A new epitope presenting system displays a HIV-1 V3 loop sequence and induces neutralizing antibodies.

The principal neutralizing domain, IGPGRAF sequence, from the V3-loop of HIV-I was inserted in two positions on the surface of the protein that makes up the capside shell of the insect flock House Virus. The hybrid proteins were expressed in insect cells via recombinant baculoviruses. Three different hybrids were used as immunogens: two with a single copy of the insert in different positions of the carrier protein and a third with two copies of the insert at the same positions as before. All hybrid proteins induced strong and broad specific immune response in guinea pigs against different V3-loop sequences, However, only one of the hybrid proteins was able to induce a strong neutralizing response against MN and IIIB HIV-1 isolates. Our results demonstrate that a very short peptide sequence of HIV-I can constitute a valuable immunogen able to induce a neutralizing response if presented to the immune system in the context of the FHV capsomer structure

Protein Cage Nanoparticles as Delivery Nanoplatforms

Protein cage nanoparticles are made of biomaterials, proteins, and have well-defined cage-like architectures designed and built by nature. They are composed of multiple copies of one or a small number of chemically identical subunits having a highly uniform nano-size and symmetric structure. Protein cage nanoparticles have genetic and chemical plasticity amenable to simultaneously introducing multiple cell-specific targeting ligands, diagnostic agents, and their corresponding therapeutic agents at desired sites depending on its purpose. A wide range of protein cage nanoparticles, such as ferritin, lumazine synthase, encapsulin, and virus-like particles, has been extensively explored and utilized in biomedical fields as effective delivery nanoplatforms of diagnostics and/or therapeutics. Highly biocompatible and plastic protein cage nanoparticles may provide a new paradigm for developing simple, but versatile in vivo delivery systems