| 1. |
- 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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| 2. |
- Jonsson, Yvonne, 1974-
(författare)
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Cytokines and immune balance in preeclampsia : a survey of some immunological variables and methods in the study of preeclampsia
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Preeclampsia is one of the most feared pregnancy complications, with a risk of maternal and fetal death and with no ideal therapy readily available. The cause of this strictly pregnancyrelated disease is still unknown and is therefore a great challenge to all researchers in the field of pregnancy-related pathophysiology.Today, the dominating theory of the origin of preeclampsia is defective initial placentation with insufficient penetration of the trophoblasts, leading to impaired maternal blood flow through narrow spiral arteries. However, the cause of this defective trophoblast behavior is not known. The maternal immune system has been proposed to have an influence on both the placentation and the subsequent systemic reactions. Therefore, it is very interesting to study the maternal immune system during preeclampsia, in hope of achieving a better understanding of this puzzling disease.Earlier studies have suggested that normal pregnancy requires a shift to a Th2/antiinflammatory type of immunity, at least directed towards the fetus and placenta, while some pregnancy complications, such as preeclampsia, could be due to a skewed Th1/proinflammatory type of immunity. However, the results from earlier studies designed to test the Th1/Th2 hypothesis in preeclampsia have not been consistent. Therefore, the aim of this thesis was to examine if established preeclampsia is associated with increased innate inflammatory responses and a deviation of adaptive responses towards Th1 when compared with normal pregnancy.Enumerations of cytokine-producing cells from peripheral blood did not show any difference in the production of IFN-γ, IL-4, IL-10 and IL-12 between women with preeclampsia and normal pregnancies. However, a decrease in the spontaneously produced levels of IL-5 was detected in cell cultures on peripheral blood mononuclear cells in women with preeclampsia. Furthermore, a decreased production of IL-10 in response to paternal antigens, believed to represent the fetus, was also detected for the preeclamptic women.Serum analysis showed increased levels of the pro-inflammatory mediators IL-6 and IL-8 during preeclampsia. Also, preeclamptic women displayed increased serum levels of the soluble IL-4 receptor, but no difference in the levels of IL-4 compared to normal pregnant women. This was an elusive finding, since the receptor was originally thought to reflect the levels of IL-4, but has recently been shown to have both agonistic and antagonistic properties on the IL-4 levels. Further studies of the local immune responses in the placenta showed no difference in the immunohistochemical staining of IL-4 and TNF-α between women with preeclampsia and women with normal pregnancies. In general, there were no hallmarks of abnormal morphology in the placental sections examined, regardless of diagnosis.In conclusion, the decreased levels of IL-10 in response to paternal antigens and the systemically increased levels of IL-6 and IL-8 suggest a specific decrease in antiinflammatory responses towards fetal antigens, together with a systemic activation of proinflammatory mediators during preeclampsia. Furthermore, the decreased production of IL-5 also indicates, at least partly, decreased Th2 responses in the established preeclampsia.
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| 3. |
- Josefsson, Ann, 1958-
(författare)
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Postpartum Depression : Epidemiological and Biological Aspects
- 2003
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Postpartum depression is by definition a major depression with an onset during the first weeks after delivery. In practice, however, the term, postpartum depression is used to characterize all kinds of depressive symptoms after childbirth. The aims of this thesis were to investigate the prevalence of depressive symptoms during late pregnancy, in the puerperium and four years after delivery, and to analyze the mothers’ estimation of personal health and their children’s behavior at the age of four. Additional goals were to test the predictive power of potential associated factors of postpartum depression during pregnancy and the puerperium and finally, to elucidate possible genetic or neuropeptidergic explanatory variables behind the development of postpartum depression.A population-based sample of 1489 women was screened with the Edinburgh Postnatal Depression Scale and the prevalence of depressive symptoms was 17% in late pregnancy and 13% postpartum. Antenatal depressed mood was related to postpartum depression. In a cross-sectional study we later found that postpartum depression was associated with subsequent depressive symptoms and current health problems four years after childbirth. Four-year-old boys of postpartum depressed mothers and children of mothers with a subsequent depressive status had more behavior problems than children of non-symptomatic mothers did, according to the mothers’ opinion.The strongest associated factors for postpartum depression, in a case-control study, were sick leave during pregnancy mainly due to pregnancy complications, e.g. hyperemesis and premature contractions and a high number of visits to the antenatal care clinic. There was no association between delivery complications or complications in the perinatal period and postpartum depression. The theory that depressive symptoms in late pregnancy or postpartum are connected with CYP2D6 genotype could not be confirmed.In a rat model, we found that pregnancy and parturition influence the concentrations of neuropeptide Y, cholecystokinin, substance P and galanin in the rat brain. This result supports the hypothesis that neuropeptidergic systems in the brain influence the mood changes around childbirth. In conclusion, postpartum depression is a common feature with influence on both maternal and child well being.
