| 1. |
- Ahlgren, Kerstin M.
(författare)
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Immunological Studies using Human and Canine Model Disorders
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The studies presented in this thesis focus on human and canine models for autoimmune disease, with the main aim to gain new knowledge about disease mechanisms and to further evaluate the dog as a model for autoimmune disease. Autoimmune Polyendocrine Syndrome type 1 (APS-1) is a hereditary human multiorgan disease caused by mutations in the autoimmune regulator (AIRE) gene. Hallmarks of APS-1 are chronic mucocutaneous candidiasis caused by Candida albicans, together with the autoimmune endocrine disorders hypoparathyroidism and adrenocortical failure. Many human diseases have an equivalent disease in dogs. Because humans share environment, and in part life style with the dogs they provide an interesting model for further genetic studies. Immune responses to Candida albicans in APS-1 patients displayed an increased secretion of the proinflammatory cytokine IL-17A and similar results were also found in AIRE deficient mice. Anticytokine autoantibodies to IL-17A, IL-17F and IL-22 were detected in APS-1 patients, and a radioligand binding assay for measuring these autoantibodies was developed and evaluated. In the canine studies we investigated whether canine diabetes mellitus could serve as a model for human autoimmune diabetes mellitus. Furthermore, we investigated type I IFN responses in Nova Scotia duck tolling retriever dogs with a systemic autoimmune disease resembling human SLE. Four assays were used in search for signs of humoral autoimmunity in diabetic dogs. However, no evidence for a type 1 diabetes-like phenotype in dogs was found. Sera from Nova Scotia duck tolling retrievers suffering from steroid-responsive meningitis arteritis elicited an increased expression of IFN-inducible genes in the canine MDCK cell line. This suggests that these dogs have an IFN signature, as seen in human SLE.
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| 2. |
- Alimohammadi, Mohammad, 1978-
(författare)
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Molecular Targets in Autoimmune Polyendocrine Syndrome Type1 and Their Clinical Implications
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Autoimmune diseases occur when the immune system attacks and destroys healthy body tissue. Autoimmunity is known to cause a wide range of disorders, and is suspected to be responsible for many more. Most autoimmune disorders are chronic and cause severe morbidity for the patients, and are also costly for society. A majority of these disorders are today considered as complex diseases with incompletely known etiology. Hence, model systems for studying the pathogenesis of autoimmunity are important to unravel its causes. Autoimmune Polyendocrine Syndrome Type 1 (APS-1), (OMIM 240300), is a rare autoimmune disorder. Patients with APS-1 progressively develop multiple organ-specific autoimmune lesions involving both endocrine and non endocrine tissues. Typical autoimmune disease components in APS-1 are hypoparathyroidism, Addison’s disease, vitiligo, alopecia and type 1 diabetes. The gene preventing APS-1 has been identified and designated Autoimmune Regulator (AIRE). It has been shown that mutations of AIRE cause loss of tolerance to self-structures, resulting in organ-specific autoimmunity. Although APS-1 is a rare syndrome occurring mainly in genetically isolated populations, the disease components of APS-1 are, in isolated forms, not unusual in the general population and affect many patients. Hence, APS-1 is an attractive model disease for studies of molecular mechanisms underlying organ-specific autoimmunity. This thesis concerns investigations in which two novel autoantigens are identified in APS-1 and used in serological diagnosis of the disease. NALP5, is identified as a parathyroid autoantigen - an important finding since autoimmune hypoparathyroidism is one of the cardinal symptoms of APS-1. Additionally, KCNRG is identified as a bronchial autoantigen in APS-1 patients with respiratory symptoms. Finally, studies that compare the immune response in APS-1 patients and the mouse model for APS-1 are presented.
