Postdoc Researcher, Institute of Clinical Chemistry and Clinical Pharmacology
University Hospital Bonn
University of Bonn
Dr. Karagiannis is a Post-Doctoral researcher in the laboratory of Dr. Christoph Wilhelm at the University Hospital of Bonn, Germany. He is an immunologist by training, having received his PhD from the University of Patras, Greece. The main focus of his research is to study the nutritional and metabolic control of innate and adaptive lymphoid cells in homeostasis and disease. During his PhD, he 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 Post-Doctoral researcher, Dr. Karagiannis 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, he 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, he studied the effect of ketone bodies, the hallmark feature of ketogenic diet, on T cell responses upon viral infection. Dr. Karagiannis discovered that ketone bodies can be used as alternative fuel promoting CD4+ T cell survival and function in vitro. Furthermore, he 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.
Cytokines 2022 Oral Presentation in Cytokines and metabolism/macrophage Symposium: “THE KETONE BODY Β-HYDROXYBUTYRATE METABOLICALLY RESTORES T CELL FUNCTION IN SEVERE COVID-19.“