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| 4. |
- Mjösberg, Jenny, 1980-
(författare)
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Regulatory T cells in human pregnancy
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- During pregnancy, fetal tolerance has to be achieved without compromising the immune integrity of the mother. CD4+CD25highFoxp3+ regulatory cells (Tregs) have received vast attention as key players in immune regulation. However, the identification of human Tregs is complicated by their similarity to activated nonsuppressive T cells. The general aim of this thesis was to determine the antigen specificity, frequency, phenotype and function of Tregs in first to second trimester healthy and severe early-onset preeclamptic human pregnancy. Regarding antigen specificity, we observed that in healthy pregnant women, Tregs suppressed both TH1 and TH2 reactions when stimulated with paternal alloantigens but only TH1, not TH2 reactions when stimulated with unrelated alloantigens. Hence, circulating paternal-specific Tregs seem to be present during pregnancy. Further, by strictly defining typical Tregs (CD4dimCD25high) using flow cytometry, we could show that as a whole, the Treg population was reduced already during first trimester pregnancy as compared with non-pregnant women. This was in contrast to several previous studies and the discrepancy was most likely due to the presence of activated non-suppressive cells in pregnant women, showing similarities to the suppressive Tregs. Although deserving confirmation in a larger sample, severe early-onset preeclampsia did not seem to be associated with alterations in the circulating Treg population. The circulating Treg population was controlled by hormones which, alike pregnancy, reduced the frequency of Foxp3 expressing cells. Yet, in vitro, pregnancy Tregs were highly suppressive of pro-inflammatory cytokine secretion and showed an enhanced capability of secreting immune modulatory cytokines such as IL-4 and IL-10, as well as IL-17, indicating an increased plasticity of pregnancy Tregs. At the fetalmaternal interface during early pregnancy, Tregs, showing an enhanced suppressive and proliferating phenotype, were enriched as compared with blood. Further, CCR6- TH1 cells, with a presumed moderate TH1 activity were enhanced, whereas pro-inflammatory TH17 and CCR6+ TH1 cells were fewer as compared with blood. This thesis adds to and extends the view of Tregs as key players in immune regulation during pregnancy. In decidua, typical Tregs seem to have an important role in immune suppression whereas systemically, Tregs are under hormonal control and are numerically suppressed during pregnancy. Further, circulating pregnancy Tregs show reduced expression of Foxp3 and an increased degree of cytokine secretion and thereby also possibly plasticity. This would ensure systemic defense against infections with simultaneous tolerance at the fetal-maternal interface during pregnancy.