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| 3. |
- Ardesjö, Brita, 1979-
(författare)
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Autoantigens in Inflammatory Bowel Disease and Primary Sclerosing Cholangitis
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Inflammatory bowel disease (IBD) comprises diseases that are characterized by chronic or relapsing inflammation of the gastrointestinal tract. Primary sclerosing cholangitis (PSC) is an extraintestinal manifestation in IBD. Immunoreactivity against an autoantigen that is expressed both in the gastrointestinal tract and the biliary tract could be the link between these diseases. A possible source of such an antigen is goblet cells. Immunostainings of normal human tissues using IBD patient sera showed goblet cell immunoreactivity against goblet cells in all parts of the gastrointestinal tract. The most frequent immunostaining was found against goblet cells in the appendix against which 84% (42/50) of IBD patients compared to 8% (4/50) of healthy blood donors showed immunoreactivity. To identify the corresponding antigen we used three different approaches, investigation of immunoreactivity to different candidate proteins compared to IBD sera, immunoscreening of an appendiceal cDNA library, and immunoprecipitation of protein lysates from mucin producing cells followed by SDS-PAGE and 2D gel electrophoresis. These approaches led to the identification of several candidate autoantigens of which complement C3 is the most promising. A novel staining pattern with strong immunoreactivity to granules and the apical membrane of biliary epithelial cells was identified with 35% (12/34) of PSC sera compared to none of healthy controls (n=28). Screening of a cDNA library from normal human choledochus identified PDZ domain containing 1 (Pdzk1) and Glutathion S transferase theta 1 (GSTT1) as potential candidates. Pdzk1 is an interesting candidate which is expressed in the intestinal tract and bile ducts. GSTT1 antibodies were not specific for PSC and are thought to develop as an alloimmune response in patients with the GSTT1-null genotype. In conclusion, we have identified specific immunoreactivity to goblet cells and biliary epithelial cells using sera from patients with IBD and PSC respectively. We have also identified several potential autoantigens.
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| 4. |
- Dalin, Frida, 1984-
(författare)
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Model diseases for studies of autoimmunity.
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The events triggering autoimmune diseases are to large extent unknown and model diseases are an important tool in studies aiming to elucidate molecular mechanisms in autoimmunity. Autoimmune Addison’s disease (AAD) is a rare disease characterized by autoimmune destruction of adrenal glands and most patients with AAD have autoantibodies against the enzyme 21‑hydroxylase in the adrenal cortex. The autoimmune destruction in AAD is however suspected to be initiated by T cells. One of the most important investigations in this thesis was to characterize the T cell response in AAD. It could be concluded the T cells in AAD patients respond to three immunodominant epitopes on the 21-hydroxylase.In addition, this thesis aims to gain updated data on comorbidities, replacement therapy, autoantibody profiles, and metabolic factors in AAD. A cohort of 660 AAD patients was studied and it was found that AAD patients are prone to develop other autoimmune conditions. AAD is one of three main disease components Autoimmune Polyendocrine Syndrome type 1 (APS-1), a rare disorder caused by mutations in the AutoImmune REgulator gene (AIRE) that can be potentially fatal without timely diagnosis. Screening for autoantibodies against interferon-ω, interferon-α4, and interleukin-22 revealed four new APS-1 patients among the AAD cohort, confirmed by the presence of disease causing mutations in the AIRE gene.Cancer Associated Retinopathy (CAR) is a paraneoplastic phenomenon arising as a consequence to an autoimmune response triggered by a malignant neoplasm present in the body. This disease is devastating and it is valuable to identify new biomarkers associated with CAR, not least from a tumor diagnostic perspective. In this thesis, a patient with osteosarcoma and CAR was studied and by screening of a proteom array, and the novel CAR autoantigen Aryl hydrocarbon receptor interacting protein-like 1 (AIPL1) was identified.In conclusion, this thesis covers studies on T cell and B cell responses in AAD. Moreover, it includes an update on clinical and immunological characterisation of AAD patients. Finally, a novel autoantigen in CAR was identified and proposed as a diagnostic marker for the paraneoplastic syndrome.
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| 5. |
- Hässler, Signe, 1976-
(författare)
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Autoimmune Regulator Deficient Mice, an Animal Model of Autoimmune Polyendocrine Syndrome Type I
- 2006
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Autoimmune diseases develop when the immune system fails to distinguish self from non-self or when the immune system is hypersensitive to endogenous or exogenous danger signals, or when a tissue erroneously sends a danger signal to the immune system. The education of the immune system to distinguish self from non-self is mainly carried out in the thymus and gives rise to central tolerance, whereas the ability to sense a danger or a healthy tissue constitutes peripheral tolerance. In these studies we have investigated the peripheral tolerance mechanisms controlled by the autoimmune regulator (Aire) gene in Aire deficient mice, an animal model of the monogenic disease autoimmune polyendocrine syndrome type I (APS I).Aire-/- mice displayed increased numbers of myeloid-derived antigen-presenting cells (APCs) in the spleen, lymph nodes and peritoneum as well as more blood monocytes and metallophilic macrophages in the spleen. Monocytes were also increased in the blood of APS I patients. Monocyte precursors displayed an accelerated development in the bone marrow of Aire-/- mice, and Aire-/- APCs had an altered phenotype that caused an increased immune response in several different contexts. Aire-/- splenic and lymph node dendritic cells had an increased ability to activate naive T cells, partly as a result of an upregulated expression of the costimulatory molecule VCAM-1. In Aire-/- mice increased activity of the metallophilic macrophages in the splenic marginal zone seems to be responsible both for the activated phenotype of marginal zone B cells and for the frequent development of marginal zone lymphoma with aging. In a TCR transgenic model Aire deficiency caused an increased superantigen-mediated TCR revision in the spleen, perhaps as a result of the altered phenotype of APCs in the spleen. Finally, Aire was shown to influence autoimmune disease development by a macrophage-dependent mechanism in diabetes induced with multiple low dose streptozotocin injections.These results indicate that Aire has an important function in peripheral tolerance by controlling the phenotype of myeloid-derived APCs and thereby regulating the activation of T and B lymphocytes.
