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Department of Pathology

magnified virus

Our Research

Our collective studies aim to understand endosome and exosome cell biology. We are particularly interested in understanding why cells tether exosomes to their plasma membrane, and what role these tethered exosomes play in various biological settings.

Exosomes are small vesicles that are released from cells. They are generated within endosomes, where they are called ‘intraluminal vesicles’ and become termed ‘exosomes’ upon fusion of that endosome with the plasma membrane. Whilst I was a post-doctoral research associate with Professor Scottie Robinson, we noticed that exosomes were often ‘stuck’ to the surface of cells, often in small clumps and clusters. This observation looked remarkably similar to the process of enveloped virus restriction, and led us to investigate the role that the protein tetherin has in tethering exosomes. I retain an active interest in endosome biology and membrane trafficking, and wish to apply our knowledge in these areas to research antigen presentation and specialised immune cell functions.

We use a range of biochemical and molecular techniques, in addition to the widespread us of light and electron microscopy. Electron microscopy is an especially important component of our research as it provides us with sufficient resolution to differentiate the plasma membrane from exosomes associated with the plasma membrane.

At the start of the COVID-19 pandemic, I decided to investigate whether SARS-CoV-2 downregulated tetherin and whether I could contribute to the fundamental SARS-CoV-2 cell biology research. I remain involved in a number of collaborative projects, both internally and externally.

Current Projects

  • Examining the role that exosomes and tethered exosomes play in antigen presentation (Sir Henry Dale Fellowship)
  • Defining the molecular mechanisms of exosome tethering (Sir Henry Dale Fellowship)
  • Investigating tetherin downregulation by SARS-CoV-2.
  • The role of tethered exosomes in breast cancer metastasis (Dr Roberta Palmulli)
  • Bioengineering exosomes with therapeutic potential (Dr Hannah Jackson)
  • Novel mechanisms of regulatory T cell mediated suppression (Co-Investigator – collaboration with Professor Klaus Okkenhaug, University of Cambridge)
  • Mechanisms of coronavirus replication (Co-Investigator – collaboration with Dr Emily Eden, UCL)

Dr James Edgar

Research Group Leader





Dr Roberta Palmulli

Research Associate



Anna Germon

Graduate Student