| 1. |
- Backteman, Karin, 1960-
(författare)
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T Cells and NK Cells in Coronary Artery Disease : Longitudinal and methodological studies in humans
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Coronary artery disease (CAD) is the leading cause of death worldwide and most often due to atherosclerosis. Atherosclerosis is a chronic inflammatory process that involves the arteries, inclouding those that supply blood to the heart muscle. Although inflammation is an important contributing factor to atherosclerosis, the mechanisms are not fully understood. One mechanism contributing to atherogenesis may involve some infectious microorganisms such as cytomegalovirus (CMV). In atherosclerosis, the arterial wall becomes infiltrated with lipids followed by different types of leukocytes and inflammatory mediators (atherogenesis). Leukocytes recirculate continuously between the blood and lymphoid organs, such as lymph nodes, where the adaptive immune response is started and regulated.The general aim of this thesis was to increase the understanding of associations between lymphocyte populations and different conditions of CAD (unstable and stable). To assess changes over time, a longitudinal follow up design was mostly used. Therefore, also perspectives of longitudinal variation were included in the thesis.Paper I showed that flow cytometric evaluation of lymphocyte populations is a robust technique that can be used in longitudinal studies, both in clinical and research settings. It was also shown that the time of sampling over the year did not have a major impact on the findings.In paper II, thoracic lymph nodes were investigated to assess whether CAD-associated changes were more prominent in comparison with blood. As expected, there were several major differences in lymphocyte composition between lymph nodes and blood. However, the analysis of thoracic lymph nodes did not reveal any further changes that were not detected in blood. Thus, blood is still the most reliable compartment for studies of lymphocyte populations in CAD since it is not possible to examine the local findings in the artery wall.Natural killer (NK) cells are innate lymphocytes with both regulatory and effector functions. In paper II and III we confirmed previous findings that CAD patients have lower proportions of NK cells in blood. However, the NK subtype and cytokine profile (paper III, measured by subtype markers and intra-cellular cytokine staining) did not differ between patients and controls. During a 12-month follow-up, the proportions of NK cells increased, although not in all patients. Failure to reconstitute NK cell levels was associated with several components of the metabolic syndrome and with a persistent low-grade inflammation as measured by plasma IL-6 levels. The findings support the notion of a protective role for NK cells in inflammation.CD4+ but not CD8+ T cells were significantly increased in patients with both unstable and stable conditions compared with healthy individuals (paper IV). Subpopulations of CD4+ T cells (CD4+CD28null) have previously been associated with CAD. However, we show that CD28null and CD28null57+ cells within the CD4+ and CD8+ T cell populations were similar in CAD patients and healthy controls. Instead, CMV seropositivity was the major determinant of expanded CD28null and CD57+ T cell fractions in both patients and healthy individuals. During the 1 year follow up the proportion of CD4+CD28null and CD8+CD28null cells increased in patients, which may reflect an accelerated immunological ageing occurring after the cardiac event.
