Natural killer T (NKT) cells are innate-like lymphocytes that bridge the gap between the innate and adaptive immune responses. Like innate immune cells, they have a mature, effector phenotype that allows them to rapidly respond to threats, compared to adaptive cells. NKT cells express T cell receptors (TCRs) like conventional T cells, but instead of responding to peptide antigen presented by MHC class I or II, NKT cell TCRs recognize glycolipid antigen in the context of CD1d. NKT cells are subdivided into classes based on their TCR and antigen reactivity. This review will focus on type I iNKT cells that express a semi invariant Valpha14Jalpha18 TCR and respond to the canonical glycolipid antigen, alpha-galactosylceramide. The innate-like effector functions of these cells combined with their T cell identity make their developmental path quite unique. In addition to the extrinsic factors that affect iNKT cell development such as lipid:CD1d complexes, co-stimulation, and cytokines, this review will provide a comprehensive delineation of the cell intrinsic factors that impact iNKT cell development, differentiation, and effector functions - including TCR rearrangement, survival and metabolism signaling, transcription factor expression, and gene regulation.
Author Info: (1) Department of Microbiology and Immunology, University of Maryland School of Medicine, 685 W. Baltimore St. HSF-1 Room 380, Baltimore, MD 21201, USA. Electronic address 
Author Info: (1) Department of Microbiology and Immunology, University of Maryland School of Medicine, 685 W. Baltimore St. HSF-1 Room 380, Baltimore, MD 21201, USA. Electronic address: susannah.shissler@umaryland.edu. (2) Department of Microbiology and Immunology, University of Maryland School of Medicine, 685 W. Baltimore St. HSF-1 Room 380, Baltimore, MD 21201, USA. 
