TUW Single molecule mobility and protein-protein interactions in CAR T-cells

There is a plethora of proteins that contribute to the identification of antigens by a T cell and to its specific response. Interestingly, even the most paradigmatic interaction process – the binding of the TCR to a peptide-loaded MHC – is far from being understood; a mechanistic understanding of the role of co-receptors is completely missing. We will use single molecule tracking and superresolution microscopy to quantify the interactions between the different membrane proteins at milliseconds time resolution. The single molecule approach offers a set of key advantages over conventional ensemble techniques: i) from the brightness of the individual spots it is possible to determine the stoichiometry of the participating molecules; ii) the position of the dye-labelled proteins can be determined at very high accuracy down to a few tens nanometers; iii) two-color single molecule tracking allows for directly recording interaction lifetimes. The high-resolution techniques will be employed for a detailed investigation of the protein interactions in CAR-T cells under resting conditions. Experiments will be performed in close collaboration with Johannes Huppa (MUW). Ultimately, targeted delivery of cells to the imaging platform will enhance throughput in single molecule experiments. We thus assist STRATEC in the development and implementation of a microfluidics system.