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No description available.

The trigeminal ganglion (TG) is a complex sensory structure and multiple lines of evidence suggest that significant differences exist in anatomical, neurochemical and physiological properties between it and its equivalent structure in the somatosensory system, the dorsal root ganglion (DRG). This is likely to be a reflection, first on the unique areas of tissue innervation of the TG and second, on the unusual responses to injury which give rise to distinct pain symptoms such as toothache, migraine and temporomandibular joint disorders. In an attempt to address this disparity in knowledge, we have carried out an in-depth in vivo study investigating neurochemical populations and cell size distributions of sensory neurons within the rat TG. We have performed a detailed analysis of expression patterns for receptor components of important inflammatory mediators, NGF (TrkA), TNFα (p55) and IL-6 (gp130), along with the thermo-transducers TRPV1 and TRPM8. For each analysis we have compared our findings with those of the rat DRG. We have shown a significantly larger population of NF200+ neurons within the TG (51%) compared to the DRG (40%), and most interestingly, the majority of NF200+ neurons in the TG were within the small to medium cell size range, conferring a nociceptive phenotype. We have for the first time, determined expression of p55 and gp130 protein levels within neurochemically defined subpopulations of the TG. We show that a large proportion (33%) of TG neurons, in particular 27% of NF200+ neurons co-express p55, and thereby have the potential to respond directly to TNFα. Furthermore, we have observed gp130 protein expression to be ubiquitous within the TG, suggesting all neurons, including non-nociceptors, could respond to IL-6. In addition, we have utilised biochemical and electrophysiological techniques in vitro to measure the functional outcome of exposure of TG neurons to IL-6. We have demonstrated that IL-6 activates the JAK/STAT signalling pathway, preferentially within NF200+ neurons. Furthermore, we have shown that IL-6 sensitises the response of TG neurons to the TRPV1 agonist capsaicin, altering the gating properties and prolonging the opening time of the channel. Taken together, our findings support the emerging picture of a complex combinatorial pattern of co-expression of sensory neurochemicals, transducers and receptor components that help to define TG neuronal modality and function. We would advocate caution in making generalisations across sensory ganglia in particular in extrapolating data from the DRG to the trigeminal ganglion.

Follicular dendritic cells (FDCs) reside in primary B-cell follicles and in the light zones of germinal centers (GCs) in secondary follicles, where their dendrites interdigitate forming extensive networks intimately interacting with B-cells. In GCs, FDCs can be found at the edges attached to the supporting reticular fibers. They trap and arrange immune complexes (ICs) in vivo and in vitro in a periodic manner with 200–500Å spacing and provide both antigen-specific and non-specific accessory signals to B-cells. FDCs exist in resting and activated states, with two characteristically different phenotypes. In their activated state, FDCs upregulate the expression of accessory molecules and cytokines important in the FDC-B cell interaction in GCs. We sought to determine the mechanisms influencing the transition of FDCs from a resting to an activated state in GCs and their impact on T-cell dependent (TD) and independent (TI)-GC reactions (GCRs). We found that IC-FDC interactions via FDC-FcgammaRIIB induce the upregulation of FDC-FcgammaRIIB, -ICAM-1, and -VCAM-1, at both the protein and mRNA levels. We also reported for the first time the expression of TLR-4 on FDCs. Moreover, engagement of FDC-TLR4 with LPS activated NF-kappaB, up-regulated expression of important FDC-accessory molecules, including FcgammaRIIB, ICAM-1, and VCAM-1, and enhanced FDC accessory activity in promoting recall IgG responses. Moreover, IC-activated FDCs produced IL-6 and FDC-IL-6 promoted GCRs, somatic hypermutation (SHM) and IgG production. Further, we reported that binding of FDCs to collagen coated surfaces induced restoration of their dendritic processes and networks in vitro. In addition, we designed an FDC-supported in vitro model capable of induction and assessment of primary human antibody responses to protein antigens characterized by class-switching and affinity maturation. Uniquely, we generated TI immune responses to TD protein Ags in the complete absence of T cell help in vivo and in vitro. In the presence of FDC-associated second signals such as BAFF and C4BP, FDC- FcgammaRIIB-periodically trapped-ICs induced the production of Ag-specific IgM, GC-development and plasmablast-differentiation in anti-Thy-1-pretreated nude mice. Purified murine and human B cells cultured in vitro with IC-bearing FDCs also showed the production of antigen–specific IgM within just 48 h.

