worcester, MA 01605, USA.
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20
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Cvija H, Kovacic N, Katavic V, Ivcevic S, Aguila HL, Marusic A, Grcevic D. Chemotactic and Immunoregulatory Properties of Bone Cells are Modulated by Endotoxin-Stimulated Lymphocytes. Inflammation 2012; 35:1618-31. [DOI: 10.1007/s10753-012-9477-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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21
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Abstract
We have discovered a distinct mature B-cell subset that accumulates with age, which we have termed age-associated B cells. These cells comprise up to 30% of mature B cells by 22 months. Despite sharing some features with other mature B-cell subsets, they are refractory to BCR and CD40 stimulation. Instead, they respond to TLR9 or TLR7 stimulation and divide maximally on combined BCR and TLR ligation, leading to Ig production and preferential secretion of IL-10 and IL-4. Although similar to follicular B cells in both B-lymphocyte stimulator (BLyS) receptor expression and BLyS binding capacity, these cells do not rely on BLyS for survival. They are neither cycling nor the result of intrinsically altered B lymphopoiesis in aged BM, but instead appear to be generated from mature B cells that exhaustively expand during the individual's lifetime. Finally, they present Ag effectively and favor polarization to a TH17 profile. Together, these findings reveal that while the magnitude of the mature primary B-cell niche is maintained with age, it is increasingly occupied by cells refractory to BCR-driven activation yet responsive to innate receptor stimulation.
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22
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Fang Y, Rowe T, Leon AJ, Banner D, Danesh A, Xu L, Ran L, Bosinger SE, Guan Y, Chen H, Cameron CC, Cameron MJ, Kelvin DJ. Molecular characterization of in vivo adjuvant activity in ferrets vaccinated against influenza virus. J Virol 2010; 84:8369-88. [PMID: 20534862 PMCID: PMC2919000 DOI: 10.1128/jvi.02305-09] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2009] [Accepted: 05/30/2010] [Indexed: 02/05/2023] Open
Abstract
The 2009 H1N1 influenza pandemic has prompted a significant need for the development of efficient, single-dose, adjuvanted vaccines. Here we investigated the adjuvant potential of CpG oligodeoxynucleotide (ODN) when used with a human seasonal influenza virus vaccine in ferrets. We found that the CpG ODN-adjuvanted vaccine effectively increased antibody production and activated type I interferon (IFN) responses compared to vaccine alone. Based on these findings, pegylated IFN-alpha2b (PEG-IFN) was also evaluated as an adjuvant in comparison to CpG ODN and complete Freund's adjuvant (CFA). Our results showed that all three vaccines with adjuvant added prevented seasonal human A/Brisbane/59/2007 (H1N1) virus replication more effectively than did vaccine alone. Gene expression profiles indicated that, as well as upregulating IFN-stimulated genes (ISGs), CpG ODN enhanced B-cell activation and increased Toll-like receptor 4 (TLR4) and IFN regulatory factor 4 (IRF4) expression, whereas PEG-IFN augmented adaptive immunity by inducing major histocompatibility complex (MHC) transcription and Ras signaling. In contrast, the use of CFA as an adjuvant induced limited ISG expression but increased the transcription of MHC, cell adhesion molecules, and B-cell activation markers. Taken together, our results better characterize the specific molecular pathways leading to adjuvant activity in different adjuvant-mediated influenza virus vaccinations.
