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Multiple sclerosis – is a dysregulated immune response the route to illness via Epstein-Barr virus reactivation?Lidén, Ellinor January 2020 (has links)
Background: Throughout human history infectious agents such as viruses have been one of the biggest threats to public health. One example of infectious agents that can cause severe malignant conditions in humans is the Epstein-Barr virus (EBV). This virus has been researched for decades but still a lot of its potential malignant functions remain to be elucidated. Autoimmunity, and especially multiple sclerosis (MS), has been strongly associated to EBV infection for a long time but the exact mechanisms behind this relationship are still largely unknown. Aim: The main aim of this study was to investigate the evidence connecting an EBV-specific dysregulated immune response to MS. Methods: This paper is written as a systematic review examining the latest science within the studied field. PubMed was searched for articles published between 2010-2020. Results: In total 15 studies were reviewed. Five out of seven studies found an altered antibody response towards EBV in patients with MS, while one demonstrated somewhat mixed results and one could not support such a pattern. Seven out of eight studies found an altered T cell response towards EBV in MS patients, while one could only support such a trend. Conclusions: This review confirms that there is strong evidence for a dysregulated EBV-specific immune response in MS patients. Evidence for a causal relationship between the failure to control a reactivated EBV infection and the progression of disease is suggestive, but this needs to be confirmed by further studies.
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Macrophage activation phenotypes in type 1 diabetes pathogenesis and therapy : Master thesisParsa, Roham January 2009 (has links)
Macrophages are an important key effector cell in the immune system which can practically be found in every tissue. Macrophages have for a long time been considered a population of cells only responsible for pro-inflammatory responses and anti-microbial activities. But over the past decade, many have come to realize the amazing plasticity of macrophages in response to different stimulations. The anti-microbial and pro-inflammatory macrophage is known as classically activated macrophages but newly discovered phenotypes have been revealed named wound-healing macrophages and regulatory macrophages. Through systematic screening we have identified an inducible macrophage activation state which has both wound-healing and regulatory capabilities activated by the novel cytokine combination IL-4/IL-10 with or without TGF-β.
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Increased Antibodies for the α7 Subunit of the Nicotinic Receptor in SchizophreniaChandley, Michelle J., Miller, Merry N., Kwasigroch, Christine Newell, Wilson, Tracy D., Miller, Barney E. 01 April 2009 (has links)
One of the etiological theories of schizophrenia is dysregulation of the immune system. Autoantibodies specific for the α7 subunit of the nicotinic receptor could potentially contribute to the pathophysiology of the disease. In this study, positive antibodies specific for the receptor were found to exist in 23% of the patients diagnosed with schizophrenia (n = 21). On the average, levels for the antibody were elevated in the schizophrenia patient population than in controls. The data also suggests that there is a significant correlation between antibody titer and age, lending support to the neurodegenerative nature of the disease.
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En litteraturstudie om curcumins effekt och säkerhet vid behandling av knäartros : Kan curcumin användas som substitut för NSAID samt paracetamol hos patienter med knäartros?Wanneborn, Felicia January 2022 (has links)