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| 2. |
- Bergström, Ida
(författare)
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Pro- and anti-inflammatory actions in coronary artery disease : with focus on CD56+ T cells and Annexin A1
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- ¨The atherosclerotic process is considered to be driven by an imbalance between proand anti-inflammatory actions. Still, the inflammatory state in patients with coronary artery disease (CAD) remains to be clarified. Annexin A1 (AnxA1) is a glucocorticoidinduced protein which may have a key role in the anti-inflammatory response as a mediator of glucocorticoid effects.The general aim of this thesis was to deepen the knowledge of pro- and antiinflammatory mechanisms in CAD via phenotypic assessments of immune cell subsets, in particular CD56+ T cells, and exploration of AnxA1. The long-term goal is to reveal basic mechanisms that will lead to the development of biomarkers, which may be used for individualized treatment and monitoring.The AnxA1 protein was constitutively expressed in both neutrophils and peripheral blood mononuclear cells (PBMCs). However, it varied considerably across PBMC subsets, being most abundantly expressed in monocytes. The AnxA1 expression was also higher in CD56+ T cells than in CD56- T cells.The expression of total AnxA1 protein in neutrophils was higher in patients with stable angina (SA) compared with controls. However, this was not accompanied by altered neutrophil activation status. Instead, the neutrophils from patients exhibited an enhanced anti-inflammatory response to exogenous AnxA1, emphasizing the potential of AnxA1 as an inhibitor of neutrophil activity. Only patients with acute coronary syndrome (ACS) showed an increase in cell surface-associated AnxA1.CAD patients, independent of clinical presentation, had increased proportions of CD56+ T cells compared with controls, a phenomenon likely to represent immunological aging. The CD56+ T cells were found to exhibit a distinct proinflammatory phenotype compared with CD56- T cells. In all T cell subsets, the expression of cell surface-associated AnxA1 was significantly increased in ACS patients, while it tended to be increased in post-ACS patients. In addition, dexamethasone clearly inhibited activation of CD56+ T cells in in vitro assays, whereas AnxA1 did not. The findings highlight the need to clarify whether the role of AnxA1 is different in T cells than in innate immune cells.In PBMCs, the mRNA levels of AnxA1 were increased in CAD patients, particularly in ACS patients. Correspondingly, the monocytes in ACS patients exhibited increased AnxA1 protein levels, both totally and on the cell surface. However, only cell surface-associated AnxA1 in monocytes correlated with the glucocorticoid sensitivity of PBMCs ex vivo. We propose the expression of cell surfaceassociated AnxA1 to be a promising candidate marker of glucocorticoid sensitivity, which needs further investigations in larger cohorts and intervention trials. Furthermore, the fact that PBMCs in post-ACS patients exhibited pro-inflammatory activity but no increase in cell surface-associated AnxA1 allow us to speculate that the glucocorticoid action and/or availability might be insufficient in these patients.
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| 3. |
- Boij, Roland, 1952-
(författare)
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Aspects of inflammation, angiogenesis and coagulation in preeclampsia
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Preeclampsia is a major challenge to obstetricians, due to its impact on maternal and fetal morbidity and mortality and the lack of preventive and treatment strategies. The overall aim of this thesis is to increase the knowledge of the pathogenesis of preeclampsia including the role of inflammation, angiogenesis and coagulation, both locally at the fetomaternal interface and in the maternal circulation. Uncompensated maternal endothelial inflammatory responses to factors from stressed trophoblasts seem to be a major contributor to the syndrome, together with an imbalance in angiogenesis and an activated coagulation system. An increasing amount of data indicates an involvement of the immune system with defect tolerance to the conceptus as an integral part of the pathogenesis, at least in early-onset preeclampsia (EOP).We showed that a single administration of human preeclampsia serum in pregnant IL-10−/− mice induced the full spectrum of preeclampsia-like symptoms including hypoxic injury in uteroplacental tissues and endotheliosis in maternal kidneys. Importantly, preeclampsia serum, as early as 12 to 14 weeks of gestation, disrupted cross talk between trophoblasts and endothelial cells in an in vitro model of endovascular activity (Tube formation test). These results indicate that preeclamptic sera can be used to better understand the pathophysiology and to predict the disorder. Preeclampsia has been associated with increased inflammation, aberrant angiogenesis and activated coagulation, but their correlation and relative contribution are unknown. We found that markers for all these mechanisms were independently associated with preeclampsia. Cytokines, chemokines, and complement factors seem all to be part of a Th1-associated inflammatory reaction in preeclampsia, more pronounced in EOP than in late-onset preeclampsia (LOP), in line with a more homogeneous pathogenesis in EOP as based on placental pathology. In women with intrauterine growth restriction (IUGR), with an anticipated pathologic placentation, only differences in levels for sFlt-1 and PlGF were found in comparison with mothers without IUGR. Thus, sFlt-1 and PlGF seem to be indicators of placental pathology, while other biomarkers might also reflect maternal endothelial pathology. Chemokines, in contrast to cytokines, may prove to be useful markers in preeclampsia.A deficiency in regulatory T (Treg) cells causing reduced immune regulatory