Defining the functional surface proteome of extracellular vesicles

As cells die in vivo they are removed by phagocytes in a process that resolves inflammation and prevents disease. For clearance of dying (apoptotic) cells to be efficient and timely, dying cells release extracellular vesicles (EV) to attract phagocytes to sites of cell death. Crucially, this interaction of EV with the immune system underpins the control of inflammation, a process central to health, regenerative medicine and many important inflammatory diseases.
This project will define the surface proteome of extracellular vesicles across the entire size range of EV generated from dying cells. This novel approach will then help identify the factors that are essential for EV control of inflammation. EV surface proteome will be linked to function as we address the following key questions: what are the key components of EV that enable communication with the immune system? Do EV of differing sizes and sources interact in a similar manner with the immune system? Is it possible to produce a synthetic EV with a defined surface proteome to act as a mimic of EV function?
Analysis of EV is a significant challenge due to EV heterogeneity. In particular, EV vary greatly in size (<50nm to >1000nm). Analysis of the smallest EV, namely exosomes, proves most challenging given existing technologies are often not sensitive enough to detect them (such as dynamic light scattering and nanoparticle tracking analysis). NanoFCM have developed a novel platform that brings together the power of flow cytometry with high sensitivity (40-50nm) for interrogation of nanoparticles. This will enable comprehensive single-EV analysis and phenotyping, providing new insight into the often difficult to detect exosome populations. Through collaboration between Aston University and NanoFCM, the EV surface will be probed at high resolution to establish a fundamental atlas of the surface proteome of EV.