ERC FUNDED PROJECTS

Asymmetric cell division is a key mechanism for the generation of cell diversity in eukaryotes. During this process, a polarized mother cell divides into non-equivalent daughters. These may differentially inherit fate determinants, irreparable damages or age determinants. Our aim is to decipher the mechanisms governing the individualization of daughters from each other. In the past ten years, our studies identified several lateral diffusion barriers located in the plasma membrane and the endoplasmic reticulum of budding yeast. These barriers all restrict molecular exchanges between the mother cell and its bud, and thereby compartmentalize the cell already long before its division. They play key roles in the asymmetric segregation of various factors. On one side, they help maintain polarized factors into the bud. Thereby, they reinforce cell polarity and sequester daughter-specific fate determinants into the bud. On the other side they prevent aging factors of the mother from entering the bud. Hence, they play key roles in the rejuvenation of the bud, in the aging of the mother, and in the differentiation of mother and daughter from each other. Recently, we accumulated evidence that some of these barriers are subject to regulation, such as to help modulate the longevity of the mother cell in response to environmental signals. Our data also suggest that barriers help the mother cell keep traces of its life history, thereby contributing to its individuation and adaption to the environment. In this project, we will address the following questions: 1 How are these barriers assembled, functioning, and regulated? 2 What type of differentiation processes are they involved in? 3 Are they conserved in other eukaryotes, and what are their functions outside of budding yeast? These studies will shed light into the principles underlying and linking aging, rejuvenation and differentiation.

2 200 000 €

Start date: 2010-05-01, End date: 2015-04-30

This interdisciplinary proposal has the objective to greatly enhance our understanding of fundamental biomineralization processes involved in the formation of calcium carbonates by marine organisms, such as corals, foraminifera and bivalves, in order to better understand vital effects. This is essential to the application of these carbonates as proxies for global (paleo-) environmental change. The core of the proposal is an experimental capability that I have pioneered during 2008: Dynamic stable isotopic labeling during formation of carbonate skeletons, tests, and shells, combined with NanoSIMS imaging. The NanoSIMS ion microprobe is a state-of-the-art analytical technology that allows precise elemental and isotopic imaging with a spatial resolution of ~100 nanometers. NanoSIMS imaging of the isotopic label(s) in the resulting biocarbonates and in associated cell-structures will be used to uncover cellular-level transport processes, timescales of formation of different biocarbonate components, as well as trace-elemental and isotopic fractionations. This will uncover the origin of vital effects. With this proposal, I establish a new scientific frontier and guarantee European leadership. The technical and scientific developments resulting from this work are broadly applicable and will radically change scientific ideas about marine carbonate biomineralization and compositional vital effects.

2 182 000 €

Start date: 2010-07-01, End date: 2015-06-30

Chronic pain syndromes are to a large extent due to maladaptive plastic changes in the CNS. A CNS area particularly relevant for such changes is the spinal dorsal horn, where inputs from nociceptive and non-nociceptive fibers undergo their first synaptic integration. This area harbors a sophisticated network of interneurons, which function as a gate-control unit for incoming sensory signals. Several different types of interneurons can be distinguished based e.g. on their neurotransmitter and neuropeptide content. Despite more than 40 years of research, our knowledge about the integration of these neurons in dorsal horn circuits and their contribution to sensory processing is still very limited. This proposal aims at a comprehensive characterization of the dorsal horn neuronal network under normal conditions and in chronic pain states with a focus on inhibitory interneurons. A genome-wide analysis of the gene expression profile shall be made from defined dorsal horn interneurons genetically tagged with fluorescent markers and isolated by fluorescence activated cell sorting. A functional characterization of the connectivity of these neurons in spinal cord slices and of their role in in vivo sensory processing shall be achieved with optogenetic tools (channelrhodopsin-2), which permit activation of these neurons with light. Finally, behavioral analyses shall be made in mice after diphteria toxin-mediated ablation of defined interneuron types. All three approaches shall be applied to naïve mice and to mice with inflammatory or neuropathic pain. The results from these studies will improve our understanding of the malfunctioning of sensory processing in chronic pain states and will provide the basis for novel approaches to the prevention or reversal of chronic pain states.

