iNKT cells limit the transformation of B cells by EBV. PBMC isolated from the blood of healthy controls were incubated in 12-well plates for 8 days with either EBV-GFP or wild-type EBV (EBV Β95-8) in the presence or absence of iNKT cells (depleted by negative selection). Representative dot plots (A) and cumulative data (B) indicating the percentage of iNKT cells (CD1d tetramer⁺/CD3⁺/CD19⁻/7-aminoactinomycin D⁻) in the peripheral T-cell population ex vivo or after iNKT cell depletion (−iNKT) (n = 7). (C-D) Fluorescence-activated cell sorter plots display CD19⁺7-aminoactinomycin D⁻ PBMC. Gated numbers indicate the frequency of GFP⁺ and GFP⁻ CD19⁺ B cells in the presence (+iNKT) or absence (−iNKT) of iNKT cells. B cells infected with wild-type EBV (EBV Β95-8) are shown as a GFP-negative control. Cumulative data indicating the relative proportion of GFP⁺CD19⁺ cells (E) and EBV DNA titer (F) (n = 7). **P < .01; ***P < .001. (G) PBMC depleted of iNKT cells were placed in 12-well plates. Isolated iNKT cells were transferred into transwell inserts and resuspended above iNKT cell-depleted PBMC. Fluorescence-activated cell sorter plots and gated numbers indicate the frequency of GFP⁺ and GFP^– CD19⁺ B cells from PBMC (+iNKT), PBMC-depleted iNKT cells (−iNKT) and PBMC with iNKT cells separated by transwell inserts (+iNKT [transwell]) infected for 8 days with EBV-GFP. Dot plot shows the frequency of GFP⁺ B cells of 6 individual healthy controls (n = 6). ***P < .001.