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1.
J Immunol ; 213(2): 109-114, 2024 Jul 15.
Article de Anglais | MEDLINE | ID: mdl-38950331

RÉSUMÉ

ATPase cation transporting 13A2 (ATP13A2) is an endolysosomal P-type ATPase known to be a polyamine transporter, explored mostly in neurons. As endolysosomal functions are also crucial in innate immune cells, we aimed to explore the potential role of ATP13A2 in the human immunocellular compartment. We found that human plasmacytoid dendritic cells (pDCs), the professional type I IFN-producing immune cells, especially have a prominent enrichment of ATP13A2 expression in endolysosomal compartments. ATP13A2 knockdown in human pDCs interferes with cytokine induction in response to TLR9/7 activation in response to bona fide ligands. ATP13A2 plays this crucial role in TLR9/7 activation in human pDCs by regulating endolysosomal pH and mitochondrial reactive oxygen generation. This (to our knowledge) hitherto unknown regulatory mechanism in pDCs involving ATP13A2 opens up a new avenue of research, given the crucial role of pDC-derived type I IFNs in protective immunity against infections as well as in the immunopathogenesis of myriad contexts of autoreactive inflammation.


Sujet(s)
Cellules dendritiques , Endosomes , Lysosomes , Récepteur-9 de type Toll-like , Humains , Cellules dendritiques/immunologie , Cellules dendritiques/métabolisme , Lysosomes/métabolisme , Lysosomes/immunologie , Récepteur-9 de type Toll-like/métabolisme , Récepteur-9 de type Toll-like/immunologie , Endosomes/métabolisme , Endosomes/immunologie , Proton-Translocating ATPases/métabolisme , Espèces réactives de l'oxygène/métabolisme , Mitochondries/métabolisme , Mitochondries/immunologie , Cellules cultivées , Interféron de type I/métabolisme , Interféron de type I/immunologie , Récepteur de type Toll-7
2.
Sci Rep ; 14(1): 14595, 2024 06 25.
Article de Anglais | MEDLINE | ID: mdl-38918496

RÉSUMÉ

There are two known mechanisms by which natural killer (NK) cells recognize and kill diseased targets: (i) direct killing and (ii) antibody-dependent cell-mediated cytotoxicity (ADCC). We investigated an indirect NK cell activation strategy for the enhancement of human NK cell killing function. We did this by leveraging the fact that toll-like receptor 9 (TLR9) agonism within pools of human peripheral blood mononuclear cells (PBMCs) results in a robust interferon signaling cascade that leads to NK cell activation. After TLR9 agonist stimulation, NK cells were enriched and incorporated into assays to assess their ability to kill tumor cell line targets. Notably, differential impacts of TLR9 agonism were observed-direct killing was enhanced while ADCC was not increased. To ensure that the observed differential effects were not attributable to differences between human donors, we recapitulated the observation using our Natural Killer-Simultaneous ADCC and Direct Killing Assay (NK-SADKA) that controls for human-to-human differences. Next, we observed a treatment-induced decrease in NK cell surface CD16-known to be shed by NK cells post-activation. Given the essential role of CD16 in ADCC, such shedding could account for the observed differential impact of TLR9 agonism on NK cell-mediated killing capacity.


Sujet(s)
Cytotoxicité à médiation cellulaire dépendante des anticorps , Cellules tueuses naturelles , Récepteur-9 de type Toll-like , Humains , Cellules tueuses naturelles/immunologie , Cellules tueuses naturelles/effets des médicaments et des substances chimiques , Cellules tueuses naturelles/métabolisme , Cytotoxicité à médiation cellulaire dépendante des anticorps/effets des médicaments et des substances chimiques , Récepteur-9 de type Toll-like/agonistes , Récepteur-9 de type Toll-like/métabolisme , Agranulocytes/métabolisme , Agranulocytes/immunologie , Agranulocytes/effets des médicaments et des substances chimiques , Activation des lymphocytes/effets des médicaments et des substances chimiques , Activation des lymphocytes/immunologie , Récepteurs du fragment Fc des IgG/métabolisme , Récepteurs du fragment Fc des IgG/immunologie , Lignée cellulaire tumorale , Cytotoxicité immunologique/effets des médicaments et des substances chimiques
3.
Int J Mol Sci ; 25(11)2024 Jun 01.
Article de Anglais | MEDLINE | ID: mdl-38892317

RÉSUMÉ

The bleomycin-induced scleroderma model is a well-established and dependable method for creating a mouse model of SSc (systemic sclerosis). In the field of skin connective tissue diseases, increasing evidence from clinical and animal experiments suggests that TLRs (Toll-like receptors) play an important role in several diseases. This study aimed to determine the role of TLR7 (Toll-like receptor 7) and TLR9 (Toll-like receptor 9) in the mechanisms of immune abnormalities and fibrosis in SSc. This study used TLR7-KO mice (TLR7-knockout mice with a balb/c background) and TLR9-KO mice (TLR9-knockout mice with a balb/c background) as well as WT mice (wild-type balb/c mice). All three kinds of mice were induced by BLM (bleomycin) in a scleroderma model as the experimental group; meanwhile, WT mice treated with PBS (phosphate-buffered saline) were used as the control group. We analyzed the fibrotic phenotype and the immunological abnormality phenotype of TLR7-deficient and TLR9-deficient mice in the SSc disease model using flow cytometry, RT-PCR (reverse transcription-polymerase chain reaction), a histological examination, and IHC (immunohistochemical staining). In a mouse model of SSc disease, the deletion of TLR7 attenuated skin and lung fibrosis, while the deletion of TLR9 exacerbated skin and lung fibrosis. The deletion of TLR7 resulted in a relative decrease in the infiltration and expression of various pro-inflammatory and fibrotic cells and cytokines in the skin. On the other hand, the deletion of TLR9 resulted in a relative increase in the infiltration and expression of various pro-inflammatory and cytokine-inhibiting cells and cytokines in the skin. Under the influence of pDCs (plasmacytoid dendritic cells), the balances of Beff/Breg (IL-6 + CD19 + B cell/IL-10 + CD19 + B cell), Th17/Treg (IL-17A + CD4 + T cell/Foxp3 + CD25 + CD4 + T cell), M1/M2 (CD86 + macrophage/CD206 + macrophage), and Th1/Th2 (TNFα + CD3 + CD4 + T cell/IL-4 + CD3 + CD4 + T cell) were biased towards the suppression of inflammation and fibrosis as a result of the TLR7 deletion. Comparatively, the balance was biased towards promoting inflammation and fibrosis due to the TLR9 deletion. In the SSc model, TLR7 promoted inflammation and fibrosis progression, while TLR9 played a protective role. These results suggest that TLR7 and TLR9 play opposite roles in triggering SSc to produce immune system abnormalities and skin fibrosis.


