My lab has a longstanding interest in the structural basis of antigen-presentation by CD1 molecules, especially CD1d. We are trying to understand how chemical modifications of the glycolipid antigen can influence both the magnitude and the quality of the iNKT cell immune response. While much of our work has been focussed on iNKT cells, we are now starting to ask whether the same principles also apply to Type II NKT cells, especially those that recognize sulfatide. Furthermore, we are interested in the evolution and species-specific adaptation of the CD1 binding groove to accommodate various lipid antigens. While it is undoubtedly clear that the CD1d binding groove has evolved to present lipids, rather than peptides, we have recently begun to characterize the structure and function of peptides that can be presented by CD1d.