Antigenicity study of the yeast-generated human parvovirus 4 (PARV4) virus-like particles.

Human parvovirus 4 (PARV4) is a novel tetraparvovirus that was isolated from intravenous drug users in 2005. Recombinant PARV4 capsid protein VP2 can form stable virus-like particles (VLPs) in yeast. These VLPs could act as antigen carriers during vaccine development. Therefore, the information about PARV4 VP2 VLP antigenic sites could advance further research in this area. In this work, human parvovirus 4 VLPs obtained from yeast were used to generate monoclonal antibodies (mAbs) in mice. Epitope mapping of the obtained mAbs showed at least three distinct antigenic sites of the VP2 protein. On top of that, molecular cloning was used to replace PARV4 VP2 antigenic sites with heterologous peptides. The chimeric PARV4 VLPs bearing polyhistidine inserts obtained from yeast were observed using electron microscopy while polyhistidine-specific antibodies detected heterologous peptides of the chimeric VP2 proteins.