Traumatic Brain Injury (TBI) mainly affects young persons in traffic accidents and the elderly in fall accidents. Improvements in the clinical management have significantly improved the outcome following TBI but survivors still suffer from depression, memory problems, personality changes, epilepsy and fatigue. The initial injury starts a series of events that give rise to a secondary injury process and despite several clinical trials there is no drug available for clinical use that targets secondary brain injury mechanisms. Some recovery of function is seen during the first months following injury but is usually limited and there are no drugs that stimulate the recovery of lost function. Some of the recovery is attributed to plasticity, the brains ability to adapt to new circumstances, and enhancing plasticity via increased axonal growth has the potential to partly restore lost function. In this thesis mice were subjected to the controlled cortical impact model of TBI and functional outcome was evaluated using Morris water maze, the cylinder test and the rotarod. Brain tissue loss was measured in all Papers but the additional histological analyses differ among the Papers. Attempts to increase axonal growth were made by interfering with Nogo receptor function in Paper I and by conditional knockout of ephA4 in Paper II. Contrary to the hypothesis cognition was impaired in Paper I but otherwise no effects of treatment were detected in Paper I and II. Much is still unknown about plasticity and despite the discouraging results of Papers I and II this treatment approach is still worth further exploration. It is firmly established that TBI results in an inflammatory response and some aspects of it may damage brain tissue. In Papers III and IV the inflammatory response was attenuated using an IL-1β directed antibody which resulted in reduced tissue loss and edema while improving cognitive function. The results from Papers III and IV are encouraging and the possibility to find a treatment based on IL-1β inhibition appears promising.

The aim of this thesis was to investigate oral cryotherapy (OC) as prophy-laxis against oral mucositis (OM) in patients given high-dose chemotherapy for stem cell transplantation (SCT). A new mouth rinse device was tested for possible additive effect to OC. For study I-III, 78 patients were randomised to OC or standard oral care (SOC). Papers I and II showed that OC patients had significantly less severe mucositis, pain, opioid use, lower C-reactive protein and less parenteral nutrition treatment (TPN). There was no difference in relapse rate, and 5-year survival was unexpectedly significantly better in the OC group (Paper III). In paper IV, the local effect of OC on the mucosa of the mouth was investigated by the use of an infrared thermograph. Change in surface temperature in eight areas of the mouth cavity was measured after cooling of the mouth in healthy volunteers. A substantial lowering of the temperature (-12.9 °C, mean) was seen which could explain the efficacy of OC. To exclude that acute cooling in itself is traumatic, the proinflammatory cytokine IL-6 was measured in saliva and showed no increase after cooling. Paper V reported a study in 40 allogeneic SCT patients. 20 were given SOC including OC and 20 in addition received Caphosol®, a calcium phosphate mouth rinse, during chemotherapy and until day 21. Severity of mucositis, use of opioids and TPN, effects on nutrition and CRP levels were measured. No significant difference was found between the groups in any of these variables, but a non-significant trend for an advantage for the combination could be seen. IL-6 saliva levels were measured. There was a substantial increase (more than 10-fold), in mean IL-6 levels from baseline to beginning of mucositis and a weak correlation between increased IL-6 levels and severity of OM, suggesting that IL-6 in saliva may be a useful marker of the inflammatory mucosal process. This thesis demonstrates that OC is effective as prophylaxis against chemotherapy-induced OM. As a consequence of this work, OC has been introduced as the standard of care in all SCT patients in our institution.

