1.
Wilms, Torben, 1973-
(författare)
Squamous cell carcinoma of the head and neck, focusing on Epstein-Barr-virus, programmed cell death ligand 1 and serum lipoproteins
2021
Doktorsavhandling (övrigt vetenskapligt/konstnärligt) abstract
Background: Squamous cell carcinoma of the head and neck (SCCHN)comprises a large group of tumours including the oral cavity and nasopharyngealarea, and typically affects older males in association with alcohol/tobacco usage.Within the oral cavity, the mobile tongue is the most common site for tumourdevelopment. The incidence of squamous cell carcinoma of the oral tongue(SCCOT) is increasing in younger people, which has been suggested to associatewith other than the traditional risk factors for this disease. Two common humanoncogenic viruses, human papillomavirus (HPV) and Epstein-Barr virus (EBV)are connected to certain types of SCCHN, in oropharynx and nasopharynxrespectively. The receptor programmed cell death 1 (PD)-1 and its ligandprogrammed cell death ligand 1 (PD-L1) are particularly relevant in immunecheckpoint control, and elevated levels have been seen in various cancer types. Alink between hyperlipidemia and cancer risk has previously been suggested. Theaim of this thesis was to investigate risk factors and prognostic features forSCCHN, by focusing on EBV, PD-L1 and serum lipoproteins.Materials and methods: Ninety-eight cases of SCCOT and 15 cases of tonsillarsquamous cell carcinoma were examined for the presence of EBV-encodedribonucleic acids (EBERs), EBV deoxyribonucleic acid (DNA) and the proteinEBV-encoded nuclear antigen-1 (EBNA-1), using in situ hybridisation,polymerase chain reaction (PCR) and immunohistochemistry respectively. Onehundred and one cases of SCCOT were examined for expression of PD-L1 intumour and surrounding immune cells using Ventana SP263immunohistochemistry assay and a QuickScore (QS) method. An estimation oftumour-infiltrating immune cells was also performed in 25 of the patients.Circulating levels of PD-L1 were measured using an electrochemiluminescenceassay platform in serum from 30 patients. Finally, serum samples from 106patients and 28 healthy controls were investigated for levels of total cholesterol,low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglycerides andlipoprotein(a).Results: In the first study, using an in situ hybridisation kit no EBER transcriptswere detected. No EBV DNA was identified with PCR analysis, andimmunohistochemistry for EBNA-1 was also negative. In the second study, highertumour cell PD-L1 levels were found in females than males (p = 0.019). Forpatients with low PD-L1 in tumour cells, better survival was shown in males thanfemales (overall survival p = 0.021, disease-free survival p = 0.020). Tumourinfiltrating natural killer (NK) T cells, immature dendritic cells (DCs) and M1macrophages correlated positively with tumour cell PD-L1 (p < 0.05). In the laststudy, the only lipoprotein showing significant difference in concentration iiibetween healthy controls and patients was HDL (p = 0.012). Kaplan-Meiersurvival curves showed that patients with high levels of total cholesterol or LDLhad better survival than patients with normal levels (p = 0.028 and p = 0.007respectively). Adjusting for the effects of age at diagnosis, TNM stage and weightchange, multivariate Cox regression models showed LDL to be an independentprognostic factor for both overall (p = 0.010) and disease-free survival (p =0.018).Conclusion: We excluded EBV as a potential player in SCCOT in both old andyoung patients and highlight the importance of appropriate controls for EBVencoded RNA in-situ hybridization (EBER-ISH) when investigating EBV inhuman diseases. Regarding PD-L1, our data supported the significance of genderon tumour cell PD-L1 expression and demonstrated combined effects of genderand PD-L1 levels on clinical outcome in patients with SCCOT. Data also indicatedthe involvement of specific immune cell types in PD-L1-regulated immuneevasion. Looking at serum lipoproteins, we found high LDL levels to be beneficialfor survival outcome in patients with SCCHN. Furthermore, the use of cholesterollowering medicine for prevention or management of SCCHN needs to be carefullyevaluated.