Introduktion: Knäartros är en degenerativ och låggradig inflammationssjukdom, som ungefär 22,9 % av alla över 40 år lider av. Det drabbar oftare kvinnor än män, och risken ökar vid bland annat fetma samt tidigare ledskador. Vid artros sker en skada på osteoblaster, kondrocyter och synoviocyter som stimulerar frisättning av tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6) samt matrixnedbrytande enzymer. Detta resulterar i smärta, ledsvullnad och degenerering av leden. Diagnos ställs genom klinisk undersökning med hjälp av exempelvis American College of Rheumatology (ACR)-kriterier. Detta kompletteras ofta med radiologisk undersökning och ibland används ett självskattningsformulär som exempelvis Western Ontario and McMaster Universities Arthritis Index (WOMAC). I WOMAC innebär en minskning av värdet en förbättring av den kliniska parametern. Artros behandlas till en början med non-steroidal anti-inflammatory drugs (NSAID)-preparat och paracetamol, mot inflammation och smärta. Curcuma longa (C. longa) även kallat gurkmeja har använts vid matlagning och traditionell medicin i nära 2500 år. Den mest aktiva enheten i C. longa är polyfenolen curcumin som utvinns från dess rhizomer. Den har visat sig vara bland annat anti-inflammatorisk och antioxidantisk, båda dessa egenskaper är viktiga vid behandling av knäartros. Curcumins biotillgänglighet är låg, men det utförs och har utförts studier för att finna formuleringar som höjer biotillgängligheten. På så vis kan effekten förbättras. Verkningsmekanismen för curcumin är inte helt klarlagd men tidigare studier tyder på att den exempelvis kan minska oxidativ stress och minska koncentrationerna av inflammatoriska biomarkörer som TNF-α, IL-1β och IL-6. Syfte: Om curcumin kan användas som ett substitut till standardbehandlingen med NSAID-preparat och paracetamol som inflammationshämmande och smärtlindrande, vid behandling av knäartros. Metod: Detta examensarbete är en litteraturstudie, sökningarna utfördes i databasen PubMed och Linnéuniversitetets Onesearch. Totalt valdes fem studier ut med kriterierna att studien skulle vara max 10 år, vara en klinisk studie samt att den primära utfallsvariabeln skulle involvera förändringar i WOMAC. Resultat: I fyra av studierna blev resultatet en statistisk signifikant minskning i kategorin WOMAC-fysisk funktion. I tre av studierna blev det en statistiskt signifikant minskning i WOMAC-smärta och i två av studierna blev det en statistiskt signifikant minskning i WOMAC-stelhet. I tre av studier minskade användningen av akutläkemedel i form av NSAID eller paracetamol varav en studie hade en statistiskt signifikant minskning jämfört med kontrollgruppen. Slutsats: Resultaten tyder på att curcumin kan vara effektiv som behandling vid knäartros. Den har visat sig ha både anti-inflammatoriska egenskaper och en smärtstillande effektt vilket tyder på att det skulle kunna vara möjligt att använda som substitut till NSAID och paracetamol. För att kunna fastställa att curcumin är en säker och effektiv behandling finns ett behov av fler och större studier.
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Cytosolic and Endosomal DNA-Sensing Pathways Differentially Regulate Inflammatory Arthritis, Autoantibody Production, and Bone Remodeling: A DissertationBaum, Rebecca A. 02 March 2016 (has links)
Autoimmune diseases such as rheumatoid arthritis (RA) are associated with debilitating chronic inflammation, autoantibody production, articular bone erosions and systemic bone loss. The underlying mechanisms and cell types that initiate these diseases are not fully understood, and current therapies mainly address downstream mechanisms and do not fully halt disease progression in all patients. Moreover, previous studies have largely focused on the role of adaptive immunity in driving these diseases, and less attention has been given to the contribution of innate immune pathways such as DNA sensor signaling pathways in initiating and/or perpetuating autoimmunity and erosive inflammatory arthritis.
Detection of microbial nucleic acids by DNA sensors such as endosomal toll-like receptors (TLRs) and cytosolic sensors is an early form of antiviral defense. Upon detection of nucleic acid, TLRs dependent on Unc93B and cytosolic sensors dependent on the adaptor stimulator of interferon genes (STING) orchestrate production of type 1 interferons and pro-inflammatory cytokines to resolve infection. Additionally, the cytosolic DNA sensor absent in melanoma 2 (AIM2), which is not dependent on STING, also recognizes microbial DNA and coordinates the cleavage of pro-IL-1β. Previous studies have largely focused on the role of these DNA sensors in macrophages and dendritic cells in the context of antiviral immunity. In recent years, however, the inappropriate recognition of host nucleic acids by these sensors has been associated with several autoimmune diseases including RA.
