Atherosclerotic lesion areas in WT and CD1d^-/- mice fed on the AD. (A) Representative histologic sections of WT and CD1d^-/- mice fed on the AD. Arrows represent the oil red O-positive atherosclerotic lesions typically observed within the internal elastic lamina (original magnification, × 40). (B) Mean lesion areas of WT and CD1d^-/- mice. Each symbol represents the lesion area of an individual mouse. Horizontal bars and numbers represent the mean of all mice within each group, and vertical bars represent SEM. (C) Prevalence of NKT cells in WT and CD1d^-/- mice. HMNCs and splenocytes were prepared and stained with FITC anti-TCRαβ, PE anti-NK1.1, and APC-CD1d/α-GalCer tetramer, as described in “Materials and methods.” Open columns represent the proportion of total NKT cells, and closed columns represent the proportion of CD1d/α-GalCer tetramer⁺ cells. Each value represents the mean ± SE calculated from more than 5 experiments. Statistical analyses were performed with the Mann-Whitney U test. †P < .01 (for closed columns and open columns); ^*P < .05.