Fotis Karagiannis, PhD
Postdoctoral Researcher
University Hospital Bonn, Germany
I am a Postdoctoral researcher in the lab of Dr. Christoph Wilhelm at the University Hospital of Bonn, Germany. I received my PhD from the University of Patras in Greece, where I investigated post-transcriptional mechanisms regulating IL-2 gene expression in naïve T cells upon activation and how any dysregulation could lead to the onset of pathogenic conditions such as autoimmune diseases. As a postdoc, I switched my focus to immunometabolism and I am now studying the nutritional and metabolic control of innate and adaptive lymphoid cells in homeostasis and disease.
As a Postdoctoral researcher, I was able to identify increased glucose and lipid uptake as the driving factor for extensive proliferation and pathogenic function of innate lymphoid cells type 2 (ILC2), promoting allergic airway inflammation. By utilizing a dietary intervention, mimicking fasting and nutrient deprivation, such as the ketogenic diet I observed the inhibition of ILC2 activation and the alleviation of allergic inflammation in mice (Karagiannis et. al., Immunity 2020). Following up on these findings of how a dietary modulation of host metabolism can regulate immune responses I studied the effect of ketone bodies, the hallmark feature of ketogenic diet, on T cell responses upon viral infection. I discovered that ketone bodies can be used as alternative fuel promoting CD4+ T cell survival and function in vitro. Furthermore, I was able to demonstrate that ketogenic diet and delivery of ketone bodies as ketone ester drink can restore CD4+ T cell metabolism and function in respiratory infections, ultimately reducing the mortality of SARS-CoV-2 infected mice.