Figure 1. Glycan-modified dendrimers and liposomes enhance antigen presentation. Although dendrimers and liposomes greatly differ in size and molecular properties, both systems allow for the display of DC-SIGN ligands, such as Le^X or Le^b, in a multivalent form. Also Toll-like receptor (TLR) ligands, such as monophosphoryl lipid A, can be incorporated in dendrimers and liposomes. Dendrimers are prepared using peptide epitopes that require little antigen-processing capacity, while liposomes can encapsulate whole peptides and adjuvants. Both Le^X/b-modified dendrimers and liposomes are highly specific for DC-SIGN and induce efficient MHC class I and MHC class II presentation to CD8⁺ and CD4⁺ T cells, respectively. Besides providing the co-stimulatory signals required for T-cell priming, TLR activation promotes antigen presentation to CD4⁺ T cells and a yet uncharacterized cross-presentation mechanism leading to the cross-priming of CD8⁺ T cells.