101
|
TSUBATA T. Negative regulation of B cell responses and self-tolerance to RNA-related lupus self-antigen. PROCEEDINGS OF THE JAPAN ACADEMY. SERIES B, PHYSICAL AND BIOLOGICAL SCIENCES 2018; 94:35-44. [PMID: 29321445 PMCID: PMC5829613 DOI: 10.2183/pjab.94.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Accepted: 09/12/2017] [Indexed: 06/07/2023]
Abstract
The antibody response to RNA-related antigens such as Sm/RNP requires the endosomal RNA sensor TLR7, and this process is crucial in the development of systemic lupus erythematosus at least in animal models. The inhibitory B cell receptor CD72 is unique because it recognizes Sm/RNP and specifically inhibits the activation of Sm/RNP-reactive B cells by activating SH2-containing protein tyrosine phosphatase 1 (SHP-1). In the normal immune system, Sm/RNP-reactive B cells are tolerized by a unique mechanism that probably involves SHP-1. These self-reactive B cells appear in the peripheral lymphoid organs, differentiate into marginal zone B cells, and then undergo apoptosis without further maturation into plasma cells. Thus, CD72 is involved in the suppression of TLR7-mediated response to RNA in complexes with nuclear proteins that are resistant to nucleases, whereas free RNAs are degraded by nucleases before they encounter the endosomal RNA sensor.
Collapse
MESH Headings
- Animals
- Antigens, CD/immunology
- Antigens, CD/metabolism
- Antigens, Differentiation, B-Lymphocyte/immunology
- Antigens, Differentiation, B-Lymphocyte/metabolism
- Autoantigens/metabolism
- B-Lymphocytes/immunology
- B-Lymphocytes/metabolism
- Down-Regulation
- Humans
- Immune Tolerance
- Lupus Erythematosus, Systemic/immunology
- Lupus Erythematosus, Systemic/metabolism
- Protein Tyrosine Phosphatase, Non-Receptor Type 6/metabolism
- RNA/immunology
- RNA/metabolism
- Ribonucleoproteins, Small Nuclear/immunology
- Ribonucleoproteins, Small Nuclear/metabolism
- Signal Transduction
- Toll-Like Receptor 7/metabolism
Collapse
Affiliation(s)
- Takeshi TSUBATA
- Department of Immunology, Medical Research Institute, Tokyo Medical and Dental University, Tokyo, Japan
| |
Collapse
|
102
|
De A, Sachdeva R, Bose A, Malik M, Jayachandran N, Pal R. Human Chorionic Gonadotropin Influences Systemic Autoimmune Responses. Front Endocrinol (Lausanne) 2018; 9:742. [PMID: 30574119 PMCID: PMC6291461 DOI: 10.3389/fendo.2018.00742] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 11/23/2018] [Indexed: 11/13/2022] Open
Abstract
Immunopathological outcomes in Systemic Lupus Erythematosus (SLE; or lupus) are believed to be autoantibody-mediated. Conditions which promote a Th2 skew (such as pregnancy) should encourage antibody production, worsening antibody-mediated diseases while ameliorating Th1/Th17-mediated diseases. Although an increased propensity toward autoreactivity can be observed in pregnant lupus patients and in pregnant lupus-prone mice, whether a unique human pregnancy-specific factor can contribute to such effects is unknown. This study assessed whether human chorionic gonadotropin (hCG, a pregnancy-specific hormone of diverse function) at physiological concentrations could mediate stimulatory influences on immune parameters in non-pregnant, lupus-prone mice, in light of the hormone's ameliorating effects on Th1-mediated autoimmunity in murine models. Results demonstrate that administration of hCG heightened global autoreactivity in such mice; antibodies to dsDNA, RNP68, Protein S, Protein C, β2-glycoprotein 1, and several phospholipids were enhanced, and hormone administration had adverse effects on animal survival. Specifically in splenic cell cultures containing cells derived from lupus-prone mice, hCG demonstrated synergistic effects with TLR ligands (up-modulation of costimulatory markers on B cells) as well as with TCR stimuli (enhanced proliferative responses, enhanced levels of cytokines, and the phosphorylation of p38). In both instances, enhanced synthesis of lupus-associated cytokines was observed, in addition to the heightened generation of autoantibodies reactive toward apoptotic blebs. These results suggest that selective transducive, proliferative, and differentiative effects of hCG on adaptive immune cells may drive autoreactive responses in a lupus environment, and may also potentially provide insights into the association between the presence of higher hCG levels (or the administration of hCG) with the presence (or appearance) of humoral autoimmunity.
Collapse
|
103
|
Abstract
Germinal centers (GCs) are dynamic microenvironments that form in the secondary lymphoid organs and generate somatically mutated high-affinity antibodies necessary to establish an effective humoral immune response. Tight regulation of GC responses is critical for maintaining self-tolerance. GCs can arise in the absence of purposeful immunization or overt infection (called spontaneous GCs, Spt-GCs). In autoimmune-prone mice and patients with autoimmune disease, aberrant regulation of Spt-GCs is thought to promote the development of somatically mutated pathogenic autoantibodies and the subsequent development of autoimmunity. The mechanisms that control the formation of Spt-GCs and promote systemic autoimmune diseases remain an open question and the focus of ongoing studies. Here, we discuss the most current studies on the role of Spt-GCs in autoimmunity.
Collapse
Affiliation(s)
- Phillip P Domeier
- a Department of Microbiology and Immunology, Penn State College of Medicine , USA
| | - Stephanie L Schell
- a Department of Microbiology and Immunology, Penn State College of Medicine , USA
| | - Ziaur S M Rahman
- a Department of Microbiology and Immunology, Penn State College of Medicine , USA
| |
Collapse
|
104
|
Castiblanco DP, Maul RW, Russell Knode LM, Gearhart PJ. Co-Stimulation of BCR and Toll-Like Receptor 7 Increases Somatic Hypermutation, Memory B Cell Formation, and Secondary Antibody Response to Protein Antigen. Front Immunol 2017; 8:1833. [PMID: 29312329 PMCID: PMC5742111 DOI: 10.3389/fimmu.2017.01833] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Accepted: 12/05/2017] [Indexed: 12/18/2022] Open
Abstract
The goal of immunization is to produce both a flood of antibodies to neutralize antigen and memory cells to accelerate the secondary response. To enhance the generation of memory B cells, we examined the effect of co-engaging BCR and toll-like receptor (TLR) 7 receptors by immunizing mice with a hapten-protein antigen, NP-CGG, and a ligand, R837 (imiquimod). During the early and late primary responses, there was no augmentation with R837 on the number of germinal center B cells or serum antibody. However, in the niche of germinal centers, R837 increased somatic hypermutation in the canonical VH1-72 gene that encodes NP-specific antibody. Increased mutation was not due to enhanced expression of activation-induced deaminase, but was likely a result of selection for high-affinity B cells with altered codons in the gene. This correlated with the appearance of antigen-specific B cells with a memory phenotype, which was intrinsic to TLR7 on B cells. To determine if these memory cells produced a recall response after a secondary challenge, spleen cells from mice that were immunized with NP-CGG and R837 were adoptively transferred into muMT recipients, and boosted with NP-CGG. Cells from mice that initially received both antigen and R837 generated a robust increase in germinal center B cells, plasmablasts, plasma cells, and serum antibody, compared with their cohorts who received antigen alone. These results support the use of co-immunization with TLR7 ligands to promote vigorous memory B cell responses to protein antigens.
Collapse
Affiliation(s)
- Diana P Castiblanco
- Laboratory of Molecular Biology and Immunology, National Institute on Aging, National Institutes of Health, Baltimore, MD, United States
| | - Robert W Maul
- Laboratory of Molecular Biology and Immunology, National Institute on Aging, National Institutes of Health, Baltimore, MD, United States
| | - Lisa M Russell Knode
- Laboratory of Molecular Biology and Immunology, National Institute on Aging, National Institutes of Health, Baltimore, MD, United States
| | - Patricia J Gearhart
- Laboratory of Molecular Biology and Immunology, National Institute on Aging, National Institutes of Health, Baltimore, MD, United States
| |
Collapse
|
105
|
Stawski L, Marden G, Trojanowska M. The Activation of Human Dermal Microvascular Cells by Poly(I:C), Lipopolysaccharide, Imiquimod, and ODN2395 Is Mediated by the Fli1/FOXO3A Pathway. THE JOURNAL OF IMMUNOLOGY 2017; 200:248-259. [PMID: 29141862 DOI: 10.4049/jimmunol.1601968] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Accepted: 10/17/2017] [Indexed: 01/15/2023]
Abstract
Endothelial cell (EC) dysfunction has been associated with inflammatory and autoimmune diseases; however, the factors contributing to this dysfunction have not been fully explored. Because activation of TLRs has been implicated in autoimmune diseases, the goal of this study was to determine the effects of TLR ligands on EC function. Human dermal microvascular ECs (HDMECs) treated with TLR3 [Poly(I:C)], TLR4 (LPS), and TLR7 (imiquimod) agonists showed decreased proliferation and a reduced total number of branching tubules in three-dimensional human dermal organoid ex vivo culture. In contrast, the TLR9 ligand class C, ODN2395, increased angiogenesis. The antiproliferative effects of TLR3, TLR4, and TLR7 ligands correlated with significant downregulation of a key regulator of vascular homeostasis, Fli1, whereas TLR9 increased Fli1 levels. Furthermore, Poly(I:C) and LPS induced endothelial to mesenchymal transition that was reversed by the pretreatment with TGF-β neutralizing Ab or re-expression of Fli1. We showed that Fli1 was required for the HDMEC proliferation by transcriptionally repressing FOXO3A. In contrast to TLR9, which suppressed activation of the FOXO3A pathway, TLR3, TLR4, and TLR7 ligands activated FOXO3A as indicated by decreased phosphorylation and increased nuclear accumulation. The inverse correlation between Fli1 and FOXO3A was also observed in the vasculature of scleroderma patients. This work revealed opposing effects of TLR9 and TLR3, TLR4, and TLR7 on the key angiogenic pathways, Fli1 and FOXO3A. Our results provide a mechanistic insight into the regulation of angiogenesis by TLRs and confirm a central role of Fli1 in regulating vascular homeostasis.
Collapse
Affiliation(s)
- Lukasz Stawski
- Section of Rheumatology, School of Medicine, Boston University, Boston, MA 02118
| | - Grace Marden
- Section of Rheumatology, School of Medicine, Boston University, Boston, MA 02118
| | - Maria Trojanowska
- Section of Rheumatology, School of Medicine, Boston University, Boston, MA 02118
| |
Collapse
|
106
|
Tsai F, Homan PJ, Agrawal H, Misharin AV, Abdala-Valencia H, Haines GK, Dominguez S, Bloomfield CL, Saber R, Chang A, Mohan C, Hutcheson J, Davidson A, Budinger GRS, Bouillet P, Dorfleutner A, Stehlik C, Winter DR, Cuda CM, Perlman H. Bim suppresses the development of SLE by limiting myeloid inflammatory responses. J Exp Med 2017; 214:3753-3773. [PMID: 29114065 PMCID: PMC5716039 DOI: 10.1084/jem.20170479] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Revised: 07/25/2017] [Accepted: 09/06/2017] [Indexed: 12/27/2022] Open
Abstract
Tsai et al. demonstrate that loss of Bim (BCL2L11) in myeloid cells in mice (LysMCreBimfl/fl) is sufficient to induce systemic autoimmunity. Kidney macrophages in LysMCreBimfl/fl mice possess a proinflammatory transcriptional signature and signal through TRIF to cause end-stage glomerulonephritis. The Bcl-2 family is considered the guardian of the mitochondrial apoptotic pathway. We demonstrate that Bim acts as a molecular rheostat by controlling macrophage function not only in lymphoid organs but also in end organs, thereby preventing the break in tolerance. Mice lacking Bim in myeloid cells (LysMCreBimfl/fl) develop a systemic lupus erythematosus (SLE)–like disease that mirrors aged Bim−/− mice, including loss of marginal zone macrophages, splenomegaly, lymphadenopathy, autoantibodies (including anti-DNA IgG), and a type I interferon signature. LysMCreBimfl/fl mice exhibit increased mortality attributed to glomerulonephritis (GN). Moreover, the toll-like receptor signaling adaptor protein TRIF (TIR-domain–containing adapter-inducing interferon-β) is essential for GN, but not systemic autoimmunity in LysMCreBimfl/fl mice. Bim-deleted kidney macrophages exhibit a novel transcriptional lupus signature that is conserved within the gene expression profiles from whole kidney biopsies of patients with SLE. Collectively, these data suggest that the Bim may be a novel therapeutic target in the treatment of SLE.