Sujet(s)
Modèles animaux de maladie humaine , Souris knockout , Sclérodermie systémique , Récepteur de type Toll-7 , Récepteur-9 de type Toll-like , Animaux , Récepteur de type Toll-7/métabolisme , Récepteur de type Toll-7/génétique , Sclérodermie systémique/métabolisme , Sclérodermie systémique/anatomopathologie , Sclérodermie systémique/immunologie , Sclérodermie systémique/génétique , Récepteur-9 de type Toll-like/métabolisme , Récepteur-9 de type Toll-like/génétique , Souris , Bléomycine/effets indésirables , Souris de lignée BALB C , Cytokines/métabolisme , Peau/anatomopathologie , Peau/métabolisme , Peau/immunologie , Fibrose , Fibrose pulmonaire/métabolisme , Fibrose pulmonaire/anatomopathologie , Fibrose pulmonaire/étiologie , Glycoprotéines membranaires
4.
J Chem Inf Model ; 64(13): 5090-5107, 2024 Jul 08.
Article de Anglais | MEDLINE | ID: mdl-38904299

RÉSUMÉ

The aberrant secretion of proinflammatory cytokines by immune cells is the principal cause of inflammatory diseases, such as systemic lupus erythematosus and rheumatoid arthritis. Toll-like receptor 7 (TLR7) and TLR9, sequestered to the endosomal compartment of dendritic cells and macrophages, are closely associated with the initiation and progression of these diseases. Therefore, the development of drugs targeting dysregulated endosomal TLRs is imperative to mitigate systemic inflammation. Here, we applied the principles of computer-aided drug discovery to identify a novel low-molecular-weight compound, TLR inhibitory compound 10 (TIC10), and its potent derivative (TIC10g), which demonstrated dual inhibition of TLR7 and TLR9 signaling pathways. Compared to TIC10, TIC10g exhibited a more pronounced inhibition of the TLR7- and TLR9-mediated secretion of the proinflammatory cytokine tumor necrosis factor-α in a mouse macrophage cell line and mouse bone marrow dendritic cells in a concentration-dependent manner. While TIC10g slightly prevented TLR3 and TLR8 activation, it had no impact on cell surface TLRs (TLR1/2, TLR2/6, TLR4, or TLR5), indicating its selectivity for TLR7 and TLR9. Additionally, mechanistic studies suggested that TIC10g interfered with TLR9 activation by CpG DNA and suppressed downstream pathways by directly binding to TLR9. Western blot analysis revealed that TIC10g downregulated the phosphorylation of the p65 subunit of nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB) and mitogen-activated protein kinases (MAPKs), including extracellular-signal-regulated kinase, p38-MAPK, and c-Jun N-terminal kinase. These findings indicate that the novel ligand, TIC10g, is a specific dual inhibitor of endosomal TLRs (TLR7 and TLR9), disrupting MAPK- and NF-κB-mediated proinflammatory gene expression.


Sujet(s)
Bibliothèques de petites molécules , Récepteur de type Toll-7 , Récepteur-9 de type Toll-like , Récepteur de type Toll-7/antagonistes et inhibiteurs , Récepteur de type Toll-7/métabolisme , Animaux , Souris , Récepteur-9 de type Toll-like/métabolisme , Récepteur-9 de type Toll-like/antagonistes et inhibiteurs , Bibliothèques de petites molécules/pharmacologie , Bibliothèques de petites molécules/composition chimique , Découverte de médicament , Simulation de docking moléculaire , Transduction du signal/effets des médicaments et des substances chimiques , Facteur de nécrose tumorale alpha/métabolisme , Humains
5.
Front Immunol ; 15: 1337384, 2024.
Article de Anglais | MEDLINE | ID: mdl-38827745

