We have been granted a strategic award from the Wellcome Trust 'The Homunculus in our Thymus: A Cellular Genomics Approach' that enables us to investigate how thymic epithelial cells (TEC) - irrespective of their cell identity - remarkably can express virtually the complete set of protein-coding genes. These studies are relevant to better understand the fundamental function of the immune system and to identify causes of autoimmune diseases.
T-cell mediated responses play a crucial role in providing protective immunity to infections and tumours. The same cells can, under pathological conditions, also be directed against an individual's own tissues resulting in autoimmunity. It is, therefore, essential that T cells can discriminate between injurious foreign and benign self-antigens. This vital competence is instructed during T-cell development by populations of thymic epithelial cells (TEC). To achieve immunological tolerance, TEC promiscuously express and present peripheral tissue-specific antigens and thus foretell the ubiquitous and tissue-specific self-antigens that mature T cells will encounter once they exit from the thymus.