In this thesis the aim was to study immune cell interactions at the maternal-fetal interface to understand the role for immune cells during healthy pregnancy development an pregnancy complications.... Show moreIn this thesis the aim was to study immune cell interactions at the maternal-fetal interface to understand the role for immune cells during healthy pregnancy development an pregnancy complications. Specifically in cases of recurrent pregnancy loss and chronic histiocytic intervillositis. Show less
Background: Childhood trauma (CT) is robustly associated with psychiatric disorders including major depressive and anxiety disorders across the life span. The innate immune system may play a role... Show moreBackground: Childhood trauma (CT) is robustly associated with psychiatric disorders including major depressive and anxiety disorders across the life span. The innate immune system may play a role in the relation between CT and stress-related psychopathology. However, whether CT influences the innate production capacity of cytokine levels following ex vivo stimulation by lipopolysaccharide (LPS), is currently unknown. Methods: Using data from the Netherlands Study of Depression and Anxiety (NESDA, n=1237), we examined whether CT (emotional neglect, emotional, physical, and sexual abuse before the age of 16), assessed by the Childhood Trauma Interview, was associated with levels in supernatants of interferon (IFN)gamma, interleukin-2 (IL -2), IL-4, IL-6, IL-8, IL-10, IL-18, monocyte chemotactic protein-1 (MCP-1), macrophage inflammatory protein (MIP)-1 alpha, MIP-1 beta, matrix metalloproteinase-2 (MMP-2), TNF alpha and TNF beta after ex vivo stimulation with LPS. Cytokines were analysed individually and cumulatively (overall inflammation index and number of cytokines in high-risk quartile (HRQ)) using linear regression analyses. Results: After adjustment for demographic, lifestyle, and health-related covariates, total CT severity was asso-ciated with the overall inflammation index (beta = 0.085, PFDR = 0.011), the number of cytokines in HRQ (beta = 0.063, P-FDR = 0.036), and individual markers of IL-2 (beta = 0.067, P-FDR = 0.036), IL-6 (beta = 0.091 PFDR = 0.011), IL-8 (beta = 0.085 P-FDR = 0.011), IL-10 (beta = 0.094 P-FDR = 0.011), MCP-1 (beta = 0.081 P-FDR = 0.011), MIP-1 alpha (beta = 0.061 P-FDR = 0.047), MIP1-beta (beta = 0.077 P-FDR = 0.016), MMP-2 (beta = 0.070 P-FDR = 0.027), and TNF beta (beta = 0.078 PFDR = 0.016). Associations were strongest for individuals with severe CT, reporting multiple types or higher frequencies of trauma. Half of the findings persisted after adjustment for psychiatric status. The findings were consistent across different CT types. Conclusion: Childhood Trauma is associated with increased LPS-stimulated cytokine levels, with evidence for a dose-response relationship. Our results highlight a dysregulated innate immune system capacity in adults with CT, which could contribute to an increased vulnerability for psychopathology and somatic disorders across the lifespan. Show less
This thesis focuses on two processes involved in fighting infections: metabolism and immune cell motility and navigation.Regarding metabolism, we present ZebraGEM 2.0, an improved whole-genome... Show moreThis thesis focuses on two processes involved in fighting infections: metabolism and immune cell motility and navigation.Regarding metabolism, we present ZebraGEM 2.0, an improved whole-genome scale metabolic reconstruction for zebrafish, that we used to study zebrafish metabolism upon infection with Mycobacterium marinum integrating gene expression data from control and infected zebrafish larvae. The chapters focusing on cell motility in response to the environment, revolve around the question of how the environmental inputs of cell-matrix interactions, cell-sized obstacles and cell-signalling upon wounding shape and guide cell motility. Show less
Background: Affective disorders involve dysregulation of major biological stress systems (hypothalamic-pituitary adrenal (HPA)-axis, immune system, autonomic nervous system (ANS)).... Show moreBackground: Affective disorders involve dysregulation of major biological stress systems (hypothalamic-pituitary adrenal (HPA)-axis, immune system, autonomic nervous system (ANS)). Suchdysregulationshave rarely beensimultaneously examined across different stress systems.Methods: In the Netherlands Study of Depression and Anxiety (n=2789), we investigated whether current or remitted depressive and/or anxiety disorders (based on the CIDI semi-structured interview), including specific symptom profiles, were associated with separate markers and cumulative indexes of the HPA-axis (cortisol awakening response, evening cortisol, dexamethasone suppression test cortisol), immune system (C-reactive protein, interleukin-6, tumor necrosis factor-alpha), and ANS (heart rate, respiratory sinus arrhythmia, pre-ejection