Immunoregulation by iNKT cells

Abstract

NKT cells are defined as cells co-expressing of the natural killer receptors such as NK1.1 or NKR-P1A (CD161) and a T cell receptor (TCR). Although NK1.1+ TCR+ lymphocytes are heterogeneous, we focus on two distinct T cell subsets express invariant T cell receptor α chains, Vα14-Jα18(Vα14i) and Vα19-Jα33(Vα19i). Vα14i NKT cells (Vα24i NKT cells for human) are restricted by CD1d and Vα19i NKT cells (Vα7.2i NKT cells for human) are restricted by MR1 molecule. These cells emerge as an unique lymphocytes subset to bridge innate and acquired immunity. Here in this review, we discuss on the role of these cells in the regulation of autoimmunity and on the potential of therapeutic target for autoimmune diseases. © 2009 The Pharmaceutical Society of Japan.