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| 6. |
- Isaksson, Magnus, 1975-
(författare)
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Initiation of Autoimmunity in Experimental Autoimmune Encephalomyelitis
- 2012
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The events that trigger an autoimmune disease remain largely unknown. To study these events animal models are necessary because symptoms of autoimmune diseases are preceded by a long asymptomatic period in humans.Experimental autoimmune encephalomyelitis (EAE) is the best characterized model for cell mediated autoimmunity and an animal model for the human disease multiple sclerosis. EAE is induced in rodents by immunization with myelin antigens (Ags) together with adjuvants. After immunization, T cells are primed in the periphery by Ag presenting cells and subsequently invade the central nervous system where they mediate parenchymal inflammation, resulting in demyelination and clinical symptoms of an ascending paralysis. It is now generally recognised that the main cell type mediating EAE is the T helper type 17 (Th17) cell.Tolerance to EAE can be attained by DNA vaccination, but how the immune response against the myelin Ags is abrogated after DNA vaccination is not known. By employing short interfering RNA technology, induction of the innate immune signalling molecule interferon (IFN) -β was found to be necessary for the protective effect of DNA vaccination in EAE. In addition, DNA vaccination inhibited subsequent autoimmune Th17 cell responses.The Toll-like receptors (TLRs) of the innate immune system have evolved to recognise conserved molecular structures on microbes and signalling through them almost exclusively converge on the molecule MyD88. Signalling via MyD88 was found to be required for induction of EAE since mice deficient in this molecule did not develop disease. Upstream signalling via TLR4 and TLR9 had tolerogenic properties.In studies of Ag presentation in EAE, two major subtypes of dendritic cells (DCs) were examined. Plasmacytoid DCs were found to have a promoting role in the induction of EAE, partly via type 1 IFNs. Myeloid DCs had a redundant role in the induction phase of EAE, neither disease severity nor encephalitogenic Th17 responses were affected by their absence during priming.These studies further demonstrate that the cells and molecules of the innate immune system exhibit a crucial role in controlling the adaptive immune system which mediates tissue damage in autoimmune diseases.
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| 7. |
- Landegren, Nils, 1986-
(författare)
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Biomarker Discovery in Tissue-specific Autoimmune Disease
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Autoimmune diseases encompass a diverse group of disorders that collectively affect 5% of the population. Despite large clinical variability, autoimmune disorders share a common etiology in that they all develop from immune responses against self. T-cell receptors and antibodies recognize distinct self-molecules and direct destructive effector mechanisms to the target organs. Characterization of autoimmune targets can help in the understanding autoimmune disease features and is of additional importance for subsequent use in clinical diagnosis.Rare monogenic disorder can provide an access to the study and understanding of mechanisms underlying common and more complex diseases. Autoimmune polyendocrine syndrome type 1 (APS1) is an autosomal recessive disorder caused by mutations in the AIRE gene, and is a valuable model of tissue-specific autoimmune disease. APS1 patients develop multiple autoimmune disease manifestations and display autoantibodies against the affected tissues.Recent development in protein array technology has opened a novel avenue for explorative biomarker studies in autoimmune disorders. Present-day protein arrays contain many thousands of full-length human proteins and enable autoantibody screens at the proteome-scale.In the current work I have utilized proteome arrays to perform a comprehensive study of autoimmune targets in APS1. Survey of established autoantigens revealed highly reliable detection of autoantibodies, and by exploring the full panel of 9000 proteins we further identified three novel, major autoantigens. Our findings revealed a marked enrichment for tissue-specific immune targets and further suggest that only a very limited portion of the proteome becomes targeted by the immune system in APS1. This work identifies prostatic transglutaminase 4 as novel male-specific autoantigen. In the mouse model of APS1 we could link TGM4 immunity with a tissue-destructive prostatitis, a compromised prostatic secretion of TGM4 and with defect in the establishment of central immune tolerance for TGM4. Our findings suggest prostate autoimmunity is a major manifestation in male APS1 patients with potential role in development of subfertility. In this doctoral work we also report on collecting duct autoantibodies in APS1 patients with interstitial nephritis and on the identification of aquaporin 2 as a collecting duct autoantigen. Collectively, the present investigations provide an overview-perspective on the autoimmune target repertoire in APS1 and identify novel autoimmune manifestations of the syndrome.