period).Results: Depressive andanxiety disorderswere significantlyassociated with changes in three biological stress systemsincluding HPA-axis hyperactivity, increased inflammatory activity, and a higher ANS tone, particularly for integrative and cumulative indexes of these stress systems (pFDR <.05) vs. controls. The strongest associations were seen with current disorders andcumulative indexes of the HPA-axis (13=.124, pFDR=.001), the immune system (13 =.057, pFDR=.032), and total cumulative index across stress systems (13=.102, pFDR=.004). Atypical, energy-related depression severity was linked to immune system markers (pFDR<0.001), melancholic depression severity to HPA-axis markers (pFDR=.032), and anxiety arousal severity to both HPA-axis and immune system markers (pFDR<0.05). Findings were partially explained by poorer lifestyle, more chronic diseases, or (especially for ANS-function) antidepressant use. Limitations: Cross-sectional analyses limit examination of temporal associations.Conclusion: Patients withdepressive and anxiety disorders showed consistent dysregulation across biological stress systems, particularly for current episodes.To understand stress system functionality in affective disorders, an integrated approach capturing cumulative stress indices within and across biological stress systems is important. Show less
Background: Childhood trauma (CT) is a risk factor for depressive and anxiety disorders. Although dysregulated biological stress systems may underlie the enduring effect of CT, the relation between... Show moreBackground: Childhood trauma (CT) is a risk factor for depressive and anxiety disorders. Although dysregulated biological stress systems may underlie the enduring effect of CT, the relation between CT and separate and cumulative activity of the major stress systems, namely, the hypothalamic-pituitary-adrenal (HPA)-axis, the immune-inflammatory system, and the autonomic nervous system (ANS), remains inconclusive.Methods: In the Netherlands Study of Depression and Anxiety (NESDA, n = 2778), we determined whether self-reported CT (as assessed by the Childhood Trauma Interview) was associated with separate and cumulative markers of the HPA-axis (cortisol awakening response, evening cortisol, dexamethasone suppression test cortisol), the immune-inflammatory system (C-reactive protein, interleukin-6, tumor necrosis factor-alpha), and the ANS (heart rate, respiratory sinus arrhythmia, pre-ejection period) in adulthood.Results: Almost all individuals with CT (n = 1330) had either current or remitted depressive and/or anxiety disorder (88.6%). Total-sample analyses showed little evidence for CT being significantly associated with the separate or cumulative stress systems' activity in adulthood. These findings were true for individuals with and without depressive and/or anxiety disorders. To maximize contrast, individuals with severe CT were compared to healthy controls without CT. This yielded slight, but significantly higher levels of cortisol awakening response (AUCg, beta =.088, p =.007; AUCi, beta =.084, p =.010), cumulative HPA-axis markers (beta =.115, p =.001), Creactive protein (beta =.055, p =.032), interleukin-6 (beta =.053, p =.038), cumulative inflammation (beta =.060, p =.020), and cumulative markers across all systems (beta =.125, p =.0003) for those with severe CT, partially explained by higher rates of smoking, body mass index, and chronic diseases.Conclusion: While our findings do not provide conclusive evidence on CT directly dysregulating stress systems, individuals with severe CT showed slight indications of dysregulations, partially explained by an unhealthy lifestyle and poorer health. Show less
Purpose of Review Caregivers of children with a chronic illness are a neglected group in medical research and patient care, and are frequently confronted with chronic psychological distress. The... Show morePurpose of Review Caregivers of children with a chronic illness are a neglected group in medical research and patient care, and are frequently confronted with chronic psychological distress. The biological consequences of this chronic distress are unclear but highly relevant, as these caregivers have a lifelong task in caring for their child. In this review, the authors specifically describe caregiver distress related to autism spectrum disorder (ASD), but the review may be relevant to other chronic diseases, including cancer. Recent Findings Epidemiological evidence illustrates the increased mortality risk in caregivers of children with ASD although some individual factors appear to diminish these risks. Biological studies demonstrate that caregiver distress can lead to dysregulation of the hypothalamic-pituitary-adrenal-axis, a pro-inflammatory state of the immune and central nervous system, and gut microbiome imbalance. Caregivers of children with a chronic illness like ASD deserve more health-related attention with respect to their psychological and physical well-being. Such attention would benefit individual caregivers, as well as their children, as both are highly interconnected. Structural psychological and physical screening of caregivers can be considered. Show less
