Experientia supplementum (2012)最新文献

Inflammasomes influence a diverse range of kidney disease, including acute and chronic kidney diseases, and those mediated by innate and adaptive immunity. Both IL-18 and in particular IL-1β are validated therapeutic targets in several kidney diseases. In addition to leukocyte-derived inflammasomes, renal tissue cells express functional inflammasome components. Furthermore, a range of endogenous substances that directly activate inflammasomes also mediate kidney injury. Many of the functional studies have focussed on the NLRP3 inflammasome, and there is also evidence for the involvement of other inflammasomes in some conditions. While, at least in some disease, the mechanistic details of the involvement of the inflammasome remain to be elucidated, therapies focussed on inflammasomes and their products have potential in treating kidney disease in the future.

Microscopy allows for the characterization of small objects invisible to the naked eye, a technique that, since its conception, has played a key role in the development across nearly every field of science and technology. Given the nanometer size of the materials explored in the field of nanotechnology, the contributions of modern microscopes that can visualize these materials are indispensable, and the ever-improving technology is paramount to the future success of the field. This chapter will focus on four fundamental areas of microscopy used in the field of nanotechnology including fluorescence microscopy (Sect. 3.1), particle tracking and photoactivated localization microscopy (Sect. 3.2), quantum dots and fluorescence resonance energy transfer (Sect. 3.3), and cellular MRI and PET labeling (Sect. 3.4). The functionality, as well as the current and recommended usage of each given imaging system, will be discussed.

Mutations in inflammasome genes are responsible for rare monogenic and polygenic autoinflammatory diseases. On the other side, genetic polymorphisms in the same molecules contribute to the development of common multifactorial diseases (i.e., autoimmune diseases, cardiovascular pathologies, cancer). In this chapter we depicted the current knowledge about inflammasome genetics.

A systems approach to elucidate the effect of infection on cell metabolism provides several opportunities from a better understanding of molecular mechanisms to the identification of potential biomarkers and drug targets. This is obvious from the fact that we have witnessed the accelerated use of computational systems biology in the last five years to study metabolic changes in pathogen and/or host cells in response to infection. In this chapter, we aim to present a comprehensive review of the recent research by focusing on genome-scale metabolic network models of pathogen-host systems and genome-wide metabolomics and fluxomics analysis of infected cells.

T cells play a pivotal role in sensitization and elicitation of type IV allergic reactions. While T helper cells sustain and maintain the differentiation of further effector cells, regulatory T cells are involved in control of cytokine release and proliferation, and T killer cells execute cellular lysis, thereby leading to certain levels of tissue damage. According to their central role, the widely applied and OECD-supported test method for the assessment of the sensitization potential of a chemical, i.e., the local lymph node assay (LLNA), relies on the detection of the immune-responsive proliferation of lymphocytes. However, most sensitization assays recently developed take advantage of the initiators of sensitization, dendritic cells (DCs) or DC-like cell lines. Here, we focus on inhibitory molecules expressed on the surface of DCs and their corresponding receptors on T cells. We summarize insight into the function of CTLA-4, the ligands of inducible co-stimulators (ICOSs), and on the inhibitory receptor programmed death (PD). The targeting of immune cell surface receptors by inhibitory molecules holds some promise with regard to the development of T cell-based sensitization assays. Firstly, a broader and more sensitive dynamic range of detection could be achieved by blocking inhibitors or by removing inhibiting regulatory T cells from the assays. Secondly, the actual expression levels of inhibitory molecules could be also a valuable indicator for the process of sensitization. Finally, inhibitory molecules in coculture test systems are supposed to have a major influence on DCs by reverse signaling, thereby affecting their differentiation and maturation status in a feedback loop. In conclusion, inhibitory ligands of DC surface receptors and/or their cognate receptors on T cells could serve as useful tools in cell-based assays, directly influencing toxicological endpoints such as sensitization.

Understanding the chemical mechanisms by which drugs and drug metabolites interact with cells of the immune system is pivotal to our knowledge of drug hypersensitivity as a whole.In this chapter, we will discuss the currently accepted mechanisms where there is scientific and clinical evidence to support the ways in which drugs and their metabolites interact with T cells. We will also discuss bioanalytical platforms, such as mass spectrometry, and in vitro test assays such as the lymphocyte transformation test that can be used to study drug hypersensitivity; the combination of such techniques can be used to relate the chemistry of drug antigen formation to immune function. Ab initio T cell priming assays are also discussed with respect to predicting the potential of a drug to cause hypersensitivity reactions in humans in relation to the chemistry of the drug and its ability to form haptens, antigens and immunogens in patients.

This year marks the 30th anniversary of the first description of the cellular distribution of actin within a yeast cell. Since then advances in both molecular genetics and imaging technologies have ensured research within these simple model organisms has blazed a trail in the field of actomyosin research. Many yeast proteins and their functions are functionally conserved in human cells. This, combined with experimental speed, minimal cost and ease of use make the yeasts extremely attractive model organisms for researching diverse cellular processes, including those involving actomyosin. In this chapter, current state-of-the-art fluorescence methodologies being applied to yeast actomyosin research, together with an honest appraisal of their limitations, such as the pitfalls that should be considered when fluorescently labelling proteins interacting within a dynamic cytoskeleton, will be discussed. Papers describing the established techniques developed for yeast localisation studies will be highlighted. This will provide the reader with an informed overview of the arsenal of imaging techniques available to the yeast actomyosin researcher and encourage them to consider novel ways these simple unicellular eukaryotes could be used to address their own research questions.

DEAD-box proteins catalyze the ATP-dependent unwinding of RNA duplexes and accompany RNA molecules throughout their cellular life. Conformational changes in the helicase core of DEAD-box proteins are intimately linked to duplex unwinding. In the absence of ligands, the two RecA domains of the helicase core are separated. ATP and RNA binding induces a closure of the cleft between the RecA domains that is coupled to the distortion of bound RNA, leading to duplex destabilization and dissociation of one RNA strand. Reopening of the helicase core occurs after ATP hydrolysis and is coupled to phosphate release and dissociation of the second RNA strand.Fluorescence spectroscopy provides an array of approaches to study intermolecular interactions, local structural rearrangements, or large conformational changes of biomolecules. The fluorescence intensity of a fluorophore reports on its environment, and fluorescence anisotropy reflects the size of the molecular entity the fluorophore is part of. Fluorescence intensity and anisotropy are therefore sensitive probes to report on binding and dissociation events. Fluorescence resonance energy transfer (FRET) reports on the distance between two fluorophores and thus on conformational changes. Single-molecule FRET experiments reveal the distribution of conformational states and the kinetics of their interconversion. This chapter summarizes fluorescence approaches for monitoring individual aspects of DEAD-box protein activity, from nucleotide and RNA binding and RNA unwinding to protein and RNA conformational changes in the catalytic cycle, and illustrates exemplarily how fluorescence-based methods have contributed to understanding the mechanism of DEAD-box helicase-catalyzed RNA unwinding.

T lymphocytes are instrumental in the prevention of infections. With their antigen-specific T cell receptor (TCR), these cells recognize short peptides in the peptide-binding groove on MHC molecules of antigen-presenting cells. However, conventional T cells can also recognize non-peptide antigens including carbohydrates, phosphate groups, organic chemicals, and metal ions. The molecular basis of the interaction of TCR with these structures in the context of MHC has been partly solved. Organic chemicals and carbohydrates are recognized when bound to MHC-associated peptides, whereas metal ions are recognized due to their ability to form non-covalent coordination bonds with MHC molecules, bound peptides, and TCR. Peptide-independent metal ion recognition has also been described.