Collapse
Affiliation(s)
- FuNien Tsai
- Division of Rheumatology, Feinberg School of Medicine, Northwestern University, Chicago, IL
| | - Philip J Homan
- Division of Rheumatology, Feinberg School of Medicine, Northwestern University, Chicago, IL
| | | | - Alexander V Misharin
- Division of Pulmonary and Critical Care, Feinberg School of Medicine, Northwestern University, Chicago, IL
| | - Hiam Abdala-Valencia
- Division of Rheumatology, Feinberg School of Medicine, Northwestern University, Chicago, IL
| | - G Kenneth Haines
- Department of Pathology, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Salina Dominguez
- Division of Rheumatology, Feinberg School of Medicine, Northwestern University, Chicago, IL
| | - Christina L Bloomfield
- Division of Rheumatology, Feinberg School of Medicine, Northwestern University, Chicago, IL
| | - Rana Saber
- Division of Rheumatology, Feinberg School of Medicine, Northwestern University, Chicago, IL
| | - Anthony Chang
- Department of Pathology, University of Chicago, Chicago, IL
| | - Chandra Mohan
- Department of Biomedical Engineering, University of Houston, Houston, TX
| | | | - Anne Davidson
- The Feinstein Institute for Medical Research, Hofstra Northwell School of Medicine, Manhasset, NY
| | - G R Scott Budinger
- Division of Pulmonary and Critical Care, Feinberg School of Medicine, Northwestern University, Chicago, IL
| | - Philippe Bouillet
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
| | - Andrea Dorfleutner
- Division of Rheumatology, Feinberg School of Medicine, Northwestern University, Chicago, IL
| | - Christian Stehlik
- Division of Rheumatology, Feinberg School of Medicine, Northwestern University, Chicago, IL
| | - Deborah R Winter
- Division of Rheumatology, Feinberg School of Medicine, Northwestern University, Chicago, IL
| | - Carla M Cuda
- Division of Rheumatology, Feinberg School of Medicine, Northwestern University, Chicago, IL
| | - Harris Perlman
- Division of Rheumatology, Feinberg School of Medicine, Northwestern University, Chicago, IL
| |
Collapse
|
107
|
Murayama G, Furusawa N, Chiba A, Yamaji K, Tamura N, Miyake S. Enhanced IFN-α production is associated with increased TLR7 retention in the lysosomes of palasmacytoid dendritic cells in systemic lupus erythematosus. Arthritis Res Ther 2017; 19:234. [PMID: 29052537 PMCID: PMC5649081 DOI: 10.1186/s13075-017-1441-7] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 09/21/2017] [Indexed: 01/04/2023] Open
Abstract
Background Interferon-α (IFN-α) is increased and plays an important role in the pathogenesis of systemic lupus erythematosus (SLE). Plasmacytoid dendritic cells (pDCs) are the main producer of IFN-α, but their IFN-α producing capacity has been shown to be unchanged or reduced when stimulated with a Toll-like receptor 9 (TLR9) agonist in patients with SLE compared to in healthy individuals. In this study, we investigated the IFN-α-producing capacity of lupus pDCs under different stimulation. Methods pDCs from patients with SLE and healthy controls (HC) were stimulated with TLR9 or TLR7 agonist, and their IFN-α producing capacity was examined by intracellular cytokine staining and flow cytometry. The correlation of IFN-α-producing capacity with serum IFN-α levels and disease activity was assessed. The effect of in vitro IFN-α exposure on IFN-α production by pDCs was examined. Localization of TLR7 in cellular compartments in pDCs was investigated. Results The IFN-α producing capacity of pDCs was reduced after TLR9 stimulation, but increased when stimulated with a TLR7 agonist in SLE compared to in HC. IFN-α production by pDCs upon TLR9 stimulation was reduced and the percentage of IFN-α+pDC was inversely correlated with disease activity and serum IFN-α levels. However, the TLR7 agonist-induced IFN-α producing capacity of lupus pDCs was enhanced and correlated with disease activity and serum IFN-α. Exposure to IFN-α enhanced IFN-α production of TLR7-stimulated pDCs, but reduced that of pDCs activated with a TLR9 agonist. TLR7 localization was increased in late endosome/lysosome compartments in pDCs from SLE patients. Conclusions These findings indicate that enhanced TLR7 responses of lupus pDCs, owing to TLR7 retention in late endosome/lysosome and exposure to IFN-α, are associated with the pathogenesis of SLE. Electronic supplementary material The online version of this article (doi:10.1186/s13075-017-1441-7) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Goh Murayama
- Department of Immunology, Juntendo University School of Medicine, 2-2-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan.,Department of Internal Medicine and Rheumatology, Juntendo University School of Medicine, Tokyo, Japan
| | - Nanako Furusawa
- Department of Immunology, Juntendo University School of Medicine, 2-2-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Asako Chiba
- Department of Immunology, Juntendo University School of Medicine, 2-2-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan.
| | - Ken Yamaji
- Department of Internal Medicine and Rheumatology, Juntendo University School of Medicine, Tokyo, Japan
| | - Naoto Tamura
- Department of Internal Medicine and Rheumatology, Juntendo University School of Medicine, Tokyo, Japan
| | - Sachiko Miyake
- Department of Immunology, Juntendo University School of Medicine, 2-2-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan.
| |
Collapse
|
108
|
Kiripolsky J, McCabe LG, Gaile DP, Kramer JM. Myd88 is required for disease development in a primary Sjögren's syndrome mouse model. J Leukoc Biol 2017; 102:1411-1420. [PMID: 28951424 DOI: 10.1189/jlb.3a0717-311r] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 09/05/2017] [Accepted: 09/11/2017] [Indexed: 12/30/2022] Open
Abstract
Sjögren's syndrome (SS) is an autoimmune disease that often results in diminished exocrine gland function. SS patients also experience systemic disease manifestations, including hypergammaglobulinemia and pulmonary and renal pathoses. MyD88 is a ubiquitously expressed adaptor molecule used by all immune cells that is required for IL-1 receptor (IL-1R), IL-18R, and most TLR signaling. The precise role of MyD88 in SS has not been evaluated, although this adaptor is critical for development of lupus, a related autoimmune disease. This study tested the hypothesis that Myd88-mediated signaling is required for local and systemic SS manifestations. To this end, we generated NOD.B10Sn-H2b /J (NOD.B10) mice that are deficient in Myd88 (NOD.B10 Myd88-/- ). We found that NOD.B10 animals that lack Myd88 show reduced exocrine and extraglandular inflammation. Moreover, these animals are protected from loss of salivary flow. Splenocytes from NOD.B10 Myd88-/- mice did not up-regulate activation markers or secrete IL-6 in response to a Myd88-dependent agonist, although BCR signaling remained intact. Finally, IgM, IgG, and anti-nuclear autoantibodies were reduced in NOD.B10 Myd88-/- mice compared with the parental strain. These data demonstrate that Myd88 is a crucial mediator of local and systemic SS disease manifestations.
Collapse
Affiliation(s)
- Jeremy Kiripolsky
- Department of Oral Biology, School of Dental Medicine, University at Buffalo, The State University of New York, Buffalo, New York, USA
| | - Liam G McCabe
- Department of Oral Biology, School of Dental Medicine, University at Buffalo, The State University of New York, Buffalo, New York, USA
| | - Daniel P Gaile
- Department of Biostatistics, School of Public Health and Health Professions, University at Buffalo, The State University of New York, Buffalo, New York, USA; and
| | - Jill M Kramer
- Department of Oral Biology, School of Dental Medicine, University at Buffalo, The State University of New York, Buffalo, New York, USA; .,Department of Oral Diagnostic Sciences, School of Dental Medicine, University at Buffalo, The State University of New York, Buffalo, New York, USA
| |
Collapse
|
109
|
Bai Y, Tong Y, Liu Y, Hu H. Self-dsDNA in the pathogenesis of systemic lupus erythematosus. Clin Exp Immunol 2017; 191:1-10. [PMID: 28836661 DOI: 10.1111/cei.13041] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/14/2017] [Indexed: 02/05/2023] Open
Abstract
Systemic lupus erythematosus (SLE) is a systemic and poly-aetiological autoimmune disease characterized by the production of antibodies to autologous double-stranded DNA (dsDNA) which serve as diagnostic and prognostic markers. The defective clearance of apoptotic material, together with neutrophil extracellular traps (NETs), provides abundant chromatin or self-dsDNA to trigger the production of anti-dsDNA antibodies, although the mechanisms remain to be elucidated. In SLE patients, the immune complex (IC) of dsDNA and its autoantibodies trigger the robust type I interferon (IFN-I) production through intracellular DNA sensors, which drives the adaptive immune system to break down self-tolerance. In this review, we will discuss the potential resources of self-dsDNA, the mechanisms of self-dsDNA-mediated inflammation through various DNA sensors and its functions in SLE pathogenesis.
Collapse
Affiliation(s)
- Y Bai
- Department of Rheumatology and Immunology, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Y Tong
- Department of Rheumatology and Immunology, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Y Liu
- Department of Rheumatology and Immunology, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - H Hu
- Department of Rheumatology and Immunology, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| |
Collapse
|
110
|
Elloumi N, Fakhfakh R, Abida O, Ayadi L, Marzouk S, Hachicha H, Fourati M, Bahloul Z, Mhiri MN, Kammoun K, Masmoudi H. Relevant genetic polymorphisms and kidney expression of Toll-like receptor (TLR)-5 and TLR-9 in lupus nephritis. Clin Exp Immunol 2017; 190:328-339. [PMID: 28763101 DOI: 10.1111/cei.13022] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/28/2017] [Indexed: 12/07/2022] Open
Abstract
Toll-like receptor (TLR) genetic polymorphisms may modify their expression causing inflammatory disorders and influencing both susceptibility and severity of lupus erythematosus. We aim to determine whether TLR-5 and TLR-9 gene polymorphisms are implicated in the susceptibility to systemic lupus erythematosus (SLE) and lupus nephritis (LN) and to evaluate their expressions and distributions in renal LN patients' biopsies. The frequencies of two SNP in the TLR-9 gene and one in the TLR-5 gene was examined in 106 SLE patients (among them 37 LN patients) and in 200 matched controls by polymerase chain reaction-restriction fragment-length polymorphisms (PCR-RFLP) analysis. TLR-9 and TLR-5 expressions were assessed by reverse transcription (RT)-PCR and immunohistochemistry carried on LN renal biopsies compared to healthy renal tissue. A significant genotypic and allelic association was revealed between TLR-9-rs352140 and both SLE and LN (P < 0·05). The TLR-9 transcript level was significantly higher in LN biopsies compared to control (P < 0·05). This increase was observed histochemically in the tubulointerstitial compartment. TLR-9 was detectable in LN glomeruli patients but not in normal control glomeruli. No allelic nor genotype association was found with TLR-5-rs5744168 in SLE. but the T allele and the TT genotype were raised significantly in the LN group (P < 0·05). A significant increase in TLR-5 gene expression in LN biopsies, which contrasted with normal kidneys (P < 0·05), was confirmed by an intense and diffuse staining for TLR-5 only in LN tubules (P < 0·05). Our data show that TLR-5 and TLR-9 are susceptible genes to LN and that their expression is dysregulated in LN patients' kidneys, supporting a role of these mediators in the pathogenesis of LN.
Collapse
Affiliation(s)
- N Elloumi
- Immunology Department, Habib Bourguiba Hospital, University of Sfax, Sfax, Tunisia
| | - R Fakhfakh
- Immunology Department, Habib Bourguiba Hospital, University of Sfax, Sfax, Tunisia
| | - O Abida
- Immunology Department, Habib Bourguiba Hospital, University of Sfax, Sfax, Tunisia
| | - L Ayadi
- Anatomopathology Department, Habib Bourguiba Hospital, University of Sfax, Sfax, Tunisia
| | - S Marzouk
- Internal Medicine Department, Hedi Chaker Hospital, University of Sfax, Sfax, Tunisia
| | - H Hachicha
- Immunology Department, Habib Bourguiba Hospital, University of Sfax, Sfax, Tunisia
| | - M Fourati
- Urology Department, Habib Bourguiba Hospital, University of Sfax, Sfax, Tunisia
| | - Z Bahloul
- Internal Medicine Department, Hedi Chaker Hospital, University of Sfax, Sfax, Tunisia
| | - M N Mhiri
- Urology Department, Habib Bourguiba Hospital, University of Sfax, Sfax, Tunisia
| | - K Kammoun
- Nephrology Department, Hedi Chaker Hospital, University of Sfax, Sfax, Tunisia
| | - H Masmoudi
- Immunology Department, Habib Bourguiba Hospital, University of Sfax, Sfax, Tunisia
| |
Collapse
|
111
|
|
112
|
Gao W, Xiong Y, Li Q, Yang H. Inhibition of Toll-Like Receptor Signaling as a Promising Therapy for Inflammatory Diseases: A Journey from Molecular to Nano Therapeutics. Front Physiol 2017; 8:508. [PMID: 28769820 PMCID: PMC5516312 DOI: 10.3389/fphys.2017.00508] [Citation(s) in RCA: 238] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2017] [Accepted: 07/03/2017] [Indexed: 12/20/2022] Open
Abstract
The recognition of invading pathogens and endogenous molecules from damaged tissues by toll-like receptors (TLRs) triggers protective self-defense mechanisms. However, excessive TLR activation disrupts the immune homeostasis by sustained pro-inflammatory cytokines and chemokines production and consequently contributes to the development of many inflammatory and autoimmune diseases, such as systemic lupus erythematosus (SLE), infection-associated sepsis, atherosclerosis, and asthma. Therefore, inhibitors/antagonists targeting TLR signals may be beneficial to treat these disorders. In this article, we first briefly summarize the pathophysiological role of TLRs in the inflammatory diseases. We then focus on reviewing the current knowledge in both preclinical and clinical studies of various TLR antagonists/inhibitors for the prevention and treatment of inflammatory diseases. These compounds range from conventional small molecules to therapeutic biologics and nanodevices. In particular, nanodevices are emerging as a new class of potent TLR inhibitors for their unique properties in desired bio-distribution, sustained circulation, and preferred pharmacodynamic and pharmacokinetic profiles. More interestingly, the inhibitory activity of these nanodevices can be regulated through precise nano-functionalization, making them the next generation therapeutics or “nano-drugs.” Although, significant efforts have been made in developing different kinds of new TLR inhibitors/antagonists, only limited numbers of them have undergone clinical trials, and none have been approved for clinical uses to date. Nevertheless, these findings and continuous studies of TLR inhibition highlight the pharmacological regulation of TLR signaling, especially on multiple TLR pathways, as future promising therapeutic strategy for various inflammatory and autoimmune diseases.
