CD1D and colitis: However, whereas the numbers of NKT cells without the α-GalCer-loaded Cd1d tetramer (type II NKT cells) were reduced in the colonic lamina propria after one week of the MCD diet, those of NKT cells with the α-GalCer-loaded Cd1d tetramer (type I NKT cells) remained unchanged (Fig 1E), and this tendency was also observed after DSS-induced colitis in Jα18-/- and CD1d-/- mice (S1 Fig).