capacity has been proposed in preeclampsia. Utilizing recent advances in flow cytometry phenotyping, we found no major alterations in circulating Treg numbers in preeclamptic women compared with normal pregnant and non-pregnant women. However, preeclampsia was associated with increased fractions of CTLA-4+ and CCR4+ cells within Treg subpopulations, which is in line with a migratory defect of Treg cells, and potentially associated with a reduced number of suppressive Treg cells at the fetomaternal interface. As we found that corticosteroid treatment affected the results, it should be accounted for in studies of EOP. Chemokines are supposed to be part of the immune adaptation in pregnancy. We found a decreased expression of CCL18 (Th2/Tregassociated), in trophoblasts from preeclamptic compared to normal pregnant women, indicating a local regulatory defect in preeclampsia, in line with our finding of a possible migratory defect of circulating Treg cells. Due to increased expression of CCL20 (Th17) and CCL22 (Th2) in first trimester placenta and increased circulating levels of CXCL10 (Th1) and CCL20 (Th17) in third trimester preeclamptic women, we suggest that CCL20 and CCL22 may be important for implantation and early placentation while in third trimester of a preeclamptic pregnancy CXCL10 and CCL20 mainly mirror maternal increased endothelial inflammation and aberrant angiogenesis. In summary, we found that preeclampsia is associated with increased inflammation, aberrant angiogenesis and activated coagulation, caused by placental factors in maternal peripheral circulation, more pronounced in the early-onset form of preeclampsia. It also appears that there is a defective modulation of the immune system in preeclamptic pregnancies. The results provide a better understanding of the pathogenesis of preeclampsia and have given suggestions to predictive markers for preeclampsia in the future.
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| 4. |
- Bruno, Valentina, 1986-
(författare)
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Clinical and immunological aspects on recurrent pregnancy loss
- 2020
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Paper I. Effects of low molecular weight heparin on the polarization and cytokine profile of macrophages and T helper cells in vitro. Sci Rep 2018. In paper I low molecular weight heparin (LMWH) in vitro effects on activation and polarization of central regulatory immune cells, such as Th cells and macrophages, were assessed, since LMWH has been widely used as an empiric treatment in recurrent pregnancy loss (RPL) and its immunological effects are not fully known. Isolated blood monocytes and T helper (Th) cells under different activation and polarizing conditions were cultured without or with LMWH at different concentrations. LMWH exposure induced an activated phenotype of macrophages, with high expression of HLA-DR and CD206 assessed by flow cytometry, associated with increased secretion of Th17-associated CCL20, and decreased secretion of CCL2 (M2-associated) and CCL22 (Th2), as measured by multiplex bead array. In accordance, LMWH exposure to Th cells reduced the proportion of CD25highFoxp3+ regulatory Tcells, and intensified IFN-γ secretion. Collectively, a mainly pro-inflammatory effect was noted on two essential tolerance-promoting cells, suggesting that potential immunological effects of LMWH may be effective mainly at an earlier gestational age to provide an appropriate implantation process in women with recurrent miscarriage. Paper II. Low-molecular-weight-heparin increases Th1- and Th17-associated chemokine levels during pregnancy in women with unexplained recurrent pregnancy loss: a randomized controlled trial. Sci Rep 2019.In paper II we investigated whether LMWH could modulate immune responses in vivo during pregnancy of women with unexplained RPL. A Swedish open multi-centre randomized controlled trial included 45 women treated with tinzaparin and 42 untreated women. Longitudinally collected plasma samples were obtained at gestational weeks (gw) 6, 18, 28 and 34 and analyzed by multiplex bead technology for levels of 11 cytokines and chemokines, chosen to represent inflammation and T-helper subset-associated immunity. LMWH-treated and untreated women showed differences during pregnancy of the Th1-associated chemokines CXCL10 (p = 0.01), CXCL11 (p < 0.001) and the Th17- associated chemokine CCL20 (p = 0.04), while CCL2, CCL17, CCL22, CXCL1, CXCL8, CXCL12, CXCL13 and IL-6 did not differ. Significantly higher plasma levels of CXCL10 and CXCL11 in treated women were detected at gw 28 and 34, compared to the untreated ones. Thus, a potential proinflammatory effect, linked mainly to Th1 immunity, was shown, suggesting an unfavorable effect of LMWH treatment, since Th1 responsea are responsible for breaking the fetal-maternal immune tolerance. Paper III. First-trimester trophoblasts obtained by chorionic villus sampling maintain tolerogenic and proteomic features in successful pregnancies despite a history of unexplained recurrent pregnancy loss. Am J Reprod Immunol. 2020.In paper III we investigate the “local” immune changes in women with RPL, since they potentially could reveal important mechanisms in RPL. Supernatants from superfluous chorionic villus sampling material culture was used in an ex vivo model, to determinate the immune proteomics profile and to perform functional assays for M2 like macrophages and regulatory T cells polarization, assessed by flow cytometry technique. Chorionic villi, human fetally derived placental tissue, were shown to induce an M2 like-phenotype and an expansion of Treg cells in an ex vivo model, and these immunological properties were maintained despite a history of RPL. Accordingly, no differences in the inflammation proteomic profile were found in RPL, compared to controls. Trophoblasts in an ex vivo model thus maintain tolerogenic and proteomic profile features in successful pregnancies, despite a history of RPL.
