Diverse CD1d-restricted T cells: diverse phenotypes, and diverse functions

Invariant CD1d-restricted T cells express NK cell markers and use a limited TCR repertoire. Here, we describe a second CD1d-restricted T cell subset t hat uses a diverse TCR repertoire. These T cells can also express NK cell m arkers and function similarly to invariant T cells. The antigens recognized by the diverse subset are likely to be different from those recognized by invariant TCRs. The variable NK1.1 antigen expression on these T cell popul ations limits its usefulness in identifying CD1d-restricted T cells. Lastly the discovery of antigens recognized by diverse CD1d-restricted T cells wi ll provide insight into their role in normal and pathological immune respon ses.