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Affiliation(s)
- Yuan Fang
- Division of Immunology, International Institute of Infection and Immunity, Shantou University Medical College, 22 Xinling Road, Shantou, Guangdong 515041, People's Republic of China, Division of Experimental Therapeutics, Toronto General Research Institute, University Health Network, 101 College Street, Toronto, Ontario M5G 1L7, Canada, Department of Immunology, University of Toronto, Toronto, Ontario, Canada, University di Sassari, Dipartimento di Scienze Biomediche, Sassari, Italy, Division of Virology, International Institute of Infection and Immunity, Shantou University Medical College, 22 Xinling Road, Shantou, Guangdong 515041, People's Republic of China, Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Thomas Rowe
- Division of Immunology, International Institute of Infection and Immunity, Shantou University Medical College, 22 Xinling Road, Shantou, Guangdong 515041, People's Republic of China, Division of Experimental Therapeutics, Toronto General Research Institute, University Health Network, 101 College Street, Toronto, Ontario M5G 1L7, Canada, Department of Immunology, University of Toronto, Toronto, Ontario, Canada, University di Sassari, Dipartimento di Scienze Biomediche, Sassari, Italy, Division of Virology, International Institute of Infection and Immunity, Shantou University Medical College, 22 Xinling Road, Shantou, Guangdong 515041, People's Republic of China, Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Alberto J. Leon
- Division of Immunology, International Institute of Infection and Immunity, Shantou University Medical College, 22 Xinling Road, Shantou, Guangdong 515041, People's Republic of China, Division of Experimental Therapeutics, Toronto General Research Institute, University Health Network, 101 College Street, Toronto, Ontario M5G 1L7, Canada, Department of Immunology, University of Toronto, Toronto, Ontario, Canada, University di Sassari, Dipartimento di Scienze Biomediche, Sassari, Italy, Division of Virology, International Institute of Infection and Immunity, Shantou University Medical College, 22 Xinling Road, Shantou, Guangdong 515041, People's Republic of China, Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - David Banner
- Division of Immunology, International Institute of Infection and Immunity, Shantou University Medical College, 22 Xinling Road, Shantou, Guangdong 515041, People's Republic of China, Division of Experimental Therapeutics, Toronto General Research Institute, University Health Network, 101 College Street, Toronto, Ontario M5G 1L7, Canada, Department of Immunology, University of Toronto, Toronto, Ontario, Canada, University di Sassari, Dipartimento di Scienze Biomediche, Sassari, Italy, Division of Virology, International Institute of Infection and Immunity, Shantou University Medical College, 22 Xinling Road, Shantou, Guangdong 515041, People's Republic of China, Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Ali Danesh
- Division of Immunology, International Institute of Infection and Immunity, Shantou University Medical College, 22 Xinling Road, Shantou, Guangdong 515041, People's Republic of China, Division of Experimental Therapeutics, Toronto General Research Institute, University Health Network, 101 College Street, Toronto, Ontario M5G 1L7, Canada, Department of Immunology, University of Toronto, Toronto, Ontario, Canada, University di Sassari, Dipartimento di Scienze Biomediche, Sassari, Italy, Division of Virology, International Institute of Infection and Immunity, Shantou University Medical College, 22 Xinling Road, Shantou, Guangdong 515041, People's Republic of China, Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Luoling Xu
- Division of Immunology, International Institute of Infection and Immunity, Shantou University Medical College, 22 Xinling Road, Shantou, Guangdong 515041, People's Republic of China, Division of Experimental Therapeutics, Toronto General Research Institute, University Health Network, 101 College Street, Toronto, Ontario M5G 1L7, Canada, Department of Immunology, University of Toronto, Toronto, Ontario, Canada, University di Sassari, Dipartimento di Scienze Biomediche, Sassari, Italy, Division of Virology, International Institute of Infection and Immunity, Shantou University Medical College, 22 Xinling Road, Shantou, Guangdong 515041, People's Republic of China, Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Longsi Ran
- Division of Immunology, International Institute of Infection and Immunity, Shantou University Medical College, 22 Xinling Road, Shantou, Guangdong 515041, People's Republic of China, Division of Experimental Therapeutics, Toronto General Research Institute, University Health Network, 101 College Street, Toronto, Ontario M5G 1L7, Canada, Department of Immunology, University of Toronto, Toronto, Ontario, Canada, University di Sassari, Dipartimento di Scienze Biomediche, Sassari, Italy, Division of Virology, International Institute of Infection and Immunity, Shantou University Medical College, 22 Xinling Road, Shantou, Guangdong 515041, People's Republic of China, Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Steven E. Bosinger
