Mechanisms and consequences of iNKT cell stimulation by glycolipid antigens from Sphingomonas bacteria

• Applicant: Dr. Gerhard Wingender
• Subject Area: Immunology
• Term: from 2006 to 2008
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 29591179

Invariant natural killer T (/NKT) cells have been implicated in diverse immune reactions, especially in the early phases, due to their rapid acquisition of effector functions. In contrast to conventional T cells, which recognize peptides, /NKT cells recognize glycolipids, i.e. sugars linked to fatty acids. However, only very recently have natural antigens for (NKT cells been identified in Sphingomonas bacteria, and /NKT cell deficient mice have a greatly delayed bacteria clearance. This finding allows us, for the first time, to explore the significance of the antigen-specific reactivity of /NKT cells in the context of microbial infections. The aim of this project is to determine how / NKT cells and the antigens they recognize are involved in the protective response to Snhinsomonas bacteria. This involves the investigation of the kinetics and mechanisms of the anti-microbial immune response following bacterial challenge. Furthermore the processing and presentation of bacterial derived /NKT cell antigens will be followed, and the interaction of /NKT cells with the respective antigen-presenting cells will be investigated. In addition the long-term effects of natural bacterial antigens on /NKT cell functions will be examined. Results acquired by studies of the model pathogen Sphingomonas will foster investigations with other pathogens bearing / NKT cell specific antigens. This work will deepen our understanding of /NKT cell biology and function, particular during microbial infections, and could led to novel immunotherapeutics.

• DFG Programme: Research Fellowships
• International Connection: USA
• Host: Professor Mitchell Kronenberg, Ph.D.