Mannose binding lectin (MBL) belongs to the collectin family of soluble pattern recognition molecules that elicit diverse biologic activities. Via multiple carbohydrate-recognition domains (CRD), MBL binds to mannose and N-acetyl-glucosamine oligosaccharides present on the surface of bacteria, fungi and yeast. Following pathogen recognition, MBL activates the complement system via MBL associated serine proteases in a manner independent of antibody and C1 complex. Deficiency in function and level of MBL is found in 25% of otherwise apparently healthy individuals, representing the most prevalent innate immune deficiency. MBL deficiency is a risk factor for the development of infections in humans and mice. The role of MBL as a modulator of infection is complex. MBL deficiency may influence proinflammatory cytokine production, expression of leukocyte adhesion molecules, or vascular damage, during the course of infection. Given that dendritic cells (DC) are antigen presenting cells (APC) with potent capacity to respond to microbial stimulation, I hypothesized that MBL deficiency may be reflected in DC functions associated with microbial stimulation. Initially, I investigated the association of MBL with human immune cells and demonstrated that in both MBL-Sufficient (MBL-S) and MBL-Deficient (MBL-D) individuals, MBL was particularly associated with monocytes. RT-PCR analysis demonstrated MBL was not transcribed by monocytes or other immune cells investigated (T, B, and NK cells, CD11c+DC, immature monocyte derived DC [MoDC], LPS matured MoDC, and granulocytes), suggesting MBL association with the cell surface may be via an adapter or co-receptor. Magnetically separated monocytes but not MoDC bound exogenous purified human plasma MBL (hpMBL). Addition of hpMBL (5 -15 µg/mL) did not induce MoDC activation, and MBL added together with lipopolysaccharide (LPS) did not induce MoDC activation above the level induced by LPS only. In the second part of this study, I used the particulate MBL ligand zymosan (Zy) as a pathogenic stimulus in a whole blood model to gain a greater understanding of the consequences of MBL deficiency. I compared surface phenotype, inflammatory cytokine production and antigen presenting capacity of blood myeloid (M)DC of MBL-D and MBL-S individuals following stimulation with Zy and MBL opsonised Zy (MBL-Zy). Blood MDC in MBL-D individuals, unlike their counterpart in MBL-S individuals, displayed unique functional characteristics, including higher production of proinflammatory cytokines IL-6 and TNF-, but poor capacity for allo-T cell effector cell induction. It appeared that stimulation with MBL-Zy reduced elevated production of IL-6 but not TNF- by blood MDC in MBL-D individuals. In the third part, expression microarray analysis was utilised to provide broad information on the genes and potential signalling pathways involved in the MDC responses in MBL-D and MBL-S individuals following stimulation with Zy and MBL-Zy. MBL-S individuals demonstrated greater capacity to induce T cell and NK cell signalling pathways than MBL-D individuals. Further, MBL acted as a regulator of important inflammatory molecules, namely T-cell receptor zeta (CD247), IFN-γ and perforin 1. The data presented in this study provides novel information on blood MDC function in MBL-S and MBL-D individuals in response to pathogen stimulation, and provided insight into mechanisms involved in the increased frequency of infection observed in MBL-D individuals.

Univ., Diss.--Bern, 1995.

Thesis (D. Min.)--Northern Baptist Theological Seminary, 2006. / Abstract. Includes bibliographical references (leaves 163-171).

Thesis (Ph. D.)--University of Georgia, 1993. / Includes bibliographical references (leaves 228-233).

Thesis (D. Min.)--Northern Baptist Theological Seminary, 2006. / Abstract. Includes bibliographical references (leaves 128-134).

