| 1. |
- Banday, Viqar, 1984-
(författare)
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Metab-Immune analysis of the non-obese diabetic mouse
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Type 1A diabetes mellitus or T1D is a chronic disease characterized by T cell mediated destruction of the insulin producing β cells in the islets of Langerhans. The classical symptoms include high glucose levels in urine and blood, polyuria, and polydipsia. Complications associated with T1D include blindness, amputations, and end-stage renal disease, and premature death. The non-obese diabetic (NOD) mouse, first described in 1980, is widely used as a model organism for T1D. T1D disease in the NOD mouse shares a number of similarities to human T1D including dependence on genetic and environmental factors. More than 30 disease associated gene regions or loci (termed insulin dependent diabetes, or Idd, loci) have been associated with T1D development in NOD. For some of these Idds, the corresponding region in human has been linked to the development of T1D in human.T1D, both in humans and mice, is recognized as a T cell mediated disease. However, many studies have shown the importance of both the metabolome and the immune system in the pathogenesis of the disease. Appearance of autoantibodies in the serum of patients is the first sign of pathogenesis. However, molecular and cellular events precede the immune attack on the β-cell immunity. It has been shown that patients who developed T1D have an altered metabolome prior to the appearance of autoantibodies. Although much is known about the pathogenesis of T1D, the contribution of the environment/immune factors triggering the disease is still to be revealed. In the present study both metabolic and immune deviations observed in the NOD mouse was analyzed. Serum metabolome analysis of the NOD mouse revealed striking resemblance to the human metabolic profile, with many metabolites in the TCA cycle significantly different from the non-diabetic control B6 mice. In addition, an increased level of glutamic acid was of the most distinguishing metabolite. A detailed bioinformatics analysis revealed various genes/enzymes to be present in the Idd regions. Compared to B6 mice, many of the genes correlated to the metabolic pathways, showed single nucleotide polymorphism (SNP), which can eventually affect the functionality of the protein. A genetic analysis of the increased glutamic acid revealed several Idd regions to be involved in this phenotype. The regions mapped in the genetic analysis harbor important enzymes and transporters related to glutamic acid. In-vitro islet culture with glutamic acid led to increased beta cell death indicating a toxic role of glutamic acid specifically towards insulin producing beta cells.In the analysis of the immune system, B cells from NOD mice, which are known to express high levels of TACI, were stimulated with APRIL, a TACI ligand. This resulted in enhanced plasma cell differentiation accompanied with increased class switching and IgG production. NOD mice have previously been shown to react vigorously to T-dependent antigens upon immunization. In this study we confirmed this as NOD mice showed an enhanced and prolonged immune response to hen egg lysozyme. Thus, serum IgG levels were significantly increased in the NOD mice and were predominantly of the IgG1 subtype. Immunofluorescence analysis revealed increased number of germinal centers in the NOD mice. Transfer of purified B and T cells from NOD to an immune deficient mouse could reproduce the original phenotype as seen in the NOD mice. Collectively, this thesis has analyzed the metabolomics and immune deviations observed in the NOD mice.
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| 2. |
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| 3. |
- Banday, Viqar Showkat, et al.
(författare)
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Contribution of both B-cell intrinsic alterations as well as non-hematopoietic-derived factors in the enhanced immune response of the NOD mouse
- 2017
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Ingår i: Autoimmunity. - : TAYLOR & FRANCIS LTD. - 0891-6934 .- 1607-842X. ; 50:6, s. 363-369
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Tidskriftsartikel (refereegranskat)abstract
- The underlying cellular and molecular mechanism for the development of Type 1 diabetes is still to be fully revealed. We have previously demonstrated that the NOD mouse, a model for Type 1 diabetes, display a prolonged and enhanced immune response to both self and non-self-antigens. The molecular explanation for this defect however, has not been determined. In this study we immunized NOD and C57BL/6 (B6) with the conventional antigen i.e. hen egg lysozyme (HEL) and analyzed B cell activation, germinal center reaction and antibody clearance. Corroborating our previous observations NOD mice responded robustly to a single immunization of HEL. Immunofluorescence analysis of the spleen revealed an increased number of germinal centers in unimmunized NOD compared to B6. However, post immunization germinal center numbers were similar in NOD and B6. NOD mice showed lower response to BCR stimulation with anti-IgM, in particular at lower concentrations of anti-IgM. Antibody clearance in vivo did not differ between the strains. To determine the cell type that is responsible for the prolonged and enhance immune response, we reconstituted NOD-RAGs with cells from primed donors in different combinations. NOD B cells were required to reproduce the phenotype; however the non-lymphoid compartment of NOD origin also played a role. Based on our results we propose that preexisting GCs in the NOD promote the robust response and alteration in the BCR signaling could promote survival of stimulated cells. Overall, this mechanism could in turn also contribute to the activation and maintenance of autoreactive B cells in the NOD mouse.
