Therapeutic proteins, a.k.a. biopharmaceuticals, are most commonly produced in expression systems derived from Chinese Hamstery Ovary (CHO) cells, thanks to great capacity of post-translational modifications like secretation, folding and glycosylation. The engineering of cells for regulation of protein expression has many options including knock-in and knock-out of genes, epigenetic studies or improvement of the expression casette of the protein of interest by e.g. promotor variants or modifications of the 5’ and 3’ untranslated region (UTR). The 3’-UTR is therefore a good optimization candidate for attempting to achieve increased expression of therapeutic proteins. The final aim of this study was to identify and design 3’-UTRs for improved expression of therapeutic proteins in HyClone™ CHO cells from GE Healthcare Bio-Sciences AB (GEHC). The impact goal is to increase the efficiency and lower the costs for pharmaceutical companies when producing biopharmaceuticals in the HyClone™ CHO cell line, leading to increased accessibility of monoclonal antibodies (mAbs) on the pharmaceutical market. The study was initiated with bioinformatic analysis of the CHO cell transcriptome from a set of RNA-seq data of HyClone™ CHO to find high expressing, context independent genes. The 3’-UTRs from the best candidate genes were used for construction of plasmids for expression of a Fc-eGFP fusion protein. Nine selected 3’-UTRs were designed, synthesized and cloned into a parent plasmid (pGE0520) creating nine plasmid variants (pGE0523-531). The constructed plasmids were used for evaluation with site directed integration (SDI) into the HyClone™ CHO cell line and expression analysis were performed by flow cytometry and antibody titer measurements from cells with successfully integrated plasmid sorted by fluorescence-activated cell sorting (FACS).   Result show a significant effect on protein expression when using different variants of 3’-UTRs. Two variants, pGE0524 and pGE0526, competing with the parent plasmid in expression levels and integration efficiency from SDI, making them candidates for further investigations against the parent plasmid. Results also show good correlation between flow cytometry data from pre- and post-sorting, which can make research for further 3’-UTRs more efficient by evaluations and prediction of expression levels before cell sorting.

Crohn's disease, a chronic inflammation of the bowel, is a multi-factorial condition where uncontrolled immune responses to luminal bacteria occur in genetically predisposed individuals. The first observable clinical signs are small ulcers that form at a specialised form of epithelium, follicle-associated epithelium (FAB). The FAB covers immune inductive sites, Peyer's patches, which function primarily as sensory areas that sample the externaI gut environment. Dendritic cells are one of the key cells that are involved in sensing luminal contents and orchestrating the gut immune system. The main aim of this thesis was to determine whether the barrier of the FAB is breached in Crohn's disease and if dysfunctional immune regulators, namely dendritic cells, playaroIe in initiating and/or maintaining the chronic intestinal inflammation. Using biopsies and surgical specimens, we were able to show that in Crohn's disease, there was an increased transmucosaI transport of Escherichia coli compared to specimens from ulcerative colitis and non-inflammatory bowel disease (IBD) controIs. Dendritic cells internalised a higher percentage of bacteria that had translocated across the FAB in the Crohn's samples. Furthermore, significantly higher concentrations of TNF-u was released upon bacterial stimulation by tissues from patients with Crohn's disease than in controIs. We went on to characterise the dendritic cells present in the Peyer's patches of patients with Crohn's disease. We found an accumulation of both immature and mature dendritic cells beneath the FAB, in the sub-epithelial dome (SED). Normally, mature dendritic cells migrate towards T cell-rich areas. However, we observed mature dendritic cells accumulating in the SED because they lacked the CCR7 migratory receptor. Furthermore, they were more prone to take-up bacteria, and produced TNF-α. To study the function of mucosal dendritic cells, we performed isolation experiments and mixed Iymphocyte reactions. Dendritic cells from both the ileum and blood of patients with active Crohn's had reduced capacity for inducing T cell proliferation than non-IBD controIs. Blood dendritic cells of patients in remission had normalised function that was similar to dendritic cells from healthy controls. The SAMPl/YitFc mice, considered an appropriate murine model for Crohn's disease, had an inherent permeability defect that increased with the chronicity of intestinaI inflammation. However unlike in human Crohn's disease, dendritic cells did not seem to playaroIe in murine ileitis. This thesis highlights the accumulation of the actively surveying dendritic cells that are prone to bacterial internalisation, and points to their possible different functional roles in active versus in-active disease; thereby confirming dendritic cells as one ofthe key components in the pathogenesis ofCrohn's disease.

No description available.

B cells have a central role in the pathogenesis of collagen-induced arthritis (CIA), an animal model of the autoimmune disease rheumatoid arthritis. In this report, a specific subset of an innate type of B cells, B-1 B cells, have been studied for the involvement in CIA. The B-1 B cells were shown to produce small amounts of collagen-specific antibodies upon stimulation in vitro, suggesting that they play a minor role in the development of CIA. This report also includes how marginal zone B cells, another innate type of B cells with natural collagen-reactivity, can be identified in the medullary sinuses of lymph nodes of collagen-immunized mice, implying involvement in auto antigen trapping.