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| 5. |
- Danielsson, Olof, 1963-
(författare)
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The Clinical and Pathological Spectrum of Idiopathic Inflammatory Myopathies : Implications for pathogenesis, classification and diagnosis
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: Idiopathic inflammatory myopathies (IIM) constitute a heterogeneous group of diseases with severe consequences for the life of affected patients. Dermatomyositis, polymyositis and inclusion body myositis (IBM) are the classical representatives of this group. The treatments given today often have limited effects, and are taken at the cost of side effects. Major obstacles in the search for more effective treatments are; (1) an incomplete understanding of the disease mechanisms, (2) difficulties to delineate homogeneous disease groups for clinical studies and (3) the sometimes challenging task to diagnose these diseases.Aims: We addressed a number of “loose ends” in the areas of pathogenesis, classification and diagnosis; mechanisms of muscle fiber degeneration in IIM, with a focus of programmed cell death (apoptosis) and invasion of muscle fibers by inflammatory cells (partial invasion); protecting and mediating factors present in muscle; the association of other diseases with IIM, in particular celiac disease ; the evaluation of two classification systems and laboratory methods for increased diagnostic performance.The studies: We included 106 patients, diagnosed at the Neuromuscular unit in Linköping, Sweden, with pathological muscle findings consistent with IIM. The incidence in the county of Östergötland (during 5 years) was 7.3 per million/year (3 patients each year). Of 88 patients with confirmed IIM 4 (4.5 %) had celiac disease, 33 (38%) had an associated systemic inflammatory disease and 5 (5.7 %) had a malignancy. Ninety-nine patients were included for a comparison of two classification systems using criteria of the European Neuromuscle Centre (Amato/ENMC), and the widely used Bohan and Peter classification, both with the addition of IBM according to Griggs et al. Using the Amato/ENMC criteria the most prevalent diagnostic group after IBM (30%) was nonspecific myositis (23%), followed by polymyositis (20%) and dermatomyositis 17%). A substantial number of patients meeting Bohan and Peter (or Griggs) criteria were excluded by Amato/ENMC criteria, most (21/23) due to lack of detectable muscle weakness. Extended muscle sectioning increased the sensitivity of a muscle biopsy by 15 % and the specificity by 22%, and showed an overlap between disease groups. Muscle biopsies from patients with IIM and controls were used to investigate pathological findings considered specific for disease groups, and for the presence of programmed cell death (apoptosis) and disease protecting and mediating factors in muscle. The presence of apoptotic muscle fiber nuclei was detected in muscle with partial invasion (however not in the invaded fibers) in the presence of granzyme B and CD8+ cytotoxic T cells. The major apoptosis inhibiting protein Bcl-2 was shown to be constitutionally expressed in healthy muscle but weakened in IIM.Conclusion: We present apoptosis as a possible disease mechanism in parallel with partial invasion of fibers. Furthermore, partial invasion may not be a suitable distinguishing feature in the pathogenesis, or for classification and diagnosis of IIM. We also introduce the anti-apoptotic Bcl-2 as a possible relevant muscle fiber protecting factor. A more extensive pathological work-up improves classification and diagnosis of IIM. The proposed Amato/ENMC creates a substantial portion of patients with non-specific or unclassified myositis. Associated diseases are common in IIM, and also include celiac disease.