Cardiovascular syndromes are the major cause of death in Western societies. The main underlying pathology is atherosclerosis, a chronic disease affecting the arteries. During atherosclerosis... Show moreCardiovascular syndromes are the major cause of death in Western societies. The main underlying pathology is atherosclerosis, a chronic disease affecting the arteries. During atherosclerosis progression, LDL, or “bad” cholesterol, accumulates in the arterial wall, resulting in the formation of a lipid-rich atherosclerotic plaque. This event activates the immune system, which increases plaque inflammation. Mast cells are components of the immune system known for their role in allergy. However, it has been established that mast cells are also important in atherosclerosis. In this PhD dissertation, we explored the interaction of mast cells with other immune cells. We examined the interrelation between mast cells and T-lymphocytes and discovered that mast cells can function as antigen presenting cells in atherosclerosis and, enhance the development of an atherosclerotic plaque via a direct interaction. Nonetheless, mast cells can also act on the Natural Killer T-cells, resulting in a protective function against atherosclerosis. Importantly, we used a relatively novel technical approach to explore the characteristics of mast cells inside human atherosclerotic plaques. We found that mast cells are highly activated and thus possibly promote disease progression. In conclusion, mast cells possess both protective and harmful effects, acting as regulators of the immune response in atherosclerosis. Show less
Metastatic cancer is aggressive and rapidly developing, making it difficult to treat, often leading to mortality. Cancer cells are not isolated, but rather survive and proliferate in complex tumor...Show moreMetastatic cancer is aggressive and rapidly developing, making it difficult to treat, often leading to mortality. Cancer cells are not isolated, but rather survive and proliferate in complex tumor microenvironments. Importantly, tumor cells “educate” immune cells to play a supportive role during cancer progression. Therefore, understanding how cancer cells and immune cells communicate is of pivotal importance to limit tumor progression. In this project, we identified the chemokine receptor CXCR4 and its correspondent ligand, CXCL12, as a key couple that regulate the interaction between tumor cells and immune cells. The research has been performed using the zebrafish xenograft model. This model offers the advantage of looking at tumor-immune cell interaction on a single cell level and in a living whole organism. The transparency of the embryo and the current genetic tools available, in combination with the ease in pharmacological approaches, make this model an excellent tool to determine and impair cancer-microenvironment inter-communication. We showed that inhibiting the CXCL12-CXCR4 axis either on the tumor side or on the immune cell side leads to impaired tumor progression, during the early phases of metastasis formation. We propose that blocking cancer-stroma communication represents a promising therapeutic strategy to fight cancer.Show less
Part I describes the prognostic effect and interactions of the immune system in breast cancer patients. Part II of the thesis describes the prognostic effect of these prognostic immune parameters... Show morePart I describes the prognostic effect and interactions of the immune system in breast cancer patients. Part II of the thesis describes the prognostic effect of these prognostic immune parameters and biomarkers molecular subtypes and stem cell marker ALDH-1, which are known to be strong breast cancer prognostic factors, in elderly breast cancer patients compared to their younger counterparts. Show less
Atherosclerose wordt veroorzaakt door een combinatie van verhoogde cholesterolniveaus en een chronische ontstekingsreactie. Deze ontstekingsreactie is het gevolg van een verstoorde balans tussen... Show moreAtherosclerose wordt veroorzaakt door een combinatie van verhoogde cholesterolniveaus en een chronische ontstekingsreactie. Deze ontstekingsreactie is het gevolg van een verstoorde balans tussen slechte, agressieve en goede, beschermende ontstekingscellen. In dit proefschrift wordt onderzocht hoe deze verstoorde balans in atherosclerose hersteld kan worden. Het onderzoek richt zich hierbij enerzijds op het remmen van de slechte ontstekingscellen en anderzijds op het stimuleren van de goede ontstekingscellen. Dit kan bereikt worden door de werking van costimulatoire en coinhibitoire eiwitten te be_nvloeden. Deze eiwitten zijn aanwezig op