Pancreatic cancer is characterized by its desmoplastic tumor microenvironment and the infiltration of immunosuppressive cells. It is a devastating disease where most patients are diagnosed at a late stage and the treatment options are few. The development of new treatments is surly needed. One treatment option explored is the use of immunotherapy with the intent to activate the immune system and change the balance from pro-tumor to anti-tumor. This thesis presents the idea of using oncolytic adenoviruses called LOAd-viruses that are armed with immunostimulatory- and microenvironment-modulating transgenes. For effective treatment of pancreatic cancer, the virus needs to be able to be given in addition to standard therapy, the chemotherapy gemcitabine. In paper I, the immunomodulatory effect of gemcitabine was evaluated in blood from pancreatic cancer patients receiving their first 28-day cycle of treatment with infusions day 1, 8 and 15 followed by a resting period. Gemcitabine reduced the level of immunosup-pressive cells and molecules but the effect did not last throughout the resting period. On the other hand, gemcitabine did not affect the level or proliferative function of effector T cells indicating that gemcitabine could be combined with immunotherapy. The LOAd700 virus expresses a novel membrane-bound trimerized form of CD40L (TMZ-CD40L). In paper II, LOAd700 showed to be oncolytic in pancreatic cancer cell lines as well as being immunostimulatory as shown by its capacity to activate dendritic cells (DCs), myeloid cells, endothelium, and to promote expansion of antigen-specific T cells. In paper III, LOAd703 armed with both 4-1BBL and TMZ-CD40L was evaluated. LOAd703 gave a more profound effect than LOAd700 on activation of DCs and the virus was also capable of reducing factors in stellate cells connected to the desmo-plastic and immunosuppressive microenvironment. In paper IV, LOAd713 armed with TMZ-CD40L in combination with a single-chain variable fragment against IL-6R was evaluated. The virus could kill pancreatic cancer cells lines through oncolysis and could also reduce factors involved in desmoplasia in stellate cells. Most interestingly, LOAd713 could reduce the up-regulation of PD-1/PD-L1 in DCs after CD40 activation. Taken together, LOAd703 and LOAd713 seem to have interesting features with their combination of immunostimulation and microenvironment modulation. At present, LOAd703 is evaluated in a clinical trial for pancreatic cancer (NCT02705196).

Much of the impetus for this research can be attributed to Kenneth W. Hinchcliff, who has studied exercise-induced pulmonary haemorrhage (EIPH) extensively. This thesis focused on EIPH in Thoroughbred racehorses competing in South Africa. Using tracheobronchoscopy, the prevalence and severity of EIPH and the association with racing performance was determined. Thereafter, the prevalence of other respiratory tract disorders and their association with racing performance is reported. This is followed by a study assessing interobserver variability using grading systems in the detection of respiratory tract disorders. Finally, there is a report on the immunopathogenesis of EIPH. Using tracheobronchoscopy after racing, the prevalence and severity of EIPH was assessed in 1,005 racehorses competing at high altitude (> 1,400 meters above sea level) and at sea level in a racing jurisdiction that does not allow the use of furosemide and nasal dilator strips. The prevalence and severity of EIPH was affected by altitude as racing at sea level was associated with a higher prevalence and greater severity of EIPH. Results also suggested that EIPH was associated with superior performance in South African Thoroughbred racehorses. Upper and lower respiratory tract disorders identified following tracheobronchoscopic examination included left arytenoid asymmetry, left laryngeal hemiplegia, epiglottic deformity, epiglottic entrapment, subepiglottic cysts, dorsal displacement of the soft palate, pharyngeal lymphoid hyperplasia (PLH), laryngeal and tracheal dirt, tracheal mucous (TM), tracheal stenosis and tracheal cartilage ring spikes in Thoroughbred racehorses after racing. Overall, there was a low prevalence of grade 2 and 3 arytenoid cartilage asymmetry, left laryngeal hemiplegia, epiglottic entrapment, subepiglottic cysts and epiglottic deformity, while more severe grades of PLH, laryngeal debris, tracheal debris, TM and tracheal cartilage ring spikes had a higher prevalence. An association with sex was identified as tracheal cartilage ring spikes occurred more often in male racehorses. Superior racing performance was identified in racehorses with grade 3 tracheal mucous and tracheal cartilage ring spikes. Endoscopic grading of EIPH, PLH, arytenoid cartilage movement (ACM), and TM was performed by 3 observers that were blinded to each racehorse’s identity and race day performance using previously established grading criteria. Excellent interobserver reliability was seen using the EIPH grading system, while the weighted kappa for PLH, ACM and TM was lower. The study demonstrated sufficient reliability for the use of the EIPH, PLH, ACM and TM grading systems in racehorses competing in South Africa. The study concluded that tracheobronchoscopy seemed to be a practical screening technique that may have prognosticative validity and clinical dependability and that would allow safe and quick assessment of the respiratory tract of a large number of racehorses in field conditions. Venous blood was collected from 10 horses in each EIPH grade classification (grade 0 to 4) following tracheobronchoscopic examinations for the determination of the presence and severity of EIPH. Following RNA isolation and cDNA synthesis, real-time PCR was used to detect equine cytokine-specific mRNA for interleukin (IL) -1, -6, -10, interferon (INF) -ã, and tumor necrosis factor (TNF) -á. Results of this study indicated that increased IL-6, and -10 mRNA production was associated with more severe forms of EIPH. Also, there was greater expression of IL-6 mRNA at sea level and TNF-á mRNA at high altitude. This study concluded that although it was unclear whether the inflammatory response observed in the study was due to pre-existing pulmonary inflammation or as a direct consequence of pulmonary bleeding, the study demonstrated a systemic correlation to pulmonary inflammation. The research reported in this thesis has contributed substantially to the determination of the prevalence, severity and affect on racing performance of respiratory tract disorders in Thoroughbred racehorses competing in South Africa. Also, determination of an association between EIPH and inflammation at a molecular level may assist future researchers in anti-cytokine therapies which may help reduce the prevalence and severity of EIPH. / Thesis (PHD)--University of Pretoria, 2007. / Companion Animal Clinical Studies / unrestricted