This dissertation aims to delineate the mechanisms by which DNA sensors contribute to inflammatory arthritis and bone remodeling in the context of a murine model of autoimmunity. In DNase II deficient mice, excessive accrual of undegraded, endogenous DNA leads to robust production of type 1 interferons (IFNs) and proinflammatory cytokines. The high levels of type 1 IFNs result in anemia and embryonic lethality; therefore, the gene for the type 1 IFN receptor (IFNaR) has also been deleted so that the mice survive. DNase II-/- IFNaR-/- double knockout (DKO) mice develop erosive inflammatory arthritis, anti-nuclear antibodies, and splenomegaly not seen in the DNase II+/- IFNaR-/- (Het) control group. To evaluate whether cytosolic or endosomal DNA sensors contribute to the clinical manifestations of DKO mice, genes involved in TLR or cytosolic sensor signaling were deleted on the DKO background. Genetically altered mice include STING/DNaseII/IFNaR TKO (STING TKO), AIM2/DNase II/IFNaR TKO (AIM2 TKO), and Unc93b/DNase II/IFNaR TKO (Unc93 TKO) mice.
Our hypothesis was that the STING, AIM2, and/or Unc93 pathways would contribute to the autoimmune manifestations in DNase II deficient mice. Rigorous examination of inflammation in these lines revealed important roles for both the STING and AIM2 pathways in arthritis. Despite the substantial effects of the STING and AIM2 pathways on arthritis, STING TKO and AIM2 TKO mice still exhibited prominent autoantibody production. Interestingly, inflammation persisted in Unc93 TKO mice while autoantibody production to nucleic acids was abrogated. Collectively, these data indicate that innate immune pathways contribute to the initiation/perpetuation of inflammatory arthritis and demonstrate that cytosolic and endosomal pathways play distinct roles in the manifestations of autoimmunity. Moreover, they reveal a previously undescribed role for AIM2 as a sensor of endogenous nucleic acids in inflammatory arthritis. Thus, therapeutics that target the STING and AIM2 pathways may be beneficial for the treatment of inflammatory joint diseases.
While the role of hematopoietic cells in driving autoimmunity has been well established, the contribution of stromal elements to disease pathogenesis is less well understood. Therefore, we generated bone marrow chimeras to delineate the contribution of hematopoietic and non-hematopoietic cells to the various autoimmune manifestations in DKO mice. These studies revealed that both donor hematopoietic and host radioresistant cells are required for inflammation in the joint as well as for other features of autoimmunity in DKO mice, including splenomegaly, extramedullary hematopoiesis, and autoantibody production. This data demonstrates that stromal host cells play a major role in DNA-driven autoimmunity. Moreover, these results suggest that targeting not only hematopoietic but also stromal elements may be advantageous in the setting of inflammatory arthritis.
In the final chapter of this thesis, a role for innate immune sensor pathways in bone is described. The majority of inflammatory arthritides have been shown to lead to systemic loss of bone. Surprisingly, however, we found that DKO mice accumulate trabecular bone in the long bones over time as well as ectopic bone in the spleens, both sites of robust DNA accrual. Moreover, deficiency of the STING pathway abrogated this bone accumulation. Collectively, these data demonstrate that DNA accrual promotes dysregulated bone remodeling through innate immune sensing pathways. These findings are the first to reveal a role for the STING pathway in bone and may unveil novel targets for the treatment of diseases associated with bone disorders.