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| 6. |
- Edström, Måns, 1984-
(författare)
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Regulation of immunity in Multiple Sclerosis : CD4+ T cells and the influence of natalizumab
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Multiple sclerosis (MS) is an autoimmune disease targeting the central nervous system (CNS) and the most common neurological cause of disability in young adults. In most cases, the disease course is characterised by the cycling of relapses and remissions, so called relapsing-remitting MS (RR-MS). Although extensively studied, the underlying mechanisms are not fully elucidated, yet CD4+ T cells have been shown to be of importance in disease pathology. A range of treatments are available; the most effective to date being natalizumab, a monoclonal antibody directed against the adhesion molecule VLA-4 on the lymphocyte surface, thereby preventing entry into the CNS.The aim of this thesis was to assess the nature of lymphocyte populations in MS. This was achieved by studying CD4+ T helper cells (TH) and regulatory T cells (TREG) in peripheral blood. In addition, the influence of natalizumab was also investigated, both regarding the effect of the drug on the composition of the peripheral lymphocyte compartment as well as its effects on CD4+ T cells in vitro.We showed an imbalance in the mRNA expression of CD4+ T helper cell lineage specific transcription factors in peripheral blood. While TH1 and TH17 associated TBX21 and RORC expression was comparable in MS and healthy individuals, the TH2 and TREG associated GATA3 and FOXP3 expression was decreased in RR-MS. Given the reciprocally inhibitory nature of TH subsets, this might imply not only diminished function of TH2 and TREG cells but also a permissive state of harmful TH1 and TH17 cells. The size of the peripheral TREG population was unaltered in RR-MS. When analysed in detail, activated and resting TREG were distinguished, showing clear differences in FOXP3 and CD39 expression. Furthermore, when investigating these subpopulations functionally, the ability of activated TREG to suppress proliferation of responder T cells was found to be decreased in RR-MS patients compared to controls. To further investigate this defect, the global gene expression of TREG was compared between patients and controls. Gene set enrichment analysis revealed an enrichment (over-expression) of chemokine receptor signalling genes in RR-MS TREG, possibly suggesting a role for chemokines in TREG function.A sizable effect of natalizumab treatment was seen in the composition of peripheral lymphocyte populations after one year of treatment. While the number of lymphocytes increased over all, the largest increase was seen in the NK and B cell compartments. Furthermore, T cells from patients with MS displayed decreased responsiveness towards antigens and mitogens in vitro. Natalizumab treatment was able to normalise the responsiveness in blood, an effect not solely dependent on the increased number of cells.The importance of CD4+ T cells in human disease, including MS, was shown by a systems biology approach; using GWAS data, genes associated with CD4+ T cell differentiation were enriched for many, not only immunerelated, diseases. Furthermore, global CD4+ T cell gene expression (by microarray) could discriminate between patients and controls. Lastly, using in vitro treated CD4+ T cells, we could show that natalizumab perturbated gene expression differently in patients responding to the drug compared to those not responding.In conclusion, our results demonstrate an imbalance of peripheral CD4+ T cells in MS, along with a functional deficiency in the case of TREG. Taken together, these aberrations might result in differentiation and activation of harmful TH1 and TH17 cells, resulting in CNS tissue damage. The importance of CD4+ T cells was further demonstrated by the finding that genes associated with CD4+ T cell differentiation constitute a pleiotropic module common to a number of diseases. Investigation of natalizumab revealed drastic changes in the peripheral lymphocyte compartment caused by treatment. It also appears as treatment might influence the responsiveness of peripheral T cells to antigens. In addition, by using CD4+ T cell transcriptomics after in vitro drug exposure, prediction of treatment outcome may be possible.
