Figure 16.
Liposomes with surface-displayed B cell epitope (membrane-proximal external region, MPER) and encapsulated T-cell epitope (HIV30) promote strong B-cell responses against MPER while minimizing off-target responses against the helper epitope. (A) Schematic of 3 forms of T-helper epitope incorporation in MPER liposomes. Only in the case of TCEP cleaved external HIV30 is the T-helper epitope displayed solely intrastructurally. (B) Mice were immunized with 150 nm MPER liposomes with soluble or incorporated HIV30 with co-delivered adjuvant-containing liposomes. Shown are serum anti-MPER and anti-HIV30 IgG titers 7 days post-boost. Liposomes with “hidden” T helper HIV30 epitopes (cleaved HIV30) elicited greatly reduced antibody responses against the helper sequence. Adapted from Hanson et al.142 Reprinted with permission from reference 142. Copyright 2014 Elsevier Ltd.