2.
Brundin, Peik M. A., 1975-
(författare)
Sex differences in immune response and sex hormone receptor expression in healthy individuals and during viral infection
2021
Doktorsavhandling (övrigt vetenskapligt/konstnärligt) abstract
There is sex-bias in morbidity and mortality from infectious diseases. Infections kill more men than women and several studies have pointed out differences in the immune system as a reason. The sex hormones estrogen, progesterone and testosterone all shape the effect of the immune response on multiple levels. Women at fertile age have been suggested to have higher proinflammatory responses from inflammatory stimuli compared to men and post-menopausal women, which has been ascribed to their higher estrogen levels. This could possibly lead to a more active pathogen response but may also result in a detrimental immunopathology to infections or development of autoimmune reaction.The overall aim of this thesis is to study the contribution of sex hormones and sex hormone receptors (SHR) to sex differences in immune response. We focus on peripheral blood mononuclear cells (PBMCs) to study such relationships in healthy individuals, as well as in individuals with asymptomatic Torque Teno Virus infection, and individuals with acute Puumala virus infection.In Paper I, we investigated expression of SHR and immune response genes in PBMC from healthy premenopausal (pre-MP) women during the menstrual cycle. The expression levels were estimated using a qPCR Array (Taqman low-density array, TLDA). SHR expression did not change significantly during the menstrual cycle, but several key immune regulatory genes were significantly more expressed during the ovulatory and mid luteal phase. Further, we separated PBMC into cell subsets (CD4+ T-cells, CD8+ T-cells, CD56+ NK-cells, CD14+ monocytes and CD19+ B-cells) and analyzed the expression through qPCR of estrogen receptors (ERs), ERα, ERβ1 (wildtype) and the isoform ERβ2. For the first time and unexpectedly, we demonstrate that the isoform ERβ2 was more abundant than wildtype ERβ1. The data from this paper provides new knowledge on the contribution of the menstrual cycle on immune response.In Paper II, we explored the use of Torque Teno Virus as a secondary functional immune marker in men and women. Expression of viral TTV DNA in PBMCs was estimated using a qPCR kit from Argene (R-gene) and analyzed in relation to serum sex hormone levels. The results showed that 50% of the men, 25% the post-MP women, and 18% of the pre-MP women were TTV+. Interestingly, all pre-MP women that were TTV+ had hormonal aberrances and were either anovulatory and/or hypothyroid. TTV+ pre-MP women also had significantly lower progesterone levels than TTV- pre-MP women. This paper indicates that the prevalence of TTV in PBMC differs between men, pre-MP and post-MP women. Furthermore, hormonal aberrances (at least in pre-MP women) will lead to increased prevalence of TTV.In Paper III we investigated the expression of ERα, ERβ1 and ERβ2 in PBMC from patients with Nephropathia epidemica, the viral zoonotic disease caused by Puumala virus, a Hanta virus known to affect more men than women. Expression of ERs in PBMCs and clinical laboratory results during the acute and convalescent phases were analyzed using a principal component analysis (PCA). The results show differences in ER expression and support previous findings that men and women have a different clinical pictureIn conclusion, the results in this thesis reveal distinct patterns of immune response related to sex hormone levels, SHR expression and the phases of the menstrual cycle supporting that there a link between sex hormone levels and immune responses. Further, we show that the ER isoform ERβ2 is more abundant in PBMCs than what was previously described. The data in this thesis adds to the knowledge to the sex differences in immune response and exemplifies the importance of taking these differences into account in the clinic.
3.
