CD1d-restricted Natural Killer T (NKT) cells expressing a single invariant T cell receptor alpha chain recognize glycolipid antigens presented by a CD1d molecule (Taniguchi et al. 2003; Kronenberg 2005)². Studies have indicated that NKT cells recognize various kinds of glycolipids derived from not only mammals but also from bacteria or marine organisms. NKT cells can produce various biological proteins such as cytokines or cytotoxic molecules upon activation. Through their production, NKT cells influence other immune cells and involve various kinds of immune responses, including autoimmunity, microbe infection, transplant immunity, tumor immunity, and allergic inflammation (Seino and Taniguchi 2004). It is expected to synthesize some glycolipids which could manipulate NKT cell function and the immune system, especially intending to treat some diseases better.