- Division of Immunology, International Institute of Infection and Immunity, Shantou University Medical College, 22 Xinling Road, Shantou, Guangdong 515041, People's Republic of China, Division of Experimental Therapeutics, Toronto General Research Institute, University Health Network, 101 College Street, Toronto, Ontario M5G 1L7, Canada, Department of Immunology, University of Toronto, Toronto, Ontario, Canada, University di Sassari, Dipartimento di Scienze Biomediche, Sassari, Italy, Division of Virology, International Institute of Infection and Immunity, Shantou University Medical College, 22 Xinling Road, Shantou, Guangdong 515041, People's Republic of China, Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Yi Guan
- Division of Immunology, International Institute of Infection and Immunity, Shantou University Medical College, 22 Xinling Road, Shantou, Guangdong 515041, People's Republic of China, Division of Experimental Therapeutics, Toronto General Research Institute, University Health Network, 101 College Street, Toronto, Ontario M5G 1L7, Canada, Department of Immunology, University of Toronto, Toronto, Ontario, Canada, University di Sassari, Dipartimento di Scienze Biomediche, Sassari, Italy, Division of Virology, International Institute of Infection and Immunity, Shantou University Medical College, 22 Xinling Road, Shantou, Guangdong 515041, People's Republic of China, Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Honglin Chen
- Division of Immunology, International Institute of Infection and Immunity, Shantou University Medical College, 22 Xinling Road, Shantou, Guangdong 515041, People's Republic of China, Division of Experimental Therapeutics, Toronto General Research Institute, University Health Network, 101 College Street, Toronto, Ontario M5G 1L7, Canada, Department of Immunology, University of Toronto, Toronto, Ontario, Canada, University di Sassari, Dipartimento di Scienze Biomediche, Sassari, Italy, Division of Virology, International Institute of Infection and Immunity, Shantou University Medical College, 22 Xinling Road, Shantou, Guangdong 515041, People's Republic of China, Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Cheryl C. Cameron
- Division of Immunology, International Institute of Infection and Immunity, Shantou University Medical College, 22 Xinling Road, Shantou, Guangdong 515041, People's Republic of China, Division of Experimental Therapeutics, Toronto General Research Institute, University Health Network, 101 College Street, Toronto, Ontario M5G 1L7, Canada, Department of Immunology, University of Toronto, Toronto, Ontario, Canada, University di Sassari, Dipartimento di Scienze Biomediche, Sassari, Italy, Division of Virology, International Institute of Infection and Immunity, Shantou University Medical College, 22 Xinling Road, Shantou, Guangdong 515041, People's Republic of China, Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Mark J. Cameron
- Division of Immunology, International Institute of Infection and Immunity, Shantou University Medical College, 22 Xinling Road, Shantou, Guangdong 515041, People's Republic of China, Division of Experimental Therapeutics, Toronto General Research Institute, University Health Network, 101 College Street, Toronto, Ontario M5G 1L7, Canada, Department of Immunology, University of Toronto, Toronto, Ontario, Canada, University di Sassari, Dipartimento di Scienze Biomediche, Sassari, Italy, Division of Virology, International Institute of Infection and Immunity, Shantou University Medical College, 22 Xinling Road, Shantou, Guangdong 515041, People's Republic of China, Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - David J. Kelvin
- Division of Immunology, International Institute of Infection and Immunity, Shantou University Medical College, 22 Xinling Road, Shantou, Guangdong 515041, People's Republic of China, Division of Experimental Therapeutics, Toronto General Research Institute, University Health Network, 101 College Street, Toronto, Ontario M5G 1L7, Canada, Department of Immunology, University of Toronto, Toronto, Ontario, Canada, University di Sassari, Dipartimento di Scienze Biomediche, Sassari, Italy, Division of Virology, International Institute of Infection and Immunity, Shantou University Medical College, 22 Xinling Road, Shantou, Guangdong 515041, People's Republic of China, Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
- Corresponding author. Mailing address: Division of Immunology, International Institute of Infection and Immunity, Shantou University Medical College, 22 Xinling Road, Shantou, Guangdong 515041, People's Republic of China. Phone and fax: (86)-754-88573991. E-mail:
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23
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Abstract
Toll-like receptors (TLR) play a central role in the initiation of the innate immune response to pathogens. Upon recognition of molecular motifs specific for microbial molecules TLR mediate pro-inflammatory cytokine secretion and enhance antigen presentation; in B cells they further promote expansion, class switch recombination and immunoglobulin secretion. As a result of their adjuvant properties, TLR ligands have become an integral component of antimicrobial vaccines. In spite of this, little is known of the direct effects of TLR engagement on B-lymphocyte function. The scope of this review is to outline the differences in TLR expression and reactivity in murine and human B-cell subsets and to provide an overview of the currently available literature. We will further discuss the possible roles of TLR in regulating B-cell effector functions and shaping antibody-mediated defence against microbial pathogens in vivo.