2 467 000 €

Start date: 2010-05-01, End date: 2016-04-30

The main objective of this research proposal is to explore the electrical properties of nanoscale devices and circuits based on nanolayers. Nanolayers cover a wide span of possible electronic properties, ranging from semiconducting to superconducting. The possibility to form electrical circuits by varying their geometry offers rich research and practical opportunities. Together with graphene, nanolayers could form the material library for future nanoelectronics where different materials could be mixed and matched to different functionalities.

1 799 996 €

Start date: 2009-09-01, End date: 2014-08-31

Comparative genomics revealed that ~5% of the human genome is conserved among mammals. This fraction is likely functional, and could harbor pathogenic mutations. We have shown (Nature 2002, Science 2003) that more than half of the constrained fraction of the genome consists of Conserved Non-Coding sequences (CNCs). Model organisms provided evidence for enhancer activity for a fraction of CNCs; in addition another fraction is part of large non-coding RNAs (lincRNA). However, the function of the majority of CNCs is unknown. Importantly, a few pathogenic mutations in CNCs have been associated with genetic disorders. We propose to i) perform functional analysis of CNCs, and ii) identify the spectrum of pathogenic CNC mutations in recognizable human phenotypes. The aims are: 1. Functional genomic connectivity of CNCs 1a. Use 4C in CNCs in various cell types and determine their physical genomic interactions. 1b. Perform targeted disruption of CNCs in cells and assess the functional outcomes. 2. Pathogenic variation of CNCs 2a. Assess the common variation in CNCs: i) common deletion/insertions in 350 samples by aCGH of all human CNCs; ii) common SNP/small indels using DNA selection and High Throughput Sequencing (HTS) of CNCs in 100 samples. 2b. Identify likely pathogenic mutations in developmental syndromes. Search for i) large deletions and duplications of CNCs using aCGH in 1500 samples with malformation syndromes, 1000 from spontaneous abortions, and 500 with X-linked mental retardation; and ii) point mutations in these samples by targeted HTS. The distinction between pathogenic and non-pathogenic variants is difficult, and we propose approaches to meet the challenge. 3. Genetic control (cis and trans eQTLs) of expression variation of CNC lincRNAs, using 200 samples.

2 353 920 €

Start date: 2010-07-01, End date: 2015-06-30

Immunological memory confers long term protection against pathogens and is the basis of successful vaccination. Following antigenic stimulation long lived plasma cells and memory B cells are maintained for a lifetime, conferring immediate protection and enhanced responsiveness to the eliciting antigen. However, in the case of variable pathogens such as influenza virus, B cell memory is only partially effective, depending on the extent of similarity between the preceding and the new viruses. The B cell response is dominated by serotype-specific antibodies and heterosubtypic antibodies capable of neutralizing several serotypes appear to be extremely rare. Understanding the basis of broadly neutralizing antibody responses is a critical aspect for the development of more effective vaccines. In this project we will explore the specificity and dynamics of human antibody responses to influenza virus by using newly developed technological platforms to culture human B cells and plasma cells and to analyze the repertoire of human naïve and memory T cells. High throughput functional screenings, structural analysis and testing in animal models will provide a thorough characterization of the human immune response. The B cell and T cell analysis aims at understanding fundamental aspects of the immune response such as: the selection and diversification of memory B cells; the individual variability of the antibody response, the mechanisms of T-B cooperation and the consequences of the original antigenic sin and of aging on the immune response. This analysis will be complemented by a translational approach whereby broadly neutralizing human monoclonal antibodies will be developed and used: i) for passive vaccination against highly variable viruses; ii) for vaccine design through the identification and production of recombinant antigens to be used as effective vaccines; and iii) for active vaccination in order to facilitate T cell priming and jump start the immune responses.