Collapse
Affiliation(s)
- Wei Gao
- Department of Respiratory Medicine, Shanghai First People's Hospital, Shanghai Jiaotong University School of MedicineShanghai, China
| | - Ye Xiong
- Department of Respiratory Medicine, Changhai Hospital, Second Military Medical UniversityShanghai, China
| | - Qiang Li
- Department of Respiratory Medicine, Shanghai First People's Hospital, Shanghai Jiaotong University School of MedicineShanghai, China
| | - Hong Yang
- Department of Respiratory Medicine, Shanghai First People's Hospital, Shanghai Jiaotong University School of MedicineShanghai, China
| |
Collapse
|
113
|
Suthers AN, Sarantopoulos S. TLR7/TLR9- and B Cell Receptor-Signaling Crosstalk: Promotion of Potentially Dangerous B Cells. Front Immunol 2017; 8:775. [PMID: 28751890 PMCID: PMC5507964 DOI: 10.3389/fimmu.2017.00775] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Accepted: 06/19/2017] [Indexed: 12/12/2022] Open
Abstract
B cells are capable of receptor-mediated responses to foreign antigens. Recognition of microbial-derived nucleic acid (NA) by toll-like receptors (TLRs) 7 and 9 in B cells has been substantiated. Endogenous NA released from damaged or dying cells can also be immunogenic in certain contexts and can incite aberrant activation of B cells. When TLR-driven B cell receptor (BCR)-activated B cells are not properly constrained, pathologic autoantibodies are produced. It is also clear that endosomal TLR7/TLR9 can operate in conjunction with BCR. In addition to BCR signaling, a balance between TLR7 and TLR9 is pivotal in the development of B cell autoreactivity. While TLR9 is important in normal memory B cell responses through BCR, TLR9 activation has been implicated in autoantibody production. Paradoxically, TLR9 also plays known protective roles against autoimmunity by directly and indirectly inhibiting TLR7-mediated autoantibody production. Herein, we summarize literature supporting mechanisms underpinning the promotion of pathological BCR-activated B cells by TLR7 and TLR9. We focus on the literature regarding known points of TLR7/TLR9 and BCR crosstalk. Data also suggest that the degree of TLR responsiveness relies on alterations of certain intrinsic B-cell signaling molecules and is also context specific. Because allogeneic hematopoietic stem cell transplantation is a high NA and B cell-activating factor environment, we conclude that B cell studies of synergistic TLR-BCR signaling in human diseases like chronic graft-versus-host disease are warranted. Further understanding of the distinct molecular pathways mediating TLR-BCR synergy will lead to the development of therapeutic strategies in autoimmune disease states.
Collapse
Affiliation(s)
- Amy N Suthers
- Department of Medicine, Division of Hematological Malignancies and Cellular Therapy, Duke Cancer Institute, Duke University Medical Center, Durham, NC, United States
| | - Stefanie Sarantopoulos
- Department of Medicine, Division of Hematological Malignancies and Cellular Therapy, Duke Cancer Institute, Duke University Medical Center, Durham, NC, United States.,Department of Immunology, Duke University Medical Center, Durham, NC, United States
| |
Collapse
|
114
|
Zharkova O, Celhar T, Cravens PD, Satterthwaite AB, Fairhurst AM, Davis LS. Pathways leading to an immunological disease: systemic lupus erythematosus. Rheumatology (Oxford) 2017; 56:i55-i66. [PMID: 28375453 PMCID: PMC5410978 DOI: 10.1093/rheumatology/kew427] [Citation(s) in RCA: 111] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Indexed: 12/25/2022] Open
Abstract
SLE is a chronic autoimmune disease caused by perturbations of the immune system. The clinical presentation is heterogeneous, largely because of the multiple genetic and environmental factors that contribute to disease initiation and progression. Over the last 60 years, there have been a number of significant leaps in our understanding of the immunological mechanisms driving disease processes. We now know that multiple leucocyte subsets, together with inflammatory cytokines, chemokines and regulatory mediators that are normally involved in host protection from invading pathogens, contribute to the inflammatory events leading to tissue destruction and organ failure. In this broad overview, we discuss the main pathways involved in SLE and highlight new findings. We describe the immunological changes that characterize this form of autoimmunity. The major leucocytes that are essential for disease progression are discussed, together with key mediators that propagate the immune response and drive the inflammatory response in SLE.
Collapse
Affiliation(s)
- Olga Zharkova
- Singapore Immunology Network, 8A Biomedical Grove, Immunos.,School of Biological Sciences, Nanyang Technological University, Singapore
| | - Teja Celhar
- Singapore Immunology Network, 8A Biomedical Grove, Immunos
| | | | - Anne B Satterthwaite
- Department of Immunology.,The Rheumatic Diseases Division, Department of Internal Medicine, UT Southwestern Medical Center at Dallas, TX, USA
| | - Anna-Marie Fairhurst
- Singapore Immunology Network, 8A Biomedical Grove, Immunos.,School of Biological Sciences, Nanyang Technological University, Singapore.,Department of Immunology
| | - Laurie S Davis
- The Rheumatic Diseases Division, Department of Internal Medicine, UT Southwestern Medical Center at Dallas, TX, USA
| |
Collapse
|
115
|
Mu Q, Kirby J, Reilly CM, Luo XM. Leaky Gut As a Danger Signal for Autoimmune Diseases. Front Immunol 2017; 8:598. [PMID: 28588585 PMCID: PMC5440529 DOI: 10.3389/fimmu.2017.00598] [Citation(s) in RCA: 327] [Impact Index Per Article: 46.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Accepted: 05/05/2017] [Indexed: 12/12/2022] Open
Abstract
The intestinal epithelial lining, together with factors secreted from it, forms a barrier that separates the host from the environment. In pathologic conditions, the permeability of the epithelial lining may be compromised allowing the passage of toxins, antigens, and bacteria in the lumen to enter the blood stream creating a “leaky gut.” In individuals with a genetic predisposition, a leaky gut may allow environmental factors to enter the body and trigger the initiation and development of autoimmune disease. Growing evidence shows that the gut microbiota is important in supporting the epithelial barrier and therefore plays a key role in the regulation of environmental factors that enter the body. Several recent reports have shown that probiotics can reverse the leaky gut by enhancing the production of tight junction proteins; however, additional and longer term studies are still required. Conversely, pathogenic bacteria that can facilitate a leaky gut and induce autoimmune symptoms can be ameliorated with the use of antibiotic treatment. Therefore, it is hypothesized that modulating the gut microbiota can serve as a potential method for regulating intestinal permeability and may help to alter the course of autoimmune diseases in susceptible individuals.
Collapse
Affiliation(s)
- Qinghui Mu
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA, USA
| | - Jay Kirby
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA, USA
| | | | - Xin M Luo
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA, USA
| |
Collapse
|
116
|
Tursi SA, Lee EY, Medeiros NJ, Lee MH, Nicastro LK, Buttaro B, Gallucci S, Wilson RP, Wong GCL, Tükel Ç. Bacterial amyloid curli acts as a carrier for DNA to elicit an autoimmune response via TLR2 and TLR9. PLoS Pathog 2017; 13:e1006315. [PMID: 28410407 PMCID: PMC5406031 DOI: 10.1371/journal.ppat.1006315] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 04/26/2017] [Accepted: 03/24/2017] [Indexed: 12/27/2022] Open
Abstract
Bacterial biofilms are associated with numerous human infections. The predominant protein expressed in enteric biofilms is the amyloid curli, which forms highly immunogenic complexes with DNA. Infection with curli-expressing bacteria or systemic exposure to purified curli-DNA complexes triggers autoimmunity via the generation of type I interferons (IFNs) and anti-double-stranded DNA antibodies. Here, we show that DNA complexed with amyloid curli powerfully stimulates Toll-like receptor 9 (TLR9) through a two-step mechanism. First, the cross beta-sheet structure of curli is bound by cell-surface Toll-like receptor 2 (TLR2), enabling internalization of the complex into endosomes. After internalization, the curli-DNA immune complex binds strongly to endosomal TLR9, inducing production of type I IFNs. Analysis of wild-type and TLR2-deficient macrophages showed that TLR2 is the major receptor that drives the internalization of curli-DNA complexes. Suppression of TLR2 internalization via endocytosis inhibitors led to a significant decrease in Ifnβ expression. Confocal microscopy analysis confirmed that the TLR2-bound curli was required for shuttling of DNA to endosomal TLR9. Structural analysis using small-angle X-ray scattering revealed that incorporation of DNA into curli fibrils resulted in the formation of ordered curli-DNA immune complexes. Curli organizes parallel, double-stranded DNA rods at an inter-DNA spacing that matches up well with the steric size of TLR9. We also found that production of anti-double-stranded DNA autoantibodies in response to curli-DNA was attenuated in TLR2- and TLR9-deficient mice and in mice deficient in both TLR2 and TLR9 compared to wild-type mice, suggesting that both innate immune receptors are critical for shaping the autoimmune adaptive immune response. We also detected significantly lower levels of interferon-stimulated gene expression in response to purified curli-DNA in TLR2 and TLR9 deficient mice compared to wild-type mice, confirming that TLR2 and TLR9 are required for the induction of type I IFNs. Finally, we showed that curli-DNA complexes, but not cellulose, were responsible elicitation of the immune responses to bacterial biofilms. This study defines the series of events that lead to the severe pro-autoimmune effects of amyloid-expressing bacteria and suggest a mechanism by which amyloid curli acts as a carrier to break immune tolerance to DNA, leading to the activation of TLR9, production of type I IFNs, and subsequent production of autoantibodies.
Collapse
Affiliation(s)
- Sarah A. Tursi
- Department of Microbiology and Immunology, Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania, United States of America
| | - Ernest Y. Lee
- Department of Bioengineering, California Nano Systems Institute, University of California, Los Angeles, California, United States of America
| | - Nicole J. Medeiros
- Department of Microbiology and Immunology, Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania, United States of America
| | - Michael H. Lee
- Department of Microbiology and Immunology, Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania, United States of America
| | - Lauren K. Nicastro
- Department of Microbiology and Immunology, Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania, United States of America
| | - Bettina Buttaro
- Department of Microbiology and Immunology, Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania, United States of America
| | - Stefania Gallucci
- Department of Microbiology and Immunology, Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania, United States of America
| | - Ronald Paul Wilson
- Department of Microbiology and Immunology, Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania, United States of America
| | - Gerard C. L. Wong
- Department of Bioengineering, California Nano Systems Institute, University of California, Los Angeles, California, United States of America
- Department of Chemistry and Biochemistry, California Nano Systems Institute, University of California, Los Angeles, California, United States of America
- * E-mail: (CT); (GCLW)
| | - Çagla Tükel
- Department of Microbiology and Immunology, Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania, United States of America
- * E-mail: (CT); (GCLW)
| |
Collapse
|
117
|
Rawlings DJ, Metzler G, Wray-Dutra M, Jackson SW. Altered B cell signalling in autoimmunity. Nat Rev Immunol 2017; 17:421-436. [PMID: 28393923 DOI: 10.1038/nri.2017.24] [Citation(s) in RCA: 185] [Impact Index Per Article: 26.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Recent work has provided new insights into how altered B cell-intrinsic signals - through the B cell receptor (BCR) and key co-receptors - function together to promote the pathogenesis of autoimmunity. These combined signals affect B cells at two distinct stages: first, in the selection of the naive repertoire; and second, during extrafollicular or germinal centre activation responses. Thus, dysregulated signalling can lead to both an altered naive BCR repertoire and the generation of autoantibody-producing B cells. Strikingly, high-affinity autoantibodies predate and predict disease in several autoimmune disorders, including type 1 diabetes and systemic lupus erythematosus. This Review summarizes how, rather than being a downstream consequence of autoreactive T cell activation, dysregulated B cell signalling can function as a primary driver of many human autoimmune diseases.
