Genetic Analysis of iNKT Cell Development and Function

Abstract

Natural killer T (NKT) cells are among the immediate and early responding immune cells and are important players in autoimmune diseases and tumor immunity. This unique subset of T cells shares properties of natural killer cells and T cells. Proper identification and characterization of NKT cell subsets is essential to understand the function and involvement of these understudied immune cells in various diseases. This review aims to summarize the known methods for identifying and characterizing NKT cells. NKT cells are divided into Type I (or invariant) and Type II, with either limited or broad TCR repertoires, respectively, that generally respond to glycolipids presented on the nonclassical MHC, CD1d. Type I NKT cells or invariant NKT cells (iNKT) are the most well studied and can be further subdivided into NKT1, NKT2, or NKT17 populations, classified based on their functional capacity. Conversely, less is known about Type II NKT cells because they have a more diverse TCR repertoire which make them hard to identify. However, genetic analyses have shed light on the development and function of all NKT subsets, which aids in their characterization. Further exploration of the role of NKT cells in various diseases will reveal the intricacies and importance of their novel functions.