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| 4. |
- Banday, Viqar Showkat, et al.
(författare)
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Elevated Systemic Glutamic Acid Level in the Non-Obese Diabetic Mouse is Idd Linked and Induces Beta Cell Apoptosis
- 2017
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Ingår i: Immunology. - : Wiley. - 0019-2805 .- 1365-2567. ; 150:2, s. 162-171
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Tidskriftsartikel (refereegranskat)abstract
- Although type 1 diabetes (T1D) is a T-cell-mediated disease in the effector stage, the mechanism behind the initial beta cell assault is less understood. Metabolomic differences, including elevated levels of glutamic acid, have been observed in patients with T1D before disease onset, as well as in pre-diabetic non-obese diabetic (NOD) mice. Increased levels of glutamic acid damage both neurons and beta cells, implying that this could contribute to the initial events of T1D pathogenesis. We investigated the underlying genetic factors and consequences of the increased levels of glutamic acid in NOD mice. Serum glutamic acid levels from a (NODxB6) F-2 cohort (n = 182) were measured. By genome-wide and Idd region targeted microsatellite mapping, genetic association was detected for six regions including Idd2, Idd4 and Idd22. In silico analysis of potential enzymes and transporters located in and around the mapped regions that are involved in glutamic acid metabolism consisted of alanine aminotransferase, glutamic-oxaloacetic transaminase, aldehyde dehydrogenase 18 family, alutamyl-prolyl-tRNA synthetase, glutamic acid transporters GLAST and EAAC1. Increased EAAC1 protein expression was observed in lysates from livers of NOD mice compared with B6 mice. Functional consequence of the elevated glutamic acid level in NOD mice was tested by culturing NOD. Rag2(-/-) Langerhans' islets with glutamic acid. Induction of apoptosis of the islets was detected upon glutamic acid challenge using TUNEL assay. Our results support the notion that a dysregulated metabolome could contribute to the initiation of T1D. We suggest that targeting of the increased glutamic acid in pre-diabetic patients could be used as a potential therapy.
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| 5. |
- Banday, Viqar Showkat, et al.
(författare)
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Increased expression of TACI on NOD B cells results in germinal centre reaction anomalies, enhanced plasma cell differentiation and immunoglobulin production
- 2016
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Ingår i: Immunology. - : Wiley. - 0019-2805 .- 1365-2567. ; 149:3, s. 297-305
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Tidskriftsartikel (refereegranskat)abstract
- B cells have an important pathogenic role in the development of type 1 diabetes in the non-obese diabetic (NOD) mouse. We have previously reported that NOD mice display an increased percentage of TACIhigh-expressing B cells compared with C57BL/6 mice and this trait is linked to chromosomes 1 and 8. In this paper the genetic association of the transmembrane activator, calcium modulator and cyclophilin ligand interactor (TACI) trait was confirmed using double congenic NOD.B6C1/Idd22 mice. TACI ligation by a proliferation-inducing ligand (APRIL) has been shown to influence plasma cell differentiation, immunoglobulin production and isotype switch. Hence, the functional consequence of the up-regulation of TACI on NOD B cells was analysed both in vitro and in vivo. NOD B cells stimulated with APRIL showed an enhanced plasma cell differentiation and class switch to IgG and IgA compared with B cells from C57BL/6 mice. Moreover, flow cytometry analyses revealed that germinal centre B cells in NOD failed to down-regulate TACI. Availability of the TACI ligand B-cell activating factor (BAFF) has been shown to be a limiting factor in the germinal centre reaction. In line with this, upon immunization with 4-hydroxy-3-nitrophenylacetyl hapten-conjugated hen egg lysozyme, NOD mice produced higher titres of low-affinity antibodies compared with C57BL/6 mice. This observation was supported by the detection of increased levels of BAFF in NOD germinal centres after immunization compared with C57BL/6 by immunofluorescence. Our results support the hypothesis that increased TACI expression on NOD B cells contributes to the pathogenesis of type 1 diabetes in the NOD mouse.