Η λεπτίνη είναι μια ορμόνη 16 kD που κωδικοποιείται απότογονίδιο obκαι παράγεται από τα λιποκύτταρα ρυθμίζοντας το ενεργειακό ισοζύγιο. Τα επίπεδα λεπτίνης στο πλάσμα είναι ανάλογα με το δείκτη σωματικής μάζας (BMI), ενώ η έκφρασή της εξαρτάται από τη νηστεία και τη σίτιση, την ινσουλίνη, τα γλυκοκορτικοειδή, καθώς και από προφλεγμονώδεις κυτταροκίνες, κύριως τον TNF-α και την IL-1. Το μόριο της λεπτίνης παρουσιάζει ομοιότητες με τη μακριά έλικα των κυτταροκινών και δρά μέσω του υποδοχέα της (OB-R), ο οποίος ανήκει στην υπεροικογένεια των υποδοχέων των κυτταροκινών και εμφανίζεται σε ποικιλία ισομορφών ενώ εκφράζεται σε διάφορους ιστούς και κύτταρα του νευροενδοκρινικού, αναπαραγωγικού, αιματοποιητικού και ανοσοποιητικού συστήματος. Η λεπτίνη εμπλεκεται και σε αυτοάνοσες καταστάσεις με το να προάγει τη διατήρηση παθογόνων Th1 κυτταρικών υποπληθυσμών. Στην παρούσα μελέτη προκειμένου να διερευνήσουμε το ρόλο της λεπτίνης σε αυτοάνοσες καταστάσεις μετρήσαμε τα επίπεδα αυτής και του υποδοχέα της σε ασθενείς με ρευματοειδή αρθρίτιδα, μια χρόνια συστεμική αυτοάνοση νόσο, για να δούμε εάν αυτά σχετίζονται με το στάδιο της νόσου ή τη θεραπεία. Ακόμη μελετήθηκε η εμπλοκή της λεπτίνης στην έκφραση προ- και αντιφλεγμονωδών κυτταροκινών στον ορό ασθενών και μαρτύρων. Τα αποτελέσματα δείχνουν πως τα επίπεδα λεπτίνης είναι υψηλά στους ασθενέις με ΡΑ. Επιπλέον τα επίπεδα λεπτίνης δεν βρέθηκε να σχετίζονται με το στάδιο της νόσου ή τη χορηγούμενη θεραπεία. Παρόλα αυτά τα αυξημένα επίπεδα λεπτίνης σε ασθενείς με ρευματοειδή αρθρίτιδα καταδεικνύουν ενδεχομένως έναν παθογενετικό ρόλο της λεπτίνης. / Leptin is a 16 kD peptide hormone, encoded by the ob gene and synthesized mainly by adipocytes to regulate the energy balance. In humans, leptin plasma levels are strongly correlated with body mass index (BMI) and the expression of leptin is regulated by fasting and feeding, insulin, glucocorticoids and pro-inflammatory cytokines, mainly TNFa and IL-1. Leptin is structurally similar to long-chain helical cytokines and it signals through its receptor, OB-R, which is a member of the cytokine receptor superfamily. OB-R comes in a variety of protein isoforms, and is expressed in several tissues and cells of the neuroendocrine system as well as the reproductive, hematopoietic and immune systems. Leptin has also been implicated in the pathogenesis of autoimmunity. It has also been suggested that leptin may promote the expansion and maintenance of pathogenic Th1-cell populations in autoimmune diseases. In this study to investigate the role of leptin in human autoimmunity, we measured leptin and OB-Rs levels inthe sera of patients suffering from rheumatoid arthritis (RA), a common chronicsystemic inflammatory disease, and tested for a possible correlation with disease activity and type of treatment. In addition, we studied whether leptin has an effect on the expression patterns of pro- and anti-inflammatory cytokine genes in PBMC isolated from RA patients and controls.Our results showed significantly elevated serum leptin levels in the rheumatoid population compared to the healthy controls.In addition, there was an absence of correlation between serum leptin levels and disease activity, as well as the nature and quantity of the medications administered to the patients. The absence of correlation between serum leptin levels and disease activity, coupled with the significantly and stably elevated levels of this hormone in the rheumatoid sera compared to the controls, are probably indicative of an insiduous pathogenetic role of leptin in rheumatoid arthritis.

Η Μυασθένεια είναι μια αυτοάνοση νόσος της νευρομυϊκής σύναψης που χαρακτηρίζεται από την παραγωγή αυτοαντισωμάτων έναντι, συνήθως, του AChR, καθώς και άλλων πρωτεϊνών της σύναψης. Στην παρούσα εργασία, πραγματοποιήθηκε μελέτη γενετικής συσχέτισης για την ταυτοποίηση πολυμορφισμών που πιθανώς εμπλέκονται στην εκδήλωση της Μυασθένειας. Για το σκοπό αυτό, επιλέχθηκαν πολυμορφισμοί οι οποίοι εδράζονται σε γονίδια που αποτελούν σημαντικούς ρυθμιστές της ανοσολογικής απόκρισης και έχουν προηγουμένως συσχετισθεί με άλλες αυτοάνοσες νόσους. Τα υποψήφια γονίδια είναι τα: interferon regulatory factor 5 (IRF-5), TNFα-induced protein 3 (TNFAIP3) και interleukin-10 (IL-10). Στη μελέτη συμμετείχαν 101 μυασθενείς και ισάριθμα υγιή άτομα ως ομάδα αναφοράς, όλοι ελληνικής καταγωγής. Οι μέθοδοι γονοτύπησης που εφαρμόσθηκαν περιλαμβάνουν τον προσδιορισμό αλληλουχίας κατά Sanger, την HRM ανάλυση, την PCR-RFLP και την PCR σε συνδυασμό με ηλεκτροφόρηση σε αγαρόζη, στην περίπτωση ενός in/del 30 bp. Μια στατιστική τάση συσχέτισης (p=0.068) ανιχνεύθηκε για τους πολυμορφισμούς στον υποκινητή της IL-10 μεταξύ των μυασθενών με πρώιμη ηλικία έναρξης της νόσου (early-onset) και αυτών που εμφάνισαν τη νόσο ηλικιακά αργότερα (late-onset). Για τους υπόλοιπους πολυμορφισμούς που μελετήθηκαν, δεν παρατηρήθηκαν στατιστικά σημαντικές διαφορές. Η μελέτη αυτή αποτελεί την πρώτη προσπάθεια συσχέτισης πολυμορφισμών των γονιδίων IRF-5 και TNFAIP3 με τη Μυασθένεια, σε οποιονδήποτε πληθυσμό. Όσον αφορά τους πολυμορφισμούς του υποκινητή της IL-10, περαιτέρω μελέτες σε πολυπληθέστερες ομάδες πιθανώς να αποκαλύψουν μια στατιστικώς ισχυρότερη συσχέτιση. / Myasthenia gravis (MG) is a heterogeneous autoimmune disease characterized by the production of autoantibodies against proteins of the postsynaptic membrane, in the neuromuscular junction. The contribution of genetic factors to MG susceptibility has been evaluated through family and twin studies, however, the precise genetic background of the disease remains elusive. We conducted a case-control association study in 101 unrelated MG patients, of Hellenic origin and 101 healthy volunteers in order to assess the involvement of common genetic variants in susceptibility to MG. We focused on three candidate genes which have been clearly associated with several autoimmune diseases, aiming to investigate their potential implication in MG pathogenesis. These are interferon regulatory factor 5 (IRF-5), TNFα-induced protein 3 (TNFAIP3), also known as A20, and interleukin-10 (IL-10), key molecules in the regulation of immune function. Genotyping was performed by PCR-RFLP, direct automated sequencing, High Resolution Melt curve Analysis (HRM) and PCR-agarose gel electrophoresis analysis in the case of a 30 bp in/del polymorphism. A statistical trend of association (p=0.068) between IL-10 promoter single nucleotide polymorphisms (SNPs) and the subgroups of early and late-onset MG patients was revealed. No statistically significant differences were observed in the rest of the variants examined. As far as we are aware, this is the first worldwide attempt to address the possible association between IRF-5 and TNFAIP3 common genetic variants and the genetic basis of MG.