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Rôle des récepteurs purinergiques P2X7 et d'apoptose Fas dans l'homéostasie des lymphocytes T et le développement des maladies auto-immunes. / Role of Purinergic P2X7 and Apoptosis Fas Receptors in T Lymphocyte Homeostasis and Autoimmune Desease DeveloppementMellouk, Amine 16 July 2018 (has links)
Mon étude a porté sur le rôle du récepteur purinergique P2X7 (P2X7R) dans les processus physiopathologiques impliqués dans le développement des maladies auto-immunes de type lupique. Les souris MRL/lpr, déficientes en récepteurs d’apoptose Fas (mutation lpr), développent spontanément ces pathologies suite à l’accumulation lymphocytes T pathogéniques CD4−CD8− (DN) B220+ dans les organes lymphoïdes secondaires. Nous avons observé que ces lymphocytes ont également un déficit d’expression en P2X7R à leur surface. Cela nous a amené à postuler que P2X7R pourrait jouer un rôle clé dans l’homéostasie des lymphocytes T et le développement du lupus. Afin de vérifier notre hypothèse, nous avons produit des souris C57BL/6J (B6) déficientes simultanément pour Fas (lpr) et P2X7R (P2X7KO). Ces souris présentent une accumulation massive de lymphocytes T DN B220+ et des titres très élevés en auto-anticorps et en cytokines proinflammatoires ce qui n’est pas le cas pour les souris B6 simples mutantes lpr ou P2X7KO confirmant pour la première fois l’implication de P2X7R dans l’homéostasie des lymphocytes T, en synergie avec le récepteur Fas. Les lymphocytes T DN pathogéniques responsables de la lymphoaccumulation sont issues majoritairement de la sous populations des lymphocytes T CD8+. L’inflammation chronique présente chez les souris B6/lpr P2X7KO induit l’activation de l’ensemble des populations lymphocytaires T CD4+ et CD8+ naïves conduisant à l’accumulation de lymphocytes T Effecteurs/Mémoires : EM et CM et atteignent parfois le stade exhausted PD1+TIM3+. Ces cellules accumulées CD4+, CD8+ et DN B220+ ont une capacité de réactivation réduite. Ce biais fonctionnel et phénotypique a été confirmé en comparant la réponse immunitaire adaptative anti-adénovirus entre des souris déficientes en Fas et/ou P2X7R. Les réponses cellulaires et humorales sont moins importantes dans les souris B6/lpr P2X7KO que B6, B6-P2X7KO. Ces réponses antivirales sont intermédiaires dans les souris B6/lpr. L’ensemble de ces résultats renforcent notre hypothèse sur le rôle synergique des récepteurs Fas et P2X7R dans l’homéostasie des lymphocytes T. Le taux d’apoptose induit par l’activation des récepteurs Fas ou P2X7R séparément est moins important dans les lymphocytes T CD8+ par rapport au lymphocytes T CD4+. La synergie Fas-P2X7R serait donc nécessaire pour l’homéostasie des lymphocytes T CD8+. Afin de préciser les mécanismes à l’origine de la maladie et d’identifier l’influence de chaque récepteur sur l’expression des loci de susceptibilité, nous avons séquencé les ARNm exprimés dans la rate et les ganglions lymphatiques des souris MRL/lpr avant et après le développement de l’auto-immunité ainsi que chez les souris B6, B6/lpr, B6 P2X7KO et B6/lpr P2X7KO. / My project aims to determine the role of the purinergic receptor P2X7 (P2X7R) in the pathophysiological processes involved in the development of autoimmune lupus-like syndrome. MRL/lpr mice, deficient for the cell death receptor Fas (lpr mutation), spontaneously develop this pathology following the accumulation of pathogenic B220+CD4−CD8− (DN) T lymphocytes in secondary lymphoid organs. We have observed that these lymphocytes are also deficient in P2X7R cell surface expression. This led us to hypothesize that P2X7R could play a key role in T cell homeostasis and lupus development. To test our hypothesis, we produced B6 mice deficient for both Fas (lpr) and P2X7R (P2X7KO). These mice, but not single mutant B6 mice (lpr or P2X7KO), develop a massive accumulation of DN B220+ T lymphocytes and high levels of autoantibodies and proinflammatory cytokines, confirming for the first time the involvement of P2X7R in T-cell homeostasis. I have found that the pathogenic DN T lymphocytes are predominantly derived from the CD8+ T lymphocyte subpopulation. Chronic inflammation in B6/lpr P2X7KO mice induces the activation of the whole CD4+ and CD8+ naïve T lymphocyte subpopulations leading to the accumulation of Effector/Memory and exhausted T lymphocytes. Accumulated T-cells lose the ability to be reactivated. To confirm these results, I compared the adaptive immune response against adenovirus between mice deficient for Fas (lpr mutation), P2X7R-deficient mice or both receptors. The cellular and the humoral responses were lower in the B6/lpr-P2X7KO mouse strain compared to B6, B6-P2X7KO and B6/lpr mouse strains. The antiviral immune response in the B6/lpr mice was lower than in B6 and B6-P2X7KO mice. These results reinforce our hypothesis about the synergistic role of both receptors in the maintaining of T cell homeostasis. Ours results suggest that Fas and P2X7R play their synergistic role in T-cell homeostasis. In collaboration with a team from the University of Taiwan, we sequenced the mRNAs expressed in the spleen and lymph nodes of MRL/lpr mice before and after the onset of the diseases as well as in the B6, B6/lpr, B6 P2X7KO and B6/lpr P2X7KO mouse strains in order to better understand the mechanism triggering the disease and to identify the role of each receptor on the expression of the susceptibility loci.