1 979 200 €

Start date: 2010-09-01, End date: 2015-08-31

Cell adhesions play an important role in the organization, growth, maturation, and function of living cells. Interaction of cells with the extracellular matrix (ECM) plays an essential role in a variety of disease states , inflammation, and repair of damaged tissues. At the cellular level, many of the biological responses to external stimuli originate at adhesion loci, such as focal adhesions (FA), which link cells to the ECM . Cell adhesion is mediated by receptor proteins such as cadherins and integrins. The precise molecular composition, dynamics and signalling activity of these adhesion assemblies determine the specificity of adhesion-induced signals and their effects on the cell. However, characterization of the molecular architecture of FAs is highly challenging, and it thus remains unclear how these molecules function together, how they are recruited to the adhesion site, how they are turned over, and how they function in vivo. In this project, I aim to conduct an interdisciplinary study that will provide a quantum step forward in the understanding of the functional organization of FAs. We will analyze, for the first time, the three-dimensional structure of FAs in wild-type cells and in cells deficient in the specific proteins involved in the cell-adhesion machinery. We will study the effect of specific geometries on the functional architecture of focal adhesions in 3D. A combination of state-of-the-art technologies, such cryo-electron tomography of intact cells, gold cluster chemistry for in situ labeling, and modulation of the underlying matrix using micro- and nano-patterned adhesive surfaces, together with correlative light, atomic force and electron microscopy, will provide a hybrid approach for dissecting out the complex process of cell adhesion.In summary, this project addresses the properties of FAs across a wide range of complexities and dimensions, from macroscopic cellular phenomena to the physical nature of these molecular assemblies

1 294 000 €

Start date: 2009-11-01, End date: 2015-10-31

The general theme is to explore the connections between reasoning and computations in mathematics. There are two main research directions. The first research direction is a refomulation of Hilbert's program, using ideas from formal, or pointfree topology. We have shown, with multiple examples, that this allows a partial realization of this program in commutative algebra, and a new way to formulate constructive mathematics. The second research direction explores the computational content using type theory and the Curry-Howard correspondence between proofs and programs. Type theory allows us to represent constructive mathematics in a formal way, and provides key insight for the design of proof systems helping in the analysis of the logical structure of mathematical proofs. The interest of this program is well illustrated by the recent work of G. Gonthier on the formalization of the 4 color theorem.

1 912 288 €

Start date: 2010-04-01, End date: 2015-03-31

Small RNA-mediated regulation of gene expression is a recent addition to fundamental gene regulatory mechanisms that directly or indirectly affect possibly every gene of a eukaryotic genome. The predominant sources of small RNA in somatic tissues are microRNA genes that encode short dsRNA hairpins of evolutionary conserved sequence. Disorders of metabolism, such as obesity and type 2 diabetes are poorly understood at a molecular level. In this application we propose to explore if miRNA regulatory networks play a role in these diseases. We will employ state of the art methods for identification of small RNAs and their regulated targets and use biochemical, cell and animal model systems to study the detailed molecular mechanisms of metabolic gene regulation by miRNAs. In addition, we will investigate the underlying principles of how RNAs are taken up by cells and develop methods that will improve delivery of miRNA mimetics or inhibitors through cell-specific uptake. The specific aims of this study are: Aim 1: To define the small regulatory miRNA content of liver, muscle and adipose tissue that are associated with abnormal glucose and lipid homeostasis and to dissect the underlying molecular pathways that govern their expression. Aim 2: To characterize the functions of miRNAs in insulin resistance, glucose uptake and production, fatty acid oxidation and lipogenesis. Aim 3: To identify factors and dissect the pathways that regulate RNA uptake by cells and to develop novel pharmacological treatment strategies to manipulate miRNA-expression. Together, this proposal will shed light on the function that miRNA regulatory networks play in metabolism and in the pathophysiology of obesity/type 2 diabetes. In addition, these studies will contribute to the development of new RNA delivery technologies that are urgently needed as experimental tools as well as for novel therapeutic strategies.