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| 6. |
- Brink, Mikael, et al.
(författare)
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Protein profiling and network enrichment analysis in individuals before and after the onset of rheumatoid arthritis
- 2019
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Ingår i: Arthritis Research & Therapy. - : BioMed Central. - 1478-6354 .- 1478-6362. ; 21:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Antibodies and upregulated cytokines and chemokines predate the onset of rheumatoid arthritis (RA) symptoms. We aimed to identify the pathways related to the early processes leading to RA development, as well as potential novel biomarkers, using multiple protein analyses.Methods: A case-control study was conducted within the Biobank of northern Sweden. The plasma samples from 118 pre-symptomatic individuals (207 samples; median predating time 4.1 years), 79 early RA patients, and 74 matched controls were analyzed. The levels of 122 unique proteins with an acknowledged relationship to autoimmunity were analyzed using 153 antibodies and a bead-based multiplex system (FlexMap3D; Luminex Corp.). The data were analyzed using multifactorial linear regression model, random forest, and network enrichment analysis (NEA) based on the 10 most significantly differentially expressed proteins for each two-by-two group comparison, using the MSigDB collection of hallmarks.Results: There was a high agreement between the different statistical methods to identify the most significant proteins. The adipogenesis and interferon alpha response hallmarks differentiated pre-symptomatic individuals from controls. These two hallmarks included proteins involved in innate immunity. Between pre-symptomatic individuals and RA patients, three hallmarks were identified as follows: apical junction, epithelial mesenchymal transition, and TGF-beta signaling, including proteins suggestive of cell interaction, remodulation, and fibrosis. The adipogenesis and heme metabolism hallmarks differentiated RA patients from controls.Conclusions: We confirm the importance of interferon alpha signaling and lipids in the early phases of RA development. Network enrichment analysis provides a tool for a deeper understanding of molecules involved at different phases of the disease progression.
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| 7. |
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| 8. |
- Carlsson, Emma
(författare)
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The importance of psychological and physical stressors on diabetes-related immunity in a young population – an interdisciplinary approach
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: The prevalence of immunological disorders such as type 1 diabetes (T1D) is increasingly common amongst children, adolescents and young adults. There is also an increase in psychosomatic symptoms (depression, insomnia, anxiety, headaches and fatigue etc.) as well as a decrease in physical activity amongst young people, affecting the well-being and overall health of our younger population. It is therefore important to study the effects of psychological and physical stressors on the immune system, to evaluate their impact on juvenile health.Aim: This thesis explores the impact of psychological and physical stressors on the cellular immune system with special focus on diabetes-related immunity in a young population, using an interdisciplinary approach.Method: When exploring the impact of psychological and physical stressors such as psychological stress due to exposure to psychological stressful experiences or degree of physical activity/training on the cellular immune system in children, adolescents and young women, peripheral blood mononuclear cells (PBMC) were stimulated with antigens (tetanus toxoid (TT) and β-lactoglobulin (βLG)) as well as diabetes-related autoantigens (insulin, heat shock protein 60 (HSP60), tyrosine phosphatase-2 (IA-2) and glutamic acid decarboxylase 65 (GAD65)) and secreted cytokines and chemokines were measured by multiplex fluorochrome technique (Luminex). Populations of Thelper (Th) cells (CD4+), T-cytotoxic (Tc) cells (CD8+), B cells (CD19+), Natural Killer (NK) cells (CD56+CD16+) as well as regulatory T (Treg) cells (CD4+CD25+FoxP3+CD127-), and their expression of CD39 and CD45RA were studied by flow cytometry. Diabetes-related parameters (glucose, C-peptide,proinsulin, pancreatic polypeptide and peptide YY) were measured to studyβ-cell activity and appetite regulation and cortisol was used as a biological marker for psychological and physical stress.Results: Children in families exposed to psychological stress showed an imbalanced cellular immune response as well as an increased immune response towards diabetes-related autoantigens. Also, previous exposure to psychological stress as well as current exposure to psychological stress in young women showed an increased immune response towards diabetes-related autoantigens. Further, previous exposure to psychological stress in young women showed increased numbers of circulating CD56+CD16+ NK cells as wellas decreased numbers of circulating CD4+CD25+FoxP3+CD127- Treg cells. High physical activity in children showed decreased spontaneous immune response as well as a decreased immune response towards diabetes-related autoantigens, while low physical activity in children showed an increased immune response towards diabetes-related autoantigens. Further, endurance training in adolescents, especially in adolescent males and young adolescents, showed an increased immune response towards the diabetes-related autoantigen IA-2.Conclusion: It is evident that psychological and physical stressors such as exposure to psychological stress and degree of physical activity/training impact the cellular immune system. Experiences associated with psychological stress seem to have a negative effect on the cellular immune system in a young population, causing an imbalance in the immune system that could possibly induce diabetes-related immunity. High physical activity in children seems to have a protective effect against diabetes-related immunity. In contrast, low physical activity in children and endurance training in adolescents seems to induce diabetes-related immunity. It is very likely that psychological stressful experiences, low physical activity and intense training such as endurance training all play important roles in the immunological process leading to the development of type 1 diabetes.