RÉSUMÉ

Fibroblastic reticular cells (FRCs) are a subpopulation of stromal cells modulating the immune environments in health and disease. We have previously shown that activation of TLR9 signaling in FRC in fat-associated lymphoid clusters (FALC) regulate peritoneal immunity via suppressing immune cell recruitment and peritoneal resident macrophage (PRM) retention. However, FRCs are heterogeneous across tissues and organs. The functions of each FRC subset and the regulation of TLR9 in distinct FRC subsets are unknown. Here, we confirmed that specific deletion of TLR9 in FRC improved bacterial clearance and survival during peritoneal infection. Furthermore, using single-cell RNA sequencing, we found two subsets of FRCs (CD55hi and CD55lo) in the mesenteric FALC. The CD55hi FRCs were enriched in gene expression related to extracellular matrix formation. The CD55lo FRCs were enriched in gene expression related to immune response. Interestingly, we found that TLR9 is dominantly expressed in the CD55lo subset. Activation of TLR9 signaling suppressed proliferation, cytokine production, and retinoid metabolism in the CD55lo FRC, but not CD55hi FRC. Notably, we found that adoptive transfer of Tlr9 -/-CD55lo FRC from mesenteric FALC more effectively improved the survival during peritonitis compared with WT-FRC or Tlr9 -/-CD55hi FRC. Furthermore, we identified CD55hi and CD55lo subsets in human adipose tissue-derived FRC and confirmed the suppressive effect of TLR9 on the proliferation and cytokine production in the CD55lo subset. Therefore, inhibition of TLR9 in the CD55lo FRCs from adipose tissue could be a useful strategy to improve the therapeutic efficacy of FRC-based therapy for peritonitis.


Sujet(s)
Fibroblastes , Péritonite , Transduction du signal , Récepteur-9 de type Toll-like , Animaux , Humains , Mâle , Souris , Modèles animaux de maladie humaine , Fibroblastes/métabolisme , Fibroblastes/immunologie , Immunomodulation , Souris de lignée C57BL , Souris knockout , Péritonite/immunologie , Péritonite/métabolisme , Récepteur-9 de type Toll-like/métabolisme , Récepteur-9 de type Toll-like/génétique
6.
Signal Transduct Target Ther ; 9(1): 163, 2024 Jun 17.
Article de Anglais | MEDLINE | ID: mdl-38880789

RÉSUMÉ

Chronic obstructive pulmonary disease (COPD) is characterised by persistent airway inflammation even after cigarette smoking cessation. Neutrophil extracellular traps (NETs) have been implicated in COPD severity and acute airway inflammation induced by short-term cigarette smoke (CS). However, whether and how NETs contribute to sustained airway inflammation in COPD remain unclear. This study aimed to elucidate the immunoregulatory mechanism of NETs in COPD, employing human neutrophils, airway epithelial cells (AECs), dendritic cells (DCs), and a long-term CS-induced COPD mouse model, alongside cyclic guanosine monophosphate-adenosine monophosphate synthase and toll-like receptor 9 knockout mice (cGAS--/-, TLR9-/-); Additionally, bronchoalveolar lavage fluid (BALF) of COPD patients was examined. Neutrophils from COPD patients released greater cigarette smoke extract (CSE)-induced NETs (CSE-NETs) due to mitochondrial respiratory chain dysfunction. These CSE-NETs, containing oxidatively-damaged DNA (NETs-DNA), promoted AECs proliferation, nuclear factor kappa B (NF-κB) activation, NF-κB-dependent cytokines and type-I interferons production, and DC maturation, which were ameliorated/reversed by silencing/inhibition of cGAS/TLR9. In the COPD mouse model, blocking NETs-DNA-sensing via cGAS-/- and TLR9-/- mice, inhibiting NETosis using mitoTEMPO, and degrading NETs-DNA with DNase-I, respectively, reduced NETs infiltrations, airway inflammation, NF-κB activation and NF-κB-dependent cytokines, but not type-I interferons due to IFN-α/ß receptor degradation. Elevated NETs components (myeloperoxidase and neutrophil elastase activity) in BALF of COPD smokers correlated with disease severity and NF-κB-dependent cytokine levels, but not type-I interferon levels. In conclusion, NETs-DNA promotes NF-κB-dependent autoimmunity via cGAS/TLR9 in long-term CS exposure-induced COPD. Therefore, targeting NETs-DNA and cGAS/TLR9 emerges as a potential strategy to alleviate persistent airway inflammation in COPD.


Sujet(s)
Pièges extracellulaires , Facteur de transcription NF-kappa B , Granulocytes neutrophiles , Nucleotidyltransferases , Broncho-pneumopathie chronique obstructive , Récepteur-9 de type Toll-like , Broncho-pneumopathie chronique obstructive/génétique , Broncho-pneumopathie chronique obstructive/immunologie , Broncho-pneumopathie chronique obstructive/anatomopathologie , Récepteur-9 de type Toll-like/génétique , Récepteur-9 de type Toll-like/immunologie , Pièges extracellulaires/immunologie , Pièges extracellulaires/génétique , Nucleotidyltransferases/génétique , Nucleotidyltransferases/immunologie , Animaux , Humains , Facteur de transcription NF-kappa B/génétique , Facteur de transcription NF-kappa B/immunologie , Facteur de transcription NF-kappa B/métabolisme , Souris , Granulocytes neutrophiles/immunologie , Granulocytes neutrophiles/anatomopathologie , Souris knockout , Auto-immunité/génétique , Mâle , ADN/génétique , ADN/immunologie , Femelle , Modèles animaux de maladie humaine , Adulte d'âge moyen
7.
Front Immunol ; 15: 1413177, 2024.
Article de Anglais | MEDLINE | ID: mdl-38903498

