Univ.-Prof. Dr. Christian Freund ist Leiter der Arbeitsgruppe Protein Biochemistry am Institut für Chemie und Biochemie der Freien Universität Berlin.
Abstract:
Defining the T cell antigens that give rise to specific immune responses requires knowledge about the mechanisms of antigen processing and presentation. In my research group we undertake mechanistically driven studies of the molecular and cellular dynamics of MHC class II molecules in order to capture and formally describe essential features of antigen processing and their impact on T cell biology. Capitalizing on biophysical, biochemical and reduced cellular settings, we probe the importance of conformational dynamics for the process of peptide selection. We utilize state-of-the-art mass spectrometry in combination with improved computing algorithms to de-convolute the complexity and compositional changes of the MHCII-bound immunopeptidomes. We thereby unravel the interplay between allotype-dependent catalyzed peptide exchange, binding affinity and proteolytic cleavage of polypeptides as major determinant of antigen presentation