Human Parvovirus B19 Vaccine Development

Human Parvovirus B19 Vaccine Development

Human parvovirus B19 (HPVB19) frequently causes erythema contagiosum, also known as fifth disease, and an arthralgia syndrome in infants, children, and even adults. B19 infections are usually asymptomatic or mildly symptomatic but vary depending on the individual's immunological and hematological status. However, primary B19 infection during pregnancy can result in hydrops fetalis and stillbirth due to mother-to-child transmission. Unfortunately, there is currently a lack of a vaccine to protect pregnant women and fetuses from B19 infection.

Overview of HPVB19

The HPVB19 virus features an icosahedral capsid constructed from 60 subunits, primarily consisting of the major protein, VP2 (constituting ~95% of the capsid structure), and the minor protein, VP1 (~5%). The proteins VP1 and VP2 are produced from a ~5.6 kb ssDNA genome, utilizing a single open reading frame (ORF) with two initiation sites. Consequently, VP1 and VP2 share identical sequences apart from an extra 227 amino acids at the N-terminus of VP1, known as the VP1 unique region (VP1u). This structural arrangement is typical among members of the parvovirus family, where an ORF designs two or three structural proteins to form the viral capsid, all terminating at the same stop codon.

Structure of HPVB19-VP2 (A) and the monomer of VP2 in the capsid of HPVB19 (B). (Sánchez-Moguel I, et al., 2023)

HPVB19 and Virus-like Particles

Virus-like particles (VLPs) mimic the structure of viruses but lack the viral genome, making them non-infectious and useful for various applications, including as vaccines or for studying viral assembly. VLPs of HPVB19 have been constructed using various combinations of VP2, VP2 + VP1, and VP1 proteins expressed in heterologous systems, suggesting flexibility in VLP construction.

Engineering Potential of HPVB19 VLP

To encapsulate, B19V VLPs can be flexibly constructed from major (VP2) and minor (VP1) capsid proteins, and the structural versatility offered by the natural chimeric form of VP1 opens up possibilities for creating multifunctional VLPs through genetic engineering. These attributes are particularly valuable for vaccine development and other biomedical applications.

• Neighboring VP2 molecules interlock via surface loops for capsid stability; however, some loops not involved in these contacts can be targeted for protein engineering.
• The C-terminal of VP2 is buried within the capsid, pointing toward the capsid's core, suggesting potential for internal encapsulation of molecules.
• The structure allows for N-terminal peptides or small protein domains to be incorporated in VP2, either alone or coassembled, owing to VP1u's demonstrated structural and functional versatility.

How We Can Help

CD BioSciences is an expert in manufacturing and engineering VLPs. Using our VLPlant^TM platform, we are committed to developing HPVB19 vaccines for our clients. Our platform enables us to offer highly customized solutions that meet the unique requirements of each client, ensuring the highest standards of safety and efficacy. Whether you are at the preliminary stages of research or ready for large-scale production, our comprehensive suite of services can be seamlessly integrated into your workflow. If you are interested in partnering with us or learning more about our advanced capabilities, please do not hesitate to contact us.

Quote and Ordering

Reference

1. Sánchez-Moguel I.; et al., Therapeutic Potential of Engineered Virus-like Particles of Parvovirus B19. Pathogens. 2023;12(8):1007.