Cell-Penetrating Peptide IMT-P8 Outperforms LDP12 for HIV Vaccine Delivery in Mice

IMT-P8 linked to the HIV Nef-MPER-V3 antigen produced significantly higher IgG antibody levels than LDP12-linked antigen. When combined with HP91 adjuvant, IMT-P8 generated the strongest humoral response. IMT-P8 also induced more robust IFN-gamma production and cytotoxic T cell activation compared to LDP12, indicating superiority as both a humoral and cellular immune activator.

Animal study in female BALB/c mice. Recombinant fusion proteins were generated linking the HIV Nef-MPER-V3 antigen to either IMT-P8 or LDP12 cell-penetrating peptides. Mice were immunized with different regimens using HP91 or HSP27 as adjuvants. Immune responses were measured via ELISA for antibodies, cytokines, and granzyme B, plus CTL proliferation assays.

Cell-penetrating peptides are a promising technology for delivering vaccine antigens directly into immune cells, potentially improving vaccine efficacy. Identifying which CPPs work best for immune stimulation helps advance peptide-based vaccine delivery platforms — relevant beyond just HIV vaccines.

Cell-penetrating peptides represent a growing toolkit for delivering biological cargo into cells. This head-to-head comparison helps refine which CPPs are best suited for vaccine applications, with broader implications for peptide-based drug delivery.

Mouse study only — immune responses in BALB/c mice may not predict human responses. Only female mice were used. No challenge study was performed, so it's unknown whether the immune responses would actually protect against HIV infection. Small-scale preclinical work.