Professor of Paediatric Gastroenterology
The gastrointestinal immune system has evolved to counteract the invasion of pathogens. To allow a strong inflammatory immune response during infection but avoid tissue damage there is a need for effective immune regulation. Defects in immune regulation lead to immunopathology such as inflammatory bowel disease or celiac disease.
About one-fifth of all patients with IBD present with initial symptoms during childhood and adolescents. In particular in the very young children patients, an underlying immunodeficiency may cause IBD-like symptoms. The analysis of immune deviation in children with IBD and IBD-like symptoms may contribute to the understanding of the complex puzzle of molecular mechanisms involved in IBD.
To investigate novel genetic defects to lead to very early onset intestinal inflammation we established the COLORS in IBD study (COLitis of early Onset - Rare diseaseS withIN IBD). COLORS in IBD has several international collaborators. In collaboration with the Sanger Center Cambridge and the Wellcome Trust Center of Human Genomics (WTCHG) Oxford, we investigate patients with pediatric-onset of IBD using next-generation sequencing.
We investigate several functional mechanisms of intestinal inflammation: antimicrobial activity in phagocytes, regulatory T cells, and epithelial barrier defects.
One key interest of the lab is to understand cytokine responses, in particular, IL-6 and IL-10 family cytokine responses.
A further area of interest is the immune response in patients with defects in the PI3K signaling pathway. One large group of patients with defects in this pathway have mutations in the phosphatase PTEN. Due to heterozygous mutations in the PTEN gene patients develop the PTEN hamartoma tumor syndrome which includes Bannayan Riley Ruvalcaba syndrome and Cowden's syndrome. We investigate the functional consequences of PTEN deficiency for the development of the mucosa-associated lymphoid tissue, B and T cell responses.
A variant in IL6ST with a selective IL-11 signaling defect in human and mouse
Schwerd T. et al, (2020), Bone Research, 8
Discovery of CD80 and CD86 as recent activation markers on regulatory T cells by protein-RNA single-cell analysis
Trzupek D. et al, (2020), Genome Medicine, 12
Deconvolution of monocyte responses in inflammatory bowel disease reveals an IL-1 cytokine network that regulates IL-23 in genetic and acquired IL-10 resistance.
Aschenbrenner D. et al, (2020), Gut
Corona Virus Disease 2019 and Paediatric Inflammatory Bowel Diseases: Global Experience and Provisional Guidance (March 2020) from the Paediatric IBD Porto Group of European Society of Paediatric Gastroenterology, Hepatology, and Nutrition.
Turner D. et al, (2020), Journal of pediatric gastroenterology and nutrition, 70, 727 - 733
Dominant-negative mutations in human IL6ST underlie hyper-IgE syndrome
Béziat V. et al, (2020), Journal of Experimental Medicine, 217