RÉSUMÉ

Introduction: Type 1 diabetes (T1D) is an autoimmune disease characterized by the destruction of insulin-producing ß cells. Toll-like receptor 9 (TLR9) plays a role in autoimmune diseases, and B cell-specific TLR9 deficiency delays T1D development. Gut microbiota are implicated in T1D, although the relationship is complex. However, the impact of B cell-specific deficiency of TLR9 on intestinal microbiota and the impact of altered intestinal microbiota on the development of T1D are unclear. Objectives: This study investigated how gut microbiota and the intestinal barrier contribute to T1D development in B cell-specific TLR9-deficient NOD mice. Additionally, this study explored the role of microbiota in immune regulation and T1D onset. Methods: The study assessed gut permeability, gene expression related to gut barrier integrity, and gut microbiota composition. Antibiotics depleted gut microbiota, and fecal samples were transferred to germ-free mice. The study also examined IL-10 production, Breg cell differentiation, and their impact on T1D development. Results: B cell-specific TLR9-deficient NOD mice exhibited increased gut permeability and downregulated gut barrier-related gene expression. Antibiotics restored gut permeability, suggesting microbiota influence. Altered microbiota were enriched in Lachnospiraceae, known for mucin degradation. Transferring this microbiota to germ-free mice increased gut permeability and promoted IL-10-expressing Breg cells. Rag-/- mice transplanted with fecal samples from Tlr9 fl/fl Cd19-Cre+ mice showed delayed diabetes onset, indicating microbiota's impact. Conclusion: B cell-specific TLR9 deficiency alters gut microbiota, increasing gut permeability and promoting IL-10-expressing Breg cells, which delay T1D. This study uncovers a link between TLR9, gut microbiota, and immune regulation in T1D, with implications for microbiota-targeted T1D therapies.


Sujet(s)
Diabète de type 1 , Microbiome gastro-intestinal , Interleukine-10 , Souris de lignée NOD , Récepteur-9 de type Toll-like , Animaux , Récepteur-9 de type Toll-like/déficit , Récepteur-9 de type Toll-like/génétique , Récepteur-9 de type Toll-like/métabolisme , Microbiome gastro-intestinal/immunologie , Interleukine-10/métabolisme , Souris , Diabète de type 1/immunologie , Diabète de type 1/microbiologie , Souris knockout , Lymphocytes B régulateurs/immunologie , Femelle , Lymphocytes B/immunologie , Lymphocytes B/métabolisme
8.
Cancer Med ; 13(11): e7387, 2024 Jun.
Article de Anglais | MEDLINE | ID: mdl-38864479

RÉSUMÉ

BACKGROUND: Promising outcomes have been observed in multiple myeloma (MM) with the use of immunotherapies, specifically chimeric antigen receptor T (CAR-T) cell therapy. However, a portion of MM patients do not respond to CAR-T therapy, and the reasons for this lack of response remain unclear. The objective of this study was to investigate the impact of miR-34a on the immunosuppressive polarization of macrophages obtained from MM patients. METHODS: The levels of miR-34a and TLR9 (Toll-like receptor 9) were examined in macrophages obtained from both healthy individuals and patients with MM. ELISA was employed to investigate the cytokine profiles of the macrophage samples. Co-culture experiments were conducted to evaluate the immunomodulatory impact of MM-associated macrophages on CAR-T cells. RESULTS: There was an observed suppressed activation of macrophages and CD4+ T lymphocytes in the blood samples of MM patients. Overexpression of miR-34a in MM-associated macrophages dampened the TLR9 expression and impaired the inflammatory polarization. In both the co-culture system and an animal model, MM-associated macrophages suppressed the activity and tumoricidal effect of CAR-T cells in a miR-34a-dependent manner. CONCLUSION: The findings imply that targeting the macrophage miR-34a/TLR9 axis could potentially alleviate the immunosuppression associated with CAR-T therapy in MM patients.


Sujet(s)
microARN , Myélome multiple , Transduction du signal , Récepteur-9 de type Toll-like , Myélome multiple/immunologie , Myélome multiple/génétique , Myélome multiple/thérapie , Myélome multiple/métabolisme , microARN/génétique , Récepteur-9 de type Toll-like/métabolisme , Récepteur-9 de type Toll-like/génétique , Humains , Animaux , Souris , Techniques de coculture , Macrophages associés aux tumeurs/immunologie , Macrophages associés aux tumeurs/métabolisme , Macrophages/immunologie , Macrophages/métabolisme , Immunothérapie adoptive/méthodes , Mâle , Femelle , Activation des macrophages/immunologie , Activation des macrophages/génétique , Lignée cellulaire tumorale
9.
Asian Pac J Cancer Prev ; 25(6): 2003-2010, 2024 Jun 01.
Article de Anglais | MEDLINE | ID: mdl-38918662

RÉSUMÉ

BACKGROUND: Inflammatory bowel diseases (IBD), Crohn's disease (CD), and ulcerative colitis (UC) are diseases that result from the combined effects of a predisposing genetic background and several environmental factors, including smoking. Some genes can influence these diseases through genetic inheritance, and their regulation is explained by gene polymorphism. However, Toll-like receptor (TLR) genes have been identified as susceptibility genes for CD and UC. METHODS: A case-control study was performed on a Turkish population composed of 105 healthy controls and  79 CD, 77 UC patients genotyped by Allele-specific PCR and PCR-RFLP for TLR9 (T-1486C) and TLR 2 (-196 to -174del) gene. Genotype and allele frequencies of TLR9 (T-1486C) and TLR 2 (-196 to -174del) gene polymorphisms compared to allele frequencies in CD and UC patients. RESULTS: No statistically significant findings were found between the CD, UC patients, and the control group in terms of both genotype distributions and allele frequencies for TLR 9 (T-1486C; rs187084) and TLR 2 (-196 to -174del; rs111200466) gene polymorphisms in a Turkish population (P > 0.05). CONCLUSION: No association was found between the TLR2 (rs111200466) and TLR 9 (rs187084) gene polymorphisms among IBD patients and the control groups in the Turkish population.