2 021 235 €

Start date: 2010-07-01, End date: 2015-06-30

If we are ever to unravel the mysteries of brain function at its most fundamental level, we will need a precise understanding of how its component neurons connect to each other. Furthermore, given the many recent advances in genetic engineering, viral targeting, and immunohistochemical labeling of specific cellular structures, there is a growing need for automated quantitative assessment of neuron morphology and connectivity. Electron microscopes can now provide the nanometer resolution that is needed to image synapses, and therefore connections, while Light Microscopes see at the micrometer resolution required to model the 3D structure of the dendritic network. Since both the arborescence and the connections are integral parts of the brain's wiring diagram, combining these two modalities is critically important. In fact, these microscopes now routinely produce high-resolution imagery in such large quantities that the bottleneck becomes automated processing and interpretation, which is needed for such data to be exploited to its full potential. We will therefore use our Computer Vision expertise to provide not only the necessary tools to process images acquired using a specific modality but also those required to create an integrated representation using all available modalities. This is a radical departure from earlier approaches to applying Computer Vision techniques in this field, which have tended to focus on narrow problems. State-of-the-art methods have not reached the level of reliability and integration that would allow automated processing and interpretation of the massive amounts of data that are required for a true leap of our understanding of how the brain works. In other words, we cannot yet exploit the full potential of our imaging technology and that is what we intend to change.

2 495 982 €

Start date: 2010-04-01, End date: 2016-03-31

MicroRNAs (miRNAs) are a novel class of genes, accounting for >1% of genes in a typical animal genome. They constitute an important layer of gene regulation that affects diverse processes such as cell differentiation, apoptosis, and metabolism. Despite such critical roles, deciphering the mechanism of action of miRNAs has been difficult, leading to multiple, partially contradictory, models of miRNA activity. Moreover, adding an additional layer of complexity, it is now emerging that miRNA activity is regulated by various mechanisms that we are only beginning to identify. Our objective is to understand how miRNAs are regulated under physiological conditions, in the roundworm Caenorhabditis elegans. We will focus on pathways of miRNA turnover, an issue of fundamental importance that has received little attention because miRNAs are widely held to be highly stable molecules. However, miRNA over-accumulation causes aberrant development and disease, prompting us to test rigorously whether degradation can antagonize miRNA activity and either identify the machinery involved, or confirm the dominance of other regulatory modalities, whose components we will identify. C. elegans is the organism in which miRNAs and many components of the miRNA machinery were discovered. However, previous studies emphasized genetics and cell biology approaches, limiting the degree of mechanistic insight that could be obtained. In addition to exploiting the traditional strengths of C. elegans, we will therefore develop and apply biochemical and genomic techniques to obtain a comprehensive understanding of miRNA regulation, enabling us to demonstrate both molecular mechanisms and physiological relevance. Given the importance of miRNAs in development and disease, identifying the regulators of these tiny gene regulators will be both of scientific interest and biomedical relevance.

1 782 200 €

Start date: 2010-05-01, End date: 2015-04-30

Nanosystems are integrated systems exploiting nanoelectronic devices. In particular, this proposal considers silicon nanowire and carbon nanotube technologies as replacement/enhancement of current silicon technologies. This proposal addresses high-risk, high-reward research, unique in its kind. The broad objective of this proposal is to study system organization, architectures and design tools which, based on a deep understanding and abstraction of the manufacturing technologies, allow us to realize nanosystems that outperform current integrated systems in terms of capabilities and performance. Thus this proposal will address modelling of technological aspects, synthesis and optimization of information processing functions from high-level specifications into the nanofabric, and new design technologies for specific aspects of nanosystems including, but not limited to, sensing and interfacing with the environment. This proposal will address also cross-cutting design goals such as ultra-low power and high-dependability design, with the overall objective of realizing nanosystems that are autonomous (w.r. to energy consumption) and autonomic (i.e., self healing). The scientific novelty of this proposal stems from the use of a nanofabric, where computation, sensing and communication are supported by a homogeneous means as well as from the study of algorithmic tools for mapping high-level functions onto the nanofabric. The intrinsic benefit of this research is to provide a design flow that extends both the technological basis and the capabilities of integrated systems, thus strengthening the industrial European position in a key sector where disruptive innovation is key for survival. The extrinsic benefit of this research is to broaden the use of nanosystems to new domains, including mobile/distributed embedded systems, health/environment management, and other areas that are critical to our lives.