Collapse
Affiliation(s)
- David J Rawlings
- Seattle Children's Research Institute, 1900 9th Avenue, Seattle, Washington 98101, USA.,Department of Immunology, University of Washington School of Medicine.,Department of Pediatrics, University of Washington School of Medicine, 750 Republican Street, Seattle, Washington 98109, USA
| | - Genita Metzler
- Seattle Children's Research Institute, 1900 9th Avenue, Seattle, Washington 98101, USA.,Department of Immunology, University of Washington School of Medicine
| | - Michelle Wray-Dutra
- Seattle Children's Research Institute, 1900 9th Avenue, Seattle, Washington 98101, USA.,Department of Immunology, University of Washington School of Medicine
| | - Shaun W Jackson
- Seattle Children's Research Institute, 1900 9th Avenue, Seattle, Washington 98101, USA.,Department of Pediatrics, University of Washington School of Medicine, 750 Republican Street, Seattle, Washington 98109, USA
| |
Collapse
|
118
|
Abstract
Self-reactive B cells are tolerized at various stages of B-cell development and differentiation, including the immature B-cell stage (central tolerance) and the germinal center (GC) B-cell stage, and B-cell tolerance involves various mechanisms such as deletion, anergy, and receptor editing. Self-reactive B cells generated by random immunoglobulin variable gene rearrangements are tolerized by central tolerance and anergy in the periphery, and these processes involve apoptosis regulated by Bim, a pro-apoptotic member of the Bcl-2 family, and regulation of B-cell signaling by various phosphatases, including SHIP-1 and SHP-1. Self-reactive B cells generated by somatic mutations during GC reaction are also eliminated. Fas is not directly involved in this process but prevents persistence of GC reaction that allows generation of less stringently regulated B cells, including self-reactive B cells. Defects in self-tolerance preferentially cause lupus-like disease with production of anti-nuclear antibodies, probably due to the presence of a large potential B-cell repertoire reactive to nucleic acids and the presence of nucleic acid-induced activation mechanisms in various immune cells, including B cells and dendritic cells. A feed-forward loop composed of anti-nuclear antibodies produced by B cells and type 1 interferons secreted from nucleic acid-activated dendritic cells plays a crucial role in the development of systemic lupus erythematosus.
Collapse
Affiliation(s)
- Takeshi Tsubata
- Department of Immunology, Medical Research Institute, Tokyo Medical and Dental University, Tokyo, 113-8510, Japan
| |
Collapse
|
119
|
Sindhava VJ, Oropallo MA, Moody K, Naradikian M, Higdon LE, Zhou L, Myles A, Green N, Nündel K, Stohl W, Schmidt AM, Cao W, Dorta-Estremera S, Kambayashi T, Marshak-Rothstein A, Cancro MP. A TLR9-dependent checkpoint governs B cell responses to DNA-containing antigens. J Clin Invest 2017; 127:1651-1663. [PMID: 28346226 DOI: 10.1172/jci89931] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Accepted: 01/26/2017] [Indexed: 01/07/2023] Open
Abstract
Mature B cell pools retain a substantial proportion of polyreactive and self-reactive clonotypes, suggesting that activation checkpoints exist to reduce the initiation of autoreactive B cell responses. Here, we have described a relationship among the B cell receptor (BCR), TLR9, and cytokine signals that regulate B cell responses to DNA-containing antigens. In both mouse and human B cells, BCR ligands that deliver a TLR9 agonist induce an initial proliferative burst that is followed by apoptotic death. The latter mechanism involves p38-dependent G1 cell-cycle arrest and subsequent intrinsic mitochondrial apoptosis and is shared by all preimmune murine B cell subsets and CD27- human B cells. Survival or costimulatory signals rescue B cells from this fate, but the outcome varies depending on the signals involved. B lymphocyte stimulator (BLyS) engenders survival and antibody secretion, whereas CD40 costimulation with IL-21 or IFN-γ promotes a T-bet+ B cell phenotype. Finally, in vivo immunization studies revealed that when protein antigens are conjugated with DNA, the humoral immune response is blunted and acquires features associated with T-bet+ B cell differentiation. We propose that this mechanism integrating BCR, TLR9, and cytokine signals provides a peripheral checkpoint for DNA-containing antigens that, if circumvented by survival and differentiative cues, yields B cells with the autoimmune-associated T-bet+ phenotype.
Collapse
|
120
|
Nickerson KM, Wang Y, Bastacky S, Shlomchik MJ. Toll-like receptor 9 suppresses lupus disease in Fas-sufficient MRL Mice. PLoS One 2017; 12:e0173471. [PMID: 28278279 PMCID: PMC5344451 DOI: 10.1371/journal.pone.0173471] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Accepted: 02/22/2017] [Indexed: 12/26/2022] Open
Abstract
Genetic deficiency in TLR9 accelerates pathogenesis in the spontaneous polygenic MRL.Faslpr murine model of systemic lupus erythematosus, despite the absence of anti-nucleosome autoantibodies. However, it could be argued that this result was dependent on Fas-deficiency rather than lupus-promoting genes in the MRL genetic background. Here we report the effects of TLR9 deficiency on autoimmune disease independent of the lpr mutation in Fas by characterizing Tlr9-/- and Tlr9+/+ mice on the Fas-intact MRL/+ genetic background. By 30 weeks of age, Tlr9-deficient MRL/+ had more severe renal disease, increased T cell activation, and higher titers of anti-Sm and anti-RNA autoantibodies than Tlr9-intact animals, as had been the case in the MRL.Faslpr model. In addition, Tlr9-deficient MRL/+ mice had increased numbers of germinal center phenotype B cells and an increase in splenic neutrophils and conventional dendritic cell populations. Thus, the disease accelerating effects of Tlr9 deficiency are separable from those mediated by the Fas mutation in the lupus-prone MRL genetic background. Nonetheless, disease acceleration in Tlr9-deficient MRL/+ mice was phenotypically distinct from that in Fas-deficient counterparts, which has important implications.
Collapse
Affiliation(s)
- Kevin M. Nickerson
- Department of Immunology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- * E-mail:
| | - Yujuan Wang
- Department of Immunology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Sheldon Bastacky
- Department of Pathology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Mark J. Shlomchik
- Department of Immunology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| |
Collapse
|
121
|
Giles JR, Neves AT, Marshak-Rothstein A, Shlomchik MJ. Autoreactive helper T cells alleviate the need for intrinsic TLR signaling in autoreactive B cell activation. JCI Insight 2017; 2:e90870. [PMID: 28239656 PMCID: PMC5313065 DOI: 10.1172/jci.insight.90870] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Accepted: 01/06/2017] [Indexed: 12/26/2022] Open
Abstract
T cells play a significant role in the pathogenesis of systemic autoimmune diseases, including systemic lupus erythematosus; however, there is relatively little information on the nature and specificity of autoreactive T cells. Identifying such cells has been technically difficult because they are likely to be rare and low affinity. Here, we report a method for identifying autoreactive T cell clones that recognize proteins contained in autoantibody immune complexes, providing direct evidence that functional autoreactive helper T cells exist in the periphery of normal mice. These T cells significantly enhanced autoreactive B cell proliferation and altered B cell differentiation in vivo. Most importantly, these autoreactive T cells were able to rescue many aspects of the TLR-deficient AM14 (anti-IgG2a rheumatoid factor) B cell response, suggesting that TLR requirements can be bypassed. This result has implications for the efficacy of TLR-targeted therapy in the treatment of ongoing disease.
Collapse
Affiliation(s)
- Josephine R. Giles
- Departments of Laboratory Medicine and Immunobiology, Yale University School of Medicine, New Haven, Connecticut, USA
- Department of Immunology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Adriana Turqueti Neves
- Department of Immunology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Ann Marshak-Rothstein
- Division of Rheumatology, Department of Medicine, University of Massachusetts School of Medicine, Worcester, Massachusetts, USA
| | - Mark J. Shlomchik
- Departments of Laboratory Medicine and Immunobiology, Yale University School of Medicine, New Haven, Connecticut, USA
- Department of Immunology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| |
Collapse
|
122
|
Devarapu SK, Lorenz G, Kulkarni OP, Anders HJ, Mulay SR. Cellular and Molecular Mechanisms of Autoimmunity and Lupus Nephritis. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2017; 332:43-154. [PMID: 28526137 DOI: 10.1016/bs.ircmb.2016.12.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Autoimmunity involves immune responses directed against self, which are a result of defective self/foreign distinction of the immune system, leading to proliferation of self-reactive lymphocytes, and is characterized by systemic, as well as tissue-specific, inflammation. Numerous mechanisms operate to ensure the immune tolerance to self-antigens. However, monogenetic defects or genetic variants that weaken immune tolerance render susceptibility to the loss of immune tolerance, which is further triggered by environmental factors. In this review, we discuss the phenomenon of immune tolerance, genetic and environmental factors that influence the immune tolerance, factors that induce autoimmunity such as epigenetic and transcription factors, neutrophil extracellular trap formation, extracellular vesicles, ion channels, and lipid mediators, as well as costimulatory or coinhibitory molecules that contribute to an autoimmune response. Further, we discuss the cellular and molecular mechanisms of autoimmune tissue injury and inflammation during systemic lupus erythematosus and lupus nephritis.
Collapse
Affiliation(s)
- S K Devarapu
- Medizinische Klinik und Poliklinik IV, Klinikum der Universität München, Munich, Germany
| | - G Lorenz
- Klinikum rechts der Isar, Abteilung für Nephrologie, Technische Universität München, Munich, Germany
| | | | - H-J Anders
- Medizinische Klinik und Poliklinik IV, Klinikum der Universität München, Munich, Germany
| | - S R Mulay
- Medizinische Klinik und Poliklinik IV, Klinikum der Universität München, Munich, Germany.
| |
Collapse
|
123
|
Simpson J, Miles K, Trüb M, MacMahon R, Gray M. Plasmacytoid Dendritic Cells Respond Directly to Apoptotic Cells by Secreting Immune Regulatory IL-10 or IFN-α. Front Immunol 2016; 7:590. [PMID: 28018356 PMCID: PMC5155015 DOI: 10.3389/fimmu.2016.00590] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Accepted: 11/29/2016] [Indexed: 12/12/2022] Open
Abstract
Plasmacytoid dendritic cells (pDCs) play a pivotal role in driving the autoimmune disease systemic lupus erythematosus, via the secretion of IFN-α in response to nuclear self-antigens complexed with autoantibodies. Apoptotic cells, generated at sites of inflammation or secondary lymphoid organs, are exposed to activated pDCs and also express the same nuclear antigens on their cell surface. Here, we show that in the absence of autoantibodies, activated pDCs directly respond to apoptotic cell-expressed chromatin complexes by secreting IL-10 and IL-6, which also induces T cells to secrete IL-10. Conversely, when activated by the viral mimetic CpG-A, apoptotic cells enhance their secretion of IFN-α. This study demonstrates that activated pDCs respond directly to apoptotic cells and may maintain tolerance via IL-10, or promote inflammation through secretion of IFN-α, depending on the inflammatory context.
Collapse
Affiliation(s)
- Joanne Simpson
- MRC Centre for Inflammation Research, The Queen’s Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | - Katherine Miles
- MRC Centre for Inflammation Research, The Queen’s Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | - Marta Trüb
- MRC Centre for Inflammation Research, The Queen’s Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | - Roisin MacMahon
- MRC Centre for Inflammation Research, The Queen’s Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | - Mohini Gray
- MRC Centre for Inflammation Research, The Queen’s Medical Research Institute, University of Edinburgh, Edinburgh, UK
| |
Collapse
|
124
|
Majer O, Liu B, Barton GM. Nucleic acid-sensing TLRs: trafficking and regulation. Curr Opin Immunol 2016; 44:26-33. [PMID: 27907816 DOI: 10.1016/j.coi.2016.10.003] [Citation(s) in RCA: 90] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Accepted: 10/28/2016] [Indexed: 12/11/2022]
Abstract
Toll-like receptors (TLRs) play an important role in innate immune responses against pathogenic microorganisms or tissue damage. Nucleic acid (NA)-sensing TLRs localize in intracellular vesicular compartments and recognize foreign-derived and host-derived nucleic acid ligands. Inappropriate activation of NA-sensing TLRs can cause pathogenic inflammation and autoimmunity. Multiple regulatory mechanisms exist to limit recognition of self-NAs. This review summarizes recent progress that has been made in understanding how NA-sensing TLRs are regulated via trafficking, proteolytic cleavage, as well as ligand processing and recognition.
Collapse
Affiliation(s)
- Olivia Majer
- Division of Immunology & Pathogenesis, Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, United States
| | - Bo Liu
- Division of Immunology & Pathogenesis, Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, United States
| | - Gregory M Barton
- Division of Immunology & Pathogenesis, Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, United States
| |
Collapse
|
125
|
Ashman RF, Singh N, Lenert PS. Abnormal thymic maturation and lymphoproliferation in MRL-Fas lpr/lpr mice can be partially reversed by synthetic oligonucleotides: implications for systemic lupus erythematosus and autoimmune lymphoproliferative syndrome. Lupus 2016; 26:734-745. [PMID: 27837196 DOI: 10.1177/0961203316676381] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
MRL-Fas lpr/lpr mice represent an excellent animal model for studying non-malignant lymphoproliferation, regeneration and systemic autoimmunity. Retro-transposon insertion into the second intron of the pro-apoptotic Fas gene appears to be responsible for both lymphoproliferation and autoimmunity, while other genes are more likely to contribute to the regenerative healing characteristic of this mouse strain. Previous studies have shown that neonatal thymectomy can halt the development of abnormal lymphoproliferation. Whereas at four weeks of age primary and secondary lymphoid organs appear to be grossly intact, vigorous lymphoproliferation and autoantibody production subsequently ensues. This is first noticeable at six weeks of age, at which time lymph nodes, spleens and thymuses, but not the bone marrow, become infiltrated with abnormal B220+CD3+CD4-CD8- T cells. Around the same time, thymuses show a significant drop in CD4+CD8+double-positive T cells generating an abnormal ratio between double-positive and single-positive thymocytes. The objective of current study was to evaluate the effect of synthetic oligonucleotides-toll-like receptor antagonists on early lymphoid development in this strain of mice. Herein, we demonstrate the ability of synthetic oligonucleotides made with the nuclease-resistant phosphorothioate backbone to partially reverse abnormal lymphoproliferation and thymic involution in pre-diseased MRL-Fas lpr/lpr mice when administered intraperitoneally starting from week four of age. This curative effect of oligonucleotides was primary sequence/secondary oligonucleotide structure-independent, suggesting an effect through the toll-like receptor 7. A similar approach may potentially benefit patients with autoimmune lymphoproliferative syndrome who, like MRL-Fas lpr/lpr mice, carry a mutation in the Fas gene.
