71 research outputs found

    Development of the filamentous fungus Thermothelomyces heterothallica C1 into a next-generation production platform for human and animal vaccines

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    engineering. The thermophilic fungus Thermothelomyces heterothallica is a robust and versatile fungal expression system for the rapid production of proteins at very high levels. In the last 6 years, the C1 protein production platform has been further improved to become a safe and efficient expression system with the prime objective of speeding up the development and production of commercial scale human and animal vaccines, monoclonal antibodies, biosimilars, as well as other therapeutic proteins at larger quantities and lower cost. C1 is a very efficient platform to produce antigens, even to generate multicomponent vaccines. The production levels of engineered C1 strains are similar in terms of yield and purity, reaching in some cases more than 2.5 g/L (in 4-5 days). In contrast to other vaccine platforms, C1 has a higher safety profile, and production can be scaled up in a more cost-effective manner using standard microbial E. coli fermenters. Stable cell lines have been developed to produce different antigens as influenza, neuraminidase, west Nile, rabies, rift valley fever..etc. Please click Download on the upper right corner to see the full abstract

    In the Hunt for Therapeutic Targets: Mimicking the Growth, Metastasis, and Stromal Associations of Early-Stage Lung Cancer Using a Novel Orthotopic Animal Model

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    BackgroundThe existing shortage of animal models that properly mimic the progression of early-stage human lung cancer from a solitary confined tumor to an invasive metastatic disease hinders accurate characterization of key interactions between lung cancer cells and their stroma. We herein describe a novel orthotopic animal model that addresses these concerns and consequently serves as an attractive platform to study tumor–stromal cell interactions under conditions that reflect early-stage lung cancer.MethodsUnlike previous methodologies, we directly injected small numbers of human or murine lung cancer cells into murine's left lung and longitudinally monitored disease progression. Next, we used green fluorescent protein-tagged tumor cells and immuno-fluorescent staining to determine the tumor's microanatomic distribution and to look for tumor-infiltrating immune cells and stromal cells. Finally, we compared chemokine gene expression patterns in the tumor and lung microenvironment.ResultsWe successfully generated a solitary pulmonary nodule surrounded by normal lung parenchyma that grew locally and spread distally over time. Notably, we found that both fibroblasts and leukocytes are recruited to the tumor's margins and that distinct myeloid cell attracting and CCR2-binding chemokines are specifically induced in the tumor microenvironment.ConclusionOur orthotopic lung cancer model closely mimics the pathologic sequence of events that characterizes early-stage human lung cancer propagation. It further introduces new means to monitor tumor–stromal cell interactions and offers unique opportunities to test therapeutic targets under conditions that reflect early-stage lung cancer. We argue that for such purposes our model is superior to lung cancer models that are based either on genetic induction of epithelial transformation or on ectopic transplantation of malignant cells

    Corporate governance and managerial risk taking: theory and evidence

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    Abstract We study how the investor protection environment affects corporate managers' incentives to take value-enhancing risks. In our model, the manager chooses higher perk consumption when investor protection is low. Since perks represent a priority claim held by the manager, lower investor protection leads the manager to implement a sub-optimally conservative investment policy, effectively aligning her risk-taking incentives with those of the debt holders. By the same token, higher investor protection is associated with riskier investment policy and faster firm growth. We test these predictions in a large Global Vantage panel. We find strong empirical confirmation that corporate risk-taking and firm growth rates are positively related to the quality of investor protection. JEL Classification: G15, G31, G34

    Persistent ER Stress Induces the Spliced Leader RNA Silencing Pathway (SLS), Leading to Programmed Cell Death in Trypanosoma brucei

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    Trypanosomes are parasites that cycle between the insect host (procyclic form) and mammalian host (bloodstream form). These parasites lack conventional transcription regulation, including factors that induce the unfolded protein response (UPR). However, they possess a stress response mechanism, the spliced leader RNA silencing (SLS) pathway. SLS elicits shut-off of spliced leader RNA (SL RNA) transcription by perturbing the binding of the transcription factor tSNAP42 to its cognate promoter, thus eliminating trans-splicing of all mRNAs. Induction of endoplasmic reticulum (ER) stress in procyclic trypanosomes elicits changes in the transcriptome similar to those induced by conventional UPR found in other eukaryotes. The mechanism of up-regulation under ER stress is dependent on differential stabilization of mRNAs. The transcriptome changes are accompanied by ER dilation and elevation in the ER chaperone, BiP. Prolonged ER stress induces SLS pathway. RNAi silencing of SEC63, a factor that participates in protein translocation across the ER membrane, or SEC61, the translocation channel, also induces SLS. Silencing of these genes or prolonged ER stress led to programmed cell death (PCD), evident by exposure of phosphatidyl serine, DNA laddering, increase in reactive oxygen species (ROS) production, increase in cytoplasmic Ca2+, and decrease in mitochondrial membrane potential, as well as typical morphological changes observed by transmission electron microscopy (TEM). ER stress response is also induced in the bloodstream form and if the stress persists it leads to SLS. We propose that prolonged ER stress induces SLS, which serves as a unique death pathway, replacing the conventional caspase-mediated PCD observed in higher eukaryotes