Sujet(s)
Rectocolite hémorragique , Maladie de Crohn , Prédisposition génétique à une maladie , Génotype , Maladies inflammatoires intestinales , Récepteur de type Toll-2 , Récepteur-9 de type Toll-like , Humains , Récepteur de type Toll-2/génétique , Études cas-témoins , Mâle , Femelle , Récepteur-9 de type Toll-like/génétique , Adulte , Maladie de Crohn/génétique , Maladies inflammatoires intestinales/génétique , Rectocolite hémorragique/génétique , Turquie , Fréquence d'allèle , Adulte d'âge moyen , Polymorphisme de nucléotide simple , Pronostic , Études de suivi , Jeune adulte
10.
J Innate Immun ; 16(1): 354-366, 2024.
Article de Anglais | MEDLINE | ID: mdl-38852581

RÉSUMÉ

INTRODUCTION: Inactivated parapoxvirus ovis (iPPVO) exerts strong immunomodulatory effects on innate immune cells, making it an attractive therapeutic candidate. However, little is known about the signaling pathways that are involved in iPPVO-induced immune responses. METHODS: In this study, we systematically analyzed how different types of dendritic cells (DCs) react to iPPVO (Zylexis, strain D1701) in both BALB/c and C57BL/6 mice by flow cytometry and ELISAs, and investigated which signaling pathway is related to DC activation by Western blotting and protein profiling. RESULTS: We demonstrated that bone marrow-derived conventional DCs (BM-cDCs) and bone marrow-derived plasmacytoid DCs (BM-pDCs) matured and secreted type I interferons in response to Zylexis stimulation in both mouse strains. Similarly, Zylexis promoted the secretion of IL-12/23p40 and TNF by pDCs. However, IL-12/23p40 and TNF secretion by cDCs were induced in BALB/c mice but not in C57BL/6 mice. Analyzing the underlying signaling pathways revealed that iPPVO-induced maturation of cDCs was Toll-like receptor 9 (TLR9) independent, while the maturation of pDCs partially depended on the TLR9 pathway. Moreover, the production of proinflammatory cytokines by cDCs and the secretion of IFN-α/ß by pDCs partially depended on the TLR9 pathway in both mouse strains. Therefore, other signaling pathways seem to participate in the response of DCs to iPPVO, supported by protein profiling. CONCLUSION: Our data provide useful insights into the diversity of iPPVO sensors and their varying effects across different strains and species.


Sujet(s)
Cellules dendritiques , Souris de lignée BALB C , Souris de lignée C57BL , Parapoxvirus , Transduction du signal , Récepteur-9 de type Toll-like , Animaux , Cellules dendritiques/immunologie , Souris , Parapoxvirus/immunologie , Récepteur-9 de type Toll-like/métabolisme , Cellules cultivées , Immunité innée , Cellules de la moelle osseuse/immunologie , Souris knockout , Infections à Poxviridae/immunologie , Femelle , Vaccins inactivés/immunologie , Spécificité d'espèce , Inactivation virale
11.
Int J Mol Sci ; 25(9)2024 Apr 25.
Article de Anglais | MEDLINE | ID: mdl-38731877

RÉSUMÉ

Epstein-Barr virus (EBV) DNA is known to be shed upon reactivation of latent EBV. Based on our previous findings linking Toll-like receptor-9 (TLR9) to an EBV DNA-driven surge in IL-17A production, we aimed to examine the therapeutic potential of TLR9 inhibition in EBV DNA-exacerbated arthritis in a collagen-induced arthritis (CIA) mouse model. C57BL/6J mice were administered either collagen, EBV DNA + collagen, EBV DNA + collagen + TLR9 inhibitor, or only the TLR9 inhibitor. After 70 days, paw thicknesses, clinical scores, and gripping strength were recorded. Moreover, affected joints, footpads, and colons were histologically scored. Furthermore, the number of cells co-expressing IL-17A, IFN-γ, and FOXP3 in joint sections was determined by immunofluorescence assays. Significantly decreased paw thicknesses, clinical scores, and histological scores with a significantly increased gripping strength were observed in the group receiving EBV DNA + collagen + TLR9 inhibitor, compared to those receiving EBV DNA + collagen. Similarly, this group showed decreased IL-17A+ IFN-γ+, IL-17A+ FOXP3+, and IL-17A+ IFN-γ+ FOXP3+ foci counts in joints. We show that inhibiting TLR9 limits the exacerbation of arthritis induced by EBV DNA in a CIA mouse model, suggesting that TLR9 could be a potential therapeutic target for rheumatoid arthritis management in EBV-infected individuals.


Sujet(s)
Arthrite expérimentale , ADN viral , Modèles animaux de maladie humaine , Herpèsvirus humain de type 4 , Récepteur-9 de type Toll-like , Animaux , Souris , Arthrite expérimentale/virologie , Arthrite expérimentale/anatomopathologie , Arthrite expérimentale/métabolisme , Polyarthrite rhumatoïde/métabolisme , Polyarthrite rhumatoïde/anatomopathologie , Polyarthrite rhumatoïde/virologie , ADN viral/génétique , Infections à virus Epstein-Barr/virologie , Infections à virus Epstein-Barr/complications , Infections à virus Epstein-Barr/anatomopathologie , Herpèsvirus humain de type 4/physiologie , Interleukine-17/métabolisme , Souris de lignée C57BL , Récepteur-9 de type Toll-like/métabolisme
12.
Int Immunopharmacol ; 134: 112250, 2024 Jun 15.
Article de Anglais | MEDLINE | ID: mdl-38749335

RÉSUMÉ

Trypanosoma brucei, a causative agent of human and animal trypanosomiasis, regularly switches its major surface antigen to avoid elimination by the immune system. Toll-like receptor 9 (TLR9) is a key modulator for resistance to host-infective trypanosomes; however, the underlying molecular mechanism remains indistinct. Thus, we first approached the issue using Tlr9-mutant mice that render them non-responsive to TLR9 agonists. After infection, T cells in the spleens of Tlr9-mutant mice were analyzed by flow cytometry and a reduction in CD8+, CD4+ T, and NKT cells was observed in Tlr9-mutant mice compared to WT mice. We further found that the responses of inflammatory cytokines in the sera were reduced in Tlr9-mutant mice after T. brucei infection. The underlying molecular mechanism was that T. b. brucei DNA activated TLR9, which consequently upregulated the expression of p38 and ERK/MAPK, resulting in host resistance to trypanosome infection. In conclusion, these findings provide novel insights into the TLR9-mediated host responses to trypanosome infection.


