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Ruan P, Wang S, Yi P, Yang M, Chen Y, Yang M. Identification of the potential TLR7 antagonists by virtual screening and experimental validation. Mol Divers 2023:10.1007/s11030-023-10660-4. [PMID: 37217769 DOI: 10.1007/s11030-023-10660-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Accepted: 05/15/2023] [Indexed: 05/24/2023]
Abstract
Toll-like receptor 7 (TLR7) is highly expressed in dendritic cells (DCs) and B cells, and its aberrant activation can promote disease progression in systemic lupus erythematosus (SLE). We utilized structure-based virtual screening and experimental validation to screen natural products from TargetMol for potential TLR7 antagonists. Our results of molecular docking and molecular dynamics simulation showed that Mogroside V (MV) strongly interacted with TLR7, with stable open-TLR7-MV and close-TLR7-MV complexes. Furthermore, in vitro experiments demonstrated that MV significantly inhibited B cell differentiation in a concentration-dependent manner. In addition to TLR7, we also revealed a strong interaction of MV with all TLRs, including TLR4. The above results suggested that MV might be a potential TLR7 antagonist deserving of further study.
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Affiliation(s)
- Pinglang Ruan
- Department of Dermatology, Second Xiangya Hospital, Central South University, Hunan Key Laboratory of Medical Epigenomics, Changsha, Hunan, China
| | - Susu Wang
- Department of Anesthesiology, Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Ping Yi
- Department of Pediatrics, The Third Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Miao Yang
- Department of Dermatology, Second Xiangya Hospital, Central South University, Hunan Key Laboratory of Medical Epigenomics, Changsha, Hunan, China
| | - Yongjian Chen
- Department of Dermatology, Hunan Provincial People's Hospital, Changsha, 410078, Hunan, China
| | - Ming Yang
- Department of Dermatology, Second Xiangya Hospital, Central South University, Hunan Key Laboratory of Medical Epigenomics, Changsha, Hunan, China.
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2
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Kim BS. Critical role of TLR activation in viral replication, persistence, and pathogenicity of Theiler's virus. Front Immunol 2023; 14:1167972. [PMID: 37153539 PMCID: PMC10157096 DOI: 10.3389/fimmu.2023.1167972] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Accepted: 04/11/2023] [Indexed: 05/09/2023] Open
Abstract
Theiler's murine encephalomyelitis virus (TMEV) establishes persistent viral infections in the central nervous system and induces chronic inflammatory demyelinating disease in susceptible mice. TMEV infects dendritic cells, macrophages, B cells, and glial cells. The state of TLR activation in the host plays a critical role in initial viral replication and persistence. The further activation of TLRs enhances viral replication and persistence, leading to the pathogenicity of TMEV-induced demyelinating disease. Various cytokines are produced via TLRs, and MDA-5 signals linked with NF-κB activation following TMEV infection. In turn, these signals further amplify TMEV replication and the persistence of virus-infected cells. The signals further elevate cytokine production, promoting the development of Th17 responses and preventing cellular apoptosis, which enables viral persistence. Excessive levels of cytokines, particularly IL-6 and IL-1β, facilitate the generation of pathogenic Th17 immune responses to viral antigens and autoantigens, leading to TMEV-induced demyelinating disease. These cytokines, together with TLR2 may prematurely generate functionally deficient CD25-FoxP3+ CD4+ T cells, which are subsequently converted to Th17 cells. Furthermore, IL-6 and IL-17 synergistically inhibit the apoptosis of virus-infected cells and the cytolytic function of CD8+ T lymphocytes, prolonging the survival of virus-infected cells. The inhibition of apoptosis leads to the persistent activation of NF-κB and TLRs, which continuously provides an environment of excessive cytokines and consequently promotes autoimmune responses. Persistent or repeated infections of other viruses such as COVID-19 may result in similar continuous TLR activation and cytokine production, leading to autoimmune diseases.
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3
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Sachdeva R, Pal R. A pregnancy hormone-cell death link promotes enhanced lupus-specific immunological effects. Front Immunol 2022; 13:1051779. [PMID: 36505418 PMCID: PMC9730325 DOI: 10.3389/fimmu.2022.1051779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Accepted: 11/04/2022] [Indexed: 11/25/2022] Open
Abstract
Women of reproductive age demonstrate an increased incidence of systemic lupus erythematosus, and reproductive hormones have been implicated in disease progression. Additionally, pregnancy can be associated with disease "flares", the reasons for which remain obscure. While apoptotic bodies are believed to provide an autoantigenic trigger in lupus, whether autoantigenic constituents vary with varying cellular insults, and whether such variations can be immunologically consequential in the context of pregnancy, remains unknown. As assessed by antigenicity and mass spectrometry, apoptotic bodies elicited by different drugs demonstrated the differential presence of lupus-associated autoantigens, and varied in the ability to elicit lupus-associated cytokines from lupus splenocytes and alter the phenotype of lupus B cells. Immunization of tamoxifen-induced apoptotic bodies in lupus-prone mice generated higher humoral autoreactive responses than did immunization with cisplatin-induced apoptotic bodies, and both apoptotic bodies were poorly immunogenic in healthy mice. Incubation of lupus splenocytes (but not healthy splenocytes) with the pregnancy hormone human chorionic gonadotropin (hCG) along with tamoxifen-induced apoptotic bodies (but not cisplatin-induced apoptotic bodies) induced increases in the secretion of lupus-associated cytokines and in the up-modulation of B cell phenotypic markers. In addition, levels of secreted autoantibodies (including of specificities linked to lupus pathogenesis) were enhanced. These events were associated with the heightened phosphorylation of several signaling intermediates. Observations suggest that hCG is a potential disease-promoting co-stimulant in a lupus-milieu; when combined with specific apoptotic bodies, it enhances the intensity of multiple lupus-associated events. These findings deepen mechanistic insight into the hormone's links with autoreactive responses in lupus-prone mice and humans.
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4
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Műzes G, Bohusné Barta B, Szabó O, Horgas V, Sipos F. Cell-Free DNA in the Pathogenesis and Therapy of Non-Infectious Inflammations and Tumors. Biomedicines 2022; 10:biomedicines10112853. [PMID: 36359370 PMCID: PMC9687442 DOI: 10.3390/biomedicines10112853] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2022] [Revised: 10/31/2022] [Accepted: 11/07/2022] [Indexed: 11/09/2022] Open
Abstract
The basic function of the immune system is the protection of the host against infections, along with the preservation of the individual antigenic identity. The process of self-tolerance covers the discrimination between self and foreign antigens, including proteins, nucleic acids, and larger molecules. Consequently, a broken immunological self-tolerance results in the development of autoimmune or autoinflammatory disorders. Immunocompetent cells express pattern-recognition receptors on their cell membrane and cytoplasm. The majority of endogenous DNA is located intracellularly within nuclei and mitochondria. However, extracellular, cell-free DNA (cfDNA) can also be detected in a variety of diseases, such as autoimmune disorders and malignancies, which has sparked interest in using cfDNA as a possible biomarker. In recent years, the widespread use of liquid biopsies and the increasing demand for screening, as well as monitoring disease activity and therapy response, have enabled the revival of cfDNA research. The majority of studies have mainly focused on the function of cfDNA as a biomarker. However, research regarding the immunological consequences of cfDNA, such as its potential immunomodulatory or therapeutic benefits, is still in its infancy. This article discusses the involvement of various DNA-sensing receptors (e.g., absent in melanoma-2; Toll-like receptor 9; cyclic GMP-AMP synthase/activator of interferon genes) in identifying host cfDNA as a potent danger-associated molecular pattern. Furthermore, we aim to summarize the results of the experimental studies that we recently performed and highlight the immunomodulatory capacity of cfDNA, and thus, the potential for possible therapeutic consideration.
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Affiliation(s)
| | | | | | | | - Ferenc Sipos
- Correspondence: ; Tel.: +36-20-478-0752; Fax: +36-1-266-0816
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5
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Zhang H, Chen Y, Jiang Y, Mao Z. DNA double-strand break repair and nucleic acid-related immunity. Acta Biochim Biophys Sin (Shanghai) 2022; 54:828-835. [PMID: 35975605 PMCID: PMC9828507 DOI: 10.3724/abbs.2022061] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
DNA damage repair and innate immunity are two conserved mechanisms that both function in cellular stress responses. Recently, an increasing amount of evidence has uncovered the close relationship between these two ancient biological processes. Here, we review the classical function of factors involved in DNA repair, and especially double-strand break repair, in innate immunity; more importantly, we discuss the novel roles of DNA repair factors in regulating innate immunity and vice versa. In addition, we also review the roles of DNA repair, innate immunity and their crosstalk in human diseases, which suggest that these two pathways may be compelling targets for disease prevention and treatment.
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Affiliation(s)
| | | | | | - Zhiyong Mao
- Correspondence address. Tel: +86-21-65978166; E-mail:
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6
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Lo SM, Hwang YS, Liu CL, Shen CN, Hong WH, Yang WC, Lee MH, Shen CR. Inhibiting TLR7 Expression in the Retinal Pigment Epithelium Suppresses Experimental Autoimmune Uveitis. Front Immunol 2022; 12:736261. [PMID: 35069523 PMCID: PMC8766412 DOI: 10.3389/fimmu.2021.736261] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Accepted: 12/13/2021] [Indexed: 11/16/2022] Open
Abstract
Experimental autoimmune uveitis (EAU), a model of human uveitis, is an organ-specific, T cell-mediated autoimmune disease. Autoreactive T cells can penetrate the blood-retinal barrier, which is a physical defense composed of tight junction-linked retinal pigment epithelial (RPE) cells. RPE cells serve as antigen-presenting cells (APCs) in the eye since they express MHC class I and II and Toll-like receptors (TLRs). Although previous studies have shown that supplementation with TLR agonists exacerbates uveitis, little is known about how TLR signaling in the RPE contributes to the development of uveitis. In this study, we isolated the RPE from EAU mice, which were induced by active immunization (aEAU) or adoptive transfer of antigen-specific T cells (tEAU). The expression of TLRs on RPE was determined, and both aEAU and tEAU mice exhibited induced tlr7 expression. The TLR7 agonist R848 was shown to induce aggressive disease progression, along with significantly elevated levels of the uveopathogenic cytokine IL-17. Furthermore, not only IL-17 but also R848 appeared to enhance the inflammatory response and to impair the barrier function of the RPE, indicating that TLR7 signaling is involved in the pathogenesis of EAU by affecting the behaviors of the RPE and consequently allowing the infiltration of autoreactive T cells intraocularly. Finally, local application of shRNA against TLR7 delivered by recombinant AAV effectively inhibited disease severity and reduced IFN-γ and IL-17. Our findings highlight an immunomodulatory role of RPE TLR7 in EAU development and provide a potential therapeutic strategy for autoimmune uveitis.
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Affiliation(s)
- Sheng-Min Lo
- Department and Graduate Institute of Medical Biotechnology and Laboratory Science, College of Medicine, Chang Gung University, Taoyuan City, Taiwan.,Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan City, Taiwan
| | - Yih-Shiou Hwang
- School of Medicine, College of Medicine, Chang Gung University, Taoyuan City, Taiwan.,Department of Ophthalmology, Lin-Kou Chang Gung Memorial Hospital, Taoyuan City, Taiwan
| | - Chao-Lin Liu
- Department of Chemical Engineering, Ming Chi University of Technology, New Taipei City, Taiwan.,Biochemical Technology R&D Center, Ming Chi University of Technology, New Taipei City, Taiwan
| | - Chia-Ning Shen
- Genomic Research Center, Academia Sinica, Taipei, Taiwan
| | - Wei-Hsin Hong
- Department and Graduate Institute of Medical Biotechnology and Laboratory Science, College of Medicine, Chang Gung University, Taoyuan City, Taiwan
| | - Wei-Cheng Yang
- Department and Graduate Institute of Medical Biotechnology and Laboratory Science, College of Medicine, Chang Gung University, Taoyuan City, Taiwan.,Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan City, Taiwan
| | - Meng-Hua Lee
- Department and Graduate Institute of Medical Biotechnology and Laboratory Science, College of Medicine, Chang Gung University, Taoyuan City, Taiwan.,Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan City, Taiwan
| | - Chia-Rui Shen
- Department and Graduate Institute of Medical Biotechnology and Laboratory Science, College of Medicine, Chang Gung University, Taoyuan City, Taiwan.,Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan City, Taiwan.,Department of Ophthalmology, Lin-Kou Chang Gung Memorial Hospital, Taoyuan City, Taiwan.,Center for Molecular and Clinical Immunology, Chang Gung University, Taoyuan City, Taiwan
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7
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Gallucci S, Meka S, Gamero AM. Abnormalities of the type I interferon signaling pathway in lupus autoimmunity. Cytokine 2021; 146:155633. [PMID: 34340046 DOI: 10.1016/j.cyto.2021.155633] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Accepted: 06/11/2021] [Indexed: 12/16/2022]
Abstract
Type I interferons (IFNs), mostly IFNα and IFNβ, and the type I IFN Signature are important in the pathogenesis of Systemic Lupus Erythematosus (SLE), an autoimmune chronic condition linked to inflammation. Both IFNα and IFNβ trigger a signaling cascade that, through the activation of JAK1, TYK2, STAT1 and STAT2, initiates gene transcription of IFN stimulated genes (ISGs). Noteworthy, other STAT family members and IFN Responsive Factors (IRFs) can also contribute to the activation of the IFN response. Aberrant type I IFN signaling, therefore, can exacerbate SLE by deregulated homeostasis leading to unnecessary persistence of the biological effects of type I IFNs. The etiopathogenesis of SLE is partially known and considered multifactorial. Family-based and genome wide association studies (GWAS) have identified genetic and transcriptional abnormalities in key molecules directly involved in the type I IFN signaling pathway, namely TYK2, STAT1 and STAT4, and IRF5. Gain-of-function mutations that heighten IFNα/β production, which in turn maintains type I IFN signaling, are found in other pathologies like the interferonopathies. However, the distinctive characteristics have yet to be determined. Signaling molecules activated in response to type I IFNs are upregulated in immune cell subsets and affected tissues of SLE patients. Moreover, Type I IFNs induce chromatin remodeling leading to a state permissive to transcription, and SLE patients have increased global and gene-specific epigenetic modifications, such as hypomethylation of DNA and histone acetylation. Epigenome wide association studies (EWAS) highlight important differences between SLE patients and healthy controls in Interferon Stimulated Genes (ISGs). The combination of environmental and genetic factors may stimulate type I IFN signaling transiently and produce long-lasting detrimental effects through epigenetic alterations. Substantial evidence for the pathogenic role of type I IFNs in SLE advocates the clinical use of neutralizing anti-type I IFN receptor antibodies as a therapeutic strategy, with clinical studies already showing promising results. Current and future clinical trials will determine whether drugs targeting molecules of the type I IFN signaling pathway, like non-selective JAK inhibitors or specific TYK2 inhibitors, may benefit people living with lupus.
