ERC FUNDED PROJECTS

Air pollution is the main urban-related environmental hazard. It appears to affect brain development, although current evidence is inadequate given the lack of studies during the most vulnerable stages of brain development and the lack of brain anatomical structure and regional connectivity data underlying these effects. Of particular interest is the prenatal period, when brain structures are forming and growing, and when the effect of in utero exposure to environmental factors may cause permanent brain injury. I and others have conducted studies focused on effects during school age which could be less profound. I postulate that: pre-natal exposure to urban air pollution during pregnancy impairs foetal and postnatal brain development, mainly by affecting myelination; these effects are at least partially mediated by translocation of airborne particulate matter to the placenta and by placental dysfunction; and prenatal exposure to air pollution impairs post-natal brain development independently of urban context and post-natal exposure to air pollution. I aim to evaluate the effect of pre-natal exposure to urban air pollution on pre- and post-natal brain structure and function by following 900 pregnant women and their neonates with contrasting levels of pre-natal exposure to air pollutants by: i) establishing a new pregnancy cohort and evaluating brain imaging (pre-natal and neo-natal brain structure, connectivity and function), and post-natal motor and cognitive development; ii) measuring total personal exposure and inhaled dose of air pollutants during specific time-windows of gestation, noise, paternal stress and other stressors, using personal samplers and sensors; iii) detecting nanoparticles in placenta and its vascular function; iv) modelling mathematical causality and mediation, including a replication study in an external cohort. The expected results will create an impulse to implement policy interventions that genuinely protect the health of urban citizens.

2 499 992 €

Start date: 2018-09-01, End date: 2023-08-31

The long-term goal of this proposal is to explore a novel immune pathway that involves an unexpected interplay between marginal zone (MZ) B cells and neutrophils. MZ B cells are strategically positioned at the interface between the immune system and the circulation and rapidly produce protective antibodies to blood-borne pathogens through a T cell-independent pathway that remains poorly understood. We recently found that the human spleen contains a novel subset of B cell helper neutrophils (NBH cells) with a phenotype and gene expression profile distinct from those of conventional circulating neutrophils (NC cells). In this proposal, we hypothesize that NC cells undergo splenic reprogramming into NBH cells through an IL-10-dependent pathway involving perifollicular sinusoidal endothelial cells. We contend that these unique endothelial cells release NC cell-attracting chemokines and IL-10 upon sensing blood-borne bacteria through Toll-like receptors. We also argue that IL-10 from sinusoidal endothelial cells stimulates NC cells to differentiate into NBH cells equipped with powerful MZ B cell-stimulating activity. The following three aims will be pursued. Aim 1 is to determine the mechanisms by which splenic sinusoidal endothelial cells induce reprogramming of NC cells into NBH cells upon sensing bacteria through Toll-like receptors. Aim 2 is to elucidate the mechanisms by which NBH cells induce IgM production, IgG and IgA class switching, and plasma cell differentiation in MZ B cells. Aim 3 is to evaluate the mechanisms by which NBH cells induce V(D)J gene somatic hypermutation and high-affinity antibody production in MZ B cells. These studies will uncover previously unknown facets of the immunological function of neutrophils by taking advantage of unique cells and tissues from patients with rare primary immunodeficiencies and by making use of selected mouse models. Results from these studies may also lead to the identification of novel vaccine strategies.

2 214 035 €

Start date: 2012-04-01, End date: 2017-09-30

"Cell-cell synapses are an exquisitely evolved means of communication between cells. During the formation of the immune synapse (IS), diverse transmembrane and membrane associated molecules are reorganized into a highly segregated structure at the T cell–Antigen-Presenting Cell (APC) contact site. As part of this process, the tubulin cytoskeleton is vectorially directed toward the center of the IS, where the microtubule-organizing center (MTOC) localizes. MTOC translocation is an early event in IS formation that brings the secretory apparatus into close apposition with the APC, thus providing the basis for polarized secretion. The proposal aims to define how the MTOC controls cytoskeletal rearrangement and communication at the IS, as a mechanism for macromolecule transport and nucleation of signalling molecules during synaptic contact. We will study the mechanisms of MTOC-mediated polarization of multivesicular bodies (MVB) and exosome delivery during IS formation, and will assess the role in these processes of MTOC translocation regulators (HDAC6) and microtubule (MT) polymerization promoters (Plk1 and EB1). MTOC-dependent mitochondrial polarization to the IS will be assessed as a bioenergetic source for cytoskeletal rearrangements, IS maturation and polarized exosomal delivery. In particular, our proposed study of the possible horizontal transfer of miRNAs during cognate interactions between immune cells has the potential to reveal how miRNAs can control the early initiation of immunity. We will investigate the mechanism of directional transfer of RNA-harbouring exosomes at the IS from T cell to APC, and will examine the functional consequences of this transfer on APC biology and on the immune response. These studies will open avenues for the treatment of immune-related diseases."

2 011 200 €

Start date: 2012-02-01, End date: 2017-01-31

The current paradigm of T cell function in the immune response is that T cells recognize antigen through the T cell antigen receptor (TCR) which transduces signals to the cytoplasm by way of cytosolic priming and effector tyrosine kinases. The TCR acts in a monovalent fashion is crosslinked by its antigen/MHC (pMHC) ligand, causing TCR triggering. However, our more recent data indicate that the TCR is organized in pre-existing oligomers, and therefore it might not require crosslinking, and that the triggered TCR adopts, upon ligand binding, an active conformation that is responsible for recruiting cytoplasmic effector molecules. We have found novel direct effectors of the TCR, including the Ras GTPase TC21 and unveiled that these effectors play an essential role in a variety of TCR signaling functions including tonic signaling and TCR downregulation. Furthermore, we have found that TC21 is required for the acquisition of pMHC by T cells from the APCs and re-express it on their own plasma membrane, becoming themselves APCs for other T cells. In this proposal we wish to explore several of the avenues open by our most recent findings, including the importance of pMHC presentation by T cells. Another objective is to study an interesting property of the conformational change in the TCR: its return to the inactive conformation even when it is still bound to its pMHC ligand (countdown effect). We also propose to use approaches that alter the size of pre-existing TCR oligomers to seek for new ways of modulating T cell activation. The last two objectives refer to study the role of TC21 as a direct effector of the B cell antigen receptor (BCR). We propose to study the involvement of TC21 in the B cell germinal center response and how the deregulation of its expression can influence the transformation of GC B cells into lymphomas. Finally, we propose to generate small molecular weight inhibitors of TC21 as potential drugs for the treatment of lymphomas.

2 491 827 €

Start date: 2014-02-01, End date: 2019-01-31