Peptide vaccines have been shown effective in preventing animal
infection in some instances, and various formulations are under evaluation for their potential clinical use in humans. In the case of the Human Immunodeficiency Virus type-1 (HIV-1)
infection, viral escape from immune surveillance restricts relevant neutralizing humoral responses to a handful of sites of vulnerability on the envelope
glycoprotein. The membrane-proximal external region (MPER) on the gp41 transmembrane subunit has been identified as the only linear B-
epitope that embodies an HIV vulnerability site. Thus, focusing humoral responses to MPER by
peptide-based immunogens is a pursued goal in
HIV vaccine development. The location of this sequence in the vicinity of the membrane interface, its composition (rich in aromatic residues), and the requirement of long-hydrophobic heavy-chain
third complementarity-determining region loops for antibody-mediated neutralization suggests that in addition to the specific
amino acid composition, antigenicity and immunogenicity of MPER can be modulated by
membrane lipids. In this chapter, we give an overview of applications of
lipid vesicles (
liposomes) to the development of MPER-targeting
vaccines, both as type-B adjuvants and
epitope structure-shaping devices.