βGL1-22/LGL1–specific type II human NKT cells provides more efficient B-cell help than type I NKT cells. Sorted human α-GalCer, βGL1-22, or LGL1 tetrameter-positive cells were incubated with purified autologous CD19⁺ B cells in the presence of vehicle or respective lipids. After 5 to 6 days of culture, cells and supernatants were harvested. The frequency of B cells with CD27^hi CD38^hi phenotype was determined by flow cytometry (A-B) and the levels of secreted IgM and IgG were measured by ELISA (C). (A) Representative contour plot showing the frequency of CD27^hi CD38^hi cells. (B) Compiled results from analyses of 3 different experiments showing the percentages of CD27^hi CD38^hi cells. (C) Levels of secreted immunoglobulin measured by ELISA. (D) FACS plot showing the presence of T_FH (PD1⁺CXCR5⁺) and non-T_FH (PD1⁻CXCR5⁻) phenotype in α-GalCer, βGL1-22, or LGL1 tetrameter-positive T cells or bulk T cells. Panel on the right shows fold change (relative to non-T_FH cells) of percent positive cells for ICOS, Bcl6, and IL-21. **P < .001; *P < .01. DMSO, dimethylsulfoxide.