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| 7. |
- Edvardsson, Maria, 1972-
(författare)
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Circulating levels and assessment of clinical laboratory analytes, in >80-year-old, apparently healthy, moderately healthy, and frail individuals
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Blood samples are often used to investigate the possible presence of disease and to make treatment decisions. In the interpretation of the results, comparison either with previous values from the same individual or with a set of appropriate group-based reference intervals are used. Current reference intervals for common laboratory analytes are often based on measurements from apparently healthy persons aged 18–65 years. Age is accompanied by a general decline in organ functions and it is difficult to determine whether a change in levels of laboratory analytes in an elderly individual can be attributed to age alone, independent of environmental or disease processes. Frailty can be seen as a consequence of age-related multifactorial deterioration – physical, cognitive and sensory – resulting in vulnerability and lack of adaptability to internal stressors such as infection or new medication and/or external stressors such as fall at home. Consensus about the definition of “frail” and “frailty” is missing, both nationally and internationally, the question arises whether different definitions of “frailty” affect the interpretation of analytes when comparing different groups of elderly.The overarching aim of the thesis was to interpret and assess circulating levels of some clinical laboratory analytes in relation to conventional reference values in ≥80-year-old, “apparently healthy”, “moderately healthy”, and “frail” individuals. Data originated from other studies, in which blood samples were collected from individuals ≥80-year-old. Comparisons in Paper I of levels of some laboratory analytes, from 138 nursing home residents (NHRs), was made with blood from reference populations, both blood donor and the NORIP study. The results indicated differences for some immunological (complement factor 3 and 4, immunoglobulin G and M) and chemical analytes (alanine aminotransferase (ALT), phosphate, albumin, sodium, creatinine and urea), but no differences in levels occurred for aspartate aminotransferase (AST), gamma-glutamyltransferase (γ-GT) or lactate dehydrogenase (LDH). It was unclear whether the differences were due to differences in age between the elderly and the reference populations or whether the elderly individuals had chronic diseases and were on medication. In Paper II, 569 individuals elderly individuals ≥80 years old were classified as “healthy”, “moderately healthy”, and “frail”, based on diseases, medications and physical and cognitive abilities. Statistical differences between the groups were found for the investigated analytes; albumin, ALT, AST, creatinine and γ-GT. In Paper IV, individuals from Paper II (n=569) were divided into two groups and thereafter divided into “apparently healthy”, “moderately healthy”, and “frail”. One group was subdivided into “apparently healthy”, “moderately healthy” and “frail” based on physical and cognitive abilities and the other group was divided based on the frailty index (FI). There was no statistical difference found between “apparently healthy” and “moderately healthy" groups, regardless of classification model used. Among “frail” individuals, differences in levels occurred for three out of the five investigated analytes: ALT, creatinine and g-GT, with lower levels occurring when the FI classification model was used. No differences in levels occurred for albumin or AST in “frail” individuals, regardless of classification model used. The aim of Paper III was to study whether 1-year changes in complete blood count (CBC) (including haemoglobin (Hb), red blood cell (RBC), erythrocyte volume fraction (EVF), mean corpuscular volume (MCV), mean corpuscular Hb concentration (MCHC), white blood cell (WBC) and platelet count (PLT)), C-reactive protein (CRP) and interleukin (IL)-1β, IL-1RA, IL-6, IL-8 and IL-10 are associated with survival in elderly NHRs aged >80 years. Elevated levels of CRP and IL-8 during 1-year follow-up were associated with reduced length of survival in elderly NHRs. Based on the present thesis it is clear that there is need for reference intervals that consider both age and health status in elderly individuals. A reasonable conclusion when interpreting levels of analytes in elderly individuals with disease or frailty is that individual evaluation based on the individual’s previous levels, is recommended.