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Affiliation(s)
- Stefania Gallucci
- Laboratory of Dendritic Cell Biology, Department of Microbiology and Immunology, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, United States.
| | - Sowmya Meka
- Laboratory of Dendritic Cell Biology, Department of Microbiology and Immunology, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, United States
| | - Ana M Gamero
- Department of Medical Genetics and Molecular Biochemistry, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, United States; Fels Cancer Institute for Personalized Medicine, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, United States
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8
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A novel humanized cutaneous lupus erythematosus mouse model mediated by IL-21-induced age-associated B cells. J Autoimmun 2021; 123:102686. [PMID: 34325305 DOI: 10.1016/j.jaut.2021.102686] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 06/15/2021] [Accepted: 06/23/2021] [Indexed: 11/23/2022]
Abstract
Cutaneous lupus erythematosus (CLE) is a relapsing autoimmune disease, but key elements that drive disease initiation and progression remain elusive. To date, the lack of ideal murine model which resemble human cutaneous lupus makes it extremely challenging for moving mechanistic discoveries and novel therapeutics. Here, we prompt a humanized murine model to develop an inducible rapid-onset murine that performs cutaneous rather than systemic lupus, depending on the successful human immune system reconstruction from active lupus patients and UVB irradiation as for essentially pathogenic triggers. In addition, we demonstrate a newly discovered population of B cell with a unique phenotype, that of the age-associated B cell (ABC, T-bet+ CD11b+), exhibits B cell clusters in humanized cutaneous lupus. In the response of IL-21 and TLR7/9 signals, recruitment of autoreactive B cells to the position of inflammation with subsequent localized antibody production of IgG2a, IgG2b, IgG3, has the potential to exacerbate ongoing inflammation and thus driving lupus-like autoimmunity in a B-cell-dominant fashion. Overall, our model provides a relevant system for exploring the pathophysiology of cutaneous lupus, a suitable model for drug development, as well as updating a potential role of IL-21 and TLR7/9 to be targeted by biologics.
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9
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Excessive Innate Immunity Steers Pathogenic Adaptive Immunity in the Development of Theiler's Virus-Induced Demyelinating Disease. Int J Mol Sci 2021; 22:ijms22105254. [PMID: 34067536 PMCID: PMC8156427 DOI: 10.3390/ijms22105254] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 05/06/2021] [Accepted: 05/13/2021] [Indexed: 01/05/2023] Open
Abstract
Several virus-induced models were used to study the underlying mechanisms of multiple sclerosis (MS). The infection of susceptible mice with Theiler’s murine encephalomyelitis virus (TMEV) establishes persistent viral infections and induces chronic inflammatory demyelinating disease. In this review, the innate and adaptive immune responses to TMEV are discussed to better understand the pathogenic mechanisms of viral infections. Professional (dendritic cells (DCs), macrophages, and B cells) and non-professional (microglia, astrocytes, and oligodendrocytes) antigen-presenting cells (APCs) are the major cell populations permissive to viral infection and involved in cytokine production. The levels of viral loads and cytokine production in the APCs correspond to the degrees of susceptibility of the mice to the TMEV-induced demyelinating diseases. TMEV infection leads to the activation of cytokine production via TLRs and MDA-5 coupled with NF-κB activation, which is required for TMEV replication. These activation signals further amplify the cytokine production and viral loads, promote the differentiation of pathogenic Th17 responses, and prevent cellular apoptosis, enabling viral persistence. Among the many chemokines and cytokines induced after viral infection, IFN α/β plays an essential role in the downstream expression of costimulatory molecules in APCs. The excessive levels of cytokine production after viral infection facilitate the pathogenesis of TMEV-induced demyelinating disease. In particular, IL-6 and IL-1β play critical roles in the development of pathogenic Th17 responses to viral antigens and autoantigens. These cytokines, together with TLR2, may preferentially generate deficient FoxP3+CD25- regulatory cells converting to Th17. These cytokines also inhibit the apoptosis of TMEV-infected cells and cytolytic function of CD8+ T lymphocytes (CTLs) and prolong the survival of B cells reactive to viral and self-antigens, which preferentially stimulate Th17 responses.
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10
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Motwani M, McGowan J, Antonovitch J, Gao KM, Jiang Z, Sharma S, Baltus GA, Nickerson KM, Marshak-Rothstein A, Fitzgerald KA. cGAS-STING Pathway Does Not Promote Autoimmunity in Murine Models of SLE. Front Immunol 2021; 12:605930. [PMID: 33854495 PMCID: PMC8040952 DOI: 10.3389/fimmu.2021.605930] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2020] [Accepted: 02/22/2021] [Indexed: 01/04/2023] Open
Abstract
Detection of DNA is an important determinant of host-defense but also a driver of autoinflammatory and autoimmune diseases. Failure to degrade self-DNA in DNAseII or III(TREX1)-deficient mice results in activation of the cGAS-STING pathway. Deficiency of cGAS or STING in these models ameliorates disease manifestations. However, the contribution of the cGAS-STING pathway, relative to endosomal TLRs, in systemic lupus erythematosus (SLE) is controversial. In fact, STING deficiency failed to rescue, and actually exacerbated, disease manifestations in Fas-deficient SLE-prone mice. We have now extended these observations to a chronic model of SLE induced by the i.p. injection of TMPD (pristane). We found that both cGAS- and STING-deficiency not only failed to rescue mice from TMPD-induced SLE, but resulted in increased autoantibody production and higher proteinuria levels compared to cGAS STING sufficient mice. Further, we generated cGASKOFaslpr mice on a pure MRL/Faslpr background using Crispr/Cas9 and found slightly exacerbated, and not attenuated, disease. We hypothesized that the cGAS-STING pathway constrains TLR activation, and thereby limits autoimmune manifestations in these two models. Consistent with this premise, mice lacking cGAS and Unc93B1 or STING and Unc93B1 developed minimal systemic autoimmunity as compared to cGAS or STING single knock out animals. Nevertheless, TMPD-driven lupus in B6 mice was abrogated upon AAV-delivery of DNAse I, implicating a DNA trigger. Overall, this study demonstrated that the cGAS-STING pathway does not promote systemic autoimmunity in murine models of SLE. These data have important implications for cGAS-STING-directed therapies being developed for the treatment of systemic autoimmunity.
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Affiliation(s)
- Mona Motwani
- Program in Innate Immunity, Division of Infectious Diseases and Immunology, Department of Medicine, University of Massachusetts Medical School, Worcester, MA, United States
| | - Jason McGowan
- Program in Innate Immunity, Division of Infectious Diseases and Immunology, Department of Medicine, University of Massachusetts Medical School, Worcester, MA, United States
| | - Jennifer Antonovitch
- Program in Innate Immunity, Division of Infectious Diseases and Immunology, Department of Medicine, University of Massachusetts Medical School, Worcester, MA, United States
| | - Kevin MingJie Gao
- Program in Innate Immunity, Division of Infectious Diseases and Immunology, Department of Medicine, University of Massachusetts Medical School, Worcester, MA, United States
| | - Zhaozhao Jiang
- Program in Innate Immunity, Division of Infectious Diseases and Immunology, Department of Medicine, University of Massachusetts Medical School, Worcester, MA, United States
| | - Shruti Sharma
- Program in Innate Immunity, Division of Infectious Diseases and Immunology, Department of Medicine, University of Massachusetts Medical School, Worcester, MA, United States
| | | | - Kevin M Nickerson
- Department of Immunology, University of Pittsburgh, Pittsburgh, PA, United States
| | - Ann Marshak-Rothstein
- Division of Rheumatology, Department of Medicine, University of Massachusetts Medical School, Worcester, MA, United States
| | - Katherine A Fitzgerald
- Program in Innate Immunity, Division of Infectious Diseases and Immunology, Department of Medicine, University of Massachusetts Medical School, Worcester, MA, United States
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11
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McWhirter SM, Jefferies CA. Nucleic Acid Sensors as Therapeutic Targets for Human Disease. Immunity 2021; 53:78-97. [PMID: 32668230 DOI: 10.1016/j.immuni.2020.04.004] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Revised: 03/26/2020] [Accepted: 04/14/2020] [Indexed: 12/11/2022]
Abstract
Innate immune sensors that detect nucleic acids are attractive targets for therapeutic intervention because of their diverse roles in many disease processes. In detecting RNA and DNA from either self or non-self, nucleic acid sensors mediate the pathogenesis of many autoimmune and inflammatory conditions. Despite promising pre-clinical data and investigational use in the clinic, relatively few drugs targeting nucleic acid sensors are approved for therapeutic use. Nevertheless, there is growing appreciation for the untapped potential of nucleic acid sensors as therapeutic targets, driven by the need for better therapies for cancer, infectious diseases, and autoimmune disorders. This review highlights the diverse mechanisms by which nucleic acid sensors are activated and exert their biological effects in the context of various disease settings. We discuss current therapeutic strategies utilizing agonists and antagonists targeting nucleic acid sensors to treat infectious disease, cancer, and autoimmune and inflammatory disorders.
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Affiliation(s)
| | - Caroline A Jefferies
- Department of Biomedical Sciences and Department of Medicine, Division of Rheumatology, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
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12
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Sha S, Pearson JA, Peng J, Hu Y, Huang J, Xing Y, Zhang L, Zhu Y, Zhao H, Wong FS, Chen L, Wen L. TLR9 Deficiency in B Cells Promotes Immune Tolerance via Interleukin-10 in a Type 1 Diabetes Mouse Model. Diabetes 2021; 70:504-515. [PMID: 33154070 PMCID: PMC7881860 DOI: 10.2337/db20-0373] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Accepted: 11/01/2020] [Indexed: 12/22/2022]
Abstract
Toll-like receptor 9 (TLR9) is highly expressed in B cells, and B cells are important in the pathogenesis of type 1 diabetes (T1D) development. However, the intrinsic effect of TLR9 in B cells on β-cell autoimmunity is not known. To fill this knowledge gap, we generated NOD mice with a B-cell-specific deficiency of TLR9 (TLR9fl/fl/CD19-Cre+ NOD). The B-cell-specific deletion of TLR9 resulted in near-complete protection from T1D development. Diabetes protection was accompanied by an increased proportion of interleukin-10 (IL-10)-producing B cells. We also found that TLR9-deficient B cells were hyporesponsive to both innate and adaptive immune stimuli. This suggested that TLR9 in B cells modulates T1D susceptibility in NOD mice by changing the frequency and function of IL-10-producing B cells. Molecular analysis revealed a network of TLR9 with matrix metalloproteinases, tissue inhibitor of metalloproteinase-1, and CD40, all of which are interconnected with IL-10. Our study has highlighted an important connection of an innate immune molecule in B cells to the immunopathogenesis of T1D. Thus, targeting the TLR9 pathway, specifically in B cells, may provide a novel therapeutic strategy for T1D treatment.