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Understanding the Role of Androgen Receptor Signaling in Modulating p38-alpha Mitogen-Activated Protein Kinase in Experimental Autoimmune EncephalomyelitisVoorhees, Grace Kathryn 01 January 2019 (has links)
Multiple Sclerosis (MS) is an inflammatory autoimmune disease of the central nervous system, characterized by axonal demyelination and multifocal inflammation. Like many autoimmune diseases, it is a sexually dimorphic disease, being 3-4 times more common in females than in males. p38α MAP kinase (MAPK) has an integral role in modulating inflammatory processes in autoimmunity. Conditionally ablating p38α MAPK in myeloid cells in B6 mice shows a sex difference in the animal model of MS, experimental autoimmune encephalomyelitis (EAE). In the absence of sex hormones, this sex difference was reversed, suggesting a role for sex hormones in modulating p38α MAPK signaling in EAE. Based on these findings, we hypothesized that pro-inflammatory functions in EAE is p38-indepdendent in the presence of androgens and p38-dependent in the presence of estrogens. For the purposes of this project, the role of androgens was evaluated. Both in vivo and in vitro techniques were used to assess how androgen receptor (AR) signaling: 1) impacts EAE pathogenesis, and 2) impacts the role of p38α in EAE pathogenesis and macrophage function. To this end, using Cre-Lox technology, we generated mice deficient in: 1) AR globally or conditionally in macrophages, as well as 2) mice doubly deficient in AR and p38α. In vivo results from p38α-sufficient global AR knockout mice show no effect of global AR deletion on EAE pathogenesis. Surprisingly, results from p38α-sufficient conditional AR knockout mice showed significant worsening in disease compared to WT counterparts, suggesting that AR signaling in myeloid cells has a protective role in EAE pathogenesis. These findings implicate a protective role for AR signaling in EAE. Studies with mice doubly deficient in p38α and AR to determine whether AR regulates the role of p38α in EAE are ongoing, but so far show no effect on AR deletion on the role of p38α MAPK. Further studies with larger cohorts of mice are needed elucidate the relationship between AR and p38α MAPK signaling in myeloid cells in EAE pathogenesis. In vitro studies using the immortalized macrophage cell line RAW 264.7 showed that pharmacologic inhibition of p38 MAPK after stimulation with LPS reduced the production of classic pro-inflammatory cytokines IL-6 and TNFα, and effect that was not affected by treatment with 5-dihydrotestosterone, suggesting that the AR does not modulate the role of p38α in cytokine production. These findings implicate no direct role of AR signaling on the functional role of p38α MAPK in the myeloid cell lineage in inflammatory and autoimmune responses.
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Genetic And Functional Approaches To Understanding Autoimmune And Inflammatory PathologiesRaza, Abbas 01 January 2020 (has links)
Our understanding of genetic predisposition to inflammatory and autoimmune diseases has been enhanced by large scale quantitative trait loci (QTL) linkage mapping and genome-wide association studies (GWAS). However, the resolution and interpretation of QTL linkage mapping or GWAS findings are limited. In this work, we complement genetic predictions for several human diseases including multiple sclerosis (MS) and systemic capillary leakage syndrome (SCLS) with genetic and functional data in model organisms to associate genes with phenotypes and diseases.
