Hepatitis B virus core particles as epitope carriers

Area of Science:

• Biotechnology
• Virology
• Immunology

Background:

• The Hepatitis B core (HBc) particle is a well-established particulate carrier for displaying foreign peptide sequences.
• Recombinant HBc protein can be expressed and correctly folded in various cell systems, including bacterial, yeast, insect, and mammalian cells.
• The unique assembly properties and structure of HBc particles facilitate substantial insertions without compromising capsid formation.

Purpose of the Study:

• To investigate the potential of HBc particles as carriers for foreign peptide insertion.
• To identify optimal sites within the HBc structure for foreign epitope display.
• To evaluate the immunological activity of inserted epitopes displayed on HBc particles.

Main Methods:

• Construction of display vectors based on the cloned HBc gene.
• Insertion of foreign epitope sequences into targeted regions of the HBc primary structure (N- and C-termini, immunodominant loop).
• Expression of recombinant HBc particles in various host cells.
• Analysis of capsid assembly and immunological activity of displayed epitopes.

Main Results:

• Substantial insertions of foreign peptide sequences into HBc particles are possible without loss of capsid-forming ability.
• The N-terminal, C-terminal, and immunodominant loop regions are suitable targets for foreign epitope insertion.
• Displayed epitopes retained, and in some cases, enhanced their original immunological activity.
• A range of viral and nonviral epitope sequences were successfully displayed.

Conclusions:

• HBc particles are highly effective and versatile carriers for displaying foreign peptide sequences and epitopes.
• The HBc display system offers a robust platform for immunological studies and potential vaccine development.
• Targeted modifications of HBc particles allow for the preservation and enhancement of the displayed epitope's immunogenicity.