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Affiliation(s)
- Sha Sha
- Department of Nephrology, The First Affiliated Hospital of Shandong First Medical University, Jinan, Shandong, China
- Institute of Endocrine and Metabolic Diseases of Shandong University, Jinan, Shandong, China
- Section of Endocrinology, School of Medicine, Yale University, New Haven, CT
| | - James A Pearson
- Section of Endocrinology, School of Medicine, Yale University, New Haven, CT
| | - Jian Peng
- Section of Endocrinology, School of Medicine, Yale University, New Haven, CT
| | - Youjia Hu
- Section of Endocrinology, School of Medicine, Yale University, New Haven, CT
| | - Juan Huang
- Section of Endocrinology, School of Medicine, Yale University, New Haven, CT
| | - Yanpeng Xing
- Section of Endocrinology, School of Medicine, Yale University, New Haven, CT
- Department of Gastrointestinal Surgery, First Hospital of Jilin University, Changchun, Jilin, China
| | - Luyao Zhang
- Section of Endocrinology, School of Medicine, Yale University, New Haven, CT
- Department of Gastrointestinal Surgery, First Hospital of Jilin University, Changchun, Jilin, China
| | - Ying Zhu
- Department of Biostatistics, School of Public Health, Yale University, New Haven, CT
| | - Hongyu Zhao
- Department of Biostatistics, School of Public Health, Yale University, New Haven, CT
| | - F Susan Wong
- Division of Infection and Immunity, School of Medicine, Cardiff University, Cardiff, U.K
| | - Li Chen
- Institute of Endocrine and Metabolic Diseases of Shandong University, Jinan, Shandong, China
| | - Li Wen
- Section of Endocrinology, School of Medicine, Yale University, New Haven, CT
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13
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Structural analysis reveals TLR7 dynamics underlying antagonism. Nat Commun 2020; 11:5204. [PMID: 33060576 PMCID: PMC7562955 DOI: 10.1038/s41467-020-19025-z] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Accepted: 09/25/2020] [Indexed: 12/22/2022] Open
Abstract
Toll-like receptor 7 (TLR7) recognizes both microbial and endogenous RNAs and nucleosides. Aberrant activation of TLR7 has been implicated in several autoimmune diseases including systemic lupus erythematosus (SLE). Here, by modifying potent TLR7 agonists, we develop a series of TLR7-specific antagonists as promising therapeutic agents for SLE. These compounds protect mice against lethal autoimmunity. Combining crystallography and cryo-electron microscopy, we identify the open conformation of the receptor and reveal the structural equilibrium between open and closed conformations that underlies TLR7 antagonism, as well as the detailed mechanism by which TLR7-specific antagonists bind to their binding pocket in TLR7. Our work provides small-molecule TLR7-specific antagonists and suggests the TLR7-targeting strategy for treating autoimmune diseases. A series of Toll-like receptor 7 (TLR7)-specific antagonists and extensive structural analysis reveal the open conformation of the receptor and the structural basis of TLR7 antagonism. One of the compounds shows efficacy in treating mouse model of systemic lupus erythematosus.
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14
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Jackson HM, Foley KE, O'Rourke R, Stearns TM, Fathalla D, Morgan BP, Howell GR. A novel mouse model expressing human forms for complement receptors CR1 and CR2. BMC Genet 2020; 21:101. [PMID: 32907542 PMCID: PMC7487969 DOI: 10.1186/s12863-020-00893-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 07/21/2020] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND The complement cascade is increasingly implicated in development of a variety of diseases with strong immune contributions such as Alzheimer's disease and Systemic Lupus Erythematosus. Mouse models have been used to determine function of central components of the complement cascade such as C1q and C3. However, species differences in their gene structures mean that mice do not adequately replicate human complement regulators, including CR1 and CR2. Genetic variation in CR1 and CR2 have been implicated in modifying disease states but the mechanisms are not known. RESULTS To decipher the roles of human CR1 and CR2 in health and disease, we engineered C57BL/6J (B6) mice to replace endogenous murine Cr2 with human complement receptors, CR1 and CR2 (B6.CR2CR1). CR1 has an array of allotypes in human populations and using traditional recombination methods (Flp-frt and Cre-loxP) two of the most common alleles (referred to here as CR1long and CR1short) can be replicated within this mouse model, along with a CR1 knockout allele (CR1KO). Transcriptional profiling of spleens and brains identified genes and pathways differentially expressed between mice homozygous for either CR1long, CR1short or CR1KO. Gene set enrichment analysis predicts hematopoietic cell number and cell infiltration are modulated by CR1long, but not CR1short or CR1KO. CONCLUSION The B6.CR2CR1 mouse model provides a novel tool for determining the relationship between human-relevant CR1 alleles and disease.
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Affiliation(s)
- Harriet M Jackson
- The Jackson Laboratory, 600 Main Street, Bar Harbor, ME, USA
- Dementia Research Institute Cardiff and Systems Immunity Research Institute, School of Medicine, Cardiff University, Cardiff, Wales, UK
| | - Kate E Foley
- The Jackson Laboratory, 600 Main Street, Bar Harbor, ME, USA
- Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, MA, USA
| | - Rita O'Rourke
- The Jackson Laboratory, 600 Main Street, Bar Harbor, ME, USA
| | | | - Dina Fathalla
- Dementia Research Institute Cardiff and Systems Immunity Research Institute, School of Medicine, Cardiff University, Cardiff, Wales, UK
| | - B Paul Morgan
- Dementia Research Institute Cardiff and Systems Immunity Research Institute, School of Medicine, Cardiff University, Cardiff, Wales, UK
| | - Gareth R Howell
- The Jackson Laboratory, 600 Main Street, Bar Harbor, ME, USA.
- Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, MA, USA.
- Graduate School of Biomedical Sciences and Engineering, University of Maine, Orono, ME, USA.
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15
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Jin YH, Kim CX, Huang J, Kim BS. Infection and Activation of B Cells by Theiler's Murine Encephalomyelitis Virus (TMEV) Leads to Autoantibody Production in an Infectious Model of Multiple Sclerosis. Cells 2020; 9:cells9081787. [PMID: 32727036 PMCID: PMC7465974 DOI: 10.3390/cells9081787] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 07/22/2020] [Accepted: 07/24/2020] [Indexed: 12/23/2022] Open
Abstract
Theiler’s murine encephalomyelitis virus (TMEV) induces immune-mediated inflammatory demyelinating disease in susceptible mice that is similar to human multiple sclerosis (MS). In light of anti-CD20 therapies for MS, the susceptibility of B cells to TMEV infection is particularly important. In our study, direct viral exposure to macrophages and lymphocytes resulted in viral replication and cellular stimulation in the order of DCs, macrophages, B cells, and T cells. Notably, B cells produced viral proteins and expressed elevated levels of CD69, an activation marker. Similarly, the expression of major histocompatibility complex class II and costimulatory molecules in B cells was upregulated. Moreover, TMEV-infected B cells showed elevated levels of antigen-presenting function and antibody production. TMEV infection appeared to polyclonally activate B cells to produce autoantibodies and further T cell stimulation. Thus, the viral infection might potentially affect the outcome of autoimmune diseases, and/or the development of other chronic infections, including the protection and/or pathogenesis of TMEV-induced demyelinating disease.
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Affiliation(s)
- Young-Hee Jin
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA;
- KM Application Center, Korea Institute of Oriental Medicine, Daegu 41062, Korea
- Center for Convergent Research of Emerging Virus Infection, Korea Research Institute of Chemical Technology, Daejeon 34114, Korea
- Correspondence: (Y.-H.J.); (B.S.K.); Tel.: +82-42-610-8850 (Y.-H.J.); +1-312-503-8693 (B.S.K.)
| | - Charles X. Kim
- Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA;
- M Health Fairview Heart Clinic, University of Minnesota Health, Edina, MN 55435, USA
| | - Jocelin Huang
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA;
- M Health Cancer Care, University of Minnesota Health, Edina, MN 55435, USA
| | - Byung S. Kim
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA;
- Correspondence: (Y.-H.J.); (B.S.K.); Tel.: +82-42-610-8850 (Y.-H.J.); +1-312-503-8693 (B.S.K.)
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16
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Nanda SK, Petrova T, Marchesi F, Gierlinski M, Razsolkov M, Lee KL, Wright SW, Rao VR, Cohen P, Arthur JSC. Distinct signals and immune cells drive liver pathology and glomerulonephritis in ABIN1[D485N] mice. Life Sci Alliance 2019; 2:2/6/e201900533. [PMID: 31694920 PMCID: PMC6836709 DOI: 10.26508/lsa.201900533] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Revised: 10/24/2019] [Accepted: 10/24/2019] [Indexed: 01/01/2023] Open
Abstract
This article shows that liver and kidney damage in a lupus-prone mouse line occurs by different mechanisms and that only drugs targeting core components of signaling pathway, such as IRAK4, are able to suppress all facets of the disease. We report that TLR7, IL-6, and the adaptive immune system are essential for autoimmunity and glomerulonephritis but not for liver pathology in mice expressing the ubiquitin-binding–defective ABIN1[D485N] mutant. The blood and organs of ABIN1[D485N] mice have exceptionally high numbers of patrolling monocytes (pMo), which develop independently of IL-6 and the adaptive immune system. They are detectable in the blood months before autoimmunity and organ pathology are seen and may have diagnostic potential. The splenic pMo, inflammatory monocytes (iMo), and neutrophils of ABIN1[D485N] mice expressed high levels of mRNAs encoding proteins released during NETosis, which together with the high numbers of monocyte-derived dendritic cells (MoDCs) may drive the liver pathology in ABIN1[D485N] mice, and contribute to the pathology of other organs. The splenic iMo of ABIN1[D485N] mice displayed high expression of mRNAs encoding proteins controlling cell division and were actively dividing; this may underlie the increased pMo and MoDC numbers, which are derived from iMo. An orally active IRAK4 inhibitor suppressed all facets of the disease phenotype and prevented the increase in pMo numbers.
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Affiliation(s)
- Sambit Kumar Nanda
- Medical Research Council Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee, UK
| | - Tsvetana Petrova
- Medical Research Council Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee, UK.,Division of Cell Signaling and Immunology, School of Life Sciences, University of Dundee, Dundee, UK
| | - Francesco Marchesi
- School of Veterinary Medicine, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Marek Gierlinski
- Division of Computational Biology, School of Life Sciences, University of Dundee, Dundee, Scotland, UK
| | - Momchil Razsolkov
- Division of Cell Signaling and Immunology, School of Life Sciences, University of Dundee, Dundee, UK
| | - Katherine L Lee
- Worldwide Medicinal Chemistry, Pfizer Inc, New York, NY, USA
| | | | - Vikram R Rao
- Inflammation and Immunology Research Unit, Pfizer Research, Cambridge, MA, USA
| | - Philip Cohen
- Medical Research Council Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee, UK
| | - J Simon C Arthur
- Division of Cell Signaling and Immunology, School of Life Sciences, University of Dundee, Dundee, UK
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17
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Identification of U11snRNA as an endogenous agonist of TLR7-mediated immune pathogenesis. Proc Natl Acad Sci U S A 2019; 116:23653-23661. [PMID: 31694883 PMCID: PMC6876158 DOI: 10.1073/pnas.1915326116] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The activation of innate immune receptors by pathogen-associated molecular patterns (PAMPs) is central to host defense against infections. On the other hand, these receptors are also activated by immunogenic damage-associated molecular patterns (DAMPs), typically released from dying cells, and the activation can evoke chronic inflammatory or autoimmune disorders. One of the best known receptors involved in the immune pathogenesis is Toll-like receptor 7 (TLR7), which recognizes RNA with single-stranded structure. However, the causative DAMP RNA(s) in the pathogenesis has yet to be identified. Here, we first developed a chemical compound, termed KN69, that suppresses autoimmunity in several established mouse models. A subsequent search for KN69-binding partners led to the identification of U11 small nuclear RNA (U11snRNA) as a candidate DAMP RNA involved in TLR7-induced autoimmunity. We then showed that U11snRNA robustly activated the TLR7 pathway in vitro and induced arthritis disease in vivo. We also found a correlation between high serum level of U11snRNA and autoimmune diseases in human subjects and established mouse models. Finally, by revealing the structural basis for U11snRNA's ability to activate TLR7, we developed more potent TLR7 agonists and TLR7 antagonists, which may offer new therapeutic approaches for autoimmunity or other immune-driven diseases. Thus, our study has revealed a hitherto unknown immune function of U11snRNA, providing insight into TLR7-mediated autoimmunity and its potential for further therapeutic applications.
