Gitta obtained her PhD in Biology at the University of Mainz and then did postdoctoral studies in London and Cambridge, followed by a postdoc at the Cancer Research Institute in Heidelberg. In 1985 she became a member of the Basel Institute for Immunology where she stayed until 1991.
In 1991 Gitta became a group leader in the Division of Molecular Immunology of the Medical Research Council National Institute for Medical Research (now part of the Francis Crick Institute) and Head of Division in 2010.
Her research interests over time included immune tolerance using T cell receptor transgenic mouse models and immunological memory focusing on CD4 memory T cells, their generation and survival.
Gitta's lab got involved in infection and inflammation research following their discovery of the differentiation factors for Th17 generation. More recently they discovered the importance of the transcription factor aryl hydrocarbon receptor (AHR), an environmental sensor, in the immune system and beyond.
Gitta obtained an ERC Advanced Investigator grant in 2009 to study physiological functions of AHR and in 2013 was awarded a Wellcome Senior Investigator Grant to expand the investigation of AHR in innate and adaptive immune cells. She obtained a CRUK grant in 2015 to study the role of AHR in intestinal tumorigenesis and a Wellcome Investigator Grant in 2018 to focus on AHR influences in the intestinal environment.
She became a Fellow of the Academy of Medical Sciences in 2005, an EMBO fellow in 2008 and a Fellow of the Royal Society in 2013.