Bhandage, Amol K., 1988-
(författare)
Glutamate and GABA signalling components in the human brain and in immune cells
2016
Doktorsavhandling (övrigt vetenskapligt/konstnärligt) abstract
Glutamate and γ-aminobutyric acid (GABA) are the principal excitatory and inhibitory neurotransmitters in the central nervous system (CNS). They both can activate their ionotropic and metabotropic receptors. Glutamate activates ionotropic glutamate receptors (iGlu - AMPA, kainate and NMDA receptors) and GABA activates GABA-A receptors which are modulated by many types of drugs and substances including alcohol. Using real time quantitative polymerase chain reaction, I have shown that iGlu and/or GABA-A receptor subunits were expressed in the hippocampus dentate gyrus (HDG), orbitofrontal cortex (OFC), dorsolateral prefrontal cortex (DL-PFC), central amygdala (CeA), caudate and putamen of the human brain and their expression was altered by chronic excessive alcohol consumption. It indicates that excitatory and inhibitory neurotransmission may have been altered in the brain of human alcoholics. It is possible that changes in one type of neurotransmitter system may drive changes in another. These brain regions also play a role in brain reward system. Any changes in them may lead to changes in the normal brain functions.Apart from the CNS, glutamate and GABA are also present in the blood and can be synthesised by pancreatic islet cells and immune cells. They may act as immunomodulators of circulating immune cells and can affect immune function through glutamate and GABA receptors. I found that T cells from human, rat and mouse lymph nodes expressed the mRNAs and proteins for specific GABA-A receptor subunits. GABA-evoked transient and tonic currents recorded using the patch clamp technique demonstrate the functional GABA-A channel in T cells. Furthermore, the mRNAs for specific iGlu, GABA-A and GABA-B receptor subunits and chloride cotransporters were detected in peripheral blood mononuclear cells (PBMCs) from men, non-pregnant women, healthy and depressed pregnant women. The results indicate that the expression of iGlu, GABA-A and GABA-B receptors is related to gender, pregnancy and mental health and support the notion that glutamate and GABA receptors may modulate immune function. Intra- and interspecies variability exists in the expression and it is further influenced by physiological conditions.
4.
5.
Lundberg, Marcus
(författare)
Characterization of the Pancreas in Type 1 and Type 2 Diabetes
2018
Doktorsavhandling (övrigt vetenskapligt/konstnärligt) abstract
Diabetes is recognized by hyperglycaemia and polyuria. Complications, reduced quality of life and staggering health-care costs are all derived from the disease. Two subclasses of diabetes are Type 1 diabetes (T1D) and Type 2 diabetes (T2D). The beta cell mass is reduced in T1D, which is generally considered to be caused by an immune-mediated beta-cell destruction, but definitive evidence for this hypothesis remains absent. Development of insulin resistance and dysfunctional beta cells are commonly recognized as important factors that contribute to fulminant T2D. The literature that describes human T1D and T2D pancreata is sparse due to the limited number of specimens available for study. If more features of the respective pancreata are described, we might be able to elucidate the mechanisms involved in the pathoaetiology of the diseases.Accordingly, in this thesis pancreatic biopsies obtained from subjects with T1D or T2D have been examined with the aim to provide a more comprehensive picture of the respective pancreata. Paper I reports that aggregates of leucocytes substantiated mostly by macrophages are present in several T2D pancreata. Furthermore, as 28% of the T2D pancreata met the consensus definition of insulitis developed for T1D, a redefinition of insulitis is proposed. In Paper II, the density of parasympathetic axons was found to be reduced in the exocrine compartment in recent-onset T1D subjects compared to non-diabetic and long-standing T1D subjects. However, no alteration was discovered in islet-associated parasympathetic axons. In Paper III, interferon-stimulated genes were found to be over-expressed in recent-onset T1D islets, but no inducer explaining this expression has been discovered. Paper IV shows that T2D islets exhibit a stress response on a transcriptional level, and expression of these genes were investigated in islets from subjects with elevated HbA1c levels but without a clinical T2D diagnosis.In conclusion, this thesis explores several new areas of the pancreas in both T1D and T2D, and demonstrate several important findings that increase our knowledge on how diabetes develops.
6.