Collapse
Affiliation(s)
- R F Ashman
- Division of Immunology, Department of Internal Medicine, Carver College of Medicine, Iowa City, IA, USA
| | - N Singh
- Division of Immunology, Department of Internal Medicine, Carver College of Medicine, Iowa City, IA, USA
| | - P S Lenert
- Division of Immunology, Department of Internal Medicine, Carver College of Medicine, Iowa City, IA, USA
| |
Collapse
|
126
|
Jackman JG, Juwarker H, Poveromo LP, Levinson H, Leong KW, Sullenger BA. Polycationic Nanofibers for Nucleic Acid Scavenging. Biomacromolecules 2016; 17:3706-3713. [PMID: 27741396 DOI: 10.1021/acs.biomac.6b01236] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Dying cells release nucleic acids (NA) and NA-containing complexes that activate inflammatory pathways of immune cells. Sustained activation of these pathways contributes to chronic inflammation frequently encountered in autoimmune and inflammatory diseases. In this study, grafting of cationic polymers onto a nanofibrous mesh enabled local scavenging of negatively charged pro-inflammatory molecules in the extracellular space. Nucleic acid scavenging nanofibers (NASFs) formed from poly(styrene-alt-maleic anhydride) conjugated with 1.8 kDa bPEI resulted in nanofibers of diameters 486 ± 9 nm. NASFs inhibited the NF-κB response stimulated by the negatively charged agonists, CpG and poly(I:C), in Ramos-blue cells but not Pam3CSK4, a nonanionic agonist. Moreover, NASFs significantly impeded NF-κB activation in cells stimulated with damage-associated molecular pattern molecules (DAMPs) released from doxorubicin killed cancer cells. In vivo application of NASFs to open wounds demonstrated nucleic acid scavenging in wounds of diabetic mice infected with Pseudomonas aeruginosa, suggesting the in vivo efficacy of NASFs. This simple technique of generating NASF results in effective localized anti-inflammation in vitro and local nucleic acid scavenging in vivo.
Collapse
Affiliation(s)
| | | | | | | | - Kam W Leong
- Department of Biomedical Engineering, Columbia University , New York, New York, United States
| | | |
Collapse
|
127
|
Akatsu C, Shinagawa K, Numoto N, Liu Z, Ucar AK, Aslam M, Phoon S, Adachi T, Furukawa K, Ito N, Tsubata T. CD72 negatively regulates B lymphocyte responses to the lupus-related endogenous toll-like receptor 7 ligand Sm/RNP. J Exp Med 2016; 213:2691-2706. [PMID: 27810925 PMCID: PMC5110020 DOI: 10.1084/jem.20160560] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Revised: 08/05/2016] [Accepted: 09/26/2016] [Indexed: 01/03/2023] Open
Abstract
Akatsu and colleagues show that CD72 specifically recognizes Sm/RNP, a lupus-related self-antigen and an endogenous TLR7 ligand, and inhibits B cell responses to Sm/RNP. In mice, CD72 prevents production of anti-Sm/RNP antibodies crucial for lupus development. Toll-like receptor 7 (TLR7) plays an essential role in development of systemic lupus erythematosus by co-stimulating B cells reactive to the endogenous TLR7 ligand Sm/ribonucleoprotein (RNP), a crucial lupus self-antigen. However, how the TLR7-mediated autoimmune response is regulated is not yet known. In this study, we demonstrate that CD72, an inhibitory B cell co-receptor known to prevent development of lupus, recognizes Sm/RNP at the extracellular C-type lectin-like domain (CTLD) and specifically inhibits B cell response to Sm/RNP. Moreover, the CTLD of CD72c, a lupus-susceptible allele, binds to Sm/RNP less strongly than that of lupus-resistant CD72a. Reduced binding of CD72c is supported by x-ray crystallographic analysis that reveals a considerable alteration in charge at the putative ligand-binding site. Thus, CD72 appears to specifically inhibit B cell response to the endogenous TLR7 ligand Sm/RNP through CTLD-mediated recognition of Sm/RNP, thereby preventing production of anti-Sm/RNP antibody crucial for development of lupus.
Collapse
Affiliation(s)
- Chizuru Akatsu
- Department of Immunology, Medical Research Institute, Tokyo Medical and Dental University, Bunkyo, Tokyo 113-8510, Japan
| | - Kenro Shinagawa
- Department of Structural Biology, Medical Research Institute, Tokyo Medical and Dental University, Bunkyo, Tokyo 113-8510, Japan
| | - Nobutaka Numoto
- Department of Structural Biology, Medical Research Institute, Tokyo Medical and Dental University, Bunkyo, Tokyo 113-8510, Japan
| | - Zhihong Liu
- Department of Immunology, Medical Research Institute, Tokyo Medical and Dental University, Bunkyo, Tokyo 113-8510, Japan.,Emergency Department, The First Affiliated Hospital of China Medical University, Shenyang, Liaoning Province 110001, China
| | - Ayse Konuskan Ucar
- Department of Immunology, Medical Research Institute, Tokyo Medical and Dental University, Bunkyo, Tokyo 113-8510, Japan
| | - Mohammad Aslam
- Department of Immunology, Medical Research Institute, Tokyo Medical and Dental University, Bunkyo, Tokyo 113-8510, Japan
| | - Shirly Phoon
- Department of Immunology, Medical Research Institute, Tokyo Medical and Dental University, Bunkyo, Tokyo 113-8510, Japan
| | - Takahiro Adachi
- Department of Immunology, Medical Research Institute, Tokyo Medical and Dental University, Bunkyo, Tokyo 113-8510, Japan
| | - Koji Furukawa
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki 305-8566, Japan
| | - Nobutoshi Ito
- Department of Structural Biology, Medical Research Institute, Tokyo Medical and Dental University, Bunkyo, Tokyo 113-8510, Japan
| | - Takeshi Tsubata
- Department of Immunology, Medical Research Institute, Tokyo Medical and Dental University, Bunkyo, Tokyo 113-8510, Japan
| |
Collapse
|
128
|
Chen L, Ishigami T, Nakashima-Sasaki R, Kino T, Doi H, Minegishi S, Umemura S. Commensal Microbe-specific Activation of B2 Cell Subsets Contributes to Atherosclerosis Development Independently of Lipid Metabolism. EBioMedicine 2016; 13:237-247. [PMID: 27810309 PMCID: PMC5264349 DOI: 10.1016/j.ebiom.2016.10.030] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Revised: 10/06/2016] [Accepted: 10/19/2016] [Indexed: 01/11/2023] Open
Abstract
The relation between B2 cells and commensal microbes during atherosclerosis remains largely unexplored. Here we show that under hyperlipidemic conditions intestinal microbiota resulted in recruitment and ectopic activation of B2 cells in perivascular adipose tissue, followed by an increase in circulating IgG, promoting disease development. In contrast, disruption of the intestinal microbiota by a broad-spectrum antibiotic cocktail (AVNM) led to the attenuation of atherosclerosis by suppressing B2 cells, despite the persistence of serum lipid abnormalities. Furthermore, pharmacological depletion of B2 cells with an anti-B2-cell surface CD23 antibody also attenuated commensal microbe-induced atherosclerosis. Moreover, expression analysis of TLR-signaling-related genes in the activated B2 cell subsets, assessed using the Toll-Like Receptor Signaling Pathway RT2 Profiler PCR Array, confirmed activation of the B2-cell autoantibody-production axis, which was associated with an increased capacity of B2 cells to bind to intestinal microbiota. Together, our findings reveal the critical role of commensal microbe-specific activation of B2 cells in the development of atherogenesis through lipid metabolism-independent mechanisms.
Collapse
Affiliation(s)
- Lin Chen
- Department of Medical Science and Cardio-Renal Medicine, Yokohama City University, Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama, Kanagawa, Japan
| | - Tomoaki Ishigami
- Department of Medical Science and Cardio-Renal Medicine, Yokohama City University, Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama, Kanagawa, Japan.
| | - Rie Nakashima-Sasaki
- Department of Medical Science and Cardio-Renal Medicine, Yokohama City University, Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama, Kanagawa, Japan
| | - Tabito Kino
- Department of Medical Science and Cardio-Renal Medicine, Yokohama City University, Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama, Kanagawa, Japan
| | - Hiroshi Doi
- Department of Medical Science and Cardio-Renal Medicine, Yokohama City University, Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama, Kanagawa, Japan
| | - Shintaro Minegishi
- Department of Medical Science and Cardio-Renal Medicine, Yokohama City University, Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama, Kanagawa, Japan
| | - Satoshi Umemura
- Department of Medical Science and Cardio-Renal Medicine, Yokohama City University, Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama, Kanagawa, Japan
| |
Collapse
|
129
|
Clancy RM, Markham AJ, Buyon JP. Endosomal Toll-like receptors in clinically overt and silent autoimmunity. Immunol Rev 2016; 269:76-84. [PMID: 26683146 DOI: 10.1111/imr.12383] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Toll-like receptors (TLRs), first identified as pattern recognition receptors, are now recognized to serve as a key interface between innate and adaptive immunity. Systemic lupus erythematosus (SLE) is characterized by both continuous and cyclic stimulation of the innate and adaptive immune system by endogenous nucleic acids released from apoptotic or necrotic cells. TLR7 and TLR9 function as innate sensors of viral infection as their ligands are ssRNA and dsDNA, respectively. Recognition of self nucleic acids by endosomal TLRs in B cells and pDCs is thought to be an important step in the pathogenesis of SLE, generating anti-nuclear antibodies and producing type I IFN. In this review, we take a specific look at how TLR7, non-coding RNA, and SSA/Ro60 can contribute to clinical autoimmunity and organ damage in the context of neonatal lupus (NL). Although 15 times less common than SLE, NL provides a unique opportunity to study two different aspects of autoimmunity: passively acquired tissue injury in a developing fetus and clinical progression of disease in an asymptomatic mother found to have anti-Ro60 autoantibodies only after identification of heart block/rash in a child. Finally, we discuss hydroxychloroquine (HCQ) use by asymptomatic subjects which may forestall the clinical expression of autoimmunity.
Collapse
Affiliation(s)
- Robert M Clancy
- Division of Rheumatology, Department of Medicine, New York University School of Medicine, New York, NY, USA
| | - Androo J Markham
- Division of Rheumatology, Department of Medicine, New York University School of Medicine, New York, NY, USA
| | - Jill P Buyon
- Division of Rheumatology, Department of Medicine, New York University School of Medicine, New York, NY, USA
| |
Collapse
|
130
|
Abstract
Finding better treatments for lupus nephritis requires an understanding of the pathogenesis of the causative systemic disease, how this leads to kidney disease, and how lupus nephritis progresses to end-stage kidney disease. Here, we provide a brief conceptual overview on the related pathomechanisms. As a main focus we discuss in detail the roles of neutrophils, dendritic cells, Toll-like receptors, and interferon-α in the pathogenesis of lupus nephritis by separately reviewing their roles in extrarenal systemic autoimmunity and in intrarenal inflammation and immunopathology.
Collapse
|
131
|
Duffy L, O'Reilly SC. Toll-like receptors in the pathogenesis of autoimmune diseases: recent and emerging translational developments. Immunotargets Ther 2016; 5:69-80. [PMID: 27579291 PMCID: PMC5001654 DOI: 10.2147/itt.s89795] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Autoinflammatory diseases are defined as the loss of self-tolerance in which an inflammatory response to self-antigens occurs, which are a significant global burden. Toll-like receptors are key pattern recognition receptors, which integrate signals leading to the activation of transcription factors and ultimately proinflammatory cytokines. Recently, it has become apparent that these are at the nexus of autoinflammatory diseases making them viable and attractive drug targets. The aim of this review was to evaluate the role of innate immunity in autoinflammatory conditions alongside the role of negative regulation while suggesting possible therapeutic targets.
Collapse
Affiliation(s)
- Laura Duffy
- Immunology and Cell Biology Group, Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, UK
| | - Steven C O'Reilly
- Immunology and Cell Biology Group, Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, UK
| |
Collapse
|
132
|
Pawaria S, Sharma S, Baum R, Nündel K, Busto P, Gravallese EM, Fitzgerald KA, Marshak-Rothstein A. Taking the STING out of TLR-driven autoimmune diseases: good, bad, or indifferent? J Leukoc Biol 2016; 101:121-126. [PMID: 27531928 DOI: 10.1189/jlb.3mr0316-115r] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Revised: 07/01/2016] [Accepted: 07/25/2016] [Indexed: 01/24/2023] Open
Abstract
Both endosomal and cytosolic-nucleic acid-sensing receptors can detect endogenous ligands and promote autoimmunity and autoinflammation. These responses involve a complex interplay among and between the cytosolic and endosomal sensors involving both hematopoietic and radioresistant cells. Cytosolic sensors directly promote inflammatory responses through the production of type I IFNs and proinflammatory cytokines. Inflammation-associated tissue damage can further promote autoimmune responses indirectly, as receptor-mediated internalization of the resulting cell debris can activate endosomal Toll-like receptors (TLR). Both endosomal and cytosolic receptors can also negatively regulate inflammatory responses. A better understanding of the factors and pathways that promote and constrain autoimmune diseases will have important implications for the development of agonists and antagonists that modulate these pathways.