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| 9. |
- Kindstedt, Elin, et al.
(författare)
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Innate lymphoid cells are present in gingivitis and periodontitis
- 2019
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Ingår i: Journal of Periodontology. - : Wiley-Blackwell. - 0022-3492 .- 1943-3670. ; 90:2, s. 200-207
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Innate lymphoid cells (ILCs) are the most recently identified leukocytes of the immune system and these cells are increasingly acknowledged to play important roles in host defence and tissue repair. ILCs are also contributors of inflammatory diseases such as asthma and colitis. We analyzed the presence and relative proportions of the different ILC subsets (ILC1, ILC2 and ILC3) in gingivitis and periodontitis. Further, we investigated if ILCs express receptor activator of nuclear factor kappa-B ligand (RANKL), a cytokine crucial for osteoclast differentiation and bone resorption.METHODS: We collected gingivitis and periodontitis soft tissue and characterized ILC subsets including RANKL expression in single-cell suspensions using flow cytometry.RESULTS: ILCs were detected both in gingivitis and periodontitis. The majority of ILCs, in both conditions, were ILC1s. Furthermore, RANKL expression was detected on a fraction of the ILC1s.CONCLUSIONS: Our discovery of the presence of ILCs both in gingivitis and periodontitis and concomitant expression of RANKL on a fraction of the ILC1 population suggest that these cells may be of importance in periodontal disease. In addition, our findings provide a new insight into the field of oral immunology.
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| 10. |
- Kolan, Shrikant, 1983-, et al.
(författare)
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Lack of non-hematopoietic SIRPα signaling disturbs the splenic marginal zone architecture resulting in accumulation and displacement of marginal zone B cells
- 2015
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Ingår i: Biochemical and Biophysical Research Communications - BBRC. - : Elsevier BV. - 0006-291X .- 1090-2104. ; 460:3, s. 645-650
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Tidskriftsartikel (refereegranskat)abstract
- Signal regulatory protein α (SIRPα) is an immunoglobulin super family protein predominantly expressed by myeloid but not lymphoid cells, and its role in lymphocyte homeostasis and function is still to be revealed. We demonstrate that mice bearing a mutant SIRPα lacking the cytoplasmic signaling domain (SIRPα MT) had an increased amount of splenic marginal zone (MZ) B cells compared to wild-type controls. Immunohistochemical analysis revealed an increased localization of MZB cells into B cell follicular areas of the white pulp in SIRPα MT spleens. However, we found no signs of an increased MZB cell activation level in MT mice. The immune response to T-independent antigens in vivo was slightly increased in SIRPα MT mice while sorted MZB from these mice responded normally to LPS in vitro. Bone marrow reconstitution experiments demonstrated that the MZB cell phenotype of SIRPα MT mice was due to lack of SIRPα signaling in non-hematopoietic cells. In contrast, MZ retention of MZ macrophages required hematopoietic SIRPα, while normal distribution of metallophilic macrophages required non-hematopoietic SIRPα signaling. In summary, these data identified SIRPα signaling in non-hematopoietic cells to play an important role in regulating the numbers and positioning MZB cell in the spleen.
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