2 499 594 €

Start date: 2010-04-01, End date: 2015-12-31

How sensory processing is occurring into the brain and how to relate behavior to neuronal activities are key questions in modern neuroscience. Understanding the neural codes underlying brain function will be of great importance for future implementation of brain-machine interfaces. This research project proposes to study the cellular and network mechanisms controlling sensory perception. In particular, we would like to precise how sensory stimuli are coded by brain networks and how these representations may be influenced by experience or modulatory brain centers. In order to address these general questions, we propose to study olfaction as model sensory system. The olfactory system is central to the behavior of rodents (animal models that we study), is highly plastic and largely modulated by the neuromodulatory brain centers. We propose to use a combination of genetic, electrophysiological, imaging and behavioral methods to study how odor information is processed in the central nervous system as it moves from the periphery to higher areas of the brain. We showed in the past that sensory information can be contained in dynamic neural ensemble. We propose to show that ensemble dynamics may be the basis of odor coding in the olfactory bulb and to describe the mechanisms underlying cortical coding that would allow us to relate neuronal activity to behavior. In addition, we hope to show the existence of a novel form of plasticity in the olfactory bulb namely ensemble plasticity. We believe that the general questions addressed in the study of these sensory systems go beyond understanding olfactory sensory perception and could potentially be generalized to the function of many brain regions.

1 399 998 €

Start date: 2009-12-01, End date: 2014-11-30

Our goal is to develop fundamentally new architectures for wireless networks that offer the convenience of wireless communication while achieving the performance, predictability and security of wired networks. The wireless channel is inherently a shared medium characterized by limited resources and complex signal interactions between transmitted signals. The question we address is how do we transmit information over wireless and how do we exploit the wireless channel properties to share its resources. Ours is a fundamentally different approach to existing strategies, that builds on new physical and packet layer sharing and cooperation paradigms that we have been working on, to extract the optimal throughput and reliability performance from the wireless medium. These are recent breakthroughs in (i) network coding and (ii) wireless cooperation. Network coding is a new area bringing a novel paradigm for network information flow that enables cooperation at a packet level to optimally share the network resources. Deployment of the first network coding ideas in wireless have already indicated benefits as large as a factor of ten in terms of throughput. Complex signal interactions caused by the inherent broadcast nature of wireless channels, is traditionally viewed as an impediment to be mitigated. Recently it has been demonstrated that one can utilize interference to develop cooperation at the wireless signal level (physical layer) for arbitrary wireless networks. This can give significant capacity advantages over techniques that mitigate interference. Both these ideas can radically affect the way information is communicated, stored and collected, and can revolutionize the design of future wireless networks. In this project we plan to addess several fundamental questions that develop on these themes. We take a complete view of these ideas by not only developing the underlying theory but also through validation on wireless testbeds.

1 771 520 €

Start date: 2009-09-01, End date: 2014-08-31

Cellular responses to external signals begin at the plasma membrane, where the dynamic assembly of receptors can regulate cellular activity. Membrane-enveloped viruses, including the human immunodeficiency virus (HIV) also assemble at the plasma membrane, exploiting mechanisms evolved for cellular trafficking. However, our physical paradigm for how proteins form mesoscale assemblies is far from complete. While the organization and dynamics of membrane proteins are heterogeneous, commonly used fluorescence-based measurements lack information at the molecular scale. In contrast, single molecule measurements limited to looking at only a few molecules in a given cell lack ensemble information. Thus, the study of protein assembly has been limited by a lack of spatially resolved, dynamic information on ensembles of molecules. We will use super-resolution fluorescence imaging techniques combined with live cell imaging and single molecule tracking to determine how the dynamics of protein assembly are coordinated. The long-term goal of my research is to use quantitative fluorescence methods to identify the physical mechanisms for protein transport and organization in cells. The objective of this proposal is to establish quantitative models of protein assembly in two specific biological systems which were selected for the distinct characteristics of their assembly, and their relevance to human health. This will test the central hypothesis that molecular assembly is enhanced by the organization of the plasma membrane in the form of cytoskeletal elements and protein-lipid platforms. This interdisciplinary research will provide an experimental foundation for a statistical description of the cell, whose behaviour is embedded in protein organization and dynamics.