Sujet(s)
Cytokines , Transduction du signal , Récepteur-9 de type Toll-like , Trypanosoma brucei brucei , Maladie du sommeil , Récepteur-9 de type Toll-like/métabolisme , Récepteur-9 de type Toll-like/agonistes , Animaux , Trypanosoma brucei brucei/immunologie , Maladie du sommeil/immunologie , Souris , Cytokines/métabolisme , Souris knockout , Souris de lignée C57BL , Humains
13.
Clin Immunol ; 264: 110234, 2024 Jul.
Article de Anglais | MEDLINE | ID: mdl-38740111

RÉSUMÉ

BACKGROUND: Natural anti-cytokine autoantibodies can regulate homeostasis of infectious and inflammatory diseases. The anti-cytokine autoantibody profile and relevance to the pathogenesis of asthma are unknown. We aim to identify key anti-cytokine autoantibodies in asthma patients, and reveal their immunological function and clinical significance. METHODS: A Luciferase Immunoprecipitation System was used to screen serum autoantibodies against 11 key cytokines in patients with allergic asthma and healthy donors. The antigen-specificity, immunomodulatory functions and clinical significance of anti-cytokine autoantibodies were determined by ELISA, qPCR, neutralization assays and statistical analysis, respectively. Potential conditions for autoantibody induction were revealed by in vitro immunization. RESULTS: Of 11 cytokines tested, only anti-IL-33 autoantibody was significantly increased in asthma, compare to healthy controls, and the proportion positive was higher in patients with mild-to-moderate than severe allergic asthma. In allergic asthma patients, the anti-IL-33 autoantibody level correlated negatively with serum concentration of pathogenic cytokines (e.g., IL-4, IL-13, IL-25 and IL-33), IgE, and blood eosinophil count, but positively with mid-expiratory flow FEF25-75%. The autoantibodies were predominantly IgG isotype, polyclonal and could neutralize IL-33-induced pathogenic responses in vitro and in vivo. The induction of the anti-IL-33 autoantibody in blood B-cells in vitro required peptide IL-33 antigen along with a stimulation cocktail of TLR9 agonist and cytokines IL-2, IL-4 or IL-21. CONCLUSIONS: Serum natural anti-IL-33 autoantibodies are selectively induced in some asthma patients. They ameliorate key asthma inflammatory responses, and may improve lung function of allergic asthma.


Sujet(s)
Asthme , Autoanticorps , Interleukine-33 , Humains , Asthme/immunologie , Autoanticorps/immunologie , Autoanticorps/sang , Interleukine-33/immunologie , Femelle , Adulte , Mâle , Adulte d'âge moyen , Animaux , Anticorps neutralisants/immunologie , Cytokines/immunologie , Cytokines/sang , Souris , Jeune adulte , Immunoglobuline E/immunologie , Immunoglobuline E/sang , Récepteur-9 de type Toll-like/immunologie , Récepteur-9 de type Toll-like/agonistes , Indice de gravité de la maladie , Immunoglobuline G/immunologie , Immunoglobuline G/sang
14.
Drug Dev Res ; 85(4): e22210, 2024 Jun.
Article de Anglais | MEDLINE | ID: mdl-38812444

RÉSUMÉ

Hepatic ischemia/reperfusion injury (IRI) remains a severe threat during liver surgery and transplantation, accounting for unfavorable clinical outcomes. Modafinil (MOD), a wakefulness-inducing compound, is increasingly disclosed to protect against IRI. However, the specific literatures covering the association between MOD and hepatic IRI are few. Here, this paper is committed to unraveling the role and response mechanism of MOD in hepatic IRI. After the establishment of hepatic IRI mice model and cell model, relevant assay kits measured the concentrations of biochemical indicators of hepatotoxicity and hematoxylin and eosin staining estimated liver morphology. Enzyme-linked immunosorbent assay, reverse-transcription quantitative polymerase chain reaction, and western blot evaluated inflammatory levels. Terminal-deoxynucleoitidyl transferase-mediated nick end labeling assay and western blot appraised apoptosis. Western blot also analyzed the expression of Toll-like receptor 9 (TLR9)/myeloid differentiation primary response gene 88 (MyD88)/p38 signaling-associated proteins. Cell counting kit-8 method judged cell viability. MOD was discovered to mitigate liver dysfunction and morphological damage, inflammatory response, apoptosis in vivo and improve cell viability, suppress inflammatory response and apoptosis in vitro. In addition, MOD inactivated TLR9/Myd88/p38 signaling both in vitro and in vivo. Further, TLR9 elevation reversed the inhibitory role of MOD in inflammatory response and cell apoptosis in vitro. Anyway, MOD blocked TLR9/Myd88/p38 signaling to exhibit anti-inflammatory and anti-apoptotic properties in hepatic IRI.


