Multivalent display of VP28 on chimeric virus-like particles enhances binding to shrimp target tissues: A novel antiviral strategy against white spot syndrome virus.

BACKGROUND AND AIM: White spot syndrome virus (WSSV) is a devastating pathogen in shrimp aquaculture, with viral protein 28 (VP28) playing a critical role in host cell attachment and entry. The extracellular domain of VP28 (residues 35-95) is immunogenic and essential for infection; however, its receptor interaction mechanisms remain incompletely elucidated. This study aimed to evaluate the tissue-binding affinity of full-length VP28 and its derived peptides (P1: Residues 35-65; P2: Residues 66-95) as well as a multimeric chimeric virus-like particle (K5-VLP) displaying VP28 on the surface of Macrobrachium rosenbergii nodavirus capsids to enhance host tissue interaction.

MATERIALS AND

METHODS

Recombinant VP28, synthetic peptides (P1, P2), and chimeric K5-VLP were produced and characterized. Binding and inhibition assays were performed using enzyme-linked immunosorbent assay and immunofluorescence microscopy on shrimp gill, hemocyte, muscle, stomach, and hepatopancreas tissues.

RESULTS

Full-length VP28 exhibited strong binding to gill, hemocyte, and muscle tissues. The P1 and P2 peptides showed moderate binding compared to rVP28. Notably, K5-VLP demonstrated a 1.7-fold higher binding affinity than rVP28 in gill tissues and significantly outperformed P1 and P2 peptides. Inhibition assays confirmed that K5-VLP more effectively interfered with VP28 binding than peptides. Structural analysis and transmission electron microscopy confirmed correct assembly and surface presentation of VP28 on the VLPs.

CONCLUSION

Multimeric display of VP28 on K5-VLP enhances its binding affinity to shrimp tissues compared to monomeric or peptide forms. This suggests a promising platform for antiviral strategies, including competitive inhibition of WSSV entry and targeted therapeutic delivery in shrimp aquaculture.