Collapse
Affiliation(s)
- Sudesh Pawaria
- Division of Rheumatology, Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA.,Program in Innate Immunity, Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Shruti Sharma
- Division of Infectious Disease, Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA; and.,Program in Innate Immunity, Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Rebecca Baum
- Division of Rheumatology, Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA.,Program in Innate Immunity, Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Kerstin Nündel
- Division of Rheumatology, Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA.,Program in Innate Immunity, Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Patricia Busto
- Division of Rheumatology, Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA.,Program in Innate Immunity, Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Ellen M Gravallese
- Division of Rheumatology, Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA.,Program in Innate Immunity, Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Katherine A Fitzgerald
- Division of Infectious Disease, Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA; and.,Program in Innate Immunity, Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Ann Marshak-Rothstein
- Division of Rheumatology, Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA; .,Program in Innate Immunity, Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| |
Collapse
|
133
|
Scavenging nucleic acid debris to combat autoimmunity and infectious disease. Proc Natl Acad Sci U S A 2016; 113:9728-33. [PMID: 27528673 DOI: 10.1073/pnas.1607011113] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Nucleic acid-containing debris released from dead and dying cells can be recognized as damage-associated molecular patterns (DAMPs) or pattern-associated molecular patterns (PAMPs) by the innate immune system. Inappropriate activation of the innate immune response can engender pathological inflammation and autoimmune disease. To combat such diseases, major efforts have been made to therapeutically target the pattern recognition receptors (PRRs) such as the Toll-like receptors (TLRs) that recognize such DAMPs and PAMPs, or the downstream effector molecules they engender, to limit inflammation. Unfortunately, such strategies can limit the ability of the immune system to combat infection. Previously, we demonstrated that nucleic acid-binding polymers can act as molecular scavengers and limit the ability of artificial nucleic acid ligands to activate PRRs. Herein, we demonstrate that nucleic acid scavengers (NASs) can limit pathological inflammation and nucleic acid-associated autoimmunity in lupus-prone mice. Moreover, we observe that such NASs do not limit an animal's ability to combat viral infection, but rather their administration improves survival when animals are challenged with lethal doses of influenza. These results indicate that molecules that scavenge extracellular nucleic acid debris represent potentially safer agents to control pathological inflammation associated with a wide range of autoimmune and infectious diseases.
Collapse
|
134
|
Achek A, Yesudhas D, Choi S. Toll-like receptors: promising therapeutic targets for inflammatory diseases. Arch Pharm Res 2016; 39:1032-49. [PMID: 27515048 DOI: 10.1007/s12272-016-0806-9] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Accepted: 08/01/2016] [Indexed: 12/19/2022]
Abstract
The health of living organisms is constantly challenged by bacterial and viral threats. The recognition of pathogenic microorganisms by diverse receptors triggers a variety of host defense mechanisms, leading to their eradication. Toll-like receptors (TLRs), which are type I transmembrane proteins, recognize specific signatures of the invading microbes and activate a cascade of downstream signals inducing the secretion of inflammatory cytokines, chemokines, and type I interferons. The TLR response not only counteracts the pathogens but also initiates and shapes the adaptive immune response. Under normal conditions, inflammation is downregulated after the removal of the pathogen and cellular debris. However, a dysfunctional TLR-mediated response maintains a chronic inflammatory state and leads to local and systemic deleterious effects in host cells and tissues. Such inappropriate TLR response has been attributed to the development and progression of multiple diseases such as cancer, autoimmune, and inflammatory diseases. In this review, we discuss the emerging role of TLRs in the pathogenesis of inflammatory diseases and how targeting of TLRs offers a promising therapeutic strategy for the prevention and treatment of various inflammatory diseases. Additionally, we highlight a number of TLR-targeting agents that are in the developmental stage or in clinical trials.
Collapse
Affiliation(s)
- Asma Achek
- Department of Molecular Science and Technology, Ajou University, Suwon, 443-749, Korea
| | - Dhanusha Yesudhas
- Department of Molecular Science and Technology, Ajou University, Suwon, 443-749, Korea
| | - Sangdun Choi
- Department of Molecular Science and Technology, Ajou University, Suwon, 443-749, Korea.
| |
Collapse
|
135
|
Inhibiting TLR9 and other UNC93B1-dependent TLRs paradoxically increases accumulation of MYD88L265P plasmablasts in vivo. Blood 2016; 128:1604-8. [PMID: 27458005 DOI: 10.1182/blood-2016-03-708065] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Accepted: 07/17/2016] [Indexed: 12/25/2022] Open
Abstract
The MYD88(L265P) mutation is found in 2% to 10% of chronic lymphocytic leukemia, 29% of activated B-cell type diffuse large B-cell lymphoma and 90% of Waldenström macroglobulinemia, making it conceptually attractive to treat these malignancies with inhibitors of endosomal Toll-like receptors (TLR9, TLR7) that activate MYD88. Here we show that genetic inhibition of endosomal TLRs has the opposite effect on accumulation of MYD88(L265P) B cells in vitro and in vivo. Activated mature B cells from wild-type, Unc93b1(3d/3d)-mutant, or Tlr9-deficient mice were transduced with retrovirus encoding MYD88(L265P) and analyzed either in vitro or after transplantation into Rag1(-/-) recipient mice. Unc93b1(3d/3d) mutation, which blocks TLR9 and TLR7 signaling, or Tlr9 deficiency suppressed MYD88(L265P) B-cell growth in vitro but paradoxically increased in vivo accumulation of MYD88(L265P) B cells as CD19(low) plasmablasts by 10- to 100-fold. These results reveal an unexpected, powerful inhibitory effect of TLR9 on MYD88(L265P) B-cell proliferation and differentiation that appears independent of TLR7, and they provide a preclinical indicator for caution in clinical trials of TLR7/9 inhibitors for MYD88(L265P) B-cell malignancies.
Collapse
|
136
|
Naradikian MS, Myles A, Beiting DP, Roberts KJ, Dawson L, Herati RS, Bengsch B, Linderman SL, Stelekati E, Spolski R, Wherry EJ, Hunter C, Hensley SE, Leonard WJ, Cancro MP. Cutting Edge: IL-4, IL-21, and IFN-γ Interact To Govern T-bet and CD11c Expression in TLR-Activated B Cells. THE JOURNAL OF IMMUNOLOGY 2016; 197:1023-8. [PMID: 27430719 DOI: 10.4049/jimmunol.1600522] [Citation(s) in RCA: 158] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Accepted: 06/20/2016] [Indexed: 01/19/2023]
Abstract
T-bet and CD11c expression in B cells is linked with IgG2c isotype switching, virus-specific immune responses, and humoral autoimmunity. However, the activation requisites and regulatory cues governing T-bet and CD11c expression in B cells remain poorly defined. In this article, we reveal a relationship among TLR engagement, IL-4, IL-21, and IFN-γ that regulates T-bet expression in B cells. We find that IL-21 or IFN-γ directly promote T-bet expression in the context of TLR engagement. Further, IL-4 antagonizes T-bet induction. Finally, IL-21, but not IFN-γ, promotes CD11c expression independent of T-bet. Using influenza virus and Heligmosomoides polygyrus infections, we show that these interactions function in vivo to determine whether T-bet(+) and CD11c(+) B cells are formed. These findings suggest that T-bet(+) B cells seen in health and disease share the common initiating features of TLR-driven activation within this circumscribed cytokine milieu.
Collapse
Affiliation(s)
- Martin S Naradikian
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104; Institute for Immunology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Arpita Myles
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104; Institute for Immunology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Daniel P Beiting
- Institute for Immunology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104; School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Kenneth J Roberts
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Lucas Dawson
- Institute for Immunology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104; School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Ramin Sedaghat Herati
- Institute for Immunology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104; Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Bertram Bengsch
- Institute for Immunology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104; Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Susanne L Linderman
- Institute for Immunology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104; Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104; Wistar Institute, Philadelphia, PA 19104; and
| | - Erietta Stelekati
- Institute for Immunology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104; Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Rosanne Spolski
- Laboratory of Molecular Immunology and the Immunology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892
| | - E John Wherry
- Institute for Immunology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104; Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Christopher Hunter
- Institute for Immunology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104; School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Scott E Hensley
- Institute for Immunology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104; Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104; Wistar Institute, Philadelphia, PA 19104; and
| | - Warren J Leonard
- Laboratory of Molecular Immunology and the Immunology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892
| | - Michael P Cancro
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104; Institute for Immunology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104;
| |
Collapse
|
137
|
Lorenz G, Lech M, Anders HJ. Toll-like receptor activation in the pathogenesis of lupus nephritis. Clin Immunol 2016; 185:86-94. [PMID: 27423476 DOI: 10.1016/j.clim.2016.07.015] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Revised: 07/11/2016] [Accepted: 07/12/2016] [Indexed: 12/29/2022]
Abstract
The pathogenesis of systemic lupus erythematosus (SLE) and lupus nephritis is complex but no longer enigmatic. Much progress has been made to on the polygenetic origin of lupus in identifying gene variants that permit the loss of tolerance against nuclear autoantigens. Along the same line in about 50% of lupus patients additional genetic weaknesses promote immune complex glomerulonephritis and filtration barrier dysfunction. Here we briefly summarize the pathogenesis of SLE with a focus on loss of tolerance and the role of toll-like receptors in the "pseudo"-antiviral immunity concept of systemic lupus. In addition, we discuss the local role of Toll-like receptors in intrarenal inflammation and kidney remodeling.
Collapse
Affiliation(s)
- Georg Lorenz
- Abteilung für Nephrologie, Klinikum rechts der Isar, Technische Universität München, Ismaninger Str. 22, 81675 Munich, Germany
| | - Maciej Lech
- Nephrologisches Zentrum, Medizinische Klinik und Poliklinik IV, Klinikum der Ludwig Maximilians Universität München, Munich, Germany
| | - Hans-Joachim Anders
- Nephrologisches Zentrum, Medizinische Klinik und Poliklinik IV, Klinikum der Ludwig Maximilians Universität München, Munich, Germany.
| |
Collapse
|
138
|
Bossaller L, Christ A, Pelka K, Nündel K, Chiang PI, Pang C, Mishra N, Busto P, Bonegio RG, Schmidt RE, Latz E, Marshak-Rothstein A. TLR9 Deficiency Leads to Accelerated Renal Disease and Myeloid Lineage Abnormalities in Pristane-Induced Murine Lupus. THE JOURNAL OF IMMUNOLOGY 2016; 197:1044-53. [PMID: 27354219 DOI: 10.4049/jimmunol.1501943] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Accepted: 05/18/2016] [Indexed: 12/15/2022]
Abstract
Systemic lupus erythematosus (SLE) is a chronic, life-threatening autoimmune disorder, leading to multiple organ pathologies and kidney destruction. Analyses of numerous murine models of spontaneous SLE have revealed a critical role for endosomal TLRs in the production of autoantibodies and development of other clinical disease manifestations. Nevertheless, the corresponding TLR9-deficient autoimmune-prone strains consistently develop more severe disease pathology. Injection of BALB/c mice with 2,6,10,14-tetramethylpentadecane (TMPD), commonly known as pristane, also results in the development of SLE-like disease. We now show that Tlr9(-/-) BALB/c mice injected i.p. with TMPD develop more severe autoimmunity than do their TLR-sufficient cohorts. Early indications include an increased accumulation of TLR7-expressing Ly6C(hi) inflammatory monocytes at the site of injection, upregulation of IFN-regulated gene expression in the peritoneal cavity, and an increased production of myeloid lineage precursors (common myeloid progenitors and granulocyte myeloid precursors) in the bone marrow. TMPD-injected Tlr9(-/-) BALB/c mice develop higher autoantibody titers against RNA, neutrophil cytoplasmic Ags, and myeloperoxidase than do TMPD-injected wild-type BALB/c mice. The TMP-injected Tlr9(-/-) mice, and not the wild-type mice, also develop a marked increase in glomerular IgG deposition and infiltrating granulocytes, much more severe glomerulonephritis, and a reduced lifespan. Collectively, the data point to a major role for TLR7 in the response to self-antigens in this model of experimental autoimmunity. Therefore, the BALB/c pristane model recapitulates other TLR7-driven spontaneous models of SLE and is negatively regulated by TLR9.
