1. |
- Adams, RA, et al.
(författare)
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Serum-circulating His-tRNA synthetase inhibits organ-targeted immune responses
- 2021
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Ingår i: Cellular & molecular immunology. - : Springer Science and Business Media LLC. - 2042-0226 .- 1672-7681. ; 18:6, s. 1463-1475
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Tidskriftsartikel (refereegranskat)abstract
- His-tRNA synthetase (HARS) is targeted by autoantibodies in chronic and acute inflammatory anti-Jo-1-positive antisynthetase syndrome. The extensive activation and migration of immune cells into lung and muscle are associated with interstitial lung disease, myositis, and morbidity. It is unknown whether the sequestration of HARS is an epiphenomenon or plays a causal role in the disease. Here, we show that HARS circulates in healthy individuals, but it is largely undetectable in the serum of anti-Jo-1-positive antisynthetase syndrome patients. In cultured primary human skeletal muscle myoblasts (HSkMC), HARS is released in increasing amounts during their differentiation into myotubes. We further show that HARS regulates immune cell engagement and inhibits CD4+ and CD8+ T-cell activation. In mouse and rodent models of acute inflammatory diseases, HARS administration downregulates immune activation. In contrast, neutralization of extracellular HARS by high-titer antibody responses during tissue injury increases susceptibility to immune attack, similar to what is seen in humans with anti-Jo-1-positive disease. Collectively, these data suggest that extracellular HARS is homeostatic in normal subjects, and its sequestration contributes to the morbidity of the anti-Jo-1-positive antisynthetase syndrome.
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- Alim, Abdul, 1983-, et al.
(författare)
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Glutamate triggers the expression of functional ionotropic and metabotropic glutamate receptors in mast cells
- 2021
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Ingår i: Cellular & Molecular Immunology. - : Springer Nature. - 1672-7681 .- 2042-0226. ; 18:10, s. 2383-2392
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Tidskriftsartikel (refereegranskat)abstract
- Mast cells are emerging as players in the communication between peripheral nerve endings and cells of the immune system. However, it is not clear the mechanism by which mast cells communicate with peripheral nerves. We previously found that mast cells located within healing tendons can express glutamate receptors, raising the possibility that mast cells may be sensitive to glutamate signaling. To evaluate this hypothesis, we stimulated primary mast cells with glutamate and showed that glutamate induced the profound upregulation of a panel of glutamate receptors of both the ionotropic type (NMDAR1, NMDAR2A, and NMDAR2B) and the metabotropic type (mGluR2 and mGluR7) at both the mRNA and protein levels. The binding of glutamate to glutamate receptors on the mast cell surface was confirmed. Further, glutamate had extensive effects on gene expression in the mast cells, including the upregulation of pro-inflammatory components such as IL-6 and CCL2. Glutamate also induced the upregulation of transcription factors, including Egr2, Egr3 and, in particular, FosB. The extensive induction of FosB was confirmed by immunofluorescence assessment. Glutamate receptor antagonists abrogated the responses of the mast cells to glutamate, supporting the supposition of a functional glutamate-glutamate receptor axis in mast cells. Finally, we provide in vivo evidence supporting a functional glutamate-glutamate receptor axis in the mast cells of injured tendons. Together, these findings establish glutamate as an effector of mast cell function, thereby introducing a novel principle for how cells in the immune system can communicate with nerve cells.
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- Carnrot, Cecilia, et al.
