Exploring biophysical properties of activated T-cells using advanced fluorescence microscopy and environmentally sensitive dyes.

Environmentally-sensitive dyes change their emission, and sometimes absorption properties, depending on their local environment - e.g. polarity, hydrophobicity, dipole moment, etc. Thus in combination with advanced fluorescence microscopy methods, they allow the direct observation and tracking of important biophysical characteristics within the cell, such as lipid order.
Lipid order is associated with the degree of packing of membrane lipids, giving rise to so-called lipid rafts or lipid domains. Lipid rafts are small, highly dynamic structures that have been proven to have a role in compartmentalising signalling molecules and thus in regulating cell signalling. However, their direct observation in live cells historically has been challenging because of their small size and dynamic nature. One example of a process where lipid rafts are believed to play a crucial role is the formation of an immunological synapse between a T-cell and an Antigen Presenting Cell (APC) - a process which requires major structural rearrangements within the cell and the recruitment and recycling of numerous signalling molecules.
This project seeks to quantify the dynamic behaviour of intracellular lipids and proteins in T-cells during IS formation using the above mentioned dyes and live cell super-resolution imaging using techniques such as Structured Illumination Microscopy, TIRF and possibly single-molecule localisation methods. It will aim to see the relation between lipid order, vesicle dynamics and cargo transported to and recycled at the interface, as well as the role of other cellular components e.g. actin.