Melanoma and Lymphocyte Cell-Specific Targeting Incorporated into a Heat Shock Protein Cage Architecture

Abstract

Protein cages, including viral capsids, ferritins, and heat shock proteins (Hsps), can serve as nanocontainers for biomedical applications. They are genetically and chemically malleable platforms, with potential as therapeutic and imaging agent delivery systems. Here, both genetic and chemical strategies were used to impart cell-specific targeting to the Hsp cage from Methanococcus jannaschii. A tumor vasculature targeting peptide was incorporated onto the exterior surface of the Hsp cage. This protein cage bound to alpha(v)beta(3) integrin-expressing cells. Cellular tropism was also imparted by conjugating anti-CD4 antibodies to the exterior of Hsp cages. These Ab-Hsp cage conjugates specifically bound to CD4(+) cells. Protein cages have the potential to simultaneously incorporate multiple functionalities, including cell-specific targeting, imaging, and therapeutic agent delivery. We demonstrate the simultaneous incorporation of two functionalities, imaging and cell-specific targeting, onto the Hsp protein cage.

Therapeutic Nanoparticles for Drug Delivery in Cancer

“…Besides this artificial targeting, a subset of viruses, such as canine parvovirus, have natural affinity for receptors such as transferrin receptors that are up-regulated on a variety of tumor cells (28). By targeting heat shock protein, a dual-function protein cage with specific targeting and doxorubicin encapsulation has been developed (29,30).…”

X-ray spatial frequency heterodyne imaging of protein-based nanobubble contrast agents

“…It should also be possible to combine the biomedical imaging function of the nanobubbles with other properties due to the flexibility of VLPs, as it is possible to modify both the inner and outer surfaces of these capsids. For example, VLPs have been targeted to specific cells including melanoma cells and lymphocytes by attaching antibodies and peptides to their outer surface [20]. They have also been used for the delivery of chemotherapeutic agents such as the anticancer drug doxorubicin [15] and photodynamic agents like singlet oxygen [21], both of which were encapsulated inside the protein cage.…”

“…Protein cage structures such as those mentioned above have been studied for their potential in materials synthesis [7,12], catalysis [13,14], drug and gene delivery [15,16], bio-imaging [17][18][19], cell targeting [20,21], and vaccine development [11]. VLPs in particular are promising, as they exist in a large range of sizes (tens to hundreds of nanometers), have well-defined, monodisperse structures, can be purified in large quantities, and can be easily modified both genetically and chemically [22][23][24][25][26][27].…”

Engineering protein self-assembling in protein-based nanomedicines for drug delivery and gene therapy

“…Fusion of this short (18 amino acids) Nterminal stretch from PduP to GFP, GST, or maltose-binding (Fan et al, 2010), and to green fluorescent protein or glutathione S-transferase proteins (Fan & Bobik, 2011) resulted in their successful encapsulation within Pdu BMC. As many peptides targeting to the vasculature of a variety of tissues, organs, and tumors have been identified , they can be used to functionalize BMC, as demonstrated for a small Hsp cage structure modified with the peptide RGD-4C or conjugation with an anti-CD4 monoclonal antibody (Flenniken et al, 2006). Release of the cargo in target cells can be enhanced by using polyhistidine tags, a powerful membrane-disrupting agent (Ferrer-Miralles et al, 2011), to promote pH-dependent disassembly in the endosomes (Dalmau, Lim, & Wang, 2009a;Dalmau, Lim, & Wang, 2009b).…”