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18
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Padilla-Salinas R, Anderson R, Sakaniwa K, Zhang S, Nordeen P, Lu C, Shimizu T, Yin H. Discovery of Novel Small Molecule Dual Inhibitors Targeting Toll-Like Receptors 7 and 8. J Med Chem 2019; 62:10221-10244. [DOI: 10.1021/acs.jmedchem.9b01201] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Rosaura Padilla-Salinas
- Department of Chemistry and Biochemistry and BioFrontiers Institute, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Rachel Anderson
- Department of Chemistry and Biochemistry and BioFrontiers Institute, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Kentaro Sakaniwa
- Graduate School of Pharmaceuticals Sciences, The University of Tokyo, Tokyo 113-0033, Japan
| | - Shuting Zhang
- School of Pharmaceutical Sciences, Tsinghua University-Peking University Joint Center of Life Science, Tsinghua University, Beijing 100082, China
| | - Patrick Nordeen
- Department of Chemistry and Biochemistry and BioFrontiers Institute, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Chuanjun Lu
- Department of Chemistry and Biochemistry and BioFrontiers Institute, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Toshiyuki Shimizu
- Graduate School of Pharmaceuticals Sciences, The University of Tokyo, Tokyo 113-0033, Japan
| | - Hang Yin
- Department of Chemistry and Biochemistry and BioFrontiers Institute, University of Colorado Boulder, Boulder, Colorado 80309, United States
- School of Pharmaceutical Sciences, Tsinghua University-Peking University Joint Center of Life Science, Tsinghua University, Beijing 100082, China
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19
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Kang H, Wu W, Yu M, Shapiro J, McElwee KJ. Increased expression of TLR7 and TLR9 in alopecia areata. Exp Dermatol 2019; 29:254-258. [DOI: 10.1111/exd.14043] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Revised: 08/20/2019] [Accepted: 09/21/2019] [Indexed: 12/20/2022]
Affiliation(s)
- Hoon Kang
- Department of Dermatology College of Medicine The Catholic University of Korea Seoul Korea
| | - Wen‐Yu Wu
- Department of Dermatology Huashan Hospital Fudan University Shanghai China
| | - Mei Yu
- Department of Dermatology and Skin Science University of British Columbia Vancouver BC Canada
| | - Jerry Shapiro
- The Ronald O. Perelman Department of Dermatology New York University School of Medicine New York NY USA
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20
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Greiling TM, Dehner C, Chen X, Hughes K, Iñiguez AJ, Boccitto M, Ruiz DZ, Renfroe SC, Vieira SM, Ruff WE, Sim S, Kriegel C, Glanternik J, Chen X, Girardi M, Degnan P, Costenbader KH, Goodman AL, Wolin SL, Kriegel MA. Commensal orthologs of the human autoantigen Ro60 as triggers of autoimmunity in lupus. Sci Transl Med 2019; 10:10/434/eaan2306. [PMID: 29593104 DOI: 10.1126/scitranslmed.aan2306] [Citation(s) in RCA: 189] [Impact Index Per Article: 37.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Revised: 11/17/2017] [Accepted: 01/19/2018] [Indexed: 12/14/2022]
Abstract
The earliest autoantibodies in lupus are directed against the RNA binding autoantigen Ro60, but the triggers against this evolutionarily conserved antigen remain elusive. We identified Ro60 orthologs in a subset of human skin, oral, and gut commensal bacterial species and confirmed the presence of these orthologs in patients with lupus and healthy controls. Thus, we hypothesized that commensal Ro60 orthologs may trigger autoimmunity via cross-reactivity in genetically susceptible individuals. Sera from human anti-Ro60-positive lupus patients immunoprecipitated commensal Ro60 ribonucleoproteins. Human Ro60 autoantigen-specific CD4 memory T cell clones from lupus patients were activated by skin and mucosal Ro60-containing bacteria, supporting T cell cross-reactivity in humans. Further, germ-free mice spontaneously initiated anti-human Ro60 T and B cell responses and developed glomerular immune complex deposits after monocolonization with a Ro60 ortholog-containing gut commensal, linking anti-Ro60 commensal responses in vivo with the production of human Ro60 autoantibodies and signs of autoimmunity. Together, these data support that colonization with autoantigen ortholog-producing commensal species may initiate and sustain chronic autoimmunity in genetically predisposed individuals. The concept of commensal ortholog cross-reactivity may apply more broadly to autoimmune diseases and lead to novel treatment approaches aimed at defined commensal species.
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Affiliation(s)
- Teri M Greiling
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT 06510, USA.,Department of Dermatology, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Carina Dehner
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Xinguo Chen
- Department of Medicine, Integrated Cardio Metabolic Centre (ICMC), Heart and Vascular Theme, Karolinska Institute, Stockholm SE-171 77, Sweden.,Bioscience, Cardiovascular, Renal & Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Kevin Hughes
- Department of Medicine, Integrated Cardio Metabolic Centre (ICMC), Heart and Vascular Theme, Karolinska Institute, Stockholm SE-171 77, Sweden.,Bioscience, Cardiovascular, Renal & Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Alonso J Iñiguez
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Marco Boccitto
- Department of Medicine, Integrated Cardio Metabolic Centre (ICMC), Heart and Vascular Theme, Karolinska Institute, Stockholm SE-171 77, Sweden.,Bioscience, Cardiovascular, Renal & Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Daniel Zegarra Ruiz
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Stephen C Renfroe
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Silvio M Vieira
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT 06510, USA
| | - William E Ruff
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Soyeong Sim
- Department of Medicine, Integrated Cardio Metabolic Centre (ICMC), Heart and Vascular Theme, Karolinska Institute, Stockholm SE-171 77, Sweden.,Bioscience, Cardiovascular, Renal & Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Christina Kriegel
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Julia Glanternik
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Xindi Chen
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Michael Girardi
- Department of Dermatology, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Patrick Degnan
- Department of Microbial Pathogenesis and Yale Microbial Sciences Institute, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Karen H Costenbader
- Division of Rheumatology, Immunology and Allergy, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Andrew L Goodman
- Department of Microbial Pathogenesis and Yale Microbial Sciences Institute, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Sandra L Wolin
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06510, USA. .,Bioscience, Cardiovascular, Renal & Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Martin A Kriegel
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT 06510, USA. .,Section of Rheumatology, Department of Medicine, Yale University School of Medicine, New Haven, CT 06510, USA
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21
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Wang X, Xia Y. Anti-double Stranded DNA Antibodies: Origin, Pathogenicity, and Targeted Therapies. Front Immunol 2019; 10:1667. [PMID: 31379858 PMCID: PMC6650533 DOI: 10.3389/fimmu.2019.01667] [Citation(s) in RCA: 86] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Accepted: 07/03/2019] [Indexed: 01/02/2023] Open
Abstract
Systemic lupus erythematosus (SLE) is characterized by high-titer serological autoantibodies, including antibodies that bind to double-stranded DNA (dsDNA). The origin, specificity, and pathogenicity of anti-dsDNA antibodies have been studied from a wider perspective. These autoantibodies have been suggested to contribute to multiple end-organ injuries, especially to lupus nephritis, in patients with SLE. Moreover, serum levels of anti-DNA antibodies fluctuate with disease activity in patients with SLE. By directly binding to self-antigens or indirectly forming immune complexes, anti-dsDNA antibodies can accumulate in the glomerular and tubular basement membrane. These autoantibodies can also trigger the complement cascade, penetrate into living cells, modulate gene expression, and even induce profibrotic phenotypes of renal cells. In addition, the expression of suppressor of cytokine signaling 1 is reduced by anti-DNA antibodies simultaneously with upregulation of profibrotic genes. Anti-dsDNA antibodies may even participate in the pathogenesis of SLE by catalyzing hydrolysis of certain DNA molecules or peptides in cells. Recently, anti-dsDNA antibodies have been explored in greater depth as a therapeutic target in the management of SLE. A substantial amount of data indicates that blockade of pathogenic anti-dsDNA antibodies can prevent or even reverse organ damage in murine models of SLE. This review focuses on the recent research advances regarding the origin, specificity, classification, and pathogenicity of anti-dsDNA antibodies and highlights the emerging therapies associated with them.
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Affiliation(s)
- Xiaoyu Wang
- Department of Dermatology, The Second Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an, China
| | - Yumin Xia
- Department of Dermatology, The Second Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an, China
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22
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Abstract
Mitochondria are the source of damage-associated molecular patterns (DAMPs), which are molecules that play a key modulatory role in immune cells. These molecules include proteins and peptides, such as N-formyl peptides and TFAM, as well as lipids, and metabolites such as cardiolipin, succinate and ATP, and also mitochondrial DNA (mtDNA). Recent data indicate that somatic cells sense mitochondrial DAMPs and trigger protective mechanisms in response to these signals. In this review we focus on the well-described effects of mitochondrial DAMPs on immune cells and also how these molecules induce immunogenic responses in non-immune cells. Special attention will be paid to the response to mtDNA.
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Affiliation(s)
- Aida Rodríguez-Nuevo
- Institute for Research in Biomedicine (IRB Barcelona). The Barcelona Institute of Science and Technology, Barcelona, Spain.,Departament de Bioquímica i Biomedicina Molecular, Facultat de Biologia, 08028 Barcelona, Spain.,CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III
| | - Antonio Zorzano
- Institute for Research in Biomedicine (IRB Barcelona). The Barcelona Institute of Science and Technology, Barcelona, Spain.,Departament de Bioquímica i Biomedicina Molecular, Facultat de Biologia, 08028 Barcelona, Spain.,CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III
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Zhang M, Yao C, Cai J, Liu S, Liu XN, Chen Y, Wang S, Ji P, Pan M, Kang Z, Wang Y. LRRK2 is involved in the pathogenesis of system lupus erythematosus through promoting pathogenic antibody production. J Transl Med 2019; 17:37. [PMID: 30670047 PMCID: PMC6343316 DOI: 10.1186/s12967-019-1786-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Accepted: 01/11/2019] [Indexed: 02/07/2023] Open
Abstract
Background Systemic lupus erythematosus (SLE) is a prototypic autoimmune disease characterized by the presence of pathogenic autoantibodies associated with polyclonal B cell hyperreactivity. Previous study reported that autophagy-related gene Leucine-rich repeat kinase 2 (LRRK2) was likely a susceptible gene for SLE. However, the pathogenic function of LRRK2 in SLE is undefined. Methods Using quantitative PCR, we compared the expression levels of LRRK2 in B cells between SLE patients and healthy controls. The expression levels of LRRK2 in in vitro induced CD19hi B cells and naïve B cells were compared as well based on RNA-seq assay. A pristane-induced lupus-like mouse model was used to explore the effects of LRRK2 on the development of SLE. IgG level, B cell subsets in the spleens and bone marrows and pathological features in the kidneys were compared between wildtype (WT) and Lrrk2−/− littermates. Results It was obvious that LRRK2 expression was dramatically up-regulated in primary B cells from SLE patients compared to those from healthy controls, as well as in activated CD19hi B cells. More significantly, LRRK2 expression in B cells was positively correlated with system lupus erythematosus disease activity index (SLEDAI), an indicator for disease severity, and serum IgG levels in SLE patients. Negative correlations were observed between LRRK2 expression and serum C3 or C4 levels, two clinical features associated with SLE-related nephritis. LRRK2 deficiency reduced the death rate of pristane treated mice. Decreased levels of total IgG and autoantibody were detected in the serum with less deposition of immune complexes and attenuated pathological symptoms in the kidneys of Lrrk2−/− mice. Consistent with the reduction in IgG production, the percentages of germinal center B cells and plasma cells decreased significantly as well with LRRK2 deficiency. Conclusions Our study demonstrates that LRRK2 expression is upregulated in B cells from SLE patients with strong correlations to disease severity. LRRK2 deficiency largely attenuates the pathogenic progress of lupus-like features in pristane-induced mice. This is probably achieved through affecting B cell terminal differentiation and subsequent immunoglobulin production. Electronic supplementary material The online version of this article (10.1186/s12967-019-1786-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Meiyu Zhang
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Chengcheng Yao
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Jun Cai
- Department of Pathology, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Shuai Liu
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Xia-Nan Liu
- Department of Clinical Laboratory, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China
| | - Yingying Chen
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Shujun Wang
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Ping Ji
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Meng Pan
- Department of Dermatology, Rui Jin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Zizhen Kang
- Department of Inflammation and Immunity, Cleveland Clinic, Cleveland, OH, 44195, USA. .,Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, OH, 44106, USA.
| | - Ying Wang
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China.
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24
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Toubi E, Vadasz Z. Innate immune-responses and their role in driving autoimmunity. Autoimmun Rev 2019; 18:306-311. [PMID: 30639645 DOI: 10.1016/j.autrev.2018.10.005] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Accepted: 10/31/2018] [Indexed: 01/11/2023]
Abstract
Autoimmunity and autoimmune diseases were always considered to be driven mainly by adaptive immune responses, namely by auto-reactive B and T cell over-activity. The continuous stimulation of dendritic cells by autoantigens increases B cell activity, driving auto-reactive B cells to increase the production of autoantibodies and of pro-inflammatory cytokines. On the other hand, a subset of dendritic cells is established being of tolerogenic properties thus becoming important in maintaining self-tolerance. However, early innate immune responses are continuously appreciated to be highly important in the development of immune-mediated inflammation in general and autoimmunity in particular. The innate immune system is a complex network of structured cells/proteins such as antigen presenting cells (macrophages and dendritic cells), the complement cascade, and many receptors/cytokines/proteins. Of these, one may mention the high expression of toll-like receptors 7 and 9 in antigen presenting cells, and B cells of systemic lupus erythematosus patients contributing to the expansion of auto-reactive B cells. C-reactive protein (CRP) and C1q are crucially important for efficient uptake of apoptotic cells. However, CRP is appreciated to have a role in maintaining anti-inflammatory responses and in altering autoimmunity. Natural killer cells (NK) are responsible for cytotoxicity responses but some of them (mainly CD56high), are important in maintaining peripheral self-tolerance, thus considered to be immune-regulatory cells. In this review we will cover most of the new data on innate immune system and discuss its importance in the development of autoimmunity. New treatments were developed following our better understanding of these pathways, the targeting of which, opened new therapeutic avenues in treating autoimmune diseases.
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Affiliation(s)
- Elias Toubi
- Division of Allergy and Clinical Immunology, Bnai-Zion Medical Center, Faculty of Medicine, Technion, Haifa, Israel
| | - Zahava Vadasz
- Division of Allergy and Clinical Immunology, Bnai-Zion Medical Center, Faculty of Medicine, Technion, Haifa, Israel.
