αGalCer-activated iNKT cells enhance T-D B-cell response to protein vaccines by facilitating Th-cell priming via licensing of the same APC. Specific IgG and T-cell responses induced in mixed BMCs and wt mice by vaccination with Ags mixed or not mixed with αGalCer, according to the schedule in Figure S1. (A) Expression of MHC-II and CD1d on circulating B cells (CD19⁺) and, in 2 representative animals displaying the expected expression on circulating B cells, on splenic DCs (CD11c⁺) of BMCs. (B) Ag-specific IgG titers induced in BMCs and wt mice by vaccination. (C) IFN-γ secretion by splenic T cells upon restimulation in vitro with CGG 10 days after immunization of mice with NP-CGG with or without αGalCer. Asterisks indicate statistically significant differences: * indicates P values less than or equal to .05; **P ≤ .01. Shown are the results from 1 experiment representative of 2 in which 5 mice per group were tested. Results are shown as mean plus or minus SEM.