Heyman, Lovisa
(författare)
Berries in Prevention of Metabolic Disease – focus on obesity, diabetes and gut microbiota
2015
Doktorsavhandling (övrigt vetenskapligt/konstnärligt) abstract
The increasing prevalence of obesity is a worldwide health problem closely linked to diet and lifestyle factors. Obesity is associated with increased risk of several metabolic disorders including insulin resistance, nonalcoholic fatty liver disease and type 2 diabetes. Hence, there is a great need to identify dietary strategies for the prevention of obesity and related diseases. This thesis investigates the potential of different berries to mediate beneficial health effects in a mouse model of diet-induced obesity and prediabetes. We found that supplementation with lingonberries, blackcurrants and bilberries reduced body weight gain, insulin resistance, low-grade inflammation and hepatic lipid accumulation in C57BL/6J mice fed a high-fat diet. Supplementation with raspberries, crowberries, blackberries or prunes had no or small effects, whereas açai berries promoted development of obesity and fatty liver compared to the control group receiving high-fat diet without berries. Global hepatic gene expression analysis revealed that the phenotype in the lingonberry and bilberry groups was coupled to an anti-inflammatory effect, including downregulation of acute-phase proteins and inflammatory mediators. Mice receiving açai displayed an upregulation of steatosis markers and genes related to lipid synthesis, in line with the exacerbation of high-fat-induced fatty liver in these mice. The HELP-tagging assay was used to identify differentially methylated CpG sites in the lingonberry group compared to the high-fat control group. Lingonberries induced genome-wide and specific alterations of DNA methylation, however the significance of these findings remains to be established. Furthermore, different batches of lingonberries were found to have different capacity to prevent obesity. However lingonberries prevented low-grade inflammation, metabolic endotoxemia and modified the gut microbiota of high-fat fed mice, including increasing the Firmicutes/Bacteroidetes ratio. These findings were independent of effects on body weight gain and achieved regardless of the source of berries. The capacity of lingonberries to counteract negative outcomes of an unhealthy diet should be further evaluated in humans, including assessment of anti-inflammation and microbiota modulation. The generated knowledge about berries and their effects on metabolism may be useful in designing future dietary strategies aimed at preventing metabolic disease.
7.
Rodríguez-Piñeiro, Ana María, et al.
(författare)
The colonic mucus protection depends on the microbiota
2015
Ingår i: Gut microbes. - : Informa UK Limited. - 1949-0976 .- 1949-0984. ; 6:5, s. 326-30
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt) abstract
The intestinal mucus is a pivotal part of our intestinal protection. It provides slow diffusion of protective molecules, trapping of luminal material as bacteria and smooth transport in the small intestine. In colon it restricts bacterial access to the epithelium limiting the responses to the enormous bacterial load present at this location. The development of these systems depends on the microbiota composition as seen in our recent study comparing the mucus phenotype in 2 colonies kept in different husbandries within the same SPF animal facility. One colony had impenetrable colonic mucus while the other colony had more penetrable mucus. The mucus phenotypes were transmitted via the microbiota and clear differences in its composition could be detected. Candidates associated with the different colonies were identified but the observed mucus difference could not be assigned to a specific bacterium.
8.
Schröder, Björn, et al.
(författare)
Intestinales Mikrobiom und Schleimhautbarriere bei chronisch entzündlichen Darmerkrankungen
2021
Ingår i: Intestinales Mikrobiom und Innere Medizin. - : UNI-MED Verlag AG. - 9783837416053 ; , s. 46-55
Bokkapitel (övrigt vetenskapligt/konstnärligt) abstract
Das intestinale Mikrobiom repräsentiert aktuell eines der Topthemen, die im Fokus der modernen Humanmedizin stehen. Doch erstaunlicherweise gab es bisher im deutschen Sprachraum keine handliche, aktuelle Übersicht zu diesem Thema. Daher werden in diesem Band zunächst Zusammensetzung und Dynamik des humanen intestinalen Mikrobioms erläutert, ehe in weiteren Kapiteln dann die wichtigsten Veränderungen und vor allem die Rolle des Mikrobioms bei zahlreichen Krankheiten wie chronisch entzündlichen Darmerkrankungen, Reizdarmsyndrom, Leber- und Gallenwegs- sowie Autoimmunerkrankungen diskutiert werden. Es folgen der Komplex Ernährung, Adipositas und Diabetes sowie Atherosklerose mit jeweils eigenen Kapiteln. Schließlich gibt es überraschende Beziehungen der Mikrobiota zur Malignomentstehung. Es folgt ein Abschnitt über Antibiotika und deren Rolle bei zum Teil dauerhaften Störungen der intestinalen Bakterien und Pilze. Am Ende des Buches wird am Beispiel von Mikrobiomtransfer ("Stuhltransplantation") und Probiotika auf die therapeutischen Konsequenzen eingegangen. Alle Kapitel sind auch für sich lesbar und verständlich.