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Association between Type I interferon and depletion and dysfunction of endothelial progenitor cells in C57BL/6 mice deficient in both apolipoprotein E and Fas ligand. Curr Res Transl Med 2018; 66:71-82. [DOI: 10.1016/j.retram.2018.02.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Revised: 10/31/2017] [Accepted: 02/07/2018] [Indexed: 11/22/2022]
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Conventional DCs from Male and Female Lupus-Prone B6.NZM Sle1/Sle2/Sle3 Mice Express an IFN Signature and Have a Higher Immunometabolism That Are Enhanced by Estrogen. J Immunol Res 2018; 2018:1601079. [PMID: 29850618 PMCID: PMC5925037 DOI: 10.1155/2018/1601079] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Revised: 01/24/2018] [Accepted: 02/07/2018] [Indexed: 12/16/2022] Open
Abstract
Type I interferons (IFN) are pathogenic in systemic lupus erythematosus (SLE) and were proposed to control the immunometabolism of dendritic cells (DCs). We previously reported that DCs from female lupus-prone mice constitutively overexpress IFN-responsive genes resembling the IFN signature found in SLE patients. As SLE has higher incidence in women than men, more so in women of reproductive age, estrogens are suggested to affect lupus pathogenesis. We investigated the effects of sex and estrogens on the IFN signature in conventional GM-CSF-bone marrow-derived DCs (cDCs), from male and female Triple Congenic B6.NZM.Sle1/Sle2/Sle3 (TCSle) lupus-prone mice or from wild-type C57BL/6 mice, generated with titrations of 17-beta-estradiol (E2). We found that cDCs from prediseased TCSle male mice express the IFN signature as female TCSle cDCs do. Estrogens are necessary but not sufficient to express this IFN signature, but high doses of E2 can compensate for other steroidal components. E2 stimulation, regardless of sex, modulates type I IFN-dependent and type I IFN-independent activation of cDCs in response to TLR stimulation. Finally, we found that TCSle cDCs from both sexes have elevated markers of immunometabolism and estrogens enhance the metabolic pathways in cDCs, suggesting a mechanistic link between estrogens, immunometabolism, and the IFN signature in lupus.
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Abstract
The pathogenesis of systemic autoimmune diseases such as systemic lupus erythematosus (SLE) is based on the loss of self-tolerance against ubiquitous autoantigens involving all mechanisms of adaptive immunity. However, data accumulating over the last decade imply an important role also for numerous elements of innate immunity, namely the Toll-like receptors in the pathogenesis of SLE. Here we discuss their role in the most common organ complication of SLE, i.e. lupus nephritis. We summarize experimental and clinical data on the expression and functional contribution of the Toll-like receptors in immune complex glomerulonephritis, and intrarenal inflammation. Based on these discoveries Toll-like receptors are evolving as therapeutic targets for the treatment of SLE and lupus nephritis.
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Cavalcante P, Barzago C, Baggi F, Antozzi C, Maggi L, Mantegazza R, Bernasconi P. Toll-like receptors 7 and 9 in myasthenia gravis thymus: amplifiers of autoimmunity? Ann N Y Acad Sci 2018; 1413:11-24. [PMID: 29363775 DOI: 10.1111/nyas.13534] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Revised: 09/25/2017] [Accepted: 09/26/2017] [Indexed: 12/12/2022]
Abstract
Pathogen infections and dysregulated Toll-like receptor (TLR)-mediated innate immune responses are suspected to play key roles in autoimmunity. Among TLRs, TLR7 and TLR9 have been implicated in several autoimmune conditions, mainly because of their ability to promote abnormal B cell activation and survival. Recently, we provided evidence of Epstein-Barr virus (EBV) persistence and reactivation in the thymus of myasthenia gravis (MG) patients, suggesting an involvement of EBV in the intrathymic pathogenesis of the disease. Considerable data highlight the existence of pathogenic crosstalk among EBV, TLR7, and TLR9: EBV elicits TLR7/9 signaling, which in turn can enhance B cell dysfunction and autoimmunity. In this article, after a brief summary of data demonstrating TLR activation in MG thymus, we provide an overview on the contribution of TLR7 and TLR9 to autoimmune diseases and discuss our recent findings indicating a pivotal role for these two receptors, along with EBV, in driving, perpetuating, and/or amplifying intrathymic B cell dysregulation and autoimmune responses in MG. Development of therapeutic approaches targeting TLR7 and TLR9 signaling could be a novel strategy for treating the chronic inflammatory autoimmune process in myasthenia gravis.
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Affiliation(s)
- Paola Cavalcante
- Neurology IV, Neuroimmunology and Neuromuscular Diseases Unit, Fondazione Istituto Neurologico "Carlo Besta", Milan, Italy
| | - Claudia Barzago
- Neurology IV, Neuroimmunology and Neuromuscular Diseases Unit, Fondazione Istituto Neurologico "Carlo Besta", Milan, Italy
| | - Fulvio Baggi
- Neurology IV, Neuroimmunology and Neuromuscular Diseases Unit, Fondazione Istituto Neurologico "Carlo Besta", Milan, Italy
| | - Carlo Antozzi
- Neurology IV, Neuroimmunology and Neuromuscular Diseases Unit, Fondazione Istituto Neurologico "Carlo Besta", Milan, Italy
| | - Lorenzo Maggi
- Neurology IV, Neuroimmunology and Neuromuscular Diseases Unit, Fondazione Istituto Neurologico "Carlo Besta", Milan, Italy
| | - Renato Mantegazza
- Neurology IV, Neuroimmunology and Neuromuscular Diseases Unit, Fondazione Istituto Neurologico "Carlo Besta", Milan, Italy
| | - Pia Bernasconi
- Neurology IV, Neuroimmunology and Neuromuscular Diseases Unit, Fondazione Istituto Neurologico "Carlo Besta", Milan, Italy
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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.
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Zhang Z, Ohto U, Shimizu T. Toward a structural understanding of nucleic acid-sensing Toll-like receptors in the innate immune system. FEBS Lett 2017; 591:3167-3181. [PMID: 28686285 DOI: 10.1002/1873-3468.12749] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Revised: 06/27/2017] [Accepted: 07/04/2017] [Indexed: 11/12/2022]
Abstract
The history of mankind has been plagued by the tug of war with viral infections. Toll-like receptors (TLRs) and other receptors of the innate immune system constitute an early defense system against invading viruses by recognizing the viral genetic material, the nucleic acids (NAs). Agonistic ligands of NA-sensing TLRs play an emerging role in the treatment of viral diseases, demonstrating a crucial role of these receptors. Recently, crystal structures have afforded new insights into TLR recognition of NAs. An aberrant activation by self-NAs, which leads to the inflammation and autoimmunity, is avoided by strict regulation of NA-TLR interaction at multiple check-points. This Review summarizes the novel structural understanding of NA-sensing by TLRs and regulatory mechanisms of these receptors.
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Affiliation(s)
- Zhikuan Zhang
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Japan
| | - Umeharu Ohto
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Japan
| | - Toshiyuki Shimizu
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Japan
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Jain S, Bose A, Bastia B, Sharma H, Sachdeva R, Jain AK, Pal R. Oxidized Hemoglobin Is Antigenic and Immunogenic in Lupus. Front Immunol 2017; 8:732. [PMID: 28694810 PMCID: PMC5483465 DOI: 10.3389/fimmu.2017.00732] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Accepted: 06/09/2017] [Indexed: 12/31/2022] Open
Abstract
Hemolysis-associated anemia is characteristic of diseases such as atherosclerosis, lupus, malaria, and leishmaniasis; the toxic effects of free hemoglobin (Hb) have been extensively described. This study was based on the premise that release of this sequestered, inflammatory molecule can result in deleterious immunological consequences, particularly in the context of pre-existing lupus. IgG anti-Hb responses were detected in the sera of lupus patients. Lupus-prone mice exhibited heightened plasma Hb levels, and ferric (Fe3+) Hb triggered preferential release of lupus-associated cytokines from splenocytes derived from aging lupus-prone mice. Anti-Hb B cell precursor frequencies were heightened in such mice, which also expressed increased titers of anti-Hb antibodies in serum and in kidney eluates. Fe3+ Hb preferentially increased the functional maturation of bone marrow-derived dendritic cells (BMDCs) from lupus-prone mice, effects abrogated upon the inhibition of Stat3. Hb interacted with lupus-associated autoantigens extruded during apoptosis and coincubation of Hb and apoptotic blebs had additional maturation-inducing effects on lupus BMDCs. Immunization with Hb in lupus-prone mice induced antigen spreading to lupus-associated moieties; Hb-interacting autoantigens were preferentially targeted and increased complement deposition and glomerulosclerosis were observed. Hb therefore demonstrates both antigenicity and immunogenicity and triggers specific immuno-pathological effects in a lupus milieu.
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Affiliation(s)
- Sonia Jain
- Immunoendocrinology Laboratory, National Institute of Immunology, New Delhi, India
| | - Anjali Bose
- Immunoendocrinology Laboratory, National Institute of Immunology, New Delhi, India
| | - Banajit Bastia
- Division of Electron Microscopy, National Institute of Pathology-ICMR, New Delhi, India
| | - Hritika Sharma
- Immunoendocrinology Laboratory, National Institute of Immunology, New Delhi, India
| | - Ruchi Sachdeva
- Immunoendocrinology Laboratory, National Institute of Immunology, New Delhi, India
| | - Arun K Jain
- Division of Electron Microscopy, National Institute of Pathology-ICMR, New Delhi, India
| | - Rahul Pal
- Immunoendocrinology Laboratory, National Institute of Immunology, New Delhi, India
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Gao S, Gong Y, Ji J, Yuan L, Han L, Guo Y, Fan X, Hou Y, Hua C. A new benzenediamine derivative modulates Toll-like receptors-induced myeloid dendritic cells activation and ameliorates lupus-like syndrome in MRLlpr/lpr mice. Eur J Pharmacol 2017; 803:94-102. [PMID: 28342978 DOI: 10.1016/j.ejphar.2017.03.048] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2016] [Revised: 03/21/2017] [Accepted: 03/22/2017] [Indexed: 11/29/2022]
Abstract
Modulators of the over-activation of myeloid dendritic cells (mDCs) by Toll-like receptors (TLRs) have an advantage in the treatment of systemic lupus erythematosus (SLE). This study was designed to evaluate the effects of FC-99, a novel benzenediamine derivative, on TLR-induced activation of mDCs, and to assess the efficacy of FC-99 in a murine model of SLE. In vitro, FC-99 inhibited the phenotypic (CD40 and MHC-II) and functional activation (IL-12 and CXCL10) of mDCs induced by TLR ligands. In vivo, MRLlpr/lpr mice displayed renal diseases associated with increased levels of proteinuria and immunoglobulin, which were ameliorated by FC-99. Enhanced accumulation and activation of mDCs in lymphoid organs was also impaired by FC-99. Additionally, FC-99 inhibited the activation of IκB-α and upregulated the expression of TNFα-induced protein 3 (TNFAIP3) in vitro and in vivo. These results indicate that FC-99 modulates TLR-induced activation of mDCs and ameliorates lupus-like syndrome in MRLlpr/lpr mice. This effect is closely associated with the inhibition of IκB-α and upregulation of TNFAIP3.
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Affiliation(s)
- Sheng Gao
- Laboratory Animal Center, Wenzhou Medical University, Wenzhou 325035, Zhejiang Province, China
| | - Yongsheng Gong
- School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou 325035, Zhejiang Province, China
| | - Jianjian Ji
- The State Key Laboratory of Pharmaceutical Biotechnology, Division of Immunology, Medical School, Nanjing University, Nanjing, Jiangsu Province, China
| | - Linbo Yuan
- School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou 325035, Zhejiang Province, China
| | - Liping Han
- School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou 325035, Zhejiang Province, China
| | - Yimin Guo
- School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou 325035, Zhejiang Province, China
| | - Xiaofang Fan
- School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou 325035, Zhejiang Province, China
| | - Yayi Hou
- The State Key Laboratory of Pharmaceutical Biotechnology, Division of Immunology, Medical School, Nanjing University, Nanjing, Jiangsu Province, China.
| | - Chunyan Hua
- School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou 325035, Zhejiang Province, China.
