Probing molecular dynamics of TNFR family members upon stimulation, in the membrane of live cells – SYMULI

Following engagement by their cognate ligand(s), receptors of the TNF family can either signal survival/ proliferation/ differentiation or cell death. Current challenges in TNFR pharmacology and aim of our project are to understand the molecular basis for the multiplicity of cellular responses controlled by TNFR ligation, essentially by bridging the gap between dynamic molecular events at the membrane following ligand binding in living cells, and transmembrane signalling. Issues such as 1) pre-ligand assembly of TNFRs, 2) lateral (re-)organization and dynamics of TNFRs in the plasma membrane upon ligand engagement and 3) interaction of TNFRs with surrounding lipid environment, are critical to understand the pharmacology of TNFRs, but have only been scantly investigated so far. The lack of deep studies possibly stems from the difficulty to combine expertises from various fields. In particular, conventional imaging technologies lack the temporal and spatial resolution to determine the properties of ligand–receptor complexes within membrane microdomains. Furthermore, the need for a full set of molecular probes to control and modulate the levels of receptor assembly, as well as the difficulties inherent with methods in lipid studies may yet have represented other limitations. The present consortium will address these issues by bringing together a high level of chemical, biochemical and biophysical expertise with strong emphasis on the development of the biochemical and chemical toolbox to control over receptor aggregation and on advanced biophotonic-based techniques such as fluorescence correlation spectroscopy (FCS) and related approaches which provide an unprecedented level of spatiotemporal resolution in live cells.