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| 8. |
- Gyllemark, Paula, 1975-
(författare)
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Tick-borne diseases and the central nervous system : clinical and immunological aspects
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Lyme neuroborreliosis (LNB) is the dominating form of disseminated infection by the tick-borne bacteria Borrelia (B.) burgdorferi in Sweden as well as in Europe. The diagnosis of the manifestation is based on typical symptoms, together with elevated mononuclear cell count in the cerebrospinal fluid (CSF) and elevated levels of Borrelia-specific antibodies in the CSF. The diagnostic arsenal has, in recent years, been complemented by analysis of the chemokine CXCL13 in the CSF, with increasing levels in the early phase of the disease, even before antibodies can be detected in the CSF. Most patients recover within a couple of months after antibiotic treatment, but a few can suffer from residual symptoms. The mechanisms behind this are still puzzling, but there are indications that the host´s immune response may play a role. Prognostic markers would be desirable and in-creased understanding of pathogenetic mechanisms may provide a basis for development of new treatment strategies. Other agents besides B. burgdorferi have, however, also been detected in ticks collected in Sweden, but the knowledge of their impact on human health and their ability to invade the central nervous system (CNS) is limited. The aims of this thesis were to investigate a set of cytokines and chemokines associated with Th1 (CXCL10), Th2 (CCL22), Th17 (IL-17A, CXCL1, CCL20) and B cell (APRIL, BAFF, CXCL13) -related im-munity and its association with recovery in patients with LNB included both retrospectively and prospectively. The chemokine CXCL13 was further analysed, comparing the performance of two different diagnostic methods. In a large cohort of patients investigated for LNB we investigated signs of other tick-borne diseases by analysing serum and CSF using both molecular and serological techniques. In the retrospective cytokine/chemokine study, all investigated cytokines and chemokines; namely, APRIL, BAFF, CXCL13, IL-17A, CXCL1, and CCL20 could be detected at elevated levels in patients with LNB compared to controls. Patients with recovery > 3 months had higher levels of APRIL, BAFF, and IL-17A. In the prospective study, patients with short recovery (< 1 month) had lower levels of CCL20 and patients with prolonged recovery (> 6 months) had higher levels of IL-17A. The analysis of the chemokine CXCL13 with both an enzyme-linked immunosorbent assay (ELISA) with a best-performanced cut-off of 56 pg/mL and bead-based (Luminex) method with a best-performance cut-off of 158 pg/mL (both assays with 100% sensitivity and specificity) displayed the im-portance of different cut-offs depending on which method that is used.In 600 patients, we analysed serum and CSF with PCR for the different tick-borne agents Ana-plasma phagocytophilum, B. burgdorfer spp. (including B. miyamotoi), Neoehrlichia (N.) mikurensis, Rickettsia spp., Babesia spp. and tick-borne encephalitis virus. N. mikurensis and B. burgdorferi could be detected by PCR in sera from two patients. Neither PCR, nor serological analysis could detect any potential co-infections.In conclusion, we can corroborate the Th17-related immunity in the pathogenesis of LNB where IL-17A and CCL20 are plausible prognostic markers. Other tick-borne pathogens with possible dissemination to the CNS seems to be uncommon in south-eastern Sweden.
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| 9. |
- Hellberg, Sandra, 1986-
(författare)
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Effects of Pregnancy and Hormones on T cell Immune Regulation in Multiple Sclerosis
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Multiple sclerosis (MS) is characterized by a dysregulated immune system leading to chronic inflammation in the central nervous system. Despite increasing number of treatments, many patients continue to deteriorate. A better understanding of the underlying disease mechanisms involved in driving disease is a pre-requisite for finding new biomarkers and new treatment targets. The improvement of MS during pregnancy, comparable to the beneficial effects of the most effective treatment, suggests that the transient and physiological immune tolerance established during pregnancy could serve as a model for successful immune regulation. Most likely the immune-endocrine alterations that take place during pregnancy to accommodate the presence of the semi-allogenic fetus contribute to the observed disease improvement.The aim of this thesis was to characterize the dysregulated immune system in MS and define potential factors and mechanisms established during pregnancy that could be involved in the pregnancy-induced effects in MS, focusing on CD4+ T cells as one of the main drivers in immunity and in the MS pathogenesis. Using a network-based modular approach based on gene expression profiling, we could show that CD4+ T cells from patients with MS displayed an altered dynamic gene response to activation, in line with a dysregulated immune system in MS. The resulting gene module disclosed cell activation and chemotaxis as central components in the deviating response, results that form a basis for further studies on its modulation during pregnancy. Moreover, a combination of secreted proteins (OPN+CXCL1-3+CXCL10-CCL2), identified