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Giltiay NV, Shu GL, Shock A, Clark EA. Targeting CD22 with the monoclonal antibody epratuzumab modulates human B-cell maturation and cytokine production in response to Toll-like receptor 7 (TLR7) and B-cell receptor (BCR) signaling. Arthritis Res Ther 2017; 19:91. [PMID: 28506291 PMCID: PMC5433084 DOI: 10.1186/s13075-017-1284-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Accepted: 03/24/2017] [Indexed: 12/03/2022] Open
Abstract
Background Abnormal B-cell activation is implicated in the pathogenesis of autoimmune diseases, including systemic lupus erythematosus (SLE). The B-cell surface molecule CD22, which regulates activation through the B-cell receptor (BCR), is a potential target for inhibiting pathogenic B cells; however, the regulatory functions of CD22 remain poorly understood. In this study, we determined how targeting of CD22 with epratuzumab (Emab), a humanized anti-CD22 IgG1 monoclonal antibody, affects the activation of human B-cell subsets in response to Toll-like receptor 7 (TLR7) and BCR engagement. Methods B-cell subsets were isolated from human tonsils and stimulated with F(ab′)2 anti-human IgM and/or the TLR7 agonist R848 in the presence of Emab or a human IgG1 isotype control. Changes in mRNA levels of genes associated with B-cell activation and differentiation were analyzed by quantitative PCR. Cytokine production was measured by ELISA. Cell proliferation, survival, and differentiation were assessed by flow cytometry. Results Pretreatment of phenotypically naïve CD19+CD10–CD27– cells with Emab led to a significant increase in IL-10 expression, and in some but not all patient samples to a reduction of IL-6 production in response to TLR7 stimulation alone or in combination with anti-IgM. Emab selectively inhibited the expression of PRDM1, the gene encoding B-lymphocyte-induced maturation protein 1 (Blimp-1) in activated CD10–CD27– B cells. CD10–CD27–IgD– cells were highly responsive to stimulation through TLR7 as evidenced by the appearance of blasting CD27hiCD38hi cells. Emab significantly inhibited the activation and differentiation of CD10–CD27–IgD– B cells into plasma cells. Conclusions Emab can both regulate cytokine expression and block Blimp1-dependent B-cell differentiation, although the effects of Emab may depend on the stage of B-cell development or activation. In addition, Emab inhibits the activation of CD27–IgD– tonsillar cells, which correspond to so-called double-negative memory B cells, known to be increased in SLE patients with more active disease. These data may be relevant to the therapeutic effect of Emab in vivo via modulation of the production of pro-inflammatory and anti-inflammatory cytokines by B cells. Because Blimp-1 is required by B cells to mature into antibody-producing cells, inhibition of Blimp1 may reduce autoantibody production. Electronic supplementary material The online version of this article (doi:10.1186/s13075-017-1284-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Natalia V Giltiay
- Division of Rheumatology, Department of Medicine, University of Washington, Seattle, WA, 98109, USA. .,Department of Immunology, University of Washington, Seattle, WA, 98109, USA.
| | - Geraldine L Shu
- Department of Immunology, University of Washington, Seattle, WA, 98109, USA
| | | | - Edward A Clark
- Division of Rheumatology, Department of Medicine, University of Washington, Seattle, WA, 98109, USA.,Department of Immunology, University of Washington, Seattle, WA, 98109, USA
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Gao S, Yuan L, Li C, Han L, Hua C. A novel small molecule compound possesses immunomodulatory properties on bone marrow-derived dendritic cells via TLR7 signaling pathway and alleviates the development of SLE. Int Immunopharmacol 2017; 47:47-52. [PMID: 28363108 DOI: 10.1016/j.intimp.2017.03.023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Revised: 03/20/2017] [Accepted: 03/22/2017] [Indexed: 11/16/2022]
Abstract
Dendritic cells (DCs) play an important role in the development and maintenance of immune tolerance. Activation of TLR7, which is expressed in DCs, is thought to contribute to the complex pathophysiology of systemic lupus erythematosus (SLE). In this study, we analyzed the in vitro and in vivo function of a novel small-molecule compound, FC-99, which was previously reported to have immunomodulatory functions. We found that FC-99 inhibited the expression of CD40 and inflammatory mediators (IL-6, IL-12, and CXCL-10), as well as R848-induced phosphorylation of IκB-α. We also present evidence that FC-99 is remarkably efficacious in the treatment of murine lupus. Interestingly, FC-99 affected the maturation and percentage of DCs in lupus-prone mice. Therefore, FC-99 may serve as a potential drug candidate for treatment of SLE.
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Affiliation(s)
- Sheng Gao
- Laboratory Animal Center, Wenzhou Medical University, Wenzhou 325035, Zhejiang Province, China
| | - Linbo Yuan
- School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou 325035, Zhejiang Province, China
| | - Cunyu Li
- Department of Orthopedics, The Third People's Hospital of Linyi, Linyi 276000, Shandong Province, China
| | - Liping Han
- School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou 325035, Zhejiang Province, China
| | - Chunyan Hua
- School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou 325035, Zhejiang Province, China.
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Mortezagholi S, Babaloo Z, Rahimzadeh P, Namdari H, Ghaedi M, Gharibdoost F, Mirzaei R, Bidad K, Salehi E. Evaluation of TLR9 expression on PBMCs and CpG ODN-TLR9 ligation on IFN-α production in SLE patients. Immunopharmacol Immunotoxicol 2017; 39:11-18. [PMID: 28049380 DOI: 10.1080/08923973.2016.1263859] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
CONTEXT Systemic lupus erythematosus (SLE) is a systemic autoimmune disease characterized by autoreactive antibodies. Recent findings revealed the importance of innate immune responses, especially Toll-like receptors (TLRs) in the pathogenesis of SLE. OBJECTIVE In this study, the level of TLR9 expression on peripheral blood mononuclear cells (PBMCs) was analyzed. The levels of produced IFN-α were also measured in supernatant of PBMCs from SLE patients and healthy controls after stimulation with CpG ODN2216 which is a plasmocytoid dendritic cell (pDC)-specific TLR9 ligand. MATERIALS AND METHODS TLR9 expression was analyzed by real-time polymerase chain reaction (PCR) and flow cytometry in 35 SLE patients and 38 healthy controls and IFN-α concentration was measured in supernatants using enzyme-linked immunosorbent assay (ELISA). RESULTS The results showed that the TLR9 expression in the mRNA and the protein level was significantly higher in PBMCs from SLE patients. However, IFN-α concentration in patients and controls significantly increased in response to CpG stimulation but this increase was significantly higher in healthy controls compared with SLE patients. Our results do not show any association between taking hydroxychloroquine and reduction in IFN-α production in SLE patients. DISCUSSION AND CONCLUSIONS Regarding the findings of the study, there is the possibility that TLR9 has played a role in SLE pathogenesis, and consequently it implies that TLRs can be considered to be the therapeutic targets for systemic autoimmunity. We may conclude that PBMCs in patients are functionally impaired in response to TLR ligation via innate response stimulating pathogen-associated molecular patterns (PAMPs).
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Affiliation(s)
- Sahar Mortezagholi
- a Department of Immunology, School of Medicine , Tabriz University of Medical Sciences , Tabriz , Iran
| | - Zohreh Babaloo
- a Department of Immunology, School of Medicine , Tabriz University of Medical Sciences , Tabriz , Iran
| | - Parisa Rahimzadeh
- b Department of Immunology, School of Public Health , Tehran University of Medical Sciences , Tehran , Iran
| | - Haideh Namdari
- c Department of Immunology, School of Medicine , Shiraz University of Medical Sciences , Shiraz , Iran
| | - Mojgan Ghaedi
- b Department of Immunology, School of Public Health , Tehran University of Medical Sciences , Tehran , Iran
| | - Farhad Gharibdoost
- d Department of Rheumatology, Rheumatology Research Center , Tehran University of Medical Sciences , Tehran , Iran
| | - Reza Mirzaei
- e Department of Immunology, School of Medicine , Tehran University of Medical Sciences , Tehran , Iran
| | | | - Eisa Salehi
- e Department of Immunology, School of Medicine , Tehran University of Medical Sciences , Tehran , Iran
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Peng S, Li C, Wang X, Liu X, Han C, Jin T, Liu S, Zhang X, Zhang H, He X, Xie X, Yu X, Wang C, Shan L, Fan C, Shan Z, Teng W. Increased Toll-Like Receptors Activity and TLR Ligands in Patients with Autoimmune Thyroid Diseases. Front Immunol 2016; 7:578. [PMID: 28018345 PMCID: PMC5145898 DOI: 10.3389/fimmu.2016.00578] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Accepted: 11/24/2016] [Indexed: 01/01/2023] Open
Abstract
OBJECTIVE Autoimmune thyroid disease (AITD) is an organ-specific disorder due to the interplay between environmental and genetic factors. Toll-like receptors (TLRs) are pattern recognition receptors expressed abundantly on monocytes. There is a paucity of data on TLR expression in AITD. The aim of this study was to examine TLR expression, activation, ligands, and downstream signaling adaptors in peripheral blood mononuclear cells (PBMCs) extracted from untreated AITD patients and healthy controls. METHOD We isolated PBMC of 30 healthy controls, 36 patients with untreated Hashimoto's thyroiditis, and 30 patients with newly onset Graves' disease. TLR mRNA, protein expression, TLR ligands, and TLR adaptor molecules were measured using real-time PCR, Western blot, flow cytometry, and enzyme-linked immunosorbent assay (ELISA). PBMC was simulated with TLR agonists. The effects of TLR agonists on the viability of human PBMC were evaluated using the MTT assay. The supernatants of cell cultures were measured for the pro-inflammatory cytokines, interleukin (IL)-6, tumor necrosis factor alpha (TNF-α), and IL-10 by ELISA. RESULTS TLR2, TLR3, TLR9, and TLR10 mRNA were significantly increased in AITD patients compared with controls. TLR2, TLR3, TLR9, high mobility group box 1 (HMGB1), and RAGE expression on monocytes was higher in patients than control at baseline and TLR agonists' stimulation. The release of TNF-α and IL-6 was significantly increased in PBMCs from AITD patients with TLR agonists, while IL-10 was significantly decreased. Downstream targets of TLR, myeloid differentiation factor 88 (MyD88), and myeloid toll/IL-1 receptor-domain containing adaptor-inducing interferon-β were significantly elevated in AITD patients. Levels of TLR2 ligands, HMGB1, and heat shock protein 60 were significantly elevated in AITD patients compared with those in controls and positively correlated with TgAb and TPOAb, while sRAGE concentration was significantly decreased in AITD patients. CONCLUSION This work is the first to show that TLR2, TLR3, and TLR9 expression and activation are elevated in the PBMCs of patients with AITD and TLRs may participate in the pathogenesis of AITD.
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Affiliation(s)
- Shiqiao Peng
- Department of Endocrinology and Metabolism, Institute of Endocrinology, Liaoning Provincial Key Laboratory of Endocrine Diseases, The First Affiliated Hospital of China Medical University, China Medical University, Shenyang, Liaoning, China
| | - Chenyan Li
- Department of Endocrinology and Metabolism, Institute of Endocrinology, Liaoning Provincial Key Laboratory of Endocrine Diseases, The First Affiliated Hospital of China Medical University, China Medical University, Shenyang, Liaoning, China,Department of Endocrinology and Metabolism, The First Hospital of China Medical University, Shenyang, China
| | - Xinyi Wang
- Department of Endocrinology and Metabolism, Institute of Endocrinology, Liaoning Provincial Key Laboratory of Endocrine Diseases, The First Affiliated Hospital of China Medical University, China Medical University, Shenyang, Liaoning, China,Department of Laboratory Medicine, The First Hospital of China Medical University, Shenyang, China
| | - Xin Liu
- Department of Endocrinology and Metabolism, Institute of Endocrinology, Liaoning Provincial Key Laboratory of Endocrine Diseases, The First Affiliated Hospital of China Medical University, China Medical University, Shenyang, Liaoning, China,Department of Intensive Care Unit, Affiliated Hospital of Qingdao University, Qingdao, China
| | - Cheng Han
- Department of Endocrinology and Metabolism, Institute of Endocrinology, Liaoning Provincial Key Laboratory of Endocrine Diseases, The First Affiliated Hospital of China Medical University, China Medical University, Shenyang, Liaoning, China
| | - Ting Jin
- Department of Endocrinology and Metabolism, Institute of Endocrinology, Liaoning Provincial Key Laboratory of Endocrine Diseases, The First Affiliated Hospital of China Medical University, China Medical University, Shenyang, Liaoning, China,Department of Endocrinology, Sir Run Run Shaw Hospital, Affiliated to School of Medicine, Zhejiang University, Hangzhou, China
| | - Shanshan Liu
- Department of Endocrinology and Metabolism, Institute of Endocrinology, Liaoning Provincial Key Laboratory of Endocrine Diseases, The First Affiliated Hospital of China Medical University, China Medical University, Shenyang, Liaoning, China,Department of Emergency, People’s Liberation Army No.202 Hospital, Shenyang, China
| | - Xiaowen Zhang
- Department of Endocrinology and Metabolism, Institute of Endocrinology, Liaoning Provincial Key Laboratory of Endocrine Diseases, The First Affiliated Hospital of China Medical University, China Medical University, Shenyang, Liaoning, China
| | - Hanyi Zhang
- Department of Endocrinology and Metabolism, Institute of Endocrinology, Liaoning Provincial Key Laboratory of Endocrine Diseases, The First Affiliated Hospital of China Medical University, China Medical University, Shenyang, Liaoning, China
| | - Xue He
- Department of Endocrinology and Metabolism, Institute of Endocrinology, Liaoning Provincial Key Laboratory of Endocrine Diseases, The First Affiliated Hospital of China Medical University, China Medical University, Shenyang, Liaoning, China
| | - Xiaochen Xie
- Department of Endocrinology and Metabolism, Institute of Endocrinology, Liaoning Provincial Key Laboratory of Endocrine Diseases, The First Affiliated Hospital of China Medical University, China Medical University, Shenyang, Liaoning, China
| | - Xiaohui Yu
- Department of Endocrinology and Metabolism, Institute of Endocrinology, Liaoning Provincial Key Laboratory of Endocrine Diseases, The First Affiliated Hospital of China Medical University, China Medical University, Shenyang, Liaoning, China,Department of Endocrinology and Metabolism, The First Hospital of China Medical University, Shenyang, China
| | - Chuyuan Wang
- Department of Endocrinology and Metabolism, Institute of Endocrinology, Liaoning Provincial Key Laboratory of Endocrine Diseases, The First Affiliated Hospital of China Medical University, China Medical University, Shenyang, Liaoning, China,Department of Endocrinology and Metabolism, The First Hospital of China Medical University, Shenyang, China
| | - Ling Shan
- Department of Endocrinology and Metabolism, Institute of Endocrinology, Liaoning Provincial Key Laboratory of Endocrine Diseases, The First Affiliated Hospital of China Medical University, China Medical University, Shenyang, Liaoning, China
| | - Chenling Fan
- Department of Endocrinology and Metabolism, Institute of Endocrinology, Liaoning Provincial Key Laboratory of Endocrine Diseases, The First Affiliated Hospital of China Medical University, China Medical University, Shenyang, Liaoning, China
| | - Zhongyan Shan
- Department of Endocrinology and Metabolism, Institute of Endocrinology, Liaoning Provincial Key Laboratory of Endocrine Diseases, The First Affiliated Hospital of China Medical University, China Medical University, Shenyang, Liaoning, China,Department of Endocrinology and Metabolism, The First Hospital of China Medical University, Shenyang, China
| | - Weiping Teng
- Department of Endocrinology and Metabolism, Institute of Endocrinology, Liaoning Provincial Key Laboratory of Endocrine Diseases, The First Affiliated Hospital of China Medical University, China Medical University, Shenyang, Liaoning, China,Department of Endocrinology and Metabolism, The First Hospital of China Medical University, Shenyang, China
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Zhang Z, Ohto U, Shibata T, Krayukhina E, Taoka M, Yamauchi Y, Tanji H, Isobe T, Uchiyama S, Miyake K, Shimizu T. Structural Analysis Reveals that Toll-like Receptor 7 Is a Dual Receptor for Guanosine and Single-Stranded RNA. Immunity 2016; 45:737-748. [DOI: 10.1016/j.immuni.2016.09.011] [Citation(s) in RCA: 232] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Revised: 06/13/2016] [Accepted: 06/30/2016] [Indexed: 11/26/2022]
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Kassiotis G, Stoye JP. Immune responses to endogenous retroelements: taking the bad with the good. Nat Rev Immunol 2016; 16:207-19. [PMID: 27026073 DOI: 10.1038/nri.2016.27] [Citation(s) in RCA: 165] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The ultimate form of parasitism and evasion of host immunity is for the parasite genome to enter the germ line of the host species. Retroviruses have invaded the host germ line on the grandest scale, and this is evident in the extraordinary abundance of endogenous retroelements in the genome of all vertebrate species that have been studied. Many of these endogenous retroelements have retained viral characteristics; some also the capacity to replicate and, consequently, the potential to trigger host innate and adaptive immune responses. However, although retroelements are mainly recognized for their pathogenic potential, recent evidence suggests that this 'enemy within' may also have beneficial roles in tuning host immune reactivity. In this Review, we discuss how the immune system recognizes and is shaped by endogenous retroelements.
