Lipid nanocapsule as vaccine carriers for his-tagged proteins: Evaluation of antigen-specific immune responses to HIV I His-Gag p41 and systemic inflammatory responses

Histidine-tagged HIV I Gag p41 bound to lipid based nanocapsules through interaction with surface accessible nickel generated a strong dose-dependent immune response when administered to BALB/c mice. The purpose of this study was to design novel nanocapsules (NCs) with surface-chelated nickel (Ni-NCs) as a vaccine delivery system for histidine (His)-tagged protein antigens. Ni-NCs were characterized for binding His-tagged model proteins through high-affinity non-covalent interactions. The mean diameter and zeta potential of the optimized Ni-NCs were 214.9nm and −14.8mV, respectively. The optimal binding ratio of His-tagged Green Fluorescent Protein (His-GFP) and His-tagged HIV-1 Gag p41 (His-Gag p41) to the Ni-NCs was 1:221 and 1:480w/w, respectively. Treatment of DC2.4 cells with Ni-NCs did not result in significant loss in the cell viability up to 24h (