| 1. |
- 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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| 2. |
- 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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| 3. |
- 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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| 4. |
- 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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| 5. |
- 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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| 6. |
- Håkansson, Irene, 1976-
(författare)
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Biomarkers and Disease Activity in Multiple Sclerosis : A cohort study on patients with clinically isolated syndrome and relapsing remitting multiple sclerosis
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis focuses on disease activity in clinically isolated syndrome (CIS) and newly diagnosed relapsing remitting multiple sclerosis (RRMS). The papers are based on data from 41 patients in a prospective longitudinal cohort study. All patients were untreated at baseline. Age- and sex-matched healthy controls (n=22) for blood and cerebrospinal fluid (CSF) samples were recruited from blood donors.Paper I evaluated the prognostic value of baseline levels of CXCL1, CXCL8, CXCL10, CXCL13, CCL22, neurofilament light chain (NFL), neurofilament heavy chain, glial fibrillary acidic protein, chitinase-3-like-1 (CHI3L1), matrix metalloproteinase-9 (MMP-9) and osteopontin in CSF in relation to disease activity during the first two years of follow-up. Disease activity was defined as clinical relapses, new T2 lesions in brain magnetic resonance imaging (MRI) and/or sustained Expanded Disability Status Scale (EDSS) progression. Absence of these three signs of disease activity was called no evidence of disease activity (NEDA-3). Logistic regression analysis showed that NFL in CSF was the best predictive marker of disease activity and correctly classified 93% of the patients with evidence of disease activity during two years of follow-up and 67% of those without.Paper II presented four year follow-up data from the cohort and also included brain volume data as well as serum levels of NFL. The correlation between NFL in CSF and serum was fairly strong (r=0.74, p<0.001). NFL in CSF was associated with new T2 lesions as well as with brain volume loss, whereas CHI3L1 in CSF was associated mainly with brain volume loss and CXCL1, CXCL10, CXCL13, CCL22 and MMP-9 in CSF were mainly associated with new T2 lesions. Taken together, paper I and II confirm and extend the knowledge of NFL as a useful biomarker in CIS and RRMS and suggests that NFL, rather than total brain volume loss, could be included in an expanded NEDA concept and used in clinical monitoring of disease activity/treatment effect. Although serum levels of NFL were correlated with the corresponding CSF levels, CSF-NFL showed a stronger association to subsequent disease activity (NEDA-3).Paper III addressed the patients´ self-reported Modified Fatigue Impact Scale (MFIS) scores in relation to other cohort study data. MFIS scores correlated with other self-assessment questionnaire data (Hospital Anxiety and Depression scale (HAD), Multiple Sclerosis Impact Scale 29 (MSIS-29) and Short Form 36 (SF-36) scores (Spearman´s rho 0.45-0.78, all p≤0.01)) but not with EDSS ratings, number of T2 lesions, total brain volume or NFL levels, indicating that subjective fatigue scores are not well reflected by some commonly used and objectively measurable disease parameters.Paper IV focused on the complement factors C1q, C3, C3a and sC5b-9 in CSF and plasma. CSFC1q was significantly higher in patients than in controls at baseline. The subgroup of patients with ongoing relapse at baseline also had higher levels of CSF-C3a than controls. Baseline levels of CSF-C1q and CSF-C3a correlated significantly with several pro-inflammatory chemokines as well as with MMP-9, CHI3L1 and NFL in CSF. Baseline CSF-C3a also correlated significantly with the number of T2 lesions and Gadolinium enhancing lesions in brain MRI at baseline, as well as with the number of new T2 lesions during follow-up. This study indicates that the complement system is involved already at early stages of MS. It also suggests that especially CSF-C1q and CSF-C3a levels are associated with other neuroinflammatory and neurodegenerative markers and that CSF-C3a levels may carry some prognostic information.
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| 7. |
- 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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