Abstract
This unit details methods for the isolation, in vitro expansion, and functional characterization of human iNKT cells. The term iNKT derives from the fact that a large fraction of murine NKT cells recognize the MHC class I-like CD1d protein, are CD4+ or CD4-CD8- (double negative), and use an identical "invariant" TCRalpha chain, which is generated by precise Valpha14 and Jalpha281 (now renamed Jalpha18) rearrangements with either no N-region diversity or subsequent trimming to nearly identical amino-acid sequence (hence, 'iNKT'). Basic Protocol 1 and Alternate Protocol 1 use multi-color FACS analysis to identify and quantitate rare iNKT cells from human samples. Basic Protocol 2 describes iNKT cell purification. Alternate Protocol 2 describes a method for high-speed FACS sorting of iNKT cells. Alternate Protocol 3 employs a cell sorting approach to isolate iNKT cell clones. A Support Protocol for secondary stimulation and rapid expansion of iNKT cells is also included. Basic Protocol 3 explains functional analysis of iNKT.