(författare)
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Marginal zone B cells are naturally reactive to collagen type II and are involved in the initiation of the immune response in collagen-induced arthritis
- 2011
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Ingår i: Cellular & Molecular Immunology. - : Springer Science and Business Media LLC. - 1672-7681 .- 2042-0226. ; 8:4, s. 296-304
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Tidskriftsartikel (refereegranskat)abstract
- Antibodies against type II collagen (CII) are essential for development of collagen-induced arthritis (CIA), but how and where the B-cell response to CII is initiated is not fully known. We show here that naive DBA/1 mice display naturally reactive IgM and IgG anti-CII producing B cells prior to immunization. The CII-reactive B cells were observed in the spleen and recognized as marginal zone (MZ) B cells. After CII immunization, CII-specific B cells expanded rapidly in the spleen, in contrast to the lymph nodes, with the initial response derived from MZ B cells and later by follicular (FO) B cells. This was evident despite that the MZ B cells were subject to stringent tolerance mechanisms by having a greater Fc gamma receptor IIb expression than the FO B cells. Further, the MZ B cells migrated to the FO areas upon immunization, possibly providing antigen and activating FO T cells and subsequently FO B cells. Thus, around CIA onset increased numbers of IgG anti-CII producing FO B cells was seen in the spleen, which was dominated by IgG2a- and IgG2b-positive cells. These data demonstrate that CII-reactive MZ B cells are present before and expand after CII immunization, suggesting an initiating role of MZ B cells in the development of CIA.
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7. |
- Chirivi, RGS, et al.
(författare)
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Therapeutic ACPA inhibits NET formation: a potential therapy for neutrophil-mediated inflammatory diseases
- 2021
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Ingår i: Cellular & molecular immunology. - : Springer Science and Business Media LLC. - 2042-0226 .- 1672-7681. ; 18:6, s. 1528-1544
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Tidskriftsartikel (refereegranskat)abstract
- Excessive release of neutrophil extracellular traps (NETs) is associated with disease severity and contributes to tissue injury, followed by severe organ damage. Pharmacological or genetic inhibition of NET release reduces pathology in multiple inflammatory disease models, indicating that NETs are potential therapeutic targets. Here, we demonstrate using a preclinical basket approach that our therapeutic anti-citrullinated protein antibody (tACPA) has broad therapeutic potential. Treatment with tACPA prevents disease symptoms in various mouse models with plausible NET-mediated pathology, including inflammatory arthritis (IA), pulmonary fibrosis, inflammatory bowel disease and sepsis. We show that citrulline residues in the N-termini of histones 2A and 4 are specific targets for therapeutic intervention, whereas antibodies against other N-terminal post-translational histone modifications have no therapeutic effects. Because citrullinated histones are generated during NET release, we investigated the ability of tACPA to inhibit NET formation. tACPA suppressed NET release from human neutrophils triggered with physiologically relevant human disease-related stimuli. Moreover, tACPA diminished NET release and potentially initiated NET uptake by macrophages in vivo, which was associated with reduced tissue damage in the joints of a chronic arthritis mouse model of IA. To our knowledge, we are the first to describe an antibody with NET-inhibiting properties and thereby propose tACPA as a drug candidate for NET-mediated inflammatory diseases, as it eliminates the noxious triggers that lead to continued inflammation and tissue damage in a multidimensional manner.
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- Gu, Peng, et al.
(författare)
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A metabolite from commensal Candida albicans enhances the bactericidal activity of macrophages and protects against sepsis
- 2023
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Ingår i: Cellular & Molecular Immunology. - London : Nature Publishing Group. - 1672-7681 .- 2042-0226. ; 20:10, s. 1156-1170
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Tidskriftsartikel (refereegranskat)abstract
- The gut microbiome is recognized as a key modulator of sepsis development. However, the contribution of the gut mycobiome to sepsis development is still not fully understood. Here, we demonstrated that the level of Candida albicans was markedly decreased in patients with bacterial sepsis, and the supernatant of Candida albicans culture significantly decreased the bacterial load and improved sepsis symptoms in both cecum ligation and puncture (CLP)-challenged mice and Escherichia coli-challenged pigs. Integrative metabolomics and the genetic engineering of fungi revealed that Candida albicans-derived phenylpyruvate (PPA) enhanced the bactericidal activity of macrophages and reduced organ damage during sepsis. Mechanistically, PPA directly binds to sirtuin 2 (SIRT2) and increases reactive oxygen species (ROS) production for eventual bacterial clearance. Importantly, PPA enhanced the bacterial clearance capacity of macrophages in sepsis patients and was inversely correlated with the severity of sepsis in patients. Our findings highlight the crucial contribution of commensal fungi to bacterial disease modulation and expand our understanding of the host-mycobiome interaction during sepsis development. © 2023, The Author(s), under exclusive licence to CSI and USTC.
