Glycosphingolipids (GSLs) bearing α-glucose (α-Glc) that preferentially stimulate human invariant NKT (iNKT) cells are provided. GSLs with α-glucose (α-Glc) that exhibit stronger induction in humans (but weaker in mice) of cytokines and chemokines and expansion and/or activation of immune cells than those with α-galactose (α-Gal) are disclosed. GSLs bearing α-glucose (α-Glc) and derivatives of α-Glc with F at the 4 and/or 6 positions are provided. Methods for iNKT-independent induction of chemokines by the GSL with α-Glc and derivatives thereof are disclosed. Methods for immune stimulation in humans using GSLs with α-Glc and derivatives thereof are provided.