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Affiliation(s)
- George Kassiotis
- Retroviral Immunology, the Francis Crick Institute, Mill Hill Laboratory, London NW7 1AA, UK.,Department of Medicine, Faculty of Medicine, Imperial College London, London W2 1PG, UK
| | - Jonathan P Stoye
- Department of Medicine, Faculty of Medicine, Imperial College London, London W2 1PG, UK.,Retrovirus-Host Interactions, the Francis Crick Institute, Mill Hill Laboratory, London NW7 1AA, UK
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Dendritic Cells in Systemic Lupus Erythematosus: From Pathogenic Players to Therapeutic Tools. Mediators Inflamm 2016; 2016:5045248. [PMID: 27122656 PMCID: PMC4829720 DOI: 10.1155/2016/5045248] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Accepted: 03/13/2016] [Indexed: 12/20/2022] Open
Abstract
System lupus erythematosus (SLE) is a multifactorial systemic autoimmune disease with a wide variety of presenting features. SLE is believed to result from dysregulated immune responses, loss of tolerance of CD4 T cells and B cells to ubiquitous self-antigens, and the subsequent production of anti-nuclear and other autoreactive antibodies. Recent research has associated lupus development with changes in the dendritic cell (DC) compartment, including altered DC subset frequency and localization, overactivation of mDCs and pDCs, and functional defects in DCs. Here we discuss the current knowledge on the role of DC dysfunction in SLE pathogenesis, with the focus on DCs as targets for interventional therapies.
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Increased expression of Toll-like receptors 7 and 9 in myasthenia gravis thymus characterized by active Epstein-Barr virus infection. Immunobiology 2015; 221:516-27. [PMID: 26723518 DOI: 10.1016/j.imbio.2015.12.007] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Revised: 12/10/2015] [Accepted: 12/10/2015] [Indexed: 11/24/2022]
Abstract
Considerable data implicate the thymus as the main site of autosensitization to the acetylcholine receptor in myasthenia gravis (MG), a B-cell-mediated autoimmune disease affecting the neuromuscular junction. We recently demonstrated an active Epstein-Barr virus (EBV) infection in the thymus of MG patients, suggesting that EBV might contribute to the onset or maintenance of the autoimmune response within MG thymus, because of its ability to activate and immortalize autoreactive B cells. EBV has been reported to elicit and modulate Toll-like receptor (TLR) 7- and TLR9-mediated innate immune responses, which are known to favor B-cell dysfunction and autoimmunity. Aim of this study was to investigate whether EBV infection is associated with altered expression of TLR7 and TLR9 in MG thymus. By real-time PCR, we found that TLR7 and TLR9 mRNA levels were significantly higher in EBV-positive MG compared to EBV-negative normal thymuses. By confocal microscopy, high expression levels of TLR7 and TLR9 proteins were observed in B cells and plasma cells of MG thymic germinal centers (GCs) and lymphoid infiltrates, where the two receptors co-localized with EBV antigens. An increased frequency of Ki67-positive proliferating B cells was found in MG thymuses, where we also detected proliferating cells expressing TLR7, TLR9 and EBV antigens, thus supporting the idea that EBV-associated TLR7/9 signaling may promote abnormal B-cell activation and proliferation. Along with B cells and plasma cells, thymic epithelium, plasmacytoid dendritic cells and macrophages exhibited enhanced TLR7 and TLR9 expression in MG thymus; TLR7 was also increased in thymic myeloid dendritic cells and its transcriptional levels positively correlated with those of interferon (IFN)-β. We suggested that TLR7/9 signaling may be involved in antiviral type I IFN production and long-term inflammation in EBV-infected MG thymuses. Our overall findings indicate that EBV-driven TLR7- and TLR9-mediated innate immune responses may participate in the intra-thymic pathogenesis of MG.
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Sánchez B, Hevia A, González S, Margolles A. Interaction of Intestinal Microorganisms with the Human Host in the Framework of Autoimmune Diseases. Front Immunol 2015; 6:594. [PMID: 26635808 PMCID: PMC4653298 DOI: 10.3389/fimmu.2015.00594] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Accepted: 11/05/2015] [Indexed: 01/03/2023] Open
Abstract
Autoimmune diseases, such as systemic lupus erythematosus (SLE), are caused by a complex interaction of environmental-, genetic-, and sex-related factors. Although SLE has traditionally been considered independent from the microbiota, recent work published during the last 5 years suggests a strong connection between SLE and the composition of our gut commensals as one of the main environmental factors linked to this disease. Preliminary data have evidenced that (i) interaction of certain microbial-derived molecules with specific cell receptors and (ii) the influence of certain commensal microorganisms over specific immune cell subsets plays an important role in the pathogenesis of SLE and SLE-like diseases. In addition, epigenetic changes driven by certain microbial groups have been recently proposed as an additional link between gut microbiota and SLE. As immune responses elicited against commensal bacteria are deeply dependent on the composition of the latter, and as microbial populations can be modified by dietary interventions, identifying the precise gut microorganisms responsible for worsening the SLE symptoms is of crucial importance for this and other SLE-related diseases, including antiphospholipid syndrome or lupus nephritis. In this minireview, the current knowledge on the relationships between microbes and SLE and SLE-related diseases is compiled and discussed.
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Affiliation(s)
- Borja Sánchez
- Department of Microbiology and Biochemistry of Dairy Products, Instituto de Productos Lácteos de Asturias, Consejo Superior de Investigaciones Científicas, Villaviciosa, Spain
| | - Arancha Hevia
- Department of Microbiology and Biochemistry of Dairy Products, Instituto de Productos Lácteos de Asturias, Consejo Superior de Investigaciones Científicas, Villaviciosa, Spain
| | - Sonia González
- Department of Functional Biology, University of Oviedo, Oviedo, Spain
| | - Abelardo Margolles
- Department of Microbiology and Biochemistry of Dairy Products, Instituto de Productos Lácteos de Asturias, Consejo Superior de Investigaciones Científicas, Villaviciosa, Spain
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Lee TP, Huang JC, Liu CJ, Chen HJ, Chen YH, Tsai YT, Yang W, Sun KH. Interactions of surface-expressed TLR-4 and endosomal TLR-9 accelerate lupus progression in anti-dsDNA antibody transgenic mice. Exp Biol Med (Maywood) 2015; 239:715-23. [PMID: 24719374 DOI: 10.1177/1535370214525299] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The hallmark of systemic lupus erythematosus (SLE) is the presence of high levels of anti-double-stranded DNA autoantibody (anti-dsDNA) in sera. In addition, pathogen infections coincide frequently with the occurrence of lupus. Our study was designed to investigate the contribution of anti-dsDNA, extracellular and intracellular Toll-like receptors (TLRs), a family of pattern-recognition receptors for sensing invading pathogens, in the pathogenesis of lupus. Although cell surface-expressed TLR4 may promote lupus progression, intracellular nucleic acid-sensing TLR9 plays either stimulatory or protective roles in different murine lupus models. To examine the role of TLR4, TLR9, and anti-dsDNA in SLE, we generated transgenic mice carrying anti-dsDNA antibody transgene and challenged the mice with TLR4- and TLR9-agonists, lipopolysaccharides (LPS), and CpG oligodeoxynucleotide (CpG ODN1826 and 2216), respectively. Splenocytes from these mice were found to secrete higher levels of interleukin-10 (IL-10) and anti-dsDNA when treated with a combination of TLR4 and TLR9 agonists (LPS + CpG). In addition, the transgenic mice were intraperitoneally administered with CpG or combined CpG and LPS to determine whether extracellular TLR4 and intracellular TLR9 activations could affect lupus progression in vivo. It was found that serum levels of anti-dsDNA antibodies and interferon-alpha were higher in CpG + LPS-treated transgenic mice than those in non-transgenic mice. Besides, elevated levels of proteinuria, blood urine nitrogen, and immune complex depositions in kidney were found in treated transgenic mice. Anti-dsDNA and simultaneous activation of surface-expressed TLR4 and endosomal TLR9 are crucial to promote the lupus progression.
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Liu F, Fan H, Ren D, Dong G, Hu E, Ji J, Hou Y. TLR9-induced miR-155 and Ets-1 decrease expression of CD1d on B cells in SLE. Eur J Immunol 2015; 45:1934-45. [DOI: 10.1002/eji.201445286] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Revised: 03/23/2015] [Accepted: 04/28/2015] [Indexed: 11/07/2022]
Affiliation(s)
- Fei Liu
- The State Key Laboratory of Pharmaceutical Biotechnology; Division of Immunology; Medical School, Nanjing University; Nanjing P. R. China
| | - Hongye Fan
- School of Life Science and Technology; China Pharmaceutical University; Nanjing, Jiangsu P. R. China
| | - Deshan Ren
- The State Key Laboratory of Pharmaceutical Biotechnology; Division of Immunology; Medical School, Nanjing University; Nanjing P. R. China
| | - Guanjun Dong
- The State Key Laboratory of Pharmaceutical Biotechnology; Division of Immunology; Medical School, Nanjing University; Nanjing P. R. China
| | - Erling Hu
- The State Key Laboratory of Pharmaceutical Biotechnology; Division of Immunology; Medical School, Nanjing University; Nanjing P. R. China
| | - Jianjian Ji
- The State Key Laboratory of Pharmaceutical Biotechnology; Division of Immunology; Medical School, Nanjing University; Nanjing P. R. China
| | - Yayi Hou
- The State Key Laboratory of Pharmaceutical Biotechnology; Division of Immunology; Medical School, Nanjing University; Nanjing P. R. China
- Jiangsu Key Laboratory of Molecular Medicine; Nanjing P. R. China
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Abstract
There is growing evidence that the commensal bacteria in the gastrointestinal tract (the gut microbiota) influence the development of autoimmunity in rodent models. Since humans have co-evolved with commensals for millennia, it is likely that people, who are genetically predisposed to autoimmunity, harbor gut microbial communities that similarly influence the onset and/or severity of disease. Beyond the current efforts to identify such disease-promoting or -preventing commensals ("pathobionts" or "symbionts"), it will be important to determine what factors modulate them. Dietary changes are known to affect both the composition and function of the gut microbial communities, which in turn can alter the innate and adaptive immune system. In this review, we focus on the relationships between diet, microbiota, and autoimmune diseases. We hypothesize that the beneficial and life-prolonging effects of caloric restriction on a variety of autoimmune models including lupus might partly be mediated by its effects on the gut microbiome and associated virome, the collection of all viruses in the gut. We give recent examples of the immunomodulatory potential of select gut commensals and their products or diet-derived metabolites in murine models of arthritis, multiple sclerosis, and type 1 diabetes. Lastly, we summarize the published phenotypes of germ-free mouse models of lupus and speculate on any role of the diet-sensitive microbiome and virome in systemic lupus and the related antiphospholipid syndrome.