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- Herrero-Cervera, A, et al.
(författare)
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Neutrophils in chronic inflammatory diseases
- 2022
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Ingår i: Cellular & molecular immunology. - : Springer Science and Business Media LLC. - 2042-0226 .- 1672-7681. ; 19:42, s. 177-191
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Tidskriftsartikel (refereegranskat)abstract
- Chronic inflammation is a component of many disease conditions that affect a large group of individuals worldwide. Chronic inflammation is characterized by persistent, low-grade inflammation and is increased in the aging population. Neutrophils are normally the first responders to acute inflammation and contribute to the resolution of inflammation. However, in chronic inflammation, the role of neutrophils is less well understood and has been described as either beneficial or detrimental, causing tissue damage and enhancing the immune response. Emerging evidence suggests that neutrophils are important players in several chronic diseases, such as atherosclerosis, diabetes mellitus, nonalcoholic fatty liver disease and autoimmune disorders. This review will highlight the interaction of neutrophils with other cells in the context of chronic inflammation, the contribution of neutrophils to selected chronic inflammatory diseases, and possible future therapeutic strategies.
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- Khalaf, Hazem, 1981-, et al.
(författare)
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Suppression of inflammatory gene expression in T cells by Porphyromonas gingivalis is mediated by targeting MAPK signaling
- 2013
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Ingår i: Cellular & Molecular Immunology. - London, United Kingdom : Nature Publishing Group. - 1672-7681 .- 2042-0226. ; 10:5, s. 413-422
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Tidskriftsartikel (refereegranskat)abstract
- There is increasing awareness of the effects of Porphyromonas gingivalis on host immune responses. Degradation of cytokines and chemokines by cysteine proteinases has previously been reported. However, the precise mechanisms by which P. gingivalis is able to alter intracellular signaling, and thus proliferation and inflammation, have not been described. We have previously reported suppression of activator protein-1 (AP-1) and degradation of IL-2 by proteinases from P. gingivalis. In the present study, we have analyzed the effects of P. gingivalis on Jurkat T-cell signal transduction and subsequent IL-2 and CXCL8 expression. We found that CXCL8, but not IL-2, gene expression levels were significantly suppressed by viable P. gingivalis. Analysis of intracellular signaling revealed an inhibitory effect of P. gingivalis on c-Jun and c-Fos, but not NF kappa B (p50 and p65), NFAT or STAT5 expression. This inhibitory effect was not due to suppression of mitogen-activated protein kinase (MAPK) (p38, erk and JNK) gene expression, but was rather due to prevention of protein kinase C (PKC) and p38 phosphorylation, as demonstrated by western blot analysis. Furthermore, SOCS1 and SOCS3 expression levels decreased following treatment of Jurkat T cells with viable P. gingivalis. The results indicate that P. gingivalis is able to suppress inflammatory gene expression by targeting the activity of MAPK pathways in T cells, which was confirmed by using specific inhibitors of NF-kappa B, PKC, ERK, p38 and JNK.
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- Malmhäll, Carina, 1959, et al.
(författare)
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MicroRNA-155 expression suggests a sex disparity in innate lymphoid cells at the single-cell level
- 2020
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Ingår i: Cellular and Molecular Immunology. - : Springer Science and Business Media LLC. - 1672-7681 .- 2042-0226. ; 17, s. 544-546
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Tidskriftsartikel (refereegranskat)abstract
- MicroRNAs (miRNAs) are small noncoding RNAs that control gene expression at the post-transcriptional level, thereby serving as important cellular regulators.1 However, miRNA expression in specific human cellular subtypes, especially at the single-cell level, remains largely unexplored. In this study, a novel method called the PrimeFlow™ RNA Assay2 was used to directly monitor miRNA expression in the cell. Notably, we demonstrate for the first time that human innate lymphoid cells (ILCs) express miR-155. We further demonstrate a clear distinction between the sexes, with a significant increase in the number of ILCs expressing miR-155 in female-derived cells compared with male-derived cells upon in vitro stimulation.
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- Mulas, Floriana, et al.
