Use of hepadnavirus core proteins as vaccine platforms

Abstract

The first virus-like particle to be tested for use as a vaccine carrier was based on the hepatitis B virus nucleocapsid protein. This viral subunit, while not infectious on its own, is a 36-nm particle that is highly immunogenic during a natural infection. The self-assembly and high degree of immunogenicity is maintained when expressed as a recombinant protein and, moreover, can confer a high degree of immunogenicity on foreign antigens linked to the particle, either chemically or genetically. This review describes the current state of the hepadnaviral core protein as a vaccine carrier.

Keywords::

• HBcAg
• HBV subunit vaccine platform
• virus-like particle
• WHcAg

Financial & competing interests disclosure

David C Whitacre is an employee, and David R Milich is a founder and shareholder in VLP Biotech, Inc., which develops vaccines based on hepadnaviral core proteins. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

No writing assistance was utilized in the production of this manuscript.

Notes

^*Characteristics common only to nonhuman hepadnaviral core proteins.

Note: due to conservation at the amino acid level (i.e., 67%), many characteristics are shared among the human and rodent hepadnaviral core proteins except, of course, bullet points 4 and 6, which are based on observation in natural human infection.

HBcAg: HBV core antigen; HBsAg: HBV surface antigen; TLR: Toll-like receptor.