[Capsid Protein of Bacteriophage Beihai32 as a Platform for Construction of Virus-Like Particles Displaying Foreign Polypeptides].

Abstract

Virus-like particles (VLPs) can be used as nanosized carriers for the presentation of various peptides, including antigens. VLPs formed by self-assembly from capsid proteins of bacteriophages with singlestranded RNA genomes can be obtained in bacterial expression systems. However, to act as a universal platform for antigen presentation, the carrier protein should retain the ability to self-assemble into VLPs upon attachment of long peptides. We have shown that the capsid protein of the bacteriophage Beihai32 can be used as a carrier of peptides at least 238 amino acid residues long. The hybrid capsid protein, to which green fluorescent protein (GFP) was attached at the C-terminus, was expressed in Escherichia coli cells and formed spherical VLPs with a diameter of about 30 nm in vivo. GFP was localized on the surface of these particles and retained the ability to fluoresce. Thus, the bacteriophage Beihai32 capsid protein is an effective platform for constructing VLPs that present long peptide antigens on their surface, and such VLPs can be the basis for new recombinant vaccines.