from the module, could be used to separate patients and controls, predict disease activity after 2 years and discriminate between high and low responders to treatment, highlighting their potential use as biomarkers for predicting disease activity and response to treatment.The pregnancy hormone progesterone (P4), a potential factor involved in the pregnancy-induced amelioration of MS, was found to significantly dampen CD4+ T cell activation. Further detailed transcriptomic profiling revealed that P4 almost exclusively down-regulated immune-related pathways in activated T cells, several related to or downstream of T cell activation such as JAKSTAT signaling, T cell receptor signaling and cytokine-cytokine receptor interaction. In particular, P4 significantly affected genes of relevance to diseases known to be modulated during pregnancy, where genes associated to MS were most significantly affected, supporting a role for P4 in the pregnancy-induced immunomodulation. By using another approach, the role of thymus in T cell regulation during pregnancy was assessed. Two established measures of thymic output, CD31 expression and TREC content, were used and showed that thymic output of T cells is maintained during human pregnancy, or even possibly increased in terms of regulatory T cells.This thesis further supports a pivotal role for CD4+ T cells and T cell activation in the MS pathogenesis and adds to the knowledge of how they could be involved in driving disease. We identified a novel strategy for capturing central aspects of the deviating response to T cell activation that could be translated into potentially clinically relevant biomarkers. Further, P4 is emerging as a promising candidate for the pregnancy-induced immunomodulation that could be of importance as a future treatment option. Lastly, maintained thymic output of T cells during human pregnancy challenges the rodent-based dogma of an inactive thymus during pregnancy. Thymic dysfunction has been reported not only in MS but also in rheumatoid arthritis, another inflammatory disease that improves during pregnancy, which highlights a potential role for thymus in immune regulation that could be involved in the pregnancy-induced amelioration.
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| 10. |
- Hellqvist, Eva, 1978-
(författare)
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Antigen interaction with B cells in two proliferative disorders : CLL and MGUS
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The aim of the work presented in this thesis was to elucidate B cell interaction with antigen in the two B cell proliferative disorders chronic lymphocytic leukemia (CLL) and monoclonal gammopathy of undetermined significance (MGUS). In the first part we investigated the antigen specificity of CLL cells and characterized Epstein-Barr virus (EBV)-transformed CLL cell lines with regard to phenotype and genotype. The second part consists of studies on the antigen presenting capacity of myelin protein zero (P0) specific MGUS B cells and their relation to T cells and development of polyneuropathy.The aim of the work presented in this thesis was to elucidate B cell interaction with antigen in the two B cell proliferative disorders chronic lymphocytic leukemia (CLL) and monoclonal gammopathy of undetermined significance (MGUS). In the first part we investigated the antigen specificity of CLL cells and characterized Epstein-Barr virus (EBV)-transformed CLL cell lines with regard to phenotype and genotype. The second part consists of studies on the antigen presenting capacity of myelin protein zero (P0) specific MGUS B cells and their relation to T cells and development of polyneuropathy.CLL cells are considered antigen experienced and different patient-derived CLL cells expressing B cell receptors (BCR) with highly homologous antigen binding sites are believed to have been selected by a common antigen at some point during the leukemogenesis. In paper I we investigated the antigen specificity of CLL-cell derived antibodies (Abs) with various IGHV gene usage and stereotyped BCR subset belonging. Identified CLL antigens included vimentin, filamin B, cofilin-1, proline rich acidic protein-1, cardiolipin, oxidized low density lipoprotein and Streptococcus pneumoniae capsular polysaccharides. Many of the CLL Abs studied displayed an oligo- or polyreactive antigen binding pattern and the identified antigens were either associated with apoptotic cells or microbial infection. This is similar to what has been described for innate natural antibodies, possibly indicating that CLL cells are derived from a natural-antibody- producing B cell population. Further characterization of CLL homology subset-2 antigen specificity showed binding to glands in human gastric mucosa corpus tissue sections for a CLL homology subset-2 Ab with HCDR3 motif-1, suggesting that this CLL subset recognize an autoantigen much like the CLL Abs tested in Paper I.Characterization of EBV-transformed CLL and normal lymphoblastoid cell lines (LCLs) in paper II showed that eight of the CLL cell lines were verified to be of authentic neoplastic origin. Indication for a biclonal CLL was found in two of the cell lines and two of the presumably normal LCLs turned out to represent the malignant CLL clone. For three cell lines no conclusive evidence for CLL origin could be found emphasizing the importance of verifying the identity of cell lines used in research.
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