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| 5. |
- Persson, Marie
(författare)
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Immune regulation during pregnancy in relation to allergy and in women undergoing in vitro fertilization
- 2012
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- During pregnancy, the fetus expresses both maternal and paternal antigens. To the mother, the paternal antigens are foreign, providing her immune system with an interesting challenge. The fact that the fetus is not normally attacked and rejected implies that mechanisms of tolerance must exist. Pregnancy has long been considered to cause a redirection of the maternal immune responses towards a less aggressive type. Allergic disease has also been associated with that same redirection of immune responses, suggesting that this deviation may be more pronounced in allergic women during pregnancy. Several observations support the concept of a role of the immune system in the etiology of unexplained infertility, associating a redirection of the immune responses towards a more aggressive type with pregnancy loss and pregnancy failure.The aim of this thesis was to investigate the immune responses during pregnancy in allergic and non-allergic women, and in infertile women undergoing IVF treatment. We hypothesized that allergic women would have a more pronounced Th2-deviation than non-allergic women towards paternal antigens during pregnancy and that an unsuccessful outcome of IVF treatment would be associated with aberrations in circulating leukocyte populations and a paternal antigen-specific Th1 and Th17 bias.An increased number of both spontaneous and paternal antigen-induced Th2-like cytokine-secreting cells in peripheral blood was associated with pregnancy in 54 women with pregnancies defined as normal. The allergic pregnant women did not have a more pronounced Th2-deviation than the non-allergic women, as measured by numbers of cytokine-secreting cells. However, when analyzing cytokine levels in cell supernatants, we did observe lower Th1 responses towards paternal antigens in the allergic compared with non-allergic women. Additionally, allergy was associated with a reduced capacity to induce anti-inflammatory IL-10 responses towards paternal antigens.In 25 infertile women undergoing IVF, the peak levels of the majority of paternal antigen-induced cytokines and leukocyte populations investigated coincided with the maximal levels of gonadotropins administered during IVF treatment, suggesting that controlled ovarian hyper-stimulation has a general stimulatory effect on the immune system and that it may be regarded as an inflammatory state. During the treatment, no differences were found regarding cytokine responses to paternal antigens in peripheral blood or the numbers or proportions of circulating leukocyte populations between women with a successful or unsuccessful outcome of IVF. We did see higher numbers of Th2-associated cytokine secreting cells and a lower proportion of lymphocytes in the pregnant compared with the non-pregnant women four weeks after embryo transfer, however, in line with previous findings of immune modulation during pregnancy.In conclusion, normal pregnancy seems to be characterized by a less aggressive type of immune responses, possibly more pronounced in allergic women. This may be of importance for the in utero influences on childhood allergy development. An unsuccessful outcome of IVF does not appear to be associated with a more aggressive type of immune responses towards paternal antigens or aberrations in circulating leukocyte populations, although this should be confirmed in a larger study. The results in this thesis also indicate that the hormonal therapy during IVF treatment has a stimulatory effect on the immune system, generating an inflammatory state.
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| 6. |
- Svensson-Arvelund, Judit, 1982-
(författare)
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Immune regulation at the fetal‐maternal interface with focus on decidual macrophages
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- A successful pregnancy requires that the maternal immune system adapts to tolerate the semi-allogeneic fetal-placental unit. This adaptation mainly occurs locally, i.e. at the fetal-maternal interface, where fetal-derived tissues come into close contact with maternal cells in the uterine endometrium (called decidua during pregnancy). Macrophages and regulatory T (Treg) cells are maternal immune cells that are enriched in the decidua and they likely play a central role in promoting fetal tolerance. However, the precise function of decidual macrophages and the factors regulating both macrophages and Treg cells in humans are unknown. The aim of this thesis was to characterize the phenotype and function of decidual macrophages from first trimester human pregnancy and to identify factors responsible for inducing tolerogenic properties in both decidual macrophages and Treg cells. CD14+ decidual macrophages showed characteristics of immune suppressive or homeostatic macrophages (expression of CD163, CD206 and CD209), mainly produced immunosuppressive cytokines, like IL-10 and IL-35, while levels of inflammatory cytokines, for instance IL-12 and IL-23, were low. Decidual macrophages also induced the expansion of CD25highFoxp3+ Treg cells, but not of Th1, Th2 and Th17 cells, in vitro. In addition, decidual macrophages preferentially secreted the monocyte- and Treg cell-associated chemokines CCL2 and CCL18, while Th1-, Th2- and Th17-related chemokines were produced at low levels. These results suggest that decidual macrophages contribute to create the unique decidual cell composition and a tolerogenic immune environment that is compatible with fetal development. Further, by comparing decidual macrophages with different in vitro macrophage subsets, we showed that M-CSF and IL-10, but not GM-CSF, Th1 or Th2 stimuli, induced macrophages that resemble decidual macrophages in terms of cell surface marker expression, cytokine andchemokine production and gene expression profile. First trimester placental tissue, in particular placental trophoblast cells, was identified as an important source of M-CSF and IL-10. We also demonstrated that human fetal-derived placental tissue can induce the characteristics of decidual macrophages (CD163+CD206+CD209+IL-10+CCL18+) and the selective expansion of functionally suppressive CD25highFoxp3+ Treg cells, the latter partly mediated through IL-10, TGF-β and TRAIL. The placenta also limited activation of Th cells, for instance by generally reduced cytokine production. Our data show that the placenta has a unique ability to induce tolerogenic immune cells with a reduced inflammatory potential, which is essential for maintaining tissue integrity and preventing inflammation-induced fetal loss.
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