Sujet(s)
Apoptose , Foie , Facteur de différenciation myéloïde-88 , Lésion d'ischémie-reperfusion , Récepteur-9 de type Toll-like , Animaux , Lésion d'ischémie-reperfusion/métabolisme , Lésion d'ischémie-reperfusion/traitement médicamenteux , Récepteur-9 de type Toll-like/métabolisme , Facteur de différenciation myéloïde-88/métabolisme , Apoptose/effets des médicaments et des substances chimiques , Souris , Mâle , Foie/métabolisme , Foie/effets des médicaments et des substances chimiques , Foie/anatomopathologie , Transduction du signal/effets des médicaments et des substances chimiques , Souris de lignée C57BL , p38 Mitogen-Activated Protein Kinases/métabolisme , Inflammation/métabolisme , Inflammation/traitement médicamenteux , Composés benzhydryliques/pharmacologie
15.
Tunis Med ; 102(4): 241-244, 2024 Apr 05.
Article de Anglais | MEDLINE | ID: mdl-38746965

RÉSUMÉ

INTRODUCTION: Toll-like- receptors (TLR) control important aspects of innate and adaptive immune responses. Renal cells are among the non-immune cells that express (TLR). Therefore, their activation might be implicated in renal tubulo-interstitial injury. AIM: The study aimed to compare TLR9 expression in patients with primary membranous nephropathy (MN) to patients with lupus membranous nephropathy. METHODS: Kidney sections from 10 Lupus nephritis (LN) patients and ten patients with primary MN were analyzed by immunohistochemistry using anti-human TLR9 antibody. RESULTS: Results showed that TLR9 expression was weak and exclusively tubular in primary MN patients' biopsies. There was a significant difference between LN patients' biopsies and primary MN patients' biopsies. TLR9 expression was more diffused in LN patients' specimen than in those with primary MN. CONCLUSION: This study focuses on molecular level pathogenesis of MN. The data suggest that the receptors TLR9 may play role in tubulointerstitial injury in the pathogenesis of LN but not primary membranous nephropathy.


Sujet(s)
Glomérulonéphrite extra-membraneuse , Glomérulonéphrite lupique , Récepteur-9 de type Toll-like , Adulte , Femelle , Humains , Mâle , Adulte d'âge moyen , Jeune adulte , Biopsie , Glomérulonéphrite extra-membraneuse/métabolisme , Glomérulonéphrite extra-membraneuse/anatomopathologie , Glomérulonéphrite extra-membraneuse/immunologie , Immunohistochimie , Tubules rénaux/anatomopathologie , Tubules rénaux/métabolisme , Glomérulonéphrite lupique/métabolisme , Glomérulonéphrite lupique/anatomopathologie , Glomérulonéphrite lupique/immunologie , Récepteur-9 de type Toll-like/métabolisme , Récepteur-9 de type Toll-like/biosynthèse
16.
Sci Rep ; 14(1): 11540, 2024 05 21.
Article de Anglais | MEDLINE | ID: mdl-38773176

RÉSUMÉ

Antisense oligonucleotides (ASOs) are synthetic single-stranded oligonucleotides that bind to RNAs through Watson-Crick base pairings. They are actively being developed as therapeutics for various human diseases. ASOs containing unmethylated deoxycytidylyl-deoxyguanosine dinucleotide (CpG) motifs are known to trigger innate immune responses via interaction with toll-like receptor 9 (TLR9). However, the TLR9-stimulatory properties of ASOs, specifically those with lengths equal to or less than 20 nucleotides, phosphorothioate linkages, and the presence and arrangement of sugar-modified nucleotides-crucial elements for ASO therapeutics under development-have not been thoroughly investigated. In this study, we first established SY-ODN18, an 18-nucleotide phosphorothioate oligodeoxynucleotide with sufficient TLR9-stimulatory activity. We demonstrated that an unmethylated CpG motif near its 5'-end was indispensable for TLR9 activation. Moreover, by utilizing various sugar-modified nucleotides, we systematically generated model ASOs, including gapmer, mixmer, and fully modified designs, in accordance with the structures of ASO therapeutics. Our results illustrated that introducing sugar-modified nucleotides in such designs significantly reduces TLR9-stimulatory activity, even without methylation of CpG motifs. These findings would be useful for drug designs on several types of ASOs.


Sujet(s)
Oligonucléotides antisens , Récepteur-9 de type Toll-like , Récepteur-9 de type Toll-like/métabolisme , Oligonucléotides antisens/pharmacologie , Oligonucléotides antisens/composition chimique , Humains , Ilots CpG , Animaux , Souris , Nucléotides/métabolisme , Nucléotides/composition chimique , Sucres/métabolisme , Sucres/composition chimique , Oligodésoxyribonucléotides/composition chimique , Oligodésoxyribonucléotides/pharmacologie
18.
Nat Commun ; 15(1): 4232, 2024 May 18.
Article de Anglais | MEDLINE | ID: mdl-38762479

RÉSUMÉ

Toll-like receptor 9 (TLR9) recognizes bacterial, viral and self DNA and play an important role in immunity and inflammation. However, the role of TLR9 in obesity is less well-studied. Here, we generate B-cell-specific Tlr9-deficient (Tlr9fl/fl/Cd19Cre+/-, KO) B6 mice and model obesity using a high-fat diet. Compared with control mice, B-cell-specific-Tlr9-deficient mice exhibited increased fat tissue inflammation, weight gain, and impaired glucose and insulin tolerance. Furthermore, the frequencies of IL-10-producing-B cells and marginal zone B cells were reduced, and those of follicular and germinal center B cells were increased. This was associated with increased frequencies of IFNγ-producing-T cells and increased follicular helper cells. In addition, gut microbiota from the KO mice induced a pro-inflammatory state leading to immunological and metabolic dysregulation when transferred to germ-free mice. Using 16 S rRNA gene sequencing, we identify altered gut microbial communities including reduced Lachnospiraceae, which may play a role in altered metabolism in KO mice. We identify an important network involving Tlr9, Irf4 and Il-10 interconnecting metabolic homeostasis, with the function of B and T cells, and gut microbiota in obesity.