    The Law and Economics of Liability Insurance: A Theoretical and Empirical Review

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    Age and work-related motives: Results of a meta-analysis

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    Item does not contain fulltextAn updated literature review was conducted and a meta-analysis was performed to investigate the relationship between age and work-related motives. Building on theorizing in life span psychology, we hypothesized the existence of age-related differences in work-related motives. Specifically, we proposed an age-related increase in the strength of security and social motives, and an age-related decrease in the strength of growth motives. To investigate life span developmental theory predictions about age-related differences in control strategies, we also examined the relationship between age and intrinsic and extrinsic motives. Consistent with our predictions, meta-analytic results showed a significant positive relationship between age and intrinsic motives, and a significant negative relationship between age and strength of growth and extrinsic motives. The predicted positive relation between age and strength of social and security motives was only found among certain subgroups. Implications of these findings for work motivation and life span theories and future research are discussed

    Shifting the limits in wheat research and breeding using a fully annotated reference genome

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    Introduction: Wheat (Triticum aestivum L.) is the most widely cultivated crop on Earth, contributing about a fifth of the total calories consumed by humans. Consequently, wheat yields and production affect the global economy, and failed harvests can lead to social unrest. Breeders continuously strive to develop improved varieties by fine-tuning genetically complex yield and end-use quality parameters while maintaining stable yields and adapting the crop to regionally specific biotic and abiotic stresses. Rationale: Breeding efforts are limited by insufficient knowledge and understanding of wheat biology and the molecular basis of central agronomic traits. To meet the demands of human population growth, there is an urgent need for wheat research and breeding to accelerate genetic gain as well as to increase and protect wheat yield and quality traits. In other plant and animal species, access to a fully annotated and ordered genome sequence, including regulatory sequences and genome-diversity information, has promoted the development of systematic and more time-efficient approaches for the selection and understanding of important traits. Wheat has lagged behind, primarily owing to the challenges of assembling a genome that is more than five times as large as the human genome, polyploid, and complex, containing more than 85% repetitive DNA. To provide a foundation for improvement through molecular breeding, in 2005, the International Wheat Genome Sequencing Consortium set out to deliver a high-quality annotated reference genome sequence of bread wheat. Results: An annotated reference sequence representing the hexaploid bread wheat genome in the form of 21 chromosome-like sequence assemblies has now been delivered, giving access to 107,891 high-confidence genes, including their genomic context of regulatory sequences. This assembly enabled the discovery of tissue- and developmental stage–related gene coexpression networks using a transcriptome atlas representing all stages of wheat development. The dynamics of change in complex gene families involved in environmental adaptation and end-use quality were revealed at subgenome resolution and contextualized to known agronomic single-gene or quantitative trait loci. Aspects of the future value of the annotated assembly for molecular breeding and research were exemplarily illustrated by resolving the genetic basis of a quantitative trait locus conferring resistance to abiotic stress and insect damage as well as by serving as the basis for genome editing of the flowering-time trait. Conclusion: This annotated reference sequence of wheat is a resource that can now drive disruptive innovation in wheat improvement, as this community resource establishes the foundation for accelerating wheat research and application through improved understanding of wheat biology and genomics-assisted breeding. Importantly, the bioinformatics capacity developed for model-organism genomes will facilitate a better understanding of the wheat genome as a result of the high-quality chromosome-based genome assembly. By necessity, breeders work with the genome at the whole chromosome level, as each new cross involves the modification of genome-wide gene networks that control the expression of complex traits such as yield. With the annotated and ordered reference genome sequence in place, researchers and breeders can now easily access sequence-level information to precisely define the necessary changes in the genomes for breeding programs. This will be realized through the implementation of new DNA marker platforms and targeted breeding technologies, including genome editing

    Non-muscle myosin II in disease: mechanisms and therapeutic opportunities

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