iNKT cells express high amounts of caspases in contrast to conventional Vβ2 T cells. (A) Expression of pro and anti-apoptotic proteins in expanded iNKT and Vβ2 T cell lysates from 3 healthy donors (Nos. 4, 6, and 9) analyzed by SDS-PAGE and subsequent western-blotting. Asterisk (*) corresponds to proteins overexpressed in iNKT cells, relative to Vβ2 T cells. (B) Detection of active caspases by flow cytometry in fresh isolated iNKT cells, Vβ2 T cells and CD3⁺ T cells from PBMCs of 3 healthy donors (Nos. 4, 6, and 9). After gating on CD3⁺TCR-iNKT⁺ (iNKT), CD3⁺TCRVβ2⁺ (Vβ2), or CD3⁺ T cells (CD3⁺), cells were stained by a fluorescent inhibitor of activated caspases (FLICA) allowing detection of activated caspases.