Investigation of tumor growth has traditionally been studied focusing only on the cancer cells. However, tumors consist of a complex tissue organization where heterotypic signaling occurs between different cell types. The cross-talk between tumor cells and other surrounding cell types may ultimately prove to be as important for the tumor cell behavior as the internal signaling cascades in the tumor cell itself.Myeloid cells, such as granulocytes and monocytes, and thrombocytes play an important role in the tumor tissue, as a tumor can be compared to a wound healing process without the normal regulation mechanisms. Platelets are thought to facilitate tumor cell extravasation by binding to the tumor cell and recruiting myeloid cells that secrete factors aiding tumor migration through the endothelial cells. Studying the content of granules and vesicles of the platelets and myeloid cells can provide important knowledge about how the tumor interactions are mediated and which key proteins that controls these processes.Serglycin is an intracellular proteoglycan that attaches chains of negatively charged glycosaminoglycans. It is thought to have a function in retaining and storing proteins in hematipoietic cells. In this project the impact of the loss of serglycin on platelets and myeloid cells was investigated, using a spontaneous insulinoma serglycin knockout mouse model. The results suggests that serglycin does not affect the amount of neutrophil granulocytes and monocytes in peripheral blood, nor does it seem to affect the amount of platelets sequestered to the tumor tissue. A co-staining for platelets and MMP9 positive granulocytes was also performed in order to assess if granulocyte-platelet interactions in the tumor were affected by loss of serglycin. Interactions between these cells were observed in both genotypes. Von Willebrand factor levels in the tumor tissue also remained unchanged upon loss of serglycin. However, preliminary experiments indicated that serglycin seems to play a role in the intracellular amounts of vimentin and VEGFB in undifferentiated primary bone marrow derived monocytes.

Cryptosporidium is a protozoan parasite infecting the intestines of its hosts, leading to acute diarrheal disease. Out of 26 recognized species, 14 are known to infect humans. Of most importance, from a human perspective are Cryptosporidium parvum and Cryptosporidium hominis, of which the former is known to have zoonotic potential. Globally, cryptosporidiosis affect people with lowered immune status particularly hard; among children under five it is the most important parasitic cause of gastroenteritis. In the region of KwaZulu-Natal, on the east coast of South Africa, Cryptosporidium is considered endemic. Drinking water is frequently collected from river systems and as Cryptosporidium spp. can be transmitted via contaminated water, this may be one source of infection. Research on the species distribution is important for outbreak investigations and prevention efforts. In water and wastewater such speciation is commonly performed using immunomagnetic separation, an antibody dependent method. There is however a suspicion that these antibodies have less affinity to some species and hence contorts the detected species distribution. An alternative approach is therefore of interest.   In the present study, Cryptosporidium diversity in wastewater collected from four different wastewater treatment plants in KwaZulu-Natal, is evaluated with an optimized antibody-free workflow and a single cell platform. It was shown that the workflow is suitable for complex samples, such as wastewater. Furthermore, diversity was assessed with amplicon sequencing, revealing four different species and genotypes. Further modifications of the methods used could benefit the field of Cryptosporidium research, along with improving global health and preventing disease outbreaks.

No description available.

No description available.

Many normal and cancerous cell lines exhibit a stable composition of cells in distinct states which can, e.g., be defined on the basis of cell surface markers. There is evidence that such an equilibrium is associated with stochastic transitions between distinct states. Quantifying these transitions has the potential to better understand cell lineage compositions. We introduce CellTrans, an R package to quantify stochastic cell state transitions from cell state proportion data from fluorescence-activated cell sorting and flow cytometry experiments. The R package is based on a mathematical model in which cell state alterations occur due to stochastic transitions between distinct cell states whose rates only depend on the current state of a cell. CellTrans is an automated tool for estimating the underlying transition probabilities from appropriately prepared data. We point out potential analytical challenges in the quantification of these cell transitions and explain how CellTrans handles them. The applicability of CellTrans is demonstrated on publicly available data on the evolution of cell state compositions in cancer cell lines. We show that CellTrans can be used to (1) infer the transition probabilities between different cell states, (2) predict cell line compositions at a certain time, (3) predict equilibrium cell state compositions, and (4) estimate the time needed to reach this equilibrium. We provide an implementation of CellTrans in R, freely available via GitHub (https://github.com/tbuder/CellTrans).

Die rheumatoide Arthritis (RA) ist eine chronisch-entzündliche Bindegewebserkrankung mit bevorzugtem Befall der Gelenke. Es bestimmen Knorpel- und Knochendestruktionen das Krankheitsbild. Eine Schlüsselrolle in der Pathogenese nehmen proliferierende, synoviale Fibroblasten (RASF) durch Auflösung der extrazellulären Matrix (EZM), durch Interaktion mit immunkompetenten Zellen und durch Produktion pro-inflammatorischer Zytokine ein. Die vorliegende Arbeit zeigt die Migrationseigenschaften von RASF und zwei verschiedenen murinen (LS48) und humanen (TK188) Fibroblastenzelllinien in einem In-vitro-Migrationsassay. Es wird der Einfluss von Antikörpern sowie verschiedener EZM-Komponenten auf die Migration der Zelllinien untersucht. Die nachfolgende Analyse phänotypischer Charakteristika stellt dabei die besondere Rolle der genannten Fibroblastenzelllinien heraus, welche eine Reihe von Gemeinsamkeiten untereinander und mit RASF besitzen. Sie zeigen ebenso erhöhte Migrationsaktivität unter dem Einfluss eines Chemoattraktants und besitzen ähnliche Destruktionsmuster von Kollagenmatrizen. Beide Zellreihen exprimieren mehr RASF-typische Proteasen, Adhäsionsmoleküle und immunologisch agierende Proteine als nicht pathologisch transformierte Fibroblasten. Ebenso weisen sie eine gesteigerte Stoffwechselaktivität und Proliferationstätigkeit auf. Diese in vitro erbrachten Hinweise auf mögliche Knorpeldestruktionen sollten Anlass für weitere In-vivo-Studien zu den genannten Zelllinien geben.