1 542 518 €

Start date: 2009-12-01, End date: 2015-11-30

Each year 1.1 million new cases of breast cancer will occur among women worldwide and 400,000 women will die from this disease. Although progress has been made in understanding breast tumor biology, most of the relevant molecules and pathways remain undefined. Their delineation is critical to a rational approach to breast cancer therapy. This proposal focuses on the role of the under-explored family of protein-tyrosine phosphatases (PTPs) in the normal and neoplastic breast. Virtually all cell signaling pathways are modulated by reversible protein tyrosine phosphorylation, which is regulated by two classes of enzymes: protein-tyrosine kinases (PTKs) and PTPs. Not surprisingly, tyrosine phosphorylation has an important role in breast development and cancer. Whereas the role of specific PTKs, like the HER2 receptor, in breast cancer is well studied, almost nothing is known about the function of specific PTPs in this disease. Our preliminary data suggest that PTP1B has an important role in breast differentiation and that both PTP1B and SHP2 play positive roles in breast cancer. The two predominant goals of this proposal are: First, to delineate the role of PTP1B and other PTPs in normal breast development and differentiation; second, to address the roles of PTP1B and other PTPs in the maintenance of breast cancer and metastasis and to assess their merits as drug targets. These studies not only use state-of-the-art ex vivo and in vivo models for studying breast pathophysiology, but also cross the boundaries between the developmental and cancer research fields and between basic science and clinical applications. Our research should ultimately lead to the rational design of targeted therapies that will improve the clinical management of patients with breast cancer.

1 571 365 €

Start date: 2010-02-01, End date: 2015-01-31

Reconstruction of methane flux from lakes: development and application of a new approach

1 554 000 €

Start date: 2009-12-01, End date: 2014-11-30

We aim to study transcriptomes with single-cell resolution, a long-standing goal in biology, to answer fundamental questions about gene regulation. The main objective concerns gene regulation during in vivo differentiation and in pluripotent cells by studying single-cells from murine preimplantation embryos, a model system with natural single-cell resolution, important biology and medical potential. This would also allow us to explore general regulatory principles of gene expression programs of individual cells. This research program will be accomplished by novel deep sequencing technology of mRNAs (mRNA-Seq) to obtain quantitative, unbiased and genome-wide gene and isoform expression measurements. We are therefore developing new experimental and computational methods for genome-wide analyses of transcriptomes at single-cell resolution. The biological significances of the proposed research are unique insights into early embryonic development. Deep sequencing of transcriptomes will also reveal post-transcriptional gene regulation important for pluripotent cells and identified pluripotency-specific gene and isoform expressions will be important for future stem cell based therapies. The inherit single-cell nature of the model system together with its important biology makes it a model systems exceptionally well suited for a systems biology approach aiming to characterize gene regulation at single-cell resolution. The novel methodology has tremendous potential to enable complete mRNA characterization of individual cells. The deep sequencing approach with state-of-the-art computational analyses is both more quantitative than previous methods and it will give readouts on alternative isoforms generated by alternative promoters, splicing and polyadenylation.