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24
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Matsumoto Y, Kobata T, Odaka M, Furukawa K, Hirata K, Yuki N. BAFF aids generation of IgG anti-ganglioside antibodies in response to Campylobacter jejuni lipo-oligosaccharide. J Neuroimmunol 2010; 218:67-72. [DOI: 10.1016/j.jneuroim.2009.10.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2009] [Revised: 09/15/2009] [Accepted: 10/14/2009] [Indexed: 11/27/2022]
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25
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Pone EJ, Zan H, Zhang J, Al-Qahtani A, Xu Z, Casali P. Toll-like receptors and B-cell receptors synergize to induce immunoglobulin class-switch DNA recombination: relevance to microbial antibody responses. Crit Rev Immunol 2010; 30:1-29. [PMID: 20370617 PMCID: PMC3038989 DOI: 10.1615/critrevimmunol.v30.i1.10] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Differentiation of naïve B cells, including immunoglobulin class-switch DNA recombination, is critical for the immune response and depends on the extensive integration of signals from the B-cell receptor (BCR), tumor necrosis factor (TNF) family members, Toll-like receptors (TLRs), and cytokine receptors. TLRs and BCR synergize to induce class-switch DNA recombination in T cell-dependent and T cell-independent antibody responses to microbial pathogens. BCR triggering together with simultaneous endosomal TLR engagement leads to enhanced B-cell differentiation and antibody responses. Te requirement of both BCR and TLR engagement would ensure appropriate antigen-specific activation in an infection. Co-stimulation of TLRs and BCR likely plays a significant role in anti-microbial antibody responses to contain pathogen loads until the T cell-dependent antibody responses peak. Furthermore, the temporal sequence of different signals is also critical for optimal B cell responses, as exemplified by the activation of B cells by initial TLR engagement, leading to the up-regulation of co-stimulatory CD80 and MCH-II receptors, which result in more efficient interactions with T cells, thereby enhancing the germinal center reaction and antibody affinity maturation. Overall, BCR and TLR stimulation and the integration with signals from the pathogen or immune cells and their products determine the ensuing B-cell antibody response.
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Affiliation(s)
- Egest J. Pone
- Institute for Immunology, School of Medicine and School of Biological Sciences, University of California, Irvine, CA 92697-4120, USA
| | - Hong Zan
- Institute for Immunology, School of Medicine and School of Biological Sciences, University of California, Irvine, CA 92697-4120, USA
| | - Jinsong Zhang
- Institute for Immunology, School of Medicine and School of Biological Sciences, University of California, Irvine, CA 92697-4120, USA
| | - Ahmed Al-Qahtani
- Institute for Immunology, School of Medicine and School of Biological Sciences, University of California, Irvine, CA 92697-4120, USA
| | - Zhenming Xu
- Institute for Immunology, School of Medicine and School of Biological Sciences, University of California, Irvine, CA 92697-4120, USA
| | - Paolo Casali
- Institute for Immunology, School of Medicine and School of Biological Sciences, University of California, Irvine, CA 92697-4120, USA
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26
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Srinivasan L, Sasaki Y, Calado DP, Zhang B, Paik JH, DePinho RA, Kutok JL, Kearney JF, Otipoby KL, Rajewsky K. PI3 kinase signals BCR-dependent mature B cell survival. Cell 2009; 139:573-86. [PMID: 19879843 DOI: 10.1016/j.cell.2009.08.041] [Citation(s) in RCA: 523] [Impact Index Per Article: 34.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2009] [Revised: 07/17/2009] [Accepted: 08/26/2009] [Indexed: 01/01/2023]
Abstract
Previous work has shown that mature B cells depend upon survival signals delivered to the cells by their antigen receptor (BCR). To identify the molecular nature of this survival signal, we have developed a genetic approach in which ablation of the BCR is combined with the activation of specific, BCR dependent signaling cascades in mature B cells in vivo. Using this system, we provide evidence that the survival of BCR deficient mature B cells can be rescued by a single signaling pathway downstream of the BCR, namely PI3K signaling, with the FOXO1 transcription factor playing a central role.