9.
Mottahedin, Amin
(författare)
Developing brain and systemic inflammation: a "Toll-like" link with consequences
2017
Doktorsavhandling (övrigt vetenskapligt/konstnärligt) abstract
The developing brain is vulnerable to external insults, and perinatal brain injury (PBI) is a major cause of life-long neurological syndromes such as cerebral palsy. Currently, no pharmaceutical intervention is available. Hypoxia/ischemia (HI), infections and inflammation are implicated in the pathogenesis of PBI. However, the crosstalk between these etiologies is not fully understood. Toll-like receptors (TLR) 3 and TLR2 are responsible for sensing viral and bacterial infections and initiating the inflammatory response. The aim of this thesis was to investigate the effect of systemic inflammation induced by activation of these TLRs on neonatal HI brain injury. We demonstrate that intraperitoneal administration of TLR3 and TLR2 ligands (PolyI:C and P3C, respectively) prior to HI increases the brain injury in neonatal mice. PolyI:C and P3C induced neuroinflammation and altered microglial phenotype as assessed by RT-qPCR, multiplex cytokine assay or flow cytometry. PolyI:C also upregulated the pro-apoptotic gene, Fasl, expression and reduced activation of pro-survival signaling molecule Akt. On the other hand, P3C suppressed mitochondrial respiration, a major mechanism of cellular energy production. P3C, unlike other TLR agonists, induced marked infiltration of leukocytes to the cerebral spinal fluid and brain of neonatal mice and rats. Confocal microscopy, Cre recombinase-mediated gene targeting and in vitro cell transmigra-tion assay revealed the choroid plexus as a site of leukocyte entry. RNA sequencing of the choroid plexus followed by transcriptome cluster analysis and Ingenuity Pathway Analysis revealed potential mechanisms of leukocyte infiltration, including a specific chemotaxis signature and cytoskeleton-related pathways. Finally, we show that N-acetylcysteine treatment inhibits TLR2-mediated leukocyte trafficking in vivo and in vitro. To conclude, this thesis describe a TLR-mediated link between systemic inflammation and developing brain with detrimental consequences on HI brain injury, suggesting potential novel therapeutic strategies.
10.