Sujet(s)
Lymphocytes B , Alimentation riche en graisse , Dysbiose , Microbiome gastro-intestinal , Inflammation , Interleukine-10 , Souris knockout , Obésité , Récepteur-9 de type Toll-like , Animaux , Obésité/immunologie , Obésité/microbiologie , Obésité/métabolisme , Dysbiose/immunologie , Dysbiose/microbiologie , Récepteur-9 de type Toll-like/métabolisme , Récepteur-9 de type Toll-like/génétique , Lymphocytes B/immunologie , Lymphocytes B/métabolisme , Inflammation/métabolisme , Souris , Alimentation riche en graisse/effets indésirables , Interleukine-10/métabolisme , Mâle , Souris de lignée C57BL , Modèles animaux de maladie humaine , Facteurs de régulation d'interféron
19.
Microbes Infect ; 26(5-6): 105336, 2024.
Article de Anglais | MEDLINE | ID: mdl-38724001

RÉSUMÉ

Myeloid-derived suppressor cells (MDSCs) are a group of heterologous populations of immature bone marrow cells consisting of progenitor cells of macrophages, dendritic cells and granulocytes. Recent studies have revealed that the accumulation of MDSCs in the mouse spleen plays a pivotal role in suppressing the immune response following JEV infection. However, the mechanisms by which JEV induces MDSCs are poorly understood. Here, it was found that JEV infection induces mitochondrial damage and the release of mitochondrial DNA (mtDNA), which further leads to the activation of TLR9. TLR9 deficiency decreases the M-MDSCs population and their suppressive function both in vitro and in vivo. Moreover, the increase of MHCⅡ expression on antigen-presenting cells and CD28 expression on T cells in TLR9-/- mice was positively correlated with M-MDSCs reduction. Accordingly, the survival rate of TLR9-/- mice dramatically increased after JEV infection. These findings reveal the connections of mitochondrial damage and TLR9 activation to the induction of M-MDSCs during JEV infection.


Sujet(s)
Souris knockout , Cellules myéloïdes suppressives , Récepteur-9 de type Toll-like , Récepteur-9 de type Toll-like/métabolisme , Récepteur-9 de type Toll-like/génétique , Animaux , Cellules myéloïdes suppressives/immunologie , Cellules myéloïdes suppressives/métabolisme , Souris , Souris de lignée C57BL , Mitochondries/métabolisme , ADN mitochondrial/génétique , ADN mitochondrial/métabolisme , Monocytes/immunologie , Monocytes/métabolisme
20.
J Immunother Cancer ; 12(4)2024 Apr 04.
Article de Anglais | MEDLINE | ID: mdl-38580334

RÉSUMÉ

BACKGROUND: Checkpoint inhibitor-induced hepatitis (CPI-hepatitis) is an emerging problem with the widening use of CPIs in cancer immunotherapy. Here, we developed a mouse model to characterize the mechanism of CPI-hepatitis and to therapeutically target key pathways driving this pathology. METHODS: C57BL/6 wild-type (WT) mice were dosed with toll-like receptor (TLR)9 agonist (TLR9-L) for hepatic priming combined with anti-cytotoxic T lymphocyte antigen-4 (CTLA-4) plus anti-programmed cell death 1 (PD-1) ("CPI") or phosphate buffered saline (PBS) control for up to 7 days. Flow cytometry, histology/immunofluorescence and messenger RNA sequencing were used to characterize liver myeloid/lymphoid subsets and inflammation. Hepatocyte damage was assessed by plasma alanine transaminase (ALT) and cytokeratin-18 (CK-18) measurements. In vivo investigations of CPI-hepatitis were carried out in Rag2-/- and Ccr2rfp/rfp transgenic mice, as well as following anti-CD4, anti-CD8 or cenicriviroc (CVC; CCR2/CCR5 antagonist) treatment. RESULTS: Co-administration of combination CPIs with TLR9-L induced liver pathology closely resembling human disease, with increased infiltration and clustering of granzyme B+perforin+CD8+ T cells and CCR2+ monocytes, 7 days post treatment. This was accompanied by apoptotic hepatocytes surrounding these clusters and elevated ALT and CK-18 plasma levels. Liver RNA sequencing identified key signaling pathways (JAK-STAT, NF-ΚB) and cytokine/chemokine networks (Ifnγ, Cxcl9, Ccl2/Ccr2) as drivers of CPI-hepatitis. Using this model, we show that CD8+ T cells mediate hepatocyte damage in experimental CPI-hepatitis. However, their liver recruitment, clustering, and cytotoxic activity is dependent on the presence of CCR2+ monocytes. The absence of hepatic monocyte recruitment in Ccr2rfp/rfp mice and CCR2 inhibition by CVC treatment in WT mice was able to prevent the development and reverse established experimental CPI-hepatitis. CONCLUSION: This newly established mouse model provides a platform for in vivo mechanistic studies of CPI-hepatitis. Using this model, we demonstrate the central role of liver infiltrating CCR2+ monocyte interaction with tissue-destructive CD8+ T cells in the pathogenesis of CPI-hepatitis and highlight CCR2 inhibition as a novel therapeutic target.


Sujet(s)
Hépatite , Monocytes , Humains , Souris , Animaux , Lymphocytes T CD8+ , Récepteur-9 de type Toll-like , Souris de lignée C57BL , Hépatite/traitement médicamenteux , Hépatite/étiologie
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