het celoppervlak van heel veel verschillende ontstekingscellen en bepalen of een ontstekingscel agressief of beschermend is. Costimulatoire eiwitten zorgen voor de activatie van een ontstekingscel, terwijl coinhibitoire eiwitten ontstekingscellen remmen. Blokkade van de costimulatoire eiwitten OX40L en CD30L remt atherosclerose, terwijl blokkade van het coinhibitoire eiwit Tim-3 atherosclerose verergert. Stimulatie van het coinhibitoire eiwit TIGIT vermindert de functie van T cellen. Een andere manier om de balans tussen goede en slechte ontstekingscellen te herstellen is door het aantal goede ontstekingscellen, zoals regulatoire T cellen en myeloid derived suppressor cellen, te laten toenemen. Eliminatie van regulatoire T cellen tot meer atherosclerose, terwijl een enorme expansie van regulatoire T cellen en myeloid derived suppressor cellen beschermend is. Show less
In peripheral arterial occlusive disease (PAOD), the formation of an atherosclerotic lesion eventually results in a significant stenosis of a major artery thereby disrupting blood flow in... Show moreIn peripheral arterial occlusive disease (PAOD), the formation of an atherosclerotic lesion eventually results in a significant stenosis of a major artery thereby disrupting blood flow in peripheral arteries towards lower limb tissue. Unfortunately, there is a substantial number of patients that suffer from severe critical limb ischemia, which is associated with a poor prognosis and high rates of amputation and mortality. Despite state-of-the-art revascularization treatment options and optimal control of co-morbidities these 'no option' patients remain at high risk for limb amputation. It is these patients that require new therapeutic applications to augment neovascularization and prevent them from limb amputation. Expansion of our current knowledge is required to gain insight in cellular and molecular mechanisms that are involved in neovascularization, to optimize revascularization therapies for patients with critical limb ischemia. This thesis provides a role for multiple leukocytes in blood flow recovery, in particular Natural Killer cells and CD4+ T lymphocytes, and shows that genetic differences in the Natural Killer gene complex induce differences in vascular remodeling. It was also shown how growth factor expression, signaling and regulation of gene expression modulate revascularization. Show less
Toll-like receptors (TLRs) are receptors that continuously scour their direct surroundings for pathogen associated molecular patterns (PAMPs) of bacterial, viral or fungal origin. TLRs can be found... Show moreToll-like receptors (TLRs) are receptors that continuously scour their direct surroundings for pathogen associated molecular patterns (PAMPs) of bacterial, viral or fungal origin. TLRs can be found at cells that play a role in the immune system. Binding of the TLR with its corresponding ligand results in a signaling cascade, which initially activates the innate immune system and can eventually result in activation of the adaptive immune system. When used as well-defined adjuvants, their combination with antigen may increase the immunogenicity of the antigen itself. This so-called vaccine principle may lead to a desired long-lasting adaptive immune response or humoral memory. Currently a total of 11 TLRs are known in humans and their specific PAMPs are directly related to the location where the receptor resides. TLRs 1, 2, 4, 5, 6, 10 and 11 are situated on the outside of the cell membrane, where they come into direct contact with membrane components of pathogens. TLRs 3, 7, 8 and 9 can be found intracellularly and their ligands mainly consist of viral components released after cellular uptake and degradation of the invader. A large diversity of natural and synthetic TLR ligands is available. The newest generation of vaccines is based on synthetic TLR ligands having a well-defined chemical structure. The research described in this thesis is a first step towards the development of well-defined vaccines, able to trigger a controlled immune response by means of using TLR 2, 7 or 9. Discussed in detail are the synthesis and the immunological evaluation of ligands and conjugates aimed at activation of Toll-like receptors 2, 7 and 9. Some examples are the synthesis of a CpG DNA-peptide conjugate (TLR 9), a Pam3Cys-peptide conjugate (TLR 2) and a 7-hydro-8-oxo-adenine-peptide conjugate (TLR 7). After synthesis of the peptide (containing the antigen), several methods were applied to conjugate it to TLR2, 7 and 9 ligands. Resulting from the research performed, is that when well chosen, covalent coupling of a TLR ligand with an antigenic peptide results in an increase of cytokine production as well as antigen presentation, two of the most desired characteristics of a synthetic vaccine of this class. It is not unlikely, that future synthetic vaccines will be sharing these properties. Show less