Focusing on MS, an autoimmune inflammatory disease of the central nervous system (CNS), we experimentally tested the effect of three of the GWAS candidate genes (SLAMF1, SLAMF2 and SLAMF7) in the experimental autoimmune encephalomyelitis (EAE) mouse model and found a male-specific locus distal to these loci regulating CNS autoimmune disease. Functional data in mouse suggests this male-specific locus modulates the frequency of immune cells including CD11b+, TCRαβ+CD4+Foxp3+, and TCRαβ+CD8+IL-17+ cells during EAE disease. Orchiectomy experiments demonstrate that this male specific phenotype is dependent on testis but not testosterone (T) or 5α-dihydrotestosterone (DHT). Using a bioinformatic approach, we identified SLAMF8 and SLAMF9 along with other differentially expressed genes in linkage with MS-GWAS predictions whose expression is testis-dependent, but not directly regulated by T or DHT, as potential positional candidates regulating CNS autoimmune disease. Further refinement of this locus is required to identify the causal gene(s) that may be targeted for prevention and/or treatment of MS in men.
Using SCLS, an extremely rare disorder of unknown etiology characterized by recurrent episodes of vascular leakage, we identified and modeled this disease in an inbred mouse strain, SJL, using susceptibility to histamine- and infection-triggered vascular leak as the major phenotypic readout. This trait “Histamine hypersensitivity” (Histh/Histh) was mapped to a region on Chr 6. Remarkably, Histh is syntenic to the genomic locus most strongly associated with SCLS in humans (3p25.3). Subsequent studies found that the Histh locus is not unique to SJL but additional mouse strains also exhibit Histh phenotype. Considering GWAS studies in SCLS are limited by the small number of patients, we utilized interval-specific SNP-based association testing among Histh phenotyped mouse strains to predict Histh candidates. Furthermore, to dissect the complexity of Histh QTL, we developed network-based functional prediction methods to rank genes in this locus by predicting functional association with multiple Histh-related processes. The top-ranked genes include Cxcl12, Ret, Cacna1c, and Cntn3, all of which have strong functional associations and are proximal to SNPs segregating with Histh.
Lastly, we utilized the power of integrating genetic and functional approaches to understand susceptibility to Bordetella pertussis and pertussis toxin (PTX) induced histamine sensitization (Bphs/Bphs), a sub-phenotype with an established role in autoimmunity. Congenic mapping in mice had earlier linked Bphs to histamine H1 receptor gene (Hrh1/H1R) and demonstrated that H1R differs at three amino acid residues in Bphs-susceptible and -resistant mice. Our subsequent studies identified eight inbred mouse strains that were susceptible to Bphs despite carrying a resistant H1R allele. Genetic analyses mapped the locus complementing Bphs to mouse Chr 6, in linkage disequilibrium with Hrh1; we have designated this Bphs-enhancer (Bphse). Similar to the approaches used for Histh, we utilized interval-specific SNP based association testing and network-based functional enrichment to predict nine candidate loci for Bphse including Atp2b2, Atg7, Pparg, Syn2, Ift122, Raf1, Mkrn2, Timp4 and Gt(ROSA)26Sor. Overall, these studies demonstrate the power of integrating genetic and functional methods in humans and animal models to predict highly plausible loci underlying QTL/GWAS data.
