Klas Kärre

Biosketch

Klas Kärre is Professor Emeritus of Molecular immunology and former Chair of The Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden, and Secretary General of The European Academy of Cancer Sciences. He earned his MD and Ph D in Tumor Biology from Karolinska Institutet. He was a postdoctoral fellow in Molecular Biology at The Pasteur Institute, Paris, France. After joining the Faculty of Karolinska Institutet, he has served on several of its Scientific and Educational Committees, on The University Board of Directors and as Director for The Strategic Research Center for studies of “Integrative Recognition in the Immune System. He is a member of The Royal Swedish Acadamy of Sciences, The European Molecular Biology Organization and an Honorary member of The American Society of Immunologists. He has served as Chairperson for The Nobel Assembly as well as for The Nobel Committee for Physiology or Medicine at Karolinska Institutet, for The Crafoord Polyarthritis Prize Committee, and for The Scientific Council of The Swedish Cancer Society. He has been a member of the Board of Directors of The Nobel Museum and The Council for Lindau-Nobel Laureate meetings. Awards include William B.Cooley Award for Distinguished Research in Basic and Clinical Tumor Immunology, Scandinavian Anders Jahre Prize for Medical Research, Yvette Mayent – Institut Curie Prize, Novartis Prize in Basic Immunology; Avery Landsteiner Prize in Immunological Research and The Swedish Royal Medal of the 12th size for Contributions in Medical Research.

Research Interests

Dr Kärres research seeks to understand NK-cell and T-cell recognition of infected, malignant or transplanted cells. He proposed that NK-cells can recognize “absence of the normal” (no self MHC) in contrast to T-cells, known to focus on “presence of the foreign” (antigen/self MHC), and coined the term “missing self” recognition. To test the hypothesis predictions, he has developed models based on MHC deficient mutant cells, on MHC transgenic mice and KO mice. These are used in bone marrow transplants allowing molecular control of “self” and “missing self” at the donor/target and recipient/effector level. The missing self hypothesis postulates a balance between activating receptors, recognizing endogenous molecules on target cells, and counteracting inhibitory receptors recognizing self MHC class I molecules. This is a central part of the current paradigm for NK-cell research on receptors and signalling pathways. The hypothesis predicts that the NK system must be “educated” by host MHC type for optimal function and “self tolerance”. Kärre uses mouse models with single or mosaic MHC gene expression to study this, with focus on a flexible ”rheostat model” for NK-education. Kärre isolated and characterized antigen processing defective cell lines, which are used to study the cell biology of MHC/peptide presentation, “empty” MHC molecules and T-cells recognizing cells despite defects in the MHC pathways. Lately, Kärre has developed an interest in translational studies of responses in patients treated with immunotherapy against cancer, in particular regarding the role of NK cells.