(författare)
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The deubiquitinase OTUB1 augments NF-κB-dependent immune responses in dendritic cells in infection and inflammation by stabilizing UBC13
- 2021
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Ingår i: Cellular & Molecular Immunology. - : Springer Science and Business Media LLC. - 1672-7681 .- 2042-0226. ; 18, s. 1512-1527
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Tidskriftsartikel (refereegranskat)abstract
- Dendritic cells (DCs) are indispensable for defense against pathogens but may also contribute to immunopathology. Activation of DCs upon the sensing of pathogens by Toll-like receptors (TLRs) is largely mediated by pattern recognition receptor/nuclear factor-kappa B (NF-kappa B) signaling and depends on the appropriate ubiquitination of the respective signaling molecules. However, the ubiquitinating and deubiquitinating enzymes involved and their interactions are only incompletely understood. Here, we reveal that the deubiquitinase OTU domain, ubiquitin aldehyde binding 1 (OTUB1) is upregulated in DCs upon murine Toxoplasmagondii infection and lipopolysaccharide challenge. Stimulation of DCs with the TLR11/12 ligand T. gondii profilin and the TLR4 ligand lipopolysaccharide induced an increase in NF-kappa B activation in OTUB1-competent cells, resulting in elevated interleukin-6 (IL-6), IL-12, and tumor necrosis factor (TNF) production, which was also observed upon the specific stimulation of TLR2, TLR3, TLR7, and TLR9. Mechanistically, OTUB1 promoted NF-kappa B activity in DCs by K48-linked deubiquitination and stabilization of the E2-conjugating enzyme UBC13, resulting in increased K63-linked ubiquitination of IRAK1 (IL-1 receptor-associated kinase 1) and TRAF6 (TNF receptor-associated factor 6). Consequently, DC-specific deletion of OTUB1 impaired the production of cytokines, in particular IL-12, by DCs over the first 2 days of T. gondii infection, resulting in the diminished production of protective interferon-gamma (IFN-gamma) by natural killer cells, impaired control of parasite replication, and, finally, death from chronic T.encephalitis, all of which could be prevented by low-dose IL-12 treatment in the first 3 days of infection. In contrast, impaired OTUB1-deficient DC activation and cytokine production by OTUB1-deficient DCs protected mice from lipopolysaccharide-induced immunopathology. Collectively, these findings identify OTUB1 as a potent novel regulator of DCs during infectious and inflammatory diseases.
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- Palm, Anna-Karin E., et al.
(författare)
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Function and regulation of self-reactive marginal zone B cells in autoimmune arthritis
- 2015
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Ingår i: Cellular & Molecular Immunology. - : Springer Science and Business Media LLC. - 1672-7681 .- 2042-0226. ; 12:4, s. 493-504
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Tidskriftsartikel (refereegranskat)abstract
- Polyreactive innate-type B cells account for many B cells expressing self-reactivity in the periphery. Improper regulation of these B cells may be an important factor that underlies autoimmune disease. Here we have explored the influence of self-reactive innate B cells in the development of collagen-induced arthritis (CIA), a mouse model of rheumatoid arthritis. We show that splenic marginal zone (MZ), but not B-1 B cells exhibit spontaneous IgM reactivity to autologous collagen II in naive mice. Upon immunization with heterologous collagen II in complete Freund's adjuvant the collagen-reactiveMZ B cells expanded rapidly, while the B-1 B cells showed a modest anti-collagen response. The MZ B cells were easily activated by toll-like receptor (TLR) 4 and 9-ligands in vitro, inducing proliferation and cytokine secretion, implying that dual engagement of the B-cell receptor and TLRs may promote the immune response to self-antigen. Furthermore, collagen-primed MZ B cells showed significant antigen-presenting capacity as reflected by cognate T-cell proliferation in vitro and induction of IgG anti-collagen antibodies in vivo. MZ B cells that were deficient in complement receptors 1 and 2 demonstrated increased proliferation and cytokine production, while Fc gamma receptor IIb deficiency of the cells lead to increased cytokine production and antigen presentation. In conclusion, our data highlight self-reactive MZ B cells as initiators of the autoimmune response in CIA, where complement and Fc receptors are relevant in controlling the self-reactivity in the cells.
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