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A proliferation inducing ligand (APRIL), une molécule, deux fonctions opposées dans l'autoimmunité / A proliferation inducing ligand (APRIL), one molecule, two opposite functions in autoimmunityBaert, Laurie 27 March 2019 (has links)
Les maladies auto-immunes résultent d’un dysfonctionnement du système immunitaire. L’étiologie de la pathologie reste souvent inconnue, compliquant la conception de traitements adaptés. Ce projet de thèse s’est focalisé sur la molécule « a proliferation inducing ligand » (APRIL), facteur de survie des plasmocytes (PC) produisant les anticorps, dans l’hépatite auto-immune (HAI) et la sclérose en plaques (SEP). Dans l’HAI, une principale caractéristique histologique est la présence d’un infiltrat lymphoplasmocytaire formant une hépatite d’interface dommageable. Dans cette maladie, nous avons d’abord pu mettre en évidence une corrélation positive entre l’expression d’APRIL et l’infiltration des PC dans les espaces portes. In vitro, nous avons observé une survie augmentée des PC du foie en présence d’APRIL. La corticothérapie communément prise par les patients HAI ne cible pas directement les PC. Cependant, nous avons remarqué une réduction simultanée de la densité de PC et de l’expression d’APRIL. Ainsi, cette étude étend le rôle de facteur de survie d’APRIL aux PC du foie dans l’HAI. Les rechutes sont fréquentes après arrêt du traitement, nous indiquant que les cellules pathogènes sont épargnées par la thérapie. Nos résultats montrent que le ciblage d’APRIL pourrait être précieux dans l’HAI. Propre de son rôle sur les PC, APRIL a été ciblée avec succès dans plusieurs maladies auto-immunes. Outre ces succès, un essai clinique visant à bloquer APRIL dans la SEP à malheureusement conduit à une exacerbation inattendue de la maladie. Nous avons été capables de montrer qu’APRIL cible un nouveau type cellulaire dans le système nerveux central, les astrocytes. La fixation d’APRIL à la surface des astrocytes dépend d’un nouveau partenaire de liaison, exprimé par ces derniers, les chondroïtines sulfates protéoglycans. Cette interaction induit la production de la cytokine anti-inflammatoire IL-10, conduisant à l’inhibition de, la prolifération des lymphocytes T auto-réactifs et la sécrétion de cytokines pro-inflammatoires. L’utilisation de souris déficientes pour APRIL dans le modèle standard de la SEP nous a permis de confirmer le rôle neuro-protecteur d’APRIL. Finalement, après injection d’APRIL recombinante dans ce modèle murin, une réduction de la sévérité de la maladie a été observée. Globalement, nous avons identifié APRIL comme une molécule à double rôle dans les maladies auto-immunes. / Autoimmune diseases result from a dysfunction of the immune system. The disease etiology is often unknown, complicating the design of appropriate treatments. This thesis project focused on the molecule “a proliferation inducing ligand” (APRIL), a survival factor for antibody-producing plasma cells (PC), in autoimmune hepatitis (AIH) and multiple sclerosis (MS). In AIH, one main histological feature is the presence of a lymphoplasmacytic infiltration forming a damaging interface hepatitis. In this disease, we first noticed a positive correlation between APRIL expression and PC infiltration in portal spaces. In vitro, we further observed an extended survival of liver PC in the presence of APRIL. The corticosteroid therapy commonly applied to AIH patients does not directly target PC. However, we noticed a concomitant reduction in portal PC density and APRIL expression. Hence, this study is extending the survival role of APRIL to liver PC in AIH. Relapses are frequent after treatment withdrawal, telling us that pathogenic cells are spared by the therapy. Our results indicate that APRIL targeting might also be valuable in AIH. Own to its role on PC, APRIL has been successfully targeted in several autoimmune diseases. Besides successes, a clinical trial aiming at APRIL blockade in MS has unfortunately led to an unexpected disease exacerbation. We have been able to show that APRIL targets a new cell type in the central nervous system, the astrocyte. The APRIL binding to astrocyte surface depends on a new binding partner, expressed by the latter, the chondroitin sulfate proteoglycans. This binding induces the production of the anti-inflammatory cytokine IL-10, leading to the inhibition of, self-reactive T-cell proliferation and pro-inflammatory cytokine secretion. Use of APRIL-deficient mice in the standard model of MS allowed us to confirm the neuroprotective role of APRIL. Finally, after recombinant APRIL injection in this model, a lowered disease severity was observed. Overall, we identified APRIL as a dual role molecule in autoimmune diseases.
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A nationwide survey of Aicardi-Goutieres syndrome patients identifies a strong association between dominant TREX1 mutations and chilblain lesions: Japanese cohort study / 本邦におけるAicardi-Goutieres症候群の全国調査の結果、TREX1遺伝子優性型変異と凍瘡症状に強い関連性を認めたAbe, Junya 24 March 2014 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第18135号 / 医博第3855号 / 新制||医||1001(附属図書館) / 30993 / 京都大学大学院医学研究科医学専攻 / (主査)教授 山田 亮, 教授 三森 経世, 教授 中畑 龍俊 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DGAM
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