Collapse
Affiliation(s)
- Lukas Bossaller
- Department of Clinical Immunology and Rheumatology, Hannover Medical School, 30625 Hannover, Germany; Division of Infectious Diseases and Immunology, University of Massachusetts Medical School, Worcester, MA 01605;
| | - Anette Christ
- Division of Infectious Diseases and Immunology, University of Massachusetts Medical School, Worcester, MA 01605; Institute of Innate Immunity, University Hospital Bonn, 53217 Bonn, Germany
| | - Karin Pelka
- Institute of Innate Immunity, University Hospital Bonn, 53217 Bonn, Germany
| | - Kerstin Nündel
- Division of Rheumatology, Department of Medicine, University of Massachusetts Medical School, Worcester, MA 01605; and
| | - Ping-I Chiang
- Division of Infectious Diseases and Immunology, University of Massachusetts Medical School, Worcester, MA 01605
| | - Catherine Pang
- Division of Infectious Diseases and Immunology, University of Massachusetts Medical School, Worcester, MA 01605
| | - Neha Mishra
- Department of Clinical Immunology and Rheumatology, Hannover Medical School, 30625 Hannover, Germany
| | - Patricia Busto
- Division of Rheumatology, Department of Medicine, University of Massachusetts Medical School, Worcester, MA 01605; and
| | - Ramon G Bonegio
- Renal Section, Department of Medicine, Boston University Medical Center, Boston, MA 021184
| | - Reinhold Ernst Schmidt
- Division of Infectious Diseases and Immunology, University of Massachusetts Medical School, Worcester, MA 01605
| | - Eicke Latz
- Division of Infectious Diseases and Immunology, University of Massachusetts Medical School, Worcester, MA 01605; Institute of Innate Immunity, University Hospital Bonn, 53217 Bonn, Germany
| | - Ann Marshak-Rothstein
- Division of Rheumatology, Department of Medicine, University of Massachusetts Medical School, Worcester, MA 01605; and
| |
Collapse
|
139
|
Wu YY, Kumar R, Iida R, Bagavant H, Alarcón-Riquelme ME. BANK1 Regulates IgG Production in a Lupus Model by Controlling TLR7-Dependent STAT1 Activation. PLoS One 2016; 11:e0156302. [PMID: 27228057 PMCID: PMC4882053 DOI: 10.1371/journal.pone.0156302] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Accepted: 04/30/2016] [Indexed: 11/18/2022] Open
Abstract
The purpose of our study was to investigate the effects of the adaptor Bank1 in TLR7 signaling using the B6.Sle1.yaa mouse, a lupus model that develops disease through exacerbated TLR7 expression. Crosses of B6.Sle1.yaa with Bank1-/- mice maintained several B and myeloid cell phenotypes close to normal wild-type levels. Most striking was the reduction in total serum IgG antibodies, but not of IgM, and reduced serum levels of autoantibodies, IL-6, and BAFF. Bank1 deficiency did modify numbers of MZ B cells and total B cell numbers, as well as expression of CXCR4 by follicular helper T cells. Other T cell changes were not observed. Bank1 deficiency did not modify numbers of germinal center B cells or plasma cells or clinical disease outcomes. Purified B cells from Bank1 deficient mice had strongly reduced Ifnb, Ifna4, Irf7, Aicda and Stat1 gene expression following TLR7 agonist stimulation. Interestingly, phosphorylation of Tyr701, but not of Ser727 of STAT1, was impaired in splenic B cells from B6.Sle1.yaa.Bank1-/- mice, as was the nuclear translocation of IRF7 in response to TLR7 agonist stimulation. Further, Bank1 deficiency in B6.Sle1.yaa mice reduced the production of IgG2c after in vitro TLR7 agonist stimulation. Our results demonstrate that Bank1 controls TLR7-mediated type I interferon production. Combined with the control of the nuclear translocation of IRF7, the modulation of STAT1 transcription and phosphorylation, Bank1 contributes to IgG production during development of autoimmune disease.
Collapse
Affiliation(s)
- Ying-Yu Wu
- Arthritis and Clinical Immunology Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, 73104, United States of America
| | - Ramesh Kumar
- Arthritis and Clinical Immunology Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, 73104, United States of America
| | - Ryuji Iida
- Arthritis and Clinical Immunology Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, 73104, United States of America
| | - Harini Bagavant
- Arthritis and Clinical Immunology Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, 73104, United States of America
| | - Marta E. Alarcón-Riquelme
- Arthritis and Clinical Immunology Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, 73104, United States of America
- Department of Medical Genomics, Pfizer/University of Granada/Andalusian Government Center for Genomics and Oncological Research (GENYO), 18016, Parque Tecnológico de la Salud (PTS), Granada, Spain
- * E-mail: ; ;
| |
Collapse
|
140
|
Abstract
The germinal center response is the delayed but sustained phase of the antibody response that is responsible for producing high-affinity antibodies of the IgG, IgA and/or IgE isotypes. B cells in the germinal center undergo re-iterative cycles of somatic hypermutation of immunoglobulin gene variable regions, clonal expansion, and Darwinian selection for cells expressing higher-affinity antibody variants. Alternatively, selected B cells can terminally differentiate into long-lived plasma cells or into a broad diversity of mutated memory B cells; the former secrete the improved antibodies to fight an infection and to provide continuing protection from re-infection, whereas the latter may jumpstart immune responses to subsequent infections with related but distinct infecting agents. Our understanding of the molecules involved in the germinal center reaction has been informed by studies of human immunodeficiency patients with selective defects in the production of antibodies. Recent studies have begun to reveal how innate immune recognition via Toll-like receptors can enhance the magnitude and selective properties of the germinal center, leading to more effective control of infection by a subset of viruses. Just as early insights into the nature of the germinal center found application in the development of the highly successful conjugate vaccines, more recent insights may find application in the current efforts to develop new generations of vaccines, including vaccines that can induce broadly protective neutralizing antibodies against influenza virus or HIV-1.
Collapse
|
141
|
Toll-like receptors and chronic inflammation in rheumatic diseases: new developments. Nat Rev Rheumatol 2016; 12:344-57. [PMID: 27170508 DOI: 10.1038/nrrheum.2016.61] [Citation(s) in RCA: 135] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
In the past few years, new developments have been reported on the role of Toll-like receptors (TLRs) in chronic inflammation in rheumatic diseases. The inhibitory function of TLR10 has been demonstrated. Receptors that enhance the function of TLRs, and several TLR inhibitors, have been identified. In addition, the role of the microbiome and TLRs in the onset of rheumatic diseases has been reported. We review novel insights on the role of TLRs in several inflammatory joint diseases, including rheumatoid arthritis, systemic lupus erythematosus, gout and Lyme arthritis, with a focus on the signalling mechanisms mediated by the Toll-IL-1 receptor (TIR) domain, the exogenous and endogenous ligands of TLRs, and the current and future therapeutic strategies to target TLR signalling in rheumatic diseases.
Collapse
|
142
|
Differences in codon bias and GC content contribute to the balanced expression of TLR7 and TLR9. Proc Natl Acad Sci U S A 2016; 113:E1362-71. [PMID: 26903634 DOI: 10.1073/pnas.1518976113] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The innate immune system detects diverse microbial species with a limited repertoire of immune receptors that recognize nucleic acids. The cost of this immune surveillance strategy is the potential for inappropriate recognition of self-derived nucleic acids and subsequent autoimmune disease. The relative expression of two closely related receptors, Toll-like receptor (TLR) 7 and TLR9, is balanced to allow recognition of microbial nucleic acids while limiting recognition of self-derived nucleic acids. Situations that tilt this balance toward TLR7 promote inappropriate responses, including autoimmunity; therefore, tight control of expression is critical for proper homeostasis. Here we report that differences in codon bias limit TLR7 expression relative to TLR9. Codon optimization of Tlr7 increases protein levels as well as responses to ligands, but, unexpectedly, these changes only modestly affect translation. Instead, we find that much of the benefit attributed to codon optimization is actually the result of enhanced transcription. Our findings, together with other recent examples, challenge the dogma that codon optimization primarily increases translation. We propose that suboptimal codon bias, which correlates with low guanine-cytosine (GC) content, limits transcription of certain genes. This mechanism may establish low levels of proteins whose overexpression leads to particularly deleterious effects, such as TLR7.
Collapse
|
143
|
Zhou Z, Ma J, Xiao C, Han X, Qiu R, Wang Y, Zhou Y, Wu L, Huang X, Shen N. Phenotypic and functional alterations of pDCs in lupus-prone mice. Sci Rep 2016; 6:20373. [PMID: 26879679 PMCID: PMC4754657 DOI: 10.1038/srep20373] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Accepted: 12/09/2015] [Indexed: 01/07/2023] Open
Abstract
Plasmacytoid dendritic cells (pDCs) were considered to be the major IFNα source in systemic lupus erythematosus (SLE) but their phenotype and function in different disease status have not been well studied. To study the function and phenotype of pDCs in lupus-prone mice we used 7 strains of lupus-prone mice including NZB/W F1, NZB, NZW, NZM2410, B6.NZMSle1/2/3, MRL/lpr and BXSB/Mp mice and C57BL/6 as control mice. Increased spleen pDC numbers were found in most lupus mice compared to C57BL/6 mice. The IFNα-producing ability of BM pDCs was similar between lupus and C57BL/6 mice, whereas pDCs from the spleens of NZB/W F1 and NZB mice produced more IFNα than pDCs from the spleens of C57BL/6 mice. Furthermore, spleen pDCs from MRL-lpr and NZM2410 mice showed increased responses to Tlr7 and Tlr9, respectively. As the disease progressed, IFN signature were evaluated in both BM and spleen pDC from lupus prone mice and the number of BM pDCs and their ability to produce IFNα gradually decreased in lupus-prone mice. In conclusion, pDC are activated alone with disease development and its phenotype and function differ among lupus-prone strains, and these differences may contribute to the development of lupus in these mice.
Collapse
Affiliation(s)
- Zhenyuan Zhou
- Shanghai Institute of Rheumatology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China
| | - Jianyang Ma
- Shanghai Institute of Rheumatology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China
| | - Chunyuan Xiao
- Shanghai Institute of Rheumatology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China
| | - Xiao Han
- Institute of Health Sciences, Shanghai Institutes for Biological Sciences (SIBS) &Shanghai Jiao Tong University School of Medicine (SJTUSM), Chinese Academy of Sciences (CAS), Shanghai, China
| | - Rong Qiu
- Institute of Health Sciences, Shanghai Institutes for Biological Sciences (SIBS) &Shanghai Jiao Tong University School of Medicine (SJTUSM), Chinese Academy of Sciences (CAS), Shanghai, China
| | - Yan Wang
- Institute of Health Sciences, Shanghai Institutes for Biological Sciences (SIBS) &Shanghai Jiao Tong University School of Medicine (SJTUSM), Chinese Academy of Sciences (CAS), Shanghai, China
| | - Yingying Zhou
- Shanghai Institute of Rheumatology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China
| | - Li Wu
- Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University School of Medicine, Beijing, China
| | - Xinfang Huang
- Shanghai Institute of Rheumatology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China
| | - Nan Shen
- Shanghai Institute of Rheumatology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China.,Institute of Health Sciences, Shanghai Institutes for Biological Sciences (SIBS) &Shanghai Jiao Tong University School of Medicine (SJTUSM), Chinese Academy of Sciences (CAS), Shanghai, China.,Division of Rheumatology and the Center for Autoimmune Genomics and Etiology (CAGE), Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States of America
| |
Collapse
|
144
|
Pacheco GV, Novelo Noh IB, Velasco Cárdenas RMH, Angulo Ramírez AV, López Villanueva RF, Quintal Ortiz IG, Alonso Salomón LG, Ruz NP, Rivero Cárdenas NA. Expression of TLR-7, MyD88, NF-kB, and INF-α in B Lymphocytes of Mayan Women with Systemic Lupus Erythematosus in Mexico. Front Immunol 2016; 7:22. [PMID: 26870038 PMCID: PMC4735402 DOI: 10.3389/fimmu.2016.00022] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Accepted: 01/15/2016] [Indexed: 01/06/2023] Open
Abstract
Background Systemic lupus erythematosus (SLE) is a chronic inflammatory autoimmune disease involving multiple organs. It is currently accepted that several genetic, environmental, and hormonal factors are contributing to its development. Innate immunity may have a great influence in autoimmunity through Toll-like receptors. TLR-7 recognizing single-strand RNA has been involved in SLE. Its activation induces intracellular signal with attraction of MyD88 and NF-kBp65, leading to IFN-α synthesis which correlate with disease activity. Objective To assess the expression of TLR-7, MyD88, and NF-kBp65 in B lymphocytes of Mayan women with SLE. Methods One hundred patients with SLE and 100 healthy controls, all of them Mayan women, were included. TLR-7 was analyzed on B and T lymphocytes, and MyD88 and NF-kB only in B lymphocytes. Serum INF-α level was evaluated by ELISA. Results Significant expression (p < 0.0001) of TLR-7 in B and T lymphocytes and serum IFN-α increased (p = 0.034) was observed in patients. MyD88 and NF-kBp65 were also increased in B lymphocytes of patients. TLR-7 and NF-kBp65 expression correlated, but no correlation with INF-α and disease activity was detected. Conclusion Data support the role of TLR-7 and signal proteins in the pathogenesis of SLE in the Mayan population of Yucatán.