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Abstract
Apoptosis is the predominant mechanism of liver cell death in autoimmune hepatitis, and interventions that can modulate this activity are emerging. The aim of this review was to describe the apoptotic mechanisms, possible aberrations, and opportunities for intervention in autoimmune hepatitis. Studies cited in PubMed from 1972 to 2014 for autoimmune hepatitis, apoptosis in liver disease, apoptosis mechanisms, and apoptosis treatment were examined. Apoptosis is overactive in autoimmune hepatitis, and the principal pathway of cell death is receptor mediated. Surface death receptors are activated by extrinsic factors including liver-infiltrating cytotoxic T cells and the cytokine milieu. The executioner caspases 3 and 7 cleave nuclear deoxyribonucleic acid, and the release of apoptotic bodies can stimulate inflammatory, immune, and fibrotic responses. Changes in mitochondrial membrane permeability can be initiated by caspase 8, and an intrinsic pathway of apoptosis can complement the extrinsic pathway. Defects in the apoptosis of activated effector cells can prolong their survival and sustain the immune response. Caspase inhibitors have been used in diverse experimental and human diseases to retard apoptosis. Oligonucleotides that inhibit the signaling of toll-like receptors can limit the presentation of auto-antigens, and inhibitors of apoptosis that extend the survival of effector cells can be blocked by antisense oligonucleotides. Mechanisms that enhance the clearance of apoptotic bodies and affect key signaling pathways are also feasible. Interventions that influence the survival of liver and effector cells by altering their apoptosis are candidates for study in autoimmune hepatitis.
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Fan H, Liu F, Dong G, Ren D, Xu Y, Dou J, Wang T, Sun L, Hou Y. Activation-induced necroptosis contributes to B-cell lymphopenia in active systemic lupus erythematosus. Cell Death Dis 2014; 5:e1416. [PMID: 25210799 PMCID: PMC4225223 DOI: 10.1038/cddis.2014.375] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Revised: 07/30/2014] [Accepted: 08/01/2014] [Indexed: 02/07/2023]
Abstract
B-cell abnormality including excessive activation and lymphopenia is a central feature of systemic lupus erythematosus (SLE). Although activation threshold, auto-reaction and death of B cells can be affected by intrinsical and/or external signaling, the underlying mechanisms are unclear. Herein, we demonstrate that co-activation of Toll-like receptor 7 (TLR7) and B-cell receptor (BCR) pathways is a core event for the survival/dead states of B cells in SLE. We found that the mortalities of CD19(+)CD27(-) and CD19(+)IgM(+) B-cell subsets were increased in the peripheral blood mononuclear cells (PBMCs) of SLE patients. The gene microarray analysis of CD19(+) B cells from active SLE patients showed that the differentially expressed genes were closely correlated to TLR7, BCR, apoptosis, necroptosis and immune pathways. We also found that co-activation of TLR7 and BCR could trigger normal B cells to take on SLE-like B-cell characters including the elevated viability, activation and proliferation in the first 3 days and necroptosis in the later days. Moreover, the necroptotic B cells exhibited mitochondrial dysfunction and hypoxia, along with the elevated expression of necroptosis-related genes, consistent with that in both SLE B-cell microarray and real-time PCR verification. Expectedly, pretreatment with the receptor-interacting protein kinase 1 (RIPK1) inhibitor Necrostatin-1, and not the apoptosis inhibitor zVAD, suppressed B-cell death. Importantly, B cells from additional SLE patients also significantly displayed high expression levels of necroptosis-related genes compared with those from healthy donors. These data indicate that co-activation of TLR7 and BCR pathways can promote B cells to hyperactivation and ultimately necroptosis. Our finding provides a new explanation on B-cell lymphopenia in active SLE patients. These data suggest that extrinsic factors may increase the intrinsical abnormality of B cells in SLE patients.
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Affiliation(s)
- H Fan
- The State Key Laboratory of Pharmaceutical Biotechnology, Division of Immunology, Medical School, Nanjing University, Nanjing, China
| | - F Liu
- The State Key Laboratory of Pharmaceutical Biotechnology, Division of Immunology, Medical School, Nanjing University, Nanjing, China
| | - G Dong
- The State Key Laboratory of Pharmaceutical Biotechnology, Division of Immunology, Medical School, Nanjing University, Nanjing, China
| | - D Ren
- The State Key Laboratory of Pharmaceutical Biotechnology, Division of Immunology, Medical School, Nanjing University, Nanjing, China
| | - Y Xu
- The State Key Laboratory of Pharmaceutical Biotechnology, Division of Immunology, Medical School, Nanjing University, Nanjing, China
| | - J Dou
- The State Key Laboratory of Pharmaceutical Biotechnology, Division of Immunology, Medical School, Nanjing University, Nanjing, China
| | - T Wang
- The State Key Laboratory of Pharmaceutical Biotechnology, Division of Immunology, Medical School, Nanjing University, Nanjing, China
| | - L Sun
- Department of Immunology and Rheumatology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Y Hou
- The State Key Laboratory of Pharmaceutical Biotechnology, Division of Immunology, Medical School, Nanjing University, Nanjing, China
- Jiangsu Key Laboratory of Molecular Medicine, Nanjing, China
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TRIpartite motif 21 (TRIM21) differentially regulates the stability of interferon regulatory factor 5 (IRF5) isoforms. PLoS One 2014; 9:e103609. [PMID: 25084355 PMCID: PMC4118895 DOI: 10.1371/journal.pone.0103609] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Accepted: 06/27/2014] [Indexed: 11/19/2022] Open
Abstract
IRF5 is a member of the Interferon Regulatory Factor (IRF) family of transcription factors activated downstream of the Toll-Like receptors (TLRs). Polymorphisms in IRF5 have been shown to be associated with the autoimmune disease Systemic Lupus Erythematosus (SLE) and other autoimmune conditions, suggesting a central role for IRF5 in the regulation of the immune response. Four different IRF5 isoforms originate due to alternative splicing and to the presence or absence of a 30 nucleotide insertion in IRF5 exon 6. Since the polymorphic region disturbs a PEST domain, a region associated with protein degradation, we hypothesized that the isoforms bearing the insertion might have increased stability, thus explaining the association of individual IRF5 isoforms with SLE. As the E3 ubiquitin ligase TRIpartite Motif 21 (TRIM21) has been shown to regulate the stability and hence activity of members of the IRF family, we investigated whether IRF5 is subjected to regulation by TRIM21 and whether dysregulation of this mechanism could explain the association of IRF5 with SLE. Our results show that IRF5 is degraded following TLR7 activation and that TRIM21 is involved in this process. Comparison of the individual IRF5 variants demonstrates that isoforms generated by alternative splicing are resistant to TRIM21-mediated degradation following TLR7 stimulation, thus providing a functional link between isoforms expression and stability/activity which contributes to explain the association of IRF5 with SLE.
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Enevold C, Nielsen CH, Jacobsen RS, Hermansen MLF, Molbo D, Avlund K, Bendtzen K, Jacobsen S. Single nucleotide polymorphisms in genes encoding toll-like receptors 7, 8 and 9 in Danish patients with systemic lupus erythematosus. Mol Biol Rep 2014; 41:5755-63. [PMID: 24919757 DOI: 10.1007/s11033-014-3447-4] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Accepted: 06/03/2014] [Indexed: 01/10/2023]
Abstract
Several studies indicate a role for toll-like receptors (TLRs) in the pathogenesis of systemic lupus erythematosus (SLE). We aimed to investigate the risk of SLE and typical clinical and serological manifestations of SLE potentially conferred by selected single nucleotide polymorphisms (SNPs) of genes encoding TLR7, TLR8, and TLR9. Using a multiplexed bead-based assay, we analyzed eight SNPs in a cohort of 142 Danish SLE patients and a gender-matched control cohort comprising 443 individuals. Our results showed an association between the rs3853839 polymorphism of TLR7 and SLE (G vs. C, P = 0.008, OR 1.60, 95 % CI 1.12-2.27 in females; P = 0.02, OR 4.50, 95 % CI 1.18-16.7 in males) confirming recent findings in other populations. Additionally, an association between the rs3764879 polymorphism of TLR8 and SLE (G vs. C, P < 0.05, OR 1.36, 95 % CI 0.99-1.86 in females; P = 0.06, OR 4.00, 95 % CI 0.90-17.3 in males) was found. None of the other investigated SNPs were associated with SLE but several SNPs were associated with clinical and serological manifestations. In summary, a previously shown association between the rs3853839 SNP of TLR7 and SLE in Asian patients was also found in Danish patients. Together with the association of several other SNPs of TLR8 and TLR9 with various clinical and serological manifestations of SLE these findings corroborate the pathogenic significance of TLRs in SLE.
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Affiliation(s)
- C Enevold
- Institute for Inflammation Research, Department of Infectious Medicine and Rheumatology, Rigshospitalet, Copenhagen, Denmark,
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Yokogawa M, Takaishi M, Nakajima K, Kamijima R, Fujimoto C, Kataoka S, Terada Y, Sano S. Epicutaneous application of toll-like receptor 7 agonists leads to systemic autoimmunity in wild-type mice: a new model of systemic Lupus erythematosus. Arthritis Rheumatol 2014; 66:694-706. [PMID: 24574230 DOI: 10.1002/art.38298] [Citation(s) in RCA: 156] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Accepted: 11/26/2013] [Indexed: 01/06/2023]
Abstract
OBJECTIVE To examine whether topical treatment of wild-type mice with Toll-like receptor 7 (TLR-7) agonists leads to lupus-like autoimmunity. METHODS Wild-type FVB/N, BALB/c, and C57BL/6 mice were treated with the topical TLR-7 agonist imiquimod or R848 administered to the ear 3 times weekly. During treatment, the mice were monitored for serum autoantibody and creatinine levels as well as histopathology of the kidneys, spleens, livers, hearts, and skin. Immunologic abnormalities were analyzed by immunohistochemistry, quantitative reverse transcription-polymerase chain reaction, and fluorescence-activated cell sorting. The role of plasmacytoid dendritic cells (PDCs) in the development of autoimmune disease was validated by in vivo treatment with an anti-PDC antibody. Diseased mice underwent ultraviolet B irradiation, to evaluate skin photosensitivity. The disease-causing effect of topical application of imiquimod was compared with that of systemic (intraperitoneal) administration. TLR-7- and TLR-9-deficient mice were used to validate the role of TLR-7. RESULTS Wild-type mice of different genetic backgrounds developed systemic autoimmune disease following 4 weeks of topical treatment with imiquimod or R848, with elevated levels of autoantibodies to double-stranded DNA and multiple organ involvement, including glomerulonephritis, hepatitis, carditis, and photosensitivity. Expression of Ifna and Mx1, the interferon-α-stimulated gene, was up-regulated in the organs of imiquimod-treated mice. However, disease caused by intraperitoneal injection of imiquimod was less severe than that induced by topical application. In vivo depletion of PDCs by a specific antibody protected mice against the autoimmunity induced by topical administration of imiquimod, suggesting a role of PDCs. Furthermore, TLR-7-deficient mice, but not TLR-9-deficient mice, were protected against autoimmunity. CONCLUSION This protocol provides a novel model of inducible systemic lupus erythematosus in wild-type mice and underscores the skin as the primary organ that allows TLR-7 agonists to induce SLE.
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50
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Gallo PM, Gallucci S. The dendritic cell response to classic, emerging, and homeostatic danger signals. Implications for autoimmunity. Front Immunol 2013; 4:138. [PMID: 23772226 PMCID: PMC3677085 DOI: 10.3389/fimmu.2013.00138] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Accepted: 05/23/2013] [Indexed: 12/18/2022] Open
Abstract
Dendritic cells (DCs) initiate and control immune responses, participate in the maintenance of immunological tolerance and are pivotal players in the pathogenesis of autoimmunity. In patients with autoimmune disease and in experimental animal models of autoimmunity, DCs show abnormalities in both numbers and activation state, expressing immunogenic levels of costimulatory molecules and pro-inflammatory cytokines. Exogenous and endogenous danger signals activate DCs to stimulate the immune response. Classic endogenous danger signals are released, activated, or secreted by host cells and tissues experiencing stress, damage, and non-physiologic cell death; and are therefore referred to as damage-associated molecular patterns (DAMPs). Some DAMPs are released from cells, where they are normally sequestered, during necrosis (e.g., heat shock proteins, uric acid, ATP, HMGB1, mitochondria-derived molecules). Others are actively secreted, like Type I Interferons. Here we discuss important DAMPs in the context of autoimmunity. For some, there is a clear pathogenic link (e.g., nucleic acids and lupus). For others, there is less evidence. Additionally, we explore emerging danger signals. These include inorganic materials and man-made technologies (e.g., nanomaterials) developed as novel therapeutic approaches. Some nanomaterials can activate DCs and may trigger unintended inflammatory responses. Finally, we will review “homeostatic danger signals,” danger signals that do not derive directly from pathogens or dying cells but are associated with perturbations of tissue/cell homeostasis and may signal pathological stress. These signals, like acidosis, hypoxia, and changes in osmolarity, also play a role in inflammation and autoimmunity.
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Affiliation(s)
- Paul M Gallo
- Laboratory of Dendritic Cell Biology, Department of Microbiology and Immunology, Temple Autoimmunity Center, Temple University School of Medicine , Philadelphia, PA , USA
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