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Affiliation(s)
- Lakshmi Srinivasan
- Program of Cellular and Molecular Medicine, Children's Hospital, and Immune Disease Institute, Harvard Medical School, Boston, MA 02115, USA
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27
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Mankaï A, Buhé V, Hammadi M, Youinou P, Ghedira I, Berthou C, Bordron A. Improvement of rituximab efficiency in chronic lymphocytic leukemia by CpG-mediated upregulation of CD20 expression independently of PU.1. Ann N Y Acad Sci 2009; 1173:721-8. [PMID: 19758221 DOI: 10.1111/j.1749-6632.2009.04614.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Lipopolysaccharide (LPS), CpG-containing phosphothioate oligonucleotides (CpG) and various cytokines impact chronic lymphocytic leukemia (CLL) B cells. For example, they influence cell cycle entry, expression of co-receptors, and CD20. Rituximab (RTX), for which CD20 molecule is the target, proved to be less efficient in CLL than in lymphoma. This is accounted for by a lower CD20 level in the former than in the latter B lymphocytes. CD20 transcription is mediated by four transcription factors, of which only purine-rich box-1 (PU.1) is reduced in CLL. We thus examined the effects of LPS, CpG, tumor necrosis factor-alpha, interferon-alpha, interleukin (IL)-3, IL-4, IL-21, granulocyte macrophage-colony stimulating factor (CSF), and granulocyte-CSF on the transcription of PU.1, and the subsequent expression of CD20. It appeared that CpG was unique in that it raised the membrane expression of CD20 on malignant B cells, owing to a PU.1 independent increase in its gene transcription. Moreover, RTX-induced complement-mediated lysis was also ameliorated. Thus, CpG accelerates the transcription of CD20 independently of PU.1, and thereby improves the efficacy of RTX in CLL.
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Affiliation(s)
- Amani Mankaï
- EA2216 Immunology and Pathology IFR148, Université de Bretagne Occidentale and Université Européenne de Bretagne, Brest, France
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28
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Abstract
Both genetic predispositions and environmental factors contribute to the development of autoimmunity. Toll-like receptors (TLR) are a family of pattern recognition receptors (PRRs), and their stimulus by pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs) is an important prerequisite for the induction of various autoimmune diseases. However, activation of specific TLRs can not only induce but also inhibit autoimmune diseases in certain mouse models. The contribution of individual TLRs to the induction of autoimmunity or tolerance involves hematopoietic as well as nonhematopoietic cells expressing combinations of different TLRs. The intercellular and intracellular orchestration of signals from different TLRs, other PRRs, and membrane-standing receptors dictates activating or inhibitory responses. Here, we summarize TLR-dependent tolerance mechanisms in B cells and intestinal epithelial cells and TLR-mediated activation mechanisms leading to the induction of Th17 T cell differentiation in different autoimmune diseases and in inflammatory bowel diseases. Understanding the opposing mechanisms of TLRs for the induction and suppression of autoimmune processes in specific diseases will help to develop novel therapies to treat autoimmunity.
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Affiliation(s)
- Maria Fischer
- Laboratory of Tolerance and Autoimmunity, German Rheumatism Research Center, Berlin, Germany
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29
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Yao SY, Soutto M, Sriram S. Bacterial cell wall products increases stabilization of HIF-1 alpha in an oligodendrocyte cell line preconditioned by cobalt chloride or desferrioxamine. J Neuroimmunol 2008; 200:17-26. [PMID: 18715655 DOI: 10.1016/j.jneuroim.2008.05.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2008] [Revised: 05/27/2008] [Accepted: 05/28/2008] [Indexed: 01/15/2023]
Abstract
We examined the effect of lipopolysaccharide (LPS) or lipotechoic acid (LTA) on the regulation of hypoxia inducible factor (HIF-1) alpha on the MO3.13 cells, a human oligodendroglial cell line. Our study shows that MO3.13 cells express the toll like receptors (TLR's) but do not increase cellular levels of HIF-1 alpha following exposure to bacterial cell wall products. When MO3.13 cells were preconditioned by desferrioxamine (DFO) or cobalt chloride (CoCl(2)) and then treated with either LPS or LTA, HIF-1 alpha levels were higher than that induced by DFO or CoCl(2) alone. The increase in HIF-1 alpha was due to increased protein stability that was mediated by activation of the ERK-MAP kinase pathway.