Background: Pembrolizumab and cetuximab are antibodies under investigation in head and neck squamous cell carcinoma (HNSCC) either as single agents or combined with cisplatin and other chemotherapeutic drugs, e.g., 5-fluorouracil and/or docetaxel. However, also the combination of both antibodies may have potential in recurrent/ metastatic (R/M) HNSCC, in particular in cisplatin-resistant or -refractory cases or patients with comorbid disease, e.g. patients with impaired renal function. Methods: To clarify potential benefit that may result from such combination, we used the FLAVINO assay, a short-time ex vivo assay to compare responsiveness of HNSCC to pembrolizumab, cetuximab and both combined regarding colony formation of epithelial cells of biopsy-derived tumor samples and their cytokine production within three days either without or with stimulation with 10 ng/mL interferon gamma (IFN-g). Vascular endothelial growth factor A (VEGF), monocyte chemoattractant protein 1 (MCP-1 or CCL2), interleukin 6 (IL-6), IL-8, IFN-g, and interferon gamma-induced protein 10 (IP-10 or CXCL10) in supernatants were measured by ELISA. Results: We detected huge heterogeneity in response to cetuximab, pembrolizumab and both combined with and without IFN-g stimulation. Moreover, we detected a link between IFN-g induced IP-10 release and improved outcome in those HNSCC patients who were capable to respond to IFN-g and pembrolizumab, cetuximab and both combined with a further increase in IP-10 production. We derived an “IP-10 score” that independent from clinical characteristics of HNSCC patients and therapy regimens applied was able to predict their outcome. Conclusions: The heterogeneity in the ex vivo response of cetuximab, pembrolizumab and both combined with and without IFN-g stimulation identifies subgroups of HNSCC patients with deviating OS.