De études récentes suggèrent une forte relation entre susceptibilité au paludisme et réponse allergique. Des niveaux élevés d’histamine plasmatique et tissulaire ont été associés à la sévérité de la maladie chez l’homme infecté par P. falciparum et dans de nombreux modèles animaux. Histamine releasing factor (HRF), une protéine pro-inflammatoire libérant l'histamine au cours des processus allergiques, est produite par le parasite au cours des infections palustres modérées et sévères, suggérant l’implication du HRF dans l’altération des réponses immunitaires et dans la pathogenèse. Les objectifs de ce travail consistaient à évaluer le rôle de la protéine parasitaire HRF dans le développement de la réponse immunitaire et à déterminer si son expression est associée à la sévérité de la maladie en étudiant deux parasites murins, PbANKA et PbNK65, déficients pour la protéine HRF (hrfΔ). Les souris infectées avec des sporozoïtes PbANKA-hrfΔ ont montré une diminution de la fréquence du neuropaludisme associée à un déficit du développement des parasites mutants au cours du stade hépatique et à une augmentation précoce systémique d’IL-6. En outre, l'infection par les parasites PbNK65-hrfΔ est caractérisée par l’élimination du parasite conduisant à une protection durable et au développement d’une mémoire immunitaire caractérisée par une augmentation d’IL-6, une diminution de l’expression de PD-1 sur les cellules T et une amélioration de la phagocytose dépendante des anticorps, confirmant l'importance de la protéine HRF dans la virulence du parasite. HRF est le premier gène de parasite Plasmodium dont l’effet direct sur la réponse immunitaire de l’hôte est démontré. / Recent findings have raised the hypothesis that clinical susceptibility to malaria may be related to allergy-type response. In human infection with P. falciparum, as well as in murine models of malaria, increased levels of histamine have been shown to be associated with disease severity. Histamine releasing factor (HRF), shown to be implicated in the release of pro-inflammatory histamine during late-phase allergy, was demonstrated to be produced by the parasite during mild and severe malaria infections suggesting that Plasmodium HRF may affect host immune responses and contributes to the pathogenesis. The objectives of this work were to evaluate the role of Plasmodium HRF in the development of the immune response and to determine whether its expression is associated with the severity of malaria disease by studying two HRF-deficient (hrfΔ) murine parasites (PbANKA and PbNK65). Infection with PbANKA-hrfΔ sporozoites showed a decrease in the frequency of ECM due to the impairment of the development of the mutant parasites in liver stages as a consequence of the up-regulation of IL-6. Infection with PbNK65-hrfΔ parasites confirmed the importance of HRF in enhancing the virulence of the parasite. Indeed, PbNK65-hrfΔ infection results in parasite clearance leading to a long-lasting protection and immune memory as reflected by an up-regulation of IL-6, a down-regulation of PD-1 expression on T cells and in the enhancement of Ab-mediated phagocytosis. HRF is the first parasite gene which directly modulates the host immune response.