Protein Engineering group

Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA-Nanociencia)

Proyect: Design of Hsp60, siRNA and gold nanoparticles bioconjugates. A new tool for immunotherapy

The chaperonin Hsp60 is a molecular chaperon formed by two rings of seven monomers placed back to back. It assists the protein folding in prokaryotes and in eukaryotic cell organelles (mitochondria) by the encapsulation of protein substrates inside the cavity defined by each ring. Extensive biochemical, biophysical and structural studies of Hsp60 bacterial homologue, GroEL, have allowed an exact knowledge of Hsp60 structure and substrate folding mechanism. This extensive knowledge has permitted Hsp60 protein engineering for its use in bio- and nano-technology. Interestingly, Hsp60 can interact with specific receptors of Antigen Presenting Cells, like Dendritic Cells (DC), being internalized. Thus, Hsp60 can load DC with antigens bound to the molecular chaperon. Therefore, this project proposes the combination of Hsp60 based nanotechnology and Hsp60 as a specific antigen vehicle for the design of a new tool for immunotherapies. Gold nanoparticle bioconjugates containing engineered Hsp60 single ring version (GroEL SR1) will be developed to act as specific vehicles for the delivery of antigens and therapy agents to Dendritic Cells: Protein engineered oligomeric (GroEL SR1)  fused to three HA peptide antigens (used as model antigens) per monomer will take advantage of the oligomeric structure of the chaperonin, because each oligomer will contain several copies of the Ag. And the peptide will be protected against proteases inside the chaperonin structure. Furthermore, the use of gold nanoparticles decorated with the engineered Hsp60 complexes and siRNA able to activate the immune system will increase the concentration of siRNA and antigens inside the Dendritic Cells. Finally, the activation of CH7C17 cell line (specific for HA recognition), after its incubation with treated DCs, will be checked.


Figure 1.  Objectives and work-flow.  To simplifie, only two GroEL(SR1) monomers are presented. Obj. 1: GroEL(SR1) modifyed to contain three antigenic petides per monomer (HA peptide, red lines) will be conjugated  with gold nanoparticles (yellow sphere). Obj 2:co-decoration of the previous gold nanoparticles  with siRNA  anti PDL1 (orange helix). Their capability to load Dendritic Cells with Antigens and siRNas will be tested in vitro.

Biomolecules & Cell D.
Molecular Biomedicine