Das Lipopolysaccharid Bindende Protein (LBP) ist ein überwiegend in der Leber synthetisiertes Akutphaseprotein. Es bindet den Zellwandbestandteil Lipopolysaccharid (LPS) Gram-negativer Bakterien und transportiert es zu zellulären Rezeptoren, wodurch das angeborene Immunsystem aktiviert wird. In dieser Arbeit wird die Regulation der LBP-Expression in Interleukin (IL)-1, IL-6 und Dexamethason (Dex) stimulierten humanen Hepatomzelllinien HuH-7 und HepG2 untersucht. Der wichtigste Stimulator ist dabei IL-6, dessen Wirkung über die Transkriptionsfaktoren (TF) Stat-3, C/EBP-beta und AP-1 vermittelt wird. Für alle 3 TF konnten aktive Bindungsstellen auf dem LBP-Promotor nachgewiesen werden. Für IL-1-Effekte die u. a. über den TF NF-kappaB vermittelt werden, konnten ebenfalls aktive Bindungsstellen nachgewiesen werden. Die Wirkung von Dex wird über Glucocorticoid Responsive Elements (GREs) vermittelt. Auf dem LBP-Promotor befinden, sich wie gezeigt werden konnte, mehrere aktive GREs, wobei einige verstärkend und einige hemmend wirken. Eine zu beobachtende Synergiewirkung von Dex und IL-6 wird durch die Aufregulation des IL-6-Rezeptors durch Dex verursacht. Die LBP-Expression kann durch TGF (Transforming Growth Factor)-beta gehemmt werden. Der TGF-beta-Signalweg über Smads ist in den Hepatomzellen aktiv, vermittelt aber nicht den TGF-beta-Hemmeffekt, sondern eine geringe stimulierende Wirkung, die bei alleiniger TGF-beta-Inkubation auftritt. Die inhibierende Wirkung von TGF-beta wird durch Gfi-1- und AP-1-Bindungsstellen vermittelt. Die Gfi-1-Bindungsstelle nimmt dabei, wie hier erstmals gezeigt werden konnte, eine herausragende Stellung ein. Die Aufklärung der LBP-Regulation und dabei besonders die Hemmung der LBP-Expression kann mittelfristig dazu beitragen, den klinischen Verlauf von inflammatorischen und infektiösen Erkrankungen zu beeinflussen und bietet daher Potenzial für neue Therapieansätze. / Lipopolysaccharide (LPS) binding protein (LBP) is an acute phase protein with the ability to bind and transfer LPS of Gram-negative bacteria. This soluble pattern recognition molecule represents an important defense principle of the host. Regulation of the hepatic acute phase response and its termination are important mechanisms for limiting systemic inflammatory activity of the host. Here were analyze the cooperation of Interleukin (IL)-1, IL-6, and Dexamethasone (Dex) at LBP expression in the hepatoma cell lines HuH-7 and Hep G2. The major inducer of LBP expression is IL-6. Within the LBP promoter numerously highly consensus binding sites such as AP-1, C/EBP-beta? and STAT3 are present, that confer transcriptional activity as shown by truncation and mutation experiments. Additionally, activate NF-kappaB sites activated by IL-1 were detected at the LBP promoter. By mutation experiments of the promoter furthermore were found differentially active glucocorticoid response elements (GREs). The promoter contains GREs enhancing the activity as well as inhibitory ones. The enhancing effect towards LBP expression by Dex was mediated by IL-6. Dex stimulated the expression of the IL-6 receptor and therefore upregulated the IL-6 pathway. Transforming Growth Factor (TGF)-beta is able to inhibit LBP expression in stimulated cells. An AP-1 binding site was identified mediating inhibitory TGF-beta effects towards LBP promoter activity. Furthermore it was shown that a growth factor independence (Gfi)-1 binding site localized near the AP-1 site is essential for mediating the TGF-beta inhibitory effect. The relevancy of the Gfi-1 site fore mediating TGF-beta effects indicates a novel mechanism for understanding inhibitory TGF-beta effects at the transcriptional level. In summary the complex regulation of LBP were elucidate which may help to eventually develop novel intervention strategies for acute phase, sepsis, and septic shock.

Ciliary neurotrophic factor (CNTF) is produced by astrocytes which have been implicated in regulating stress responses. We found that CNTF in the medial amygdala (MeA) promotes despair or passive coping, i.e., immobility in an acute forced swim stress, in female mice, while having no effect in males. Neutralizing CNTF antibody injected into the MeA of wildtype females reduced activation of downstream STAT3 (Y705) 24 and 48 h later. In concert, the antibody reduced immobility in the swim test in females and only after MeA injection, but not when injected in the central or basolateral amygdala. Antibody injected into the male MeA did not affect immobility. These data reveal a unique role of CNTF in female MeA in promoting despair or passive coping behavior. Moreover, 4 weeks of chronic unpredictable stress (CUS) increased immobility in the swim test and reduced sucrose preference in wildtype CNTF+/+, but not CNTF-/- littermate, females. Following CUS, 10 min of restraint stress increased plasma corticosterone levels only in CNTF+/+ females. In males, the CUS effects were present in both genotypes. Further, CUS increased CNTF expression in the MeA of female, but not male, mice. CUS did not alter CNTF in the female hippocampus, hypothalamus and bed nucleus of stria terminalis. This suggests that MeA CNTF has a female-specific role in promoting CUS-induced despair or passive coping, behavioral anhedonia and neuroendocrine responses. Compared to CNTF+/+ mice, CNTF-/- mice did not show differences in CUS-induced anxiety-like behavior and sensorimotor gating function as measured by elevated T-Maze, open field and pre-pulse inhibition of the acoustic startle response. Together, this study reveals a novel CNTF-mediated female-specific mechanism in stress responses and points to opportunities for developing treatments for stress-related disorders in women.