Collapse
Affiliation(s)
- Guillermo Valencia Pacheco
- Laboratorio de Hematología, Centro de Investigaciones Regionales Dr. Hideyo Noguchi, Universidad Autónoma de Yucatán , Mérida , Mexico
| | | | | | | | | | - Irma G Quintal Ortiz
- Laboratorio de Hematología, Centro de Investigaciones Regionales Dr. Hideyo Noguchi, Universidad Autónoma de Yucatán , Mérida , Mexico
| | - Ligia G Alonso Salomón
- Laboratorio de Hematología, Centro de Investigaciones Regionales Dr. Hideyo Noguchi, Universidad Autónoma de Yucatán , Mérida , Mexico
| | - Norma Pavía Ruz
- Laboratorio de Hematología, Centro de Investigaciones Regionales Dr. Hideyo Noguchi, Universidad Autónoma de Yucatán , Mérida , Mexico
| | - Nubia A Rivero Cárdenas
- Laboratorio de Hematología, Centro de Investigaciones Regionales Dr. Hideyo Noguchi, Universidad Autónoma de Yucatán , Mérida , Mexico
| |
Collapse
|
145
|
Sharma S, Fitzgerald KA, Cancro MP, Marshak-Rothstein A. Nucleic Acid-Sensing Receptors: Rheostats of Autoimmunity and Autoinflammation. THE JOURNAL OF IMMUNOLOGY 2015; 195:3507-12. [PMID: 26432899 DOI: 10.4049/jimmunol.1500964] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Distinct families of germline-encoded pattern recognition receptors can sense both microbial and endogenous nucleic acids. These DNA and RNA sensors include endosomal TLRs and cytosolic sensors upstream of stimulator of type I IFN genes (STING) and MAVS. The existence of overlapping specificities for both foreign and self nucleic acids suggests that, under optimal conditions, the activity of these receptors is finely tuned to effectively mediate host defense yet constrain pathogenic self-reactivity. This equilibrium becomes disrupted with the loss of either TLR9 or STING. To maintain immune protection, this loss can be counterbalanced by the elevated response of an alternative receptor(s). Unfortunately, this adjustment can lead to an increased risk for the development of systemic autoimmunity, as evidenced by the exacerbated clinical disease manifestations of TLR9-deficient and STING-deficient autoimmune-prone mice. These studies underscore the delicate balance normally maintained by tonic signals that prevent unchecked immune responses to nucleic acids released during infections and cellular duress or death.
Collapse
Affiliation(s)
- Shruti Sharma
- Program in Innate Immunity, Department of Medicine, University of Massachusetts Medical School, Worcester, MA 01605; and
| | - Katharine A Fitzgerald
- Program in Innate Immunity, Department of Medicine, University of Massachusetts Medical School, Worcester, MA 01605; and
| | - Michael P Cancro
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104
| | - Ann Marshak-Rothstein
- Program in Innate Immunity, Department of Medicine, University of Massachusetts Medical School, Worcester, MA 01605; and
| |
Collapse
|
146
|
Naradikian MS, Hao Y, Cancro MP. Age-associated B cells: key mediators of both protective and autoreactive humoral responses. Immunol Rev 2015; 269:118-29. [DOI: 10.1111/imr.12380] [Citation(s) in RCA: 106] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Martin S. Naradikian
- Department of Pathology and Laboratory Medicine; Perelman School of Medicine at the University of Pennsylvania; Philadelphia PA USA
| | - Yi Hao
- Department of Microbiology; Tongji Medical College; Huazhong University of Science and Technology, Wuhan, China
| | - Michael P. Cancro
- Department of Pathology and Laboratory Medicine; Perelman School of Medicine at the University of Pennsylvania; Philadelphia PA USA
| |
Collapse
|
147
|
Wu YW, Tang W, Zuo JP. Toll-like receptors: potential targets for lupus treatment. Acta Pharmacol Sin 2015; 36:1395-407. [PMID: 26592511 DOI: 10.1038/aps.2015.91] [Citation(s) in RCA: 119] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 09/08/2015] [Indexed: 12/18/2022] Open
Abstract
Systemic lupus erythematosus (SLE) is a complex autoimmune disease characterized by the loss of tolerance to self-nuclear antigens. Accumulating evidence shows that Toll-like receptors (TLRs), previously proven to be critical for host defense, are implicated in the pathogenesis of autoimmune diseases by recognition of self-molecules. Genome-wide association studies, experimental mouse models and clinical sample studies have provided evidence for the involvement of TLRs, including TLR2/4, TLR5, TLR3 and TLR7/8/9, in SLE pathogenesis. A number of downstream proteins in the TLR signaling cascade (such as MyD88, IRAKs and IFN-α) are identified as potential therapeutic targets for SLE treatment. Numerous antagonists targeting TLR signaling, including oligonucleotides, small molecular inhibitors and antibodies, are currently under preclinical studies or clinical trials for SLE treatment. Moreover, the emerging new manipulation of TLR signaling by microRNA (miRNA) regulation shows promise for the future treatment of SLE.
Collapse
|
148
|
Celhar T, Hopkins R, Thornhill SI, De Magalhaes R, Hwang SH, Lee HY, Yasuga H, Jones LA, Casco J, Lee B, Thamboo TP, Zhou XJ, Poidinger M, Connolly JE, Wakeland EK, Fairhurst AM. RNA sensing by conventional dendritic cells is central to the development of lupus nephritis. Proc Natl Acad Sci U S A 2015; 112:E6195-204. [PMID: 26512111 PMCID: PMC4653170 DOI: 10.1073/pnas.1507052112] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Glomerulonephritis is a common and debilitating feature of systemic lupus erythematosus (SLE). The precise immune mechanisms that drive the progression from benign autoimmunity to glomerulonephritis are largely unknown. Previous investigations have shown that a moderate increase of the innate Toll-like receptor 7 (TLR7) is sufficient for the development of nephritis. In these systems normalization of B-cell TLR7 expression or temporal depletion of plasmacytoid dendritic cells (pDCs) slow progression; however, the critical cell that is responsible for driving full immunopathology remains unidentified. In this investigation we have shown that conventional DC expression of TLR7 is essential for severe autoimmunity in the Sle1Tg7 model of SLE. We show that a novel expanding CD11b(+) conventional DC subpopulation dominates the infiltrating renal inflammatory milieu, localizing to the glomeruli. Moreover, exposure of human myeloid DCs to IFN-α or Flu increases TLR7 expression, suggesting they may have a role in self-RNA recognition pathways in clinical disease. To our knowledge, this study is the first to highlight the importance of conventional DC-TLR7 expression for kidney pathogenesis in a murine model of SLE.
Collapse
Affiliation(s)
- Teja Celhar
- Singapore Immunology Network, A*STAR, 138648 Singapore
| | - Richard Hopkins
- Institute of Molecular and Cell Biology, A*STAR, 138673 Singapore
| | | | | | - Sun-Hee Hwang
- Department of Immunology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9093
| | - Hui-Yin Lee
- Singapore Immunology Network, A*STAR, 138648 Singapore
| | - Hiroko Yasuga
- Singapore Immunology Network, A*STAR, 138648 Singapore; School of Biological Sciences, Nanyang Technological University, 637551 Singapore
| | - Leigh A Jones
- Singapore Immunology Network, A*STAR, 138648 Singapore; Institute of Molecular and Cell Biology, A*STAR, 138673 Singapore
| | - Jose Casco
- Department of Immunology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9093
| | - Bernett Lee
- Singapore Immunology Network, A*STAR, 138648 Singapore
| | - Thomas P Thamboo
- Department of Pathology, National University Hospital, 119074 Singapore
| | - Xin J Zhou
- Department of Pathology, Baylor University Medical Center, Dallas, TX 75246
| | | | - John E Connolly
- Institute of Molecular and Cell Biology, A*STAR, 138673 Singapore; Institute of Biomedical Studies, Baylor University, Waco, TX76798
| | - Edward K Wakeland
- Department of Immunology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9093
| | - Anna-Marie Fairhurst
- Singapore Immunology Network, A*STAR, 138648 Singapore; Department of Immunology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9093; School of Biological Sciences, Nanyang Technological University, 637551 Singapore;
| |
Collapse
|
149
|
Kolhatkar NS, Brahmandam A, Thouvenel CD, Becker-Herman S, Jacobs HM, Schwartz MA, Allenspach EJ, Khim S, Panigrahi AK, Luning Prak ET, Thrasher AJ, Notarangelo LD, Candotti F, Torgerson TR, Sanz I, Rawlings DJ. Altered BCR and TLR signals promote enhanced positive selection of autoreactive transitional B cells in Wiskott-Aldrich syndrome. ACTA ACUST UNITED AC 2015; 212:1663-77. [PMID: 26371186 PMCID: PMC4577851 DOI: 10.1084/jem.20150585] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Accepted: 08/11/2015] [Indexed: 12/29/2022]
Abstract
Wiskott-Aldrich syndrome (WAS) is an X-linked immunodeficiency disorder frequently associated with systemic autoimmunity, including autoantibody-mediated cytopenias. WAS protein (WASp)-deficient B cells have increased B cell receptor (BCR) and Toll-like receptor (TLR) signaling, suggesting that these pathways might impact establishment of the mature, naive BCR repertoire. To directly investigate this possibility, we evaluated naive B cell specificity and composition in WASp-deficient mice and WAS subjects (n = 12). High-throughput sequencing and single-cell cloning analysis of the BCR repertoire revealed altered heavy chain usage and enrichment for low-affinity self-reactive specificities in murine marginal zone and human naive B cells. Although negative selection mechanisms including deletion, anergy, and receptor editing were relatively unperturbed, WASp-deficient transitional B cells showed enhanced proliferation in vivo mediated by antigen- and Myd88-dependent signals. Finally, using both BCR sequencing and cell surface analysis with a monoclonal antibody recognizing an intrinsically autoreactive heavy chain, we show enrichment in self-reactive cells specifically at the transitional to naive mature B cell stage in WAS subjects. Our combined data support a model wherein modest alterations in B cell-intrinsic, BCR, and TLR signals in WAS, and likely other autoimmune disorders, are sufficient to alter B cell tolerance via positive selection of self-reactive transitional B cells.
Collapse
Affiliation(s)
- Nikita S Kolhatkar
- Department of Immunology and Department of Pediatrics, University of Washington School of Medicine, Seattle, WA 98195
| | - Archana Brahmandam
- Department of Immunology and Department of Pediatrics, University of Washington School of Medicine, Seattle, WA 98195 Center for Immunity and Immunotherapies, Seattle Children's Research Institute, Seattle, WA 98101
| | - Christopher D Thouvenel
- Department of Immunology and Department of Pediatrics, University of Washington School of Medicine, Seattle, WA 98195 Center for Immunity and Immunotherapies, Seattle Children's Research Institute, Seattle, WA 98101
| | - Shirly Becker-Herman
- Department of Immunology and Department of Pediatrics, University of Washington School of Medicine, Seattle, WA 98195 Center for Immunity and Immunotherapies, Seattle Children's Research Institute, Seattle, WA 98101
| | - Holly M Jacobs
- Department of Immunology and Department of Pediatrics, University of Washington School of Medicine, Seattle, WA 98195 Center for Immunity and Immunotherapies, Seattle Children's Research Institute, Seattle, WA 98101
| | - Marc A Schwartz
- Department of Immunology and Department of Pediatrics, University of Washington School of Medicine, Seattle, WA 98195
| | - Eric J Allenspach
- Department of Immunology and Department of Pediatrics, University of Washington School of Medicine, Seattle, WA 98195
| | - Socheath Khim
- Department of Immunology and Department of Pediatrics, University of Washington School of Medicine, Seattle, WA 98195 Center for Immunity and Immunotherapies, Seattle Children's Research Institute, Seattle, WA 98101
| | - Anil K Panigrahi
- Department of Pathology and Laboratory Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104
| | - Eline T Luning Prak
- Department of Pathology and Laboratory Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104
| | - Adrian J Thrasher
- Molecular Immunology Unit, Section of Molecular and Cellular Immunology, Centre for Immunodeficiency, University College London Institute of Child Health, London WC1N 1EH, England, UK
| | | | - Fabio Candotti
- Genetics and Molecular Biology Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892
| | - Troy R Torgerson
- Department of Immunology and Department of Pediatrics, University of Washington School of Medicine, Seattle, WA 98195 Center for Immunity and Immunotherapies, Seattle Children's Research Institute, Seattle, WA 98101
| | - Ignacio Sanz
- Lowance Center for Human Immunology and Division of Rheumatology, Department of Medicine, Emory University, Atlanta, GA 30322 Lowance Center for Human Immunology and Division of Rheumatology, Department of Medicine, Emory University, Atlanta, GA 30322
| | - David J Rawlings
- Department of Immunology and Department of Pediatrics, University of Washington School of Medicine, Seattle, WA 98195 Department of Immunology and Department of Pediatrics, University of Washington School of Medicine, Seattle, WA 98195 Center for Immunity and Immunotherapies, Seattle Children's Research Institute, Seattle, WA 98101
| |
Collapse
|
150
|
Abstract
Nucleic acid sensing by innate receptors initiates immune defences against viruses and other pathogens. A hallmark of this response is the release of interferons (IFNs), which promote protective immunity by inducing IFN-stimulated genes (ISGs). A similar ISG signature is found in autoinflammatory and autoimmune conditions, indicating that chronic activation of nucleic acid-sensing pathways may contribute to these diseases. Here, we review how nucleic acid-sensing pathways are currently being targeted pharmacologically with both agonists and antagonists. We discuss how an improved understanding of the biology of these pathways is leading to novel therapies for infections, cancer, and autoimmune and autoinflammatory disorders, and how new therapeutics will, in turn, generate a deeper understanding of these complex diseases.
Collapse
|