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| 8. |
- Nordmark, Gunnel, 1961-
(författare)
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Clinical and Experimental Studies in Primary Sjögren’s Syndrome and Systemic Lupus Erythematosus
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Autoimmune mechanisms and genetic susceptibility contribute to the pathogenesis of primary Sjögren’s syndrome and SLE. These chronic systemic autoimmune diseases have many serological and clinical features in common and have an impact on daily life. The studies in this thesis aim to elucidate their autoimmune mechanisms, define susceptibility genes and evaluate effects of androgen supplement on health-related quality of life. Autoantibodies against α-fodrin, a widely distributed cytoskeletal protein, were detected at similar frequencies in sera from patients with primary and secondary Sjögren’s syndrome and SLE. Consequently, testing for antibodies against α-fodrin would not add diagnostic value compared to conventional serological analysis and does not discriminate between these diseases. The type I interferon (IFN) system was found to be activated in primary Sjögren’s syndrome. IFN-α containing cells were detected in minor salivary gland biopsies, while sera from patients with primary Sjögren’s syndrome induced IFN-α production in the presence of apoptotic and necrotic cell material. This ability of sera correlated with the presence of antibodies against RNA-binding proteins and IFN-α production was dependent on RNA in immune complexes. The natural interferon producing cells/plasmacytoid dendritic cells (NIPC/PDC) were the IFN-α producers and blocking of FcγRIIa inhibited the production. Single nucleotide polymorphisms (SNPs) in two genes in the type I IFN signalling pathway, those for tyrosine kinase 2 and interferon regulatory factor 5, were strongly associated with SLE in a Swedish, Finnish and Icelandic population. The minor allele frequencies were lower in SLE patients than in healthy controls. These SNPs may decrease the function of the type I IFN system, thereby conferring protection against SLE. Supplementation with dehydroepiandrosterone (DHEA) in glucocorticoid treated women with SLE led to mild improvements in health-related quality of life in respect of mental well-being and sexuality, whereas physical well-being was unaffected.
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| 9. |
- Sahlqvist, Anna-Stina, 1980-
(författare)
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Genetic Characterization of Chicken Models for Autoimmune Disease
- 2012
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Autoimmune diseases are endemic, but the disease mechanisms are poorly understood. A way to better understand these are to find disease-regulating genes. However, this is difficult as the diseases are complex, with several genes as well as environmental factors influencing the development of disease. A way to facilitate the search for genes responsible for the diseases is to use comparative genomic studies. Animal models are relatively easy to analyze since control of environment and breeding are obtained.The University of California at Davies – line 200 (UCD-200) chickens have a hereditary disease that is similar to systemic sclerosis. Using a backcross between UCD-200 chickens and red junglefowl (RJF) chickens we identified three loci linked to the disease. The loci contained immune-regulatory genes suggested to be involved in systemic sclerosis in humans, as well as a previously unidentified linkage between systemic sclerosis in UCD-200 chickens and IGFBP3.The Dark brown (Db) gene enhances red pheomelanin and restricts expression of eumelanin in chickens. The Db phenotype is regulated by an 8 kb deletion upstream of SOX10. Pigmentation studies are potentially useful when trying to identify pathogenic mechanisms and candidate genes in vitiligoThe Obese strain (OS) of chickens spontaneously develops an autoimmune thyroiditis which closely resembles human Hashimoto’s thyroiditis. By using an intercross between OS chickens and RJF chickens, we found several disease phenotypes that can be used in an ongoing linkage analysis with the goal to find candidate genes for autoimmune disease. An important phenotype to record and add to the linkage analysis is autoantibodies against thyroid peroxidase, since this phenotype is a key feature in Hashimoto’s thyroiditis. Previous attempts to measure these titres in OS chickens have failed, hence an assay was developed for this purpose.
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