CD1 molecules present both self lipids and microbial lipids. Recent studies
have elucidated novel antigenic structures that can be presented by CD1 fo
r T cell stimulation, as well as new pathways for lipid-antigen presentatio
n. Additionally, the development of lipid-CD1 tetramers now permits the tra
cking of CD1-reactive T cells during immune responses. Despite this, the ro
les of CD1-reactive T cells in both host defense and immune regulation rema
in to be unequivocally defined.