1 654 384 €

Start date: 2010-02-01, End date: 2015-01-31

Signal representations with Fourier and wavelet bases are central to signal processing and communications. Non-linear approximation methods in such bases are key for problems like denoising, compression and inverse problems. Recently, the idea that signals that are sparse in some domain can be acquired at low sampling density has generated strong interest, under various names like compressed sensing, compressive sampling and sparse sampling. We aim to study the central problem of acquiring continuous-time signals for discrete-time processing and reconstruction using the methods of sparse sampling. Solving this involves developing theory and algorithms for sparse sampling, both in continuous and discrete time. In addition, in order to acquire physical signals, we plan to develop a sampling theory for signals obeying physical laws, like the wave and diffusion equation, and light fields. Together, this will lead to a sparse sampling theory and framework for signal processing and communications, with applications from analog-to-digital conversion to new compression methods, to super-resolution data acquisition and to inverse problems in imaging. In sum, we aim to develop the theory and algorithms for sparse signal processing, with impact on a broad range of applications.

1 839 174 €

Start date: 2010-05-01, End date: 2015-04-30

This proposal envisages a research program in the field of systems and signals that will lead to innovative and agile mathematical modeling as well as model-based signal processing and control tools for applications in biology and medicine. The project's goal is to bridge the gap between systems biology, on one hand, and medical signal processing and control engineering, on the other. Mathematical models of systems biology will be used to devise algorithms for biological data processing and computerized medical interventions. Experimental biological and clinical data will be utilized to estimate and characterize the parameters of mathematical models derived for biological phenomena and mechanisms. An extensive collaboration network of medical researchers from Sweden and abroad will provide the project team with necessary experimental data as well as with access to medical competence. The envisaged tools are expected to be applicable more generally but their efficacy will be demonstrated in two main application areas. These areas are endocrinology and neurology for which the use of formal control engineering and signal processing methods is currently deemed to be most promising. The proposed program will result in novel systems and signals tools for medical research and health care enabling multi-input multi-output modeling and analysis of endocrine regulations and providing model-based algorithms for individualized drug dose titration.

2 379 000 €

Start date: 2010-04-01, End date: 2015-03-31

One of the central mysteries of immunology is self-tolerance. How does the human body select ~10e12 T lymphocytes, that are reactive to foreign pathogens but tolerant to normal cellular constituents of the host? Over the last few years, my laboratory identified 2 fundamental mechanisms used by thymocytes to establish T cell tolerance. We demonstrated that the affinity threshold for negative selection is a constant for all thymocytes expressing MHC I restricted TCRs. This binding affinity threshold (KD H 6 ¼M; estimated T1/2 H 2 sec) is the fundamental biophysical parameter used by TCRs to delete autoimmune T cells. We also established how the TCR generates distinct signals for positive and negative selection. At the selection threshold, a small increase in ligand affinity for the T-cell antigen receptor leads to a marked change in the activation and subcellular localization of Ras and mitogen-activated protein kinase (MAPK) signaling intermediates. The ability to compartmentalize signaling molecules differentially within the cell endows the thymocyte with the ability to convert a small change in analogue input (affinity) into a digital output (positive versus negative selection) and provides the molecular basis for central tolerance. In the present application, we plan to fully understand 1-how the biophysical events during antigen binding to the TCR initiate an intracellular signal; 2-how these signals program an unambiguous cell fate and 3-how the system fails, when an autoimmune T cell is generated and activated. We will use a combination of transgenic and knockout mice, biochemistry and molecular imaging to fully define how the TCR functions as a molecular switch.

1 930 000 €

Start date: 2010-04-01, End date: 2015-03-31

Parkinson s disease is one of the common causes of disability in the aging population, representing a major health problem for the affected individuals and a socioeconomic burden to the society. In the present proposal, the applicant puts forward an ambitious but feasible program to tackle a number of significant issues that remain unsolved in the field. He combines his strong track record in animal models of Parkinson s disease and novel cell and gene therapy-based therapeutic strategies with powerful bio-imaging techniques in order to make bold steps towards translation of new and better treatments to patients suffering from this illness. He does so in a manner that combines, on one hand, the strength of clearly-defined hypotheses and well-established tools for results towards clinical translation, with high-risk high-reward projects that hold the potential to yield ground-breaking discoveries in implementation of novel imaging techniques, on the other.

1 508 940 €

Start date: 2009-11-01, End date: 2014-10-31