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Affiliation(s)
- Song-yi Yao
- Department of Neurology, Multiple Sclerosis Research Center, Vanderbilt University Medical Center, Nashville, Tennessee 37212, USA
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Chandra R, Villanueva E, Feketova E, Machiedo GW, Haskó G, Deitch EA, Spolarics Z. Endotoxemia down-regulates bone marrow lymphopoiesis but stimulates myelopoiesis: the effect of G6PD deficiency. J Leukoc Biol 2008; 83:1541-50. [PMID: 18353927 DOI: 10.1189/jlb.1207838] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Bone marrow (BM) dysfunction is an important component of immunomodulation. This study investigated alterations in cell content, apoptotic responses, and cell proliferation in BM, blood, and spleen in endotoxemic mice (LPS from Escherichia coli). As the decreased antioxidant status associated with glucose-6-phosphate dehydrogenase (G6PD) deficiency has been shown to modulate the innate immune response, we also tested whether a G6PD mutation (80% decrease in cellular enzyme activity) alters BM responses during endotoxemia. LPS decreased BM myeloid (CD45(+)CD11b(+)) and B lymphoid (CD45(+)CD19(+)CD11b(-)) cell content compared with controls. In contrast, LPS increased CD11b(+) myeloid but decreased T and B cell counts in the circulation. Endotoxemia inhibited spontaneous, heat shock, and H(2)O(2)-induced apoptosis as well as proliferative activity in BM lymphoid cells. In contrast, BM myeloid cell apoptosis was not altered, and their proliferative activity was increased during endotoxemia. Following LPS, splenic myeloid cell content was increased, and T and B cell content was unchanged; furthermore, splenocytes showed increased apoptosis compared with controls. BM cell content, including lymphoid and myeloid cells, was greater in G6PD mutant than wild-type (WT) mice, and LPS decreased BM cell counts to a greater degree in mutant than WT mice. Endotoxemia caused widespread inhibition of BM cytokine and chemokine production; however, IL-6 production was increased compared with controls. LPS-induced IL-6 production was decreased in G6PD mutant animals compared with WT. This study indicates that endotoxin inversely affects BM myeloid and lymphoid cell production. LPS-induced down-regulation of B cell production contributes to the generalized lymphopenia and lymphocyte dysfunction observed following nonspecific immune challenges.
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Affiliation(s)
- Rachna Chandra
- Department of Surgery, University of Medicine and Dentistry of New Jersey-New Jersey Medical School, Newark, NJ 07103, USA
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31
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Abstract
Systemic lupus erythematosus (SLE) highlights the dangers of dysregulated B cells and the importance of initiating and maintaining tolerance. In addition to central deletion, receptor editing, peripheral deletion, receptor revision, anergy, and indifference, we have described a new mechanism of B cell tolerance wherein dendritic cells (DCs) and macrophages (MPhis) regulate autoreactive B cells during innate immune responses. In part, DCs and MPhis repress autoreactive B cells by releasing IL-6 and soluble CD40L (sCD40L). This mechanism is selective in that IL-6 and sCD40L do not affect Ig secretion by naïve cells during innate immune responses, allowing immunity in the absence of autoimmunity. In lupus-prone mice, DCs and MPhis are defective in secretion of IL-6 and sCD40L and cannot effectively repress autoantibody secretion suggesting that defects in DC/MPhi-mediated tolerance may contribute to the autoimmune phenotype. Further, these studies suggest that reconstituting DCs and MPhis in SLE patients might restore regulation of autoreactive B cells and provide an alternative to immunosuppressive therapies.
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Affiliation(s)
- Barbara J Vilen
- Department of Microbiology, University of North Carolina, CB 7290, Chapel Hill, NC 27599, USA.
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