Klawonn, Anna, 1985-
(författare)
Molecular Mechanisms of Reward and Aversion
2017
Doktorsavhandling (övrigt vetenskapligt/konstnärligt) abstract
Various molecular pathways in the brain shape our understanding of good and bad, as well as our motivation to seek and avoid such stimuli. This work evolves around how systemic inflammation causes aversion; and why general unpleasant states such as sickness, stress, pain and nausea are encoded by our brain as undesirable; and contrary to these questions, how drugs of abuse can subjugate the motivational neurocircuitry of the brain. A common feature of these various disease states is involvement of the motivational neurocircuitry - from mesolimbic to striatonigral pathways. Having an intact motivational system is what helps us evade negative outcomes and approach natural positive reinforcers, which is essential for our survival. During disease-states the motivational neurocircuitry may be overthrown by the molecular mechanisms that originally were meant to aid us.In study I, to investigate how inflammation is perceived as aversive, we used a behavioral test based on Pavlovian place conditioning with the aversive inflammatory stimulus E. coli lipopolysaccharide (LPS). Using a combination of cell-type specific gene deletions, pharmacology, and chemogenetics, we uncovered that systemic inflammation triggered aversion by MyD88-dependent activation of the brain endothelium followed by COX1-mediated cerebral prostaglandin E2 (PGE2) synthesis. Moreover, we showed that inflammation-induced PGE2 targeted EP1 receptors on striatal dopamine D1 receptor–expressing neurons and that this signaling sequence induced aversion through GABA-mediated inhibition of dopaminergic cells. Finally, inflammation-induced aversion was not an indirect consequence of fever or anorexia but constituted an independent inflammatory symptom triggered by a unique molecular mechanism. Collectively, these findings demonstrate that PGE2-mediated modulation of the dopaminergic circuitry is a key mechanism underlying inflammation-induced aversion.In study II, we investigate the role of peripheral IFN-γ in LPS induced conditioned place aversion by employing a strategy based on global and cell-type specific gene deletions, combined with measures of gene-expression. LPS induced IFN-ɣ expression in the blood, and deletion of IFN-ɣ or its receptor prevented conditioned place aversion (CPA) to LPS. LPS increased the expression of chemokine Cxcl10 in the striatum of normal mice. This induction was absent in mice lacking IFN-ɣ receptors or Myd88 in blood brain barrier endothelial cells. Furthermore, inflammation-induced aversion was blocked in mice lacking Cxcl10 or its receptor Cxcr3. Finally, mice with a selective deletion of the IFN-ɣ receptor in brain endothelial cells did not develop inflammation-induced aversion. Collectively, these findings demonstrate that circulating IFN-ɣ binding to receptors on brain endothelial cells which induces Cxcl10, is a central link in the signaling chain eliciting inflammation-induced aversion.In study III, we explored the role of melanocortin 4 receptors (MC4Rs) in aversive processing using genetically modified mice in CPA to various stimuli. In normal mice, robust aversions were induced by systemic inflammation, nausea, pain and kappa opioid receptor-induced dysphoria. In sharp contrast, mice lacking MC4Rs displayed preference towards most of the aversive stimuli, but were indifferent to pain. The unusual flip from aversion to reward in mice lacking MC4Rs was dopamine-dependent and associated with a change from decreased to increased activity of the dopamine system. The responses to aversive stimuli were normalized when MC4Rs were re-expressed on dopamine D1 receptor-expressing cells or in the striatum of mice otherwise lacking MC4Rs. Furthermore, activation of arcuate nucleus proopiomelanocortin neurons projecting to the ventral striatum increased the activity of striatal neurons in a MC4R-dependent manner and elicited aversion. Our findings demonstrate that melanocortin signaling through striatal MC4Rs is critical for assigning negative motivational valence to harmful stimuli.The neurotransmitter acetylcholine has been implied in reward learning and drug addiction. However, the role of cholinergic receptor subtypes in such processes remains elusive. In study IV we investigated the function of muscarinic M4Rs on dopamine D1R expressing neurons and acetylcholinergic neurons, using transgenic mice in various reward-enforced behaviors and in a “waiting”-impulsivity test. Mice lacking M4-receptors from D1-receptor expressing neurons exhibited an escalated reward seeking phenotype towards cocaine and natural reward, in Pavlovian conditioning and an operant self-administration task, respectively. In addition, the M4-D1RCre mice showed impaired waiting impulsivity in the 5-choice-serial-reaction-time-task. On the contrary, mice without M4Rs in acetylcholinergic neurons were unable to learn positive reinforcement to natural reward and cocaine, in an operant runway paradigm and in Pavlovian conditioning. Immediate early gene expression mirrored the behavioral findings arising from M4R-D1R knockout, as cocaine induced cFos and FosB was significantly increased in the forebrain of M4-D1RCre mice, whereas it remained normal in the M4R-ChatCre mice. Our study illustrates that muscarinic M4Rs on specific neural populations, either cholinergic or D1R-expressing, are pivotal for learning processes related to both natural reward and drugs of abuse, with opposing functionality.
